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Biomedical subjects

F J Veith

Publications and source records attributed to F J Veith.

At least 145 records · Page 8Linked to original sources
PubMed1994

Is percutaneous balloon angioplasty appropriate in the treatment of graft and anastomotic lesions responsible for failing vein bypasses?

We reviewed 95 cases of vein graft and anastomotic lesions treated with percutaneous transluminal balloon angioplasty (PTA) and 30 cases treated surgically. The therapy was deemed a failure if the lesion recurred or if the graft closed. The 21-month patency rate of lesions treated surgically was 86%, which was significantly better than the 42% patency rate for all lesions treated with PTA (P < 0.01). An evaluation of the lesion and graft characteristics that could influence the patency of stenotic lesions treated with PTA included: lesion length, minimum graft diameter, lesion location, and lesion type. The 66% patency rate at 24 months for the 41 simple lesions (single, nonrecurrent, < 15 mm in length, and within grafts > or = 3 mm minimal diameter) was significantly better than the 17% patency rate for the 50 complex lesions (multiple, recurrent, > or = 15 mm in length, or within grafts < 3 mm in minimal diameter) (P < 0.01). In addition, the 21-month patency rate for the surgically treated group (86%) was not significantly better than that of the angioplasty-treated simple lesions (66%). When feasible, vein graft lesions are best treated with simple surgical interventions. PTA can be useful to maintain the patency of severely compromised grafts prior to surgical repair, to treat simple lesions difficult to reach surgically, and for patients with medical contraindications for an operation.

Aged↗
PubMed1994

Transfemoral endovascular stented graft treatment of aorto-iliac and femoropopliteal occlusive disease for limb salvage.

BACKGROUND: Endovascular stented grafts employ a new technique that blends intravascular stent and prosthetic graft technologies. These devices may be used to treat arterial aneurysms, occlusive disease, and vascular injuries. This report describes the application of stented grafts to the treatment of limb-threatening ischemia secondary to occlusive disease of the aorta, iliac, and femoral arteries. METHODS: Three patients with limb-threatening ischemia and severe comorbid medical illnesses were treated with transvascular stented grafts that were composed of 6-mm thin-walled polytetrafluoroethylene grafts and Palmaz balloon expandable stents. The grafts were inserted through a cutdown in an artery remote from the site of occlusion and introduced into the vascular system within 14-Fr introducer sheaths. RESULTS: Technical success was documented in all three patients with restoration of arterial continuity following stent graft deployment. Patency and limb salvage has been achieved to 1 year. One patient required further dilatation of the proximal stent at 6 weeks. Complications were limited to an iliofemoral deep vein thrombosis in one patient. CONCLUSIONS: Endovascular stented grafts can be inserted to treat limb-threatening ischemia. Although these initial results are encouraging, greater experience in more patients observed for longer periods of time is necessary before this technique can be advocated for widespread use.

Aortic Diseases↗
PubMed1994

Transfemoral endoluminal stented graft repair of a popliteal artery aneurysm.

This report describes the use of an endoluminally placed stented graft to repair a large (2.6 by 2.6 by 15 cm) popliteal aneurysm in a 63-year-old man with advanced heart disease. Two balloon-expandable stents were attached to a 6 mm polytetrafluoroethylene graft, which was inserted with the patient receiving local anesthetic through a proximal superficial femoral artery arteriotomy. Repeat arteriography and duplex ultrasonography performed up to 3 months after the procedure documented graft and distal artery patency and complete aneurysmal exclusion without distal emboli. This experience demonstrates technical feasibility and early graft patency. However, additional experience and follow-up will be needed to assess the value of this minimally invasive procedure in the management of popliteal aneurysmal disease.

Aneurysm↗
PubMed1994

Selective preservation of infected prosthetic arterial grafts. Analysis of a 20-year experience with 120 extracavitary-infected grafts.

OBJECTIVE: The authors report on their 20-year experience with 120 patients with infected extracavitary prosthetic arterial grafts (95 polytetraflouroethylene, 25 Dacron). Throughout this experience, an effort was made, when appropriate, to salvage all or a portion of these infected grafts. METHODS: When patients had arterial bleeding (20 cases) or systemic sepsis (6 cases), immediate graft excision was performed. When the infected graft was occluded (43 cases), subtotal graft excision was performed, leaving an oversewn 2- to 3-mm graft remnant to maintain patency of the artery. Complete graft preservation was attempted in 51 cases in which the graft was patent, the patient was not septic, and the anastomoses were intact. Aggressive operative wound debridement was repeated, as necessary, to achieve wound healing. The preferred method of revascularization, when necessary, included secondary bypasses tunneled through uninfected (often lateral) routes. Follow-up averaged 3 years (range, 1 month-20 years). RESULTS: This strategy resulted in a hospital mortality of 12% (14/120) and a hospital amputation rate in survivors of 13% (14/106 threatened limbs). Of the surviving patients treated by complete graft preservation, the hospital amputation rate was only 4% (2/45) and long-term complete graft preservation was successful in 71% (32/45) of cases. Partial graft preservation also proved successful in 85% (35/41) of surviving patients who had occluded grafts. Successful complete graft preservation was as likely when gram-negative or gram-positive bacteria were cultured from the wound, with the exception of Pseudomonas (successful graft preservation in only 40% [4/10] of cases). CONCLUSION: Based on this 20-year experience, the authors conclude that selective partial or complete graft preservation represents a simpler and better method of managing infected extracavitary prosthetic grafts than routine total graft excision.

Aged↗
PubMed1994

Human greater saphenous vein: histologic and ultrastructural variation.

This study describes the varied histologic features and ultrastructure of human saphenous veins obtained from patients undergoing infrainguinal arterial reconstruction. Portions of 30 remnant veins were fixed at arterial pressure (100 mmHg). Vein specimens were obtained from 13 men and 17 women, with a mean age of 70.2 years. Ten veins (33%) were from diabetic patients. Samples of fixed veins were prepared for light and electron microscopy. The luminal surface contained valves and redundant intimal folds at the site of ligated side branches. Microvalves were present at the orifices of several 1-mm vein tributaries. The endothelial cells lining the intima were often discontinuous and were aligned in a variable pattern. The thicknesses of the vein walls varied from 20 to 360 microns, with increased connective tissue matrix in the intima and medial layers of thick-walled veins. Some 10% of the veins demonstrated spindle cells in the intima; these cells had a smooth muscle cell phenotype and varied with respect to the degree of cellular differentiation. Regions of vein wall calcification were occasionally seen and were always present in association with a thickened vein intima. Variations in the structure of the saphenous vein from patients undergoing bypass surgery are common. The relationship between altered saphenous vein morphology and subsequent vein graft stenosis needs to be defined.

Adult↗
PubMed1993

Prospective randomized comparison of in situ and reversed infrapopliteal vein grafts.

A three-centre prospective randomized trial was undertaken to compare the efficacy of in situ and reversed saphenous vein grafts for long bypasses to tibial and peroneal arteries. Of 162 patients entered into the study, 82 received an in situ graft and 80 a reversed vein graft. All operations were for limb salvage and the two groups of patients were well matched for age, sex, incidence of diabetes, smoking habits and coronary artery disease. At a maximum follow-up of 3 years there were 48 primary graft failures: 19 in the in situ group and 29 in the reversed vein group. Of these, three in situ grafts and seven reversed grafts were salvaged by secondary intervention. Secondary cumulative patency rates calculated at 3 years after operation were 68 and 66 per cent respectively for in situ and reversed grafts (P not significant). Cumulative limb salvage rates were 78 per cent for in situ grafts and 87 per cent for reversed grafts (P not significant). Separate analysis of a subgroup with small veins (< or = 3.5 mm minimum diameter) showed cumulative patency rates at 2 years of 74 per cent for in situ grafts and 60 per cent for reversed grafts (P not significant). These results indicate that for veins > 3.5 mm in diameter the in situ and reversed techniques for operation are equally effective. Some doubt remains about the best way of using smaller veins; a large number of such veins need to be studied to resolve this question.

Aged↗
PubMed1993

Analysis of balloon dilatation of human vein graft stenoses.

Controversy continues as to whether percutaneous transluminal angioplasty (PTA) or surgical revision is the ideal modality for the treatment of failing grafts. This prompted a histopathologic analysis of failing human vein graft segments subjected to ex vivo balloon dilatation to define variables responsible for the discrepant results. Fifteen vein graft lesions from 14 patients with failing infrainguinal bypasses were recovered after surgical excision. Each graft lesion was focal and uniform in length (2.1 +/- 0.3 cm). Rings sectioned from adjacent regions of each vein graft lesion before and after balloon inflation were processed for histologic study, photomicrography, and image analysis. Angioplasty balloon size was selected on the basis of preoperative arteriograms. Graft lesions were divided into three groups based on lesion thickness and the degree of fibrosis and cellularity seen on sections stained with Masson's trichrome. The luminal area before angioplasty was not significantly different for the three groups (p > 0.2). Vein grafts with thick intimas (group 1) had significantly less luminal dilatation after angioplasty as compared with less thick intimal lesions (groups 2 and 3; p < 0.001). Those lesions with varying degrees of cellularity (groups 2 and 3) showed no significant differences in luminal diameter after angioplasty. However, the cellular lesions in group 2 consistently formed multiple intimal flaps that could produce PTA failures even with good luminal restoration. The varying histology of vein graft lesions and associated differences in intimal thickness and cellularity may be responsible for the inconsistent results following PTA. Estimates of wall thickness before angioplasty, particularly in the intimal area, may be helpful in evaluating which lesions might benefit most from PTA.

Angioplasty, Balloon↗
PubMed1993

A new look at intraoperative completion arteriography: classification and management strategies for intraluminal defects.

Completion arteriography is widely regarded as an essential component of infrainguinal bypasses. However, the significance of various intraluminal filling defects is poorly defined, and strategies for managing these defects are unclear. Completion arteriography was performed by a standard technique in 78 infrapopliteal bypasses and were evaluated prospectively for the presence of angiographic defects. Thirty-nine arteriograms (50%) had no visible abnormality (grade O). Six arteriograms (8%) had minimal (grade I) defects, i.e., round lucencies (bubbles) or valve leaflets. Eighteen arteriograms (23%) had moderate (grade II) defects, i.e., uniform smooth tapering (up to 90% of luminal diameter) of the graft or outflow artery, irregular intraluminal filling defect (less than 60% of luminal diameter) within the distal graft or its adjacent outflow artery, or incomplete or faint graft opacification. Fifteen arteriograms (19%) had severe (grade III) defects, i.e., total cutoff of graft or outflow artery opacification or irregular intraluminal filling defect (greater than 60%) in the distal graft or adjacent outflow artery. Completion arteriograms were further stratified for type of bypass and outflow characteristics. All 24 bypasses with grade I or grade II defects on completion arteriography had no further surgical treatment. However, the 18 bypasses with grade II defects on completion arteriography had minimal nonsurgical manipulations consisting of repeat arteriography without or with papaverine infusion or urokinase instillation. In all 18, repeat arteriography showed improvement in the defect. The 15 bypasses with grade III defects had further surgical intervention (graftotomy, thrombectomy, vein patching, interposition graft, or graft extension). One-month and 1-year patency rates for grafts with grade I and grade II defects (87% and 79%, respectively) were not significantly worse than those for the 39 grafts with no arteriographic abnormalities (87% and 82%, respectively). In contrast, grafts with grade III defects had significantly worse (p < 0.01) 1-month and 1-year patency rates (33% and 20%, respectively) despite aggressive surgical correction of the arteriographic defects. These results emphasize the value of repeat completion arteriography and minimal interventional strategies when grade I or II defects are seen on arteriography. The poor outcome with surgical correction of grade III defects suggests that completion arteriography may not always define the full extent of the problem or that the corrective surgical maneuvers were either incomplete or detrimental.

Aged↗
PubMed1993

Is surveillance to detect failing polytetrafluoroethylene bypasses worthwhile?: Twelve-year experience with ninety-one grafts.

PURPOSE: The purpose of this study was to review the 91 failing polytetrafluoroethylene (PTFE) grafts that were treated at our institution over the past 12 years to better understand their cause and improve the diagnosis and treatment of these grafts. METHODS: Eighty-five patients with 91 failing grafts were retrospectively reviewed. The 144 graft-threatening lesions associated with these grafts were characterized by location (inflow artery, outflow artery, anastomosis, or graft body) and treatment method used (surgery, balloon angioplasty, or thrombolysis). RESULTS: Progression of atherosclerotic disease was the predominant cause of failing PTFE grafts with 43 inflow lesions and 83 outflow lesions, accounting for 87% of all lesions identified. Ten lesions (7%) were noted within the prosthetic grafts, whereas only eight (6%) lesions were noted at the anastomoses. Forty stenotic lesions 2 cm in length or less were treated with percutaneous transluminal balloon angioplasty, whereas 100 lesions were treated by patch angioplasty or graft extensions. The remaining four lesions, present within the prosthetic grafts, were treated with thrombolytic therapy. The 5-year cumulative patency rate for all failing PTFE grafts was 71%, whereas that of failing femoropopliteal PTFE grafts was 64%. The 5-year limb salvage rate for all failing PTFE grafts was 73%. CONCLUSIONS: The progression of inflow and outflow disease is the predominant cause of failing PTFE grafts, which suggests that this process is a more important cause of PTFE graft thrombosis than is generally recognized. Frequent PTFE graft surveillance may permit detection of some threatening lesions before graft thrombosis occurs and may help maintain and prolong graft patency. The enhanced 5-year patency and limb salvage rates for treated failing PTFE grafts compared with the known poor outcome after reinterventions for PTFE graft failure support the conclusion that surveillance of PTFE grafts is worthwhile.

Adult↗
PubMed1993

Angioplasty, bypass surgery, and amputation for lower extremity peripheral arterial disease in Maryland: a closer look.

Tunis and colleagues attempted to assess the effect of peripheral angioplasty in a large population with descriptive epidemiologic methods. Their study suffered from a vague statement of purpose, inappropriate and inadequate outcome measures, undetermined differences in prevalence of peripheral vascular disease and prevalence of risk factors for bypass/amputation in 1989 versus 1979, no differentiation between levels of amputation or between primary and secondary amputation, lack of a unique ICD-9-CM code indicating angioplasty for peripheral vascular disease of the lower extremities, lack of unique patient identifiers, a mistaken perception of the adoption of angioplasty as "widespread" in Maryland, and the assumption of uniform coding accuracy throughout the period of study. We conclude that the study design of Tunis et al was inadequate to determine the beneficial effects of angioplasty or bypass surgery in the treatment of peripheral vascular disease. Moreover, the conclusion by Coffman (2) that "invasive procedures are indicated only for the severely ischemic limb" is completely unsupported by the study data. Physicians should not attempt to apply the results of the study by Tunis et al to individual case situations. It should be further appreciated that the study findings do not provide an adequate basis for policy-making decisions. It is clear that important clinical questions concerning the roles of angioplasty, bypass, and amputation should be answered with more definitive studies.

Algorithms↗
PubMed1993

Comparison of duplex ultrasonography and ascending contrast venography in the diagnosis of venous thrombosis.

The application of duplex ultrasonography to the diagnosis of venous thrombosis requires validation by comparison of the duplex findings with the results of ascending contrast venography. In this study, 2534 veins were examined by both methods with contrast venography results serving as the standard for comparison. In this setting, duplex ultrasonography proved to be 100% sensitive and 99% specific for venous thrombosis. Duplex ultrasonography is as reliable as venography in the diagnosis of venous thrombosis and has no associated risks or known complication. In addition, duplex ultrasonography provides information regarding pathologic anatomy that is comparable to the detail provided by high-quality venography. The authors conclude that duplex ultrasonography should be the diagnostic method of choice for evaluating patients with suspected venous thrombosis.

Contrast Media↗
PubMed1993

Distribution of c-myc oncoprotein in healthy and atherosclerotic human carotid arteries.

PURPOSE: Smooth muscle cell (SMC) proliferation is a central event in the development of arteriosclerotic plaque. Regulation of this proliferative process is controlled in part by the action of specific peptide growth factors that may influence early cell-cycle regulatory gene expression. Such "early" response genes include the protooncogene c-myc, which has been implicated in the induction of cell proliferation and differentiation. We compared the distribution of the c-myc protooncogene product in healthy and atherosclerotic human carotid arteries to determine its cellular and tissue localization. METHODS: Samples of six carotid artery plaques from six patients were rapidly frozen in liquid nitrogen at the time of carotid endarterectomy. Three nondiseased human carotid arteries obtained at organ harvest from brain-dead organ donors were similarly prepared. Frozen sections were labeled with a polyclonal rabbit anti-c-myc antibody that recognizes the 64 kd c-myc human protein. The percentages of cells positive for c-myc (c-myc index) and the intensity of antibody labeling were determined. RESULTS: Normal human carotid artery demonstrated minimal, isolated cell staining, with single scattered grains of immunocytochemical staining product seen in SMC nuclei. The myc index was 14.7% +/- 3.5% positive cells. In comparison, SMCs from carotid plaque showed a significant predominance of c-myc immunoreactive cells (89.8% +/- 4%; p < 0.001). The intensity of c-myc staining was greater in plaque SMCs, with many of the cells demonstrating confluence of immunocytochemical precipitate throughout 50% of SMC nuclei. CONCLUSIONS: Although the exact role of enhanced expression of the c-myc protooncogene in atherosclerosis is unclear, a cooperative influence of abnormal early cell-cycle gene expression and humoral factors may initiate the atherogenic process. The c-myc gene and other protooncogenes are early molecular markers of cell-cycle activity, which may be important in the development of atherosclerosis and occlusive vascular disease.

Adult↗
PubMed1993

Saphenous vein angioscopy: a valuable method to detect unsuspected venous disease.

PURPOSE: The presence of preexisting saphenous vein lesions adversely affects graft patency. Despite careful preoperative venous duplex examination and meticulous intraoperative evaluation, clinically significant saphenous vein disease may remain undetected. We evaluated angioscopy as a means to better detect these vein lesions. METHODS: Ninety saphenous vein remnants, obtained at bypass surgery, were perfusion fixed for subsequent angioscopic and histologic evaluation. The specimens were categorized by independent examiners on the basis of the angioscopic or light microscopic findings. Of the 90 vein remnants, 66 were normal by angioscopic criteria. Fifty-three (80%) of these angioscopically normal vein segments were normal histologically, and all 24 angioscopically abnormal saphenous vein remnants showed disease on microscopic examination. RESULTS: Angioscopy correctly identified sclerotic vein segments (n = 20) by irregular white plaques, whereas postphlebitic veins (n = 3) demonstrated multiple lumens, fibrous strands, and thickened opaque valve cusps on angioscopic evaluation. Absence of an angioscopic lumen was confirmed histologically in occluded veins (n = 2). Angioscopy failed to identify thick-walled (n = 10) and varicose (n = 2) vein segments as abnormal; one sclerotic segment was normal angioscopically, thereby lowering the sensitivity of angioscopy. CONCLUSIONS: Angioscopy detected unsuspected preexisting saphenous vein disease in five patients undergoing arterial reconstruction with saphenous vein. Because the use of angioscopy is a reliable means of prospectively assessing the vein for most preexisting lesions, its routine use may ultimately improve graft patency.

Angioscopy↗