Assessing the Variability of the Twelfth Rib as a Landmark for Percutaneous Nephrolithotomy Using Computed Tomography.

Background: The variability in length of the twelfth rib is mentioned in the literature but has never been formally studied. The highly variable rib length provides a challenge for urologists seeking a consistent landmark for Percutaneous Nephrolithotomy (PCNL). We set out to determine whether the twelfth rib is safe to use as a consistent landmark for surgery. Methods: Single centre, cross-sectional retrospective observational study and analysis of CT scans of 100 adults who had imaging between 23rd March and 12th April 2020. The distance from the mid-sagittal line to the twelfth rib tip in the axial plane was measured as was the distance from the twelfth rib tip to the kidney, spleen and liver. Results: Length from the mid-sagittal line to the right twelfth rib tip varied from 46 (percentile 95% CI 40 to 57) to 136mm (percentile 95% CI 133 to 138). On the left, the distances varied from 55 (percentile 95% CI 50 to 64) to 134mm (percentile 95% CI 131 to 135). Twenty-three percent of people had an organ lying between the tip of the twelfth rib and the kidney on the right and 11% on the left. Conclusion: The twelfth rib is highly variable in length. Similar variability was recorded in the distance from the tip to intra-abdominal organs. Due to the frequency of organs lying between the tip of the rib and the kidney it should not be used as a landmark for accessing the kidney without prior knowledge of an individual patient's anatomy as seen on imaging.

Utility of Routine Intraoperative Ureteral Frozen Section Analysis at Radical Cystectomy: Outcomes from a Regional Australian Center.

INTRODUCTION: The objective of this study was to look at the usefulness and cost effectiveness of intraoperative frozen section analysis (FSA) of the ureters at the time of radical cystectomy. METHODS: Pathology notes of patients undergoing radical cystectomy for primary bladder cancer between the years 2000-2015 at our institution were reviewed. RESULTS: A total of 196 ureteric specimens from 98 patients were reviewed. Of the 98 patients, 9% (n = 9) had positive ureteric margins, of which all were ≥ T2, with 44% (4 of 9) being T = 4. In all cases of positive FSA, preoperative clinical staging was ≥ T2. In cases where cancer staging was upgraded post-cystectomy, there were no cases of positive FSA. After adjusting for tumor stage in ≥ T2a, using Cox regression analysis, positive frozen section was associated with a 4.2 fold increase in overall mortality (95%CI 1.3-13.8; p = 0.02). Cost associated with FSA was AU$1,351.90 to obtain 1 positive result. CONCLUSION: Patients with positive ureteric FSA are at higher risk of mortality post cystectomy, despite excision to negative tissue. However, FSA of the distal ureters at cystectomy were unlikely to be positive unless the bladder cancer stage was ≥ T2. Hence, routine ureteric FSA may not be necessary in patients undergoing cystectomy for non-muscle invasive bladder tumors.

Modified supine versus prone percutaneous nephrolithotomy: Surgical outcomes from a tertiary teaching hospital.

PURPOSE: The traditional prone positioning of percutaneous nephrolithotomy (PCNL) is associated with various anesthetic and logistic difficulties. We aimed to compare the surgical outcomes of PCNLs performed using our modified supine position with those performed in the standard prone position. MATERIALS AND METHODS: A prospective group of 236 renal units (224 patients) undergoing PCNL were included in this 2 site study: 160 were performed in the modified supine position were compared with 76 undergoing PCNL in the prone position. The outcomes of radiation dose, radiation time, stone free rate, body mass index (BMI), stone size, operative time, length of stay (LOS), in hospital and complications were compared. Chi-square and t-tests were used. RESULTS: There were no significant differences in mean radiation time, radiation dose or stone size between the modified supine and prone groups. The supine group had a higher mean BMI (31 kg/m(2) vs. 28 kg/m(2), p=0.03), shorter mean surgical time (93 minutes vs. 123 minutes, p<0.001), shorter mean LOS (2 days vs. 3 days, p=0.005) and higher stone free rate (70% vs. 50%, p=0.005). There were no differences in septic or bleeding complications but the prone group had a higher rate of overall complications. CONCLUSIONS: Modified supine PCNL has significantly lower operative time, shorter LOS and higher stone-free rate compared with prone in our series, while remaining a safe procedure.

Blood transfusion, embolisation and nephrectomy after percutaneous nephrolithotomy (PCNL).

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Percutaneous treatment for renal stone disease is associated with a risk of significant morbidity. Our large UK series provides contemporary data on the risk of vascular complications and admission to the Intensive Care Unit (ICU) after PCNL. When compared with recent international databases, these data support the current evidence that better outcomes can be achieved in centres performing large numbers of procedures. These data add to the debate for the centralisation of specialist stone surgery. OBJECTIVE: To audit the outcome of percutaneous nephrolithotomy (PCNL) at a UK stone centre over a 10-year period, and provide patients with understandable contemporary data on blood loss and vascular risk. PATIENTS AND METHODS: A single centre retrospective analysis of all PCNLs undertaken between April 2000 and December 2010. The association between transfusion and patient age, operative duration and positive preoperative mid-stream urine (MSU) sample was subject to statistical analysis. RESULTS: Data on 568 patients was analysed. 21 were paediatric cases with a mean (range) age of 8 (2-16) years; 547 were adult cases with a mean (range) age of 55 (17-84) years. 3.8% of adult patients (21/547) received a blood transfusion; mean age 60 years (55 years in those not transfused) with a mean operative duration of 119 min (103 min in those not transfused). 23.8% of patients transfused had a confirmed preoperative urinary tract infection compared with 16.1% of those not transfused. Seven patients underwent angiography, with five having selective arterial embolisation (0.9%). There were no deaths in this series although one patient (0.2%) required an urgent nephrectomy due to cardiovascular instability from bleeding. CONCLUSIONS: Large UK series that provides contemporary data for consent on vascular risk at PCNL. The risk of transfusion is associated with increased patient age, operative duration and the presence of a positive preoperative MSU sample. Data compares favourably with other large published series, and supports the argument for centralisation of percutaneous stone management.