Anatomical basis for the clinical application of the arterial supply of musculus pectoralis major

Vascularisation of pectoralis maior myocutaneous flap: anatomical study in human fetuses and cadavers

Pectoral major flap is one of most frequently used flaps in head and neck reconstruction. The wide attractiveness of this flap is based on secure vascular stalk made from pectoral branch of thoracoacromial artery. The aim of study was to analyze the variations in vascular supply of pectoral major muscle. The investigation was performed on 30 fetuses from 20 to 36 gestation week both gender. For determining vascular network the samples injected with barium sulphate were subjected to Spalteholtz technique, and on 30 fresh cadavers where and we performed injection of Metilen blue 1% in pectoral branch of thoracoacromial artery. In 87% we found one pectoral branch and in 13 % two branches for pectoral muscle were found. Before entering the muscle, pectoral branch is dividing in two terminal branches (67%). In all cases lateral part of pectoral muscle is supplied by branch of lateral thoracic artery. The average area of dyed skin was 13 x 20 cm in region between III and VI rib and from parasternal line to anterior axillar line. The average distance of most distal part of dyed skin to midclavicular point was 24 cm. The pectoral branch of thoracoactomial artery obtains main blood supply for pectoral major muscle mass and despite of anatomical variations can be defined as main pedicle for musculocutaneous flap. Dyed skin confirms that pectoral major flap has defined skin territory sufficient for reconstructions in head and neck area.

The Segmental Pectoralis Major Free Flap

BACKGROUND

The pectoralis major muscle may be suited for free transplantation of a segment of the muscle. We investigated the length and diameter of its vascular pedicle to determine its feasibility.

METHODS

The length of the pedicle, its arterial diameter, and its entry point into the muscle were determined in 17 cadaveric flaps.

RESULTS

The pedicle length up to the medial border of the pectoralis minor muscle averaged 6.6 cm. The mean external arterial diameter was 1.8 mm, and the venous diameter was consistently larger. The vascular pedicle consistently entered the muscle lateral to the midpoint of, and a mean of, 8.8 cm caudal to the clavicular line.

CONCLUSION

The vascular length and diameter are sufficient for microvascular anastomosis. Although an anatomic landmark for the cranial border of the flap could not be defined, the sternocostal part of the pectoralis major muscle may potentially be used as a segmental free flap.

The alternative supply of the pectoralis major flap based medially in cases with previous surgical use of the internal thoracic artery: an anatomical study

In the present study we analyzed the anatomical basis for the use of the pectoralis major muscle based on alternative pedicles in order to evaluate its clinical applications in cases of potential lesion of the internal thoracic artery. The patterns of blood supply depending on the internal thoracic artery, previously dissected for coronary by-pass surgery, were studied in both sides of five embalmed cadavers and five anterior thoracic walls taken from autopsies. The secondary vascular pedicles depending on the internal thoracic artery for the pectoralis major muscle were dissected and injected with physiological saline stained solution in the embalmed cadavers. Moreover, studies of intravascular injection by means of radio-opaque contrast and physiological saline stained solution were carried out in the anterior thoracic walls obtained from clinical autopsies. The results showed that complete injection of the pectoralis major muscle was achieved depending exclusively on the two proximal perforating branches of the two first intercostal spaces, which represented the vascular pedicle for medial transposition of the pectoralis major flap, in cases with previous dissection of the internal thoracic artery for coronary by-pass.

Anatomical study concerning the origin and course of the pectoral branch of the thoracoacromial trunk for the pectoralis major flap

The patterns of the feeding vessels to each muscle determine the extent of their safe transposition and the muscle's value as a pedicled flap in reconstructive surgery. This study aimed to demonstrate the point of origin and the intra- and submuscular course of the pectoral branch of the thoracoacromial trunk (TAT) for pectoralis major (PM) flap surgery. Seventy sides of the PM were dissected based on a clinical reference line that has been used for several decades. The branching point of the TAT from the axillary artery was located lateral to the midclavicular line on the right-sided specimens (100%) and medial to the midclavicular line on the left sides (86%). The branching patterns of the pectoral branch to the PM muscle from the TAT were classified into three types. In type I the pectoral branches originated directly from the TAT (55 cases, 78.6%). In type II (11 cases, 15.7%) and type III (4 cases, 5.7%) the pectoral branch divided from the medial and lateral pedicle of the TAT, respectively. The course of the pectoral branch from the TAT in the PM was categorized into three patterns according to the degree of proximity to the midclavicular line. In 49 cases (70%), the pectoral branch in the PM ran within 1 cm of the midclavicular line. The other cases ran 2 cm (20 cases, 29%) and 3 cm (1 case, 1%) from the midclavicular line, respectively. These results provide topographic data of the pectoral branch based on anatomical landmarks, and will be useful in surgical planning as well as the procedure for PM flap surgery.

Extraanatomical revascularization of the artery of Adamkiewicz: anatomical study

Spinal cord ischemia is a major cause of complications after operative and endovascular treatment of descending thoracic or thoracoabdominal aortic aneurysms. Prior revascularization of the intercostal artery (IA) giving rise to the artery of Adamkiewicz (AA) using an artery of the thoracic wall would preserve circulation in the AA and allow obstruction of the IA at its origin. The purpose of this study was to determine the feasibility of revascularization of the IA giving rise to the AA using three thoracic wall arteries, i.e., lateral thoracic artery, thoracodorsal artery, and descending scapular artery. A total of 16 specimens from 8 cadavers (6 men and 2 women) were prepared. The length and diameter of the thoracic wall arteries were measured to ascertain the feasibility of revascularization of the IA giving rise to the AA. In addition, 12 preoperative spinal cord arteriograms were studied. We found that revascularization of the IA giving rise to the AA using thoracic wall arteries is feasible. This technique could be used to prevent spinal cord complications after treatment of descending thoracic or thoracoabdominal aortic aneurysms.