Saphenous vein patch grafts in carotid endarterectomy

Eversion Carotid Endarterectomy: A Safe, Advantageous Alternative to Conventional Carotid Endarterectomy

Objective: To compare the results and time and cost efficacy of eversion carotid endarterectomy (ECEA) with standard carotid endarterectomy (SCEA).

Methods: A retrospective analysis of 88 carotid endarterectomies performed by the residents under the guidance of the senior author between January 1, 1991, and December 31, 1993, was done. Fifty-five patients underwent SCEA (44 vein patch, 11 primary closure) and 33 had ECEA. The two groups were compared for operative time, intraoperative evaluation, cost, immediate and delayed morbidity, and restenosis (≥ 50%).

Results: The two groups were found to be similar for age, sex ratio, and associated diseases. The indications for surgery were transient ischemic attack (TIA) (57% ECEA, 64% SCEA), previous stroke with minimal residual deficit (9% ECEA, 17% SCEA), and asymptomatic high-grade stenosis (34% ECEA, 19% SCEA). The average operative time for ECEA was significantly less (99.2 vs 135.2 minutes, P < 0.02). The mean blood loss was also less for ECEA (86 vs 181 cc). Two SCEA patients had immediate postoperative thrombosis resulting in 1 cerebrovascular accident (CVA) (1.8%), and 3 SCEA patients had cranial nerve injuries. In follow-up, 1 patient with SCEA had restenosis and 1 had a CVA unrelated to carotid disease. Morbidity associated with ECEA included 1 unsuccessful ECEA requiring interposition vein grafting and 1 intraoperative repair of an intimal flap. There was no associated residual morbidity. There was no significant difference in stroke rate between the two groups. The operative cost (excluding surgeon fee) was 28% higher for SCEA patients.

Conclusion: Eversion carotid endarterectomy is a safe procedure and can be an important addition to a surgeon's armamentarium in efforts to cut costs while maintaining quality.

Surgical Techniques from Intraoperative Angiographic and Velocimetric Controls in 43 Consecutive Carotid Bifurcation Endarterectomies

From January to November, 1985, 43 carotid bifurcation endarterectomies (CE) were performed with intraoperative functional (Doppler spectrum analy sis) and morphologic (angiography) controls.

In the first 20 cases, after thromboendarterectomy and direct suture, Dop pler showed absence of or no significant variations of frequency in 17 cases, a frequency increase corresponding to a less than 45% diameter reduction steno sis at the apex of the suture in 2 cases, and no flow in the internal carotid artery (ICA) in 1 case. Angiography confirmed the thrombosis in the above mentioned case and showed 3 less than 50% stenoses at the distal end of the arteriotomy: 2 already recognized by Doppler in small-size ICAs and 1 in a medium-size ICA without significant changes of flow. The reason for thrombosis was a distal intimal flap, which was successfully removed; the 2 stenoses in which Doppler and angiography agreed were corrected by patch angioplasty. In the last 23 cases, patch angioplasty was performed routinely in small-size ICAs (6 cases); in 1 case, first treated by a direct suture, Doppler and angiography showed a medium-grade stenosis, immediately corrected; in 1 case both techniques showed a 50% stenosis in a common carotid artery, immediately corrected. The execution of intraoperative angiography in this group of patients al lowed the authors to define the indication for the use of patch angioplasty, never previously employed. Nevertheless, the authors state that, on account of loss of time, costs, and exposure to radiations, intraoperative angiography must be reserved for those cases selected by Doppler spectrum analysis. This method seems to be highly sensitive in recognizing significant technical defects that could lead to an immediate or late failure.

Carotid Artery Pseudoaneurysm After Carotid Endarterectomy: Case Series and a Review of the Literature

Background: Pseudoaneurysm (PA) after carotid endarterectomy (CEA) is a rare complication with incidence less than 1%. There is a potential for rupture, embolization, thrombosis or compression of cranial nerves. Objective: We reviewed our experience and compare it to the literature to raise awareness of this rare though serious condition. It is crucial to treat these patients early to avoid the hazardous consequences. Methods: A review of the case records of patients who had CEA at University Hospital Birmingham (UHB) NHS Foundation Trust from 1990-2007, was undertaken. Information of patients including their aetiology, presenting features, treatment and results was collected. The English-language literature was searched using PubMed database for post CEA pseudoaneurysm. Results: Five patients developed post CEA PA. This represents 0.4% of the 1200 CEA performed at our hospital in the last 18 years. The timing of their presentation varied from three days to eight months after the original operation. All had patch reconstruction after CEA. Patches were intact at exploration of the PAs. There was one death and one stroke. The literature revealed 154 carotid PAs after CEA and two cases following carotid stenting 52 of these cases had infected PA. Patients with synthetic patches have the least incidence of infection. More than 80% had open surgery and 9% had endovascular repair. Conclusion: Post CEA surveillance is necessary to detect patients with PA early. Factors that favour infection must be avoided. Endovascular repair of carotid PA should be encouraged in specialised centres.

Resistência tensional do pericárdio bovino fixado em glutaraldeído comparada com a da veia safena magna

CONTEXTO: O uso do pericárdio bovino como remendo na endarterectomia de carótida é uma alternativa à veia safena magna. As vantagens do pericárdio incluem facilidade de obtenção, menor tempo operatório e principalmente menor índice de ruptura. OBJETIVO: Avaliar a resistência tensional do pericárdio bovino tratado com glutaraldeído e compará-la com a da veia safena magna. MÉTODOS: Os remendos de pericárdio bovino (grupo I, n = 20) e de veia safena magna (grupo II, n = 20) foram recortados em dimensões iguais (50 x 5 mm) e preparados de modo habitual a sua utilização. Os grupos foram submetidos a ensaio de tração e comparados em relação a força de ruptura, força máxima e tensão de ruptura utilizando-se o teste t de Student. A correlação da espessura do remendo com a força de ruptura também foi analisada utilizando-se o coeficiente de correlação linear de Pearson. RESULTADOS: Os parâmetros força de ruptura e força máxima foram significativamente maiores no grupo dos remendos de pericárdio bovino: 1,97 versus 1,36 kgf (p = 0,001230) e 2,27 versus 1,51 kgf (p = 0,0001087), respectivamente. A tensão de ruptura média para o material pericárdio bovino também foi maior (193,99±43,05 versus 49,19±22,96 kgf/cm², p = 7,603e-16) do que na veia safena. A correlação entre a espessura e a força de ruptura foi considerada moderada (r = 0,5032993) para o pericárdio bovino e baixa (r = 0,3062166) para o grupo da veia safena. CONCLUSÃO: Os autores concluem que a resistência do pericárdio bovino à ruptura foi considerada adequada neste estudo, e é significativamente maior que a da veia safena magna, retirada da região da coxa. Além disso, a espessura do remendo em ambos os grupos não apresenta boa correlação com sua resistência a ruptura.

Reconstructive surgery of the extracranial arteries

The first carotid endarterectomy (CEA) is usually accredited to Eastcott who reported in 1954 the successful incision of a diseased carotid bulb with end-to-end anastomosis of the internal carotid artery (ICA) to the common carotid artery (CCA). During the following years surgeons were quick to adopt and improve the intuitively attractive procedure. But by the early to mid 1980s several leading neurologists began to question the growing number of CEAs performed at that time. Six major CEA trials were then designed which are now completed or nearing completion. Most conclusive data are available from the North American Symptomatic Carotid Endarterectomy Trial (NASCET) for symptomatic carotid disease, and from the Asymptomatic Carotid Atherosclerosis Study (ACAS) for asymptomatic carotid disease. The key result of these studies is that CEA is beneficial to high grade symptomatic and asymptomatic carotid stenosis. While the benefit in symptomatic disease is clear, it may be negligible in asymptomatic patients suffering from other medical conditions, the most important being coronary artery disease. Since the conclusions from the different studies vary significantly, guidelines and recommendations with regard to CEA have been issued by a number of interest groups, so-called consensus conferences. The best known guidelines are published by the American Heart Association (AHA). However, the practice of interest groups to issue guidelines is currently being criticized, the main reason being that interest groups have different ideas and all claim the right to issue guidelines. At present we recommend CEA for symptomatic high-grade stenosis in patients without significant coincident disease. With regard to asymptomatic stenosis we suggest surgery to otherwise healthy patients if the stenosis is very narrow or progressive. Preoperative evaluation has changed over the years. Currently we recommend duplex sonography in combination with intra- and extracranial magnetic resonance angiography (MRA). Concurrent coronary artery disease is a major consideration in the perioperative management, and the use of a specific algorithm is recommended. Surgery is performed under general anaesthesia with intraoperative monitoring such as electroencephalography (EEG) and transcranial Doppler (TCD). A temporary intraluminal shunt is used selectively if after cross-clamping the flow velocity in the middle cerebral artery (MCA) falls to below 30 to 40% of baseline. For years we employed routine barbiturate neuroprotection during cross-clamping. At the present time we use barbiturate selectively, if the flow velocity in the MCA falls to below 30 to 40% of baseline and if the use of a temporary intraluminal shunt is not possible due to difficult anatomic conditions. The reason to abandon systematic barbiturate protection was to accelerate recovery from anaesthesia. Our patients are monitored overnight on the ICU or a surveillance unit. Routine hospitalization after surgery is 5 to 7 days with a control duplex sonography being performed prior to discharge. A number of details with regard to surgical technique and perioperative management are a matter of discussion. Our surgical routine is described here step by step. Such management resulted in 6 major complications among the 402 cases with 4 of cardiopulmonary and 2 of cerebrovascular origin. For the future we can expect the development of percutaneous transluminal techniques competing with standard carotid endarterectomy. At the present time several comparative studies are under way. Irrespective of the technical approach to treat carotid stenosis, several other issues have to be clarified before long. One of the major unresolved items is the timing of treatment after completed stroke. In this regard prospective trials need to be performed. Although numerically not as important as carotid stenosis, vertebral artery (VA) and subclavian artery (SA) stenoses are more and more accepted as indication for surgical

A fifteen-year experience with carotid endarterectomy after a formal operative protocol requiring highly frequent patch angioplasty

PURPOSE

The early and late outcomes of carotid endarterectomy (CEA) following a rigid protocol of patch angioplasty or occasionally interposition bypass grafting, when the arteriotomy required to obtain a complete internal carotid end point extended distal to the bulb segment, and primary closure, when it was limited to the bulb, were studied.

METHODS

From November 1983 to August 1998, 1360 consecutive primary CEAs were performed on 1133 patients (621 men, 512 women), with a mean age of 67 years. Of these patients, 3.8% (51) had primary closure, 66.4% (903) had greater saphenous vein patch angioplasty, 28.4% (386) had synthetic (359 Dacron, 27 polytetrafluoroethylene) patch angioplasty, and 1.4% (20) had vein interposition bypass grafting procedures. Indications were transient ischemic attack in 34.7% of patients (472), stroke in 16.6% of patients (226), nonlateralizing symptoms in 10.9% of patients (148), and asymptomatic stenosis 70% or greater in 37.8% of patients (514). The mean follow-up period was 4.6 years.

RESULTS

The 30-day mortality rate was 1.0% (13 patients; 11 cardiac-related deaths, 2 strokes). The 30-day stroke rate was 1.3% (18 patients; 13 ipsilateral strokes, 5 major, 8 minor). The combined 30-day stroke and death rate was 2.1%. Four of the strokes (1 death) were caused by the hyperperfusion syndrome. The 30-day ipsilateral major stroke or mortality rate was 1.2% (16 patients). The 30-day rate of ipsilateral major stroke or death from stroke was 0.4% (5 patients). There were two synthetic and one vein patch internal carotid occlusions in 30 days. Synthetic-patched CEAs were predicted by means of Cox proportional hazards analysis to have higher risk ratios than saphenous vein-patched CEAs for early and late stroke (1. 3; 95% CI, 1.7 to 1.0; P =.04), for 50% or greater restenosis (2.4; 95% CI, 3.4 to 1.6; P <.001), and for 70% or greater restenosis (2. 5; 95% CI, 3.6 to 1.7; P <.001). The cumulative mortality rate (Kaplan-Meier) was 13% at 5 years and 31% at 10 years. The cumulative stroke rate was 7% at 5 years and 14% at 10 years. The 50% or greater restenosis rate was higher in women than in men at 5 years (9% versus 5%; P =.02, Wilcoxon), but tended to equalize later. The 50% or greater restenosis rate was higher in synthetic-patched CEAs than in saphenous vein-patched CEAs (12% versus 1% at 1 year; 17% versus 3% at 4 years; and 24% versus 10% at 8 years; P <.001 by means of log-rank and Wilcoxon). Restenosis after 5 years was more frequently located in the distal common carotid artery (13 of 20 cases). Late reoperations were more frequent and occurred earlier in synthetic-patched CEAs (eight cases at a mean of 1.6 years) than vein-patched CEAs (14 cases at a mean of 6.9 years; P =.01). No strokes and one restenosis of 50% or greater occurred in the 51 primarily closed CEAs.

CONCLUSION

Patch angioplasty reconstruction of CEAs with arteriotomies that extend distal to the carotid bulb gives excellent early and long-term outcomes. Saphenous vein-patched CEAs are superior to synthetic patched CEAs for stroke and restenosis prevention. Primary closure is safe and durable when complete end points and arteriotomies are within the carotid bulb.

Prospective randomized trial of bilateral carotid endarterectomies: primary closure versus patching

BACKGROUND AND PURPOSE

Although several studies have compared the results of carotid endarterectomy (CEA) with primary closure (PC) versus patch closure, none have compared the outcome of bilateral CEAs with patch versus PC performed on the same patient. This prospective randomized study compares the clinical outcome and incidence of recurrent stenosis (>/=80%) for CEA with PC versus patch closure in patients with bilateral CEAs.

METHODS

This study includes 74 patients with bilateral CEAs with PC on one side and patching on the other. Patients were randomized to sequential operative treatment of either patching/PC or PC/patching. Postoperative duplex ultrasounds and clinical follow-up were done at 1, 6, and 12 months and every year thereafter. A Kaplan-Meier analysis was used to estimate the risk of significant restenosis (>/=80%).

RESULTS

Demographic characteristics and the mean operative diameter of the internal carotid artery were similar for both PC and patching. The mean follow-up was 29 months (range, 6 to 65 months). The incidence of ipsilateral stroke was 4% for PC versus 0% for patching. PC had a significantly higher incidence of neurological complications (transient ischemic attacks and stroke combined) than patching (12% versus 1%; P=0.02). Operative mortality was 0%. PC had a higher incidence of recurrent stenosis (22% versus 1%; P<0.003) and total internal carotid artery occlusion (8% versus 0%; P=0.04) than patching. Restenoses necessitating a repeated CEA were also higher for PC (14%) than for patching (1%; P=0.01). The Kaplan-Meier analysis showed that patching had a significantly better cumulative patency rate than PC (P<0.01). This analysis also showed that freedom from recurrent stenosis at 24 months was 75% for PC and 98% for patching.

CONCLUSIONS

Patch closure is less likely than PC to cause ipsilateral stroke, transient ischemic attacks, and recurrent carotid stenosis. The higher rate of unilateral recurrent stenosis may suggest that local factors play a more significant role than systemic factors in the etiology of recurrent carotid stenosis.

Repair of carotid endarterectomy with a collagen-impregnated fabric graft

Saphenous vein patch closure of carotid endarterectomies may decrease the risk of acute postoperative occlusion and recurrent stenosis. However, the disadvantages of a vein patch include postoperative rupture and pseudoaneurysm formation.

OBJECT

The authors sought to assess the effectiveness of collagen-impregnated fabric grafts as substitutes for saphenous vein grafts.

METHODS

In this report the authors prospectively analyzed 290 consecutive carotid endarterectomies in which a secondary closure was accomplished using a knitted double-velour graft. The 30-day major neurological morbidity and mortality rate was 1.7%. There were no postoperative occlusions or wound hematomas. The rate of recurrent carotid artery stenosis was less than 1%, and the graft site in one patient became infected.

CONCLUSIONS

For surgeons who prefer a secondary closure of carotid endarterectomies, the synthetic graft may prove to be a viable alternative to a saphenous vein.

Prospective randomized trial of carotid endarterectomy with primary closure and patch angioplasty with saphenous vein, jugular vein, and polytetrafluoroethylene: long-term follow-up

PURPOSE

This study examines the long-term clinical outcome and the incidence of recurrent stenosis (> or = 50%) after carotid endarterectomy (CEA) with primary closure (PC) versus vein patch closure (VPC), saphenous (SVP), and jugular vein (JVP) and polytetrafluoroethylene patch closure (PTFE-P).

METHODS

A total of 399 CEAs were randomized into the following groups: 135 PC, 134 PTFE-P, and 130 VPC (SVP alternating with JVP). Postoperative duplex ultrasound scans were performed at 1, 6, and 12 months and every year thereafter. The mean follow-up was 30 months with a range of 1 to 62 months, and demographic characteristics were similar in all groups. Kaplan-Meier analysis was used to estimate the risk of restenosis and the stroke-free survival.

RESULTS

The incidence of ipsilateral stroke was 5% (seven of 135) for PC, 1% (one of 134) for PTFE-P, and 0% for VPC (PC vs VPC, p = 0.008; PC vs PTFE-P, p = 0.034). Seven strokes occurred in the perioperative period. All three groups had similar mortality rates. The cumulative stroke-free survival rate at 48 months was 82% for PC, 84% for PTFE-P, and 88% for VPC (p < 0.01 for PC vs PTFE-P or VPC). PC had a higher incidence of recurrent stenosis and occlusion (34%) than PTFE-P (2%) and VPC (9%) (SVP 9%, JVP 8%) (p < 0.001). PTFE-P had a lower recurrent stenosis rate than VPC (p < 0.045). Restenoses necessitating a redo CEA were also higher for PC (11%) than for PTFE-P (1%) and VPC (2%) (p < 0.001). Women with PC had a higher recurrent stenosis rate than men (46% vs 23%, p = 0.008). Kaplan-Meier analysis showed that freedom from recurrent stenosis at 48 months was 47% for PC, 84% for VPC, and 96% for PTFE-P (p < 0.001). The SVP and JVP results were comparable. The mean operative diameter of the internal carotid artery was similar in patients with or without restenosis. Significantly more late internal carotid artery dilatations occurred in the VPC group compared with the PC group.

CONCLUSIONS

Patch closure (VPC or PTFE-P) is less likely than PC to cause perioperative stroke. Patching was also superior in lowering the incidence of late recurrent stenoses, especially in women.

Geometric dimension changes with carotid endarterectomy reconstruction

PURPOSE

The geometry of carotid endarterectomy (CEA) reconstruction is a major determinant of carotid bifurcation hemodynamics that, in turn, may play a significant role in the likelihood of early postoperative thrombosis and early and late restenosis. The purpose of this study was to measure the geometry of various types of CEA reconstructions.

METHODS

Six carotid artery diameters and lengths were measured during surgery, before and after CEA. Three reconstruction methods were used in 562 CEA procedures: a greater saphenous vein patch in 389, a synthetic patch in 157, and primary closure in 16. Veins 6 mm or more in distended diameter were trimmed before use as a patch. Synthetic patches were 8 to 11 mm in width. Patch reconstruction was used when the length of the arteriotomy required to obtain a complete distal endarterectomy end point extended beyond the internal carotid artery bulb. Saphenous vein patches were used when it was available and adequate. Neither gender nor internal carotid artery diameter was used as a criteria for the selection of the reconstruction method.

RESULTS

Before endarterectomy, the 302 male carotid arteries had 7% to 15% greater linear dimensions than the 260 female arteries (p < 0.001). Both vein and synthetic patch reconstruction produced up to 16% changes in linear dimensions except for almost doubling of the length of the internal carotid bulb. Patching made the elliptical common carotid bulb significantly more round, but the maximum diameter of curvature of the carotid bulb remained unchanged. Primary closure slightly decreased the diameter of the internal carotid bulb.

CONCLUSIONS

CEA patch reconstruction has two major effects on carotid geometry: an increase in internal carotid bulb length and a more round common carotid bulb. The former allows for a gradual transition from the terminal common carotid bulb to the uniform diameter more distal internal carotid artery. It also separates the two major causes of disturbed flow: the bifurcation and the step-down in internal carotid artery diameter. Primary closure has minimal effect on preoperative geometry.

Prospective randomized trial of carotid endarterectomy with primary closure and patch angioplasty with saphenous vein, jugular vein, and polytetrafluoroethylene: perioperative (30-day) results

PURPOSE

The early outcomes of carotid endarterectomy (CEA) with primary closure (PC) versus vein patch closure (saphenous vein [SVP] and jugular vein [JVP]) and polytetrafluoroethylene patch closure (PTFE-PC) were compared.

METHODS

Three hundred ninety-nine CEAs were randomized into the following groups: 135 PC, 134 PTFE-PC, and 130 vein patch closure (SVP alternating with JVP). Surviving patients underwent a carotid color duplex ultrasonographic scan 1 month after surgery. Demographic characteristics were similar in all groups.

RESULTS

The incidence of perioperative cerebrovascular accidents (CVAs) was 4.4% for PC, 0.8% for PTFE-PC, and 0% for vein patch closure (PC vs vein patch, p = 0.0165; PC vs all patching [vein and PTFE], p = 0.007). The perioperative CVA and reversible ischemic neurologic deficit (RIND) combined rates for all patching were superior to PC (1.5% vs 5.2%; p = 0.04). These combined rates were also superior for vein patch closure when compared with PC (0.8% vs 5.2%; p = 0.037). The mean diameter of the internal carotid artery was similar in patients who had perioperative neurologic deficits and those who did not. After 1 month of follow-up, 11.9% of the PC arteries were narrowed 50% or more in contrast to 2.3% for PTFE-PC, 3.1% for SVP, and 10.3% for JVP.

Complications resulting from saphenous vein patch graft after carotid endarterectomy

OBJECTIVE

Reducing surgical risks to the minimum in carotid endarterectomy has become crucial, especially with the results of recent clinical trials extending indications to asymptomatic patients. The use of the saphenous vein patch graft (SVPG) has been suggested to reduce early postoperative thrombosis and cerebral infarct as well as late recurrent stenosis. However, the exact risks and complications involved in this technique are not known.

METHODS

During a 23-year period (1972-1994), 2888 carotid endarterectomies with SVPG for primary carotid stenosis were performed by the Neurosurgical Cerebrovascular Service at the Mayo Clinic. The data from all patients were retrospectively analyzed, emphasizing postoperative complications related to SVPG.

RESULTS

There were five postoperative vein ruptures (0.17%), four cases of aneurysm formation, and three cases of deep infection necessitating surgical intervention. The vein patch ruptured in one male patient and four female patients (mean age, 69 yr). All ruptures occurred within 4 days of the primary operation, including two during the first 24 hours. All patients with rupture underwent emergency surgery and were found to have intact suture lines and tears in the middle of the grafts. Two patients recovered without deficits, one suffered major disability, and the other two died. Aneurysm of the patch developed in two male patients and two female patients (mean age, 71 yr). All of the patients developed painless pulsatile neck masses 1 to 9 years after the initial surgery; two also had recurrent ischemic symptoms. All of the patients with aneurysms underwent surgical correction without consequences.

CONCLUSION

Although the benefit of routine use of SVPG in carotid endarterectomy is still the focus of debate, this analysis showed that its use adds a small but definite risk of serious complications related to inherent weakness of the venous tissue. If a surgeon chooses to use a patch graft, our recommendation is for use of a synthetic material rather than vein.

Carotid endarterectomy with homologous vein patch angioplasty: a review of 1006 cases

PURPOSE

Because homologous vein is rarely used in vascular reconstructions, we evaluated the homologous vein as a patch for the reconstruction of the carotid bifurcation after endarterectomy.

METHODS

Excess vein harvested during open heart operations was either refrigerated in saline solution or cryopreserved in a solution of 10% dimethyl sulfoxide. Donors were tested for transmissible infections, and the veins were cultured for common pathogens. Data were analyzed from 837 consecutive patients (1006 cases) who underwent carotid endarterectomy with homologous vein patch angioplasty between 1981 and 1993.

RESULTS

The perioperative mortality rate was 0.8% (eight patients). Two deaths (0.2%) were attributed to ipsilateral strokes. Ischemic strokes occurred in 12 patients (1.2%; 10 ipsilateral), and ipsilateral transient ischemic attacks occurred in three patients (0.3%). Follow-up data were obtained for 482 patients (56%; mean follow-up time, 61 months; range, 1 to 132 months). Ipsilateral recurrent symptoms occurred in eight patients (1.7%; seven strokes, one transient ischemic attack). Of the 63 late deaths (13%), the majority (25 patients; 40%) were caused by complications of coronary artery disease. The 10-year overall survival rate was 76% +/- 3.2%, and the 10-year rate of freedom from late ipsilateral morbidity was 96% +/- 1.4%. The 10-year rate of freedom from late stenosis (a reduction in diameter of > or = 20%) in the 220 arteries (22%) that were studied by duplex scan was 84% +/- 2.3%.

CONCLUSIONS

The postoperative mortality and neurologic morbidity rates of carotid endarterectomy with homologous vein patch angioplasty are similar to those in the best series with all types of closure. The existing long-term follow-up data indicate that the homologous vein is a durable patch that behaves like other patches used in the same location.

Technical issues in carotid artery surgery 1995

In reviews in the 1980s, we discussed both indications for and surgical techniques in carotid endarterectomy. Significant changes in the practice of extracranial cerebrovascular reconstruction have occurred over the past few years. The newest indications and cooperative study data have recently been discussed by Camarata and Heros in this topic review series. In this article, we aim to review the advances in operative monitoring and surgical techniques of the last decade. We would be remiss, however, not to note that the latest Asymptomatic Carotid Atherosclerosis Study data, released in September 1994, indicate that carotid endarterectomy is significantly superior to medical therapy for asymptomatic stenosis of > 60%. These data, along with the North American Symptomatic Carotid Endarterectomy Trial results, will revitalize and lend scientific validity to carotid artery reconstruction.

Surgical treatment of recurrent carotid artery stenosis

Ninety-two surgical procedures were performed in 82 patients for recurrent carotid artery stenosis. The etiology was recurrent atherosclerosis in 45 cases, myointimal hyperplasia in 20, organized thrombus without a significant underlying plaque in 20, and scarring along the proximal arteriotomy site in seven. The operations included a repeat endarterectomy in 66 cases and reconstruction with an interposition graft in 22. All five major neurological complications occurred in symptomatic patients, and included three instances of intraoperative embolization during exposure of the carotid artery. The majority of neurological complications occurred in symptomatic patients who had intraluminal thrombus confirmed at surgery. There were four perioperative deaths, due to cerebral hemorrhage in two patients and myocardial infarction in two. In the patients whose original surgery was performed at the Mayo Clinic, the risk of recurrent carotid artery stenosis was 3.1% with a primary closure compared to 1.6% when a patch graft was used. These results indicate that surgery for recurrent carotid artery stenosis is technically more difficult and carries a significantly higher risk than surgery for primary disease. The difficulty is due to the friable recurrent plaque associated with intraluminal thrombus, which increases the risk of embolization during carotid artery exposure. In the majority of patients with recurrent atherosclerosis, a repeat endarterectomy can be achieved. However, in some patients, there is scarring without a definite plane of cleavage between the recurrent disease and the underlying media, making an endarterectomy difficult. In these cases, excision of the diseased segment and reconstruction with an interposition graft is the best treatment. The findings presented here also suggest that closure of the original arteriotomy with a patch graft decreases the risk of recurrent carotid artery stenosis.

Benefits of carotid patching: a prospective randomized study with long-term follow-up

A prospective study with random selection between primary closure and saphenous vein patching after carotid endarterectomy was conducted. Patients were evaluated with intravenous digital subtraction angiography during the initial postoperative period, followed by duplex scanning at 3 and 6 months, and then yearly examinations. The series consisted of 129 carotid endarterectomies, of which 62 were primary closures and 67 were patch procedures. Both groups were identical with regard to risk factors, symptoms, and postoperative control digital subtraction angiography. Restenosis was defined as a stenosis with > or = 50% diameter reduction, as assessed by duplex scanning. Of special interest was the development of restenosis along with the occurrence of cerebrovascular symptoms at long-term follow-up. The follow-up data from the 129 carotid endarterectomies are presented in a life-table analysis. The mean length of follow-up was 5 years (range 1 to 96 months). During the follow-up period 38 patients who had undergone 39 operations died (mortality rate 30%); three deaths were attributed to cerebral causes (two in-hospital deaths due to intracerebral hemorrhage and one cerebral hemorrhage after 6 months). Restenosis occurred in 25 cases (19%). This restenosis was detected in 5 of 45 men with primary closure (11%), 12 of 17 women with primary closure (70%), 7 of 49 men with patch closure (14%), and 1 of 18 women with patch closure (5.5%). The difference between patch and primary closures was found to be statistically significant (hazard ratio 0.39; 95% confidence interval 0.17 to 0.91; p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized controlled trial of patch angioplasty for carotid endarterectomy. The Joint Vascular Research Group

A randomized controlled trial was performed to evaluate patch angioplasty for patients undergoing carotid endarterectomy. There were 213 patient episodes affecting 148 men and 65 women, with 109 allocated to patch angioplasty. Following surgery six patients suffered transient ischaemic attacks but these did not delay discharge from hospital. Six individuals (four patched operations, two not patched) required re-exploration for postoperative haemorrhage and eight (two patched procedures, six not) had potentially serious neurological problems after operation. Of these eight patients, four (none receiving patch angioplasty) underwent re-exploration and in each case a clot was removed and a patch inserted; three of the four made a good long-term recovery. The other four patients suffered completed strokes from which one died. Two further patients (one patched procedure, one not) died after operation from myocardial events, giving an overall 30-day stroke or mortality rate of 2.8 per cent. Objective follow-up assessment with duplex scanning at 1 year was completed by 94.8 per cent of patients; significantly more vessel restenoses and occlusions were observed in those not receiving patches (P < 0.01). Patch angioplasty reduces the number of immediate postoperative complications, and significantly lowers vessel restenosis and occlusion rates at 1 year after operation.

Does routine patch angioplasty after carotid endarterectomy lessen the risk of perioperative stroke?

From 1964 through 1991 we performed primary closure of the arteriotomy in 1173 patients and patch angioplasty in 506 patients after carotid endarterectomy. The decision to patch was made at the surgeon's discretion. In general a patch was used for small arteries. In the primary closure group 32 patients (2.7%) had a perioperative stroke and in the patch angioplasty group 17 (3.4%) had a stroke. The difference (2.7% vs. 3.4%) was not significant (p < 0.5275, Fisher's exact two-tailed test). A total of 240 arteries were closed with a vein patch and 11 (4.6%) of these patients had a stroke; 266 were closed with a synthetic patch (Dacron, 211; polytetrafluoroethylene, 55) and six of the patients had a stroke (2.3%). The difference in stroke rate between the vein and synthetic patch groups (4.6% vs. 2.3%) was not significant (p < 0.2159). Patch angioplasty cannot be shown to reduce the incidence of perioperative stroke. Late carotid patency was not studied. This study supports a policy of selective patch angioplasty based on arterial size rather than patching all carotid arteries. When a patch is used, we prefer filamentous Dacron as the patch material.

Carotid endarterectomy complicated by vein patch rupture

Saphenous vein patch angioplasty has been used to improve the results of carotid endarterectomy by decreasing the incidence of postoperative occlusion and recurrent stenosis. A rare but potentially lethal complication of this technique is aseptic necrosis and rupture of the vein patch during the postoperative period. We report three cases of this phenomenon and review an additional 13 cases from the literature. This event generally occurs without warning 2 to 7 days postoperatively and may result in death or stroke. At reoperation, the central portion of the vein patch is necrotic, without evidence of infection. Technical considerations in the harvesting and preparation of these grafts are reviewed, as are the physical parameters predisposing certain vein patches to rupture. Saphenous vein harvested from the ankle has been linked to every reported case. Small diameter veins in particular appear to carry a higher risk of rupture.

Histological comparison of autogenous canine fascia lata, Gore-Tex, lyophilized human fascia lata, and autogenous canine vein for vascular patch graft material in a canine arteriotomy model

Autogenous fascia lata has found little clinical use as a vascular patch graft material. Previous experience, however, suggests that it possesses attributes that might make it useful in this regard. To assess its efficacy as a vascular patch graft, nine adult mongrel dogs each underwent four arteriotomies with placements of patch grafts. The four sites included both carotid arteries and both femoral arteries. In each animal, one of four patch graft materials (autogenous canine fascia lata, Gore-Tex, lyophilized human fascia lata, and autogenous canine vein) were placed as patch material at the arteriotomy site utilizing 7-0 running sutures and loop magnification. The site for placement of each graft material was rotated serially in the animals so that each site would have equal numbers of all four graft materials applied. The animals were killed at either 6 to 8 weeks or 11 to 12 weeks after angiography of all four vessels. The specimens were then evaluated histologically. No difference was observed among any of the patch graft materials with regard to myofibroblast plaque formation. Inflammatory responses were noted to be substantially less in the canine fascia lata group than in the other three groups. Granuloma formation, however, appeared to be most significant in the autogenous canine vein group. Only one vessel was occluded. Aneurysm or pseudoaneurysm formation was not noted in any specimen. It appears from the above results that autogenous fascia lata may be an appropriate alternative to currently utilized arterial patch graft materials and that it should be evaluated further for this purpose.

Blowout of carotid venous patch angioplasty

Two cases of vein patch blowout were observed five and seven days after carotid bifurcation endarterectomy with patch angioplasty. Both patients died in spite of emergency reoperation. One patient developed respiratory failure with subsequent fatal cardiac arrest seven days after reoperation; the other died of extensive hemispheric infarction on the fifth postoperative day. At reoperation both ruptures were found to be located in the middle of the patch whereas the suture lines were intact. Both patients were hypertensive. In the first case, an accessory saphenous vein retrieved from the calf had been the only venous material available for the patch, while the other patient had varicose veins in the contralateral leg. Pathology revealed central transmural tissue necrosis in one of the disrupted patches. A review of the literature regarding morphologic alterations of free vein grafts placed within the arterial circulation as well as hemodynamics in patched arterial segments may provide additional insight as to the inherent benefits and risks of vein patch angioplasty after carotid endarterectomy. When considering vein patch angioplasty, particular attention should be directed to the gross aspect of the vein to be used as well as to any antecedent history of phlebitis.

Does carotid restenosis predict an increased risk of late symptoms, stroke, or death?

The identification of carotid restenosis as an unexpected late complication of carotid endarterectomy has prompted concerns regarding its importance as a source of new cerebral symptoms, stroke, and death. To investigate these concerns, we analyzed a consecutive series of 507 patients undergoing 566 carotid endarterectomies, each documented as technically satisfactory. Post-operative duplex Doppler examination data at 3 days, 1, 3, 6, 12 months, and annually thereafter in 484 arteries (85.5%) permitted classification of these arteries according to the most severe degree of postoperative stenosis: normal (n = 306); 1% to 19% (n = 89); 20% to 50% (n = 40); more than 50% (n = 49, including 8 occluded). The incidence of more than 50% restenosis was 14.5% in female and 7.7% in male patients (p = 0.003). Life table analyses to 10 years revealed a significantly greater life expectancy among those with restenosis (p = 0.05). Stroke was also less likely in patients with restenosis, although this difference did not reach statistical significance. When survival and stroke were both endpoints, the likelihood of patients with more than 50% restenosis remaining alive and stroke free was also greater than the less than 20% stenotic group (p = 0.03). Thus patients with carotid restenosis were less likely than patients with normal postoperative scans to have late symptoms, stroke, or early death.

Prospective study of the effectiveness and durability of carotid endarterectomy

In a series of 252 consecutive patients who underwent 282 carotid endarterectomies, we conducted clinical and angiographic follow-up for 2 to 6 years (mean, 3.2 years). Digital subtraction angiography (DSA) was done postoperatively in 95% of cases. Clinical follow-up was achieved in 97% of cases, and DSA follow-up was obtained in 66% of cases. The overall group had a 1% operative minor morbidity (three cases of minimal new neurologic deficit), no major morbidity, and a 0.7% mortality (one death from stroke and one from myocardial infarction). Complications correlated well with the patient's preoperative risk category. During follow-up, 10 minor strokes, only 1 of which was attributable to the reconstructed artery, and 10 transient ischemic attacks, 3 of which were presumably related to recurrent stenosis, occurred. Asymptomatic mild to moderate restenosis of the internal carotid or common carotid artery was identified in 10% of follow-up DSAs and severe stenosis or occlusion in 3%. Stenosis in the opposite common carotid or internal carotid artery progressed in 48 cases (26% of follow-up DSAs and ultrasound studies), and 10 of these became symptomatic. An actuarial analysis of patients who had endarterectomy indicated that the cumulative probability of ipsilateral stroke was 1.5% at 1 month and 2% at 5 years. The cumulative probability of ipsilateral stroke, transient ischemic attack, or reversible ischemic neurologic deficit was 4% at 1 month and 8% at 5 years or less than 1% per year after the first month, with censoring at the time of the second surgical procedure.

Patch angioplasty in carotid endarterectomy. Advantages, concerns, and controversies

There is much controversy in the literature regarding the precise role of patch angioplasty in carotid endarterectomy. Our report summarizes the theoretical and experimental considerations, including the hemodynamic effects and biologic behavior of the graft, associated with this technique. We present a detailed review of the literature regarding the clinical efficacy of patch angioplasty in carotid endarterectomy, including the early results, the late results, and the incidence and nature of carotid restenosis. We address concerns about the use of patch angioplasty, including the duration of cross-clamping, potential problems with the graft and suture-line disruption, and graft atherogenesis. We conclude that most recent literature indicates that patch angioplasty decreases acute complications (notably carotid occlusion) after carotid endarterectomy and prevents or delays carotid restenosis. As pressure increases to achieve a minimal rate of perioperative morbidity, many surgeons are expected to adopt patch angioplasty in more of their cases. However, in the absence of conclusive results from a prospective randomized study, opinion will continue to be divided regarding the routine versus the selective use of patch grafting in carotid endarterectomy. We present criteria for randomized trials of this technique.

Intraoperative evaluation of PTFE, Dacron and autogenous vein as carotid patch materials

Between 1983 and 1986 we prospectively randomized 71 consecutive carotid endarterectomy patients to receive patch closure with one of three materials. Autogenous saphenous vein was used in 18 cases, Dacron velour (Sauvage Filamentous) in 30 cases, and PTFE (Gore-Tex CV patch) was used in 23 cases. Blood loss in the excess of 300 ml was seen in 43% (10/23) of the PTFE group in contrast to only 22% (5/23) of the ASV group and 17% (4/23) of the Dacron group. Persistent suture hole bleeding requiring the use of a significantly larger amount of oxidized cellulose (p less than .001) was noted in the PTFE group. Operating time from clamp release to end of procedure was significantly greater in the PTFE group (p less than .05), reflecting the delay associated with suture hole bleeding. In addition, the handling characteristics of PTFE were inferior to those of Dacron or autogenous saphenous vein. Needle penetration was relatively difficult. PTFE was thicker, less flexible, and a less satisfactory match to the endarterectomized carotid than the other materials.

Carotid endarterectomy without indwelling shunts and intraoperative electrophysiologic monitoring

Although carotid endarterectomy is a common surgical procedure in North America, controversies exist regarding the type of anesthesia, the use of indwelling shunts and the need for intraoperative cerebral monitoring. We present a prospective study of 100 carotid endarterectomies performed over a three year period by a single surgeon without the use of indwelling shunts, patch grafts, or EEG monitoring. The combined stroke and mortality rate was 1%. Our results confirm those of other authors; that indwelling shunts and EEG monitoring are not absolutely essential for a satisfactory outcome in carotid endarterectomies.

Role of EEG monitoring and cross-clamping duration in carotid endarterectomy

The usefulness of electroencephalographic (EEG) monitoring as well as the significance of the period of cross clamping in carotid endarterectomy have not been completely defined. In particular, the clinical importance of major EEG changes has not been fully investigated and some recent studies seem to indicate that the method has little value. As to the duration of cross clamping, there is strong evidence that occlusion times of about 15 minutes are tolerated under general anesthesia, but no information is available regarding longer periods of occlusion. The authors describe a consecutive series of 141 carotid endarterectomies in which the patients with EEG changes were shunted only when occlusion was anticipated to last longer than 30 minutes. Early major EEG changes (during the first 4 minutes) occurred in 14% of the cases. In the absence of EEG changes, long occlusion periods of 40 to 50 minutes were well tolerated. In contrast, the 20 patients with major persistent EEG changes did not tolerate protracted occlusion and three of them had immediate postoperative neurological complications. It seems that, in these circumstances, the incidence of neurological deficit is a function of the duration of cross clamping: these three patients had undergone occlusion for 15 to 30 minutes. Their deficits partially resolved. On the basis of these results it is concluded that: EEG recording is a reliable monitoring system in carotid artery cross clamping. No major strokes due to temporary carotid artery occurred in the series. The clinical significance of major persistent EEG changes is not negligible. Cross clamping for longer than 15 minutes in the presence of significant EEG alterations is potentially dangerous.

Prevention of early restenosis and thrombosis-occlusion after carotid endarterectomy by saphenous vein patch angioplasty

The hypothesis that saphenous vein patch angioplasty protects against early postoperative restenosis and thrombosis-occlusion was tested by comparing the clinical outcome and carotid artery status of 100 carotid endarterectomies with and 100 without saphenous vein patch angioplasty performed by a single surgeon over a 30-month period. The patient population, selection, perioperative management, and the technical aspects of the operation, except for the vein patch, were essentially identical in both groups. Carotid artery status was assessed by direct continuous wave Doppler and Gee OPG at three to six months and again at one year postoperatively. There were two hospital deaths, both in the nonpatched group, one cardiac and the other neurologic due to internal carotid thrombosis. Two reversible neurological deficits due to thrombosis and one due to restenosis occurred in the non-patched group. Asymptomatic greater than 50% diameter restenosis occurred in four and asymptomatic occlusion in one non-patched carotids. There were no restenosis, no occlusions and no neurologic symptoms in the patched group. Morbidity, mortality, restenosis or thrombosis-occlusion occurred in 10/100 (10%) non-patched and 0/100 (0%) patched arteries (p less than 0.01 by Chi Square). Restenosis or thrombosis-occlusion occurred in 9/100 (9%) of non-patched and 0/100 (0%) patched arteries (p less than 0.01). These results support the use of saphenous vein patch angioplasty reconstruction of carotid endarterectomy to protect against early restenosis and thrombosis-occlusion.

Multicenter retrospective review of results and complications of carotid endarterectomy in 1981

A multicenter retrospective audit of carotid endarterectomies performed during 1981 was completed with 46 institutions contributing 3,328 cases. Overall, there was a 2.5% risk of transient neurological dysfunction following surgery and a 6% risk of stroke or death. The intra-institutional combined major morbidity and mortality varied from 21% to 0. Those institutions with greater than 700 beds had a statistically lower incidence of stroke or death than did other institutions. The incidence of stroke or death postoperatively was significantly lower for patients who were operated on for amaurosis fugax or for unspecified reasons. Those patients who were operated on for a progressing stroke had a higher incidence of stroke but this group was at greatest risk for stroke without surgery. The incidence of postoperative stroke or death was related to the type of arterial repair; vein patch grafting was statistically better than both fabric patch grafting and primary closure. When all patients who were not monitored during surgery were compared to all patients who had electroencephalographic (EEG) monitoring, there was found to be a significant statistical difference in favor of the EEG group. Endarterectomy combined with coronary artery bypass or simultaneous bilateral endarterectomies had a statistically significant higher incidence of stroke or death than did unilateral carotid endarterectomy.

Recurrent carotid stenosis. Results and complications of 57 operations

Among 1992 patients undergoing carotid endarterectomy from January 1972 through December 1984, 57 operations were performed in 51 patients for recurrent carotid stenosis. Thirty-four of these cases had undergone initial surgery at this institution while 23 had endarterectomy elsewhere. Fifty-two of the 57 operations were for symptomatic disease while five were for evidence of a progressing lesion. All operative procedures were monitored with intracerebral blood flow measurements and continuous electroencephalograms. Twenty-three patients required intraoperative shunting. There were no complications related to shunt usage or to the period of temporary occlusion in patients who did not require shunting. Recurrent stenosis was related to intimal hyperplasia in 14 cases, recurrent atherosclerosis with interluminal thrombi or degenerated plaque in 27, unexplained soft thrombus in eight, proximal scarring in six, and to aneurysms in two. Intimal hyperplasia was the most common cause for restenosis within 2 years from the date of surgery and developed earlier in patients with a primary closure than in patients closed with a patch graft. The operative complication rate was 10.5% or 4 times the risk of surgery for primary atherosclerosis at this institution. Complications were attributed primarily to intraoperative and postoperative thromboembolic events related to apparent increased thrombogenicity of these vessels. The highest complication rate occurred in the group of patients undergoing surgery for thrombotic material in the internal carotid artery, either primary or with underlying atherosclerosis. There were no neurological complications in the group with myointimal hyperplasia. The authors' experience suggests that on-lay patch grafting without endarterectomy should be used in patients with myointimal hyperplasia. Patients with complicated recurrent atherosclerosis can be treated with endarterectomy and patch grafting, but interposition vein grafts should be considered in cases in which the vessels are extensively damaged by the recurrent plaque or with an unexplained thrombus at the site of previous endarterectomy.

Correlation of postoperative and two-year follow-up angiography with neurological function in 99 carotid endarterectomies in 86 consecutive patients

Eighty-six consecutive patients in 1982 underwent 99 endarterectomies and routine postoperative digital subtraction angiography. Ten vessels were closed primarily and 89 with a patch graft. Minor morbidity was 2%, major morbidity 0%, and mortality 1%, but these varied according to the patient's preoperative medical and neurological function and angiographic findings. Postoperative patency for the common carotid artery (CCA) and internal carotid artery (ICA) was 100% and for the external carotid artery (ECA) 97%. Seventy-nine vessels were evaluated by a DSA 2 years after surgery. There was one asymptomatic occlusion in follow-up and one symptomatic re-stenosis in a patient with a proven heparin induced hypercoagulability state. The three postoperative ECA occlusions were associated with a lethal postoperative stroke, the only ICA occlusion in follow-up, and a 50% stenosis of the CCA in follow-up at the site of ECA occlusion. Vein patch grafting protected the ICA but not the CCA from recurrent stenosis. The carotid slim sign on preoperative angiograms is judged to indicate a patient at high risk of stroke morbidity.