Comparative analysis of patients undergoing lower extremity bypass using in-situ and reversed great saphenous vein graft techniques
Authors: Chang Heepeel , Veith Frank J , Rockman Caron B , Maldonado Thomas S , Jacobowitz Glenn R , Cayne Neal S , Garg Karan 
Published: April 2022

Objective

Autologous great saphenous vein (GSV) is considered the conduit of choice for lower extremity bypass (LEB). However, the optimal configuration remains the source of debate. We compared outcomes of patients undergoing LEB using in-situ and reversed techniques.

Methods

The Vascular Quality Initiative database was queried for patients undergoing LEB with a single-segment GSV in in-situ (ISGSV) and reversed (RGSV) configurations for symptomatic occlusive disease from 2003 to 2021. Patient demographics, procedural detail, and in-hospital and follow-up outcomes were collected. The primary outcome measures included primary patency at discharge or 30 days and one year. Secondary outcomes were secondary patency, and reinterventions at discharge or 30 days and one year. Cox proportional hazards models were created to determine the association between bypass techniques and outcomes of interest.

Results

Of 8234 patients undergoing LEBs, in-situ and reversed techniques were used in 3546 and 4688 patients, respectively. The indication for LEBs was similar between the two cohorts. ISGSV was performed more frequently from the common femoral artery and to more distal targets. RGSV bypass was associated with higher intraoperative blood loss and longer operative time. Perioperatively, ISGSV cohort had higher rates of reinterventions (13.2 vs 11.1%; p = 0.004), surgical site infection (4.2 vs 3%; p = 0.003), and lower primary patency (93.5 vs 95%; p = 0.004) but a comparable rate of secondary patency (99 vs 99.1%; p = 0.675). At 1 year, in-situ bypasses had a lower rate of reinterventions (19.4% vs 21.6%; p=0.02), with similar rates of primary (82.6 vs 81.8%; p = 0.237) and secondary patency (88.7 vs 88.9%; p = 0.625). After adjusting for significant baseline differences and potential confounders, in-situ bypass was independently associated with decreased risks of primary patency loss (HR 0.9; 95% CI, 0.82–0.98; p = 0.016) and reinterventions (HR 0.88; 95% CI, 0.8–0.97; p = 0.014) but a similar risk of secondary patency loss (HR 0.99; 95% CI, 0.86–1.16; p = 0.985) at follow-up, compared to reversed bypass. A subgroup analysis of bypasses to crural targets showed that in-situ and reversed bypasses had similar rates of primary patency loss and reinterventions at 1 year. Among patients with chronic limb-threatening ischemia, in-situ bypass was associated with a decreased risk of reinterventions but similar rates of primary and secondary patency and major amputations at 1 year.

Conclusions

In patients undergoing LEBs using the GSV, in-situ configuration was associated with more perioperative reinterventions and lower primary patency rate. However, this was offset by decreased risks of loss of primary patency and reinterventions at 1 year. A thorough intraoperative graft assessment with adjunctive imaging may be performed to detect abnormalities in patients undergoing in-situ bypasses to prevent early failures. Furthermore, closer surveillance of reversed bypass grafts is warranted given the higher rates of reinterventions.