Julien Dagenais

Excisional Precision Matters: Understanding the Influence of Excisional Volume Loss on Renal Function After Partial Nephrectomy

Renal function after partial nephrectomy (PN) may depend on modifiable factors including ischemia time, excision of healthy parenchyma (excisional volume loss, EVL), and reconstructive methods. We retrospectively reviewed our institutional robotic PN database to identify the predictors of glomerular filtration rate (GFR) preservation (GFR-P) at 3-12 mo postoperatively, during which GFR decline plateaus. Baseline clinical, sociodemographic, and radiologic characteristics were captured. Univariate and multivariate (MV) linear regression analyses were performed and marginal effects were employed to examine the relative effect of EVL on renal function. A total of 647 patients who underwent robotic PN had GFR data at a median follow-up of 6 mo. On MV models, EVL was significantly correlated with GFR-P following log transformation (p=0.001). Each doubling of EVL caused a 1.5% decrease in GFR-P. Ischemia time and tumor complexity were not significantly associated with GFR-P. In summary, GFR-P after PN appears to be significantly associated with the excised volume of benign parenchyma. PATIENT SUMMARY At a high-volume tertiary care center, we investigated the impact of surgical factors on kidney function after kidney cancer surgery. We found that the surgical precision with which the tumor is excised significantly impacts kidney function at 3-12 mo after surgery.

When Partial Nephrectomy is Unsuccessful: Understanding the Reasons for Conversion from Robotic Partial to Radical Nephrectomy at a Tertiary Referral Center

Purpose: We sought to identify the preoperative factors associated with conversion from robotic partial nephrectomy to radical nephrectomy. We report the incidence of this event. Materials and Methods: Using our institutional review board approved database, we abstracted data on 1,023 robotic partial nephrectomies performed at our center between 2010 and 2015. Standard and converted cases were compared in terms of patients and tumor characteristics, and perioperative, functional and oncologic outcomes. Logistic regression analysis was done to identify predictors of radical conversion. Results: The overall conversion rate was 3.1% (32 of 1,023 cases). The most common reasons for conversion were tumor involvement of hilar structures (8 cases or 25%), failure to achieve negative margins on frozen section (7 or 21.8%), suspicion of advanced disease (5 or 15.6%) and failure to progress (5 or 15.6%). Patients requiring conversion were older and had a higher Charlson score (both p <0.01), including an increased prevalence of chronic kidney disease (p = 0.02). Increasing tumor size (5 vs 3.1 cm, p <0.01) and R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar lines and hilar location) score (9 vs 8, p <0.01) were also associated with an increased risk of conversion. Worse baseline renal function (OR 0.98, 95% CI 0.96–0.99, p = 0.04), large tumor size (OR 1.44, 95% CI 1.22–1.7, p <0.01) and increasing R.E.N.A.L. score (p = 0.02) were independent predictors of conversion. Compared to converted cases, at latest followup standard robotic partial nephrectomy cases had similar short‐term oncologic outcomes but better renal functional preservation (p <0.01). Conclusions: At a high volume center the rate of robotic partial nephrectomy conversion to radical nephrectomy was 3.1%, including 2.2% of preoperatively anticipated nephrectomy cases. Increasing tumor size and complexity, and poor preoperative renal function are the main predictors of conversion.

Perioperative morbidity, oncological outcomes and predictors of pT3a upstaging for patients undergoing partial nephrectomy for cT1 tumors

ObjectivesTo evaluate perioperative morbidity, oncological outcome and predictors of pT3a upstaging after partial nephrectomy (PN).Materials and methodsRetrospective study of 1042 patients who underwent PN for cT1N0M0 renal cell carcinoma between 2007 and 2015. A total of 113 cT1 patients were upstaged to pT3a, while 929 were staged as pT1. Demographic, perioperative and pathological variables were reviewed. We compared the clinico-pathological characteristics, perioperative morbidity and oncological outcomes between pT3a and pT1 groups. Multivariate regression evaluates variables associated with T3a upstaging. Recurrence-free survival (RFS) and overall survival analyses were performed. Survival curves were compared using log-rank test.ResultsThe pT3a tumors were high complexity tumors (median RENAL score 8 vs. 7, p < 0.01), higher hilar (h) location (27.5 vs. 14.8%, p < 0.01), higher grade (57.5 vs. 38.2%, p < 0.01), and higher positive surgical margins (18.6 vs. 5.8%, p < 0.01. Patients with pT3a had a higher estimated blood loss, transfusion rate, ischemia time and overall complications, though there were no differences in median e-GFR decline and major (Grade III-V) complications. Five-year RFS was 78.5% for pT3a group vs. 94.6% for pT1 group (log-rank p < 0.01). Male gender (OR 2.2, p < 0.01), and R.E.N.A.L. score (OR 2.3, p = 0.01) were preoperative predictors of upstaging. We acknowledge limitations in our study, most are inherent problems of retrospective studies.ConclusionPerioperative morbidity, after partial nephrectomy, is acceptable in cT1/pT3 tumors in comparison to cT1/pT1; however, upstaged patients had a worse oncological outcome. cT1/pT3a tumors are associated with adverse clinico-pathological features. Preoperative risk predictors of upstaging were higher R.E.N.A.L. score and male gender.

Patterns and Predictors of Recurrence after Partial Nephrectomy for Kidney Tumors

Purpose: We sought to identify patterns and predictors of recurrence in patients with clinically localized renal cell carcinoma managed by partial nephrectomy. Materials and Methods: We performed a retrospective study of 830 consecutive cases of partial nephrectomy done between 2007 and 2015 for clinically localized renal cell carcinoma at a single institution. Patient demographics and pathological characteristics were correlated with recurrence patterns (overall, local and distant) and overall survival using Kaplan‐Meier and Cox regression analyses. Differences in the recurrence patterns were evaluated. Results: Median patient age was 61 years and median tumor size was 3.1 cm. Overall, 11.6% of tumors were stage pT3, 39.3% were high grade, 2.9% had lymphovascular invasion and 7.1% had positive margins. Higher grade, higher stage, positive surgical margins and increased R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of deepest tumor portion to collecting system or sinus, anterior/posterior and location relative to polar line) score were associated with shorter disease‐free survival on Kaplan‐Meier analysis. On multivariable regression pT (p <0.01), grade (p <0.01) and R.E.N.A.L. score (p = 0.03) remained independent predictors of disease‐free survival. Predictors of metastasis were pT stage (HR 4.5) and grade (HR 3.9, both p <0.01), while R.E.N.A.L. score (HR 3.2, p = 0.03) was the single predictor of local recurrence. Five‐year disease‐free and overall survival probabilities were 91% and 94%, respectively. Local recurrence manifested and developed earlier than metastasis (median 13 vs 22 months, p <0.01). Conclusions: High pT stage, high grade and high R.E.N.A.L. score increase the risk of disease recurrence after partial nephrectomy. The pT stage and grade are predictors of metastasis, while R.E.N.A.L. score predicts local recurrence. Because relapse features and risk factors differ between the 2 recurrence patterns, they should be studied separately in the future.

Perinephric and Sinus Fat Invasion in Stage pT3a Tumors Managed by Partial Nephrectomy

Micro‐Abstract From an anatomic perspective, stage pT3a tumors with sinus fat invasion (SFI) after partial nephrectomy could be considered more likely to develop recurrence than tumors with perinephric fat invasion (PFI). We included 85 patients with pT3a SFI and 58 patients with pT3a PFI in the present retrospective study. We compared the clinicopathologic characteristics, perioperative morbidity, and oncologic outcomes between the SFI and PFI groups. Progression‐free survival and overall survival analyses were performed. Survival curves were compared using the log‐rank test. SFI compared with PFI was not associated with an increased risk of progression or cancer‐specific death. Introduction We evaluated the influence of perinephric fat invasion (PFI) compared with sinus fat invasion (SFI) on disease‐free survival (DFS) and cancer‐specific survival (CSS) after partial nephrectomy (PN) for stage pT3a renal cell carcinoma (RCC). Materials and Methods Data were recorded from the consecutive records of patients who had undergone underwent PN for cT1‐T2 RCC from 2007 to 2016. Of these patients, 143 had stage pT3a with SFI or PFI found on final pathologic examination. The demographic, perioperative, and pathologic variables were reviewed. DFS and CSS analyses were performed. The factors predicting disease progression in this population were assessed. Results After a median follow‐up period of 28 months (range 15‐41 months), 19 patients (13.3%) had developed recurrence, including 5 local and 14 distant metastases, with 11 cancer‐specific deaths (7.7%). No differences were found in DFS (5 years, 60.9% vs. 55.3%; log‐rank P = .7) or CSS (5 years, 81% vs. 74.2%; log‐rank P = .8) between the SFI and PFI groups. For the pT3a fat invasion population, the 2‐ and 5‐year DFS and CSS rates were 83.6% and 58.6% and 93.6% and 78%, respectively. SFI (P = .5) and positive surgical margins (P = .1) did not predict for progression. On multivariate Cox regression, increased tumor size (hazard ratio, 1.5; 95% confidence interval, 1.1‐1.9; P < .01) and higher tumor grade (hazard ratio, 3.6; 95% confidence interval, 1.1‐4.6; P = .04) were independent predictors of disease progression in the pT3a fat invasion population. Conclusion In our series of patients with pT3a RCC after PN, SFI compared with PFI was not associated with an increased risk of progression or cancer‐specific death.

Concurrent Robotic Pyelolithotomy and Partial Nephrectomy: Tips and Tricks

OBJECTIVE With the evolution of robot-assisted surgery in the urology field, this technology is being applied to treat many genitourinary conditions.1 Although incidence of urolithiasis and renal neoplasm has increased, encountering both entities in a single kidney is noteworthy. Our video exhibits the concurrent management of a renal calculus and an ipsilateral renal neoplasm using a robotic platform. MATERIALS AND METHODS A 53-year-old man was diagnosed with a 1.7-cm left renal pelvis calculus and a 4.7-cm enhancing ipsilateral upper pole renal mass (R.E.N.A.L score 8a) after an episode of flank pain. After reviewing preoperative imaging, a single-setting approach using a robotic platform was planned. Main steps of our robotic technique on the case included (1) kidney defatting and mobilization, (2) hilum and ureter dissection up to the renal pelvis, (3) intraoperative ultrasound for tumor demarcation and stone localization, (4) anterior robotic pyelolithotomy,2 (5) double J stent placement and pyelotomy closure, (6) excision of renal mass, and (7) renorrhaphy. Perioperative outcomes were recorded. RESULTS The operative time was 180 minutes and the estimated blood loss was 100 mL. Warm ischemia time was 17 minutes. There were no intra- or postoperative complications. The patient was discharged home on postoperative day 3. Final pathology reported a 3.4-cm mass consistent with a clear cell renal carcinoma, with a tumor, nodes, metastases (TNM) staging pT1aNx and negative surgical margin. The double J stent was removed after 4 weeks, and the patient remained asymptomatic at 1 month postoperatively. CONCLUSION Pyelolithotomy and robotic partial nephrectomy can be performed effectively when treating patients with concurrent kidney mass and renal stone using the same surgical access. This minimally invasive approach should be contemplated as an option when managing patients with both conditions in an ipsilateral kidney. Furthermore, it will diminish the necessity of various surgeries while preserving renal function and maintaining oncological outcomes. We underline that the association of both procedures increases the likelihood of technical complications and risk for clot-related or stone-related ureteral obstruction, infection, and urine leak.

Infrared Light Structured Sensor Three-dimensional Approach to Estimate Kidney Volume: A Validation Study

OBJECTIVE To validate a new procedure for the three-dimensional estimation of total renal parenchyma volumeusing a structured-light infrared laser sensor. METHODS To evaluate the accuracy of the sensor for assessing renal volume, we performed 3 experiments. Twenty freshly excised porcine kidneys were obtained. Experiment A, the water displacement method was used to obtain a determination of the renal parenchyma volume after immersing every kidney into 0.9% saline. Thereafter a structured sensor (Occipital, San Francisco, CA) was used to scan the kidney. Kidney sample surface was presented initially as a mesh and then imported into MeshLab (Visual Computing Lab, Pisa, Italy) software to obtain the surface volume. Experiment B, a partial excision of the kidney with measurement of the excised volume and remnant was performed. Experiment C, a renorrhaphy of the remnant kidney was performed then measured. Bias and limits of agreement (LOA) were determined using the Bland-Altman method. Reliability was assessed using the intraclass correlation coefficient (ICC). RESULTS Experiment A, the sensor bias was -1.95mL (LOA: -19.5 to 15.59, R2 = 0.410) with slightly overestimating the volumes. Experiment B, remnant kidney after partial excision and excised kidneyvolume were measured showing a sensor bias of -0.5mL (LOA -5.34 to 4.20, R2= 0.490) and -0.6mL (LOA: -1.97.08 to 0.77, R2 = 0.561), respectively. Experiment C, the sensor bias was -0.89mL (LOA -12.9 to 11.1, R2= 0.888). ICC was 0.9998. CONCLUSION The sensor is a reliable method for assessing total renal volume with high levels of accuracy.

cT1a renal masses 2 cm managed with Robotic Partial Nephrectomy: a propensity-score matched comparison of perioperative Outcomes

Purpose: We performed a single center evaluation to compare perioperative, pathological and functional outcomes of robotic partial nephrectomy of T1a renal masses less than vs greater than 2 cm. Materials and Methods: Propensity score 1:1 matching of queried patients was performed using the institutional robotic partial nephrectomy database from January 2007 to January 2017. Matching was done by patient age, gender, race, body mass index, the Charlson comorbidity index, smoking status, diabetes, hypertension, hyperlipidemia, ASA® (American Society of Anesthesiologists®) score, estimated glomerular filtration rate, chronic kidney disease stage and R.E.N.A.L. (radius, exophytic/endophytic properties, nearness of tumor to collecting system or sinus, anterior/posterior, location relative to polar line and abutting main renal artery or vein) score. We analyzed the records of 524 patients, including 262 with a renal mass less than 2 cm vs 262 with a renal mass 2 cm or greater. Perioperative, pathological and functional outcomes were evaluated. Results: Smaller renal masses (less than 2 cm) were associated with significantly lower operative time, blood loss, ischemia time (mean ± SD 14.3 ± 9.58 vs 21.5 ± 9.51 minutes, p <0.001) and intraoperative transfusions (0% vs 2.7%, p = 0.015). Moreover, we found superior early renal functional outcomes as assessed by the estimated glomerular filtration rate on postoperative day 1 (mean 83.1 ± 21.3 vs 76.6 ± 22.0 mg/ml/1.73 m2, p = 0.001), greater parenchymal preservation (mean 89.9% ± 9.45% vs 83.6% ± 8.20%, p <0.001) and a trend toward a lower rate of postoperative complications (13.5% vs 19.5%, p = 0.080). A higher incidence of malignancy was found in larger tumors (85.9% vs 74.8%, p = 0.002) but no difference was recorded in positive surgical margins. Conclusions: Robotic partial nephrectomy tends to be a low morbidity treatment modality for renal masses less than 2 cm. Although active surveillance is a common option for such tumors, robotic partial nephrectomy remains an alternative in select patients.

Imaging strategy and outcome following partial nephrectomy

OBJECTIVES The aim of this study was to analyze the outcomes of surveillance after partial nephrectomy (PN) in a single institution and the relevance of imaging studies in detecting recurrence. MATERIAL AND METHODS Retrospective study of 830 patients who underwent PN for localized renal cell carcinoma between 2007 and 2015 at a single institution. We studied the characteristics of recurrence according to pathological and clinical features and elaborated risk groups. The type and the total number of imaging studies performed during surveillance or until recurrence were evaluated. Outcomes of surveillance were analyzed. RESULTS There were 48 patients (5.8%) diagnosed with recurrence during median 36 [21-52] months follow-up, including local recurrence in 18 patients (37.5%) and metastasis in 30 patients (62.5%). Totally, 17/18 patients (94.4%) with local recurrence and 26/30 patients (86.6%) with metastasis were diagnosed within the first 36 months after PN. When studying the recurrence rate, and time-to-recurrence, 2 risk groups emerged. Patients with pathological characteristics (tumors with pT1b or higher or high-grade tumor or positive surgical margin status) or patients with anatomical characteristics (high or moderate R.E.N.A.L. score) or both had high recurrence rate. Chest x-ray and abdominal ultrasound detected 7.7% and 3.4% of all recurrences, respectively, whereas computed tomography scan and magnetic resonance imaging scan detected the rest. Of the 48 patients diagnosed with recurrence, 44 (91.6%) were suitable for secondary active treatment (systemic, surgery, and radiotherapy) including 26 (54.2%) suitable for metastasectomy. The rate of relapse after secondary treatment was 43.5% (16.6% for the local recurrence group and 60.7% for metastasis group). CONCLUSION Local recurrence emerges earlier than distant metastasis. Patients with any adverse pathological or anatomical features should be considered as high-risk group and followed closely in the first 36 months after PN with cross-sectional studies. Secondary active treatment is suitable for most patients, while surgical treatment fits fewer patients. Local recurrence is associated with increased rates of metastatic progression.