Overcoming the Axillary Nerve Blind Spot Through the Deltopectoral and Axillary Approaches: A Cadaveric Study

The aim of this study was to evaluate the feasibility of exploring the axillary nerve (AN) at the 6 o'clock position (blind spot) using the deltopectoral approach, with the interval lateral to the conjoint tendon (CJT) or combined with the axillary approach.

Four ANs were dissected combining the deltopectoral approach-medial to the CJ (A), the deltopectoral approach-lateral to the CJT (B) and the axillary approach (C) in 3 sequences: A-B-C, B-A-C, and C-B-A. After the first approach was completed, the proximal and distal margins were marked. Additional exposure with the second and third approaches and the 6 o'clock position were also marked. Then, the AN was excised and the amount of exposed nerve with the 3 approaches was measured.

The deltopectoral approach-medial to the conjoint tendon did not allow exposure of the AN at the 6 o'clock position. Six o'clock position exposure was accomplished using the lateral interval of the deltopectoral and the axillary approaches. A deltopectoral approach lateral to the CJT allowed exploration of the AN at the blind spot, but not the terminal branches. The axillary approach was able to expose the AN at the 6 o'clock position, the terminal branches, but not the nerve-muscle junction. Combining the 3 approaches exposed 81% to 94% of the total length of the AN.

The deltopectoral approach allowed visualization of the AN at the 6 o'clock position when explored lateral to the CJT. The axillary approach allowed visualization of the terminal branches of the AN and the 6 o'clock position of the glenoid.

The deltopectoral approach lateral to the conjoint tendon allows the surgeon to assess continuity of the AN at the 6-o'clock position and to perform a neurolysis. If nerve repair, nerve grafting, or nerve transfer is attempted, a combination of the 3 approaches could be used.