British Journal of Plastic Surgery (1997), 50, 37k-379 0 1997 The British Association of Plastic Surgeons
Ischial pressure sore coverage: a rationale for flap selection
R. D. Foster, J. P. Anthony, S. J. Mathes and W. Y. Hoffman
Division of Plastic and Reconstructive Surgery, University of California at San Francisco, California, USA
SUMMARY The role of wound debridement and flap coverage in treating pressure sores is clearly established. However, criteria and supportive clinical data for specific flap selection and the sequence of flaps for coverage of the ischium remain ill-defined. From 1979-1995, 114 consecutive patients underwent flap coverage of 139 ischial pressure sores. Preoperative risk factors, prior flap history, defect size, flap success, complication rates, and the length of hospitalization were retrospectively evaluated and compared for 112 flaps in 87 patients. Flap success was defined as a completely healed wound. Average follow-up was 10 months (range: 1 month-9 years).
Overall, 83% (93/l 12) of the flaps healed. In the majority of cases (75%, 84/l 12), wound debridement and flap reconstruction was achieved in a single stage. However, there were significant differences in the healing rates among the various flaps used. The inferior gluteus maximus island flap and the inferior gluteal thigh flap had the highest success rates, 94% (32/34) and 93% (25/27), respectively, while the V-Y hamstring flap and the tensor fascia lata flap had the poorest healing rates, 58% (7/12) and 50% (6/12), respectively. Flap success was not significantly affected by the age of the patient or the prior number of flaps used and preoperative risk factors were equally distributed across all types of flaps. The overall complication rate was 37% (41/112), most commonly from a slight wound edge dehiscence (n = 16) that healed with local wound care within one month postoperatively.
Results of this study show that proper flap selection and the appropriate sequence of flap use significantly improve success rates for ischial pressure sore coverage in both the short- and long-term. Based upon flap reliability (successful healing rates), reusability, and the need to preserve as many future flap options as possible, a rationale for flap selection is presented which can be individualized to any patient.
Accepted current surgical management of pressure sores consists of thorough debridement including involved bone, followed by flap coverage. Despite this and other non-surgical measures, pressure sore recurrence rates can still exceed 50%.* Frustration with these results has prompted a subset of surgeons to suggest that perhaps some or all of these patients have little to gain from any operative treatment.* However, much of the data to support this pessimistic view is based on initial operative success rates of only 80%.* Since pressure sores which fail to heal while the patient is hospitalized virtually never heal after discharge, the early postoperative results will clearly contribute to future outcomes.
Our experience has led us to believe that the most important step for early treatment success is appropri- ate flap selection. The spectrum of flaps used for ischial coverage includes the gluteus maximus, poster- ior thigh,4 hamstring,5 biceps fernoTis tensor fascia lata, gracilis, rectus abdominis and anterior thigh flaps.O Despite this wide variety of coverage options, the ischium remains the most difficult pressure sore site to treat.
The optimal approach to pressure sore coverage should include utilization of the most reliable flap to achieve a healed wound, while preserving as many future flap options as possible. Despite the widespread use of myocutaneous flaps in the treatment of pressure sores, few studies have critically analysed flap reliability, comparing one flap to another. The purpose of this study was to examine our 17-year surgical experience
with flap reconstruction for ischial pressure sore coverage and to compare and contrast flap reliability rates in obtaining a healed wound. Treatment efficacy was also analysed from several other perspectives including a flaps versatility for reuse, thereby main- taining as many future flap options as possible. Based upon these results, we have substantiated a rationale for flap coverage designed to treat a patient over his/her lifetime.
Patients and methods
From 1979 to 1995, 114 consecutive patients under- went flap coverage of 139 ischial pressure sores. From this group, there was adequate information available to permit detailed analysis of patients records for 112 flaps in 87 unselected patients (64 men, 23 women). Several patients had bilateral and/or recurrent ischial sores. The mean age of the patients was 49 years (range 16-90 years).
Chronic wounds (present for > 3 months) repre- sented 52% (58/112) of the total number of cases. In most cases the patients were paraplegic (89%) or quadraplegic (4%) and only 7% were ambulatory. In 75% (84/l 12) of the cases, the patients had their pres- sure sore debrided and reconstructed in a single stage. Patients were confined to bedrest postoperatively, usu- ally on an air-fluid bed, for lo-14 days followed by a programme of gradually increased weight-bearing (sitting) on the ischial area.
Ischial pressure sores 375
Table 1 Flaps selected and primary healing rates
Flap No. of eases Healed primarily (S) (54)
Inferior gluteus maximus island 34 (30.4) 94 Gluteal thigh 21(24.1) 93 Gracilis 16 (14.3) 75 V-Y hamstring 12 (10.7) 58 Tensor fascia lata 12 (10.7) 50 Anterior thigh 6 (5.3) 100 Rectus abdominis 5 (4.5) 100
Flap success and primary healing were defined as a healed wound within one month postoperatively, usually corresponding to the time of wound suture removal during the patients first follow-up visit. Reconstructive failure was defined as a case resulting in a non-healed wound. Follow-up ranged from 1 month to 9 years (average 10.7 months).
The flap selection for ischial sore coverage is listed in Table 1. Only musculocutaneous and/or fasciocuta- neous flaps were included in this series. The inferior gluteus maximus island flap was most commonly used (30.4%, 34/l 12) followed by the inferior gluteal thigh flap (24.1%, 27/112). Five of the six ambulatory patients were reconstructed with gracilis flaps. Flap success (healing) was compared between each flap. Risk factors for impaired wound healing, based on prior wound healing studies,2.z and complication rates were determined for each reconstruction. The age of the patient, number of prior flaps and defect size following debridement were analysed independently to test their effect on subsequent flap success. Significance was determined post hoc by the Chi squared test.
Overall, 83% (93/l 12) of the flaps healed primarily. 89% (75/84) of the cases treated in a single stage (debridement and flap reconstruction) healed primar- ily. For grossly infected (necrotic tissue) sores treated in a single stage, flap success was also 89%.
For flaps in which we had a significant experience (>lO cases), the inferior gluteus maximus island flap and the inferior gluteal thigh flap, had the highest success rates, 94% (32/34) and 93% (25/27), respectively (Table l), followed by the gracilis flap, the V-Y ham- string flap and the tensor fascia lata flap. The hospital stay averaged 21 days, 16.5 days for patients without prior complicated medical histories. The time to heal averaged 38 days. The earliest time healing could have occurred, as defined in this study, was 28 days (the earliest time of suture removal).
Complications occurred in 41 (37%) of the recon- structions (Table 2). There were no intraoperative deaths or significant donor site complications. A slight wound edge dehiscence (not > 1 cm in length or width) occurred in 16 patients but all of these wounds healed with local wound care alone within one month post- operatively. When flaps failed to heal, requiring further operative management, it was usually the result of
Table 2 Complications
Slight wound edge dehiscence (healed with local wound care) 16 Partial flap necrosis 10 Wound infection 5 Wound dehiscence (requiring reoperation) 5 Died, unrelated causes 2 Aspiration pneumonia 1 Intraop. myocardial infarct 1 Deep venous thrombosis 1
either partial flap necrosis (n = lo), inadequate debridement and the subsequent failure to adequately control infection (n = 5) or wound dehiscence (n = 5). Reoperation following instances of treatment failure involved either readvancement of a flap or harvesting of a different flap. The results of these decisions are included in the flap selection totals in Table 1. Flap necrosis was seen exclusively in one of three flaps: the tensor fascia lata flap (n = 5), gracilis (n = 3), and the V-Y hamstring (n = 2). Flap necrosis of the tensor fascia lata and gracilis flaps was always confined to the distal one third of the flap. Three out of five cases of wound dehiscence that ultimately failed to heal involved the proximal suture line across the V-Y ham- string flap. The other two cases of dehiscence were attributed to excessive tension with the wound closure. None of the ambulatory patients experienced signili- cant limitations to their range of motion or gait in the long term.
Among individual flaps, the inferior gluteus maxi- mus island flap appears to be very reliable. Although 6 cases resulted in a slight wound dehiscence success- fully managed with local wound care, no specific fac- tor(s) could be identified that would limit this flaps use. The only failed flap was the result of inadequate debridement. The inferior gluteal thigh flap was also very reliable. The two cases of failed reconstructions with the inferior gluteal thigh flap were the result of inadequate debr