Near-infrared fluorescence for minimally invasive management of colovesical fistula

BACKGROUND

Sigmoid resection with primary colorectal anastomosis is the procedure of choice for colovesical fistula (CVF). Ureteral injuries occur in up to 10% of patients undergoing laparoscopic pelvic surgery,¹ and prophylactic double-J stenting carries potential complications.² Near-infrared fluorescence via retrograde indocyanine green (ICG) injection through an ureteral probe rapidly stains the urothelium, compensating for the limited tactile feedback and possibly replacing stents.

TECHNIQUE

The tip of a 6Fr Pollack catheter is introduced in the left ureter via cystoscopy to allow subsequent injection of ICG. The Visera Elite II OTV-S300^® video system with near-infrared scope (Olympus, Shinjuku, Tokyo, Japan) or the Da Vinci system Si or Xi with firefly technology (Intuitive Surgical Inc., Sunnyvale, CA, USA) is used. Four ports are placed as for laparoscopic left colectomy. Ureteral injection of 5ml of ICG (Verdye^® 5mg/ml, Diagnostic Green GmbH, Aschheim, Germany) can guide dissection until the bladder wall is completely dissected from the sigmoid. Next, after the inferior mesenteric vessels are divided and the rectum is stapled, an intravenous 5ml bolus of ICG is injected to test the adequacy of colonic perfusion and identify the ideal anastomotic site. A standard Knight–Griffen colorectal anastomosis is then performed (Figure 1). The ureteral catheter is removed at the end of the procedure. An outpatient cystoscopy is performed 2 weeks later to confirm complete bladder healing.

Figure 1 .

(a) Sagittal CT scan view in a patient with complicated sigmoid diverticulitis. The arrow shows the site of CVF with air bubbles inside the bladder (c) and in the fistulous tract contiguous to the sigmoid colon (c). (b) Laparoscopic view of the inflammatory pseudotumour with a fibrotic area surrounding the CVF. (c, d) Use of ICG-fluorescence to identify the left ureter before and after CVF dissection. The position of the left iliac artery is indicated (ia). (e) View of the pelvis after dissection of CVF. The bladder is filled with methylene blue solution, and there is no evidence of leakage (arrow). (f) Hydropneumatic test shows no leakage from the colorectal anastomosis (arrow). CT = computed tomography; CVF = colovesical fistula; ICG = indocyanine green.

DISCUSSION

Retrograde ICG injection through an ureteral probe provides a high signal-to-background noise ratio and allows to track the entire course of the left ureter even when obscured by fibrotic tissue. This method can prevent ureteral injury and reduce morbidity associated with secondary procedures. Our experience consists of two patients, one treated laparoscopically,³ and the more recent one treated with a robotic approach. Finally, an intravenous ICG bolus can reduce the risk of colorectal anastomotic leakage and avert a defunctioning ileostomy.