Excision of a Fibrosarcoma in the Right Forelimb and Reconstruction with Full-Thickness Autologous Graft in a Dog
Authors: Galeno Lygia Silva , Medeiros Brenda Lurian Do Nascimento , Nascimento Dayana Maria do , Silva Thiago Vargas da , Amorim Wenderson Rodrigues de , Souza Thiago Martins , Araújo Bruno Martins Araújo Martins , Silva Francisco Lima 
Published: June 2021

Background: Fibrosarcomas are malignant neoplasms originating from fibroblasts that are normally located in the skin, subcutaneous tissue and adjacent to bones. The main treatment for fibrosarcoma is surgery. The removal of large neoplasms from dogs’ limbs usually leads to the formation of large skin defects, often preventing primary occlusion and thus requiring reconstructive surgery to close the wound. This paper reports on the surgical procedure and postoperative complications pursuant to the excision of a fibrosarcoma in the right forelimb and reconstruction with a full-thickness autologous graft in a dog.Case: We report a case of a 12-year-old Brazilian mastiff presenting a nodule located in the distal segment of the right forelimb, which had grown over a 2-year period.  Blood and imaging tests were performed, which showed no changes and excluded the possibility of metastasis. The cytological examination was suggestive of a mesenchymal neoplasm.  The patient underwent tumor excision surgery followed by reconstructive surgery with a full-thickness autologous graft to close the defect. The neoplasm was excised by means of a circular geometric figure incision using a 3 cm margin. The defect resulting from removal of the tumor was kept constantly moistened and wrapped in surgical compresses until grafting was performed. The graft was harvested from the region of the right flank based on a surgical field mold taken from the recipient bed. After harvesting the graft, all the subcutaneous tissue was removed until the hair follicles were visible. Fenestrations were then made throughout the entire graft and it was placed in the recipient bed and closed with 4-0 nylon using simple interrupted sutures. After the surgical procedure, the graft was covered with a water-based lubricating gel and bandaged, and the limb was immobilized. Cephalexin, meloxicam, tramadol and dipyrone were used as postoperative medications. The bandage was changed every 72 h. The postoperative complications observed involved the formation of seroma, infection and necrosis of the graft, which was removed and debrided on the 9th postoperative day. The defect generated after removal of the graft was treated using hydrocolloid dressings, which were changed every 5 days.  Seven changes of the hydrocolloid dressings were required to ensure complete closure of the defect. A histopathological examination of the neoplasia revealed that it was a fibrosarcoma. Discussion: Fibrosarcomas are neoplasms with a low degree of malignancy, which metastasize only in an advanced stage of the disease. Treatment consists of surgical resection with a wide safety margin. Full-thickness skin grafts include the epidermis and the entire dermis and are applied to cover major defects in flexor surfaces and defects in distal extremities. The main reasons for skin graft failure are separation between the graft and the recipient bed, infection and movement. The formation of seroma mechanically separates the graft from its bed, impairing nutrition and revascularization. Hydrocolloids, which are flexible and highly absorbent membranes composed of pectin, gelatin and carboxymethyl cellulose, are useful in treating a variety of wounds. The complications that occurred in this case are consistent with others reported in the literature. The treatment of the open wound with hydrocolloid dressings proved to be quite satisfactory, allowing for complete healing of the wound.