Independent external validation of a nomogram to define risk categories for a significant decline in estimated glomerular filtration rate after robotic-assisted partial nephrectomy.

OBJECTIVE: To validate the Martini nomogram predicting the decline in estimated glomerular filtration rate after robotic-assisted partial nephrectomy. METHODS: Estimated glomerular filtration rate of 406 patients from a single surgeon series was calculated before robotic-assisted partial nephrectomy and at postoperative intervals. To determine the risk group, we calculated the total score and corresponding risk of significant estimated glomerular filtration rate reduction at 15 months using the Martini nomogram. The primary outcome was a reduction in estimated glomerular filtration rate of ≥25% from preoperative levels between 1 and 12 months after surgery. RESULTS: The median length of follow up for this study was 12 months (interquartile range 6-12 months). Overall, 134 (33%) patients were in the low-, 143 (35%) in the intermediate-, 119 (29%) in the high- and 10 (2%) in the very high-risk groups. The Kaplan-Meier estimates for the probability of significant estimated glomerular filtration rate reduction by 12 months after robotic-assisted partial nephrectomy was 12.9% in the low-risk group, 24.0% in the intermediate-risk group, 49.7% in the high-risk group and 40.0% in the very high-risk group. Harrell's C-index for discriminating between those with and without a significant reduction in estimated glomerular filtration rate 1-12 months after robotic-assisted partial nephrectomy was 0.73 (95% confidence interval 0.68-0.78). CONCLUSIONS: The risk groups proposed by the Martini nomogram are accurate in predicting those at higher risk for a >25% decline in postoperative estimated glomerular filtration rate after robotic-assisted partial nephrectomy at 12 months.

Mayo Adhesive Probability (MAP) score of non-donated kidney aids in predicting post-operative renal function following donor nephrectomy.

BACKGROUND: To examine the association of preoperative Mayo Adhesive Probability (MAP) scores in the donor (MAPd) and non-donor kidneys (MAPnd) with post-donation renal function. METHODS: Three hundred thirty-one patients undergoing hand assisted laparoscopic donor nephrectomy (HALDN) were reviewed. MAPd and MAPnd were obtained. Estimated glomerular filtration rate (eGFR) was recorded preoperatively and at 1 day, 1 month, and 6 months postoperatively. RESULTS: Two hundred females and 131 males were evaluated with median BMI 26.4 kg/m2 (range 17.1-39.6) and median age 45 years (range 19-78). MAPd score was 0 for 231 patients (69.8%) and > 0 for 100 patients (30.2%). MAPnd score was 0 for 234 patients (70.7%) and > 0 for 97 patients (29.3%). The median preoperative eGFR was 86.6 ml/min/1.73m2 (range 48.8-138.4). After adjusting for preoperative eGFR, BMI, ASA score, and kidney sidedness, postoperative eGFR was associated with MAP score in the non-donated kidney (p = 0.014) but not in the donated kidney (p = 0.24). Compared to donors with MAPnd = 0, donors with a MAPnd > 0, mean eGFR was - 2.33 ml/min/1.73m2 lower at postoperative day 1 (95% CI - 4.24 to - 0.41, p = 0.018), - 3.02 ml/min/1.73m2 lower at 1 month (95% CI - 5.11 to - 0.93, p = 0.005), and - 2.63 ml/min/1.73m2 lower at 6 months postoperatively (95% CI - 5.01 to - 0.26, p = 0.030). CONCLUSIONS: MAP score > 0 in the non-donated kidney is associated with worse renal function in the 6 months following HALDN.

Utility of the Aortic-Lesion-Attenuation-Difference (ALAD) and Peak Early-Phase Enhancement Ratio (PEER) to differentiate benign from malignant renal masses.

INTRODUCTION: To evaluate the utility of the Aorta-Lesion-Attenuation-Difference (ALAD) and Peak Early-phase Enhancement Ratio (PEER) on contrast-enhanced computed tomography (CT) to differentiate between the appearances of chromophobe renal cell carcinoma, clear cell renal cell carcinoma, and oncocytoma. MATERIAL AND METHODS: ALAD and PEER values were retrospectively measured by a reviewer from 119 patients with surgically resected renal masses (chromophobe renal cell carcinoma n = 29, clear cell renal cell carcinoma n = 28, and oncocytoma n = 62). The ALAD value is expressed as: ALAD = Hounsfield Units aorta - Hounsfield Units mass. PEER is expressed as (Hounsfield Units contrast tumor - Hounsfield Units non-contrast tumor):( Hounsfield Units contrast cortex - Hounsfield Units non-contrast cortex). RESULTS: The ALAD median was 27.6 for oncocytomas, 68.5 for chromophobe renal cell carcinoma, and 55.4 for clear cell renal cell carcinoma. A significant difference between ALAD values of oncocytoma and chromophobe renal cell carcinoma was observed in the nephrographic (area under the ROC curve 0.92) and excretory phases (area under the ROC curve 0.95). The PEER median was 0.74 for oncocytomas and 0.37 for chromophobe renal cell carcinoma. The PEER values significantly differed while comparing oncocytomas and chromophobe renal cell carcinoma in the nephrographic and excretory phases. CONCLUSIONS: Preoperative contrast-enhanced CT ALAD and PEER values both significantly differentiate between chromophobe renal cell carcinoma and oncocytoma. PEER may be more effective in contrast-enhanced CT scans lacking distinct phases.

The association between race and age of diagnosis of retinoblastoma in United States children.

PURPOSE: To explore the associations between race and retinoblastoma diagnosis in United States children. METHODS: In this analytical nonconcurrent cohort study, we used 1988-2018 data from the Surveillance, Epidemiology, and End-Results (SEER) database. Children ages 0-17 with retinoblastoma were included (n = 758); those with missing data were excluded (n = 11; final cohort: n = 747). The exposure variable was race (White, Black, Asian/Pacific Islanders, American Indian/Alaska Native), and the outcome variable was diagnosis of retinoblastoma before versus after 2 years of age. Covariates included sex, rural-urban continuum, ethnicity, decade of diagnosis, and laterality of disease. Unadjusted and adjusted logistic regression analyses were performed to calculate odds ratios and 95% confidence intervals. RESULTS: No statistically significant association was found between racial/ethnic groups (OR = 0.61-0.99; P = 0.92) and age at diagnosis (OR = 0.86; P = 0.66). Females were more likely to be diagnosed earlier than males (OR = 0.62; 95% CI, 0.44-0.88; P = 0.042). No association was found between urban versus rural subjects (OR = 1.02; 95% CI, 0.60-1.75) or between decades (OR = 0.81; 95% CI, 0.54-1.22 and OR 0.96; 95% CI, 0.62-1.47). CONCLUSIONS: We found no statistically significant difference between racial/ethnic groups for diagnosis of children with retinoblastoma after 2 years of age. Future studies could explore why females are more likely than males to be diagnosed before 2 years of age.

Validation of the Mayo Adhesive Probability score as a predictor of adherent perinephric fat and outcomes in open partial nephrectomy.

BACKGROUND: Adherent perinephric fat (APF) contributes to surgical complexity and can be associated with adverse perioperative outcomes for partial nephrectomy (PN). The Mayo Adhesive Probability (MAP) score accurately predicts the presence of APF during robotic-assisted partial nephrectomy (RAPN). Our primary aim is to validate MAP score as a predictor of APF in open partial nephrectomy (OPNx). METHODS: We reviewed 105 consecutive OPNx (100 patients) performed by a single surgeon with intraoperative determination of APF. We evaluated the ability of the MAP score to discriminate between those with APF and those without APF by estimating the area under the receiver operating characteristic curve (AUROCC). The association of perioperative outcomes with APF was evaluated as well. RESULTS: Forty-three patients [49%; 95% confidence interval (CI), 39-59%] had intraoperative identification of APF. The MAP score had excellent ability to predict APF in OPNx (AUROCC, 0.82; 95% CI, 0.74-0.92). APF was observed in 6% of patients with a MAP score of 0-1, 27% with score 2, 52% with score 3, 75% with score 4, and 90% with score 5. The presence of APF was associated with longer operative times (P=0.004) and higher estimated blood loss (EBL) (P=0.003). Although not statistically significant, our study did suggest that APF may be associated with postoperative complications and prolonged length of stay (LOS) (>3 days). CONCLUSIONS: MAP score accurately predicts the presence of APF in patients undergoing OPNx. APF is associated with longer operative time and higher blood loss in OPNx.

Perioperative Outcomes of Laparoscopic Radical Nephrectomy for Renal Mass in Patients on Dialysis or with Renal Transplant in Place Compared to Normal Controls.

Background: The risk of renal cell carcinoma (RCC) development in the native kidney of patients on dialysis or with a renal transplant is increased compared to the general population. This study examines perioperative outcomes of laparoscopic radical nephrectomy (LN) in dialysis patients or renal transplant patients compared to normal controls. Methods: Four hundred twelve consecutive LN were evaluated (July 2007 to October 2018). Patients were divided into three groups (control, dialysis, and transplant). Perioperative outcomes, including operating room time (OT), postoperative complications, hospital length of stay, and 90-day readmission rates, were evaluated for the three groups. Results: There were 62 patients in the dialysis group, 20 renal transplants, and 330 normal controls. Dialysis patients were younger (median: 58 years versus 67 years; P = .002) and predominantly male (73% versus 59%, P = .047). Dialysis patients compared to controls had shorter total OT (median: 133 versus 149; P = .022), more papillary RCC (27% versus 10%; P < .001), and fewer high grade tumors (73% [8/11] versus 94% [100/106]; P = .038). Renal transplant patients had a higher rate of 90-day readmission (20% versus 6%; P = .034) and more papillary RCC (30% versus 10%; P = .016) compared to controls. Conclusion: LN on dialysis patients does not alter expected perioperative outcomes compared to a large cohort of control LN. LN on renal transplant patients carries a higher 90-day readmission rate than control LN.

Association of Ancillary Pathology Findings in Non-neoplastic Renal Parenchyma and Renal Outcomes of Robotic-Assisted Partial Nephrectomy.

Background: To evaluate robotic-assisted partial nephrectomy (RAPN) renal outcomes associated with ancillary pathology findings in non-neoplastic renal parenchymal tissue. Methods: Tissue samples from 378 RAPNs were analyzed for glomerular disease (GD), vascular disease (VD), and tubulointerstitial disease (TD). One hundred and fifty-two patients were excluded due to insufficient non-neoplastic tissue for analysis and 4 patients were excluded due to calyceal diverticulum. Non-neoplastic tissue was evaluated for GD (negative, moderate, or global), VD (absent, mild, moderate, or severe), and TD (present or absent). Associations of ancillary pathology factors with patient characteristics were explored using the non-parametric Kendall tau-test and propensity score adjusted longitudinal mixed effects regression models were used to evaluate associations of these pathology factors with changes in estimated glomerular filtration rate (eGFR) following RAPN. Results: One hundred and fifty-three (68.9%) patients had hypertension and 50 (22.5%) patients had diabetes. The majority of patients did not have any GD (N = 158, 71.2%) or TD (N = 186, 83.8%) while 129 (58.1%) had VD. VD was categorized as absent (N = 93, 41.9%), mild (N = 45, 20.3%), moderate (N = 76, 34.2%), and severe (N = 8, 6.8%). Older age (P = 0.018), hypertension (P < 0.001), and high grade MAP score (P = 0.047) were associated with a higher number of ancillary pathology factors. High grade MAP score (P = 0.03, P = 0.002) and hypertension (P = 0.02, P < 0.001) were individually associated with GD severity and VD severity, respectively. Older age was also individually associated with VD severity (P = 0.002) and hypertension was associated with TD (P = 0.04). Moderate-to-severe VD was associated with a worse change in eGFR from pre-RAPN to 1-month post-RAPN compared to those with mild or no VD (difference in mean change, -3.4 ml/kg/1.73m2; 95% CI, -6.6 to -0.2 ml/kg/1.73m2; P = 0.036). Conclusions: Moderate-to-severe VD in non-neoplastic renal parenchyma is associated with post-operative changes in eGFR. Older age, hypertension, and high grade MAP scores are associated with the number of ancillary pathologies observed in RAPN specimens.

Pre-operative factors that predict trifecta and pentafecta in robotic assisted partial nephrectomy.

To prospectively evaluate factors that predict achievement of trifecta and pentafecta following robotic-assisted partial nephrectomy (RAPN). Clinical variables of 330 RAPNs performed for a single renal tumor were analyzed for association with post-operative trifecta and pentafecta achievement. Trifecta was defined as warm ischemia time (WIT) ≤ 25 min, negative surgical margins, and no post-operative complications ≥ Clavien grade 3. Pentafecta was defined as trifecta criteria plus > 90% preservation of estimated glomerular filtration rate (eGFR) and no stage upgrade of chronic kidney disease from pre-operative up to 12 months post-RAPN. After adjustment for multiple testing, p < 0.007 was considered statistically significant. Among 330 patients, trifecta was achieved in 280 patients (84.8%). Among the 152 patients with eGFR available at 12 months following RAPN, pentafecta was achieved in 39 (25.8%). A lower R.E.N.A.L. score was associated with increased odds of achieving trifecta (OR 3.38, p < 0.001) and pentafecta (OR 2.83 p < 0.001). No other pre-operative characteristics were associated with trifecta or pentafecta. Patients who achieved trifecta had a lower median estimated blood loss (EBL) (300 vs 400, p = 0.029) and shorter operative time (223 vs 234 min, p = 0.004) compared to patients without trifecta. There were no significant differences in EBL or operative time in patients who achieved or failed to achieve pentafecta. R.E.N.A.L score is the only pre-operative variable associated with achieving trifecta and pentafecta following RAPN. Lower EBL and operative time are associated with trifecta but not pentafecta outcomes.

Determinants and Implications of Excised Parenchymal Mass on Robotic-Assisted Partial Nephrectomy Outcomes.

OBJECTIVES: To evaluate the association between excised parenchymal mass (EPM) and postoperative renal function (eGFR) following robotic-assisted partial nephrectomy (RAPN). EPM is the amount of healthy renal parenchyma excised during partial nephrectomy in order to achieve safe surgical margins. METHODS: We evaluated 406 consecutive RAPN performed by a single surgeon to eliminate variations in technique as a factor in EPM. EPM (mL) = (specimen volume * π/6) - (tumor volume * π/6). RENAL score was categorized as easy (4-6), moderate (7-9), or hard (10-12). EPM was grouped into four categories: ≤ 3.9 mL, 4.0-9.9 mL, 10.0-17.7 mL, and >17.7 mL. eGFR was evaluated preoperatively, postoperative day 1 (POD1), 1 month, and 6 months postoperatively. RESULTS: Median age was 63 years (22-84 years), 252 (62.1%) were male, and median EPM was 9.9 mL (interquartile range 3.9 to 17.7 mL). The median EPM and interquartile range for each RENAL category was 3.7 mL (2.0, 7.9), 12 mL (5.7, 19.4), and 16.2 mL (7.9, 24.3), respectively. Higher EPM was associated with worse changes in eGFR at POD1 (P = 0.005) and 1 month after RAPN (P = 0.002) but was not statistically significant at the 6-month time period (P = 0.35) CONCLUSION: Increased tumor complexity is associated with an increase in EPM during RAPN. Increased EPM is associated with eGFR decline at POD1 and 1 month post RAPN but not at 6 months postoperatively.

Assessment of Advanced Perioperative Outcomes to Identify the True Learning Curve of Robotic-assisted Partial Nephrectomy.

OBJECTIVES: To evaluate the learning curve of robotic-assisted partial nephrectomy as it pertains to operative time (OT) and advanced perioperative variables such as achievement of trifecta, postoperative complications, 30-day readmission rates (RR), warm ischemia time (WIT), and functional volume loss (FVL). METHODS: We evaluated 418 consecutive robotic-assisted partial nephrectomy performed by a single surgeon between February 2008 and April 2019. Multivariable log-log regression models were used to evaluate the associations between case number and continuous outcomes (OT, WIT, and FVL). Multivariable logistic regression models were used to evaluate the association of case number with dichotomous outcomes (trifecta, postoperative complications, RR). RESULTS: Among the 406 eligible patients included in the study, 252 (62.1%) were male, median age was 63 years (range, 22-84), and median body mass index was 29 kg/m2 (interquartile range 26-33). Surgeon experience was associated with shorter OT (-2.5% per 50% increase in case number; 95% confidence interval; P <.001) and plateaus around 77 cases performed. There was slight improvement with trifecta (odds ratio [per 50% increase in cases] = 1.08; 95% confidence interval) and the plateau was also at 77 cases, however, this was not statistically significant (P = .086). We did not find statistically significant associations of surgeon experience with FVL (P = .77), postoperative complications (P = .74), WIT (P = .73), or 30-day RR (P = .33). CONCLUSION: There does not appear to be a relationship between surgical experience and grade 3 or higher postoperative complications, 30-day RR, WIT, or FVL. Trifecta outcomes and maximum OT performance appear to be optimized at approximately 77 cases.

Contact surface area and its association with outcomes in robotic-assisted partial nephrectomy.

BACKGROUND: Renal tumor scoring systems, such as the contact surface area value, aim to assist in predicting outcomes following robotic-assisted partial nephrectomy. The aim of this study is to identify associations between specific postoperative outcomes and the contact surface area of renal masses. METHODS: We analyzed 332 consecutive robotic-assisted partial nephrectomies and calculated contact surface area for renal tumors with the contact surface area formula (CSA = 2πrd), where π ≈ 3.14, r = greatest tumor radius (cm), and d = greatest tumor depth (cm). RESULTS: Higher contact surface area was associated with longer warm ischemia time (P < .001), higher estimated blood loss (P < .001), and longer length of hospital stay (LOS) (P < .001). Higher contact surface area was significantly associated with decreased renal function at 1 day, 1 month, and 6 months following robotic-assisted partial nephrectomy. CONCLUSIONS: Contact surface area is associated with certain outcomes following robotic-assisted partial nephrectomy and may be a useful predictive tool.

Tumefactive Fat Necrosis with Multinucleate Giant Cell Reaction Mimicking Recurrent Renal Cell Carcinoma following Percutaneous Renal Cryoablation.

Multinucleate Giant Cell (GC) reaction is a biological response that occurs secondary to infection, an implanted foreign body, tissue injury, or inflammation. In rare instances GC reactions have been reported following tissue ablation. Multinucleate GC reactions and tumefactive fat necrosis both have the ability to mimic cancer recurrence or metastasis and can appear as enhancing masses. We discuss a case of a surgically resected retroperitoneal perinephric mass thought to be recurrent renal cell carcinoma (RCC) that was pathologically confirmed as tumefactive fat necrosis with multinucleate GC reaction 2 years following percutaneous cryoablation of a small renal mass.

Elimination of surgical drains following robotic-assisted partial nephrectomy.

To prospectively evaluate outcomes of robotic-assisted partial nephrectomy (RAPN) following elimination of surgical drains. 100 consecutive drainless RAPN performed by a single surgeon were analyzed following a previously published quantitative assessment of drain creatinine/serum creatinine ratios. This cohort was compared to 100 preceding RAPN with drains. Variables analyzed included pre-operative patient/tumor characteristics and post-operative outcomes including post-operative estimated glomerular filtration rate (eGFR), length of hospital stay (LOS), and complications. There was no significant difference in median patient age, sex, body mass index, ASA score, or pre-operative eGFR between the two groups. The preceding 100 patients with drains did have larger median renal size (3.5 vs 2.6 cm, p < 0.001), higher median RENAL scores (9 vs 8, p < 0.001), and longer warm ischemia time (21 vs 18 min, p = 0.004). Patients without drains had shorter median LOS (2.0 days vs 3.0 days, p < 0.001), fewer Grade III or higher post-operative complications (4% vs 10%, p = 0.007), and no difference in 1 month percent change in eGFR (- 13% vs - 11%, p = 0.84). After adjusting for confounding variables there was no difference in LOS (OR 1.50, p = 0.31), Grade III-V complications (OR 1.49, p = 0.63), or 1 month percent change in eGFR (OR 2.3, p = 0.41) between the two groups. One patient in the drainless group required a post-operative drain for a urine leak diagnosed 10 days following RAPN. Omission of drains is safe in RAPN and does not appear to offer a clinical advantage.

Contrast enhanced ultrasound characterization of surgically resected renal masses in patients on dialysis.

Objective: Diagnostic work-up of suspicious renal masses has traditionally been conducted with contrast-enhanced computed tomography (CECT) and/or magnetic resonance imaging (MRI). However, patients who are not candidates for intravenous contrast due to allergy, renal insufficiency, or those on dialysis are discouraged from utilizing traditional contrast imaging due to risks of anaphylaxis, nephrotoxicity, or further kidney damage. We evaluated contrast-enhanced ultrasound (CEUS) in patients on dialysis who would benefit from alternative imaging options to CECT or MRI.Methods: Following IRB approval, nine renal masses from eight patients (aged 54-74 years) with chronic renal insufficiency were evaluated with CEUS and shown to be enhancing after the intravenous administration of ultrasound contrast agent. The ultrasound contrast agent Lumason (Sulfur hexafluoride lipid type-A microspheres, Bracco Diagnostics, Monroe Township, NJ, USA) was utilized. Enhancement was considered present when microbubble contrast agent was visualized within the lesion of interest.Results: Nine CEUS enhancing masses were pathologically examined following laparoscopic radical nephrectomy. Eight of the nine lesions were renal cell carcinoma (two clear cell, four papillary, two cystic). One resected mass was an unspecified benign renal lesion.Conclusions: In this sample of surgically resected tumors, CEUS was effective in characterizing renal lesions as solid neoplasms or complex cystic lesions suspicious for neoplasm-findings which merit further investigation.