Carotid patch angioplasty: Immediate and long-term results

Carotid patch angioplasty: long-term results

Immediate and

David Rosenthal, MD, Joseph P. Archie, Jr., MD,* Raul Garcia-Rinaldi, MD, ** M. Annette Seagraves, MD, David R. Baird, MD, James F. McKinsey, MD, Pano A. Lamis, MD, Michael D. Clark, MD, Luke S. Erdoes, MD, Travis Whitehead, BS, and L. Laszlo PaUos, PhD,*** Atlanta, Ga., Raleigh, N.C., and Houston, Texas

To determine the benefit of carotid patch angioplasty, a retrospective study of 1000 consecutive carotid endarterectomies was done. Based on the type of carotid endarterectomy closure, patients were divided into four groups: 250 had primary closure, 250 had expanded polytetrafluoroethylene patch, 250 had Dacron patch, and 250 had saphenous vein patch. On the basis of operative technique or type of carotid artery closure, no statistical difference was found in the incidence of postoperative stroke (p > 0.25): primary closure 1.6% (4), expanded polytetrafluoroethylene 2.0% (5), Dacron patch 1.6% (4), and saphenous vein patch (0). Postoperative carotid patency was determined by B- mode ultrasonography, and 717 patients were evaluated in follow-up extending to 6 years (mean 37.8 months). Based on the method of carotid endarterectomy closure, no.significant difference (p > 0.25) was found in the incidence of significant restenosis (>50% diameter reduction): primary closure 4.0% (7), expanded polytetrafluoroethylene 4.0% (6), Dacron 5.4% (9), and saphenous vein 1.0% (2). Significant restenosis was most frequent in habitual smokers (93%, 25/28) and females (78%, 22/28) despite the method of carotid endarterectomy closure. No statistical difference was found in the incidence of late ipsilateral stroke either (do > 0.25): primary closure 2.9% (5), expanded polytetrafluoroethylene 2% (3), Dacron 5% (3), and saphenous vein 0%. These results indicate that the incidence of postoperative stroke, regardless of method of arterial closure, was not statistically different. The method of carotid closure did not appear to affect the occurrence of late ipsilateral stroke or restenosis; however, patch angioplasty with saphenous vein appears appropriate in habitual smokers, and likely in patients with small internal carotid arteries. (J VASC SURG 1990;12:326-33.)

Controversy continues to surround the benefit of carotid patch angioplasty at the time of carotid endarterectomy (CEA). Its advocates claim a reduced incidence of both perioperative neurologic deficits and late restenosis with various patch materials. But excellent clinical results have also been reported with primary carotid artery closure.

To determine the value of carotid patch angioplasty in (1) reducing the incidence of perioperative stroke, (2) reducing the occurrence of late ipsilateral stroke, and (3) preventing the occurrence of restenosis, a multicenter retrospective study of 1000 consecutive CEAs was conducted.

From Georgia Baptist Medical Center, Atlanta, Ga., Wake Medical Center, Raleigh, NC, ~ West Houston Medical Center, Hous- ton, Texas, ~ Department of Management, Georgia State Uni- versity, Atlanta, Ga. **~

Presented at the Fourteenth Annual Meeting of the Southern Association for Vasollar Surgery, Acapulco, Mexico, Jan. 24- 27, 1990.

Reprint requests: David Rosenthal, MD, 315 Boulevard N.E., Suite 412, Atlanta, GA 30312.

24/6/22760

326

MATERIAL AND ME T H O D S

A multicenter retrospective review of 1000 consecutive CEAs from 1982 through 1988 was per, formed. The centers consisted of Wake Medical Cen- ter, Raleigh, N.C., West Houston Medical Center, Houston, Texas, and Georgia Baptist Medical Cen- ter, Atlanta, Ga. The study was performed by having four surgeons (D.R., J.P.A., R.G.R., P.A.L.) sub- mit their last 250 consecutive CEAs for review. Eight hundred forty-nine patients underwent 1000 CEAs: 250 endarterectomies were performed with saphenous vein patch angioplasty (CEA/SV), 250 with expanded polytetrafluoroethylene patch angioplasty (CEA/e-PTFE), (W. L. Gore and Associates, Elkton, Md.), 250 with Dacron patch angioplasty (CEA/D) (Bard Cardiovascular, Billerica, Mass.) and 250 with primary closure (CEA/PC). Because patient selection was nonrandomized, all statistical conclusions must be guarded. Indications for operation included hemispheric transient ischemic attacks (TIAs) (338 patients), amaurosis fugax (129 pa-

Volume 12 Number 3 September 1990 Carotid patch angioplasty 327

I - Z I l l 0 E I&l a,

80.4------

40.4------

20,4-------

0

lib CE/SV m CE/PTFE

OE/PO

- i R - l - - i ~ 4 i H H a

i mi CAHD HT DM SMOKING

Fig. 1. Patient profile risk factors, CAHD, coronary artery heart disease; HT, hypertension; DM, diabetes mellims; CE/SV, carotid endarterectomy/saphenous vein; CE/PTFE, carotid endarterectomy/polytetrafluoroethylene patch; CE/D, carotid endarterectomy/Dacron patch; CE/PC, carotid endarterectomy/primary closure.

tients), symptoms of vertebrobasilar insufficiency (244 patients), reversible ischemic neurologic deficit (RIND) or stroke (138 patients), and asymptomatic arteriographic high-grade stenosis (>75%) (151 patients).

The patient profile risk factors were similar among the four operated groups (Fig. 1). Six hundred forty-four patients were men. The mean age was 43 years (range 39 to 88 years). A history consistent with coronary artery heart disease was present in 568 patients, hypertension was present in 424 patients, and 108 patients had diabetes mellitus. Six hundred

. fifty-six patients had a history of cigarette smoking. Nine hundred sixty-seven patients underwent four- vessel arch arteriography with visualization of the extracranial and intracranial circulation; the remain- ing patients had digital intravenous subtraction arteriography.

General endotracheal anesthesia was used in all but five operations, which were done with local an- esthetic. Patients in the e-PTFE and Dacron groups underwent CEA with a routine shunt. Twenty-eight (11%) patients in the CEA/SV group had shunts placed selectively based on the collateral cerebral perfusion pressure method in which a shunt was used when the pressure was less than 18 mm Hg, s and 17 (7%) patients in the CEA/PC group had shunt

Table I. Postoperative neurologic deficits

Carotid endarterectomy Transient Permanent (n = looo)* % (~s) % (13)

CEA/PC (250) 2.0 (5) 1.6 (4) CEA/e-PTFE (250) 1.6 (4) 2.0 (5) CEA/D (250) 1.6 (4) 1.6 (4) CEA/SV (250) 0.8 (2) 0 (0)

CEA/PC, Carotid cndarterectomy/primary closure; CEA/e- PTFE, expanded polytetrafluoroethylene patch; CEA/D, Dacron patch; CEA/SV, saphcnous vein patch. ~Nurnber of cases is in parentheses (p > 0.25)

placement for evidence of electroencephalographic ischemia.

All patients were evaluated clinically in the immediate postoperative period (30 days); long-term follow-up of these patients ranged from 6 months to 6 years (mean _+ SD 33, 37.8 months; median 26 months; range 72 months). One hundred thirty-two patients were lost to long-term follow-up. Long-term (>30 days) carotid patency was evaluated by spectral analysis and real time B-mode ultrasonography in 717 patients (Georgia Baptist Medical Center: John- son & Johnson Autosector V, Johnson & Johnson Ultrasound Inc., Ramsey, New Jersey; West Hous- ton Medical Center: Diasonics DRF 400, Diasonics Inc., Millpitas, California; Wake Medical Center:

328 Rosenthal et al.

Table II. Indication for operation and postoperative deficit

Journal of VASCULAR

SURGERY

Transient (15) Permanent (13) Indication for

operation CEA/PC CEA/ePTFE CEA/D CEA/SV CEA/PC CEA/ePTFE CEA/D CEA/SV

TIA 2 2 2 2 2 2 AF 1 VBI 2 1 1 2 1 2 1 Post RIND/CVA 1 1 1 1 1 Asx

AF, Amaurosis fugax; VBI, vertebrobasilar insufficiency; RIND, reversible ischemic neurologic deficits; CVA, cerebrovascular accident; ASX, asymptomatic high grade stenosis (>75%)

Table HI. Incidence of carotid restenosis (76)

Significant Insignificant restenosis (>50%) restenosis Female Smoker

CEA (n = 717) % (24) % (52) % (63) % (72)

CEA/PC (172) ~ 4.0 (7) 7.6 (13) 73 (19/26) 77 (26/26) CEA/ePTFE (149) 4.0 (6) 8.1 (12) 70 (14/20) 100 (20/20) CEA/D (166) 5.4 (9) 10.2 (17) 75 (21/28) 75 (21/28) CEA/SV (230) 1.0 (2) 4.3 (10) 75 (9/12) 92 (11/12)

~Numbers of cases are in parentheses. (p > 0.25)

Table IV. Recurrent stenosis after CEA/SV

Hemodynamically significant Hemodynamically insignificant

Interval Interval Interval A t No. of recurrence recurrence Recurrence No. of recurrence Recurrence (mo) ~ r isk Withdrawn in interval (%) free (%) recurrence (%) free (%)

0-12 230 37 0 0 100 1 0.4 99.6 12-24 193 48 0 0 100 3 1.7 97.9 24-36 119 74 1 1.2 98.8 2 2.4 95.5 36-48 64 55 0 0 98.8 2 5.4 90.1 48-60 50 14 1 2.3 96.5 2 4.7 85.4

~Interval is up to but does not include the second figure.

ATL Ultramark 8, Advanced Technologies Labora- tories, Bothell, Washington). Frequencies above 5 KHz with spectral broadening throughout sys- tole and increased diastolic frequency were consid- ered consistent with a hemodynamicaUy significant restenosis (>50% diameter reduction)) During follow-up, arteriography was performed when a hemodynamically significant restenosis was identified. Eighty-four percent (717) of patients were available for long-term follow-up. Statistical analysis was performed by chi-square analysis, Student's t test and life-table method where appropriate.

RESULTS

Nine patients (1%) died within the immediate (< 30 days) postoperative period. Five of these deaths were due to perioperative myocardial infarction. Two occurred in patients who suffered strokes in the post-

operative period and died of stroke-related causes (pneumonia, multisystem failure); one resulted from an e-PTFE patched artery disruption, subsequent" stroke, and progressive multisystem failure; and an- other occurred in a hypertensive patient who sus- tained an ipsilateral intracranial hemorrhage on the third postoperative day.

Thirteen (1.3%) postoperative strokes and 15 (1.5%) transient (TIA/RIND) neurologic postop-' erative deficits occurred (Table I). Nine of the postoperative strokes were thromboembolic in origin and were documented at emergency reoperation. These CEA sites were thrombosed because of technical error in six cases: intimal flaps were identified in four patients (2 CEA/PC, 2 CEA/D), whereas a" lateral tear (CEA/PC) and a "clamp injury" site (CEA/D) accounted for the two other strokes. Thre~. other postoperative strokes were due to intracranial


Table V. Recurrent stenosis after CEA/ePTFE

Hemodynamically significant

Interval Interval A t No. of recurrence recurrence

(mo) r isk Withdrawn in interval (%)

Hemodysamically insignificant

Interval Recurrence No. of recurrence Recurrence free (%) recurrence (%) free (%)

0-12 149 55 2 0.2 12-24 94 38 0 0 24-36 56 I8 1 2.0 36-48 38 7 1 2.8 48-60 31 12 2 8.0 60-72 19 4 0 0

98.4 2 1.6 98.4 98.4 2 2.6 95.8 96.4 3 6.3 89.5 93.6 3 8.8 80.7 85.6 1 4.0 76.7 85.6 1 5.9 70.8

Table VI. Recurrent stenosis after CEA/PC



(too) r isk Withdrawn in interval (%)

Hemodynamically insignificant


0-12 173 36 1 0.6 I2-24 137 31 1 0.8 24-36 106 31 0 0 36-48 75 16 2 2.9 48-60 59 18 3 6.0 60-72 41 3 0 0

99.4 0 0 100 99.3 2 1.6 99.4 99.3 8 8.0 9L4 96.4 0 0 91.4 90.4 3 6.0 85.4 90.4 0 0 85.4

Table VII. Recurrent stenosis after CEA/D



(mo) r isk Withdrawn in interval (%)

Hemodynamically insignificant


0-12 166 46 3 2.1 12-24 120 29 2 1.9 24-36 91 18 1 1.2 36-48 73 11 i 1.5 48-60 62 7 2 3.4 69-72 55 18 0 0

97.9 5 3.5 96.5 96 6 5.7 90.8 94.8 2 2.4 88.4 93.3 4 6.0 82.4 89.9 0 0 82.4 89.9 0 0 82.4

embolic "showers," which were verified with arteriography at repeat operation (2 CEA/e-PTFE, 1 CEA/D). Two strokes (CEA/e-PTFE) resulted from unknown causes. One stroke occurred after sponta- neous disruption of an e-PTFE patched artery and the last postoperative stroke occurred 3 days after CEA/PC when a markedly hypertensive patient suffered an ipsilateral intracranial hemorrhage and ul- timately died.

The incidence of postoperative neurologic complications was evaluated on the basis of indication for operation (Table II). Most neurologic deficits occurred in patients who underwent CEA for TIAs, regardless of the method of artery closure, but this was not statistically significant (p > 0.25).

The four-vessel arch arteriograms of patients who experienced a postoperative neurologic defidt were

reviewed. Of the 15 patients who experienced transient postoperative deficits, 11 had ulcerated plaque disease, as had five of 13 patients who had a postoperative stroke. Only one patient with a postoperative deficit had a contralateral occlusion. Six had severe (>75% stenosis) contralateral carotid occlusive disease, whereas intracranial occlusive disease (stenosis at the siphon or stenoses within the Circle of Willis) was noted in nine patients with postoperative deficits.

Postoperative carotid disruption occurred in two patients, one in the CEA/e-PTFE group (0.4%) and one in the CEA/SV group (014%); this patient suffered a RIND. No carotid disruptions occurred in the CEA/D or CEA/PC group.

On the basis of 717 routine serial noninvasive examinations extending to 6 years (mean 37.8

330 Rosenthal et aL

Journal of VASCULAR

SURGERY

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,,=, ,,=

95

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ua 85 0 n.. , , , .~ t'h ,~

230 193

• CE/SV \ 62 55 • CE/e PTFE \ • CE/PC _. • CE/D ~ 19

O 0 I I I I I I 12 24 36 48 60 72

MONTHS

Fig. 2. Cumulative incidence of hemodynamically significant restenosis after carotid endarterectomy. PC, primary closure; 1), Dacron; SV, saphenous vein; CE/SV, carotid endarterectomy/saphenous vein; CE/PTFE, carotid endarterectomy/polytetrafluoroethylene patch; CE/D, carotid endarterectorny/Dacron patch; CE/PC, carotid endarterectomy/primary closure.

months), 76 (11%) of the arteries had evidence of restenosis at the date of last follow-up, yet only four of these patients (0.5%) were symptomatic: 24 (3%) had hemodynamically significant and 52 (76) hemodynamically insignificant restenosis (Table III). Of the 86 patients who developed restcnosis, 63 (73%) were women and 72 (83%) were smokers who continued to smoke after CEA (Table III). The presence of hypertension, diabetes mellitus, or coronary arteriosclerotic heart disease did not adversely affect late carotid patency. No statistical difference was :found between groups in the incidence of significant or insignificant restenosis (>0.25)(Tables IV through VII, Fig. 2).

In follow-up, 98% (704/717) of the patients available for evaluation remained stroke-free (Table VIII). Thirteen strokes occurred on the same side as previous CEA: five (2.9%) in the CEA/PC group, three (2%) CEA/e-PTFE, five (3%) CEA/D, and none in the CEA/SV group. This, however, was not statistically significant (p > 0.25) (Tables IX through XII, Fig. 3). Among these 13 patients, only two strokes occurred in patients with recurrent stenotic disease (1 CEA/D, 1 CEA/PC). Both patients had arteriography, which demonstrated macroexcavated

plaque with an approximate 75% stenosis. The patient who had a primary closure at initial CEA ul- timately underwent a "redo" procedure with vein patch angioplasty, and the other patient refused operation.

DISCUSSION

Carotid endarterectomy is the most common peripheral vascular operation performed in the United States today, yet there is no consensus among surgeons regarding the role and benefit of carotid patch angioplasty at the time of endarterectomy. In this review, the incidence of postoperative stroke was statistically similar, regardless of the method of carotid closure at endarterectomy. All patients in the study had some form of "cerebral protection" during CEA: mandatory shunt, collateral cerebral perfusion pressures or electroencephalographic surveillance. Therefore inadequate cerebral blood f low during CEA could not be named as the principal cause of a postoperative neurologic deficit. I f patch angioplasty is used to close the artery, the use of a shunt should be mandatory when no other means of cerebral protection is being used, because patch angioplasty takes more time than primary closure. This precaution pre-

Volume ]̀ 2 Number 3 September ].990 Carotid patch angioplasty 331

,=,, E uJ

1 0 0 230 173 193 137 119 106 64 50

95

IZ:

• CE/SV v-. " CE/e PTFE z 90 m ¢ CE/PC O • CE/D LU

59 91 ~ 73 62"~ 55

38 31 \ 19

41

O0 I i I I I

12 24 36 48 60 72

MONTHS

Fig. 3. Cumulative ipsilateral stroke free rate after carotid endarterectomy. PC, primary closure; D, Dacron; SV, saphenous vein; CE/SV, carotid endarterectomy/saphenous vein; CE/PTFE, carotid endarterectomy/polytetrafluoroethylene patch; CE/D; carotid endarterectomy/Dacron patch; CE/PC, carotid endarterectomy/primary closure.

vents any potential challenge from prolonged ischemia. Technical errors that cause carotid thrombosis and cerebral emboli seems to account for most neurologic deficits after CEA. The method of carotid closure, or the material used, does not appear to be as important as the technical abilities and judgment ~of the surgeon in an operation where perfection is *he only acceptable standard.

It was of interest to note the low incidence of ipsilateral stroke in late follow-up (13 patients), despite the presence of restenosis documented by B- mode ultrasonography (76 patients). This observa- t ion has been reported by others and may be related to the gradual development of collateral vessels around a slowly developing stenotic carotid lesion and the understanding that embolization from ma- croulcerated plaque is probably more important than stenosis in causing neurologic symptoms, ls In this study all asymptomatic (82 patients)recurrent stenotic plaques were weakly echoreflective and ho- mogeneous, suggestive of a high lipid content without evidence of plaque hemorrhage, whereas symptomatic recurrent stenotic plaques (4 patients) showed echo characteristics consistent with plaque hemorrhage and/or intraluminal debris. The low incidence of symptomatic restenosis (0.5%) indicates

Table VIII. Incidence of late ipsilateral stroke

(n = 7]7) % (13)

CEA/PC (172) 2.9 (5) CEA/ePFTE (149) 2 (3) CEA/D (166) 3 (5) CEA/SV (230) (0)

Number of cases in parentheses. (p > 0.2S)

that a conservative course of action (i.e., serial du- plex scanning) may be appropriate, especially when smooth, homogenous plaque is identified, because "redo" carotid surgery is extremely hazardous.

Not surprisingly, the incidence of restenosis among women was nearly four times higher than for men. Restenosis may be potentiated in women by a hormonal mcchanism and / or increased level of platelet activity and arteries that are inherently smaller in caliber. 4 In Several studies restenoses in women were reportedly caused by myointimal hyperplasiaS,6; however, we could not verify this cause among our patients.

There are obvious difficulties in trying to compare a series of patients from different institutions, with

332 Rosenthal et al.

Journal of VASCULAR

SURGERY

Table IX. Late ipsilateral stroke after CEA/SV

Cumulative Interval* No. of strokes Interval stroke free rate

(too) A t risk Withdrawn in interval rate (%) (%)

0-12 230 37 0 0 100 12-24 193 48 0 0 100 24-36 1199 74 00 0 100 36-48 64 55 0 0 100 48-60 50 14 0 0 100

*Interval is up to but does not include the second figure.

Table X. Late ipsilateral stroke after CEA/ePTFE


(mo) A t risk Withdrawn in interval rate (%) (%)

0-12 149 55 1 .8 99.2 12-24 94 38 0 0 99.2 24-36 56 18 0 0 99.2 36-48 38 7 2 5.7 93.5 48-60 31 12 0 0 93.5 60-72 19 4 0 0 93.5

Table XI. Late ipsilateral stroke after CEA/PC


(too) A t risk Withdrawn in interval rate (%) (%)

0-12 173 36 0 0 100 12-24 137 31 0 0 100 24-36 106 31 0 0 100 36-48 75 16 2 3.0 97.0 48-60 59 18 1 2.0 95.0 69-72 41 3 2 5.1 89.9

Table XII. Late ipsilateral stroke after CEA/D


(mo) A t risk Withdrawn in interval rate (%) (%)

0-12 166 46 1 .7 99.3 12-24 120 29 1 .9 98.4 24-36 91 18 2 2.7 95.7 36-48 73 11 1 1.4 94.3 48-60 62 7 0 0 94.3 60-72 55 18 0 0 94.3

no reliable way of equating differences in indications for operation, variations in population base, and sur- gical expertise. Nevertheless, aware of these potential variables we undertook this review to evaluate a large series of patients, operated on by experienced surgeons, to see if carotid patch angioplasty with various patch materials was superior to primary closure in

preventing postoperative stroke, late ipsilatera[ stroke, and restenosis. Our results indicate that postoperative neurologic complications, regardless of method of arterial closure, were not statistically different, and that technical errors that cause throm- boemboli seem to account for most postoperative deficits after CEA. The method of carotid closure"


does not appear to affect the occurrence o f late ip- ~silateral stroke, and although patch angioplasty was not statistically superior to primary closure in preventing restenosis, it appears to be appropriate in habitual smokers and patients with small internal carotid arteries, most o f w h o m are women, where the chances o f restenosis seem highest. We could not

~determine the best patch material, but in patients with peripheral arterial insufficiency, where concerns about wound healing or the potential need for an in situ saphenous vein graft are present, a prosthetic patch seems advisable. With its low thrombogenicity, 79 infection resistance, 1°-12 and lack o f dilation, 8 'e-PTFE may become the most appropriate prosthetic material for carotid patch angioplasty. This, however, was not documented by our report and needs further evaluation.

Ongoing studies may determine the clinical sig- nificance o f rcstenosis after CEA since most reste-

,-nosed carotid artcries do not cause neurologic symptoms. As noninvasive diagnostic techniques continue to cvolvc, the natural history o f the carotid artery after endartercctomy will be better understood, and the most appropriate and durable method o f carotid artery closure can be tailored to each patient. Until randomized trials answer these questions, a techni-

•cally perfect operation appears to be the surest means of rcducing thc incidencc o f perioperativc stroke, late ipsilateral stroke, and restenosis.

REFERENCES 1. O'Donnell TF, Callone AD, Scott G, et al. Ultrasound char-

acteristics of recurrent carotid disease: hypothesis explaining the low incidence of symptomatic recurrence. J VASC SURG 1985;2:26-41.

2. Piepgras DG, Sundt TM, Marsh RW, et al. Recurrent carotid stenosis. Ann Surg 1986;203:205-13.

3. DeGroute DR, Lynch TJ, Jamil Z, Hobson RW. Carotid restenosis: long-term noninvasive follow-up after carotid endarterectomy. Stroke 1987;18:1031-6.

4. Thomas M, Otis SM, Rush M, et al. Recurrent carotid artery stenosis follow endarterectomy. Ann Surg 1984;200:74-8.

5. Claggett GP, Rich NM, McDonald PT, et al. Etiologic factors for recurrent carotid artery stenosis. Surgery 1983;93: 313-8.

6. Cossman D, Callow AD, Stein A, Matsmoto G. Early restcnosis after carotid endarterectomy. Arch Surg 1978;113: 275-8.

7. Wolf P, Grimley R. In vitro thrombogenicity test of materials in arterial prostheses. Hemostasis 1984;13:113-8.

8. Callow AD, ConnoUy R, O'Dormell TF, et al. Platelet-arterial synthetic graft interaction and its modification. Arch Surg 1982;117:1447-55.

9. Shoenfeld NA, Connolly R, Ramberg K, et al. The systemic activation by Dacron grafts. Surg Gynecol Obstet 1988; 166:454-7.

10. Yeager RA. Aortic and peripheral prosthetic graft infection: differential management and causes of mortality. Am J Surg 1985;150:36-43.

11. Schmitt DD, Brandyk OF, Peguct AJ, Towne JB. Bacterial adherence to vascular prostheses. J VAsc SUV, G 1986;3:732- 40.

12. Rosenman JE, Pearce WH, Kempczinski RF. Bacterial adherence to vascular grafts after in vitro bacteremia. J Surg Res 1985;38:648-55.

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Carotid patch angioplasty: Immediate and long-term results