On a Hunt for the "True" Septocutaneous Perforator: A Histology Cross-Section Study

Modern trends in reconstructive surgery involve the use of free perforator flaps to reduce the donor site morbidity. The course of perforator vessels has a great anatomic variability and demands detailed knowledge of the anatomical relationships and the variability of the course of the perforators. The numerous modifications to perforator nomenclature proposed by various authors resulted in confusion rather than simplification. In our study, we focused on the hypothesis that a septocutaneous perforator traverses from the given source vessel to the deep fascia adherent to but not to within the septum itself.

Sixty-nine septocutaneous perforators from three different limb donor sites (lateral arm flap, anterolateral thigh flap, and radial forearm free flap) were collected from the gross pathology specimens of 14 fresh cadavers. The gross picture and the cross-sections with the histological cross-sections on different levels were examined to determine the position of the vessel to the septal tissue.

Of the observed 69 septal perforators, 61 (88.5%) perforators were adherent to but not within the septum. The remaining eight (12.5%) perforators passed through the septum. All these eight perforators were found in multiple different cross-section levels (2 of 19 in lateral arm flap, 3 of 27 in anterolateral thigh flap, and 3 of 23 in radial forearm free flap).

Although septocutaneous vessels appear identical macroscopically, microscopically two types of vessels with paraseptal and intraseptal pathways are observed. The majority of these vessels are merely adherent to the septum having a paraseptal pathway, while a minority are within the septum and are "true" septocutaneous perforators. It is advisable to dissect with a piece of the septum in order to avoid damage or injury to the perforator.