Buruli ulcer - Management of Mycobacterium ulcerans disease
This chapter will assist you to perform simple operations and to choose which patients to refer for specialized management.
- All excisions must include a margin of healthy tissue.
- Sutures should be removed only when the wound has securely healed.
- Contractures always need early referral to a major hospital.
- Exsanguinate affected limbs by elevation alone.
Currently, surgery is the only proven effective treatment for M. ulcerans disease. Combination antibiotic therapy targeting M. ulcerans may be a beneficial adjunct to surgery. Note: its efficacy is not proven. Antibiotics may be necessary to control super-infection. These agents may be chosen on the basis of disease presentation and the practitioner’s experience. Antibiotic therapy should be subsequently tailored according to culture and sensitivity results.
Papule: The procedure is the same as for a nodule. Depending upon the location of the lesion, the wound may be difficult to close by suture. If the wound edges cannot be brought together without undue tension, it is better to stop the bleeding and to leave the wound open. A split-skin graft should then be applied at a later date. Otherwise, the wound should be dressed and the patient referred to hospital.
Nodules : should be excised only by appropriately trained health care providers. You must remove a nodule with a clear margin of normal tissue (Fig. 15a–d). The line of excision should be parallel to any nearby joint flexion crease. Remember to send a sample of the excised tissue for laboratory examination. Depending on the location, some lesions may be excised and the wound closed primarily by suture without undue tension. Large surgical wounds require split-skin grafting. Sutures are removed at 7 to 14 days, depending on the location of the wound and the progress of healing.
Plaque: This is a more serious form of the disease which requires extensive excision (Fig. 16a–c) followed by split-skin grafting. Skin grafting over a flexion crease necessitates post-operative splinting and subsequent therapy to minimize flexion contracture.
Oedematous form: This form of the disease is complex. Urgent referral to a specialized centre is mandatory. Initial management should include elevation of the affected limb. At the specialist centre, an exploratory incision is made along the long axis of the oedematous area followed by blunt dissection of the affected tissue to reduce bleeding (Fig. 17a–d*). Electro-cautery is an effective way of reducing blood loss.
The plane of excision usually spares deep fascia but, in some advanced cases extending deep to the fascia, the excision may include deep fascia and even muscle. Wherever possible, a pneumatic tourniquet is applied— but not for longer than two hours.
The surgical treatment of small ulcerative lesions is the same as that for nodules and papules (Fig. 18a*). Larger lesions require excision (sometimes in stages) and split-skin grafting (Fig. 18b-d*). Apply a pneumatic tourniquet whenever possible. Prior to surgery, secondarily infected lesions should be dressed, affected limbs elevated and appropriate antibiotics administered.
Technique of excision
The required excision may be extensive. Large lesions may require staged excision, one area at a time. The excision must include healthy tissue at the lateral and deep margins. The deep fascia should be preserved if not involved but involved deep fascia must be removed, taking care not to open tendon sheaths or joints and not to damage important nerves and blood vessels. When diseased tissues have not been removed adequately, repeated excisions may be necessary. It is recommended that extensive lesions should be treated only at level two and level three services.
Split-skin grafting technique
Skin for grafting may be harvested using a razor or scalpel blade (Fig. 19*), a Humby type knife or an electric dermatome.
The usually preferred sites for harvesting split-skin include the external aspect of the thigh and upper arm, the buttocks, the internal and external aspects of the forearm and the external aspect of the lower leg (in some instances, experienced surgeons choose split-skin graft donor sites that are later less visible).
To lessen friction, lubricate the intended donor site with a little sterile vaseline or liquid paraffin. Stretch the skin of the donor site by means of a metal plate at each end. Take thin split-skin grafts to allow donor-site healing within 21 days. Keep the skin graft moist with normal saline at all times.
To cover large areas, split-skin grafts may be expanded, preferably using a skin graft expander which does not require expensive disposable components.
Split-skin grafts may be secured at their edges and junctions using sutures or staples. Suture fixation of all full thickness skin grafts is advised. Vaseline gauze is applied, then a further thick absorbent dressing and a bandage.
Materials which may be used to make splints include: plaster of Paris for brief immobilization, aluminium, wood (which may be carved), fibreglass, and polyvinylchloride (PVC).
An alternative for the lower and upper limbs is suspension with slings and cords (Fig. 20), thus maintaining the joints in appropriate positions during the post-operative period.
Remove the surgical dressings on the third or fourth post-operative day unless there is haematoma or infection. Thereafter, change the dressings daily or on alternate days. As soon as the graft has taken (at about 10 days post-operatively) commence mobilization.
To prevent joints from becoming stiff, limbs are best splinted with their joints in the following positions:
- knee in extension
- ankle at a right angle
- elbow in extension
- wrist in extension
- metacarpo-phalangeal joints in flexion
- interphalangeal joints in extension
Complications and sequelae
Complications such as contractures and loss of body parts, for example, the eye, ear, nose, and breast, always necessitate early referral to a major hospital for surgery and reconstruction. Specialist teams may visit district or local hospital services to provide treatment, such as the release of contractures. Contractures should be released only as far as is safe, taking into account tension on blood vessels and nerves. Skin defects are then covered by grafts or flaps, including musculo-cutaneous and muscle flaps.
Involvement of the genitalia constitutes a serious complication requiring immediate referral for specialized attention (Fig. 21*).
After cleaning and dressing, eyelid and eye involvement necessitate urgent referral to a specialized centre (Fig. 22a and 22b*).
The face, neck and breast
After the initial management, patients with lesions on the face, neck and breast must be referred to a specialized centre (Fig. 23, 24, 25*).
Involvement of bone
Bone involvement occurs by direct extension from a surface lesion into the bone or an adjacent joint or as osteomyelitis. Patients with bone involvement must be referred immediately to a specialized centre.
Surgical treatment of osteomyelitis
At operation, a limited exposure of the swelling and/or fistula track suffices for drainage of the abscess and for debridement of the gelatinous infected tissue. Extensive excision is not often required but, in some instances, definitive excision of infected soft tissues may be indicated. Post-operatively (Fig. 26a*), the wound may be irrigated with antiseptic solutions (Fig. 26b*).
A drain is inserted and the wound is partially closed but, at times, an experienced surgeon will close the wound to prevent secondary infection. If present, an open wound should be dressed regularly until satisfactory granulation tissue develops and split-skin grafting can be performed. Granulating wounds can be sequentially grafted as areas become clean enough for grafting.
Localized epiphyseal lesions (e.g. lesions involving the femoral condyles, the tibial plateau and the small bones of the hand and foot) often require repeated partial removal of involved bone in order to preserve the adjacent articular structures. The application of splints, plaster of Paris casts with windows or external fixation is essential to support the bone and thus to prevent pathological fractures—without interfering with wound care. X-rays at four to six weekly intervals are recommended to follow bone healing.
Surgical treatment of reactive osteitis
Reactive osteitis is a much less serious condition which should be treated conservatively. As retaining hypertrophied periosteum protects the underlying bone, debridement over bone is best limited to curettage, preserving as much periosteum as possible. Daily dressings lessen the risk of progression of bone involvement and promote the growth of granulations.
Necrotic cortical bone should be removed only after it has fully demarcated, as manifested by the growth of granulation tissue around and beneath it. Excessive bone removal must be avoided.
The ulcer may be excised and then partially grafted while awaiting separation of devitalized cortical bone. Grafting is completed after removal of the sequestrum. In the meanwhile, immobilization in the preferred position guards against pathological fractures and later contractures.
When there is extensive or circumferential tissue loss over a joint (e.g. elbow, wrist, knee, ankle), external fixation is applied at the time of the first procedure to keep the joints in the best possible position for function (Fig. 27*). As noted above, external fixation facilitates dressings. External fixation is removed when healing is complete.
Amputation should only be performed when reconstructive measures are impossible or have failed. It is rarely
necessary. Ordinarily, the decision to amputate a limb should be taken in consultation with a specialist but severe
uncontrollable bleeding may, occasionally, constitute a sufficient indication for an immediate life saving amputation.
Steps for amputation are illustrated in figure 28.
Other clear indications for amputation include:
- completion of a necrotic auto-amputation;
- septicaemia/gangrene that would be life threatening without amputation;
- destruction of the function of a foot;
- extensive bone destruction.
What you should not do!
- Do not prolong dressing regimens when excision is appropriate.
- Do not rush to immediate excision.
- Avoid prolonged non-specific antibiotic therapy.
- Do not rely on specific antibiotics alone.
- Do not perform incisional or punch biopsy of a small lesion. Excisional biopsy is preferable.
- Do not infiltrate a local anaesthetic into any lesion.
- Do not apply an Esmarch bandage over a lesion. Exsanguinate the limb by elevation alone.
- Do not allow excessive blood loss (use a pneumatic tourniquet wherever possible).
- Do not rely on curettage alone (except for osteomyelitis or when major structures are involved).
- Do not count on spontaneous healing.
- Do not burn your patient (after autoclaving remember to cool your instruments before use, especially your graft mesher).
- Do not cover possibly infected tissue with a skin flap (flap cover requires special training).
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