A review of the TOPHAT (Turned-down Onto Pericapsular-tissue Hemisectioned Amputated Toe) filleted toe flap technique for wound coverage during ray amputations

Abstract

Background: Wound healing post ray amputation for toe gangrene is commonly complicated by adjacent digital loss after applying Topical Negative Pressure Wound Therapy (TNPWT). This is either due to mechanical soft tissue erosion or trauma to the adjacent digital artery from direct pressure effect. This ultimately results in exposure of the adjacent Metatarsal-Phalangeal Joint (MTPJ) with eventual gangrene and a larger wound bed, thus mandating further ray amputation and subsequently enlarge the wound bed. We describe the use of the TOPHAT filleted toe flap technique – a combination of a filleted toe flap to protect the adjacent MTPJ capsule and a novel Negative Pressure Wound Therapy with instillation and dwell-time (NPWTi-d) dressing technique. The fillet flap protects the adjacent joint capsule and reduce the wound burden whilst allowing the wound to benefit from TNPWT, thereby accelerating wound healing. Methods: We conducted a prospective review of patients with toe gangrene requiring ray amputations who underwent the TOPHAT filleted toe flap technique in our institution from 2019 and 2020. Complications such as wound dehiscence, hematoma, flap necrosis and secondary infection were recorded. Other outcomes recorded were time taken to final skin grafting and time taken for complete wound epithelialisation. Results: 9 patients underwent treatment with the TOPHAT filleted toe flap technique between 2019 and 2020. 2 patients had minimal tip necrosis of the flap which required minor debridement. All except 2 patients whom declined further treatment, progressed to definitive skin coverage with skin grafting. One patient had progressive arterial disease despite successful skin grafting and required above knee amputation. The mean time to final skin grafting was 49.5 days post-operatively and the mean time to final wound epithelialisation was 107.5 days post-operatively. Patients were all satisfied with the outcomes and were able to return to pre-morbid function. Conclusions: The TOPHAT filleted toe flap technique has a consistent vascular supply that provides durable soft tissue coverage. It is a robust and easily reproducible technique to accelerate wound healing after ray amputations even in patients with peripheral vascular disease.