Biomedical subjects

D F Bandyk

Publications and source records attributed to D F Bandyk.

At least 19 recordsLinked to original sources

PubMed2000

Intraoperative duplex monitoring of infrainguinal vein bypass procedures.

PURPOSE: The purpose of this study was to evaluate intraoperative duplex scanning of infrainguinal vein bypass grafts to detect technical and hemodynamic problems, monitor their repair, and correlate findings with the incidence of thrombosis and stenosis repair rates within 90 days of operation. METHODS: Color duplex scanning was used at operation to assess vein/anastomotic patency and velocity spectra waveforms of 626 infrainguinal vein bypass grafts (in situ saphenous, 228 grafts; nonreversed translocated saphenous, 170 grafts; reversed saphenous, 147 grafts; alternative [arm, lesser saphenous], 81 grafts) to the popliteal (n = 267 grafts), infrageniculate (n = 323 grafts), or pedal artery (n = 36 grafts). The entire bypass graft was scanned after intragraft injection of papaverine hydrochloride (30-60 mg) to augment graft flow. Vein/anastomotic/artery segments with velocity spectra that indicate highly disturbed flow (peak systolic velocity, >180 cm/sec; spectral broadening; velocity ratio at site, >3) were revised. Grafts with a low peak systolic velocity less than 30 to 40 cm/s and high outflow resistance (absent diastolic flow) underwent procedures (distal arteriovenous fistula, sequential bypass grafting) to augment flow; if this was not possible, the grafts were treated with an antithrombotic regimen, including heparin, dextran, and antiplatelet therapy. RESULTS: Duplex scanning prompted revision of 104 lesions in 96 (15%) bypass grafts, including 82 vein/anastomotic stenoses, 17 vein segments with platelet thrombus, and 5 low-flow grafts. Revision rate was highest (P <.01) for alternative vein bypass grafts (27%) compared with the other grafting methods (reversed vein bypass grafts, 10%; nonreversed translocated, 13%; in situ, 16%). A normal intraoperative scan on initial imaging (n = 464 scans) or after revision (n = 67 scans) was associated with a 30-day thrombosis rate of 0.2% and a revision rate of 0.8% for duplex-detected stenosis (peak systolic velocity, >300 cm/s; velocity ratio, >3.5). By comparison, 20 of 95 bypass grafts (21%) with a residual (n = 29 grafts) or unrepaired duplex stenosis (n = 53 grafts) or low flow (n = 13 grafts) had a corrective procedure for graft thrombosis (n = eight grafts) or stenosis (n = 12 grafts; P <.001). Overall, 8% of patients with bypass grafts underwent a corrective procedure within 90 days of operation. Secondary graft patency was 99.4% at 30 days and 98.8% at 90 days (eight graft failures). CONCLUSION: The observed 15% intraoperative revision rate coupled with a low 90-day failure/revision rate (2.5%) for bypasses with normal papaverine-augmented duplex scans supports the routine use of this diagnostic modality to enhance the precision and early results of infrainguinal vein bypass procedures.

Anastomosis, Surgical↗

PubMed2000

Magnetic resonance angiography is an accurate imaging adjunct to duplex ultrasound scan in patient selection for carotid endarterectomy.

PURPOSE: The purpose of this study was to evaluate the accuracy of magnetic resonance angiography (MRA) for categorizing the severity of carotid disease relative to duplex ultrasound scan and cerebral contrast arteriography (CA) to determine if MRA imaging could replace the need for cerebral angiography in cases of indeterminate or inadequate duplex scan imaging. METHODS: Seventy-four carotid bifurcations in 40 patients undergoing 45 carotid endarterectomies from 1996 to 1998 were imaged with duplex ultrasound scan; MRA (two-dimensional neck and three-dimensional intracranial, time-of-flight technique); and biplanar, digital subtraction cerebral arteriography. Studies were blindly reviewed by one reader who used established threshold velocity criteria for the duplex scan and the North American Symptomatic Carotid Endarterectomy Trial method for MRA and CA to determine the percentage of diameter reduction of the internal carotid artery (ICA). Disease severity was grouped into four categories (< 50%, 50%-74%, 75%-99% stenosis and occlusion), and the results of MRA and duplex ultrasound scan were compared with CA. RESULTS: Sensitivity, specificity, positive predictive value, and negative predictive value for detection of > 50% ICA stenosis were 100%, 96%, 98%, and 100% for MRA and 100%, 72%, 88%, and 100% for duplex ultrasound scan, respectively; similarly, for detection of > 75% ICA stenosis values were 100%, 77%, 76%, and 100% for MRA and 90%, 74%, 72%, and 91% for duplex ultrasound scan, respectively. Both MRA and duplex ultrasound scan accurately differentiated all cases of > 95% stenosis (n = 7) from occlusion (n = 4). Short length ICA flow gaps were present on MRA in all cases of 75% to 99% stenosis and one half of cases of CA-defined 50% to 74% stenosis. In patients with 50% to 74% stenosis, the mean angiographic stenosis was significantly greater when a flow gap was present on MRA (64% +/- 6%) versus no flow gap (57% +/- 7%) (P =.04). There was overall agreement among duplex ultrasound scan, MRA, and CA in 73% of carotids imaged. Of the 24% discordant results between MRA and duplex ultrasound scan, MRA correctly predicted disease severity in all cases, and inaccurate duplex ultrasound scan results were due to overestimation in 83% of cases. The operative plan was altered by CA findings in only one patient (2%) after duplex ultrasound scan and MRA. CONCLUSIONS: MRA can accurately categorize the severity of carotid occlusive disease. Duplex ultrasound scan facilitates patient selection for carotid endarterectomy in most cases, but adjunct use of MRA improves diagnostic accuracy for > 75% stenoses and may obviate the need for cerebral arteriography when duplex scan results are inconclusive or demonstrate borderline disease severity.

Aged↗

PubMed1999

A rational algorithm for duplex scan surveillance after carotid endarterectomy.

PURPOSE: This study was undertaken to determine the appropriate timing and frequency of duplex ultrasound scanning after carotid endarterectomy (CEA) for the detection of high-grade stenosis caused by recurrent carotid stenosis or contralateral atherosclerotic disease progression. METHODS: In 221 patients who underwent 242 CEAs, duplex scanning was performed before, during, and after operation (in 3-month to 6-month intervals). High-grade internal carotid artery (ICA) stenosis (peak systolic velocity, >300 cm/s; diastolic velocity, >125 cm/s; ICA/common carotid artery ratio, >4) prompted the recommendation for repair. An average of four postoperative scanning procedures was performed during a mean follow-up period of 27.4 months. RESULTS: Intraoperative duplex scan results prompted the immediate revision of 12 repairs (4.9%), and one perioperative stroke (<1%) occurred. Six CEAs (2.7%) had asymptomatic recurrent stenosis (>50% diameter-reduction [DR]; systolic velocity, >125 cm/s) develop. Only one of six patients had >75% DR stenosis develop and underwent reoperation (<1% yield for CEA surveillance). The yield of surveillance of the unoperated ICA was higher (P =.003), and 12% of unoperated sides had progressive stenosis (n = 21) or occlusion (n = 3) develop, which led to seven CEAs for high-grade stenosis. Disease progression to >75% DR stenosis was five times as frequent (P =.002) in patients with >50% DR stenosis initially. All patients but one who required contralateral endarterectomy for disease progression had >50% ICA stenosis when first seen. During the follow-up period, no disabling strokes ipsilateral to an operated carotid artery occurred, but three strokes occurred in the hemisphere of the contralateral unoperated ICA. CONCLUSION: The yield of duplex scan surveillance after CEA was low. Only 13 patients (5.9%) had severe disease develop to warrant additional intervention. Progression of contralateral disease rather than restenosis was the most common abnormality that was identified. Duplex scanning at 1-year to 2-year intervals after CEA is adequate when a technically precise repair is achieved and minimal contralateral disease (<50% DR) is present. A policy of duplex scan surveillance and reoperation for high-grade stenosis was associated with a 1.6% incidence rate of disabling stroke during the follow-up period.

Adult↗

PubMed1999

Surgical and endovascular intervention for infrainguinal vein graft stenosis.

PURPOSE: The purpose of this study was to evaluate the stenosis-free patency of open repair (vein-patch angioplasty, interposition, jump grafting) and percutaneous transluminal balloon angioplasty (PTA) of 144 vein graft stenoses that were detected during duplex scan surveillance after infrainguinal vein bypass grafting. METHODS: Patients who underwent revision of an infrainguinal vein bypass graft were analyzed for type of vein conduit, vascular laboratory findings leading to revision, repair techniques, assisted graft patency rate, procedure mortality rate, and restenosis of the repair site. RESULTS: The time of postoperative revision ranged from 1 day to 133 months (mean, 13 months). One hundred eighteen primary and 26 recurrent stenoses (peak systolic velocity, >300 cm/s) in 52 tibial and 35 popliteal vein bypass grafts were identified by means of duplex scanning. The repairs consisted of 77 open procedures (vein-patch angioplasty, 28; vein interposition, 33; jump graft, 9; primary repair, 3) and 67 PTAs. No patient died as a result of intervention. Cumulative assisted graft patency rate (life-table analysis) was 91% at 1 year and 80% at 3 years. At 2 years, cumulative assisted graft patency rate was comparable for saphenous vein grafts (reversed, 94%; in situ, 88%; nonreversed, 63%) and alternative vein grafts (89%). Stenosis-free patency rate at 2 years was identical (P =.55) for surgical intervention (63%) and endovascular intervention (63%) but varied with type of surgical revision (P =.04) and time of intervention (<4 months, 45%; >4 months, 71%; P =.006). The use of duplex scan-monitored PTA to treat focal stenoses (<2 cm) and late-appearing stenoses (>3 months) was associated with a stenosis-free patency rate that was 89% at 1 year. After intervention, the alternative vein bypass grafts necessitated twice the reinterventions per month of graft survival (P =.01). Bypass graft to the popliteal versus infrageniculate arteries, site of graft stenosis (vein conduit, anastomotic region), and repair of a primary versus a recurrent stenosis did not influence the outcome after intervention. CONCLUSION: The revision of duplex scan-detected vein graft stenosis with surgical or endovascular techniques was associated with an excellent patency rate, including when intervention on alternative vein conduits or treatment of restenosis was necessary. When PTA was selected on the basis of clinical and duplex scan selection criteria, the endovascular treatment of focal vein graft stenosis was effective, durable, and comparable with the surgical revision of more extensive lesions.

Adult↗

PubMed1999

Duplex features of vein graft stenosis and the success of percutaneous transluminal angioplasty.

PURPOSE: To determine if criteria exist that are correlated to a successful outcome after balloon angioplasty for vein graft stenosis. METHODS: During a 5-year period, duplex surveillance of 380 infrainguinal vein bypasses identified 76 hemodynamically failing grafts (87 stenoses) requiring intervention. Percutaneous transluminal angioplasty (PTA) was selected over surgical repair based on 3 criteria: time interval from primary grafting procedure, vein graft diameter, and stenosis length. The 28 (32%) stenoses (20 grafts) treated by PTA were used in a retrospective analysis to test if any variables favored a successful outcome. Patient and lesion characteristics, graft patency, and restenosis following PTA were correlated with duplex features of the stenosis recorded prior to, immediately after, and at 3- to 6-month intervals postprocedurally. RESULTS: Lesion characteristics that correlated with a successful outcome were vein size > or = 3.5 mm, lesion length < 2 cm, and appearance > 3 months after surgery. Conduit type, PTA site, patient demographics, and indication for bypass did not correlate with PTA durability. Nineteen lesions in 13 grafts met these criteria (group 1), while 9 stenoses in 7 grafts did not (group 2). Lesion severity based on duplex velocity measurements were similar in both groups before (p = 0.40) and after (p = 0.32) treatment. During the mean 21-month follow-up, group 1 grafts required less intervention (p = 0.035). At last follow-up, hemodynamic changes were durable in group 1 (p = 0.0068) but not in group 2 (p = 0.39). CONCLUSIONS: Selection of vein graft stenoses for treatment by PTA can be based on temporal and duplex data. PTA of short (< 2 cm) stenoses in good caliber veins (> or = 3.5 mm) appearing > 3 months after bypass placement was durable with a late intervention rate of approximately 10%. Direct surgical repair or replacement is recommended for early (< 3 months) and/or long segment stenoses that develop in small caliber conduits.

Aged↗

PubMed1999

Duplex imaging of lower extremity bypasses, angioplasties, and stents.

Duplex scan surveillance after lower extremity bypass and endovascular interventions can have a favorable impact on outcome. Its application during an arterial intervention to exclude technical or hemodynamic abnormalities and as part of a postoperative surveillance program to detect stenosis has been shown to improve patency. Results of duplex imaging can identify the arterial reconstruction at high risk of failure/thrombosis, which requires more intensive surveillance. Based on stenosis severity and anatomy, duplex scanning can suggest which repair technique (open surgery vs percutaneous balloon angioplasty [PTA]) is more appropriate. The use of duplex imaging during PTA of graft or peripheral artery stenoses (duplex-monitored balloon angioplasty) is recommended to verify normalization of velocity spectra, because this end point is associated with improved stenosis-free patency. A duplex surveillance program combined with correction of progressively stenotic lesions is recommended after lower limb bypass and PTA.

Algorithms↗

PubMed1997

Natural history of infrainguinal vein graft stenosis relative to bypass grafting technique.

PURPOSE: To determine whether the incidence of vein graft stenosis is related to bypass grafting technique and thus modification of postoperative surveillance protocols may be required. METHODS: From 1991 to 1996, 338 infrainguinal vein bypasses constructed using in situ (n = 131), reversed (n = 120), nonreversed translocated (n = 48), or spliced/upper extremity vein (n = 39) grafting techniques were evaluated by intraoperative duplex scanning to optimize bypass construction and serially thereafter to detect developing vein graft stenoses. Bypass procedures were performed in 322 patients for critical limb ischemia (83%), claudication (13%), or popliteal aneurysm (4%). Using life-table analysis, graft patency and revision/failure rates were compared relative to grafting technique, need for operative revision, and intraoperative duplex scan results. RESULTS: Three-year primary and secondary graft patency rates were higher (p < 0.001) for in situ bypass grafts (85%/97%) compared with reversed (57%/83%), nonreversed translocated (62%/78%), or alternative (51%/76%) vein bypass grafts. During a mean follow-up interval of 19 months, the incidence of graft revision was higher for reversed saphenous (23%) and alternative (28%) vein bypass grafts compared with in situ (10%) or nonreversed (16%) saphenous vein bypass grafts. Despite a normal intraoperative graft duplex scan, the revision/failure rate of reversed vein grafts was 2.5 times greater than in situ/nonreversed translocated vein conduits (primary patency rate at 3 years, 60% vs 87%, p = 0.009). Bypass grafts modified at operation on the basis of duplex scanning were two times more likely to require postoperative revision than grafts with normal intraoperative scans. CONCLUSIONS: The incidence of postoperative graft stenosis and need for revision varies with bypass grafting technique. Reversed vein bypasses and grafts modified at operation may be more prone than in situ vein bypass grafts to develop stenosis and thus require intensive surveillance. Infrainguinal vein graft failure and the need for revision may be reduced by the adoption of bypass grafting techniques that include valve lysis and intraoperative duplex scan assessment.

Adult↗

PubMed1996

Anatomic patterns of carotid endarterectomy healing.

BACKGROUND: Restenosis after carotid endarterectomy is a dynamic process likely influenced by surgical technique as well as by anatomic, hemodynamic, and patient factors. METHODS: To characterize the healing of carotid endarterectomy sites, intraoperative and serial postoperative color duplex scans were performed in 126 patients (136 repairs). Vessel-wall imaging, midstream spectral analysis, and measurements of diameter and cross-sectional area from common carotid artery (CCA) and internal carotid artery (ICA) segments were compared (at 3, 6, 15, and 30 months) and severity of lumen stenosis was determined. RESULTS: After primary closure (n = 15), patch angioplasty (n = 121), or intraoperative revision based on duplex scanning (n = 5), 12 repairs had mild residual flow abnormalities and 1 repair had a moderate flow abnormality. Mean ICA bulb diameter was greater in patched repairs (0.81 cm, range 0.6 to 1.1 cm) than primary closed repairs (0.7 cm, range 0.45 to 0.8 cm). No ICA occluded during follow-up (mean 24 months), and three repairs, two in the ICA and one in the CCA, demonstrated 50% to 75% diameter reduction at 9 months. Lumen cross-sectional area of vein-patched repairs increased 0.6 cm2 to 0.76 cm2 (P < 0.01) in the ICA and 0.69 cm2 to 1.1 cm2 (P < 0.01) in the CCA segments by 3 months compared with intraoperative measurement. Four patients with progressive dilatation of the patch segment to a mean of 1.77 cm2 developed asymptomatic posterior wall mural thrombus. Postoperative blood flow velocities measured through the repair were similar to intraoperative values. Minor intraoperative hemodynamic abnormalities were not associated with the development of restenosis, and changes in repair site anatomy occurred within 3 months with little change thereafter. CONCLUSIONS: We have found intraoperative scanning useful for detection of anatomic defects and associated turbulence, lesions that should be immediately corrected. Surgical technique that achieves normal intraoperative carotid flow hemodynamics and B-mode ultrasonic vessel wall appearance should predict an endarterectomized segment free of significant residual plaques and neointimal hyperplasia. Tailoring of the vein patches to achieve lumen diameters < 1 cm is recommended because of the dilataton likely to develop after surgery that may lead to vessel wall mural thrombus.

Analysis of Variance↗

PubMed1996

Secondary recurrent carotid stenosis.

PURPOSE: Recurrent carotid stenosis after carotid endarterectomy has been extensively reported. The occurrence, however, of another ipsilateral restenosis that requires a third carotid operation is rare. The purpose of this study was to evaluate possible risk factors and the most efficacious management of the patient with "secondary" recurrent carotid stenosis. METHODS: A survey of the Southern Association for Vascular Surgery was performed, and 31 patients who had had surgery for secondary recurrent carotid stenosis were identified. RESULTS: The mean interval between the recurrent stenosis operation and secondary recurrent carotid stenosis was 39.8 months (range, 9 to 83 months). At the third operation, 21 patients underwent carotid patch angioplasty and 10 underwent carotid resection with an interposition saphenous vein graft. No postoperative strokes or deaths occurred; three patients (10%) had a peripheral nerve injury. Nine early (< 24 mo) secondary recurrent carotid stenoses occurred, and these patients underwent patch angioplasty. Twenty-three female, cigarette-smoking patients and 20 patients with elevated lipid levels had early restenosis and were identified as being at high risk for the development of another stenosis. A fourth significant stenosis developed in five of these high-risk patients who had saphenous vein patch angioplasty at their third carotid operation; eight other high-risk patients had carotid resection with an interposition saphenous vein graft, and no other stenosis developed. CONCLUSION: Patients who have secondary recurrent carotid stenoses can safely undergo a third carotid operation. Female habitual smokers with elevated lipid levels and an early restenosis appear to be at high risk of secondary recurrent carotid stenoses. When surgery is necessary, carotid resection with an interposition saphenous vein graft appears more durable than patch angioplasty.

Adult↗

PubMed1996

Nature and management of duplex abnormalities encountered during infrainguinal vein bypass grafting.

PURPOSE: This study was undertaken to evaluate the application of duplex scanning during infrainguinal vein grafting procedures to verify vein conduit preparation, anastomotic patency, and graft hemodynamics. METHODS: Between 1991 and 1995, 275 infrainguinal vein bypasses (in situ, 114; reversed, 82; nonreversed translocated, 48; spliced alternative/arm vein, 31) to the popliteal (n = 116) or an infrageniculate artery (n = 159) were scanned during surgery for sites of color Doppler flow abnormality. Duplex-detected defects were graded with peak systolic velocity and velocity ratio criteria. Sites that demonstrated highly disturbed flow (peak systolic velocity > 180 cm/sec, velocity ratio > 2.4) were immediately revised by direct repair, patch angioplasty, or interposition grafting. RESULTS: Intraoperative duplex scanning prompted revision of 50 abnormalities in 43 of the 275 grafts (16%), including 32 vein and seven anastomotic stenoses, nine vein segments with platelet thrombus, and two bypasses with low flow. The intraoperative revision rate was lowest (p < 0.02) for reversed saphenous vein bypasses (7%) compared with other grafting techniques (in situ, 20%; nonreversed translocated, 15%; spliced alternative vein, 23%). The revision rates of popliteal and tibial bypasses were similar (14% vs 17%). A normal result shown by intraoperative scan (235 bypasses) was associated with a low 90-day thrombosis (0.4%) and revision (2%) rate, whereas six of 15 grafts (40%) with residual and 13 of 25 grafts (52%) with unrepaired duplex abnormalities required corrective procedures (p < 0.001). One graft failed within 3 months (secondary patency rate, 99%). CONCLUSIONS: Intraoperative duplex scanning accurately predicted the technical adequacy of infrainguinal vein grafts and was particularly useful in assessing bypasses constructed with valve lysis techniques or alternative veins. Early graft revisions indicated by duplex monitoring for thrombosis or stenosis were the result of a progression of residual defects and platelet thrombus formation rather than inadequate graft run-off flow.

Aneurysm↗

PubMed1996

In situ repair of mycotic abdominal aortic aneurysms with rifampin-bonded gelatin-impregnated Dacron grafts: a preliminary case report.

Treatment of mycotic aortic aneurysm by excision and extraanatomic bypass is difficult to apply when the infectious process involves the visceral arteries. On the basis of experimental studies in our laboratory that demonstrated prolonged antistaphylococcal activity of rifampin-bonded, gelatin-impregnated Dacron grafts after implantation in the arterial circulation, this conduit was successfully used for in situ replacement of a native aortic infection in two patients. Both patients had fever, leukocytosis, abdominal or back pain, and a computed tomographic scan that demonstrated contained rupture of a mycotic aneurysm. Preoperative computed tomography-guided aspiration and culture of periaortic fluid from one patient grew Staphylococcus aureus. Treatment consisted of prolonged (6 weeks) culture-specific parenteral antibiotic therapy, excision of involved aorta, oxychlorosene irrigation of the aortic bed, and restoration of aortic continuity by in situ prosthetic replacement. A preliminary right axillobifemoral bypass was performed in the patient who had an infection involving the suprarenal and infrarenal aorta. In both patients intraoperative culture of aorta wall recovered S. aureus. Patients were discharged at 20 and 21 days. Clinical follow-up and computed tomographic imaging of the replacement graft beyond 10 months after surgery demonstrated no signs of residual aortic infection. In the absence of gross pus and frank sepsis, the use of an antibiotic-bonded prosthetic graft with antistaphylococcal activity should be considered in patients who have arterial infections caused by S. aureus when excision and ex situ bypass are not feasible.

Aged↗

PubMed1995

Antistaphylococcal activity of rifampin-bonded gelatin-impregnated Dacron grafts.

The affinity of rifampin to bond to Dacron permits implantation of a vascular prosthesis with anti-staphylococcal bioactivity. The performance of rifampin-bonded Dacron grafts was evaluated in vitro and in vivo to develop a bonding technique with optimal graft bioactivity which was then used for in situ reconstruction of a biofilm graft infection. In vitro bioactivity was measured at 24-hr intervals for three types of Dacron prostheses (plain, gelatin, and collagen-impregnated) exposed to rifampin at varied concentrations and immersion times. Gelatin-impregnated grafts demonstrated superior bioactivity (P < 0.05). Rifampin concentration and graft type had a greater effect on bioactivity than immersion time (P < 0.01). Gelatin-impregnated grafts immersed in a 60 mg/ml rifampin solution for 15 min produced optimum bioactivity. Six grafts prepared in this fashion were used to replace the canine aorta. The level and duration of in vivo antistaphylococcal activity to Staphylococcus aureus and Staphylococcus epidermidis were less (P < 0.05) than those measured in vitro, but rifampin levels exceeded the study strain maximum inhibitory concentration for up to 48 hr. In a canine model, the rifampin-bonded gelatin-impregnated (N = 14) or nonbonded control (N = 10) grafts were used as in situ replacement for an established aortic graft infection caused by S. epidermidis. Replacement with a rifampin-bonded graft resulted in successful anatomic healing of perigraft and anastomotic tissue. Persistent biofilm colonization was confirmed in 8 of 10 controls versus 4 of 14 rifampin-bonded grafts (P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Failure of foot salvage in patients with end-stage renal disease after surgical revascularization.

PURPOSE: This report ascertained factors responsible for for failure of foot salvage in patients with end-stage renal disease (ESRD) after undergoing infrainguinal bypass for critical ischemia. METHODS: A retrospective review of 69 distal arterial reconstructions performed in 53 patients with ESRD (hemodialysis [n = 37], kidney transplantation [n = 10], peritoneal dialysis [n = 6]) for foot gangrene (n = 28), nonhealing ulcer (n = 25), or ischemic rest pain (n = 16) was conducted. Endpoints of surgical morbidity, limb loss, and graft patency were correlated with extent of preoperative tissue loss and presence of diabetes mellitus. RESULTS: The 30-day operative mortality rate was 10%, and the patient survival rate at 2 years was 38%. The primary graft patency rate was 96% at 30 days, 72% at 1 year, and 68% at 2 years. Eleven of 22 foot amputations performed during the mean follow-up period of 14 months (range 3 to 96 months) occurred within 2 months of revascularization. Mechanisms responsible for limb loss included graft failure (n = 9), foot ischemia despite a patent bypass (n = 8), and uncontrolled infection (n = 5). Overall, 59% of amputations were performed in limbs with a patent bypass to popliteal or tibial arteries. Healing of forefoot amputations was prolonged, but all limb loss beyond 9 months of revascularization was due to graft failure. The limb salvage rate at 1 year decreased (p = 0.13) from 74% to 51% in patients admitted with gangrene. Only two of seven patients admitted with forefoot gangrene experienced foot salvage. CONCLUSION: Failure of foot salvage in patients with ESRD and critical ischemia was due to wound healing problems rather than graft thrombosis. Earlier referral for revascularization, before development of extensive tissue ischemia and infection, is recommended. Primary amputation should be considered in patients admitted with forefoot gangrene, particularly if it is complicated by infection.

Adult↗

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.

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