Superior Epigastric Vessels Research Articles

Closure of mediastinal wounds with deepithelialized rectus abdominis musculocutaneous flaps.

Deep and narrow mediastinal defect after sternal debridement can be effectively obliterated by deepithelialized vertical rectus abdominis musculocutaneous flaps, based on the superior epigastric vessels. This composite flap has sufficient mass to obviate the need for additional vascularized tissue and is, therefore, offered as an alternative to multiple flap procedures. It offers a superior cosmetic appearance and better chest stability than a traditional island myocutaneous flap. Eleven patients had their mediastinal wounds repaired by this method with a low complication rate and good final results.

Microvascular transfer of the rectus abdominis muscle and myocutaneous flap in rats

A rat microvascular free rectus myocutaneous flap model with a superior epigastric vessel pedicle is presented. The rectus muscle has a predictable "flow-through" axial vascular system consisting of superior and inferior epigastric vessels anastomosing under the fascial sheath, and six to seven musculocutaneous perforating branches to the skin. The superior epigastric artery and vein, averaging 0.45 mm and 0.5 mm in diameter, can be used as the vascular pedicle in muscle or myocutaneous flap transplantation. Eight muscle and 15 myocutaneous flaps were transplanted to the groin. The myocutaneous flaps averaged 3.5 cm by 1.2 cm in size; the pedicle length averaged 11 mm. The 5 day survival was 100% for muscle flaps and 67% for myocutaneous flaps. The rectus myocutaneous flap is believed to be the first true myocutaneous model in the rat.

Fuel Metabolism in a Pig Myocutaneous Island Flap Model

Unilateral denervated myocutaneous island flaps based on the superior epigastric vessels were raised in 24 pigs and the metabolic changes during the first 6 postoperative hours were monitored. Secondary to flap elevation, decreased arteriovenous (A-V) differences in oxygen, glucose, and alanine levels were observed, indicating the opening of A-V shunts and increased arterialization of the venous blood. Venous outflow increased during the first 3 hours, but the A-V differences in all metabolites were constant over the entire 6-hour observation period. Exchange of intermediary metabolites therefore increased within the first 3 hours, after which a steady state was established. The main flap fuels seemed to be fatty acids, muscle proteins, and glycogen, whereas blood-borne carbohydrates and ketone bodies played only a minor role as energy sources. Anaerobic metabolism was increased secondary to flap elevation from 2 to 6 percent as compared with preelevation values. No changes were found in concentrations of plasma catecholamines, which were constantly high. An average weight gain of 3 to 4 percent per hour was equally distributed to skin, subcutis, panniculus carnosus, and muscle. Thus the flap seemed to adapt to the new perfusion pattern within a few hours by a slightly increased anaerobic metabolism, but still with an oxidative metabolism of more than 90 percent.

Surgical Augmentation of Skin Blood Flow and Viability in a Pig Musculocutaneous Flap Model

A porcine rectus abdominis musculocutaneous (TRAM) flap model was designed and validated in nine pigs. This TRAM flap was based on the deep inferior epigastric (DIE) vessels with an 8 x 18 cm transverse skin paddle at the superior end of the rectus abdominis muscle. The model was subsequently used to test our hypothesis of surgical augmentation of flap viability by vascular territory expansion. Specifically, we observed that ligation of the superior epigastric (SE) vessels at 4, 7, 14, and 28 days (N = 6 to 8) prior to raising the TRAM flaps significantly increased (p less than 0.05) the length and area of the viable skin in the transverse skin paddles of the treatment flaps compared with the contralateral shammanipulated control flaps. This significant increase in skin viability was seen to be accompanied by a significant increase (p less than 0.05) in skin and muscle capillary blood flow in the treatment TRAM flaps compared with the controls (N = 9). The mechanism of vascular territory expansion is unclear. We postulate that hypoxia resulting from the ligation of the superior epigastric vessels prior to the flap surgery may play a role in the triggering of the deep inferior epigastric artery to take over some of the territory previously perfused by the superior epigastric artery. This would then increase the skin and muscle capillary blood flow in the transverse paddle when the TRAM flap was raised on the deep inferior epigastric vascular pedicle.

Refinements in Vaginal Reconstruction Using Rectus Abdominis Flaps

An improved method for vaginal reconstruction after pelvic exenteration or abdominal perineal resection is provided by the distally based rectus abdominis flap. This extended flap carries a skin paddle from the upper abdomen on the rectus abdominis muscle and deep inferior epigastric vascular pedicle. The skin paddle is inversely tubed to form a vaginal pouch and delivered transpelvically to the perineum. In addition to providing a vaginal reconstruction for sexual function, this reconstruction lessens pelvic wound complications in the exenteration patient by filling endopelvic dead space and revascularizing these frequently irradiated wounds. This method provides a neovagina with a single flap and does not involve additional donor sites in the thighs. Transpelvic passage from above not only fills endopelvic dead space better than thigh flaps, but also it allows retention of a vaginal cuff in supralevator resections. Another significant advantage of this reconstruction is its great reliability with minimal incidence of paddle loss. This flap design illustrates a type of flap refinement in which specific flaps can carry tissue from adjacent vascular territories because of anastomotic vessels between the two vascular territories, such as the vascular watershed between the deep inferior epigastric and superior epigastric vessels in this case.

TRAM Flap Safety Optimized with Intraoperative Doppler

Anatomic studies have clearly documented the variable position of the deep superior epigastric vessels in the rectus abdominis muscle. In our opinion, only that part of the rectus abdominis muscle containing the vascular pedicle should be transposed with the TRAM flap. The Doppler probe provides a simple method of identifying the dominant intramuscular vascular axis. It consistently alerts the surgeon to any unusual position of a vessel at the costal margin or within the rectus abdominis muscle. This knowledge enables a conservative yet safe dissection of the vascular pedicle, rectus abdominis muscle, and its sheath. This in turn will enable a competent abdominal closure. The Doppler technique is safe, simple, quick, noninvasive, familiar to most surgeons, and applicable to all patients.

Microsurgical Transfer of the Rectus Abdominis Muscle Using the Superior Epigastric Vessels

A microsurgical transplant of the rectus abdominis muscle based on its superior pedicle is described. This procedure represents a salvage maneuver used in a patient in whom the inferior pedicle was found to have been previously injured. Vessels of adequate caliber and a pedicle of sufficient length were found by dissecting the superior epigastric pedicle to the level of the costal margin. In cases in which rectus flap harvest is complicated by a damaged deep inferior epigastric pedicle, we recommend exploration of the superior pedicle before abandoning the flap.

Vertical rectus abdominis musculocutaneous flap for chest wall reconstruction after irradiation.

We have used a contralateral vertical rectus abdominis musculocutaneous flap based upon the superior epigastric vessels in six patients to provide coverage after resection of locally recurrent breast carcinoma in irradiated tissues. Primary healing of defects as large as 16 cm X 35 cm has been obtained using this technique. Although there is no evidence to suggest that such a procedure significantly lengthens survival, it was clearly beneficial to the quality of life in these patients. Our results suggest that older patients with relatively indolent disease receive the greatest benefit from this procedure.

Reconstructing chest walls with vertical abdominal fasciocutaneous flaps.

Our experience with the vertical fasciocutaneous flap in the reconstruction of chest wall defects is described. The vascular supply of this vertical abdominal fasciocutaneous flap comes from perforating vessels stemming from superior epigastric vessels. The flap can be elevated in the same way as a standard fasciocutaneous or vascular island flap with a small part of the rectus muscle and superior epigastric vessels attached. This type of flap was used in 16 patients with major anterior chest wall excisional defects. The average size of the flap was approximately 10 by 33 cm. Superficial necrosis was observed in 2 patients and distal 2 cm total skin loss was observed in one patient. All other flaps survived completely.