LAPAROSCOPIC PARTIAL NEPHRECTOMY: EFFECT OF WARM ISCHEMIA ON SERUM CREATININE

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

BACKGROUND

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

METHODS

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

RESULTS

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

DISCUSSION

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

Perioperative anemia predicts kidney injury after partial nephrectomy

Purpose

Partial nephrectomy (PN) induced kidney injury is still a challenging clinical matter that has not been completely conquered. This study aimed to explore the influences of perioperative anemia on renal function after PN.

Materials and Methods

A total of 114 patients undergoing PN were retrospectively studied. Serum creatinine was tested preoperatively and 24 hours and 3 days after PN to evaluate the occurrence of acute kidney injury (AKI). Perioperative anemia was evaluated on the basis of the hemoglobin (Hb) value at 24 hours and 3 days postoperation. Patients were then followed up for the development of chronic kidney disease (CKD). Associations between perioperative anemia and postoperative AKI and CKD were determined.

Results

The cumulative incidence of perioperative anemia was 33.33% in the study. A total of 32.46% of patients suffered from postoperative AKI, and 16.67% of patients progressed to CKD. The incidences of AKI and CKD in perioperative anemia patients were dramatically exceeded in those without anemia. Further statistical analyses indicated that perioperative anemia was a relevant factor for postoperative kidney injury, presenting the highest odds ratio of 31.272 for postoperative AKI and 17.179 for postoperative CKD. Receiver operating characteristic curve analysis showed that ΔHb=(preoperative Hb)-(postoperative Hb nadir) was a meaningful predictor of postoperative kidney injury, with an area under the curve of 0.784 for predicting postoperative AKI and 0.805 for postoperative CKD.

Conclusions

Perioperative anemia can predict kidney injury after PN, and ΔHb shows a meaningful predictive value for postoperative AKI and CKD.

Effectiveness and safety of partial nephrectomy-no ischemia vs. warm ischemia: Systematic review and meta-analysis

PURPOSE

This study aimed to determine the effectiveness and safety of partial nephrectomy (PN) without ischemia compared with PN with warm ischemia for reducing the deterioration in renal function in patients with cT1 renal tumors.

MATERIALS AND METHODS

We conducted a systematic review that included patients over 18 years of age who underwent PN with or without warm ischemia for cT1 renal tumors. The primary outcome was impaired renal function. A search strategy was performed in MEDLINE, EMBASE, LILACS, CENTRAL, the article reference lists, and the unpublished literature to reach saturation of the information. We assessed the risk of bias with the methodological index for nonrandomized studies (MINORS) tool, and we performed a meta-analysis according to the type of variable.

RESULTS

We found a total of 5,682 articles, of which 14 met the inclusion criteria. Seven studies evaluated renal function, identifying a difference in means (MD) of 3.50 (95% confidence interval [CI], 1.16 to 5.83), favoring no ischemia. We did not find any significant differences regarding intraoperative bleeding or operative time (MD, 55 mL; 95% CI, -33.16 to 144.08; and MD, 1.87; 95% CI, -20.47 to 24.21; respectively).

CONCLUSIONS

In this study, PN without ischemia showed a decrease in deterioration of the estimated glomerular filtration rate compared with warm ischemia.

Modified Nephrometry Score With Body Mass Index More Accurately Predicts Ischemic Time in Transabdominal Laparoscopic Partial Nephrectomy for Small Renal Masses

OBJECTIVE

To accurately predict the ischemic time (IT) and select candidates for transabdominal laparoscopic partial nephrectomy (LPN).

METHODS

Transabdominal LPN was performed for 135 Japanese patients with renal masses <7 cm in diameter between 2009 and 2016 by a single surgeon in a single institute. The renal parenchymal sutures were done with a combination of felt, Hem-o-lok and Lapra-Ty. The original R.E.N.A.L. nephreometry score (NS) was modified as follows. In terms of the tumor size (R), 1, 2, and 3 points were given for ≤2.5, 2.5-4, and >4 cm, respectively. For tumor location (A), 1, 2, and 3 points were given for anterior, on the coronal plane, and posterior, respectively.

RESULTS

The median IT was 24.6 minutes. Using the original NS, 64, 65, and 6 patients were categorized into low (4-6), moderate (7-9), and high (10-12) complexity, respectively. With the modified NS, 42, 75, and 18 patients were categorized into low (5-7), moderate (8-11), and high (12-15) complexity, respectively. Pearson's correlation coefficient (R) between the original NS and IT was 0.297, whereas the R was improved to 0.388 when the modified NS was employed. If the modified NS was low complexity, 95.2% achieved IT <30 minutes. Of them, none showed IT ≥30 minutes if the body mass index was <25 kg/m².

CONCLUSION

The modified NS had a better correlation to the IT than the original NS for patients with tumor sizes <7 cm who underwent transabdominal LPN. The modified NS with body mass index is a practical tool to select candidates for transabdominal LPN.

The preoperative stratification of patients based on renal scan data is unable to predict the functional outcome after partial nephrectomy

INTRODUCTION

eGFR-categories are used to predict functional outcome after partial nephrectomy (PN); no study categorized patients according to preoperative renal scan (RS) data. Aim of the study was to evaluate if stratification of patients according to RS is a reliable method to predict minor/major loss of renal function after PN.

MATERIALS AND METHODS

We considered patients who underwent PN and RS pre-/post-PN for T1 tumor in our Institution (2007-2017). Demographics, perioperative and specifically functional data were analysed. On the basis of the baseline Split Renal Function (SRF), patients were stratified into risk-categories: 1) baseline operated-kidney SRF range 45-55%; 2) baseline operated-kidney SRF < 45%. Risk categories were analysed with postoperative functional outcome: postoperative operated-kidney SRF decrease below 90% of baseline was considered significant loss of function. Contingency tables and univariate/multivariate regression were analysed looking for independent factors of postoperative functional impairment.

RESULTS

224 patients were analysed, 125 (55.8%) maintained >90% of their baseline function. Worse probability of maintaining ≥90 baseline renal function was found in patients with Charlson's Comorbidity Index (CCI≥3) (p=0.004) and patients with PADUA score ≥8 (p=0.023). After stratification by baseline renal function, ischemia was the only independent factor: no effect on patients with poorer baseline renal function. Patients with baseline SRF 45-55% who did not experience ischemia had the highest probability to maintain ≥90% baseline SRF (p=0.028). Ischemia >25 minutes was detrimental (p=0.017).

CONCLUSIONS

Stratification of patients by SRF before PN is not a reliable predictor of renal functional outcome. Ischemia seems to scarcely influence patients with poorer renal function.

Laparoscopic Management of Kidney Cancer: Updated Review

BACKGROUND

Laparoscopy has emerged as the preferred option for the surgical management of kidney cancer. Although many reports have been published regarding the operative outcome of renal cell carcinoma (RCC) and upper-tract transitional cell carcinoma (TCCA) treated laparoscopically, few review the oncologic outcome of these pathologies treated with laparoscopic techniques.

METHODS

We review the literature regarding the laparoscopic approaches, the complications related to laparoscopic surgery, and the long-term oncologic results of laparoscopic radical nephrectomy, partial nephrectomy, and nephroureterectomy.

RESULTS

Laparoscopic radical nephrectomy has become the new standard of care for most patients with suspected RCCs that are not amenable to nephron-sparing procedures. Laparoscopic techniques for managing RCC and TCCA are safe, follow well-established guidelines for surgical dissection, and meet or exceed perioperative convalescence and oncologic outcomes compared to traditional open procedures. The surgical techniques and the long-term outcome data for laparoscopic partial nephrectomy continue to mature.

CONCLUSIONS

Laparoscopy is a minimally invasive option available to most patients with kidney cancer. The immediate benefits of laparoscopy are well established and include less estimated blood loss, decreased pain, shorter perioperative convalescence, and improved cosmesis. Long-term oncologic outcomes of patients treated laparoscopically for kidney tumors resemble those of the open surgical approach.

Optimising renal cancer patients for nephron-sparing surgery: a review of pre-operative considerations and peri-operative techniques for partial nephrectomy

Nonmodifiable factors including pre-operative renal function and amount of healthy renal tissue preserved are the most important predictive factors that determine renal function after partial nephrectomy. Ischaemia time is an important modifiable risk factor and cold ischaemia time should be used if longer ischaemia time is anticipated. New techniques may have a role in maximising postoperative kidney function, but more robust studies are required to understand their potential benefits and risks.

Impact of robotic partial nephrectomy with and without ischemia on renal functions: experience in 34 cases

OBJECTIVE

In this study we aimed to compare renal functions in patients who underwent robotic partial nephrectomy (RPN) with on-clamp and zero- ischemia techniques.

MATERIAL AND METHODS

Between 2009 and 2015, 12 off-clamp and 22 on-clamp RPN procedures were performed on a total of 34 patients in two centers. The main outcome parameters examined were serum creatinine, and estimated glomerular filtration rate (eGFR) during preoperative, immediate postoperative periods, and at postoperative 3^rd months.

RESULTS

There were no statistically significant differences between on-clamp and zero- ischemia groups regarding age, ASA score, BMI, PADUA and R.E.N.A.L. nephrometry scores, operation time and tumor size (p>0.05). Significant differences were found in the duration of hospital stay (3.8±0.9 days vs. 3.0±0.9 days) and amount of blood loss (85.9±49.6 mL vs. 183.3±176.2 mL) between the on-clamp and zero-ischemia groups (p<0.05). Statistically significant differences were found between preoperative and immediate post-operative periods, in terms of eGFR and serum creatinine levels in both groups. Moreover, statistically significant differences were found between preoperative and postoperative 3^rd month periods, in the on-clamp group in terms of eGFR and serum creatinine levels. In the zero-ischemia group, the decrease in eGFR and serum creatinine levels at postoperative 3^rd month relative to the preoperative period was not statistically significant.

CONCLUSION

Off-clamp RPN technique is superior, in short-term outcomes involving renal functions, compared to on clamp approach. However, long- term data regarding the renal functions should be evaluated to arrive at a definitive decision.

Urinary l-type fatty acid-binding protein is a predictor of early renal function after partial nephrectomy

Purpose: Urinary biomarkers of renal injury urinary may identify loss of renal function following nephron-sparing surgery (NSS). This study was designed to evaluate whether urinary l-type fatty acid-binding protein (l-FABP) is an early biomarker of loss of renal function after NSS. Specifically, the kinetics of urinary l-FABP level after NSS and its correlation with factors related to ischemic renal injury were analyzed.

Methods: This study prospectively evaluated 18 patients who underwent NSS between July and December 2014, including 12 who underwent laparoscopic and six who underwent robot-assisted partial nephrectomy. Urinary l-FABP concentrations were measured preoperatively and 1, 2, 3, 6, 12, 24, 48, and 72 h after renal artery declamping. Loss of renal function loss was calculated by comparing the effective renal plasma flow, as determined by ^99mTc-mercaptoacetyltriglycine (MAG3) clearance, on the operated and normal sides. The decrease in estimated glomerular filtration rate from before surgery to six months after surgery was also measured.

Results: Urinary l-FABP concentration peaked within 2 h of declamping, which may quantify nephron damage caused by ischemia. The decrease in MAG3 reduction ratio correlated with both the ischemia time and peak urinary l-FABP concentration. Peak urinary l-FABP concentration showed a significant correlation with MAG3 reduction ratio.

Conclusions:l-FABP is a suitable urinary biomarker for predicting the extent of ischemic renal injury.

Renal Ischemia and Function After Partial Nephrectomy: A Collaborative Review of the Literature

CONTEXT

Partial nephrectomy (PN) is the current gold standard treatment for small localized renal tumors.; however, the impact of duration and type of intraoperative ischemia on renal function (RF) after PN is a subject of significant debate.

OBJECTIVE

To review the current evidence on the relationship of intraoperative ischemia and RF after PN.

EVIDENCE ACQUISITION

A review of English-language publications on renal ischemia and RF after PN was performed from 2005 to 2014 using the Medline, Embase, and Web of Science databases. Ninety-one articles were selected with the consensus of all authors and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

EVIDENCE SYNTHESIS

The vast majority of reviewed studies were retrospective, nonrandomized observations. Based on the current literature, RF recovery after PN is strongly associated with preoperative RF and the amount of healthy kidney parenchyma preserved. Warm ischemia time (WIT) is modifiable and prolonged warm ischemia is significantly associated with adverse postoperative RF. Available data suggest a benefit of keeping WIT <25min, although the level of evidence to support this threshold is limited. Cold ischemia safely facilitates longer durations of ischemia. Surgical techniques that minimize or avoid global ischemia may be associated with improved RF outcomes.

CONCLUSIONS

Although RF recovery after PN is strongly associated with quality and quantity of preserved kidney, efforts should be made to limit prolonged WIT. Cold ischemia should be preferred when longer ischemia is expected, especially in presence of imperative indications for PN. Additional research with higher levels of evidence is needed to clarify the optimal use of renal ischemia during PN.

PATIENT SUMMARY

In this review of the literature, we looked at predictors of renal function after surgical resection of renal tumors. There is a strong association between the quality and quantity of renal tissue that is preserved after surgery and long-term renal function. The time of interruption of renal blood flow during surgery is an important, modifiable predictor of postoperative renal function.

The association between the anatomical features of renal tumours and the functional outcomes of robot-assisted partial nephrectomy

INTRODUCTON

We evaluated the the association between PADUA scores and postoperative renal function (after robot-assisted partial nephrectomy [RAPN]) and between PADUA scores and warm ischemic time (during RAPN).

METHODS

We reviewed the clinical records of 106 patients who underwent RAPN for a single localized renal tumour between April 2009 and June 2012. Postoperative renal function was evaluated using estimated glomerular filtration rate (eGFR) in 85 patients who were followed for at least 6 months. PADUA scores for renal tumours were calculated using contrast-enhanced computed tomography images, if needed, along with magnetic resonance images in some cases.

RESULTS

A PADUA score ≥10 and WIT ≥30 minutes were observed in 18 (17.0%) and 51 (48.1%) cases, respectively. PADUA scores were significantly correlated with WIT (p = 0.019) and percent change in eGFR at 6 months postoperatively (p = 0.005). PADUA score (continuous variable, odds ratio [OR] 1.694, p = 0.007) and the high-risk group (PADUA score ≥10) (OR 5.429; p = 0.020) were significantly associated with a WIT of ≥30 minutes by multivariate analysis. A 1-point increase in the PADUA score was associated with an eGFR decrease of >20% at 6 months after RAPN (OR 1.799; p = 0.076). In addition, a PADUA score ≥10, or high risk, (OR 13.965; p = 0.003) was an independent predictor of an eGFR decrease of >20% at 6 months after RAPN.

CONCLUSIONS

The PADUA classification can reliably predict WIT and postoperative renal functional outcome after RAPN. Furthermore, the study suggests that anatomical aspects of renal tumours are associated with functional outcome after RAPN.

Do we need to clamp the renal hilum liberally during the initial phase of the learning curve of robot-assisted nephron-sparing surgery?

Objective. We aimed to compare the results of our initial robot-assisted nephron-sparing surgeries (RANSS) performed with or without hilar clamping. Material and Method. Charts of the initial RANSSs (n = 44), which were performed by a single surgeon, were retrospectively reviewed. R.E.N.A.L. nephrometry system, modified Clavien classification, and M.D.R.D. equation were used to record tumoral complexity, complications, and estimated glomerular filtration rate (eGFR), respectively. Outcomes of the clamped (group 1, n = 14) versus off-clamp (group 2, n = 30) RANSSs were compared. Results. The difference between the two groups was insignificant regarding mean patient age, mean tumor size, and mean R.E.N.A.L. nephrometry score. Mean operative time, mean estimated blood loss amount, and mean length of hospitalization were similar between groups. A total of 4 patients in each group suffered 11 Clavien grade ≥2 complications early postoperatively. Open conversion rates were similar. The difference between the 2 groups in terms of the mean postoperative change in eGFR was insignificant. We did not encounter any local recurrence after a mean follow-up of 18.9 months. Conclusions. Creating warm-ischemic conditions during RANSS should not be a liberal decision, even in the initial phases of the learning curve for a highly experienced open surgeon.

Retroperitoneal laparoscopic partial nephrectomy for moderately complex renal hilar tumors

OBJECTIVES

To report our initial experience in retroperitoneal laparoscopic partial nephrectomy (LPN) for moderately complex renal hilar tumors and summarize the feasibility of the retroperitoneal laparoscopic approach.

MATERIALS AND METHODS

14 patients with renal hilar tumors underwent retroperitoneal LPN between June 2010 and January 2012 at our institution. All of the masses were confirmed in the hilar location by computed tomography preoperatively and then evaluated with the R.E.N.A.L. nephrometry scoring system; all were defined as moderately complex lesions. A three-port retroperitoneal approach with a dorsal incision was used in all cases. Patient baseline demographics, perioperative outcomes and pathological characteristics were recorded based on a retrospective data collection and telephone interview.

RESULTS

All operations were performed successfully without conversion to radical nephrectomy or open surgery. Only two complications of perirenal fluid collection occurred, but the patients recovered with active surveillance. Mean operative time was 134.3 min, mean estimated blood loss 133.2 ml, mean warm ischemia time 30.6 min and mean retroperitoneal drainage 2.2 days. Mean postoperative hospital stay was 4.7 days. No recurrence or metastasis occurred in these patients at a mean follow-up of 18.6 months.

CONCLUSIONS

Our initial experience suggests that retroperitoneal LPN is a feasible, safe and effective procedure for moderately complex renal hilar tumors. Although it remains technically challenging, this approach can be recommended in some complex cases when in experienced hands.

Changes in renal function after laparoscopic partial nephrectomy: comparison with laparoscopic radical nephrectomy

Purpose

To evaluate alterations in renal function after laparoscopic radical nephrectomy (LRN) and laparoscopic partial nephrectomy (LPN) for renal tumors.

Materials and Methods

From March 2008 to August 2011, we performed 175 cases of laparoscopic kidney resection. Among these, we excluded patients who received perioperative immunotherapy or target therapy and also patients with a preoperative estimated glomerular filtration rate (eGFR) <60 mL/min. A total of 32 patients undergoing LPN and 92 patients undergoing LRN were enrolled. We retrospectively reviewed the changes in eGFR (by the modification of diet in renal disease method) at the following time points: preoperative, postoperative 1 week, and postoperative 1, 3, 6, and 12 months.

Results

The mean warm ischemia time of the LPN group was 22 minutes (range, 0 to 47 minutes). Mean eGFR values (mL/min/1.73 m²) during postoperative week 1 and 1, 3, 6, and 12 months were 70.8, 71.5, 76.7, 76.0, and 75.3 in the LPN group and 52.1, 50.6, 52.8, 53.4, and 52.4 in the LRN group, respectively. One year after the operation, 6.3% (2 patients) of LPN patients and 68.5% (63 patients) of LRN patients had progressed to chronic renal insufficiency (eGFR<60 mL/min/1.73 m²).

Conclusions

Renal function recovered slightly after LPN and LRN and was maintained constantly after 3 months. However, renal function showed different patterns of decrease. Despite the concern for warm ischemia, LPN can preserve renal function better than can LRN. LPN should be considered for selected patients to prevent chronic renal insufficiency.

Robot-assisted partial nephrectomy in contemporary practice

Laparoscopic renal surgery is associated with reduced blood loss, shorter hospital stay, enhanced cosmesis, and more rapid convalescence relative to open renal surgery. Laparoscopic partial nephrectomy (LPN) is a minimally invasive, nephron-sparing alternative to laparoscopic radical nephrectomy (RN) for the management of small renal masses. While offering similar oncological outcomes to laparoscopic RN, the technical challenges and prolonged learning curve associated with LPN limit its wider dissemination. Robot-assisted partial nephrectomy (RAPN), although still an evolving procedure with no long-term data, has emerged as a viable alternative to LPN, with favorable preliminary outcomes. This article provides an overview of the role of RAPN in the management of renal cell carcinoma. The clinical indications and principles of surgical technique for this procedure are discussed. The oncological, renal functional, and perioperative outcomes of RAPN are also evaluated, as are complication rates.

Renal functional and perioperative outcomes of off-clamp versus clamped robot-assisted partial nephrectomy: matched cohort study

OBJECTIVE

To evaluate the potential benefit of performing off-clamp robot-assisted partial nephrectomy as it relates to renal functional outcomes, while assessing the safety profile of this unconventional surgical approach.

METHODS

Twenty-nine patients who underwent off-clamp robot-assisted partial nephrectomy for suspected renal cell carcinoma at Washington University between March 2008 and September 2011 (group 1) were matched to 29 patients with identical nephrometry scores and comparable baseline renal function who underwent robot-assisted partial nephrectomy with hilar clamping during the same period (group 2). The matched cohorts' perioperative and renal functional outcomes were compared at a mean 9-month follow-up.

RESULTS

Mean estimated blood loss was 146.4 mL in group 1, versus 103.9 mL in group 2 (P = .039). Mean hilar clamp time was 0 minutes in group 1 and 14.7 minutes in group 2. No perioperative complications were encountered in group 1; 1 Clavien-2 complication (3.4%) occurred in group 2 (P = 1.000). At 9-month follow-up, mean estimated glomerular filtration rate in group 1 was 79.9 versus 84.8 mL/min/1.73 m(2) preoperatively (P = .013); mean estimated glomerular filtration rate in group 2 was 74.1 versus 85.8 mL/min/1.73 m(2) preoperatively (P < .001). Hence, estimated glomerular filtration rate declined by a mean of 4.9 mL/min/1.73 m(2) in group 1 versus 11.7 mL/min/1.73 m(2) in group 2 (P = .033).

CONCLUSION

Off-clamp robot-assisted partial nephrectomy is associated with a favorable morbidity profile and relatively greater renal functional preservation compared to clamped robot-assisted partial nephrectomy. Nevertheless, the benefit is small in renal functional terms and may have very limited clinical relevance.

Causes of diminished renal function in the affected kidney after partial nephrectomy

OBJECTIVE

To determine the cause of diminished renal function in the affected kidney after partial nephrectomy (PN) for renal tumour, we analyzed the relationship between operative data and postoperative recovery with respect to renal function.

PATIENTS AND METHODS

From May 2005 to December 2010, pre- and postoperative (1 week and 3 months after the procedure) renal function was evaluated by 99mTc- mercaptoacetyltriglycine clearance in 51 patients treated with open partial nephrectomy (OPN; n = 24) and laparoscopic partial nephrectomy (LPN; n = 27). LPN was performed via retroperitoneal (RPLPN; n = 14) or transperitoneal (TPLPN; n = 13) routes. Renal cooling was performed after renal hilar clamping in OPN and RPLPN, although not in TPLPN.

RESULTS

There were 10 patients (two in OPN, six in TPLPN, two in RPLPN) who had diminished renal function in the affected kidney from 1 week to 3 months after PN. Warm ischaemia (versus cold ischaemia; P = 0.017) during renal hilar clamping resulted in diminished renal function. Using multivariate analysis, renal cooling influenced postoperative diminished renal function (P = 0.008).

CONCLUSIONS

Successful preservation of renal function after PN depends on renal cooling during renal hilar clamping. Cold ischaemia for avoiding renal damage is recommended if renal hilar clamping is necessary for tumour extraction.

Does prolonged warm ischemia after partial nephrectomy under pneumoperitoneum cause irreversible damage to the affected kidney?

PURPOSE

We determined the effects of warm ischemia time on the recovery of renal function after partial nephrectomy under pneumoperitoneum.

MATERIALS AND METHODS

In this prospective study 37 consecutive patients who underwent laparoscopic partial nephrectomy or robot-assisted partial nephrectomy between June 2008 and May 2009 to remove a single cT1 renal tumor were evaluated using (99m)Tc-diethylenetriamine pentaacetic acid renal scintigraphy preoperatively, and at 3 and 12 months postoperatively.

RESULTS

The most significant reduction in the glomerular filtration rate of the affected kidney at 3 and 12 months after surgery (p = 0.018, p = 0.036, respectively) was seen for a warm ischemia time cutoff of 28 minutes. The glomerular filtration rate of the affected kidney was consistently and significantly reduced at 3 and 12 months postoperatively (-22.4% to -30.6%, p <0.001) in patients with a warm ischemia time greater than 28 minutes. In contrast, no significant glomerular filtration rate change was seen in patients with a warm ischemia time of 28 minutes or less. In terms of the contributional change of the affected kidney to total renal function, there is a trend toward a recovery after an initial decrease in both groups with a warm ischemia time greater than 28 minutes vs 28 minutes or less. On multivariate analysis warm ischemia time was a strong independent predictor of glomerular filtration rate reduction even 12 months after surgery (β = -1.3; 95% CI -1.8, -0.7; p <0.001).

CONCLUSIONS

If the warm ischemia time is greater than 28 minutes during laparoscopic partial nephrectomy or robot-assisted partial nephrectomy, the functional damage to the affected kidney progresses even up to 1 year after surgery.

'Zero ischaemia', sutureless laparoscopic partial nephrectomy for renal tumours with a low nephrometry score

Study Type - Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Ischaemic injury produced by hilar clamping during partial nephrectomy is the main determinant of renal function loss. The exact measurement of ipsilateral renal function loss can be underestimated by serum creatinine levels and estimated GFR. Few reports of unclamped laparoscopic partial nephrectomy (LPN) are available in the literature, although this technique shows promising results. The present study includes a series of patients with the longest follow-up of LPN without hilar clamping and without parenchymal reconstruction. Excellent cancer control and optimum renal functional preservation suggest that this technique could be performed in selected patients, i.e. those with small and peripheral tumours (also classified as low nephrometry score tumours).

OBJECTIVE

To describe the technique and report the results of 'zero ischaemia', sutureless laparoscopic partial nephrectomy (LPN) for renal tumours with a low nephrometry score.

PATIENTS AND METHODS

Between August 2003 and January 2010, data from 101 consecutive patients who underwent 'zero ischaemia', sutureless LPN were collected in a prospectively maintained database. Inclusion criteria were tumour size ≤ 4 cm, predominant exophytic growth and intraparenchymal depth ≤ 1.5 cm, with a minimum distance of 5 mm from the urinary collecting system. Hilar vessels were not isolated, tumour dissection was performed with 10-mm LigaSure(TM) (Covidien, Boulder, CO, USA) and haemostasis was performed with coagulation and biological haemostatic agents without reconstructing the renal parenchyma. Clinical, perioperative and follow-up data were collected prospectively, and modifications of functional outcome variables were analysed using the paired Wilcoxon test.

RESULTS

The median (range) tumour size was 2.4 (1.5-4) cm, and the median (range) intraparenchymal depth was 0.7 (0.4-1.4) cm. Hilar clamping was not necessary in any patient, and suture was performed in four patients to ensure complete haemostasis. The median (range) operation duration was 60 (45-160) min, and median (range) intraoperative blood loss was 100 (20-240) mL. Postoperative complications included fever (n= 4), low urinary output (n= 3) and haematoma, which was treated conservatively (n= 2). The median (range) hospital stay was 3 (2-5) days. The pathologist reported 30 benign tumours and renal cell carcinoma in 71 cases (pT1a in 69 patients, and pT1b in two patients). At a median follow-up of 57 months, one patient underwent radical nephrectomy for ipsilateral recurrence. The 1-year median (range) decrease of split renal function at renal scintigraphy was 1 (0-5) %.

CONCLUSIONS

Zero ischaemia LPN is a reasonable approach to treating small and peripheral tumours, and a sutureless procedure is feasible in most cases. This technique has a low complication rate and provides excellent functional outcome without impairing oncological results.

Pilot study evaluation of standard laparoscopic suturing and a novel parenchymal apposition mechanism for minimally invasive renal reconstruction

OBJECTIVES

The most technically demanding portion of a laparoscopic partial nephrectomy is the renorrhaphy. The purpose of this study was to determine whether a parenchymal apposition mechanism (PAM) device would be as effective as standard laparoscopic technique (SLT) with respect to efficiency, capability, and safety of renal defect closure.

MATERIALS AND METHODS

In this pilot study, participants were recruited to perform surgical reconstruction of a standardized renal parenchymal defect with both SLT and the PAM. The PAM prototype was engineered using two salmon egg hooks connected by absorbable suture and placed within a V-shaped foam delivery mechanism. After hook placement, tensioning of the connecting suture using a Weck clip apposed the defect edges. Each participant performed a single closure with SLT and with the PAM device of a standardized defect in ex vivo porcine kidneys. Closure time, tissue trauma/damage during closure, and the intraparenchymal pressure were recorded.

RESULTS

A total of 13 subjects, 7 medical students, 3 residents, 2 fellows, and 1 attending were enrolled. There was no statistical difference between the two methods of closure in average time for closure. In a subgroup analysis of subjects who had performed laparoscopic reconstructive procedures as the primary surgeon, SLT was significantly faster than PAM (P=.036). Mean pressures achieved in attempted closure using SLT and PAM were not significantly different (0.38 N for both groups; P=.99). The mean parenchymal trauma rating was not significantly different between the groups; however, the upper limit of the range of trauma ratings was greater in the standard closures.

CONCLUSION

This pilot study demonstrated the feasibility of PAM use in an ex vivo porcine kidney model. Additional testing and continued design modifications are necessary to explore its use in laparoscopic reconstruction of the kidney and other organs.

Intra-operative erythropoietin during laparoscopic partial nephrectomy is not renoprotective

PURPOSE

In pre-clinical studies, acute erythropoietin (EPO) administration has been shown to mitigate the deleterious effects of ischemia/reperfusion injury. We reviewed our clinical experience with intraoperative EPO administration as a potential renoprotective agent during laparoscopic partial nephrectomy (LPN).

METHODS

Patients who underwent LPN at our institution between August 2008 and March 2010 received 500 IU/kg EPO 30 min prior to hilar occlusion. Those who underwent LPN between August 2006 and July 2008 without receiving EPO were selected as controls. Demographic, clinical, perioperative, and estimated glomerular filtration rate (eGFR) data were compared for the cohorts preoperatively, and during short-term (<6 months) and long-term (≥6 months) follow-up.

RESULTS

Short-term eGFR was evaluable for 39 EPO and 29 controls, while long-term eGFR was evaluable for 26 EPO and 27 controls. Baseline demographic and clinical features of the cohorts were similar. For EPO versus controls, median short and long-term follow-up was 19 days versus 22 days and 10.2 months versus 11.9 months, respectively. Mean preoperative, postoperative, and % change in eGFR were statistically similar for the cohorts during short- and long-term follow-up, without and with adjustment for baseline renal function (unadjusted P-values = 0.28, 0.095, and 0.38, respectively, short term, and 0.61, 0.50, and 0.69, respectively, long term).

CONCLUSIONS

In this retrospective study, a single dose of EPO prior to hilar occlusion during LPN had no added protective impact on postoperative eGFR in the short or long term. Prospective evaluation in patients with solitary kidneys may better elucidate its potential renoprotective role in this setting.

Current status of partial nephrectomy for renal mass

The standard treatment for a small mass has shifted from radical nephrectomy to partial nephrectomy. The benefits of partial nephrectomy, including preserving renal function, prolonging overall survival, preventing postoperative chronic kidney disease, and reducing cardiovascular events, have been discussed in many studies. With the accumulation of surgeons' experience and simplification of the operative procedures, the warm ischemic time has become shorter despite the indication of tumor size becoming larger. With the help of intraoperative ultrasound, partial nephrectomy can be performed for an endophytic renal mass. Recently, laparoscopic partial nephrectomy has become well indicated for most renal tumors in many centers with advanced laparoscopic expertise. Open partial nephrectomy remains indicated for complex tumors. With technical innovation, robotic partial nephrectomy shows at least comparable perioperative outcomes with a benefit for challenging cases. Laparoendoscopic single-site partial nephrectomy has recently been tried in limited indications and seems to be feasible.

Combining open and laparoscopic surgery for partial nephrectomy

PURPOSE

We present a simple and easy to apply surgical approach for partial nephrectomy that combines open and laparoscopic surgery allowing for vascular control in technically challenging renal tumors and for reduction of ischemia time.

PATIENTS AND METHODS

Five patients underwent partial nephrectomy using the combined laparoscopic/open approach. After complete laparoscopic mobilization of the kidney and securing of the renal vessels, the kidney is transferred extracorporally through a small pararectal incision for tumor resection.

RESULTS

The technique was feasible in all cases, with no conversion needed. In three cases, no clamping of the renal artery was necessary. The mean operative time was 219 minutes (range 195-260 min). Pathologic examination revealed no malignancy in two (40%) cases. The estimated median blood loss was 500 mL (range 250-1000 mL). Renal function decreased from 84.9 mL/min (range 48.0-89.0 mL/min) to 78.8 mL/min (range 52.6-82.6 mL/min). Mean hospital stay was 5 days (range 3-14 d).

CONCLUSION

Based on our initial experience, we propose a feasible surgical option for minimally invasive partial nephrectomy, which is, in particular, suitable for technically challenging renal tumors (endophytic and central tumors, large tumors, tumors in solitary kidneys).

Feasibility of Robotic Partial Nephrectomy in a UK Cancer Centre

Objective:

To present our initial peri-operative and pathological outcome data of 23 patients to establish the feasibility of robotic partial nephrectomy (RPN) in a UK cancer centre.

Patient and methods:

Clinical data from 23 patients who underwent RPN in a single institution between April 2008 and January 2010 were analysed. The RENAL Nephrometry Scoring System was applied to our series.

Results:

Mean patient age was 54.6 years with a mean tumour size of 2.53 cm. The median operative time was 198 min and warm ischaemia time (WIT) 30 min. There were two conversions and four patients required transfusion, with no other major complications. Histology confirmed renal cell carcinoma in 17 cases. All surgical margins were negative and to date there have been no local or distant recurrences. A mean RENAL score of 5.56 suggested that all the lesions had a low—moderate complexity and were therefore suitable for partial nephrectomy.

Conclusion:

RPN achieved acceptable WITs, blood loss and complication rates and oncological outcomes. We conclude that this technique is a feasible alternative to open surgery and conventional laparoscopic partial nephrectomy. The urological community need to establish the place for each technique although surgeon preference is likely to be a significant factor.

Robot-assisted laparoscopic partial nephrectomy for tumors greater than 4 cm and high nephrometry score: feasibility, renal functional, and oncological outcomes with minimum 1 year follow-up

OBJECTIVES

Minimally invasive robotic assistance is being increasingly utilized to treat larger complex renal masses. We report on the technical feasibility and renal functional and oncologic outcomes with minimum 1 year follow-up of robot-assisted laparoscopic partial nephrectomy (RALPN) for tumors greater than 4 cm.

MATERIALS AND METHODS

The urologic oncology database was queried to identify patients treated with RALPN for tumors greater than 4 cm and a minimum follow-up of 12 months. We identified 19 RALPN on 17 patients treated between June 2007 and July 2009. Two patients underwent staged bilateral RALPN. Demographic, operative, and pathologic data were collected. Renal function was assessed by serum creatinine levels, estimated glomerular filtration rate, and nuclear renal scans assessed at baseline, 3, and 12 months postoperatively. All tumors were assigned R.E.N.A.L. nephrometry scores (http://www.nephrometry.com).

RESULTS

The median nephrometry score for the largest tumor from each kidney was 9 (range 6-11) while the median size was 5 cm (range 4.1-15). Three of 19 cases (16%) required intraoperative conversion to open partial nephrectomy. No renal units were lost. There were no statistically significant differences between preoperative and postoperative creatinine and eGFR. A statistically significant decline of ipsilateral renal scan function (49% vs. 46.5%, P = 0.006) was observed at 3 months and at 12 mo postoperatively (49% vs. 45.5%, P = 0.014). None of the patients had evidence of recurrence or metastatic disease at a median follow-up of 22 months (range 12-36).

CONCLUSIONS

RALPN is feasible for renal tumors greater than 4 cm with moderate or high nephrometry scores. Although there was a modest decline in renal function of the operated unit, RALPN may afford the ability resect challenging tumors requiring complex renal reconstruction. The renal functional and oncologic outcomes are promising at a median follow-up of 22 months, but longer follow-up is required.

Feasibility and outcomes of partial nephrectomy for resection of at least 20 tumors in a single renal unit

PURPOSE

Patients with hereditary renal cancer are at increased risk for recurrent bilateral multifocal tumors and may require aggressive nephron sparing surgery to prevent renal replacement therapy. We evaluated feasibility and outcomes in patients who underwent partial nephrectomy with removal of at least 20 tumors in a single renal unit at 1 setting.

MATERIALS AND METHODS

We retrospectively reviewed the records of 30 patients who underwent a total of 34 partial nephrectomies with removal of at least 20 tumors at our institution from 1993 to 2008. Operative reports and hospital records were reviewed for perioperative data, and renal functional and oncologic outcomes. We compared preoperative and postoperative renal function with the 2-tailed t test.

RESULTS

There were no deaths and only 1 renal unit was lost. A median of 26.5 tumors was removed. Median estimated blood loss was 3,500 ml and median operative time was 9 hours. Perioperative complications developed in greater than 50% of cases. There was a statistically significant decrease in the estimated glomerular filtration rate at 3 months (67 vs 59 ml/minute/1.73 m(2), p < 0.001). Only 1 patient had metastatic disease. Eight of the 34 operated kidneys required subsequent intervention during the median followup of 52 months (range 4 to 187).

CONCLUSIONS

Aggressive partial nephrectomy to resect multiple tumors is technically feasible. There was a significant decrease in postoperative renal function but more than 80% of preoperative renal function was preserved in this cohort except in 1 patient. Also, oncologic outcomes were encouraging at intermediate term followup.