Simultaneous reconstruction of smiling eye using V-shaped long latissimus dorsi muscle transfer in patients with flaccid facial paralysis

Various neurovascular free muscle transfers for smile reconstruction in patients with facial paralysis have been reported. However, these methods focused on peri-oral smiling rather than eye smiling. Although the lower eyelid does not contribute significantly to eyelid closure, dynamic reanimation of the upward movement of the lower eyelid, with bulging of the malar region, during smiling is important in smile reconstruction. Herein, we present a novel procedure for smiling eye and peri-oral smiling. The V-shaped latissimus dorsi muscle flap containing the descending branch (DB) of the thoracodorsal nerve (TDN) was employed. Muscle-A (15-17 cm), which is located along the main trunk of the DB, is much longer than muscle-B (10-12 cm), which is along the branch of DB. A distal stump of the TDN involved in muscle-B was prepared. The true trunk and distal stump of the TDN were sutured to the contralateral facial and ipsilateral masseteric nerves, respectively. The central region of muscle-A was positioned at the lateral part of the lower eyelid; the distal end of long muscle-A was affixed to the temporal region, which enabled peri-ocular movements and narrowing of the palpebral fissures alongside peri-oral smiling when muscle-A contracted. Nine patients with complete flaccid facial paralysis were treated. All patients attained muscle contraction induced by the ipsilateral masseteric and contralateral facial nerves. The smiling eye atmosphere was observed in seven of nine patients. This procedure simultaneously improves paralytic ectropion at rest and aids eyelid closure and enables early voluntary smile and a later spontaneous smile.