Super-mini percutaneous nephrolithotomy (PCNL) vs standard PCNL for the management of renal calculi of <2 cm: a randomised controlled study.

OBJECTIVE: To compare the effectiveness and safety of standard percutaneous nephrolithotomy (sPCNL) and super-mini PCNL (SMP). PATIENTS AND METHODS: A total of 150 patients presenting with renal calculi of <2 cm were randomised to either sPCNL (Group 1) or SMP (Group 2). Randomisation was based on centralised computer-generated numbers. Variables studied included: stone-free rates (SFRs), operative time, intra- and postoperative complications, postoperative pain score, analgesic requirement, and hospital stay. Statistical analysis was performed using a t-test or Mann-Whitney U-test for continuous variables and chi-squared test or Fisher's exact test for categorical variables. RESULTS: Between September 2018 and April 2019, 75 patients were included in each group. The SFRs of the groups were similar (97.33 vs 98.66%, P = 0.56). The mean (sd) operative time was significantly longer in Group 2, at 36.40 (14.07) vs 23.12 (11.96) min (P < 0.001). The mean (sd) decrease in haemoglobin was significantly less in Group 2, at 3.0 (4.9) vs 7.5 (6.5) g/L (P < 0.001). The mean (sd) pain score at 24 h was significantly lower in Group 2, at 0.3 (0.46) vs 0.75 (0.53) (P < 0.001). The mean (sd) analgesic requirement was significantly less in Group 2, at 67 (22.49) vs 91.5 (30.56) mg tramadol (P < 0.001). The mean (sd) hospital stay was significantly less in Group 2, at 28.38 (3.6) vs 39.84 (3.7) h (P < 0.001). CONCLUSIONS: SMP is equally as effective as sPCNL for managing renal calculi of <2 cm, with improved safety. Although SMP is associated with a longer operative time, it has a significantly lower incidence of bleeding and postoperative pain, and a shorter hospital stay.

An In-vivo Prospective Study of the Diagnostic Yield and Accuracy of Optical Biopsy Compared with Conventional Renal Mass Biopsy for the Diagnosis of Renal Cell Carcinoma: The Interim Analysis.

BACKGROUND: Lack of accuracy in preoperative imaging leads to overtreatment of benign renal masses (RMs) or indolent renal cell carcinomas (RCCs). Optical coherence tomography (OCT) is real time and high resolution, enabling quantitative analysis through attenuation coefficient (µOCT, mm-1). OBJECTIVE: To determine the accuracy and diagnostic yield of OCT and renal mass biopsy (RMB) for the differentiation of benign RMs versus RCC and oncocytoma versus RCC. DESIGN, SETTING, AND PARTICIPANTS: From October 2013 to June 2016, 95 patients with solid enhancing RMs on cross-sectional imaging were prospectively included. All patients underwent subsequent excision or ablation. INTERVENTION: Percutaneous, image-guided, needle-based OCT followed by RMB in an outpatient setting under local anaesthesia. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Accuracy and diagnostic yield, µOCT correlated to resection pathology or second biopsy during ablation. Tables (2×2) for RMB, receiver operating characteristic curve for OCT. Mann-Whitney test to differentiate µOCT of RMs. RESULTS AND LIMITATIONS: RMB diagnostic yield was 79% with sensitivity, specificity, positive predictive value, and negative predictive value (NPV) of 100%, 89%, 99%, and 100%, respectively. Diagnostic yield and added value of OCT to differentiate RCC from benign was 99% and 15%, respectively. Significant difference was observed in median µOCT between benign RMs (3.2mm-1, interquartile range [IQR]: 2.65-4.35) and RCCs (4.3mm-1, IQR: 3.70-5.00), p=0.0171, and oncocytomas (3.38mm-1, IQR: 2.68-3.95) and RCCs (4.3mm-1, IQR: 3.70-5.00), p=0.0031. OCT showed sensitivity, specificity, positive predictive value. and NPV of 91%, 56%, 91%, and 56%, respectively, to differentiate benign RMs from RCCs and 92%, 67%, 95%, and 55%, respectively, to differentiate oncocytoma from RCC. Limitations include two reference standards and heterogeneity benign RMs. CONCLUSIONS: Compared with RMB, OCT has a higher diagnostic yield. OCT accurately distinguishes benign RMs from RCCs, and oncocytoma from RCCs, although specificity and NPV are lower. PATIENT SUMMARY: Optical coherence tomography, a new optical scan, exhibits similar sensitivity and positive predictive value than renal mass biopsy, although lower specificity and negative predictive value. Optical coherence tomography has a higher diagnostic yield for diagnosing renal cell carcinoma.