Pectoral-branch entry-point anatomy and a standardised skeletonisation workflow for the pectoralis major island flap: an anatomical description and observational clinical analysis in adult chinese males.

purposeTo define the most distal entry point (MDEP) of the pectoral branch in adult Chinese males, integrate it into a standardised Landmark-Axis-Plane (LAP) skeletonisation workflow for the pectoralis major island flap, and describe its clinical performance under IDEAL Stage 2a.

methodsThe anatomical phase measured the MDEP in 20 formalin-fixed adult Chinese male cadavers (40 hemithoraces). The clinical phase analysed 194 males (skeletonised, n = 74; conventional, n = 120) treated contemporaneously by two surgical teams at a single centre using a target trial emulation framework with propensity-score overlap weighting and logistic regression with robust sandwich variance estimation. The primary endpoint was 30-day Clavien-Dindo grade ≥ III complications. The technique and team were strictly collinear; all estimates are noncausal.

resultsThe MDEP lay 6.2-6.5 cm below the midclavicular point, predominantly at the third rib or third intercostal space. Severe complications occurred in 5 of 74 (6.8%) skeletonised patients versus 27 of 120 (22.5%) conventional patients (weighted OR 0.27, 95% CI 0.10-0.78, P = 0.016); flap necrosis was also lower (OR 0.12, 95% CI 0.03-0.58). E-value analysis indicated that the primary association is vulnerable to moderate unmeasured confounding. QuickDASH data are descriptive only (62.8% of non-responders had died).

conclusionThe MDEP provides a reproducible bony-landmark reference for pedicle skeletonisation in adult Chinese males. The LAP workflow was associated with fewer severe complications, but strict technique-team collinearity and sensitivity to unmeasured confounding preclude a causal interpretation. Multicentre IDEAL Stage 2b validation is required.