Variation in surface marking of superior epigastric vessels. A guide to safe laparoscopic port insertion.

This study aimed to map surface markings of the superior epigastric artery, to provide safe landmarks for the placement of trochars in laparoscopic surgery. Seventeen cadavers were dissected and surface anatomy of the superior epigastric artery was defined at two levels: the xiphoid process, and midway between the xiphoid process and umbilicus. Safe sites for insertion of ports were determined in cadavers by dissecting and locating the main trunks of the superior epigastric artery. At the level of the xiphoid process, the distance from the midline ranged from 3.9cm to 4.8cm with a mean of 4.3cm (SD +/- 0.2cm) while midway between the xiphoid process and umbilicus, the distance of the superior epigastric artery from the midline ranged from 4 to 7.5cm, with a mean of 5.7cm (SD +/- 0.7cm). In this area the artery is vulnerable to damage, hence it can be declared as a danger zone.

The clinical anatomy of the internal thoracic veins.

The branching pattern and adequacy of the internal thoracic veins (ITV) are important factors, providing useful information on the availability of vessels and their appropriateness as an option for anastomoses in plastic and reconstructive surgery. During 100 cadaveric examinations of the anterior thoracic wall it was observed that ITVs were formed by the venae commitantes of ITAs, which united to form a single vein (one for the right side and one for the left) draining into the right and left brachiocephalic veins. The tributaries of ITVs corresponded to the branches of ITA. The right internal thoracic vein bifurcated at the 2(nd) rib in 36% of the specimens, at the 3(rd) rib in 30% of the specimens, at the 4(th) rib in 10% of the specimens and in 24% of the specimens it remained a single vein. The left internal thoracic vein bifurcated at the 3(rd) rib in 52% of specimens, at the 4(th) rib in 20% of specimens and in 28% of the specimens it remained as a single vein. In addition, it was observed that in 78% of specimens ITVs were connected to each other by a venous arch. This arch displayed four distinct morphologies: transverse (n = 7), oblique (n = 16), U-shaped (n = 51) and double-arched (n = 4). All 78 arches were posterior to the xiphisternal joint and no artery accompanied them. In the remaining specimens, RITV and LITV exhibited a venous plexus formation. The distance from the sternum to ITV gradually decreased as the vessel passed caudally; the diameter of the vessel similarly decreased along the vein's caudal course. The frequent appearance of two concomitant veins on both sides of the thorax may offer the opportunity to reduce venous congestion by two vein anastomoses. More detailed knowledge of the anatomy of ITV may prove useful in planning surgical procedures in the anterior thorax in order to avoid unexpected bleeding.

Anatomic and clinical considerations of an internal mammary artery harvest.

In an effort to understand the perceived correlation of internal mammary artery harvesting and wound healing difficulties in the inferior margins of the sternotomy incision, we showed the cutaneous vascular perfusion in the sternal and xiphoid areas by India ink injection studies in cadavers. With these studies, we demonstrated an inherent paucity of nutrient supply to the inferior sternum and xiphoid area. The classic internal mammary artery harvest further compromises the blood supply to these areas. We believe that limiting the most inferior dissection of the internal mammary artery and not including the distal bifurcation leaves intact the lateral musculophrenic nutrient supply to the inferior sternum and xiphoid area and to the ipsilateral abdominal rectus muscle. These guidelines will help to prevent ischemic complications of this area and may aid in reconstruction. If the bifurcation is harvested, we believe that the removal of the avascular xiphoid cartilage at the time of the initial bypass procedure may eliminate this as a potential septic focus.