Near infrared ray-guided partial cystectomy using da Vinci Firefly® technology and intraoperative cystoscopy for urachal cyst, suspected of urachal tumor.

Abstract

Purpose: Urachal cyst is a type of congenital anomaly that may undergo malignant transformation. Partial cystectomy with en-bloc resection of the urachus is appropriate treatment for urachal remnants. We performed near infrared ray-guided surgery (NIRGS) for the accurate localization of tumor margins using the Firefly^® technology of the da Vinci surgical system and intraoperative cystoscopy. In the normal visible light mode, we could not recognize the cystoscopic light. However, after changing to the Firefly^® mode, the near infrared rays transmitted through the bladder wall were visible as green images.

Materials and methods: The patient is a 76-year-old woman. She was referred to urology for a tumor at the dome of the bladder. Cystoscopy revealed a round submucosal mass at the dome of the bladder. The possibility of a urachal tumor could not be excluded. Since she was already diagnosed with rectal cancer and scheduled to undergo robot-assisted laparoscopic proctosigmoidectomy, we performed robot-assisted partial cystectomy during the same operative session.

Results: The rectum was removed by a surgeon with robot-assistance. Then we detached the median umbilical ligament from just below the umbilicus toward the bladder. Both medial umbilical ligaments were dissected from abdominal wall to the dome of the bladder. A simultaneous cystoscopic light depicted the bladder boundaries of the mass with the Firefly^® mode. There was no residual tumor at the resected margin, and pathological findings revealed that the urachal cyst was benign.

Conclusions: Robot-assisted partial cystectomy for urachal tumors is technically feasible. NIRGS should be considered in selected cases.