Burns (1992) 18, (6), 510-512
Printed in Great Brifuin
Reconstruction of exposed sternum following electrical burns using a superior transverse rectus abdominis musculocutaneous flap R. K. Sharma Department
of Plastic Surgery, Postgraduate
of Medical Research, Chandigarh,
An unusual case of a patient with electrical burns with exposed sternum was reconstntcfed using a stlperior transverse recks abdominis flap (also known as ‘epigustic rectu5flap?. The clinical rarity of the condition and the innovation of the reconsfructive method is disnrssed.
Introduction Electrical bums of the sternum are very unusual, and reconstruction of the exposed sternum is quite a challenging task. Although many methods have been described in the literature (Seyfer and Graeber, 1989; Shaw et al., 1990) a simpler alternative, the superior transverse rectus abdominis musculocutaneous flap (Superior TRAM) is not mentioned for reconstruction. Impressed with the results of this flap in breast reconstruction by us (unpublished) and others (Psillakis et al., 1983; Vasconez et al., 1983), we applied this flap in a patient for reconstruction of a midline sternal skin defect due to electrical bums. To the best of our knowledge, such a usage of this flap has not been reported in the English language literature.
Case report B.R., a 40-year-old male, was admitted to our unit with multiple bum injuries sustained by accidentally touching a high tension electric cable. He was found to have gangrene of the right hand, skin necrosis over the sternum and the right patella (Figure I). There was no clinical evidence of any cardiovascular involvement.
Figure I. The electrical burns over the sternum. 0 1992 But&worth-Heinemann 0305-4179/92/060510-03
Figure 2. Defect over the sternal region following excision of the burn wound. Right side superior transverse rectus abdominis flap has been marked.
Figure 3. Flap sutured into the defect. The donor site has been closed primarily.
of exposed sternum following electrical bums
Figure 4. Flap after 1 year.
The electrocardiogram was normal. There was no clinical or radiological evidence of any pulmonary involvement. After initial resuscitation and stabilization, the patient was taken for surgery. The right midforearm was amputated and the right patella covered with a local fasciocutaneous flap. Debridement of the sternal bum resulted in exposure of the cartilage. This exposed sternum required flap coverage. A right-sided superior transverse rectus abdominis musculocutaneous island flap of 7 x 3 in (17.8 x 7.6 cm) was raised (Figure 2) and turned through 90” to be inset over the sternum (Figure 3). The rest of the area was split skin grafted. The flap and donor site healing was uneventful. Figure4 shows the well-settled flap I year later. Technique of raising theflap The technique has been described in detail by Vasconez et al. (1983). The flap extends from midline to midaxillary line in the epigastric region. A width of B-10 cm can be closed primarily. The elevation is started from lateral to medial side including the fascia of intercostal muscles in the flap. At the lateral border of the rectus muscle, the anterior rectus sheath is opened and incised inferiorly and medially, keeping the midline linea alba intact. The rectus muscle is divided inferiorly and lifted off the posterior rectus sheath in a cephalad direction. The musculocutaneous flap is retracted superiorly until the superior epigastric artery is seen on its deep surface. The rectus muscle and the overlying fascia are detached from the costal margin, ligating the intercostal perforators in the process. Now the flap is an island. To lengthen the short pedicle, the 7th costal cartilage is resected subperichondrally for about 3-4 cm. The flap is turned by 90” and inset into the defect.
The donor area can be closed primarily.
Discussion Electrical bums affecting the sternal area are not very common. Large series of electrical bums (Burke et al., 1977; Wilkinson and Wood, 1978; Haberal, 1986; Haberal et al., 1989) have not described sternal involvement. Newsomn et al. (1972) report
with high voltage
with a midstemal entrance wound with multiple visceral injuries. In our patient, there was no evidence of damage to either lungs, heart or any other mediastinal contents. It is believed that when the current passes through the thorax, the current density is distributed over such a large area that the amount of heat generated is not great enough to cause internal damage (DiVincenti et al., 1969; Burke et al., 1977). Skin grafts alone are not sufficient for coverage of the exposed sternal cartilage. Moreover, as the cartilage is devoid of a direct vascular supply, systemic antibiotics are ineffective for the definitive treatment of costochondritis (Molleken et al., 1989). Therefore, coverage with a wellvascularized flap is essential in such a situation. Management could include various local flaps of skin (Shaw et al., 1990), advancement and turnover flaps of the pectoralis major muscle (Tobin, 1989), turnover of the rectus abdominis muscle (Coleman and Bostwick, 1989), latissimus dorsi muscle (Molleken et al., 1989) and omentum. The latissimus dorsi muscle has a secondary role in reconstruction of sternal wounds and is suitable only for a high sternal defect. Moreover, it entails considerable dissection and change of posture. Possible damage to the internal mammary perforators precludes the use of the pectoralis muscle as a turnover flap. Although vertical rectus abdominal muscle or a musculocutaneous flap based upon the superior pedicle could also provide cover for sternal defects, it involves sacrifice of the rectus abdominis muscle function. Maruyama et al. (1985) described the use of a vertical fasciocutaneous flap for chest wall coverage but this may be insufficient to cover the entire sternum. The use of omentum necessitates opening the abdomen and its attendant morbidity. A superior TRAM flap has been utilized extensively in the reconstruction of the breast (Psillakis et al., 1983; Vasconez et al., 1983). The flap is supplied by perforating branches of the superior epigastric artery which is present on the deep surface of the rectus muscle. Part of the rectus muscle on which the skin paddle is designed is also taken. There are many advantage; in using this-flap for chest wall reconstruction, especially sternal defects: The flap can be raised in a supine position, thus avoiding the need for a change of posture as is required with a latissimus dorsi flap. There is very little sacrifice of the rectus muscle as only the upper part of the muscle (about 5-7cm) is taken, keeping the posterior rectus sheath intact. The donor site can be closed primarily. The flap can still be used even if there is interruption of the internal mammary artery high in its course because of rich anastomotic connections between the internal mammary artery and intercostal vessels on both sides (Miller et al., 1988; Coleman and Bostwick, 1989).
References Burke J. F., Quinby W. C., Bondoc C. et al. (1977) Pattern of high tension electrical injury in children and adolescents and their management. Am. J stcrg. 133, 492. Coleman J. J. and Bostwick J. (1989) Rectus abdominis musclemusculocutaneous flap in chest wall reconstruction. Stlrg. Clin. North Am. 69, 1007. DiVincenti F. C., Moncrief J. A. and Pruitt B. A. Jr (1969) Electrical injuries, a review of 65 cases. J Trauma 9, 497.
Haberal M. (1986) Electrical bums, a five year experience - 1985 Evans lecture. 1. Trauma 26, 103. Haberal M., Oner Z., Gulay H. et al. (1989) Severe electrical injury. Bums 15,60. Maruyama Y., Qhnishi K. and Chung C. C. (1985) Vertical abdominal fasciocutaneous flaps in reconstruction in chest wall defects. Br. 1. Phst. Surg. 38, 230. Miller L. B., Bostwick J., Hartrampf C. F. et al. (1988) The superiorly based rectus abdomonis flap: predicting and enhancing its blood supply based upon anatomic and clinical study. P/a& Reconstr. Surg. 81, 713. Molleken B. R. W., Mathes S. A. and Chang N. (1989) Latissimus dorsi muscle, musculocutaneous flap in chest wall reconstruction. Sqg. C/in. North. Am. 69, 977. Newsome T. W., Curreri P. W. and Eurenius, K. (1972) Visceral injuries: an unusual complication of the electrical bum. Arch. Surg. 105, 494. Psillakis J. M., Woisky R. and Guillanno S. (1983) Rectus abdominis de-epithelised musculocutaneous island flap as a silicone substitute in breast reconstruction. Ann. Phsf. Surg. 10, 492.
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Shaw, W. W., Aston, S. J. and Zide, B. M. (1990) In: McCarthy J. G. (ed.), Chest Wall Reconsfruction in Plastic Surgery, vol. 6. Philadelphia: W. B. Saunder, pp. 3675. Tobin G. R. (1989) Pectoralis major muscle-musculocutaneous flap for chest wall reconstruction. Surg. Clin. North. Am. 69, 991. Vasconez L. O., Psillakis J. and Giebeik R. J. (1983) Breast reconstruction with contralateral rectus abdominis myocutaneous flap. Plast. Reconstr. Surg. 71, 668. Wilkinson C. and Wood M. (1978) High voltage electric injury. Am. J. Surg. 136,693.
Paper accepted 24 June 1992.
Correspondence should be addressed fo: Dr R. K. Sharma, Assistant Professor, Department of Plastic Surgery, PGI Chandigarh 160012, India.