Expanded polytetrafluoroethylene patch angioplasty in carotid endarterectomy Valentine J. Rhodes, MD, Brick, NJ. Purpose: This study retrospectively reviewed the experience with expanded polytetraflu- oroethylene (ePTFE) patches for carotid endarterectomy in 924 consecutive procedures (753 patients) during a 17-year period. 2Vlethods: The records of all patients who underwent ePTFE patch angioplasty for carotid artery stenosis performed by orte surgeon were reviewed. The eriterion for surgery was stenosis of 80% or greater. Follow-up by use of noninvasive methods was done by 6 months after operation the first year and annuaUy thereafter. Recurrent stenosis was confirmed with angiography. Life-table analysis was used to estimate the risk ofrestenosis. Results: Early morbidity and mortality included six deaths (0.6%), seven nonfatal strokes (0.9%), and 19 hemorrhages. Two postoperative infections occurred. There were no important aneurysmal dilations and no late hemorrhages. With a mean follow-up of 41.4 months (fange 0 to 197), recurrent stenosis necessitating reoperation developed in 28 patients (3.7%). There were two late strokes. Life-table analysis indicated a 89% probability of freedom from stenosis at 120 months. Conclusions: In cases in which the decision to perform patch angioplasty is made at surgery, an ePTFE patch is an excellent alternative to autogenous saphenous rein, with a low rate ofrecurrences requiring operation and acceptable rates of perioperative and postoperative morbidity and mortality. (J VAsc SURG 1995;22:724-31.) Carotid endarterectomy has been alternately re- garded with caution, enthusiasm, distrust, and then renewed enthusiasm after the publication of the North American Symptomatic Carotid Endarterec- mmy Trial (NASCET)) More recent results from the Asymptomatic Carotid Atherosclerosis Study (ACAS) 2 have further confirmed the merit ofcarotid endarterectomy in the prevention of stroke. Debate continues, however, about the value of patch angio- plasty for preventing recurrent stenosis and postoper- ative thrombosis and the benefits of saphenous vein versus synthetic patches. Before 1976, patch angioplasty was performcd only in selected cases in our praetice. However, an apparently higher rate of recurrent stenosis and peri- operative thrombosis in patients having primary clo- sure as compared with patch angioplasty prompted an increase in the use of patches. Initially, only vein From Central Jersey Vascular Specialists, Brick. Presented at the Ninth Annual Meeting of the Eastem Vascular Society, May 4-7, 1995, Buffalo, N.Y. Reprint requests: Valentine I. Rhodes, MD, Central Jersey Vascular Specialists, Inc., Ocean Medical Park, 206 Jack Martin Blvd., Brick, New Jersey 08724. Copyright © 1995 by The Society for Vascular Surgery and International Society for Cardiovascular Surgery, North Ameri- can Chapter. 0741-5214/95/$5.00 + 0 24/6/68964 724 patches were used. These appeared to be associated with a lower rate of recurrent stenosis than that after primary closure, but several of the patches developed aneurysmal dilation, and two patients had late disrup- tions that required emergency reoperation. These problems motivated a switch to cxpanded polytetra- fluoroethylene (ePTFE; Gore-tex, W.L. Gore & As- sociates, Elkton, Md.) for patch angioplasty, and, since 1976, all carotid endarterectomies have been performed with this material. The purpose of this smdy is to review the outcome with respect to peri- operative morbidity and death and postoperative re- current stenosis and stroke in a large series ofcarotid endarterectomies with ePTFE patch angioplasty. MATERIAL AND METHODS The records of all patients who tmderwent ePTFE patch angioplasty for carotid artery stenosis per- formed by one surgeon were reviewed. All proce- dures were done between 1976 and 1993. Before operation, all patients had stenosis of 80% or greater (percentage of vessel diameter), as determined by oculopneumoplethysmography (OPG) and echo- flow ultrasonography (used from 1976 to 1980), spectral frequency analysis or OPG-Gee (1981 to 1985), or duplex ultrasonography (1985 to 1993), and confirmed with angiography. Seventy-six percent
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`JOURNAL OF VASCULAR SURGERY Volume 22, Number ó Rhodes 725 A b..~__.~~~~s / POSTERIOR VlEW L J v 4rnrn 7cm 7rnrn LATERAL VIEW Fig. 1. Posterior (A) and lateral (B) views show size, shape, and location ofePTFE patch used in carotid endarterectomy. Dotted circle in posterior view represents approximate location of orifice of external carotid artery. of these patients had symptoms; 24% were symptom free. Operative teehnique. General endotracheal an- esthetic was used in all cases. A crescent-shaped incision was made from just below the mastoid process down to the cricoid cartilage, at least 1 cm beyond the portion of the vessel to be endarterecto- mized. This long incision allows mobilization of sufficient sternocleidomastoid muscle to obtain wide exposure of the carotid artery above and below the level of the occluding lesion. The carotid artery was skeletonized and looped with vessel loops. Vascular clamps were not used because clamp injury may increase the risk of subsequent formation of athero- matous plaque. In most patients 7500 units of intravenous heparin were administered initially, fol- lowed by an additional 1000 units per hour. Large patients required 10,000 units. Fivc minutes after the first administration of heparin, the carotid vessels were occluded by placing traction on the vessel loops, and a Pruitt-Inahara shunt (Ideas For Medicine, Inc., North Clearwater, Fla.) was inserted (except in five cases). A Freer dissector (Codman Surgical Products, Raynharn, Mass.) was used to remove the plaque to the adventitial layer. Tacking sutures were placed only if the distal intima was nonadherent. Before January 1988 the ePTFE pätches were fashioned from vascular grafts; since then 0.4 mm ePTFE thin-walled cardiovascular patches have becn used.
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`JOURNAL OF VASCULAR SURGERY 726 Rhodes December 3.995 Table I. Patient demographics and risk factors for arterial disease Mean age (fange) in yr 70.7 (26-90) Sex Men 417 Wonnen 336 Peripheral occlusion or stenosis 333 Abdominal aortic aneurysm 20 Myocardial infarction 71 Previous cartoid endarterectomy 5 Smoking 551 Diabetes 241 Chronic hypertension 521 Hyperlipidemia 274 Chronic obstructive pulmonary disease 141 Polycythemia 10 The ePTFE patch was trimmed and tapered to the appropriate size (approximately 4 mm wide at the apex, 7 mm wide at the bulb, and 7 cm long) to reconstruct the original shape of the carotid bulb and replace at least 50% of the endarterectomized wall of the artery, thereby ensuring that less of the throm- bogenic arterial surface area was in contact with circulating platelets (Fig. 1). During the suturing process, the patch was stretched to preclude "scalloping" between sutures that could result in bleeding. Running sumre was used in all cases, with deep bites (1 to 3 mm) taken of the arterial wall. The deep bite depth allows sculpting of the carotid bulb, thereby helping to prevent formation of a dilation. It may also assist in preventing suture hole bleeding because the extraar- terial tissue is gathered into the suture over the edge of the patch. Polypropylene suture material (Prolene; Ethicon, Inc., Somerville, N.J. ) was used initially, hut ePTFE CV-6 suture (Gore-tex) on a TT-9 needle was used exclusively after it became available in January 1986. Thrombin-soaked oxidized cellulose and digi- tal pressure were applied to stop any bleeding before closure. Drains were not placed unless the wound continued to bleed; in such cases, a Jackson-Pratt drain (Baxter Health Care Corp., Deerfield, Ill.) was inserted through a separate stab wound. The heparin was reversed with 25 to 50 mg of intravenous protamine. Surveillance protocol. Patients were assessed for neurologic symptoms and monitored for recurrent stenosis (percentage of vessel diameter) and devel- opment of aneurysmal dilation and occlusion with noninvasive methods by 6 months after operation the first year and annually thereafter, although those with evidence of recurrent stenosis were exan~ined more offen. OPG with standard criteria a and echo-flow ultrasonography were used from 1976 to 1980, and spectral frequency analysis or Gee-OPG was used from 1981 to 1985. In evaluations with spectral analysis, any patient having spectral broadening consistent with stenosis of 30% or greater was considered to have recurrence and was monitored more dosely. Duplex ultrasonography began to be used in 1985, and color-flow Doppler evaluation was added in 1992. Angiographic assessment was done in patients in whom duplex scanning indicated stenosis of 80% or greater and in patients with symptoms of stenosis of 65% or greater but less than 80% whose symptoms did not clear while they were receiving aspirin or warfarin therapy and in whom no other canse could be identified. Angiography was performed through- out the series when the analysis indicated stenosis of 80% or greater or the patient had development of symptoms. Severe recurrent stenosis was confirmed at surgery. Data analysis. The data were analyzed with re- spect to arteries rather than patients at risk. Life-table analysis was performed to determine restenosis-free survival rates. RESULTS An ePTFE patch was used to complete 924 consecutive carotid patch angioplasties in 753 pa- tients. The patients' demographic data and risk factors for arterial disease on entry into the study are provided in Table I. Before operation, contralateral carotid artery occlusion was present in 80 patients, and contralateral vertebral occlusion was observed in 13. In 235 patients the contralateral carotid artery was normal; in 147 patients staged bilateral endar- terectomy was required. The total of 753 patients, including the 147 who underwent bilateral proce- dures, had 900 initial operations. The additional 24 ePTFE patch operations in this series were on 20 patients with recurrent carotid artery stenosis and 4 with other underlying disease in whom reoperation was necessary for stenosis at another site. Six (0.6%) patients died during operations, five of myocardial infarction and one of stroke. Five patients had a nonfatal stroke during surgery. One patient had a stroke on the contralateral side 72 hours after endarterectomy, and another had a stroke as a result of intracranial occlusion (normal results on carotid duplex ultrasonography) on the ipsilateral side 2 weeks after operation. Therefore the 30-day stroke rate was 0.7%. All seven patients recovered completely within 2 months. Of the seven nonfatal strokes, three were in patients with asymptomatic severe stenosis. Nineteen patients (1.2%) had perioperative hem-
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`JOURNAL OF VASCULAR SURGERY Volume 22, Number 6 Rhodes 727 100 m o ù~ 95 90 85 80 0 I ! ~ 37 12 24 36 48 60 72 84 96 108 120 Months Fig. 2. Lifc-table analysis ofrisk ofrccurrcnt stenosis after carotid endarterectomy with ePTFE patch angioplasty. Numbers on middle line represent number of patients at risk. • Upper 95% CI --I-- Percent stenosis free Lower 95% CI orrhage in the neck requiring reoperation; transfu- sions were necessary in six of them. In five of the 19 (0.5%), the bleeding was from the suture holes in the patch in cases in which polypropylene suture had been used. Another patient had arterial wall failure, and the remalnder had diffuse oozing necessitating llgation or cautery ofsmall bleeding sites. There were no cases of late postoperative bleeding. Two patients had an operative cerebral hemor- rhage. One had a complete and the other a partial recovery. Four patients had severe suture line failure requiring reoperation within 72 hours of surgery; the failure was due to breakage of the polypropylene suture in two cases and arterial wall failure in the others. Three patients had perioperative transient ischemic attacks (TIAs). These occurred immediately after surgery in one patient, 2 weeks after operation in another, and 3 weeks after operation in the third. All three patients had normal results on duplex scanning or angiography. Three cases of cerebral edema occurred in the immediate postoperative period. The edema resolved, and the patients recov- ered completely. Infection occurred in two patients (0.2%). One was treated with removal of the ePTFE patch and implantation of a new one and the other with removal of the prosthesis and replacement with an autog- enous rein patch. Both patients also received systemic and topical antibiotic therapy. The infections re- solved without further sequelae, and both patients remained weil during the follow-up period. Follow-up averaged 41.4 months (range 0 to 197). Detectable recurrent stenosis developed in 84 patients (8.9%); 42 (4.5%) had less than 50% stenosis, and 19 (2.0%) had 50% to 65% stenosis. In 10 of these 19, the stenosis subsequently progressed by about 10% during the first year. None of the patients with recurrent stenosis ofless than 80% had symptoms. Recurrent stenosis of 80% or greater developed, and reoperation was necessary in 28 patients (3.7%). Because two of these 28 patients had bilateral recurrence, and three had two recurrences on the same side, 33 reoperations were performed as a result of recurrence. Of these, 23 (70%) were in patients with symptoms (ipsilateral TIAs), and 10 (30%) were performed in symptom-free patients. At surgery the only patent portion of the lumen in several of the arteries operated on was a slit under the patch; the remainder of the lumen was obliterated by fibrous tissue.
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`(cid:127)OURNAL OF VASCULAR SURGERY 728 Rhodes December 1995 Table II. Recurrent carotid artery stenosis after carotid endarterectomy with ePTFE patch Arteries with restenosis Interval (mo.) No. at ~isk »_ 80% ~ No. lost to evaluation~ Recurrence free (% ± SE) 0-1 924 1 40 100 _+ 0 1-3 883 2 30 99.9 ± 0.1 3-9 851 3 115 99.7 ± 0.2 9-12 733 4 24 99.3 ± 0.3 12-24 705 6 146 98.7 ± 0.4 24-36 553 6 117 97.8 -+ 0.5 36-48 430 2 112 96.6 ± 0.7 48-60 316 2 90 96.1 _+ 0.8 60-72 224 2 70 95.4 ± 0.9 72-84 152 3 35 94.4 ± 1,2 84-96 114 0 34 92.3 ± 1,7 96-108 80 1 23 92.3 ± 1,7 108-120 56 1 18 90.9 -+ 2,1 > 120 37 0 37 89.0 ± 2,8 ~In 28 patients. ?ßecause of death, loss to follow-up, infection, reoperation not caused by recurrence, or end of smdy. All recurrent stenoses were observed within 114 months, and all but five appeared within 73 months. At 5 years there were 26 hemodynamicaUy important recurrent stenoses (3.0%). Freedom from stenosis as determined by life-table analysis is shown in Fig. 2 and Table II. At last follow-up the probability of freedom from stenosis was 89%. There were two late strokes. One occurred in the patient who had a postoperative infection and replacement of the ePTFE patch with a vein patch. The stroke occurred on the ipsilateral side 5 years after surgery. The patient's condition stabilized with a 3% to 5% deficient in the upper limb on the side affected. The other stroke, also ipsilateral, occurred about 8 years after operation; the patient underwent reoperation and had a complete recovery by 6 months after the surgery. Throughout the series there were no late occlusions of the ePTFE patch graft and no late TIAs referable to the ipsilateral carotid artery territory and not included in the recurrent stenosis group. Before duplex scanning became available, angi- ography performed in patients with symptoms or recurrence on spectral analysis found no clinically important aneurysms. Duplex scanning has revealed some minor dilations in carotid bulbs, but none were considered to have clinical implications. DISCUSSION The publication of the North American Symp- tomatic Carotid Endarterectomy Trial, ~ the Asymp- tomatic Carotid Atherosclerosis Study, 2 and the American Heart Association's guidelines for carotid endarterectomy 4 have clarified the indications for carotid artery surgery and eliminated some of the controversy surrotmding the procedure. On the other hand, the debate on the value of primary approxi- mation versus patch angioplasty in preventing recur- rent carotid artery stenosis continues, especially because recurrence has been observed more fre- quently since noninvasive imaging techniques such as duplex scanning became widely available. Although only 20% to 25% of cases of recurrent stenosis will progress to manifestation of neurologic symptoms, the disorder remains an important cause of late morbidity and death.s Several studies have demonstrated that the use of a patch in carotid endarterectomy significantly lowers the rate of recurrent stenosis, s8 and the 2.4% incidence ofsevere recurrent stenosis ( _> 80%) in this series ofpatch angioplasties supports those results. In attempting to explain the antirestenosis effect of patches, Deriu et al. 9 speculated that enlarging the lumen retards the development of intimal lesions. Zierler et al. 10 theorized that a patch favorably affects hemodynamic flow by altering the geometric con- figuration and compliance of the carotid bulb. Increasing the circumference of the lumen may also play a part. Interestingly, a multicenter study comparing the incidence of recurrent stenosis after balloon angio- plasty and stent deployment in the coronary arteries found that the most accurate predictor of restenosis was the minimal lumen diameter immediately after the procedure, regardless of the type of intervention used. n It is theoretically possible that similar reste- nosis mechanisms are at work in the carotid artery system and that enlarging file arterial lumen with a patch may not prevent the development of intimal hyperplasia per se but may keep the vessel from narrowing to the point of becoming stenotic. ~2 Although patch angioplasty has been found to be
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`JOURNAL OF VASCULAR SURGERY Volume 22, Number 6 Rhodes 729 beneficial in preventing restenosis, many authors still consider it appropriate only in women, patients with a history of smoking, or patients with peripheral arterial insufficiency or small arteries.la'14 Ten Holter et al., e however, have reported that patching signifi- cantly reduced the incidence of restenosis in men and women. Once the decision to perform patch angioplasty has been made, the surgeon must decide whether to use a vein patch or a synthetic material. The most important disadvantage of saphenous vein patches is the irregularity of their mechanical integrity, which varies according to the site of harvest 14 and may pre- dispose them to aneurysmal dilation and disruption. In contrast, ePTFE has high tensile strength, 15,16 which may make it more resistant to the hemody- namic forces accompanying an increased lumen di- ameter and less likely to dilate or disrupt. This series of 924 cases had no clinically important aneurysmal dilations and no disruptions. A synthetic patch also offers the advantage of saving the saphenous vein for arterial reconstructions or bypass grafting that might subsequently become necessary. Another consideration in patching is the width of the material. Fietsam et a1.17 support primary closure or the use of a narrow patch that closely approximates the original arterial diameter because of their experi- mental data indicating that this produces less hemo- dynamic instability and flow separation and their belief that these factors contribute to restenosis. On the other hand, clinical studies have shown that primary closure appears to contribute to subsequent arterial narrowing. 5-7 It may be that an appropriately sized ePTFE patch placed over the carotid bulb causes the reversed flow to occur over the patch rather than the endarterectomized portion of the artery, thereby exposing the native vessel to fewer circulating platelets that could form aggregates and subsequent thrombosis and late stenosis. A narrow patch would not replace enough of the rough endarterectomized arterial surface with the less thrombogenic ePTFE surface to avoid such aggregation. In this series, all patches were sized to replace 50% or more of the endarterectomized wall of the artery. Operative needle hole or late postoperative bleed- ing has been reported with the use of ePTFE carotid artery patches) 8-2° These occurrences have generally been related to the use of needle/suture combinations in which the needle is larger in diameter than the suture, so that the suture does not completely fill the hole made in the patch by the needle. In other studies of the use of ePTFE in carotid endarterectomy, 13,2~ no bleeding problems have been observed. Reduc- tion of blood loss has been found to be associated with a needle/suture diameter ratio of 1:1, 22 and the ePTFE suture we use has such a ratio. Wc believe that the needle/suture combination we use, along with the routine use of a heparin reversal protocol, 23 contrib- uted to the absence of important operative and any late postoperative bleeding in this series. Although this series did not involve a randomized study of patching compared with primary approxi- mation or vcin patching versus synthetic patching, its consistently excellent results indicate that if the decision to perform patch angioplasty is made at surgery, ePTFE is an excellent alternative to autog- enous saphenous vein, with a low rate of recurrences that require reoperation, minimal aneurysmal dila- tion, and acceptable perioperative and postoperative morbidity and mortality rates. REFERENCES 1. North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis. NEngl J Med 1991;325:445-53. 2. Fisher M, Martin A, Cosgrove M, Norris IW. The NASCET- ACAS plaque project. Stroke 1993;24(suppl 12):I24-5. 3. Gee W. Carotid physiology with ocular pneumoplethysmog- raphy. Stroke 1982; 13:66673. 4. Moore WS. The American Heart Association consensus statement on guidelines for carotid endarterectomy. Semin Vasc Surg I995;8:77-81. 5. Archie Jp Jr. Prevention of early restenosis and thrombosis- occlusion after carotid endarterectomy by saphenous vein patch angioplasty. Stroke 1986;17:901-5. 6. Ten Holter IBM, Ackerstaff RGA, Thoe Schwartzenberg GWS, et al. The impact of vein patch angioplasty on long-term surgical outcome after carotid endarterectomy: a prospective follow-up study with serial duplex scanning. J Cardiovasc Surg 1990;31:58-65. 7. Karl D, Snyder SO, Gandhi RH, et al. Long-term follow-up for recurrent stenosis: a prospective randomized study of expanded polytetrafluoroethylene patch angioplasty versus primary closure after carotid endarterectomy. J Vasc SURe 1994;19:198-205. 8. Katz MM, Jones GT, Degenhardt J, Gunn B, Wilson J, Katz S. The use of patch angioplasty to alter the incidence of carotid restenosis following thromboendarterectomy. J Cardiovasc Surg 1987;28:2-8. 9. Deriu GP, Ballotta E, Bonavina L, et al. The rationale for patch-graft angioplasty after carotid endarterectomy: early and long-term follow-up. Stroke 1984;I5:972-9. 10. Zierler RE, Bandyk DF, Thiele BL, Strandness E Jr. Carotid artery stenosis following endarterectomy. Arch Surg 1982; 117:I408-I5. li. Fischman DL, Leon MB, Baim DS, et al. A randomized comparison of coronary-stent placement and balloon angio- plasty in the treatment of coronary artery disease. N Engl J Med 1994;331:496-501. 12. Ouriel K, Green RM. Clinical and technical factors influenc- ing recurrent carotid stenosis and occlusion after endarterec- tomy. J VASC SURG I987;5:702-6. 13. Rosenthal D, Archie JP Jr, Garcia-Rinaldi R, et al. Carotid
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`JOURNAL OF VASCULAR SURGERY 730 Rhodes December 1995 patch angioplasty: immediate and long-term results. J VASC SURG 1990; 12:326-33. 14. Archie JP, Green JJ Jr. Saphenous vein rupture pressure, rupmre stress, and carotid endarterectomy vein patch recon- struction. Surgery 1990;107:389-96. 15. KowligiRR, TaylorHH, Wollner SA. Physicalproperties and testing methods for PTFE cardiovascular patches. J Biomater Appl 1993;7:353-61. 16. Donovan DL, Schmidt SP, Townshend SP, Njus GO, Sharp WV. Material and structural characterization of human saphenous vein. J VASC SURG 1990;12:623-6. 17. Fietsam R, Ranval T, Cohn S, Brown OW, Bendick P, Glover IL. Hemodynamic effects of primary closure versus patch angioplasty of the carotid artery. Ann Vasc Surg 1992;6: 443-9. 18. LeGrand DR, Linehan RL. The suitability ofexpanded PTFE for carotid patch angioplasty. Ann Vasc Surg 1990;4:209-12. 19. Carney WI, Lilly MP. Intraoperative evaluation of PTFE, Dacron, and autogenous vein as carotid patch materials. Ann Vasc Surg 1987;1:583-6. 20. McCready RA, Siderys H, Pittman JN, et al. Delayed postoperative bleeding from polytetrafluoroethylene carotid artery patches. J VASC SUr, G 1992;15:661-3. 21. Lord RSA, Raj TB, Stary DL, Nash PA, Graham AR, Goh KH. Comparison of saphenous rein patch, polytetrafluoro- ethylene patch, and direct arteriotomy closure after carotid endarterectomy-part 1: perioperative results. J VASC SURG 1989;9:521-9. 22. Miller CM, Sangiolo P, Jacobson JH II. Reduced anastomotic bleeding using new sumres with a needle-suture diameter of one. Surgery 1987;101:156-60. 23. Treiman KL, Cossman DV, Foran RF, Levin PM, Cohen JL, Wagner WH. The influence of neutralizing heparin after carotid endarterectomy on postoperative stroke and wound hematoma. J VAsc SURG 1990;12:440-6. Submitted May 11, 1995; accepted Aug. 29, 1995. DISCUSSION Dr. Harry L. Bush, Jr. (New York, N.Y.). Dr. Rhodes has reported an operative mortality rate of approximately 0.6% and a perioperative stroke rate of less than 1%, both of which are clearly significantly lower than the kind of outcomes that have been suggested by numerous national and interdisciplinary groups in terms of carotid artery surgery. Obviously this experience goes back a way and spans the time interval that most of these controversies were being raised across the country. Certainly these excellent results demonstrate the safety and durability of the operation when the patients are properly selected and the surgery is performed expertly. It's a personal decision whether to patch or use primary closure, and, for many people, selective use of the patch where you have a difficult end point or a small internal carotid artery or an unusually long endarterectomy is certainly a clear indication for some people to use the selective approach to patch angioplasty. It's not clear in terms of national experience that there has been a clear benefit shown to use a routine patch, and this is obviously a decision that most of us have to make on the basis of our own experience and the environment that we work in. Have you ever considered taking a more selective approach and foregoing what for you has been an excellent technique? Has the extra time that it takes to do the sumring for the pätch or the extra time required for use of the shunt ever made you reconsider the possibility of selectively using the patch and therefore the shunt? Once a decision has been made to patch, the hext question obviously is what material to use for the patch angioplasty, and you'll find advocates for the use of the proximal or distal portion of the greater saphenous rein, for use of cervical veins, and for use of Dacron and PTFE. I find that use of the spatulated portion of the external jugular rein provides a very durable material for this, although this would be at best controversial. However, most of the questions come to mind about the use of the prosthetic material. One of the complications for which you've evolved your technique relates to bleeding. People have reported both early and late bleeding complications, and you seem to have had an appropriate level for both ofthose. How did you evolve your difference in the use of suture material in relation to needle hole bleeding? What material are you using for your patch, are you using the 0.4 or 0.6 cardiovascular patch, or are you taking an existing graft that has a thicker wall and has been shown to have less difficulty with the needle hole bleeding? Conversely, it's also harder to ger the sutures to go through it. I gather there was really no incidence of acute thrombosis in this group of patients, or at least that couldn't be identified immediately and rectified at that time. Now, one of the other things that comes to mind is that one of the reasons that people advocate use of the patch is to decrease reoperations. Do you believe that your need for reoperation in these patients could be related to the routine use of the patch material? Is there anything about the healing of this kind of patch that increases the risk for thromboembolic or recurrent disease? Dr. Valentine J. Rhodes. The decision whether to patch is an individual one. For me it has worked. I perform patch angioplasty on all of my patients because Fm more comfortable with it. In the very early days (1969 to 1976), I performed straight endarterectomies followed by vein patching fol- lowed by Dacron, but Dacron in those days was a little different than Dacron today, and I wasn't happy with it. It's
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`JOURNAL OF VASCULAR SURGERY Volume 22, Number 6 Rhodes 731 true when I used to cut up the old grafts I didn't have any bleeding problem regardless of the kind of suture I used, bnt I've been using the 0.4 cardiovascular carotid artery patches since they first came out. That's when I had to use the 6-0 one on a TF9 needle. I noticed that if I even used a PT9, which is the cutting tip needle, that there was too much bleeding from the suture holes to satisfy me, and if I used polypropylene there was excessive bleeding from the suture holes. And that's when I checked and found that there is a discrepancy in the diameter of the sumre versus the needle with polypropylene and some of the other sutures. And when I looked at the literature, I noticed that most of the people who were commenting on excessive bleeding from the needle holes were using much larger needles. One example was the use of a TH13 piercing tip needle, which is the cutting edge on a 7-0 sumre. This needle diameter is significantly larger than that of the suture and there were probably a series of fountains of blood. And it's true, the cardiovascular patch is much less forgiving as rar as bleeding from the suture holes than a vein would be or a straight endarterectomy, of conrse. I can't comment on Dacron because I have no experience with modern Dacron used as a patch on a carotid artery. In my experience, the patch gave me better results, so that's why I've stayed with it. I had three incidents of acute thromboses. In one situation, the patient woke up and was fine. While the patient was being transferred to the stretcher, weakness in the arm started to develop. I immediately had the patient reanesthetized. The patient was still intubated. I performed a thrombectomy, and that patient had no neurologic deficit. The other two incidents occurred in the recovery room in the days before I started resecting kinks. These are listed under the acute strokes, and what I found was that the patch made the artery stift, and with the systolic thrust the artery was driven forward against the kink and thrombosed. I believe that was the cause, and that's what started me resecting aH kinks. I don't know whether that's a valid assumption, but that's when I started resecting all the kinks. There have been no acute thromboses in the last 380. The 5-year recurrence rate was 1.6% in the total group. Now most of the series are talking about 5-year recurrence rates. When I continued the follow-up beyond 5 years, I started seeing the atherosclerotic recurrences and they're calculated in the graft. But the recurrence rate at the first 5 years was 1.6%. Dr. Robert W. Hobson II (Newark, N.J.). Some surgeons advocate the use of autologous patch material. I want to ask Dr. Dardik to comment on his advocacy for autologous patches from cervical veins. Does choice of synthetic versus autologous patches make a difference in the final analysis? Dr. Herbert Dardik (Englewood, NJ.). We are in the midst ofa comparative study that includes cervical and saphenous veins, infrequently prosthetic