DZIELIMY SIĘ DOŚWIADCZENIEM
Applying vertical rectus abdominis muscle (VRAM) flap in surgical treatment of extensive chest wall injury after deep infection of the sternotomy wound

Introduction

Deep wound infection with mediastinitis is a rare, but extremely dangerous complication. Among patients predisposed to complications by various factors, the need is emphasised to perform cardiosurgical procedures with utmost care. It is particularly important to avoid damage to the bones and vascularisation of the sternum, and to use secure suturing techniques. In the selected group of patients it is also possible to stabilise the sternal edges with the use of the technique described by Robicsek. Moreover, it is crucial to individualise the treatment of patients predisposed to wound healing complications and to apply sternum sewing bands, antibiotic sponges or bone cement at the sternum. If wound healing irregularities are suspected after a cardiosurgical procedure, the wound should be closely monitored and wise medical decisions are essential.

If wound infection is suspected, an appropriate, intensive and multidirectional treatment should be applied. Such a treatment consists of a surgical procedure called debridement, the scope of which depends on the area of healing complications and the antibiotics administered. Hyperbaric oxygen treatment is also an option. The surgical procedure includes opening the wound, applying dressing with antiseptics, applying vacuum dressing, as well as extensive removal of infected tissues from the mediastinum, applying high-volume flow drainage and renewed suturing of the sternal bones. In some cases, excessive sternal damage or chronic bone infection develop. In these patients, as a consequence of the necessary, excessive surgery, significant loss of tissue in the anterior chest wall and the related respiratory failure occur. This requires surgical reconstruction of the anterior chest wall. In such a procedure, pedicled, well supplied with blood omentum majus flap, thoracic or abdominal muscles are used [1, 2]. Additionally, healing is facilitated with the immunological and regenerative features of the omentum [3, 4].

Case description

The patient, female, aged 59, diagnosed with coronary vascular disease, COPD, obesity, type 2 diabetes, steroid induced adrenal insufficiency, thyroid insufficiency, underwent coronary artery bypass grafting with two venous grafts: to the anterior descending branch and obtuse marginal branch. Standard prophylactic antibiotic therapy was administered, namely second generation cephalosporin for three days after the procedure. No complications were observed in the post-operative period until the seventh day after the procedure, when dehiscence was found of the sternotomy wound, and the culture of the effusion grew single colonies of methicillin-resistant skin Staphylococcus MRCNS. The patient had no fever. On the 8th day the patient was discharged to the rehabilitation hospital in a good general condition. The following day she returned with dehiscence and sternal instability. The day after, mediastinum was surgically opened, the effusion and necrotic tissues were removed, Braunovidol irrigation

(10 ml in 500 ml saline) and renewed closure of the sternal edges were performed. Tissue and effusion cultures grew Enterobacter cloacae ESBL colonies. Targeted antibiotic therapy with ciprofloxacin was administered. Mechanical ventilation was performed. Regardless of the treatment, the wound reopened. Another surgery was suggested to the patient. In this reoperation, the mediastinum was lined with gauze strips with antiseptics and the wound was left unclosed. Additional antibiotic therapy with clindamycin was administered. Numerous cultures of wound smears, as well as bacteriological tests of blood, bronchial washing and vascular catheters were performed. Depending on the results of these tests, the antibiotic therapy was modified. After 2 weeks of mechanic ventilation, tracheotomy was performed. Vacuum assisted closure (VAC) was applied. The infection of mediastinum caused excessive tissue necrosis, which resulted in anterior chest wall instability and made it impossible for the patient to breathe sufficiently without support. The patient remained conscious and was mechanically ventilated.

Figure 1 shows the wound around three months after the first surgery. In the mid chest between the breasts, at the level of the body and xiphoid process of the sternum, round wound can be seen, approximately 20 cm in diameter, surrounded by a thick cicatricial band with traces of the removed sutures. The wound bed is covered with reddish-pink granulation tissue, yellowish-green fibrin and serous effusion. In the right part of the wound cicatrized pectoralis major muscle is visible. In the bottom and top areas of the wound, pouches with serous effusion are shown.

In this situation, reoperation was suggested to the patient, after seven days of hyperbaric oxygen therapy. This improved the general condition of the patient and negative culture results were obtained.

The procedure consisted of removing necrotic tissues, stump ribs and sequesters within the remnants of the sternal bone. Then the wound was rinsed with 3 litres of warm saline solution of an iodine antiseptic. After extending the incision towards the upper abdominal midline, the omentum majus flap was accessed. During the omentum preparation numerous adhesions were found that resulted from previous abdominal surgeries. A rupture of the spleen capsule occurred, which necessitated spleen removal – due to haemorrhage. Prepared well supplied with blood omentum majus flap was transposed to mediastinum to fill the space were tissues were removed. There still remained a significant loss of skin, muscle and bone tissues of the chest wall. This space was filled with the pedicled, rotated by 180° myocutaneous flap of the right rectus abdominis muscle. The right and left pectoralis major muscles were mobilised to the depth of approximately 8 cm from the chest wall in order for these myocutaneous flaps to be sutured, with fascial suture, to the rotated flap of the rectus muscle (VRAM) that filled the defect (Fig. 2). Concluding the procedure, Redon drains were left in the abdominal cavity and under the muscle flaps. Skin sutures were tied without tension.

Four days post-operatively, the distal fragment of the VRAM became necrotic in the skin and subcutaneous tissue, and was therefore removed. On the 16th day post-operatively, hyperbaric oxygen treatment was applied again.

Post-operatively, gradual improvement of the patient’s respiratory efficiency was observed. The patient underwent active respiratory rehabilitation. After three weeks the patient was able to breathe without support for 9 hours a day. On the 23rd day post-operatively the patient refused further treatment with hyperbaric oxygen. After further three weeks a skin transplant was performed around the distal segment of the VRAM.

In the following three months of hospitalisation the general condition of the patient gradually deteriorated due to the development of an infection of the lung tissue. As a consequence, respiratory insufficiency increased and permanent ventilation was necessary. Laboratory test results showed decreased antibody level. Around 4 months after the last surgery and 7 months after the primary surgery the patient died due to fungal sepsis.

Discussion

Applying the pedicled, myocutaneous flap of TRAM (transverse rectus abdominis muscle) was first described in the 1980s by C. Hartrampfa et al. [5, 6]. Since then, it has become a golden standard in thoracic reconstruction procedures where patient’s own tissues are used.

The advantage is the well provided with blood island of skin and adipose tissue, vascularised by perforators from superior and inferior epigastric vessels that anastemose at the level of the navel.

Due to the long pedicle that consists of the rectus abdominis muscle, the flap has a high potential for rotation and constitutes a perfect material not only to reconstruct the anterior chest wall structures but also a resistant material for significant wall defect closures. In a classical thoracic reconstruction, the pubic attachment of the rectus abdominis muscle is cut and the prepared island of skin and adipose tissue is supplied with blood by superior epigastric vessels that arise from internal thoracic vessels.

In this case, with internal thoracic vessels preserved, it was possible to transfer the island of skin and adipose tissue on one rectus abdominis muscle with the axis of the island of skin and adipose tissue parallel to the rectus abdominis muscle – the so called VRAM (vertical rectus abdominis muscle) flap [7-9]. The extensive tissue loss around sternum required the use of the largest possible surface area of the flap (Fig. 3). The defect of the mediastinum tissues below the layer of the muscle fascia was filled with the pedicled omentum majus flap, transposed from the abdominal cavity. The advantage of this type of flaps is that the omentum actively limits infections and wound effusion.

The advantage of using VRAM in surgical closure of extensive chest tissue injuries is the use of the rectus abdominis muscle as the layer that stabilises the edges of pectoral muscles. This allowed, in the described case, to improve significantly the anterior chest wall stability and, as a result, the patient’s respiratory efficiency. Furthermore, the island of skin and adipose tissue may act as dressing, well supplied with blood, which closes the surface of the wound [10].

Conclusions

1. Although the treatment of the patient after coronary revascularisation, which lasted more than 7 months, ended tragically, all stages of surgical treatment of patients with cardiac conditions are important.

2. Simultaneous use of both the VRAM and omental flaps is feasible and safe to stabilise the chest and fill extensive tissue loss.

References

1. Jones G, Jurkiewicz MJ, Bostwick J, Wood R, Bried JT, Culbertson J, Howell R,

Eaves F, Carlson G, Nahai F. Management of the infected median sternotomy wound with muscle flaps. The Emory 20-year experience. Ann Surg 1997; 225: 766-776.

2. Schroeyers P, Wellens F, Degrieck I, De Geest R, Van Praet F, Vermeulen Y,

Vanermen H. Aggressive primary treatment for poststernotomy acute

mediastinitis: our experience with omental- and muscle flaps surgery. Eur

J Cardiothorac Surg 2001; 20: 743-746.

3. Collins D, Hogan AM, O’Shea D, Winter DC.The omentum: anatomical, metabolic, and surgical aspects. J Gastrointest Surg 2009; 13: 1138-1146.

4. Kitano M. Omentoplasty in thoracicsurgery. Gen ThoracCardiovasc Surg 2008; 56: 483-489.

5. Scheflan M, Hartrampf CR, Black PW. Breast reconstruction with a trans­verse abdominal island flap. Plast Reconstr Surg 1982; 69: 908-909.

6. Hartrampf CR Jr. The transverse abdominal island flap for breast recon­struction. A 7-year experience. Clin Plast Surg 1988; 15: 703-716.

7. Baumann DP, Butler CE. Component separation improves outcomes in VRAM flap donor sites with excessive fascial tension. Plast Reconstr Surg 2010; 12: 1573-1580.

8. Nelson RA, Butler CE. Surgicaloutcomes of VRAM versus thigh flaps for immediate reconstruction of pelvic and perineal cancer resection defects. Plast Reconstr Surg 2009; 123: 175-183.

9. Erdmann D, Küntscher M, Petracic A, Sauerbier M, Menke H, Schirren J, Dienemann H, Germann G. Plastic surgery coverage of osteocutaneous defects of the sternum area with the vertical and transversal rectus abdominis muscle (VRAM/TRAM) flap. [Article in German]. Chirurg 2000; 71: 1156-1160.

10. Quiroga Martínez J, Gualis Cardona J, Gregorio Crespo B, Cabanyes Candela S,

Cilleruelo Ramos A, Duque Medina JL. Utility of omentoplasty for postster­notomy mediastinitis secondary to myocardial revascularization surgery. [Article in Spanish]. Arch Bronconeumol 2008; 44: 113-115.