Experience and technique for the endovascular management of iatrogenic subclavian artery injury

BACKGROUND

Inadvertent subclavian artery catheterization during attempted central venous access is a well-known complication. Historically, these patients are managed with an open operative approach and repair under direct vision via an infraclavicular and/or supraclavicular incision. We describe our experience and technique for endovascular management of these injuries.

METHODS

Twenty patients were identified with inadvertent iatrogenic subclavian artery cannulation. All cases were managed via an endovascular technique under local anesthesia. After correcting any coagulopathy, a 4-French glide catheter was percutaneously inserted into the ipsilateral brachial artery and placed in the proximal subclavian artery. Following an arteriogram and localization of the subclavian arterial insertion site, the subclavian catheter was removed and bimanual compression was performed on both sides of the clavicle around the puncture site for 20 min. A second angiogram was performed, and if there was any extravasation, pressure was held for an additional 20 min. If hemostasis was still not obtained, a stent graft was placed via the brachial access site to repair the arterial defect and control the bleeding.

RESULTS

Two of the 20 patients required a stent graft for continued bleeding after compression. Both patients were well excluded after endovascular graft placement. Hemostasis was successfully obtained with bimanual compression over the puncture site in the remaining 18 patients. There were no resultant complications at either the subclavian or the brachial puncture site.

CONCLUSION

This minimally invasive endovascular approach to iatrogenic subclavian artery injury is a safe alternative to blind removal with manual compression or direct open repair.

Initial successful management of type I endoleak after endovascular aortic aneurysm repair with n-butyl cyanoacrylate adhesive

OBJECTIVE

Transcatheter embolization with coils and other agents has been described as a treatment method for type II endoleak after endovascular aortic aneurysm repair (EVAR). Type I endoleak has not been treated commonly with such therapies, although most investigators believe they warrant definitive intervention. The liquid adhesive n-butyl 2-cyanoacrylate (n-BCA) is often used to treat congenital arteriovenous malformations. The objective of this study is to report our initial experience in treating type I endoleak with n-BCA and with a variety of other interventions.

METHODS

A retrospective review was performed of 270 patients who underwent EVAR at our institution between January 1994 and December 2002. Of these, 24 patients had type I endoleak (8.9%), diagnosed either intraoperatively (n = 13, 52%) or during follow-up (n = 12, 48%). Among these 24 patients, 17 had proximal leaks and the remaining 8 patients had distal leaks. These cases form the focus of this study.

RESULTS

Twenty-two leaks required endovascular intervention, with the following success rate: n-BCA, 12 of 13 cases (92.3%); extender cuffs, 4 of 5 cases (80%); coils with or without thrombin, 3 of 4 cases (75%). In one patient with persistent endoleak despite attempted endovascular intervention the device ultimately was surgically explanted, and the patient did well. Of six patients with endoleak initially managed expectantly, two eventually underwent attempts at definitive intervention, both with n-BCA. Three sealed spontaneously before definitive intervention could be performed; and in one 97-year-old patient who refused intervention, the aneurysm subsequently ruptured and the patient died. In total, 13 patients with type I endoleak underwent n-BCA transcatheter embolotherapy. No serious complications were directly related to this therapy. Colon ischemia developed in one patient, and was believed to be a result of thromboembolism during wire and catheter manipulation rather than n-BCA treatment. Twelve of these 13 leaks remain sealed at mean follow-up of 5.9 months (range, 0-19 months).

CONCLUSION

Our initial use of n-BCA occlusion suggests that it may be an effective and safe method of treatment of type I endoleak after EVAR. In particular, n-BCA embolotherapy may be especially useful in treating type I endoleak not amenable to placement of extender cuffs. Larger case series and longer follow-up are needed before this treatment is more broadly recommended. Type I endoleak after EVAR can be treated successfully with a variety of endovascular methods, and surgical explantation is rarely required.

Endovascular abdominal aortic aneurysm (AAA) repair since the FDA approval. Are we going too far?

BACKGROUND

Since the FDA approval of endovascular devices for abdominal aortic aneurysm (AAA) repair, clinicians have been relaxing the strict inclusion criteria of the clinical trials. We have reviewed our experience during and after the clinical trials to examine changes in patient selection, technical aspects of the procedure, and outcome.

METHODS

A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed.

RESULTS

Endovascular AAA repair was attempted in 130 patients: 46 (35.4%) as a part of clinical trials (Group I), and 84 (64.6%) since the FDA approval of the devices (Group II). Significant differences in patient selection included: a higher proportion of short (<15 mm) proximal necks in Group II (28.6 vs 0.0%, p<0.001), and a higher proportion of iliac occlusive disease in Group II (48.8 vs 15.4%, p=0.001). Additional trends suggested that Group II AAA's were more complex, including increased proximal neck angulation, increased proximal calcification, increased presence of proximal thrombus, and increased iliac tortuosity. Significant differences in technical aspects of the procedure included increased usage of iliac angioplasty (46.4 vs 13.3%, p<0.001), iliac stenting (31 vs 8.9%, p<0.01), and conduit access to the external iliac artery (10.7 vs 0%, p=0.03) in Group II. Analysis of outcome revealed a decreased incidence of the following in Group II cases: conversions to open repair (2.4 vs 10.9%), lower extremity ischemia (3.6 vs 13.0%), and graft limb occlusion (2.4 vs 8.7%). Other major perioperative complications did not differ significantly between the 2 groups. However, although the overall rate of any endoleak noted in the postoperative course was decreased in Group II cases (26.2 vs 32.6%), the incidence of proximal or distal attachment site leaks has increased (11.9 vs 4.3%, p=0.14). Although this comparison did not reach statistical significance, the magnitude of the increase is concerning.

CONCLUSIONS

Although we have been able to offer endovascular AAA repair to a larger number of patients since FDA approval, endovascular management of increasingly complex proximal necks and increased iliac artery disease appears to have increased the incidence of attachment site endoleaks. Although many of these leaks have been successfully managed with adjunctive endovascular procedures, their increasing incidence is worrisome and suggests that we may need to re-evaluate current inclusion criteria for using this technology. Although difficult access issues have been handled with adjunctive procedures, the presence of a short, angulated proximal neck may be difficult to overcome, and may not be well suited for endovascular repair with the currently available devices.

Carotid endarterectomy in patients 55 years of age and younger

Prior studies have suggested that young patients may be more prone to recurrent disease after carotid endarterectomy (CEA). The goal of this study was to review a series of CEAs performed on younger patients (< or = 55 years) and to determine if these patients are more likely to develop recurrent stenosis. A review was conducted of CEAs performed from 1985 through 1994. Analysis was performed on a study group of 94 young patients who underwent 109 CEAs during this time. A control group of 222 patients older than 55 years who underwent 256 CEAs during the years 1991 through 1993 was selected for comparison. During a mean of nearly 4 years of follow-up, younger patients were significantly more likely to experience a late failure of CEA, including total occlusion of the operated artery, or recurrent stenosis requiring redo surgery. Careful patient evaluation is important in choosing younger patients who require CEA. Implications of these data include mandating careful noninvasive follow-up examinations for younger patients undergoing CEA.

Carotid endarterectomy in female patients: are the concerns of the Asymptomatic Carotid Atherosclerosis Study valid?

OBJECTIVES

Although the results of the Asymptomatic Carotid Atherosclerosis Study clearly demonstrated the benefit of surgical over medical management of severe carotid artery stenosis, the results for women in particular were less certain. This was to some extent because of the higher perioperative complication rate observed in the 281 women (3.6% vs 1.7% in men). The objective of this study was to review a large experience with carotid endarterectomy in female patients and to determine whether the perioperative results differed from those of male patients.

METHODS

A review was conducted of a prospectively compiled database on all carotid endarterectomies performed between 1982 and 1997. Operations performed in 991 female patients were compared with those performed in 1485 male patients.

RESULTS

Female patients had a significantly lower incidence of diabetes, coronary artery disease, and contralateral carotid artery occlusion than did male patients. Female patients had a significantly higher incidence of hypertension. There were no significant differences in the age, smoking history, anesthetic route, shunt use, or clamp tolerance between the two groups. Of 991 female patients, 659 (66.5%) had preoperative symptoms, whereas 332 (33.5%) cases were performed for asymptomatic stenosis. Among 1485 male patients, 1041 (70.1%) had symptoms, and 444 (29.9%) were symptom free before surgery. There were no significant differences noted in the perioperative stroke rates between men and women overall (2.3% vs 2.4%, P =.92), or when divided into symptomatic (2.5% vs 3.0%, P =.52) and asymptomatic (2.0% vs 1.2%, P =.55) cases.

CONCLUSIONS

Carotid endarterectomy can be performed with equally low perioperative stroke rates in men and women in both symptomatic and asymptomatic cases. In this series, symptom-free female patients had the lowest overall stroke rate. The concerns of the Asymptomatic Carotid Atherosclerosis Study regarding the benefit of carotid endarterectomy in female patients should therefore not prevent clinicians from recommending and performing carotid endarterectomy in appropriately selected symptom-free female patients.

Transcatheter embolization of complex pelvic vascular malformations: results and long-term follow-up

OBJECTIVES

Vascular malformations of the pelvis are rare and present a difficult therapeutic challenge. Surgical treatment is notoriously difficult and carries a high likelihood of recurrence. Surgical proximal ligation of a feeding vessel may in fact be contraindicated, because it can make subsequent transcatheter therapy impossible. The purpose of this study was to review our results with transcatheter embolization therapy in symptomatic complex pelvic vascular malformations in 35 patients.

METHODS

A retrospective review was conducted of a prospectively compiled database of all patients undergoing transcatheter therapy of a pelvic vascular malformation at our institution.

RESULTS

The mean age of the patients was 34 years (range, 16 months-66 years), and 51% were male. The most common presenting symptoms included pain (59%), a visible or palpable lesion (62%), associated palpable pulsation or thrill (44%), hemorrhage (27%), congestive heart failure (18%), and symptoms due to mass effect (35%). A significant number of patients had undergone previous, unsuccessful attempted surgical treatment of the lesion (32%). The most common type of lesion noted on arteriography was arteriovenous shunting (89%). Patients required a mean of 2.4 embolization procedures (range, 1-11 procedures) over a mean period of 23.3 months (range, 1-144 months). The most common agents used were rapidly polymerizing acrylic adhesives. The most common vessels involved and treated were branches of the hypogastric artery (82%). More than one procedure were performed in 20 patients (53%). Seven were planned as staged embolizations, whereas 13 were due to residual or recurrent symptoms. Adjunctive surgical procedures were performed subsequent to embolization therapy in five patients (15%). Eighty-three percent of patients were asymptomatic or significantly improved at a mean follow-up of 84 months (range, 1-204 months).

CONCLUSIONS

Pelvic vascular malformations are difficult to eradicate completely, and recurrences are common. Many patients require multiple therapeutic interventions. However, most of these difficult cases have good results in the long term. Transcatheter embolization plays a significant role in, and may be the treatment of choice for, symptomatic pelvic vascular malformations.

Causes of perioperative stroke after carotid endarterectomy: special considerations in symptomatic patients

In order to maximize the efficacy of carotid endarterectomy (CEA), the rate of perioperative stroke must be kept to a minimum. A recent analysis of carotid surgery at our institution found that most perioperative strokes were due to technical errors resulting in thrombosis or embolization. From 1992 through 1997 we have performed nearly 1200 additional CEAs; the purpose of this study was to examine recent trends in the causes of perioperative stroke, with specific attention to differences in symptomatic and asymptomatic patients. The records of 1041 patients undergoing 1165 CEAs were reviewed from a prospectively compiled database. Analysis of these data showed that a history of preoperative stroke appears to increase the risk of perioperative stroke after CEA. Surgical factors associated with perioperative stroke include an inability to tolerate clamping, use of an intraarterial shunt, and having surgery performed under general anesthesia; these factors are clearly interrelated and only the use of intraarterial shunting remains a risk factor by multivariate analysis. Over half of all perioperative strokes (54%) appear to be caused by intraoperative or postoperative thrombosis and embolization. The patient requiring use of intraarterial shunting and/or with a preoperative stroke most likely has a significant watershed area of brain at increased risk of infarction. However, technical errors are still the most common cause of perioperative stroke in these high-risk patients. Such high-risk patients may manifest clinical stroke from small emboli that may be tolerated by asymptomatic clamp-tolerant patients. Technical precision and appropriate cerebral protection are particularly critical for successful outcomes in high-risk patients.

Lower extremity paraparesis or paraplegia subsequent to endovascular management of abdominal aortic aneurysms

Lower extremity paraplegia or paraparesis is an extremely rare event after operative repair of infrarenal abdominal aortic aneurysms (AAAS). We report two such cases that occurred after endovascular repair or attempted endovascular repair of routine AAAS. To our knowledge, these are the first two cases reported specifically in the literature. These cases may have significant implications with regard to the endovascular management of AAAS, because atheroembolization to the spinal cord appears to be the underlying cause.

Immediate reexploration for the perioperative neurologic event after carotid endarterectomy: is it worthwhile?

PURPOSE

When managing a new neurologic deficit after carotid endarterectomy (CEA), the surgeon is often preoccupied with determining the cause of the problem, requesting diagnostics tests, and deciding whether the patient should be surgically reexplored. The goal of this study was to analyze a series of perioperative neurologic events and to determine if careful analysis of their timing and mechanisms can predict which cases are likely to improve with reoperation.

METHODS

A review of 2024 CEAs performed from 1985 to 1997 revealed 38 patients who manifested a neurologic deficit in the perioperative period (1.9%). These cases form the focus of this analysis.

RESULTS

The causes of the events included intraoperative clamping ischemia in 5 patients (13.2%); thromboembolic events in 24 (63.2%); intracerebral hemorrhage in 5 (13.2%); and deficits unrelated to the operated artery in 4 (10.5%). Neurologic events manifesting in the first 24 hours after surgery were significantly more likely to be caused by thromboembolic events than by other causes of stroke (88.0% vs. 12.0%, P<.002); deficits manifesting after the first 24 hours were significantly more likely to be related to other causes. Of 25 deficits manifesting in the first 24 hours after surgery, 18 underwent immediate surgical reexploration. Intraluminal thrombus was noted in 15 of the 18 reexplorations (83. 3%); any technical defects were corrected. After the 18 reexplorations, in 12 cases there was either complete resolution of or significant improvement in the neurologic deficit that had been present (66.7%).

CONCLUSIONS

Careful analysis of the timing and presentation of perioperative neurologic events after CEA can predict which cases are likely to improve with reoperation. Neurologic deficits that present during the first 24 hours after CEA are likely to be related to intraluminal thrombus formation and embolization. Unless another etiology for stroke has clearly been established, we think immediate reexploration of the artery without other confirmatory tests is mandatory to remove the embolic source and correct any technical problems. This will likely improve the neurologic outcome in these patients, because an uncorrected situation would lead to continued embolization and compromise.

Internal jugular vein thrombosis in association with the ovarian hyperstimulation syndrome

Thrombosis of the internal jugular vein is a rare entity with the potential for serious consequences. Most of the reported cases of jugular venous thrombosis have occurred in the presence of an indwelling venous catheter, an established hypercoagulable state, or in association with head and neck sepsis. This report presents a case of a patient in whom jugular venous thrombosis developed during the first trimester of pregnancy after in vitro fertilization. Thromboembolism in these circumstances can be related to a condition known as the ovarian hyperstimulation syndrome. The presentation of severe neck pain in pregnant women, especially in those who have undergone assisted reproduction procedures, should prompt evaluation by duplex scan to evaluate the jugular veins for thrombosis. Anticoagulation is the treatment of choice.

Redo carotid surgery: An analysis of materials and configurations used in carotid reoperations and their influence on perioperative stroke and subsequent recurrent stenosis

OBJECTIVE

The ideal method of arterial reconstruction in operations for recurrent carotid disease after prior endarterectomy is unknown. The goal of this study was to review a series of carotid reoperations and to determine whether the surgical technique influenced the rate of perioperative stroke, late stroke, or secondary restenosis.

METHODS

A retrospective review was conducted of 82 carotid reoperations performed on 74 patients at our institution.

RESULTS

The patient population included 39 men (52.7%) and 35 women (47.3%), with a mean age of 67.5 years. The indications for redo surgery included transient ischemic attack or amaurosis fugax in 35.3% of the patients, stroke in 6.1%, and asymptomatic restenosis (>80%) in 58.5%. Patch angioplasty with or without redo endarterectomy was used in 47 cases (57.3%), with saphenous vein in 26 (31.7%), Dacron in 15 (18.3%), and polytetrafluoroethylene in 6 (7.3%). Interposition grafting was used in 35 cases (42.7%), with saphenous vein in 9 (11.0%), Dacron in 10 (12.2%), and polytetrafluoroethylene in 16 (19.5%). The perioperative complications included three strokes (3.7%). There was a trend toward increased perioperative neurologic complications with interposition grafting when compared with patch angioplasty (8.6% vs 2.1%), although this did not reach statistical significance. Long-term clinical follow-up was obtained in all cases with a mean duration of 35 months, with follow-up duplex scanning performed in 89.2%. The late failures of redo surgery included four significant secondary restenoses and five total occlusions. There was a trend towards improved long-term results with interposition grafting as opposed to patch angioplasty. However, the cases in which reconstruction was performed with a vein had a significantly higher rate of late failures (stroke, secondary recurrent stenosis, or occlusion) than those in which reconstruction was performed with any prosthetic material (26.7% vs 2.3%; P =.002 by Fisher exact test).

CONCLUSION

The use of autologous material for redo carotid surgery in any configuration appears to significantly increase the rate of subsequent recurrent stenosis or total occlusion of the operated artery. The reason for this finding is unclear but may be related to both host and technical factors. Prosthetic material may be more durable in the long-term for redo carotid surgery. Interposition grafting for redo carotid surgery may increase the perioperative neurologic complication rate to some degree; however, this was not statistically significant in this series. Interposition grafting may be a more durable solution in long-term follow-up than redo endarterectomy and patch angioplasty. A longer follow-up period will be needed to confirm this conclusion.

Report of a single-institution experience using the EVT endovascular abdominal aortic aneurysm graft in 25 patients

The purpose of this study was to review a single-institution experience with the Endovascular Technologies [(EVT) Menlo Park, CA] transfemoral, endovascular system of abdominal aortic aneurysm repair. This study was performed at a medical center participating in the phase 1 and phase 2 evaluations of the EVT device. We reviewed the 25 cases performed at our institution. The patient population consisted of 21 males (84%) and 4 females (16%), with a mean age of 73.4 years. A total of eight tube grafts (32%) and 17 bifurcated grafts (68%) were attempted. Twenty-two of the twenty-five grafts were successfully implanted endovascularly (88%). Implantation failures were due to tortuosity or inadequate caliber of the iliac arteries, or incorrect positioning of the graft. The results show that endovascular repair of abdominal aortic aneurysms is an appropriate treatment for selected patients. Conversions to open repair have decreased as experience has grown; careful patient selection can minimize the number of unsuccessful implantations. Patient selection and accurate technique can also minimize the number of endoleaks.

Anesthetic methods in reoperative carotid surgery

It has been suggested that general anesthesia is the preferred method for reoperative carotid surgery for several reasons, including: the difficulty of the reoperative dissection; the disease may extend unusually high into the internal carotid artery; and the reconstruction required may be more complex than a typical endarterectomy. The purpose of this study is to show that reoperative carotid surgery can be performed safely under regional anesthesia. The records of 109 reoperative carotid operations performed on 96 patients over the past 25 years were reviewed. Procedures performed under regional anesthesia were compared to those performed under general anesthesia with respect to patient characteristics, intraoperative courses, and perioperative results. Regional anesthesia was utilized in 79 operations (72.5%); 30 operations were performed with general anesthesia (27.5%). The two patient groups were essentially equivalent with regard to atherosclerotic risk factors, preoperative neurologic symptoms, and the prevalence of contralateral total occlusion. The etiologies for recurrent disease included recurrent atherosclerosis (50.4%), intimal hyperplasia (30.3%), and vein patch aneurysm (9.2%). The methods of reconstruction employed included saphenous vein patch (47.7%), vein interposition graft (11.9%), prosthetic patch (20.2%), and prosthetic graft (20.2%). Perioperative strokes occurred in one case performed under regional anesthesia (1.3%), and in two cases under general anesthesia (6.6%); this difference was not statistically significant. Reoperative carotid artery surgery can be performed under regional anesthesia safely in the majority of instances. The aforementioned theoretical factors in favor of general anesthesia could also lead to technical difficulties with intraarterial shunt insertion. Having the patient awake, even if just long enough to prove that the patient will tolerate carotid artery clamping, might simplify many of these operations by avoiding shunt insertion. Regional anesthesia should therefore be considered an acceptable option in cases of reoperative carotid surgery.

A unique approach in the management of vena caval thrombosis in a patient with Klippel-Trénaunay syndrome

Vena caval thrombosis has posed a surgical therapeutic challenge for many years. Historically, spiral vein grafts and synthetic materials used as prostheses have had variable results. The use of the stent may serve as a more promising alternative when used in the capacity to relieve caval obstruction. A case is reported in which a young woman with Klippel-Trénaunay syndrome has exercise intolerance and associated hypotensive cardiovascular collapse caused by inferior vena caval thrombosis. Recanalization of her inferior vena cava was successfully achieved and subsequently maintained through the placement of two Wallstents across the lesion. Although most venous stenting procedures have thus far been used in the treatment of venous obstruction caused by malignancy, inferior vena cava stenting in this patient with inferior vena caval thrombosis and Klippel-Trénaunay syndrome suggests that venous stenting might offer an alternative therapeutic modality in treating a broader spectrum of occlusive venous disease.

Comparison of lumbar and thoracic epidural narcotics for postoperative analgesia in patients undergoing abdominal aortic aneurysm repair

OBJECTIVE

To determine whether there is an advantage of thoracic over lumbar epidural narcotics for postoperative analgesia in patients undergoing abdominal aortic aneurysm repair.

DESIGN

A prospective randomized study.

SETTING

Subjects were inpatients at an academic medical center.

PARTICIPANTS

Fifty-two patients scheduled for elective abdominal aortic aneurysm repair.

INTERVENTIONS

Subjects were randomly assigned to receive lumbar or thoracic epidural narcotics. Group 1 (n = 26) had lumbar, and group 2 (n = 26) had thoracic epidural catheters placed preoperatively. All patients were monitored with pulmonary artery catheters and arterial catheters, and had general endotracheal anesthesia, in addition to epidural anesthesia with 2% lidocaine. All patients received 5 mg of epidural morphine after intubation. Pain scores were monitored hourly for 36 hours using a visual analog scale, and additional narcotics were given, depending on the level of pain. Complications caused by epidural narcotics were recorded.

RESULTS

There was no difference between groups as to the daily dose of narcotics or the time between narcotic doses. Hourly pain scores showed significant differences during hours 6, 7, 8, 20, 34, and 36, with pain scores being lower in group 1. There was no difference in the rate of complications between the groups.

CONCLUSION

There is no advantage of thoracic over lumbar epidural analgesia using morphine in patients undergoing abdominal aortic aneurysm repair.

Natural history and management of the asymptomatic, moderately stenotic internal carotid artery

PURPOSE

Although it has been widely accepted as the evidence supporting prophylactic carotid endarterectomy, aspects of the Asymptomatic Carotid Atherosclerosis Study have left unease among clinicians who must decide which individuals without symptoms should undergo surgery. Additional confusion has been created by the fact that the several large randomized trials investigating the efficacy of carotid endarterectomy have classified and analyzed different categories of carotid stenosis. In an effort to provide more information on the natural history of asymptomatic, moderate carotid artery stenosis (50% to 79%), we have reviewed data on approximately 500 arteries.

METHODS

Records of our vascular laboratory from 1990 to 1992 were reviewed. We identified 425 patients with asymptomatic, moderate carotid artery stenosis; 71 patients had bilateral stenoses in this category, resulting in 496 arteries for study.

RESULTS

The mean length of follow-up was 38 +/- 18 months. New ipsilateral strokes occurred in 16 (3.8%) patients. New ipsilateral transient ischemic attacks occurred in 25 (5.9%) patients. Documented progression of stenosis occurred in 48 (17%) of the 282 arteries for which a repeat duplex examination was available. Arteries that progressed to > 80% stenosis were significantly more likely to have caused strokes than those that remained in the 50% to 79% range (10.4% vs 2.1%, p < 0.02). Conversely, arteries that remained stable in the degree of stenosis were significantly more likely to have remained asymptomatic than those that progressed (92.7% vs 62.5%, p < 0.001). With life-table analysis the estimated cumulative ipsilateral stroke rate was 0.85% at 1 year, 3.6% at 3 years, and 5.4% at 5 years. The respective estimated cumulative transient ischemic attack rates were 1.9%, 5.5%, and 6.3%. The respective estimated cumulative rates for progression of stenosis were 4.9%, 16.7%, and 26.5%. Life-table comparison of ipsilateral stroke revealed a significantly higher cumulative rate among arteries that progressed in the degree of stenosis than among those that remained stable (p < 0.001).

CONCLUSIONS

Based on the low rate of permanent neurologic events in these cases, prophylactic carotid endarterectomy for the asymptomatic, moderately stenotic internal carotid artery cannot currently be recommended. The only factor that appears to predict increased risk for future stroke is progression of stenosis. Careful follow-up with serial repeat duplex examinations must be performed in these patients. Until there are widely accepted duplex parameters that can provide all clinicians with accurate identification of arteries with narrowing corresponding to 60% stenosis as defined by the Asymptomatic Carotid Atherosclerosis Study, all surgeons will need to be aware of specifically how their noninvasive laboratories are deriving their results. For the many laboratories that continue to use the University of Washington criteria, 80% should remain the level above which prophylactic carotid endarterectomy is warranted.

Causes of the increased stroke rate after carotid endarterectomy in patients with previous strokes

Patients who have sustained a preoperative stroke are at increased risk for perioperative stroke after carotid endarterectomy. At our institution this risk was recently shown to be increased two-to threefold. The purpose of this study was to investigate the reasons for the increased surgical risk in these patients. Records of 606 patients undergoing 704 consecutive carotid endarterectomies from 1988 through 1993 were reviewed. Patients who suffered preoperative strokes (n = 183) were compared to those who were either asymptomatic or experienced only transient ischemic attacks (TIAs) preoperatively (n = 423). Of the 183 patients who had suffered preoperative strokes, eight patients who experienced perioperative strokes after endarterectomy were compared with 175 who successfully underwent surgery. Patients with a prior stroke had an increased perioperative stroke rate (4.4% versus 1.2%, p = 0.01). They had a significantly higher incidence of hypertension (62.6% versus 47.9%, p < 0.001), cardiac disease (54.7% versus 40.7%, p = 0.001), and positive smoking history (52% versus 40.6%, p = 0.01) than did the asymptomatic/TIA patients. The presence of contralateral total occlusion was also significantly increased (22% versus 10.3%, p < 0.001). Although not statistically significant due to the overall small number of patients who sustained perioperative strokes, the preoperative stroke patients who sustained perioperative strokes had a higher incidence of hypertension (87.5% versus 61.5%) and contralateral total occlusion (37.5% versus 21.3%) than did those who successfully underwent surgery. Patients with both a prior stroke and contralateral total occlusion had a 7.5% perioperative stroke rate. Patients with both a prior stroke and hypertension had a 6.1% perioperative stroke rate. The perioperative strokes in patients with prior strokes were not related to the severity of the prior stroke, the interval between the stroke and surgery, the use of a shunt, or the type of anesthesia employed. Patients who have sustained preoperative strokes have a higher incidence of significant medical illnesses and overall cerebrovascular disease. Hypertension and total occlusion of the contralateral carotid artery appear to be particularly poor prognostic indicators of outcome after endarterectomy in these patients. Patients who have sustained preoperative strokes may be more likely to display clinical neurologic symptoms in response to any form of cerebral ischemia. In this higher risk subgroup, intraoperative and surgeon-dependent factors appear to play less of a role.

A comparison of regional and general anesthesia in patients undergoing carotid endarterectomy

PURPOSE

The optimal anesthetic for use during carotid endarterectomy is controversial. Advocates of regional anesthesia suggest that it may reduce the incidence of perioperative complications in addition to decreasing operative time and hospital costs. To determine whether the anesthetic method correlated with the outcome of the operation, a retrospective review of 3975 carotid operations performed over a 32-year period was performed.

METHODS

The records of all patients who underwent carotid endarterectomy at our institution from 1962 to 1994 were retrospectively reviewed. Operations performed with the patient under regional anesthesia were compared with those performed with the patient under general anesthesia with respect to preoperative risk factors and perioperative complications.

RESULTS

Regional anesthesia was used in 3382 operations (85.1%). There were no significant differences in the age, gender ratio, or the rates of concomitant medical illness between the two patient populations. The frequency of perioperative stroke in the series was 2.2%; that of myocardial infarction, 1.7%; and that of perioperative death, 1.5%. There were no statistically significant differences in the frequency of perioperative stroke, myocardial infarction, or death on the basis of anesthetic technique. A trend toward higher frequencies of perioperative stroke (3.2% vs 2.0%) and perioperative death (2.0% vs 1.4%) in the general anesthesia group was noted. In examining operative indications, however, there was a significant increase in the percentage of patients receiving general anesthesia who had sustained preoperative strokes when compared with the regional anesthesia patients (36.1% vs 26.4%; p < 0.01). There was also a statistically significant higher frequency of contralateral total occlusion in the general anesthesia group (21.8% vs 15.4%; p = 0.001). The trend toward increased perioperative strokes in the general anesthesia group may be explicable either by the above differences in the patient populations or by actual differences based on anesthetic technique that favor regional anesthesia.

CONCLUSIONS

In a retrospective review of a large series of carotid operations, regional anesthesia was shown to be applicable to the vast majority of patients with good clinical outcome. Although the advantages over general anesthesia are perhaps small, the versatility and safety of the technique is sufficient reason for vascular surgeons to include it in their armamentarium of surgical skills. Considering that carotid endarterectomy is a procedure in which complication rates are exceedingly low, a rigidly controlled, prospective randomized trial may be required to accurately assess these differences.

The surgical management of carotid artery stenosis in patients with previous neck irradiation

BACKGROUND

A history of therapeutic irradiation to the neck complicates the management of carotid artery occlusive disease. Serious surgical concerns are raised regarding alternative incisions, difficult dissections, and adequate wound closure. Pathology may be typical atherosclerotic occlusive disease or radiation-induced arteritis. In order to establish guidelines for the treatment of these patients, we have reviewed our operative experience.

PATIENTS AND METHODS

A review of our operative experience over the past 15 years revealed 10 patients with a history of prior irradiation to the neck who underwent 14 carotid operations.

RESULTS

The indications for radiation included laryngeal carcinoma and lymphoma. Five patients had undergone previous radical neck dissections, and four patients had permanent tracheostomies. The surgical indications were asymptomatic high-grade stenosis in 7 cases, transient ischemic attack in 4 cases, stroke in 2 cases, and a pseudoaneurysm in 1 case. Conventional carotid endarterectomy with patch angioplasty was used in 10 of the 14 operations. In the remaining four operations, saphenous vein interposition grafting was utilized to replace the diseased segment of carotid artery secondary to a panarteritis. Wound closure required dermal grafting in two of five cases where surgery was performed ipsilateral to a prior radical neck dissection. One perioperative cerebral infarction occurred; there were no other neurologic or non-neurologic complications. All patients are doing well in one- to five-year follow-up, with serial postoperative duplex scans demonstrating no signs of recurrent stenosis.

CONCLUSIONS

Patients with a history of irradiation to the neck should be screened for the presence of carotid disease. Carotid occlusive disease should be treated surgically in these patients with the usual indications. Intraoperative surgical management is similar to that of non-irradiated patients. Concerns about difficulty in achieving an adequate endarterectomy plane and about problems with wound closure have generally been unfounded.