Surgeons map final venous outflow routes in submental island flap reconstruction

A persistent puzzle in this operation is the flap’s venous anatomy, which varies considerably between patients, and the question of which vein actually carries the flap’s blood out once the tissue is transferred. A new retrospective study of 20 patients, published in BMC Surgery, addresses this by distinguishing the first venous confluence encountered during dissection from what the authors call the final dominant venous outflow route, the pathway that ultimately matters for maintaining venous drainage during flap transfer.

The study included 20 consecutive patients who underwent tumor resection followed by immediate submental island flap reconstruction between February 2017 and February 2019. Because the sample was small and outcome events were sparse, the analyses were purely descriptive rather than statistical.

The cohort split into three pedicle configurations: 13 flaps were antegrade, five were perforator-based, and two were reverse-flow. When the researchers mapped where the final dominant outflow ultimately drained, they found it entered the external jugular system in 12 patients and the internal jugular system in eight. Notably, all three pedicle configurations occurred with both outflow patterns, meaning the type of pedicle constructed did not predict which venous system served as the dominant outflow.

Mean pedicle length was 6.7 plus or minus 0.3 centimeters, with a range of 6.2 to 7.4 centimeters. Surgical outcomes in the series were favorable: all 20 flaps survived completely. Transient venous congestion occurred in three patients, but there were no cases of partial necrosis, total flap loss, or reoperation for vascular compromise.

The authors’ central conclusion is that final dominant venous outflow did not correspond to any specific pedicle configuration in this cohort. Instead, they argue that identifying the final outflow route during surgery may help the surgeon recognize which vein is considered important to preserve, and prompt assessment of pedicle tension, kinking, twisting, and compression after the flap has been transferred.

The team is careful to frame the limits of the work. The findings are described as descriptive technical observations and should not be interpreted as causal or definitive criteria for pedicle selection. In particular, the two reverse-flow cases are explicitly judged insufficient to support broad conclusions regarding safety or general applicability. The retrospective design and the small, single-cohort sample further constrain how far the results can be generalized.

For surgeons performing submental island flap reconstruction, the study’s practical message is procedural rather than prescriptive: trace the venous pathway during dissection rather than assuming the first confluence represents the dominant outflow, and after transfer, check the pedicle for tension, kinking, twisting, and compression. Whether systematically identifying the final outflow route changes flap outcomes compared with conventional practice would require comparative studies, which this descriptive series was not designed to provide.

The article was published open access in BMC Surgery on 28 October 2026, with the author team led by Yawen Bai and colleagues including senior author Jianfeng Sheng. As an early-shared, peer-reviewed accepted version subject to further edits, the paper offers a documented anatomical framework for one of the more variable aspects of this reconstructive technique, while leaving questions of efficacy and broader applicability open for future research.

Subject of Research: Venous outflow patterns and pedicle management in submental island flap reconstruction

Article Title: Final dominant venous outflow patterns and intraoperative pedicle management in submental island flap reconstruction: a retrospective descriptive study of 20 patients

Article References: Bai, Y., Tang, P., Hu, J., Zeng, Z., Wang, W., & Sheng, J. (2026). Final dominant venous outflow patterns and intraoperative pedicle management in submental island flap reconstruction: a retrospective descriptive study of 20 patients. BMC Surgery. https://doi.org/10.1186/s12893-026-04291-3

Image Credits: AI Generated

DOI: 10.1186/s12893-026-04291-3

Keywords: submental island flap, venous outflow, pedicle management, reconstructive surgery, head and neck reconstruction, retrospective study, flap survival, venous congestion, external jugular system, internal jugular system, BMC Surgery, Final