TOWING THE STENT TO MANAGE MALIGNANT GASTRO-ENTERO-COLONIC FISTULA AND COLONIC OBSTRUCTION

INTRODUCTION
Gastro-entero-colonic fistulas resulting from either stomach or colonic malignancies are highly morbid and challenging to manage.

CASE PRESENTATION
A 51-year-old male patient was referred to us with an iatrogenic gastro-entero-colonic fistula that resulted from the misdeployment of a colonic stent to bypass a malignant splenic flexure stenosis. The stent had already migrated but led to this complex fistula with bacterial overgrowth, large-volume diarrhea, weight loss, and episodic feculent vomiting. The patient was felt to be at high risk for adjuvant chemo or surgical intervention. One approach to solve this issue was to place a partially covered stent so that it could embed and bypass the fistula. None of the existing stents have a long enough deployment assembly to easily pass the stent across the fistula location.

ENDOSCOPIC METHOD
As expected, we failed to advance a partially covered stent over a steel wire (with its tip in the transverse colon). We used an innovative approach to modify a partially covered stent with a towing silk suture placed in the stent delivery system (Image 1). A single balloon scope without the ballon but with a scope stiffener was passed orally and then via the fistula into the colon. It was eventually brought out via the anal canal to grasp the towing suture on the stent delivery shaft with toothed forceps. The stent was loaded onto the steel wire. A combined approach of gentle pulling on the towing suture with the trans-fistula scope and gentle pushing from the anal side allowed the stent to reach across the fistula, as shown in Image 2. The stent was deployed appropriately under fluoroscopic guidance while visually examining it with the scope at the level of the fistula. This combined approach correctly placed the covered part of the stent across the fistula and uncovered parts proximal and distal to the fistula in the colon with an excellent seal. No contrast lead was noted at the end of the procedure. The patient tolerated the procedure well and resumed oral intake. Bacterial overgrowth was treated with antibiotics, and chemotherapy was started.

CONCLUSION
A novel approach of placing a towing suture on the stent delivery system effectively drives the short delivery system of a partially covered stent to optimally deploy the stent to resolve symptoms related to a complex malignant fistula.