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Biomedical subjects

D F Bandyk

Publications and source records attributed to D F Bandyk.

At least 37 records · Page 2Linked to original sources
PubMed1995

The origin of infrainguinal vein graft stenosis: a prospective study based on duplex surveillance.

PURPOSE: The purpose of this study was to determine the origin of vein graft lesions and their propensity for progression based on prospective duplex surveillance of 135 infrainguinal vein bypasses. METHODS: One hundred sixteen greater saphenous, 13 spliced, five cephalic, and one superficial femoral vein grafts were evaluated by color duplex imaging at surgical procedure, 1 and 6 weeks, 3 and 6 months, and every 3 to 6 months thereafter. Duplex-identified lesions were graded by peak systolic velocity and velocity ratio criteria and were either followed or subjected to revision. RESULTS: Early postoperative duplex surveillance allowed stratification of infrainguinal grafts into two subsets. Of 91 (67%) grafts with normal early scans (at 3 months), only two (2.2%) developed de novo stenoses (at 6 and 8 months) that required revision. Forty-four grafts with abnormal duplex scans had a focal flow abnormality (peak systolic velocity > 150 cm/sec, velocity ratio > 1.5) in the graft body (n = 24) or anastomotic region (n = 20). In 14 grafts the flow abnormality (mean peak systolic velocity = 217 cm/sec, velocity ratio = 2.3) normalized. Ten additional grafts exhibited a moderate, persistent graft stenosis (mean peak systolic velocity 248 cm/sec, velocity ratio = 3.3) that was not repaired. All 20 grafts with lesions that progressed to high-grade stenosis (mean peak systolic velocity = 362 cm/sec, velocity ratio = 7.2) and were revised had a residual flow abnormality confirmed at operation, or it appeared by 6 weeks. In the entire series six (4.4%) grafts failed during the mean 12-month follow-up interval (range 3 to 30 months), 4 with unrepaired defects and two after revision. CONCLUSIONS: Prospective duplex surveillance verified that de novo graft stenosis was uncommon (< 2.2%) after reversed and in situ saphenous vein bypass grafting. Graft stenoses developed at sites of unrepaired defects or early appearing conduit abnormalities. An early appearing duplex focal flow abnormality warranted careful surveillance, because one half of such sites progressed to a high-grade stenosis. Grafts with normal early duplex scans exhibited a low incidence of stenosis development or occlusion, and thus less intense postoperative surveillance can be recommended.

Adult↗
PubMed1995

Vascular injury associated with extremity trauma.

Limb salvage in patients with combined orthopaedic and vascular injuries is highly dependent on the severity of injury and the expeditious diagnosis and treatment of vascular trauma. Diagnostic arteriography should be used selectively to identify an occult injury in patients with an abnormal physical examination or to establish the anatomy and precise location of injury. Measurement of limb pressures using a Doppler device and use of duplex ultrasonography are valuable adjuncts in the rapid evaluation of patients with trauma for arterial injury. When unequivocal evidence of arterial injury is present and the operative approach is established easily by the mechanism and site of injury, treatment should not be delayed by confirmatory arteriography. Vascular repair should precede orthopaedic stabilization particularly if critical ischemia is present. Amputation rates after extremity trauma continue to decrease because of rapid patient transport (decrease in warm ischemia time) and a team approach to injury repair. Technical success of restoring arterial patency and limb perfusion is achieved in > 95% of patients. Early amputation is related to prolonged ischemia and soft tissue injury that precludes a viable, functional extremity. Late amputation is done for disability, a useless, painful limb, or chronic infection.

Algorithms↗
PubMed1994

Does arterial inflow failure cause distal vein graft thrombosis? A prospective analysis of 450 infrainguinal vascular reconstructions.

Classically, inadequate arterial inflow, diseased runoff, and poor bypass conduit quality have all been cited as causes of infrainguinal vein graft failure. To examine the role of arterial inflow failure as a specific cause of vein graft thrombosis, we prospectively analyzed 450 consecutive infrainguinal vascular reconstructions by means of a strict duplex scan surveillance protocol at three teaching institutions from 1986 to 1993. Sixteen incidences of arterial inflow failure (11 occlusions and five high-grade stenoses) above previously placed infrainguinal vein grafts were identified in 14 patients and confirmed by arteriography. Despite these inflow failures, all 14 autogenous vein infrainguinal reconstructions remained patent on arteriography. These inflow failures were observed from 2 to 72 months (mean 16 months) after infrainguinal reconstruction. Immediate successful inflow repair was performed in 13 of the 16 failures. Conversely, among 450 grafts followed, 37 acute graft occlusions occurred-all with arteriographically or noninvasively documented normal inflow. Thus no graft in the series has yet failed as a result of inflow occlusion (mean follow-up 22 months; range 1 to 78 months). We thus conclude that properly constructed infrainguinal saphenous vein bypass grafts with an intact endothelium often remain patent through low-flow collateral vessels despite total arterial inflow occlusion. These data thus challenge the premise that arterial inflow disease is a major cause of infrainguinal vein bypass occlusion.

Adult↗
PubMed1994

Intraoperative duplex scanning of arterial reconstructions: fate of repaired and unrepaired defects.

PURPOSE: Because unrecognized lesions can cause an arterial reconstruction to fail, duplex ultrasonography was evaluated as an intraoperative aid to assess technical adequacy and provide criteria for which lesions should be repaired immediately versus safely followed. METHODS: Since 1990 intraoperative color duplex scanning(7 to 10 MHz linear array probe, pulsed-wave Doppler test spectrum analysis) was used to assess the frequency and severity of residual lesions in 368 patients after carotid endarterectomy (n = 210), infrainguinal vein bypass (n=135) or visceral/renal reconstruction (n = 23). Duplex scan results were categorized as normal or abnormal, with immediate repair of lesions demonstrating both lumen reduction and severe focal flow abnormalities (peak systolic velocity [Vp] > 150 to 180 cm/sec;velocity ratio [Vr] > 2.4). Arteriography was also performed in 81% of lower limb bypass procedures. RESULTS: Duplex scanning identified technical (residual plaque, stricture) or intrinsic defects (platelet thrombus, distal thrombosis) requiring revision in 37 (10%) of the reconstructions. Infrainguinal bypass had the highest incidence of corrected defects (14%) and adverse events (3%). No adverse events occurred in patients with normal duplex scan results or after carotid endarterectomy. Overall, 76% of identified defects were corrected (carotid, 17 of 24; infrainguinal bypass, 19 of 24; visceral bypass, 1 of 1). Unrepaired flow defects (Vp = 150 to 190 cm/sec; Vr = 1.8 to 2.5) led to one graft occlusion and three early revisions. Postoperative duplex scanning demonstrated residual stenosis in seven of 12 patients with unrepaired defects, two of 36 patients with repaired defects, and five of 312 patients with normal scan results (p < 0.001). CONCLUSION: Based on the types of lesions corrected and the low (< 0.5%) complication rate after a normal or modified arterial reconstruction, duplex scanning was found to be a valuable intraoperative aid. Unrepaired defects require close surveillance for progression.

Algorithms↗
PubMed1994

The utility and durability of vein bypass grafts originating from the popliteal artery for limb salvage.

BACKGROUND: Short vein grafts originating from sites distal to the common femoral artery have been reported to be useful in selected patients with tibial artery disease. From 1987 to 1993, we performed 504 consecutive infrainguinal vein bypass grafts, of which 56 (11%) originated from the popliteal artery, 25 above and 31 below the knee. PATIENTS AND METHODS: The patients were 16 women and 37 men, with a mean age of 62.4 years. Eighty-seven percent were diabetic, 57% had clinically obvious coronary artery disease, and 28% had end-stage renal disease (ESRD). The indication for surgery was ulceration or gangrene in 93% of cases. We preferentially used reversed greater saphenous vein harvested from the thigh to optimize conduit quality and avoid lower leg wound complications. The outflow artery sites were: dorsal pedal (17), posterior tibial (14), peroneal (10), anterior tibial (8), lateral or medial plantar (5), and sequential tibial (2). All patients were followed postoperatively with serial duplex surveillance. The mean follow-up was 12.5 months (range 1 to 66). RESULTS: In-hospital mortality was 5.4%. Mortality at 24 months was 19% overall and 38% in patients with ESRD. Limb salvage was 77% at 3 years, 92% in patients with normal renal function versus 59% in those with ESRD (P < 0.003). Primary graft patency by life-table analysis was 94% at 1 month and 84% at 3 years. Five patients with patent grafts required amputation, 4 early and 1 late. Eight months after surgery, 1 patient (1.8%) developed superficial femoral artery stenosis which was diagnosed by duplex surveillance and successfully treated by percutaneous transluminal balloon angioplasty. CONCLUSIONS: Vein bypass grafts originating from the popliteal artery are effective and durable. Proximal disease progression rarely poses a significant threat to long-term graft patency. Patients with ESRD, blind tibial outflow tracts, and extensive forefoot lesions appear to be at increased risk of limb loss even with continued graft patency.

Adult↗
PubMed1994

Prosthetic graft infection.

This article outlines the tenets and basic data critical for the management of prosthetic graft infections. Diagnostic algorithms and treatment options appropriate for patients with symptoms and signs suggestive of graft infection are presented.

Anti-Bacterial Agents↗
PubMed1993

Durability of the in situ bypass following modification of abnormal vein segment.

Modification procedures performed during in situ bypass grafting to correct an injured or inadequate saphenous vein segment result in a significant increase in the incidence of vein graft complications in the follow-up period. Modification procedures were performed in 96 in situ saphenous vein bypasses and consisted of primary closure (n = 28), vein patch angioplasty (n = 31), or resection and/or replacement (n = 37). At 4 years primary patency was 54%, secondary patency was 73%, and limb salvage was 89%. The incidence of subsequent vein graft stenosis and revision or graft failure was similar for grafts requiring vein patch angioplasty (7 of 31, 23%), primary repair (9 of 28, 32%), and resection and/or replacement (16 of 37, 43%) (p not equal to ns). Only 4 bypass revisions were performed for stenosis at the site of the original modification procedure. The type of vein graft repair did not significantly affect the primary patency at 18 months (primary closure, 65%, vein patch angioplasty, 66%, and resection and/or replacement, 58%) or the secondary patency at 30 months (primary closure, 80%, vein patch angioplasty, 90%, and resection and/or replacement, 77%). Modified autogenous conduits maintain patency and limb salvage but are prone to develop graft complications in the follow-up period.

Coronary Artery Bypass↗
PubMed1993

Determinants of successful peroneal artery bypass.

PURPOSE: The purpose of this study was to identify the determinants of long-term success with the peroneal artery bypass. METHODS: Seventy-seven consecutive peroneal artery bypasses performed between 1981 and 1990 were reviewed to evaluate the influence of venous conduit modification, surgeon experience, patency of the dorsalis pedis or posterior tibial artery at the ankle, and the quality of the peroneal collateral branches and pedal arch. The average follow-up was 34 months (range 1 to 92 months). RESULTS: The 5-year primary and secondary patency rates were 61% and 92%, respectively. Modification of the vein graft at the initial procedure was necessary in 26 (34%). This led to a reduced (p < 0.001) 5-year primary patency rate of 22% compared with 80% for unmodified conduits. Operative results improved with surgeon experience. The 5-year secondary patency rate of grafts placed before 1985 was 82% compared with 98% for subsequent grafts (p < 0.03). The initial postoperative mean ankle/brachial index for grafts revised for hemodynamic failure or thrombosis in the follow-up period was 0.84 compared with 0.95 in grafts that did not require revision (p < 0.04). The presence of a patent dorsalis pedis or posterior tibial artery at the ankle and an intact pedal arch did not significantly influence primary or secondary patency. The 5-year secondary graft patency rate for patients with a patent dorsalis pedis or posterior tibial artery at the ankle was 88%. CONCLUSIONS: The peroneal artery should be selected for outflow when it is the single tibial runoff vessel and is preferable to a bypass to an inframalleolar arterial segment. The quality of the venous conduit and the technical skill of the surgeon are the two most important factors in the success of bypasses to the peroneal artery.

Aneurysm↗
PubMed1993

Biologic characteristics of long-term autogenous vein grafts: a dynamic evolution.

PURPOSE: The venous conduit as an arterial substitute has dynamic biologic properties that affect its durability. This study evaluated the morphologic and physiologic characteristics of 72 lower extremity vein grafts functioning at 4.5 to 21.6 years (median 6.6 years). METHODS: The entire graft was imaged with use of color duplex ultrasonography and then classified as normal (class I), abnormal but not graft-threatening (class II), or abnormal and graft-threatening (class III) for the proximal, middle, and distal thirds. Thirty-one grafts (43%) were classified as normal, whereas 41 (57%) were classified as abnormal, with 58 class II and 15 class III segments. RESULTS: Three types of abnormalities were found by duplex imaging: nonstenotic wall plaques, discrete stenoses, and aneurysmal dilation. Aneurysms developed in five of seven grafts that had required thrombectomy in the distant past (mean of 40 months). There were 70 postoperative revisions in 38 limbs (53%). In 23 (60%) the conduit was revised, in 11 (29%) the revisions corrected progression of native artery atherosclerotic disease, and in 4 (11%) both types of revisions were required. Eleven grafts were revised in the first 30 days to correct technical errors. Eighteen limbs were revised between 1 and 24 months, with 12 (67%) of the revisions correcting stenotic lesions in the conduit or at one of the anastomoses. After 24 months 12 (67%) of 18 limbs were revised to correct progression of occlusive disease in the inflow or outflow vessels. At the time of this study 18 (67%) of the 27 conduits revised for intrinsic lesions were abnormal by color duplex imaging, and they harbored 12 (80%) of the 15-graft-threatening lesions. CONCLUSIONS: Autogenous vein remains the most durable arterial conduit, but vigilant surveillance is essential because the atherosclerotic environment continually produces lesions that may imperil the longevity of the graft.

Adult↗
PubMed1993

The importance of intraoperative detection of residual flow abnormalities after carotid artery endarterectomy.

PURPOSE: The efficacy of carotid endarterectomy in the prevention of strokes mandates low perioperative morbidity, as well as a low incidence of late ipsilateral stroke. This prospective study involving 430 patients (461 carotid endarterectomies) correlated the results of intraoperative assessment with end points of stroke and residual/recurrent internal carotid artery (ICA) stenosis. METHODS: Adequacy of the repair was assessed by ultrasound studies (duplex scan and pulsed Doppler spectral analysis) alone (n = 142), ultrasound studies and arteriography (n = 268), or clinical inspection (n = 51). After operation, duplex ultrasonography was used to confirm patency and categorize severity of ICA stenosis. At operation 26 carotid endarterectomy sites (5.6%), were revised based on intraoperative studies. RESULTS: Perioperative (30-day) morbidity rates were similar in patients with normal, mildly abnormal, or no ultrasound completion studies. There were six permanent (1.3%) and 12 temporary (2.6%) neurologic deficits and six deaths, including four fatal strokes and two fatal myocardial infarctions. By life-table analysis, the incidence of greater than 50% diameter-reducing ICA stenosis or occlusion was increased (p < 0.007, log-rank test) in patients with residual flow abnormality or no study. More important, patients with normal intraoperative flow studies had a significantly lower rate of late ipsilateral stroke compared with the remaining patient cohort (p = 0.04, log-rank test). During the mean 30-month follow-up interval, the incidence of late stroke was increased (p = 0.00016) in patients with ICA restenosis or occlusion (3/35) compared with patients without recurrent stenosis (3/426). CONCLUSION: Confirmation of a normal repair at operation affords the best opportunity to minimize ischemic neurologic events and anatomic restenosis after carotid endarterectomy.

Blood Flow Velocity↗
PubMed1993

Treatment of bacteria-biofilm graft infection by in situ replacement in normal and immune-deficient states.

PURPOSE: Complications of grafts infected with coagulase-negative staphylococci can be eradicated by antibiotic administration, tissue debridement, and in situ graft replacement, but successful treatment may be diminished in a setting of altered immune function. METHODS: In a canine model of an established aortic graft infection from Staphylococcus epidermidis, outcomes after in situ replacement were compared between normal dogs and animals made immune-deficient by administration of azathioprine (50 mg/day) and prednisone (10 mg/day). In situ replacement of an infected infrarenal aortic graft with either antibiotic-bonded (silver-ciprofloxacin: Ag-cipro) or conventional polytetrafluoroethylene (PTFE) grafts was performed in 17 control and 18 immune-deficient animals. RESULTS: Four weeks after implantation of a Dacron graft colonized with a biofilm of S. epidermidis, all study animals demonstrated a bacterial biofilm infection with perigraft inflammation or abscess, and in immune-suppressed dogs the incidence of perianastomotic aortitis was increased (p < 0.05). Six weeks after in situ replacement both the Ag-cipro and conventional PTFE grafts were healed without signs of infection in controls, but anatomic evidence of persistent infection and increased S. epidermidis recovery was observed in immune-suppressed animals that underwent in situ replacement of a standard (five of seven) versus antibiotic-bonded (one of 11) PTFE graft (p < 0.006). Overall in situ replacement with an antibiotic-bonded graft yielded a lower frequency of S. epidermidis recovery (two of 19 Ag-cipro graft biofilm with positive culture results versus nine of 16 conventional graft biofilm with positive culture results; (p < 0.003). CONCLUSIONS: This study supports the efficacy of in situ replacement for low-grade graft infections caused by S. epidermidis in normal hosts and demonstrates superiority of antibiotic-bonded grafts in immune-deficient hosts.

Animals↗
PubMed1993

Intraoperative thrombolysis in peripheral arterial occlusion.

Thromboembolic occlusion of peripheral arteries continues to be associated with significant morbidity, mortality and loss of limbs. Surgical intervention with prompt revascularization by clot extraction, alone or in combination with arterial bypass, remains the standard therapy for critical ischemia with imminent tissue loss. Mechanical thrombectomy using a balloon catheter has been the preferred technique for distal embolus or thrombus extraction. Unfortunately, complete thrombectomy is rare, and the procedure is associated with arterial wall injury. Intraoperative thrombolytic therapy is an attractive adjunct to catheter thrombectomy alone and is appropriate in the care of a significant number of patients with acute limb ischemia. Its safety and efficacy have been confirmed in the laboratory and in a limited number of patients. The authors review experimental and clinical data and report their experience with 19 patients.

Acute Disease↗
PubMed1993

Thrombolysis in peripheral arterial graft occlusion.

Acute thrombosis of arterial bypass grafts in the lower extremities poses a significant risk for limb loss. Graft salvage in patients affected by this complication remains a challenge. The vascular surgeon must consider the spectrum of treatment options (thrombolysis, thrombectomy, graft replacement) in managing acute graft thrombosis. Oral anticoagulants should be considered in patients with low-flow polytetrafluoroethylene (PTFE) grafts and after successful thrombolysis, with or without revision. The role of thrombolytic therapy for occluded vein grafts is less clear, but successful lysis is likely in patients who present within 48 hours of graft thrombosis and the etiology includes a correctable graft stenosis.

Acute Disease↗
PubMed1993

Symptomatic recurrent carotid stenosis and aneurysmal degeneration after endarterectomy.

BACKGROUND: Aneurysmal degeneration of a carotid reconstruction was not recognized until the patient, who was known to have recurrent carotid artery stenosis, had a thromboembolic stroke. This sequelae of carotid endarterectomy is a serious complication, associated with a high morbidity and mortality rate. This review was conducted to establish the risk of transient ischemic attack and stroke for patients found to have recurrent carotid stenosis associated with aneurysmal degeneration of the carotid artery after endarterectomy. METHODS: A case is reported, and 100 literature references of aneurysmal degeneration of the carotid artery after endarterectomy were reviewed. RESULTS: False aneurysm from anastomotic disruption was the most common presentation identified in the cases reviewed. Nineteen of the patients had a significant neurologic event; however, three (50%) of six patients with aneurysm and recurrent carotid artery stenosis had a transient ischemic attack or stroke. CONCLUSIONS: The incidence of neurologic symptoms is markedly increased when recurrent carotid artery stenosis is associated with carotid aneurysm. During postoperative surveillance after endarterectomy, the identification of recurrent carotid artery stenosis requires evaluation for aneurysmal degeneration of the carotid artery with duplex scanning. These patients are at significant risk for transient ischemic attack and stroke. This rare complication merits operative repair.

Aneurysm↗
PubMed1992

Use of stress thallium imaging to stratify cardiac risk in patients undergoing vascular surgery.

Reduction of the cardiac morbidity associated with major vascular procedures requires identification of high risk patients prior to operation. This retrospective study reviews the records of 126 consecutive patients who underwent 141 major vascular procedures to determine the accuracy of preoperative clinical, laboratory (ECG), and cardiac function testing (stress thallium-201 scintigraphy, left ventricular ejection fraction scan) in predicting perioperative cardiac complications. An abnormality on oral dipyridamole or treadmill thallium imaging was demonstrated prior to 71 (61%) of 116 procedures and included 20 fixed and 51 reperfusion (reversible) defects. No patient died within 30 days of operation, but 11 minor (ventricular arrhythmia) and 15 major (myocardial infarction, ischemic congestive heart failure) cardiac complications occurred. A reperfusion defect on stress thallium imaging accurately (94% sensitivity, 56% specificity, 98% negative predictive value) identified high-risk patients while accepted clinical rating systems (Goldman, Cooperman, Eagle) and preoperative level of left ventricular ejection fraction were less predictive of adverse cardiac events. Patients without myocardium at risk by coronary angiography, but a reperfusion defect on stress thallium imaging were found to be at high risk for a cardiac complication. The study data support the use of stress thallium imaging to stratify cardiac risk prior to major arterial surgery.

Adult↗