Iatrogenic submucosal tunnel in the ureter: a rare complication during advancement of the guide wire

BACKGROUND: Inserting a guide wire is a common practice during endo-urological procedures. A rare complication in patients with ureteral stones where an iatrogenic submucosal tunnel (IST) is created during endoscopic guide wire placement. OBJECTIVE: Summarize data on IST. DESIGN: Retrospective descriptive study of patients treated from from October 2009 until January 2015. SETTING: King Fahd Hospital of the University, Al-Khobar, Saudi Arabia. PATIENTS AND METHODS: Patients with ureteral stones were divided to 2 groups. In group I (335 patients), the ureteral stones were removed by ureteroscopy in one stage. Group II (97 patients) had a 2-staged procedure starting with a double J-stent placement for kidney drainage followed within 3 weeks with ureteroscopic stone removal. MAIN OUTCOME MEASURE(S): Endoscopic visualization of ureteric submucosal tunneling by guide wire. RESULTS: IST occurred in 9/432 patients with ureteral stones (2.1%). The diagnosis in group I was made during ureteroscopy by direct visualization of a vanishing guide wire at the level of the stone (6 patients). In group II, IST was suspected when renal pain was not relieved after placement of the double J-stent or if imaging by ultrasound or intravenous urography showed persistent back pressure to the obstructed kidney (3 patients). The condition was subsequently confirmed by ureteroscopy. CONCLUSION: Forceful advancement of the guide wire in an inflamed and edematous ureteral segment impacted by a stone is probably the triggering factor for development of IST. Definitive diagnosis is possible only by direct visualization during ureteroscopy. Awareness of this potential complication is important to guard against its occurrence. LIMITATIONS: Relatively small numbers of subjects and the retrospective nature of the study.