The reoperative potential of infrainguinal bypass: Long-term limb and patient survival

What Is the Secondary Patency of Thrombosed Bypasses of the Lower Limbs Cleared by Fibrinolysis In Situ?

BACKGROUND

In case of acute thrombosis, lower limb bypasses can, in certain cases, be cleared by local intra-arterial fibrinolysis (LIF). The aim of this study is to evaluate the secondary patency of thrombosed bypasses after fibrinolysis.

METHODS

This retrospective study includes all patients hospitalized for thrombosed bypasses of the lower limbs that were treated with in situ fibrinolysis using urokinase, between 2004 and 2013, in 2 French university hospital centers. Fibrinolysis was indicated in case of recent thrombosis (<3 weeks) provoking acute limb ischemia without sensory-motor deficit and in the absence of general contraindications. The secondary patency of the grafts was defined as the time after fibrinolysis without a new thrombotic event.

RESULTS

There were 207 patients, hospitalized for recent thrombosis of 244 bypasses. The LIF was efficient in 74% of the cases (n = 180). Secondary patency of these bypasses was 54.2% and 32.4% overall, 68.3% and 50.3% for the suprainguinal bypasses, and 48.3% and 21.5% for the infrainguinal bypasses at 1 and 5 years, respectively. There is a significant difference (P = 0.002) regarding the permeability of the suprainguinal and infrainguinal bypasses. The survival rate was 75% (±6.4%) at 5 years and the limb salvage rate was 89% (±3.3%), 78.2% (±5.1%), and 75% (±5.8%) at 1, 3, and 5 years, respectively. The only independent factor influencing the secondary patency of infrainguinal bypasses that was significant in a multivariate analysis was the infragenicular localization of the distal anastomosis (P = 0.023).

CONCLUSIONS

LIF is an effective approach that often allows the identification of the underlying cause, permitting elective adjunctive treatment of the underlying cause. Although LIF is at least as effective as its therapeutic alternatives described in the literature, the secondary patency of the bypasses remains modest and encourages close monitoring, particularly in patients with an infragenicular bypass.

Recanalization of native superficial femoral artery chronic total occlusion after failed femoropopliteal bypass in patients with critical limb ischemia

OBJECTIVES

This study aimed to examine the outcomes of endovascular recanalization for native superficial femoral artery (SFA) chronic total occlusion (CTO) in patients with critical limb ischemia (CLI) after femoropopliteal bypass failure with limited surgical revascularization options.

BACKGROUND

Endovascular recanalization of native artery occlusions has been recently used as a new alternative for threatened limbs after bypass graft occlusion. The feasibility and efficacy has not been widely reported.

METHODS

We retrospectively analyzed 45 consecutive patients (45 limbs) undergoing endovascular recanalization of native SFA occlusion following failed femoropopliteal bypass between June 2010 and December 2016.

RESULTS

All limbs had Transatlantic Inter-Society Consensus class C (26.7%, 12/45) or D (73.3%, 33/45) lesions with a mean lesion length of 29.8 cm. The technical success rate was 95.6% (43/45 limbs). The ABI showed a significant increase from 0.3 ± 0.1 pre-procedure to 0.7 ± 0.1 post-procedure (P < 0.01). Two early (<30 days) below-knee amputations due to acute thrombotic ischemia occurred during perioperative period and resulted in one death due to myocardial infarction. The mean follow-up was 42.7 months (1-62 months). Two patients were lost to follow up. The primary patency rates at 12 and 36 months were 54% and 51%, respectively. Secondary patency rates at 12 and 36 months were 78% and 61%, respectively. Limb salvage rate was 95% and amputation-free survival rate was 88% at both 12 and 36 months.

CONCLUSION

Recanalization of native SFA CTO due to failed femoropopliteal bypass offers a feasible and safe alternative to surgical reconstruction with acceptable limb salvage.

Color-Flow Duplex Hemodynamic Assessment of Runoff in Ischemic Lower Limb Revascularization

The objective of this study was to evaluate the existence of hemodynamic arterial flow correlation between preoperative duplex scanning (DS) and intraoperative direct outflow resistance (IDOR) measurements in ischemic lower limb revascularization.

Sixty-eight ischemic lower limbs were submitted to preoperative DS. Anatomic and hemodynamic arterial characteristics of the outflow system were recorded, and the results were considered in the distal anastomosis placement site decision making. IDOR measurements were obtained at the same arterial segment, and Pearson's correlation coefficient test was performed to study the preoperative DS power in predicting the intraoperative outflow resistance.

DS was technically satisfactory and helped define the distal anastomosis site in 93.2% of the cases (supragenicular popliteal artery, 19 [27.9%]; infragenicular popliteal artery, 10 [14.7%]; crural artery, 31 [57.4%]). A positive correlation could be found between preoperative DS and IDOR (0.450; p < .001). This correlation was particularly powerful in the crural artery (0.715; p < .001) when compared with the popliteal arterial segment (0.237; p = .192).

Preoperative DS may help define the best distal arterial and outflow segment to be revascularized based on anatomic and hemodynamic parameters. There is a positive flow correlation between preoperative DS and IDOR that seems to be stronger in crural revascularization surgery.

Applicability of the Society for Vascular Surgery's Objective Performance Goals for Critical Limb Ischemia to Current Practice of Lower-Extremity Bypass

BACKGROUND

In 2009, the Society for Vascular Surgery (SVS) established objective performance goals (OPGs) for critical limb ischemia (CLI) based on data from previous, randomized, controlled trials of lower-extremity bypass (LEB). These OPG sought to establish a benchmark of outcomes to which one could compare future endovascular therapy. However, the cohort used to develop the OPG excluded all patients who required prosthetic conduit and those with end-stage renal disease (ESRD), possibly limiting the generalizability of these results and the subsequent guidelines. The goal of this study was to determine if the SVS OPG are applicable to the current population of patients undergoing LEB.

METHODS

All patients who underwent infrainguinal LEB for CLI from January 2010 to December 2013 were identified in a prospectively maintained database. Patients were stratified into OPG eligible and ineligible (non-OPG) groups based on their demographic and operative characteristics. OPG eligible patients were further stratified into high risk and average risk. Outcomes included 30-day major adverse limb events (MALEs), 30-day major adverse cardiovascular events (MACE), 1-year survival, and 1-year freedom from amputation.

RESULTS

A total of 89 individual patients were identified. Only 43 (48%) patients met OPG inclusion criteria and 46 (52%) were not OPG eligible (non-OPG). The 30-day MALE was 8.7% (13.0% non-OPG vs. 7.0% OPG, P = 0.34). The 30-day MACE was 11.2% (13.0% non-OPG vs. 9.3% OPG, P = 0.58). One-year survival was 80.3% ± 4.5% (71.2% non-OPG vs. 90.0% OPG, P = 0.21). One-year freedom from amputation was 71.7% ± 5.5% (58.8% non-OPG vs. 84.0% OPG, P = 0.03).

CONCLUSIONS

The SVS OPG for LEB are likely not generalizable to current practice as 51% of patients would have been excluded from the SVS cohort because of ESRD and prosthetic conduit. Most SVS OPG (30-day MALE, 1-year survival, and 1-year limb salvage) were attainable in patients who met SVS OPG inclusion criteria; but for the patients who are not OPG eligible, new benchmarks are needed.

Repetitive bypass and revisions with extensions for limb salvage after multiple previous failures

The optimal treatment of patients facing imminent amputation after multiple (≥2) failed prior ipsilateral bypasses is unclear. We analyzed a group of patients undergoing multiple lower extremity bypasses for limb salvage to assess the utility of attempting multiple revascularizations. From 1990 to 2005, 105 revascularization procedures were performed in 55 limbs of 54 patients with imminent limb-threatening lower extremity ischemia after failure of ≥2 prior infrainguinal bypasses in the same leg. Fifty-five operations were the third procedure (Group A) and 50 operations were the fourth or more (Group B). We compared primary/secondary patency and limb salvage rates by Society for Vascular Surgery criteria. Limb salvage rates did not differ between patients undergoing a third bypass and those undergoing four or more bypasses at one year (62 versus 65%, NS) or at three years (58 versus 61%, NS). Secondary patency was not different between groups (76 versus 76%, P = NS) at one and three years (71 versus 70%, NS). Primary patency also did not differ between the two groups, at one year (24 versus 35%, NS), or at three years (11 versus 15%, NS). No differences were observed in morbidity and mortality rates between the groups. In conclusion, the likelihood of success of repetitive limb revascularization was unrelated to the number of previous failures. The expected incremental failure rate with each successive bypass was not found. These results, coupled with the three-year limb salvage rate of over 50% in patients who otherwise would have required amputation, lend support to aggressive use of limb revascularization in selected patients even after two or more failed bypasses.

Modifiable patient factors are associated with reverse vein graft occlusion in the era of duplex scan surveillance

OBJECTIVE

Modifiable patient factors that contribute to graft occlusion may be addressed after surgery. To determine risk factors associated with reverse vein graft (RVG) occlusion, we examined the characteristics and duplex scan surveillance (DS) patterns of patients with RVGs.

METHODS

Patients treated with RVG from January 1996 through December 2000 were identified from a prospective registry. The study population consisted of all patients with RVGs performed during the study period with grafts that subsequently occluded. Patients whose grafts remained patent served as age-matched and gender-matched control subjects. The prescribed DS regimen was every 3 months for the first postoperative year and every 6 months thereafter. Early DS failure was defined as having no DS within the first 3 months. Cox proportional hazards analysis was used to compare the two groups. Hazard ratios were calculated.

RESULTS

During the study period, 674 patients underwent RVG. Fifty-five patients with occluded RVGs were compared with 118 with patent RVGs. The follow-up period for occluded grafts was 13.40 +/- 12.59 months and for patent grafts was 32.40 +/- 15.61 months. Dialysis therapy, a known hypercoagulable state, continued smoking, and DS failure were independent factors associated with RVG occlusion. The hazards ratio for dialysis was 6.45 (95% CI, 3.07 to 13.51; P <.001), for current smoking was 4.72 (95% CI, 2.5 to 8.85; P <.001), for hypercoagulable state was 2.99 (95% CI, 1.47 to 6.10; P =.003), and for early DS failure was 2.43 (95% CI, 1.29 to 4.59; P =.006).

CONCLUSION

Continued smoking and failure to undergo DS within the first three postoperative months are modifiable factors associated with RVG occlusion. Smoking cessation and graft surveillance must be stressed to optimize patency of infrainguinal RVGs.

Tissue loss, early primary graft occlusion, female gender, and a prohibitive failure rate of secondary infrainguinal arterial reconstruction

PURPOSE

This study tested the hypothesis that a subset of secondary infrainguinal arterial reconstructions show prohibitive failure rates.

METHODS

Records of 79 consecutive patients, 44 men and 35 women, with a mean age of 60 years, who underwent secondary infrainguinal bypass from 1992 to 2000 at the University of Michigan Hospital, were reviewed. Data were analyzed with life-table analysis, logistic regression, and descriptive statistics.

RESULTS

Secondary infrainguinal reconstructions were performed in patients who had undergone earlier ipsilateral bypasses once (n = 35) or twice (n = 44). Among the prior procedures, 68% (n = 54) were done at an institution other than the authors'. Comorbidities included coronary artery disease (72%), tobacco use (77%), and diabetes mellitus (34%), but no patient had hemodialysis-dependent renal failure. Disabling claudication, with average ankle brachial index of 0.48, had been the indication for the primary operation in 77% of cases. Femoral-popliteal bypass was the primary procedure in 67%, with a prosthetic graft used in 62%. The mean patency duration of these earlier bypasses was 25 months. The indication for the final bypass was rest pain or tissue loss in 51% of patients, with an average ankle brachial index of 0.37. The most common procedure was a femoral-distal bypass with autologous vein (63%). Mean patency duration of the secondary bypasses was 30 months. Graft failure within 30 days of operation occurred in 22 patients (28%), and amputation was necessitated in 86% of these patients. The presence of rest pain or tissue loss, when accompanied with a history of early prior graft thrombosis in female patients, correlated with worse mean patency rates, recurrent graft failure (P </=.05), and a 94% amputation rate. Men in a similar setting incurred a 57% amputation rate. No association of final patency existed with regard to age, number of prior bypasses, conduit types, tobacco use, or diabetes.

CONCLUSION

Secondary infrainguinal bypasses are associated with an increased rate of graft failure and significant limb loss, particularly in those with a history of rest pain or tissue loss, female gender, and early prior graft failure. More appropriate initial operations in carefully selected patients and aggressive postoperative graft surveillance is speculated to improve these outcomes.

Management of Failed or Failing Infrainguinal Bypasses with Distal Correctable Lesions

The goal of this study was to assess the management of failed or failing infrainguinal bypasses with distal correctable lesions. A retrospective analysis of 94 procedures was performed for 72 (77%) failed and 22 (23%) failing infrainguinal bypasses with distal correctable lesions in 94 patients. The 94 procedures included 50 (53%) balloon angioplasties and 44 (47%) distal vein graft extensions from the previous graft to the distal artery. Preprocedural thrombolytic therapy was performed in 62 of 94 limbs with a failed graft, and complete thrombolysis was achieved in 30 of 94. The results of thrombolytic therapy (complete or incomplete thrombolysis) or the means of revision procedure (balloon angioplasty or distal vein graft extension) did not affect the patency. Lower patency was observed for women, patients with a secondary bypass, and grafts with multiple episodes of revision. We conclude that the patency of failing infrainguinal bypasses after revision of distal lesions was affected not by means of therapy but by previous vascular procedures, the usual risk factors, and female gender.

The effect of supplemental oxygen on the transarterial wall oxygen gradients at a prosthetic vascular graft to artery anastomosis in the rabbit

Artery wall hypoxia has been proposed to contribute to many kinds of artery wall pathology, including atherosclerosis and intimal hyperplasia. The purpose of this study was to determine the effect of supplemental oxygen on the transarterial wall oxygen gradients at a prosthetic vascular device (PVG)-to-artery anastomosis. The transarterial wall oxygen gradient in the infrarenal aorta of New Zealand White rabbits housed for 42 days in a 40% supplemental oxygen was measured with an oxygen microelectrode 2 mm distal to a PVG-to-artery anastomosis. Oxygen tensions were significantly increased throughout the artery wall at all time points in the supplemental oxygen groups compared to those in non-oxygen-supplemented groups. Within the oxygen-supplemented groups, the outer artery wall had diminished oxygen tensions immediately following creation of the anastomosis, with a slow return to control oxygen tensions on postanastomosis day 42 which correlated with a return of the vasa vasorum. These changes were noted without differences in blood pressure or arterial blood oxygen concentrations within the oxygen-supplemented group. Artery wall hypoxia noted following the creation of a PVG-to-artery anastomosis can be eliminated and artery wall oxygen tensions significantly increased by the administration of supplemental oxygen.

Vascular surgeons--do they make a difference in peripheral vascular disease?

BACKGROUND

The purpose of this study was to quantitate the effect of surgeons with added qualifications in general vascular surgery on aortic and peripheral vascular surgery performed in a community hospital.

METHODS

We performed a retrospective study covering a 22-year period and comparing indications, procedures, and results of surgeons who had added qualifications in general vascular surgery with those of board certified general and thoracic surgeons in a private hospital. In Period I (1975-1982), there were 702 vascular procedures all performed by thoracic (65%) and general (35%) surgeons. In Period II (1982-1997), there were 2590 vascular procedures performed by vascular surgeons (73%), general surgeons (7%), and thoracic surgeons (20%). A further comparison was done to examine the results of surgeons with added qualifications in general vascular surgery with board certified general and thoracic surgeons within Period II.

RESULTS

The volume and frequency of different types of vascular surgery changed significantly from Period I to Period II with lower extremity prosthetic reconstructions decreasing from 12% to 8.2% and autogenous lower extremity bypasses increasing from 15% to 36%. The percentage of distal reconstructions increased significantly from 27% of the total vascular surgeries in Period I to 44.3% in Period II. In Period II, vascular surgeons operated on older patients, had decreased mortality, decreased length of stay, and performed more distal bypasses than board certified general and thoracic surgeons.

CONCLUSIONS

The development of vascular surgery as a separate specialty appears to have had a beneficial effect on the types of vascular surgery and the results when compared in a contemporaneous or retrospective fashion.

Redo bypass surgery to the infrapopliteal arteries for critical leg ischaemia

OBJECTIVES

to evaluate the results of redo bypass surgery to the infrapopliteal artery and the value of adjuvant arteriovenous fistula (AVF) in this setting.

DESIGN

retrospective study.

MATERIALS

fifty-one redo reconstructions to the infrapopliteal arteries were done for critical leg ischaemia in 45 patients who have had primary infrainguinal reconstructions to the popliteal artery in 20 cases (39%), the crural arteries in 18 (35%), and the pedal arteries in 13 (25%).

METHODS

a PTFE prosthesis was used in 21 cases (41%). A Miller cuff was used in 16 prosthetic grafts. Adjuvant AVF was added to three autogenous vein and 12 prosthetic grafts.

RESULTS

at 2 years, the primary patency rate was 42%, the secondary patency was 43%, the limb salvage was 67%, the survival was 77%, and 53% of patients were alive with salvaged leg. The primary patency rate with a vein graft was 44% at 1 year, with prosthesis plus AVF 67%, but with prosthesis without AVF only 19%. Secondary patency rates were similar. Prosthetic graft with AVF and those without AVF achieved a 1-year leg salvage rate of 100% and 51%, respectively (p =0.01). Patients with adjuvant AVF had a worse 2-year survival rate that those without AVF (31% vs 89%) (p =0.007; RR: 8.87, CI 95%: 1.62-48.42).

CONCLUSIONS

redo bypass surgery using autogenous vein graft may achieve satisfactory long-term results. The use of adjuvant AVF may improve patency of redo infrapopliteal prosthetic bypass grafts.

Secondary distal extension of infrainguinal bypass: long-term limb and patient survival

The potential benefits of secondary distal extension vein grafts required after failing or failed initial infrainguinal bypasses were evaluated. Outcomes of secondary distal extension bypass procedures (n = 58) performed between July 1983 and March 1993 were reviewed. Patients (n = 51) had critical ischemia or tissue loss, with an average of 2.8 previous vascular procedures. The 58 initial infrainguinal bypasses included 38 above-the-knee and 13 below-the-knee femoropopliteal, 5 femorodistal, and 2 popliteal-distal. Thirty-nine of the 58 femoropopliteal grafts were prosthetic. The extension bypasses included popliteal-tibial, graft-tibial, and peroneal-plantar. They were performed for recurrent or persistent ischemia after failed initial infrainguinal bypasses in limbs, and with still-patent bypasses. All extension bypasses were vein conduits. Mean follow-up was 59 (range: 6 to 164) months. The cumulative life-table 5-year survival rate for all patients was 95%. The 27-month limb-salvage rate was 70%. Our findings indicate that patients with advanced peripheral vascular disease may have prolonged survival, and extension bypasses contribute significantly to their limb salvage. Thus, aggressive application of extension bypass to save threatened limbs is supported.

Predictors of outcome when reoperating for early infrainguinal bypass occlusion

The purpose of this study is to identify factors that predict outcome after intervention for early (<30 days) infrainguinal graft thrombosis. We reviewed the medical records, arteriograms, and follow-up studies of patients who underwent infrainguinal bypass for limb salvage between 8/91 and 9/98 and whose graft failed <30 days from the index procedure. Five factors were analyzed: (1) conduit: single segment saphenous vein versus alternative vein or composite conduit (20 vs. 13 patients); (2) repair modality: construction of a new graft at the time of the initial take-back procedure versus local revision and/or thrombectomy alone (12 vs. 21 patients); (3) run-off: good run-off versus poor run-off (20 vs. 13 patients); (4) operative findings: the presence of a correctable problem versus noncorrectable problem (20 vs. 13 patients); and (5) surgical history: previous versus no previous ipsilateral bypass (16 vs. 17 patients). These variables are statistically significant risk factors that can be used in combination to predict outcome. Unless a focal lesion clearly responsible for graft occlusion is found, complete graft replacement should be considered even if the new bypass must be prosthetic. The costs and morbidity of repeated procedures argue for primary amputation when adverse risk factors exist.

Transarterial wall oxygen gradients at a prosthetic vascular graft to artery anastomosis in the rabbit

PURPOSE

Artery-wall hypoxia has been proposed to contribute to many kinds of artery-wall pathologic conditions, including atherosclerosis and intimal hyperplasia. Intimal hyperplasia is common at sites of arterial injury, including an anastomosis. The purpose of this study was to determine the effect of a prosthetic vascular graft (PVG)-to-artery anastomosis on the delivery of oxygen to the artery wall.

METHODS

The transarterial wall oxygen gradient in the infrarenal aorta of New Zealand White rabbits 2 mm distal to a PVG-to-artery anastomosis was measured with an oxygen microelectrode.

RESULTS

Oxygen tensions were significantly decreased in the outer artery wall immediately after the creation of the anastomosis and showed a further decrease in oxygen tensions at days 7 and 14, which correlated with the absence of a vasa vasorum. After day 14, the oxygen tensions gradually increased, returning to normal by postanastomosis day 42, correlating with a return of the vasa vasorum. These changes were noted without differences in blood pressure or arterial blood oxygen concentrations.

CONCLUSION

The delivery of oxygen to the artery wall is altered by the creation of a PVG-to-artery anastomosis. Low arterial oxygen tensions at a PVG-to-artery anastomosis support a role for artery-wall hypoxia in the formation of intimal hyperplasia at the site of a PVG-to-artery anastomosis.

Long-term outcome after early infrainguinal graft failure

PURPOSE

To determine the long-term outcome and prognostic factors after early infrainguinal graft failure (< 30 days).

METHODS

Retrospective analysis of limb salvage data, patency data, and prognostic risk factors in 112 new infrainguinal bypass grafts from 1985 to 1995 that occluded within 30 days of operation.

RESULT

Thirty-six femoropopliteal and 76 femorotibial/femoropedal arterial bypass ("index") procedures were performed for rest pain (50%), tissue loss (31%), or disabling claudication (19%). In 103 patients, an immediate additional revascularization ("takeback") procedure was performed at the time of early graft failure. Life table analysis of the takeback procedures for threatened limbs (n = 84) revealed limb salvage rates of 74%, 54%, 40%, and 31% at 1 month, 1 year, 3 years, and 5 years, respectively. The 1-month limb salvage rate (threatened limbs) was 12% (1 of 8) in patients who were not taken back for revascularization and 33% (4 of 12) in patients who had undergone more than one takeback procedure within 30 days. The secondary graft patency rates for the takeback procedures (n = 103) were 70%, 37%, 27%, and 23% at 1 month, 1 year, 3 years, and 5 years, respectively. Univariate and life table analysis revealed that patients who were given anticoagulation medication after the index procedure (before graft thrombosis) or patients who had undergone previous ipsilateral leg revascularization had significantly lower rates of limb salvage and graft patency (p < 0.05). The limb salvage rate was also significantly worse in patients who had single-vessel runoff compared with those who had multiple-vessel runoff (p < 0.01). Thrombectomy and revision or complete graft replacement had a better secondary patency rate than thrombectomy alone (p < 0.05). Autogenous vein grafts had better outcome than polytetrafluoroethylene-containing grafts, but statistical significance was not achieved. No significant differences in limb salvage or graft patency rates were found between femoropopliteal versus femorotibial/femoropedal bypass grafting, age, gender, previous inflow surgery, diabetes, hypertension, smoking, or cardiac, renal, or pulmonary disease.

CONCLUSION

The long-term limb salvage and graft patency rates after takeback revascularization procedures for early graft failure are poor. Despite poor outcome, a single takeback procedure appears warranted in all patients. Multiple takeback procedures, however, do not appear to be justified, especially in patients who are given anticoagulation medication after the index bypass procedure, repeat leg bypass procedures, or if there is no potential for graft revision.

The concept of knee salvage: why does a failed femorocrural/pedal arterial bypass not affect the amputation level?

OBJECTIVES

There is continued controversy over whether a failed distal bypass influences the level of amputation. This issue is important as the number of arterial bypass grafts undertaken for critical ischaemia is increasing, followed by an increasing number of failed grafts.

SETTING

Teaching hospital. STUDY DESIGN AND MATERIALS: A prospective analysis of 109 consecutive femorocrural/pedal bypass grafts performed between June 1991 and January 1995 on patients presenting with severe critical lower limb ischaemia (CLI) to a single vascular unit. A further 43 amputations for non-reconstructible distal disease were also analysed.

CHIEF OUTCOME MEASURES

Mortality, amputation, rehabilitation, survival and knee salvage rates. The Kaplan-Meier method was used for comparison of factors associated with knee preservation.

RESULTS

Primary amputees had a higher in-hospital mortality (18% vs. 10%) but similar 3 year survival rates (30%) compared with secondary amputees (36.6%). Patients with successful grafts showed a trend towards better survival (61.9% at 3 years) compared to amputees (38.6% at 42 months, p = 0.061). Below- to above-knee amputation ratio was similar in the two groups (0.85 in secondary vs. 0.95 in primary amputees). Factors significantly associated with knee salvage at 3 years were shown to be: the condition of the inflow (81.9% for good vs. 43.1% for impaired, p = 0.000) the state of the profunda femoris artery (good 93%, impaired 71%, occluded 37% p = 0.0001) and the graft material (vein 81.8% vs. PTFE 59.8%, p = 0.033). The presence of tissue loss (p = 0.0523) and secondary procedures (p = 0.0879) showed a trend to become significant. Multivariate and Cox regression analysis showed that the most important factors were the inflow (p = 0.001), the state of the profunda (p = 0.001), the graft material (p = 0.034) and previous revascularisation attempts (p = 0.019).

CONCLUSIONS

The factors which determine knee loss are a compromised inflow state, the presence of an inadequate profunda femoris, previous revascularisation attempts and the use of synthetic graft material. Most of these factors (with the exception of infection related to revascularisation) are present before reconstructive arterial surgery is performed and this study shows that failure of a distal graft does not affect the final amputation level.

Comparison of clinical follow-up and duplex surveillance of infrainguinal vein bypasses

The evidence in support of surveillance has been principally based on the favourable primary-assisted patency of stenosed grafts following revision (60-80% at 5 years) compared with the poor secondary patency of revised occluded grafts (20-40% at 5 years). Both the capital cost and workload generated by surveillance are considerable. More information is needed on the benefits of surveillance compared with clinical follow-up. A retrospective comparison of 50 vein grafts (44 reversed, six in situ) undergoing colour-coded duplex surveillance and 50 vein grafts (46 reversed, four in situ) under clinical follow-up, with duplex scans obtained only when clinically indicated, has been performed. Four (8%) stenoses of > or = 50% were identified in the surveillance group. One 50% proximal anastomotic stenosis failed to progress on sequential scans. Three stenoses were treated (one mid graft, two popliteal) by vein patch angioplasty (two cases) and transluminal angioplasty (one case). Both groups were followed-up for 12 months. Secondary patency at 12 months (88% surveillance; 80% clinical follow-up) was not significantly different (P = 0.3). Similarly, limb salvage at 12 months (94% surveillance; 88% controls) was not significantly different (P = 0.4). A large randomized prospective study comparing duplex surveillance and clinical follow-up is warranted.

Problems related to the definition of "distal" bypass and "secondary" patency rates. A paper for debate

The large variations observed in "distal" bypass patency rates and the abuse of life-table analysis have encouraged most Vascular Committees to develop standards for evaluating results. However, problems continue to persist. Some of these do not relate to statistical analysis but to the lack of definition of both secondary patency and "distal" when referring to arterial bypass grafts to the lower limb. We present various problems and propose some strict definitions for each type of infrainguinal reconstruction, based on the inflow and outflow levels, together with a modification of the definitions of primary assisted and secondary patency.

Preferred strategies for secondary infrainguinal bypass: lessons learned from 300 consecutive reoperations

PURPOSE

To determine the optimal surgical strategies in reoperative infrainguinal bypass, we reviewed our results in 300 consecutive secondary bypasses in 251 patients operated on between Jan. 1, 1975, and Nov. 1, 1993.

METHODS

There were 168 men (67%) and 83 women (33%), with a mean age of 64.8 years and a typical distribution of risk factors including smoking (76.4%), diabetes (33.7%), and coronary artery disease (47.1%). The indications for surgery were limb-threatening ischemia in 83.5% and severe claudication in 16.5% of patients. The majority of conduits (n = 213) were autogenous vein and were composed of a single segment of greater saphenous vein in 121 bypasses (57%) and various alternative veins including composite, arm, and lesser saphenous vein in 92 bypasses (43%). Prosthetic conduits included 69 polytetrafluoroethylene, 16 umbilical vein, and two Dacron grafts.

RESULTS

There was one perioperative death (0.3%) and a 25% total morbidity rate including a 1.7% myocardial infarction rate. There was a 28.6% early (< 30 days) graft failure and 10.7% early amputation rate for prosthetic bypass grafts compared with 13.6% early graft failure and 5.6% early amputation rates for vein grafts. Autogenous vein bypasses had higher 5-year secondary patency rates than had prosthetic grafts (51.5% +/- 4.6% vs 27.4% +/- 6.1%, p < 0.001). Results with autogenous vein bypass improved significantly from the 1975 to 1984 to the 1985 to 1993 interval with 5-year secondary patency rates increasing from 38.3% +/- 6.9% to 59.1% +/- 5.8% (p = 0.017) and 5-year limb-salvage rates increasing from 40.4% +/- 7.6% to 72.4% +/- 6.6% (p < 0.001). Vein grafts to the popliteal and tibial outflow levels had equivalent long-term results. Vein grafts completed for claudication demonstrated results superior to those for limb salvage, with a 5-year secondary patency rate of 75.8% +/- 8.1% versus 52.3% +/- 7.9% (p = 0.048). Secondary autogenous vein bypass grafting performed after early primary graft failure (< 3 months) did particularly poorly, with only a 27.2% +/- 7.7% 4-year secondary patency rate. Greater saphenous veins tended to perform better than alternative vein bypasses, with a 5-year secondary patency rate of 68.5% +/- 6.0% compared with 48.3% +/- 10.5% (p = 0.09) and a 5-year limb-salvage rate of 77.8% +/- 7.4% versus 54.2% +/- 11.8% (p = 0.046).

CONCLUSIONS

When patients suffer a recurrence of limb-threatening ischemia at the time of infrainguinal graft failure, aggressive attempts at secondary revascularization with autogenous vein are warranted based on the low surgical morbidity and mortality rates and the improved patency and limb salvage rates that are currently attainable.

Epidemiology of leg amputation: the influence of vascular surgery

The number of amputations performed for vascular disease in Denmark has decreased from 1777 (34.5 per 100,000 population) in 1983 to 1288 (25.0 per 100,000) in 1990, a reduction of 28 per cent. This decline coincided with an increase in vascular surgical activity of up to 100 per cent, including a marked rise in the rate of femorodistal reconstruction. Moreover, regional variation in vascular surgical activity correlated with percentage reduction in amputation rate (rS = 0.65, P < 0.01). The relative number of above-knee amputations also decreased in favour of more distal levels during the period studied. These findings suggest that vascular surgery may be responsible for the lower amputation rate.

Is thrombolysis of occluded popliteal and tibial bypass grafts worthwhile?

PURPOSE

We analyzed the short- and long-term results for patients undergoing thrombolysis of occluded infrainguinal bypass grafts at our institution over a 62-month period.

METHODS

Thirty-one patients with 40 episodes of graft thrombosis in 33 grafts managed by thrombolysis were retrospectively reviewed. The effects of graft age, material, and anatomy, symptoms, treatment, anticoagulation, and occlusion duration were evaluated for impact on patency after thrombolysis. Dose and duration of therapy with use of the technique of pulse-spray thrombolysis was assessed.

RESULTS

Thrombolysis successfully reestablished patency in 92% of grafts treated. Mean lysis time and urokinase dose were 118 minutes and 607,000 units, respectively. Responsible lesions were identified and treated by angioplasty or surgery in 35 of 37 cases. The patency rate after thrombolysis was 28% at 30 months, and the secondary patency rate was 46% at 18 months. Duration of occlusion, symptoms, treatment, graft anatomy, and prior graft revision did not impact on patency. Mean secondary patency was 21.5 months in grafts in place over 1 year and 7.0 months in grafts in place for less than 1 year. Mean secondary patency was 23.8 months in polytetrafluoroethylene grafts and 8.4 months in vein grafts. The limb salvage rate was 84% at 30 months, and the patient survival rate was 84% at 42 months.

CONCLUSIONS

Pulse-spray thrombolysis is effective in rapidly recanalizing thrombosed infrainguinal grafts. Grafts failing in the first year after placement should generally be replaced, reserving thrombolysis and revision for grafts greater than 1 year old. Vein grafts tolerate thrombosis less well than synthetic conduits and have decreased long-term patency.

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

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

Value of continued efforts at limb salvage despite multiple graft failures

Treatment of patients with limb-threatening ischemia after multiple failed bypasses remains difficult and controversial. Further revascularization procedures despite failure of the original procedure may be viewed as futile. The purpose of this report is to determine the efficacy of third or fourth revascularization procedures after the original and second procedures fail. Over a 10-year period from January 1, 1983, to December 31, 1992, 312 infrainguinal bypasses were performed on 271 consecutive patients for foot salvage. The overall limb salvage rate was 84%, and the operative mortality rate was 3.7% (10 patients). Sixteen patients (5.8%) had repeat infrainguinal bypasses performed after failure of two or more prior bypass procedures in the same leg. Twenty-three reconstructions were performed in these 16 patients. There were no operative deaths. One half of these patients had major amputations performed within the first year following their tertiary or fourth reconstructive procedure. Sixty-two percent of patients have survived longer than 3 years after their third or fourth procedure. One half of these patients have maintained graft patency and an excellent quality of life. Only 22% of the patients requiring amputation ambulated with a prosthesis, whereas all revascularized patients ambulated. Although this subset of patients is known to have an increased risk of repeated graft failure and limb loss, we believe continued efforts at limb salvage despite multiple previous graft failures is justified.

Femorofemoral bypass for aortofemoral graft limb occlusion: a ten-year experience

PURPOSE

Aortofemoral bypass (AFB) is a durable reconstruction; however, graft limb occlusion occurs in 10% to 20% of patients and results in limb ischemia. Treatment of AFB limb occlusion has been debated, but many recommended femorofemoral bypass (FFB). FFB grafts have had excellent patency rates. The durability of FFB specifically for AFB limb occlusion has not been reported. This study retrospectively examined a 10-year experience with FFB for AFB limb occlusion to determine FFB performance.

METHODS

Between 1982 and 1992, FFB was performed on occluded AFB limbs in 22 patients (14 men and 8 women). Reoperation was performed for disabling claudication in five cases, but the remaining 17 patients (77%) had critical limb ischemia. FFB originated from the contralateral patent AFB limb in all cases. Distal anastomosis was to the common femoral artery (n = 8) or the profunda femoris (n = 14). FFB graft patency was confirmed by direct Doppler arterial examination over a mean follow-up of 47 months.

RESULTS

The cumulative life-table primary patency rate of FFB was 54% at 5 years. Reoperative procedures performed in nine cases resulted in a secondary patency rate of 84% at 5 years. The limb salvage rate was also 84% at 5 years, reflecting the impact of successful reoperation. Major amputations (two below-knee, one above-knee) were necessary in only three cases. There were no perioperative deaths after FFB, and the cumulative 5-year survival rate was 77%.

CONCLUSION

Aortic graft limb occlusion occurs less frequently than failure of infrainguinal grafts making the success of specific reoperative strategies difficult to document reliably. This study suggests that FFB is a safe and durable alternative for AFB limb failure. An aggressive policy of reoperation has resulted in successful extension of FFB graft function and an excellent rate of limb salvage.

Repeat leg bypass after multiple prior bypass failures

PURPOSE

The optimal treatment of patients with severe lower extremity ischemia after multiple failed prior bypasses is unclear. It is presently unknown whether failure of attempted revascularization in these patients is so likely that such operation should not be elected. We have maintained an aggressive surgical policy of repeated revascularization regardless of prior failures. A review of our clinical experience with this difficult patient group was performed to determine the results of this policy.

METHODS

From 1980 to 1992, 85 revascularization procedures were performed in 81 patients with lower extremity ischemia after failure of two or more prior infrainguinal bypasses in the same leg. All patients were prospectively entered and monitored in our vascular registry. Seventy-two operations were the third procedure, six operations were the fourth procedure, and seven operations were the fifth procedure on the same extremity. Twenty-six of the 85 procedures (30%) were revisions of failing grafts discovered by routine surveillance methods, whereas 59 were replacements of thrombosed grafts. Autogenous reconstruction was used in 67 procedures (79%), and prosthetic reconstruction was used in 18 procedures (21%). The distal anastomosis was to the popliteal artery in 19 patients and infrapopliteal artery in 66.

RESULTS

Mean time to failure of the first leg bypass was 24 months and 4.9 months for the second bypass. Detailed hematologic screening revealed identifiable hypercoagulable disorders in nine (15%) of 59 patients screened after 1987. All nine had anticardiolipin antibodies. The operative mortality rate was 4%. Mean follow-up after the most recent operation was 17 months. The primary patency rate at 4 years was 79.8%. The limb salvage rate was 69.6% at 4 years.

CONCLUSIONS

These results indicate that limb revascularization after two or more failed leg bypasses results in low operative mortality rates and surprisingly good primary patency and limb salvage rates at 4 years. The patient survival rate through 4 years is unexpectedly high. In our opinion these results justify an aggressive policy of limb vascularization after multiple failed prior bypasses.

Femorocrural grafting and regrafting: does polytetrafluoroethylene have a role?

Between 1980 and 1988, 263 patients received 307 femorocrural bypass grafts. 180 were primary infrainguinal grafts, 106 secondary, 18 tertiary and three quaternary. Rest pain or tissue loss was the indication in 96% of cases. Outflow vessels were the tibioperoneal trunk (n = 34), posterior tibial artery (n = 115), peroneal artery (n = 89) and anterior tibial artery (n = 69). 88 primary vein grafts were completed. 201 polytetrafluoroethylene (PTFE) grafts were inserted (92 primary and 109 subsequent reconstructions). There were no direct PTFE to crural vessel anastomoses. A Miller cuff was used in the majority (n = 175). The three year primary patency for primary vein grafts (36%) was similar to primary PTFE grafts (29%), but significantly higher than subsequent PTFE grafts (20%) (p = 0.03). Three year foot salvage for primary vein grafts (65%) was similar to primary PTFE (64%), but significantly better than subsequent PTFE (42%) (p = 0.02). The results support both redo femorocrural grafting for critical ischaemia, as judged by foot salvage rates, and the use of PTFE with a distal vein cuff in primary and subsequent femorocrural reconstruction if autologous vein is not available.

Re-intervention after vascular surgery for critical leg ischaemia

Re-operation after arterial bypass in the leg is common, may be seen as failure by many and can appear expensive to budget holders. Secondary reconstruction may not be undertaken for these reasons. The indications for and outcome of further intervention have been studied in 395 primary presentations with critical leg ischaemia, all of whom underwent arterial reconstruction. During the study period the primary amputation rate was 3%, and 10% of reconstructed patients presented with skin necrosis or gangrene. One hundred and twenty-nine reconstructions (32%) were to crural vessels in the lower third of the calf. Mean follow-up was 3 years, 1 month mortality was 2% and overall mortality 20%. One hundred and seventy-three (44%) patients required further intervention: 118 (30%) for recurrence of ipsilateral ischaemic symptoms and 55 (14%) in the presence of a patent primary graft (mostly operations on the contralateral leg). A total of 695 secondary operations were required over follow-up, a mean 1.75 additional operations per patient per 3 years. Following recurrence of ischaemia, graft revision or secondary revascularisation was undertaken in 98 of 118 (84%) legs whilst the remaining 19 legs had an amputation performed after primary graft failure. Secondary reconstruction was successful in salvaging 63 limbs to mean follow-up, a 64% success rate from revisional surgery. At mean follow-up 339 of 395 limbs remain viable (86% limb salvage), secondary graft patency is 79% and primary graft patency 63%. Failure to re-intervene after primary graft failure would reduce limb salvage at 3 years to 70% with corresponding loss of 63 legs.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiological intervention for the failing in situ vein bypass

With close surveillance, deteriorating hemodynamics may signal a failing in situ bypass that can be salvaged by timely intervention. The purpose of this report is to summarize our experience with in situ bypass salvage using interventional radiology. Twenty-nine patients underwent arteriography following bypass occlusion or when an ankle/brachial index reduction of greater than 0.15 was detected between two consecutive office visits. Eighteen percutaneous transluminal dilatations were performed; one patient underwent repeat dilatation after 36 months, a second had four dilatations over 40 months. Ten significant arteriovenous fistulae were identified and were successfully embolized with 3 mm coils. One patient underwent excision of a retained valve. Six patients had initial fibrinolytic therapy for graft occlusion. The morbidity of these interventions was low; one bypass was disrupted following percutaneous transluminal dilatation but was successfully salvaged surgically. The average time from the original surgery to intervention was six months (one to 26 months); and the average follow-up after intervention was 22 months (three to 62 months) over which time patency was maintained in the majority. When a correctable problem is identified with appropriate vascular lab surveillance, interventional radiology is a useful alternative to surgery for bypass salvage.

A ten-year experience with one hundred fifty failing or threatened vein and polytetrafluoroethylene arterial bypass grafts

Between Jan. 1, 1980, and Dec. 31, 1989, 2187 infrainguinal revascularization procedures were performed. In 130 of these cases with patent bypasses, hemodynamic deterioration was suspected, and urgent arteriography was performed. Twenty additional patients with aortofemoral, femorofemoral, or axillofemoral bypasses demonstrated hemodynamic deterioration. In 93% of failing grafts the condition was suspected because of recurrent symptoms or changes in the pulse examination. Two hundred eighty-five high-grade stenotic or occlusive lesions were identified in inflow arteries, outflow arteries, within the graft, or at proximal or distal anastomoses associated with these 150 grafts. One hundred sixty-one (57%) of these lesions were in patients with failing vein grafts; 115 (40%) were in patients with failing polytetrafluoroethylene (PTFE) grafts; and 9 (3%) were associated with failing composite vein/PTFE grafts. Stenotic lesions less than 5 cm in length were initially treated with percutaneous transluminal balloon angioplasty (PTA). Occlusive lesions, stenoses greater than 5 cm in length, and PTA failures were treated surgically. The overall 6-year cumulative secondary patency rate for failing grafts was 65%, and the limb salvage rate was 75%. The extended patency rate after the first intervention in the failing state was 56% at 5 years. The 5-year secondary patency rate for grafts initially treated with PTA (58%) was not significantly different (p = 0.25) from that for grafts treated initially with surgery (71%). Percutaneous transluminal angioplasty was effective for inflow stenoses of the iliac, femoral, and popliteal arteries and for some outflow lesions.(ABSTRACT TRUNCATED AT 250 WORDS)