Ascending-to-Descending Aortic Bypass: A Simple Solution to a Complex Problem Sameh M. Said, MD, Harold M. Burkhart, MD, Joseph A. Dearani, MD, Heidi M. Connolly, MD, and Hartzell V. Schaff, MD Divisions of Cardiovascular Surgery and Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
Background. Surgical correction of complex aortic coarctation can be associated with significant risks. Extraanatomic bypass may represent a safer alternative. Methods. Between January 1985 and December 2012, 80 consecutive patients with complex coarctation underwent ascending-to-descending aortic bypass through a median sternotomy. Patients were a median age of 42 years (range, 15 to 75 years), and 51 (64%) were males. Recurrent coarctation was present in 52 patients (65%), with 6 (8%) having undergone balloon dilatation. Uncontrolled hypertension was present in 63 patients (79%). The most common concomitant pathology was aortic valve stenosis in 21 patients (26%), subaortic stenosis in 10 (13%), and Shone complex in 4 (5%). Results. There were no early deaths. The most common concomitant procedures were aortic valve replacement, coronary artery bypass grafting, and resection of subaortic stenosis. The mean aortic cross-clamp and cardiopulmonary bypass times were 33 ± 40 and 106 ± 54 minutes,
respectively. Morbidity included atrial fibrillation in 17 patients (21%) and reexploration for bleeding in 6 (8%). There was no paraplegia or stroke. Upper extremity blood pressure significantly improved (p < 0.001). Mean systolic blood pressure decreased from 153 ± 26 mm Hg preoperatively to 123 ± 15 mm Hg postoperatively. Mean follow-up was 7 ± 6 years (maximum, 22 years). Late deaths occurred in 5 patients (6%) and were not graftrelated. Three patients (4%) required reoperation for repair of periprosthetic regurgitation in 2 and mitral valve replacement in 1. Conclusions. The ascending-to-descending aortic bypass can be performed with low morbidity and mortality. It is an effective solution to complex aortic coarctation and represents a safe single-stage approach for patients with concomitant cardiac pathology.
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repair of coarctation and concomitant cardiac pathology through a median sternotomy [5]. In this article, we review our experience with ascending–descending aortic bypass for complex aortic coarctation.
ntreated aortic coarctation results in persistent systemic hypertension with its related sequelae, including accelerated coronary artery disease, stroke, or aortic dissection. It has also been associated with premature death secondary to progressive heart failure [1]. Excellent surgical outcomes have been achieved with repair of simple aortic coarctation though a left posterolateral thoracotomy, with a 5% to 30% incidence of recurrence [2, 3] requiring reintervention. “Complex” coarctation is a term several authors have used to describe coarctation that is associated with other cardiac lesions or is technically challenging to repair. There is no consensus about the ideal approach for recurrent coarctation or complex coarctation [4]. Traditional options in these circumstances may include a staged approach with sternotomy and thoracotomy, a single-stage approach through sternotomy, and finally, catheter-based interventions combined with sternotomy. Extraanatomic bypass with ascending-to-descending aortic bypass represents a strategy that allows a single-stage
Accepted for publication Feb 4, 2014. Presented at the Sixtieth Annual Meeting of the Southern Thoracic Surgical Association, Scottsdale, AZ, Oct 30–Nov 2, 2013. Address correspondence to Dr Burkhart, Mayo Clinic, Division of Cardiovascular Surgery, 200 First St SW, Rochester, MN 55905; e-mail: [email protected].
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2014;-:-–-) Ó 2014 by The Society of Thoracic Surgeons
Patients and Methods Mayo Foundation Institutional Review Board approved the current study. Informed consent was obtained from patients to participate in the research.
Patients Between January 1985 and December 2012, 80 consecutive patients with complex coarctation underwent ascending– descending posterior pericardial aortic bypass through a median sternotomy. Patients were a median age of 42 years (range, 15 to 75 years), and 51 (64%) were males.
Preoperative Data The indications for the operation were uncontrolled systemic hypertension (systolic blood pressure 140 mm Hg despite therapy with antihypertensive medications) in 63 patients (79%) in the setting of complex native coarctation or recurrent coarctation after previous repair. Among these, 3 patients had history of hypertensive encephalopathy. Congestive heart failure was present in 5 patients (6%). Recurrent coarctation was present in 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.02.030
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52 patients (65%), with 6 (8%) having undergone previous balloon dilatation. A bicuspid aortic valve was identified in 47 patients (59%). Pseudoaneurysms in the distal arch were identified in 5 patients (6%), and 1 patient (1%) had a history of endocarditis. Coarctation with concomitant cardiac pathology was present in 31 patients (39%), including aortic valve stenosis in 21 (26%), subaortic stenosis in 10 (13%), and Shone complex in 4 (5%). Other noncardiac concomitant pathology included intracranial aneurysms in 4 patients (5%) and cerebral arteriovenous malformation in 1 (1%). Patient characteristics are summarized in Table 1.
Surgical Technique Our surgical technique of ascending–descending bypass has previously been published [6, 7]. Patients underwent a standard median sternotomy, and cardiopulmonary bypass was instituted by using an arterial cannula high in the ascending aorta and right-angle bicaval cannulae. We prefer bicaval cannulation because this allows the heart to be positioned out of the pericardial well and dropped into the right pleural space, without compromising the venous return. This further facilitates exposure of the distal descending thoracic aorta for construction of the distal anastomosis. Normothermia or a mild degree of hypothermia was used in 72 patients (90%), and 8 (10%) underwent a brief period of hypothermic circulatory arrest. Aortic cross-clamp with cardioplegic arrest was used in the presence of concomitant Table 1. Patient Characteristics Characteristics Male gender Hypertension Recurrent coarctation Native aortic coarctation Arch pseudoaneurysm Congestive heart failure Hypertensive encephalopathy Concomitant pathology Cardiac Bicuspid aortic valve Aortic valve stenosis Subaortic stenosis Shone complex Non-cardiac Intracranial aneurysm Cerebral AVM Previous balloon dilatation Previous operation Coarctation repair IAA repair VSD repair Aortic valve replacement Resection of SAS
No.
%
51 63 52 28 5 5 3
64 79 65 35 6 6 4
47 21 10 4
59 26 13 5
4 1 6
5 1 8
52 3 3 2 2
65 4 4 3 3
AVM ¼ arteriovenous malformation; IAA ¼ interrupted aortic arch; SAS ¼ subaortic stenosis; VSD ¼ ventricular septal defect.
cardiac pathology to facilitate intracardiac procedures. Two patients underwent ascending-descending bypass without the use of cardiopulmonary bypass. The posterior pericardium was opened in a longitudinal fashion over the descending thoracic aorta just cephalad to the diaphragm, paying attention to the nearby esophagus (Fig 1A). The distal anastomosis was constructed using a running 4-0 polypropylene suture after the application of a side-biting clamp on the exposed segment of the descending thoracic aorta, with a goal femoral arterial pressure of at least 40 mm Hg to ensure adequate distal perfusion (Figs 1B–1D). The average graft size was 20 2.7 mm (range, 14 to 28 mm). Importantly, we interpose the intact posterior pericardium between the esophagus and graft with a few tacking sutures to isolate the anastomosis from the esophageal wall. The graft is then passed anterior or posterior to the inferior vena cava on the right side along the free wall of the right atrium (Fig 1E) or to the left side, behind the left ventricle and on top of the main pulmonary artery, before joining the ascending aorta. We prefer positioning the proximal anastomosis on the far distal portion of the lateral aspect of the ascending aorta because this will facilitate an aortotomy should a future operation be required (Fig 1F). The proximal anastomosis is performed in the same manner as the distal anastomosis using a partial occluding clamp and a running 4-0 polypropylene suture. Concomitant procedures were performed in 44 patients (55%; Table 2). The most common were aortic valve replacement in 21 patients, followed by resection of subaortic stenosis in 10 and coronary artery bypass grafting in 7. Medical records were reviewed to obtain demographic characteristics, associated medical conditions, details of operations, and results of the echocardiographic examinations.
Statistical Analysis Descriptive statistics for categoric variables are reported as frequency and percentage, and continuous variables are reported as mean SD or as median with the range, as appropriate. Categoric variables were compared between valve types with the c2 test. Continuous variables were compared with the two-sample t test or the Wilcoxon rank sum test as appropriate. A p value of less than 0.05 was considered statistically significant. SAS 9.13 software (SAS Institute, Cary, NC) was used for statistical analysis.
Results All 80 patients underwent ascending–descending posterior pericardial bypass through a median sternotomy. Cardiopulmonary bypass was used in 78 patients. The mean aortic cross-clamp time was 33 40 minutes, and cardiopulmonary bypass time was 106 54 minutes. The mean size of the bypass graft was 20 2.7 mm (range, 14 to 28 mm). The bypass graft was positioned on the right side along the free wall of the right atrium in 77 patients, and was posterior to the inferior vena cava in 42 (Fig 2A) and anterior in 35 (Fig 2B). The graft in the remaining 3 patients was positioned to the left side (Fig 2C).
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Fig 1. Illustrations show our technique of ascending–descending posterior pericardial aortic bypass. (A) The heart is elevated out of the pericardial well and into the right hemithorax. (B) An adequate area of the distal descending thoracic aorta is chosen for the distal anastomosis, and a side-biting vascular clamp is applied. (C) The distal anastomosis is constructed using continuous 4-0 polypropylene suture. (D) Air is removed from the graft. (E) The graft can be routed to the right side along the free wall of the right atrium to complete the proximal anastomosis. (F) The proximal anastomosis is constructed in a similar fashion with a side-biting clamp applied on the most distal portion of the lateral aspect of the ascending aorta to facilitate potential future aortotomy. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
There were no early deaths. The most common complications (Table 3) were atrial fibrillation in 17 patients (21%) and deep vein thrombosis and pulmonary embolism Table 2. Operative Characteristics Characteristic CPB time, mean SD min AXC time, mean SD min Bypass graft Size, mean SD (range) mm Route Posterior to IVC Anterior to IVC To the left Concomitant procedures Aortic valve replacement Resection of SAS CABG AA replacement Mitral valve replacement Modified Bentall Maze Mitral valve repair Aortic valve repair Konno VSD closure PFO closure Tricuspid valve repair
Value 106 54 33 40 20 2.7 (14–28) 42 35 3 21 10 7 5 3 2 2 2 1 1 1 1 1
AA ¼ ascending aorta; AXC ¼ aortic cross-clamp; CABG ¼ coronary artery bypass graft; CPB ¼ cardiopulmonary bypass; IVC ¼ inferior vena cava; PFO ¼ patent foramen ovale; SAS ¼ subaortic stenosis; SD ¼ standard deviation; VSD ¼ ventricular septal defect.
in 2 (3%). Reexploration for postoperative bleeding was performed in 6 patients (8%). Transient paraparesis occurred in 1 patient, who was 1 of the only 2 patients in the series who did not undergo the operation with cardiopulmonary bypass. Visual field defects, which improved during follow-up, developed in another patient. There was no incident of paraplegia or stroke. There was no difference in outcomes based on the location or the route of the bypass graft (p ¼ 0.57). The mean follow-up was 7 6 years (maximum, 22 years). Long-term survival was excellent. Late mortality included 5 patients (6%) and was not related to the bypass graft (Fig 3). Three patients (4%) required late reoperation for repair of periprosthetic regurgitation in 2 and mitral valve replacement in 1. Upper extremity blood pressure significantly improved (p < 0.001). The mean systolic blood pressure decreased from 153 26 mm Hg preoperatively to 123 15 mm Hg postoperatively (Fig 4). The mean diastolic blood pressure also decreased from 78 15 mm Hg preoperatively to 67 12 mm Hg postoperatively (Fig 5). This improvement persisted during the follow-up period, with a mean systolic blood pressure of 121 12 mm Hg and a mean diastolic blood pressure of 68 9 mm Hg (p < 0.001). There was also a significant reduction in the mean number of antihypertensive medications taken postoperatively, from 1.7 1.4 preoperatively to 1.1 0.8 postoperatively (p ¼ 0.04); however, this difference was not significant at long-term follow-up (p ¼ 0.06; Fig 6). No graft-related complications were detected during the follow-up period.
Comment Robert Gross pioneered the surgical correction of native aortic coarctation and investigated the use of the aortic
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Fig 2. The bypass graft can be positioned on the right side along the right atrial free wall either (A) anterior or (B) posterior to the inferior vena cava or (C) along the left side anterior to the pulmonary artery. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
homograft as an interposition graft in patients who were not candidates for end-to-end anastomosis. However, the first successful repair was performed in Sweden a few months earlier by Crafoord and Nylin [8]. Recurrent coarctation is still a controversial subject, beginning with the proper definition to the best way of treatment. The literature is full of various reports that define recurrent coarctation according to severity. Some require a blood pressure gradient of more than 20 to 30 mm Hg with an imaging modality showing at least 50% narrowing in the descending aorta [9]. In the current study, patients who underwent reoperation for recurrent coarctation had preoperative crosssectional imaging confirming the recurrence. The current management of these patients is to use catheter-based interventions in the form of balloon angioplasty with or without stent placement [10, 11], realizing the long-term risks with stents are unknown. Recurrent coarctation was present in 52 patients (65%) in our study, and 6 of them (8%) had previously undergone balloon dilatation, without longterm success. Surgical intervention for recurrent coarctation though a left thoracotomy may be hazardous because of the altered anatomy, the need for distal arch reconstruction, and the risk to the recurrent laryngeal nerve.
The ascending–descending bypass represents a valuable and safer option in these situations [12]. In the series reported by Massey and Shore [13], 6 patients underwent ascending–descending bypass, comprising 5 with recoarctation, 2 combined with aortic valve replacement, and 1 with primary repair of coarctation combined with replacement of the ascending aorta. Postpericardiotomy syndrome occurred in 1 patient postoperatively, but no other complications were noted. The postoperative gradient was not significant in any patient [13]. Coarctation of the aorta can occur as an isolated anomaly; however, it can be associated with other cardiovascular pathology, which adds to the complexity of future intervention. Its association with bicuspid aortic valve is well known and occurs in at least 50% of patients [14]. In the current series, 47 patients (59%) had a bicuspid aortic valve. Complex coarctation of the aorta continues to be controversial in regards to the best and safest approach. Coarctation in association with other cardiac pathology can be approached in a one-stage or two-staged approach. Extraanatomic bypass may represent a reasonable and safe option in these circumstances to facilitate a single-stage approach to the coarctation and to the intracardiac pathology. In the current series, there were no perioperative deaths and minimal morbidity. The long-term results are
Table 3. Operative Outcomes Outcome Mortality Early Late Morbidity Atrial fibrillation Reexploration for bleeding Pulmonary embolism Postpericardiotomy syndrome Sternal dehiscence Seizures Visual field defect Paraparesis Paraplegia
No.
%
0 5
0 6
17 6 2 2 1 1 1 1 0
21 8 3 3 1 1 1 1 0
Fig 3. Kaplan-Meier survival curve (black line) shows long-term survival of the patients in the current study. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
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Fig 4. Upper extremity systolic blood pressure (SBP) improved significantly after the ascending–descending bypass (p < 0.001). This improvement was in the early postoperative period and continued during the follow-up (FU). The horizontal line in the middle of each box indicates the median, the diamond in the center shows the mean and its confidence interval, the top and bottom borders of the box mark the 75th and 25th percentiles, respectively, the whiskers mark the 90th and 10th percentiles, and the circles indicate outliers. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
satisfactory, and no graft-related complications occurred. We did not see any evidence of pseudoaneurysms, patientgraft mismatch, dissection, or graft or anastomotic narrowing. No patient had an aortic-to-esophageal fistula, which has been a concern raised by others [15]. We always interpose the intact posterior pericardium between the esophagus and graft with a few tacking sutures to isolate the anastomosis from the esophageal wall.
Fig 5. Upper extremity diastolic blood pressure (DBP) improved significantly after the ascending-descending bypass (p < 0.001). This improvement was in the early postoperative period and continued during the follow-up (FU). The horizontal line in the middle of each box indicates the median, the diamond in the center shows the mean and its confidence interval, the top and bottom borders of the box mark the 75th and 25th percentiles, respectively, the whiskers mark the 90th and 10th percentiles, and the circle indicates an outlier. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
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Fig 6. The average number of antihypertensive medications decreased significantly during the early postoperative period after the ascending–descending bypass (p ¼ 0.04); however, this difference did not persist during the long-term follow-up (FU; p ¼ 0.06) which may reflect the older age of our patient population at the time of reoperation. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
Edie and colleagues [16] and Wukasch and colleagues [17] first described bypass of the aorta through a median sternotomy. Vijayanagar and colleagues [18] described aortic bypass posterior to the heart, which was further modified by several authors, including Sweeney and colleagues [3], Powell and colleagues [19], and Robicsek and colleagues [20]. Although some authors describe the possibility of performing ascending–descending aortic bypass without the use of the heart–lung machine, we prefer to use it because it allows maintenance of adequate perfusion pressure and hemodynamic stability during manipulation of the heart. We have described previously our indications for ascending–descending bypass, and these include complex coarctation with concomitant intracardiac pathology that requires simultaneous repair and adults with surgical recurrent coarctation after previous repair when the extraanatomic bypass appears to be a safer alternative to anatomic repair [21]. Complex coarctation may include arch stenosis, aortic calcification, long-segment coarctation, or recurrent coarctation not amenable to percutaneous treatment. The posterior pericardial approach is our preferred technique; however, this bypass has also been described through a right thoracotomy approach [22]. In patients who are at risk for future reoperation, the route of the ascending–descending bypass graft should be considered. The bypass graft can pass anterior or posterior to the inferior vena cava on the right side along the free wall of the right atrium or to the left side, behind the left ventricle and on top of the main pulmonary artery, before joining the ascending aorta. We noticed no difference in outcome by the route used for the graft; however, it is an important consideration for reoperation. We also prefer positioning the proximal anastomosis on the far distal portion of the lateral aspect of the ascending aorta
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because this will facilitate an aortotomy if needed in a future operation. Paraplegia is one of the most feared complications after aortic operations and has been reported in patients after reoperations for coarctation [23]. Several strategies have been proposed to minimize the risk of paraplegia; however, it is still a risk. In the current study, we did not document paraplegia in any patient, which points to the safety of the ascending–descending bypass in the reoperative settings. In fact, a decrease in the risk of spinal cord injury might be expected with the posterior pericardial approach because of the location of the distal anastomosis, which is made to the distal thoracic aorta above the diaphragm. Paraparesis occurred early postoperatively in 1 patient in our study, a 33-year-old woman who experienced right lower extremity weakness that was attributed to spinal cord ischemia. She had undergone two previous thoracotomies for coarctation repair and also an unsuccessful balloon angioplasty. This patient is 1 of the only 2 patients in the current series in whom cardiopulmonary bypass was not used to perform the ascending–descending bypass. This was transient weakness and resolved during the follow-up period, but this case may reflect the importance of cardiopulmonary bypass in these situations to maintain distal perfusion and avoid intraoperative hypotension with heart manipulation, especially in the reoperative settings. Decompression of the heart with cardiopulmonary bypass has an advantage of improving exposure of the descending aorta, especially in adult patients where exposure may be limited. Aneurysms and pseudoaneurysms are reported after operations for aortic coarctation. Von Kodolitsch and colleagues [24] reported a series of 25 patients who underwent reoperation for aneurysms after previous coarctation repair. The aneurysms were located in the ascending aorta in 8 of these patients, whereas the aneurysms (pseudoaneurysms) in the remaining 17 were at the site of the repair [24]. In the current study, we identified 5 patients (6%) with preoperative pseudoaneurysms at the site of a previous coarctation repair. This added to the complexity of the repair; however, 2 of these patients underwent concomitant carotid-to-subclavian bypass in preparation for stenting and were stented, 2 patients have had no interventions so far, and 1 patient died of a cause not related to the pseudoaneurysm. Our current approach in the presence of aortic pseudoaneurysm, unless it is going to be addressed through a thoracotomy, is to plan a staged approach, addressing the concomitant cardiac pathology, and performing an ascending-to-descending aortic bypass, first followed by aortic stenting at the second stage. Hypertension is frequently associated with coarctation, and many studies have shown that older age at repair is a predictor for persistent late systemic hypertension [25, 26]. The landmark report by Clarkson and colleagues [27] described the long-term results after the coarctation operation. The authors identified that age at the time of the operation influenced the risk of late hypertension. Patients who were older than 20 years at the time of the
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operation were more likely to have late hypertension than those operated on when they were between 5 and 19 years old (p ¼ 0.007) [27]. In the current study, 63 patients (79%) had uncontrolled systemic hypertension preoperatively. Blood pressure significantly improved after the operation and during the follow-up period (p < 0.001). The mean systolic blood pressure decreased from 153 26 mm Hg preoperatively to 123 15 mm Hg postoperatively, and this improvement persisted during the follow-up period (p < 0.001). There was also a significant reduction in the mean number of antihypertensive medications taken postoperatively, from 1.7 1.4 preoperatively to 1.1 0.8 postoperatively (p ¼ 0.04); however, this difference was not significant at long-term follow-up (p ¼ 0.06), which may reflect the older age of the patients at the time of reintervention. We tend to reserve the posterior pericardial approach and ascending–descending bypass for adults with complex or recurrent coarctation but are reluctant to use this approach in pediatric patients. The concern is that with ongoing somatic growth, tension will increase on the graft and may be a factor in development of pseudoaneurysm or patient–graft mismatch. In conclusion, the ascending–descending aortic bypass graft through a posterior pericardial approach appears to be effective in relieving aortic gradient and improving systemic blood pressure. It represents a safer solution to complex coarctation and permits a single-stage approach to coarctation associated with other cardiac pathology that requires simultaneous surgical intervention.
References 1. Cohen M, Fuster V, Steele PM, Driscoll D, McGoon DC. Coarctation of the aorta: long-term follow-up and prediction of outcome after surgical correction. Circulation 1989;80: 840–5. 2. Foster ED. Reoperation for aortic coarctation. Ann Thorac Surg 1984;38:81–9. 3. Sweeney MS, Walker WE, Duncan JM, Hallman GL, Livesay JJ, Cooley DA. Reoperation for aortic coarctation: techniques, results, and indications for various approaches. Ann Thorac Surg 1985;40:46–9. 4. Wang R, Sun LZ, Hu XP, et al. Treatment of complex coarctation and coarctation with cardiac lesions using extraanatomic aortic bypass. J Vasc Surg 2010;51:1203–8. 5. Izhar U, Schaff HV, Mullany CJ, Daly RC, Orszulak TA. Posterior pericardial approach for ascending aorta-todescending aorta bypass through a median sternotomy. Ann Thorac Surg 2000;70:31–7. 6. Said SM, Dearani JA, Burkhart HM, Schaff HV. Extraanatomic bypass graft for recurrentaortic arch obstruction. Oper Techn Thorac Cardiovasc Surg 2012;17:261–70. 7. Burkhart HM, Dearani JA, Connolly HM, Schaff HV. Ascending-descending posterior pericardial bypass of complex coarctation of the aorta. Semin Thorac Cardiovasc Surg Pediatr Card Surg Ann 2011;14:116–9. 8. Crafoord C, Nylin G. Congenital coarctation of the aorta and its surgical treatment. J Thorac Surg 1945;14:347–61. 9. Serfontein SJ, Kron IL. Complications of coarctation repair. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2002;5:206–11. 10. Castaneda-Zuniga WR, Lock JE, Vlodaver Z, et al. Transluminal dilatation of coarctation of the abdominal aorta. An experimental study in dogs. Radiology 1982;143:693–7.
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11. Mann C, Goebel G, Eicken A, et al. Balloon dilation for aortic recoarctation: morphology at the site of dilation and longterm efficacy. Cardiol Young 2001;11:30–5. 12. McKellar SH, Schaff HV, Dearani JA, et al. Intermediate-term results of ascending descending posterior pericardial bypass of complex aortic coarctation. J Thorac Cardiovasc Surg 2007;133:1504–9. 13. Massey R, Shore DF. Surgery for complex coarctation of the aorta. Int J Cardiol 2004;97(Suppl):67–73. 14. Becker AE, Becker MJ, Edwards JE. Anomalies associated with coarctation of the aorta. Particular references to infancy. Circulation 1970;41:1067–75. 15. Kanter KR, Erez E, Williams WH, Tam VK. Extra-anatomic aortic bypass via sternotomy for complex aortic arch stenosis in children. J Thorac Cardiovasc Surg 2000;120:885–90. 16. Edie RN, Janani J, Attai LA, Malm JR, Robinson G. Bypass grafts for recurrent or complex coarctations of the aorta. Ann Thorac Surg 1975;20:558–66. 17. Wukasch DC, Cooley DA, Sandiford FM, Nappi G, Reul GJ Jr. Ascending aorta abdominal aorta bypass: indications, technique, and report of 12 patients. Ann Thorac Surg 1977;23: 442–8. 18. Vijayanagar R, Natarajan P, Eckstein PF, Bognolo DA, Toole JC. Aortic valvular insufficiency and postductal aortic coarctation in the adult: combined surgical management through medial sternotomy: a new surgical approach. J Thorac Cardiovasc Surg 1980;79:266–8. 19. Powell WR, Adams PR, Cooley DA. Repair of coarctation of the aorta associated with intracardiac repair. Tex Heart Inst J 1983;10:409–13.
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20. Robicsek F, Hess PJ, Vajtai P. Ascending-distal abdominal aorta bypass for treatment of hypoplastic aortic arch and atypical coarctation in the adult. Ann Thorac Surg 1984;37: 261–3. 21. Connolly HM, Schaff HV, Izhar U, Dearani JA, Warnes CA, Orszulak TA. Posterior pericardial ascending–descending aortic bypass: an alternative surgical approach for complex coarctation of the aorta. Circulation 2001;104(Suppl): I133–7. 22. Arakelyan V, Spiridonov A, Bockeria L. Ascending-todescending aortic bypass via right thoracotomy for complex (re-) coarctation and hypoplastic aortic arch. Eur J Cardiothoracic Surg 2005;27:815–20. 23. Brewer LA 3rd, Fosburg RG, Mulder GA, Verska JJ. Spinal cord complications following surgery for coarctation of the aorta: a study of 66 cases. J Thorac Cardiovasc Surg 1972;64: 368–81. 24. Von Kodolitsch Y, Aydin MA, Koschyk DH, et al. Predictors of aneurysmal; formation after surgical correction of aortic coarctation. J Am Coll Cardiol 2002;39:617–24. 25. Toro-Salazar OH, Steinberger J, Thomas W, Rocchini AP, Carpenter B, Moller JH. Long-term follow-up of patients after coarctation of the aorta repair. Am J Cardiol 2002;89: 541–7. 26. Brown ML, Burkhart HM, Connolly HM, et al. Coarctation of the aorta: lifelong surveillance is mandatory following surgical repair. J Am Coll Cardiol 2013;62:1020–5. 27. Clarkson PM, Nicholson MR, Barratt-Boyes BG, Neutze JM, Whitlock RM. Results after repair of coarctation of the aorta beyond infancy. Am J Cardiol 1983;51:1481–8.
DISCUSSION DR JAMES S. TWEDDELL (Milwaukee, WI): That was an excellent presentation, wonderfully done, and I would like to thank you for sending me the manuscript, also. You and your colleagues from Mayo Clinic have summarized a large experience for treatment of complex arch obstruction using extraanatomic bypass grafting. For the most part, the operations were done on cardiopulmonary bypass with mild hypothermia, and the results were excellent, with no mortality, very low morbidity, and improved blood pressure control. I think that is really just outstanding, and I congratulate the authors on those results. The technique has been well described and illustrated in your presentation and one I have used myself. I have a couple of questions. First, can you tell us how you selected patients for the extraanatomic bypass grafting? Certainly, concomitant cardiac pathology requiring repair would be one potential indication for approach to the front, but are there patients in this category, sort of in the fourth decade of life, with coarctation where you might approach them through a thoracotomy? DR SAID: Thank you very much Dr Tweddell. There are multiple factors that should be considered, and these include the number of prior thoracotomies, which would further increase the risk of recurrent laryngeal nerve injury, the need for circulatory arrest, quality of the ascending aorta and the arch, and the presence of calcifications, and finally, concomitant aortic arch hypoplasia. The presence of one or more of these factors will make us lean towards median sternotomy as an approach; otherwise, thoracotomy will be reasonable. DR TWEDELL: Thank you. As you illustrated here, patients with coarctation frequently have a bicuspid aortic valve. These patients have a high lifetime risk of aortic valve surgery, and despite careful graft placement, reoperation on patients with an
extraanatomic bypass graft can be challenging. Did the use of this approach change your threshold for aortic valve surgery? DR SAID: As shown in the study, over half of these patients had bicuspid aortic valve and 21 of them required concomitant aortic valve replacement. However, our indication is still following the guidelines regarding the gradient and the aortic valve area. The reoperation rate in our series was low and included only 3 patients, and none of these reoperations involved the native bicuspid aortic valve itself. The reoperation risk is there, and we take certain precautions in expectation of resternotomy (eg, the location of the bypass graft and location of the proximal anastomosis in anticipation of future aortotomy). So we try to do it on the far lateral side and more higher on the ascending aorta. DR TWEDELL: Thank you. In your manuscript, you comment that 5 patients had a pseudoaneurysm in the distal arch at the time of their extraanatomic repair. It wasn’t exactly clear how you managed those. Were they small and insignificant and followed or did you do something with them at the time of surgery? How are you managing those patients now? DR SAID: Let’s look at the profile of these 5 patients first. They all had at least two prior thoracotomies for repair of coarctation; 3 of them had concomitant arch hypoplasia. We don’t advocate this approach to avoid pseudoaneurysm, because we are not dealing with the main pathology. However, 2 of these patients underwent concomitant carotid-to-subclavian bypass in preparation for stenting, and they were stented; 2 patients had no interventions so far; and 1 patient died, however, it was not related to the pseudoaneurysm. So our current approach for the presence of pseudoaneurysm, unless it is going to be addressed through a thoracotomy, is to do a staged approach, addressing the concomitant cardiac
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pathology, the ascending to descending bypass, and preparation for stenting at the second stage. DR TWEDELL: Temporary clinically evident spinal cord ischemia was found in 1 patient. Yesterday morning there was a very nice presentation on the potential subclinical presence of spinal cord ischemia in patients who have aortic cross-clamping. When I have used this strategy, I am struck by the fact that the bucket clamp or Satinsky clamp that you place on the descending thoracic aorta at the level of the diaphragm, it is hard to exclude enough to do an anastomosis without completely occluding the descending aorta for a little while. I have always thought that the use of bypass with mild hypothermia is probably a good idea in that case, because I am giving myself a little spinal cord protection perhaps just as a byproduct of that strategy. In this one patient where you had the temporary evidence of a neurologic problem, bypass wasn’t used, and I would like to hear your comments on that. Do you think, in fact, frequently that the descending aorta is being completely occluded by that clamp? Would you recommend bypass and mild hypothermia for these patients for that indication? DR SAID: Thank you. That is a very important point. This patient was the only patient that developed a paraparesis, and the case was done without the use of cardiopulmonary bypass, and placement of the side-biting clamp on the descending aorta is critical as it may be nearly occluding its lumen especially in females and when the size of the descending aorta is small. This patient was done early in the series, and our approach to all the ascending–descending bypasses now is to use cardiopulmonary bypass. First, it allowed for adequate heart decompression and adequate placing of the clamp. Second, we monitor the arterial pressure in the femoral artery, and we have a low threshold for cannulating the femoral artery in addition, and Y-this to the arterial line of the pump, and third, we use mild hypothermia. DR TWEDELL: Thank you very much. Excellent presentation. DR MARCO RICCI (Miami, FL): Dr Said, one additional question. Going back to the question that Dr Tweddell was asking
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about patient selection, I have not seen your manuscript, but in your abstract, you stated that the 80 patients were consecutive. I am not clear as to whether, for example, in a patient with isolated coarctation of the aorta without any arch compromise you used this approach (ie, ascending–descending bypass), and do you never use, for example, a left thoracotomy with a left subclavian to descending thoracic bypass, which is also a safe alternative. So could you describe briefly why you chose to select the approach that requires cardiopulmonary bypass as opposed to the left thoracotomy approach that does not? DR SAID: The left thoracotomy approach will be considered only for patients with low-risk redo thoracotomy. Looking at the profile of our patients, most of them had multiple thoracotomies, multiple interventions before, plus they are adult patients, and sometimes it is very difficult to get a clamp proximally on the arch through a left thoracotomy in adults. In addition, if there is an arch hypoplasia, which was a feature in a lot of these patients, it will be difficult to address this from a thoracotomy because of the limited mobility of the arch and the descending aorta in adults. DR KRISTINE GULESERIAN (Dallas, TX): I really enjoyed your presentation. I wonder whether you have had any experience with a technique that we use in Dallas, something called the “bucket handle” procedure, essentially an extraanatomic ascending-to-descending thoracic aortic bypass performed through a right thoracotomy off bypass to avoid exactly what you have mentioned with regard to concerns with proximal arch hypoplasia, limited aortic arch mobility, potential for recurrent nerve injury et cetera? DR SAID: We have never done it through a right thoracotomy; however, it is a well-published technique. We think there may be also some difficulty through a right thoracotomy to expose a sizable segment of the descending thoracic aorta, plus it will require a relatively large incision to approach that. However, it is a well-recognized technique; in fact, we refer to it in the discussion portion of our manuscript.
Background. Surgical correction of complex aortic coarctation can be associated with significant risks. Extraanatomic bypass may represent a safer alternative. Methods. Between January 1985 and December 2012, 80 consecutive patients with complex coarctation underwent ascending-to-descending aortic bypass through a median sternotomy. Patients were a median age of 42 years (range, 15 to 75 years), and 51 (64%) were males. Recurrent coarctation was present in 52 patients (65%), with 6 (8%) having undergone balloon dilatation. Uncontrolled hypertension was present in 63 patients (79%). The most common concomitant pathology was aortic valve stenosis in 21 patients (26%), subaortic stenosis in 10 (13%), and Shone complex in 4 (5%). Results. There were no early deaths. The most common concomitant procedures were aortic valve replacement, coronary artery bypass grafting, and resection of subaortic stenosis. The mean aortic cross-clamp and cardiopulmonary bypass times were 33 ± 40 and 106 ± 54 minutes,
respectively. Morbidity included atrial fibrillation in 17 patients (21%) and reexploration for bleeding in 6 (8%). There was no paraplegia or stroke. Upper extremity blood pressure significantly improved (p < 0.001). Mean systolic blood pressure decreased from 153 ± 26 mm Hg preoperatively to 123 ± 15 mm Hg postoperatively. Mean follow-up was 7 ± 6 years (maximum, 22 years). Late deaths occurred in 5 patients (6%) and were not graftrelated. Three patients (4%) required reoperation for repair of periprosthetic regurgitation in 2 and mitral valve replacement in 1. Conclusions. The ascending-to-descending aortic bypass can be performed with low morbidity and mortality. It is an effective solution to complex aortic coarctation and represents a safe single-stage approach for patients with concomitant cardiac pathology.
U
repair of coarctation and concomitant cardiac pathology through a median sternotomy [5]. In this article, we review our experience with ascending–descending aortic bypass for complex aortic coarctation.
ntreated aortic coarctation results in persistent systemic hypertension with its related sequelae, including accelerated coronary artery disease, stroke, or aortic dissection. It has also been associated with premature death secondary to progressive heart failure [1]. Excellent surgical outcomes have been achieved with repair of simple aortic coarctation though a left posterolateral thoracotomy, with a 5% to 30% incidence of recurrence [2, 3] requiring reintervention. “Complex” coarctation is a term several authors have used to describe coarctation that is associated with other cardiac lesions or is technically challenging to repair. There is no consensus about the ideal approach for recurrent coarctation or complex coarctation [4]. Traditional options in these circumstances may include a staged approach with sternotomy and thoracotomy, a single-stage approach through sternotomy, and finally, catheter-based interventions combined with sternotomy. Extraanatomic bypass with ascending-to-descending aortic bypass represents a strategy that allows a single-stage
Accepted for publication Feb 4, 2014. Presented at the Sixtieth Annual Meeting of the Southern Thoracic Surgical Association, Scottsdale, AZ, Oct 30–Nov 2, 2013. Address correspondence to Dr Burkhart, Mayo Clinic, Division of Cardiovascular Surgery, 200 First St SW, Rochester, MN 55905; e-mail: [email protected].
Ó 2014 by The Society of Thoracic Surgeons Published by Elsevier Inc
(Ann Thorac Surg 2014;-:-–-) Ó 2014 by The Society of Thoracic Surgeons
Patients and Methods Mayo Foundation Institutional Review Board approved the current study. Informed consent was obtained from patients to participate in the research.
Patients Between January 1985 and December 2012, 80 consecutive patients with complex coarctation underwent ascending– descending posterior pericardial aortic bypass through a median sternotomy. Patients were a median age of 42 years (range, 15 to 75 years), and 51 (64%) were males.
Preoperative Data The indications for the operation were uncontrolled systemic hypertension (systolic blood pressure 140 mm Hg despite therapy with antihypertensive medications) in 63 patients (79%) in the setting of complex native coarctation or recurrent coarctation after previous repair. Among these, 3 patients had history of hypertensive encephalopathy. Congestive heart failure was present in 5 patients (6%). Recurrent coarctation was present in 0003-4975/$36.00 http://dx.doi.org/10.1016/j.athoracsur.2014.02.030
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52 patients (65%), with 6 (8%) having undergone previous balloon dilatation. A bicuspid aortic valve was identified in 47 patients (59%). Pseudoaneurysms in the distal arch were identified in 5 patients (6%), and 1 patient (1%) had a history of endocarditis. Coarctation with concomitant cardiac pathology was present in 31 patients (39%), including aortic valve stenosis in 21 (26%), subaortic stenosis in 10 (13%), and Shone complex in 4 (5%). Other noncardiac concomitant pathology included intracranial aneurysms in 4 patients (5%) and cerebral arteriovenous malformation in 1 (1%). Patient characteristics are summarized in Table 1.
Surgical Technique Our surgical technique of ascending–descending bypass has previously been published [6, 7]. Patients underwent a standard median sternotomy, and cardiopulmonary bypass was instituted by using an arterial cannula high in the ascending aorta and right-angle bicaval cannulae. We prefer bicaval cannulation because this allows the heart to be positioned out of the pericardial well and dropped into the right pleural space, without compromising the venous return. This further facilitates exposure of the distal descending thoracic aorta for construction of the distal anastomosis. Normothermia or a mild degree of hypothermia was used in 72 patients (90%), and 8 (10%) underwent a brief period of hypothermic circulatory arrest. Aortic cross-clamp with cardioplegic arrest was used in the presence of concomitant Table 1. Patient Characteristics Characteristics Male gender Hypertension Recurrent coarctation Native aortic coarctation Arch pseudoaneurysm Congestive heart failure Hypertensive encephalopathy Concomitant pathology Cardiac Bicuspid aortic valve Aortic valve stenosis Subaortic stenosis Shone complex Non-cardiac Intracranial aneurysm Cerebral AVM Previous balloon dilatation Previous operation Coarctation repair IAA repair VSD repair Aortic valve replacement Resection of SAS
No.
%
51 63 52 28 5 5 3
64 79 65 35 6 6 4
47 21 10 4
59 26 13 5
4 1 6
5 1 8
52 3 3 2 2
65 4 4 3 3
AVM ¼ arteriovenous malformation; IAA ¼ interrupted aortic arch; SAS ¼ subaortic stenosis; VSD ¼ ventricular septal defect.
cardiac pathology to facilitate intracardiac procedures. Two patients underwent ascending-descending bypass without the use of cardiopulmonary bypass. The posterior pericardium was opened in a longitudinal fashion over the descending thoracic aorta just cephalad to the diaphragm, paying attention to the nearby esophagus (Fig 1A). The distal anastomosis was constructed using a running 4-0 polypropylene suture after the application of a side-biting clamp on the exposed segment of the descending thoracic aorta, with a goal femoral arterial pressure of at least 40 mm Hg to ensure adequate distal perfusion (Figs 1B–1D). The average graft size was 20 2.7 mm (range, 14 to 28 mm). Importantly, we interpose the intact posterior pericardium between the esophagus and graft with a few tacking sutures to isolate the anastomosis from the esophageal wall. The graft is then passed anterior or posterior to the inferior vena cava on the right side along the free wall of the right atrium (Fig 1E) or to the left side, behind the left ventricle and on top of the main pulmonary artery, before joining the ascending aorta. We prefer positioning the proximal anastomosis on the far distal portion of the lateral aspect of the ascending aorta because this will facilitate an aortotomy should a future operation be required (Fig 1F). The proximal anastomosis is performed in the same manner as the distal anastomosis using a partial occluding clamp and a running 4-0 polypropylene suture. Concomitant procedures were performed in 44 patients (55%; Table 2). The most common were aortic valve replacement in 21 patients, followed by resection of subaortic stenosis in 10 and coronary artery bypass grafting in 7. Medical records were reviewed to obtain demographic characteristics, associated medical conditions, details of operations, and results of the echocardiographic examinations.
Statistical Analysis Descriptive statistics for categoric variables are reported as frequency and percentage, and continuous variables are reported as mean SD or as median with the range, as appropriate. Categoric variables were compared between valve types with the c2 test. Continuous variables were compared with the two-sample t test or the Wilcoxon rank sum test as appropriate. A p value of less than 0.05 was considered statistically significant. SAS 9.13 software (SAS Institute, Cary, NC) was used for statistical analysis.
Results All 80 patients underwent ascending–descending posterior pericardial bypass through a median sternotomy. Cardiopulmonary bypass was used in 78 patients. The mean aortic cross-clamp time was 33 40 minutes, and cardiopulmonary bypass time was 106 54 minutes. The mean size of the bypass graft was 20 2.7 mm (range, 14 to 28 mm). The bypass graft was positioned on the right side along the free wall of the right atrium in 77 patients, and was posterior to the inferior vena cava in 42 (Fig 2A) and anterior in 35 (Fig 2B). The graft in the remaining 3 patients was positioned to the left side (Fig 2C).
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Fig 1. Illustrations show our technique of ascending–descending posterior pericardial aortic bypass. (A) The heart is elevated out of the pericardial well and into the right hemithorax. (B) An adequate area of the distal descending thoracic aorta is chosen for the distal anastomosis, and a side-biting vascular clamp is applied. (C) The distal anastomosis is constructed using continuous 4-0 polypropylene suture. (D) Air is removed from the graft. (E) The graft can be routed to the right side along the free wall of the right atrium to complete the proximal anastomosis. (F) The proximal anastomosis is constructed in a similar fashion with a side-biting clamp applied on the most distal portion of the lateral aspect of the ascending aorta to facilitate potential future aortotomy. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
There were no early deaths. The most common complications (Table 3) were atrial fibrillation in 17 patients (21%) and deep vein thrombosis and pulmonary embolism Table 2. Operative Characteristics Characteristic CPB time, mean SD min AXC time, mean SD min Bypass graft Size, mean SD (range) mm Route Posterior to IVC Anterior to IVC To the left Concomitant procedures Aortic valve replacement Resection of SAS CABG AA replacement Mitral valve replacement Modified Bentall Maze Mitral valve repair Aortic valve repair Konno VSD closure PFO closure Tricuspid valve repair
Value 106 54 33 40 20 2.7 (14–28) 42 35 3 21 10 7 5 3 2 2 2 1 1 1 1 1
AA ¼ ascending aorta; AXC ¼ aortic cross-clamp; CABG ¼ coronary artery bypass graft; CPB ¼ cardiopulmonary bypass; IVC ¼ inferior vena cava; PFO ¼ patent foramen ovale; SAS ¼ subaortic stenosis; SD ¼ standard deviation; VSD ¼ ventricular septal defect.
in 2 (3%). Reexploration for postoperative bleeding was performed in 6 patients (8%). Transient paraparesis occurred in 1 patient, who was 1 of the only 2 patients in the series who did not undergo the operation with cardiopulmonary bypass. Visual field defects, which improved during follow-up, developed in another patient. There was no incident of paraplegia or stroke. There was no difference in outcomes based on the location or the route of the bypass graft (p ¼ 0.57). The mean follow-up was 7 6 years (maximum, 22 years). Long-term survival was excellent. Late mortality included 5 patients (6%) and was not related to the bypass graft (Fig 3). Three patients (4%) required late reoperation for repair of periprosthetic regurgitation in 2 and mitral valve replacement in 1. Upper extremity blood pressure significantly improved (p < 0.001). The mean systolic blood pressure decreased from 153 26 mm Hg preoperatively to 123 15 mm Hg postoperatively (Fig 4). The mean diastolic blood pressure also decreased from 78 15 mm Hg preoperatively to 67 12 mm Hg postoperatively (Fig 5). This improvement persisted during the follow-up period, with a mean systolic blood pressure of 121 12 mm Hg and a mean diastolic blood pressure of 68 9 mm Hg (p < 0.001). There was also a significant reduction in the mean number of antihypertensive medications taken postoperatively, from 1.7 1.4 preoperatively to 1.1 0.8 postoperatively (p ¼ 0.04); however, this difference was not significant at long-term follow-up (p ¼ 0.06; Fig 6). No graft-related complications were detected during the follow-up period.
Comment Robert Gross pioneered the surgical correction of native aortic coarctation and investigated the use of the aortic
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Fig 2. The bypass graft can be positioned on the right side along the right atrial free wall either (A) anterior or (B) posterior to the inferior vena cava or (C) along the left side anterior to the pulmonary artery. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
homograft as an interposition graft in patients who were not candidates for end-to-end anastomosis. However, the first successful repair was performed in Sweden a few months earlier by Crafoord and Nylin [8]. Recurrent coarctation is still a controversial subject, beginning with the proper definition to the best way of treatment. The literature is full of various reports that define recurrent coarctation according to severity. Some require a blood pressure gradient of more than 20 to 30 mm Hg with an imaging modality showing at least 50% narrowing in the descending aorta [9]. In the current study, patients who underwent reoperation for recurrent coarctation had preoperative crosssectional imaging confirming the recurrence. The current management of these patients is to use catheter-based interventions in the form of balloon angioplasty with or without stent placement [10, 11], realizing the long-term risks with stents are unknown. Recurrent coarctation was present in 52 patients (65%) in our study, and 6 of them (8%) had previously undergone balloon dilatation, without longterm success. Surgical intervention for recurrent coarctation though a left thoracotomy may be hazardous because of the altered anatomy, the need for distal arch reconstruction, and the risk to the recurrent laryngeal nerve.
The ascending–descending bypass represents a valuable and safer option in these situations [12]. In the series reported by Massey and Shore [13], 6 patients underwent ascending–descending bypass, comprising 5 with recoarctation, 2 combined with aortic valve replacement, and 1 with primary repair of coarctation combined with replacement of the ascending aorta. Postpericardiotomy syndrome occurred in 1 patient postoperatively, but no other complications were noted. The postoperative gradient was not significant in any patient [13]. Coarctation of the aorta can occur as an isolated anomaly; however, it can be associated with other cardiovascular pathology, which adds to the complexity of future intervention. Its association with bicuspid aortic valve is well known and occurs in at least 50% of patients [14]. In the current series, 47 patients (59%) had a bicuspid aortic valve. Complex coarctation of the aorta continues to be controversial in regards to the best and safest approach. Coarctation in association with other cardiac pathology can be approached in a one-stage or two-staged approach. Extraanatomic bypass may represent a reasonable and safe option in these circumstances to facilitate a single-stage approach to the coarctation and to the intracardiac pathology. In the current series, there were no perioperative deaths and minimal morbidity. The long-term results are
Table 3. Operative Outcomes Outcome Mortality Early Late Morbidity Atrial fibrillation Reexploration for bleeding Pulmonary embolism Postpericardiotomy syndrome Sternal dehiscence Seizures Visual field defect Paraparesis Paraplegia
No.
%
0 5
0 6
17 6 2 2 1 1 1 1 0
21 8 3 3 1 1 1 1 0
Fig 3. Kaplan-Meier survival curve (black line) shows long-term survival of the patients in the current study. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
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Fig 4. Upper extremity systolic blood pressure (SBP) improved significantly after the ascending–descending bypass (p < 0.001). This improvement was in the early postoperative period and continued during the follow-up (FU). The horizontal line in the middle of each box indicates the median, the diamond in the center shows the mean and its confidence interval, the top and bottom borders of the box mark the 75th and 25th percentiles, respectively, the whiskers mark the 90th and 10th percentiles, and the circles indicate outliers. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
satisfactory, and no graft-related complications occurred. We did not see any evidence of pseudoaneurysms, patientgraft mismatch, dissection, or graft or anastomotic narrowing. No patient had an aortic-to-esophageal fistula, which has been a concern raised by others [15]. We always interpose the intact posterior pericardium between the esophagus and graft with a few tacking sutures to isolate the anastomosis from the esophageal wall.
Fig 5. Upper extremity diastolic blood pressure (DBP) improved significantly after the ascending-descending bypass (p < 0.001). This improvement was in the early postoperative period and continued during the follow-up (FU). The horizontal line in the middle of each box indicates the median, the diamond in the center shows the mean and its confidence interval, the top and bottom borders of the box mark the 75th and 25th percentiles, respectively, the whiskers mark the 90th and 10th percentiles, and the circle indicates an outlier. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
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Fig 6. The average number of antihypertensive medications decreased significantly during the early postoperative period after the ascending–descending bypass (p ¼ 0.04); however, this difference did not persist during the long-term follow-up (FU; p ¼ 0.06) which may reflect the older age of our patient population at the time of reoperation. Reprinted from [6]. By permission of Mayo Foundation for Medical Education and Research. All rights reserved.
Edie and colleagues [16] and Wukasch and colleagues [17] first described bypass of the aorta through a median sternotomy. Vijayanagar and colleagues [18] described aortic bypass posterior to the heart, which was further modified by several authors, including Sweeney and colleagues [3], Powell and colleagues [19], and Robicsek and colleagues [20]. Although some authors describe the possibility of performing ascending–descending aortic bypass without the use of the heart–lung machine, we prefer to use it because it allows maintenance of adequate perfusion pressure and hemodynamic stability during manipulation of the heart. We have described previously our indications for ascending–descending bypass, and these include complex coarctation with concomitant intracardiac pathology that requires simultaneous repair and adults with surgical recurrent coarctation after previous repair when the extraanatomic bypass appears to be a safer alternative to anatomic repair [21]. Complex coarctation may include arch stenosis, aortic calcification, long-segment coarctation, or recurrent coarctation not amenable to percutaneous treatment. The posterior pericardial approach is our preferred technique; however, this bypass has also been described through a right thoracotomy approach [22]. In patients who are at risk for future reoperation, the route of the ascending–descending bypass graft should be considered. The bypass graft can pass anterior or posterior to the inferior vena cava on the right side along the free wall of the right atrium or to the left side, behind the left ventricle and on top of the main pulmonary artery, before joining the ascending aorta. We noticed no difference in outcome by the route used for the graft; however, it is an important consideration for reoperation. We also prefer positioning the proximal anastomosis on the far distal portion of the lateral aspect of the ascending aorta
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because this will facilitate an aortotomy if needed in a future operation. Paraplegia is one of the most feared complications after aortic operations and has been reported in patients after reoperations for coarctation [23]. Several strategies have been proposed to minimize the risk of paraplegia; however, it is still a risk. In the current study, we did not document paraplegia in any patient, which points to the safety of the ascending–descending bypass in the reoperative settings. In fact, a decrease in the risk of spinal cord injury might be expected with the posterior pericardial approach because of the location of the distal anastomosis, which is made to the distal thoracic aorta above the diaphragm. Paraparesis occurred early postoperatively in 1 patient in our study, a 33-year-old woman who experienced right lower extremity weakness that was attributed to spinal cord ischemia. She had undergone two previous thoracotomies for coarctation repair and also an unsuccessful balloon angioplasty. This patient is 1 of the only 2 patients in the current series in whom cardiopulmonary bypass was not used to perform the ascending–descending bypass. This was transient weakness and resolved during the follow-up period, but this case may reflect the importance of cardiopulmonary bypass in these situations to maintain distal perfusion and avoid intraoperative hypotension with heart manipulation, especially in the reoperative settings. Decompression of the heart with cardiopulmonary bypass has an advantage of improving exposure of the descending aorta, especially in adult patients where exposure may be limited. Aneurysms and pseudoaneurysms are reported after operations for aortic coarctation. Von Kodolitsch and colleagues [24] reported a series of 25 patients who underwent reoperation for aneurysms after previous coarctation repair. The aneurysms were located in the ascending aorta in 8 of these patients, whereas the aneurysms (pseudoaneurysms) in the remaining 17 were at the site of the repair [24]. In the current study, we identified 5 patients (6%) with preoperative pseudoaneurysms at the site of a previous coarctation repair. This added to the complexity of the repair; however, 2 of these patients underwent concomitant carotid-to-subclavian bypass in preparation for stenting and were stented, 2 patients have had no interventions so far, and 1 patient died of a cause not related to the pseudoaneurysm. Our current approach in the presence of aortic pseudoaneurysm, unless it is going to be addressed through a thoracotomy, is to plan a staged approach, addressing the concomitant cardiac pathology, and performing an ascending-to-descending aortic bypass, first followed by aortic stenting at the second stage. Hypertension is frequently associated with coarctation, and many studies have shown that older age at repair is a predictor for persistent late systemic hypertension [25, 26]. The landmark report by Clarkson and colleagues [27] described the long-term results after the coarctation operation. The authors identified that age at the time of the operation influenced the risk of late hypertension. Patients who were older than 20 years at the time of the
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operation were more likely to have late hypertension than those operated on when they were between 5 and 19 years old (p ¼ 0.007) [27]. In the current study, 63 patients (79%) had uncontrolled systemic hypertension preoperatively. Blood pressure significantly improved after the operation and during the follow-up period (p < 0.001). The mean systolic blood pressure decreased from 153 26 mm Hg preoperatively to 123 15 mm Hg postoperatively, and this improvement persisted during the follow-up period (p < 0.001). There was also a significant reduction in the mean number of antihypertensive medications taken postoperatively, from 1.7 1.4 preoperatively to 1.1 0.8 postoperatively (p ¼ 0.04); however, this difference was not significant at long-term follow-up (p ¼ 0.06), which may reflect the older age of the patients at the time of reintervention. We tend to reserve the posterior pericardial approach and ascending–descending bypass for adults with complex or recurrent coarctation but are reluctant to use this approach in pediatric patients. The concern is that with ongoing somatic growth, tension will increase on the graft and may be a factor in development of pseudoaneurysm or patient–graft mismatch. In conclusion, the ascending–descending aortic bypass graft through a posterior pericardial approach appears to be effective in relieving aortic gradient and improving systemic blood pressure. It represents a safer solution to complex coarctation and permits a single-stage approach to coarctation associated with other cardiac pathology that requires simultaneous surgical intervention.
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11. Mann C, Goebel G, Eicken A, et al. Balloon dilation for aortic recoarctation: morphology at the site of dilation and longterm efficacy. Cardiol Young 2001;11:30–5. 12. McKellar SH, Schaff HV, Dearani JA, et al. Intermediate-term results of ascending descending posterior pericardial bypass of complex aortic coarctation. J Thorac Cardiovasc Surg 2007;133:1504–9. 13. Massey R, Shore DF. Surgery for complex coarctation of the aorta. Int J Cardiol 2004;97(Suppl):67–73. 14. Becker AE, Becker MJ, Edwards JE. Anomalies associated with coarctation of the aorta. Particular references to infancy. Circulation 1970;41:1067–75. 15. Kanter KR, Erez E, Williams WH, Tam VK. Extra-anatomic aortic bypass via sternotomy for complex aortic arch stenosis in children. J Thorac Cardiovasc Surg 2000;120:885–90. 16. Edie RN, Janani J, Attai LA, Malm JR, Robinson G. Bypass grafts for recurrent or complex coarctations of the aorta. Ann Thorac Surg 1975;20:558–66. 17. Wukasch DC, Cooley DA, Sandiford FM, Nappi G, Reul GJ Jr. Ascending aorta abdominal aorta bypass: indications, technique, and report of 12 patients. Ann Thorac Surg 1977;23: 442–8. 18. Vijayanagar R, Natarajan P, Eckstein PF, Bognolo DA, Toole JC. Aortic valvular insufficiency and postductal aortic coarctation in the adult: combined surgical management through medial sternotomy: a new surgical approach. J Thorac Cardiovasc Surg 1980;79:266–8. 19. Powell WR, Adams PR, Cooley DA. Repair of coarctation of the aorta associated with intracardiac repair. Tex Heart Inst J 1983;10:409–13.
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20. Robicsek F, Hess PJ, Vajtai P. Ascending-distal abdominal aorta bypass for treatment of hypoplastic aortic arch and atypical coarctation in the adult. Ann Thorac Surg 1984;37: 261–3. 21. Connolly HM, Schaff HV, Izhar U, Dearani JA, Warnes CA, Orszulak TA. Posterior pericardial ascending–descending aortic bypass: an alternative surgical approach for complex coarctation of the aorta. Circulation 2001;104(Suppl): I133–7. 22. Arakelyan V, Spiridonov A, Bockeria L. Ascending-todescending aortic bypass via right thoracotomy for complex (re-) coarctation and hypoplastic aortic arch. Eur J Cardiothoracic Surg 2005;27:815–20. 23. Brewer LA 3rd, Fosburg RG, Mulder GA, Verska JJ. Spinal cord complications following surgery for coarctation of the aorta: a study of 66 cases. J Thorac Cardiovasc Surg 1972;64: 368–81. 24. Von Kodolitsch Y, Aydin MA, Koschyk DH, et al. Predictors of aneurysmal; formation after surgical correction of aortic coarctation. J Am Coll Cardiol 2002;39:617–24. 25. Toro-Salazar OH, Steinberger J, Thomas W, Rocchini AP, Carpenter B, Moller JH. Long-term follow-up of patients after coarctation of the aorta repair. Am J Cardiol 2002;89: 541–7. 26. Brown ML, Burkhart HM, Connolly HM, et al. Coarctation of the aorta: lifelong surveillance is mandatory following surgical repair. J Am Coll Cardiol 2013;62:1020–5. 27. Clarkson PM, Nicholson MR, Barratt-Boyes BG, Neutze JM, Whitlock RM. Results after repair of coarctation of the aorta beyond infancy. Am J Cardiol 1983;51:1481–8.
DISCUSSION DR JAMES S. TWEDDELL (Milwaukee, WI): That was an excellent presentation, wonderfully done, and I would like to thank you for sending me the manuscript, also. You and your colleagues from Mayo Clinic have summarized a large experience for treatment of complex arch obstruction using extraanatomic bypass grafting. For the most part, the operations were done on cardiopulmonary bypass with mild hypothermia, and the results were excellent, with no mortality, very low morbidity, and improved blood pressure control. I think that is really just outstanding, and I congratulate the authors on those results. The technique has been well described and illustrated in your presentation and one I have used myself. I have a couple of questions. First, can you tell us how you selected patients for the extraanatomic bypass grafting? Certainly, concomitant cardiac pathology requiring repair would be one potential indication for approach to the front, but are there patients in this category, sort of in the fourth decade of life, with coarctation where you might approach them through a thoracotomy? DR SAID: Thank you very much Dr Tweddell. There are multiple factors that should be considered, and these include the number of prior thoracotomies, which would further increase the risk of recurrent laryngeal nerve injury, the need for circulatory arrest, quality of the ascending aorta and the arch, and the presence of calcifications, and finally, concomitant aortic arch hypoplasia. The presence of one or more of these factors will make us lean towards median sternotomy as an approach; otherwise, thoracotomy will be reasonable. DR TWEDELL: Thank you. As you illustrated here, patients with coarctation frequently have a bicuspid aortic valve. These patients have a high lifetime risk of aortic valve surgery, and despite careful graft placement, reoperation on patients with an
extraanatomic bypass graft can be challenging. Did the use of this approach change your threshold for aortic valve surgery? DR SAID: As shown in the study, over half of these patients had bicuspid aortic valve and 21 of them required concomitant aortic valve replacement. However, our indication is still following the guidelines regarding the gradient and the aortic valve area. The reoperation rate in our series was low and included only 3 patients, and none of these reoperations involved the native bicuspid aortic valve itself. The reoperation risk is there, and we take certain precautions in expectation of resternotomy (eg, the location of the bypass graft and location of the proximal anastomosis in anticipation of future aortotomy). So we try to do it on the far lateral side and more higher on the ascending aorta. DR TWEDELL: Thank you. In your manuscript, you comment that 5 patients had a pseudoaneurysm in the distal arch at the time of their extraanatomic repair. It wasn’t exactly clear how you managed those. Were they small and insignificant and followed or did you do something with them at the time of surgery? How are you managing those patients now? DR SAID: Let’s look at the profile of these 5 patients first. They all had at least two prior thoracotomies for repair of coarctation; 3 of them had concomitant arch hypoplasia. We don’t advocate this approach to avoid pseudoaneurysm, because we are not dealing with the main pathology. However, 2 of these patients underwent concomitant carotid-to-subclavian bypass in preparation for stenting, and they were stented; 2 patients had no interventions so far; and 1 patient died, however, it was not related to the pseudoaneurysm. So our current approach for the presence of pseudoaneurysm, unless it is going to be addressed through a thoracotomy, is to do a staged approach, addressing the concomitant cardiac
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pathology, the ascending to descending bypass, and preparation for stenting at the second stage. DR TWEDELL: Temporary clinically evident spinal cord ischemia was found in 1 patient. Yesterday morning there was a very nice presentation on the potential subclinical presence of spinal cord ischemia in patients who have aortic cross-clamping. When I have used this strategy, I am struck by the fact that the bucket clamp or Satinsky clamp that you place on the descending thoracic aorta at the level of the diaphragm, it is hard to exclude enough to do an anastomosis without completely occluding the descending aorta for a little while. I have always thought that the use of bypass with mild hypothermia is probably a good idea in that case, because I am giving myself a little spinal cord protection perhaps just as a byproduct of that strategy. In this one patient where you had the temporary evidence of a neurologic problem, bypass wasn’t used, and I would like to hear your comments on that. Do you think, in fact, frequently that the descending aorta is being completely occluded by that clamp? Would you recommend bypass and mild hypothermia for these patients for that indication? DR SAID: Thank you. That is a very important point. This patient was the only patient that developed a paraparesis, and the case was done without the use of cardiopulmonary bypass, and placement of the side-biting clamp on the descending aorta is critical as it may be nearly occluding its lumen especially in females and when the size of the descending aorta is small. This patient was done early in the series, and our approach to all the ascending–descending bypasses now is to use cardiopulmonary bypass. First, it allowed for adequate heart decompression and adequate placing of the clamp. Second, we monitor the arterial pressure in the femoral artery, and we have a low threshold for cannulating the femoral artery in addition, and Y-this to the arterial line of the pump, and third, we use mild hypothermia. DR TWEDELL: Thank you very much. Excellent presentation. DR MARCO RICCI (Miami, FL): Dr Said, one additional question. Going back to the question that Dr Tweddell was asking
Ann Thorac Surg 2014;-:-–-
about patient selection, I have not seen your manuscript, but in your abstract, you stated that the 80 patients were consecutive. I am not clear as to whether, for example, in a patient with isolated coarctation of the aorta without any arch compromise you used this approach (ie, ascending–descending bypass), and do you never use, for example, a left thoracotomy with a left subclavian to descending thoracic bypass, which is also a safe alternative. So could you describe briefly why you chose to select the approach that requires cardiopulmonary bypass as opposed to the left thoracotomy approach that does not? DR SAID: The left thoracotomy approach will be considered only for patients with low-risk redo thoracotomy. Looking at the profile of our patients, most of them had multiple thoracotomies, multiple interventions before, plus they are adult patients, and sometimes it is very difficult to get a clamp proximally on the arch through a left thoracotomy in adults. In addition, if there is an arch hypoplasia, which was a feature in a lot of these patients, it will be difficult to address this from a thoracotomy because of the limited mobility of the arch and the descending aorta in adults. DR KRISTINE GULESERIAN (Dallas, TX): I really enjoyed your presentation. I wonder whether you have had any experience with a technique that we use in Dallas, something called the “bucket handle” procedure, essentially an extraanatomic ascending-to-descending thoracic aortic bypass performed through a right thoracotomy off bypass to avoid exactly what you have mentioned with regard to concerns with proximal arch hypoplasia, limited aortic arch mobility, potential for recurrent nerve injury et cetera? DR SAID: We have never done it through a right thoracotomy; however, it is a well-published technique. We think there may be also some difficulty through a right thoracotomy to expose a sizable segment of the descending thoracic aorta, plus it will require a relatively large incision to approach that. However, it is a well-recognized technique; in fact, we refer to it in the discussion portion of our manuscript.
