Meta-analysis of polytetrafluoroethylene bypass grafts to infrapopliteal arteries

CONTEXT

Reports of polytetrafluoroethylene (PTFE) bypass grafting to the infrapopliteal arteries have often used survival analysis of acceptable quality to describe a wide range of long-term results. In theory, these results may be combined if variability between series and time intervals is considered.

OBJECTIVE

Meta-analysis was performed to gain insight into long-term graft patency and foot preservation after PTFE bypass grafting to infrapopliteal arteries.

DATA SOURCE

Studies published from 1982 through 2001 were identified from the PubMed database and pertinent original articles.

STUDY SELECTION

Three investigators selected 43 studies that used survival analysis, reported 2-year patency rates, and included at least 15 bypass procedures. Data extraction and transformation: Based on standard life-tables or survivor curves, an interval success rate was calculated for each month in each series. The monthly success rates were combined across series, enabling construction of pooled survivor curves.

DATA SYNTHESIS

Random-effects meta-analysis yielded 5-year pooled estimates (SE) of 30.5% (7.6%) for primary graft patency, 39.7% (5.5%) for secondary graft patency, and 55.7% (5.0%) for foot preservation. During the entire follow-up, pooled estimates were slightly higher for series of PTFE grafts with adjunctive procedures compared with series of PTFE grafts only. Sensitivity analysis: A simulation using only unfavorable assumptions showed a decrease of less than 5% at 5 years for all outcomes, and smaller differences at subgroup meta-analysis. Funnel plots suggested that publication bias was unlikely.

CONCLUSION

This meta-analysis indicated moderate success for PTFE bypass grafts to infrapopliteal arteries, but the role of adjunctive procedures at the distal anastomosis remains uncertain.

Non-Greater Saphenous Vein Grafting for Infrageniculate Bypass

Infrainguinal bypass grafting with greater saphenous vein has proven to be a highly effective procedure with primary 5-year patency and limb salvage rates exceeding 80 per cent. However, because of prior usage or intrinsic venous disease the greater saphenous vein is often not available as a conduit. Numerous studies have shown that patency rates for prosthetic bypass grafting to the infrageniculate vessels are clearly inferior to that reported for greater saphenous vein bypass. In this report we summarize our experience with the use of alternate autogenous vein grafting to the infrageniculate vessels. The records of all patients undergoing autogenous bypass grafting to the infrageniculate vessels using a conduit other than the greater saphenous vein between 1992 and 1999 were reviewed. Graft survival curves were plotted using the Kaplan-Meier method and results are reported using the Society for Vascular Surgery/International Society for Cardiovascular Surgery guidelines. Forty-eight patients underwent a total of 51 infrageniculate bypass procedures using non-greater saphenous autogenous conduits. Thirty-nine patients had reconstructions performed with single segments of arm vein, two had their operations performed with lesser saphenous vein, and ten had grafts created with two segments of non-greater saphenous autogenous vein. Twenty-one grafts were performed to the infrageniculate popliteal artery and 30 were performed to the tibial vessels. Primary and primary assisted patency rates at 30 months were 49 and 75 per cent. Limb salvage was 87 per cent. Infrainguinal bypass grafting using non-greater saphenous autogenous conduits can yield quite satisfactory intermediate limb salvage and patency rates. However, close graft surveillance and prompt intervention are required to avoid graft failure.

Improved patency of infrainguinal polytetrafluoroethylene bypass grafts using a distal Taylor vein patch

OBJECTIVE

The purpose of this study was to evaluate graft patency and limb salvage rates for infrainguinal polytetrafluoroethylene (PTFE) bypass grafts using distal anastomotic Taylor vein patch in patients lacking suitable vein conduit.

METHODS

We reviewed 44 patients who underwent infrainguinal bypass between January 1996 and August 2000 using 6-mm PTFE and a distal Taylor vein patch. Postoperative oral anticoagulation was administered to 80% of patients. Graft patency was confirmed during follow-up with serial graft duplex scanning.

RESULTS

Operative indications were rest pain, nonhealing ulcer, or gangrene in 76% of patients, 43% of whom had undergone previous ipsilateral leg bypass. Distal anastomotic sites were the below-knee popliteal (29%) and tibial-peroneal arteries (67%). At 1 month, 1 year, and 2 years, respectively, the primary patencies (SE <10%) were 86%, 71%, and 71%; limb salvage rates were 95%, 75%, and 66%; and mortality rates were 5%, 20%, and 20%.

CONCLUSIONS

These early results with PTFE and distal Taylor vein patch are promising, and markedly superior to previous reports of PTFE without anastomotic modification. Further long-term follow-up will be necessary to determine the 3- to 5-year durability of such reconstructions.