Faculty Bibliography

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

The natural history and clinical significance of type II or branch vessel endoleaks following endovascular aortic aneurysm (AAA) repair remain unclear. Some investigators have suggested that these endoleaks have a benign course and outcome and that they can be safely observed. The purpose of this study was to document the natural history and outcome of all type II endoleaks that have occurred following endovascular AAA repair at our institution. A review of a prospectively compiled database of all endovascular AAA repairs performed at our institution was performed. From this review, we determined that type II endoleaks appear to have a relatively benign course, with a reasonable chance of spontaneously sealing within a 2-year period. No cases of rupture or aneurysm enlargement were documented in patients with open type II leaks. However, almost one-third of the patients did not manifest a type II leak until after their initial CT scan. The implications of such a 'delayed' leak are unclear. Careful follow-up remains mandatory in patients with type II endoleaks to better define outcome

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

To determine whether choice of material used for patch closure following carotid artery endarterectomy (CAE) influences rates of early or late restenosis, stroke, and death, 274 consecutive CAEs were retrospectively reviewed. Saphenous vein (SV) was used in 159 (58.0%) procedures; everted, double-thickness jugular vein (JV) was used in 25 (9.1%); and knitted Dacron (KD) was used in 90 (32.9%). Primary closure was not used in this series. There were four perioperative strokes: two (1.3%) in SV, one (4%) in JV, and one (1.1%) in KD (NS). Follow-up was obtained on 263 (96%) operated arteries (mean 41.5 months). Duplex scan results were available for 236 (89.7%) of these arteries (mean follow-up time 33.7 months). There were three (2%) late strokes in SV and two (2.2%) in KD (NS). In long-term follow-up, one patient (0.7%) in SV and two (2.4%) in KD developed > 80% stenosis (NS). One patient (0.7%) in SV, one (5.3%) in JV, and one (1.2%) in KD had total occlusion of the operated vessel (NS). Three procedures (2.2%) in SV, 1 (5.3%) in JV, and 7 (8.5%) in KD demonstrated moderate stenosis (50-79%) (NS). Three-year follow-up shows that choice of patch material does not affect early or late stroke rate, stroke-related death rate, rate of high-grade (> 80%) restenosis, or rate of total occlusion. There is a higher incidence of moderate stenosis in KD. Although our results and a review of the literature do not indicate that these patients are at increased risk for symptoms or progression of stenosis, they should be followed by duplex scanning to ensure that this is the case

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

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

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

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

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

Endoleak is the persistence of blood flow outside the lumen of an endograft, but within an aneurysm sac or adjacent vessel being treated by the graft. Diagnosis may be difficult, and treatment remains somewhat controversial. The purpose of this article is to discuss the clinical significance and appropriate management of endoleaks within the context of our current understanding of this phenomenon. The diagnosis of an endoleak can be made by conventional angiography, duplex ultrasound, intravascular ultrasound (IVUS), and computed tomography (CT) angiography. All of these modalities are effective, although CT angiography may be the most sensitive. Endoleaks can be categorized into 5 classes: (1) perigraft flow around the proximal end of the endograft; (2) perigraft flow around the distal end of the endograft; (3) flow through a defect in the body of the endograft; (4) flow between segments of a multicomponent endovascular graft; and (5) flow between arterial branches within an aneurysm sac. The first 4 classes have been shown to represent a clinical situation in which systemic arterial pressure is transmitted to an inadequately excluded aneurysm sac, placing the sac at risk of rupture. In contrast, branch-flow leaks do not appear to carry an increased risk of rupture, provided there is no increase in aneurysm sac diameter. However, an increase in the diameter of an aneurysm sac after endograft implantation may be a sign of occult endoleak, even if not visualized by current imaging techniques. Thus, we believe that collateral branch leaks with no associated aneurysm sac expansion may be observed with regular follow-up by CT angiography. All other endoleaks should be treated with adjunctive endovascular maneuvers or explanation of the endograft with standard open repair-in short, routine follow-up imaging on endografts to detect the presence of late endoleaks or aneurysm sac expansion