Advancements in Performance of Percutaneous Nephrolithotomy in Ambulatory Surgery Centers: Outcomes and Lessons From 1250+ Cases.

OBJECTIVE: To evaluate the safety and efficacy of routine ambulatory percutaneous nephrolithotomy (PCNL) in a freestanding ambulatory surgical center. METHODS: Patients were treated between 2015 and 2022 by one of three experienced endourologists in Maryland. The surgery center is free-standing, with the nearest hospital approximately 10 minutes away. Patient characteristics and surgical datapoints, including need for transfer, were gathered prospectively at the time of surgery. Subset analyses were performed in patients with staghorn calculi or elevated body mass index, as they represent higher-risk populations. RESULTS: A total of 1267 patients underwent ambulatory PCNL with a median stone diameter of 32 mm. The average recovery time was 87 minutes, with 1.7% of patients requiring transfer to the hospital, generally for postoperative hypotension or inadequate pain control. 166 patients with body mass index >40 were safely treated, with no significant difference in transfer rate (P = .5). 2.8% of patients had a complication, with the majority being Clavien-Dindo grade I or II. 88 patients with staghorn calculi were treated, with a 6% transfer rate. Staghorn calculi were the only factor found on multivariable analysis to be a significant predictor of transfer (OR 3.56 (1.17-10.82) P < .05). CONCLUSION: Ambulatory PCNL may safely be performed in a surgery center in most patients. These outcomes reflect the real-world experience of high-volume surgeons and demonstrate a multiyear paradigm shift in PCNL from an inpatient procedure to an outpatient procedure in a surgery center.

Novel treatment of upper tract urothelial carcinoma in situ with docetaxel in BCG refractory patients.

INTRODUCTION: Patients with upper-tract carcinoma in situ (UT-CIS) that have failed treatment with BCG are recommended for radical nephroureterectomy (RNU). We describe a cohort of patients with BCG-refractory UT-CIS that were treated with docetaxel, a novel agent in the approach to topical therapy. METHODS: Patients with pathologically proven UT-CIS from 2012 to 2020 with an imperative indication for organ preservation and history of BCG-refractory disease were included. Each patient underwent ureteroscopy with biopsy and selective cytology pre- and postinduction, and after each maintenance course. Complete response (CR) was defined as the absence of visualized lesions on ureteroscopy, negative selective cytology, and absence of clinical progression. No response (NR) was defined as persistence of lesions after induction or absence of visualized lesions with persistently positive cytology. RESULTS: Seven patients and 10 renal units were treated. Six of the 10 renal units had initial CR (60%). Three patients with NR went on to have RNU, one of which subsequently died due to cancer-specific mortality. One patient with bilateral disease had NR in 10 renal unit and cure in the other. This patient subsequently developed recurrence in his remaining renal unit. A second patient had CR in both kidneys for 6 years, but 1 year after finishing maintenance regimen developed HG disease in 1 ureter. Average follow-up was 33 months. CONCLUSION: This study demonstrates efficacy of docetaxel as a treatment option for patients with UT-CIS with a contraindication to RNU after failing BCG. Response rates of 60% appear to be similar to those of BCG-refractory bladder CIS.

Deceived by a CT Scan: The Case of the Misrepresented Stone Size.

Background: CT has become the gold standard for radiographic evaluation of urolithiasis. CT is highly sensitive for detecting kidney stones and provides valuable information regarding stone size, composition, location, and overall stone burden. Although CT can provide reliable estimations of stone size, we have encountered an instance in which it can be deceiving. Motion artifact in CT images can cause a warping distortion effect that makes renal stones appear larger than they actually are. Case Presentation: We describe a case of a 37-year-old woman with a history of kidney stones and obesity presenting with intermittent flank pain and gross hematuria, found to have a large lower pole renal calculus that appeared deceptively large on CT imaging. Given the apparent size and location of the stone, the patient was counseled and consented for a percutaneous nephrolithotomy (PCNL). Although the stone was initially suspected to be >2 cm based on the preoperative CT scan, intraoperative pyelography revealed a much smaller than expected radio-dense stone. The patient was stone free after PCNL without any immediate postoperative complications. However, her course was later complicated by delayed bleeding causing significant clot hematuria, perinephric hematoma, and reactive pleural effusion. Conclusion: Although CT is especially valuable in preparing for surgery based on its ability to outline collecting system anatomy, it is important to remember that it can be deceiving. Correlation with kidney, ureter, and bladder radiograph and ultrasound is critical to understanding the clinical case and planning the optimal surgical approach.

Infected Renal Cyst: Elusive Diagnosis and Percutaneous Management.

Background: Benign renal cysts are relatively common in older adults, usually found incidentally on CT. However, an infected renal cyst is a rare complication. While a course of antibiotic therapy is generally the first-line treatment, indications for definitive operative intervention include chronic pain, recurrent urinary tract infection, hematuria, abscess formation, and/or impaired renal function. Case Presentation: A 61-year-old male urologist with no significant medical history was hospitalized at an outside facility for fever, chills, and abdominal pain. Initial diagnosis was pyelonephritis in the setting of a recently passed stone, with absence of hydronephrosis and a large, simple right renal cyst, but he failed to improve with intravenous antibiotics and developed intractable hiccups. Serial CT scans demonstrated onset of mild upper pole hydronephrosis and no change in the benign-appearing simple cyst. Interventional radiology planned drainage of the upper pole calices with a diagnosis of infundibular stenosis, but upon insistence of a urology consultant who suspected occult infection of the cyst, drains were placed into the collecting system and the cyst, with the return of a jet of purulent fluid upon cyst puncture. Conclusion: The patient subsequently recovered and was discharged and seen at our facility where he was definitively treated with percutaneous endoscopic marsupialization of the cyst into the collecting system and fulguration of the infected cyst wall with complete resolution.

Do patients with Stage 3-5 chronic kidney disease benefit from ischaemia-sparing techniques during partial nephrectomy?

OBJECTIVE: To analyse whether selective arterial clamping (SAC) and off-clamp (OC) techniques during robot-assisted partial nephrectomy (RPN) are associated with a renal functional benefit in patients with Stage 3-5 chronic kidney disease (CKD). PATIENTS AND METHODS: The change in estimated glomerular filtration rate (eGFR) over time was compared between 462 patients with baseline CKD 3-5 that underwent RPN with main arterial clamping (MAC) (n = 375, 81.2%), SAC (n = 48, 10.4%) or OC (n = 39, 8.4%) using a multivariable linear mixed-effects model. All follow-up eGFRs, including baseline and follow-up between 3 and 24 months, were included in the model for analysis. The median follow-up was 12.0 months (interquartile range 6.7-16.5; range 3.0-24.0 months). RESULTS: In the multivariable linear mixed-effects model adjusting for characteristics including tumour size and the R.E.N.A.L. (Radius; Exophytic/Endophytic; Nearness; Anterior/Posterior; Location) Nephrometry Score, the change in eGFR over time was not significantly different between SAC and MAC RPN (ß = -1.20, 95% confidence interval [CI] -5.45, 3.06; P = 0.582) and OC and MAC RPN (ß = -1.57, 95% CI -5.21, 2.08; P = 0.400). Only 20 (15 MAC, two SAC, three OC) patients overall had progression of their CKD stage at last follow-up. The mean ischaemia time was 17 min for MAC and 15 min for SAC. There was no benefit to SAC or OC in terms of blood loss, perioperative complications, length of stay, or surgical margins. CONCLUSION: SAC and OC techniques during RPN were not associated with benefit in preservation of eGFR in patients with baseline CKD.

The Impact of Obesity in Patients Undergoing Robotic Partial Nephrectomy.

Introduction: As the prevalence of obesity increases worldwide, an increasing proportion of surgical candidates have an elevated body mass index (BMI), with associated metabolic syndrome. Yet there exists limited evidence regarding the effect of elevated BMI on surgical outcomes in robotic surgeries. We examined whether obese patients had worse perioperative outcomes and postoperative renal function after robotic partial nephrectomies (RPNs). Materials and Methods: We performed a multi-institutional analysis of 1770 patients who underwent RPNs between 2008 and 2015, allowing time for the data set to mature. Associations between BMI, as a continuous and categorical variable, and perioperative outcomes, acute kidney injury (AKI, >25% reduction in estimated glomerular filtration rate [eGFR]) at discharge, and change in eGFR per month were analyzed. AKI and eGFR were evaluated using multivariable logistic and linear regression models adjusted for confounders, including age, Charlson comorbidity index, tumor size, and the identity of the surgeon. Results: In total 45.2% (n = 529) of patients were found to be obese, with a greater prevalence of hypertension and diabetes in overweight and obese patients. Obese patients were more likely to have malignant tumors (>77% vs 68%, p < 0.001) and trended toward having larger tumors (3.0 cm vs 2.8 cm; p = 0.061). Heavier patients required longer operative times (166-196 minutes vs 155 minutes; p < 0.001), although equivalent warm ischemia times (p = 0.873). Obesity did not correlate with an increased complication rate (p > 0.05). On multivariable analysis, obesity (odds ratio [OR] = 1.81; p = 0.031), male sex (OR = 1.54; p = 0.028), and larger tumor size (OR = 1.23; p < 0.001) were associated with a significant increase in the likelihood of AKI at discharge. BMI above normal weight was not associated with greater eGFR decline per month post-RPN. Conclusions: Obesity was associated with equivalent perioperative outcomes and long-term renal function. Further research is warranted into how obesity and metabolic syndrome may foster a more aggressive tumor environment. RPN appears to be an equally safe operative option for patients regardless of obesity status.

Reevaluating Warm Ischemia Time as a Predictor of Renal Function Outcomes After Robotic Partial Nephrectomy.

OBJECTIVE: To explore whether variation of warm ischemia time (WIT) is associated with functional and perioperative outcomes following robotic partial nephrectomy (RPN). MATERIALS AND METHODS: Six hundred sixty eight patients, each with 2 kidneys, undergoing RPNs for a cT1 tumor were identified from a U.S. multi-institutional database. The associations between WIT, normal excisional volume loss (EVL), and surgical and renal function outcomes, including acute kidney injury at discharge and percent change in eGFR at up to 24 months post-RPN, were evaluated using Spearman's rank correlation test as well as multivariable models controlling for tumor, surgeon, and patient characteristics. RESULTS: WIT was weakly correlated with EVL (r = 0.32, P < .001), blood loss (r = 0.34, P < .001), and length of stay (r = 0.35, P < .001). WIT was found to be significantly associated with acute kidney injury at discharge (odds ratio = 6.23; confidence interval 1.52, 30.39). Extended WIT was not found to be significantly associated with renal function decline at 1 year post RPN (P > .05). CONCLUSION: Extended WIT is associated with worse perioperative outcomes. While controlling for tumor size and EVL, effects on short-term renal function were still seen after as short as 20 minutes. Efforts to limit warm ischemia time should continue to be implemented during RPN to maximize postoperative renal function.

Is Off Clamp Always Beneficial During Robotic Partial Nephrectomy? A Propensity Score-Matched Comparison of Clamp Technique in Patients with Two Kidneys.

OBJECTIVE: The majority of patients undergoing partial nephrectomy (PN) present with a clinical T1a tumor with both kidneys present. Some groups have advocated using off-clamp (Off-C) techniques to eliminate warm ischemia whenever possible, even when elective. We evaluated whether Off-C technique during robotic PN (RPN) provides any functional benefit over main arterial clamping (MAC) in these patients. Subjects/Patients and Methods: A total of 351 patients with a R.E.N.A.L. nephrometry score (RNS) <10, T1a tumor, and two kidneys who underwent RPN from five high-volume surgeons between 2008 and 2016 were retrospectively identified from a multi-institutional database. MAC and Off-C patients were 2 to 1 nearest neighbor propensity score matched on tumor size, RNS, % endophytic, tumor location, age, gender, body mass index, comorbidities, baseline estimated glomerular filtration rates (eGFRs), and surgeon performing the RPN. Preoperative, surgical, and postoperative outcomes were compared. RESULTS: After propensity score matching, 82 MAC and 41 Off-C RPN patients were compared with no remaining statistically significant differences in baseline demographic or tumor-specific characteristics, including tumor size (p = 0.203) or RNS (p = 0.744). There were no significant differences in complications (p = 0.141), positive surgical margins (p = 0.625), or non-neoplastic parenchymal volume removed (p = 0.138). Off-C RPN had significantly higher estimated blood loss (100 mL vs 50 mL, p < 0.001), but no increased rate of transfusion (p = 0.328). There were no significant differences in rates of acute kidney injury (p = 0.132) nor percentage change in eGFRs (p = 0.763) at discharge. Freedom from progression of chronic kidney disease (CKD) stage was 87.7% for MAC and 91.1% for Off-C at 12 months. The percentage change in eGFRs (p = 0.457) and CKD stage progression (p = 0.866) was not different at last follow-up (median 9.2 months). CONCLUSION: Our data showed that the use of Off-C RPN marginally increased blood loss without providing a renal function benefit. In two-kidney patients presenting with a T1a renal tumor, Off-C RPN may not be necessary.

Predictors of Medical and Surgical Complications After Robot-Assisted Partial Nephrectomy: An Analysis of 1139 Patients in a Multi-Institutional Kidney Cancer Database.

INTRODUCTION: Previous robot-assisted partial nephrectomy (RAPN) studies have identified various predictors of overall and major postoperative complications, but few have evaluated the specific role of these factors in the development of medical and surgical complications. In this study, we present an analysis of the modifiable and nonmodifiable variables influencing medical and surgical complications in a contemporary series of patients who underwent RAPN and were followed in a prospectively maintained, multi-institutional kidney cancer database. METHODS: A retrospective review of all patients who underwent RAPN at four institutions between 2008 and 2015 was performed. Multivariable logistic regression models were used to determine predictors of medical and surgical postoperative complications. RESULTS: Data from 1139 patients were available for analysis. Sixty-seven patients (5.8%) experienced a medical postoperative complication, and 82 (7.1%) experienced a surgical complication. Decreasing baseline estimated glomerular filtration rate (eGFR) (odds ratio [OR] = 0.98, p = 0.003), greater estimated blood loss (EBL) (OR = 1.002, p = 0.001), and operating surgeon (OR = 8.01, p < 0.001) were associated with an increased likelihood of surgical complications, while decreasing baseline eGFR (OR = 0.99, p = 0.054) and operating surgeon (OR = 1.96, p = 0.054) were associated with an increased likelihood of medical complications. CONCLUSION: We present complication risks in a large contemporary cohort of patients undergoing robotic partial nephrectomy (RPN) with only 11.3% of patients experiencing a medical or surgical postoperative complication. Prospective candidates for robotic PN with poor baseline renal function and/or risk factors for greater EBL, including a high body mass index, or a complex renal mass should be counseled appropriately on their increased risk for a medical or surgical postoperative complication.

Selective arterial clamping does not improve outcomes in robot-assisted partial nephrectomy: a propensity-score analysis of patients without impaired renal function.

OBJECTIVES: To assess the benefit of selective arterial clamping (SAC) as an alternative to main renal artery clamping (MAC) during robot-assisted partial nephrectomy (RAPN) in patients without underlying chronic kidney disease (CKD). PATIENTS AND METHODS: Our study cohort comprised 665 patients without impaired renal function undergoing MAC (n = 589) or SAC (n = 76) during RAPN from four medical institutions in the period 2008-2015. We compared complication rates, positive surgical margin (PSM) rates, and peri-operative and intermediate-term renal functional outcome between 132 patients undergoing MAC and 66 undergoing SAC after 2-to-1 nearest-neighbour propensity-score matching for age, sex, body mass index, RENAL nephrometry score, tumour size, baseline estimated glomerular filtration rate (eGFR), American Society of Anesthesiologists (ASA) score, Charlson comorbidity index (CCI) and warm ischaemia time (WIT). RESULTS: In propensity-score-matched patients, PSM (5.7 vs 3.0%; P = 0.407) and complication rates (13.8 vs 10.6%; P = 0.727) did not differ between the MAC and SAC groups. The incidence of acute kidney injury for MAC vs SAC (25.0 vs 32.0%; P = 0.315) within the first 30 days was similar. At a median follow-up of 7.5 months, the percentage reduction in eGFR (-9.3 vs -10.4%; P = 0.518) and progression to CKD ≥ stage 3 (7.2 vs 8.5%; P = 0.792) showed no difference. CONCLUSIONS: Our study findings show no difference in PSM rates, complication rates or intermediate-term renal functional outcomes between patients with unimpaired renal function who underwent SAC vs those who underwent MAC. When expected WIT is low, the routine use of SAC may not be necessary. Further studies will need to determine the role of SAC in patients with a solitary kidney or with significantly impaired renal function.

R.E.N.A.L. Nephrometry Score Predicts Non-neoplastic Parenchymal Volume Removed During Robotic Partial Nephrectomy.

OBJECTIVE: To assess the association between the R.E.N.A.L. Nephrometry score, the amount of non-neoplastic parenchymal volume (NNPV) removed, and the renal function decline in patients undergoing robotic partial nephrectomy (RPN). PATIENTS AND METHODS: The Multi-institutional Mount Sinai Kidney Cancer Database was used to identify 1235 patients who underwent RPN between January 2008 and February 2016, of whom 366 had complete data, including NNPV removed. Mann-Whitney U tests and univariable linear regression models were used to assess the relationships between R.E.N.A.L. Nephrometry score, warm ischemia time (WIT), and NNPV removed. Univariable and multivariable regression models were then used to assess the independent relationships of each of these variables with percent change in estimated glomerular filtration rates (eGFR) and acute kidney injury (AKI) within the first 30 postoperative days in addition to percent change in eGFR and progression to chronic kidney disease at a median follow-up of 6.9 months. RESULTS: Increasing R.E.N.A.L. Nephrometry score was shown to be a predictor of WIT (ß = 0.92, p < 0.001) and of NNPV removed (ß = 6.21, p < 0.001) in univariable analyses. In multivariable analysis, postoperative reduction in eGFR within the first 30 days of surgery was associated with both R.E.N.A.L. Nephrometry score (ß = -2.02, p < 0.001) and NNPV removed (ß = -5.19, p = 0.015). R.E.N.A.L. Nephrometry score (OR = 1.21, p = 0.013) and NNPV removed (OR = 1.90, p = 0.013) were also associated with an increased likelihood of AKI within the first 30 days. No significant association in this cohort was found between R.E.N.A.L. Nephrometry score, NNPV removed, or WIT and renal function decline at 6.9 months. CONCLUSION: The preoperative R.E.N.A.L. Nephrometry score can be used to predict postoperative pathologically determined healthy renal volume loss or NNPV removed. Removal of not just the tumor but also the healthy surrounding parenchyma is important in determining renal function decline. As our understanding of the importance of renal volume loss grows, NNPV removed gains increasing utility as an easily determinable postoperative variable.