ORIGINAL ARTICLE
A 16-Year Experience in Minimally Invasive Aortic Valve Replacement Context for the Changing Management of Aortic Valve Disease Igor Gosev, MD, Tsuyoshi Kaneko, MD, Siobhan McGurk, BS, Scott R. McClure, MD, Ann Maloney, BA, and Lawrence H. Cohn, MD
Objective: The aim of this study was to evaluate short- and long-term morbidity and mortality in patients with aortic valve disease who had minimally invasive aortic valve replacement (AVR) through upper hemisternotomy. Methods: From July 1996 to June 2012, a total of 1639 patients underwent minimally invasive aortic valve surgery (AVR). Patient data were extracted from hospital electronic records after institutional review board approval. Outcomes of interest included postoperative complication rates, perioperative mortality, and long-term survival. Results: The mean agewas 67 years (SD, 14 years; range, 22Y95 years). Of the total cohort, 211 (13%) underwent reoperative AVR. Postoperatively, 2.3% (37/1639) had reoperations to correct bleeding, 2.7% (44/1639) had strokes, 20.4% (334/1639) had new-onset atrial fibrillation, and 1.5% (24/1639) required permanent pacemakers. Only 34% (571/1639) of the patients received packed red blood cells. The median discharge was on day 6 (5Y8), and 72.2% of the patients (1184/1639) were discharged home. Operative mortality was 2.9% (48/1639), and long-term survival at 1, 5, 10, and 15 years was 96%, 93%, 92%, and 92%, respectively. Operative mortality was 5.7% (12/208) for the reoperative patients. Conclusions: The upper hemisternotomy approach for AVR is safe and reliable, especially for patients undergoing reoperations and those older than 80 years. Key Words: Minimally invasive surgery, Mini-sternotomy, Aortic valve replacement. (Innovations 2014;9:104Y110)
Accepted for publication December 29, 2013. From the Division of Cardiac Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA USA. Presented at the Annual Scientific Meeting of the International Society for Minimally Invasive Cardiothoracic Surgery, June 12 Y 15, 2013, Prague, Czech Republic. Disclosure: The authors declare no conflicts of interest. Address correspondence and reprint requests to Igor Gosev, MD, Division of Cardiac Surgery, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115 USA. E-mail: [email protected]. Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery ISSN: 1556-9845/14/0902-0104
104
A
ortic valve replacement (AVR) with biological or mechanical prosthesis is the standard of care for treating symptomatic aortic valve stenosis and regurgitation.1 During the past 16 years, minimally invasive approaches to AVR have seen increased use and recently became one of the most common cardiac surgery procedures performed. After initial reports by Cosgrove and Sabik2 in 1996, Cohn et al3 in 1996, and Benetti et al4 in 1997, minimally invasive AVR through upper hemisternotomy became the predominant approach.5 Minimally invasive AVR promotes expeditious healing and accelerated return to baseline physical health by way of minimizing surgical trauma.3,6 Standard AVR typically requires exposure of the heart and its vessels through a complete sternotomy. A minimally invasive approach via upper hemisternotomy allows access to the heart through a small incision 6 to 9 cm in length, with less tissue dissection and without fully separating the sternum. It provides excellent visualization of the ascending aorta and the aortic root and allows for direct cannulation of the right atrium (RA) and/or vent and retrograde cannula placement in most of the cases. In addition, some studies suggest that minimally invasive surgery reduces blood loss,7Y11 surgical trauma and pain,7Y9 time on the ventilator,9Y11 and length of hospital stay8 and may accelerate recovery.4Y7 Patients with a wide anterior-posterior chest diameter, scoliosis, or significant chest wall deformity or patients who have contraindications to transesophageal echocardiography (TEE) have a relative contraindication for a hemisternotomy approach because of difficulty with exposure of the ascending aorta and the aortic valve or inability to control distension/deairing of the left ventricle because of a lack of imaging.12 Multiple technological advancements have made an upper hemisternotomy approach to AVR easier, safer, and faster than in the early days. Vacuum-assisted cardiopulmonary bypass (CPB), smaller and more flexible cannulas, advancements in TEE technology, and carbon dioxide application to the operative field as well as better understanding of the myocardial protection have created an environment where minimally invasive AVRs are not reserved only for high-volume academic centers but are a feasible treatment modality for all medical institutions.13 In recent years, transcatheter aortic valve implantation (TAVR) has become an accepted option for high-risk patients.14 Perioperative outcomes as well as 1- and 2-year survival in patients without significant aortic insufficiency after TAVR are similar to those after surgical AVR.15,16 Innovations & Volume 9, Number 2, March/April 2014
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
In this article, we present our 16-year experience with this minimally invasive technique.
MATERIALS AND METHODS Patients and Data Definitions We identified 1639 consecutive patients who underwent minimally invasive aortic valve surgery between July 1996 and June 2012. Patient data were collected at the time of presentation and extracted from hospital electronic medical records. Data were coded according to The Society of Thoracic Surgeons (STS) National Adult Cardiac Database definitions, version 2.52. Operative mortality included all in-hospital deaths or those within 30 days of surgery if discharged. Long-term survival data were collected via query of the Social Security Death Index, via the state Department of Public Health, and by routine follow-up. This study was approved by our institutional review board.
Operative Technique After induction of general anesthesia and central line placement, external defibrillator pads and TEE probe are placed. As previously described,3 a 6- to 8-cm midline sternal incision is made, and the sternum is separated down to the fourth intercostal space, where it is then horizontally separated to the right. The thymal fat is spread apart, the pericardium is opened, and stay sutures are placed. The sutures are retracted to the dermal layer of the skin. This maneuver usually brings the aorta at the edge of the sternal incision. Occasional blood pressure drop is noticed with decreased inflow from the inferior vena cava and is resolved with loosening the right-sided stay sutures. After full heparinization and aortic assessment with an epiaortic ultrasound, the aorta is directly cannulated with Terumo Sarns Soft Flow-Flow 7-mm extended aortic cannula (Terumo, Tokyo, Japan). In cases of good RA exposure, a direct three-stage Medtronic 29F MC2X venous cannula is placed; otherwise, a percutaneous Medtronic Biomedicus femoral 21F venous cannula (Medtronic, Minneapolis, MN USA) is placed through the femoral vein at the superior vena cavaYRA junction with the help of TEE. After vacuum-assisted bypass is initiated, the aorta is directly cross-clamped, and antegrade cardioplegia is administered to the aortic root. In cases of more than mild aortic insufficiency, direct ostial cardioplegia is applied after the oblique aortotomy is performed. A retrograde cardioplegia catheter is not regularly used, but, if needed, it can be placed through the jugular vein in reoperative cases or RA appendage with the help of TEE. A decompression vent can be placed through the right superior pulmonary vein or directly through the aortic root. The aortic valve is then excised, and the aortic annulus is decalcified. After sizing, the new valve is sutured in place with interrupted pledgeted Ethibond (Ethicon, Sommerville, NJ, USA) sutures. The aorta is closed with a double running suture. The placement of temporary pacing wires and chest tubes after the valve has been sutured in place and after aortotomy has been closed can be challenging and needs to be performed while the patient is still on bypass and the heart is empty to prevent injuring the right ventricle. After adequate hemostasis and TEE-guided deairing, the patient is taken off CPB, the sternum is approximated with four or five wires, and the skin is closed in the usual fashion.
Minimally Invasive Aortic Valve Replacement
In miniYreoperative procedures, patients receive pace port pulmonary catheters after induction because of the inability to place temporary pacemaker wires on the right ventricle surface at the end of the procedure. Patients are then placed on CPB via axillary or femoral artery and femoral vein. After cannulation, the anterior sternal table is divided with an oscillation saw, and the posterior table is divided with the help of Mayo scissors. Limited dissection of the aorta and surrounding structures, just sufficient for cross-clamping of the aorta, is then performed, leaving all the patent coronary grafts untouched. Aortotomy is often shaped on the basis of the location of the proximal anastomosis of the patent grafts. In the case of a patent left internal thoracic artery, the graft is left in place in moderate to deep hypothermia (20-CY24-C), and systemic hyperkalemia (6Y8 mEq/mL) is used to arrest the heart. As previously described by Tabata et al,17 systemic hyperkalemia is accomplished by instilling potassium chloride directly into the CPB circuit. Ultrafiltration, after the cross-clamp was removed, was used to clear the high level of potassium.
Statistical Analysis Continuous variables with normal distributions are presented as means and SDs. Nonnormally distributed variables are presented as medians and interquartile ranges (IQRs). Categorical variables are presented as number and percentage of subjects. Long-term survival was estimated by Kaplan-Meier analysis or life tables (percentage surviving and SE); intergroup comparisons were conducted using log-rank tests. The criterion of significance was P G 0.05. Statistical analyses were performed using the Statistical Package for the Social Sciences version 13.0 (Statistical Package for the Social Sciences, Inc, Chicago, IL USA).
RESULTS Patient Characteristics The mean (SD) patient age was 67.0 (14.4) years (range, 22Y95), and 967 patients (59%) were men; 572 (35%) were in New York Heart Association class III or IV (Table 1). A total of 134 patients (8%) had history of atrial fibrillation (AF), and 72 (4%) had history of renal failure, and 211 (13%) were reoperative patients. The reoperative patients’ mean (SD) age was 74 (13) years, and 165 (79%) were men. The predicted STS mortality for eligible patients (surgery dates after 2002, when STS data collection began at our institution) was calculated at 3.2% (SD, 2.7%) and 6.2% for the reoperation subgroup. Stratified by age, 227 (14%) were younger than 50 years, 255 were 50 to 59 years old (16%), 355 were between 60 and 69 years old (22%), 439 were 70 to 79 years old (27%), and the remaining 363 patients were 80 years or older at the time of surgery (22%). Of these, 63% were also reoperations. Their characteristics are presented in Table 1.
Operative Procedures The operative procedures are shown in Table 2; a total of 1619 patients underwent AVR, whereas 20 had an aortic valve repair. Of the patients having AVR, 1353 patients (83.6%) received biological valves and 266 (16.4%) received mechanical valves. Upper hemisternotomy was performed in 1578 of the 1635 patients; 33 patients had a right-sided parasternal approach
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
105
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Gosev et al
TABLE 1. Demographic Data for Patients Undergoing Minimally Invasive Aortic Valve Surgery N Age, mean (SD), y Male, n (%) Atrial fibrillation, n (%) Renal failure, n (%) Preoperative creatinine, mean (SD) NYHA III/IV, n (%) Ejection fraction, median (IQR), % STS-predicted mortality,* mean (SD)
All Patients
Reoperations
Reoperations Q80 y
1639 66.8 (14.4) 967 (59) 134 (8.2) 72 (4.4) 1.06 (0.60) 579 (35.3) 60 (55Y65) 3.2 (2.7)
211 (12.7) 74.0 (12.8) 165/208 (79) 30 (14.2) 18 (8.7) 1.18 (0.43) 107/208 (51.4) 55 (45Y60) 6.2 (3.5)
68/211 (30.3) 83.8 (2.9) 45/63 (71.4) 11 (16.2) 4 (5.9) 1.26 (0.33) 40/63 (63.5) 55 (50Y60) V
Em dash indicates that the authors were unable to calculate for a representative sample. *Available for patients from 2002 forward only. IQR indicates interquartile range; NYHA, New York Heart Association.
and 7 patients had their valves replaced through a right thoracotomy. Previous procedures for the reoperative patients included coronary artery bypass grafting (CABG), 74% (157/211); AVR, 13% (28/211); and CABG/AVR, 5% (11/211), and 15 patients underwent various other procedures including mitral and congenital procedures. The median CPB perfusion and cross-clamp times were 101 minutes (IQR, 80Y134 minutes) and 70 minutes (IQR, 55Y95 minutes), respectively. In the octogenarian group, perfusion time was 97 minutes (IQR, 78Y128 minutes) and cross-clamp time was 66 minutes (IQR, 54Y87 minutes; data not shown).
Postoperative Course Operative mortality was 2.9% (47/1639), which was an observed to expected (O/E) mortality ratio of 0.91; for the reoperative group, 12 of 211 patients had an operative mortality
TABLE 2. Operative Procedures and Outcomes Incision type for AVR, n Upper hemisternotomy, n (%) Right parasternal, n (%) Right thoracotomy, n (%) Left thoracotomy, n (%) Valve implanted, n (%) Mechanical Biological Incision type for AVP, n Upper hemisternotomy, n (%) Right parasternal, n (%) Reoperations, n (%) Previous procedure, n (%) CABG AVR CABG/AVR Other Bypass time, median (IQR), min Cross-clamp time, median (IQR), min
1619 1578 (97.5) 33 (2.0) 7 (G1.0) 1 (G1.0)
of 5.7%, for an O/E ratio of 0.92 (Table 3). In the octogenarian group, the O/E mortality ratio was 0.721; predicted STS mortality was 6.8%, whereas observed mortality was only 4.9% (18/364). The reoperative octogenarians experienced 2.8% operative mortality despite predicted STS mortality of 9.7% (O/E ratio of 0.289l; data not shown). Postoperative outcomes are shown in Table 3. Overall, 2.3% of the patients (37/1639) had reoperations for bleeding; in the reoperative group, 8 (4%) of 211 patients had significant bleeding. Only 34% (571/1639) of the patients required blood transfusions, and postoperative strokes affected 2.7% (44/1639) of the patients. New-onset AF was seen in 20.4% (334/1639) of the patients, whereas 1.46% (24/1639) had a heart block that required permanent pacemaker implantation. The reoperative patients received more blood transfusions (142/211, 67%) but otherwise had rates of postoperative complications similar to the group as a whole. For the octogenarians, 45.3% (165/364) required blood transfusions and 3.8% (14/364) had reoperations for bleeding. Stroke affected 4.4% of the patients (16/364). Newonset AF was seen in only 16.5% of the patients (60/364), and
TABLE 3. Postoperative Complications and Patient Outcomes All
Reoperations
157 (74.4) 28 (13.3) 11 (5.2) 15 (7.1) 101 (80Y134) 70 (55Y95)
Complications, n (%) Reoperation for bleeding 37 (2.3) 8 (3.8) Stroke 44 (2.7) 9 (4.3) Heart block 24 (1.5) 10 (4.7) New-onset AF 334 (20.4) 43 (20.4) Patients transfused with pRBC, n (%) 571 (34.8) 142 (67.3) Units per transfused patient, median (IQR) 2 (1Y2) 4 (2Y6) Discharge disposition, n (%) Home 1184 (72.2) 115 (54.5) Rehabilitation 383 (23.4) 78 (37.0) Other 72 (4.4) 6 (2.8) ICU stay, median (IQR), h 39 (24Y70) 48 (24Y111) Postoperative LOS, median (IQR), d 6 (5Y8) 7 (6Y11) Operative mortality, n (%) 47 (2.9) 12 (5.7) Observed/expected ratio 0.91 0.92
AVR indicates aortic valve replacement; AVP, aortic valve repair (plasty); CABG, coronary artery bypass grafting; IQR, interquartile range.
AF indicates atrial fibrillation; ICU, intensive care unit; IQR, interquartile range; LOS, length of stay; pRBC, packed red blood cell.
106
266 (16.4) 1353 (83.6) 20 19 (95.0) 1 (5.0) 211 (12.9)
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Minimally Invasive Aortic Valve Replacement
TABLE 4. Long-term Survival; Cumulative Proportion Surviving With SE G50 y 50Y59 y 60Y69 y 70Y79y Q80 y
n (%)
Mean, y
1y
5y
10 y
15 y
227 (13.8) 255 (15.6) 355 (21.7) 439 (26.8) 363 (22.1)
15.2 14.2 13.4 9.6 7.3
99.1 (0.6) 97.6 (1.0) 95.7 (1.1) 93.8 (1.2) 86.8 (1.8)
97.2 (1.1) 92.8 (1.7) 86.1 (1.8) 79.1 (2.1) 63.8 (2.9)
93.2 (2.3) 87.2 (2.7) 84.5 (2.3) 49.1 (3.4) 27.0 (4.4)
91.0 (2.6) 79.4 (6.3) 65.9 (5.5) 22.3 (4.7) 18.9 (5.1)
All groups significantly different from each other, P e 0.03.
1.9% (7/364) needed postoperative pacemaker implantation (data not shown). The median length of stay postoperatively was 6 days (IQR, 5Y8 days), and more than 70% of the patients (1184/1639) were discharged home. The median length of stay for the octogenarians was 8 days (IQR, 6Y10 days), and 40.1% (146/364) of them were discharged home, whereas 53.6% (195/364) were discharged to extended care facilities.
Long-term Survival Overall, survival at 1, 5, and 10 years were 94% (SE, 1%), 83% (SE, 1%), and 66% (SE, 3%), respectively (data not shown). Long-term mortality was evaluated by stratifying age (Table 4), whereas Figure 1 displays the survival curves from the KaplanMeier analysis. Overall, the mean survival was estimated at 11.6 years, 15.2 years for the patients younger than 50 years,
14.2 years for the 50- to 59-year-old group, 13.4 years for the 60- to 69-year-old group, 9.6 years for the 70- to 79-year-old group, and 7.3 years for the octogenarians. Figure 2 compares survival for the primary surgery patients, the reoperative patients, and the octogenarians.
DISCUSSION Study Limitations This study is subject to all the limitations of a single-center, retrospective study design. The findings presented herein may have limited generalizability. Further, the selection of patients for minimally invasive procedures is not random, nor is there a formal protocol; the decision is made on a case-by-case basis on the basis of the clinical evaluation of the surgeon, in consultation with the patient. Minimally invasive aortic valve surgery was first introduced by Cleveland Clinic2 and Brigham and Women’s Hospital in 1996.3 Initial approaches were through an incision parallel to the sternum on the right side with resection of the third and the fourth rib cartilage or transsternal incision at the level of the third interspace with ligation of both internal thoracic arteries. Because of the need for peripheral cannulation, occasional chest wall instability, and the difficult conversion to full sternotomy, both approaches were later abandoned in favor of a J-shaped upper hemisternotomy approach. An upper hemisternotomy with an extension into the fourth intercostal space provides an excellent view of the aorta and the aortic valve, enables easy
FIGURE 1. Survival stratified by age at the time of surgery. Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
107
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Gosev et al
FIGURE 2. Reoperative and octogenarian patient survival compared with primary patients younger than 80 years.
conversion into full sternotomy, does not require any specialized instruments, and has a shorter learning curve compared with some other minimally invasive approaches. An upper hemisternotomy provides the same safety and long-term survival as full sternotomy but, as noted in some comparative studies, is associated with reduced pain, fewer complications related to incision and sternum instability, reduced blood loss and transfusion requirements, shorter time on the ventilator,
shorter intensive care unit stay, shorter overall hospital stay, and improved patient satisfaction.4Y11 However, data from multiple retrospective studies have not shown a significant difference in the overall hospital mortality or long-term survival.6Y9 Younger patients who undergo minimally invasive AVR have reduced blood loss and shorter respiratory support times and report less pain, faster return to preoperative level of activity, and overall greater satisfaction with the procedure when
FIGURE 3. Surgical approach to octogenarians undergoing aortic valve replacement (AVR), 1997Y2010.
108
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
compared with standard valve replacement patients.8 Patients of both sexes and all age groups appreciate the cosmetic effect of a small skin incision with minimally invasive approach that helps them better cope with their disease and, in some instances, integrate back to their everyday routine faster. Octogenarians, because of their relative frailty and likelihood of multiple comorbidities, are the population that stands to benefit most from minimally invasive AVR. As the very elderly US population grows, more patients of greater age are referred for cardiac surgery. In our center, octogenarians have gone from being less than 20% of AVR patients in 1997 to approximately 30% of patients in 2012. Also in this time frame, octogenarians have gone from ~12% of minimally invasive patients during the first 5 years of our series to greater than 27% since 2006, ten years after the procedure became available at our institution. Our previously published data on this high-risk cohort, which has a predicted mortality of 10%, showed operative mortality of only 3% and excellent long-term survival, with more than 85% of the patients surviving more than 10 years.13 This is consistent with our current findings. For octogenarians, more then 50% were in New York Heart Association class III/IV compared with only 35% of patients overall. Some early studies have shown that postponing patient referral for surgery in aortic stenosis, because of underestimating symptom severity while overestimating the risks of valve replacement surgery, is associated with less than 50% survival after 2 years.18 Data from the European Heart Survey indicate that up to 30% of patients older than 75 years with symptomatic aortic stenosis were denied surgical referral mostly because of age; frailty and risk scores based on their comorbidities played only a minor role in this decision making.19,20 Our practice since 1997 has been a trend toward more AVRs done in this high-risk patient population through minimally invasive approach (Fig. 3). In the context of these data, a reasonable argument can be made that cardiologists should be less hesitant to refer their very elderly patients for surgical intervention at institutions that have established minimally invasive programs for AVR. Data for reoperative minimally invasive AVR are limited yet consistently demonstrate reduced blood loss, fewer transfusions, and faster recovery compared with repeat full sternotomy.21,22 Patients who undergo mini-AVR report less pain and faster return to their everyday routine. Our series consists of 208 patients in a 16-year period, with the previous procedure predominantly being CABG and AVR. Our perioperative mortality was only 2.8% compared with the STS-predicted mortality of 9.7% in octogenarians having reoperative cardiac surgery. Transcatheter aortic valve implantation has become an established technique for inoperable and high-risk patients14. The PARTNER (Placement of AoRTic TraNscathetER Valve) trial showed noninferiority of TAVR over surgical AVR. Stroke, perioperative myocardial infarction, and overall survival have been similar between two groups.14,15 However, TAVR patients have a significantly higher rate of vascular complications and worse 1- and 2-year survival in subgroups of patients with even mild residual aortic insufficiency.15,16 In conclusion, an upper hemisternotomy approach for AVR is safe and feasible. In our experience, procedure benefits are seen in all age groups. Younger patients benefit from better pain control, whereas very elderly patients accrue benefits from
Minimally Invasive Aortic Valve Replacement
shorter ventilation times and faster transfer from the intensive care unit. Reoperative patients are subjected to minimal dissection, which preserves patent grafts and reduces transfusion requirements.
REFERENCES 1. Bonow RO, Carabello BA, Chatterjee K, et al., for the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2008;52:e1Y e142. 2. Cosgrove DM III, Sabik JF. Minimally invasive approach for aortic valve operations. Ann Thorac Surg. 1996;62:596 Y597. 3. Cohn LH, Adams DH, Couper GS, et al. Minimally invasive cardiac valve surgery improves patient satisfaction while reducing costs of cardiac valve replacement and repair. Ann Surg. 1997;226:421Y 426. 4. Benetti FJ, Mariani MA, Rizzardi JL, Benetti I. Minimally invasive aortic valve replacement. J Thorac Cardiovasc Surg. 1997;113:806 Y807. 5. Gillinov AM, Banbury MK, Cosgrove DM. Hemisternotomy approach for aortic and mitral valve surgery. J Card Surg. 2000;15:15Y20. 6. Mihaljevic T, Cohn LH, Unic D, Aranki SF, Couper GS, Byrne JG. One thousand minimally invasive valve operations: early and late results. Ann Surg. 2004;240:529Y534. 7. Soltesz EG, Cohn LH. Minimally invasive valve surgery. Cardiol Rev. 2007;15:109Y115. 8. Sharony R, Grossi EA, Saunders PC, et al. Propensity score analysis of a six-year experience with minimally invasive isolated aortic valve replacement. J Heart Valve Dis. 2004;13:887Y 893. 9. Liu J, Sidiropoulos A, Konertz W. Minimally invasive aortic valve replacement (AVR) compared to standard AVR. Eur J Cardiothorac Surg. 1999;16(suppl 2):S80YS83. 10. Bonacchi M, Prifti E, Giunti G, Frati G, Sani G. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study. Ann Thorac Surg. 2002;73:460Y465. 11. Ma¨chler HE, Bergmann P, Anelli-Monti M, et al. Minimally invasive versus conventional aortic valve operations: a prospective study in 120 patients. Ann Thorac Surg. 1999;67:1001Y1005. 12. Kim BS, Soltesz EG, Cohn LH. Minimally invasive approaches to aortic valve surgery: Brigham experience. Semin Thorac Cardiovasc Surg. 2006;18:148Y153. 13. ElBardissi A, Shekar P, Couper GS, Cohn LH. Minimally invasive aortic valve replacement in octogenarian, high-risk, transcatheter aortic valve implantation candidates. J Thorac Cardiovasc Surg. 2011;141:328Y335. 14. Smith CR, Leon MB, Mack MJ, et al., for the PARTNER Trial Investigators. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364:2187Y2198. 15. Kodali SK, Williams MR, Smith CR, et al., for the PARTNER Trial Investigators. Two-year outcomes after transcatheter or surgical aortic-valve replacement. N Engl J Med. 2012;366:1686Y1695. 16. Zahn R, Gerckens U, Linke A, et al., for the German Transcatheter Aortic Valve Interventions-Registry Investigators. Predictors of one-year mortality after transcatheter aortic valve implantation for severe symptomatic aortic stenosis. Am J Cardiol. 2013;112:272Y279. 17. Tabata M, Khalpey Z, Shekar PS, Cohn LH. Reoperative minimal access aortic valve surgery: minimal mediastinal dissection and minimal injury risk. J Thorac Cardiovasc Surg. 2008;136:1564 Y1568. 18. Horstkotte D, Loogen F. The natural history of aortic valve stenosis. Eur Heart J. 1988;9(suppl E):57Y64. 19. Freed BH, Sugeng L, Furlong K, et al. Reasons for nonadherence to guidelines for aortic valve replacement in patients with severe aortic stenosis and potential solutions. Am J Cardiol. 2010;105:1339 Y1342. 20. Iung B, Cachier A, Baron G, et al. Decision-making in elderly patients with severe aortic stenosis: why are so many denied surgery? Eur Heart J. 2005; 26:2714 Y2720.
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
109
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Gosev et al
21. Byrne JG, Aranki SF, Couper GS, Adams DH, Allred EN, Cohn LH. Reoperative aortic valve replacement: partial upper hemisternotomy versus conventional full sternotomy. J Thorac Cardiovasc Surg. 1999; 118:991Y997.
22. Tabata M, Umakanthan R, Khalpey Z, et al. Conversion to full sternotomy during minimal-access cardiac surgery: reasons and results during a 9.5-year experience. J Thorac Cardiovasc Surg. 2007;134: 165 Y169.
CLINICAL PERSPECTIVE This retrospective case series examined the 16-year experience at the Brigham and Women’s Hospital with minimally invasive aortic valve surgery. It is a very large series encompassing over 1,600 patients. The authors showed acceptable morbidity and mortality rates. Particularly impressive was the low morbidity in octogenarians, who comprised 22% of this series. The observed mortality in this group was only 4.9%, wheras the predicted STS mortality was 6.8%. They showed similar excellent results in the reoperative group. The median length of stay following these procedures was 6 days and over 70% of patients were discharged home. There was a very acceptable 5-year survival rate of 83% for the entire group. This is a comprehensive report from one of the pioneering centers in minimally invasive aortic valve surgery. It shows the excellent results that can be obtained at experienced centers. The weakness of this report is that while it is a large series, it is selective and there was no control group. However, this series clearly demonstrates that minimally invasive aortic valve replacement is effective in experienced hands and has superb outcomes.
110
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
A 16-Year Experience in Minimally Invasive Aortic Valve Replacement Context for the Changing Management of Aortic Valve Disease Igor Gosev, MD, Tsuyoshi Kaneko, MD, Siobhan McGurk, BS, Scott R. McClure, MD, Ann Maloney, BA, and Lawrence H. Cohn, MD
Objective: The aim of this study was to evaluate short- and long-term morbidity and mortality in patients with aortic valve disease who had minimally invasive aortic valve replacement (AVR) through upper hemisternotomy. Methods: From July 1996 to June 2012, a total of 1639 patients underwent minimally invasive aortic valve surgery (AVR). Patient data were extracted from hospital electronic records after institutional review board approval. Outcomes of interest included postoperative complication rates, perioperative mortality, and long-term survival. Results: The mean agewas 67 years (SD, 14 years; range, 22Y95 years). Of the total cohort, 211 (13%) underwent reoperative AVR. Postoperatively, 2.3% (37/1639) had reoperations to correct bleeding, 2.7% (44/1639) had strokes, 20.4% (334/1639) had new-onset atrial fibrillation, and 1.5% (24/1639) required permanent pacemakers. Only 34% (571/1639) of the patients received packed red blood cells. The median discharge was on day 6 (5Y8), and 72.2% of the patients (1184/1639) were discharged home. Operative mortality was 2.9% (48/1639), and long-term survival at 1, 5, 10, and 15 years was 96%, 93%, 92%, and 92%, respectively. Operative mortality was 5.7% (12/208) for the reoperative patients. Conclusions: The upper hemisternotomy approach for AVR is safe and reliable, especially for patients undergoing reoperations and those older than 80 years. Key Words: Minimally invasive surgery, Mini-sternotomy, Aortic valve replacement. (Innovations 2014;9:104Y110)
Accepted for publication December 29, 2013. From the Division of Cardiac Surgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA USA. Presented at the Annual Scientific Meeting of the International Society for Minimally Invasive Cardiothoracic Surgery, June 12 Y 15, 2013, Prague, Czech Republic. Disclosure: The authors declare no conflicts of interest. Address correspondence and reprint requests to Igor Gosev, MD, Division of Cardiac Surgery, Brigham and Women’s Hospital, 75 Francis St, Boston, MA 02115 USA. E-mail: [email protected]. Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery ISSN: 1556-9845/14/0902-0104
104
A
ortic valve replacement (AVR) with biological or mechanical prosthesis is the standard of care for treating symptomatic aortic valve stenosis and regurgitation.1 During the past 16 years, minimally invasive approaches to AVR have seen increased use and recently became one of the most common cardiac surgery procedures performed. After initial reports by Cosgrove and Sabik2 in 1996, Cohn et al3 in 1996, and Benetti et al4 in 1997, minimally invasive AVR through upper hemisternotomy became the predominant approach.5 Minimally invasive AVR promotes expeditious healing and accelerated return to baseline physical health by way of minimizing surgical trauma.3,6 Standard AVR typically requires exposure of the heart and its vessels through a complete sternotomy. A minimally invasive approach via upper hemisternotomy allows access to the heart through a small incision 6 to 9 cm in length, with less tissue dissection and without fully separating the sternum. It provides excellent visualization of the ascending aorta and the aortic root and allows for direct cannulation of the right atrium (RA) and/or vent and retrograde cannula placement in most of the cases. In addition, some studies suggest that minimally invasive surgery reduces blood loss,7Y11 surgical trauma and pain,7Y9 time on the ventilator,9Y11 and length of hospital stay8 and may accelerate recovery.4Y7 Patients with a wide anterior-posterior chest diameter, scoliosis, or significant chest wall deformity or patients who have contraindications to transesophageal echocardiography (TEE) have a relative contraindication for a hemisternotomy approach because of difficulty with exposure of the ascending aorta and the aortic valve or inability to control distension/deairing of the left ventricle because of a lack of imaging.12 Multiple technological advancements have made an upper hemisternotomy approach to AVR easier, safer, and faster than in the early days. Vacuum-assisted cardiopulmonary bypass (CPB), smaller and more flexible cannulas, advancements in TEE technology, and carbon dioxide application to the operative field as well as better understanding of the myocardial protection have created an environment where minimally invasive AVRs are not reserved only for high-volume academic centers but are a feasible treatment modality for all medical institutions.13 In recent years, transcatheter aortic valve implantation (TAVR) has become an accepted option for high-risk patients.14 Perioperative outcomes as well as 1- and 2-year survival in patients without significant aortic insufficiency after TAVR are similar to those after surgical AVR.15,16 Innovations & Volume 9, Number 2, March/April 2014
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
In this article, we present our 16-year experience with this minimally invasive technique.
MATERIALS AND METHODS Patients and Data Definitions We identified 1639 consecutive patients who underwent minimally invasive aortic valve surgery between July 1996 and June 2012. Patient data were collected at the time of presentation and extracted from hospital electronic medical records. Data were coded according to The Society of Thoracic Surgeons (STS) National Adult Cardiac Database definitions, version 2.52. Operative mortality included all in-hospital deaths or those within 30 days of surgery if discharged. Long-term survival data were collected via query of the Social Security Death Index, via the state Department of Public Health, and by routine follow-up. This study was approved by our institutional review board.
Operative Technique After induction of general anesthesia and central line placement, external defibrillator pads and TEE probe are placed. As previously described,3 a 6- to 8-cm midline sternal incision is made, and the sternum is separated down to the fourth intercostal space, where it is then horizontally separated to the right. The thymal fat is spread apart, the pericardium is opened, and stay sutures are placed. The sutures are retracted to the dermal layer of the skin. This maneuver usually brings the aorta at the edge of the sternal incision. Occasional blood pressure drop is noticed with decreased inflow from the inferior vena cava and is resolved with loosening the right-sided stay sutures. After full heparinization and aortic assessment with an epiaortic ultrasound, the aorta is directly cannulated with Terumo Sarns Soft Flow-Flow 7-mm extended aortic cannula (Terumo, Tokyo, Japan). In cases of good RA exposure, a direct three-stage Medtronic 29F MC2X venous cannula is placed; otherwise, a percutaneous Medtronic Biomedicus femoral 21F venous cannula (Medtronic, Minneapolis, MN USA) is placed through the femoral vein at the superior vena cavaYRA junction with the help of TEE. After vacuum-assisted bypass is initiated, the aorta is directly cross-clamped, and antegrade cardioplegia is administered to the aortic root. In cases of more than mild aortic insufficiency, direct ostial cardioplegia is applied after the oblique aortotomy is performed. A retrograde cardioplegia catheter is not regularly used, but, if needed, it can be placed through the jugular vein in reoperative cases or RA appendage with the help of TEE. A decompression vent can be placed through the right superior pulmonary vein or directly through the aortic root. The aortic valve is then excised, and the aortic annulus is decalcified. After sizing, the new valve is sutured in place with interrupted pledgeted Ethibond (Ethicon, Sommerville, NJ, USA) sutures. The aorta is closed with a double running suture. The placement of temporary pacing wires and chest tubes after the valve has been sutured in place and after aortotomy has been closed can be challenging and needs to be performed while the patient is still on bypass and the heart is empty to prevent injuring the right ventricle. After adequate hemostasis and TEE-guided deairing, the patient is taken off CPB, the sternum is approximated with four or five wires, and the skin is closed in the usual fashion.
Minimally Invasive Aortic Valve Replacement
In miniYreoperative procedures, patients receive pace port pulmonary catheters after induction because of the inability to place temporary pacemaker wires on the right ventricle surface at the end of the procedure. Patients are then placed on CPB via axillary or femoral artery and femoral vein. After cannulation, the anterior sternal table is divided with an oscillation saw, and the posterior table is divided with the help of Mayo scissors. Limited dissection of the aorta and surrounding structures, just sufficient for cross-clamping of the aorta, is then performed, leaving all the patent coronary grafts untouched. Aortotomy is often shaped on the basis of the location of the proximal anastomosis of the patent grafts. In the case of a patent left internal thoracic artery, the graft is left in place in moderate to deep hypothermia (20-CY24-C), and systemic hyperkalemia (6Y8 mEq/mL) is used to arrest the heart. As previously described by Tabata et al,17 systemic hyperkalemia is accomplished by instilling potassium chloride directly into the CPB circuit. Ultrafiltration, after the cross-clamp was removed, was used to clear the high level of potassium.
Statistical Analysis Continuous variables with normal distributions are presented as means and SDs. Nonnormally distributed variables are presented as medians and interquartile ranges (IQRs). Categorical variables are presented as number and percentage of subjects. Long-term survival was estimated by Kaplan-Meier analysis or life tables (percentage surviving and SE); intergroup comparisons were conducted using log-rank tests. The criterion of significance was P G 0.05. Statistical analyses were performed using the Statistical Package for the Social Sciences version 13.0 (Statistical Package for the Social Sciences, Inc, Chicago, IL USA).
RESULTS Patient Characteristics The mean (SD) patient age was 67.0 (14.4) years (range, 22Y95), and 967 patients (59%) were men; 572 (35%) were in New York Heart Association class III or IV (Table 1). A total of 134 patients (8%) had history of atrial fibrillation (AF), and 72 (4%) had history of renal failure, and 211 (13%) were reoperative patients. The reoperative patients’ mean (SD) age was 74 (13) years, and 165 (79%) were men. The predicted STS mortality for eligible patients (surgery dates after 2002, when STS data collection began at our institution) was calculated at 3.2% (SD, 2.7%) and 6.2% for the reoperation subgroup. Stratified by age, 227 (14%) were younger than 50 years, 255 were 50 to 59 years old (16%), 355 were between 60 and 69 years old (22%), 439 were 70 to 79 years old (27%), and the remaining 363 patients were 80 years or older at the time of surgery (22%). Of these, 63% were also reoperations. Their characteristics are presented in Table 1.
Operative Procedures The operative procedures are shown in Table 2; a total of 1619 patients underwent AVR, whereas 20 had an aortic valve repair. Of the patients having AVR, 1353 patients (83.6%) received biological valves and 266 (16.4%) received mechanical valves. Upper hemisternotomy was performed in 1578 of the 1635 patients; 33 patients had a right-sided parasternal approach
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
105
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Gosev et al
TABLE 1. Demographic Data for Patients Undergoing Minimally Invasive Aortic Valve Surgery N Age, mean (SD), y Male, n (%) Atrial fibrillation, n (%) Renal failure, n (%) Preoperative creatinine, mean (SD) NYHA III/IV, n (%) Ejection fraction, median (IQR), % STS-predicted mortality,* mean (SD)
All Patients
Reoperations
Reoperations Q80 y
1639 66.8 (14.4) 967 (59) 134 (8.2) 72 (4.4) 1.06 (0.60) 579 (35.3) 60 (55Y65) 3.2 (2.7)
211 (12.7) 74.0 (12.8) 165/208 (79) 30 (14.2) 18 (8.7) 1.18 (0.43) 107/208 (51.4) 55 (45Y60) 6.2 (3.5)
68/211 (30.3) 83.8 (2.9) 45/63 (71.4) 11 (16.2) 4 (5.9) 1.26 (0.33) 40/63 (63.5) 55 (50Y60) V
Em dash indicates that the authors were unable to calculate for a representative sample. *Available for patients from 2002 forward only. IQR indicates interquartile range; NYHA, New York Heart Association.
and 7 patients had their valves replaced through a right thoracotomy. Previous procedures for the reoperative patients included coronary artery bypass grafting (CABG), 74% (157/211); AVR, 13% (28/211); and CABG/AVR, 5% (11/211), and 15 patients underwent various other procedures including mitral and congenital procedures. The median CPB perfusion and cross-clamp times were 101 minutes (IQR, 80Y134 minutes) and 70 minutes (IQR, 55Y95 minutes), respectively. In the octogenarian group, perfusion time was 97 minutes (IQR, 78Y128 minutes) and cross-clamp time was 66 minutes (IQR, 54Y87 minutes; data not shown).
Postoperative Course Operative mortality was 2.9% (47/1639), which was an observed to expected (O/E) mortality ratio of 0.91; for the reoperative group, 12 of 211 patients had an operative mortality
TABLE 2. Operative Procedures and Outcomes Incision type for AVR, n Upper hemisternotomy, n (%) Right parasternal, n (%) Right thoracotomy, n (%) Left thoracotomy, n (%) Valve implanted, n (%) Mechanical Biological Incision type for AVP, n Upper hemisternotomy, n (%) Right parasternal, n (%) Reoperations, n (%) Previous procedure, n (%) CABG AVR CABG/AVR Other Bypass time, median (IQR), min Cross-clamp time, median (IQR), min
1619 1578 (97.5) 33 (2.0) 7 (G1.0) 1 (G1.0)
of 5.7%, for an O/E ratio of 0.92 (Table 3). In the octogenarian group, the O/E mortality ratio was 0.721; predicted STS mortality was 6.8%, whereas observed mortality was only 4.9% (18/364). The reoperative octogenarians experienced 2.8% operative mortality despite predicted STS mortality of 9.7% (O/E ratio of 0.289l; data not shown). Postoperative outcomes are shown in Table 3. Overall, 2.3% of the patients (37/1639) had reoperations for bleeding; in the reoperative group, 8 (4%) of 211 patients had significant bleeding. Only 34% (571/1639) of the patients required blood transfusions, and postoperative strokes affected 2.7% (44/1639) of the patients. New-onset AF was seen in 20.4% (334/1639) of the patients, whereas 1.46% (24/1639) had a heart block that required permanent pacemaker implantation. The reoperative patients received more blood transfusions (142/211, 67%) but otherwise had rates of postoperative complications similar to the group as a whole. For the octogenarians, 45.3% (165/364) required blood transfusions and 3.8% (14/364) had reoperations for bleeding. Stroke affected 4.4% of the patients (16/364). Newonset AF was seen in only 16.5% of the patients (60/364), and
TABLE 3. Postoperative Complications and Patient Outcomes All
Reoperations
157 (74.4) 28 (13.3) 11 (5.2) 15 (7.1) 101 (80Y134) 70 (55Y95)
Complications, n (%) Reoperation for bleeding 37 (2.3) 8 (3.8) Stroke 44 (2.7) 9 (4.3) Heart block 24 (1.5) 10 (4.7) New-onset AF 334 (20.4) 43 (20.4) Patients transfused with pRBC, n (%) 571 (34.8) 142 (67.3) Units per transfused patient, median (IQR) 2 (1Y2) 4 (2Y6) Discharge disposition, n (%) Home 1184 (72.2) 115 (54.5) Rehabilitation 383 (23.4) 78 (37.0) Other 72 (4.4) 6 (2.8) ICU stay, median (IQR), h 39 (24Y70) 48 (24Y111) Postoperative LOS, median (IQR), d 6 (5Y8) 7 (6Y11) Operative mortality, n (%) 47 (2.9) 12 (5.7) Observed/expected ratio 0.91 0.92
AVR indicates aortic valve replacement; AVP, aortic valve repair (plasty); CABG, coronary artery bypass grafting; IQR, interquartile range.
AF indicates atrial fibrillation; ICU, intensive care unit; IQR, interquartile range; LOS, length of stay; pRBC, packed red blood cell.
106
266 (16.4) 1353 (83.6) 20 19 (95.0) 1 (5.0) 211 (12.9)
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Minimally Invasive Aortic Valve Replacement
TABLE 4. Long-term Survival; Cumulative Proportion Surviving With SE G50 y 50Y59 y 60Y69 y 70Y79y Q80 y
n (%)
Mean, y
1y
5y
10 y
15 y
227 (13.8) 255 (15.6) 355 (21.7) 439 (26.8) 363 (22.1)
15.2 14.2 13.4 9.6 7.3
99.1 (0.6) 97.6 (1.0) 95.7 (1.1) 93.8 (1.2) 86.8 (1.8)
97.2 (1.1) 92.8 (1.7) 86.1 (1.8) 79.1 (2.1) 63.8 (2.9)
93.2 (2.3) 87.2 (2.7) 84.5 (2.3) 49.1 (3.4) 27.0 (4.4)
91.0 (2.6) 79.4 (6.3) 65.9 (5.5) 22.3 (4.7) 18.9 (5.1)
All groups significantly different from each other, P e 0.03.
1.9% (7/364) needed postoperative pacemaker implantation (data not shown). The median length of stay postoperatively was 6 days (IQR, 5Y8 days), and more than 70% of the patients (1184/1639) were discharged home. The median length of stay for the octogenarians was 8 days (IQR, 6Y10 days), and 40.1% (146/364) of them were discharged home, whereas 53.6% (195/364) were discharged to extended care facilities.
Long-term Survival Overall, survival at 1, 5, and 10 years were 94% (SE, 1%), 83% (SE, 1%), and 66% (SE, 3%), respectively (data not shown). Long-term mortality was evaluated by stratifying age (Table 4), whereas Figure 1 displays the survival curves from the KaplanMeier analysis. Overall, the mean survival was estimated at 11.6 years, 15.2 years for the patients younger than 50 years,
14.2 years for the 50- to 59-year-old group, 13.4 years for the 60- to 69-year-old group, 9.6 years for the 70- to 79-year-old group, and 7.3 years for the octogenarians. Figure 2 compares survival for the primary surgery patients, the reoperative patients, and the octogenarians.
DISCUSSION Study Limitations This study is subject to all the limitations of a single-center, retrospective study design. The findings presented herein may have limited generalizability. Further, the selection of patients for minimally invasive procedures is not random, nor is there a formal protocol; the decision is made on a case-by-case basis on the basis of the clinical evaluation of the surgeon, in consultation with the patient. Minimally invasive aortic valve surgery was first introduced by Cleveland Clinic2 and Brigham and Women’s Hospital in 1996.3 Initial approaches were through an incision parallel to the sternum on the right side with resection of the third and the fourth rib cartilage or transsternal incision at the level of the third interspace with ligation of both internal thoracic arteries. Because of the need for peripheral cannulation, occasional chest wall instability, and the difficult conversion to full sternotomy, both approaches were later abandoned in favor of a J-shaped upper hemisternotomy approach. An upper hemisternotomy with an extension into the fourth intercostal space provides an excellent view of the aorta and the aortic valve, enables easy
FIGURE 1. Survival stratified by age at the time of surgery. Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
107
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Gosev et al
FIGURE 2. Reoperative and octogenarian patient survival compared with primary patients younger than 80 years.
conversion into full sternotomy, does not require any specialized instruments, and has a shorter learning curve compared with some other minimally invasive approaches. An upper hemisternotomy provides the same safety and long-term survival as full sternotomy but, as noted in some comparative studies, is associated with reduced pain, fewer complications related to incision and sternum instability, reduced blood loss and transfusion requirements, shorter time on the ventilator,
shorter intensive care unit stay, shorter overall hospital stay, and improved patient satisfaction.4Y11 However, data from multiple retrospective studies have not shown a significant difference in the overall hospital mortality or long-term survival.6Y9 Younger patients who undergo minimally invasive AVR have reduced blood loss and shorter respiratory support times and report less pain, faster return to preoperative level of activity, and overall greater satisfaction with the procedure when
FIGURE 3. Surgical approach to octogenarians undergoing aortic valve replacement (AVR), 1997Y2010.
108
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
compared with standard valve replacement patients.8 Patients of both sexes and all age groups appreciate the cosmetic effect of a small skin incision with minimally invasive approach that helps them better cope with their disease and, in some instances, integrate back to their everyday routine faster. Octogenarians, because of their relative frailty and likelihood of multiple comorbidities, are the population that stands to benefit most from minimally invasive AVR. As the very elderly US population grows, more patients of greater age are referred for cardiac surgery. In our center, octogenarians have gone from being less than 20% of AVR patients in 1997 to approximately 30% of patients in 2012. Also in this time frame, octogenarians have gone from ~12% of minimally invasive patients during the first 5 years of our series to greater than 27% since 2006, ten years after the procedure became available at our institution. Our previously published data on this high-risk cohort, which has a predicted mortality of 10%, showed operative mortality of only 3% and excellent long-term survival, with more than 85% of the patients surviving more than 10 years.13 This is consistent with our current findings. For octogenarians, more then 50% were in New York Heart Association class III/IV compared with only 35% of patients overall. Some early studies have shown that postponing patient referral for surgery in aortic stenosis, because of underestimating symptom severity while overestimating the risks of valve replacement surgery, is associated with less than 50% survival after 2 years.18 Data from the European Heart Survey indicate that up to 30% of patients older than 75 years with symptomatic aortic stenosis were denied surgical referral mostly because of age; frailty and risk scores based on their comorbidities played only a minor role in this decision making.19,20 Our practice since 1997 has been a trend toward more AVRs done in this high-risk patient population through minimally invasive approach (Fig. 3). In the context of these data, a reasonable argument can be made that cardiologists should be less hesitant to refer their very elderly patients for surgical intervention at institutions that have established minimally invasive programs for AVR. Data for reoperative minimally invasive AVR are limited yet consistently demonstrate reduced blood loss, fewer transfusions, and faster recovery compared with repeat full sternotomy.21,22 Patients who undergo mini-AVR report less pain and faster return to their everyday routine. Our series consists of 208 patients in a 16-year period, with the previous procedure predominantly being CABG and AVR. Our perioperative mortality was only 2.8% compared with the STS-predicted mortality of 9.7% in octogenarians having reoperative cardiac surgery. Transcatheter aortic valve implantation has become an established technique for inoperable and high-risk patients14. The PARTNER (Placement of AoRTic TraNscathetER Valve) trial showed noninferiority of TAVR over surgical AVR. Stroke, perioperative myocardial infarction, and overall survival have been similar between two groups.14,15 However, TAVR patients have a significantly higher rate of vascular complications and worse 1- and 2-year survival in subgroups of patients with even mild residual aortic insufficiency.15,16 In conclusion, an upper hemisternotomy approach for AVR is safe and feasible. In our experience, procedure benefits are seen in all age groups. Younger patients benefit from better pain control, whereas very elderly patients accrue benefits from
Minimally Invasive Aortic Valve Replacement
shorter ventilation times and faster transfer from the intensive care unit. Reoperative patients are subjected to minimal dissection, which preserves patent grafts and reduces transfusion requirements.
REFERENCES 1. Bonow RO, Carabello BA, Chatterjee K, et al., for the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2008 focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Writing Committee to revise the 1998 guidelines for the management of patients with valvular heart disease). Endorsed by the Society of Cardiovascular Anesthesiologists, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons. J Am Coll Cardiol. 2008;52:e1Y e142. 2. Cosgrove DM III, Sabik JF. Minimally invasive approach for aortic valve operations. Ann Thorac Surg. 1996;62:596 Y597. 3. Cohn LH, Adams DH, Couper GS, et al. Minimally invasive cardiac valve surgery improves patient satisfaction while reducing costs of cardiac valve replacement and repair. Ann Surg. 1997;226:421Y 426. 4. Benetti FJ, Mariani MA, Rizzardi JL, Benetti I. Minimally invasive aortic valve replacement. J Thorac Cardiovasc Surg. 1997;113:806 Y807. 5. Gillinov AM, Banbury MK, Cosgrove DM. Hemisternotomy approach for aortic and mitral valve surgery. J Card Surg. 2000;15:15Y20. 6. Mihaljevic T, Cohn LH, Unic D, Aranki SF, Couper GS, Byrne JG. One thousand minimally invasive valve operations: early and late results. Ann Surg. 2004;240:529Y534. 7. Soltesz EG, Cohn LH. Minimally invasive valve surgery. Cardiol Rev. 2007;15:109Y115. 8. Sharony R, Grossi EA, Saunders PC, et al. Propensity score analysis of a six-year experience with minimally invasive isolated aortic valve replacement. J Heart Valve Dis. 2004;13:887Y 893. 9. Liu J, Sidiropoulos A, Konertz W. Minimally invasive aortic valve replacement (AVR) compared to standard AVR. Eur J Cardiothorac Surg. 1999;16(suppl 2):S80YS83. 10. Bonacchi M, Prifti E, Giunti G, Frati G, Sani G. Does ministernotomy improve postoperative outcome in aortic valve operation? A prospective randomized study. Ann Thorac Surg. 2002;73:460Y465. 11. Ma¨chler HE, Bergmann P, Anelli-Monti M, et al. Minimally invasive versus conventional aortic valve operations: a prospective study in 120 patients. Ann Thorac Surg. 1999;67:1001Y1005. 12. Kim BS, Soltesz EG, Cohn LH. Minimally invasive approaches to aortic valve surgery: Brigham experience. Semin Thorac Cardiovasc Surg. 2006;18:148Y153. 13. ElBardissi A, Shekar P, Couper GS, Cohn LH. Minimally invasive aortic valve replacement in octogenarian, high-risk, transcatheter aortic valve implantation candidates. J Thorac Cardiovasc Surg. 2011;141:328Y335. 14. Smith CR, Leon MB, Mack MJ, et al., for the PARTNER Trial Investigators. Transcatheter versus surgical aortic-valve replacement in high-risk patients. N Engl J Med. 2011;364:2187Y2198. 15. Kodali SK, Williams MR, Smith CR, et al., for the PARTNER Trial Investigators. Two-year outcomes after transcatheter or surgical aortic-valve replacement. N Engl J Med. 2012;366:1686Y1695. 16. Zahn R, Gerckens U, Linke A, et al., for the German Transcatheter Aortic Valve Interventions-Registry Investigators. Predictors of one-year mortality after transcatheter aortic valve implantation for severe symptomatic aortic stenosis. Am J Cardiol. 2013;112:272Y279. 17. Tabata M, Khalpey Z, Shekar PS, Cohn LH. Reoperative minimal access aortic valve surgery: minimal mediastinal dissection and minimal injury risk. J Thorac Cardiovasc Surg. 2008;136:1564 Y1568. 18. Horstkotte D, Loogen F. The natural history of aortic valve stenosis. Eur Heart J. 1988;9(suppl E):57Y64. 19. Freed BH, Sugeng L, Furlong K, et al. Reasons for nonadherence to guidelines for aortic valve replacement in patients with severe aortic stenosis and potential solutions. Am J Cardiol. 2010;105:1339 Y1342. 20. Iung B, Cachier A, Baron G, et al. Decision-making in elderly patients with severe aortic stenosis: why are so many denied surgery? Eur Heart J. 2005; 26:2714 Y2720.
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
109
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
Innovations & Volume 9, Number 2, March/April 2014
Gosev et al
21. Byrne JG, Aranki SF, Couper GS, Adams DH, Allred EN, Cohn LH. Reoperative aortic valve replacement: partial upper hemisternotomy versus conventional full sternotomy. J Thorac Cardiovasc Surg. 1999; 118:991Y997.
22. Tabata M, Umakanthan R, Khalpey Z, et al. Conversion to full sternotomy during minimal-access cardiac surgery: reasons and results during a 9.5-year experience. J Thorac Cardiovasc Surg. 2007;134: 165 Y169.
CLINICAL PERSPECTIVE This retrospective case series examined the 16-year experience at the Brigham and Women’s Hospital with minimally invasive aortic valve surgery. It is a very large series encompassing over 1,600 patients. The authors showed acceptable morbidity and mortality rates. Particularly impressive was the low morbidity in octogenarians, who comprised 22% of this series. The observed mortality in this group was only 4.9%, wheras the predicted STS mortality was 6.8%. They showed similar excellent results in the reoperative group. The median length of stay following these procedures was 6 days and over 70% of patients were discharged home. There was a very acceptable 5-year survival rate of 83% for the entire group. This is a comprehensive report from one of the pioneering centers in minimally invasive aortic valve surgery. It shows the excellent results that can be obtained at experienced centers. The weakness of this report is that while it is a large series, it is selective and there was no control group. However, this series clearly demonstrates that minimally invasive aortic valve replacement is effective in experienced hands and has superb outcomes.
110
Copyright * 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery
Copyright © 2014 by the International Society for Minimally Invasive Cardiothoracic Surgery. Unauthorized reproduction of this article is prohibited.
