Carotid endarterectomy after NASCET and ACAS: a statewide study. North American Symptomatic Carotid Endarterectomy Trial. Asymptomatic Carotid Artery Stenosis Study.

PURPOSE: Since the North American Symptomatic Carotid Endarterectomy Trial (NASCET) and the Asymptomatic Carotid Artery Stenosis Study (ACAS) established the efficacy of carotid endarterectomy at large academic centers, there have been two community-based studies of outcomes after this operation. The purpose of this study was to perform a statewide survey to evaluate postoperative morbidity and mortality after carotid endarterectomy among patients throughout Maine. METHODS: A statewide registry was established to collect prospective data on carotid operations from January 1 to December 31, 1995. All surgeons and hospitals in the state were solicited to participate. All carotid endarterectomies were intended to be included; the only exclusion criterion was out-of-state residence. Comorbidities, preoperative studies, surgical indications, operative technique, and postoperative outcomes were analyzed. State administrative data were used to assess registry coverage. RESULTS: Ten of 17 hospitals participated, and 58% of all carotid endarterectomies performed in the state were included. Three hundred sixty-four operations were entered into the registry. Forty-four percent of the operations were performed for transient ischemic attack, 37% for asymptomatic stenosis, and 19% for stroke. The postoperative stroke rate was 2.5% with a total neurologic complication rate of 4.7% (transient ischemic attack and stroke). There was one postoperative death (mortality rate 0.3%). Patients with symptoms had a higher incidence of postoperative stroke (4.0% vs 0% asymptomatic; p < 0.05) and transient ischemic attacks (3.8% vs 0.8% asymptomatic). Hospital stroke rates varied from 0% to 7%. Stroke rate did not differ significantly between low-volume hospitals (2 to 28 patients/year, 3.3%) and high-volume hospitals (29 to 101 patients/year, 2.3%) or between low-volume surgeons (fewer than 11 operations/year, 1.7%) and high-volume surgeons (more than 12 operations/year, 2.4%). Among 26 reporting surgeons, stroke rate varied from 0% to 10%; the absolute number of strokes per surgeon varied between zero and two. CONCLUSION: The statewide registry showed a postoperative stroke plus death rate of 2.8%, comparable with the NASCET and ACAS findings. Although this study had inherent limitations, the results from one state, including a variety of community practices, achieved results comparable with those of landmark trials.

Vascular endothelial growth factor increases the mitogenic response to fibroblast growth factor-2 in vascular smooth muscle cells in vivo via expression of fms-like tyrosine kinase-1.

Vascular endothelial growth factor (VEGF) has traditionally been considered an endothelial cell-specific factor inducing angiogenesis and vascular permeability in vivo. In the present study, expression of VEGF and its receptors, fetal liver kinase-1 (flk-1) and fms-like tyrosine kinase-1 (flt-1), was examined in rat carotid arteries after balloon injury. Although VEGF and flk-1 were not detectable, high levels of flt-1 mRNA and protein were expressed by smooth muscle cells (SMCs) in the neointima, as demonstrated by en face in situ hybridization and Western blotting. Intimal SMC proliferation in chronically denuded rat carotid arteries was unaffected by intraluminal infusion of VEGF, whereas fibroblast growth factor (FGF)-2 increased the number of replicating SMCs 4-fold. Pretreatment with VEGF doubled the mitogenic response to infused FGF-2 by increasing SMC replication in deeper layers of the intima. VEGF increased the permeability of chronically denuded vessels to plasma proteins but had no effect on the uptake of locally infused biotinylated FGF-2. These findings demonstrate that vascular SMCs express functional flt-1 receptors after arterial injury and that VEGF has synergistic effects with FGF-2 on SMC proliferation. These effects are likely to be mediated by a VEGF-mediated increase in permeability as well as a direct interaction between the VEGF and FGF signaling pathways.

Abdominal vascular catastrophes.

Abdominal vascular catastrophes are due to rupture of arterial aneurysms or arterial occlusion leading to end organ ischemia. In this article, we will discuss rupture of abdominal aortic aneurysms and visceral artery aneurysms. Arterial occlusion secondary to embolism, thrombosis and dissection will be presented. Mesenteric ischemia secondary to low flow states, venous thrombosis and other conditions will also be covered. These uncommon, but frequently fatal pathological processes, are of interest to both general and vascular surgeons.

Should percutaneous transluminal renal artery angioplasty be applied to ostial renal artery atherosclerosis?

PURPOSE: The purpose of this study was to review the results of percutaneous transluminal renal artery angioplasty (PTRA) in patients with atherosclerosis to assess safety, anatomic and functional outcome, and differences in outcome between ostial and nonostial lesions. METHODS: We used retrospective review of 52 consecutive patients who had undergone attempted PTRA for renal artery atherosclerosis during the calendar years 1987 to 1992. RESULTS: Fifty-two patients had 60 renal arteries on whom PTRA was attempted. The mean age was 68 years. Atherosclerosis was generalized in 81% of the patients. The indication for angioplasty was salvage of functioning renal parenchyma in 81% of patients. Eight patients were undergoing dialysis at the time of attempted PTRA. Five arteries (8%) could not be dilated. There were one cardiac death and two arterial complications requiring surgery within 30 days. Thirty-five percent of patients with available angiograms had an anatomic improvement above a threshold of one stenotic group (30% to 40% diameter improvement), with residual stenosis of less than 50%. Half of patients treated for hypertension had improvement in their hypertension. Overall, there was no change in creatinine levels before and after the procedure. Four of eight patients undergoing dialysis at the time of PTRA were able to discontinue dialysis during follow-up. Four patients (11%) required surgical bypass and five patients (14%) required chronic dialysis during follow-up. CONCLUSIONS: Modest success at low risk can be expected from PTRA in a group of patients with severe atherosclerosis. No significant difference in results between ostial and nonostial lesions was noted.

The neurovascular outcome of scapulothoracic dissociation.

PURPOSE: The purpose of this study was to define the role of acute revascularization in the management of scapulothoracic dissociation (SD), a rare injury of the upper extremity in which severe traction to the shoulder girdle results in combined arterial, brachial plexus, and musculoskeletal injury. METHODS: The results of a retrospective study of 11 patients with SD who were compared with 41 patients from the literature are presented. RESULTS: All 11 patients were involved in high-speed accidents. All patients had chest wall hematoma, absent radial pulse, and complete brachial plexus palsy. All patients had subclavian or axillary occlusion shown by angiography; one patient with simultaneous brachial artery injury had limb-threatening ischemia. No patient had active bleeding from the injured artery. Six limbs were revascularized, five were not. All five non-revascularized limbs remained viable. No patient had delayed hemorrhage. No patient had significant neurologic recovery; all limbs remained insensate and functionless. Two viable arms underwent late amputation because of neurologic dysfunction. CONCLUSION: The infrequent occurrence of delayed hemorrhage and limb-threatening ischemia and the dismal functional outcome of the brachial plexus injury suggest a conservative policy toward revascularization for the arterial injury in SD.

Changing patterns in surgery for chronic renal artery occlusive diseases.

We report 66 patients undergoing 69 operations for chronic renal artery occlusive diseases operated on at two institutions between January 1985 and June 1990. Etiology was atherosclerosis in 59 patients (90%); fibromuscular disease in four (6%), and three children with nonfibromuscular disease stenosis (4%). Atherosclerosis was local in 10 and generalized in 49 (83% of all patients). Fifty operations (72%) were for salvage of renal function. Average serum creatinine was 2.3 mg/dl and was elevated in 46 patients (70%). Donor arteries for reconstruction were aorta 20 (29%), aortic graft 16 (23%), and other abdominal arteries 33 (48%). Twenty-one patients had concomitant vascular procedures including 16 aortic replacements. The two operative deaths (3%) followed aortic replacements. Three grafts (4%) occluded before discharge from the hospital. Eighty-six percent of patients undergoing renal salvage avoided long-term dialysis. In past decades fibromuscular disease and localized atherosclerosis were the most frequent renal artery occlusive diseases undergoing surgery, hypertension was the predominant indication, and the most frequent operation was aortorenal bypass. As a result of improved pharmacologic management of hypertension and the development of percutaneous transluminal dilation, most patients in this series had far advanced generalized atherosclerosis, and renal salvage was the most frequent indication for operation. As a consequence of the severity of the atherosclerosis, 48% of operations avoided the aorta, 23% replaced the aorta, and aortorenal bypass was used in only 29%.

Blunt trauma to the carotid arteries.

Blunt carotid artery trauma is an uncommon but potentially dangerous clinical entity. We report eight patients from a 10-year interval who sustained blunt injuries to the carotid arteries. Six of eight patients suffered a hyperextension injury or had a cervical spine fracture or both. Arteriography revealed four arterial dissections and four thrombotic occlusions. Two asymptomatic common carotid artery occlusions and one dissection with transient ischemic attacks had successful arterial reconstructions. Five patients were treated nonoperatively: three internal carotid artery dissections with minor or no neurologic deficit; one asymptomatic thrombosis; and one internal carotid artery thrombosis with a major fixed neurologic deficit that did not improve. No patient died, and seven of eight made a complete neurologic recovery or remained asymptomatic. The diagnosis of blunt carotid artery injuries should be suspected in patients with neck hyperextension injuries or with cervical spine fractures as well as in patients with neurologic deficits not explained by intracranial trauma. Duplex scanning may be a useful noninvasive study. Surgery is indicated for selected patients with accessible lesions who have minor or no neurologic deficits. Asymptomatic patients with small intimal flaps or dissections may be successfully treated nonoperatively.

Autogenous vein graft repair of injured extremity arteries: early and late results with 134 consecutive patients.

Autogenous vein tissue is recognized as the preferred material for extremity revascularizations that require the use of a conduit. However, the results after vascular repair of injured extremity arteries with autogenous vein interposition or bypass grafts have not been well defined. This study was done to determine both the early and late patency and limb salvage rates as well as the graft infection rate of autogenous vein repairs of injured extremity arteries. The records of 134 consecutive patients with acute extremity arterial injuries requiring repair with a reversed autogenous vein graft over a recent 5-year period were reviewed. Follow-up graft patency was defined by the presence of a palpable pulse and an extremity Doppler-derived pressure index of greater than or equal to 0.9 distal to the arterial repair. Cumulative patency was assessed by the life-table method. Acute graft thrombosis occurred in two patients, one of whom underwent successful graft thrombectomy. Four patients (3%) required extremity amputation: one patient with a thrombosed vein graft and three patients with patent vein grafts but nonsalvageable limbs as a result of myonecrosis (2) or osteomyelitis (1). No perioperative graft infections occurred. One hundred twenty-eight patients (97%) had an intact extremity and a patent vein graft at the time of hospital discharge. One hundred three patients (80%) were examined at 30 days, and all grafts were patent. Seventy-three patients (57%) were available for follow-up at intervals exceeding 6 months, and 40 patients (31%) were followed-up for periods exceeding 24 months.(ABSTRACT TRUNCATED AT 250 WORDS)

The natural history of intimal flaps in a canine model.

The natural history of arterial intimal flaps has not been well defined. This study characterizes the natural history of unrepaired intimal flaps. Thirty-nine 1-, 2-, and 3-mm hemispheric, distally based intimal flaps were made in 4- to 5-mm diameter canine femoral and carotid arteries. Twenty arteries had 2- and 3-mm intimal flaps and were monitored for short-term arterial thrombosis and flap extension. Nineteen had 1- and 2-mm intimal flaps and were monitored for thrombosis, long-term development of neointimal hyperplasia, arterial stenosis, and persistence of the flap. While 40% of the arteries with 3-mm intimal flaps developed thrombosis in 3 to 5 days, only 3% of the arteries with 1- or 2-mm intimal flaps developed thrombosis. Most 1- to 2-mm intimal flaps resolved and the subsequent development of neointimal hyperplasia or arterial stenosis was minimal. Arteries with hemodynamically significant stenoses from intimal flaps warrant repair, while arteries with smaller intimal flaps may not require repair.

A rapid, accurate, noninvasive technique for diagnosing critical and subcritical stenoses in aortoiliac arteries.

Accurate hemodynamic evaluation of the aortoiliac system for the purpose of determining the need for an inflow procedure currently requires invasive pressure measurements. This study was undertaken to evaluate a noninvasive technique with the aortofemoral transfer function. Twenty-eight human aortoiliac segments were studied with intraarterial pressure measurements, with and without papaverine injection, and by calculation of the Doppler-derived mean power frequency index obtained by digital signal processing of aortic and femoral spectra. The procedure is menu driven and can be performed by any duplex ultrasound technologist. This technique involves recording 20 aortic and 20 femoral Doppler signals, requiring less than 1 minute of data acquisition time. Intraarterial pressure measurements were used to classify arteries into the three following groups: (1) normal arteries, (2) arteries with subcritical stenoses, and (3) arteries with critical stenoses. The mean power frequency index of group 1 arteries (n = 7) was 0.63 +/- 0.04, of group 2 arteries (n = 6) was 0.46 +/- 0.02, and of group 3 arteries (n = 15) was 0.21 +/- 0.05. These mean power frequency index values were significantly different by analysis of variance (ANOVA) (p less than 0.0001). Each group could be differentiated from the other groups with a sensitivity of 0.83 to 1.00, a specificity of 1.00, and an accuracy of 0.92 to 1.00 compared to intraarterial pressure measurements, including papaverine testing. Measurement of the mean power frequency index is a rapid, noninvasive technique that diagnoses and quantifies aortoiliac stenoses with an accuracy similar to intraarterial pressure measurements.

Computerized topographic brain mapping during carotid endarterectomy.

Computerized topographic brain mapping processes standard electroencephalographic data and displays it in a color map, thus simplifying interpretation. During a 2-year period, 65 carotid endarterectomies were performed with the use of brain mapping as the sole criterion for shunt replacement. Forty-three patients (66%) were found to have abnormal brain maps preoperatively. Ten patients (15%) developed ischemic changes after cross-clamping (all resolved after shunt placement). Postoperative brain maps were unchanged in 54 patients (83%) and improved in 7 patients (11%). A new, small focal abnormality was identified in 4 patients without shunts (6%), none of whom had a change in neurologic status. The overall major morbidity and mortality was 1.5%. Computerized brain mapping is a sensitive and readily interpretable means of monitoring cerebral perfusion during carotid surgery. We found the computerized electroencephalographic data to be a dependable criterion for selective shunting and for confirmation of shunt patency during carotid endarterectomy.

Hollenhorst plaques: retinal manifestations and the role of carotid endarterectomy.

The ocular examinations and hospital records of 64 patients with Hollenhorst plaques were retrospectively reviewed to document any associated visual defects and to determine if carotid endarterectomy prevented the occurrence of new plaques or symptoms. One hundred nine Hollenhorst plaques were seen in 75 eyes; 18 had multiple plaques simultaneously. Visual field defects were noted in 14 eyes, four of which corresponded to the location of Hollenhorst plaques. Twenty-eight carotid endarterectomies were performed ipsilateral to a Hollenhorst plaque: 24 patients had no symptoms; four patients developed new ipsilateral asymptomatic Hollenhorst plaques at 1 to 50 months after operation. Two late strokes occurred, one of which was ipsilateral to a new Hollenhorst plaque, during a mean follow-up of 50 months (range 8 to 102 months). Thirty-seven eyes with asymptomatic Hollenhorst plaques did not undergo ipsilateral operation. Two eyes developed new Hollenhorst plaques during a mean follow-up of 23 months (range 1 to 132 months). Eight eyes in patients with no symptoms had multiple Hollenhorst plaques, one of which was associated with a subsequent stroke. Of the 29 eyes with a single Hollenhorst plaque, one subsequently experienced an ipsilateral stroke, and another had a transient ischemic attack (1 and 3 years later, respectively). Visual field defects infrequently corresponded to locations of Hollenhorst plaques. The cerebral hemisphere ipsilateral to asymptomatic plaques had a slightly increased risk of subsequent transient ischemic attack or stroke compared to the contralateral side without Hollenhorst plaques. The number of simultaneous Hollenhorst plaques in the retinal circulation did not predict clinical outcome.(ABSTRACT TRUNCATED AT 250 WORDS)

Lupus-like anticoagulants and lower extremity arterial occlusive disease.

Lupus-like anticoagulants (LLA), lupus anticoagulant and/or anticardiolipin antibody, are increasingly recognized in association with venous and arterial thrombotic events. We recently reviewed our experience with patients undergoing revascularization for lower-limb ischemia who were found to have LLA. Nine patients had LLA based on a prolongation of the partial thromboplastin time or by anticardiolipin assay by an enzyme-linked immunosorbent assay system. The ages of the patients ranged from 23 to 57 years. There were seven (78%) men, six (67%) blacks, two (22%) diabetic patients, and three (33%) hypertensive patients. One patient had systemic lupus erythematosus. All patients except one were cigarette smokers. Four patients had concurrent regulatory protein abnormalities: three protein C deficiencies, one protein S deficiency, and one plasminogen deficiency. The nine patients had 10 lower-extremity arterial reconstructions with two postoperative failures within 30 days. Patients were anticoagulated with heparin or aspirin after all but one operation. Patients at risk were identified on the basis of age (less than 51 years), unexplained early graft thrombosis, or history of venous or arterial thrombotic events. This group of patients is believed to be at risk for early postoperative thrombosis. Postoperative anticoagulation after revascularization for patients with LLA may be beneficial.

Open transmetatarsal amputation in the treatment of severe foot infections.

Severe forefoot infections may lead to limb loss, even if addressed aggressively. Infection or gangrene that compromises the plantar skin flap may preclude a standard transmetatarsal or midfoot amputation, thereby culminating in a below-knee amputation. We report a series of forefoot infections with loss of the distal plantar skin. Open or guillotine amputation at the mid-metatarsal level led to a high rate of healing and a durable stump, provided that the level of infection did not extend beyond the metatarsal heads. Wound closure was obtained by wound contracture alone or by use of partial-thickness skin grafting. Rehabilitation was dependable. The association of diabetes mellitus or gangrene did not adversely affect outcome. Open transmetatarsal amputation is a safe surgical option preferable to midfoot or below-knee amputation for the treatment of severe forefoot infection that does not extend proximally beyond the metatarsal heads.

The role of isolated profundaplasty for the treatment of rest pain.

This study was undertaken to determine the efficacy and durability of profundaplasty and define preoperative factors predictive of success. The hospital charts, vascular laboratory data, and arteriograms of 20 patients having 21 isolated profundaplasties for ischemic rest pain between 1979 and 1987 were reviewed. Follow-up extended to 72 months (mean, 26 months). Early success was achieved in 12 extremities (57%) and life-table analysis showed continued success to six years in 11 extremities (55%). Of the multiple preoperative factors assessed, only a low-thigh/ankle gradient pressure index (TAGI) of less than 0.55 was predictive of success. Life-table analysis for limbs with a TAGI of less than 0.55 showed an 89% success rate at six years compared with only a 32% success rate for limbs with a TAGI of more than 0.55. Isolated profundaplasty for the treatment of ischemic rest pain can be an efficacious and durable procedure when patients are selected based on objective hemodynamic measurements.

Hypercoagulable states and lower limb ischemia in young adults.

This study prospectively evaluates hypercoagulable states in patients under 51 years of age undergoing lower extremity revascularization for ischemia and assesses early outcome after operation. Twenty patients whose ages range from 23 to 50 years (mean 40.8 years) were identified prospectively who underwent lower extremity revascularization and evaluation of hypercoagulability. Fifteen patients were male (75%), 10 were black (50%), six had hypertension (30%), and four were diabetic (20%). All but two were cigarette smokers (90%). Seven aortoiliac procedures and 13 infrainguinal procedures were performed. Six patients had one or more abnormalities of regulatory proteins (protein S deficiency, four; protein C deficiency, three; presence of lupus-like anticoagulant, three; plasminogen deficiency, two). Eight of 17 patients in whom platelet aggregation profiles were obtained showed increased reactivity (47%). Only 4 of 17 patients (24%) were normal when tested for all parameters. Arterial or graft thrombosis developed in four of the 20 patients within 30 days after operation. Hypercoagulability was found in all four patients whose revascularizations failed. A high incidence of hypercoagulable states was found in patients under 51 years of age with lower limb ischemia requiring revascularization. Hypercoagulability may have contributed to early postoperative thrombosis of the vascular procedure.