Permanent denervation of latissimus dorsi muscle: a useful technique in immediate breast reconstruction

ABSTRACT Background: Division of the thoracodorsal nerve during Latissimus Dorsi (LD) breast reconstruction is commonly indicated to reduce incidence of postoperative twitching or contracture. A high incidence of postoperative LD muscle contraction was noticed at a retrospective analysis of our material of LD breast reconstructions treated by simple nerve resection. Anatomical studies with a prospective clinical trial are set up to outline a successful denervation procedure. Methods: An anatomical study evaluating thoracodorsal nerve course on 15 fresh cadavers was performed. Later on 40 consecutive immediate LD breast reconstructions were divided random in equal groups with different muscle denervation: (group A) by means of distal nerve resection through a dorsal approach, and (group B) by proximal nerve resection and clipping through an axillary approach. Presence of postoperative contracture was evaluated at 2 years follow-up, by evidence of muscle strand in the axilla during contraction and confirmed instrumentally. Statistical analysis of data was performed by Fisher’s exact test. Results: Cadaver dissections showed a distal branching of thoracodorsal nerve, before entering the muscle, in 20% of cases. Incidence of postoperative LD muscle contracture was (7/20) 35% in group A and 0% in Group B at 2 years follow-up. Statistical analyses confirmed, a significant lower rate of contracture in the proximal denervation group (p=0,004). Conclusion: Type A Thoracodorsal nerve resection may be responsible for inadequate LD muscle denervation, due to incomplete nerve section or early muscle reinnervation. Type B proximal nerve resection and clipping allows for effective muscle denervation reducing incidence of post-operative contracture (p= 0.004).