Intraluminal migration of a spacer with small bowel obstruction: a case report of rare complication

Radiotherapy is effective for locally recurrent rectal cancer. The risk of bowel radiation injury depends on the radiation dose. Basic radiation protection principles include increasing the distance between normal tissue and site of radiation, to reduce overall radiation exposure [1]. For this purpose, spacer placement between the small bowel and local recurrent rectal tumors before the application of radiotherapy is becoming a prevalent procedure. However, in a very few cases, radiotherapy can result in uncommon complications such as intraluminal migration of the spacer. Here, we present a case of complete spacer migration into the small bowel presenting as small bowel obstruction.The patient was a 60-year-old man with a negative past medical history. In June 2005, he was diagnosed with advanced rectal cancer with bladder invasion and underwent abdominoperineal resection with partial cystectomy and vesicoureteral anastomosis. The final TNM stage was stage IIIB (T4N3M0). Two years after the first surgery, follow-up positron emission tomography/computed tomography (PET-CT) scan showed locally recurrent rectal cancer in front of the sacrum. He opted to receive radiotherapy, but this proved difficult due to the close proximity of the recurrent tumor to the small bowel in the pelvic cavity. To prevent exposure of the small bowel to the irradiation, a polytetrafluoroethylene spacer measuring 15 × 10 cm was placed between the tumor and small bowel. The spacer was secured in place with 3-0 Vicryl suture. A CT scan showed the spacer was positioned appropriately in the desired location (Figure 1). One month after the second surgery, radiotherapy was performed without any adverse events. Systematic chemotherapy was continued and there were no sign of tumor growth.Two years after the second surgery, he presented to the emergency department with left abdominal pain, nausea and vomiting. A CT scan of the abdomen showed dilated small bowel and spacer migration to the abdominal ca