Anatomical Considerations to Optimize Sensory Recovery in Breast Neurotization with Allograft

Abstract

Background:Breast numbness is a recognized problem following mastectomy and subsequent reconstruction. Contemporary literature acknowledges the positive role of breast neurotization, but it is characterized by a variety of technical approaches and substantial heterogeneity with respect to the degree of recovered sensibility that remains suboptimal in comparison with other sensory nerve reconstructions. This study’s purpose was to provide an anatomical basis for observed inconsistencies and therein provide a principle that can be used to develop a technical approach that will optimize sensory recovery.Methods:Anatomical dissections on 6 fresh cadavers, that is, 12 hemi-abdominal flaps and 12 hemi-chest dissections, were performed. The technical aspects of harvesting the abdominal flap with a nerve target, that is, inclusion of a sensory nerve branch only, recipient nerves in the chest, and the applications of allograft for acquired nerve gap reconstruction were investigated.Results:Abdominal flaps that include sensory-only intercostal nerve 10–12 segments and identification of recipient chest wall intercostal nerves 2–4 could be consistently performed. The dissection and extraction of the donor sensory nerve target allowed preservation of the motor rectus innervation. The acquired nerve gap was easily bridged by an interposing allograft, allowing free arch of rotation for flap inset, suitable for either single or dual neurotization.Conclusions:We provide a likely anatomical explanation for suboptimal sensory recovery after deep inferior epigastric perforator (DIEP) flap breast neurotization, as mixed intercostal autograft is prohibitive to maximal sensory recovery. Breast neurotization with allograft that bridges sensory donor intercostal nerves to sensory recipient intercostal nerves should anatomically optimize restoration of breast sensibility.

Breast sensibility in bilateral autologous breast reconstruction with unilateral sensory nerve coaptation

“…Sensory nerve coaptations were performed according to the technique introduced by Spiegel et al [9,10] The recipient nerve is the anterior cutaneous branch (ACB) of the second or third intercostal nerve (ICN), as these branches are localized in the same surgical field as the recipient vessels. The donor nerve was a sensory branch of the 10th to 12th intercostal nerve in DIEP flaps [11,12] and a branch of the lateral femoral cutaneous nerve (LFCN), and sometimes an anterior cutaneous branch of the femoral nerve (ACFN) in LTP flaps [13,14]. The main criterion for selecting the donor nerve was a localization in the vicinity of the dominant perforator, so that a tensionless coaptation could be performed.…”

Flap Neurotization in Breast Reconstruction with Nerve Allografts: 1-year Clinical Outcomes

“… 25 The second concern is related to the inability to selectively target sensory nerve fibers, as motor fibers are included by default in an attempt to obtain a long nerve segment with the flap. 21 …”

“…Furthermore, we implemented a technique that limits the dissection of the donor nerve to the sensory branch only. 4 , 21 This allows the surgeon to preserve motor innervation to the rectus abdominis muscle and facilitate coaptation to the sensory fibers only. Because the nerve segment obtained is short, the use of a material that bridges the nerve gap of ~40 mm, that is typically encountered upon flap transfer, is mandatory (Fig.…”

“… 17 – 20 To address the existing heterogeneity, a simple approach was recently proposed that utilizes nerve allografts and has all the characteristics of a desirable surgical technique, namely technical simplicity, minimal donor-site morbidity, selective coaptation to sensory nerve fibers, prevention of axonal loss, and tensionless repair. 4 , 21 …”

“…1 ). 4 , 21 Of note, the nerve allograft was routinely trimmed to permit tension-free epineural nerve coaptation, while minimizing redundancy to decrease the time to sensory recovery (Fig. 2 ).…”