Reconstruction of the Chest Wall

Transcription

1 HOW TO DO IT Reconstruction of the Chest Wall Reed 0. Dingman, M.D., and Louis C. Argenta, M.D. ABSTRACT Reconstruction of the chest wall can now be accomplished reliably and expeditiously. Past experience with local flaps and split-thickness skin grafts recommends their continued use when appropriate. Recent studies in blood flow have demonstrated that very large muscles with or without the overlying skin can be moved primarily and reliably. The four most reliable myocutaneous flaps for chest wall reconstruction are described. Microsurgery allows movement of large segments of skin and muscle from expendable areas of the body to the chest wall. Recent advances in plastic surgery have made reconstruction of the chest wall a reliable procedure. Defects due to extirpation of tumors, trauma, radiation injuries, congenital and developmental deformities, and infection may require chest wall reconstruction. The objectives of chest wall reconstructive procedures are restoration of continuity for physiological respiration, protection of vital intrathoracic organs, and a satisfactory cosmetic result. The ideal reconstruction would replace all missing structures, i.e., covering tissues, supportive structures, and lining of visceral cavities. Replacement of all these elements may not be necessary and in some instances is not possible. When correcting an existing defect, a reconstructive procedure should be planned carefully before the operating room is entered. Alternative plans should be considered since, at times, a surgeon inadvertently finds himself with a larger defect than anticipated. The situation requires knowledge of various other alternatives for reconstruction. From the Section of Plastic Surgery, Department of Surgery, University of Michigan School of Medicine, Ann Arbor, MI. Presented at the Sixty-fifth Annual Clinical Congress of the American College of Surgeons, Chicago, IL, Oct 21-26, Accepted for publication Aug 14, Address reprint requests to Dr. Argenta, C7038 Outpatient Bldg, Box 22, University Hospital, AM Arbor, MI Options from which the surgeon may select a procedure must be designed to repair a specific defect. The operation should be that which will achieve the desired result in the simplest manner and rehabilitate the patient most fully. The alternatives for reconstruction are: (1) primary closure; (2) split-thickness skin grafts; (3) local skin flaps; (4) muscle flaps; (5) myocutaneous flaps; (6) flaps transferred from a distance; and (7) free flaps. Underlying supportive structures of fascia, bone graft, or synthetic prostheses may be necessary with any of these procedures. Reconstructive Procedures Primary Closure Primary closure is the most frequently used method of chest wall reconstruction and is performed routinely in most patients requiring a thoracic surgical procedure. Because of the excellent blood supply to the skin of the chest wall, extensive undermining may be undertaken and tissue mobilized to close the wound. Care should be taken, particularly in the young female patient, to avoid distortion of the breasts. Split-Thickness Skin Graft A split-thickness skin graft is a relatively simple procedure with a high probability of success both in clean wounds and in areas of infection (Fig 1). In many instances this graft can be applied primarily. In a chronically contaminated wound which has established granulation tissue, thin, meshed split-thickness skin grafts can provide permanent, physiological, and cosmetically acceptable coverage. They can also be used as a temporary cover in wounds for which flap coverage may be desired later. Despite literature to the contrary, we have many patients who have been treated successfully with split-thickness skin grafts applied after major radiation burns to the chest wall. In several patients, skin grafts were applied to visceral pleura or to pericardium. All of these patients have adjusted physiologically to the de by The Society of Thoracic Surgeons

2 203 How to Do It: Dingman and Argenta: Reconstruction of Chest Wall A B Fig 7. (A)A large chest wall ulcer developed in this patient 2 years after she had orthovoltage radiation therapy for breast carcinoma. Debridement was carried down to the pericardium and visceral pleura. A splitthickness skin graft was then applied. (B) Twenty-two years after the Operation, the patient has no impairment of respiration and is an active golfer. he has mobilized an inadequate amount of tissue. gasic principles of flap design must be followed to properly rotate the tissue L21. closed under tension are doomed to failure. The donor site must be an area of healthy tissue. The use of tissue damaged by previous operation or radiation therapy is fraught with potential complication [31. Although such flaps may bleed profusely at the time of elevation, they frequently fail because of poor capillary circulation. Intravenously administered fluorescein should be used at the time of operation to document flap viability [4]. Tubed distant flaps rotated about the torso or carried on the patient s arm are time-consuming and unreliable. Modern surgical techniques have rendered such procedures antiquated and unnecessary. fect without more extensive chest wall reconstruction. Several have survived more than 25 years without breakdown of the split-thickness skin graft. Local Flap When full-thickness tissue is required for reconstruction of smaller chest wounds, local flaps should be considered (Fig 2) [l]. The design of the flap is critical. The flap must be planned to carry an axial blood supply. It must be remembered that a large skin flap is required O m e n f a l Flap to close a small defect. Flaps should be designed The omentum is extremely useful in closure of at least 25% larger than the defect to be closed thoracic wounds where full-thickness chest wall or the surgeon may be embarrassed to find that structures have been lost, in covering exposed

3 204 The Annals of Thoracic Surgery Vol 32 No 2 August 1981 Fig 2. This patient underwent resection of a large portion of the right anterior chest for sarcoma. A large, laterally based flap was rotated. The distal margin of the flap was partially lost and was covered with a splitthickness skin graft at a later date. Such large local flaps are no longer needed. Lt Fig 3. The arc of rotation and areas that can be covered by the ornentum based on the right gastroepiploic artery. This flap can cover any portion of the anterior chest wall or substantial portions of the posterior chest. prostheses, and in areas of infection [5-71. The omentum is a bipedicled layer of fused peritoneum supplied by the right and left gastroepiploic arteries (Fig 3). Both of the pedicles may be left intact, or one can be divided for further length. The right gastroepiploic artery is usually dominant and should be preserved if possible. The adult omentum is approximately 20 cm in length and 35 cm in width. The omentum in a child less than 1 year old is usually too small to reach beyond the lowest portion of the anterior chest. In most instances, the omentum can be passed subcutaneously onto the chest wall without difficulty. Extreme care must be taken to secure the base of the omentum to the anterior abdominal wall to prevent internal hernia and bowel strangulation [81. The omentum can be used in conjunction with prosthetic meshes and is an excellent recipient for skin grafts. Its extreme vascularity makes it an excellent choice in contaminated wounds. Its ability to form dense vascular adhesions also allows it to vascularize bone grafts. A large amount of serous oozing occurs from the omentum for several days. Therefore, drainage of these wounds is recommended. Pectoralis Major Flap The principal muscle of the anterior chest wall derives its blood supply primarily from the thoracoacromial artery, which runs beneath the

4 205 How to Do It: Dingman and Argenta: Reconstruction of Chest Wall muscle on an axis parallel to the muscle fibers. A large vein and the lateral pectoral nerve accompany the artery in its course. The pectoralis major can be taken as a muscle flap or as a myocutaneous unit [ Because of the multiple perforators entering the skin through the muscle, large areas of the overlying skin can be transferred with the muscle. The neurovascular bundle can be approached best from the lateral aspect of the muscle and should be kept under direct observation during the subsequent dissection. The lateral tendinous insertion of the muscle can also be transected to provide a true island flap. This provides greater mobility in a medial direction without compromising circulation. Undermining and primary closure of the donor defect can usually be accomplished, but in larger defects, split-thickness skin grafts may be required. Primary use of this flap is in coverage of anterior chest wall defects, especially sternal wounds (Fig 4). Adequate mobilization of both pectoralis muscles allows closure of the largest sternal wound. This flap can be used in concert with the omentum in patients with sternal de- Fig 4. The arc of rotation and area that can be covered by the pectoralis myocutaneous flap on the chest wall. Division of the insertion of the pectoralis muscle greatly facilitates the movement of the flap. hiscence or deep anterior mediastinal wounds. Loss of the pectoralis muscle can be a major disability for patients who must do heavy manual labor. The pectoralis muscle also has been used to fill large sternal defects by dividing the insertion of the muscle and its dominant blood supply, then rolling the entire muscle medially over itself. The muscle in this case is supplied by intercostal perforators. Because the muscle is then denervated, marked atrophy should be anticipated. The small number of such flaps that have been performed successfully render this procedure still experimental. Latissimus Dorsi Flap At the present time, the latissimus dorsi myocutaneous flap is the most commonly used and most dependable flap for chest wall reconstruction [12, 131. Although described at the turn of the century and then in 1950 by Campbell 1141 for chest reconstruction, it is only recently that this flap has been used extensively. The muscle can be elevated with or without the overlying skin. Under most circumstances it is a dispensable muscle. The latissimus dorsi is a very broad, thin muscle which originates from the lower sixth thoracic vertebra, lumbar and sacral vertebrae, and the iliac crest. The fibers then converge into a thin strip beneath the scapula and insert onto the humerus. The thoracodorsal artery, a terminal branch of the subscapular artery, is the major blood supply entering the undersurface of the muscle approximately 10 cm from its insertion. There is also a fairly extensive collateral plexus in the area of the serratus anterior muscle. For this reason, even in patients in whom the thoracodorsal artery has been previously divided in an axillary dissection, the latissimus dorsi muscle is frequently viable and can be turned based on this plexus In general, if the anterior border of the muscle becomes prominent when the patient pushes down on the hips, the muscle will be adequate for rotation. The thoracodorsal artery need not be dissected out, and the cephalad dissection of the flap should be done only to the point that allows adequate rotation. This muscle is best approached by dissecting downward from the tip of the scapula and separating the

5 206 The Annals of Thoracic Surgery Vol 32 No 2 August 1981 A B Fig 5. (A) The arc of rotation and area that can be covered by the latissimus dorsi myocutaneousflap. This is the most versatile and dependable flap for chest wall coverage. (B) This patient underwent full-thickness chest wall resection, including three ribs, for recurrent carcinoma of the breast. A latissimus dorsi myocutaneous flap was transposed over the defect, and the wound was closed primarily. No rib grafts were placed. thin latissimus dorsi from the serratus anterior. The plane can then be easily entered to elevate as large a flap as necessary. An island of skin over the muscle up to 10 x 16 cm can be taken safely and closed primarily. Larger defects may require split-thickness skin grafts for closure. Because of its very long pedicle, this flap has a wide arc of rotation and can be used to cover almost any point on the chest wall (Fig 5). The latissimus dorsi can also be rotated medially as a turnover flap across the midline to fill defects of the opposite posterior chest wall (Fig 6) [16]. In this case the major blood supply from the thoracodorsal artery is divided, and the muscle retains its vascularity from the multiple branches of the intercostal and upper lumbar arteries. The muscle alone is rotated upon itself, and a split-thickness skin graft must be applied. The major use of this rotation of the latissimus dorsi would be to allow closure of large defects of the lower rib cage when the contralateral latissimus dorsi has been destroyed. Clinical experience with this flap is limited, and the flap should not be employed in this manner if other methods suffice. Rectus Abdominus Flap The rectus abdominus is a long, thick muscle spanning the abdomen from the anterior crest of the pelvis to the lower rib cage. The vascular supply to the muscle and overlying skin is bipedicle. Both the superior and inferior epigastric arteries course on the posterior surface of the muscle and perforate it to supply the overlying skin. A musculocutaneous flap, slightly more than one-half of the muscle length, can be based either superiorly or inferiorly. When the point of rotation is based superiorly, the flap will reach to most of the anterior chest or to the inferior portion of the axilla. The donor defect can be closed primarily without weakening the abdominal wall too much. This is a large, well-vascularized, and. dependable flap [171. It is particularly useful when bulk is needed to fill cavities in the anterior chest. It is imperative that the ipsilateral inter-

6 207 How to Do It: Dingman and Argenta: Reconstruction of Chest Wall Fig 6. A cadaver dissection demonstrating transposition of the latissimus dorsi across the midline. Note the small perforating vessels along the medial aspect of the muscle. In such cases, a split-thickness skin graft must be applied over the muscle. nal mammary artery be intact or the flap will not survive. Free Flap The transfer of skin and muscle to fill almost any defect on the body can now be accomplished through microvascular anastomoses [ An experienced and well-trained microvascular surgeon approaches almost 100% patency of 1 and 2 mm vascular anastomoses. Because of the numerous potential local muscle and skin flaps available, there are relatively few indications for a free flap on the chest. If necessary, however, this option is available. The usual donor sources are (1) the latissimus dorsi because of its very long vascular pedicle which allows anastomoses in a noncompromised area, (2) the tensor fascia lata which can be made up to 40 X 20 cm in size, (3) the dorsalis pedis which can measure 10 x 12 cm, and (4) the groin flap which can be up to 15 X 20 cm. Ancillary Procedures Resection of as many ribs as necessary should be accomplished to meet the primary aims of the procedure. In patients with infection, any involved cartilage must be removed or chronic drainage will result. Grossly infected and nonviable bone should also be removed. Viable bone, which lies in an infected field, will heal when covered with healthy muscle flaps. There are many documented cases of osteomyelitis resolving when adequately covered by a wellvascularized muscle. Three contiguous ribs can be removed without compromising respiratory status. Removal of four ribs usually results in a flail condition. Larger defects should be buttressed with rib grafts preferably taken from the opposite chest wall. The ultimate fate of rib grafts for buttressing is not well documented. There is evidence that the omentum when applied to a rib graft can accomplish revascularization to maintain its viability. Theoretically a rib graft incorporated into a myocutaneous flap should also become vascularized. Fascia lata has been successfully used to buttress large defects [21]. Few long-term results have been reported, however. Resection or loss of the sternum can result in chest wall instability with respiratory compromise [221. Most surgeons believe that rib grafts should be used to stabilize the anterior chest wall when the sternum is absent. Some surgeons, however, have closed such defects successfully by simply transposing innervated pectoralis major myocutaneous flaps over the wound. Synthetics such as Marlex [23,24] and various other materials [251 have been used successfully for many years. Infection has been the major complication, and when it occurs, the synthetic must be removed completely. It has been our experience that with the constant to-and-fro motions of respiration, most synthetics will, in time, fatigue and fracture. However, by then, the flap is frequently solid enough to support respiration. Comment Advances in plastic surgery have made reconstruction of the chest wall a reliable procedure. The rapid evolution of muscle, muscle-skin

7 208 The Annals of Thoracic Surgery Vol 32 No 2 August 1981 (myocutaneous), and free flaps provides the reconstructive surgeon with options unavailable 5 years ago. Standard older methods of treatment have been presented here as well as newer methods. Surgeons operating on the chest wall should have a thorough knowledge of all alternative methods for reconstruction. Cooperation between thoracic and reconstructive surgeons in these areas achieves maximal benefits for the patient. References 1. Woods JE, et al: Management of radiation necrosis and advanced cancer of the chest wall in patients with breast malignancy. Plast Reconstr Surg 63:235, Grabb WC: Clinical aspects of skin flaps. In Grabb WC, Myers MB (eds): Skin Flaps. Boston, Little, Brown, 1975, p Brown JB, et al: Application of permanent pedicle blood-caving flaps. Plast Reconstr Surg 8:335, Myers MB: Fluorescence: its application in medicine. Visual Med 1:12, Alday ES, Goldsmith HS: Surgical technique for omental lengthening based on arterial anatomy. Surg Gynecol Obstet 135:103, Dupont C, Menard Y: Transportation of the greater omentum for reconstruction of the chest wall. Plast Reconstr Surg 49:263, Jurkiewiu MJ, Arnold PG: The omentum: an account of its use in the reconstruction of the chest wall. Ann Surg 185:548, Hakulius L: Fatal complication after use of the greater omentum for reconstruction of the chest wall. Plast Reconstr Surg 62:796, Ariyan S: The pectoralis major myocutaneous flap. Plast Reconstr Surg 63:73, Arnold PG, Pairolero PC: Use of pectoralis major muscle flaps to repair defects of anterior chest wall. Plast Reconstr Surg 63:205, Brown RG. Flemine WH. Turkiewicz MT: An is- land flap of the pectoralis major muscle. Br J Plast Surg 30:161, Bostwick J 111, Nahai F, Wallace JG, Vasconez LO: Sixty latissimus dorsi flaps. Plast Reconstr Surg 63:31, McGraw JB, Penix JO, et al: Repair of major defects of the chest wall and spine with latissimus dorsi myocutaneous flap. Plast Reconstr Surg 62:197, Campbell DA: Reconstruction of the anterior thoracic wall. J Thorac Surg 19:456, Maxwell GP, et al: Vascular considerations in the use of a latissimus dorsi myocutaneous flap after a mastectomy with axillary dissection. Plast Reconstr Surg 64:771, Bostwick J 111, Scheflan M, Nahai F, Jurkiewicz MJ: The "reverse" latissimus dorsi muscle and musculocutaneous flap: anatomical and clinical considerations. Plast Reconstr Surg 65:395, Mathes SJ, Bostwick J: Rectus abdominus myocutaneous flap to reconstruct abdominal wall defects. Br J Plast Surg 30:282, Maxwell GP: Experience with thirteen latissimus dorsi myocutaneous free flaps. Plast Reconstr Surg 64:1, Maxwell GP, et al: A free latissimus dorsi myocutaneous flap. Plast Reconstr Surg 62:462, Serafin D, et al: Transfer of free flaps to provide well vascularized, thick cover for breast reconstruction after radical mastectomy. Plast Reconstr Surg 62:527, Watson WL, James AG: Fascia lata grafts for chest wall defects. J Thorac Surg 16:399, Bisgard JD, Swenson SA: Tumors of the sternum: report of a case with special operative technique. Arch Surg 56:570, Graham J, Usher FC, et al: Marlex as a prosthesis in repair of thoracic wall defects. Ann Surg 151:469, Usher FC: Knitted Marlex mesh. Arch Surg 82:771, Beardsley JM: The use of tantalum plate when resecting large areas of the chest wall. J Thorac Surg 19: