Sequential femoral-tibial bypass grafting for limb salvage.

Bypass grafting to distal lower extremity vessels continues to be associated with a high rate of graft occlusion. By utilizing a sequential side-to-side anastomosis between saphenous vein and popliteal artery in femoral-tibial bypass grafts, runoff can be increased and graft patency thereby improved. Sequential femoral-tibial grafts were employed in seven patients with gangrene, trophic changes, or restpain, all of whom had single-vessel runoff by arteriography. All seven sequential grafts established to a distal vessel in addition to the popliteal artery have remained open for periods of five to 27 months as determined by palpable graft or foot pulses. Two patients undersent below-knee amputation within six months of operation but had patent grafts at the time of amputation. In three patients ischemic ulcers resolved and in two patients toe amputations healed successfully. Sequential bypass grafting is a technique aimed at improving the patency rate of femoral-tibial bypass grafts by augmenting runoff.     

The predictive value of blood flow velocity in femoro-distal bypass

The predictive value of peroperative blood flow measurements has been evaluated in a prospective study of femoro-distal bypass grafts. Seventy grafts placed in patients with critical ischaemia were assessed with a minimum follow-up of 2 years. Thirty-one grafts were performed using autogenous saphenous vein (ASV), 27 using a polytetrafluoroethylene prosthesis (PTFE) and in 12 human umbilical vein (HUV) was used. Six grafts failed early (within 1 month of operation) and 19 failed late, giving an overall patency rate of 60% at 5 years. ASV grafts had a significantly better patency rate than either prosthetic material. Analysis of flow rates measured before and after regional vasodilatation revealed no significant differences between types of graft or between grafts that subsequently failed and those remaining patent. Flow velocity prior to vasodilatation was significantly higher in patent grafts (mean 13.6) compared to those failing early (mean 6.3), but not compared to those failing late (mean 9.4). Flow velocities were also significantly higher in ASV grafts than prosthetic grafts. Flow velocity measured after vasodilatation was significantly higher in grafts remaining patent (mean 28.4) than those which failed late (mean 19.2). It is concluded that flow velocity is of value in the prediction of graft outcome. Graft velocity after vasodilatation of less than 20 cm/s. Predicted failure in 19 of 25 grafts that occluded. We are currently evaluating the selective use of anticoagulants in femoropopliteal grafts with a maximal flow velocity below 20 cm/s.     

Questionable value of adjuvant arteriovenous fistula in pedal bypass at high risk for early failure

Results of an adjuvant arteriovenous fistula (AVF) in pedal bypass surgery in the presence of poor status of the recipient artery, severely impaired intraoperative runoff, or revision for early failure and flow restitution were analyzed in a retrospective study. From January 1998 to December 2006, 24 adjuvant AVFs were constructed in autologous vein or composite pedal bypasses with low intraoperative bypass flow, poor status of the pedal artery, or during successful early bypass revision to prevent graft failure. All infrainguinal bypass operations were registered in a computerized database and prospectively followed. Pedal bypasses with adjunctive AVF were reviewed for fistula function, graft patency, limb salvage, and patient survival. Primary and secondary bypass patency rates at 1 year were 59% and 77%, respectively, with an AVF patency of 36%. Four legs were amputated despite a patent bypass with patent AVF on three occasions. The corresponding limb salvage rate was 65% at 1 year. Patient survival was 50% at 3 years. Adjuvant AVF constructed in grafts considered at high risk for early failure in pedal vein graft or composite bypass does not seem to prevent future graft failure. In patent bypasses the fistula has a significant tendency for spontaneous occlusion. It may be considered in the use of prosthetic composite pedal grafts in selected cases.     

Peripheral resistance measurement in the assessment of severe peripheral vascular disease

Thirty-seven patients undergoing femoropopliteal, fifteen undergoing femorodistal reconstruction and seven below knee amputees were subjected to prospective measurement of peripheral resistance. Resistance was significantly higher in the amputation and femorodistal groups than in the femoropopliteal group (P less than 0.03 and P less than 0.005 at 76 ml/min). In the femoropopliteal group patients with three vessel runoff had a significantly lower resistance than those with two or single vessel runoff (P less than 0.01). In the femoropopliteal group resistance of patent grafts at four months was significantly less than thrombosed grafts (P less than 0.006). Patients with a resistance less than 1200 mPRU had a significantly better patency than those in whom the resistance was greater than 1200 mPRU (P less than 0.05). Taking all the failed grafts there was a significant correlation between graft patency and resistance (P less than 0.003). Resistance measurement has been shown to correlate with the severity of the disease, with runoff defined radiographically and with graft patency. In a simplified form it may prove a useful adjunct to other methods of assessment in patients with distal disease.     

The fate of arm veins used for aorta-coronary bypass grafts

Arm veins have been a common second choice conduit for those patients having insufficient saphenous veins for coronary bypass operations. To define the patency and durability of arm vein grafts, we reviewed our patients with one or more arm vein grafts used for coronary revascularization between 1974 and 1982. A total of 59 patients required at least one arm vein graft and 51 are presently alive. Postoperative arteriograms were obtained in 28 patients. Of 56 arm vein grafts used, 32 (57%) were patent and 24 (43%) had failed at 2 years. Seven of the patent grafts had a localized area of stenosis. Sixteen internal mammary artery grafts also had been used in this group of patients, and 15 (93%) were patent. We conclude that arm vein grafts have a high failure rate and are not as dependable as saphenous vein grafts or internal mammary artery grafts.     

Does arterial inflow failure cause distal vein graft thrombosis?

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 arteriograpnically 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.The views expressed herein are those of the authors and do not reflect the official policy of the Department of Defense or other departments of the U.S. government.Presented at the Eighteenth Annual Meeting of the Peripheral Vascular Surgery Society, Washington, D.C., June 6, 1993.     

Reoperations for myocardial revascularization.

Reoperations solely for myocardial revascularization were performed in 219 consecutive patients (1967 to 1975). Indications were (1) graft failure, 46 (21 per cent); (2) progressive atherosclerosis, 42 (19 per cent); (3) incomplete revascularization, 39 (18 per cent); and (4) combinations, 92 (42 per cent). Primary operations included bypass grafts in 100 patients; mammary artery implants, 87; and combinations of direct and indirect procedures, 32. Reoperations performed were single bypass, 141 patients; double, 61; and triple or other coronary artery operations, 17. Eight patients died within 30 days of operation (3.7 per cent). Major postoperative complications included hepatitis, 24 (11 per cent); myocardial infarction, 19 (9 per cent); bleeding, 21 (10 per cent); and respiratory insufficiency, 12 (5 per cent). Follow-up for 202 long-term survivors was complete (mean 29 months). In patients who originally underwent direct revascularization, Class I or II (N.Y.H.A.) was attained in 35 of 43 (81 per cent) of those reoperated upon for primary graft failure, in 14 of 15 (93 per cent) of those with progressive atherosclerosis, and in 27 of 33 (82 per cent) of patients with combined indications. Arteriography was performed after the reoperation in 55 patients (mean interval 17 months), and 65 of 77 (84 per cent) grafts were patent. Nineteen of 22 grafts performed for primary graft failure were patent. We have made the following conclusions: (1) Reoperation for direct myocardial revascularization can be accomplished with low mortality rates although morbidity is high; (2) complete relief of symptoms was achieved in 65 per cent of survivors; (3) results in patients reoperated upon for graft failure alone were similar to results in those operated upon for progressive atherosclerosis or combined indications; and (4) high graft patency was found in secondary grafts constructed to arteries involved with primary graft failure.     

Early experience utilizing the in situ saphenous vein technique in 54 patients

We have compared our early and late experience utilizing in situ saphenous vein bypass graft for lower extremity arterial occlusive disease in 54 patients who underwent in situ femoral to popliteal and distal bypass grafts between July of 1983 and February 1985. There were 3 femoral to above-knee popliteal bypasses, 27 femoral to below-knee popliteal bypass grafts, 12 femoral to anterior tibial dorsalis pedis bypass grafts, 10 femoral to posterior tibial bypass grafts and 2 femoral to peroneal in situ bypass grafts. The operative indications were progressive disabling claudication in 8 (15%) and limb salvage in 46 (85%). Eighty-nine percent of the limb salvage patients had 0-1 vessel runoff by arteriogram. Cumulative life table patency of the 54 in situ bypass grafts was 79% at 20 months. One hundred percent of the patients who were operated on for disabling claudication had patent grafts at 20 months. Seventy-eight percent of the limb salvage patients had patent grafts. Fourteen of the limb salvage patients required amputation and of these 14, 10 had patent grafts at the time of amputation. There were 8 deaths in the series. Our results demonstrate that a definite learning curve exists with this technique, however, once established, long-term patency and improved limb salvage statistics can be obtained.     

Intra-operative graft blood flow related to failure of femoro-popliteal bypass grafts

The prognostic significance of intra-operative blood flow, as measured by electromagnetic flowmetry, was investigated in 127 limbs, which were operated on with a reversed femoropopliteal saphenous vein bypass graft because of symptomatic atherosclerotic occlusion of the superficial femoral artery. Thromboses occurring in the first postoperative month are defined as early failures and thereafter as late failures. There were three early graft failures. The basal and augmented flow rates during pharmacological vasodilation of these grafts were less than half those of the grafts remaining patent. Eight additional late graft occlusions occurred. Whereas the basal blood flow of these grafts did not differ significantly from that of the grafts which remained patent, the maximal flow rate was significantly lower (p less than 0.05). The overall incidence of graft failure at basal and maximal flow rates of 100 ml/min or less and 150 ml/min or less, respectively, was 35%, while, at higher flow rates, this incidence was reduced to 5% (p less than 0.001). This study emphasizes that intra-operative femoropopliteal vein graft flow provides prognostic indications of graft failure.     

Autogenous veins and velour dacron in femoropopliteal arterial bypass.

Sixty-five patients treated by femoropopliteal bypass in 1974 were surveyed; the mean follow-up time was 10.4 months. The one year cumulative patency rate for velour Dacron was 50 percent; this was less successful than were the results from a comparable group in which vein grafts were used (79 percent). These poor results were due principally to the high failure rate of velour Dacron in patients suffering from clinically severe ischemia. In these only one in four grafts remained patent. If a less than perfect arteriographic runoff was obtained, only one in three still functioned. These results occurred despite high intraoperative graft flows. It appears that velour Dacron may be acceptable in patients treated for claudication if no adequate vein is available. This prosthesis gives an unacceptably high failure rate in patients with severe ischemia.     

Minimum internal diameter of the greater saphenous vein is an important determinant of successful femorodistal bypass grafting that is independent of the quality of the runoff

The greater saphenous vein is assessed as part of the workup for femorodistal bypass surgery in our unit. The aim of this study was to determine whether the minimum internal diameter (MID) of the vein predicted graft patency and limb salvage in femorodistal bypass surgery, independently of the quality of the runoff. A consecutive series of 67 infrainguinal vein bypass grafts were performed on 62 patients with critical lower limb ischemia. All were followed for at least 1 year. The MID of the greater saphenous vein was calculated from preoperative saphenograms, and all of the arteriograms were scored for their runoff using an ad hoc method approved by the Society for Vascular Surgery. The cumulative patency of all vein grafts at 3 years was 59 +/- 7% (SE), and the limb salvage was 85 +/- 5%. All femoropopliteal bypass grafts were patent at 3 years if the MID of the vein was greater than 3.0 mm. The crural bypass patency was 66 +/- 12% for an MID greater than 3.0 mm and only 27 +/- 12% for an MID less than 3.0 mm. Every extra point on the runoff score increased the hazard of bypass failure by 16% (95% CI 1.0-34; p < .05). Vein diameter and runoff score were independent of one another (r2 = -.106). The MID of the greater saphenous vein is a major determinant of outcome in infrainguinal vein bypass surgery independent of the arterial runoff.     

Prediction of early graft failure with intraoperative completion duplex ultrasound scan

PURPOSE: The purpose of this study was to determine intraoperative hemodynamic parameters that predict early failure of infragenicular vein grafts with intraoperative completion duplex ultrasound scan. METHODS: We reviewed the results of intraoperative duplex scans that were selectively performed after completion of 45 tibial/pedal vein bypass grafts at high risk for failure. Bypass was performed for rest pain (39%) or tissue loss (61%), and 60% of the cases were disadvantaged because of compromised vein quality or poor arterial outflow. A 10-MHz low-profile transducer was used to scan the entire graft at bypass completion. All grafts were determined to be technically adequate (absence of retained valves, arteriovenous fistulas, or localized velocity increases and the presence of bypass-dependent distal pulses). Peak systolic velocity (PSV) and end diastolic velocity (EDV) were also measured at each anastomosis, in the outflow artery and in the proximal and distal portions of each graft. Resistive indices (RI) were calculated at each measurement point (PSV-EDV/PSV). Statistical analysis was performed with unpaired t test, chi(2) test, and multivariate analyses. RESULTS: Twenty infragenicular vein bypass grafts (44%) thrombosed within 12 months. Intraoperative hemodynamic parameters were significantly different between grafts that remained patent or thrombosed. EDV was lower (5 +/- 1 cm/s versus 13 +/- 3 cm/s; P =.02) and RI was higher (0.90 versus 0.81; P <.01) in the proximal portions of grafts that thrombosed within 12 months. Distal EDV was also lower (6 +/- 1 cm/s versus 15 +/- 2 cm/s; P <.01) and distal RI was higher (0.89 versus 0.78; P <.01) in grafts that thrombosed. With multivariate analysis, only low distal EDV was predictive of early graft failure (P <.05). Distal bypass EDV of less than 8 cm/s predicated early graft thrombosis with 76% sensitivity and 75% specificity (positive predictive value, 71%; negative predictive value, 78%). Absence of diastolic flow (EDV of 0 cm/s) predicted early graft failure with 100% specificity and 100% positive predictive value. CONCLUSION: In this initial experience, low EDV measured with intraoperative duplex scan was associated with early thrombosis of tibial level vein grafts. When such values are observed, measures should be taken to improve graft hemodynamic parameters. Prospective study of infragenicular vein bypass grafts may better define hemodynamic parameters predictive of early graft thrombosis.     

The influence of smoking and plasma factors on prosthetic graft patency

The effects of smoking and plasma risk factors on the patency of prosthetic femoro-popliteal bypass grafts were investigated in 93 patients entered into a multicentre trial of prosthetic graft materials (70 patients had patent grafts and 23 patients had occluded grafts 2 years after surgery). The smoking markers thiocyanate and fibrinogen were significantly higher in patients with occluded grafts, whereas LDL-cholesterol was significantly higher in patients with patent grafts 2 years after bypass. Based on smoking markers, graft patency in smokers was 57% at 2 years by life table, compared to 78% in non-smokers. P less than 0.05. Fibrinogen was an important variable, predicting graft occlusion with graft patency in patients with below median fibrinogen levels, being 84% at 2 years by life table compared to 51% in those with above median fibrinogen levels, P less than 0.025. Although increased levels of LDL-cholesterol have been associated with accelerated atherosclerosis, patients with above median levels of LDL-cholesterol had improved graft patency (83%) at 2 years compared to patency in patients with below median LDL-cholesterol (60%), P less than 0.05. The plasma risk factors associated with the failure of prosthetic grafts are similar to those associated with the failure of saphenous vein grafts, indicating that higher fibrinogen levels and smoking may contribute to an hypercoagulable state. Greater efforts are needed to stop patients smoking after vascular reconstruction.     

Long-term results of catheter-directed thrombolysis to treat infrainguinal bypass graft occlusion: the urokinase era

PURPOSE: This study was undertaken to review the long-term results of catheter-directed thrombolysis in treatment of infrainguinal bypass graft occlusion. METHODS: From January 1987 to December 1998, 67 patients with 69 acutely occluded infrainguinal arterial bypass grafts (48 vein grafts, 21 prosthetic grafts) underwent treatment with catheter-directed thrombolysis with urokinase. Long-term results were assessed with Kaplan-Meier life-table analysis, and factors predictive of success were determined with multivariate analysis. RESULTS: Thrombolysis was aborted in 7 patients (10%) because of major complications or technical failure and was unsuccessful in restoring graft patency (相似文献   

Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow

HYPOTHESIS: Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow. DESIGN: Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period. SETTING: University teaching hospital. PATIENTS: Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs). INTERVENTIONS: All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10). MAIN OUTCOME MEASURES: Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival. RESULTS: All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04). CONCLUSION: Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.     

Single nucleotide polymorphism (G994-->T) in the plasma platelet-activating factor-acetylhydrolase gene is associated with graft patency of femoropopliteal bypass

BACKGROUND: Plasma platelet-activating factor-acetylhydrolase (PAF-AH) is known to catalyze platelet-activating factor (PAF). The single nucleotide polymorphism (SNP) of plasma PAF-AH gene (G994 -->T in exon 9) is associated with a decreased level of plasma PAF-AH activity. This study analyzed the risk of the SNP on graft occlusion of femoropopliteal bypass in patients with atherosclerotic occlusive disease. METHODS: We retrospectively assessed the patency of 50 above-knee femoropopliteal bypass grafting in 50 patients. Genomic DNA was analyzed for the mutant allele. Plasma PAF-AH activity was measured by radioimmunoassay. RESULTS: The 10-year cumulative primary patency of the bypass was 78.5% in GG (normal genotype) and 50.0% in GT (heterozygous) or TT (homozygous deficient) (P <.05, Kaplan-Meier method). The relative risk of graft failure in GT or TT genotypes was 1.68 (P =.08, Cox proportional hazards model). PAF-AH activity (nmol/min/50 microL) was 1.92 +/- 0.82 in patients with patent grafts and 1.42 +/- 0.47 in those with occluded grafts (mean +/- standard deviation; P <.05, unpaired t test). CONCLUSIONS: The SNP of plasma PAF-AH was associated with a decreased primary graft patency of above-knee femoropopliteal bypass. The risk of graft failure may increase when patients have the SNP. To confirm the independent risk of graft failure by the SNP, further study is necessary and prospective study should be performed.     

Does the efficacy of dorsalis pedis artery bypasses vary among diabetic patients of different ethnic backgrounds?

Hispanic patients suffer from a high rate of leg amputations, far beyond what would be expected from the high prevalence of diabetes in this population. This raises questions about the efficacy of bypass operations across ethnic lines. We focused this review on dorsalis pedis bypasses, as these are frequently performed in diabetic patients. We compared outcomes between Hispanics and non-Hispanics and sought to identify factors predictive of failure or complications. The authors conducted a retrospective review of 144 dorsalis pedis bypasses in 106 men and 29 women with a mean age of 62 years. Eighty-two percent were Hispanic; 96% of cases were done for tissue loss, and 4% for rest pain. Twenty-five percent of patients experienced perioperative complications; these were more frequent in non-Hispanics than Hispanics (40% vs 22%, p = 0.05). The most frequent complications were wound related (11%). The 30-day mortality was 1.5% and 30-day graft thrombosis was 5%. Follow-up ranged from 1 to 62 months and averaged 12 months. Eighty-one percent of the limbs at risk were saved, although 36% of cases required minor foot amputations. Estimated primary graft patency was 68% at 30 months. The 30-month Kaplan-Meier curves for primary patency, assisted patency, and limb salvage were not statistically different between Hispanics and non-Hispanics (p > 0.4). Grafts that remained patent had higher duplex-derived intraoperative flow velocities in the dorsalis pedis artery than grafts that eventually failed (121 +/-69 vs 74 +/-26 cm/sec, p = 0.02). In grafts that remained patent, dorsalis pedis velocity decreased from the perioperative period to the 8 to 12 weeks time point, whereas no change was seen in grafts that eventually failed (mean decline of 48 +/-76 vs 1 +/-58 cm/sec, p = 0.02). No other factors were predictive of graft failure. The results of dorsalis pedis bypass in Hispanic patients compare favorably to those seen in other ethnic groups. This suggests that other factors must account for the high amputation rates seen in Hispanics, such as a frequent occurrence of nonreconstructible disease or unaccounted for cardiovascular risk factors. The usefulness of duplex-derived flow velocities in the dorsalis pedis to predict long-term graft patency warrants further investigation.     

Seven-year follow-up of expanded polytetrafluoroethylene (PTFE) femoropopliteal bypass grafts.

Expanded polytetrafluoroethylene (PTFE) grafts have proven to be an acceptable short-term alternative for femoropopliteal reconstruction in those patients without suitable autologous saphenous vein. One hundred and twenty-seven femoropopliteal arterial bypass operations utilizing PTFE grafts were performed in 105 patients. Seven-year follow-up is now available for 20 grafts, 6-year follow-up for 47 grafts, and 5-year follow-up for 62 grafts. Graft occlusion was determined by angiography, Doppler assessment, loss of previously palpable pulses, or return of symptoms. Thirty nonocclusive graft losses were due to death, infection, aneurysm, amputation, or proximal occlusive disease. Overall cumulative patency rate, according to occlusive criteria alone and calculated by the life-table method, was 74% at 6 months, 63% at 1 year, 48% at 3 years, 40% at 5 years, and 35% at 7 years. Excluding early bypass failures (less than 1 year patency), 75% of grafts were patent at 3 years, 63% at 5 years, and 55% patent 7 years following operation. Diabetes mellitus was associated with a significantly lower patency rate. Patency rates were not adversely affected by graft diameter, distal popliteal anastomotic site, number of patent runoff vessels, preoperative symptoms, or prior arterial reconstruction. In patients without suitable autologous saphenous vein, the PTFE graft has proven to be a durable and dependable long-term alternative for femoropopliteal reconstruction.     

Intra-Operative Graft Blood Flow Related to Failure of Femoro-Popliteal Bypass Grafts

The prognostic significance of intra-operative blood flow, as measured by electromagnetic flowmetry, was investigated in 127 limbs, which were operated on with a reversed femoropopliteal saphenous vein bypass graft because of symptomatic atherosclerotic occlusion of the superficial femoral artery. Thromboses occurring in the first postoperative month are defined as early failures and thereafter as late failures. There were three early graft failures. The basal and augmented flow rates during pharmacological vasodilation of these grafts were less than half those of the grafts remaining patent. Eight additional late graft occlusions occurred. Whereas the basal blood flow of these grafts did not differ significantly from that of the grafts which remained patent, the maximal flow rate was significantly lower (p<0.05). The overall incidence of graft failure at basal and maximal flow rates of 100 ml/min or less and 150 ml/min or less, respectively, was 35%, while, at higher flow rates, this incidence was reduced to 5% (p<0.001). This study emphasizes that intra-operative femoropopliteal vein graft flow provides prognostic indications of graft failure.     

Radial artery flow-through graft: a new conduit for limb salvage

OBJECTIVE: Patients with severe peripheral occlusive disease may present especially challenging problems because of previous bypass surgery, location of ulcers, or extremely poor runoff. We used the radial artery with its overlying skin flap as a bypass conduit, called the radial artery flow-through (RAFT) graft in 10 such patients. METHODS: From November 1999 to January 2002, 10 patients had limb-threatening ischemia at presentation. All had severe inframalleolar vascular occlusive disease. Four patients had undergone previous conventional bypass procedures. Two grafts remained patent, but distal ulcers failed to heal. Eight patients were men. Seven patients had diabetes mellitus. All patients but one had nonhealing ulcers. In most cases, a composite femoral-tibial bypass graft was constructed by sewing the RAFT graft end-to-end to either the greater saphenous vein or, in one patient, to a polytetrafluoroethylene graft. In all cases, the radial venous comitans were sewn to a nearby superficial vein. In 5 patients the skin paddle was positioned to cover the ulcer; in the remaining patients the skin paddle was used to close the foot incision over the distal anastamosis. Postoperative graft surveillance was performed with Duplex scanning or contrast medium-enhanced angiography. RESULTS: Thromboses developed in 2 grafts during follow-up. In 1 of these patients below-knee amputation was performed. Another patient required below-knee amputation because of continuing infection in the foot despite a patent RAFT graft. In 1 patient thrombosis developed in the vein graft, but the RAFT graft extension remained patent. All other RAFT grafts were patent in their entirety at 15 (+/-6) months. CONCLUSIONS: The RAFT graft is a new option for treating limb-threatening ischemia. The skin paddle may be useful in selected patients for wound coverage.