Recurrent pedal hobnail (Dabska-retiform) hemangioendothelioma with forefoot reconstructive surgery using a digital fillet flap

Utility of the Digital Fillet Flap

The digital fillet flap provides a good option for coverage of forefoot soft tissue deficits. Understanding of the anatomy, coupled with careful patient selection, improves surgical outcomes. Similar to other fasciocutaneous flaps, the surgeon needs to be familiar with delay techniques and proper inset to minimize complications.

Digital Fillet Flaps: A Systematic Review

Digital fillet flaps have a consistent vascular supply and provide durable soft-tissue coverage. Despite their readily available nature, their use in the foot remains limited. This systematic review was undertaken to determine the size defect that could be covered, the potential postoperative complications, and the durability of a digital fillet flap. Studies were eligible for inclusion if they involved use of the entire digit for soft-tissue coverage of defects of any etiology, reported complications, and had any length of follow-up time. A total of 9 studies met all the inclusion criteria, for a total of 34 patients with a combined mean age of 47.1 years and a combined mean follow-up time of 9.3 months. Complications consisted of continued infection and partial or total necrosis of the flap. Digital fillet flaps were able to cover defects up to a combined mean size of 15.6 cm2. Coverage was found to be best for forefoot ulcerations. The flaps had limited donor site morbidity and provided full coverage of exposed vital and osseous structures that was able to withstand forces applied during weight bearing, The procedure is simple and straightforward, reducing operating time and the need for more complex soft-tissue reconstructive procedures.

LEVELS OF EVIDENCE

Therapeutic, Level IV: Systematic review.

Traumatic Forefoot Reconstructions With Free Perforator Flaps

The forefoot is critical to normal walking; thus, any reconstruction of forefoot defects, including the soft tissues, must be carefully done. The free perforator flap, with its physiologic circulation, lower donor site morbidity, and minimal thickness is the most popular technique in plastic and microsurgery, and is theoretically the most suitable for such forefoot reconstruction. However, these flaps are generally recognized as more difficult and time-consuming to create than other flaps. In 41 patients with traumatic forefoot defects, we reconstructed the forefoot integument using 5 types of free perforator flaps. The overall functional and cosmetic outcomes were excellent. Three flaps required repeat exploration; one survived. The most common complications were insufficient perfusion and the need for second debulking. The key to our success was thoroughly debriding devitalized bone and soft tissue before attaching the flap. Forefoot reconstruction with a free perforator flap provides better function, better cosmesis, better weightbearing, and better gait than the other flaps we have used.

Hemangioendothelioma

Hemangioendothelioma is the term used to name those vascular neoplasms that show a borderline biological behavior, intermediate between entirely benign hemangiomas and highly malignant angiosarcomas. Although originally spindle cell hemangioendothelioma was proposed as a specific clinicopathologic variant of hemangioendothelioma, currently, it is considered as an entirely benign lesion, and thus, the name spindle cell hemangioma seems to be the most accurate for this lesion. Authentic hemangioendotheliomas involving the skin and soft tissues include papillary intralymphatic angioendothelioma (also known as Dabska tumor), retiform hemangioendothelioma, kaposiform hemangioendothelioma, epithelioid hemangioendothelioma, pseudomyogenic hemangioendothelioma (also known as epithelioid sarcoma-like hemangioendothelioma), and composite hemangioendothelioma. Each of these neoplasms exhibit characteristic histopathologic features. The most characteristic finding of papillary intralymphatic hemangioendothelioma consists of papillary tufts, with a central hyaline core lined by hobnail-like endothelial cells protruding into the lumina. Retiform hemangioendothelioma is an infiltrative neoplasm composed of elongated arborizing vessels, arranged in an anastomosing pattern that resembles that of the rete testis, and lined by a single layer of hobnail-like endothelial cells that protrude within the narrow lumina. Kaposiform hemangioendothelioma is composed of several solid poorly circumscribed nodules, and each nodule is composed of a mixture of small capillaries and solid lobules of endothelial cells arranged in a glomeruloid pattern. A frequent finding consists of the presence of areas of lymphangiomatosis adjacent to the solid nodules. Epithelioid hemangioendothelioma is composed of cords, strands, and solid aggregates of round, oval, and polygonal cells, with abundant pale eosinophilic cytoplasm, vesicular nuclei, and inconspicuous nucleoli, embedded in a fibromyxoid or sclerotic stroma. Many neoplastic cells exhibit prominent cytoplasmic vacuolization as an expression of primitive vascular differentiation. Pseudomyogenic hemangioendothelioma is a poorly circumscribed, fascicular lesion with infiltrative borders composed of round or oval neoplastic cells, with vesicular nuclei and inconspicuous nucleoli, and ample homogeneous eosinophilic cytoplasm, giving them a rhabdomyoblastic appearance. Finally, composite hemangioendothelioma is the term used to name locally aggressive vascular neoplasms of low-grade malignancy showing varying combinations of benign, low-grade malignant, and high-grade malignant vascular components. From the immunohistochemical point of view, proliferating cells of all hemangioendotheliomas express a lymphatic endothelial cell immunophenotype. Most hemangioendotheliomas are low-grade vascular neoplasms, with a tendency to recur locally and a low metastatic potential, mostly to regional lymph nodes. Epithelioid hemangioendothelioma, especially large lesions and those located in deep soft tissues, seems to have a more aggressive biological behavior.

Soft tissue reconstruction pyramid in the diabetic foot

Foot complications and ulceration are well-known sequelae to uncontrolled diabetes. Patients with chronic foot ulcers or wounds resulting from surgical debridement of deep-space infections are at continued risk for development of osteomyelitis and potential amputation. Moreover, these wounds often necessitate multiple outpatient clinic visits, daily dressing care, and prolonged periods of non-weight bearing, all of which have been shown to adversely affect the patient's quality of life. After a prudent period of wound-healing response, the authors believe that early and aggressive soft tissue reconstruction is in the patient's best interest and is crucial for resolution of the chronic nonhealing wound. The options for soft tissue coverage and the logical progression of application of these techniques in the diabetic foot will be described.