Extended Free Deep Inferior Epigastric Flap for Closure of a Thoracolumbar Defect

Midline defects of the back caused by surgical infection, pressure sore, radiation injury, and trauma still represent a reconstructive challenge. In particular, defects caused by repeated debridements after spinal instrumentation and postoperative wound infection should be closed with well-perfused soft tissue to prevent a relapse of infection and to guarantee stable coverage of the internal fixation. In this context, we present the case of a 47-year-old woman with osteogenesis imperfecta. The reduced synthesis of collagen type I, which constitutes 90% of the bony matrix, had effected a severe scoliosis and kyphosis necessitating posterior thoracolumbar instrumented fusion of the T2-L1 segment (Fig. [1]). Six weeks after the operation, the patient had developed an infected pressure ulcer overlying a metal rod. For 18 months before transfer to our department, multiple debridements and local flaps (including a latissimus muscle turnover flap and a gluteal rotation flap from the right side and two local fasciocutaneous flaps) had been performed unsuccessfully resulting in a 20 cm × 10 cm defect with deep dead space and exposed bone and metal. Because of incomplete bony fusion, the internal metal stabilization could not be removed.

Figure 1 X-ray of the spine depicting the internal instrumentation.

The previous efforts to close the defect had minimized the remaining reconstructive options to free tissue transfer. An extended free deep inferior epigastric flap, its anterior sheath, and paraumbilical perforators were harvested. The flap measurements were 42 cm × 12 cm (Fig. [2]). The inferior epigastric artery was anastomosed to the thoracodorsal artery, and the muscular portion was brought into the deep dead space to coat the exposed bone and metal. Two years after the final reconstruction, the soft tissue coverage remained stable providing sufficient padding for the spine (Fig. [3]) even in the lowermost part of the defect, which received only the fasciocutaneous portion of the flap.

Figure 2 Primarily closed donor site showing the flap extension.

Figure 3 The flap coverage of the back.

In the past, latissimus dorsi, trapezius, gluteus maximus, or paraspinous muscle flaps and associated fasciocutaneous flaps have been used individually or in combination as advancement, rotation, uni- or bipedicled, turnover, free and island flaps.[1] Local fasciocutaneous flaps require extensive undermining of the skin bearing the risk of wound-edge failure. They may not provide sufficient padding[2] or potential for elimination of residual infection.[3] In our case, the previous attempts of wound closure had left the surroundings of the defect heavily scarred with diminished blood supply. Because of the size of the wound and the preexisting infection, we considered a musculocutaneous flap the best treatment; however, the latissimus turnover and a gluteal flap had already been used.

The epigastric vascular arcade forms the abdominal portion of a link between the subclavian and iliac vessels. This deep epigastric system, which supplies a wide area of the anterior abdominal wall, provides excellent communications between sizable vessels and a great density of paraumbilical perforators. One of the best reconstructive uses of this vascular arcade is the extended inferior epigastric flap, which is a multicomponent transfer formed of an axial component (inferior epigastric artery), muscular component (rectus abdominis muscle), and a fasciocutaneous component. The resulting flap can measure nearly one quarter of the body height. The longest flap done by Taylor et al[4] reached as far as the midaxillary line. The extended version is based on the perforators, which warrant special attention. Taylor[5] originally harvested only one perforator and luckily enough the flap survived. In our case, we included two paraumbilical perforators. To approach the vessels from both medial and lateral directions, our patient was temporarily tilted from the lateral into a 45-degree position to dissect the medial row of perforators. As almost the entire anterior sheath of the rectus was incorporated in the flap design, the fascial defect of 12 cm × 6 cm was supported with a Vicryl-Prolene (Ethicon Products, 22851 Norderstedt, Germany) mesh before closure of the abdominal donor site.

The advantages of the flap described are its enormous size due to the extensive centrifugal paraumbilical blood supply and the caliber and length of its inferior epigastric pedicle, which makes the deep inferior epigastric flap one of the most robust and most consistently vascularized flaps. When compared with the original description of the flap by Taylor et al,[5] we merely increased its versatility by using it as a free flap for a difficult clinical problem. Easy design, rapid raising, and its suppleness make it a feasible solution for the coverage of large defects. Without the need for an intraoperative positional change of the patient, this one-stage procedure is a speedy and reliable reconstructive option.

REFERENCES

• 1 Hill C, Riaz M. A new twist to the myocutaneous turnover flap for closure of a spinal defect.  Plast Reconstr Surg. 1998;  102 1167-1170
• 2 Ramirez O M, Ramasastry S S, Granick M S, Pang D, Futrell J W. A new surgical approach to closure of large lumbosacral meningomyelocele defects.  Plast Reconstr Surg. 1987;  80 799-809
• 3 Ramasastry S S, Schlechter B, Cohen M. Reconstruction of posterior trunk defects.  Clin Plast Surg. 1995;  22 167-185
• 4 Taylor G I, Corlett R, Boyd J B. The versatile deep inferior epigastric (inferior rectus abdominis) flap.  Br J Plast Surg. 1984;  37 330-350
• 5 Taylor G I, Corlett R, Boyd J B. The extended deep inferior epigastric flap: a clinical technique.  Plast Reconstr Surg. 1983;  72 751-765