Evaluating Acetate as a Renoprotective Agent After Kidney Ischemia in a Porcine Model.

Objective: Renoprotection from reperfusion injury appears to be conferred by HIF-2a activation, which can be stimulated by exogenous acetate administration. The study objective was to assess whether administration of acetate in a porcine model can mitigate kidney injury related to ischemia-reperfusion after renal hilar occlusion. Methods: A porcine single-kidney model was created by performing a laparoscopic nephrectomy followed by animal recovery. After 2 days, the animals underwent laparoscopic hilar dissection. Block randomization was used to assign pigs into one of four experimental groups. One treatment block of pigs received 150 mEq of sodium acetate intravenously during 90 minutes of en bloc occlusion of the renal hilum (herein noted as "cross-clamping"). Another block received 0.75 g/kg of oral sodium acetate for 3 days prior to cross-clamping. A third block received no acetate and underwent hilar dissection without cross-clamping (negative control). The final block received no acetate and underwent cross-clamping (positive control). Serum creatinine was used to estimate renal function post-nephrectomy. Results: A total of 16 animals (4 pigs in each group) completed the study protocol. Median pig weight was 34.6 kg. One pig receiving IV acetate was excluded from the final analysis because of unrecoverable renal failure after cross-clamping. There was a significantly lower mean serum creatinine for the IV acetate group compared with the positive control group 72 hours after cross-clamping (p = 0.012). The same effect was not observed for the pigs receiving oral acetate. By day 7, renal function had recovered without significant difference in all groups. Conclusions: We observed that the administration of intravenous acetate conferred a significant renoprotective benefit in our single kidney ischemia-reperfusion porcine model 72 hours after hilar occlusion. This work is hypothesis-generating, and further work in human subjects undergoing renal hilar occlusion during partial nephrectomy is warranted.

Retzius-sparing vs. posterior urethral suspension: similar early-phase post-robotic radical prostatectomy continence outcomes.

Stress urinary incontinence (SUI) is a risk of robotic-assisted radical prostatectomy (RP) which can be a frustrating problem for both surgeons and patients. We aim to compare short-term continence outcomes between patients undergoing Retzius Sparing RP (RS-RP) and those undergoing standard RP with the inclusion of a PUS suture technique and suprapubic tube (PUS-RP). A retrospective review of 105 consecutive patients who underwent RP was performed, comparing patients who underwent RS-RP and PUS-RP. Our main outcome was pad usage as a surrogate for SUI. Patients were evaluated 4 weeks following RP and again at approximately 3 months. Continence was defined as no pad usage or up to one safety pad per day. Risk factors associated with not being continent were identified using univariate and multivariate analyses. In our cohort, 52 patients underwent RS-RP and 53 patients underwent PUS-RP. The two groups had similar patient demographics. Although not statistically significant, there was a higher rate of a positive surgical margin in the RS-RP compared to PUS-RP (25% vs 15%, p = 0.204). At one month follow-up for PUS-RP and RS-RP, there was no significant difference in the frequency of continent men (69.2% vs. 76.9%, p = 0.302). At 3-month follow-up for the two groups of patients, again, there was no significant difference in the frequency of continence for PUS-RP and RS-RP (86.2% vs 88%, p = 0.824). Patients who underwent RS-RP had similar rates of continence to those patients undergoing PUS-RP in the short-term post-operative period.

Characterization of Demographical Histologic Diversity in Small Renal Masses With the Clear Cell Likelihood Score.

OBJECTIVE: This study aimed to develop a diagnostic model to estimate the distribution of small renal mass (SRM; ≤4 cm) histologic subtypes for patients with different demographic backgrounds and clear cell likelihood score (ccLS) designations. MATERIALS AND METHODS: A bi-institution retrospective cohort study was conducted where 347 patients (366 SRMs) underwent magnetic resonance imaging and received a ccLS before pathologic confirmation between June 2016 and November 2021. Age, sex, race, ethnicity, socioeconomic status, body mass index (BMI), and the ccLS were tabulated. The socioeconomic status for each patient was determined using the Area Deprivation Index associated with their residential address. The magnetic resonance imaging-derived ccLS assists in the characterization of SRMs by providing a likelihood of clear cell renal cell carcinoma (ccRCC). Pathological subtypes were grouped into four categories (ccRCC, papillary renal cell carcinoma, other renal cell carcinomas, or benign). Generalized estimating equations were used to estimate probabilities of the pathological subtypes across different patient subgroups. RESULTS: Race and ethnicity, BMI, and ccLS were significant predictors of histology (all P < 0.001). Obese (BMI, ≥30 kg/m 2 ) Hispanic patients with ccLS of ≥4 had the highest estimated rate of ccRCC (97.1%), and normal-weight (BMI, <25 kg/m 2 ) non-Hispanic Black patients with ccLS ≤2 had the lowest (0.2%). The highest estimated rates of papillary renal cell carcinoma were found in overweight (BMI, 25-30 kg/m 2 ) non-Hispanic Black patients with ccLS ≤2 (92.3%), and the lowest, in obese Hispanic patients with ccLS ≥4 (<0.1%). CONCLUSIONS: Patient race, ethnicity, BMI, and ccLS offer synergistic information to estimate the probabilities of SRM histologic subtypes.

Patient-Reported Outcomes for Robot-Assisted Laparoscopic Extravascular Renal Vein Stent Placements for Nutcracker Syndrome.

Introduction: Nutcracker phenomenon is the compression of the left renal vein between the superior mesenteric artery (SMA) and the abdominal aorta. Nutcracker syndrome refers to the presence of nutcracker phenomenon with symptoms. Between 2016 and 2022, we performed 18 robot-assisted laparoscopic extravascular renal vein stent (RALERVS) placements. We sought to assess patient-reported outcomes of RALERVS placement by a single institution. Methods: We performed a single-center retrospective review of 18 patients with a minimum of 3 months follow-up. Symptoms were assessed utilizing a questionnaire conducted with a 5-point Likert scale at a minimum of 3 months postoperatively. Five on the Likert scale was severe while 1 was none. Primary study outcomes compared pre- and postoperative patient-reported symptom scores. Results: Twelve out of 18 patients responded to the survey. The average length of time from date of operation to completion of survey was 2.6 years. Average age of the cohort was 36 years with a mean BMI of 19.4 kg/m2. There was only one man. Mean operative time was 137 minutes and mean estimated blood loss was 12 mL. Mean preoperative SMA angle was 19° and mean postoperative SMA angle was 36°. Patients reported that flank pain, abdominal pain, nausea, headaches, back pain, pelvic pain, and early satiety improved (p < 0.05). Ten of 12 respondents would recommend RALERVS for nutcracker syndrome. Conclusion: RALERVS demonstrates an effective treatment for nutcracker syndrome. Patients reported improved symptoms at 3 months postoperatively across multiple domains. Further studies need to be conducted to assess long-term durability of the extravascular renal vein graft.

Mitochondrial metabolism in primary and metastatic human kidney cancers.

Most kidney cancers display evidence of metabolic dysfunction1-4 but how this relates to cancer progression in humans is unknown. We used a multidisciplinary approach to infuse 13C-labeled nutrients during surgical tumour resection in over 70 patients with kidney cancer. Labeling from [U-13C]glucose varies across cancer subtypes, indicating that the kidney environment alone cannot account for all metabolic reprogramming in these tumours. Compared to the adjacent kidney, clear cell renal cell carcinomas (ccRCC) display suppressed labelling of tricarboxylic acid (TCA) cycle intermediates in vivo and in organotypic slices cultured ex vivo, indicating that suppressed labeling is tissue intrinsic. Infusions of [1,2-13C]acetate and [U-13C]glutamine in patients, coupled with respiratory flux of mitochondria isolated from kidney and tumour tissue, reveal primary defects in mitochondrial function in human ccRCC. However, ccRCC metastases unexpectedly have enhanced labeling of TCA cycle intermediates compared to primary ccRCCs, indicating a divergent metabolic program during ccRCC metastasis in patients. In mice, stimulating respiration in ccRCC cells is sufficient to promote metastatic colonization. Altogether, these findings indicate that metabolic properties evolve during human kidney cancer progression, and suggest that mitochondrial respiration may be limiting for ccRCC metastasis but not for ccRCC growth at the site of origin.

Predicting Oncologic Outcomes in Small Renal Tumors.

BACKGROUND: Most patients diagnosed with renal cancer today present with small renal masses (SRMs). Although these patients have a low risk of dying from their disease and many are followed with active surveillance protocols, a small subset of renal cell carcinomas (RCCs) behave aggressively. Knowledge regarding features of aggressive behavior would enable better adoption of active surveillance strategies among these patients. OBJECTIVE: We sought to improve prognostic models to predict metastasis-free survival after nephrectomy through focused analyses of clinicopathologic characteristics of SRMs associated with adverse outcomes. DESIGN, SETTING, AND PARTICIPANTS: We identified consecutive patients with surgically resected SRMs (≤4 cm) at the University of Texas Southwestern Kidney Cancer Program between 1998 and 2020. In addition, we evaluated the ability of SRMs to form tumors when implanted in mice, an indicator of tumor aggressiveness. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We examined the clinicopathologic factors associated with metastasis including prospectively performed BAP1 immunohistochemistry at our Clinical Laboratory Improvement Amendments laboratory. Multivariable Cox proportional hazard regression was used to predict metastasis-free survival. RESULTS AND LIMITATIONS: A total of 3900 evaluable nephrectomies (from 3674 ethnically diverse patients) were identified, of which 1984 (51%) were SRMs including 1720 RCC. Of these patients with RCC (SRMRCC), 1576 did not have synchronous or metachronous larger RCCs and among these, 37 (2%) developed metastases. SRMRCC that metastasized were significantly enriched for aggressive morphologic phenotypes and engrafted in mice at comparable rates as larger metastatic tumors. BAP1 loss remained significantly associated with metastasis-free survival after accounting for TNM (tumor-node-metastasis) stage and SSIGN (stage, size, grade, and necrosis) score in multivariable analysis. CONCLUSIONS: We identified clinicopathologic features that influence metastasis-free survival for patients with SRMRCC. If validated independently, these data should assist with patient prognosis and help with active surveillance strategies. PATIENT SUMMARY: We report the identification of features of aggressiveness in small renal tumors that influence the likelihood of metastases after surgery.

The Operating Room Black Box: Understanding Adherence to Surgical Checklists.

OBJECTIVE: We report for the first time the use of the Operating Room Black Box (ORBB) to track checklist compliance, engagement, and quality. BACKGROUND: Implementation of operative checklists is associated with improved outcomes. Compliance is difficult to monitor. Most studies report either no assessment of checklist compliance or deployed in-person short-term assessment. The ORBB a novel artificially intelligence-driven data analytic platform affords the opportunity to assess checklist compliance without disrupting surgical workflow. METHODS: This was a retrospective review of prospectively collected ORBB data. Operative cases included elective surgery at a quaternary referral center. Cases were analyzed as prepolicy change (first 9 months) or as a postpolicy change (last 9 months). Measures of checklist compliance, engagement, and quality were assessed. RESULTS: There were 3879 cases that were performed and monitored for checklist compliance between August 15, 2020, and February 20, 2022. The overall scores for compliance, engagement, and quality were 81%, 84%, and 67% respectively. When broken down by phase, the scores for time-out were compliance 100%, engagement 98%, and quality 61%. Scores for the debrief phase were 81% for compliance, 98% for engagement, and 66% for quality. After a hospital policy change, the debrief scores improved significantly (85%; P <0.001 for compliance, 88%; P <0.001 for engagement and 71%; P <0.001 for quality). CONCLUSIONS: ORBB provides the unprecedented ability to assess not only compliance with surgical safety checklists but also engagement and quality. Utilization of this technology allows the assessment of compliance in near real time and to accurately address safety threats that may arise from noncompliance.