Coverage of the infected wound

Impediments to wound healing

Chronic wounds will often heal in a short period of time if factors that inhibit wound healing are identified and managed. Recombinant growth factor therapy may provide an added stimulus to healing in certain types of chronic wounds. However, there remains no substitute for a physiologic environment conducive to tissue repair and regeneration, without which the efficacy of growth factor therapy is questionable. Some of the most commonly encountered and clinically significant impediments to wound healing include wound hypoxia, infection, presence of debris and necrotic tissue, use of anti-inflammatory medications, a diet deficient in vitamins or minerals, or general nutritional deficiencies, tumors, environmental factors, and metabolic disorders, such as diabetes mellitus. Treatment of chronic wounds should be directed against the main etiologic factors responsible for the wound. Moreover, factors that may impede healing must be identified and, if possible, corrected, for healing to occur.

Pressure ulcers

Pressure ulcers are localized areas of tissue necrosis that result from unrelieved pressure. They are graded or staged according to the degree of tissue damage observed. The main etiologic factors include pressure, shearing forces, friction, and moisture. The clinical course may be complicated by several conditions including infection, sepsis, osteomyelitis, fistulas, and carcinoma. Preventive measures in persons at risk can significantly reduce the incidence of pressure ulcers. Successful management should address the four etiologic factors as well as the general condition of the patient.

The fate of lower extremities with failed free flaps

This study reviews the outcome of patients with failed free flaps to lower extremities. The failure rate was 10 percent (41 of 413 flaps) over a 13-year period. Trauma patients (83 percent of all patients) had a failure rate of 11 percent, while nontrauma patients had a failure rate of 6.7 percent. The most common cause of failure was venous thrombosis (34 percent). Eight of 36 patients (22 percent) went on to amputation after the failed free flap; all were trauma patients. Patients with tibia-fibula fractures had a 35 percent amputation rate (6 of 17 patients) after a failed free flap. Seventy-eight percent of the patients (28 of 36) had salvage of their extremities by split-thickness skin graft, local flaps, or a second free flap. Long-term follow-up was available in 24 of 36 patients (67 percent), 20 of whom were salvaged without amputation. Of the patients whose limbs were salvaged, none had undergone an amputation at a mean follow-up of 6.2 years. All were ambulating, but 7 (35 percent) had intermittent wound breakdown. Despite an initial free-flap loss, the majority of extremities can be salvaged with subsequent procedures. However, on long-term follow-up, a large percentage of patients continue to have wound problems.

Lower limb salvage: microvascular reconstruction of post-traumatic soft tissue and skeletal defects

This study reviews the principles of reconstructive microsurgery for lower limb salvage after severe open tibial fractures. Initial decision-making principles are reviewed with reference to useful scoring systems directed at appropriate patient selection for limb salvage. Soft tissue reconstruction is discussed with emphasis on timing and selection. Skeletal reconstruction focuses on available options and indications.

The transpelvic rectus abdominis flap: its use in the reconstruction of extensive perineal defects

We present our experience of rectus abdominis flaps tunnelled transpelvically in 12 patients (mean age 48.4 years, range 19-72 years) with a diverse range of surgical pathologies, the largest reported series to date. Satisfactory obturation of the pelvic cavity and control of radionecrotic tissue sepsis was achieved. Average duration of hospital stay was 17.6 days with a mean follow-up of 18.7 months. The rectus abdominis flap provides a significant volume of well-vascularised tissue, ideally suited for reconstruction of extensive perineal defects after tumour ablative surgery. When tunnelled transpelvically, the flap is unique in its ability to obturate the pelvic inlet, eliminating the distressing complication of perineal bowel herniation and allowing for perineal radiotherapy.

Blood flow in free muscle flaps measured by color Doppler ultrasonography

Color Doppler ultrasonography, a noninvasive method for studying changes in blood flow, has been used to monitor 18 patients with free microvascular lower limb muscle flaps. The peak, mean, and minimum velocities, resistance indices, and diameters of the flap pedicle arteries and also of the limb recipient arteries proximal to the microvascular anastomoses were measured at 2 and 6 weeks and 3, 6, and 9 months after surgery. The peak velocities did not significantly differ from each other, but the mean velocity in the flap pedicle arteries was 12.5% higher than that in the recipient arteries throughout the study period. End diastolic velocity in the pedicle was positive (toward the ultrasound probe) at 2 weeks (mean, 2 cm/sec, SD 10), 6 weeks (mean, 5 cm/sec, SD 16), and 3 months (mean, 3 cm/sec, SD 13) after surgery and significantly higher (P < 0.05) than at 6 months (mean, 7 cm/sec, SD 11), when the pattern of blood flow was normal forward/backward flow during systole/diastole. The resistance indices of the pedicle at 2 weeks (Ri = 0.978), 6 weeks (Ri = 0.936), and 3 months (Ri = 1.001) were significantly lower (P < 0.05) than at 6 months (Ri = 1.108), when the pedicle and recipient artery indices were the same. The diameter of the pedicle arteries was 14% smaller than those of the recipient arteries, but did not change during follow-up. This prospective clinical study shows that blood flow in the pedicle of a free microvascular muscle flap is increased until 6 months after surgery, mainly due to the increased minimum velocity of the pedicle in diastole and decreased resistance index. These findings can be attributed to the loss of vessel tone after denervation and are in accordance with earlier studies showing that denervated muscles lose their autoregulation and that blood flow increases, but that these phenomena subside with time. Increased blood flow in free muscle flaps can explain the high success rate of microanastomoses and positive effect on wound healing.

Anatomic basis for use of a gracilis muscle flap

The aim of this study was to specify certain anatomic features of the gracilis m. with a view to the use of muscular or myocutaneous flaps. It was based on dissection of 84 gracilis muscles in 42 subjects as well as selective injection of the main pedicle of 20 muscles. This established the following points: 1) The arterial supply is abundant, consisting of several pedicles reaching the muscle on its deep aspect. The main neurovascular pedicle arises from the deep vessels of the thigh, via either the a. of the adductors (73%), the medial circumflex a. (19.2%) or as a double supply from both arteries (7.7%); 2) The cutaneous vascularisation over the gracilis m., derived from the solitary main pedicle, is inconstant. In 20 injections, it was satisfactory in 11 cases, poor in 5 and absent in 4; 3) The distal tendon of the gracilis m. is closely related to the posterior branch of the saphenous n. to the leg, which it crosses in an elongated X; 4) A simple method of calculation based on the distance between the upper border of the pubis and the medial femoral epicondyle allows quite precise determination of the point of entry of the main pedicle into the gracilis m. 5) Complete dissection of the main pedicle adds to the available length of the muscle flap.

Treatment of chronic recurrent synovial fistulae with myofascial flaps

Chronic recurrent synovial fistulae of the knee are uncommon. They can occur as a surgical complication or as a consequence of traumatic injuries. Conservative treatment is usually adequate for initial management, but no consensus exists about the treatment for chronic or recurrent cases and the literature on the subject is scarce. Two cases are presented in which initial conservative and subsequent conventional surgical management failed and reconstruction with regional myofascial flaps was required.

Dynamic properties of blood flow and leukocyte mobilization in infected flaps

Two aspects of the inflammatory response to infection--blood flow alteration and leukocyte mobilization--are investigated in the canine model. The elevation of paired musculocutaneous (MC) and random pattern (RP) flaps allowed comparison of healing flaps with significant differences in blood flow (lower in random pattern flaps) and resistance to infection (greater in musculocutaneous flaps). Blood flow changes as determined by radioactive xenon washout were compared in normal skin and distal flap skin both after elevation and following bacterial inoculation. Simultaneous use of In-111 labeled leukocytes allowed determination of leukocyte mobilization and subsequent localization in response to flap infection. Blood flow significantly improved in the musculocutaneous flap in response to infection. Although total leukocyte mobilization in the random pattern flap was greater, the leukocytes in the musculocutaneous flap were localized around the site of bacterial inoculation within the dermis. Differences in the dynamic blood flow and leukocyte mobilization may, in part, explain the greater reliability of musculocutaneous flaps when transposed in the presence of infection.

Perineal, vulval and vaginoperineal reconstruction using the rectus abdominis myocutaneous flap

Poor perineal healing is a major complication of total or partial pelvic exenteration especially when the pelvis and perineum have previously been irradiated. Perineal, vulval or vaginoperineal reconstruction was performed in five women using the inferiorly based rectus abdominis myocutaneous flap. Primary perineal wound healing occurred in all patients and no flap-related complications developed. Primary healing of abdominal wall wounds occurred in all patients without incisional hernia. Three of the patients had an anterior or total pelvic exenteration with continent urinary diversion by the Mitrofanoff technique. Two of the patients had complete vaginal reconstruction and one patient had after-loading catheters inserted for postoperative interstitial irradiation. The patients were in hospital for 42, 28, 21, 17 and 15 days respectively. The longest stays were associated with training for self-catheterization of the continent urinary diversion. Median follow-up was 9 months. One patient developed two perineal recurrences at 16 months which were resected, and she remains disease-free 6 months later.

Oxygen as an isolated variable influences resistance to infection

The relative importance of oxygen in relation to resistance to infection was assessed in 24 mongrel dogs. Rectus abdominis musculocutaneous (MC) and corresponding cutaneous random pattern (RP) flaps based at the level of the xiphoid were elevated, replaced, and sutured. Immediately after the surgical procedure, 0.1 ml saline containing 10(8) Staphylococcus aureus/ml was injected intradermally into six fields of each flap. After the operation, the dogs were caged in controlled environments with different oxygen concentrations at 12%, 21%, and 45% for 3 days. After 24, 48, and 72 hours, lesion size was measured. Different lesion size was noted between the hypoxic and the hyperoxic groups in the MC flaps from the first day on and in the RP flaps from the second day on (p less than 0.05). Resistance to infection with S. aureus is oxygen dependent, particularly when tissue PO2 is below 40 mmHg.

The physiology of wound healing

Many of the biochemical events of wound healing are prisoners of the victim's physiologic state. Although the initial local events of inflammation occur normally in any viable tissue, the subsequent reparative capacities of macrophages, fibroblasts, and endothelial cells are seriously impaired by any compromise of local perfusion and oxygenation. In particular, the bacteriocidal capacities of granulocytes are heavily dependent on local oxygenation/perfusion, nutrition, and endocrine status. This article depicts the local mechanisms of repair with special attention to the means by which physiologic and nutritional support at the clinical level influence repair, even to a point at which wound healing may exceed contemporary expectations. Without appropriate physiologic, nutritional, and endocrine support, wound healing often fails totally. It is now possible, although not always easy, to achieve optimal physiologic support.

Free serratus anterior muscle transplantation for hand reconstruction

Free transplantation of the serratus anterior muscle has allowed salvage or reconstruction of difficult hand injuries with advantages compared to traditional methods. Free muscle tissue adds vascularity to poorly vascularised and potentially infected wounds and allows hand elevation and early mobilisation. Dynamic reinnervation is possible with segmental preservation of the long thoracic nerve. The serratus anterior muscle is easily harvested and has a long, reliable vascular pedicle. It is thin, easily contoured to the defect and can be separated into its component slips. The muscle provides stable coverage when covered with a meshed split thickness skin graft. Scapular winging does not occur since only the lower two or three slips of muscle are used. The muscle has been used in 15 complex hand wounds, three within a week of revascularisation or digital replantation for hand salvage. Three dynamic muscle transfers were performed to restore thumb opposition with one simultaneous toe-to-thumb transplantation.

Reconstruction of posterior neck and skull with vertical trapezius musculocutaneous flap

The vertical trapezius musculocutaneous flap has been successfully utilized for reconstruction in 13 patients with complex posterior skull and neck defects. This flap based on its vascular pedicle, the descending branch of the transverse cervical artery, provides well-vascularized tissue for coverage of defects related to chronic osteomyelitis, tumor extirpation, osteoradionecrosis, and dehisced cervical laminectomy wounds. Emphasis on flap design, including the location of the skin island, allows adequate wound coverage, direct donor site closure, and muscle function preservation. With its large size and wide arc of rotation, the vertical trapezius musculocutaneous flap provides reliable coverage for posterior trunk, cervical, and skull defects.

Chemosurgical debridement of osteomyelitic bone by zinc chloride fixative

Zinc chloride fixative (as described in fixed-tissue Mohs surgery) is useful as a chemical debridement method for osteomyelitic bone. We describe a case of an 86-year-old female with a 67-year history of an osteomyelitic ulcer of the anterior tibia. Previous attempts at surgical extirpation of the bone followed by immediate or delayed repair by orthopedic and plastic surgery services had eventuated in recurrence of the basic osteomyelitic process. Below-the-knee amputation was recommended as the only alternative to treatment. However, we chose to apply zinc chloride fixative which penetrated the full thickness of cortical bone and revealed a wider and deeper extent of the infectious process than previously recognized. Following removal of the fixed bone, a muscle flap repair followed by split-thickness skin grafting was done by plastic surgery. The patient remains ulcer and symptom free 31 months postoperatively. We feel zinc chloride fixative is useful as an adjunct to other surgical means of extirpation of bone as it is tissue sparing and more accurately determines the extent of involved bone when infected.

Free vascularized flaps for lower extremity reconstruction

Large wounds of the lower extremity, particularly distal to the knee, have been difficult to cover by traditional means such as skin grafts, local flaps, cross-leg flaps and jump flaps. These wounds, particularly when associated with fractures and osteomyelitis, have frequently resulted in amputation of the lower extremity. Microvascular surgical techniques have allowed the transfer of large flaps of skin and/or muscle from a remote site of the body to the defect in the leg for soft tissue coverage and additional blood supply to the defect. Although these techniques are more tedious and require longer operating times, they usually shorten the patient's hospital stay, heal the wounds faster and shorten disability time. With wider experience, improved techniques and greater microsurgical skill, lower limbs with large defects due to trauma or tumor resection can be salvaged and reconstructed with acceptable risks and minimal donor site morbidity.

Improved management of the perineal wound after proctectomy

In an effort to avoid the failures of perineal wound healing that are common after proctectomy, 57 patients who had abdominoperineal resection of the rectum or total proctocolectomy for ulcerative colitis (35 patients), Crohn's colitis (12), or carcinoma (10) had primary closure of the levator muscles and perineal tissues. No attempt was made to approximate the pelvic peritoneum. The small bowel was allowed to fill the pelvic space, which was also drained by suction catheters brought out through the lower abdominal wall. The skin and subcutaneous tissues were allowed to heal by secondary intention in seven patients who had excessive preoperative perineal sepsis from fistulas, deep fissures, and abscesses. All seven wounds healed within 2 months. Of the other 50 patients, whose wounds were closed to the skin, 48 were discharged with completely healed perineal wounds. Two patients had sterile pelvic hematomas that drained through the perineum and delayed wound healing 1 month and 2 months. There were no postoperative perineal, pelvic, or intraabdominal abscesses. Immediate postoperative ambulation was allowed. There was no increased short-term or long-term incidence of small bowel obstruction related to this procedure, nor did perineal hernia occur after long-term observation (mean: 5.3 years). This method of accomplishing perineal wound healing is simpler, safer, more comfortable, and remarkably effective in eliminating the prolonged morbidity of an unhealed perineal wound. It is superior to any other reported method of managing the perineal wound in patients with inflammatory bowel disease and may be applicable to the treatment of cancer without compromising the chances for cure.

Urologic use of gracilis muscle flap for nonhealing perineal wounds and fistulas

A chronic sinus or urinary fistula in the perineum secondary to surgery and/or radiation therapy for pelvic malignancy may cause serious morbidity and be difficult to treat. The gracilis muscle, either by itself or as a myocutaneous flap, has excellent properties for aiding in healing. Over a six-year period, three nonhealing perineal wounds and three urinary fistulas have healed after the gracilis muscle flap procedure.

A survey of 77 major infectious complications of median sternotomy: a review of 7,949 consecutive operative procedures

Sternal wound infections developed following 77 (0.97%) of 7,949 operative procedures involving median sternotomy at New York University Medical Center from 1976 to 1984. Risk factors associated with the development of a sternal wound infection included combined revascularization and valve replacement, early reexploration for bleeding, prolonged low cardiac output syndrome, and prolonged ventilatory support (greater than 24 hours). Concomitant infection at other sites with the same organism as cultured from the sternum was present in 42% of the patients. Thirty-seven patients (48%) were treated with radical debridement followed by closed antibiotic irrigation. In 31 other patients (40%), the wounds were debrided and left to heal by open granulation. Both initial treatments had equally high success rates (78.4% and 74.2%, respectively). However, the open granulation method resulted in a hospital stay that was an average of 10 days longer than the closed antibiotic irrigation method. Muscle flaps were used to expedite healing of open granulation in 9 patients. Analysis of the results of different treatment strategies revealed that if debridement was accomplished within 20 days of the initial cardiac procedure, 76% of the patients could be successfully treated with closed antibiotic irrigation. Conversely, if treatment was delayed for longer than 20 days, 81% of the patients were treated with open granulation (p less than 0.001). Also noted was an inverse relationship between the serum blood urea nitrogen (BUN) level and the success rate of initial treatment with closed antibiotic irrigation. Patients with a serum BUN level of less than 40 mg/dl at the time of debridement had a 90% success rate as opposed to a success rate of 38% when the BUN level was 40 mg/dl or greater. The data presented suggest the following conclusions. Early diagnosis is crucial to successful treatment of sternal wound infection. When diagnosis can be established within 20 days, 80% of infections can be eradicated by the simple approach of debridement and closed antibiotic irrigation. When diagnosis is delayed, however, prompt debridement followed by muscle flaps is the procedure of choice. Open granulation alone, while successful, unnecessarily prolongs the hospital course.

The use of a rectus abdominis myocutaneous flap to reconstruct a groin defect

An inferiorly based rectus abdominis myocutaneous skin flap was used carrying a large transversely aligned superior abdominal skin paddle to close successfully an infected and seriously compromised wound in the contralateral groin. The versatility of the rectus abdominis myocutaneous muscle unit, with its dual blood supply, is indicated yet again.

Gracilis muscle flap for the persistent perineal sinus of inflammatory bowel disease

A persistent perineal sinus may develop in patients undergoing proctocolectomy for inflammatory bowel disease. Healing may resist the traditional methods of wound management. Wide excision including coccygectomy, transposition of the vascularized gracilis muscle flap into the rigid cavity, and wound closure have led to healing in 12 of 15 patients and vast improvement in two others. There has been only one failure. Aggressive reoperation can achieve success after initial failure. Women may present a more difficult challenge than men. A primary wound healing deficit may be present.