S.P. Zanetti

Surgical teaching in urology: patient safety and educational value of ‘LIVE’ and ‘SEMI-LIVE’ surgical demonstrations

AbstractPurposeTo evaluate the opinion of urologists and their audience regarding patient safety and educational value of live surgical demonstrations (LSD) and semi-live surgical demonstrations (semi-LSD).MethodsFollowing the ‘2017 Challenges in Endourology’ meeting, a survey addressing patient safety and the educational value of LSD and semi-LSD was disseminated online to all participants. Survey outcomes of LSD and semi-LSD were compared. ResultsAll 279 respondents attended both LSD and semi-LSD. Overall, 53% of said respondents stated that patient safety was always the highest priority for LSD, while 74% noted the same for semi-LSD. The complication risk in LSD was perceived equal by 57% of the respondents when compared to cases of similar difficulty in routine practice, while 38% perceived it as a greater risk. For semi-LSD, the complication risk was perceived equal by 84%, while 5% perceived it to be a greater risk in comparison to general practice. On a scale from 0 (no value) to 10 (highly valuable), the average educational value of LSD and semi-LSD was rated 8.4 and 8.3, respectively. A substantial percentage of the surgeons who perform LSD express concerns that live surgery is not the optimal setting to ensure patient safety.ConclusionsLSD remains a popular tool for surgical education among urologists and their audience. However, patient safety remains a concern and is perceived less of a concern for semi-LSD. The educational value of LSD and semi-LSD was scored equally high. Therefore, we should consider to advocate the use of semi-LSD more often.

Intra-operative post-perfusion micro-nephrolithotomy for renal allograft lithiasis: A case report.

Increasing demand drives the expansion of criteria for kidney donation, and nephrolithiasis is now considered a relative contraindication. We report for the first time a case of intra-operative, postperfusion kidney allograft micronephrolithotomy. A 64-year-old man with end-stage renal disease secondary to Alport syndrome underwent primary deceased donor kidney transplantation at our center. Pre-operative ultrasound of the donor identified a 7-mm calculus in the anterior, lower pole calyx. The kidney was extra-peritoneally implanted in the right iliac fossa and reperfused homogenously. Stone retrieval with a flexible ureteroscope failed due to the narrow calyceal infundibulum. Instead, the calculus was removed using the micropercutaneous nephrolithotomy system under ultrasonographic guidance. The calyx was punctured using a 4.85 Fr needle and the stone was fragmented to dust using a Holmium laser. No bleeding was observed. The post-operative course was uneventful. Outpatient follow up demonstrated good function of the graft which was stone free on ultrasound. Postperfusion micropercutaneous nephrolithotomy for kidney allograft calculi offers a safe and feasible option when pre-operative or intra-operative retrograde intrarenal surgery fails.

Clinical utility of computed tomography Hounsfield characterization for percutaneous nephrolithotomy: a cross-sectional study

BackgroundComputed Tomography (CT) is considered the gold-standard for the pre-operative evaluation of urolithiasis. However, no Hounsfield (HU) variable capable of differentiating stone types has been clearly identified. The aim of this study is to assess the predictive value of HU parameters on CT for determining stone composition and outcomes in percutaneous nephrolithotomy (PCNL).MethodsSeventy seven consecutive cases of PCNL between 2011 and 2016 were divided into 4 groups: 40 (52%) calcium, 26 (34%) uric acid, 5 (6%) struvite and 6 (8%) cystine stones. All images were reviewed by a single urologist using abdomen/bone windows to evaluate: stone volume, core (HUC), periphery HU and their absolute difference. HU density (HUD) was defined as the ratio between mean HU and the stone’s largest diameter. ROC curves assessed the predictive power of HU for determining stone composition/stone-free rate (SFR).ResultsNo differences were found based on the viewing window (abdomen vs bone). Struvite stones had values halfway between hyperdense (calcium) and low-density (cystine/uric acid) calculi for all parameters except HUD, which was the lowest. All HU variables for medium-high density stones were greater than low-density stones (p < 0.001). HUC differentiated the two groups (cut-off 825 HU; specificity 90.6%, sensitivity 88.9%). HUD distinguished calcium from struvite (mean ± SD 51 ± 16 and 28 ± 12 respectively; p = 0.02) with high sensitivity (82.5%) and specificity (80%) at a cut-off of 35 HU/mm. Multivariate analysis revealed HUD ≥ 38.5 HU/mm to be an independent predictor of SFR (OR = 3.1, p = 0.03). No relationship was found between HU values and complication rate.ConclusionsHU parameters help predict stone composition to select patients for oral chemolysis. HUD is an independent predictor of residual fragments after PCNL and may be fundamental to categorize it, driving the imaging choice at follow-up.