A Safe and Effective Technique for Harvesting the Occipital Artery for Posterior Fossa Bypass Surgery: A Cadaveric Study

The occipital artery (OA) is an important donor artery for posterior fossa revascularization. Harvesting the OA is believed to be difficult and time consuming due to its 3-dimensional course through different suboccipital tissue layers. We propose a safe and effective means of dissecting the OA.The course of the OA was explored in 5 cadaveric heads (10 sides). The OA was divided into 3 segments based on the vertical muscle layer it ran through; subcutaneous, transitional, and intramuscular. Three different approaches were attempted, and their respective advantages and disadvantages were assessed.The subcutaneous segment of the OA was found to run above the galea without traversing any vertical layers, and was thus easily dissected down to the superior nuchal line (SNL). The segment between the SNL and the digastric groove, traditionally the suboccipital segment, was divided into transitional and intramuscular segments. After detaching and retracting the suboccipital muscles, the OA was found to run in a single vertical layer of connective tissue. Dissection of the transitional segment was more involved as it ran between the SNL and the superior edge of the splenius capitis muscle, and vertically through the galea aponeurotica and the tendon of the sternocleidomastoid muscle.This segmentation provided a safe and effective procedure for harvesting the OA, in which dissection of the transitional segment is a critical step. Although the course of the OA is complex, precise anatomical knowledge of the suboccipital muscles and a stepwise dissection make harvesting the OA relatively simple.