Papers from the Peripheral Vascular Surgery Society 1989 Meeting
The Suitability of Expanded PTFE for Carotid Patch Angioplasty Daniel R. LeGrand, MD, Rita L. Linehan, CST, I n d i a n a p o l i s , I n d i a n a
From June 1985 to December 1988, 175 consecutive patients underwent 204 carotid endarterectomies with routine use of expanded PTFE patch angioplasty. Two patients (1%) suffered strokes and there were no transient ischemic attacks or deaths in the immediate postoperative period. All carotid endarterectomies were performed with an intraluminal shunt without cerebral monitoring. The indications for carotid endarterectomy were symptoms (83% of patients) or no symptoms of internal carotid artery atherosclerotic stenoses (12.7% of patients). Neurological assessment, Doppler and real-time ultrasound were performed at six months, twelve months and then annually. Over the follow-up period there were one asymptomatic occlusion and two high grade symptomatic stenoses which required reoperation. (Ann Vasc Surg 1990; 4:209-212). KEY WORDS:
Expanded PTFE patch angioplasty; carotid endarterectomy.
Currently, much controversy exists in the literature regarding the precise rote of patch angioplasty in carotid endarterectomy and the impact on operative outcome. This study describes the results of a series of routinely patched carotid endarterectomies using expanded potytetrafluoroethylene (ePTFE) and compares these results with other published series. Since this is not a randomized study, the controversy of " t o patch" or "not to patch" cannot be addressed. However, assuming
From St. Wncent's Hospital and Health Care Center, Indianapolis, Indiana. Presented at the Annual Meeting o[ the Peripheral Vascuhlr Surget3' Society, N e w York, N e w York, June 17, 1989. Reprint requests: Daniel R, LeGrand, MD, 8402 Harcourt Road, Indianapolis, Indiana 46260.
the decision has been made to use a patch, this study demonstrates that excellent results, comparable to saphenous vein patch angioplasty, can be obtained using ePTFE. In the early years of carotid endarterectomy, patch angioplasty was popular and was believed to contribute to vessel patency [12]. However, with refinements in vascular techniques, patch angioplasty came to be used more selectively, especially in cases of nanow or traumatized arteries [3]. More recently the role of patching the carotid artery after endarterectomy has been widely debated. It has been suggested that routine patching is associated with better operative results and a lower rate of recurrent atherosclerotic stenosis. When the decision to patch has been made, saphenous vein has been the material of choice for most surgeons. However, the use of saphenous vein eliminates a potential source for a conduit for future revasculariza-
209
ePTFE FOR CAROTID P A T C H A N G I O P L A S T Y
210
TABLE I.--Indications for surgery Stroke TIA Asymptomatic Nonfocal Amaurosis fugax
Patients 33 69 26 58 18
Percentage 16% 33.8% 12.7% 28.4% 8.8%
tions and has the inherent risks of patch rupture and dilation. To overcome these potential pitfalls of saphenous vein patch ePTFE was used exclusively in this series.
METHODS From June 1985 to December 1988, 204 carotid endarterectomies were performed on 175 patients. The operations were performed at two community hospitals with essentially identical arteriographic, operative, and intensive care unit facilities and personnel. All procedures were performed entirely by the author. Early in the series remnants of ePTFE grafts were used for the patch and, more recently, the commercially available cardiovascular patch (0.6 mm thickness) has been employed. The indications for surgery are summarized in Table I. All asymptomatic carotid stenoses reduced the lumen by greater than 75%. Standard two-view, arch, four-vessel arteriograms were obtained in all patients except one who had a good quality real-time ultrasound study and a history of cardiac arrest with contrast medium. General endotracheal anesthesia was used in all but two operations: these were performed in a staged fashion on the same patient using local anesthesia. Optical 2.5 power magnification was used for all procedures. A small, Argyle, in-lying shunt was used in all cases. No cerebral monitoring was employed, nor was any attempt made at rigid control of arterial carbon dioxide levels by the anesthesiologist. Heparinization was employed in all patients (100/x/kg). Routine ePTFE patch angioplasty (3-5 mm width) was employed in all cases. The arteriotomy extended 4-5 mm distal to the preserved endothelium of the internal carotid artery, and a good quality distal end point with complete removal of the tongue of the plaque was achieved. End-point tacking sutures were employed in fewer than 5% of the endarterectomies. Careful flushing of the arteriotomy was performed frequently with heparinized, lactated Ringers solution to aid in removing debris and to diminish the adherence of blood to the back of the ePTFE patch. Early in the series running 6--0 Prolene suture was utilized to accomplish the angioplasty, but with the release of the ePTFE suture, it became the exclu-
ANNALS OF VASCULAR SURGERY
TABLE II.--Demographic data and risk factors Risk Factor Bilateral carotid endarterectomies Males Females Smokers Diabetic Hypertensive Coronary artery disease
Number of patients 29 (17%) 91 (52%) 84 (48%) 79 (45%) 77 (44%) 117 (67%) 60 (34%)
Total patients = 175 Average age = 67.96years
sive suture. Systemic blood pressure was maintained at or below 180 mm Hg in the postoperative period using intravenous hydralazine, sodium nitroprusside or nitroglycerin. All patients were observed in an intensive care environment for at least six hours. Demographic data and risk factors are summarized in Table II. Follow-up was accomplished utilizing real-time ultrasound and Doppler spectral analysis** at six months, twelve months and annually thereafter. Ninety-nine percent of the patients were seen in follow-up and the numbers available at each followup point is indicated in Figure 1. The degree of restenosis represented the amount of luminal reduction on real-time ultrasound; the results are summarized in Table III.
RESULTS No patient died in the immediate postoperative period. The perioperative complications, including neurologic events and occlusions, are listed in Table IV. Neither of the patients who required reexploration for hematoma had bleeding from the suture line. Follow-up included real-time ultrasound and spectral analysis of Doppler signals and was performed at six months, twelve months, and then annually thereafter. Only I% of patients were lost to follow-up and 17 (8.3%) died during the period of follow-up. Two patients developed symptomatic high grade stenoses proximal to the patch on the common carotid artery and required reoperation. These and the other long-term complications are listed in Table IV. Restenoses were discovered in 8.2% of the patients and are summarized in Table III. As noted, 7.4% had less than 50% stenoses. Operative time for the series averaged 105 minutes (-+ 10 minutes).
*Manufactured by ATL Laboratories, Bothelt, Washington. tManufactured by Biosound, Indianapolis, Indiana.
ePTFE FOR CAROTID P A T C H A N G I O P L A S T Y
VOLUME 4 N o 3 - 1990
211
TABLE IV.--Perioperative and long-term
GRAPH I
complications
Number of patients
250
Perioperative TIA Stroke Hematoma (requiring exploration) Myocardial infarction Long-Term Infection Pseudoaneurysm Asymptomatic occlusion Symptomatic restenoses
203
200
172
150 14t
Percentage
0 2 2
0 1% 1%
0
0
0 0 1 2
0 0 0.5% 1%
Patients
t05
100
6
12
18
24
30
36
H onchs FOLLOW-UP
Fig. 1. Number of patients available at follow-up.
DISCUSSION As more surgeons employ patch angioplasty in hopes of decreasing the morbidity and mortality as well as the restenosis of carotid endarterectomy, the controversy of whom to patch and what to use will only grow stronger. Currently, three prospective randomized trials all indicate patch angioplasty to be valuable. Clagett and associates [4] found that 20% of 154 carotid endarterectomies met criteria for obligatory patching: internal carotid artery (ICA) < 5 mm arteriotomy extending more than 3 cm beyond ICA origin, tortuous or kinked ICA, or crooked or spiraled arteriotomy. In the remaining randomized patients there was a 12.9% restenosis rate in patched carotids and 1.7% in primarily closed vessels. However, there was only one significant restenosis while the remainder were in the range of
TABLE III.--Degree of restenoses represented on real-time ultrasound Degree
Number of patients
0-25% 25-50% 50-75% 75-100% Total
6 9 -3 18
Percentage 3% 4.4% 0 1.4% 8.2%
25-50%. These results suggested layering of thrombus in the dilated part of the vein patch and raise the question of whether the patch was made too large or whether it dilated with time. Clagett and associates concluded that vein patch should be used selectively in patients with small arteries and other anatomic risk factors for acute postoperative occlusion. They stopped short of recommending routine use in women, patients with multiple systemic risk factors, and settings where perioperative morbidity and mortality exceed 5-6%. Eiketboom and coworkers [5] in their prospective randomized study demonstrated that patching reduced the rate of recurrent stenosis (3.5% versus 21% in primarily closed arteries). However, the benefit was only evident in women. They also discussed the choice of patch material and felt that, from a theoretical point of view, saphenous vein should be preferable to synthetic materials such as Dacron or ePTFE because vein is easier to handle, less thrombogenic, and more resistant to infection. An obvious disadvantage of saphenous vein is the possibility of patch rupture, patch dilation, and loss of vein for future coronary or extremity revascularization. To compare routine vein patching versus selective patching, Hertzer and colleagues [6] prospectively looked at 917 consecutive carotid endarterectomies. The immediate neurologic complication rate was 3.1% in nonpatched and 0.7% in veinpatched vessels. Recurrent stenoses were noted in 4.8% of patched vessels and 14% of nonpatched vessels after three years of follow-up. Hertzer concludes, " I f vein patching can make good results even better at our center, then it could substantially enhance the mediocre outcome that apparently is encountered at many others." Certainly the three studies summarized above established the value of patching, but the type of patch is addressed in the prospective randomized study comparing primary closure versus patching with saphenous vein and ePTFE performed by Lord and associates [7]. This study demonstrated a sig-
212
ePTFE FOR CAROTID PATCH A N G I O P L A S T Y
nificant reduction in perioperative neurologic complications from 10% in primarily closed vessels to 2.3% in vein-patched and 2.1% in ePTFE-patched vessels. There were no stenoses in the patched-on IV-DSA performed at one month compared with 19% detected in direct arteriotomy closure. Of note, 18% of the vein-patched and 9% of the ePTFEpatched vessels developed aneurysmal dilation. In summary, Lord and associates noted a decreased rate of neurologic complications and restenosis in patched arteries and that the ePTFE patch resisted dilation [7].
CONCLUSION The use of patch angioplasty will remain controversial until the subgroup in whom it may be beneficial is defined. Just as in shunting, the routine use of a patch is not necessary in the vast majority of patients. However, the planned use of a patch eliminates decision errors and allows for an aggressive approach to endarterectomy and a technically uncomplicated reconstruction in almost all cases [8]. By utilizing ePTFE the pitfalls of vein patch angioplasty, e.g., patch rupture, patch dilation, and loss of vein for future revascularizations, are eliminated. The results of using ePTFE patch angioplasty, as demonstrated in this study, are excellent with tow morbidity and mortality rates.
n u n
ANNALS OF VASCULARSURGERY
ACKNOWLEDGMENT We give special acknowledgment to Cindy Kolar, Selma Gies and Charlene Whinnery for their assistance in the preparation of this manuscript.
REFERENCES 1. CALLOW AD. The Leriche Memorial Lecture. Fact or fancy: a 20-year personal perspective on the detection and management of carotid occlusive disease. J Cardiovasc Surg 1988;21:641-658. 2. DEBAKEY ME, CRAWFORDS ES, MORRIS GC, et al. Patch graft angioplasty in vascular surgery. J Cardiovasc Surg 1962:3:106-141. 3. THOMPSON JE, PATMAN RD. TALKINGTON DM. Carotid surgery for cerebrovascular insufficiency. Curr Probl Surg 1978;15:1-68. 4. CLAGETT GP, PATTERSON CB, FISCHER DF Jr, et al. Vein patch versus primary closure for carotid endarterectomy. J Vasc Surg 1989;9:213-223. 5. EIKELBOOM BC, ACKERSTAFF RGA, HOENEVELD H, et al. Benefits of carotid patching: a randomized study. J Vasc Surg 1988;7:240-24. 6. HERTZER NR, BEVEN EG, O'HARA PJ, et al. Prospective study of vein patch angioplasty during carotid endarterectomy. Am Surg 1987;206:628-635. 7. LORD RSA. RAJ TB, STARY DL, et al. Comparison of saphenous vein patch, polytetrafluoroethylene patch, and direct arteriotomy closure after carotid endarterectomy. Part I. Perioperative results. J Vase Surg 1989;9:521-529. 8. ARCHtE JP. Prevention of early restenosis and thrombosisocclusion after carotid endarterectomy by saphenous vein angiography. Stroke 1986;17:90t-905.
The Suitability of Expanded PTFE for Carotid Patch Angioplasty Daniel R. LeGrand, MD, Rita L. Linehan, CST, I n d i a n a p o l i s , I n d i a n a
From June 1985 to December 1988, 175 consecutive patients underwent 204 carotid endarterectomies with routine use of expanded PTFE patch angioplasty. Two patients (1%) suffered strokes and there were no transient ischemic attacks or deaths in the immediate postoperative period. All carotid endarterectomies were performed with an intraluminal shunt without cerebral monitoring. The indications for carotid endarterectomy were symptoms (83% of patients) or no symptoms of internal carotid artery atherosclerotic stenoses (12.7% of patients). Neurological assessment, Doppler and real-time ultrasound were performed at six months, twelve months and then annually. Over the follow-up period there were one asymptomatic occlusion and two high grade symptomatic stenoses which required reoperation. (Ann Vasc Surg 1990; 4:209-212). KEY WORDS:
Expanded PTFE patch angioplasty; carotid endarterectomy.
Currently, much controversy exists in the literature regarding the precise rote of patch angioplasty in carotid endarterectomy and the impact on operative outcome. This study describes the results of a series of routinely patched carotid endarterectomies using expanded potytetrafluoroethylene (ePTFE) and compares these results with other published series. Since this is not a randomized study, the controversy of " t o patch" or "not to patch" cannot be addressed. However, assuming
From St. Wncent's Hospital and Health Care Center, Indianapolis, Indiana. Presented at the Annual Meeting o[ the Peripheral Vascuhlr Surget3' Society, N e w York, N e w York, June 17, 1989. Reprint requests: Daniel R, LeGrand, MD, 8402 Harcourt Road, Indianapolis, Indiana 46260.
the decision has been made to use a patch, this study demonstrates that excellent results, comparable to saphenous vein patch angioplasty, can be obtained using ePTFE. In the early years of carotid endarterectomy, patch angioplasty was popular and was believed to contribute to vessel patency [12]. However, with refinements in vascular techniques, patch angioplasty came to be used more selectively, especially in cases of nanow or traumatized arteries [3]. More recently the role of patching the carotid artery after endarterectomy has been widely debated. It has been suggested that routine patching is associated with better operative results and a lower rate of recurrent atherosclerotic stenosis. When the decision to patch has been made, saphenous vein has been the material of choice for most surgeons. However, the use of saphenous vein eliminates a potential source for a conduit for future revasculariza-
209
ePTFE FOR CAROTID P A T C H A N G I O P L A S T Y
210
TABLE I.--Indications for surgery Stroke TIA Asymptomatic Nonfocal Amaurosis fugax
Patients 33 69 26 58 18
Percentage 16% 33.8% 12.7% 28.4% 8.8%
tions and has the inherent risks of patch rupture and dilation. To overcome these potential pitfalls of saphenous vein patch ePTFE was used exclusively in this series.
METHODS From June 1985 to December 1988, 204 carotid endarterectomies were performed on 175 patients. The operations were performed at two community hospitals with essentially identical arteriographic, operative, and intensive care unit facilities and personnel. All procedures were performed entirely by the author. Early in the series remnants of ePTFE grafts were used for the patch and, more recently, the commercially available cardiovascular patch (0.6 mm thickness) has been employed. The indications for surgery are summarized in Table I. All asymptomatic carotid stenoses reduced the lumen by greater than 75%. Standard two-view, arch, four-vessel arteriograms were obtained in all patients except one who had a good quality real-time ultrasound study and a history of cardiac arrest with contrast medium. General endotracheal anesthesia was used in all but two operations: these were performed in a staged fashion on the same patient using local anesthesia. Optical 2.5 power magnification was used for all procedures. A small, Argyle, in-lying shunt was used in all cases. No cerebral monitoring was employed, nor was any attempt made at rigid control of arterial carbon dioxide levels by the anesthesiologist. Heparinization was employed in all patients (100/x/kg). Routine ePTFE patch angioplasty (3-5 mm width) was employed in all cases. The arteriotomy extended 4-5 mm distal to the preserved endothelium of the internal carotid artery, and a good quality distal end point with complete removal of the tongue of the plaque was achieved. End-point tacking sutures were employed in fewer than 5% of the endarterectomies. Careful flushing of the arteriotomy was performed frequently with heparinized, lactated Ringers solution to aid in removing debris and to diminish the adherence of blood to the back of the ePTFE patch. Early in the series running 6--0 Prolene suture was utilized to accomplish the angioplasty, but with the release of the ePTFE suture, it became the exclu-
ANNALS OF VASCULAR SURGERY
TABLE II.--Demographic data and risk factors Risk Factor Bilateral carotid endarterectomies Males Females Smokers Diabetic Hypertensive Coronary artery disease
Number of patients 29 (17%) 91 (52%) 84 (48%) 79 (45%) 77 (44%) 117 (67%) 60 (34%)
Total patients = 175 Average age = 67.96years
sive suture. Systemic blood pressure was maintained at or below 180 mm Hg in the postoperative period using intravenous hydralazine, sodium nitroprusside or nitroglycerin. All patients were observed in an intensive care environment for at least six hours. Demographic data and risk factors are summarized in Table II. Follow-up was accomplished utilizing real-time ultrasound and Doppler spectral analysis** at six months, twelve months and annually thereafter. Ninety-nine percent of the patients were seen in follow-up and the numbers available at each followup point is indicated in Figure 1. The degree of restenosis represented the amount of luminal reduction on real-time ultrasound; the results are summarized in Table III.
RESULTS No patient died in the immediate postoperative period. The perioperative complications, including neurologic events and occlusions, are listed in Table IV. Neither of the patients who required reexploration for hematoma had bleeding from the suture line. Follow-up included real-time ultrasound and spectral analysis of Doppler signals and was performed at six months, twelve months, and then annually thereafter. Only I% of patients were lost to follow-up and 17 (8.3%) died during the period of follow-up. Two patients developed symptomatic high grade stenoses proximal to the patch on the common carotid artery and required reoperation. These and the other long-term complications are listed in Table IV. Restenoses were discovered in 8.2% of the patients and are summarized in Table III. As noted, 7.4% had less than 50% stenoses. Operative time for the series averaged 105 minutes (-+ 10 minutes).
*Manufactured by ATL Laboratories, Bothelt, Washington. tManufactured by Biosound, Indianapolis, Indiana.
ePTFE FOR CAROTID P A T C H A N G I O P L A S T Y
VOLUME 4 N o 3 - 1990
211
TABLE IV.--Perioperative and long-term
GRAPH I
complications
Number of patients
250
Perioperative TIA Stroke Hematoma (requiring exploration) Myocardial infarction Long-Term Infection Pseudoaneurysm Asymptomatic occlusion Symptomatic restenoses
203
200
172
150 14t
Percentage
0 2 2
0 1% 1%
0
0
0 0 1 2
0 0 0.5% 1%
Patients
t05
100
6
12
18
24
30
36
H onchs FOLLOW-UP
Fig. 1. Number of patients available at follow-up.
DISCUSSION As more surgeons employ patch angioplasty in hopes of decreasing the morbidity and mortality as well as the restenosis of carotid endarterectomy, the controversy of whom to patch and what to use will only grow stronger. Currently, three prospective randomized trials all indicate patch angioplasty to be valuable. Clagett and associates [4] found that 20% of 154 carotid endarterectomies met criteria for obligatory patching: internal carotid artery (ICA) < 5 mm arteriotomy extending more than 3 cm beyond ICA origin, tortuous or kinked ICA, or crooked or spiraled arteriotomy. In the remaining randomized patients there was a 12.9% restenosis rate in patched carotids and 1.7% in primarily closed vessels. However, there was only one significant restenosis while the remainder were in the range of
TABLE III.--Degree of restenoses represented on real-time ultrasound Degree
Number of patients
0-25% 25-50% 50-75% 75-100% Total
6 9 -3 18
Percentage 3% 4.4% 0 1.4% 8.2%
25-50%. These results suggested layering of thrombus in the dilated part of the vein patch and raise the question of whether the patch was made too large or whether it dilated with time. Clagett and associates concluded that vein patch should be used selectively in patients with small arteries and other anatomic risk factors for acute postoperative occlusion. They stopped short of recommending routine use in women, patients with multiple systemic risk factors, and settings where perioperative morbidity and mortality exceed 5-6%. Eiketboom and coworkers [5] in their prospective randomized study demonstrated that patching reduced the rate of recurrent stenosis (3.5% versus 21% in primarily closed arteries). However, the benefit was only evident in women. They also discussed the choice of patch material and felt that, from a theoretical point of view, saphenous vein should be preferable to synthetic materials such as Dacron or ePTFE because vein is easier to handle, less thrombogenic, and more resistant to infection. An obvious disadvantage of saphenous vein is the possibility of patch rupture, patch dilation, and loss of vein for future coronary or extremity revascularization. To compare routine vein patching versus selective patching, Hertzer and colleagues [6] prospectively looked at 917 consecutive carotid endarterectomies. The immediate neurologic complication rate was 3.1% in nonpatched and 0.7% in veinpatched vessels. Recurrent stenoses were noted in 4.8% of patched vessels and 14% of nonpatched vessels after three years of follow-up. Hertzer concludes, " I f vein patching can make good results even better at our center, then it could substantially enhance the mediocre outcome that apparently is encountered at many others." Certainly the three studies summarized above established the value of patching, but the type of patch is addressed in the prospective randomized study comparing primary closure versus patching with saphenous vein and ePTFE performed by Lord and associates [7]. This study demonstrated a sig-
212
ePTFE FOR CAROTID PATCH A N G I O P L A S T Y
nificant reduction in perioperative neurologic complications from 10% in primarily closed vessels to 2.3% in vein-patched and 2.1% in ePTFE-patched vessels. There were no stenoses in the patched-on IV-DSA performed at one month compared with 19% detected in direct arteriotomy closure. Of note, 18% of the vein-patched and 9% of the ePTFEpatched vessels developed aneurysmal dilation. In summary, Lord and associates noted a decreased rate of neurologic complications and restenosis in patched arteries and that the ePTFE patch resisted dilation [7].
CONCLUSION The use of patch angioplasty will remain controversial until the subgroup in whom it may be beneficial is defined. Just as in shunting, the routine use of a patch is not necessary in the vast majority of patients. However, the planned use of a patch eliminates decision errors and allows for an aggressive approach to endarterectomy and a technically uncomplicated reconstruction in almost all cases [8]. By utilizing ePTFE the pitfalls of vein patch angioplasty, e.g., patch rupture, patch dilation, and loss of vein for future revascularizations, are eliminated. The results of using ePTFE patch angioplasty, as demonstrated in this study, are excellent with tow morbidity and mortality rates.
n u n
ANNALS OF VASCULARSURGERY
ACKNOWLEDGMENT We give special acknowledgment to Cindy Kolar, Selma Gies and Charlene Whinnery for their assistance in the preparation of this manuscript.
REFERENCES 1. CALLOW AD. The Leriche Memorial Lecture. Fact or fancy: a 20-year personal perspective on the detection and management of carotid occlusive disease. J Cardiovasc Surg 1988;21:641-658. 2. DEBAKEY ME, CRAWFORDS ES, MORRIS GC, et al. Patch graft angioplasty in vascular surgery. J Cardiovasc Surg 1962:3:106-141. 3. THOMPSON JE, PATMAN RD. TALKINGTON DM. Carotid surgery for cerebrovascular insufficiency. Curr Probl Surg 1978;15:1-68. 4. CLAGETT GP, PATTERSON CB, FISCHER DF Jr, et al. Vein patch versus primary closure for carotid endarterectomy. J Vasc Surg 1989;9:213-223. 5. EIKELBOOM BC, ACKERSTAFF RGA, HOENEVELD H, et al. Benefits of carotid patching: a randomized study. J Vasc Surg 1988;7:240-24. 6. HERTZER NR, BEVEN EG, O'HARA PJ, et al. Prospective study of vein patch angioplasty during carotid endarterectomy. Am Surg 1987;206:628-635. 7. LORD RSA. RAJ TB, STARY DL, et al. Comparison of saphenous vein patch, polytetrafluoroethylene patch, and direct arteriotomy closure after carotid endarterectomy. Part I. Perioperative results. J Vase Surg 1989;9:521-529. 8. ARCHtE JP. Prevention of early restenosis and thrombosisocclusion after carotid endarterectomy by saphenous vein angiography. Stroke 1986;17:90t-905.
