A "conservative" method of thoracic wall dissection: a proposal for teaching human anatomy.

The common methods of dissection exposing the thoracic organs include crossing of the wall together with wide resection of its muscular planes. In order to preserve these structures, a little demolishing technique of the thoracic wall is proposed, entering the thoracic cavity without extensive resection of the pectoral muscles. This method is based on the fact that these muscles rise up from the wall, like a bridge connecting the costal plane with the upper limb, and that the pectoralis major shows a segmental constitution. SUPERIOR LIMIT: Resect the sternal manubrium transversely between the 1st and the 2nd rib. The incision is prolonged along the 1st intercostal space, separating the first sterno-costal segment of the pectoralis major from the second one, and involving the intercostal muscles as far as the medial margin of the pectoralis minor. This muscle must be raised up, and the transverse resection continued below its medial margin latero-medially along the 1st intercostal space, to rejoin the cut performed before. Then, the incision of the 1st intercostal space is prolonged below the lateral margin of the pectoralis minor, which must be kept raised up, medio-laterally as far as the anterior axillary line. INFERIOR LIMIT: It corresponds to the inferior border of the thoracic cage, resected from the xiphoid process to the anterior axillary line, together with the sterno-costal insertions of the diaphragm. Then, an incision of the sterno-pericardial ligaments and a median sternotomy from the xiphoid process to the transverse resection of the manubrium should be performed. LATERAL LIMIT: From the point of crossing of the anterior axillary line with the inferior limit, resect the ribs from the 10th to the 2nd one. The lateral part of the pectoralis major must be raised up, so that the costal resection may be continued below it. Then, at the lateral extremity of the superior incision, the first and the second sternocostal segment of the pectoralis major must be divaricated, to resect the 2nd and the 3rd rib. It is helpful increasing the distance between pectoralis major and thoracic wall by adducing the arm on the chest. Finally, open the two halves of the thoracic wall, like shutters of a window rotating on the hinges, formed by the non-resected intercostal muscles and by the intercostal portions of the serratus anterior, along the anterior axillary line.

The complex arrangement of an "aorto-jejunal paraduodenal" fossa, as revealed by dissection of human posterior parietal peritoneum.

Peritoneal fossae derive from normal or anomalous coalescence of the peritoneum during fetal development, or from the course of retroperitoneal vessels. Clinically, internal abdominal hernias may be housed inside these fossae. In this report from an autopsy, a singular peritoneal fossa was delimited superiorly by an arcuate serous fold, raised up by the inferior mesenteric vein, and infero-posteriorly by two (right and left) avascular folds, extending from the abdominal aorta to the jejunum. The right fold reached the duodeno-jejunal flexure, which was located on the right side of the aorta. The left fold subdivided into two, anterior and posterior, secondary folds. The anterior fold reached the superior edge of the first jejunal loop, and the posterior fold turned medially to connect with the inferior edge of the proximal limb of the same loop. This fossa consisted of three recesses: superior, Located behind the subserous vascular arch, antero-inferior and postero-inferior, separated by interposition of the left posterior secondary fold, between the jejunum and aorta. The complex arrangement of this fossa suggests that it might have originated from a coalescence arising beyond the duodeno-jejunal flexure and including the first jejunal loop, and from the subserous course of the inferior mesenteric vein. Because of displacement to the right of the flexure, processes of coalescence in a location normally occupied by the ascending duodenum might have occurred in a similar pattern for the jejunum, involving the mesoduodenum and the proximal part of the mesentery. Labyrinthine fossae like this might cause strangulation of internal abdominal hernias and hinder intraoperative maneuvers.