Renal Function Following Nephron Sparing Procedures: Simply a Matter of Volume?

The Outcome of Sutureless in Partial Nephrectomy: A Systematic Review and Meta-Analysis

Purpose

To compare the effect of sutureless versus standard suture (double-layer suture) during renorrhaphy in laparoscopic or robotic-assisted partial nephrectomy on perioperative and renal function outcomes.

Methods

PubMed, Embase, and other sources were searched for randomized controlled trials or retrospective studies comparing sutureless partial nephrectomy versus standard suture partial nephrectomy. A systematic review and meta-analysis were performed by two reviewers independently.

Results

Five retrospective studies were included with a total of 634 patients. The results showed that there was a significant difference in the decline of estimated glomerular filtration rate (I² = 98.5%; WMD, -4.19 ml/min; 95% CI, -7.64 to -0.73; P < 0.001) and no significant difference in postoperative complications (I² = 0; RR, 1.31; 95% CI, 0.61 to 2.81; P = 0.623). A significant advantage in terms of operating time (I² = 53.9%; WMD, -29.08 min; 95% CI, -33.06 to -25.10; P = 0.069) and warm ischemia time (I² = 38.5%; WMD, -6.17 min; 95% CI, -6.99 to -5.36; P = 0.165) favored sutureless, while there was no significant difference in blood loss (I² = 58.1%; WMD, 3.10 ml; 95% CI, -39.18 to 45.38; P = 0.049).

Conclusion

Sutureless during renorrhaphy is feasible and safe compared with standard suture. Sutureless can shorten the operating time and warm ischemia time without increasing postoperative complications, and thus, it protects renal function.

Estimated Glomerular Filtration Rate Decline at 1 Year After Minimally Invasive Partial Nephrectomy: A Multimodel Comparison of Predictors

Background

Long-term renal function after partial nephrectomy (PN) is difficult to predict as it is influenced by several modifiable and nonmodifiable variables, often intertwined in complex relations.

Objective

To identify variables influencing long-term renal function after PN and to assess their relative weight.

Design, setting, and participants

A total of 457 patients who underwent either robotic (n = 412) or laparoscopic PN (n = 45) were identified from a multicenter international database.

Outcome measurements and statistical analysis

The 1-yr estimated glomerular filtration rate (eGFR) percentage loss (1YPL), defined as the eGFR percentage change from baseline at 1 yr after surgery, was the outcome endpoint. Predictors evaluated included demographic data, tumor features, and operative and postoperative variables. Bayesian multimodel analysis of covariance was used to build all possible models and compare the fit of each model to the data via model Bayes factors. Bayesian model averaging was used to quantify the support for each predictor via the inclusion Bayes factor (BF_incl). High-dimensional undirected graph estimation was used for network analysis of conditional independence between predictors.

Results and limitations

Several models were found to be plausible for estimation of 1YPL. The best model, comprising postoperative eGFR percentage loss (PPL), sex, ischemia technique, and preoperative eGFR, was 207 times more likely than all the other models regarding relative predictive performance. Its components were part of the top 44 models and were the predictors with the highest BF_incl. The role of cold ischemia, solitary kidney status, surgeon experience, and type of renorraphy was not assessed.

Conclusions

Preoperative eGFR, sex, ischemia technique, and PPL are the best predictors of eGFR percentage loss at 1 yr after minimally invasive PN. Other predictors seem to be irrelevant, as their influence is insignificant or already nested in the effect of these four parameters.

Patient summary

Kidney function at 1 year after partial removal of a kidney depends on sex, the technique used to halt blood flow to the kidney during surgery, and kidney function at baseline and in the early postoperative period.

Split renal function after treatment of small renal masses: comparison between radiofrequency ablation and laparoscopic partial nephrectomy

BACKGROUND

Radiofrequency ablation (RFA) and laparoscopic partial nephrectomy (LPN) are used to treat small renal masses (SRM; ≤4 cm), although there are conflicting results in the changes in creatinine and estimated glomerular filtration rate (eGFR) after treatment. On contrast-enhanced computed tomography (CE-CT) images, the quantity and quality of renal function can be evaluated by calculating the split renal function (SRF).

PURPOSE

To compare renal function after RFA or LPN treatment of SRMs through evaluation of the SRF in the affected kidney.

MATERIAL AND METHODS

Single T1a renal tumors successfully treated with RFA (n = 60) or LPN (n = 31) were retrospectively compared. The SRF was calculated on pre-treatment CE-CT images and the first follow-up exam after completed treatment. Serum creatinine and eGFR values were collected simultaneously. To compare renal function outcomes, Student's t-test and multivariable linear regression models (adjusted to RFA/LPN treatment, pre-treatment SRF/eGFR, BMI, age, tumor characteristics, and Charlson Comorbidity Index) were used.

RESULTS

SRF was reduced in both groups, although reduction was greater in the LPN group (LPN -5.7%) than in the RFA group (RFA -3.5%; P = 0.013). After adjusted analysis, the LPN group still had greater SRF reduction (difference 3.2%, 95% confidence interval 1.3-1.5; P = 0.001). There was no difference between groups in the change of creatinine/eGFR after treatment.

CONCLUSION

Both RFA and LPN are nephron-sparing when treating SRMs. However, in this series, reduction of SRF in the affected kidney was smaller after RFA, having a more favorable preservation of renal function than LPN.

Chronic Kidney Disease After Partial Nephrectomy in Patients With Preoperative Inconspicuous Renal Function - Curiosity or Relevant Issue?

BACKGROUND

Chronic kidney disease (CKD) is a severe long-term complication after partial nephrectomy (PN). Clinical and scientific focus lies on patients with impaired renal function at the time of surgery. Little data is available on patients with normal preoperative renal function (NPRF).

PATIENTS AND METHODS

Patients who underwent PN with a preoperative estimated glomular filtration rate > 60 mL/min/1.73m² were retrospectively examined at 8 European urologic centers. The occurrence of new onset CKD ≥ stage III after surgery (sCKD) was defined as the primary endpoint. Group comparisons and risk correlations were determined. Based on this data, a risk stratification model for sCKD was developed.

RESULTS

Of the 1315 patients with NPRF included, 249 (18.9%) developed sCKD after a median follow-up of 44 months (range, 6-255 months). Pair analysis and univariable regression revealed age, arterial hypertension, American Society of Anesthesiologists score, tumor stage, surgical approach, intraoperative blood loss, perioperative blood transfusions and preoperative CKD stage as predictors for sCKD development. Multivariate analysis confirmed perioperative blood transfusion (hazard ratio [HR], 2.96; P ≤ .0001), age (≥ 55 years; HR, 2.60; P = .0002), tumor stage (> pT1; HR, 2.15; P = .025), and preoperative CKD stage (stage II vs. I; HR, 3.85; P ≤ .0001) as independent risk factors. A model that stratified patient risk for new onset CKD was highly significant (P < .0001).

CONCLUSION

Every fifth patient with NPRF developed sCKD following PN. Elderly patients with higher tumor stage and who require blood transfusion appear to be at increased risk. Based on our risk stratification, patients with ≥ 2 risk factors are candidates for an early, nephrologic follow-up.

Near-infrared fluorescence imaging for intraoperative margin assessment during robot-assisted partial nephrectomy

OBJECTIVES

To demonstrate how using a standardised dosing strategy of indocyanine green (ICG) dye with near-infrared fluorescence (NIRF) imaging can be used to differentiate renal tumours from normal renal parenchyma during robot-assisted partial nephrectomy (RAPN).

PATIENTS AND METHODS

We reviewed a prospectively collected database of 361 consecutive RAPNs using NIRF between June 2011 and March 2018, and determined the rate at which differential fluorescence was achieved. Tumour and kidney fluorescence or afluorescence were recorded intraoperatively and compared to histological results on final pathology.

RESULTS

Of 330 tumours, after 31 exclusions for nonvisible tumours due to adherent fat, completely intrarenal location or for incomplete data, 288 (87.3%) successfully exhibited differential fluorescence. Among the predominant histologies, 249 of 277 (89.9%) renal cell carcinomas did not fluoresce, as well as 23 of 32 (71.9%) oncocytomas. Real-time gross assessment of resection margin for fluorescence yielded a positive margin rate on final pathology of 0.30%.

CONCLUSION

When administered with a standardised ICG-dosing strategy, NIRF successfully achieved differential fluorescence in a large majority of tumours during RAPN with an exceedingly low positive margin rate.