Limb salvage after infrainguinal bypass graft failure

OBJECTIVE: The purpose of this study was to examine the outcome of patients in whom an infrainguinal bypass graft failed. METHODS: This was a retrospective analysis of consecutive patients undergoing infrainguinal bypass grafting in a single institution over 8 years. RESULTS: Six hundred thirty-one infrainguinal bypass grafts were placed in 578 limbs in 503 patients during the study period. The indication for surgery was limb-threatening ischemia in 533 patients (85%); nonautologous conduits were used in 259 patients (41%), and 144 (23%) were repeat operations. After a mean follow-up of 28 +/- 1 months (median, 23 months; range, 0-99 months), 167 grafts (26%) had failed secondarily. The rate of limb salvage in patients with graft failure was poor, only 50% +/- 5% at 2 years after failure. The 2-year limb salvage rate depended on the initial indication for bypass grafting: 100% in patients with claudication (n = 16), 55% +/- 8% in patients with rest pain (n = 49), and 34% +/- 6% in patients with tissue loss (n = 73; P <.001). The prospect for limb salvage also depended on the duration that the graft remained patent. Early graft failure (<30 days; n = 25) carried a poor prognosis, with 2-year limb salvage of only 25% +/- 10%; limb salvage was 53% +/- 5% after intermediate graft failure (<2 years, n = 110) and 79% +/- 10% after late failure (>2 years, n = 15; P =.04). Multivariate analysis revealed shorter patency interval before failure (P =.006), use of warfarin sodium (Coumadin) postoperatively (P =.006), and infrapopliteal distal anastomosis (P =.01) as significant predictors for ultimate limb loss. CONCLUSION: The overall prognosis for limb salvage in patients with failed infrainguinal bypass grafts is poor, particularly in patients with grafts placed because of tissue loss and those with early graft failure.     

Follow-up of infrainguinal graft thrombolysis: analysis of predictors of clinical success

HYPOTHESIS: Thrombolysis is an accepted technique to salvage a failed infrainguinal bypass graft. Careful case selection, including consideration of the native arterial runoff and the type and location of the graft, will portend a better clinical outcome and prolonged graft patency. DESIGN: Retrospective study of an inception cohort of 91 acutely thrombosed grafts. SETTING: Academic tertiary care center. PATIENTS: We analyzed 91 consecutive occluded grafts in 69 patients for secondary graft patency and clinical outcome. INTERVENTION: Regional transcatheter thrombolysis. MAIN OUTCOME MEASURES: Technical success, secondary graft patency, and the need for major limb amputation. RESULTS: Immediate technical success resulting in restoration of flow was achieved in 80 (88%) of 91 cases. Angioplasty or additional surgical intervention (eg, patch, interposition graft, or jump graft to a more distal site) was performed in 44 subjects (64%). Longer duration of secondary patency was associated with synthetic vs vein grafts (P =.03), popliteal vs distal (tibial/pedal) insertion of the anastomosis (P =.008), and intact native arterial outflow (P =.003). Twenty-three cases required major limb amputation in the follow-up period, but 17 (74%) of these had reocclusion within 30 days of thrombolysis. Only 43 grafts (47%) were found to be patent at 1-year follow-up. CONCLUSIONS: In carefully selected cases, thrombolytic therapy is an effective means to restore limb viability in patients with occluded infrainguinal grafts. Long-term patency rates, although similar to those of surgical series, remain poor.     

Angiographic criteria for prediction of early graft failure of secondary infrainguinal bypass surgery

Complete intraoperative postreconstruction angiograms were obtained during 93 reoperations after failed femoropopliteal and femorodistal bypass grafts to evaluate the predictive value of a new method of angiographic runoff assessment. Good runoff was defined as patency of two or three lower leg arteries to the foot, or one patent vessel continuous with an intact anterior or posterior foot arch in femoropopliteal and proximal femorodistal bypasses, and integrity of both arches in low femorodistal bypasses. All other outflow patterns were considered poor. The cumulative 1-year patency rate was 61% with a 79% limb salvage rate after reoperations performed in limbs with good runoff. In reoperations with poor runoff, the patency rate was only 5% with a 22% limb salvage rate. In reoperations with good runoff, and 85% patency rate of vein grafts compared to 43% of prosthetic grafts clearly demonstrated the importance of graft material on early outcome. The improved prediction of early outcome with this new method of angiographic runoff evaluation might allow more rational management of patients with failed infrainguinal grafts.     

The consequences of a failed femoropopliteal bypass grafting: comparison of saphenous vein and PTFE grafts

OBJECTIVES: Although there are numerous reports comparing saphenous vein (SV) and polytetrafluoroethylene (PTFE) with respect to the patency rates for femoropopliteal bypass grafts, the clinical consequences of failed grafts are not as well described. This study compares the outcomes of failed SV and PTFE grafts with a specific emphasis on the degree of acute limb ischemia caused by graft occlusion. METHODS: Over a 6-year period, 718 infrainguinal revascularization procedures were performed, of which 189 were femoropopliteal bypass grafts (SV, 108; PTFE, 81). Society for Vascular Surgery/International Society for Cardiovascular Surgery (SVS/ISCVS) standardized runoff scores were calculated from preoperative arteriograms. Clinical categories of acute limb ischemia resulting from graft occlusion were graded according to SVS/ISCVS standards (I, viable; II, threatened; III, irreversible). Primary graft patency and limb salvage rates at 48 months were calculated according to the Kaplan-Meier method. RESULTS: Patients were well matched for age, sex, and comorbidities. Chronic critical ischemia was the operative indication in most cases (SV, 82%; PTFE, 80%; P =.85). Runoff scores and preoperative ankle-brachial index measurements were similar for the two groups (SV, 6.0 +/- 2.5 [SD] and 0.51 +/- 0.29; PTFE, 5.3 +/- 2.8 and 0.45 +/- 0.20; P =.06 and P =.12). The distal anastomosis was made below the knee in 60% of SV grafts and 16% of PTFE grafts (P <.001). Grade II ischemia was more likely to occur after occlusion of PTFE grafts (78%) than after occlusion of SV grafts (21%; P =.001). Emergency revascularization after graft occlusion was required for 28% of PTFE failures but only 3% of SV graft failures (P <.001). Primary graft patency at 48 months was 58% for SV grafts and 32% for PTFE grafts (P =.008). Limb salvage was achieved in 81% of SV grafts but only 56% of PTFE grafts (P =.019). CONCLUSIONS: Patients undergoing femoropopliteal bypass grafting with PTFE are at greater risk of ischemic complications from graft occlusion and more frequently require emergency limb revascularization as a result of graft occlusion than patients receiving SV grafts. Graft patency and limb salvage are superior with SV in comparison with PTFE in patients undergoing femoropopliteal bypass grafting.     

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.     

Pedal branch artery bypass: a viable limb salvage option

PURPOSE: We reviewed our experience with pedal branch artery (PBA) bypass to confirm the role of these target arteries for limb salvage and to identify patient and technical factors that may be associated with graft patency and limb salvage. METHODS: In this retrospective study we analyzed 24 vein grafts to PBAs performed from 1988 to 1998 for limb salvage in 23 patients who had no suitable tibial, peroneal, or dorsal pedal target arteries. These PBA grafts were compared with 133 perimalleolar posterior tibial, defined at or below the ankle, or dorsalis pedis bypass grafts performed contemporaneously; the Kaplan-Meier life table was used in the analysis of graft patency and limb salvage. Life table analyses and logistic regression analysis of prognostic patient variables were also performed. RESULTS: The PBA bypass represented 3% of infrainguinal revascularizations for chronic critical limb ischemia at our institution over the study period. Patients who received PBA bypasses were more likely to be male (92% vs. 69%, P =.02) with lower incidences of overt coronary artery disease (33% vs. 50%, P =.12) and stroke (0% vs 15%, P =.04), and a higher incidence of end-stage renal disease (21% vs 8%, P =.06) than those undergoing perimalleolar bypass. Seventeen percent of PBA bypasses were performed with the anterior lateral malleolar artery, a vessel not previously described as a common bypass target. Two-year primary patency and limb salvage for PBA versus perimalleolar bypass was 70% versus 80% (P =.16) and 78% versus 91% (P = .28), respectively. Patency and limb salvage rates were no different in bypasses with above-knee or below-knee inflow arteries. CONCLUSION: An autogenous vein bypass to the PBA, though rarely required, provides acceptable primary patency and limb salvage when compared with perimalleolar tibial artery bypass when no suitable, more proximal target arteries are available. The PBA bypass should be considered before major amputation is undertaken.     

Long-term outcome of infrainguinal bypass grafting in patients with serologically proven hypercoagulability

OBJECTIVE: The purpose of this study was to test the hypothesis that the long-term outcome of infrainguinal bypass grafting in patients with congenital or acquired hypercoagulability is inferior to the results in patients without documented clotting disorders. METHODS: The study was a retrospective analysis of consecutive patients from January 1994 to January 2001. RESULTS: Five hundred eighty-two infrainguinal bypass grafts were created in 456 patients. Indication for surgery was limb-threatening ischemia in 84%; prosthetic conduits were implanted in 38%. Seventy-four grafts were created in 57 patients with one or more serologically proven hypercoagulable states, including heparin-induced platelet aggregation (n = 37), anticardiolipin antibodies (n = 11), lupus anticoagulant (n = 8), protein C or S deficiency (n = 7), antithrombin III deficiency (n = 3), and factor V Leiden mutation (n = 1). Patients with hypercoagulability were younger (63 +/- 2 years versus 69 +/- 1 years; P =.007), more likely to have undergone prior revascularization attempts (38% versus 21%; P =.003), and more likely to have chronic anticoagulation therapy after surgery (46% versus 25%; P =.001). After 5 years (median follow-up, 19 months), patients with hypercoagulability had poorer primary patency (28% +/- 7% versus 35% +/- 5%; P =.004), primary assisted patency (37% +/- 7% versus 45% +/- 6%; P =.0001), secondary patency (41% +/- 7% versus 53% +/- 6%; P =.0001), limb salvage (55% +/- 8% versus 67% +/- 6%; P =.009), and survival (61% +/- 8% versus 74% +/- 4%; P =.02) rates. Multivariate analysis identified only prosthetic conduit choice (P =.0001), hypercoagulability (P =.0003), and limb salvage indication (P =.01) as independent predictors of graft failure. CONCLUSION: Patients with serologically proven hypercoagulability have inferior long-term patency, limb salvage, and survival rates after infrainguinal bypass. The high prevalence rate (13%) of diverse hypercoagulable states in this patient population supports serologic screening, especially in referral practices.     

Angiographic scoring of vascular occlusive disease in the diabetic foot: relevance to bypass graft patency and limb salvage

OBJECTIVE: We graded the severity of occlusive disease in foot vessels of patients with diabetes and correlated the scoring obtained with graft patency and limb salvage. METHODS: In this retrospective review of 199 limbs studied by means of angiography in 117 patients with diabetes mellitus, 124 limbs underwent bypass grafting. Each dorsalis pedis (DP), lateral plantar (LP), and medial plantar (MP) artery was assigned a score according to the reporting standards of the Joint Vascular Societies Council (0, no stenosis > 20%; 1, 21%-49% stenosis; 2, 50%-99% stenosis; 2.5, < half the vessel length occluded; 3, > half the vessel length occluded.) A foot score (DP + MP + LP + 1) was calculated for each foot (1 to 10). The mean follow-up period was 14 months. RESULTS: For all 199 limbs and for the 124 limbs that underwent bypass grafting, the mean scores were similar for the DP, MP, and LP (1.8 +/- 1.0, 1.9 +/- 1.0, 1.9 +/- 1.0, respectively; P >.4). Only the MP and LP correlated with each other (r = 0.57; P <.0001). There were no scoring differences between limbs with symptoms and limbs that did not undergo bypass grafting. Bypass graft patency correlated with both the foot score and the MP score for tibial and inframalleolar grafts (P <.04). Patency correlated with the LP score only for inframalleolar bypass grafting procedures. The DP score alone did not differ between bypass grafts that remained patent and bypass grafts that failed. Bypass grafts in limbs with a foot score less than 7 and an MP score less than 2 had only a 2% failure rate. A foot score greater or equal to 7 was associated with a 30% failure rate for all bypass grafts (41% for inframalleolar grafts). Bypass grafts with low foot scores that failed did so much later than bypass grafts with high foot scores that failed (17 +/- 11 months vs 6 +/- 8 months; P <.02), possibly reflecting different etiologies for the failure. The limb salvage rate correlated with foot score (P <.05). The limbs that were saved had an average foot score of 6.4 +/- 2.0, versus 7.2 +/- 1.4 for limbs that required amputation. CONCLUSION: In patients with diabetes mellitus, the foot score is a useful tool for predicting the likelihood of graft patency and limb salvage for infrapopliteal revascularization. However, the relatively high bypass success rate (70%) in the presence of a high foot score (>or= 7) does not allow its use in identifying the subgroup of patients who are unlikely to benefit from bypass grafting surgery. It cannot be used as a means of selecting patients for primary amputation.     

Outflow resistance and early occlusion of infrainguinal bypass grafts

Distal outflow vascular resistance (VR) has been measured intra-operatively during 67 infrainguinal bypass procedures to establish whether it might have a role as a predictive test for early graft thrombosis. The graft outflow was popliteal artery above the knee (48), popliteal artery distal to the knee (6) or a single calf vessel (13). VR was measured before anastomosis of the graft, calculated from the relationship between pressure and flow in the outflow artery during infusion of the patient's own blood at a constant rate. VR was measured before and after vasodilation with papaverine. Primary graft patency at 30 days was documented. In the 10 limbs in which graft thrombosis occurred, VR was 1167 +/- 367 mPRU, significantly higher than VR in 57 limbs with a patent graft, 850 +/- 310 mPRU (P = 0.02, Mann-Whitney U test). After papaverine, VR was 823 +/- 368 mPRU in the limbs with a thrombosed graft, significantly higher than that of limbs with a patent graft, 463 +/- 211 mPRU (P = 0.001). VR appeared to show most promise as a predictor of early thrombosis in the group of femoro-tibial and femoro-peroneal grafts. In this group, the value of 800 mPRU after papaverine was 92% efficient and was 80% sensitive, 100% specific and had a predictive value of 100% for early thrombosis. Distal outflow VR is an important factor in early graft thrombosis and might have a practical application as a predictor of early thrombosis of femoro-distal bypass grafts.     

Autogenous composite vein bypass graft for infrainguinal arterial reconstruction

PURPOSE: Lower extremity arterial reconstruction in the absence of adequate greater saphenous vein remains a challenging problem in contemporary vascular practice. The purpose of this review is to evaluate the long-term results of autogenous composite vein grafts used for infrainguinal arterial bypass grafting. METHODS: We retrospectively evaluated a prospective vascular registry and reviewed inpatient and office records. RESULTS: From June 1983 to September 1999, 165 autogenous composite vein infrainguinal bypass grafts were performed in 154 patients (87 men, 67 women; mean age, 69 years). The mean follow-up was 25 months (range, 3-147). Patients had the usual risk factors, including a 30% incidence of prior coronary bypass grafting. Forty-eight percent of bypass grafts were performed after failed previous reconstructions, and 90% were performed for limb salvage. The conduits were comprised of 2 segments (75%), 3 segments (23%), and 4 segments (2%). The distal anastomosis was at the popliteal level in 17% and the tibial/pedal level in 83%. The 30-day operative mortality rate was 1.8%. Perioperative graft failure (< 30 days) occurred in 18 bypass grafts (11%), resulting in early amputation (< 30 days) in 1.2%. The overall 5-year cumulative patency rates were 44% +/- 5% for primary patency, 63% +/- 5% for primary-assisted patency (PAP), and 65% +/- 5% for secondary patency (SP). A high revision rate for stenosis or thrombosis was required during follow-up to maintain patency of the grafts (27%). Limb salvage was 81% +/- 5% at 5 years. Primary reconstructions with composite vein fared significantly better than secondary reconstructions (SP 76% vs 54% at 5 years, P <.01). Arm vein composites showed superior patency compared with greater saphenous vein composites (SP 79% vs 61% at 5 years, P <.05). CONCLUSIONS: Infrainguinal reconstruction with autogenous composite vein results in durable graft patency and limb salvage rates in patients with few alternatives for revascularization. Intensive graft surveillance with aggressive graft revision is necessary to achieve these results.     

Comparative analysis of autogenous infrainguinal bypass grafts in African Americans and Caucasians: the association of race with graft function and limb salvage

OBJECTIVE: African Americans (AAs) are at risk for developing diabetes mellitus and atherosclerosis. Whether race influences the results of infrainguinal arterial reconstruction is unclear. The purpose of this study was to compare the results of autogenous infrainguinal bypasses in AAs and Caucasians to determine the association of race with graft function and limb salvage. METHODS: This was a retrospective, comparative cohort study of AA and Caucasian patients who had undergone autogenous infrainguinal bypass surgery. Only single-limb bypasses in each patient cohort were considered in this analysis. In patients who had undergone bilateral lower limb bypasses, the first limb bypass was chosen as the index bypass procedure. RESULTS: From January 1985 to December 2003, 1459 autogenous infrainguinal bypasses were performed in 1459 patients for lower limb ischemia. Within this group, 89 AA patients/vein grafts formed the study cohort. The control group comprised 1370 Caucasian patients/vein grafts. Compared with the Caucasian cohort, AA patients were significantly younger (median age, 65 vs 70 years, respectively; P = .001) and predominantly female (57% vs 41%, respectively; P = .002). AA patients also had a higher prevalence of diabetes mellitus, hypertension, cerebrovascular disease, congestive heart failure, and dialysis-dependent renal failure. More AA than Caucasian patients presented with gangrene (34% vs 16%, respectively; P = .001), and more underwent bypass surgery for limb salvage indications (91% vs 81%, respectively; P = .01). The venous conduit used was predominantly the greater saphenous vein (AA, 83%; Caucasian, 85%), and the site of distal anastomosis was at the tibial/pedal level in 67% of AA and 61% of Caucasian patients. Overall morbidity (AA, 28%; Caucasian, 23%) and 30-day mortality (AA, 3%; Caucasian, 3%) were similar. Thirty-day graft failure was significantly greater in AAs than Caucasians (12% vs 5%, respectively; P = .003). The overall 5-year primary graft patency (+/-SE) was significantly worse in AA patients (AA, 52% +/- 6%; Caucasian, 67% +/- 2%; P = .009). The 5-year limb salvage rate (+/-SE) was also significantly worse in AA patients (AA, 81% +/- 5%; Caucasian, 90% +/- 1%; P = .04). With the Cox proportional hazard model, significant risk factors associated with primary graft failure were AA race, age younger than 65 years, female sex, secondary reconstructions, tibial bypasses, and critical limb ischemia. Significant risk factors associated with limb loss were age younger than 65 years, female sex, absence of coronary disease, presence of critical limb ischemia, and secondary reconstructions. CONCLUSIONS: Autogenous infrainguinal bypass surgery in AAs is associated with poorer primary graft patency and limb salvage rates compared with those of Caucasians. This may partially account for the higher rate of limb loss in AA patients with peripheral arterial occlusive disease.     

Long-term results justify autogenous infrainguinal bypass grafting in patients with end-stage renal failure.

INTRODUCTION: Infrainguinal bypass grafting for limb-threatening ischemia in patients with end-stage renal disease is generally thought to be associated with increased operative risk and poor long-term outcome. This retrospective study was undertaken to examine the modern-era, long-term results of infrainguinal bypass grafting in dialysis-dependent patients. METHODS: Over the past 5 years in a single institution, 425 lower extremities (368 consecutive patients) were revascularized for the indication of limb salvage. Sixty-four patients (82 limbs) were dialysis-dependent at the time of revascularization, and this group was analyzed separately. They exhibited statistically significant higher incidences of diabetes (83% vs 56%; P <.001), hypertension (91% vs 74%; P <.001), and more distal vascular disease, which required a greater proportion of proximal anastomoses at the popliteal level (24% vs 11%; P <.01) and distal anastomoses at the infrapopliteal level (75% vs 65%; P <.05). RESULTS: Despite the higher prevalence of comorbid conditions and distal disease in patients with renal failure, their perioperative 30-day mortality rate remained low (4.9%) and was not significantly different from that in patients with functioning kidneys (2.9%; P = not significant). After a median follow-up of 11 months (range, 0-60 months), the 3-year autogenous conduit secondary graft patency in patients with renal failure was no different than in patients with functioning kidneys (67% +/- 9% vs 64% +/- 5%; P = not significant). Nonautogenous conduits in dialysis-dependent patients exhibited a significantly poorer outcome with only 27% +/- 12% remaining secondarily patent at 2 years. As expected, both limb salvage and patient survival were significantly less in patients with renal faiture, although both exceeded 50% at 3 years (limb salvage 59% +/- 8% vs 68% +/- 5%; P <.05; patient survival 60% +/- 8% vs 86% +/- 4%; P <.001). The often-quoted phenomenon of limb loss, despite a patent bypass graft, occurred infrequently in this study (n = 3 of 82 limbs). CONCLUSION: Infrainguinal revascularization can be performed in dialysis-dependent patients with acceptable perioperative and long-term results, especially in patients in whom adequate autologous conduit is available.     

Early results of infragenicular revascularization based solely on duplex arteriography

PURPOSE: Recent reports have both advocated and questioned the utility of duplex arteriography (DA) as the sole preoperative imaging modality for planning infragenicular revascularization. This study compares the outcome of patients with critical limb ischemia who underwent infragenicular vein grafts on the basis of DA alone versus conventional preoperative contrast arteriography (CA). METHODS: The study group is composed of 23 consecutive patients who underwent infragenicular vein bypass grafting solely on the basis of preoperative DA from 1998 to 1999. They were compared with 50 consecutive patients who underwent infragenicular vein bypass grafting after CA from 1996 to 1998. Peak systolic velocity and end-diastolic velocity of potential target arteries were recorded during DA studies. In situ saphenous vein grafts were used preferentially, and technical adequacy of all grafts was assessed with completion duplex or arteriography. RESULTS: DA and CA groups were comparable on the basis of age and risk factors. In one limb (4%), the target artery selected by DA was abandoned because of dense calcification. No other revision in target or inflow artery was required on the basis of intraoperative completion studies. At 1 year, primary graft patency (78% vs 70%, P =.72) and limb salvage (70% vs 81%, P =.21) were comparable between the two groups. In the DA group, mean preoperative target artery peak systolic velocity in patent versus failed grafts was 49 +/- 18 cm/s versus 31 +/- 9 cm/s (P =.04), whereas mean end-diastolic velocity was 22 +/- 7 cm/s versus 14 +/- 8 cm/s (P =.08). CONCLUSION: Infragenicular revascularization directed by DA alone provides early graft patency and limb salvage rates comparable to similar procedures that are based on CA. Preoperative DA target artery velocities may predict outcome and improve target selection. These initial results justify further clinical testing of DA as the primary imaging modality for planning infragenicular vein grafts.     

Warfarin improves the outcome of infrainguinal vein bypass grafting at high risk for failure

Objective: Patients with marginal venous conduit, poor arterial runoff, and prior failed bypass grafts are at high risk for infrainguinal graft occlusion and limb loss. We sought to evaluate the effects of anticoagulation therapy after autogenous vein infrainguinal revascularization on duration of patency, limb salvage rates, and complication rates in this subset of patients. Methods:This randomized prospective trial was performed in a university tertiary care hospital and in a Veterans Affairs Hospital. Fifty-six patients who were at high risk for graft failure were randomized to receive aspirin (24 patients, 27 bypass grafts) or aspirin and warfarin (WAR; 32 patients, 37 bypass grafts). All patients received 325 mg of aspirin each day, and the patients who were randomized to warfarin underwent anticoagulation therapy with heparin immediately after surgery and then were started on warfarin therapy to maintain an international normalized ratio between 2 and 3. Perioperative blood transfusions and complications were compared with the Student t test or with the χ² test. Graft patency rates, limb salvage rates, and survival rates were compared with the Kaplan-Meier method and the log-rank test. Results: Sixty-one of the 64 bypass grafts were performed for rest pain or tissue loss, and 3 were performed for short-distance claudication. There were no differences between the groups in ages, indications, bypass graft types, risk classifications (ie, conduit, runoff, or graft failure), or comorbid conditions (except diabetes mellitus). The cumulative 5-year survival rate was similar between the groups. The incidence rate of postoperative hematoma (32% vs 3.7%; P = .004) was greater in the WAR group, but no differences were seen between the WAR group and the aspirin group in the number of packed red blood cells transfused, in the incidence rate of overall nonhemorrhagic wound complications, or in the overall complication rate (62% vs 52%). The immediate postoperative primary graft patency rates (97.3% vs 85.2%) and limb salvage rates (100% vs 88.9%) were higher in the WAR group as compared with the aspirin group. Furthermore, the cumulative 3-year primary, primary assisted, and secondary patency rates were significantly greater in the WAR group versus the aspirin group (74% vs 51%, P = .04; 77% vs 56%, P = .05; 81% vs 56%, P = .02) and cumulative limb salvage rates were higher in the WAR group (81% vs 31%, P = .01). Conclusions: Perioperative anticoagulation therapy with heparin increases the incidence rate of wound hematomas, but long-term anticoagulation therapy with warfarin improves the patency rate of autogenous vein infrainguinal bypass grafts and the limb salvage rate for patients at high risk for graft failure. (J Vasc Surg 1998;28:446-57.)     

Statin therapy is associated with improved patency of autogenous infrainguinal bypass grafts

OBJECTIVE: HMG-CoA reductase inhibitors (statins) broadly reduce cardiovascular events, effects that are only partly related to cholesterol lowering. Recent studies suggest important anti-inflammatory and antiproliferative properties of these drugs. The purpose of this study was to determine the influence of statin therapy on graft patency after autogenous infrainguinal arterial reconstructions. METHODS: A retrospective analysis of consecutive patients (1999-2001) who underwent primary autogenous infrainguinal reconstructions with a single segment of greater saphenous vein was performed. Patients were categorized according to concurrent use of a statin. Graft lesions (identified by duplex surveillance) and interventions were tabulated. Comparisons between groups were made by using the Fisher exact test for categorical variables and the Student t test for continuous variables. Patency, limb salvage, and survival were compared by log rank test. A stepwise Cox proportional hazards analysis was then employed to ascertain the relative importance of factors influencing graft patency. RESULTS: A total of 172 patients underwent 189 primary autogenous infrainguinal arterial reconstructions (94 statin, 95 control) during the study period. The groups were well matched for age, indication, and atherosclerotic risk factors. Procedures were performed primarily for limb salvage (92%), with 65% to an infrapopliteal target. Perioperative mortality (2.6%) and major morbidity (3.2%) were not different between groups. There was no difference in primary patency (74% +/- 5% vs 69% +/- 6%; P =.25), limb salvage (92% +/- 3% vs 90% +/- 4%; P =.37), or survival (69% +/- 5% vs 63% +/- 5%; P =.20) at 2 years. However, patients on statins had higher primary-revised (94% +/- 2% vs 83% +/- 5%; P <.02) and secondary (97% +/- 2% vs 87% +/- 4%; P <.02) graft patency rates at 2 years. Of all factors studied by univariate analysis, only statin use was associated with improved secondary patency (P =.03) at 2 years. This was confirmed by multivariate analysis. The risk of graft failure was 3.2-fold higher (95% confidence interval, 1.04-10.04) for the control group. Perioperative cholesterol levels (available in 47% of patients) were not statistically different between groups. CONCLUSIONS: Statin therapy is associated with improved graft patency after infrainguinal bypass grafting with saphenous vein.     

Infrainguinal bypass grafting in patients with end-stage renal disease: improving outcomes?

OBJECTIVE: This study was undertaken to examine recent trends in the outcomes of patients with end-stage renal disease (ESRD) undergoing infrainguinal bypass grafting (IBG) with autogenous vein. METHODS: A retrospective analysis of all IBGs performed on patients with ESRD at a single tertiary care institution during the interval 1993 to 1999 was undertaken. The comparison groups consisted of concurrent series of patients with elevated creatinine (creatinine level > 1.2 mg/dL) and patients with normal renal function undergoing IBG. Procedural variables, angiographic runoff scores, and extent of tissue necrosis at presentation were correlated with outcome. Categoric parameters were compared with chi(2) analysis; rates were computed with life-table analysis. RESULTS: Of an overall cohort of 622 IBGs performed during this interval, 78 IBGs (12.5%) were performed on 60 patients with ESRD, with a perioperative mortality rate of 1.3% that was comparable to controls. All reconstructions in the ESRD cohort were for limb salvage indications. Four-year survival, primary, assisted primary, and secondary patency rates for the ESRD group were 51% +/- 9%, 60% +/- 11%, 86% +/- 5%, and 86% +/- 5%, respectively; these were not statistically different from the control groups. Limb salvage in the ESRD group was 77% +/- 6% at 4 years and was significantly less then either the elevated creatinine (92% +/- 4%; P <.02) or the normal renal function group (90% +/- 2%: P <.02). Of 16 amputations in the ESRD group, nine were performed in limbs with patent grafts. The only absolute predictor of limb loss despite a patent graft was the presence of a heel ulcer more than 4 cm in diameter. Age, runoff score of the International Society for Cardiovascular Surgery/Society for Vascular Surgery, isolated tibial bypass graft, and location of distal anastomosis were not predictive of hemodynamic failure. CONCLUSIONS: Patients with ESRD constitute an increasing proportion of patients undergoing IBG in a tertiary care setting. Four-year survival, perioperative mortality, and graft patency rates are similar to patients with normal renal function and support an aggressive approach to this population. Major limb amputation despite a patent graft remains a problem of unique frequency in patients with ESRD. Adequate predictors of hemodynamic failure of IBG in this group do not exist, although a heel ulcer more than 4 cm may indicate an unsalvageable foot.     

Potential predictors of outcome in patients with tissue loss who undergo infrainguinal vein bypass grafting.

PURPOSE: Aggressive attempts at limb salvage in patients with ischemic tissue loss are justified by favorable initial results in most patients. The identification of patients whose conditions will not benefit from attempted revascularization remains difficult. METHODS: This study was designed as a retrospective review of prospectively collected clinical data. The subjects were 210 consecutive patients who underwent infrainguinal vein bypass grafting for ischemic tissue loss in the setting of an academic medical center. Bypass grafting was to the popliteal artery in 56 patients, to the infrapopliteal arteries in 131 patients, and to the pedal arteries in 23 patients. The follow-up examination was complete in 209 of 210 patients. One hundred twenty-five patients underwent blinded review of duplex scan venous mapping and arteriography to determine simplified vein and run-off scores. The outcome measures were the influence of risk factors, venous conduit, and runoff on mortality, limb loss, and graft failure at the 6-month follow-up examination. RESULTS: One hundred seventy patients (81%) were alive and had limb salvage. Nineteen patients (9.1%) died, with need for a simultaneous inflow procedure and end-stage renal disease being most commonly associated with mortality. Thirty-three patients (15.8%) had undergone amputation: 18 after graft failure, and 15 for progressive tissue loss despite a patent graft. Amputation was significantly more common in patients with diabetes (P =.05) and with poor runoff scores (poor runoff, 44.4% vs good runoff, 7.4%; P <.01). Amputation despite a patent graft also correlated with runoff (poor runoff, 41.7% vs good runoff, 4.3%; P <.01). Twenty-five patients had graft failure without amputation, so that only 145 patients (69.4%) were alive, had limb salvage, and had a patent graft. Run-off score was the strongest predictor of outcome, with 70% of patients with poor run-off scores having death, amputation, or graft failure. CONCLUSION: Aggressive use of infrainguinal vein bypass grafting in patients with ischemic tissue loss results in a high rate of initial limb salvage but significant morbidity and mortality. Arteriographically determined runoff scores appear to potentially identify patients at high risk for a poor initial outcome and may provide a method of selecting patients for primary amputation.     

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.     

Effectiveness of surveillance of infrainguinal grafts.

OBJECTIVE: To audit the surveillance programme of infrainguinal vein graft in a tertiary vascular unit, and find out how effective it was in preventing occlusion of grafts. DESIGN: Retrospective study. SETTING: Teaching hospital, Scotland. SUBJECTS: 59 consecutive patients who had 61 vein grafts between 1996 and 1998 for critical limb ischaemia. INTERVENTIONS: Grafts scanned at 3-monthly intervals for at least a year, and clinical review. MAIN OUTCOME MEASURES: Survival with an intact limb and patency of the graft. RESULTS: 52 of the 59 patients (90%) were alive at the time of follow up, and 55 of the 61 involved limbs (90%) were intact. Median follow up was 660 days (range 180-1995). 23 stenoses were detected by the surveillance programme. 17 grafts were revised, all of which were patent at follow up, and 8 other grafts occluded requiring 6 major amputations. One-year cumulative primary, primary-assisted, and secondary patency, and limb salvage rates were 63%, 88%, 88%, and 90% respectively. CONCLUSIONS: Surveillance of infrainguinal grafts by duplex scanning is effective and has resulted in high rates of limb salvage and secondary patency in patients who presented with critical ischaemia.