Importance of lateral row perforator vessels in deep inferior epigastric perforator flap harvesting

Free flaps based on perforator vessels, and in particular the deep inferior epigastric perforator (DIEP) flap, are currently being applied in abdominal reconstruction. However, one of the main disadvantages is the operative complexity. Through anatomical study and clinical experience with the DIEP flap in breast reconstruction, the intramuscular path of the perforator vessels was comparatively studied, to establish the main anatomical parameters that favor procedure planning. Thirty DIEP flaps from 15 fresh cadavers were used. The number, location, and intramuscular course of the perforator vessels were determined. In addition, an initial clinical study was performed in 31 patients using 35 DIEP flaps in breast reconstruction. The number, location, and the intramuscular course of the perforators were assessed. In the cadaver study, 191 perforator vessels were detected (6.4 vessels per flap). Thirty-four percent were located in the lateral row, and the rectilinear course was observed in 79.2 percent of these vessels. In the medial row, only 18.2 percent of the perforator vessels presented this configuration (p = 0.001). Thirty-one patients underwent DIEP flap breast reconstruction, with 26 immediate and four bilateral reconstructions. In 22 of 35 flaps (62.9 percent), two perforators were used. In 25 flaps (71.4 percent), the lateral row perforators with a rectilinear course were observed. Mean operative time was 7 hours and 37 minutes. Two total flap losses and two partial necroses were observed. The majority of the lateral row perforators presented a rectilinear intramuscular course, which was shorter than that of the medial row perforators. This anatomical characteristic favors dissection with reduced operative time and vascular lesion morbidity, resulting in an important anatomical parameter for DIEP flap harvesting.     

The vascular anatomy of the lower anterior abdominal wall: a microdissection study on the deep inferior epigastric vessels and the perforator branches

The deep inferior epigastric artery provides the main blood supply to the lower abdominal wall. Microdissection of the artery, its main branches, and the perforator vessels was undertaken in 20 cadavers. The artery was found to be associated with two veins in most of the cases (90 percent). The lateral division of the deep inferior epigastric artery and the perforator vessels it gives are more dominant (80 percent of cases) than the medial perforators (20 percent of cases). The lateral perforators were greater in number (80) and more consistent than those that arose from the medial division (28). The musculocutaneous perforators are the most important perforators supplying the anterior abdominal wall. An average of 5.4 large perforators (>0.5 mm in diameter) were dissected in each case. These perforators are mostly contained in the area lying laterally and below the umbilicus, with an average distance of 4 cm from the umbilicus. The musculocutaneous perforators may have a direct or indirect course. Larger perforators (>0.5 mm in diameter) were found to have a direct course through the subcutaneous fat to the skin. Smaller perforators do not reach the skin but terminate at the level of the deep fat layer by branching after piercing the rectus sheath. The direct perforator vessels with their associated veins (microdissection) keep a consistent diameter before dividing at the subdermal level and end by contributing to the subdermal plexus.     

The vascular territories of the superior epigastric and the deep inferior epigastric systems

The vascular territories of the superior and the deep inferior epigastric arteries were investigated by dye injection, dissection, and barium radiographic studies. By these means it was established that the deep inferior epigastric artery was more significant than the superior epigastric artery in supplying the skin of the anterior abdominal wall. Segmental branches of the deep epigastric system pass upward and outward into the neurovascular plane of the lateral abdominal wall, where they anastomose with the terminal branches of the lower six intercostal arteries and the ascending branch of the deep circumflex iliac artery. The anastomoses consist of multiple narrow "choke" vessels. Similar connections are seen between the superior and the deep inferior epigastric arteries within the rectus abdominis muscle well above the level of the umbilicus. Many perforating arteries emerge through the anterior rectus sheath, but the highest concentration of major perforators is in the paraumbilical area. These vessels are terminal branches of the deep inferior epigastric artery. They feed into a subcutaneous vascular network that radiates from the umbilicus like the spokes of a wheel. Once again, choke connections exist with adjacent territories: inferiorly with the superficial inferior epigastric artery, inferolaterally with the superficial circumflex iliac artery, and superiorly with the superficial superior epigastric artery. The dominant connections, however, are superolaterally with the lateral cutaneous branches of the intercostal arteries. For breast reconstruction, it would appear that prior ligation of the deep inferior epigastric artery would be of advantage when elevating the lower abdominal skin on a superiorly based rectus abdominis musculocutaneous flap. The vascularity of this flap would be further increased by positioning some part of the skin paddle over the dense pack of large paraumbilical perforators. Based on these anatomic studies, the relative merits of the superior and deep inferior epigastric arteries with respect to local and distant tissue transfer using various elements of the abdominal wall are discussed in detail.     

Clinical applications of the extended deep inferior epigastric flap

The extended deep inferior epigastric flap, described by Taylor et al. in 1983, consists of the lower portion of the rectus abdominis muscle and a superolateral fasciocutaneous extension based on the periumbilical perforators. We have used this flap four times to close large defects of the abdomen, groin, and thigh and twice as a free flap to close wounds of the head and leg. There were no ischemic complications, and there was uncomplicated wound healing in the recipient and in the donor wounds. We recommend this highly versatile and reliable flap as one to be considered early in planning the closure of large wounds.     

Intimal thickenings in the inferior epigastric artery and coronary bypass

OBJECTIVE: To investigate the relationship between the inferior epigastric artery and the development of pathological intimal thickenings. MATERIAL AND METHODS: The inferior epigastric artery structure was studied with conventional histology techniques, histochemistry, immunohistochemistry and morphometry. RESULTS: The inferior epigastric artery develops 2 types of intimal thickenings: physiological and pathological. In our study, the pathological or atherosclerotic thickenings in this artery were not very common: they were present in 28% of the analysed cases. Vessel flow was not affected as shown by the intimal thickness index (I.T.I.) and the lumen reduction index (L.R.I.). The alpha-actin technique confirmed the role of the smooth muscle cells in the genesis of the thickening. Furthermore, histochemistry demonstrated that the extracellular matrix is rich in highly sulphated acid mucopolysaccharides. CONCLUSION: The inferior epigastric artery seems to be a good candidate for grafting in coronary revascularization because of the low susceptibility to thickening of its intima and the minimal repercussion on its blood flow.     

Radiation effects on breast reconstruction with the deep inferior epigastric perforator flap

Immediate breast reconstruction has important advantages over delayed reconstruction, including a shorter operative time and decreased psychological distress for the patient. However, the authors' experiences with the deep inferior epigastric perforator flap demonstrate variable aesthetic outcomes among patients who undergo radiation postoperatively. To establish an association between radiation and poor postoperative results, a matched-pairs analysis was conducted. Thirty irradiated patients were paired with 30 nonirradiated patients, according to age and body mass index. For each group, the incidence of fat necrosis, fibrosis/shrinkage, and flap contracture was recorded. In addition, an aesthetic evaluation was conducted to compare before-and-after images of 10 irradiated patients with those of 10 nonirradiated patients from similar time periods. The images were randomized and blindly evaluated by a panel of eight judges. A five-point scale was used to evaluate symmetry, aesthetic proportion, and the appearance of the superior pole. Statistical analysis demonstrated a significant difference in the score changes for irradiated and nonirradiated patients, according to all three criteria. Nonirradiated patient scores increased by one-half point, and irradiated patient scores decreased by one-half point. In addition, the incidences of fat necrosis, fibrosis, and flap contracture were all significantly higher among the irradiated group. These results suggest that when possible, reconstruction should be delayed until after radiation therapy is complete. Persons who smoke or are obese may be at particular risk for complications following radiation therapy.