Solving vessel caliber mismatch in microvascular anastomosis: A comprehensive review, novel techniques, and a surgical guide for optimal outcomes

Caliber mismatch in microvascular anastomosis can significantly increase procedural difficulty and elevate the risk of thrombosis. A comprehensive literature search in PubMed, Scopus, Web of Science, and Google Scholar was conducted to identify articles addressing surgical techniques for overcoming caliber mismatch in microvascular anastomosis. Various techniques described in the literature were found: modifications of end-to-end anastomosis, the use of end-to-side anastomosis, the application of vessel grafts and the use of vessel couplers. In this review, we critically analyze these techniques and introduce additional technical variations. We discuss the options and express our preferred choice of methods based on specific clinical scenarios: if an alternative vessel (either new or isolated further away) is not found, the severity of the mismatch guides the choice. When less then 1/3 our choice is for vessel dilation and oblique cut of the smaller vessel end (if necessary with the adjunct of a titanium small Ligaclip in an oblique fashion to avoid a cul-de-sac). If caliber mismatch is around or over 1/3, we would prefer an end to side anastomosis.