Free flap failure in a patient with a long standing, infected, squamous cell carcinoma.

A 40-year-old patient presented with a long history of a pilonidal sinus, which had been operated on several times during the last 20 years. On clinical examination the patient had a large tumour in the sacral and perineal region, with involvement of the rectal wall. General surgeons first attempted to excise the tumour with wide healthy margins, and close the wound by local flaps. After partial flap necrosis and wound dehiscence, the patient underwent a reconstruction with a free latissimus dorsi myocutaneous flap. During the anastomosis it was noted that the recipient vessel walls were brittle, mainly at the arterial site, so the arterial anastomosis had to be done three times. Despite this the artery thrombosed again 12 hours later. Biopsy specimens were taken from the anastomotic sites and studied under light microscopy. There were signs of acute intramural inflammation, with many polymorphonuclear leukocytes present in microabscesses, and spots of necrosis in the elastic layer at the site of the recipient artery. In conclusion, the long lasting infection was considered to be the main factor that caused the anastomosis to fail, leading to thrombosis, through alteration of the vessel walls. The anomalies in the vessel walls were found at some distance from the clinically diseased area, further than is usually found in acute infection. The use of primary arteriovenous vein graft loops or long vein grafts so that the anastomosis can be made on undamaged vessels, and possibly a less traumatic anastomosis such as the ''sleeve'' type, should be considered for similar cases.