Large-to-Small End-to-Side Venous Anastomosis in Free Flap Transfer

Abstract

Background: Vessel size discrepancy is one of the major risk factors for anastomotic failure in free flap transfer. The situation becomes challenging for reconstructive microsurgeons when the recipient vein is much smaller than the flap vein. We investigated the feasibility of large-to-small end-to-side venous anastomosis for such cases. Materials and methods: The subjects were 16 consecutive patients who underwent a free flap transfer for oncologic defects with a large-to-small end-to-side venous anastomosis. The larger flap vein was anastomosed to the side slit of the smaller recipient vein under an operating microscope. Surgical details and postoperative outcome were investigated retrospectively. Results: An anterolateral thigh flap was used in five patients, a superficial inferior epigastric artery flap in four, a thoracodorsal artery perforator flap in three, and a latissimus dorsi musculocutaneous flap and a fibular osteocutaneous flap in two patients each. The internal mammary vein and the anterior tibial vein were most frequently used as a recipient vein (four patients each), followed by the deep inferior epigastric vein (three patients). The extent of vessel size discrepancy ranged from 1.3-to 3.3-fold, and the mean discrepancy was 1.9-fold. No anastomotic failure occurred postoperatively, and the flap survived in all patients. Conclusions: Large-to-small end-to-side venous anastomosis can be a versatile option when only a small vein is available as a recipient vein. Internal mammary, deep inferior epigastric, and anterior tibial veins are good candidates for this technique.

Selection of deep or superficial recipient vein in lower extremity reconstruction using free flap: A systematic review and meta‐analysis

“…End‐to‐side anastomosis may be an option for overcoming vein size discrepancy (Lee et al, 2019; Shimbo et al, 2022). Moreover, the usefulness of large‐to‐small end‐to‐side venous anastomosis has been reported (Miyamoto et al, 2020). Anastomosis to both deep and superficial veins may allow for either vein to act as a backup system.…”

Analysis of Anastomotic Venous Factors in Traumatic Lower Extremity Injuries Reconstructed by Free Flap

“…Notably, the ETS anastomosis group had a lower proportion of cases within 7-90 days from injury to coverage than ETE anastomosis groups, suggesting that ETS anastomosis groups were selected in comparatively advantageous conditions. Although ETS venous anastomoses have been mainly reported in the head and neck region [13], there have been several successful reports in the lower extremity [5,6]. In addition, flow-through venous anastomosis has also been shown to have a lower rate of microvascular complications than ETE anastomosis in oncologic lower extremity reconstruction [14].…”

“…ETS anastomosis is superior to flow-through anastomosis when there is a vessel size mismatch between recipient and donor vessels. Miyamoto et al reported that large-to-small ETS venous anastomosis can be a breakthrough option when only a small recipient vein is available [6]. We used Y-shaped ETS anastomosis because Y-shaped ETS venous anastomosis can theoretically prevent anastomotic complications by broadening anastomotic diameter; however, one flap using this method resulted in venous thrombosis, possibly due to PTVD.…”

“…Venous size mismatch was shown to be a high-risk factor in flap complications in end-to-end (ETE) venous anastomoses during lower extremity reconstruction [2,3], and the deep venous system has been more reliable as a recipient site for outflow compared with the superficial venous system [4]. Furthermore, end-toside (ETS) venous anastomoses have been shown to be safe with a low rate of microvascular complications in lower extremity reconstructions [5,6]. However, there is some controversy over whether one-or two-vein anastomoses offer optimal venous outflow in these reconstructions [3,4,[7][8][9].…”

Efficacy of the microscopic parachute end-to-side technique for creating large-to-small venous anastomoses in free flaps in the extremities

“… 6 , 7 However, deep veins selected as the recipient veins often have a small diameter, and the surgeon sometimes struggles when performing a complicated anastomosis of large flap veins to small recipient veins (large-to-small anastomosis). 8 , 9 This venous size discrepancy is thought to influence thrombus formation, 2 , 10 , 11 and it can be difficult to select the optimal recipient veins and perform venous anastomosis in cases with a vessel size discrepancy in a free flap.…”