One or two venous pedicles by anastomoses for free flaps in reconstruction of the lower extremity: A systematic review and meta-analysis

Background Microsurgical free tissue transfers are a mainstay of lower extremity reconstruction. Despite being a reliable source of soft tissue, complications do arise. Venous congestion is among the most common causes of flap failure in lower extremity reconstruction, an issue that is attributed to venous stasis and impaired venous return in this region. There remains significant debate whether dual venous drainage improves outcomes. The aim of this study was thus to compare one versus two venous anastomoses in lower limb free flap reconstruction. Methods A systematic review of Medline, EMBASE, EBSCO CINAHL, SCOPUS, Proquest Dissertations and Theses Global, Cochrane Library, and PROSPERO from inception to May 20, 2020, was conducted. Two independent reviewers screened titles and extracted data. Our primary outcome was total free flap necrosis. Secondary outcomes were partial flap necrosis, minor complications, flap reoperation, venous thrombosis, and amputation. Methodological quality was assessed using the MINORS criteria and level of evidence. Results Three-hundred and fourteen unique titles were identified. All studies were level VI evidence and had a mean MINORS score of 16.1/24. Seven studies (comprising 1499 patients, 910 single venous anastomoses, and 579 double venous anastomoses) met criteria for inclusion. The mean (SD) patient age was 46.5 (7.1) years. Double venous anastomoses did not reduce the rate of minor complications, flap takeback, venous thrombosis, total flap necrosis, or partial flap necrosis when compared to a single vein (all p > .05). Conclusion In microvascular lower extremity reconstruction, two venous anastomoses did not reduce the rate of minor or major complications.