Sensory recovery and the role of innervated flaps in autologous breast reconstruction-a narrative review

Background and Objective: Continuing (micro)surgical developments result in satisfactory aesthetic outcomes after autologous breast reconstruction. However, sensation recovers poorly and remains a source of dissatisfaction and potential harm. Sensory nerve coaptation is a promising technique to improve sensation in the reconstructed breast. Methods: In this literature review an overview of current knowledge about sensory recovery in autologous breast reconstruction and the role of innervated flaps is presented. A thorough PubMed search was conducted, using the terms "autologous breast reconstruction", "innervated" and "sensation". Key Content and Findings: The breast skin is predominantly innervated by the second until sixth intercostal nerve. Some nerves can occasionally be spared during mastectomy, especially during nipple-sparing mastectomy, but transection of sensory nerves is inevitable and leads to impaired sensation. Besides unpleasant, this is unanticipated by patients and negatively influences quality of life. Coaptation between the third anterior intercostal nerve and a sensory nerve from the donor site improves sensory recovery. The donor site and nerve vary, depending on the flap type chosen. The sensory nerves from the commonly used abdominal DIEP flap originate from the 7th until 12th thoracic spinal nerves. Non-abdominal flaps, including the back, buttocks, or thigh area, can also be accompanied with a sensory nerve. Nerve coaptation can be performed directly, or by using grafts or conduits to obtain tensionless repair if necessary. It can be utilized in both immediate as well as delayed autologous breast reconstruction. No adverse outcomes of nerve coaptation have been described. And, most importantly: improved sensory recovery improves patient satisfaction and quality of life. Conclusions: Restoring sensation is, besides restoring aesthetic appearance, an important goal in breast reconstruction. Current evidence unambiguously demonstrates superiority of innervated flaps compared to non-innervated flaps. Sensory recovery initiates earlier and it approaches normal sensation more closely in innervated flaps, without associated risks or extensive increase in operating time. This improves patient satisfaction and quality of life. It is, therefore, a valuable addition to autologous breast reconstruction. These findings encourage implementation of sensory nerve coaptation in standard clinical care.