Arteries and veins behind the thoracic vertebrae with special reference to the cutaneous blood supply

One thousand and thirty eight dorsal cutaneous vessels, which emerged onto the superficial fascia behind the thoracic vertebrae, were examined with regard to the point at which they perforated the fascia, their diameters, intermuscular courses and origins. Large vessels (more than 1 mm in diameter) were mainly distributed at the T1-T4 level. The intermuscular courses could be classified into three groups: a descending scapular course arising from the transverse cervical vessels (4.0%), a nerve-accompanying vertebral course (68.6%) and a deep vertebral course arising from other origins (27.4%). Vessels with a nerve-accompanying course ran through the middle sized (3-4 vertebral segments long) semispinalis muscle slips and descended over 1-2 vertebral segments. Vessels with a deep vertebral course, including the posterior external vertebral venous plexus, were located around the rotatores muscle. Vessels with a deep vertebral course as well as those following a nerve-accompanying course frequently emerged onto the fascia with a nerve since the former merged into the nerve-accompanying vessels immediately before perforating the fascia. The potential clinical applications of these results are discussed.