Zhamshid Okhunov

The Comparison of Three Renal Tumor Scoring Systems: C-Index, P.A.D.U.A., and R.E.N.A.L. Nephrometry Scores

BACKGROUND AND PURPOSE The centrality-index (C-Index), preoperative aspects and dimensions used for anatomic (P.A.D.U.A.) classification, and radius.exophyic/endophytic.nearness.anterior/posterior.location (R.E.N.A.L.) nephrometry schemes were developed as standardized scoring systems (SS) to quantify anatomic characteristics of kidney tumors. The objective of this study was to establish reliability and assess relationships between these three SS and perioperative and postoperative variables. PATIENTS AND METHODS A retrospective chart review was performed in 101 patients who underwent laparoscopic partial nephrectomy. The nephrometry schemes were correlated with intraoperative and postoperative parameters using Spearman correlations. In addition, interobserver reliability was assessed on 50 of the patients by interclass correlations comparing the scores assigned by two residents and one fellow who reviewed preoperative CT studies of these patients. RESULTS The interobserver correlation was 0.84 for the C-Index, 0.81 for the P.A.D.U.A., and 0.92 for the R.E.N.A.L. scoring systems, demonstrating excellent interobserver reliability. All three SS were significantly associated with warm ischemia time (WIT) (C-Index, P=-0.44; P.A.D.U.A., P=0.25; R.E.N.A.L., P=0.32) and percent change in creatinine level (C-Index, P=- 0.33; P.A.D.U.A., P=0.37; R.E.N.A.L., P=0.37). There were no significant associations between any of the three SS assessed and the occurrence of complications, operative time, or estimated blood loss. No significant correlation was found between the P.A.D.U.A. and R.E.N.A.L. SS and length of stay; however, C-Index did show a significant relationship for patients with lower scores having longer hospital stays (P=-0.21). CONCLUSIONS All three scoring systems demonstrated reliability among observers and represent novel methods of quantitatively describing renal tumors. They were all associated with WIT, percent change in creatinine level, and tumor size. They did not, however, correlate with any other perioperative parameters investigated. At this time, these SS provide a common language for describing renal tumors.

Impact of ischemia on renal function after laparoscopic partial nephrectomy: a multicenter study.

PURPOSE We assessed the influence of renal ischemia on long-term global renal function after laparoscopic partial nephrectomy in patients with 2 functioning kidneys in a large, multicenter cohort. MATERIALS AND METHODS Collected data included demographic, clinical and surgical characteristics, tumor parameters and renal function outcomes at 4 institutions in a total of 401 patients with 2 functioning kidneys who underwent laparoscopic partial nephrectomy. Renal function was assessed in the immediate postoperative period (days 1 to 3) and at last followup (greater than 1 month) using the estimated glomerular filtration rate calculated by the 4-variable Modification of Diet in Renal Disease equation. Ischemia time and covariates were modeled on the percent change in the estimated glomerular filtration rate using linear regression. RESULTS Median ischemia time was 29 minutes (IQR 22, 34). The postoperative change and the last (long-term) change in the estimated glomerular filtration rate were -16% and -11%, respectively. Median time to the last estimated glomerular filtration rate measurement was 13 months (IQR 6, 24). On multivariate analysis shorter ischemia and operative times, external or ureteral irrigation with cold saline and female gender were associated with less postoperative percent change in the estimated glomerular filtration rate. Smaller tumor size and absent diabetes were associated with less of a final percent change in the estimated glomerular filtration rate. Ischemia time was not associated with a percent change in the estimated glomerular filtration rate at last followup. CONCLUSIONS Within the range of times in these series renal ischemia did not have a clinically significant impact on global renal function in patients with 2 functioning kidneys who underwent laparoscopic partial nephrectomy, as measured by the estimated glomerular filtration rate.

Evaluation and Comparison of Urolithiasis Scoring Systems Used in Percutaneous Kidney Stone Surgery

PURPOSE Contemporary predictive tools for percutaneous nephrolithotomy outcomes include the Guy stone score, S.T.O.N.E. nephrolithometry and the CROES nephrolithometric nomogram. We compared each scoring system in the same cohort to determine which was most predictive of surgical outcomes. METHODS We retrospectively reviewed the records of patients who underwent percutaneous nephrolithotomy between 2009 and 2012 at a total of 3 academic institutions. We calculated the Guy stone score, the S.T.O.N.E. nephrolithometry score and the CROES nephrolithometric nomogram score based on preoperative computerized tomography images. A single observer at each institution reviewed all images and assigned scores. Univariate and multivariate analysis was done to determine the most predictive scoring system. RESULTS We enrolled 246 patients in study. In stone-free patients vs those with residual stones the mean Guy score was 2.2 vs 2.7, the mean S.T.O.N.E. score was 8.3 vs 9.5 and the mean CROES nomogram score was 222 vs 187 (each p <0.001). Logistic regression revealed that the Guy, S.T.O.N.E. nephrolithometry and CROES nomogram scores were significantly associated with stone-free status (p = 0.02, 0.004 and <0.001, respectively). The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss (p <0.0001 and 0.03) and length of stay (p = 0.03 and 0.009, respectively). The CROES nomogram did not predict estimated blood loss or length of stay. CONCLUSIONS All scoring systems and the stone burden equally predicted stone-free status. The Guy and S.T.O.N.E. nephrolithometry scores were associated with estimated blood loss and length of stay. A single scoring system should be adopted to unify reporting.

Evaluation of the impact of three-dimensional vision on laparoscopic performance.

INTRODUCTION Recent technological advancements have led to the introduction of new three-dimensional (3D) cameras in laparoscopic surgery. The 3D view has been touted as useful during robotic surgery, however, there has been limited investigation into the utility of 3D in laparoscopy. MATERIALS AND METHODS We performed a prospective, randomized crossover trial comparing a 0° 3D camera with a conventional 0° two-dimensional (2D) camera using a high definition monitor (Karl Storz, Tuttlingen, Germany). All participants completed six standardized basic skills tasks. Quality testing scores were measured by the number of drops, grasping attempts, and precision of needle entry and exiting. Additionally, resolution, color distribution, depth of field and distortion were measured using optical test targets. RESULTS In this pilot study, we evaluated 10 medical students, 7 residents, and 7 expert surgeons. There was a significant difference in the performance in all the six skill tasks, for the three levels of surgical expertise and training levels in 2D vs 3D except for the cut the line quality score and the peg transfer quality score. Adjusting for the training level, 3D camera image results were superior for the number of rings left (p=0.041), ring transfer quality score (p=0.046), thread the rings (no. of rings) (p=0.0004), and thread the rings quality score (p=0.0002). The 3D camera image was also superior for knot tying (quality score) (p=0.004), peg transfer (time in seconds) (p=0.047), peg transfer pegs left (p=0.012), and for peg transfer quality score (p=0.001). The 3D camera system showed significantly less distortion (p=0.0008), a higher depth of field (p=0.0004) compared with the 2D camera system. CONCLUSION 3D laparoscopic camera equipment results in a significant improvement in depth perception, spatial location, and precision of surgical performance compared with the conventional 2D camera equipment. With this improved quality of vision, even expert laparoscopic surgeons may benefit from 3D imaging.

Perioperative outcomes of off‐clamp vs complete hilar control laparoscopic partial nephrectomy

Whats known on the subject? and What does the study add?

Anatomical Variation Between the Prone, Supine, and Supine Oblique Positions on Computed Tomography: Implications for Percutaneous Nephrolithotomy Access

OBJECTIVE To determine anatomical variations between the prone, supine, and supine oblique positions that are likely to affect percutaneous renal access. MATERIAL AND METHODS Twenty patients underwent computed tomography urograms in the supine and prone positions. Twenty patients underwent supine oblique and prone scans. Mean nephrostomy tract length, maximum access angle, and anterior-posterior renal position were calculated. RESULTS Mean nephrostomy tract length was shorter in the prone position (82.6 mm right kidney, 85.4 mm left kidney) compared with the supine position (108.3 mm right kidney, P<.001; 103.7 mm left kidney, P<.001). Prone tract length was also shorter than supine oblique tract length (86.1 mm vs 96.5 mm; P=.048). Mean maximum access angle was significantly greater (P=.018 right kidney; P=.007 left kidney) in the prone position (right kidney 99.7°, left kidney 104.0°) compared with the supine position (right kidney 87.7°, left kidney 89.4°). The same was true for the prone compared with the supine oblique position (75.8° vs 58.7°; P=.004). No difference was noted in anterior-posterior renal position between the supine and prone positions (20.3 mm vs 26.7 mm; P=.094) or supine oblique and prone positions (22.8 mm vs 15.6 mm; P=.45). CONCLUSIONS The prone position is associated with a significantly shorter nephrostomy tract length and more potential access sites, which may improve ease and safety of percutaneous renal access.

Image-guided percutaneous renal cryoablation: Preoperative risk factors for recurrence and complications

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Comparison of percutaneous and laparoscopic renal cryoablation for small (<3.0 cm) renal masses.

PURPOSE We reviewed our experience with laparoscopic cryoablation (LCA) and percutaneous cryoablation (PCA) in the management of small renal tumors and compared clinical outcomes, short-term oncologic results, and patient complications. PATIENTS AND METHODS A retrospective comparison of two prospectively collected oncologic databases was performed. Ninety patients underwent PCA for 99 lesions and 81 patients underwent an LCA for 97 lesions. Patient characteristics, perioperative data, and tumor characteristics were recorded including age, estimated blood loss, complication rate, tumor size, and tumor pathology. RESULTS Patients in both the PCA and LCA groups had similar demographic and tumor characteristics. The PCA group had two major complications (2%), and the LCA group had three major complications (3.7%) (P = 0.374). In the LCA group, estimated blood loss was associated with tumor location with hilar tumor demonstrating a significantly higher mean blood loss (191 mL) compared with endophytic, mesophytic, and exophytic tumors (70 mL, 71 mL, 73.5 mL), respectively (P = 0.05). Malignancies rated in the PCA and LCA groups were 50.5% and 60.0%, respectively (P < 0.05). In the PCA group, nine (9.1%) patients demonstrated treatment failure with a persistent enhancement in the ablation bed. All nine were treated with a subsequent PCA. One patient had subsequent tumor bed enhancement and underwent an open radical nephrectomy. Treatment failed in three (3.1%) patients in the LCA cohort (incomplete ablation or recurrence). CONCLUSIONS With short-term follow-up, both LCA and PCA are safe and effective treatments for small renal masses. Patients undergoing PCA had a reduced hospital stay and a lower surgical complication rate, albeit with an elevated re-treatment rate. Long-term data is needed to establish long-term oncologic efficacy. Renal function did not significantly change in patients after cryoablation, including patients with a solitary kidney.

The debate over percutaneous nephrolithotomy positioning: a comprehensive review.

PURPOSE We summarized the arguments for and against prone and supine percutaneous nephrolithotomy, and determined whether any clinical characteristics warrant 1 position over the other. MATERIALS AND METHODS We searched PubMed® for articles on prone anesthesia, abdominal organ movement between the prone and supine positions, and percutaneous nephrolithotomy case series since 1998. RESULTS The prone position is associated with a decrease in the cardiac index and an increase in pulmonary functional residual capacity. An increased risk of liver and spleen injury exists for upper pole puncture with the patient supine. Potential injury to the colon is greatest during prone lower pole access. A greater surface area for percutaneous access exists with the patient prone. The supine position decreases surgeon radiation exposure and promotes spontaneous stone drainage during the procedure. Two comparative series show that the supine position is associated with significantly shorter operative time. In contrast, noncomparative case series suggest decreased operative time and blood loss when treating staghorn calculi with the patient prone. CONCLUSIONS Each position is feasible but more randomized studies are needed to accurately determine the relative efficacy and morbidity of the 2 positions.

Management of urolithiasis in patients after urinary diversions

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