A machine learning approach using stone volume to predict stone-free status at ureteroscopy.

INTRODUCTION: To develop a predictive model incorporating stone volume along with other clinical and radiological factors to predict stone-free (SF) status at ureteroscopy (URS). MATERIAL AND METHODS: Retrospective analysis of patients undergoing URS for kidney stone disease at our institution from 2012 to 2021. SF status was defined as stone fragments < 2 mm at the end of the procedure confirmed endoscopically and no evidence of stone fragments > 2 mm at XR KUB or US KUB at 3 months follow up. We specifically included all non-SF patients to optimise our algorithm for identifying instances with residual stone burden. SF patients were also randomly sampled over the same time period to ensure a more balanced dataset for ML prediction. Stone volumes were measured using preprocedural CT and combined with 19 other clinical and radiological factors. A bagged trees machine learning model with cross-validation was used for this analysis. RESULTS: 330 patients were included (SF: n = 276, not SF: n = 54, mean age 59.5 ± 16.1 years). A fivefold cross validated RUSboosted trees model has an accuracy of 74.5% and AUC of 0.82. The model sensitivity and specificity were 75% and 72.2% respectively. Variable importance analysis identified total stone volume (17.7% of total importance), operation time (14.3%), age (12.9%) and stone composition (10.9%) as important factors in predicting non-SF patients. Single and cumulative stone size which are commonly used in current practice to guide management, only represented 9.4% and 4.7% of total importance, respectively. CONCLUSION: Machine learning can be used to predict patients that will be SF at the time of URS. Total stone volume appears to be more important than stone size in predicting SF status. Our findings could be used to optimise patient counselling and highlight an increasing role of stone volume to guide endourological practice and future guidelines.

Percutaneous Nephrolithotomy for De Novo Urolithiasis After Kidney Transplantation: A Systematic Review of the Literature.

Introduction and Objective: Renal transplantation is the treatment for end-stage renal disease that offers better quality of life and survival. Among the possible complications that might affect allografts, urolithiasis might have severe consequences, causing acute kidney injury (AKI) or septic events in immunocompromised patients. Allograft stones might be treated with percutaneous nephrolithotomy (PCNL). The aim of this Cochrane style review was to assess the safety and efficacy of PCNL in patients with renal transplant. Methods: A comprehensive search in the literature was performed including articles between July 1982 and June 2023, with only English original articles selected for this review. Results: The final review encompassed nine articles (108 patients). The mean age was 46.4 ± 8.7 years, with a male:female ratio of 54:44. The average time from transplantation to urolithiasis onset was 47.54 ± 23.9 months. Predominant symptoms upon presentation were AKI (32.3%), followed by urinary tract infection and fever (24.2%), and oliguria (12.9%). The mean stone size was 20.1 ± 7.3 mm, with stones located in the calices or pelvis (41%), ureteropelvic junction (23.1%), or proximal ureter (28.2%). PCNL (22F-30F) was more frequently performed than mini-PCNLs (16F-20F) (52.4% vs 47.6%). Puncture was guided by ultrasound (42.9%), fluoroscopy (14.3%), or both (42.9%). The stone-free rate (SFR) and complication rates were 92.95% (range: 77%-100%) and 5.5%, respectively, with only one major complication reported. Postoperatively, a ureteral stent and nephrostomy were commonly placed in 47%, with four patients needing a second look PCNL. During an average follow-up of 32.5 months, the recurrence rate was 3.7% (4/108), and the mean creatinine level was 1.37 ± 0.28 mg/dL. Conclusions: PCNL remains a safe and effective option in de novo allograft urolithiasis, allowing to treat large stones in one-step surgery. A good SFR is achieved with a low risk of minor complications. These patients should be treated in an endourology center in conjunction with the renal or transplant team.

Extended pelvic lymph node dissection during robotic prostatectomy: antegrade versus retrograde technique.

BACKGROUND: Robot-assisted radical prostatectomy (RARP) with extended lymphadenectomy (ePLND) is the gold standard for surgical treatment of prostate cancer (PCa). Recently, the en-bloc ePLND has been proposed but no studies reported on the standardization of the technique. The aim of the study is to describe different standardized en-bloc ePLND, the antegrade and the retrograde ePLND, and to compare their surgical and oncological outcomes. MATERIALS & METHODS: From January 2018 to September 2019, all patients subjected to RARP plus ePLND by one single surgeon were enrolled. ePLND was performed in a retrograde fashion by starting laterally to the medial umbilical ligament from the internal inguinal ring proceeding towards the ureter, or in an antegrade way by starting from the ureter at its crossing with the common iliac artery and proceeding towards the femoral canal. Patients' demographic data, clinical and surgical data were collected. Each en-bloc ePLND was categorized as "efficient" or "inefficient" by the operator, as surrogate of surgeon's satisfaction. RESULTS: Antegrade and retrograde ePLND were performed in 41/105 (group A) and 64/105 (group R) patients, respectively. The two groups (A vs R) had similar median (IQR) number of lymph nodes retrieved [20 (16.25-31.5) vs 19 (15-26.25); p = 0.18], ePLND time [33.5 (29.5-38.5) min vs 33.5 (26.5-37.5) min; p = 0.4] and post-operative complications [8/41 (19.5%) vs 9/64 (14.1%); p = 0.61]. In group A, 3/41 (7.3%) clinically significant lymphoceles were reported, while 1/64 (1.6%) in group R (p = 0.3). 33/41 (80.5%) and 28/64 (44%) procedures were scored as efficient 59 in group A and R, respectively (p = 0.01). On multivariate regression, only BMI (B = 0.93; 95% CI 0.29-1.56; p = 0.005) was associated with a longer ePLND time. CONCLUSIONS: The study indicates that antegrade and retrograde en-bloc extended pelvic lymph node dissection (ePLND) have comparable surgical and oncologic outcomes, supporting the importance of standardizing the procedure rather than focusing on the direction. Although both techniques aligned with current evidence regarding lymph node invasion and complications, the antegrade approach was subjectively perceived as safer due to early isolation of critical anatomical landmarks. Encouragement for the use of en-bloc ePLND, regardless of direction, is emphasized to improve prostate cancer staging accuracy and procedural standardization.

Safety and Efficacy of "Dusting and Pop-Dusting" with High-Power Laser for Treatment of Large Pediatric Stones with Ureteroscopy and Lasertripsy: Prospective Outcomes from a University Teaching Hospital.

Introduction: The wide use of high-power laser has changed the landscape of ureteroscopy and lasertripsy (URSL). We wanted to look at the role and outcomes of high-power holmium:yttrium-aluminum-garnet laser for URSL in pediatric stone disease. Methods: A prospective analysis of consecutive pediatric patients treated with "Dusting and Pop-dusting" using a high-power laser was done between January 2016 and March 2022. The project was registered with our audit committee. Data were analyzed for patient demographics, stone characteristics, operative details, procedural outcomes, and complications. Stone-free rate (SFR) was defined as fragments ≤2 mm on postoperative ultrasound imaging 2-3 months after the procedure. Results: A total of 35 patients underwent 43 procedures (1.2 procedure/patient) during the study period with a mean age of 9.4 years (range 1-16 years) and a male:female ratio of 13:22. The stone location was in the kidney in 32 (91.4%) patients of which 8 were in multiple renal locations. The mean stone size was 18 mm (range 10-39 mm), with the pre- and post-stent rates of 37% and 56%, respectively. An access sheath was used in 19 (44%) procedures. The overall SFR on ultrasound scan was 94% (n = 33) with no procedural complications noted in our series and a mean length of stay of 0.9 days. Conclusion: Pediatric URSL using a high-power laser achieves a high SFR even for large and multiple renal stones with no complications noted in our prospective series. Parents must, however, be counseled about the need for staged procedures, which might be needed for large stones.

Should endoscopic laser excision be offered as the first-line management for patients with eroded mesh? Outcomes of a systematic review of literature.

PURPOSE OF REVIEW: Mesh erosions following previous synthetic sling/mesh surgery for stress urinary incontinence (SUI) have become increasingly common. This systematic review provides evidence for the role of laser excision as a first-line management in patients with eroded mesh. RECENT FINDINGS: Fourteen articles (173 patients) were included for the final review. Among these, 138 patients (79.8%) were submitted to trans-urethral laser excision of eroded urethral/bladder mesh over a median time to presentation of 36.6 months. Over a median follow-up of 23.6 months, 88 (63.7%) reported a complete resolution, 32 (23.2%) reported persistence or recurrence of SUI and 17 (12.3%) presented with recurrent mesh erosion. The success rate after a single endoscopic procedure was 66.5, vs. 93.5% after additional endoscopic procedures, with only 9 (6.6%) requiring open surgical excision. Overall, there were seven (5.1%) postoperative complications including two urethrovaginal fistulas, two UTIs and haematuria each, and one case of urethral diverticulum. SUMMARY: Laser excision of eroded mid-urethral slings into either the bladder or urethra is a challenging complication of minimally invasive incontinence surgery. Laser excision was able to achieve a good success rate with single or staged endoscopic procedure with a low risk of complication. It represents a valid first treatment option, although patients should be managed in mesh referral centres in collaboration with uro-gynaecology teams.

Ureteroscopy and lasertripsy with pop dusting using high power holmium laser for large urinary stones > 15 mm: 6.5-year prospective outcomes from a high-volume stone center.

INTRODUCTION: Ureteroscopy and stone lasertripsy (URSL) is a recognized technique for treatment of urinary tract stones. Holmium:Yag laser has been successfully used for this purpose for the last two decades. More lately, pulse modulation with Moses technology and high power lasers have been introduced with the result of faster and more efficient stone lasertripsy. Pop dusting is a two-stage combined treatment using a long pulse Ho:YAG laser, initially in contact mode with the stone 'dusting' (0.2-0.5 J/40-50 Hz) followed by non-contact mode 'pop-dusting' (0.5-0.7 J/20-50 Hz). We wanted to look at the outcomes of lasertripsy for renal and ureteric stones using a high-power laser machine. METHODS: Over a period of 6.5 years (January 2016-May 2022), we prospectively collected data for patients undergoing URSL for stones larger than 15 mm treated using high power Ho:YAG laser (60W Moses or 100W laser). Patient parameters, stone demographics and outcomes of URSL were analyzed. RESULTS: A total of 201 patients, underwent URSL for large urinary stones. In 136 patients (61.6%) stones were multiple and the mean single and cumulative stone size was 18 mm and 22.4 mm respectively. A pre- and post-operative stent was placed in 92 (41.4%) and 169 (76%) respectively. The initial and final stone free rate (SFR) were 84.5% and 94% respectively and 10% patients underwent additional procedure to achieve stone free status. 7 (3.9%) complications were recorded, all related to UTI/sepsis, with 6 Clavien II and 1 Clavien IVa complication. CONCLUSION: Dusting and pop-dusting has shown to be successful and safe with the ability to treat large, bilateral or multiple stones with low retreatment and complication rates.

Outcomes of Paediatric Cystine Stone Management: Results of a Systematic Review.

PURPOSE OF REVIEW: We wanted to analyse the outcomes of surgical (SWL, URS, PCNL) and medical management of cystine stones in the paediatric population in terms of stone-free status and complication rates, based on all the available literature evidence. RECENT FINDINGS: A systematic review of literature was performed for all studies with paediatric cystine stone management. Twelve studies met the eligibility criteria, of which 4 analysed outcomes of SWL, 2 of URS and 3 of PCNL and 3 focused on the effect of either alkalising agents (potassium citrate, citric acid) or cysteine-binding thiol (CBT) agents (tiopronin, penicillamine). The reported SFR in studies ranged from 50 to 83%, 59 to 100% and 63 to 80.6%, with a complication rate of 2.8-51%, 14-27% and 12.9-15.4% with SWL, URS and PCNL, respectively. Paediatric cystine stones treatment should aim at complete stone clearance, preservation of renal function and prevention of further recurrences. SWL achieves inferior results in case of cystine stones. URS and PCNL are safe and effective procedures in the paediatric population, with a low rate of major complications. Adherence to medical prevention therapies may prolong recurrence-free periods.

Role of Pediatric Ureteral Access Sheath and Outcomes Related to Flexible Ureteroscopy and Laser Stone Fragmentation: A Systematic Review of Literature.

Context: Flexible ureteroscopy and laser lithotripsy (FURSL) represent a good treatment option for pediatric urolithiasis. Scarce evidence is available about the safety and efficacy of the concomitant use of a ureteral access sheath (UAS) in the setting of pediatric ureteroscopy (URS). Objective: To acquire all the available evidence on UAS usage in pediatric FURSL, focusing on intra- and postoperative complications and stone-free rates (SFRs). Evidence acquisition: We performed a systematic literature research using PubMed/MEDLINE, Embase, and Scopus databases. The inclusion criteria were cohorts of pediatric patients <18 yr old, submitted to URS for FURSL, reporting on more than ten cases of UAS placement. The primary outcomes were prestenting rates, operating time, ureteric stent placement rates after surgery, rates and grades of complications, ureteral injuries, and overall SFR. A total of 22 articles were selected. Evidence synthesis: In total, 26 intraoperative and 130 postoperative complications following URS with UAS placement were reported (1.8% and 9.18% of the overall procedures, respectively). According to the Clavien-Dindo classification, 32 were classified as Clavien I, 29 as Clavien II, 43 as Clavien I or II, six as Clavien III, and one as Clavien IV. Twenty-one cases of ureteral injuries (1.59%) were noted in the whole cohort; most of them were ureteral perforation or extravasation, and were treated with a temporary indwelling ureteric stent. The overall SFR after a single URS procedure was 76.92%; after at least a second procedure, it was 84.9%. Conclusions: FURSL is a safe and effective treatment option for pediatric urolithiasis. UAS use was associated with a low rate of ureteric injuries, mostly treated and resolved with a temporary indwelling ureteric stent. Patient summary: We performed a systematic literature research on the utilization of a UAS during ureteroscopy for stone treatment in pediatric patients. We assessed the outcomes related to the rates of intra- and postoperative complications and the rates of efficacy of the procedure in the clearance of stones. The evidence shows a low rate and grade of complications associated with UAS placement and good stone-free outcomes. A ureteric injury may occur in 1.6% of cases, but it is usually managed and resolved with a temporary indwelling ureteric stent.

Association of Kidney Stones and Recurrent UTIs: the Chicken and Egg Situation. A Systematic Review of Literature.

PURPOSE OF REVIEW: Kidney stone disease (KSD) and recurrent urinary tract infections (rUTI) are frequently concomitant conditions. We conducted a systematic review to determine the association of UTI in patients with KSD and to assess the outcomes of kidney stone treatment in the resolution of rUTI. RECENT FINDINGS: Our systematic review included 17 papers and a strong association between KSD and rUTI was demonstrated by numerous studies. Surgical clearance of kidney stones usually resulted in the resolution of UTI, but discordant data persist regarding recurrence rates after surgery. In vitro studies might unveil the causative role of bacteria in the formation of "metabolic" stones. Our SR clearly shows that UTI and KSD are mutually coexisting, and reciprocally causal and such patients should be counselled for proactive intervention by stone removal especially when UTIs are recurrent or additional risk factors are present irrespective of stone composition. To prevent further UTI episodes, if possible, a stone culture must be obtained for an effectively targeted antibiotic treatment regime tailored to bacterial prevalence.

Sexual and ejaculatory function after holmium laser enucleation of the prostate and bipolar transurethral enucleation of the prostate: a single-center experience.

Currently available surgical treatments for Lower Urinary Tract Symptoms (LUTS) due to Benign Prostatic Obstruction (BPO) are associated with an increased risk of sexual dysfunction. The aim of our study is to compare sexual and ejaculatory function after Holmium Laser Enucleation of the Prostate (HoLEP) and Bipolar Transurethral Enucleation of the Prostate (B-TUEP). We performed a retrospective analysis of data prospectively collected from 62 (44.9%) and 76 (55.1%) patients who underwent HoLEP and B-TUEP, respectively. Erectile function and ejaculation characteristics were assessed with the International Index of Erectile Function-Erectile Function (IIEF-EF) domain and the Male Sexual Health Questionnaire-Ejaculatory function (MSHQ-EJ) questionnaires. Our study recorded no change in erectile function and no significant difference in rates of preserved antegrade ejaculation after both surgeries. One month after surgery, rates of physical pain/discomfort and perceived decreased physical pleasure during ejaculation were higher in HoLEP than B-TUEP patients (all p < 0.03). Moreover, HoLEP patients were more bothered by their ejaculatory difficulties than B-TUEP men (p = 0.03). At 3- and 12-months follow-up, all ejaculation-related differences disappeared. In conclusion, both procedures are valid alternatives for BPO treatment as they offer comparable urinary and sexual outcomes in the long term. However, in the first month after surgery, HoLEP patients present with more ejaculatory difficulties.

Development of a Novel Clinical and Radiologic Risk Score to Predict Septic Complications After Urinary Decompression in Patients with Obstructive Uropathy.

Background: Well-defined clinical predictors of sepsis after upper tract drainage for obstructive uropathy are lacking. The study aim is to develop a data-driven score to predict risk of sepsis after decompression of the upper urinary tract. Materials and Methods: Complete clinical and radiologic data from 271 patients entering the emergency department for obstructive uropathy and submitted to stent/nephrostomy tube decompression were evaluated. The Charlson Comorbidity Index (CCI) was used to score comorbidities. The definition of sepsis was an increase in ≥2 Sequential Organ Failure Assessment points (or a postoperative persistently elevated score +1 additional increase) and documented blood or urine cultures. Descriptive statistics and stepwise multivariable logistic regression modeling with receiver operating characteristic analysis were performed to obtain a composite risk score to predict the risk of sepsis after surgery. This study was approved by our local Ethics Commitee (Prot. 25508). Results: Fifty-five (20.3%) patients developed sepsis. At multivariable analysis, CCI ≥2 (odds ratio [OR] 3.10; 95% confidence interval [CI] 1.36-7.04), maximum body temperature ≥38°C (OR 4.35; 95% CI 1.89-9.44), grade III-IV hydronephrosis (OR 2.37; 95% CI 1.10-4.98), HU of the dilated collecting system ≥7.0 (OR 4.47; 95% CI 2.03-9.81), white blood cells ≥15 × 103/mmc (OR 2.77; 95% CI 1.24-6.19), and C-reactive protein ≥10 (OR 3.27; 95% CI 1.41-7.56) were independently associated with sepsis. The positive predictive value of a true sepsis increased incrementally as a function of number of positive variables, ranging from 1.6% to 100.0% among patients with 1 and 6 positive variables, respectively. Conclusion: Our risk score identifies accurately patients with an increased risk of sepsis after urinary decompression for obstructive uropathy, hence improving clinical management.

Bipolar Transurethral Enucleation of the Prostate: Is it a size-independent endoscopic treatment option for symptomatic benign prostatic hyperplasia?

BACKGROUND: Bipolar Transurethral Enucleation of the Prostate (B-TUEP) is recommended as a first-choice treatment for benign prostatic obstruction in prostates >80 ml. Differently, B-TUEP is only considered as an alternative option after TURP for smaller prostates (30-80 ml). The aim of our study is to assess the relation between prostate size and surgical outcomes after B-TUEP. METHODS: We performed a retrospective analysis of data collected from 172 patients submitted to B-TUEP. Patients were segregated according to tertiles of prostate volume (PV) (≤60 ml, 61-110 ml, >110 ml). For each group we evaluated enucleation efficacy (enucleated weight/enucleation time), complication rates, urinary and sexual function parameters. Functional and sexual parameters were compared between groups at baseline, 1 and 3 months follow up. Descriptive statistics and linear and logistic regression models tested the association between PV and postoperative complications/outcomes. RESULTS: Operative time and weight of enucleated adenomas increased along with prostate volumes (all p≤0.01). Enucleation efficacy was higher in men with PV >110 ml compared to other groups (p≤0.001). Length of hospital stay, catheterization time and rates of postoperative complications, such as transfusion and clot evacuation rates and bladder neck/urethral strictures, were comparable between groups. Urinary symptoms improved at 1-and 3-months in each group as compared to baseline evaluation (all p<0.01) but they did not differ according to PV. In each group maximum urinary flow and post-void residual volume significantly improved at 3 months compared to baseline (all p≤0.01), without differences according to PV. Sexual symptoms were similar between groups at each follow up assessment. At multivariable linear and logistic regression analysis, prostate volume was not associated with postoperative functional outcomes and complications. Conversely, patient's comorbid status and antiplatelet/anticoagulation use were independently associated with postoperative complications. CONCLUSION: According to our findings, B-TUEP should be considered a "size independent procedure" as it can provide symptom relief in men with prostates of all sizes with the same efficacy and safety profile.

The Impact of Surgical Strategy in Robot-assisted Partial Nephrectomy: Is It Beneficial to Treat Anterior Tumours with Transperitoneal Access and Posterior Tumours with Retroperitoneal Access?

Available comparison of transperitoneal robot-assisted partial nephrectomy (tRAPN) and retroperitoneal robot-assisted partial nephrectomy (rRAPN) does not consider tumour's location. The aim of this study was to compare perioperative morbidity, and functional and pathological outcomes after tRAPN and rRAPN, with the specific hypothesis that tRAPN for anterior tumours and rRAPN for posterior tumours might be a beneficial strategy. A large global collaborative dataset of 1169 cT1-2N0M0 patients was used. Propensity score matching, and logistic and linear regression analyses tested the effect of tRAPN versus rRAPN on perioperative outcomes. No differences were observed between rRAPN and tRAPN with respect to complications, operative time, length of stay, ischaemia time, median 1-yr estimated glomerular filtration rate (eGFR), and positive surgical margins (all p>0.05). Median estimated blood loss and postoperative eGFR were 50 versus100ml (p<0.0001) and 82 versus 78ml/min/1.73 m2 (p=0.04) after rRAPN and tRAPN, respectively. At interaction tests, no advantage was observed after tRAPN for anterior tumours and rRAPN for posterior tumours with respect to complications, warm ischaemia time, postoperative eGFR, and positive surgical margins (all p>0.05). The techniques of rRAPN and tRAPN offer equivalent perioperative morbidity, and functional and pathological outcomes, regardless of tumour's location. PATIENT SUMMARY: Robot-assisted partial nephrectomy can be performed with a transperitoneal or a retroperitoneal approach regardless of the specific position of the tumour, with equivalent outcomes for the patient.

A case of acute bleeding from a small, asymptomatic renal angiomyolipoma (AML) during pneumoperitoneum induction for a rectal tumor resulting in acute hematuria and anemia.

Angiomyolipoma (AML) is a benign renal mesenchymal tumor. Active surveillance is considered the most appropriate option for most AMLs. The major complication of AML is its spontaneous bleeding in the retroperitoneum that could be life-threatening for the patient. In this case, acute bleeding from a sporadic AML was reported immediately after the induction of a 12 mmHg pneumoperitoneum during a planned laparoscopic resection of the rectum for oncological reasons. After immediate stabilization the patient underwent angiography of the renal artery and super-selective vascular embolization. Although rare, spontaneous rupture of asymptomatic AML should always be considered, especially in intraoperative setting.

The critical role of lymph node dissection in selecting high-risk nonmetastatic renal cancer candidates for adjuvant therapy after nephrectomy.

BACKGROUND: The role of lymph node dissection (LND) during nephrectomy for renal cell carcinoma (RCC) is controversial. We looked at the clinical usefulness of performing LND to stratify the risk of patients with RCC and select candidates for systemic treatment after nephrectomy. MATERIALS AND METHODS: We identified 730 patients with nonmetastatic RCC treated with nephrectomy and LND at a single center. We compared the accuracy and clinical usefulness of a base model including factors defining high-risk patients according to the S-TRAC trial [(pT3 and Grade≥2 and performance status score ≥1) or pT4] relative to the base model plus pN stage for the prediction of early progression after surgery. RESULTS: LN invasion resulted the most informative predictor of early progression (odds ratio: 6.39; 95% confidence interval [CI]: 3.26, 12.54; P < 0.0001). The accuracy was higher (P = 0.008) for the model implemented with pN (area under the curve: 0.76; 95% CI: 0.71, 0.80) as compared to the base model (area under the curve: 0.72; 95% CI: 0.68, 0.76). Performing LND to select patients for postoperative systemic treatment, resulted in a slightly higher net benefit as compared to a strategy defining risk on the base of factors other than pN. Patients with high-risk disease showed a large difference in the risk of progression according to pN-status (1-year risk: 58% [95% CI: 45, 72] for pN1; 31% [95% CI: 25, 38] for pN0; P < 0.001). CONCLUSIONS: Performing LND at the time of nephrectomy improves risk stratification, resulting into a small but nonnegligible clinical advantage for selecting high-risk patients for further treatment after surgery. Further trials should investigate whether high-risk pN1 patients would benefit from a different postoperative management.

The Association of Uromodulin Genotype with Renal Cancer Aggressiveness.

The aim of the study was to investigate the association of the uromodulin (UMOD) genotype with patient health status and with renal cell carcinoma (RCC) aggressiveness. The UMOD genotype at the top single nucleotide variant rs4293393 was determined in a cohort of 211 patients diagnosed with a renal mass and treated with surgery. Clinical data were prospectively collected. Due to the higher frequency of allele T relative to the lower frequency of allele C, recessive homozygous (CC), and heterozygous (TC) patients were grouped together and compared with homozygous (TT) patients. Mann-Whitney and chi-square tests were used to compare clinical characteristics after stratification for the UMOD genotype. UMOD genotype frequencies resulted TT and TC-CC in 67% (n=141) and 33% (n=70) of the population, respectively. The rate of cM1 RCC at clinical staging was higher in patients with genotype TT relative to patients with genotype TC-CC (18% vs 1%, p=0.001). Similarly, the rate of pT3-pT4 (41% vs 25%, p=0.047) and lymphovascular invasion (29% vs 13%, p=0.02) RCC at final pathology were higher in patients with genotype TT relative to patients with genotype TC-CC. PATIENT SUMMARY: In patients diagnosed with renal cell carcinoma and treated with surgery, uromodulin homozygous genotype is associated with more aggressive renal cell carcinoma clinical and pathological characteristics.

The side and the location of the primary tumor does not affect the probability of lymph node invasion in patients with renal cell carcinoma.

PURPOSE: To evaluate the role of side and location of the primary renal cell carcinoma (RCC) on the risk of lymph node invasion (LNI) and/or nodal progression (NP) during follow-up. MATERIALS AND METHODS: We evaluated 2485 patients with unilateral RCC, surgically treated in a single tertiary care referral center. Outcomes were LNI at surgery and/or NP during follow-up. We studied if RCC side (left vs. right) and location (upper vs. middle vs. hilar vs. lower area vs. more than one area) affected the probability of LNI and/or NP at follow-up. RESULTS: Overall, 43 and 15% of patients underwent lymph node dissection and had LNI at surgery, respectively. During follow-up, 2.2% of patients had NP. Higher rates of LNI and NP were observed for patients with primary tumor located in more than one anatomical kidney area relative to patients with tumor in a single area (upper 11% vs. middle 10% vs. hilar 0%, vs. lower 12% vs. more than one area 26%, p < 0.01). cM1, cN1, pT2/pT3/pT4 disease and Fuhrman grade 3/4 were independent predictors of the study outcome (all p ≤ 0.01). Neither the RCC side nor the location reached the independent predictor status (all p > 0.1). CONCLUSIONS: Patients with single-side and more than one anatomical kidney area affected by RCC have higher rate of LNI at surgery and/or NP at follow-up. Neither side nor location of primary RCC tumor is related to the risk of harboring LNI at surgery and/or developing NP at follow-up.

When to Perform Preoperative Bone Scintigraphy for Kidney Cancer Staging: Indications for Preoperative Bone Scintigraphy.

OBJECTIVE: To identify an objective and reproducible strategy for preoperative staging bone scintigraphy (BS) in patients diagnosed with renal cell carcinoma (RCC), because in the absence of objective criteria, the decision to perform preoperative BS remains a subjective practice. PATIENTS AND METHODS: The study included a total of 2008 patients with RCC treated with surgery and prospectively included into an institutional database. The study outcome was the presence of 1 or more bone lesions suspicious for metastases at staging BS. A multivariable logistic regression model predicting a positive BS was fitted. The predictors consisted of the preoperative clinical tumor (cT) and clinical nodal (cN) stages, the presence of systemic symptoms, and the platelet-to-hemoglobin (PLT/Hb) ratio. RESULTS: The rate of positive BS was 4% (n = 81). At the multivariable logistic regression analysis, cT2, cN1, the presence of systemic symptoms, and the PLT/Hb ratio were all associated with am increased risk of positive BS (P <.05). Following the 2000-sample bootstrap validation, the concordance index was 0.77 (proposed model) vs 0.63 (decision making based on symptoms only). At the decision curve analysis, the proposed strategy was associated with a higher net benefit. If BS is performed when the risk of positive result is >5%, a negative BS is spared in 80% and a positive BS is missed in 2% of the population only. CONCLUSION: Using preoperative variables, it is possible to accurately estimate the risk of positive BS at RCC staging using preoperative characteristics. Compared with the strategy supported by available guidelines, the proposed model was more objective, statistically more accurate, and clinically associated with higher net benefit.

Lymph node dissection should not be dismissed in case of localized renal cell carcinoma in the presence of larger diseases.

OBJECTIVE: To assess whether even in the group of localized renal cell carcinoma (RCC), some patients might harbor a disease with a predilection for lymph node invasion (LNI) and/or lymph node (LN) progression and might deserve lymph node dissection (LND) at the time of surgery. MATERIALS AND METHODS: Between 1990 and 2014, 2,010 patients with clinically defined T1-T2N0M0 RCC were treated with nephrectomy and standardized LND at a single tertiary care referral center. The endpoint consists of the presence of LNI and/or nodal progression, defined as the onset of a new clinically detected lymphadenopathy (>10mm) in the retroperitoneal lymphatic area with associated systemic progression or histological confirmation or both. We tested the association between clinical characteristics and the endpoint of interest. Predictors consisted of age at surgery, clinical tumor size, preoperative hemoglobin, and platelets levels. Multivariable logistic regression model and smoothed Lowess method were used. RESULTS: LNI was recorded in 14 cases (2.2%). The median follow-up after surgery was 68 months. During the study period, 23 patients (1.1%) experienced LN progression; 91% of those patients experienced LN progression within 3 years after surgery. Combining the 2 endpoints, 36 patients (1.8%) had LNI and/or LN progression. Clinical tumor size was the only independent predictors of LNI and/or LN progression (OR = 1.25). A significant increase of the risk of LNI and/or LN progression was observed in RCC larger than 7cm (cT2a or higher). CONCLUSIONS: LNI and/or LN progression is a rare entity in patients with localized RCC. Nonetheless, patients with larger tumors might still benefit from LND because of a non-negligible risk of LNI and/or LN progression.