Feasibility of omitting cortical renorrhaphy during robot-assisted partial nephrectomy: a matched analysis

Predictors of renal function deterioration at one year after off-clamp non-renorrhaphy partial nephrectomy

BACKGROUND

Preservation of renal function is an important goal in renal cell carcinoma-related surgery. Although several case-dependent techniques for renal pedicle clamping and hemostasis have been used, their effects on long-term renal function are controversial.

METHODS

The clinical records of 114 patients who underwent off-clamp non-renorrhaphy open partial nephrectomy at our hospital were retrospectively reviewed. Perioperative estimated glomerular filtration rate (eGFR) preservation was calculated, and predictors of eGFR decline 12 months post-surgery and overtime deterioration of renal function were identified using a multivariate regression analysis.

RESULTS

The median patient age was 65 years, and the median tumor size was 27 mm. The mean eGFR preservation at 1, 3, and 12 months post-surgery were 90.1%, 89.0%, and 86.9%, respectively. eGFR decline at 1 and 3 months were associated with poor eGFR preservation at 12 months with the odds ratio (95% confidence interval (CI)) of 1.97 and 3.157, respectively. Multivariate regression analyses revealed that tumor size was an independent predictor of eGFR decline at 12 months. Among 65 patients with eGFR preservation over 90% at 1 month post-surgery, eGFR value of 28 patients deteriorated below 90% at 12 months post-surgery compared with preoperative eGFR. Tumor size and eGFR preservation at 1 month were independent predictors of long-term renal function deterioration.

CONCLUSION

Tumor size predicted eGFR decline 12 months post-surgery. Only a mild decline in eGFR was observed between 3 and 12 months after open partial nephrectomy. Tumor size and eGFR preservation at 1 month predicted the deterioration of renal function over time.

Impact of Robotic-Assisted Partial Nephrectomy with Single Layer versus Double Layer Renorrhaphy on Postoperative Renal Function

We aimed to investigate the differences in renal function between patients who underwent single inner-layer renorrhaphy (SILR) or double-layer renorrhaphy (DLR) among those with renal tumors who underwent robot-assisted partial nephrectomy (RAPN). This retrospective multicenter cohort study was conducted between November 2018 and October 2023 at two institutions and included patients who underwent RAPN. In total, 93 eligible patients who underwent RAPN were analyzed. Preoperative renal function and prevalence of chronic kidney disease were not significantly different between the two groups. Although urinary leakage was observed in three patients (5.9%) in the SILR group, there was no significant difference between the two groups regarding surgical outcomes (p = 0.249). Serum creatinine levels after RAPN were significantly lower in the SILR group than in the DLR group on postoperative days 1 and 365 following RAPN (p = 0.04). The estimated glomerular filtration rate (eGFR) was significantly lower in the DLR group than in the SILR group only on postoperative day 1; however, there was no significant difference between the two groups thereafter. Multivariate analysis showed that the method of renorrhaphy was not a predictor for maintaining renal function after RAPN even though it was associated with eGFR on postoperative day 1.

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.

Outcomes and Techniques of Robotic-Assisted Partial Nephrectomy (RAPN) for Renal Hilar Masses: A Comprehensive Systematic Review

Background: Robot-assisted partial nephrectomy (RAPN) is increasingly being employed in the management of renal cell carcinoma (RCC) and it is expanding in the field of complex renal tumors. The aim of this systematic review was to consolidate and assess the results of RAPN when dealing with entirely central hilar masses and to examine the various methods used to address the surgical difficulties associated with them. Methods: A thorough literature search in September 2023 across various databases focused on RAPN for renal hilar masses, adhering to PRISMA guidelines. The primary goal was to evaluate RAPN's surgical and functional outcomes, with a secondary aim of examining different surgical techniques. Out of 1250 records, 13 full-text manuscripts were reviewed. Results: Evidence is growing in favor of RAPN for renal hilar masses. Despite a predominance of retrospective studies and a lack of long-term data, RAPN shows positive surgical outcomes and preserves renal function without compromising cancer treatment effectiveness. Innovative suturing and clamping methods are emerging in surgical management. Conclusions: RAPN is a promising technique for managing renal hilar masses in RCC, offering effective surgical outcomes and renal function preservation. The study highlights the need for more long-term data and prospective studies to further validate these findings.

Impact of Inner Layer Renorrhaphy Suture on Renal Artery Pseudoaneurysm Formation Following Robotic-assisted Partial Nephrectomy

OBJECTIVE

To report the impact of resection base inner layer renorrhaphy suture type on renal artery pseudoaneurysm (RAP) rate following robotic-assisted partial nephrectomy (RAPN).

METHODS

Five hundred and sixty-three consecutive RAPNs performed by a single surgeon were retrospectively reviewed. Patients were classified into 3 categories: (1) No base suture, (2) monofilament barbed suture (2-0 V-Loc 180 absorbable suture, Medtronic, Minneapolis, MN), (3) polyglactin 910 (2-0 Vicryl coated suture, Ethicon Inc, Cincinnati, OH). In a secondary analysis, we evaluated suturing (Vicryl and V-Loc) vs no base suture. All patients had outer cortical renorrhaphy performed with 0-Vicryl suture utilizing the standard sliding clip technique.

RESULTS

One hundred ten patients (19.5%) had V-Loc suturing, 255 patients (45.3%) had Vicryl suturing, and 198 patients (35.2%) had no base suture. Patients had a median age of 62.8years (interquartile range: 53.5-69.7) and median RENAL score was 8 (6-9). Median mass size from preoperative imaging was 3.0 cm (2.5-4.0) for V-Loc, 3.3 cm (2.5-4.2) for Vicryl, and 2.0 cm (1.8-3.0) for no base suture (P < .001). Overall, 21 patients (3.7%) developed a symptomatic postoperative RAP. The rate of RAP was 3.6% (4/110) for V-Loc, 3.9% (10/255) for 2-0 Vicryl, and 3.5% (7/198) for no base suture (P = 1.00). Similarly, the rate of RAP was 3.5% (7/198) for no base suture and 3.8% (14/365) for base suture (P = 1.00).

CONCLUSION

Utilization of base suture and type of base suture used during RAPN was not predictive of postoperative RAP development.

Renorrhaphy techniques in minimally invasive partial nephrectomy: a systematic review of the literature

INTRODUCTION

In the absence of consensus on the optimal approach to renorrhaphy in partial nephrectomy, this systematic review aims to assess the various renorrhaphy techniques and their impact on surgical outcomes.

EVIDENCE ACQUISITION

A systematic review of the literature was performed in March 2022, using PubMed and Scopus, without time restrictions and research filters for studies investigating renorrhaphy techniques in partial nephrectomy. Studies providing sufficient details on renorrhaphy techniques and their outcomes during minimally invasive partial nephrectomy (PN) were included in this analysis.

EVIDENCE SYNTHESIS

Thirty-one studies with 5720 patients were included in the analysis. In most studies, tumor diameter was <4 cm. RENAL and PADUA scores as well as tumor locations were heterogeneous between the studies. The results of the use of hemostatic agents were conflicting among different studies with limited evidence regarding the benefits of its routine use in partial nephrectomy. The use of barbed and running sutures was associated with a reduced warm ischemia time. While some studies showed a decreased warm ischemia time when omitting cortical renorrhaphy, others found that it may lead to higher incidence of minor complications without any significant improvement in other outcomes.

CONCLUSIONS

There is ongoing research to determine the optimal approach to renorrhaphy. The current evidence on the routine use of hemostatic agents is limited. The use of certain techniques such as barbed sutures, sliding clips and running sutures reduced the warm ischemia time. The omission of cortical renorrhaphy is still controversial.

Comparison of robot-assisted partial nephrectomy with soft coagulation and double-layer technique for complex and non-complex tumors

OBJECTIVES

To compare the postoperative outcomes of robot-assisted partial nephrectomy when only the inner layer is sutured (single-layer technique with soft coagulation) with those when sutures are placed in the inner and outer layers (double-layer technique) in patients with and without complex renal tumors.

METHODS

This retrospective three-institution study included 371 patients with renal tumors who underwent robot-assisted partial nephrectomy with a double-layer technique or a single-layer technique with soft coagulation. Tumors that were cT1b, completely embedded, located in the renal portal, or had a RENAL score of ≥10 were considered complex. Relevant data were collected from hospital records. Propensity score matching was performed to minimize selection bias.

RESULTS

Propensity score matching created 83 patient pairs with non-complex tumors and 32 with complex tumors. Regardless of tumor complexity, there was no significant difference in operation time, console time, warm ischemia time, positive surgical margin rate, or length of hospital stay between the double-layer and single-layer groups. Although Clavien-Dindo grade I-II urinomas not requiring intervention were significantly more common in the single-layer group regardless of tumor complexity, there was no significant between-group difference in the rate of decline in renal function or grade III-IV complications.

CONCLUSION

Single-layer suturing with soft coagulation achieves renal function and perioperative outcomes comparable to those of double-layer suturing regardless of complexity.

Robotic-assisted partial nephrectomy: single-layer cortical renorrhaphy is associated with reduced rate of renal artery pseudoaneurysm compared to double-layer renorrhaphy

The study compares the outcome of patients who underwent single-layer outer cortical renorraphy (SLOCR) and double-layer cortical renorraphy (DLR) in our institution. The retrospective analysis of 181 patients who underwent RAPN was performed. Propensity score matching was accomplished on 67 patients using age, BMI, size, distance from collecting system, hilar location and pathological stage. Intraoperative factors assessed included warm ischemia time, renorraphy time, blood loss and operative duration (Levey et al. in Clin Chem 53:766-772, 2007) Post-operative hospital stay, complications like renal artery pseudoaneurysm (RAP), hemorrhage, urine leak and reduction in eGFR were measured. The 67 patients in SLOCR group were compared with similar number in the DLR group using propensity score matching. Warm ischemia time (P < .001), renorraphy time (P < .001) and symptomatic pseudoaneurysm (RAP) rate (P < .001) were significantly less in SLOCR group. SLOCR is associated with reduced rate of symptomatic post-operative RAP.

The efficacy of modified binding technique for renorrhaphy during robotic partial nephrectomy: surgical and functional outcomes from single-center experience

BACKGROUND

To compare the traditional single-layer and double-layer suture renorrhaphy with modified "Binding" suture renorrhaphy (whole rim of the wound was closed by the all-layer flow suture starting from the parenchyma cut edges to hilum, followed by the final defect closure) in robotic partial nephrectomy (RPN) for treating localized renal cell carcinoma in our large institutional experience.

METHODS

We retrospectively reviewed clinical data of 406 consecutive patients who underwent RPN from May 2018 and December 2020 in our center. The demographic and oncologic outcome variables were compared between different renal reconstruction groups and the effect of these suture techniques on renal function outcomes was also evaluated.

RESULTS

For the single-layer group, median operative time and warm ischemic time were significantly less than that of the double-layer and "Binding" groups (p < 0.001), while the significantly lower eGFR drop (p = 0.014) was also detected within postoperative 3 months from baseline, but this difference lost its statistical significance from 3th month to the last follow-up. The changes in postoperative creatinine values were clinically insignificant among the three groups. In a sub-analysis over 258 patients with moderate/high nephrometry score, those patients who underwent "Binding" suture had an undifferentiated warm ischemic time, estimated blood loss, and length of hospitalization stay with a decreased risk of Grade III complications (postoperative hemorrhage requiring intervention) and improved renal function recovery during the whole follow-up.

CONCLUSION

Single-layer suture renorrhaphy may be associated with better renal functional preservation and could prove to be reliable in patients with low-complexity tumor (RENAL score ≤ 6). Patients with moderate/high-complexity tumor (RENAL score ≥ 7) might represent a subgroup of patients having a functional benefit after "Binding" suture renorrhaphy even in the long-term period.

Surgical and functional outcomes of robot-assisted versus laparoscopic partial nephrectomy with cortical renorrhaphy omission

To evaluate the surgical and functional outcomes between robot-assisted (CRO-RAPN) vs. laparoscopic (CRO-LPN) methods of cortical-renorrhaphy-omitting partial nephrectomy. Between July 2012 and June 2020, patients with localized clinical T1-2 renal masses who underwent CRO-RAPN or CRO-LPN were reviewed. The outcomes of the two groups were compared using propensity-score matching. Trifecta was defined as negative surgical margin, warm ischemic time < 25 min, and absence of complications of Clavien-Dindo grade III or more until three months postoperatively. The preservation rate of the estimated glomerular filtration rate (eGFR) was evaluated at six months postoperatively. Among 291 patients (CRO-RAPN, n = 210; CRO-LPN, n = 81) included in the study, 150 matched pairs of patients were analyzed. Compared to the CRO-LPN group, the CRO-RAPN group was associated with shorter warm ischemic time (13 min vs. 20 min, P < 0.001), shorter total operation time (162 min vs. 212 min, P < 0.001), less estimated blood loss (40 mL vs. 119 mL, P = 0.002), lower incidence of overall complications (3% vs. 16%, P = 0.001), higher preservation rate of eGFR at six months postoperatively (93% vs. 89%, P = 0.003), and higher trifecta achievement rate (84% vs. 64%, P = 0.004). CRO-RAPN contributed to shorter warm ischemic time, less blood loss, fewer complications, and higher preservation of renal function, all of which allowed this technique to achieve a higher rate of trifecta compared to CRO-LPN.

Temporal Study of Renal Volume Losses in Patients with Robotic Partial Nephrectomies

Purpose: Robotic partial nephrectomies (RPNs) by their nature are associated with renal volume loss. Our goal of this study is to examine renal volume loss over time post partial nephrectomy. Materials and Methods: Fifty patients were followed for 1-year post-RPN with two-layer renorrhaphy and the sliding clip technique. This was done with a preoperative CT scan to assess renal mass and location. Patients post-RPN were imaged at time points 3 days, 6 months, and 12 months. Results: Patient demographics were 82% men with a median (interquartile range [IQR]) age of 57 (45-67) years and all were of Japanese descent. The medians (IQR) for warm ischemia time were 18 minutes (14-22), total operative time was 181.5 minutes (169.3-218.5), and estimated blood loss was 20 mL (10-50). The tumor characteristics had a median (IQR) diameter of 2.8 cm (2.5-3.4) with a RENAL score of 7 (6-8). The renal CT showed median (IQR) volume losses at 3 days of -1% (-7.1, 1.8), at 6 months of -15.3% (-20.6, -11.2), and at 12 months of -16.3% (-19.0, -12.8). Significance was seen at the 3 days to 6 months comparison for volume loss (p < 0.0001). Mean (standard deviation) estimated glomerular filtration rate (GFR) losses were as follows: at discharge 0.5% (12.9), 1 month -6.4% (11.8), 6 months -4.6% (9.8), and 12 months -3.6% (11.9). Statistical analysis showed significance for GFR loss at the comparison between discharge to 1 and 6 months (p = 0.01, p = 0.04). Conclusion: The initial volume loss seen postsurgery from resected healthy tissue was not significant and only became relevant at longer time points, suggesting that loss could be from atrophy. Volume loss over time supports the hypothesis that suture renorrhaphy is a primary cause of volume loss when warm ischemia time is <25 minutes.

Comparison of parenchymal volume loss assessed by three-dimensional computed tomography volumetry and renal functional recovery between conventional and robot-assisted laparoscopic partial nephrectomy

OBJECTIVES

We retrospectively investigated if robot-assisted laparoscopic partial nephrectomy (RAPN) contributes to a decrease in resected parenchymal volume (RPV), an increase in postoperative parenchymal volume (PPV), and an improvement of postoperative renal function when compared with conventional laparoscopic partial nephrectomy (LPN) using a three-dimensional image analysis system.

METHODS

Patients who underwent LPN (n = 37) and RAPN (n = 66) from November 2013 to November 2018 were included in this study. All patients had a tumor diameter of 4 cm or less. Patients with an anatomical or functional single kidney were excluded. RPV and PPV were measured using SYNAPSE VINCENT®. The surgical outcomes were compared between the two groups.

RESULTS

Warm ischemic time in the RAPN group was significantly shorter than that in the LPN group (p < 0.001). The ratio of RPV to tumor volume (RPV/TV) in the RAPN group was significantly lower than that in the LPN group (p = 0.016). PPV in the RAPN group was significantly higher than that in the LPN group (p = 0.049). The decreased estimated glomerular filtration rate in the RAPN group was significantly lower than that in the LPN group on days 1, 7, 30, 90, and 180 after surgery.

CONCLUSIONS

Postoperative renal function in the RAPN group was significantly better than that in the LPN group in both the short and long term. In addition to a short warm ischemia time, the decreased RPV/TV and increased PPV may have contributed to the improvement of postoperative renal function.

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.

Assessment of surgical outcomes of off-clamp open partial nephrectomy without renorrhaphy for ≥T1b renal tumours

PURPOSE

To assess the surgical outcomes of off-clamp open partial nephrectomy without renorrhaphy. In the era of robot-assisted surgeries, open partial nephrectomy remains a surgical option for  ≥ T1b renal tumours. Although the necessity of renal pedicle clamping and renorrhaphy in open partial nephrectomy for larger tumours remains to be discussed, reports on this issue are rare.

METHODS

Twenty-seven open partial nephrectomies for  ≥ T1b renal tumours were performed without renal pedicle clamping or renorrhaphy. A soft coagulation system was used to control bleeding from the resection bed. Surgical results, complications, and predictors of perioperative estimated glomerular filtration rate (eGFR) preservation at 1 month and 3 months after surgery were analysed.

RESULTS

The median estimated volume of blood loss was 420 mL. The rates of perioperative eGFR preservation were 88.9 and 87.3% at 1 and 3 months after surgery, respectively. Tumour size was an independent predictor of perioperative eGFR preservation at 1 month after surgery, whereas age and exophytic/endophytic properties of the tumour were independent predictors of perioperative eGFR preservation at 3 months after surgery.

CONCLUSION

Open partial nephrectomy without renal pedicle clamping or renorrhaphy could be safely performed for  ≥ T1b renal tumours, even when tumours were entirely endophytic and located close to the renal pedicle. Mild perioperative eGFR reduction was observed. Although surgical indications should be carefully considered in these cases, off-clamp open partial nephrectomy without renorrhaphy is a feasible procedure for patients with  ≥ T1b renal tumours.

How to improve outcome in nephron-sparing surgery: the impact of new techniques

PURPOSE OF REVIEW

Nephron-sparing partial nephrectomy is the state of the art for localized small renal mass and it is gaining attention also for more advanced cases. In the present narrative review, we discuss the new developments that have occurred in the advancement of this approach over the past few years.

RECENT FINDINGS

Off-clamp, selective/superselective clamp and early-unclamping techniques are safe and feasible approaches, with potentially superior functional outcomes, and noninferior complications rate and oncological outcomes, when compared with main artery clamping. Renorrhaphy must preserve the physiological vascularization of residual parenchyma. Running sutures, particularly using barbed wires, shorten the operating and ischemia times. A further advantage could derive from avoiding a double-layer suture. Transperitoneal robot-assisted partial nephrectomy (RAPN) and retroperitoneal RAPN can be considered equivalent in terms of perioperative morbidity, functional and oncologic outcomes, regardless of tumor's location, thus the choice of the approach should be driven by the surgeon's expertise. Future improvements should be introduced by the single-port robotic surgery, which seems to be safe and feasibly also in an off-clamp manner.

SUMMARY

Significant advances have recently been achieved in nephron-sparing surgery technique. However, future studies with standardized reporting of these new techniques are needed to assess the real impact of them on early and long-term functional outcomes.

Selective Suturing or Sutureless Technique in Robot-assisted Partial Nephrectomy: Results from a Propensity-score Matched Analysis

BACKGROUND

Despite efforts aimed at preserving renal function, the functional decline after robot-assisted partial nephrectomy (RAPN) is not negligible. To address the risk of intraparenchymal vessel injuries during renorrhaphy, with consequent loss of functional renal parenchyma, we introduced a new surgical technique for RAPN.

OBJECTIVE

To compare perioperative patient outcomes between selective-suturing or sutureless RAPN (suRAPN) and standard RAPN (stRAPN).

DESIGN, SETTING, AND PARTICIPANTS

Ninety-two consecutive patients undergoing RAPN for a renal mass performed by a high-volume surgeon at a European tertiary center were included. Propensity-score matching was used to account for baseline differences between suRAPN and stRAPN patients.

INTERVENTION

RAPN using a selective-suturing or sutureless technique versus standard RAPN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Perioperative outcomes included operative time, blood loss, length of stay, and intraoperative and 30-d postoperative complications. We also evaluated trifecta achievement (warm ischemia time ≤25 min, negative surgical margins, and no perioperative complications) and the incidence of postoperative acute kidney injury (AKI). We applied χ² tests, t tests, and Kruskal-Wallis tests to assess differences in perioperative outcomes between suRAPN and stRAPN.

RESULTS AND LIMITATIONS

Overall, 29 patients (31%) were treated with suRAPN. Only one suRAPN patient experienced intraoperative complications (p = 0.9). Two suRAPN patients (6.9%) and four stRAPN patients (13.8%) experienced 30-d postoperative complications (p = 0.3). Operative time (110 vs 150 min; p < 0.01) and length of stay (2 vs 3 d; p = 0.02) were shorter for suRAPN than for stRAPN. The trifecta outcome was achieved in 25 suRAPN patients (86%) and 20 stRAPN patients (70%; p = 0.1). Only one suRAPN patient (3.4%) versus five stRAPN patients (17%) experienced postoperative AKI (p = 0.2). Finally, the decrease in the estimated glomerular filtration rate at 6-mo follow-up was lower in the suRAPN (-5.2%) than in the stRAPN group (-9.1%; p < 0.01). Lack of randomization represents the main study limitation.

CONCLUSIONS

A selective-suturing or sutureless technique in RAPN is feasible and safe. Moreover, suRAPN is a lower-impact surgical procedure. We obtained promising results for trifecta and functional outcomes, but prospective randomized trials are needed to validate the impact of selective suturing or a sutureless technique on long-term functional outcomes.

PATIENT SUMMARY

We assessed a new technique in robotic surgery to remove part of the kidney because of kidney cancer. Our new technique involves selective suturing or no suturing of the area from where the tumor is removed. We found that the rate of complications did not increase and the operating time and length of hospital stay were shorter using this new technique.

Surgical innovation revisited: A historical narrative of the minimally invasive “Agarwal sliding‐clip renorrhaphy” technique for partial nephrectomy and its application to an Australian cohort

Objective

To evaluate local clinical outcomes of sliding clip renorrhaphy, from inception to current utilization for open, laparoscopic, and robotically assisted partial nephrectomy.

Methods

We reviewed prospectively maintained databases of three surgeons performing partial nephrectomies with the sliding‐clip technique at teaching hospitals between 2005 and 2019. Baseline characteristics, operative parameters, including surgical approach, RENAL Nephrometry Score, and post‐operative outcomes, including Clavien‐Dindo classification of complications, were recorded for 76 consecutive cases. We compared perioperative and 90‐day events with patient and tumor characteristics, stratified by operative approach and case complexity, using Wilcoxon rank‐sum test for continuous variables and the Chi‐squared or Fisher's exact test, for binary and categorical variables, respectively.

Results

Open surgery (n = 15) reduced ischemia time and operative time, but increased hospital admission time. Pre‐ and post‐operative estimated glomerular filtration rates did not change significantly by operative approach. Older patients (P = .007) and open surgery (P = .003) were associated with a higher rate of complications (any‐grade). Six grade ≥3 complications occurred: these were associated with higher RENAL Nephrometry Score (P = .016) and higher pathological tumor stage (P = .045). Limits include smaller case volumes which incorporate the learning curve cases; therefore, these data are most applicable to lower volume teaching hospitals.

Conclusion

The sliding‐clip technique for partial nephrectomy was first described by Agarwal et al and has low complication rates, acceptable operative time, and preserves renal function across open and minimally invasive surgeries. This series encompasses the initial learning curve with developing the technique through to present‐day emergence as a routine standard of practice.

Comparison of Sutureless and Conventional Laparoscopic Partial Nephrectomy: A Propensity Score-Matching Analysis

Objective: To compare the functional outcome, safety and efficacy of sutureless and conventional laparoscopic partial nephrectomy.

Methods: After the inclusion and exclusion criteria were applied, our study reviewed 379 patients with T1 stage renal tumors. We applied propensity score matching (PSM) to limit potential baseline confusion. Perioperative and functional outcomes between sutureless laparoscopic partial nephrectomy (sLPN) and conventional laparoscopic partial nephrectomy (cLPN) groups were compared and analyzed before and after PSM.

Results: Of our 379 patients with T1 stage renal tumors, 199 and 180 were identified in the cLPN and sLPN groups, respectively. After applying PSM with preoperative features, 116 patients in the cLNP group were paired to 116 patients in the sLNP group. We found that all differences in preoperative baseline characteristics disappeared. All the preoperative characteristics (age, gender, tumor diameter, RENAL nephrometry score, side, preoperative eGFR, hypertension, diabetes mellitus, ASA score) were not statistically different between the two groups. The operative time (OT) (p < 0.001) and warm ischemia time (WIT) (p < 0.001) of the sLPN group were of shorter duration than that of the cLPN group. The eGFR baseline was almost equal, but there was a statistically smaller decrease in eGFR in the sLPN than in the cLPN group 1 week after surgery (14.3 vs. 7.4, p < 0.001) and after 6 months (11.9 vs. 5.0, p < 0.001). After both preoperative features and WIT were included in PSM, fifty-one pairs of patients were identified between the groups, the WIT difference between them disappeared, while the decrease in eGFR between the groups remained as it was previously at 1 week (15.4 vs. 8.6, p < 0.001) and at 6 months (13.0 vs. 6.2, p < 0.001).

Conclusion: Sutureless laparoscopic partial nephrectomy is as safe and effective as conventional laparoscopic partial nephrectomy, and compared to cLPN, sLPN can effectively reduce the WIT, retain more renal parenchyma and protect renal function.

A Multi-institutional Review of Single-access Percutaneous Nephrolithotomy for Complex Staghorn Stones

BACKGROUND

With the heterogeneous distribution of novel surgical technologies and variable physician training, there is a need to re-evaluate contemporary outcomes of percutaneous nephrolithotomy (PCNL) for complex staghorn stones.

OBJECTIVE

To evaluate contemporary outcomes of guideline-supported treatment for patients with staghorn kidney stones using single-access PCNL in multiple North American centers.

DESIGN, SETTING AND PARTICIPANTS

We performed a multi-institutional retrospective review of staghorn stones managed from January 1, 2017 to January 1, 2019, inclusive. We excluded patients with more than a single percutaneous access per renal unit and those who underwent a concomitant contralateral procedure.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Safety (Clavien-Dindo complications) and efficacy in terms of a strictly defined stone-free rate were examined for single-access PCNL performed on staghorn stones with a Guy's stone score of 3-4.

RESULTS AND LIMITATIONS

We evaluated 301 patients meeting the inclusion criteria with an average age of 57 yr (range 18-87). All stones had a Guy's stone score of 3 (36.2%) or 4 (63.8%). The mean (± standard deviation) stone burden was 191.4 ± 49.8 mm². Of the 297 patients (98.6%) who underwent computed tomography on postoperative day 1, 132 (44.4%) showed no residual stone, 111 (37.3%) had a largest fragment <4 mm, and 54 (18.2%) had a fragment ≥4 mm after primary single-access PCNL. Secondary procedures were performed in 117 patients (38.9%). Imaging at 3 mo demonstrated that 210/257 patients (82%) were stone-free. The overall complication rate was 17.9%, with 11 patients (3.7%) experiencing Clavien-Dindo grade ≥3 complications.

CONCLUSIONS

Single-access PCNL for complex staghorn stones is safe and effective. High stone-free rates with minimal morbidity are achievable with current techniques.

PATIENT SUMMARY

This study confirms that single-access percutaneous nephrolithotomy provides excellent outcomes in the treatment of complex kidney stones. This surgical technique has both safe and effective outcomes that are reproducible across multiple centers in North America.

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.

Robotic and open partial nephrectomy for tumors in a solitary kidney

Introduction and objective:

Traditionally, patients with renal masses in solitary kidneys were managed with an open partial nephrectomy. With improving techniques, robotic-assisted partial nephrectomy in the setting of a solitary kidney is increasingly utilized. The objective of this study was to compare open partial nephrectomy and robotic-assisted partial nephrectomy outcomes in solitary kidney patients.

Methods:

A retrospective study of 536 total patients who underwent partial nephrectomy between 2004–2016 was performed. Of these patients, 23 had a renal mass in a solitary kidney. Patient demographics, perioperative values, and surgical outcomes were analyzed using descriptive statistics to compare open partial nephrectomy to robotic-assisted partial nephrectomy.

Results:

Of the 23 patients in the cohort, 52% ( n=12) underwent open partial nephrectomy and 48% ( n=11) underwent robotic-assisted partial nephrectomy. Patient characteristics were not significantly different. The mean (standard deviation) nephrometry score was 6.9 (1.8) for open partial nephrectomy and 6.1 (1.9) for robotic-assisted partial nephrectomy ( p=0.290). The mean (standard deviation) pre-operative creatinine was 1.2 (0.3) in open partial nephrectomy and 1.5 (0.4) in robotic-assisted partial nephrectomy, which did not reach statistical significance ( p=0.110). No difference in postoperative kidney function, Clavien grade 3 or higher complication rate, blood loss, or hospitalization length was noted.

Conclusion:

Although traditionally patients with a tumor in a solitary kidney are counseled to undergo open partial nephrectomy, robotic-assisted partial nephrectomy is a safe alternative with no decrease in postoperative renal function when compared with a similar cohort of patients undergoing open partial nephrectomy in a solitary kidney.

Level of evidence:

Level II

Canadian Update on Surgical Procedures (CUSP) Urology Group consensus for intraoperative hemostasis during minimally invasive partial nephrectomy

INTRODUCTION

Partial nephrectomy remains the gold standard in the management of small renal masses. However, minimally invasive partial nephrectomy (MIPN) is associated with a steep learning curve, and optimal, standardized techniques for time-efficient hemostasis are poorly described. Given the relative lack of evidence, the goal was to describe a set of actionable guiding principles, through an expert working panel, for urologists to approach hemostasis without compromising warm ischemia or oncological outcomes.

METHODS

A three-step modified Delphi method was used to achieve expert agreement on the best practices for hemostasis in MIPN. Panelists were recruited from the Canadian Update on Surgical Procedures (CUSP) Urology Group, which represent all provinces, academic and community practices, and fellowship-and non-fellowship-trained surgeons. Thirty-two (round 1) and 46 (round 2) panellists participated in survey questionnaires, and 22 attended the in-person consensus meeting.

RESULTS

An initial literature search of 945 articles (230 abstracts) underwent screening and yielded 24 preliminary techniques. Through sequential survey assessment and in-person discussion, a total of 11 strategies were approved. These are temporally distributed prior to tumor resection (five principles), during tumor resection (two principles), and during renorrhaphy (four principles).

CONCLUSIONS

Given the variability in tumor size, depth, location, and vascularity, coupled with limitations of laparoscopic equipment, achieving consistent hemostasis in MIPN may be challenging. Despite over two decades of MIPN experience, limited evidence exists to guide clinicians. Through a three-step Delphi method and rigorous iterative review with a panel of experts, we ascertained a guiding checklist of principles for newly beginning and practicing urologists to reference.

Robot-Assisted Laparoscopic Partial Nephrectomy Vs Conventional Laparoscopic Partial Nephrectomy: Functional and Surgical Outcomes of a Prospective Single Surgeon Randomized Study

Background: Laparoscopic partial nephrectomy (LPN) and robot-assisted partial nephrectomy (RAPN) are commonly used techniques for treating small renal masses. Regarding renal function (RF) preservation, no superiority of one technique over the other has yet been definitely demonstrated. Objective: To compare functional and surgical outcomes of LPN and RAPN. Patients and Methods: Between 2015 and 2019, we prospectively randomized 115 patients with cT1-T2 renal masses to LPN in total ischemia or RAPN in selective ischemia. Primary endpoint was RF preservation, assessed by renal scintigraphy (RS). RS assessments were performed preoperatively and at 6 months follow-up. Secondary endpoints included clinical, histopathologic, and surgical outcomes. Results: One hundred eight patients were included in the final analysis. Patient and tumor characteristics were comparable. No significant difference in RS values after 6 months was observed between both groups. Median (interquartile range) RF change after 6 months was -18.0% (-26.5 to -11.0) in LPN group and -20.0 (-33.2 to -12.0) in RAPN group (p = 0.3). Mean (standard deviation [SD]) warm ischemia time was 21.1 (6.1) minutes in LPN group and 19.6 (7.7) minutes in RAPN group (p = 0.2). No positive surgical margins (PSMs) occurred in the LPN group, whereas RAPN group had PSM in 4.9% (n = 3); p = 0.099. Renal volume loss after 6 months was 27.5% (22.7-45.7) in the LPN group vs 37.5 (13.7-54.2) in the RAPN group (p = 0.5). Mean operative times were lower in the LPN group (192.3 minutes [SD 44.5] vs 230.2 minutes [SD 59.6], p = 0.001). More complications occurred in the LPN group (31% vs 21%, p = 0.075). Transfusion rates were 15% for LPN and 11% for RAPN. Conclusions: In terms of preserving RF, LPN in total ischemia and RAPN in selective ischemia are comparable. In most patients, RF decrease of the affected kidney after PN seems to not exceed 25%, regardless of the surgical approach.

Renal Volume Loss During Partial Nephrectomy Due to Resected Healthy Parenchyma: A Tool for Quick Estimation

Purpose: Our objective is to evaluate a technique for estimating the amount of healthy margin resected during partial nephrectomy (PN). Materials and Methods: The resected healthy margin volume was determined by planimetry (gold standard), which was performed in a prospective manner on 30 freshly resected renal masses by cross-sectional slicing every ∼5 mm. A single cross-sectional slice containing the largest tumor diameter (bivalved tumor) was chosen to build a model for estimating the amount of healthy kidney removed. This single-slice technique was then applied to a second series of patients (n = 39) status post PN. Three-dimensional models were created using pre- and postoperative CT scans to determine the overall volume loss following PN. Results: The median (range) for tumor diameter and tumor volume was 3.2 cm (1-6.1) and 10.7 cm³ (0.5-101.9), respectively, for the 30 PN specimens used to build the single-slice estimation equation. The median (range) healthy margin volume calculated by planimetry and single slice technique was 9.0 cm³ (1.0-22.1) and 7.8 cm³ (1.0-31.0), respectively (p = 0.37). The Pearson correlation was 0.84, and the median (range) percent difference between the planimetry and single slice techniques was -0.5% (-39% to 57%). For the 39 PN patients, the median (range) total renal volume loss, 25.8 cm³ (3-79), was significantly greater than the volume of healthy margin removed during resection, 5.7 cm³ (1-22), p < 0.001. Conclusions: The healthy margin resected during PN differs widely and can be estimated from a single cross-section. The healthy margin resected accounted for <50% of the total volume loss seen during PN.

Omitting Cortical Renorrhaphy in Robot-Assisted Partial Nephrectomy: Is it Safe? A Single Center Large Case Series

Introduction: Preserving renal function after robot-assisted partial nephrectomy (RAPN) is important and influenced by the technique of renal reconstruction among other parameters, including ischemia time and amount of healthy renal tissue resected. It is believed that reconstruction with a second layer of cortical renorrhaphy is necessary to prevent urinary leaks and postoperative bleeding, but this is associated with the potential loss of healthy renal parenchyma and may result in worse outcomes postoperatively. Purpose: To assess the safety of omitting cortical renorrhaphy during RAPN. Patients and Methods: A retrospective analysis of 146 consecutive patients undergoing a RAPN with single or double layer renorrhaphy at the Wirral University Teaching Hospital from 2014 to 2019. Data obtained included: Patient demographics, tumor RENAL nephrometry, Perioperative parameters; blood loss, duration, and warm ischemia time (WIT), Postop complications, change in estimated glomerular filtration rate (eGFR) (pre and 3 months postop), length of stay, and oncologic outcomes. Results: In total 146 patients were identified. One hundred-six had double renorrhaphy and 40 inner layer only renorrhaphy. No significant differences were seen between these two cohorts in terms of patient demographics, RENAL nephrometry score, tumor size, or location. Perioperative parameters showed a reduced duration of surgery in the single renorrhaphy group with a mean of 125 minutes compared to143 minutes in the double renorrhaphy (p = 0.006) and a tendency toward a shorter WIT of 12.9 minutes vs 14.0 minutes reaching borderline statistical significance (p = 0.05) but no difference in blood loss volume (p = 0.25). Postoperatively there was no statistical difference in the length of hospital stay (p = 0.85), loss in eGFR at 3 months (0.06), or complication (p = 0.56). After a median follow-up of 35 months no recurrences or deaths were observed in either group. Conclusions: Omission of cortical renorrhaphy appears feasible and safe with no urine leaks or excess complications observed.

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.

Renorrhaphy techniques and effect on renal function with robotic partial nephrectomy

PURPOSE

The role of robotic partial nephrectomy (RPN) is becoming increasingly prevalent in managing small renal masses. Renal functional outcomes have been reported with relation to the amount of healthy renal parenchyma resected and ischemia time; however, there is limited data on the effect of renorrhaphy on long-term renal function. Our aim is to evaluate the impact of renorrhaphy technique on renal functional outcomes.

METHODS

A nonsystematic literature review was performed to retrieve articles assessing renorrhaphy techniques and renal function outcomes, specifically focusing on single-layer vs. traditional two-layer renorrhaphy.

RESULTS

Performing single-layer renorrhaphy while omitting cortical renorrhaphy appears to improve renal function postoperatively, based on very limited studies in the literature that were evaluated.

CONCLUSION

Single-layer renorrhaphy may be associated with improved postoperative renal function and could prove to be useful in patients with chronic renal insufficiency or solitary kidney. The ongoing clinical trial NCT02131376 may provide further information on the impact of renorrhaphy technique on long-term renal function.

The Use of Tissue Adhesive for Tumor Bed Closure during Partial Nephrectomy is Associated with Reduced Devascularized Functional Volume Loss

Objectives

To quantitatively compare the functional renal volume loss, following nephron sparing surgery (NSS) between patients in whom tumor bed closure was done by biological tissue adhesive and those who were managed by standard suture technique.

Methods

From our institutional NSS database we retrospectively collected patients who had two sequential quantitative single-photon emission computed tomography of ^99mTc-dimercaptosuccinic acid uptake studies, the first study immediately before surgery and the second one 3-6 months following surgery. The study group included 69 patients: 26 (37.7%) patients in the sealant group (BioGlue®) and 43 (62.3%) patients in the standard suture group.

Results

No statistically significant differences were noted in the baseline clinical and pathological characteristics of the studied groups. However, there were several statistically significant differences in operative variables: patients in the suture group had larger amount of blood loss (3-fold), longer ischemia time (26.6 vs. 21 minutes,) and slightly longer operation time. Patients in whom tumor bed was closed by sutures had nearly 3-fold higher parenchymal loss compared to patients managed by sealant (26.28 vs. 8.92 ml, p = 0.048).

Conclusions

The use of tissue sealant during tumor bed reconstruction is associated with reduced devascularized parenchymal mass loss and should be considered among modifiable surgical factors during NSS.

Optimization of renal function preservation during robotic partial nephrectomy

Over the past few years, the role of robotic-assisted partial nephrectomy (RPN) has exponentially grown. Multiple recognized factors contribute to postoperative renal function in patients undergoing RPN. The aim of this review is to identify these potential factors, and to evaluate strategies that may help optimize the goal of renal function preservation. A nonsystematic literature review was performed to retrieve the most recent evidence on factors contributing to renal function post-RPN. Analyzed elements include baseline factors (tumor complexity and patient characteristics), intraoperative (surgical) factors (control of the renal hilum and type of ischemia, resection technique, renorrhaphy technique), and pharmacotherapeutics. In conclusion, the advantages of robotic surgery in the setting of partial nephrectomy (PN) are becoming well established. Maximal preservation of renal function remains a priority goal of the procedure, and it is influenced by a plethora of factors. Adequate patient selection using radiomics, control of comorbidities, utilization of evidence-based intraoperative techniques/strategies, and postoperative care are key components of postoperative preservation of renal function. Further investigations regarding these factors and their effects on long-term renal function are necessary and will continue to aid in guiding appropriate patient care.

Systematic Review and Pooled Analysis of the Impact of Renorrhaphy Techniques on Renal Functional Outcome After Partial Nephrectomy

Despite the important relationship between renorrhaphy and functional outcomes of partial nephrectomy, the urological guidelines do not provide recommendations about the optimal renorrhaphy technique. We carried out the first pooled literature analysis of the impact of suture technique on ultimate renal function after partial nephrectomy. Three studies comparing interrupted versus running suture including data on glomerular filtration rate (GFR) were included, for a total of 124 versus 269 patients. No significant differences were found between pre- and postoperative GFR in either patients who received an interrupted suture (weighted mean difference, -4.88ml/min, 95% confidence interval [CI] -11.38; 1.63, p=0.14) or those who received a running suture (-3.42ml/min, 95% CI -9.96; 3.12, p=0.31). Three studies comparing single- versus double-layer renorrhaphy included data on GFR (321 vs 199 patients). A benefit in functional outcomes favored single-layer technique (-3.19ml/min, 95% CI -8.09; 1.70, p=0.2 vs -6.07ml/min, 95% CI -10.75; -1.39, p=0.01). In conclusion, our quantitative synthesis suggests a renal functional benefit of the single-layer closure during partial nephrectomy. PATIENT SUMMARY: The available studies on renal functional data included in the present review suggest that "less is more" for renorrhaphy after partial nephrectomy. The single-layer renorrhaphy technique showed advantages in renal functional outcomes compared with the double-layer technique.

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.

Ischemia Techniques in Nephron-sparing Surgery: A Systematic Review and Meta-Analysis of Surgical, Oncological, and Functional Outcomes

CONTEXT

The optimal ischemia technique at partial nephrectomy (PN) for renal masses is yet to be determined.

OBJECTIVE

To summarize and analyze the current evidence about surgical, oncological, and functional outcomes after different ischemia techniques (cold, warm, and zero ischemia) at PN.

EVIDENCE ACQUISITION

A computerized systematic literature search was performed by using PubMed (MEDLINE) and Science Direct. Identification and selection of the studies were conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) criteria. Outcomes of interest were estimated blood loss (EBL), overall complications, positive surgical margins, local tumor recurrence, and renal function preservation. Meta-analysis and forest-plot diagrams were performed. Overall pooled estimates, together with 95% confidence intervals (CIs), of the incidence of all parameters were obtained using a random effect model (RE-Model) on the log transformed means (MLN), proportion, or standardized mean change, as deemed appropriate.

EVIDENCE SYNTHESIS

One hundred and fifty-six studies were included. No clinically meaningful differences were found in terms of EBL after cold (mean: 215.5; 95% CI: 154.2-276.8m), warm (mean: 201.8; 95% CI: 175.0-228.7ml), or zero (mean: 261.2; 95% CI: 171.0-351.3ml) ischemia technique. Overall, postoperative complications were recorded in 14.1% (95% CI: 6.7-27.4), 11.1% (95% CI: 10.0-12.3), and 9.7% (95% CI: 7.7-12.2) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Positive surgical margins were recorded in 4.8% (95% CI: 1.9-10.9), 4.0% (95% CI: 3.4-4.8), and 5.6% (95% CI: 3.1-9.8) of patients after cold, warm, and zero ischemia (p<0.01), respectively. Local recurrence was recorded in 3.2% (95% CI: 1.9-5.2) and 3.1% (95% CI: 0.7-11.5) of patients after warm and zero ischemia (p<0.01), respectively. The log₂ of estimated glomerular filtration ratio mean changes were-1.37 (95% CI:-3.42 to 0.68),-1.00 (-2.04 to 0.03), and-0.71 (-1.15 to-0.27) ml/min after cold, warm, and zero ischemia, respectively. Low level of evidence, retrospective nature of most of included studies, a high risk of selection bias, and heterogeneity within included studies limited the overall quality of the analysis.

CONCLUSIONS

The effect of ischemia technique at PN is still debatable and subject to confounding by several factors, namely, patients' selection criteria, surgical technique used, and percentage of functional parenchyma spared during surgery. These confounders bias available evidence and were addressed by only a small part of available studies. Unfortunately, the overall quality of literature evidences and the high risk of selection bias limit the possibility of any causal interpretation about the relationship between the ischemia technique used and surgical, oncological, or functional outcomes. Thus, none of the available ischemia technique could be recommended over the other.

PATIENT SUMMARY

The present analysis shows that none of the available ischemia techniques, namely, cold, warm, or zero ischemia, is universally superior to the others, and other factors play a role in the surgical outcome.

Approach for Renal Tumors With Low Nephrometry Score Through Unclamped Sutureless Laparoscopic Enucleation Technique: Functional and Oncologic Outcomes

PURPOSE

We report an unclamped sutureless laparoscopic simple enucleation (LSE) technique for renal tumors with low nephrometry score and analyze complication rates as well as functional and oncologic outcomes.

PATIENTS AND METHODS

We reviewed the data of 143 consecutive patients who underwent sutureless laparoscopic tumor enucleation with zero ischemia by a single experienced laparoscopic surgeon. The inclusion criteria for LSE with zero ischemia were tumor size ≤ 5 cm and RENAL nephrometry score of 4 to 6. The following data were collected: age, gender, body mass index, tumor side, renal function, tumor characteristics, American Society of Anesthesiologists score, operative time, positive surgical margins, estimated blood loss, and surgical complications.

RESULTS

The median RENAL score of patients was 4.7. Median tumor size was 2.7 cm. Conversion to open surgery and hilum vessels clamped were not necessary in any patient. There were no changes in postoperative creatinine values and estimated glomerular filtration rate. The median operation duration time was 78.2 minutes, and median estimated blood loss was 110.2 mL. The median hospital stay was 3.8 days. A total of 2.8% of the patients had positive surgical margins at pathologic examination. Of the 143 patients, 7% developed fever after surgery requiring an adequate antibiotic regimen, 1.4% developed postoperative bleeding requiring blood transfusions, and 0.7% had postoperative urinary leakage from the drainage requiring double-J stent position.

CONCLUSION

The unclamped sutureless LSE is a rational and safe approach to renal tumors with a low nephrometry score. This surgical technique does not increase the complication rate despite the reduction in parenchymal mass excised and the absence of hilar control.

Robot-assisted partial nephrectomy: How to minimise renal ischaemia

Renal ischaemia research has shown an increase in renal damage proportional to ischaemic time. Therefore, we assessed the importance of renal ischaemic times for warm and cold ischaemia approaches, and explored the different surgical techniques that can help to minimise renal ischaemia in robot-assisted partial nephrectomy (RAPN). Minimising renal ischaemia during nephron-sparing surgery (NSS) is a key factor in preserving postoperative renal function. Current data support a safe warm ischaemia time (WIT) of ≤25 min and cold ischaemic time of ≤35 min, resulting in no significant deterioration in renal function. In general, patients undergoing NSS have increased comorbidities, including chronic kidney disease, and in these patients it is difficult to predict their postoperative renal function recovery. With RAPN, efforts should be made to keep the WIT to <25 min, as minimising the ischaemic time is vital for preservation of overall renal function and remains a modifiable risk factor. Parenchymal or segmental artery clamping, early unclamping or off-clamp techniques can be adopted when ischaemic times are likely to be >25 min, but may not lead to superior functional outcome. Careful preoperative planning, tumour factors, and meticulous surgical technique are critical for optimum patient outcome.

Preoperative Nomograms for Predicting Renal Function at 1 Year After Partial Nephrectomy

INTRODUCTION

Partial nephrectomy (PN) reduces the risk of postoperative chronic renal insufficiency (CRI). However, some patients still develop CRI after PN, and may eventually require dialysis. Being able to predict renal function before PN helps in counseling patients and managing expectations. We aimed to construct nomograms that predict estimated glomerular filtration rates (eGFRs), defined by the modification of diet in renal disease (MDRD) and the chronic kidney disease epidemiology collaboration (CKD-EPI) formulae, at 1 year after PN, using only preoperative covariates as predictors.

PATIENTS AND METHODS

We identified patients who underwent PN in our institution between 2004 and 2016, with known postoperative serum creatinine levels at 1 year. The preoperative covariates included patients' demographics, chronic comorbid conditions, tumor characteristics, and preoperative renal status. The endpoints were eGFRs at 1 year after PN, calculated using the MDRD and the CKD-EPI formulae. We first identified preoperative covariates with significant associations with the endpoints by Pearson correlation and independent samples t-test. Suitable covariates were then included in two multivariate linear regression models, for constructing and internally validating two nomograms.

RESULTS

461 patients were eligible for analysis. The percentage of patients with eGFR below 60 mL/min/1.73 m² increased from 25% before PN to 35% at 1 year after PN. We included age, gender, African American race, body mass index, preoperative creatinine level, ipsilateral renal volume, solitary kidney status, tumor diameter, hypertension, diabetes, ischemic heart disease, and previous stroke in the multivariate linear regression models for nomogram construction. Internal validation showed bootstrap-corrected coefficients of determination of 0.61 and 0.70, for predicting eGFRs defined by the MDRD and CKD-EPI formulae, respectively.

CONCLUSIONS

We constructed and internally validated two nomograms to predict eGFRs at 1 year after PN, using only preoperative covariates as predictors.

Determinant factors for chronic kidney disease after partial nephrectomy

The objective of this review is to evaluate the factors that determine the development or deterioration of Chronic Kidney Disease (CKD) after partial nephrectomy (PN).

When current literature is reviewed, it is found that factors that influence renal function after partial nephrectomy, are multifactorial. Those are divided into pre-surgical factors, such as hypertension, diabetes mellitus, urolithiasis, obesity, metabolic syndrome among others; intra-surgical factors, like the surgical technique used, the remaining healthy tissue, the experience of the surgeon, the time and type of ischemia among others. Lastly, post-surgical factors, also impose some influence on the post-surgical renal performance.

It was also found that minimally invasive surgery, in addition to its known advantages, seems to offer a greater field of action in the future that will allow more nephrons preservation in any future surgical scenario.

Finally, the current trend is to perform PN on all patients, in whom surgery is technically feasible regardless of the approach used, without risking oncological outcomes, patient safety, and without being exposed to any additional complications.

Impact of preoperative calculation of nephron volume loss on future of partial nephrectomy techniques; planning a strategic roadmap for improving functional preservation and securing oncological safety

OBJECTIVES

To assess the correlation of the resected and ischaemic volume (RAIV), which is a preoperatively calculated volume of nephron loss, with the amount of postoperative renal function (PRF) decline after minimally invasive partial nephrectomy (PN) in a multi-institutional dataset.

PATIENTS AND METHODS

We identified 348 patients from March 2005 to December 2013 at six institutions. Data on all cases of laparoscopic (n = 85) and robot-assisted PN (n = 263) performed were retrospectively gathered. Univariable and multivariable linear regression analyses were used to identify the associations between various time points of PRF and the RAIV, as a continuous variable.

RESULTS

The mean (sd) RAIV was 24.2 (29.2) cm³ . The mean preoperative estimated glomerular filtration rate (eGFR) and the eGFRs at postoperative day 1, 6 and 36 months after PN were 91.0 and 76.8, 80.2 and 87.7 mL/min/1.73 m² , respectively. In multivariable linear regression analysis, the amount of decline in PRF at follow-up was significantly correlated with the RAIV (β 0.261, 0.165, 0.260 at postoperative day 1, 6 and 36 months after PN, respectively). This study has the limitation of its retrospective nature.

CONCLUSION

Preoperatively calculated RAIV significantly correlates with the amount of decline in PRF during long-term follow-up. The RAIV could lead our research to the level of prediction of the amount of PRF decline after PN and thus would be appropriate for assessing the technical advantages of emerging techniques.

The Synergistic Influence of Ischemic Time and Surgical Precision on Acute Kidney Injury After Robotic Partial Nephrectomy

OBJECTIVE

To examine the dynamic and potentially synergistic influence of warm ischemia time (WIT) and excisional volume loss (EVL) on predicted rates of postpartial acute kidney injury (AKI) across a range of tumor complexities, and to investigate whether these modifiable variables sensitize the kidney to each other's damaging influence.

MATERIALS AND METHODS

We retrospectively reviewed 1245 patients between 2006 and 2016 with bilateral kidneys and enhancing renal masses in our single-institution robotic partial nephrectomy (PN) database. EVL was calculated as the difference between specimen and tumor volume based on pathologic measurements. Multivariate logistic regressions, followed by marginal effects, were run to examine the interaction of ischemia type, EVL, and radius, exophytic/endophytic properties, nearness of deepest tumor portion to collecting system or sinus, anterior/posterior and location relative to polar line score on rates of AKI.

RESULTS

We found a significant interaction effect of WIT and log EVL on predicted AKI (P < .001). Each doubling of EVL caused a 4.03% and 8.46% increased probability of AKI for WIT of <25 and >25 minutes, respectively. At an EVL of >5.5 cm³, prolonged WIT had statistically greater odds of causing AKI. These predicted effects on AKI were amplified for increasing radius, exophytic/endophytic properties, nearness of deepest tumor portion to collecting system or sinus, anterior/posterior and location relative to polar line scores (P < .001).

CONCLUSION

Although the adverse functional effects of WIT and parenchymal volume loss during PN have previously been described in isolation, our findings suggest that their influence on AKI is synergistic, especially in complex tumors. As such, additional attention should be given to limiting warm ischemia and maximizing surgical precision to avoid a "double hit" on postoperative renal function.

Current Paradigm for Ischemia in Kidney Surgery

PURPOSE

Partial nephrectomy is the accepted standard of care for treatment of patients with small renal masses. The primary goal while performing partial nephrectomy is cancer control with a secondary important goal of maximizing renal function preservation with minimal perioperative morbidity. Recent studies have highlighted the importance of renal parenchymal quality and quantity postoperatively rather than duration of ischemia in determining long-term renal function. We review the available data regarding perioperative renal function optimization with special interest in ischemia during partial nephrectomy, highlighting the controversies and establishing future lines of investigation.

MATERIALS AND METHODS

We performed a comprehensive literature review for the years 1970 to 2014 via MEDLINE(®), PubMed(®) and the Cochrane Library. Review was consistent with the PRISMA (Preferred Reporting Items for Systemic Reviews and Meta-Analyses) criteria. We used MeSH (Medical Subject Headings) terms for the search including "acute kidney injury/failure," "carcinoma, renal cell/carcinoma of kidney/neoplasm of kidney," "kidney failure, chronic/end-stage kidney disease," "ischemia-reperfusion" and "warm ischemia/cold ischemia." Relevant review articles were included. Abstracts from major urological/surgical conferences were reviewed. All studies included were performed in adults, were written in English and had an abstract available.

RESULTS

Our traditional knowledge of renal ischemia is derived from animal studies, ie kidney transplant and retrospective partial nephrectomy series that indicate the risk of renal function impairment for every minute of ischemia. Careful evaluation of historical studies highlights flaws of the use of ischemia duration as a dichotomous marker (25 or 30 minutes) while predicting renal function outcomes. Recent studies have revealed no effect of duration of ischemia on ultimate kidney function in the short or long term. Quality and quantity of parenchyma preserved postoperatively are key predictors of ultimate renal function after partial nephrectomy. Traditionally partial nephrectomy has been performed with hilar occlusion to provide a relatively bloodless surgical field allowing effective oncologic control during tumor excision with secure management of blood vessels, collecting system and renal reconstruction. Selective clamping and nonclamping techniques have been proposed to avoid the perceived harmful effects of ischemia, although they convert a complex surgery into a more challenging procedure, potentially limiting the widespread use of partial nephrectomy for management of renal cancers. Promising urine and blood-based biomarkers (NGAL, KIM-1) in the context of critical care settings and global stress have been observed to predict acute kidney injury. Within the partial nephrectomy environment the usefulness of those markers needs to be further investigated. To date, no study has proved their usefulness in the setting of partial nephrectomy.

CONCLUSIONS

Based on the available evidence, use of a single cutoff for duration of ischemia time as a dichotomous value for renal function outcomes in the setting of partial nephrectomy is flawed. Renal ischemia is a controversial topic with a shifted paradigm within the last decade. Current evidence has shown that patients with 2 kidneys undergoing nephron sparing surgery can tolerate ischemia times of more than 30 minutes without a clinically significant decline in renal function. Biomarkers predictive of renal tubular injury fail to predict acute kidney injury in the context of partial nephrectomy. Indications for partial nephrectomy could be significantly expanded as the safety of limited renal ischemia is now better understood.