Pork Belly: A Simulation Training Model for Intramuscular Perforator Dissection

Abstract

Background: Free tissue transfer has evolved from muscle flaps to fasciocutaneous flaps. Dissection of the intramuscular course of feeding vessels is technically challenging. Simulation-based microsurgery skills acquisition is moving toward nonliving training models. Living porcine model or human cadavers are currently cost-ineffective methods for the early learning curve in teaching intramuscular dissection. The aim of this study was to validate an inexpensive ex vivo porcine model simulating harvest of the deep inferior epigastric artery perforator (DIEAP) flap, specifically including perforator intramuscular dissection.

Methods: An initial needs analysis and anatomical dissections (characteristics of vascular anatomy) established the necessity and surgical design (step-by-step) of the ex vivo DIEAP flap harvesting model. A pilot study utilizing objective assessment methodology (time to complete flap raising and hand motion analysis) demonstrated the surgeons' performance. A detailed feedback questionnaire was used to assess the participants' perception of this model.

Results: Fifty-seven participants completed the initial needs analysis. Fifteen pork bellies were dissected and the vascular anatomical characteristics of the inferior epigastric vessels are presented. Eight surgeons performed the step-by-step flap design demonstrating construct validity in flap raising and intramuscular dissection. All surgeons completed the ex vivo DIEAP harvesting and they recommend this model as the first step in training for intramuscular dissection.

Conclusions: The pork belly simulation is a cheap, easy, ethically considerate, and high-fidelity simulation model for intramuscular dissection for the DIEAP free flap. This study guides future validation trials to explore if the absence of physiological blood flow affects skills acquisition in the intramuscular dissection learning curve. The pork belly could be the first step in perforators dissection before progressing to the in vivo porcine model.

Fig. 1.

Photographs of the pork belly and underlying vessels. The pork belly (A). Horizontal semiellipti- cal skin markings for the porcine semi-DIEAP flap, along with the expected course of the deep inferior epigastric pedicle (B). Flap elevation and intramuscular dissection of pedicle (C). Successful flap harvesting demonstrating the 2 perforators and the pedicle length (D).

Fig. 2.

Photographs of intramuscular dissection. Suprafascial perforators (A). Intramuscular penetration of perforators (B). Intramuscular dissection identifying the origin of the DIE pedicle (C). Multiple perforators in a row originating from the DIE pedicle (D).

Fig. 3.

Photographs of the DIE pedicle. (A) The perforator vessels (B) with a submillimeter scale. The measurement of the pedicle length (C and D). Two perforators leading to the main pedicle demonstrating 2 techniques: small muscle cuff perforator dissection and intramuscular dissection and skeletonizing of the vessel (E and F).