The subscapular arterial tree may be used as a source of microvascular conduits to replace damaged or diseased portions of arteries. The anatomy of the subscapular tree was delineated and the arterial conduit was used successfully as a bypass conduit in five patients.

We studied the subscapular arterial tree anatomy to define its usefulness as a microarterial graft. Fifty-five preserved cadaver subscapular arterial trees were dissected. All branches measured were at least 10 mm long and 1 mm in external diameter. All vessels studied were accessible from a supine position with the arm abducted 90 degrees.

The subscapular artery had a consistent origin from the axillary artery and measured on average 4.3 mm. The circumflex scapular artery originated from the subscapular artery in 87% and directly from the axillary artery in 13%. The origin of the circumflex scapular artery was an average of 20 mm from the subscapular artery origin. The thoracodorsal artery averaged two branches to the latissimus dorsi muscle with the longest segment measuring an average of 133 mm (67-180). An average of 2.5 branches to the serratus anterior were found with the longest branch averaging 131 mm in length. The thoracodorsal nerve joined the vascular pedicle at a mean distance of 61 mm from the subscapular artery origin and passed anterior to the pedicle in 77% of cases. The results documented a high probability (0.93) of finding at least two branches of clinically useful size at pedicle lengths of over 120 mm.

The subscapular arterial tree offers a predictable and versatile donor site that would satisfy the needs of many microvascular reconstructions. The results of cadaver dissections allow estimation of the probability of finding any required number of branches at a given pedicle length.

The subscapular arterial tree has been used as a bypass conduit in five patients with arterial disease distal to the wrist. Arterial conduits have an anatomic taper with the lumen of the artery progressing from larger to smaller as blood flows from proximal to distal. This taper minimizes or eliminates size mismatch, reduces turbulence and improves patency. In distinction to venous conduits, arterial conduits are technically easier to suture and have improved patency rates. The five patients have been followed for one to six years with an average of three years. One patient with Raynaud’s had a subsequent digital sympathectomy. Five of five grafts remain patent. Five of five patients achieved symptomatic relief of rest pain. No amputations have been performed.

The subscapular arterial tree has a reliable branching pattern documented in 55 cadavers. Its successful use as a bypass conduit for vascular disease distal to the wrist was documented in five patients. In these patients, an arterial conduit is preferred to a venous conduit.

Probability of the presence of a number of branches of a given length from the origin of the subscapular tree

LENGTH OF BRANCH (mm)
BRANCHES		0-29	30-59	60-89	90-119	120-149	150+
1		1.00	1.00	1.00	1.00	.098	.047
2		0.93	0.98	0.85	0.98	0.93	0.35
3		0.56	0.76	0.45	0.8	0.64	0.13
4			0.09	0.05	0.24	0.15	0.05
5			0.02		0.05	0.04
6					0.02