1299 Observational Study of The Use of Spinal Anaesthesia As an Alternative to General Anaesthetic For Ureteroscopy During The COVID-19 Pandemic

Introduction General anaesthetic has traditionally been felt to be more appropriate than spinal anaesthesia for patients undergoing ureteroscopy as it is difficult to achieve a suitably high block. During the COVID-19 pandemic, our centre moved elective operating to an alternative day-case surgical environment where the anaesthetic team performed predominantly spinal anaesthesia and were therefore very experienced with this modality. In view of concerns of COVID-19 transmission by aerosolisation during the intubation and extubation phases of general anaesthetic, spinal anaesthesia as an alternative first line modality was trialled with the option of converting to general anaesthesia if surgery could not be achieved safely and comfortably for the patient. Method During a three-month period, unless contraindicated, spinal anaesthesia was used as the first line anaesthetic for ureteroscopy cases. A retrospective study of outcomes was then undertaken. Results 44 patients were treated with a conversion rate to general anaesthetic of 9% (n = 4). There was a complication rate of 20% (n = 9); 4 partial procedures, 4 readmissions with symptomatic residual fragments or sepsis and 1 patient required post-operative overnight stay due to anaesthetic. Spinal anaesthetic time averaged 25minutes. Conclusions The global COVID-19 pandemic has led to change in practice and we have demonstrated that spinal anaesthesia is a valuable alternative to general anaesthetic in the majority of ureteroscopy cases. When undertaken by an experienced anaesthetic team, using this method does not significantly add to procedure time.

Novel Use of a Modified Triangular Prismatic Double-J Stent for 2- to 3-cm Renal Stones after One-Stage Retrograde Intrarenal Surgery

Objectives: To initially evaluate the outcomes of the modified triangular prismatic double-J (DJ) stent in the management of 2- to 3-cm renal stones after one-stage retrograde intrarenal surgery (RIRS). Methods: Patients with 2- to 3-cm renal stones who underwent one-stage RIRS with indwelling DJ stents were retrospectively evaluated. Eighty-eight patients who were placed the triangular prismatic DJ stents and 64 patients who received standard DJ stents were randomly included. The clinical characteristics and intraoperative and postoperative outcomes of the 2 groups were compared and analyzed. Results: The 2 groups had similar baseline characteristics. The urinary symptom score and pain score did not differ between groups (p > 0.05). The residual fragments of the 2 groups were similar 1 day after operation (p = 0.134). There was no significant difference in residual fragments in the lower calyx between groups at the time of stent removal (p = 0.834). The patients in the modified group had better spontaneous passage of residual fragments in the nonlower calyx than those in the standard group during the 2 weeks with the stents (p = 0.005). Fewer patients in the modified group had residual fragments (>4 mm) in the nonlower calyx (p = 0.026) and ureter (p = 0.010) than the patients with standard stents at the time of stent removal. Conclusion: The indwelling triangular prismatic DJ stent is a safe and efficient treatment method. Patients with these stents had better spontaneous residual fragment passage than those with the standard DJ stents.

Intraoperative cone beam computed tomography for detecting residual stones in percutaneous nephrolithotomy: a feasibility study

Cone beam computed tomography (CBCT) provides multiplanar cross-sectional imaging and three-dimensional reconstructions and can be used intraoperatively in a hybrid operating room. In this study, we investigated the feasibility of using a CBCT-scanner for detecting residual stones during percutaneous nephrolithotomy (PCNL). Intraoperative CBCT-scans were made during PCNL procedures from November 2018 until March 2019 in a university hospital. At the point where the urologist would have otherwise ended the procedure, a CBCT-scan was made to image any residual fragments that could not be detected by either nephroscopy or conventional C-arm fluoroscopy. Residual fragments that were visualized on the CBCT-scan were attempted to be extracted additionally. To evaluate the effect of this additional extraction, each CBCT-scan was compared with a regular follow-up CT-scan that was made 4 weeks postoperatively. A total of 19 procedures were analyzed in this study. The mean duration of performing the CBCT-scan, including preparation and interpretation, was 8 min. Additional stone extraction, if applicable, had a mean duration of 11 min. The mean effective dose per CBCT-scan was 7.25 mSv. Additional extraction of residual fragments as imaged on the CBCT-scan occurred in nine procedures (47%). Of the follow-up CT-scans, 63% showed a stone-free status as compared to 47% of the intraoperative CBCT-scans. We conclude that the use of CBCT for the detection of residual stones in PCNL is meaningful, safe, and feasible.

Flexible Nephroscopy: A Step Towardsc Complete Stone Clearance in PCNL

ObjectivesTo determine the usefulness of flexible nephroscopy after per-cutaneous nephrolithotomy (PCNL) in detecting residual fragments. Materials and MethodsA prospective study was conducted between January 2018 and December 2019 on patients undergoing standard PCNL using a flexible nephroscope to inspect all the calyces for residual stones. When residual stones were noted, either they were removed by basketing or by performing additional puncture to ensure complete clearance. Patients were followed up for 6 months and at the end of 1 month a plain CT KUB was done to look for residual fragments. ResultsThe study cohort included 212 patients. Significant RFs were found in 28 patients during flexible nephroscopy and in two patients at 1 month follow up CT scan. All patients were stone free during 6 months follow up. ConclusionFlexible nephroscopy during PCNL decreases the chance of residual fragments and thereby reducing the chance of re-procedure rates.

Stone Clearance by Computed Tomography after Percutaneous Nephrolithotomy: A Descriptive Cross-sectional Study

Introduction: Percutaneous nephrolithotomy has the highest stone free rate among other procedures with relatively higher complication rate. Post-operative imaging after stone surgeries has not been uniform. This study was done to study about the stone clearance by computed tomography after percutaneous nephrolithotomy. Methods: The descriptive cross-sectional study was conducted in the Department of Urology, Bir Hospital for six months duration. The patients undergoing percutaneous nephrolithotomy and those with intra-operative fluoroscopic clearance were evaluated with a low dose computed tomography after 48 hours to assess residual fragments its size and location. Patient’s demographics, stone characteristics and complications were compared between the stone free and with residual stone patients. Results: Out of 72 percutaneous nephrolithotomy performed, 40 patients were included in the study. Low dose computed tomography kidney, ureter and bladder after 48 hours of surgery detected residual fragments in 11 (27.5%) patients. The RFs size of <4mm were found in 7 (63.63%) of cases whereas RFs of >4mm were found in 4 (36.36%). The stone size was 352.47 ± 97.47 mm2 and 254.79 ± 172.68mm2 in group with residual fragments and stone free group respectively. Conclusions: Low dose computed tomography kidney, ureter and bladder done for assessment of stone clearance after 48 hours of percutaneous nephrolithomy detected residual in around one fourth of patients, however majority of them had residual fragments <4mm. Intra-operative fluoroscopic clearance may over estimate stone clearance after percutaneous nephrolithomy as about one third of patients still may have residual fragments of >4mm size.