Microdissection study of venous drainage in the submental artery perforator flap: Constant-pressure latex perfusion in fresh neck dissection specimens with intraoperative comparison.

[BACKGROUND] The submental artery perforator flap (SMAPF) is an important option for reconstructing head and neck tumor defects. Venous injury represents one of the critical factors leading to flap compromise. This study aimed to investigate the anatomical characteristics and courses of the SMAPF venous drainage system using constant-pressure latex perfusion technique.

[METHODS] This controlled study involved 26 fresh neck dissection specimens perfused with latex at 110 mmHg, followed by microdissection and measurements. Additionally, we performed intraoperative measurements in 38 patients undergoing SMAPF reconstruction. We compared data between groups to verify perfusion technique accuracy and analyzed anatomical relationships among the venae comitantes of the submental artery (VCSA), submental vein (SMV), and venae comitantes of the facial artery (VCFA).

[RESULTS] VCSA was consistently present in all specimens and clinical cases, with single-branch configuration in 65.4% and double-branch configuration in 34.6%. Two VCSA drainage patterns were identified: complete accompanying type (46.2%), where VCSA accompanied the submental artery for an average length of 4.15 ± 0.45 cm before draining into VCFA with collateral branches draining into SMV; and partial accompanying type (53.8%), where VCSA separated from the submental artery after 2.02 ± 0.31 cm and drained directly into SMV. Intraoperative vascular measurements showed no statistical difference from specimen data (p > 0.05).

[CONCLUSION] Constant-pressure latex perfusion accurately reproduces vascular anatomy. SMV functions as the primary venous drainage pathway for SMAPF, while VCSA assists in collecting submental venous return. Operative strategies should be adapted according to the VCSA drainage pattern encountered intraoperatively. This study provides important anatomical evidence for clinical application of SMAPF.