In-Service Exam
Pressure Sore - 2003





An ambulatory 75-year-old man has a 6-cm grade IV pressure ulcer on the sacrum. The most appropriate management is reconstruction with which of the following?

(A) Bilateral gluteal myocutaneous advancement flaps
(B) Unilateral superior/inferior gluteal myocutaneous rotation flap
(C) Unilateral superior gluteal artery perforator flap
(D) Thin split-thickness skin graft

The correct response is Option C.

The unilateral superior gluteal artery perforator flap is most appropriate for reconstruction of the area of the sacrum affected by the pressure ulcer. Perforator flaps can be based on either the superior or inferior gluteal artery. They provide adequate myocutaneous coverage and at the same time preserve the gluteal muscles on the involved side. As a result, morbidity at the donor site will be minimized, which is especially important in this patient because he is ambulatory.

Although a bilateral superior/inferior gluteal myocutaneous advancement flap supplies sufficient soft-tissue coverage for pressure ulcers, harvest of the inferior and superior gluteal muscles will result in significant morbidity at the donor site. Harvest of a gluteal myocutaneous rotation flap sacrifices muscle function and also is not the procedure of choice in an ambulatory patient. Thin split-thickness skin grafts do not provide stable coverage of pressure ulcers.

References
1. Higgins JP, Orlando GS, Blondeel PN. Ischial pressure sore reconstruction using an inferior gluteal artery perforator (IGAP) flap. Br J Plast Surg. 2002;55:83.
2. Ramirez OM, Orlando JC, Hurwitz DJ. The sliding gluteus maximus myocutaneous flap: its relevance in ambulatory patients. Plast Reconstr Surg. 1984;74:68.
3. Verpaele AM, Blondeel PN, Van Landuyt K, et al. The superior gluteal artery perforator flap: an additional tool in the treatment of sacral pressure sores. Br J Plast Surg. 1999;52:385.

A 50-year-old man with a two-year history of paraplegia develops a grade IV right ischial pressure ulcer with a diameter of 4 cm. Total ischiectomy is performed, and the wound is covered with a gluteal thigh flap. Which of the following complications is most likely in this patient?

(A) Flap loss
(B) Left ischial pressure ulcer
(C) Marjolin's ulcer
(D) Pulmonary thromboembolism
(E) Urethrocutaneous fistula

The correct response is Option B.

Although total ischiectomy decreases the rate of recurrence of ischial pressure ulcers, removal of one ischium transfers the weight to the opposite side when the patient sits, increasing the likelihood of an ulcer on that side. One study showed an incidence of contralateral ischial pressure ulcers of 28% in patients who had undergone total ischiectomy. In contrast, patients who underwent total bilateral ischiectomy, in which weight bearing is transferred to the perineum and pelvis, were more likely to develop perineal ulcers and urethrocutaneous fistulas. Fistulas were shown to occur in 58% of patients who had undergone this procedure.

Necrosis leading to flap loss is rare in flap transfers involving a major vascular pedicle.

Marjolin's ulcer, or malignant degeneration, has an incidence of 0.5% in patients with pressure ulcers, and also occurs in other types of chronic wounds. Aggressive squamous cell carcinomas are associated; lymph node involvement is estimated at 60%, and mortality rates are high.

Thromboembolism is a frequent cause of death immediately after the onset of paraplegia but is not common in patients with long-term paraplegia undergoing routine excision and reconstruction procedures.

References
1. Hackler RH, Zampieri TA. Urethral complications following ischiectomy in spinal cord patients: a urethral pressure study. J Urol. 1987;137:253-255.
2. Mustoe T, Upton J, Varcellino V, et al. Carcinoma in chronic pressure sores: a fulminant disease process. Plast Reconstr Surg. 1986;77:116-121.
3. Phillips LG, Robson MC. Pressure ulcerations. In: Jurkiewicz MJ, Krizek TJ, Mathes SJ, et al, eds. Plastic Surgery: Principles and Practice. Saint Louis, Mo: CV Mosby Co; 1990;2:1223-1251.

In a patient who has a large, deep, chronic grade III pressure ulcer of the ischium, calcium alginate dressings are most likely to be used because they have which of the following properties?

(A) Ability to absorb exudate
(B) Ability to provide a moist environment for epithelialization
(C) Antiinflammatory activity
(D) Antimicrobial activity
(E) Hemostatic activity

The correct response is Option A.

Calcium alginate dressings are xerogels, or dry dressings that become gel-like in the presence of exudate; therefore, they are commonly used for grossly exudative wounds, such as deep ulcers, because they are able to absorb a large quantity of exudate. These dressings contain mannuronic and guluronic acids and are derived from Laminaria seaweed. Patients with exudative wounds typically require frequent dressing changes with other types of dressing because maceration (resulting from the excess moisture) can develop around the margins of the wound. In contrast, alginate dressings need to be changed only every 24 to 48 hours.

Alginate dressings provide a moist environment that is conducive to wound healing, but secondary bio-occlusive dressings should also be applied to prevent drying. They provide an environment that is favorable to epithelialization, which is less pertinent than contraction in a patient with a pressure ulcer. Alginates are thought to decrease infection by trapping microorganisms and cellular debris, but do not have inherent antimicrobial properties. Because these dressings promote inflammation, they can cause foreign body reactions in some patients. Calcium alginates have procoagulant activity and have been used to cover skin graft donor sites, but this is not a factor in a patient who has a chronic wound.

References
1. Disa J, Alizadeh K, Smith JW, et al. Evaluation of combined sodium alginate and bio-occlusive membrane dressing in the management of split thickness donor sites. Ann Plast Surg. 2001;46:405-408.
2. Ladin DA. Understanding dressings. Clin Plast Surg. 1998;25:433-441.
3. Moffat CJ, Oldroyd MI. Assessing a calcium alginate dressing in management of pressure sores. J Wound Care. 1992;1:22-44.

An 18-month-old boy has a 25-cm pigmented lesion on his back. Which of the following is the most appropriate management?

(A) Observation with photographic mapping
(B) Intralesional injection of interferon gamma
(C) Dermabrasion
(D) Tunable dye laser ablation
(E) Excision

The correct response is Option E.

This 18-month-old boy has a giant congenital nevus on the back. Congenital nevi can be classified as "giant" according to several criteria, including those lesions that are larger than 20 cm in diameter, lesions that are greater than twice the size of the patient's palm, and those nevi for which excision and primary closure cannot be performed as a single procedure. Because of the potential for malignant transformation, surgical excision of the entire lesion is recommended. Although the actual risk for melanoma is controversial, one study reported that approximately 8% of patients with giant congenital nevi developed melanoma during the first 15 years after the initial appearance of the nevus.

Although observation with serial photographic mapping is advocated in patients with familial dysplastic nevus syndrome, it is not appropriate in a patient with a giant congenital nevus because of the association with malignancy. Intralesional injection of interferon gamma is indicated for patients who have confirmed malignant melanoma. Dermabrasion and laser ablation will not remove all of the immature melanocytes within the lesion. In addition, the resultant hypopigmentation seen following treatment may hinder any future monitoring for signs of malignant degeneration.

References
1. Casson P, Colen S. Dysplastic and congenital nevi. Clin Plast Surg. 1993;20:105-111.
2. Gosain AK, Santoro TD, Larson DL, et al. Giant congenital nevi: a 20-year experience and an algorithm for their management. Plast Reconstr Surg. 2001;108:622-631.