[26] Failure of ureteric access sheath insertion in virgin ureters: a prospective cohort study

Objective: To identify the failure rate of insertion of a ureteric access sheath (UAS) during primary flexible ureteroscopy (FURS), in order to improve preoperative patient’s counselling as well as identify patients who might benefit from pre-stenting FURS. Methods: This is a single-surgeon single tertiary care centre prospective cohort study. All patients who underwent primary FURS for proximal ureteric or renal stones from November 2014 to May 2018 were included in the study. We used one type of UAS 10/12-F coaxial UAS from Rocamed. Data collected included: age, gender, body mass index (BMI), previous spontaneous passage of stones, and congenital anomalies. Descriptive analysis was done. Results: The study included 128 patients and they all underwent primary FURS. In all, 73.4% (94 patients) were males, 26.6% (34) were females. The failure rate of primary UAS insertion was 11.7% (15 patients), the mean age of the failure group was 43.2 years and 14/15 were males. Six were obese with BMI of >30 kg/m2 and six had a previous episode of spontaneous stone passage. None of the failed patients had anatomical abnormalities. In all, 113 patients (88.3%) had a successful primary FURS and insertion of a UAS. The mean age was 46.3 years and 27.4% (31 patients) were females. In all, 50.4% (57 patients) of the success group had previous episodes of spontaneous stone passage. Conclusion: A very low failure rate was obtained in unstented patients. Female patients and patients with an episode of spontaneous stone passage were more likely to be accessed primarily. Our study helps the urologist to make an informed consent and facilitate the decision of pre-stenting in selected patients