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

Abstract

Background Autologous breast reconstruction (ABR) has grown in popularity due to improved aesthetic and long-term patient reported outcomes, but data regarding sensory reinnervation of autologous flaps remain limited. Traditionally, the lateral cutaneous branch of the fourth intercostal nerve has been used for flap neurotization, but the use of the anterior cutaneous branch of the intercostal nerves (ACB) offer a more optimal location to the microsurgical field when using internal mammary vessels for the microanastomosis. This study aimed to evaluate the optimum ACB recipient site level for sensory nerve coaptation in ABR. Methods Twelve hemi-chests were dissected from six fresh cadaveric females. Costal cartilages were removed and the anterior cutaneous intercostal nerve (ACB) and the lateral (subcutaneous) division of the anterior cutaneous branch (LACB) of the intercostal nerve were exposed. Anatomical measurements were recorded, and nerve samples were evaluated histologically with carbonic anhydrase staining to differentiate sensory fascicles. Assessment of fascicular diameter, axonal counts, and fascicular area were compared. Results A total of 75 nerve specimens were assessed. The ACB was identified at all levels (100%) and the subcutaneous LACB was noted consistently in the second to fourth rib space (96% cadavers), with a median length of 43, 37.5, and 37 mm, respectively. Across all rib spaces, the fascicular and axonal counts were comparable between the LACB and ACB. Nerves in the second intercostal space had a significantly larger mean fascicular area mean (112,816 ± 157,120 µm2) compared with that in the fourth (mean 26,474 ± 38,626 µm2), p = 0.03. Axonal count of sensory fascicles was the highest in the second intercostal nerves (p < 0.05). Conclusion This study provides anatomical and histological basis to determine the optimum recipient site choice for sensory coaptation in microsurgical breast reconstruction. This would aid in operative decision-making regarding the ideal recipient anterior cutaneous intercostal nerve branches for recipient site coaptation in ABR.

Learning Sensory Nerve Coaptation in Free Flap Breast Reconstruction

“…31,20 Cutaneous nerves encountered during flap dissection may be 9 mistaken for vascular perforators 21 , and preexisting abdominal scars can reduce their discernibility. But with few exceptions of unfavorable or altered anatomy, nerves should in fact be present and detectable: previous studies located the anterior cutaneous branches of all upper six intercostal nerves in 12/12 female cadaveric hemi-chests 32 , abdominal donor nerves in 100/100 DIEP flaps 33 , and one or two branches of the lateral femoral cutaneous nerve during 10/10 cadaveric LTP flap dissections. 34 Our data cannot reveal the mechanisms behind the larger than expected number of unidentified nerves in our cohort (i.e., at least 14 recipient site nerves and 22 donor site nerves; figure 3).…”

“…Insufficient recipient nerve 10 length was recorded only three times in our cohort; a recent cadaveric study advises that by dissecting the lateral subcutaneous division of anterior cutaneous branches, recipient nerve lengths of about 4 cm can reliably be obtained. 32 At the coaptation stage, tensionless repair is crucial, for even minimal tension between donor and recipient nerve can impair functional recovery. 39 Our cohort included 10 cases where a gap prohibited direct coaptation, one of which was managed with an autograft from the abdomen.…”

Anatomical View of Thoracodorsal Artery Variants Using Computed Tomography Angiography

“…[20][21][22][23][24][25] Of these, the LD flap has been used most often in breast reconstruction. 26 With consistent advances in the field of breast reconstruction in the recent years, the types of reconstruction methods have also become more diverse. 27,28 While prosthetic reconstruction still accounts for a significant portion of all reconstructive surgeries, reconstructive methods using autologous tissues have become more and more popular, resulting in studies on various donor sites.…”

Histological Compatibility in Distal Neurotizations: A Systematic Review

“…The counting methods involve manual histomorphometric procedures 1 using photographs and assisted by free computer programs such as ImageJ or Fiji 8 9 or semiautomated software such as Bioquant Osteo, 2 3 10 in addition to electron transmission microscopy data for calculations of areas and sheath thicknesses with greater accuracy. 11 Results are subjected to statistical analysis using analysis of variance (ANOVA) or the Shapiro–Wilk test in commercial programs.…”