Three-year Oncologic and Renal Functional Outcomes After Robot-assisted Partial Nephrectomy

Background

With the wider adoption of minimally invasive partial nephrectomy (PN), intermediate- and long-term outcomes data are needed to make firm conclusions about oncologic and functional efficacy, especially for robot-assisted PN (RPN).

Objective

To report intermediate-term oncologic and renal functional outcomes of RPN.

Design, setting, and participants

We performed a chart review of patients who had undergone RPN since June 2006; patients with a minimum of 2 yr of follow-up were included in this study. Length of follow-up was calculated from the date of surgery to the date of last clinical follow-up. Patients who were either lost to follow-up or who had follow-up outside of our center were sent surveys.

Intervention

Transperitoneal RPN with or without hilar clamping.

Outcome measurements and statistical analysis

The demographic, preoperative, and postoperative data were statistically analyzed. The Kaplan-Meier method was used to calculate overall survival (OS), cancer-specific survival (CSS), and cancer-free survival (CFS). Upstaging of chronic kidney disease (CKD) was calculated, as well. Univariate and multivariate analyses were performed to show predicting factors for the latest estimated glomerular filtration rate (eGFR).

Results and limitations

Of 427 patients, 134 had a minimum follow-up of 2 yr, and 70 had a minimum of 3–6 yr of follow-up. The mean age was 59.1 ± 12.5 yr, body mass index (BMI) was 29.8 ± 6.2 kg/m², and Charlson comorbidity index (CCI) score was 4.2 ± 1.6. The mean tumor size on computed tomography (CT) scan was 3.0 ± 1.6 cm, RENAL score was 7.2 ± 1.8, estimated blood loss (EBL) was 270.7 ± 291.9 ml, operative time was 189.1 ± 54.8 min, and warm ischemia time (WIT) was 17.9 ± 10.3 min. A total of two intraoperative complications (1.5%) and five high-grade Clavien complications (3.7%) occurred. Patients stayed on average for 3.7 ± 1.7 d in the hospital, and the average follow-up was 3.0 ± 0.9 yr. OS was 97.01% at 3 yr and 90.20% at 5 yr; CFS was 98.92% at 3 yr and 98.92% at 5 yr; and CSS was 99.04%, as projected by the Kaplan-Meier method. The mean preoperative GFR was 88.2 ± 0.8 ml/min per 1.73 m²; the latest postoperative GFR was 80 ± 24 ml/min per 1.73m², with a 8 ± 17.4% change. There was a 20.2% upstaging of CKD postoperatively, but no patients started dialysis.

Conclusions

This study reaffirms that RPN is effective in renal function preservation and oncologic control at an intermediate follow-up interval.     

Robotic Partial Nephrectomy for Renal Tumors Larger Than 4 cm

Background

Minimally invasive partial nephrectomy (PN) is most commonly performed for renal tumors ≤4 cm in size. Robotic PN (RPN) for tumors >4 cm has not been assessed.

Objective

To evaluate the safety and feasibility of RPN for tumors >4 cm in the context of patients undergoing RPN for tumors ≤4 cm.

Design, setting, and participants

We reviewed data for 71 consecutive patients who underwent transperitoneal RPN at a tertiary care center between August 2007 and September 2009 by a single surgeon. Patients were stratified into two groups: 15 with tumors >4 cm on preoperative imaging (group 1) and 56 patients with tumors ≤4 cm (group 2).

Intervention

All patients underwent transperitoneal RPN by a single surgeon.

Measurements

Preoperative, perioperative, pathologic, and functional outcomes data were analyzed and compared between groups. We used χ² and student t tests for categorical and continuous variables, respectively. A p value <0.05 was considered statistically significant.

Results and limitations

Mean radiographic tumor size was 5.0 cm (4.1–7.9) for group 1 and 2.1 cm (0.7–3.8) for group 2. No significant differences were found between groups for estimated blood loss, total operative time, hospital stay, complication rates, and change in estimated glomerular filtration rate. Patients with larger tumors had longer median warm ischemia times (25 vs 20 min; p = 0.011). Limitations of our study include the retrospective nature the analysis, small sample size, and single-surgeon experience.

Conclusions

In our initial experience, RPN for tumors >4 cm is safe and feasible, showing comparable outcomes to RPN for smaller tumors, although with longer warm ischemia times. Future studies with extended follow-up are necessary to determine the viability of RPN for large tumors as an effective form of treatment.     

Application of a Vasculature Model and Standardization of the Renal Hilar Approach in Laparoscopic Partial Nephrectomy for Precise Segmental Artery Clamping

Background

Clamping the segmental renal artery instead of the main renal artery during nephron-sparing surgery is a promising technique to decrease warm ischemia injury. Understanding vasculature characteristics and adopting an appropriate hilar approach to segmental arteries are essential to the technique.

Objective

To study the role of the vasculature model and to standardize the renal hilar approach in segmental renal artery dissection during laparoscopic partial nephrectomy (LPN).

Design, setting, and participants

A retrospective analysis of a consecutive series of 82 patients who underwent LPN with a precise clamping technique from December 2009 to June 2011 with a mean follow-up of 20 mo.

Surgical procedure

Three-dimensional dynamic renal vascular models were established based on dual-source computed tomographic angiography. Clamping number, clamping position, and a different hilar approach accessing target segmental arteries were determined preoperatively. Target arteries were dissected and clamped based on the model. Tumor excision and renorrhaphy were performed under regional parenchymal ischemia.

Outcome measurements and statistical analysis

Renal vascular characteristics and surgical outcomes were analyzed. The outcomes among different surgical approaches were compared using one-way analysis of variance test or Fisher exact test.

Results and limitations

All surgeries were performed successfully without converting to main renal artery clamping or radical nephrectomy. The median operative time was 90 min, and the mean clamping time was 24 min. The median estimated blood loss (EBL) was 200 ml, and six patients received blood transfusions. Five patients had hematuria without any intervention. One patient had a postoperative hemorrhage and received selective embolization intervention. Statistical analysis showed that appropriate surgical approaches chosen from the models led to comparable operative times, EBL, and complication rates. The limitation of the study lies on its retrospective feature.

Conclusions

A renal vasculature model provides effective orientation for a precise clamping technique. A standardized hilar approach based on the model optimizes the surgical procedure and leads to satisfactory surgical outcomes.     

Robot-Assisted Partial Nephrectomy: An International Experience

Background

Robot-assisted partial nephrectomy (RAPN) is emerging as a viable approach for nephron-sparing surgery (NSS), though many reports to date have been limited by evaluation of a relatively small number of patients.

Objective

We present the largest multicenter RAPN experience to date, culling data from four high-volume centers, with focus upon functional and oncologic outcomes.

Design, setting, and participants

A retrospective chart review was performed for 183 patients who underwent RAPN at four centers between 2006 and 2008.

Surgical procedure

RAPN was performed using methods outlined in the supplemental video material. Though operative technique was similar across all institutions, there were minor variations in trocar placement and hilar control.

Measurements

Perioperative parameters, including operative time, warm ischemic time, blood loss, and perioperative complications were recorded. In addition, we reviewed functional and oncologic outcomes.

Results and limitations

Mean age at treatment was 59.3 yr. Mean tumor size was 2.87 cm. Mean total operative time was 210 min while mean ischemic time was 23.9 min. Calyceal repair was required in 52.1% of procedures. Mean estimated blood loss was 131.5 ml. Sixty-nine percent of excised tumors were malignant, of which 2.7% exhibited positive surgical margins. The incidence of major complications was 8.2%. At up to 26 mo follow-up, there have been no documented recurrences and no significant change in serum creatinine (1.03 vs 1.04 mg/dl, p = 0.84) or estimated glomerular filtration rate (eGFR) from baseline (82.2 vs 79.4 mg/ml per square meter, p = 0.74). The study is limited by its retrospective nature, and the outcomes are likely influenced by the robust prior laparoscopic renal experience of each of the surgeons included in this study.

Conclusions

RAPN is a safe and efficacious approach for NSS, offering short ischemic times, as well as perioperative morbidity equivalent to other standard approaches. Moreover, RAPN is capable of providing patients with excellent functional and oncologic outcomes.     

R-LESS Partial Nephrectomy Trifecta Outcome Is Inferior to Multiport Robotic Partial Nephrectomy: Comparative Analysis

Background

Trifecta achievement in partial nephrectomy (PN) is defined as the combination of warm ischemia time ≤20 min, negative surgical margins, and no surgical complications.

Objective

To compare trifecta achievement between robotic, laparoendoscopic, single-site (R-LESS) PN and multiport robotic PN (RPN).

Design, setting, and participants

Data from 167 patients who underwent RPN from 2006 to 2012 were retrospectively analyzed.

Outcome measurements and statistical analysis

Primary outcome measurement was trifecta achievement; secondary outcome was the perioperative and postoperative comparison between groups. The measurements were estimated and analyzed with SPSS v.18 using univariable, multivariable, and subgroup analyses.

Results and limitations

Eighty-nine patients were treated with RPN and 78 were treated with R-LESS PN. Baseline characteristics of both groups were similar. Trifecta was achieved in 38 patients (42.7%) in the multiport RPN group and 20 patients (25.6%) in the R-LESS PN group (p = 0.021). Patients in the R-LESS PN group had longer mean operative time, warm ischemia time, and increased estimated glomerular filtration rate (eGFR) percentage change. No significant differences were found between the two groups in days of hospitalization, blood loss, postoperative eGFR, positive surgical margins, and surgical complications. Patients with increased PADUA and RENAL scores, infiltration of the collecting system, and renal sinus involvement had an increased probability of not achieving the trifecta. In regression analysis, the type of procedure and the tumor size could predict trifecta accomplishment (p = 0.019 and 0.043, respectively). The retrospective study, the low number of series, and the controversial definition of trifecta were the main limitations.

Conclusions

The trifecta was achieved in significantly more patients who underwent multiport RPN than those who underwent R-LESS PN. R-LESS PN could be an alternative option for patients with decreased tumor size, low PADUA and RENAL scores, and without renal sinus or collecting system involvement.

Patient summary

In this study, we looked at the outcomes of patients who had undergone robotic partial nephrectomy. We found that conventional robotic partial nephrectomy is superior to R-LESS partial nephrectomy with regard to the accomplishment of negative margins, reduced warm ischemia time, and minimal surgical complications.     

Robotic Partial Nephrectomy with Superselective Versus Main Artery Clamping: A Retrospective Comparison

Background

Concerns have been raised regarding partial nephrectomy (PN) techniques that do not occlude the main renal artery.

Objective

Compare the perioperative outcomes of superselective versus main renal artery control during robotic PN.

Design, setting, and participants

A retrospective analysis of 121 consecutive patients undergoing robotic PN using superselective control (group 1, n = 58) or main artery clamping (group 2, n = 63).

Intervention

Group 1 underwent tumor-specific devascularization, maintaining ongoing arterial perfusion to the renal remnant at all times. Group 2 underwent main renal artery clamping, creating global renal ischemia.

Outcome measurements and statistical analysis

Perioperative and functional data were evaluated. The Pearson chi-square or Fisher exact and Wilcoxon rank sum tests were used.

Results and limitations

All robotic procedures were successful, all surgical margins were negative, and no kidneys were lost. Compared with group 2 tumors, group 1 tumors were larger (3.4 vs 2.6 cm, p = 0.004), more commonly hilar (24% vs 6%, p = 0.009), and more complex (PADUA 10 vs 8, p = 0.009). Group 1 patients had longer median operative time (p < 0.001) and transfusion rates (24% vs 6%, p < 0.01) but similar estimated blood loss (200 vs 150 ml), perioperative complications (15% vs 13%), and hospital stay. Group 1 patients had less decrease in estimated glomerular filtration rate at discharge (0% vs 11%, p = 0.01) and at last follow-up (11% vs 17%, p = 0.03). On computed tomography volumetrics, group 1 patients trended toward greater parenchymal preservation (95% vs 90%, p = 0.07) despite larger tumor size and volume (19 vs 8 ml, p = 0.002). Main limitations are the retrospective study design, small cohort, and short follow-up.

Conclusions

Robotic PN with superselective vascular control enables tumor excision without any global renal ischemia. Blood loss, complications, and positive margin rates were low and similar to main artery clamping. In this initial developmental phase, limitations included more perioperative transfusions and longer operative time. The advantage of superselective clamping for better renal function preservation requires validation by prospective randomized studies.

Patient summary

Preserving global blood flow to the kidney during robotic partial nephrectomy (PN) does not lead to a higher complication rate and may lead to better postoperative renal function compared with clamped PN techniques.     

Precise Segmental Renal Artery Clamping Under the Guidance of Dual-source Computed Tomography Angiography During Laparoscopic Partial Nephrectomy

Background

Minimizing warm ischemic (WI) injury is one technical focus of partial nephrectomy (PN). Inducing regional ischemia in the tumor area by clamping segmental renal arteries has become an alternative method to decrease WI injury.

Objective

To study the technical feasibility of precise segmental artery clamping under the guidance of dual-source computed tomography (DSCT) angiography during laparoscopic partial nephrectomy (LPN) and to analyze the factors affecting surgical outcomes.

Design, setting, and participants

Retrospective analysis of 125 patients with unilateral kidney tumor treated from December 2009 to November 2011 with a mean follow-up of 18 mo.

Intervention

All patients received retroperitoneal LPN with the feeding segmental arteries precisely clamped. Most of the target branches were dissected close to the hilar parenchyma. The tumor was excised after precise clamping and renorrhaphy was performed.

Outcome measurements and statistical analysis

Univariable and multivariable logistic regression analyses were performed for categorical variables, and continuous variables were analyzed by linear regression.

Results and limitations

The target branches were isolated and clamped successfully in all patients without clamping the main renal artery. Median estimated blood loss (EBL) was 200 ml, and nine patients received blood transfusion. The accuracy of feeding artery orientation by DSCT angiography reached 93.6%. Tumor size, location, and growth pattern independently influenced the number of clamped branches. The number of clamped branches was significantly associated with postoperative renal function and EBL. Limitations of this study include its retrospective nature and that data are from a single-surgeon series.

Conclusions

The precise segmental artery clamping technique under the guidance of DSCT angiography is feasible and efficient to excise the tumor and to protect the normal parenchyma. The number of clamped branches is associated with tumor characteristics and can predict EBL and loss of renal function.     

Robotic partial nephrectomy versus laparoscopic cryoablation for the small renal mass

Background

Open partial nephrectomy (OPN) remains the gold standard for treatment of small renal masses (SRMs). Laparoscopic cryoablation (LCA) has provided encouraging outcomes. Robotic partial nephrectomy (RPN) represents a new promising option but is still under evaluation.

Objective

Compare the outcomes of RPN and LCA in the treatment of patients with SRMs.

Design, setting, and participants

We retrospectively analyzed the medical charts of patients with SRMs (≤4 cm) who underwent minimally invasive nephron-sparing surgery (RPN or LCA) in our institution from January 1998 to December 2010.

Intervention

RPN and LCA.

Measurements

Perioperative complications and functional and oncologic outcomes were analyzed.

Results and limitations

A total of 446 SRMs were identified in 436 patients (RPN, n = 210; LCA, n = 226). Patients undergoing RPN were younger (p < 0.0001), had a lower American Society of Anesthesiologists score (p < 0.001), and higher baseline preoperative estimated glomerular filtration rate (eGFR) (p < 0.0001). Mean tumor size was smaller in the LCA group (2.2 vs 2.4 cm; p = 0.004). RPN was associated with longer operative time (180 vs 165 min; p = 0.01), increased estimated blood loss (200 vs 75 ml; p < 0.0001), longer hospital stay (72 vs 48 h; p < 0.0001), and higher morbidity rate (20% vs 12%, p = 0.015). Mean follow-ups for RPN and LCA were 4.8 mo and 44.5 mo, respectively (p < 0.0001). Local recurrence rates for RPN and LCA were 0% and 11%, respectively (p < 0.0001). Mean eGFR decrease after RPN and LCA was insignificant at 1 mo, at 6 mo after surgery, and during last follow-up. Limitations include retrospective study design, length of follow-up, and selection bias.

Conclusions

Both techniques remain viable treatment options in the management of SRMs. A higher incidence of perioperative complications was found in patients undergoing RPN. However, the technique was not predictive of the occurrence of postoperative complications. Early oncologic outcomes are promising for RPN, which also seems to be associated with better preservation of renal function. Long-term follow-up and well-designed prospective comparative studies are awaited to corroborate these findings.     

Robotic Partial Nephrectomy with Sliding-Clip Renorrhaphy: Technique and Outcomes

Background

Robotic partial nephrectomy (RPN) is emerging as an alternative to traditional laparoscopic partial nephrectomy (LPN). Despite the potential advantages of the robotic approach, renorrhaphy remains a challenging portion of the procedure.

Objective

To present our technique and outcomes for RPN, including sliding-clip renorrhaphy.

Design, setting, and participants

Between 2007 and 2008, 50 patients underwent RPN performed by a single attending surgeon.

Surgical procedure

In this paper, we describe our technique for RPN, including a sliding-clip renorrhaphy, which is distinguished by the use of Weck Hem-O-Lock clips that are slid into place under complete control of the surgeon seated at the console and secured with a LapraTy clip. For the first 13 procedures, traditional tied-suture or assistant-placed clip closures were performed; sliding-clip renorrhaphy was performed in the remaining 37 cases.

Results and limitations

Mean tumor size was 2.5 cm. Mean operative time was 145.3 min, and mean overall warm ischemia time was 17.8 min. Mean estimated blood loss was 140.3 ml. The learning curve for overall operative time was 19 cases; the learning curve for portions of the case performed under warm ischemia (including tumor resection and renorrhaphy) was 26 cases. The introduction of a sliding-clip renorrhaphy produced significant reductions in overall operative time and warm ischemia time, while blood loss and hospital stay remained stable over our experience. Limitations of RPN include cost and increased reliance on the bedside assistant.

Conclusions

Sliding-clip renorrhaphy provides an efficient and effective repair that is under nearly complete control of the surgeon. This technique appears to contribute to significantly shorter overall operative times and, perhaps most critically, to shorter warm ischemia times. The learning curve for RPN using this technique appears to be foreshortened compared with LPN.     

Robotic Laparoendoscopic Single-Site Surgery Using GelPort as the Access Platform

Background

Laparoendoscopic single-site surgery (LESS) allows for the performance of major urologic procedures with a single small incision and minimal scarring. The da Vinci Surgical System provides advantages of easy articulation and improved ergonomics; however, an ideal platform for these procedures has not been identified.

Objective

To evaluate the GelPort laparoscopic system as an access platform for robotic LESS (R-LESS) procedures.

Design, setting, and participants

Since April 2008, 11 R-LESS procedures have been completed successfully in a single institutional referral center. For the last four consecutive cases, the GelPort has been used as an access platform through a 2.5–5-cm umbilical incision.

Intervention

R-LESS cases performed with the GelPort included pyeloplasty (n = 2), radical nephrectomy (n = 1), and partial nephrectomy (n = 1).

Measurements

Perioperative data were obtained for all patients including demographic data, operative indications, operative records, length of stay, complications, and pathologic analysis.

Results and limitations

For both pyeloplasty cases, average operative time (OR time) was 235 min and estimated blood loss (EBL) was 38 cm³. For the patient undergoing radical nephrectomy for a 5.1-cm renal tumor, OR time was 200 min and EBL was 250 cm³. The final patient underwent partial nephrectomy without renal hilar clamping for an 11-cm angiomyolipoma with OR time of 180 min and EBL of 600 cm³. All R-LESS procedures attempted with the GelPort were completed successfully and without complication. Average length of hospital stay was 1.75 d (range: 1–2). The partial nephrectomy patient required transfusion of 1 U of packed red blood cells.

Conclusions

Use of the GelPort as an access platform for R-LESS procedures provides adequate spacing and flexibility of port placement and acceptable access to the surgical field for the assistant, especially during procedures that require a specimen extraction incision. Additional platform and instrumentation development will likely simplify R-LESS procedures further as experience grows.     

Multi-institutional analysis of robotic partial nephrectomy for hilar versus nonhilar lesions in 446 consecutive cases

Background

Minimally invasive approaches to partial nephrectomy have been rapidly gaining popularity but require advanced laparoscopic surgical skills. Renal hilar tumors, due to their anatomic location, pose additional technical challenges to the operating surgeon.

Objective

We compared the outcomes of robot-assisted partial nephrectomy (RPN) for hilar and nonhilar tumors in our large multicenter contemporary series of patients.

Design, setting, and participants

We retrospectively reviewed prospectively collected data on 446 consecutive patients who underwent RPN by renal surgeons experienced in minimally invasive techniques at four academic institutions from June 2006 to March 2010. Patients were stratified into two groups: those with hilar lesions and those with nonhilar lesions.

Measurements

Patient demographics, operative outcomes, and postoperative outcomes, including oncologic outcomes, were recorded.

Results and limitations

Forty-one patients (9%) had hilar renal masses; 405 patients (91%) had nonhilar masses. There was no statistical differences in patient demographics except for larger median tumor size in the hilar cohort (3.2 cm vs 2.6 cm; p = 0.001). The only significant difference in operative outcomes was an increase in warm ischemia times for the hilar group versus the nonhilar group (26.3 ± 7.4 min vs 19.6 ± 10.0 min; p = <0.0001). There were no differences in postoperative outcomes; however, there was a trend for increased risk of malignancy and higher stage tumors in the hilar lesion group. Final pathologic margin status was similar in both groups. Only one patient in the nonhilar group had evidence of recurrence at 21 mo. The study was limited by the lack of standard anatomic classification of renal tumors and the potential influence of the surgeons’ prior robotic experience.

Conclusions

The data represent the largest series of its kind and strongly suggest that RPN is a safe, effective, and feasible option for the minimally invasive approach to renal hilar tumors with no increased risk of adverse outcomes compared with nonhilar tumors in the hands of experienced robotic surgeons.     

Determinants of Laparoscopic Donor Nephrectomy Outcomes

Background

Pure laparoscopic donor nephrectomy (LDN) is a unique intervention because it carries known risks and complications, yet carries no direct benefit to the donor. Therefore, it is critical to continually examine and improve quality of care.

Objective

To identify factors affecting LDN outcomes and complications.

Design, setting, and participants

A retrospective analysis of prospectively collected data for 1204 consecutive LDNs performed from March 2000 through August 2012.

Intervention

LDN performed at an academic training center.

Outcome measurements and statistical analysis

Using multivariable regression, we assessed the effect of age, sex, body mass index (BMI), laterality, and vascular variation on operative time, estimated blood loss (EBL), complications, and length of stay.

Results and limitations

The following variables were associated with longer operative time (data given as parameter estimate plus or minus the standard error): female sex (9.09 ± 2.43; p < 0.001), higher BMI (1.03 ± 0.32; p = 0.001), two (7.87 ± 2.70; p = 0.004) and three or more (22.45 ± 7.13; p = 0.002) versus one renal artery, and early renal arterial branching (5.67 ± 2.82; p = 0.045), while early renal arterial branching (7.81 ± 3.85; p = 0.043) was associated with higher EBL. Overall, 8.2% of LDNs experienced complications, and by modified Clavien classification, 74 (5.9%) were grade 1, 13 (1.1%) were grade 2a, 10 (0.8%) were grade 2b, and 2 (0.2%) were grade 2c. There were no grade 3 or 4 complications. Three or more renal arteries (odds ratio [OR]: 2.74; 95% CI, 1.05–7.16; p = 0.04) and late renal vein confluence (OR: 2.42; 95% CI, 1.50–3.91; p = 0.0003) were associated with more complications. Finally, we did not find an association of the independent variables with length of stay. A limitation is that warm ischemia time was not assessed.

Conclusions

In our series, renal vascular variation prolonged operative time and was associated with more complications. While complicated donor anatomy is not a contraindication of LDN, surgical decision-making should take into consideration these results.     

Impact of the Learning Curve on Perioperative Outcomes in Patients Who Underwent Robotic Partial Nephrectomy for Parenchymal Renal Tumours

Background

Robot-assisted partial nephrectomy (RAPN) is an emerging, minimally invasive technique to treat patients with small renal masses.

Objective

To evaluate the impact of the learning curve on perioperative outcomes such as operative times and warm ischaemia times (WIT), blood loss, overall complications, and renal function impairment in patients who underwent RAPN.

Design, setting, and participants

We collected prospectively the clinical and pathologic records of 62 consecutive patients who underwent RAPN between September 2006 and November 2009 for renal tumours at a nonacademic teaching institution by a single surgeon with extensive prior robotic experience.

Interventions

The surgeon used transperitoneal RAPN with excision of an adequate rim of healthy peritumour renal parenchyma.

Measurements

Perioperative parameters, pathologic outcome, and short-term outcomes for renal function were recorded. The effects of the learning curve on the previous reported perioperative and functional outcomes was studied.

Results and limitations

The mean pathologic tumour size was 2.8 ± 1.3 cm. A pelvicaliceal repair was needed in 33 cases (53%). The mean console time was 91 ± 33 min (range: 52–180), with a mean WIT of 20 ± 7 min (range: 9–40). Warm ischaemia (<20 min) and console times were optimised after the first 30 (p < 0.001) and 20 cases (p < 0.001), respectively. Pathologic results yielded a positive surgical margin (PSM) rate of 2%. Mean creatinine level changed from a baseline value of 1.02 ± 0.38 mg/dl to 1.1 ± 0.7 mg/dl 3 mo after surgery. Estimated glomerular filtration rate changed from a baseline value of 81.17 ± 29 to 80.5 ± 29 (millilitres per minute per 1.73 m²) 3 mo postoperatively.

Conclusions

RAPN is a viable option for nephron-sparing surgery in patients with renal carcinoma. Specifically, in the hands of a surgeon with extensive robotic experience, RAPN requires a short learning curve to reach WIT <20 min, console times <100 min, limited blood loss, and acceptable overall complication rates.     

Technique and Outcomes of Robot-assisted Retroperitoneoscopic Partial Nephrectomy: A Multicenter Study

Background

Robot-assisted retroperitoneoscopic partial nephrectomy (RARPN) may be used for posterior renal masses or with prior abdominal surgery; however, there is relatively less familiarity with RARPN.

Objective

To demonstrate RARPN technique and outcomes.

Design, setting, and participants

A retrospective multicenter study of 227 consecutive RARPNs was performed at the Swedish Medical Center, the University of Michigan, and the University of California, Los Angeles, from 2006 to 2013.

Surgical procedure

RARPN.

Outcome measurements and statistical analysis

We assessed positive margins and cancer recurrence. Stepwise regression was used to examine factors associated with complications, estimated blood loss (EBL), warm ischemia time (WIT), operative time (OT), and length of stay (LOS).

Results and limitations

The median age was 60 yr (interquartile range [IQR]: 52–66), and the median body mass index (BMI) was 28.2 kg/m² (IQR: 25.6–32.6). Median maximum tumor diameter was 2.3 cm (IQR: 1.7–3.1). Median OT and WIT were 165 min (IQR: 134–200) and 19 min (IQR: 16–24), respectively; median EBL was 75 ml (IQR: 50–150), and median LOS was 2 d (IQR: 1–3). Twenty-eight subjects (12.3%) experienced complications, three (1.3%) had urine leaks, and three (1.3%) had pseudoaneurysms that required reintervention. There was one conversion to radical nephrectomy and three transfusions. Overall, 143 clear cell carcinomas (62.6%) composed most of the histology with eight positive margins (3.5%) and two recurrences (0.9%) with a median follow-up of 2.7 yr. In adjusted analyses, intersurgeon variation was associated with complications (odds ratio [OR]: 3.66; 95% confidence interval, 1.31–10.27; p = 0.014) and WIT (parameter estimate [PE; plus or minus standard error]: 4.84 ± 2.14; p = 0.025). Higher surgeon volume was associated with shorter WIT (PE: −0.06 ± 0.02; p = 0.002). Higher BMI was associated with longer OT (PE: 2.09 ± 0.56; p < 0.001). Longer OT was associated with longer LOS (PE: 0.01 ± 0.01; p = 0.002). Finally, there was a trend for intersurgeon variation in OT (PE: 18.5 ± 10.3; p = 0.075).

Conclusions

RARPN has acceptable morbidity and oncologic outcomes, despite intersurgeon variation in WIT and complications. Greater experience is associated with shorter WIT.

Patient summary

Robot-assisted retroperitoneoscopic partial nephrectomy has acceptable morbidity and oncologic outcomes, and there is intersurgeon variation in warm ischemia time and complications.     

Robotic partial nephrectomy without renal hilar occlusion

Study Type – Therapy (case series)
Level of Evidence 4

OBJECTIVE

To evaluate operative outcomes among patients undergoing robotic partial nephrectomy (RPN) without renal hilar clamping.

PATIENTS AND METHODS

This was a prospective observational study of patients undergoing RPN under perfused conditions (pRPN). Patients with solitary, radiographically enhancing renal cortical lesions gave consent for pRPN. Salient demographic data, including age, body mass index (BMI) and preoperative tumour size were obtained. Operative data, including mean operative time, estimated blood loss (EBL), and the presence of any complications, were collected. Renal function was evaluated before and after RPN. Remote adverse events were noted. The pRPN group was then retrospectively compared to a contemporary group of patients who had RPN with renal hilar occlusion. Endpoints for comparison included operative time, warm ischaemia time, EBL, length of hospitalization, and the rate of adverse events.

RESULTS

Between February 2008 and December 2008, eight had underwent pRPN; the mean age was 59.3 years, mean BMI 28.7 kg/m², mean operative time 167 min, mean EBL 569 mL and mean hospitalization 3.75 days. Pathology showed renal cell carcinoma in five patients and oncocytoma in three; the mean tumour size was 2.4 cm. Final pathological margins were negative in all patients. Adverse events included one transfusion and one deep venous thrombosis. When compared to the contemporary group who had RPN with hilar clamping, the operative time was shorter (P = 0.035) and EBL greater (P = 0.018) in the pRPN group. There was no significant difference between the groups in transfusion rate, and no significant difference in renal function before and after surgery either group.

CONCLUSIONS

For selected small renal cortical masses, RPN is safe without renal hilar occlusion. The EBL was higher during pRPN but with no significant difference in the rate of transfusion.     

Robot-assisted laparoscopic partial nephrectomy: step-by-step contemporary technique and surgical outcomes at a single high-volume institution

Background

Robotic technology is being increasingly adopted in urologic surgery.

Objective

To describe a contemporary surgical technique and report cumulative surgical outcomes of robot-assisted laparoscopic partial nephrectomy (RALPN) at our tertiary care institution.

Design, setting, and participants

Medical charts of consecutive patients who underwent RALPN between June 2006 and November 2011 were reviewed from a prospectively maintained, institutional review board-approved database.

Surgical procedure

The main steps of our current surgical technique are described in this video tutorial: patient positioning and trocar placement; bowel mobilization; hilar dissection; tumor identification and demarcation; clamping of the hilum; tumor excision; renorraphy; hilar unclamping; and tumor retrieval.

Outcome measurements and statistical analysis

Patients’ characteristics and main surgical outcomes were analyzed.

Results and limitations

A total of 400 patients (mean age: 58.5 yr, mean body mass index: 30.7 kg/m²) were included in this analysis. Mean renal tumor size was 3.17 cm (standard deviation [SD]: 1.64) and mean RENAL score was 7.2 (SD: 2). Six patients (1.5%) presented with a solitary kidney. Mean total operative time was 190.3 min (SD: 57), and mean warm ischemia time was 19.2 min (SD: 10.72). In 36 cases (9%), an unclamped hilum technique was used. After a mean follow-up of 12.4 mo (SD: 12.2), there was a decline of −9.2 ml/min per 1.73 m² (SD: 26.56) in estimated glomerular filtration rate. Most renal masses were malignant (74.5%), and the overall mean tumor size was 3.05 cm (SD: 1.66). Renal cell carcinoma with a clear cell histology represented the most frequent malignant diagnosis (64.4% of cases). A positive margin was observed in nine cases (2.25%). A total of 11 intraoperative complications (2.7%) occurred, and a conversion to open or laparoscopic PN was required in six cases (1.5%). A postoperative complication occurred in 61 cases (15.3%), the majority of them being low grade.

Conclusions

The standardization of each surgical step has allowed for optimization of RALPN and ultimately improved its outcomes and expanded its indications.     

Robotic versus laparoscopic partial nephrectomy for complex tumors: comparison of perioperative outcomes

Background

Recent studies showed that robotic partial nephrectomy (RPN) offered outcomes at least comparable to those of laparoscopic partial nephrectomy (LPN). LPN can be particularly challenging for more complex tumors.

Objective

To compare the perioperative outcomes of patients undergoing LPN or RPN for a single renal mass of moderate or high complexity.

Design, setting, and participants

A retrospective analysis was performed for 381 consecutive patients who underwent either LPN (n = 182) or RPN (n = 199) between 2005 and 2011 for a complex renal mass (RENAL score ≥7). Perioperative outcomes were compared. Predictors of postoperative renal function were assessed using multivariable linear regression analysis.

Intervention

LPN or RPN.

Outcome measurements and statistical analysis

Perioperative outcomes were compared. Predictors of postoperative renal function were assessed using multivariable linear regression analysis.

Results and limitations

There was no significant difference between the two groups with respect to patient age, gender, side, American Society of Anesthesiologists score, Charlson comorbidity index (CCI), or tumor size. Patients undergoing LPN had a slightly lower body mass index (29.2 kg/m² compared with 30.7 kg/m², p = 0.02) and preoperative estimated glomerular filtration rate (eGFR) (81.1 compared with 86.0 ml/min per 1.73 m², p = 0.02). LPN was associated with an increased rate of conversion to radical nephrectomy (RN) (11.5% compared with 1%, p < 0.001) and a higher decrease in percentage of eGFR (−16.0% compared with −12.6%, p = 0.03). There were no significant differences with respect to warm ischemia time (WIT), estimated blood loss, transfusion rate, or postoperative complications. WIT, preoperative eGFR, and CCI were found to be predictors of postoperative eGFR in multivariable analysis. No difference in perioperative outcomes was found between moderate and high RENAL score subgroups. The retrospective study design was the main limitation of this study.

Conclusions

RPN provides functional outcomes comparable to those of LPN for moderate- to high-complexity tumors, but with a significantly lower risk of conversion to RN. This situation is likely because of the technical advantages offered by the articulated robotic instruments. A prospective randomized study is needed to confirm these findings.     

Laparoendoscopic Single-site Partial Nephrectomy: A Multi-institutional Outcome Analysis

Background

Laparoendoscopic single-site surgery (LESS) has been developed in an attempt to further reduce the surgical trauma associated with conventional laparoscopy. Partial nephrectomy (PN) represents a challenging indication for LESS.

Objective

To report a large multi-institutional series of LESS-PN and to analyze the predictors of outcomes after LESS-PN.

Design, setting, and participants

Consecutive cases of LESS-PN done between November 2007 and March 2012 at 11 participating institutions were included in this retrospective analysis.

Intervention

Each group performed LESS-PN according to its own protocols, entry criteria, and techniques.

Outcome measurements and statistical analysis

Demographic data, main perioperative outcome parameters, and perioperative complications were gathered and analyzed. A multivariable analysis was used to assess the factors predicting a short (≤20 min) warm ischemia time (WIT), the occurrence of postoperative complication of any grade, and a favorable outcome, arbitrarily defined as a combination of the following events: short WIT plus no perioperative complications plus negative surgical margins plus no conversion to open surgery or standard laparoscopy.

Results and limitations

A total of 190 cases were included in this analysis. Mean renal tumor size was 2.6, and PADUA score 7.2. Median operative time was 170 min, with median estimated blood loss (EBL) of 150 ml. A clampless technique was adopted in 70 cases (36.8%), and the median WIT was 16.5 min. PADUA score independently predicted length of WIT (low vs high score: odds ratio [OR]: 5.11 [95% confidence interval (CI), 1.50–17.41]; p = 0.009; intermediate vs high score: OR: 5.13 [95% CI, 1.56–16.88]; p = 0.007). The overall postoperative complication rate was 14.7%. The adoption of a robotic LESS technique versus conventional LESS (OR: 20.92 [95% CI, 2.66–164.64]; p = 0.003) and the occurrence of lower (≤250 ml) EBL (OR: 3.60 [95% CI, 1.35–9.56]; p = 0.010) were found to be independent predictors of no postoperative complications of any grade. A favorable outcome was obtained in 83 cases (43.68%). On multivariate analysis, the only predictive factor of a favorable outcome was the PADUA score (low vs high score: OR: 4.99 [95% CI, 1.98–12.59]; p < 0.001). Limitations of the study were the retrospective design and different selection criteria for the participating centers.

Conclusions

LESS-PN can be safely and effectively performed by experienced hands, given a high likelihood of a single additional port. Anatomic tumor characteristics as determined by the PADUA score are independent predictors of a favorable surgical outcome. Thus patients presenting tumors with low PADUA scores represent the best candidates for LESS-PN. The application of a robotic platform is likely to reduce the overall risk of postoperative complications.     

Predictors of warm ischemia time and perioperative complications in a multicenter, international series of robot-assisted partial nephrectomy

Background

Warm ischemia time (WIT) and complication rates are two important parameters for evaluating the perioperative results of robot-assisted partial nephrectomy (RAPN). Few data are available about the clinical predictors of WIT and overall complications.

Objective

To identify clinical predictors of WIT and perioperative complications.

Design, setting, and participants

This is a retrospective study including 347 patients who underwent RAPN for suspicious renal cell carcinoma (RCC) at four referral centers from September 2008 to September 2010.

Intervention

All patients underwent RAPN using the da Vinci S Surgical System with hilar clamping.

Measurements

WIT >20 min and overall complication rates were the main outcomes. Postoperative complications were classified according to the Clavien/Dindo system. Moreover, the following perioperative variables were considered: clinical tumor size, anatomical tumor characteristics according to Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) classification score, surgeon experience, console time, blood loss, and upper collecting system (UCS) repair.

Results and limitations

WIT >20 min was reported in 125 (36%) cases. Intraoperative and postoperative complications were observed in 10 (2.9%) and 41 (11.8%) cases, respectively. Surgeon experience (odds ratio [OR]: 6.381; 95% confidence interval [CI], 3.687-11.042; p < 0.001), clinical tumor size (OR: 1.022; 95% CI, 1.002-1.044; p = 0.03), the other anatomic characteristics determined by the PADUA classification score (OR: 1.294; 95% CI, 1.080-1.549; p = 0.005), and the UCS repair (OR: 2.987; 95% CI, 1.728-5.165; p < 0.001) turned out to be independent predictors of WIT >20 min. Similarly, surgeon experience (OR: 3.937; 95% CI, 2.011-7.705; p < 0.001), clinical tumor size (OR: 1.033; 95% CI, 1.009-1.058; p = 0.007), and the other anatomical characteristics determined by the PADUA classification score (OR: 1.427; 95% CI, 1.149-1.773; p < 0.001) turned out to be independent predictors of overall complication rates. The retrospective design is the main limitation of this multicenter, international study. Therefore, some patient characteristics and comorbidities were not recorded.

Conclusions

Anatomic tumor characteristics as determined by the PADUA classification score were independent predictors of WIT and overall complications, once adjusted for the effects of surgeon experience and clinical tumor size.