Incidence Of Recurrent Stenosis Research Articles

Article Commentary: Late Outcomes of Carotid Artery Stenting: A Critical Review

The role of carotid artery stenting (CAS) as an alternative to carotid endarterectomy for the treatment of extracranial carotid occlusive disease for stroke prevention continues to evolve. Although technical and device refinements aimed at making CAS safer continue to this day, safety as measured by 30-day and 1-year outcomes has been the primary recipient of regulatory and practice attention. Relatively less emphasis has been placed on the incidence of recurrent stenosis after CAS and the efficacy of CAS in late stroke prevention. Data on late outcomes of CAS, including factors of potential influence, have been emerging and are addressed in this review.

頸動脈ステント留置術 頸動脈ステント留置術後の長期予後

Between January 2004 and December 2009, we performed carotid artery stenting (CAS) for 220 sides. Among them, we evaluated 142 sides of 136 cases at follow-up ＞1 year, and studied the long-term occurrence of recurrent stenosis (＞50% by ultrasound or angiography), ipsilateral ischemic stroke, unstable angina pectoris (u-AP) or acute myocardial infarction (AMI), and death. Over a median follow-up period of 36.6 months, the incidence of recurrent stenosis was 8.5% (12 sides), with only 1 side leading to neurological symptoms. Among them, 6 sides of recurrent stenosis occurred in the first 12 months after CAS. This suggests recurrent stenosis is caused by intima hyperplasia rather than by progressive atherosclerosis. Ipsilateral ischemic strokes occurred in 2.8% (4 sides), but only 1 side derived from carotid stenosis after stenting. U-AP and AMI occurred in 4.2% (6 cases) after CAS. Twelve cases resulted in death, though no death was caused by carotid stenosis or ischemic stroke. Stenting for carotid stenosis is an effective treatment to prevent stroke over long terms. Recurrent stenosis after CAS occurs more frequently than previous reports indicate. We should be aware of coronary disease events.

Results of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) study to treat symptomatic stenoses at 2 years: a multinational, prospective, randomised trial

The SPACE trial is a multinational, prospective, randomised study to test the hypothesis that carotid artery stenting is not inferior to carotid endarterectomy for treating patients with severe symptomatic carotid artery stenosis. We did not prove non-inferiority of carotid artery stenting compared with carotid endarterectomy for the 30-day complication rate, and we now report the results at 2 years. Between March, 2001, and February, 2006, patients with symptomatic, severe (>or=70%) carotid artery stenosis were recruited to this non-inferiority trial and randomly assigned with a block randomisation design to have carotid artery angioplasty with stenting or carotid artery endarterectomy. 2-year endpoints include several clinical endpoints and the incidence of recurrent carotid stenosis of at least 70%. Clinical and vascular follow-up was done by a certified neurologist. Analyses were by intention to treat and per protocol. This trial is registered with ISRCTN, number 57874028.12. 1 214 patients were randomly assigned (613 were randomly assigned to carotid angioplasty with stenting and 601 were randomly assigned to carotid endarterectomy). In both the intention-to-treat and per-protocol analyses the Kaplan-Meier estimates of ipsilateral ischaemic strokes up to 2 years after the procedure and any periprocedural stroke or death do not differ between the carotid artery stenting and the carotid endarterectomy groups (intention to treat 9.5%vs 8.8%; hazard ratio (HR) 1.10, 95%CI 0.75 to 1.61; log-rank p=0.62; per protocol 9.4%vs 7.8%; HR 1.23, 95%CI 0.82 to 1.83; log-rank p=0.31). In both the intention-to-treat and per-protocol populations, recurrent stenosis of 70% or more is significantly more frequent in the carotid artery stenting group compared with the carotid endarterectomy group, with a life-table estimate of 10.7% versus 4.6% (p=0.0009) and 11.1% versus 4.6% (p=0.0007), respectively. Only two incidences of recurrent stenoses after carotid artery stenting led to neurological symptoms. After 2 years' follow-up, the rate of recurrent ipsilateral ischaemic strokes reported in the SPACE trial is similar for both treatment groups. The incidence of recurrent carotid stenosis at 2 years, as defined by ultrasound, is significantly higher after carotid artery stenting. However, it cannot be excluded that the degree of in-stent stenosis is slightly overestimated by conventional ultrasound criteria.

Carotid Endarterectomy with Bovine Pericardium Patch Angioplasty: Mid-Term Results

The objective of this study was to assess the efficacy of bovine pericardium (BP) as a patch material in carotid endarterectomy (CEA) in terms of peri- and postoperative complications and the incidence of recurrent stenosis. During a 4-year period, 148 CEAs were performed in 138 consecutive patients. The study group included elective, emergency, and combined with cardiac operation CEAs in both symptomatic and asymptomatic carotid artery disease patients. Patch angioplasty using the BP followed the standard CEA in all patients. Postoperative follow-up included clinical examination and periodical color duplex scans at 3, 6, and 12 months and yearly thereafter. Surgical outcome was evaluated by the operation-related parameters, early and late mortality and morbidity rates, and the incidence of recurrent stenosis. All CEAs were performed without any unfavorable event. In the early postoperative period, there were no deaths and the morbidity consisted of transient cranial nerve paresis (4.7%) in seven patients and two ipsilateral strokes (1.4%). During the follow-up period, three patients (2%) developed significant carotid restenosis, though they remain asymptomatic, while there were no deaths related to the CEA. Patch angioplasty of the carotid artery using BP showed unwittingly early and mid-term surgical outcome. Our results demonstrate the BP to be a suitable patch material for routine use in carotid surgery.

Synthetic patch angioplasty proves useful in carotid endarterectomy

Patch angioplasty is performed to prevent recurrent stenosis after carotid endarterectomy (CEA). Controversy surrounds the selection of the patch material, with supporters for both autogenous tissue and synthetic patches. We reported on the efficacy of synthetic patch angioplasty. Thirty-four carotid endarterectomies with synthetic patch angioplasty, Hemashield Finesse® and Gore-Tex®, were performed on 32 patients. Twenty-eight of the thirty-four cases were classified as elective CEA and six were emergency CEA. The clinical outcome, perioperative complications, and incidence of recurrent stenosis (> or =50%), as detected by MRA and ultrasonography, were examined. Postoperatively, one severe acute stroke patient who underwent emergency CEA died from gastrointestinal bleeding. The perioperative permanent neurologic morbidity was 0% in elective CEA, and five of the six emergency CEA patients recovered. The total permanent morbidity and mortality rate in all CEA with synthetic patch angioplasty was 2.9%. No recurrent stenosis or further stroke occurred in the postoperative long-term follow-up period. Synthetic patch angioplasty in CEA is considered useful to prevent recurrent stenosis, and to avoid vein harvest site complications and patch rupture as previously described with vein patch angioplasty. Finally, there have been no thrombotic complications using synthetic patch angioplasty in emergency CEA.

Polyester vs. Bovine Pericardial Patching during Carotid Endarterectomy: Early Neurologic Events and Incidence of Restenosis

PurposeThe aim of this report was to compare polyester vs. bovine pericardial patching during CEA with regards to the incidence of early neurologic events and recurrent stenosis.Patients and methodsOne hundred and twenty-five consecutive patients with high grade symptomatic (14%) or asymptomatic (86%) carotid artery stenosis (>70%) who underwent 139 CEAs by a single surgeon between January 1997 and April 2001 were retrospectively reviewed. Patients were assessed postoperatively clinically and with routine follow-up duplex scanning. Recurrent stenosis was defined as a narrowing in the common or internal carotid artery of more than 50% by duplex ultrasound examination.ResultsFrom January 1997 to May 1999, a polyester patch was routinely used in 81 (58%) patients, while between June 1999 and April 2001, a bovine pericardium patch was exclusively used in 59 (42%) patients. There were no ipsilateral postoperative TIAs or strokes in either group. The combined 30-day mortality rate for both groups was 0.8%. One patient in the polyester patch group died from cardiopulmonary complications 10 days after discharge. The length of follow-up in the bovine pericardial patch group was 3–28 months (mean 12 months), while in the polyester patch group was 1–50 months (mean 24.5 month). One patient developed a carotid pseudoaneurysm of the suture line in the bovine pericardium patch group caused by a local infection after previous neck dissection and radiation. The incidence of recurrent stenosis was two patients (4%) in the bovine pericardium group as opposed to six patients (7.6%) in the polyester patch group.ConclusionAlthough this is a preliminary report, it is concluded that bovine pericardium provides excellent perioperative results and is at least comparable to polyester patching in terms of safety. Our study with short term follow up suggests that bovine pericardium patching during carotid endarterectomy may have a lower restenosis rate compared to knitted polyester patching. Clear superiority of bovine pericardium as a patch material awaits a prospective randomised study with long-term follow-up.

Polyester vs. bovine pericardial patching during carotid endarterectomy: early neurologic events and incidence of restenosis

Purpose: The aim of this report was to compare polyester vs. bovine pericardial patching during CEA with regards to the incidence of early neurologic events and recurrent stenosis. Patients and methods: One hundred and twenty-five consecutive patients with high grade symptomatic (14%) or asymptomatic (86%) carotid artery stenosis (>70%) who underwent 139 CEAs by a single surgeon between January 1997 and April 2001 were retrospectively reviewed. Patients were assessed postoperatively clinically and with routine follow-up duplex scanning. Recurrent stenosis was defined as a narrowing in the common or internal carotid artery of more than 50% by duplex ultrasound examination. Results: From January 1997 to May 1999, a polyester patch was routinely used in 81 (58%) patients, while between June 1999 and April 2001, a bovine pericardium patch was exclusively used in 59 (42%) patients. There were no ipsilateral postoperative TIAs or strokes in either group. The combined 30-day mortality rate for both groups was 0.8%. One patient in the polyester patch group died from cardiopulmonary complications 10 days after discharge. The length of follow-up in the bovine pericardial patch group was 3–28 months (mean 12 months), while in the polyester patch group was 1–50 months (mean 24.5 month). One patient developed a carotid pseudoaneurysm of the suture line in the bovine pericardium patch group caused by a local infection after previous neck dissection and radiation. The incidence of recurrent stenosis was two patients (4%) in the bovine pericardium group as opposed to six patients (7.6%) in the polyester patch group. Conclusion: Although this is a preliminary report, it is concluded that bovine pericardium provides excellent perioperative results and is at least comparable to polyester patching in terms of safety. Our study with short term follow up suggests that bovine pericardium patching during carotid endarterectomy may have a lower restenosis rate compared to knitted polyester patching. Clear superiority of bovine pericardium as a patch material awaits a prospective randomised study with long-term follow-up.

Carotid endarterectomy with reimplantation of the internal carotid artery: perioperative risk, and incidence of recurrent stenosis in 167 procedures

Between 1990–1998, 167 carotid endarterectomies with reimplantation were performed on 153 patients. Indications for operation were asymptomatic stenosis >60% (50.2%), transient ischemic attacks (17.4%), amaurosis fugax (14.4%) and previous stroke (18%). Our method involves transection of the internal carotid artery at its origin, standard endarterectomy without any eversion maneuver and reimplantation. Our results showed one postoperative stroke, which occurred at the contralateral side and no deaths with an overall perioperative morbidity and mortality rate of 0.59%. In addition, two (1.19%) transient ischemic attacks and one (0.59%) temporary ataxic event were noted with complete resolution of the symptoms. The 5-yr primary patency rate was 96% with a 95% 5-yr freedom from ipsilateral stroke. The mean follow up period was 22 months. In conclusion, we believe that our method, is relatively easy to perform, it has excellent results and it eliminates some of the disadvantages associated with the eversion technique.

Eversion versus conventional carotid endarterectomy: Late results of a prospective multicenter randomized trial

Objective: The durability of carotid endarterectomy (CEA) may be affected by carotid restenosis. The data from randomized trials show that the highest incidence of restenosis after CEA occurs from 12 to 18 months after surgery. The optimal CEA technique to reduce perioperative complications and restenosis rates is still undefined. This study examines the long-term clinical outcome and incidence of recurrent stenosis in patients who undergo eversion CEA. Previously published perioperative results of this study did not show statistically significant differences in study endpoints between the eversion and standard techniques. Methods: From October 1994 to March 1997, 1353 patients with surgical indications for carotid stenosis were randomly assigned to undergo eversion (n = 678) or standard CEA (n = 675; primary closure, 419; patch, 256). Withdrawal from the assigned treatment occurred in 1.6% of the patients (in 13 assigned to eversion CEA, and in nine assigned to standard CEA). The clinical and duplex scan follow-up examination was 99% complete, and the mean follow-up interval was 33 months (range, 12 to 55 months). The primary outcomes were perioperative and late major stroke and death, carotid restenosis (stenosis ≥ 50% of the lumen diameter detected at duplex scanning), and carotid occlusion. The primary evaluation of study outcomes was conducted on the basis of an intention-to-treat analysis. Results: Restenosis was found at duplex scanning in 56 patients (19 in the eversion group, and 37 in the standard group). Within the standard group, the restenosis rates were 7.9% in the primary closure population and 1.5% in the patched population. Of the patients with restenosis, 36% underwent cerebral angiography that confirmed restenosis in all cases. The cumulative restenosis risk at 4 years was significantly lower in the group that underwent treatment with eversion CEA as compared with the standard group (3.6% vs 9.2%; P = .01), with an absolute risk reduction of 5.6% and a relative risk reduction of 62%. Eighteen patients would have had to undergo treatment with eversion CEA to prevent one restenosis during the 4-year period. The incidence rate of ipsilateral stroke was 3.3% in the eversion population and 2.2% in the standard group. There were no significant differences in the cumulative risks of ipsilateral stroke (3.9% for eversion, and 2.2% for standard; P = .2) and death (13.1% for eversion, and 12.7% for standard; P = .7)) in the two groups. Of the 18 variables that were examined for their influence on restenosis, eversion CEA (hazard ratio, 0.3; 95% confidence interval, 0.2 to 0.6; P = .0004) and patch CEA (hazard ratio, 0.2; 95% confidence interval, 0.07 to 0.6; P = .002) were negative independent predictors of restenosis with multivariate Cox proportional hazards regression analysis. Conclusion: The EVEREST (EVERsion carotid Endarterectomy versus Standard Trial) showed that eversion CEA is safe, effective, and durable. No statistically significant differences were found in late outcome between the eversion and standard techniques at the available follow-up examination. (J Vasc Surg 2000;31:19-30.)

Timing and frequency of perioperative carotid color-flow duplex scanning: A preliminary report

Purpose: The results of intraoperative and early postoperative carotid color-flow duplex scanning (CFS) after endarterectomy were reviewed to determine whether any perioperative studies could be eliminated. Methods: Patients undergoing carotid endarterectomy with intraoperative CFS between 1986 and 1997 were identified. Early postoperative CFS was performed between 1 day and 3 weeks postoperatively, then it was performed again at 6 months postoperatively. Results: During the study period, 560 patients, 325 men and 235 women, underwent 621 carotid endarterectomies. A satisfactory intraoperative carotid CFS was completed in 611 (98.4%) patients. There were 20 (3.2%) vessels with a major defect that required revision for fronds or flaps (n = 11), retained atheroma (n = 5), low flow (n = 2), high velocity or turbulence (n = 1), or dissection (n = 1). Another 146 vessels (23.5%) had minor defects, such as retained proximal atheromas or small (less than 3 mm) fronds, but were not revised. The remaining 445 vessels were normal. The first postoperative CFS was normal in all the revised carotids and in 138 (94.5%) vessels with minor intraoperative defects. At 6 months, recurrent stenosis (more than 75% area reduction) was identified in 1 of 18 revised carotids (5.5%), 4 of 138 vessels (2.9%) with minor defects, and 17 of 406 vessels (4.2%) that were normal intraoperatively. The incidence of recurrent stenosis was not significantly different in the three groups ( P = .7). Conclusion: Intraoperative CFS is useful because major unsuspected defects can be corrected immediately, thus avoiding potential neurologic morbidity. However, the postoperative day 1 CFS can be eliminated in most cases, because it does not provide any relevant clinical information. (J Vasc Surg 1999;29:833-7.)

Elevated Lipoprotein(a) and increased incidence of restenosis after femoropopliteal PTA. Rationale for the higher risk of recurrence in females?

It has been shown that the incidence of recurrent stenosis following successful percutaneous transluminal coronary angioplasty (PTCA) is correlated with serum Lipoprotein(a) [Lp(a)] levels. The aim of the present study was to examine the influence of Lp(a) on restenosis after primarily successful femoropopliteal PTA. One hundred and thirty nine consecutive patients with peripheral arterial occlusive disease (PAOD) and successful femoropopliteal PTA were studied. Follow-up included clinical examination and non-invasive laboratory testing (pulse volume recordings, ankle-brachial arterial pressure measurement) in every patient before and after 1, 3, 6 and 12 months following intervention. Duplex sonography was performed 1 year after PTA. Suspicion of restenosis (≥ 50% diameter reduction) was verified by angiography. Lp(a) was determined using ELISA technique (mg/dl). Twelve months after successful PTA no restenosis was found in 82 patients (59%: group A). The one-year recurrence rate of 41% (group B) was due to significant restenosis in 35 patients (25%) and reocclusion in 22 patients (16%). The corresponding mean values ± S.E.M. for Lp(a) were as follows: group A, 28 ± 5.3; group B, 59 ± 11 ( P < 0.01). Women showed a higher frequency of recurrences (55%) versus men (30%, P < 0.01) also corresponding with a higher Lp(a) level (51.8 ± 8 versus 32.7 ± 5; P < 0.05). Furthermore Lp(a) aggravated the well known increased risk for recurrence in multiple stenoses or occlusions of ≥ 5 cm in length. There were no significant differences between groups A and B with respect to age, diabetes, hyperlipidaemia, obesity and cigarette smoking. The results support the view that Lp(a) is an independent risk factor for recurrence after PTA in the femoropopliteal area. It might also be a causal basis for the higher incidence of recurrences in female PAOD patients.

Evaluation of Everted External Jugular Vein for Patch Angioplasty

Patch angioplasty of the carotid artery is believed to prevent iatrogenic narrowing, as well as reduce potential thrombosis and minimize the incidence of recurrent stenosis. Vascular surgeons prefer autogenous vein, although polytetrafluorothylene and Dacron have been utilized successfully. Saphenous vein harvested from the groin is probably the safest owing to its thickness. External and internal jugular vein have both been used because of their convenience and proven efficacy. These veins are, however, thin, and patch failure and subsequent rupture have been recorded. Recently advocates of this patch have everted the vein and employed double-layer closure for carotid patch angioplasty for additional strength. The authors constructed and examined everted and singlelayer external jugular vein patches placed for five days in canine carotid and femoral arteries. Each vein patch demonstrated necrosis of the intimal layer with an inflammatory and fibrous rebuilding process identified in the media and adventitia. The single-layer patch was identical in characteristics; however, the double-layer patch possessed a dual thickness of the above-mentioned morphologic changes.

An outcome analysis of carotid endarterectomy: The incidence and natural history of recurrent stenosis

This report identifies the incidence of recurrent carotid stenosis after carotid endarterectomy (CEA) and records the natural history of the disease process to gain further insight into its proper management. A prospective surveillance protocol with duplex imaging and velocity spectral analysis was used to detect recurrent stenosis ( > 50% diameter reduction) and to document the clinical outcomes of patients who underwent CEA. Between 1984 and 1993, 619 consecutive CEAs were performed in 587 patients. Recurrent carotid stenosis developed in 48 CEA sites (7.8%) during a mean follow-up interval of 34 months (range, 2 to 118 months). Normal results on intraoperative assessment correlated with a 5.6% incidence of recurrent stenosis, compared with a 19% incidence when a residual hemodynamic abnormality was present (p < 0.0003). In the first year after surgery, there were no transient ischemic attacks, strokes, or carotid occlusions from recurrent stenosis, compared with a 27% morbidity rate in later follow-up (p < 0.01). Three patients with recurrent stenosis subsequently had occlusion at the CEA site, two of whom had severe ipsilateral strokes. The incidence of recurrent carotid stenosis is low. Patients are at significant risk for neurologic morbidity when a recurrent stenosis occludes. With a 0.3% incidence of late stroke resulting from carotid bifurcation disease, these data confirm that CEA does provide long-term protection from stroke.

Late carotid restenosis: Aetiologic factors for recurrent carotid artery stenosis during long-term follow-up

During a fourteen-year-period 257 patients underwent carotid endarterectomy in an unselected population of 700,000 inhabitants. The incidence of haemodynamically significant restenosis was 13.5% in 133 vessels in 116 patients studied by duplex scanning 28 to 209 months following carotid endarterectomy. The most striking differences between patent and restenosed cases were in serum cholesterol, triglyceride and HDL-cholesterol levels. The patients with a long-term low cholesterol (less than 6.5 mmol/l), low triglyceride (less than 1.42 mmol/l) and high HDL cholesterol (greater than 1.0 mmol/l) levels had significantly less high grade restenosis (P less than 0.05). Apolipoprotein A-I and B had no significant effect, but if the lowest limit of normal apolipoprotein A-I level was considered as 1.27 g/l the difference was significant. The frequency of a high-grade restenosis in patients with diabetes mellitus and coronary heart disease was not significantly increased, but supports the view that these are risk factors in the development of atherosclerotic changes in an operated carotid artery. The incidence of recurrent stenosis appears to be unrelated to hypertension, claudication, obesity, smoking, operative factors or to the indication for surgery. Men were more prone than women to get a high-grade restenosis. Postoperative treatment with acetylsalicylic acid was most effective, the incidence was only half of that expected, whereas the anticoagulants or a combination of acetylsalicylic acid and dipyridamole were of no benefit. Haematocrit, RBC, platelet count and thrombocrit were contradictory.

Late patency of the carotid artery after endarterectomy. Problems of definition, follow-up methodology, and data analysis

To determine the relative incidence of recurrent carotid stenosis (RCS) and the effect of methodology on data analysis and interpretation, late results were obtained for 232 patients (270 procedures) from 1 to 51 months (mean 22 months) after carotid endarterectomy (group A). Patency of the carotid artery was confirmed by postoperative intravenous digital subtraction angiography (DSA) for most of the series, and a subset (subgroup A1) of 113 patients (129 procedures) also received DSA studies at later intervals of 4 to 49 months (mean 26 months). There were 23 late deaths and five late strokes. Only two of the strokes were ipsilateral to previous endarterectomy, and both of these patients had normal follow-up DSA studies. Late DSA imaging revealed either no RCS or only trivial defects (20% diameter or less) in 111 arteries, moderate (36% to 60%) RCS in nine, severe (70% to 90%) RCS requiring secondary procedures in eight, and internal carotid occlusion in one. Depending on the definition of RCS (secondary operation vs ⩾30% angiographic lesions), the cohort selected for analysis (group A vs subgroup A1), and the approach to calculations (crude vs cumulative), the incidence of recurrent stenosis after carotid reconstruction in this single study could be expressed within the extraordinarily wide range of 3% to 32%. Although carotid endarterectomy was associated with uniformly low risk for late stroke, these results confirm that the reported recurrence rate may be substantially influenced by the method in which data are grouped and manipulated. Consistently presented data are essential to any comparisons concerning the surgical therapy for extracranial disease.

Turbulence occurring after carotid bifurcation endarterectomy: A harbinger of residual and recurrent carotid stenosis

The goal of carotid endarterectomy is to remove an obstructing or embologenic lesion and reconstruct a durable arterial segment free of flow abnormality. The technical adequacy of 250 endarterectomy sites in 235 patients was assessed at operation by pulsed Doppler spectral analysis and arteriography and was correlated with postoperative patency, the incidence of residual and recurrent stenosis, and clinical outcome. Duplex scanning was used after operation to categorize disease severity. At operation, 10 patients (4%) had angiographic and Doppler flow abnormalities identified in the internal carotid artery. Vessel exploration identified intimal flaps, platelet aggregation, or stricture. Residual flow disturbances at the endarterectomy site correlated with perioperative thrombosis and stroke, angiographic abnormalities, primary closure of the arteriotomy, and a postoperative duplex scan consistent with stenosis. In 175 patients (182 sites) with normal arterial flow after carotid bifurcation endarterectomy, no thrombotic events occurred and the incidence of recurrent stenosis (life-table analysis) was zero at 3 months, 5% at 1 year, and 9% at 2 years. The incidence of occlusion and recurrent stenosis was increased (8% at 3 months, 18% at 1 year, and 21% at 2 years) in 68 arteries with residual flow disturbance identified at operation. Assessment of endarterectomy sites for turbulence identifies anatomic lesions that threaten patency and increase the incidence of residual and recurrent stenosis.

Recurrent carotid stenosis after autologous tissue patching.

This study was carried out to evaluate two techniques of widening the carotid bifurcation with autologous material after endarterectomy to determine whether the incidence of recurrent stenosis could be reduced. As a control, a similar series was performed without patching. Autologous saphenous vein was used as a patch in one group of patients, whereas in another, the bifurcation was widened by suturing the external carotid to the internal carotid artery, advancing the bifurcation by several centimeters, a technique we termed bifurcation advancement. All three groups were studied at least 1 year after operation by means of Doppler ultrasonography. We found no difference in either of the patched techniques compared with unpatched controls. Significant recurrent stenosis (greater than 50% diameter reduction) was found in 12.5% of reconstructions with a vein patch, 12.5% of those with bifurcation advancement, and 16.6% of those with simple closure. The overall incidence of significant recurrent stenosis was 13.8%, with symptoms occurring in 2.7%.

Recurrent carotid stenosis after autologous tissue patching

This study was carried out to evaluate two techniques of widening the carotid bifurcation with autologous material after endarterectomy to determine whether the incidence of recurrent stenosis could be reduced. As a control, a similar series was performed without patching. Autologous saphenous vein was used as a patch in one group of patients, whereas in another, the bifurcation was widened by suturing the external carotid to the internal carotid artery, advancing the bifurcation by several centimeters, a technique we termed bifurcation advancement. All three groups were studied at least 1 year after operation by means of Doppler ultrasonography. We found no difference in either of the patched techniques compared with unpatched controls. Significant recurrent stenosis (greater than 50% diameter reduction) was found in 12.5% of reconstructions with a vein patch, 12.5% of those with bifurcation advancement, and 16.6% of those with simple closure. The overall incidence of significant recurrent stenosis was 13. 8%, with symptoms occurring in 2. 7%.

Effect of nifedipine on recurrent stenosis after percutaneous transluminal coronary angioplasty

This double-blind, randomized study evaluated the effect of nifedipine on restenosis after coronary angioplasty. Two hundred forty-one patients with dilation of 271 coronary sites were randomized at the time of hospital discharge to receive nifedipine, 10 mg (123 patients), or placebo (118 patients) four times daily for 6 months. No patient was known to have coronary artery spasm. The mean duration of therapy was 4.4 +/- 2 (mean +/- SD) months for nifedipine and 4.3 +/- 2 months for placebo. A restudy angiogram was available in 100 patients (81%) in the nifedipine group and 98 patients (83%) in the placebo group. A recurrent coronary stenosis was noted in 28% of patients in the nifedipine group and in 29.5% of those in the placebo group (p = NS). The mean diameter stenosis was 36.4 +/- 23% for the nifedipine group and 36.7 +/- 23% for the placebo group (p = NS). By pill count, 78% of patients receiving nifedipine and 82% of those receiving placebo complied with the study drug regimen. Coronary stenosis recurred in 33% of patients in the placebo group and in 29% of patients in the nifedipine group who complied with the regimen and had angiograms (p = NS). In conclusion, the study did not demonstrate a significant beneficial effect of nifedipine on the incidence of recurrent stenosis after successful percutaneous transluminal coronary angioplasty.

Technical Aspects of Carotid Artery Surgery

This article reviews the step-by-step description of the author's operative technique in performing a carotid endarterectomy. Technical precision remains the most important factor in reducing the risk of perioperative stroke. An in dwelling shunt is used selectively based upon the internal carotid back pressure or intraoperative monitoring of the electroencephalogram. Intraoperative use of a sterile Doppler probe permits comfirmation of flow abnormalities detected in noninvasive examinations preoperatively, documents flow in an indwelling shunt, and assures patency of the carotid artery and its branches after endar terectomy. Postoperatively noninvasive diagnostic techniques permit assessment of carotid integrity in patients suffering neurologic deficits, and serial studies provide objective evidence of the incidence of recurrent stenosis or disease pro gression. Using these diagnostic and therapeutic principles the author reviews the results of his series of patients in a residency training program.