Modified Takazawa anatomical classification of renal pelvicalyceal system based on three-dimensional virtual reconstruction models

Extreme Percutaneous Nephrolithotomy: A Case Series of Procedures Requiring Five or More Access Tracts

Introduction: Percutaneous nephrolithotomy (PCNL) remains the gold standard treatment for patients with complete staghorn stones, for which multiple access tracts may be required. In this study, we describe a series of patients undergoing PCNL with a minimum of five dilated access tracts. Materials and Methods: We performed a multi-institutional retrospective review of 10 patients with complete staghorn stones who underwent PCNL requiring five or more access tracts. We recorded patient demographics, stone characteristics postoperative complications, and stone-free rates (SFRs). The primary endpoint was any postoperative complication. Secondary endpoints included SFR, operative time, and length of stay. SFR was defined as absence of stones or residual fragments <4 mm. Results: A total of 10 patients from two institutions were included. Access tract number ranged from 5 to 11, and median stone volume was 233,042 mm3. Seven patients (70%) experienced postoperative complications, ranging from Clavien II to IVa. Three patients (30%) required blood transfusions. Median operative time was 312 minutes ranging from 180 to 560 minutes. Five patients (50%) were stone-free after the initial procedure. Of those with residual fragments, 4 (40%) required reoperation to be rendered stone-free. Median length of stay was 2.5 days, with a range of 1-6 days. Conclusion: To our knowledge, this is the largest series of patients undergoing PCNL with five or more access tracts reported to date. This study confirms that PCNL with five or more tracts is feasible and relatively safe, albeit with a high rate of complications in the immediate postoperative period.

Kidney collecting system anatomy applied to endourology - a narrative review

OBJECTIVE

To evaluate the surgical anatomy of the kidney collecting system through a narrative review of the literature, highlighting its importance during diagnosis and its approach during surgical procedures for the treatment of renal stones.

MATERIAL AND METHODS

We carried out a review about the anatomy of the kidney collecting system. We analyzed papers published in the past 40 years in the databases Pubmed, Embase and Scielo, and we included only papers in English and excluded case reports, editorials and opinions of specialists.

RESULTS

Renal collecting system could be divided in four groups: A1 - kidney midzone (KM), drained by minor calyx that are dependent on the superior or the inferior caliceal groups; A2 - KM drained by crossed calyx, one draining into the superior caliceal group and another draining into the inferior caliceal group; B1 - KM drained by a major caliceal group independent of both the superior and inferior groups; and B2 - KM drained by minor calyx entering directly into the renal pelvis. Some details and anatomic variations of the collecting system are related to clinical and radiological aspects, particularly perpendicular calyces, interpyelocalyx space, position of calyces in relation to renal border, classification of the renal collecting system, infundibular diameter and the angle between the lower infundibulum and renal pelvis.

CONCLUSION

The knowledge of intra-renal collecting system divisions and variations as the angle between the renal pelvis and lower infundibula, position of the calices in relationship with renal edge and the diameter and position of the calyces are important for the planning of minimally invasive renal surgeries.

The Number and Size of Individual Kidney Medullary Pyramids is Associated with Clinical Characteristics, Kidney Biopsy Findings, and CKD Outcomes among Kidney Donors

SIGNIFICANCE STATEMENT

Segmentation of multiple structures in cross-sectional imaging is time-consuming and impractical to perform manually, especially if the end goal is clinical implementation. In this study, we developed, validated, and demonstrated the capability of a deep learning algorithm to segment individual medullary pyramids in a rapid, accurate, and reproducible manner. The results demonstrate that cortex volume, medullary volume, number of pyramids, and mean pyramid volume is associated with patient clinical characteristics and microstructural findings and provide insights into the mechanisms that may lead to CKD.

BACKGROUND

The kidney is a lobulated organ, but little is known regarding the clinical importance of the number and size of individual kidney lobes.

METHODS

After applying a previously validated algorithm to segment the cortex and medulla, a deep-learning algorithm was developed and validated to segment and count individual medullary pyramids on contrast-enhanced computed tomography images of living kidney donors before donation. The association of cortex volume, medullary volume, number of pyramids, and mean pyramid volume with concurrent clinical characteristics (kidney function and CKD risk factors), kidney biopsy morphology (nephron number, glomerular volume, and nephrosclerosis), and short- and long-term GFR <60 or <45 ml/min per 1.73 m 2 was assessed.

RESULTS

Among 2876 living kidney donors, 1132 had short-term follow-up at a median of 3.8 months and 638 had long-term follow-up at a median of 10.0 years. Larger cortex volume was associated with younger age, male sex, larger body size, higher GFR, albuminuria, more nephrons, larger glomeruli, less nephrosclerosis, and lower risk of low GFR at follow-up. Larger pyramids were associated with older age, female sex, larger body size, higher GFR, more nephrons, larger glomerular volume, more nephrosclerosis, and higher risk of low GFR at follow-up. More pyramids were associated with younger age, male sex, greater height, no hypertension, higher GFR, lower uric acid, more nephrons, less nephrosclerosis, and a lower risk of low GFR at follow-up.

CONCLUSIONS

Cortex volume and medullary pyramid volume and count reflect underlying variation in nephron number and nephron size as well as merging of pyramids because of age-related nephrosclerosis, with loss of detectable cortical columns separating pyramids.

Diagnostic performance of fluorescence in situ hybridization (FISH) in upper tract urothelial carcinoma (UTUC): a systematic review and meta-analysis

BACKGROUND

Fluorescence in situ hybridization (FISH) is a technique that uses fluorescently labeled DNA probes. Many studies have evaluated the ROC curve (sensitivity and specificity) with the FISH method to diagnose upper tract urothelial carcinoma (UTUC). The current meta-analysis was performed to examine the diagnostic power of the FISH method in UTUC.

METHODS

We reviewed databases and methodically obtained papers for analysis until April 25th, 2022. The Meta-disc V.1.4 and Comprehensive Meta-Analysis V.3.3 software calculated the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, area under the curve (AUC), and summary receiver-operating characteristic (SROC). The I² and Chi-square tests were used to examine the heterogeneity. Finally, the publication bias was estimated using Begg's and Egger's tests.

RESULTS

A total of 13 articles included 1,067 participants (439 cases and 628 controls). The overall pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were 0.72 (95% CI 0.67-0.76), 0.95 (95% CI 0.93-0.97), 10.42 (95% CI 5.84-18.60), 0.29 (95% CI 0.21-0.40), 38.55 (95% CI 18.58-79.96), and 0.91, respectively. No publication bias was reported based on Begg's and Egger's tests (Begg's p = 0.200; Egger's p = 0.151).

CONCLUSION

This paper clearly shows that the high specificity and acceptable sensitivity of the FISH method make it a promising diagnostic method for UTUC in urine samples. However, further research with higher statistical numbers is needed to strengthen the correlation and be used for diagnostic applications.