Robot-assisted Laparoscopic Partial Nephrectomy: Step-by-step Contemporary Technique and Surgical Outcomes at a Single High-volume Institution

Management of renal sinus angiomyolipoma: modified robotic nephron-sparing surgery in a single center

BACKGROUND

Renal sinus angiomyolipoma (RSAML) is a rare and typically complex renal tumor. The objective is to present our single-center experience with a modified technique of robotic nephron-sparing surgery (NSS) for treating RSAML.

METHODS

We retrospectively evaluated 15 patients with RSAMLs who were treated with robotic NSS at the Department of Urology of Tongji hospital, ranging from November 2018 to September 2022. Renal vessels and ureter were dissected. The outer part of RSAML was resected. The rest of tumor was removed by bluntly grasp, curettage and suction. Absorbable gelatin sponges were filled in the renal sinus. The preoperative parameters, operative measures and postoperative outcomes were all collected. Follow-up was performed by ultrasonography and estimated glomerular filtration rate (eGFR).

RESULTS

Robotic NSS was successfully performed in all the patients, without any conversion to open surgery or nephrectomy. The mean operation time was 134.13 ± 40.56 min. The mean warm ischemia time was 25.73 ± 3.28 min. The median estimated blood loss was 100 [50, 270] ml and 1 patient required blood transfusion. The mean drainage duration was 5.77 ± 1.98 days. The median postoperative hospital stay was 6.90 [5.80, 8.70] days. Two patients experienced postoperative urinary tract infection (Clavien-Dindo Grade II). During the median follow-up of 25.53 ± 15.28 months, patients received 91.18% renal function preservation. No local recurrence occurred in all the patients.

CONCLUSIONS

Robotic NSS for RSAML is a complicated procedure that demands technical expertise and a well-designed strategy is critical in the operation. Treating RSAML with modified robotic NSS is safe, effective and feasible.

Single-layer versus double-layer renorrhaphy technique during robot-assisted partial nephrectomy: impact on perioperative outcomes, complications, and functional outcomes

BACKGROUND

The debate between single-layer and double-layer renorrhaphy techniques during robot-assisted partial nephrectomy (RPN) represents a subject of ongoing discourse. The present analysis aims to compare the perioperative and functional outcomes of single- versus double-layer renorrhaphy during RPN.

METHODS

Study data were retrieved from prospectively maintained institutional database (Jan2018-May2023). Study population was divided into two groups according to the number of layers (single vs. double) used for renorrhaphy. Baseline and perioperative data were compared. Postoperative surgical outcomes included type and grade of complications as classified according to Clavien-Dindo. Serum creatinine and estimated glomerular filtration rate were used to measure renal function.

RESULTS

Three hundred seventeen patients were included in the analysis: 209 received single-layer closure, while 108 underwent double-layer renorrhaphy. Baseline characteristics were not statistically different between the groups. Comparable low incidence of intraoperative complications was observed between the cohorts (P=0.5). No difference was found in terms of mean (95% CI) Hb level drop postoperation (single-layer: 1.6 g/dL [1.5-1.7] vs. double-layer: 1.4 g/dL [1.2-1.5], P=0.3). Overall and "major" rate of complications were 16% and 3%, respectively, with no difference observed in terms of any grade (P=0.2) and major complications (P=0.7). Postoperative renal function was not statistically different between the treatment modalities. At logistic regression analyses, no difference in terms of probability of overall (OR 0.82 [0.63-1.88]) and major (OR 0.94 [0.77-6.44]) complications for the number of suture layers was observed.

CONCLUSIONS

Single-layer and double-layer renorrhaphy demonstrated comparable perioperative and functional outcomes within the setting of the present study.

Implementation of single-port robotic urologic surgery: experience at a large academic center

The Single-Port (SP) robotic system is increasingly being implemented in the United States, allowing for several minimally invasive urologic procedures to be performed. The present study aims to describe our single-center experience since the adoption of the SP platform. We retrospectively collected and analyzed consecutive SP cases performed at a major teaching hospital in the Midwest (Rush University Medical Center) from December 2020 to December 2023. Demographic variables were collected. Surgical and pathological outcomes were analyzed in the overall cohort and for each type of procedure. The study timeframe was divided into two periods to assess the evolution of SP technical features over time. In total, 160 procedures were performed, with robot-assisted radical prostatectomy (RARP) being the most common (49.4%). Overall, 54.4% of the procedures were extraperitoneal, with a significantly higher adoption of this approach in the second half of the study period (30% vs 74.3%, p < 0.001). A "plus one" assistant port was adopted in 38.1% of cases, with a shift towards a "pure" single-port surgery in the most recent procedures (21.1% vs 76.7%, p < 0.001). The median LOS was 33.5 h (30-48), with a rate of any grade and CD ≥ 3 postoperative complications of 9.4% and 2.5%, respectively, and a 30-day readmission rate of 1.9%. SP robotic surgery can be safely and effectively implemented for various urologic procedures. With increasing experience, the SP platform allows shifting away from transperitoneal procedures, potentially minimizing postoperative pain, and shortening hospital stay and postoperative recovery.

Patient-specific, deliverable, and self-expandable surgical guide development and evaluation using 4D printing for laparoscopic partial nephrectomy

Accurate lesion diagnosis through computed tomography (CT) and advances in laparoscopic or robotic surgeries have increased partial nephrectomy survival rates. However, accurately marking the kidney resection area through the laparoscope is a prevalent challenge. Therefore, we fabricated and evaluated a 4D-printed kidney surgical guide (4DP-KSG) for laparoscopic partial nephrectomies based on CT images. The kidney phantom and 4DP-KSG were designed based on CT images from a renal cell carcinoma patient. 4DP-KSG were fabricated using shape-memory polymers. 4DP-KSG was compressed to a 10 mm thickness and restored to simulate laparoscopic port passage. The Bland-Altman evaluation assessed 4DP-KSG shape and marking accuracies before compression and after restoration with three operators. The kidney phantom's shape accuracy was 0.436 ± 0.333 mm, and the 4DP-KSG's shape accuracy was 0.818 ± 0.564 mm before compression and 0.389 ± 0.243 mm after restoration, with no significant differences. The 4DP-KSG marking accuracy was 0.952 ± 0.682 mm before compression and 0.793 ± 0.677 mm after restoration, with no statistical differences between operators (p = 0.899 and 0.992). In conclusion, our 4DP-KSG can be used for laparoscopic partial nephrectomies, providing precise and quantitative kidney tumor marking between operators before compression and after restoration.

Longitudinal changes in renal parenchymal volume and function status after partial nephrectomy: a retrospective cohort study

BACKGROUND

The ipsilateral renal parenchymal volume (RPV) experiences a sharp decrease shortly after partial nephrectomy (PN), mainly due to surgical remove or devascularization of kidney tissue. However, the subsequent change of RPV and its association with glomerular filtration rate (GFR) fast decline remains unknown. Our objective was to investigate the change of ipsilateral RPV and renal function status from new baseline (1-12 months after PN) to latest follow-up (≥1 year) after PN, and to explore factors associated with ipsilateral RPV decrease rate and correlation between RPV decrease and GFR fast decline.

MATERIALS AND METHODS

A retrospective review of 367 patients with PN was conducted. Three-dimensional reconstruction of computed tomography (CT)/MRI images was performed for RPV calculation. Spectrum score was used to assess the degree of acute kidney injury (AKI) in the operated kidney after PN. GFR decline greater than 3 ml/min/1.73 m 2 /year was defined as GFR fast decline. One hundred fourteen patients underwent abdominal surgery was used as control. Predictive factors for subsequent decrease of RPV rate and GFR fast decline were evaluated by linear and logistic regression, respectively.

RESULTS

With a median interval time of 21.1 (interquartile range:13.8-35.5) months, median ipsilateral RPV significantly decreased from 118.7 (interquartile range:100.7-137.1) ml at new baseline to 111.8 (IQR: 92.3-131.3) ml at latest follow-up. The interval time [β: 1.36(0.71-2.01), P <0.001] and spectrum score [β: 5.83 (2.92-8.74), P <0.001] were identified as independent predictors of ipsilateral RPV decrease rate. GFR fast decline was observed in 101 (27.5%) patients. Annual ipsilateral RPV decrease rate [odds ratio:1.67 (1.05-2.67), P =0.03] and overweight [odds ratio:1.63 (1.02-2.60), P =0.04] were independent predictors of GFR fast decline.

CONCLUSIONS

Ipsilateral RPV experienced a moderate but significant decrease during follow-up after PN, especially in those with severer acute kidney injury. The presence of GFR fast decline was found to be associated with reduction of ipsilateral RPV, particularly in overweight individuals.

Perioperative and oncological outcomes of robot-assisted laparoscopic partial nephrectomy for cystic and solid renal masses: Evidence from controlled trials

To evaluate the outcomes of robot-assisted partial nephrectomy (RAPN) for solid and cystic renal tumors. We systematically searched the Cochrane Library, PubMed, EMBASE, and Scopus databases up to March 2023. Review Manager 5.4 performed a pooled analysis of the data for random effects. Besides, sensitivity and subgroup analyses to explore heterogeneity, Newcastle-Ottawa scale, and GRADE to evaluate study quality and level of evidence. Five observational studies comprising 1353 patients (Cystic tumor: 183; Solid tumor: 1083) were included in this study. Compared to solid masses, cystic masses were associated with fewer major complications (odds ratio [OR] = 2.2; 95% confidence intervals [CI] = 1.17 to 4.13; p = 0.01). Additionally, no significant differences were observed between the two groups in terms of operative time, warm ischemia time, blood loss, hospital stay, intraoperative complications, postoperative complications, transfusion rate, postoperative estimated glomerular filtration rate (eGFR), eGFR preservation, positive surgical margin (PSM), recurrence, overall survival (OS), cancer-specific survival (CSS), recurrence-free survival (RFS) and trifecta achievement. RAPN can be performed in cystic renal tumors with perioperative, functional, and oncologic outcomes like those achievable in solid tumors. However, our findings need further validation in a large-sample prospective randomized study.

Trimethylamine-N-oxide (TMAO) and predicted risk of cardiovascular events after partial nephrectomy

INTRODUCTION

Emerging evidence suggests that uremic toxins, in particular trimethylamine-N-oxide(TMAO), indoxyl-sulfate(IS), and p-cresyl-sulfate(PCS), may associate with increased risk of cardiovascular events(CVe). However, whether uremic toxins increase after partial nephrectomy(PN) and their correlation with risk for CVe remains unknown.

METHODS

100 patients managed with PN were retrospectively reviewed. TMAO/IS/PCS levels were examined by liquid chromatography-mass-spectrometry. Renal-parenchymal-volume-preservation(RPVP) was estimated from CT scans. Predicted risks for CVe were obtained using the Framingham score. Linear regression assessed association between uremic toxins, GFR and risk of CVe. Logistic regression evaluated factors associated with post-PN TMAO.

RESULTS

TMAO, IS and PCS increased from 1.7, 3.7 and 3.5 μmol/L before PN to 3.6, 5.4 and 7.4 μmol/L at latest follow-up, respectively, while GFR declined from 102 to 93 ml/min/1.73 m2 (all p<0.001). TMAO, IS and PCS levels all negatively correlated with GFR(all p<0.001). Predicted 10-year risk of CVe increased from 1.1% pre-PN to 1.7% post-PN(p<0.001), primarily due to increased age(p<0.001), blood pressure(p = 0.002) and total cholesterol(p = 0.003). TMAO(β = 0.038) and GFR (β = -0.02) were independent predictors for predicted 10-year CVe risk on multivariable-analysis. Increased TMAO was an early and sustained finding maintained through 5 years, unlike IS, PCS and eGFR. On multivariable analysis, increased pre-PN TMAO(OR = 2.79) and decreased RPVP(OR = 3.23) were identified as independent risk factors for higher post-PN TMAO, while ischemia type/duration failed to correlate.

CONCLUSION

Uremic toxin levels increased after PN correlating with reduced GFR. Higher TMAO independently associated with greater predicted 10-year CVe risk. Parenchymal mass preserved rather than ischemia time or type associated with increased TMAO.

Feasibility study of a novel robotic system for transperitoneal partial nephrectomy: An in vivo experimental animal study

PURPOSE

To evaluate the safety and feasibility of partial nephrectomy with the use of the novel robotic system in an in vivo animal model.

METHODS

Right partial nephrectomy was performed in female pigs by a surgical team consisting of one surgeon and one bedside assistant. Both were experienced in laparoscopic surgery and trained in the use of the novel robotic system. The partial nephrectomies were performed using four trocars (three trocars for the robotic arms and one as an assistant trocar). The completion of the operations, set-up time, operation time, warm ischemia time (WIT) and complication events were recorded. The decrease in all variables between the first and last operation was calculated.

RESULTS

In total, eight partial nephrectomies were performed in eight female pigs. All operations were successfully completed. The median set-up time was 19.5 (range, 15-30) minutes, while the estimated median operative time was 80.5 minutes (range, 59-114). The median WIT was 23.5 minutes (range, 17-32) and intra- or postoperative complications were not observed. All variables decreased in consecutive operations. More precisely, the decrease in the set-up time was calculated to 15 minutes between the first and third attempts. The operative time was reduced by 55 minutes between the first and last operation, while the WIT was decreased by 15 minutes during the consecutive attempts. No complications were noticed in any operation.

CONCLUSIONS

Using the newly introduced robotic system, all the advantages of robotic surgery are optimized and incorporated, and partial nephrectomies can be performed in a safe and effective manner.

Long-term effect of acute ischemic injury on the kidney underwent clamped partial nephrectomy

GFR reaches a new baseline, primarily correlating with nephron-mass preservation, 1-12 months after partial nephrectomy (PN). However, does the ipsilateral GFR experience subsequent decline, and does acute ischemic injury has long-term effect on the operated kidney? 319 patients with two kidneys and unilateral clamped PN were analyzed. All had preoperative, new-baseline, and latest follow-up imaging/serum creatinine levels. Annual ipsilateral GFR decline rate (AIGDR) was defined as new-baseline GFR minus latest follow-up GFR normalized by new-baseline GFR, per year. Spectrum score was used to reflect the degree of acute ischemic injury in the operated kidney. 100 subjects searching for health screening served as controls. Predictive factors for AIGDR were assessed. The median AIGDR was 2.25%, significantly higher than controls (0.88%, p = 0.036). With some contralateral hypertrophy, the global annual GFR decline was similar to that of controls (0.81% vs. 0.88%, p = 0.7). Spectrum score correlated significantly with AIGDR (p = 0.037). These results support that acute ischemic injury has long-term effect on the operated kidney.

Zero ischemia robotic partial nephrectomy: Oncological and functional outcomes of a multicenter study

BACKGROUND

The functional and oncological outcomes of zero ischemia robotic partial nephrectomy (RPN) procedures were evaluated.

METHODS

A total of 56 patients underwent zero ischemia RPN transperitoneally, and their data were collected prospectively. Radius, exo/endophytic, nearness, anterior/posterior, location (R.E.N.A.L.) nephrometry, and PADUA scores were calculated. Patient and tumor characteristics were evaluated. Intra- and perioperative (0-30 days) complications were evaluated by Clavien classification. The change in serum creatinine, and estimated glomerular filtration rates (eGFR) were evaluated during preoperative, immediate postoperative periods, and at postoperative 6th months.

RESULTS

The mean age of the patients was 52.2 ± 8.1 (27-75) years. R.E.N.A.L. nephrometry and PADUA scores were 6.1 ± 1.3 and 7.3 ± 1.0, respectively. The duration of surgery was 108.4 ± 18.2 min and estimated blood loss was 166.2 ± 124.7 mL. There were no intraoperative complications in any of the patients. Clavien Grade 1 and 3 complications were seen in 2 patients in the perioperative period. In the perioperative period (1-30 days), one patient required blood transfusion and angiographic intervention due to postoperative bleeding (Clavien Grade 3), and one patient required hospitalisation due to prolonged subileus (Clavien Grade 1) that resolved conservatively. The radiological and pathological tumor sizes were 3.1 ± 1.1 cm and 2.8 ± 1.4 cm, respectively. The surgical margins were positive in two patients with tumour sizes of 1.5 and 4 cm. Neither local recurrence nor distant metastasis was detected, during 33.6 ± 12.3 (3-76) months. There were no statistically significant differences between preoperative eGFR and serum creatinine levels, compared with those of immediate postoperative and postoperative 6th month periods.

DISCUSSION

Zero ischemia RPN is a safe and applicable method with acceptable oncological and functional outcomes in small renal tumors and even in selected larger renal tumors.

Late complications and 5 years outcomes of robotic partial nephrectomy in France: prospective assessment in the French Kidney Cancer Research Network (UroCCR 10)

PURPOSE

To describe the practice of robotic-assisted partial nephrectomy (RAPN) in France and prospectively assess the late complications and long-term outcomes.

METHODS

Prospective, multicenter (n = 16), observational study including all patients diagnosed with a renal tumor who underwent RAPN. Preoperative, intraoperative, postoperative, and follow-up data were collected and stored in the French research network for kidney cancer database (UroCCR). Patients were included over a period of 12 months, then followed for 5 years.

RESULTS

In total, 466 patients were included, representing 472 RAPN. The mean tumor size was 3.4 ± 1.7 cm, most of moderate complexity (median PADUA and RENAL scores of 8 [7-10] and 7 [5-9]). Indication for nephron-sparing surgery was relative in 7.1% of cases and imperative in 11.8%. Intraoperative complications occurred in 6.8% of patients and 4.2% of RAPN had to be converted to open surgery. Severe postoperative complications were experienced in 2.3% of patients and late complications in 48 patients (10.3%), mostly within the first 3 months and mainly comprising vascular, infectious, or parietal complications. At 5 years, 29 patients (6.2%) had chronic kidney disease upstaging, 21 (4.5%) were diagnosed with local recurrence, eight (1.7%) with contralateral recurrence, 25 (5.4%) with metastatic progression, and 10 (2.1%) died of the disease.

CONCLUSION

Our results reflect the contemporary practice of French expert centers and is, to our knowledge, the first to provide prospective data on late complications associated with RAPN. We have shown that RAPN provides good functional and oncologic outcomes while limiting short- and long-term morbidity.

TRIAL REGISTRATION

NCT03292549.

A Novel Technique of Renorrhaphy in Difficult Partial Nephrectomies by Single-Layered Parenchymal Imbrication

Background In partial nephrectomies, achieving the trifecta outcome of negative tumor margins, no surgical complications, and minimal decline in renal function depends on various factors, with the complexity of the tumor described by the nephrometry score being chief among them. These factors often motivate surgeons toward a minimally invasive route even if the preferred route is an open approach. We describe an innovative renorrhaphy technique that overcomes the commonly encountered difficulty in reconstructing the renal parenchyma after resecting a complex tumor with a single-layered parenchymal imbrication (SLPI) technique. Methodology We conducted a retrospective review of case records of the patients who had undergone partial nephrectomies in our center from March 2017 to March 2021. The patients who underwent the SLPI technique were chosen, and data were extracted. Data collected included patients' preoperative imaging findings; intraoperative parameters such as ischemia time, blood loss, and number of renal arteries; and postoperative factors such as margin positivity rate, urine leak, secondary bleeding, follow-up imaging, and recurrence rates. Results A total of 28 patients were included in our study. The estimated blood loss was 234 mL (standard deviation [SD] = 55 mL), warm ischemia time was 31 minutes (SD 4 minutes), a hospital stay of 3 days (SD 2 days), two minor complications, two intraoperative complications, and one margin positivity. There were no major complications or recurrences. Conclusions The novel technique of SLPI renorrhaphy can help deal with complex renal masses and is an easily reproducible technique both in open and minimally invasive approaches.

Impact of perinephric fat volume and the Mayo Adhesive Probability score on time to clamping in robot-assisted partial nephrectomy

The aim of this study is to evaluate the association of perinephric fat volume (PNFV) and the Mayo Adhesive Probability (MAP) score with time to clamping (TTC) in robot-assisted partial nephrectomy (RAPN). The study subjects consisted of 73 tumors in 72 patients who underwent transperitoneal RAPN at a single cancer center between February 2020 and July 2022. Clinical characteristics including R.E.N.A.L. nephrometry score, MAP score and PNFV were evaluated in a multivariate analysis in relation to TTC, which was classified into two groups based on median TTC. PNFV and MAP score were analyzed separately. PNFVs were measured by SYNAPSE VINCENT^® by a single expert urologist. Median TTC was 67 (range: 36-119) min. Spearman's rank correlation analysis indicated that a significant correlation was observed between PNFV and MAP score with a value of 0.81 (p < 0.0001). Univariate analysis revealed that R.E.N.A.L. nephrometry score ≥ 7 (p = 0.036), posterior tumor location (p = 0.033), MAP score ≥ 3 (p = 0.02) and PNFV ≥ 250 ml (p = 0.02) were significant factors for prolonged TTC. In a multivariate analysis including PNFV (analysis 1), R.E.N.A.L. nephrometry score ≥ 7 (OR 3.54, p = 0.018) and PNFV ≥ 250cm³ (OR 3.94, p = 0.010) were independent factors for prolonged TTC. Similarly for MAP score (analysis 2), R.E.N.A.L. nephrometry score ≥ 7 (OR 3.54, p = 0.018) and MAP score ≥ 3 (OR 3.94, p = 0.010) were independent factors for prolonged TTC. Both MAP score and PNFV may have a significant impact on TTC.

Single-port versus multiport partial nephrectomy: a propensity-score-matched comparison of perioperative and short-term outcomes

The objective of this study was to compare the perioperative and short-term functional and oncological outcomes of single-port and multiport robotic-assisted laparoscopic partial nephrectomy using propensity-score analysis. We evaluated all patients who underwent robotic partial nephrectomy at our institution between January 2019 and October 2020. Patient demographics, intraoperative data, and postoperative outcomes were collected and analyzed. Propensity-score matching was performed on age, sex, body mass index, prior abdominal surgery, and nephrometry score using the optimal matching method. A post hoc sensitivity analysis was performed to examine the robustness of the results. In total, 48 and 238 patients underwent single-port and multiport robotic partial nephrectomy, respectively. Following propensity-score matching, 48 multiport cases were matched 1:1 to single-port cases. The single-port cohort had lower median opioid use at postoperative day 1 (4.6 vs 9.8 MME, p = 0.0209) and cumulative hospital stay (5.1 vs 9.3 MME, p = 0.0357). Single port also had a shorter median length of stay (1.4 vs 1.6 days, p = 0.0045), although the post hoc sensitivity analysis showed no difference between the groups [- 0.13 (95% CI; - 0.580, 0.315, p = 0.5607). There were no significant differences in operative time, estimated blood loss, ischemia time, transfusions received, or positive margin rates. In conclusion, based on our early experience, single-port robotic partial nephrectomy is a safe and acceptable alternative to multiport robotic partial nephrectomy, providing comparable perioperative and postoperative outcomes while reducing inpatient opioid use.

A Comparison of Functional and Oncologic Outcomes between Partial Nephrectomy and Radiofrequency Ablation in Patients with Chronic Kidney Disease after Propensity Score Matching

Purpose: This study aimed to compare functional and oncological outcomes between partial nephrectomy (PN) and radiofrequency ablation (RFA) for a small renal mass (SRM, ≤4 cm) in patients with chronic kidney disease (CKD). Materials and Methods: Patients with CKD who underwent either PN or RFA for SRM between 2005 and 2019 were included. Patients were stratified into two categories: CKD stage 2 and CKD stage 3 or higher. We performed propensity score matching (PSM) analysis in patients with CKD stage 2 and CKD stage 3 or higher. We compared the functional and oncological outcomes between two groups according to CKD stage before and after PSM. Results: Among 1332 patients, 1195 patients were CKD stage 2 and 137 patients were CKD stage 3 or higher. After PSM analysis using age, pre-treatment eGFR, and clinical tumor size as matching variables, the PN and RFA groups had 270 and 135 CKD stage 2 patients, respectively, and both had 53 patients each with CKD stage 3 or higher. There were no significant differences in percent change in eGFR at 1 year post-operation between groups in patients with CKD stage 2 and stage 3 or higher. Among all patients with tissue-proven malignancy, the 5-year recurrence-free survival (RFS), cancer-specific survival, and overall survival were significantly higher in the PN group. However, only the 5-year RFS was significantly higher in the PN group after matching. Conclusion: Mortality is low in patients with SRM, and functional outcomes were not significantly different between the two treatments. RFA could be an alternative treatment modality in patients who are poor candidates for surgery.

Analysis of executional and procedural errors in dry‐lab robotic surgery experiments

Background

Analysing kinematic and video data can help identify potentially erroneous motions that lead to sub‐optimal surgeon performance and safety‐critical events in robot‐assisted surgery.

Methods

We develop a rubric for identifying task and gesture‐specific executional and procedural errors and evaluate dry‐lab demonstrations of suturing and needle passing tasks from the JIGSAWS dataset. We characterise erroneous parts of demonstrations by labelling video data, and use distribution similarity analysis and trajectory averaging on kinematic data to identify parameters that distinguish erroneous gestures.

Results

Executional error frequency varies by task and gesture, and correlates with skill level. Some predominant error modes in each gesture are distinguishable by analysing error‐specific kinematic parameters. Procedural errors could lead to lower performance scores and increased demonstration times but also depend on surgical style.

Conclusions

This study provides insights into context‐dependent errors that can be used to design automated error detection mechanisms and improve training and skill assessment.

New longitudinal component of the RENAL nephrometry score for predicting the operative complexity in transperitoneal robot-assisted partial nephrectomy

BACKGROUND

In transperitoneal robot-assisted partial nephrectomy (RAPN), an L score of 3 points according to RENAL nephrometry scoring system does not necessarily denote operative complexity. This study aimed to assess the efficacy of the newly defined longitudinal component to analyze the operative complexity of RAPN Methods: We retrospectively analyzed transperitoneal RAPNs performed by a single experienced surgeon for renal tumors between 2017 and 2020. L component was defined as L'1 for medially located tumors, L'2 for >50% below the polar line, and L'3 for >50% above the polar line. Multivariate regression analysis was performed to test associations between prolonged console time and preoperative factors. The perioperative outcomes were compared among the three cohorts of L' components using propensity score matching: L'1 vs. L'3 and L'1 vs. L'2.

RESULTS

A total of 220 cases (L'1: 107, L'2, 65, L'3: 48) were analyzed. The median console time was prolonged (>130 min) in 55 patients (median 108, interquartile range: 90-130 min). Longitudinal location (L'3 odds ratio: 2.93, P = 0.01; L'2 odds ratio: 2.32, P = 0.04), high Mayo adhesive probability score (P = 0.001), multiple renal arteries (P = 0.03), and large size (P = 0.04) were significantly associated with prolonged console time. After matching, 26 cases of L'1 and L'3 and 43 cases of L'1 and L'2 were selected. Console time (132 vs. 108 min, P = 0.017) and warm ischemia time (17 vs. 22 min, P = 0.03) were significantly longer in L'3 than in L'1. The difference in console time between L'1 and L'2 was not statistically significant (100 vs. 111 min, P = 0.08) Conclusion: In the new longitudinal assessment, upper location predicted prolonged console time compared to a medial or lower location. The L' component may help preoperatively assess operative complexity.

Parenchymal Mass Loss During Partial Nephrectomy: Role of Devascularized Parenchymal Mass and Excised Parenchymal Mass and Impact on Functional Preservation

This study included 93 patients with renal masses who underwent standard partial nephrectomy or tumor enucleation. After surgery, parenchymal mass loss caused by devascularization resulted in more damage to renal function than excised parenchymal mass loss. Surgeons should seek better techniques to decrease devascularization during reconstruction.

INTRODUCTION

To evaluate the importance of devascularized parenchymal mass(DPM) and excised parenchymal mass(EPM) in functional preservation after standard partial nephrectomy(SPN).

PATIENTS AND METHODS

Forty-one patients who underwent pure tumor enucleation(TE) and 52 patients who underwent SPN with necessary data were included. As no EPM was lost in TE, the TE samples were used to estimate the degree of volume shrinkage that occurred when the measurements were performed in vivo with blood flow versus ex vivo without, and the shrinkage ratio was calculated as specimen volume divided by tumor volume in vivo. In SPN, the specimen volume comprised tumor volume plus EPM. The EPM was calculated as specimen volume divided by shrinkage ratio minus tumor volume in vivo. The DPM was defined as total ipsilateral parenchymal mass loss minus EPM. T tests, χ² test, and Mann-Whitney U tests were employed to compare clinical characteristics. Multivariate analysis was used to identify variables that correlated with glomerular filtration rate(GFR) preservation.

RESULTS

The mean sizes of devascularized and excised parenchymal masses were 13.6 cm³ and 5.2 cm³ (P = .01), which accounted for 7.8% and 3.4% of preoperative ipsilateral parenchymal mass (P = .03) in SPN, respectively. The shrinkage ratio was 0.71 and correlation coefficient was 0.965. After stepwise regression, DPM, and preoperative GFR were significantly associated with global GFR preservation.

CONCLUSION

The DPM comprises most of parenchymal mass loss after SPN and plays a more important role than EPM on functional outcomes. Surgeons should pay more attention to reducing devascularization during partial nephrectomy.

Surgical outcomes of robot-assisted laparoscopic partial nephrectomy for cystic renal cell carcinoma

To compare the surgical outcomes of robot-assisted partial nephrectomy (RAPN) between patients with cystic renal cell carcinoma (cRCC) and those with solid RCC (sRCC). We retrospectively analyzed 1065 patients who underwent RAPN between 2013 and 2020 for a pathological diagnosis of RCC. Patients were divided into two groups: cRCC and sRCC. cRCC was diagnosed according to the Bosniak classification system. To minimize selection bias between the two groups, patient variables (patient characteristics) and tumor factors (such as size and complexity) were adjusted using 1:1 propensity score matching. Of the 1065 patients, 94 (9%) were diagnosed with cRCC. Bosniak categories of IIF, III, and IV were noted in 4 (4.2%), 31 (33%), and 59 (63%) patients, respectively. After matching, 83 patients each were assigned to the cRCC and sRCC groups. The operation time in cRCC tended to be longer than in sRCC but not significantly different (164 vs. 150 min, P = 0.0767). Other surgical outcomes, such as change in estimated glomerular filtration rate ( - 5.2 vs.  - 7.2%, P = 0.1577), perioperative complications (14.5 vs. 15.7%, P = 0.9225), estimated blood loss (62 vs. 58 mL, P = 0.5613), or negative surgical margin status (100 vs 99%, P = 0.236), were not significantly different between the two groups. During the follow-up period of about 2 years, one and two patients showed recurrence in the cRCC and sRCC groups, respectively. The surgical outcomes of RAPN were similar between cRCC and sRCC, demonstrating the feasibility of RAPN for cRCC.

Laparoscopic heminephrectomy in a horseshoe kidney affected by xanthogranulomatous pyelonephritis: A modified approach

Horseshoe kidney (HSK) is a common congenital kidney anomaly that is encountered frequently by urologists. It is rare for HSK to be affected by xanthogranulomatous pyelonephritis (XGP), a potentially life-threatening condition. The standard of care for XGP is open nephrectomy, but recently a few case reports have been published showing the feasibility of minimally invasive surgery to deal with XGP. We present a case of HSK affected by XGP treated successfully with modified laparoscopic transperitoneal heminephrectomy. The rarity of such a combination, the modified approach, and the successful outcome encouraged us to report it.

Varying Outcomes among Patients with Large Angiomyolipomas according to the Treatment Method

PURPOSE

This study aimed to evaluate the outcomes of large angiomyolipoma (AML) treatment by selective arterial embolization (SAE) versus nephron-sparing surgery (NSS) using a robotic surgical system.

MATERIALS AND METHODS

Between January 2011 and June 2018, we retrospectively reviewed 25 patients who underwent robot-assisted partial nephrectomy (RAPN) or SAE for large AMLs. Ten patients underwent RAPN, and 15 underwent SAE. Patient demographics, AML characteristics, and operative and postoperative clinical outcomes were recorded and analyzed. Outcomes were compared between patients who underwent RAPN and patients who underwent SAE. Specifically, changes in renal function and size were evaluated after the treatment.

RESULTS

The mean age of the patients was 52.9 years, and 22 of 25 patients were female. The mean maximum AML diameter on computed tomography was 8.9 cm, and 8 patients had multiple masses. Twenty-two of 25 patients had moderate to high RENAL complexity. Patients who underwent SAE had more symptoms (p = 0.018) and higher RENAL complexity scores (p = 0.013) on average. On average, tumor size decreased by 99% among RAPN patients and by 58% among SAE patients (p = 0.001). Although the mean pretreatment estimated glomerular filtration rate (eGFR) was higher among RAPN patients (99.8 vs. 80.0 mL/min/1.73 m2, p = 0.043), there were no significant changes in eGFR in either group after the treatment. One patient in the RAPN group experienced complications, but the postoperative ileus resolved without intervention.

CONCLUSIONS

Both RAPN and SAE were effective and feasible treatment options for large AMLs. The AML characteristics and the condition of the patient might be important in determining the appropriate treatment method.

Laparoscopic augmented reality registration for oncological resection site repair

PURPOSE

Resection site repair during laparoscopic oncological surgery (e.g. laparoscopic partial nephrectomy) poses some unique challenges and opportunities for augmented reality (AR) navigation support. This work introduces an AR registration workflow that addresses the time pressure that is present during resection site repair.

METHODS

We propose a two-step registration process: the AR content is registered as accurately as possible prior to the tumour resection (the primary registration). This accurate registration is used to apply artificial fiducials to the physical organ and the virtual model. After the resection, these fiducials can be used for rapid re-registration (the secondary registration). We tested this pipeline in a simulated-use study with [Formula: see text] participants. We compared the registration accuracy and speed for our method and for landmark-based registration as a reference.

RESULTS

Acquisition of and, thereby, registration with the artificial fiducials were significantly faster than the initial use of anatomical landmarks. Our method also had a trend to be more accurate in cases in which the primary registration was successful. The accuracy loss between the elaborate primary registration and the rapid secondary registration could be quantified with a mean target registration error increase of 2.35 mm.

CONCLUSION

This work introduces a registration pipeline for AR navigation support during laparoscopic resection site repair and provides a successful proof-of-concept evaluation thereof. Our results indicate that the concept is better suited than landmark-based registration during this phase, but further work is required to demonstrate clinical suitability and applicability.

Long-Term Oncologic Outcomes After Laparoscopic and Robotic Tumor Enucleation for Renal Cell Carcinoma

OBJECTIVES

Tumor enucleation (TE) optimizes parenchymal preservation with promising short-term oncologic outcomes compared with standard partial nephrectomy (SPN). However, researches/literatures about long-term oncologic outcomes for TE after minimally invasive surgery are scarce. We aim to analyze long-term oncologic outcomes after laparoscopic and robotic tumor enucleation for renal cell carcinoma (RCC).

PATIENTS AND METHODS

We retrospectively analyzed 146 patients who underwent TE with either laparoscopic or robotic approach for localized RCC in our center. Local recurrence, cancer specific survival (CSS), recurrence free survival (RFS), and overall survival (OS) were the main outcomes. Survival curves were generated using a Kaplan-Meier method. Perioperative outcomes and pathological outcomes were also analyzed.

RESULTS

Overall, 98 male and 48 female patients were eligible for the study. The median tumor size was 3.4 cm with a median R.E.N.A.L. score of seven. Warm ischemia was used in 143 patients with a median ischemia time of 20 min and three patients had zero ischemia. Five patients (3.4%) had major complications (> Clavien IIIa) and only two were related to urinary system. The median global glomerular filtration rate (GFR) preserved after surgery was 93%. Pseudocapsule invasion was reported in 50 tumors (34%) and positive surgical margins were found in 3/146 (2.1%) tumors. At a median follow-up of 66 months, local recurrence happened in two patients (1.4%), and systemic recurrence happened in six patients (4.2%). The 5-year CSS, RFS, OS were 95.7, 89.6, and 91.9%, and the 10-year CSS, RFS, OS were 93.8, 89.6, and 90.0%, respectively.

CONCLUSION

This study indicates that tumor enucleation with laparoscopic or robotic approach in experienced hands for the treatment of RCC appears oncologically safe with a median follow-up of more than 5 years. Prospective studies with more patients and longer follow-up will be required to further evaluate oncologic safety after TE.

Functional and oncologic outcomes of robot-assisted simple enucleation with and without renal arterial cold perfusion in complex renal tumors: a propensity score-matched analysis

BACKGROUND

To compare robot-assisted simple enucleation with renal arterial cold perfusion (RACP-RASE) and RASE alone in complex renal tumors with regard to perioperative, functional and oncologic outcomes by propensity score-matched analysis.

METHODS

Data from 351 patients who underwent RACP-RASE or RASE for complex renal tumors were recorded between September 2014 and December 2017. Propensity score-matched analysis was performed on age, sex, BMI, ECOG score, tumor side and size, preoperative estimated glomerular filtration rate (eGFR), RENAL score and PADUA score.

RESULTS

The study included 31 RACP-RASE and 320 RASE procedures. RENAL score and PADUA score were higher and tumor diameter was greater under RACP-RASE than RASE. After matching, the two groups were similar in estimated blood loss (208.3 vs 230.7 ml; p = 0.696) and ischemic time (34.8 vs 32.8 min; p = 0.342). The RACP-RASE group had significantly longer operative time than the RASE group (264.1 ± 55.7 vs 206.9 ± 64.0 min, p = 0.001). There was no difference in the incidence of postoperative complications between the two groups (13.8% vs 24.1%; p = 0.315), as was the overall incidence of positive surgical margins (3.4 vs 0%; p = 1.000). The changes in eGFR significantly differed between the two groups at 3 months (p = 0.018) and 12 months (p = 0.038). More patients in the RASE group were CKD upstaged (p = 0.043). At multivariable analysis, preoperative eGFR and the type of procedure were significant predictive factors for a change of more than 10% in eGFR at 3 months postoperatively. There was no local recurrence or distant metastasis during follow-up.

CONCLUSIONS

RACP-RASE is an effective and safe technique for complex renal tumors that can provide appropriate temporary arterial occlusion and renal hypothermic perfusion. Renal arterial cold perfusion may be helpful in protecting renal function in RASE as compared with warm ischemia.

Robotic Partial Nephrectomy: Update on Techniques

Surgical techniques for robot-assisted partial nephrectomy are driven by the aims of simplifying the most challenging surgical steps, maximizing functional and oncologic outcomes, and consistently pushing the envelope on possibilities. Over the past several years, we have seen an emergence in not only innovation in surgical technique, and robotic platforms, but integration of a variety of imaging techniques. We believe with developing robotic expertise, practicing urologists will continue to push the envelope in nephron preservation and complication-free recovery.

On-clamp versus purely off-clamp robot-assisted partial nephrectomy in solitary kidneys: comparison of perioperative outcomes and chronic kidney disease progression at two high-volume centers

BACKGROUND

Minimal literature describes the impact of hilar control on the progression to chronic kidney disease (pCKD) after robotic partial nephrectomy (RPN) in solitary kidneys (SK). The aim of this study was to compare purely off-clamp (ocRPN) vs. on-clamp robotic partial nephrectomy (onRPN) in SK and to identify predictors of pCKD at two high-volume centers.

METHODS

Between December 2013 and October 2019, 54 patients with SK underwent ocRPN and onRPN for renal tumors at two institutions. Baseline and perioperative data were analyzed. Newly onset of CKD stage 3b,4,5 (CKD3b,4,5) was assessed by Kaplan-Meier curves and compared for warm ischemia time (WIT) with the log-rank test. Cox regression analysis was used to identify predictors of pCKD.

RESULTS

At a median follow-up of 13 months (IQR 6.3-34), newly onset of CKD3b and CKD 4.5 were observed in 11.1% and 7.4% of patients, respectively. onRPN was associated with a higher risk of progression to CKD 3b,4,5 stages (P=0.034) and higher rate of perioperative complications (P=0.03). On univariable analysis eGFR at discharge (eGFRd), positive surgical margins status (PSM) and WIT were predictors of newly onset of CKD3b,4,5 (each P<0.05). Multivariable analysis identified eGFRd (HR 0.88; CI 95% 0.81-0.96) and WIT (HR 1.09; CI 95% 1.02-1.16) as independent predictors of pCKD (each P<0.01). Main limitations include the retrospective nature of the study, the short-term follow-up and the lack of data adjustment for parenchymal volume loss.

CONCLUSIONS

eGFRd and WIT during RPN are independent predictors of pCKD in SK. In this setting a critical reduction of WIT should be achieved according to the oncologic outcome. In patients with SK, WIT represents the only surgical modifiable factor of RPN for avoiding a quicker onset of pCKD.

Endophytic Renal Cell Carcinoma Treated with Robot-Assisted Surgery: Functional Outcomes - A Comprehensive Review of the Current Literature

INTRODUCTION

Robotic surgery for the management of localized renal cell carcinoma (RCC) has gained increasing popularity during the last decade. An endophytic renal tumour represents a surgical technical challenge in terms of identification and resection related to the lack of external visual cues on the kidney surface.

MATERIALS AND METHODS

There is little evidence of functional outcomes of robotic surgery on treating endophytic masses. For this reason, we wanted to review the contemporary literature on the functional outcomes of endophytic RCC treated with robotic surgery.

RESULTS

Many studies investigating robotic partial nephrectomy for totally endophytic RCC confirmed the good functional results of this approach at intermediate follow-up. The greater relative importance of volume loss versus ischaemia duration in predicting long-term renal function after partial nephrectomy is now established, and the robotic technique may facilitate volume preservation. Accurate use of intra-operative ultrasonography, enucleation, and intra-operative techniques using near-infrared fluorescence imaging with indocyanine green dye could minimize excision of the parenchyma and prevent devascularization of adjacent healthy parenchyma.

CONCLUSIONS

Unfortunately, the overall quality of the literature evidence and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the surgical technique used and functional outcomes.

Feasibility and necessity of the fourth arm of the da Vinci Si surgical system for robot-assisted partial nephrectomy

BACKGROUND

To investigate the feasibility of the fourth arm of the da Vinci Si system for robot-assisted partial nephrectomy (RAPN).

METHODS

Fifty-eight consecutive patients underwent RAPN with the same port placements. After reviewing the surgical videos and records, 38 patients showing usefulness of the fourth arm were categorized into Group A and those not showing usefulness into Group B. The background data, tumor characteristics, and perioperative outcomes were compared between the groups.

RESULTS

Group B had a larger proportion of tumors located on the inner side of the kidney, and the console time was significantly longer. Multivariable logistic regression analysis showed that tumors located on the inner side of the kidney were associated with the non-use of the fourth arm of the da Vinci Si system during RAPN.

CONCLUSIONS

Our findings suggested that use of fourth arm in RAPN by da Vinci Si should be considered for each tumor location.

Predicting Adherent Perinephric Fat Using Preoperative Clinical and Radiological Factors in Patients Undergoing Partial Nephrectomy

BACKGROUND

The decision to perform a partial nephrectomy (PN) relies largely upon the complexity of the renal mass and its surrounding anatomy. The presence of adherent perinephric fat (APF) can increase surgical complexity and extend operative times. The accurate prediction of APF may improve surgical planning and aid in decision making for the surgical approach.

OBJECTIVE

We sought to develop and externally validate a score that predicts APF based on preoperative clinical and radiological prognostic factors.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed 495 consecutive patients who underwent open or minimally invasive PN. APF was defined as the presence of "dense," "adherent," or "sticky" perinephric fat at the time of dissection by the surgeon, and this did not require subcapsular dissection. Additionally, we analyzed an independent cohort of 285 patients for external validation.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

A score model was developed using multivariate logistic regression analysis. Calibration of the fitted model was assessed graphically with a plot of the predicted versus the actual probability of APF, and discrimination was assessed by calculating the area under the receiver operating characteristic curve.

RESULTS AND LIMITATIONS

Of the 495 patients, 95 (19%) had APF. Patients with APF had longer operative (p=0.02) and arterial clamp (p=0.01) times than non-APF patients. On multivariate analyses, diabetes mellitus (p=0.009), posterior perinephric fat thickness (p<0.001), and perinephric stranding (p<0.001) were predictors of encountering APF in PN. A risk score ranging from 0 to 4 was developed based on these three variables to predict APF. The scoring system demonstrated good discrimination of 0.82 and 0.84 for the development and external validation cohorts, respectively.

CONCLUSIONS

The APF score can accurately predict the presence of APF in patients with a small renal mass who are planning to undergo PN. This score could aid in pre- and intraoperative planning and impact the surgical approach.

PATIENT SUMMARY

The presence of "sticky" fat surrounding the kidney in patients undergoing partial nephrectomy has previously been linked to longer operative times, intraoperative complications, and surgical conversion. In our study, we found that this feature is more often presented in patients with diabetes mellitus, and thicker and more inflammatory fat on renal imaging. Based on these findings, we developed a risk score that can accurately predict this feature before surgery, in order to improve surgical planning and better counsel the patients.

Preoperative proteinuria is associated with increased rates of acute kidney injury after partial nephrectomy

Purpose

We investigated the association between preoperative proteinuria and early postoperative renal function after robotic partial nephrectomy (RPN).

Patients and Methods

We retrospectively reviewed 1121 consecutive RPN cases at a single academic center from 2006 to 2016. Patients without pre-existing CKD (eGFR≥60 mL/min/1.73m²) who had a urinalysis within 1-month prior to RPN were included. The cohort was categorized by the presence or absence of preoperative proteinuria (trace or greater (≥1+) urine dipstick), and groups were compared in terms of clinical and functional outcomes. The incidence of acute kidney injury (AKI) was assessed using RIFLE criteria. Univariate and multivariable models were used to identify factors associated with postoperative AKI.

Results

Of 947 patients, 97 (10.5%) had preoperative proteinuria. Characteristics associated with preoperative proteinuria included non-white race (p<0.01), preoperative diabetes (p<0.01) and hypertension (HTN) (p<0.01), higher ASA (p<0.01), higher BMI (p<0.01), and higher Charlson score (p<0.01). The incidence of AKI was higher in patients with preoperative proteinuria (10.3% vs. 4.6%, p=0.01). The median eGFR preservation measured within one month after surgery was lower (83.6% vs. 91%, p=0.04) in those with proteinuria; however, there were no significant differences by 3 months after surgery or last follow-up visit. Independent predictors of AKI were high BMI (p<0.01), longer ischemia time (p<0.01), and preoperative proteinuria (p=0.04).

Conclusion

Preoperative proteinuria by urine dipstick is an independent predictor of postoperative AKI after RPN. This test may be used to identify patients, especially those without overt CKD, who are at increased risk for developing AKI after RPN.

Cold Versus Warm Ischemia Robot-Assisted Partial Nephrectomy: Comparison of Functional Outcomes in Propensity-Score Matched "At Risk" Patients

OBJECTIVES

To compare functional outcomes of warm ischemia RPN (wRPN) to cold ischemia RPN (cRPN) in "at risk" patients.

MATERIALS AND METHODS

Retrospective review of institutional database queried for all patients who underwent cRPN/wRPN (January 2007-December 2016). For the study purpose, patients with solitary kidney and/or history of partial nephrectomy and/or multiple tumors and/or preoperative estimated Glomerular Filtration Rate (eGFR) <60 mL/minute were extracted. To reduce inherent biases, groups were matched on key variables related to renal function through a greedy matching algorithm with no replacement. Renal functional outcomes were evaluated by eGFR drops at 1-3 days and at 1, 3, 6, and 12 months postoperatively. A linear mixed effects model was used to assess eGFR at each follow-up who received either cRPN or wRPN. Follow-up was treated as a factor variable to account for nonlinear time trends. Contrast analysis was used to compare cRPN vs wRPN groups at each follow-up, using Sidak-Holm p-value adjustments for multiple comparisons.

RESULTS

Out of 19 cRPN patients and 279 wRPN patients, 14 cRPN patients were finally matched 1:1 with no replacement to 14 wRPN. There was no significant difference in preoperative eGFR for matched patients undergoing cRPN vs wRPN. Since the first postoperative day, cRPN patients had higher eGFR. The difference was statistically significant since the third month postoperatively (mean difference = 18.201, 95% confidence interval [CI]: 1.930-34.472) and remained at both the sixth month (mean difference = 18.839, 95% CI: 2.568-35.109) and the 12th month (mean difference = 21.277, 95% CI: 5.006-37.547) follow-up.

CONCLUSIONS

Accounting for unmodifiable and modifiable factors, in a cohort of highly selected patients "at risk" for postoperative significant decline in renal function after RPN, renal functional outcomes appear to be superior with cold ischemia technique.

How well do software assistants for minimally invasive partial nephrectomy meet surgeon information needs? A cognitive task analysis and literature review study

INTRODUCTION

Intraoperative software assistance is gaining increasing importance in laparoscopic and robot-assisted surgery. Within the user-centred development process of such systems, the first question to be asked is: What information does the surgeon need and when does he or she need it? In this article, we present an approach to investigate these surgeon information needs for minimally invasive partial nephrectomy and compare these needs to the relevant surgical computer assistance literature.

MATERIALS AND METHODS

First, we conducted a literature-based hierarchical task analysis of the surgical procedure. This task analysis was taken as a basis for a qualitative in-depth interview study with nine experienced surgical urologists. The study employed a cognitive task analysis method to elicit surgeons' information needs during minimally invasive partial nephrectomy. Finally, a systematic literature search was conducted to review proposed software assistance solutions for minimally invasive partial nephrectomy. The review focused on what information the solutions present to the surgeon and what phase of the surgery they aim to support.

RESULTS

The task analysis yielded a workflow description for minimally invasive partial nephrectomy. During the subsequent interview study, we identified three challenging phases of the procedure, which may particularly benefit from software assistance. These phases are I. Hilar and vascular management, II. Tumour excision, and III. Repair of the renal defects. Between these phases, 25 individual challenges were found which define the surgeon information needs. The literature review identified 34 relevant publications, all of which aim to support the surgeon in hilar and vascular management (phase I) or tumour excision (phase II).

CONCLUSION

The work presented in this article identified unmet surgeon information needs in minimally invasive partial nephrectomy. Namely, our results suggest that future solutions should address the repair of renal defects (phase III) or put more focus on the renal collecting system as a critical anatomical structure.

"At-risk" kidney: How surgical factors influence renal functional preservation after partial nephrectomy

OBJECTIVES

To investigate the influence of surgical modifiable factors on chronic kidney disease upstaging in a contemporary cohort of patients with normal and "at-risk" kidneys undergoing partial nephrectomy.

METHODS

We reviewed 778 consecutive patients with (n = 634)/without (n = 144) chronic kidney disease or risk factors for chronic kidney disease in our institutional partial nephrectomy database. Chronic kidney disease upstaging was assessed using glomerular filtration rate measurements preoperatively and at 3-12 months postoperatively. Using a multivariate logistic regression, baseline clinicodemographic factors, and the operative measurements of excisional volume loss and warm and cold ischemia time on rates of chronic kidney disease upstaging were determined. Marginal effects were used to analyze the impact of ischemia time and generate interaction curves.

RESULTS

Chronic kidney disease/risk factors for chronic kidney disease had equivalent rates of chronic kidney disease upstaging as the healthy kidney cohort (31.5% vs 38.2%, P = 0.15). Of the entire cohort, 2.8% were upstaged to stage IV-V chronic kidney disease. Multivariate analysis found a significant association between chronic kidney disease upstaging and excisional volume loss in both cohorts (no chronic kidney disease/risk factors for chronic kidney disease: odds ratio 1.63, P = 0.04; chronic kidney disease/risk factors for chronic kidney disease: odds ratio 1.42, P = 0.001). Only in the chronic kidney disease/risk factors for chronic kidney disease cohort, there was an association between ischemia type/duration and chronic kidney disease upstaging (odds ratio 1.04, P = 0.04). Warm ischemia began to predict an increased risk of chronic kidney disease upstaging at 17.6 min, which became statistically significant at 49 min.

CONCLUSIONS

Chronic kidney disease upstaging is common after partial nephrectomy. Although volume loss unequivocally affects rates of upstaging irrespective of baseline renal function, warm ischemia time disproportionately influences "at-risk" kidneys. Therefore, strong consideration should be given to minimizing volume loss and using cold ischemia when extended clamp times are anticipated in "at-risk" kidneys.

A systematic management algorithm for perioperative complications after robotic assisted partial nephrectomy

Nephron-sparing surgery (NSS) is the treatment of choice for T1 renal cell carcinoma (RCC). Since the first robotic assisted partial nephrectomy (RAPN) was performed in 2004, NSS is being implemented with increasing frequency. RAPN will likely become the gold standard procedure for T1 RCC due to improved dexterity, enhanced visualization, shorter learning curve, quicker recovery time, and shortened warm ischemic time. Although RAPN appears to be the preferred treatment for select renal tumours, there are notable complications in up to 35% of cases. While complications associated with RAPN are well-described, there is a lack of literature describing appropriate management strategies. Herein, we review complications associated with RAPN and design an appropriate systematic management algorithm.

Predictors of positive surgical margins in patients undergoing partial nephrectomy: A large single-center experience

OBJECTIVE

To identify preoperative factors that predict positive surgical margins in partial nephrectomy.

MATERIAL AND METHODS

Using our institutional partial nephrectomy database, we investigated the patients who underwent partial nephrectomy for malignant tumors between January 2011 and December 2015. Patient, tumor, surgeon characteristics were compared by surgical margin status. Multivariable logistic regression was used to identify independent predictors of positive surgical margins.

RESULTS

A total of 1025 cases were available for analysis, of which 65 and 960 had positive and negative surgical margins, respectively. On univariate analysis, positive margins were associated with older age (64.3 vs. 59.6, p<0.01), history of prior ipsilateral kidney surgery (13.8% vs. 5.6%, p<0.01), lower preoperative eGFR (74.7 mL/min/1.73 m² vs. 81.2 mL/min/1.73 m², p=0.01), high tumor complexity (31.8% vs. 19.0%, p=0.03), hilar tumor location (23.1% vs. 12.5%, p=0.01), and lower surgeon volume (p<0.01). Robotic versus open approach was not associated with the risk of positive margins (p=0.79). On multivariable analysis, lower preoperative eGFR, p=0.01), hilar tumor location (p=0.01), and lower surgeon volume (p<0.01) were found to be independent predictors of positive margins.

CONCLUSION

In our large institutional series of partial nephrectomy cases, patient, tumor, and surgeon factors influence the risk of positive margins. Of these, surgeon volume is the single most important predictor of surgical margin status, indicating that optimal oncological outcomes are best achieved by high-volume surgeons.

Suture techniques during laparoscopic and robot-assisted partial nephrectomy: a systematic review and quantitative synthesis of peri-operative outcomes

OBJECTIVE

To summarize the available evidence on renorrhaphy techniques and to assess their impact on peri-operative outcomes after minimally invasive partial nephrectomy (MIPN).

MATERIALS AND METHODS

A systematic review of the literature was performed in January 2018 without time restrictions, using MEDLINE, Cochrane and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement recommendations. Studies providing sufficient details on renorrhaphy techniques during laparoscopic or robot-assisted partial nephrectomy and comparative studies focused on peri-operative outcomes were included in qualitative and quantitative analyses, respectively.

RESULTS

Overall, 67 and 19 studies were included in the qualitative and quantitative analyses, respectively. The overall quality of evidence was low. Specific tumour features (i.e. size, hilar location, anatomical complexity, nearness to renal sinus and/or urinary collecting system), surgeon's experience, robot-assisted technology, as well as the aim of reducing warm ischaemia time and the amount of devascularized renal parenchyma preserved represented the key factors driving the evolution of the renorrhaphy techniques during MIPN over the past decade. Quantitative synthesis showed that running suture was associated with shorter operating and ischaemia time, and lower postoperative complication and transfusion rates than interrupted suture. Barbed suture had lower operating and ischaemia time and less blood loss than non-barbed suture. The single-layer suture technique was associated with shorter operating and ischaemia time than the double-layer technique. No comparisons were possible concerning renal functional outcomes because of non-homogeneous data reporting.

CONCLUSIONS

Renorrhaphy techniques significantly evolved over the years, improving outcomes. Running suture, particularly using barbed wires, shortened the operating and ischaemia times. A further advantage could derive from avoiding a double-layer suture.