Extensive Chest Wall Tissue Loss and its Management by Vertical Rectus Abdominis Myocutaneous Flap.

Extensive electric burn around the chest in children is rare and this type of injury always poses a great challenge for its management. A 12-year-old male child with extensive electric burn of the chest wall was admitted to hospital. It was a neglected case of 9 days old burn; the young boy was in critical condition having systemic features of toxemia with widespread necrosis of the skin, subcutaneous tissues, and muscles along with exposed bones (ribs and sternum) with the risk of impending rupture of pleura through the exposed intercostal spaces. After initial resuscitation, a thorough debridement of all necrotic tissues was done. Thereafter, a superiorly based vertical rectus abdominis myocutaneous flap was harvested to cover the exposed bones and intercostal spaces. The remaining raw areas were skin grafted. The child made an excellent recovery with good outcome.

INTRODUCTION

Electric burn has the potential to cause full thickness tissue damage beneath intact and unburnt skin. When electric current passes through the muscle, it may lead to severe muscle damage. However, extensive electric burn involving both surfaces of the chest with exposure of the sternum and ribs is extremely uncommon among children.[1] Reconstruction and coverage of such wide defect of the chest wall are as much urgent as it is challenging to the treating surgeon. Here, we present such a difficult case managed successfully with early debridement and coverage by a vertical rectus abdominis myocutaneous (VRAM) flap.

CASE REPORT

A 12-year-old male child was admitted to our burn unit with a history of 9 days old electric burn. He suffered fourth-degree extensive burn on the front of his chest extending onto the lower part of neck and left shoulder; there was deep second-degree burn on all over his back as well. Total body surface area involved was around 23%. However, as it was a case of electric burn, deeper tissue involvement was extensive. The patient had been initially treated in a local hospital; however, because of deteriorating health condition, he was brought to our institute. At the time of admission, he had systemic features of toxemia with high rise of temperature, tachycardia, tachypnea, and pallor. Foul-smelling wound was present across the chest wall, covered with thick, black eschar with pus pouring out at places from underneath the eschar.

Under general anesthesia, a thorough wound debridement was done. During debridement, we found that there was widespread necrosis of pectoralis major muscles bilaterally which was more on the right side. Intercostal muscles on both sides of sternum were necrosed. The whole sternum including right sternoclavicular joint and the right second, third, and fourth ribs along with their costochondral junctions was exposed [Figure 1a]. The necrosed portions of the pectoralis and intercostal muscles were debrided resulting in exposure of the parietal pleura at places, for example, right second and third and left sixth spaces. However, the pleura was not opened at any place. There was deep second-degree burn on his back (exit wound), which was also debrided.

Figure 1

(a) Wound over the anterior chest wall after debridement; (b and c) dimension and elevation of the vertical rectus abdominis myocutaneous flap

As the pleura was exposed at places and also because the exposed bones and joints warranted a stable flap cover, we decided to cover the wound with a well-vascularized flap. A superiorly based, left-sided, VRAM flap was planned [Figure 1b]. Integrity of the vascular pedicle was confirmed with the help of handheld Doppler. After skin incision, rectus sheath was incised exposing the rectus muscle; the muscle was then divided near its lower end and the deep inferior epigastric vessels were ligated [Figure 1c]. The rectus muscle was then elevated off the posterior sheath in retrograde manner, along with the skin paddle, up to the costal margin preserving the superior epigastric pedicle which enters the muscle in its upper part on its deep surface. The skin paddle measured about 22 cm × 9 cm. The flap was then placed over the chest wound, with the skin paddle facing outward. It reached up to right sternoclavicular joint, effectively covering the whole of the sternum, exposed second, third, and fourth ribs on the right side and exposed intercostal spaces along with the rents therein [Figure 2a]. As the other areas over the chest were still infected and necrosed, they were debrided and allowed to granulate.

Figure 2

(a) Vertical rectus abdominis myocutaneous flap over the chest and abdomen closed primarily, (b) patient after 2 months on follow-up visit

Within subsequent 2–3 days, the patient's general condition gradually improved. There was satisfactory growth of granulation tissue over the uncovered chest wound which was skin grafted. The child made an excellent recovery and was discharged on the 21st postadmission day. After 2 months, the patient came on follow-up visit when we found the flap, its donor site, and the skin-grafted areas completely healed [Figure 2b].

DISCUSSION

Electric burn is one of the common forms of burn injury suffered by the children all over world.[2] Frequently, the incidents occur in household environment and the affected body part is upper extremity (fingers and wrist).[1] However, extensive and full thickness electric burn over the chest is very rare among children, even rare among adults. In today's clinical practice, chest wall defects are mainly encountered among adult patients due to resection of malignancy involving chest wall or breast; or it may be either due to complication of median sternotomy after cardiothoracic procedures or due to trauma.[3]

In such situation, reconstruction of the chest wall is always a surgical challenge because it contains the two important closed cavities, i.e., pleural cavity and pericardial cavity, both containing vital organs and structures. These spaces are closed and physiologically so important that, whenever opened, they need to be reconstructed urgently and effectively.[4] In our case, there was widespread necrosis of the soft tissue of anterior chest wall along with exposed cartilages and bones; there was also risk of exposure of the plural cavity through the second and third intercostal spaces. Grossi et al.[5] have shown in their study that in such a scenario, the traditional method of “debridement and irrigation only” over the chest wound increases chances of complications. Early intervention and coverage by a well-vascularized tissue-like a muscle flap can significantly decrease these complication rates[6] and may also augment the vascularity of the exposed ribs.[1]

For reconstruction of the chest wall defects, the most commonly used muscles are latissimus dorsi and pectoralis major;[7] sometimes, omentum is also used.[3] However, in our case, there was deep second-degree burn on the back, thus precluding use of latissimus dorsi muscle flap. As both of the pectoralis major muscles were widely necrosed, they were also not suitable for use as muscle flap. The only workhorse flap available was VRAM flap based on the superior epigastric artery pedicle.

Rectus abdominis is a Type III muscle flap as per Mathes and Nahai classification,[8] which means that it has got two dominant vascular pedicles, one is superior epigastric artery and other is inferior epigastric artery. Of these two, inferior epigastric vessel is comparatively robust.[9] A muscle-only or musculocutaneous pedicled flap can be raised on either of these pedicles and can be used to reconstruct defects of various regions. As a musculocutaneous flap, the skin paddle can be transversely oriented (transverse rectus abdominis myocutaneous, well known for breast reconstruction) or it may be vertically oriented (VRAM). The inferior pedicled (inferior epigastric artery) VRAM is used in pelvic, perineal, genital, and upper thigh defects, whereas a superior pedicled (superior epigastric artery) VRAM can be used to reconstruct the upper abdomen and chest wall defects. The advantage of rectus abdominis myocutaneous flap is that there is no gross functional loss following its use as a flap.

Between the two rectus abdominis muscles, the left-sided VRAM flap was chosen because there was extensive burn on the right side and intraoperative handheld Doppler study showed left superior epigastric vessel to be patent. In the remaining wound, abundant granulation developed after debridement, as expected, because of rich vascular supply of chest wall by multiple intercostal vessels and their perforators. These facilitated early skin grafting and ultimately complete healing of all wounds.

CONCLUSION

Postelectric burn extensive chest wall defect with exposure of sternum, ribs, and multiple intercostal spaces is a rare clinical situation among children. In such cases, early debridement and coverage by well-vascularized tissue can protect the underlying important organs, thus preventing possible catastrophes.

FINANCIAL SUPPORT AND SPONSORSHIP

Nil.

CONFLICTS OF INTEREST

There are no conflicts of interest.