Clinical results of TRAM flap delay by selective embolization of the deep inferior epigastric arteries

Preoperative selective embolization of the deep inferior epigastric arteries constitutes a new technique in TRAM flap delay. Whereas surgical ligation of these vessels has proved to be an effective delay procedure in experimental and clinical settings, it requires an additional operative step under general anesthesia. Despite the introduction of the free TRAM leading to improved flap perfusion, this microsurgical technique is not always available because of the requirements of specialized equipment and staff, longer operating hours, and subsequently higher expenses. The search for a minimally invasive, easy, and inexpensive technique to improve perfusion of the pedicled TRAM flap led us to selective embolization of the deep inferior epigastric arteries by an angiographic procedure. After 4 years of experience with this technique, we now present the first clinical results. Breast reconstruction by a delayed pedicled TRAM flap was performed in 40 patients with a mean age of 48.4 years (range, 31 to 66 years). The mean interval between embolization and surgery was 3.6 months. Postoperative data concerning flap survival and complications were available for all patients. Embolization of the deep inferior epigastric arteries was performed bilaterally in 35 patients (87.5 percent) and unilaterally in 5 patients (12.5 percent). Radiotherapy had been applied in 21 patients (52.5 percent) before surgery. Postoperative flap complications consisted of partial necrosis in three (7.5 percent), fat necrosis in one (2.5 percent), impaired wound healing in five (12.5 percent), and postoperative bleeding in two patients (5 percent). Abdominal wound healing complications occurred in six patients (15 percent), abdominal wall weakness in eight (20 percent), and hernia formation in four (10 percent). Surgical corrections were performed at the breast (TRAM flap) in 22 patients (55 percent) and at the abdomen (donor site) in 9 (22.5 percent). Preoperative selective embolization of the deep inferior epigastric arteries constitutes an alternative delay procedure for the pedicled TRAM flap. It is superior to the conventional procedure without delay, offers several advantages compared with surgical ligation of these vessels, and represents an alternative to the free TRAM flap in selected cases.     

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.     

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.     

Perforator topography of the deep inferior epigastric perforator flap in 100 cases of breast reconstruction

The anatomic topography of the perforators within the rectus muscle and the anterior fascia largely determines the time needed to harvest the perforator free flap and the difficulty of the procedure. In 100 consecutive cases, the topographic patterns of the perforators were investigated. In 65 percent, a short intramuscular course was seen. In 16 percent, a perforator at the tendinous intersection was encountered. In 9 percent, the largest perforator was found to have a long intramuscular course. In 5 percent, a subfascial course was found, and in another 5 percent, a paramedian course was found. In 74 percent of flaps, just one perforator was used, whereas two perforators were dissected in 20 percent. Only in 6 percent of flaps were three perforators used. A long intramuscular course (>4 cm) lengthens the dissection substantially, especially when the intramuscular course is in a step-wise pattern. The subfascial course requires precarious attention at the early stage of the perforator dissection when splitting the fascia. The perforators at the tendinous intersections are the most accessible and require a short but intense dissection in the fibrotic tissue of intersection. A paramedian perforator, medial to the rectus muscle, is a septocutaneous rather than a musculocutaneous perforator. The straightforward dissection almost extends up to the midline. Therefore, dissection always is performed at one side and, if no good perforators are present, continued at the intact contralateral side. The size of these perforators and their location in the flap determine the choice. One perforator with significant flow can perfuse the whole flap. If in doubt, two perforators can be harvested, especially if they show a linear anatomy so that muscle fibers can be split. The only interference with the muscle exists in splitting the muscle fibers. A perforator that lies in the middle of the flap is preferable. For a large flap, a perforator of the medial row provides better perfusion to zone 4 than one of the lateral row because of the extra choke vessel for the lateral row perforators. The clinical appearance of the perforators is the key element in the dissection of the perforator flap. Perforator topography determines the overall length and difficulty of the procedure.     

Electromyographic assessment of rectus abdominis muscle function after deep inferior epigastric perforator flap surgery

SUMMARY: The authors evaluated rectus abdominis muscle function after deep inferior epigastric perforator (DIEP) flap elevation. Fifteen consecutive patients who were operated on for breast reconstruction with a free DIEP flap were included in the study. A turn-amplitude electromyographic analysis was used. For each patient, the muscle activity was recorded in the portion of the muscle that was split for the epigastric perforator vessel dissection, and also in the similar portion of the contralateral nondissected muscle. A first electromyographic examination was carried out soon after surgery (mean follow-up, 9 weeks), and a second electromyographic examination was carried out at a later date (mean follow-up, 15 months). The mean activity of the dissected muscles was 50 percent of the activity of the nondissected muscles at the first electromyographic examination and 70 percent at the second electromyographic examination. The authors suggest that the DIEP flap procedure induces a partial denervation of the rectus abdominis muscle in the area of dissection and that reinnervation occurs over time because the entire width of the muscle and sufficient segmental motor innervation are preserved.     

The deep inferior epigastric perforator flap for breast reconstruction in overweight and obese patients

The authors retrospectively reviewed the computerized records of 71 women undergoing 80 deep inferior epigastric perforator (DIEP) flap reconstructions after mastectomy over a 1-year period. There were 33 normal, 26 overweight, and 12 obese patients. No statistically significant difference in flap complications was found between groups. Overall fat necrosis rates were 11.4 percent for the normal-weight patients, 6.7 percent for the overweight patients, and 6.7 percent for the obese patients. Postoperative hospital time was similar for all groups. The occurrence of abdominal wall fascial laxity was uncommon and similar for all groups. Large (>900 g) reconstructions were completed without prohibitive complications in the reconstruction flap. The DIEP flap represents a significant advance in autologous breast tissue reconstruction. Although concerns regarding fat necrosis rates in DIEP flaps have been voiced, the authors did not see an increasing rate of fat necrosis in their overweight and obese patients, and their overall rate of fat necrosis is comparable to rates reported for free transverse rectus abdominis myocutaneous (TRAM) flaps. Also, increasing body mass index did not seem to affect the rate of delayed complications of the abdominal wall, such as abdominal wall hernia or bulging. Although it was not statistically significant, the authors did observe a trend toward increased wound-healing complications with increasing body mass index. Their data also support the claim that the complete sparing of the rectus abdominis muscles afforded by the DIEP flap avoids abdominal wall fascial bulging or defects often seen in obese TRAM reconstruction patients. Because flap and wound complication rates are similar or superior to those of other autologous tissue reconstruction techniques and the occurrence of abdominal wall defects is all but eliminated, the DIEP flap likely represents the preferred autologous breast reconstruction technique for overweight and obese patients.     

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.     

Comparison of the deep inferior epigastric perforator flap and free transverse rectus abdominis myocutaneous flap in postmastectomy reconstruction: a cost-effectiveness analysis

This study compared the deep inferior epigastric perforator (DIEP) flap and the free transverse rectus abdominis myocutaneous (TRAM) flap in postmastectomy reconstruction using a cost-effectiveness analysis. A decision analytic model was used. Medical costs associated with the two techniques were estimated from the Ontario Ministry of Health Schedule of Benefits for 2002. Hospital costs were obtained from St. Joseph's Healthcare, a university teaching hospital in Hamilton, Ontario, Canada. The utilities of clinically important health states related to breast reconstruction were obtained from 32 "experts" across Canada and converted into quality-adjusted life years. The probabilities of these various clinically important health states being associated with the DIEP and free TRAM flaps were obtained after a thorough review of the literature. The DIEP flap was more costly than the free TRAM flap ($7026.47 versus $6508.29), but it provided more quality-adjusted life years than the free TRAM flap (28.88 years versus 28.53 years). The baseline incremental cost-utility ratio was $1464.30 per quality-adjusted life year, favoring adoption of the DIEP flap. Sensitivity analyses were performed by assuming that the probabilities of occurrence of hernia, abdominal bulging, total flap loss, operating room time, and hospital stay were identical with the DIEP and free TRAM techniques. By assuming that the probability of postoperative hernia for the DIEP flap increased from 0.008 to 0.054 (same as for TRAM flap), the incremental cost-utility ratio changed to $1435.00 per quality-adjusted life year. A sensitivity analysis was performed for the complication of hernia because the DIEP flap allegedly diminishes this complication. Increasing the probability of abdominal bulge from 0.041 to 0.103 for the DIEP flap changed the ratio to $2731.78 per quality-adjusted life year. When the probability of total flap failure was increased from 0.014 to 0.016, the ratio changed to $1384.01 per quality-adjusted life year. When the time in the operating room was assumed to be the same for both flaps, the ratio changed to $4026.57 per quality-adjusted life year. If the hospital stay was assumed to be the same for both flaps, the ratio changed to $1944.30 per quality-adjusted life year. On the basis of the baseline calculation and sensitivity analyses, the DIEP flap remained a cost-effective procedure. Thus, adoption of this new technique for postmastectomy reconstruction is warranted in the Canadian health care system.