Anatomical Study of SCIAP (Superficial Circumflex Iliac Artery Perforator) and SIEA (Superificial Inferior Epigastric Artery) Flaps for Flap Harvest Training in the Swine Model.

[INTRODUCTION] Microsurgery training necessitates a progression from basic to advanced techniques, utilizing artificial models, cadaver labs, and live animals. Living animals are of paramount importance to simulate flap harvest and have a real-life experience with immediate feedback on the quality of dissection. Pigs are effective models for flap harvest training since the anatomy is comparable to that of humans, and so are many flap models. This study introduces the superficial circumflex iliac artery perforator (SCIAP) and superficial inferior epigastric artery (SIEA) flaps in pigs.

[MATERIALS AND METHODS] Dissections were performed on 10 female swine (Sus scrofa domesticus, ssp. Large white; 35-40 kg) during a perforator flaps dissection course organized by the Italian Society for Microsurgery (SIM: Società Italiana di Microchirurgia). Adhering to ethical guidelines and the 3R principles, animals were anesthetized and euthanized humanely post-procedure. Twenty SCIAP and 20 SIEA flaps were harvested: vessel anatomy and presence, anatomical landmarks, pedicle caliber and length, flap viability, and design were evaluated.

[RESULTS] The SCIAP and SIEA were present on both sides in all animals (100%). The SCIAP was constantly found between 4 and 6 cm medially to the ASIS. After giving off the SCIAP, the SIEA always arose from the SCIAP continuing medially toward the abdomen, giving off small branches (4-8) to the skin. Mean pedicle length (distance between origin from the femoral vessel end entry into the flap) was 8.035 cm for the SCIAP artery (SD ± 0.09), 8.04 cm for the SCIAP vein (SD ± 0.11), 14.98 cm for the SIEA artery (SD ± 0.10), and 14.98 cm for the SIEA vein (SD ± 0.24). Mean arterial caliber was 2.201 mm for the SCIAP (SD ± 0.24) and 1.89 mm for the SIEA (SD ± 0.217). Mean vein caliber was 2.23 mm for the SCIAP (SD ± 0.18) and 2.14 mm for the SIEA (SD ± 0.162). In total, 20 SCIAP and 20 SIEA flaps were harvested. Two of them (one SCIAP and one SIEA) showed signs of hypoperfusion with a 95% viability rate. The SCIAP flap was located 4-6 cm medial to the ASIS, while the SIEA was found along a line connecting the ASIS and the midpoint of a line connecting the second and third nipples.

[CONCLUSION] The SCIAP and SIEA flaps in pigs offer a valuable addition to microsurgical training, replicating important human flaps. Their consistent anatomy and the ability to harvest them in different positions enhance their utility in training programs. These findings support the integration of these flaps into pig model courses, optimizing animal use and training efficacy in line with the 3R principles.