Herbert I. Machleder

Bacteriologic and surgical determinants of survival in patients with mycotic aneurysms

Mycotic aneurysms are a fulminant infectious process frequently resulting in rupture and death if not properly treated. A review of the University of California, Los Angeles, medical records identified 10 patients with extrathoracic, extracranial mycotic aneurysms. In addition, a search of the English literature revealed 178 patients with 243 mycotic aneurysms. These patients were reviewed to identify the aneurysm location, etiology, bacteriology, and modality of treatment in order to determine the relationship between these factors and the outcome. The femoral artery was the most common site (38%), followed by the abdominal aorta (31%). Arterial trauma was the primary etiology in 42% of mycotic aneurysms. In 25% no clear source of infection could be identified. Staphylococcus aureus was cultured from 28% of mycotic aneurysms, and Salmonella from 15%. A trend toward the involvement of more gram-negative aerobes and anaerobes is noted. Aortic aneurysms were repaired with in situ Dacron in 61% of patients with a 32% mortality rate and 16% reinfection rate. Simple ligation of femoral artery mycotic aneurysms resulted in a 34% incidence of ischemia necessitating amputation. Methods of treatment of superior mesenteric, carotid, iliac, and peripheral arteries are also analyzed. On the basis of these data, specific surgical procedures are recommended for the treatment of mycotic aneurysms.

Evaluation of a new treatment strategy for Paget-Schroetter syndrome: Spontaneous thrombosis of the axillary-subclavian vein *

PURPOSE The purpose of this study was to evaluate the efficacy of a staged, multimodal algorithm of therapy for durable correction of Paget-Schroetter syndrome. METHODS Fifty consecutive patients were entered into a sequential treatment program for spontaneous axillary-subclavian vein thrombosis. Forty-three had initial thrombolytic or anticoagulant treatment followed by longer-term warfarin sodium therapy. Thirty-six (72%) underwent surgical correction of the underlying structural abnormality, and nine patients had postoperative balloon angioplasty. RESULTS At the time of final evaluation, 93% of patients with a patent vein and 64% of those with an occluded vein were essentially free of symptoms. After surgical correction there were no episodes of recurrent thrombosis in a mean follow-up period of 3.1 years. Urokinase was the most effective pharmacologic agent for clot lysis (p = 0.003), and restoration of initial patency was the most significant factor in establishing final venous patency determined venographically (p = 0.0003). CONCLUSIONS It was concluded that a staged, multimodal approach to the Paget-Schroetter syndrome can effectively restore venous patency, reduce rethrombosis, and return normal function. The most effective sequence included transcatheter thrombolytic therapy, 3 months of anticoagulation therapy with warfarin sodium, and transaxillary first rib resection and decompression, followed by balloon angioplasty in cases of residual stricture.

Long-term results of infrainguinal revascularization with polytetrafluoroethylene: A ten-year experience☆

Two hundred fifty-eight patients underwent 322 infrainguinal revascularizations with use of polytetrafluoroethylene (PTFE) between 1978 and 1988. The indication was limb salvage in 190 (59%) reconstructions. Two hundred nineteen (68%) were above-knee, and 75 (23%) were below-knee femoropopliteal bypasses. Twenty-eight (8.6%) were femoral-infrapopliteal bypasses, all done for limb salvage. Follow-up ranged from 24 to 144 months (mean, 66 months). The perioperative mortality rate (1 to 30 days) was 3.4% (9 patients), with no significant difference according to indication (2.9% vs 3.7%). Actuarial primary patency at 8 years for the entire series of femoropopliteal bypasses was 53% (above knee 53%; below knee 39%; p less than 0.05), and improved with additional procedures for a secondary patency of 72%. Femoropopliteal bypasses done for severe claudication had an 8-year actuarial primary patency of 63%, compared with 38% for limb salvage (p less than 0.02). Actuarial limb salvage in the latter group at 8 years was 66%. Femoral-infrapopliteal reconstructions with PTFE had a significantly lower primary patency at 3 years (22%, with a 37% limb salvage). Sixty-four percent of the failures for all reconstructions (N = 111) occurred within 12 months, with remarkable stabilization of patency curves beyond that interval. This experience represents the largest reported series of PTFE reconstruction with longest follow-up to date and may serve as a basis for comparison of other conduits. These results suggest an important role for PTFE in femoropopliteal revascularization and a limited role of this prosthetic conduit in femoral-infrapopliteal arterial reconstructions.

The superiority of synthetic arterial grafts over autologous veins in carotid-subclavian bypass

From May 1964 to June 1983, 36 carotid-subclavian bypasses were done in 36 patients who had symptomatic lesions at the origin of the common carotid and/or subclavian arteries at the Center for Health Sciences of the University of California, Los Angeles. Ages ranged from 28 to 82 years (mean, 58 years). Eighteen bypasses were done with prosthetic grafts, 13 done with autogenous vein, and five were transpositions with primary anastomosis of the subclavian and carotid arteries. Follow-up was available on all patients and ranged from 9 to 156 months (mean, 51.5 months). The graft patency rate at 5 years determined by actuarial methods and documented by clinical examination, noninvasive evaluation, and/or arteriography was 94.1% for prosthetic grafts and 58.3% for vein grafts (p less than 0.01). The 5-year cerebrovascular accident (CVA) rate for patients with carotid-subclavian bypass done with prosthetic grafts was 6% in contrast to 39% for those with vein grafts (p less than 0.0545). All reconstructions done by transposition and primary anastomosis remain patent and there have been no late CVAs. We conclude that prosthetic grafts are the arterial substitute of choice in carotid-subclavian bypass. Transposition and primary anastomosis between the carotid and subclavian artery, when technically feasible, may be preferable to the use of free grafts in carotid-subclavian reconstruction.

Is the preferential use of polytetrafluoroethylene grafts for femoropopliteal bypass justified

The objective of this review is to analyze the long-term results of femoropopliteal bypass done preferentially with polytetrafluoroethylene (PTFE) grafts in patients who presumably had saphenous vein available. The results are analyzed according to preoperative variables in an attempt to determine those instances in which PTFE grafts may be preferred for the first reconstruction and to identify those patients who benefited from vein preservation. From 1979 to 1985, 146 femoropopliteal bypass operations were performed in 120 patients with 6 mm PTFE grafts used preferentially. The results with follow-up at 5 years are analyzed by actuarial methods. The patency rate at hospital discharge was 100%. The overall primary patency rate at 5 years was 57%. Reconstructions above the knee (101) and below the knee (45) had significantly different 5-year patency rates (63% vs 44%, p less than 0.03). Sixty-two reconstructions done to alleviate disabling claudication had a 5-year primary patency rate of 69% and no amputations. Eighty-one reconstructions were done to treat critical ischemia with a 5-year patency rate of 49% and a 5-year foot salvage rate of 73%. When secondary operations were required to treat graft failures, the 4-year cumulative patency rate of the secondary reconstruction was 18% when performed with a prosthetic graft, in contrast to 70% when performed with the spared saphenous vein. We conclude that femoropopliteal reconstruction with PTFE grafts is a reasonable alternative for older patients with disabling claudication. Patients with critical ischemia will likely benefit from preservation of the vein with initial femoropopliteal reconstruction done with PTFE. Staged infrainguinal revascularization for foot salvage may improve present results. In this regard the sequence PTFE-then-vein carries a higher predicted patency rate than the sequence vein-then-PTFE.

Aortic mural thrombus: An occult source of arterial thromboembolism

During a 28-year period from 1955 to 1983, two cases of massive repetitive arterial thromboembolism from nonaneurysmal aortic mural thrombus were diagnosed antemortem and successfully corrected at the University of California, Los Angeles Medical Center. Within the same time period, 48 cases of nonaneurysmal aortic mural thrombus were identified in 10,671 consecutive autopsies (0.45% incidence). Eight of these patients had evidence of distal embolization (17%), and three had major thromboembolic occlusions, which were considered the proximate cause of death (6%). The latter three patients represented 9% of autopsy-confirmed deaths from peripheral arterial thromboembolism. The diagnosis was established in a 49-year-old man and a 51-year-old woman after a long course marked by recurrent arterial embolization. Despite multiple evaluations, which included angiography, the diagnosis remained elusive until clinical suspicion resulted in complete biplane aortographic survey. Although the morphologic characteristics of this lesion are quite striking, subtle angiographic changes and lack of familiarity with the clinical presentation contribute to the difficulty and infrequency of diagnosis. This unique lesion comprises an important segment of the so-called cryptogenic sources of arterial embolization and can be corrected by a definitive surgical procedure.

Can clinical evaluation and noninvasive testing substitute for arteriography in the evaluation of carotid artery disease

The objective of this study was to prospectively assess the value of combining clinical assessment and noninvasive testing in predicting the spectrum of carotid bifurcation pathology, as subsequently proven by arteriography, in order to determine the safety and accuracy of performing carotid endarterectomy without angiography. A panel of eight specialists representing vascular surgery, neurology, and neurosurgery were presented with the history, physical findings, and noninvasive test results (GEE-OPG and duplex scan) of 85 patients. They were asked to make an anatomic prediction of the status of each carotid artery (170 arteries) as to whether the bifurcation was normal, ulcerated, had a hemodynamically significant stenosis, or was occluded. The predictions were then prospectively evaluated and correlated with angiographic findings; 159 of 170 (93.5%) carotid arteries were accurately characterized; 73 of 80 (91%) symptomatic carotid arteries and 86 of 90 (95.5%) asymptomatic arteries were correctly characterized; 61 of 61 (100%) stenoses of hemodynamic significance, nine of 14 (64.3%) ulcerations without stenosis, and 18 of 18 (100%) of total occlusions were accurately identified by the panel. Twenty-nine patients have subsequently had 32 carotid endarterectomies without angiography, and the predicted lesion was confirmed at the time of exploration. The combination of clinical assessment and noninvasive testing, particularly duplex scanning, when performed in a laboratory with validated accuracy may with defined qualification be safely used as a substitute for contrast angiography.

Perigraft seroma: Clinical, histologic, and serologic correlates☆☆☆

A 14 year retrospective study of perigraft seroma, defined as an enlarging sterile fluid collection at the site of a prosthetic graft, revealed well-documented cases in 5 of 118 extraanatomical bypasses (4.2 percent), 3 of 248 aortic reconstructive procedures (1.2 percent), and 1 of 395 femoropopliteal bypasses (0.3 percent). These nine cases involved four polytetrafluoroethylene and five Dacron grafts. There were five graft thromboses, one instance of limb loss, two graft infections, two deaths, and 13 separate surgical procedures related to the perigraft seroma. Histologic studies revealed a fibrous pseudomembrane lining the perigraft seroma wall and immature fibroblasts lining the graft. Sera from three patients with perigraft seroma, five patients with well-incorporated prosthetic grafts, and three healthy volunteer subjects were tested for in vitro evidence of fibroblast inhibition against fibroblast tissue cultures derived from the pseudomembrane of a perigraft seroma. Control fetal calf serum, sera from all three healthy subjects, and sera from all five patients with well-incorporated grafts allowed fibroblast proliferation. In contrast, sera from all three patients with perigraft seroma inhibited fibroblast growth. Furthermore, sera collected 1, 2, and 3 months after graft removal from one patient and serum collected 3 months after spontaneous resolution of a perigraft seroma from another patient failed to inhibit fibroblasts. We have concluded that patients with perigraft seroma have a high rate of graft and limb loss and require multiple reoperations. The pathogenesis of perigraft seroma appears to involve a humoral fibroblast inhibitor which prevents maturation and proliferation of perigraft fibroblasts, leading to poor graft incorporation. The decrease of inhibition below detectable levels after graft removal or spontaneous resolution of the perigraft seroma suggests that the graft may induce host production of the inhibitor. Effective therapy of perigraft seroma may include fibroblast modulation, removal of the inciting graft, or both.

Carotid-Subclavian Bypass for Brachiocephalic Occlusive Disease: Choice of Conduit and Long-term Follow-up

BACKGROUND AND PURPOSE Atherosclerotic disease of the proximal brachiocephalic circulation may produce disabling symptoms referable to cerebral or upper extremity hypoperfusion and embolization. Bypass of occlusive lesions can provide durable relief of symptoms with minimal complications. The ideal conduit for carotid-to-subclavian and subclavian-to-carotid bypass remains controversial, and it is not clear whether the outflow vessel influences patency and survival. METHODS We performed a retrospective analysis of 60 consecutive carotid-to-subclavian and subclavian-to-carotid bypass procedures. Occlusive lesions were documented preoperatively by arteriography. Patency was determined during follow-up by ultrasound or duplex examination. Actuarial patency, symptom-free survival, and overall survival rates were calculated by the life-table method and analyzed by log-rank test. RESULTS Arterial transposition demonstrated the highest long-term patency rate (100.0 +/- 0.0%). Polytetrafluoroethylene grafts demonstrated the highest bypass graft patency rate (95.2 +/- 4.6%), followed by Dacron grafts (83.9 +/- 10.5%) and saphenous vein grafts (64.8 +/- 16.5%). Symptom-free survival paralleled patency rates, but these differences did not achieve statistical significance. While there were no differences in patency or symptom-free survival by outflow vessel, the overall survival of patients with common carotid lesions was significantly lower than that of patients with subclavian lesions (62.7 +/- 12.8% versus 100.0 +/- 0.0%; P < .05). CONCLUSIONS The outflow vessel does not affect long-term patency in carotid and subclavian bypass procedures; however, patients with common carotid disease demonstrate significantly poorer long-term survival. Transposition results in superior long-term patency, with a trend toward lower results for synthetic grafts and relatively poor results for autogenous vein grafts.

Cause and noninvasive detection of restenosis after carotid endarterectomy

The incidence of significant restenosis after carotid endarterectomy was studied with ocular pneumoplethysmography. Of 105 operations, symptomatic restenosis occurred in 4.8 percent and asymptomatic restenosis in 6.6 percent. No preoperative factors were identified to be associated with subsequent recurrence. However, technical problems with the end-point of the endarterectomy were associated with restenosis. Half of the restenoses occurred in the first 6 months of operation. The results focus on the need for special attention to the technical management of end-point problems and the need for early noninvasive follow-up to detect a substantial proportion of early restenoses.