Endoluminal graft repair of abdominal aortic aneurysms by vascular surgeons at a nonclinical trial center.

The purpose of this study was to compare the early results and complication rates of commercially available endoluminal grafts (ELG) for abdominal aortic aneurysm (AAA) by a team of vascular surgeons at a nontrial center with those of published results from trial centers. A retrospective chart review of all patients undergoing endoluminal graft repair of AAA was made at the medical center. From October 1, 1999, to December 31, 2000, a team of vascular surgeons electively repaired AAAs in 100 patients at a regional referral center. Of these patients, 49 underwent repair with a commercially available ELG (35 AneuRx, 14 Ancure) whereas the remaining were repaired with an open operation. In the ELG group, the primary technical success rate was 100% with a 30-day mortality rate of 2.0%. The average hospital length of stay was 3.28 days with ICU stay of 1.20 days. The average operative estimated blood loss was 501 mL (100-2,500) with average transfusions of 0.49 unit packed red blood cells (prbc) (0-6). Eighty-eight percent of ELG patients left the hospital without complication. Seven patients (14%) required 11 follow-up procedures for complications including endoleak, limb or graft thrombosis, graft stenosis, distal embolization, or wound complications. Three of 26 patients (11%) with 6-month computed tomography follow-up had evidence of endoleak (2 have subsequently undergone lumbar embolization). Only 1 6-month follow-up patient had shown increased aneurysm size before endoleak treatment. A team of board-certified vascular surgeons at a nonclinical trial center can safely perform ELG for AAA with results similar to those of published series from trial centers.

Behçet's disease: endovascular management of a ruptured peripheral arterial aneurysm.

Traditionally, bypass grafts are at a high risk for thrombosis or anastomotic degeneration in patients with Behçet's disease. We report the successful deployment of a vein-covered stent across the neck of a ruptured peripheral arterial aneurysm, via a remote site access, with intermediate-term follow-up. Covered stents may represent an attractive alternative to open surgical bypass for the management of aneurysms in patients with Behçet's disease.

Mechanical thrombectomy as a first-line treatment for arterial occlusion.

The use of percutaneous mechanical thrombectomy devices to restore flow to an acutely ischemic limb is gaining popularity. Potential benefits include the minimally invasive nature of the procedure, rapid blood flow restoration, and a decrease in the dose and duration of adjunctive pharmacologic thrombolytic agents when required. A detailed description of the currently available mechanical thrombectomy devices, preclinical device evaluation, and published clinical trials for the management of acute limb-threatening ischemia are provided.

Infection in the ischemic lower extremity.

Infections in the lower extremity of the patient with ischemia can cover a broad spectrum of different diseases. An understanding of the particular pathophysiologic circumstances in the ischemic extremity can be of great value in understanding the natural history of the disease and the potential complications that may occur. Optimizing blood flow to the extremity by using revascularization techniques is important for any patient with an ischemic lower extremity complicated by infection or ulceration. Infections in the ischemic lower extremity require local débridement and systemic antibiotics. For severe infections, such as necrotizing fasciitis or the fetid foot, more extensive local débridement and even amputation may be required. Fundamentals of managing prosthetic graft infection require removing the infected prosthesis, local wound débridement, and systemic antibiotics while attempting to preserve viability of the lower extremity using autogenous graft reconstruction.

Evaluating institutional variability of duplex scanning in the detection of carotid artery stenosis.

PURPOSE: Duplex scanning is widely used to measure carotid artery stenosis, but the issue of variability between institutions must be raised. To examine for this potential variability, we evaluated two ATL Ultramark 9 duplex machines at two hospitals within our institution. METHODS: Stenosis was calculated angiographically as in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Internal carotid artery (ICA) to common carotid artery (CCA) peak systolic velocity (PSV) ratios were determined using the two ATL machines. Receiver operating characteristic (ROC) curves were generated for each hospital. RESULTS: ROC curves varied significantly. The area under the curve from hospital 1 was 0.95 (SE = 0.021); the area under the curve from hospital 2 was 0.87 (SE = 0.034). The curves were essentially statistically different (P = 0.0516). COMMENTS: We showed a difference in predicting diameter stenosis utilizing ICA PSV/CCA PSV ratios at two hospitals within our institution. Variability is likely due to technologists, since equipment and physician interpreters were the same. Criteria must be developed for each different machine in each laboratory. Quality assurance is critical to minimize variability.

Baker's cysts mimicking the symptoms of deep vein thrombosis: diagnosis with venous duplex scanning.

PURPOSE: The purpose of this study was to determine the incidence and characteristics of Baker's cysts discovered during venous duplex examinations to rule out deep vein thrombosis (DVT). METHODS: We reviewed the vascular laboratory charts of patients found to have Baker's cysts during venous duplex studies to rule out DVT from October 1988 through December 1995. RESULTS: Ninety-five (3.1%) of 3072 patients who underwent venous duplex studies were found to have 111 Baker's cysts. Seven of the 95 had coexistent DVT. Ten patients had ruptured cysts, whereas six patients had cysts that compressed the popliteal vein. CONCLUSION: The presentation of DVT and that of a Baker's cyst are similar enough to be difficult to distinguish by clinical examination. Careful examination of the popliteal fossa should be performed during venous duplex examinations regardless of the indication for the study.

Role of venous duplex scanning in patients with suspected pulmonary embolism.

PURPOSE: We examined the use of venous duplex scanning (VDS) in the diagnosis of pulmonary embolism (PE) at our institution. METHODS: Patients undergoing lower extremity VDS from October 1988 through June 1995 were cross-referenced with those who underwent ventilation perfusion (V/Q) scans and pulmonary angiography (PA) for PE. RESULTS: A total of 664 of 3534 VDS were for "rule out PE." Deep venous thrombosis was found in 13%. A total of 256 VDS were in conjunction with V/Q scans in 249 patients, with only 8% undergoing PA. Deep venous thrombosis was present in 18% for those with both V/Q and VDS compared with 10% (p < 0.01) for those with VDS as the sole study. The order in which V/Q, VDS, and PA were obtained and the relationship of positive studies was examined. CONCLUSION: We found no pattern to the sequence of tests ordered. V/Q scan rather than VDS should be the first study in the evaluation of PE. PE was diagnosed or excluded in nearly one third of patients based on V/Q as the initial study. A total of 29% of VDS could have been avoided. Treatment could be determined on the basis of VDS as the initial study in only 13%. We found only 14% incidence of positive PA in patients with nondiagnostic V/Q scans. We advocate judicious use of diagnostic tests in a stepwise fashion to appropriately treat patients with suspected PE.

Bilateral chylothorax following thoracic duct ligation: case report and review of the literature.

Bilateral chylothorax following thoracic duct injury is a rare occurrence. Since 1907 there have been only six reports in the literature of this potentially serious complication. We report a case of bilateral chylothorax following ligation of the cervical thoracic duct during a left subclavian to carotid artery transposition.

Current management of coexistent intra-abdominal pathology in patients with abdominal aortic aneurysms.

In conclusion, it can be seen that coexistent intra-abdominal pathology and aortic aneurysms demands an individualized approach to determine a treatment plan for a given patient. Life expectancy must be balanced against the risk of a complication developing in either the treated or untreated condition as well as the potential for increased morbidity associated with combined procedures. If combined procedures are performed, they must be undertaken only if the aneurysm resection has gone smoothly. Efforts must be directed at protecting the prosthetic graft from direct contamination that may accompany the secondary procedure. In general, the symptomatic lesion should be treated first. If both conditions are asymptomatic, the relative risks and benefits of treatment must be balanced against the probability that one or both of the conditions will become symptomatic.

Effects of Furegrelate (Upjohn 63557A) on patency and platelet deposition after canine carotid endarterectomy.

Platelet deposition upon endarterectomy sites is a likely cause for early postoperative thrombosis, embolism and restenosis. Platelets aggregate by the thromboxane-prostacycline mechanism. Thromboxane synthetase inhibitors which have been safely administered to humans should reduce platelet deposition after surgical therapy and therefore reduce peri-operative mortality and the prevalence of stroke. A randomized prospective controlled trial was designed to determine vessel patency and platelet deposition associated with the use of 3 mg/kg and 30 mg/kg of Furegrelate (Upjohn U63557A) daily in dogs, who were to have carotid endarterectomy. The 46 treated and 46 control dogs had total carotid patency of 96% and 76% respectively (P less than 0.01). Fourteen dogs treated with 30 mg/kg Furegrelate had no occlusions, compared with a 19% prevalence in 13 controls (P less than 0.02). Furegrelate 10 mg/kg significantly lowered platelet aggregation. Platelet deposition was not significantly changed, however. The reason for this disparity was a probable persistence of vessel wall factors which promoted platelet deposition. This approach might therefore lower rates of peri-operative thrombosis but it would be very unlikely to alter the incidence of restenosis or embolism. Further research could be directed towards modifying the stimuli for platelet deposition upon the endarterectomy site.

Infrarenal aortic aneurysm: unusual cause of paraparesis.

A male patient recently presented to our Unit with anterior spinal artery syndrome involving his lower limbs. This neurological condition was an unusual manifestation of an infrarenal abdominal aortic aneurysm with local dissection occluding the infrarenal lumbar arteries. The incidence, anatomy, aetiology, and management of the condition associated with aortic aneurysms are described.

The role of plaque morphology and diameter reduction in the development of new symptoms in asymptomatic carotid arteries.

To determine the natural history of changes in plaque morphology and luminal diameter of atherosclerotic carotid arteries, we used duplex scanning to follow-up (1) the contralateral artery in 289 patients who had undergone carotid endarterectomy, with a mean follow-up 22 months and a range of 0 to 48 months and (2) the carotid arteries in 130 patients who had no surgical treatment and had been symptom free, with a mean follow-up period of 15 months and a range of 0 to 48 months. Plaques were graded as to the ratio of echolucency to echogenicity, with type 1 being most echolucent and type 4 being most echogenic. A normal-appearing artery was classified as type 5. Heterogeneous plaques (types 1 and 2) occurred significantly more (p less than 0.001) in symptomatic preoperative arteries than in asympatomatic arteries. Follow-up of the asymptomatic vessels showed that the majority of plaques either remained the same or became more echogenic (fibrous). Approximately one fourth of plaques in each group degenerated (more echolucent). Thirty-one patients (10.7%) developed new symptoms in the contralateral asymptomatic group, with 10 patients (3.5%) having strokes. Fourteen of 130 (10.8%) patients, or 5.4% of vessel territories at risk, in the primary asymptomatic group developed new symptoms, with only two strokes occurring. In the contralateral asymptomatic group those patients who initially had greater than 75% stenoses fared worse than those with primary asymptomatic disease with greater than 75% stenosis. Although the overall development of new symptoms is low in both populations, our data indicate that those patients with heterogeneous plaques or whose plaques have undergone change may be at risk for new symptoms. Longer follow-up studies are needed to define the role of plaque changes in the development of symptoms. For now we advocate a conservative "wait and see" approach to symptom-free patients with greater than 75% stenoses and calcified plaques. We suggest a more aggressive approach, recommending early surgical intervention, to those few patients with heterogeneous plaques.

Amaurosis fugax: the importance of carotid plaque morphology.

Amaurosis fugax, or transient monocular blindness, was first associated with carotid bifurcation disease in 1951. Although amaurosis fugax is often considered by vascular surgeons to be premonitory for cerebral stroke, recent studies indicate that this disease process may be more benign than previously thought. A total of 97 patients presented with amaurosis fugax to our vascular laboratory from November 1983 to January 1988. There were 81 males and 16 females, mean age 67.2 years. The common, internal and external carotid arteries were imaged in standard longitudinal and cross-sectional views. Repeat scans were performed at six months and 12 months after the first visit, then yearly thereafter. Out study confirms the correlation between heterogeneous, complex carotid plaques and the development of amaurosis fugax. Endarterectomy can safely be performed in this group of patients, preventing further symptoms or development of stroke. We advocate duplex scanning to assess the carotid bifurcation and allow non-invasive follow-up of disease progression.

The spectrum of carotid artery disease in asymptomatic patients.

A spectrum of asymptomatic patients with carotid bifurcation disease exists, with varying degrees of risk for each sub-group. With Duplex scanning we studied the carotid arteries of several asymptomatic populations: volunteers at a health fair, patients referred to our vascular laboratory because of cervical bruits or associated vascular disease, and the contralateral asymptomatic vessels in those patients who had previously undergone endarterectomy. Volunteers had an extremely low incidence of carotid disease, possibly reflecting a bias of more healthy individuals attending a health fair. The contralateral asymptomatic vessels and vessels in the hospital asymptomatic group both had similar disease, with mainly fibrous or calcific plaques. Occurrence of new carotid territory symptoms was low in each hospital group. However, there were more strokes in the territory of the contralateral asymptomatic vessels, suggesting a greater risk for these patients. Symptomatic vessels tend to have plaques that are heterogeneous and echolucent. Change in plaque morphology may eventually become the best predictor of stroke risk, but longer follow-up studies of plaque progression are needed. In the meantime, the characteristics of asymptomatic populations in carotid artery studies must be carefully defined.

The use of deep duplex scanning to predict hemodynamically significant aortoiliac stenoses.

Hemodynamic assessment of aortoiliac occlusive disease is necessary for successful arterial reconstruction of the aorta and legs. Various methods have been proposed and "pull-through" intra-arterial pressures are the "gold standard." Deep Doppler duplex imaging was supplemented with real-time spectral analysis and velocity measurements in 29 cases. Twenty-three of these patients needed arteriography. One hundred sixty-six (166) arterial segments extending from the proximal aorta to the common femoral arteries were independently graded on duplex scans and arteriograms. For severe occlusive disease, duplex scanning is highly accurate (sensitivity 82%, specificity 93%). Velocity measurements were useful in determining the hemodynamic significance of stenoses. Peak systolic velocities in stenoses were measured with a duplex scanner. The pressure gradient calculated with the modified Bernoulli equation (delta P = 4Vmax2) correlated well with the gradients measured during arteriography (r = 0.9, n = 11). These noninvasive velocity measurements and Bernoulli calculations alert arteriographers to obtain special views of suspected areas and suggest the need for "pull-through" pressures and possible balloon angioplasty. In addition, these noninvasive measurements are useful to follow up patients who have mild to moderate aortoiliac disease and after angioplasty.

Duplex B-mode imaging for the diagnosis of deep venous thrombosis.

Real-time B-mode venous imaging has numerous advantages for the diagnosis of acute deep venous thrombosis (DVT). During the 11 months ending Feb 1, 1986, we examined 431 patients for possible acute DVT using a 5-MHz hand-held continuous wave Doppler stethoscope and a duplex real-time B-mode imager. Clots were seen in 86 patients in multiple views and cross sections. Normal veins completely collapsed with probe pressure on the skin. Blood flow was seen and heard, and abnormal flow was detected. There were no false-negatives (100% sensitivity). Early in the study, two false-positives occurred (78% specificity), but these errors will not recur. These tests are accurate, noninvasive, and inexpensive. They differentiate acute from chronic thrombosis and are repeatable. Duplex imaging may become the "gold standard" for the diagnosis of DVT.