Anatomical study of innervated transverse rectus abdominis musculocutaneous and deep inferior epigastric perforator flaps

Abstract

The present study investigated anterior cutaneous branches of the 10th, 11th and 12th intercostal nerves. Innervated transverse rectus abdominis musculocutaneous (TRAM) flap and deep inferior epigastric perforator (DIEP) flap are often used in breast reconstruction. To innervate these flaps effectively, the appropriate anterior cutaneous branches of intercostal nerves must be selected. Dissection of 40 sides of 20 cadavers (5 male, 15 female) was performed. Nerves were classified into four groups according to vertical location from rectus abdominis (RA) entry points. Group 1 was situated from 0-19% of the umbilicus-to-pubic tubercle distance; Group 2, 20-39%; Group 3, 40-59%; and Group 4, 60-79%. Mean number of nerves per side was 1.4 in Group 1, 1.2 in Group 2, 1.1 in Group 3 and 0.2 in Group 4. The arcuate line was situated 32 +/- 9% below the umbilicus. Group 3 and 4 nerves tended to enter the RA more laterally than Group 1 nerves. Most nerves separated into 1-2 cutaneous branches while branching off several muscular branches. Several nerves in Groups 1 and 2 displayed no cutaneous branches. More muscular branches were present in Groups 1 and 2 than in Groups 3 and 4. Distance from lateral edge of the RA sheath to RA entry point was longer in Groups 1 and 2 than in Group 4. Cutaneous points, indicating entry points of a nerve into the dermis, were situated slightly more inferior than RA entry points. To innervate flaps effectively, a nerve entering the RA slightly superior to the expected sensory recovery area should be chosen. Clinically, Group 1 or 2 nerves seem to be selected in many TRAM or DIEP flap cases. If the cutaneous branch in Group 3 or 4 is easy to separate from RA, this can be included in the flap along with a main nerve, and might enable the flap to recover sensation in a wider area or reinforce the occasional lack of a sensory branch from Group 1 or 2. The present findings provide the basis for more precise dissection of TRAM and DIEP flaps, and should facilitate reliable preservation of sensation in flaps.

Refining the course of the thoracolumbar nerves: A new understanding of the innervation of the anterior abdominal wall

“…Yap et al (2002) confirmed this, naming these large trunk communications, the ''intercostal plexus'' (Yap et al, 2002). Whilst other studies have also noted this extensive communication (Sakamoto et al, 1996;Mori et al, 2007), some have failed to observe communication between any or all of the segmental nerves at all (Monkhouse and Khalique, 1986;Duchateau et al, 1988).…”

“…Yap et al (2002) described such a plexus, by stating that ''nerves are closely related to the DIEA vascular axis'' (Yap et al, 2002) and other authors have also described communications at this level (Monkhouse and Khalique, 1986;Hammond et al, 1995;Tansatit et al, 2006). In contrast, some authors did not report communications between adjacent segmental nerves at this site (Duchateau et al, 1988;Mori et al, 2007). This longitudinal plexus was confirmed histologically as containing multiple nerves (see Fig.…”

“…Davies et al in 1931 described this innervation (Davies et al, 1931), stating that L1 fibers are always distributed to rectus abdominis, and others have since also confirmed this contribution from L1 (Roberts et al, 1983;Sakamoto et al, 1996). However, many authors deny contribution from L1 in their series (Monkhouse and Khalique, 1986;Duchateau et al, 1988;Mawera et al, 1995;Yap et al, 2002;Tansatit et al, 2006;Mori et al, 2007).…”

Pedicled Deep Inferior Epigastric Perforator Flap for Total Phallic Reconstruction

“…The mixed intercostals nerves deliver sensory branches joining with the perforating vessels of deep inferior epigastric vessels and running together to the skin. 3,4 If the sensory branches of the 11th intercostal nerves were chosen to be coapted with the dorsal penile nerves, the neopenis would recover more perfectly. Any of the sensory branches of the 10th, 11th, or 12th intercostal nerve could be chosen according to the selected perforators.…”

A Cadaveric Anatomical and Histological Study of Recipient Intercostal Nerve Selection for Sensory Reinnervation in Autologous Breast Reconstruction

“…It has been reported that the use of innervated autologous flaps in breast reconstruction can provide protection from flap injury and trauma, recovery of erogenous sensation, and an overall higher patient satisfaction. [2][3][4][5][6][7] Despite these advantages, breast reinnervation is not commonly performed due to concern of extended operative time and variable clinical results. Furthermore, several studies have reported spontaneous reinnervation of flaps from adjacent skin.…”