Assessment of volume preservation performed before or after partial nephrectomy accurately predicts postoperative renal function: Results from a prospective multicenter study

Purpose

Partial nephrectomy (PN) is standard for small renal masses, improving renal function by preserving renal parenchyma compared with radical nephrectomy. Recent work demonstrated that postoperative surgeon assessment of volume preservation (SAVP) and 3D imaging measurements agree and correlate with postoperative function. We hypothesize preoperative assessment of volume preservation (PAVP) with PN based on preoperative imaging will reliably indicate postoperative renal function.

Nephron-sparing surgery is superior to radical nephrectomy in preserving renal function benefit even when expanding indications beyond the traditional 4-cm cutoff

ObjectivesTo analyze to what extent partial nephrectomy (PN) is superior to radical nephrectomy (RN) in preserving renal function outcome in relation to tumor size indication.Methods and materialsClinical data from 973 patients operated at 9 academic institutions were retrospectively analyzed. Glomerular filtration rate (GFR) before and after surgery was calculated with the abbreviated Modification of the Diet in Renal Disease equation. For a fair comparison between the 2 techniques, all imperative indications for PN were excluded. A shift to a less favorable GFR group following surgery was considered clinically significant.ResultsMedian age at diagnosis was 60 years (19–91). Tumor size was smaller than 4 cm in 665 (68.3%) cases and larger than 4 cm in 308 (31.7%) cases. PN and RN were performed in 663 (68.1%) and 310 (31.9%) patients, respectively. In univariate analysis, patients undergoing PN had a smaller risk for developing significant GFR change following surgery than those undergoing RN did. This was true for tumors≤4 cm (P = 0.0001) and for tumors>4 cm (P = 0.0001). In multivariate analysis, the following criteria were independent predictive factors for developing significant postoperative GFR loss: the use of RN (P = 0.0001), preoperative GFR<60 ml/min (P = 0.0001), tumor size≥4 cm (P = 0.0001), and older age at diagnosis (P = 0.0001).ConclusionsThe renal function benefit carried out by elective PN over RN persists even when expanding nephron-sparing surgery indications beyond the traditional 4-cm cutoff.     

Baseline renal function,ischaemia time and blood loss predict the rate of renal failure after partial nephrectomy

OBJECTIVE

To identify independent predictors of renal failure after partial nephrectomy (PN) in patients with renal cell carcinoma (RCC).

PATIENTS AND METHODS

Data were available for 166 patients with pathological T1‐3 N0M0 RCC treated with PN. Renal failure after PN was defined as a decrease in glomerular filtration rate (GFR) of >25% (RIFLE criteria). The GFR before and after PN was estimated using the Modification of Diet in Renal Disease study group equation. Univariable and multivariable logistic regression models were used to assess a decrease of >25% in GFR from the preoperative level. Candidate predictor variables were age, gender, PN indication (absolute vs relative), preoperative GFR, tumour size, perioperative blood loss, surgery duration and clamping time.

RESULTS

After PN, 22 (13.3%) patients had a decrease in GFR of >25%. The perioperative blood loss (P = 0.02), clamping time (P = 0.04) and preoperative GFR (P = 0.002) were independent predictors of a decrease in GFR of >25%.

CONCLUSIONS

We identified two important potentially modifiable variables that should be considered in the planning of PN, i.e. the clamping time and blood loss. It is possible that selective referral to experienced surgeons who can perform PN within short surgical and clamping times, and with minimal blood loss, could minimize the rate of renal failure, especially in patients with an underlying renal function impairment.     

Renal function and adaptive changes in patients after radical or partial nephrectomy

Introduction

Renal function after renal surgery depends on the volume of renal parenchyma loss and improves in the postoperative period. However, the knowledge on kidney function after radical (RN) and partial (PN) nephrectomy is still insufficient. The aim of this study is to analyze the global renal function and compensatory hyperfunction of the non-operated kidney in patients with renal cancer after RN or PN.

Methods

Fifty-one patients of mean age 62.2?years with renal cancer were included. Thirty-three RN and eighteen PN were performed. We measured creatinine serum concentrations, and we estimated glomerular filtration rate (eGFR) preoperatively and postoperatively at two time intervals: 3 and 12?months after surgery. Additionally, we assessed effective renal plasma flow (ERPF) in dynamic scintigraphy preoperatively and 12?months after surgery.

Result

At the baseline, all mean measured values were comparable in RN and PN groups (P?>?0.05). Three?months after surgery, creatinine level increased in both groups, more remarkably in RN group (128?mmol/l vs. 95?mmol/l; P?2 vs. 70?ml/min/1.73?m²; P?P?>?0.05). The mean ERPF of the operated kidney in PN group decreased by 24.7% (149?ml/min).

Conclusion

The deterioration of renal function after partial nephrectomy is nearly insignificant clinically. In 1-year postoperative observation, the renal function does not improve. This causes potential compensatory mechanisms to be insufficient.     

No difference in renal function outcomes for patients with oncocytoma managed with active surveillance vs. partial nephrectomy

ObjectivesTo investigate the difference in renal function outcomes for patients with oncocytomas undergoing active surveillance (AS) vs. partial nephrectomy (PN).MethodsWe reviewed our institutional database for patients with biopsy/surgically confirmed oncocytoma from 2000-2020. The primary outcome was to assess for differences in renal function outcomes in patients undergoing AS vs. PN. We fit two generalized estimating equation (GEE) with an interaction term between follow up time and management strategy to predict 1) mean eGFR for patients managed with AS and PN and 2) the probability of progression to CKD stage III or greater.ResultsWe identified 114 eligible patients, of which 32 were managed with AS. Median follow-up was 21 months vs. 44 months for PN vs. AS patients. AS patients tended to be older (median: 72 years vs. 65 years, P<0.001) and have lower baseline renal function (median: eGFR: 71 mL/min/1.73m² vs. 82 mL/min/1.73m², P<0.001) compared with PN patients. Renal mass size from baseline imaging was similar between patients undergoing PN vs. AS (2.8 cm vs. 2.9 cm, P=0.634). For patients undergoing PN vs. AS, there was not a significant difference in predicted longitudinal eGFR (-0.079, 95% CI -0.18-0.023, P=0.129) or predicted probability of progression to CKD stage III or greater (OR: 0.61, 95% CI: 0.16-2.33, P=0.47).ConclusionsIn our institutional dataset, patients undergoing AS or PN with an oncocytoma had similar long-term renal function outcomes. Given similar renal function outcomes in patients undergoing AS and PN, surgery should remain reserved for select patients with oncocytomas.     

A comprehensive assessment of frailty status on surgical,functional and oncologic outcomes in patients treated with partial nephrectomy—A large,retrospective, single-center study

BackgroundPartial nephrectomy (PN) is a challenging procedure, which can be associated with severe complications. In consequence, the search for accurate and independent indicators of unfavorable surgical outcomes appears warranted. We aimed at evaluating the impact of frailty status on surgical, functional and oncologic outcomes in patients undergoing PN for renal cell carcinoma (RCC).MethodsA retrospective, single-center study including 1,282 patients treated with PN for clinically localized cT₁ RCC was performed. The modified Frailty Index (mFI) was used to assess preoperative frailty. Multivariable logistic, Poisson and linear regression analyses(MVA) tested the effect of frailty on complications, acute kidney injury(AKI), renal function decline after PN. Cumulative incidence and competing-risk analyses investigated survival outcomes.ResultsOf 1,282 patients, 220 (17%) were frail. Overall, 982 (76%) vs. 123 (9.6%) vs. 171 (13%) patients underwent open vs. laparoscopic vs. robot-assisted PN. Median follow-up was 66 (IQR: 35–107) months. At MVA, frailty status predicted increased risk of complications [Odds ratio (OR): 1.46, 95%CI 1.17–1.84; P < 0.001]. Moreover, frail patients were at higher risk of postoperative AKI (OR: 1.95, 95%CI 1.13–3.35; P = 0.01). In frail patients, renal function permanently decreased over time (P = 0.01) without any renal function plateau or improvement during the follow-up, which were instead observed in the nonfrail cohort. At competing-risks analyses, frailty status predicted higher risk of other-cause mortality [Hazard ratio (HR): 1.67, 95%CI 1.05–2.66; P = 0.02], but not of cancer-specific mortality (P = 0.3).ConclusionsFrailty status predicts higher risk of adverse surgical outcomes after PN. Moreover, greater renal function decline was observed in frail patients, compared with nonfrail patients. Finally, the risk of OCM significantly overcomes the risk of dying due to RCC in frail patients.     

Evolution of glomerular filtration rate, renal injury markers, anemia, and angiotensin blockers use after change from calcineurin inhibitors to sirolimus in transplant patients with neoplasia versus chronic allograft nephropathy

Background

The change from calcineurin inhibitors (CNI) to sirolimus (SRL) is a safe alternative in transplant patients with neoplasia (NEO) whereas the results of conversion for chronic allograft nephropathy (CAN) are controversial, depending on the histologic score, degree of proteinuria, and glomerular filtration rate (GFR). Our aim in this study was to compare GFR, proteinuria, albuminuria, blood pressure (BP) effects, and anemia after switching to sirolimus (SRL) among renal transplant recipients with CAN versus NEO.

Methods

Fifty-five kidney transplant recipients with conversion from CNI to SRL owing to CAN or NEO were analyzed for the variables at 6 months before, at the time of, and at 6 months and 1, 2, and 3 years after the switch to SRL.

Results

There were no differences between CAN and NEO in the slope of estimated GFR (mL/min/1.73 m² by Cockcroft-Gault formula) at 1 year (−5.5 vs 3.7; P = .007) and at 2 years (−3.86 vs −10.3; P = .01). The values of proteinuria (mg/24 h/1.73 m²) before (665 ± 136 vs 329 ± 69; P = .036) as well as at 1 (1,122 ± 306 vs 863 ± 190; P = .478) and at 2 years after conversion (1,360 ± 430 vs 457 ± 154; P = .045) showed some significant differences, as did the use of both antiangiotensin agents, angiotensin-converting enzyme inhibitor and angiotensin receptor blocker at the moment of switch (35% vs 0%; P = .005) at 1 year (69% vs. 6% P = .02) and at 2 years (67% vs 28%; P = .047). There were no differences in graft survival (log rank: P = .515). By logistic regression analysis, the best covariate associated with GFR >45 mL/min at 2 years was GFR >60 mL/min at the moment of switch to SRL (odds ratio, 1.33; 95% confidence interval, 1.002-1.74).

Conclusions

The evolution of renal damage was more important in the CAN group requiring greater use of 2 angiotensin antagonists for control of proteinuria. We probably need histologic and serologic biomarkers to show which patients with CAN will show a bad evolution after the change to SRL.     

Parenchymal volume analysis to assess longitudinal functional decline following partial nephrectomy

Objective

To identify factors associated with longitudinal ipsilateral functional decline after partial nephrectomy (PN).

Patients and Methods

Of 1140 patients managed with PN (2012–2014), 349 (31%) had imaging/serum creatinine levels pre-PN, 1–12 months post-PN (new baseline), and >3 years later necessary for inclusion. Parenchymal-volume analysis was used to determine split renal function. Patients were grouped as having significant renal comorbidity (Cohort_SRC: diabetes mellitus with insulin-dependence or end-organ damage, refractory hypertension, or severe pre-existing chronic kidney disease) vs not having significant renal comorbidity (Cohort_NoSRC) preoperatively. Multivariable regression was used to identify predictors of annual ipsilateral parenchymal atrophy and functional decline relative to new baseline values post-PN, after the kidney had healed.

Results

The median follow-up was 6.3 years with 87/226/36 patients having cold/warm/zero ischaemia. The median cold/warm ischaemia times were 32/22 min. Overall, the median tumour size was 3.0 cm. The preoperative glomerular filtration rate (GFR) and new baseline GFR (NBGFR) were 81 and 71 mL/min/1.73 m², respectively. After establishment of the NBGFR, the median loss of global and ipsilateral function was 0.7 and 0.4 mL/min/1.73 m²/year, respectively, consistent with the natural ageing process. Overall, the median ipsilateral parenchymal atrophy was 1.2 cm³/year and accounted for a median of 53% of the annual functional decline. Significant renal comorbidity, age, and warm ischaemia were independently associated with ipsilateral parenchymal atrophy (all P < 0.01). Significant renal comorbidity and ipsilateral parenchymal atrophy were independently associated with annual ipsilateral functional decline (both P < 0.01). Annual median ipsilateral parenchymal atrophy and functional decline were both significantly increased for Cohort_SRC compared to Cohort_NoSRC (2.8 vs 0.9 cm³, P < 0.01 and 0.90 vs 0.30 mL/min/1.73 m²/year, P < 0.01, respectively).

Conclusions

Longitudinal renal function following PN generally follows the normal ageing process. Significant renal comorbidities, age, warm ischaemia, and ipsilateral parenchymal atrophy were the most important predictors of ipsilateral functional decline following establishment of NBGFR.     

Percutaneous cryoablation versus partial nephrectomy for cT1b renal tumors: An inverse probability weight analysis

PurposeTo investigate differential clinical outcomes in patients treated with partial nephrectomy (PN) vs. percutaneous cryoablation (PCA) for cT1b renal tumors.Materials and methodsWe retrospectively analyzed the records of 119 patients who had undergone PN (n = 90) or PCA (n = 29) for cT1b renal tumors. Inverse probability weighting (IPW) was used for balancing patient demographics, including renal function and tumor complexity. Perioperative complications, renal function preservation rates, and oncological outcomes such as local recurrence-free, metastasis-free, cancer-specific, and overall survival were compared using IPW-adjusted restricted mean survival times (RMSTs).ResultsPCA was more likely to be selected for octogenarians (odds ratio: 11.4, 95% confidence interval [CI]: 3.33–45.1). During the median follow-up of 43 months in the PCA group and 36.5 months in the PN group, unablated local residue or local recurrence was noted in 6 patients in the PCA group and local recurrence was noted in 4 patients in the PN groups. Of the 6 patients in the PCA group, 4 underwent salvage PCA, and local control had been achieved at the last visit. In the IPW-adjusted population, PCA had significantly worse local recurrence-free survival compared with PN (IPW-adjusted RMST difference: -22.7 months, 95% CI: -45.3 to -0.4, P = 0.046). IPW-adjusted RMST for metastasis-free survival (P = 0.23), cancer-specific survival (P = 0.77), and overall survival (P = 0.11) did not differ between PCA and PN. In addition, PN was not a predictor for local control failure at the last visit (odds ratio: 0.30, 95%CI: 0.05–1.29). There were no statistically significant differences between PN and PCA in renal function preservation or overall/severe complication rates.ConclusionsIn patients with cT1b renal tumor, although the local recurrence rate is higher for PCA than for PN, PCA provides comparable distant oncologic outcomes. PCA can be an alternative treatment option for elderly, comorbid patients, even those with cT1b renal tumors.     

Early renal transplantation after donor renal angiography affects initial graft function

Background

Renal angiography of a living donor is a common radiologic examination before transplantation. However, the contrast agent used during this procedure can cause contrast nephropathy. There are insufficient data regarding whether this radiocontrast exposure detoriates renal function and survival after transplantation. In this study, we analyzed the effects of radiocontrast exposure to donors before transplant surgery on the incidence of delayed graft function (DGF) and on the outcomes of recipients at 1 year posttransplantation.

Methods

We divided 80 living donor transplantations according to the duration between the renal angiography and the transplantation procedure: Group 1 as early transplantation at ≤20 days (n = 42) versus group 2 of late transplantation at ≥20 days (n = 38). We retrospectively collected acute rejection episodes and graft survival at 1 year, monthly serum creatinine values of, DGF, proteinuria at 1 month, GFR at posttransplant day 3 month 1, and 1 year.

Results

There were 10 group 1 recipients (23.8%) and 2 group 2 (5.3%) subjects who experienced ≥1 acute rejection episode in the 1st posttransplant year (P = .02); 1 patient in each group experienced graft loss at 1 year (P = .941). DGF was observed in 9 (22%) versus 1 patient (2.6%) in group 2 (P = .009). Posttransplant day 3 creatinine values were significantly higher (P = .005) with significantly lower GFR values (P = .043) in group 1. However, creatinine and GFR levels were similar at 1 month and 1 year. Month 1 proteinuria levels were significantly higher in group 1 (P = .014). There was a significant negative correlation between renal angiography time and month 1 proteinuria (P = .014).

Conclusions

Early renal transplantation (within 2 weeks after renal angiography) in living kidney donors can detoriate initial graft function and cause DGF.     

Comparison of rates and risk factors for development of anaemia and erythropoiesis-stimulating agent utilization after radical or partial nephrectomy

Study Type – Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? The consequences and significance of iatrogenically‐induced CKD are poorly understood. Most data regarding risk of CKD and its complications are inferred from the medical literature. This is the first study to examine impact of surgical management of renal masses on development of anaemia. Patients who underwent radical nephrectomy had a significantly higher incidence of anaemia and ESA utilization than a contemporary well‐matched cohort that underwent partial nephrectomy. The results obtained add to the growing body of data supporting the use of partial nephrectomy in the management of clinically appropriate renal masses.

OBJECTIVE

• ? To examine the incidence of and risk factors for the development of anaemia and erythropoiesis‐stimulation agent (ESA) treatment in patients undergoing radical nephrectomy (RN) and partial nephrectomy (PN) because anaemia is a significant cause of morbidity in chronic kidney disease.

PATIENTS AND METHODS

• ? The study comprised a retrospective review of 905 patients (610 RN/295 PN; mean age, 57.5 years; mean follow‐up, 6.4 years) who underwent surgery for renal tumours at two institutions from July 1987 to June 2007.
• ? Demographics, disease characteristics and pre‐ and postoperative (i.e. renal function, metabolic parameters, anaemia and ESA treatment) were recorded.
• ? Data were analyzed within subgroups based on treatment (RN vs PN).
• ? Multivariate analysis was conducted to determine the risk factors for developing anaemia after surgery.

RESULTS

• ? Tumour size (cm) was significantly larger for RN (RN 7.0 vs PN 3.7; P < 0.001). No significant differences were noted with respect to demographics and preoperative anaemia (RN 16.4% vs PN 18.6%; P= 0.454) and ESA‐treatment (RN 0.7% vs PN 1.4%; P= 0.499).
• ? After surgery, significantly less de novo anaemia (PN 4.1% vs RN 17.5%; P < 0.001) and ESA utilization (PN 2.7% vs RN 13.4%; P < 0.001) occurred in the PN cohort.
• ? Multivariate analysis showed that age ≥60 years (odds ratio, OR, 1.62; P= 0.008), African American ethnicity (OR, 2.30; P < 0.001), smoking (OR, 1.60; P= 0.013), glomerular filtration rate (GFR) <60 mL/min/1.73 m² (OR, 4.09; P < 0.001), ≥1+ proteinuria (OR, 2.19; P < 0.03), metabolic acidosis (OR, 4.08; P= 0.007) and RN (OR, 2.58; P < 0.001) were significantly associated with de novo anaemia.

CONCLUSIONS

• ? Patients who underwent RN had a significantly higher prevalence of anaemia and ESA‐treatment compared to a well‐matched cohort that underwent PN.
• ? In addition to RN, age ≥60 years, African American ethnicity, history of smoking, GFR < 60 mL/min/1.73 m², proteinuria and metabolic acidosis were associated with developing anaemia.

     

Simultaneous versus staged partial nephrectomies for bilateral synchronous solid renal masses

ObjectivesThe optimal management approach for synchronous bilateral renal masses is unknown, particularly regarding surgical sequencing of bilateral partial nephrectomy (PN). We evaluated the impact of simultaneous vs. staged bilateral PN on renal functional, perioperative, and oncologic outcomes.Patients and MethodsWe reviewed our institutional nephrectomy registry to identify patients who underwent simultaneous or staged (within 6 months) bilateral PN for nonmetastatic bilateral synchronous solid renal masses between 1980 and 2015. Short-term and long-term renal function changes were assessed at 3 and 12 months, respectively. Perioperative outcomes were pooled across staged surgeries by taking the sum of each outcome. Local recurrence-free, distant metastases-free, cancer-specific, and overall survival were estimated using the Kaplan-Meier method. Outcomes were compared by surgical sequencing approach. A sensitivity analysis was performed that grouped approaches by preoperative intent.ResultsAmong the 107 patients studied, 77 (72%) underwent simultaneous and 30 (28%) underwent staged PN. The majority of PN were performed by open approach. Clinicopathologic features were similar between groups. Patients who underwent simultaneous PN had lower mean short-term (−6% vs. −24%, P = 0.015) and median long-term (−4% vs. −22%, P < 0.001) reduction in eGFR vs. staged PN, respectively. Furthermore, patients with simultaneous PN had lower pooled length of stay (median 6 vs. 8 days, P < 0.001), rate of urine leak (3% vs. 17%, P = 0.018), and rate of high-grade complications (8% vs. 23%, P = 0.044), relative to staged PN, respectively. However, on sensitivity analysis, only differences in long term reduction in estimated glomerular filtration rate and length of stay remained. There were no significant differences in oncologic outcomes between groups.ConclusionsOur results suggest that when technically feasible, simultaneous PN yields comparable outcomes vs. staged PN, offering a reasonable surgical sequencing approach for patients presenting with bilateral synchronous renal masses.     

Postoperative renal function after partial nephrectomy for renal cell carcinoma in patients with pre‐existing chronic kidney disease: A comparison with radical nephrectomy

We assessed whether adequately functioning parenchyma is preserved in patients with pre‐existing chronic kidney disease (CKD) after partial nephrectomy (PN) compared with those who underwent radical nephrectomy (RN). A total of 95 patients with pre‐existing CKD who underwent curative surgery for pathological T1a‐T2N0M0 renal cell carcinoma with a follow‐up period of 12 months or more were the subject of the present study. Of these, 51 patients underwent RN, and 44 PN. Renal function was assessed by using the estimated glomerular filtration rate (e‐GFR). We classified the subjects into two groups according to the preoperative e‐GFR: preoperative e‐GFR 45–59 mL/min/1.73 m² (68 patients); and 30–44 mL/min/1.73 m² (27 patients). In the former group, the probability of freedom from new onset of e‐GFR <45 mL/min/1.73 m² stemmed from the significant difference between the PN and RN groups (P = 0.006; PN: 2 years 64%; RN: 2 years 22%). In contrast, in the latter group, the probability of freedom from new onset of e‐GFR <30 mL/min/1.73 m² was not associated with a significant difference between PN and RN group (P = 0.80). Overall survival and the number of the patients who went on to develop end‐stage renal disease requiring renal replacement therapy between PN and RN were not significantly different in each group. Death from renal cell carcinoma was not noted in either group. PN could significantly prevent development to late‐stage CKD in patients with preoperative e‐GFR 45–59 mL/min/1.73 m² compared with RN. Patients with preoperative e‐GFR 30–44 mL/min/1.73 m² should be reviewed in a more strict study.     

Predictors for progression in immunoglobulin A nephropathy with significant proteinuria

Aim: Proteinuria is a primary factor requiring treatment in immunoglobulin (Ig)A nephropathy. The purpose of this study was to assess the relevance of treatment response and relapse of proteinuria with renal function decline. Methods: One hundred and twenty‐five biopsy‐proven primary IgA nephropathy patients who had more than 1.0 g/day proteinuria at the first assessment were studied. All patients underwent anti‐proteinuric treatment, and the association of the rate of renal function decline with treatment responsiveness, clinical and laboratory data was investigated. Results: The treatment response of the patients was: 30.4% complete response (<0.3 g/day proteinuria), 32.8% partial response (0.3–1.0 g/day), 23.2% minimal response (decrement but not reduced to <1 g/day) and 13.6% no response (no decrement of proteinuria). The slope of renal function decline (?1.06 vs?1.24 mL/min per 1.73 m²/year, P = 0.580) was comparable between complete and partial response groups, but they were slower than those of minimal or non‐response groups (P < 0.001). In multivariate analysis including other parameters, mean arterial pressure (MAP; β = –0.240, P = 0.004) during follow up, minimal (β = –0.393, P < 0.001) and non‐response (β = –0.403, P < 0.001) were significant predictors. In further investigation of complete and partial response groups, MAP (β = –0.332, P = 0.001) and relapse of proteinuria (β = –0.329, P = 0.001) were independently associated with slope of renal decline. Conclusion: Achievement of less than 1.0 g/day proteinuria and MAP were important for limiting the loss of renal function, and relapse of proteinuria should be closely monitored in proteinuric IgA nephropathy.     

One hundred six live kidney donors in a single German transplantation center: renal, physical, and psychological follow-up

ObjectiveThe objective of this study was to analyze the psychological and physical status as well as renal outcomes of 106 live kidney donors between 1993 and 2003.MethodsWe performed general and nephrological examinations, including measurements of creatinine clearance (ClCr), proteinuria, and 24-hour blood pressure monitoring. We evaluated the psychological and general health situation using the standardized SF-36 questionnaire.ResultsWe evaluated 69/106 (65%) live kidney donors at 5.3 ± 0.4 years after donation. The reason for the 37 drop-outs were unknown current address (n = 21), refusal of study participation (n = 14), and death due to accident and suicide (n = 2). In the 69 donors renal function was well preserved: serum creatinine 1.3 ± 0.0 mg/dL; ClCr 81 ± 2 mL/min; postdonation to predonation ClCr ratio 0.73 ± 0.02; and proteinuria 104 ± 11 mg/d. None of the donors experienced renal failure, although 36/69 (52%) patients have developed de novo hypertension. Compared with normotensive donors, the hypertensive subgroup was significantly older at the time of donation (50.7 ± 1.4 vs 46.4 ± 1.6 years; P = .010) and had a longer interval since donation (6.4 ± 0.2 vs 3.9 ± 0.1 years; P = .001). SF-36 questionnaire results in live kidney donors showed higher scores regarding physical (54.3 ± 0.8 vs 49.3 ± 0.1; P = .048) and psychological health (53.8 ± 0.6 vs 50.7 ± 0.1; P = .043) compared with the average German population.ConclusionOur cohort of live kidney donors showed good renal outcomes and superior SF-36 scores in both physical and psychological health compared with the German population. The risk of de novo hypertension increased with age and time after donation. Blood pressure screening should be regularly performed especially in the long term after donation.     

Comparison of hilar clamping and non-hilar clamping partial nephrectomy for tumours involving a solitary kidney

Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? It has been long recognized that ischemic injury to the kidney occurs when the blood supply to the kidney is interrupted by clamping of the renal artery (warm and cold ischemia). We developed a new technique of non‐clamping, non‐ischemic partial nephrectomy with this in mind. This article looks at the results of clamping vs non‐clamping partial nephrectomies in solitary kidneys, where the impact of ischemic injury is most accurately reflected. The technique of non‐ischemic partial nephrectomy accounts for 33% better preservation of renal function, when compared to ischemic partial nephrectomy. This new technique should be used in patients with a solitary kidney, patients with bilateral tumours, and patients with already impaired renal function.

OBJECTIVE

? To compare outcomes of hilar clamping and non‐hilar clamping partial nephrectomy for tumours involving a solitary functional kidney.

patientS AND METHODS

? Between 1990 and 2009, 104 partial nephrectomies, excluding bench and autotransplant procedures, were performed on solitary functional kidneys. ? An institutional review board‐approved retrospective review was performed analyzing patient demographics, operative data, complications, oncological outcomes and estimated glomerular filtration rate (GFR). ? GFR was calculated using the abbreviated Modification of Diet in Renal Disease equation. ? Preoperative GFR was compared to Early GFR (lowest measured GFR 7–100 days postoperatively) and to Late GFR (GFR 101–365 days postoperatively). ? Multiple linear regression analysis was performed to assess covariates affecting Late GFR. ? Kaplan–Meier estimator was utilized to compare renal cell carcinoma (RCC) specific survival and non‐RCC‐related survival.

RESULTS

? In total, 29 partial nephrectomies with hilar clamping and 75 partial nephrectomies without hilar clamping were performed in solitary kidneys. Median follow‐up was 57 months. ? There was no difference in tumour size, location and the number of tumours resected between the two groups. Mean ischaemia time for the clamping group was 25 min. ? Some 97% of the clamping procedures were performed with cold ischaemia. ? There was no difference in intra‐operative estimated blood loss, transfusion requirement or length of hospital stay. ? The complication rate and spectrum of complications were similar between the two groups. ? The two groups had similar preoperative GFR and Early GFR. The non‐clamping group had a significantly smaller percent decrease in Late GFR (11.8% vs 27.7%, P= 0.01) than the clamping group. ? The non‐clamping group was significantly more likely to have a less than 10% decrease in Late GFR compared to the clamping group (60.9% vs 17.7%, P= 0.002). ? On multivariate analysis, only hilar clamping was significantly associated with decreased Late GFR (estimate 15.0, P= 0.02). ? Surgical margin positivity rate was higher in the clamping group (21% vs 4%, P= 0.01); however, the local recurrence rate between the two groups was similar. ? The clamping and non‐clamping groups had similar 5‐year RCC‐specific survival and 5‐year non‐RCC‐related survival.

CONCLUSIONS

? Partial nephrectomy without hilar clamping in solitary kidneys provides similar cancer control compared to partial nephrectomy with hilar clamping. ? Partial nephrectomy without clamping was associated with superior preservation of Late GFR. ? No difference was detected in GFR early after surgery, possibly indicating that there may be ongoing renal loss after hilar clamping.     

Evolución de la función renal en pacientes con cáncer renal cT1 después de nefrectomía parcial y radical laparoscópica. Factores predictores de deterioro de función renal

Introduction and objectivesTo analyze the evolution of kidney function after laparoscopic partial nephrectomy (PN) and radical nephrectomy (RN) and to identify predictive factors for deterioration in kidney function.Material and methodRetrospective study of patients with two kidneys, glomerular filtration rate (GFR) > 60 mL/min/1.73 m², and single renal tumor cT1, treated in our center between 2005 and 2018.ResultsA total of 372 patients met the inclusion criteria for the study; 156 (41.9%) were treated by RN and 216 (58.1%) by PN. There was a difference of 26.75 mL/min/1.73 m² in GFR between RN and PN at discharge. Age > 60 years, postoperative complications (OR 2.97, p = 0.005) and RN (OR 10.03, p = 0.0001) were predictors of GFR<60 mL/min/1.73 m² at discharge. Only RN (OR 7.69, p = 0.0001) behaved as an independent prognostic factor for GFR<45 mL/min/1.73m2 at discharge. The median follow-up of the series was 57 (IQR 28-100) months. At the end of the follow-up period, nine (6%) patients treated with RN developed severe chronic kidney disease (CKD) and three (2%) developed end stage renal disease (ESRD). Age > 70 years, diabetes mellitus (DM) (HR 2.12, p = 0.001), arterial hypertension (AHT) (HR 1.73, p = 0.01) and RN (HR 2.88, p = 0.0001) behaved as independent predictors of GFR<60 mL/min/1.73 m². The independent predictors for GFR< 45 mL/min/1.73m2 were age >70 years, DM (HR 1.99 CI 95% 1.04-3.83, p = 0.04) and RN (HR 5.88 CI 95% 2.57-13.45, p = 0.0001).ConclusionsRN is a short- and long-term risk factor for CKD, although with a low probability of severe CKD or ESRD in patients with preoperative GFR > 60 mL/min/1.73 m². Age, DM and AHT contribute to worsening renal function during follow-up.     

Increase in 24-Hour Protein Excretion Immediately After Donation Is Associated With Decreased Functional Recovery in Living Kidney Donors

ObjectivesIn this study, we evaluated the occurrence of proteinuria in living kidney donors during the immediate postdonation period, aiming to determine its clinical significance in renal function recovery.Patients and methodsWe enrolled living kidney donors with predonation protein excretion rate (PER) < 150 mg/24 h. Participants were divided into 2 groups according to immediate postdonation PER (4 days after nephrectomy): non-microproteinuria (non-mPr; PER < 150 mg/24 h), n = 244; and immediate postdonation microproteinuria (ImPr; PER ≥ 150 mg/24 h), n = 605.ResultsEstimated glomerular filtration rate (eGFR) did not differ significantly between groups immediately after nephrectomy but was consistently lower in the ImPr group 1 week to 1 year postdonation (1-year postdonation eGFR: ImPr group, 63.6 ± 12.1 mL/min/1.73 m²; non-mPr group, 68.6 ± 12.3 mL/min/1.73 m²; P = .001). Immediate postdonation microproteinuria was an independent predictor of eGFR at 1 year postdonation (β [standard error] = -2.68 [1.15], 95% confidence interval -4.94 to -0.42, P = .02), along with predonation eGFR, age, and sex. Immediate postdonation microproteinuria was more common in donors who were older or male and occurred in 71.3% of kidney donors, suggesting renal injury in this period.ConclusionsAlthough proteinuria generally resolves, its impact persists and can impair renal function recovery. Donors who are older and male are more likely to undergo immediate hyperfiltration after donation.     

Renal Consequences of Diabetes After Kidney Donation

Whether diabetes after kidney donation is associated with an accelerated GFR decay in the remaining kidney has not been studied. We determined the incidence of diabetes in kidney donors, and compared GFR change over time in diabetic to nondiabetic donors, in addition to the effect of diabetes mellitus (DM) on the development of proteinuria, hypertension, and end‐stage renal disease (ESRD). Of the 4014 donors, 309 (7.7%) developed diabetes at a median age of 56.0 years and after a median of 18 years after donation. The difference in annual estimated GFR (eGFR) change between diabetic and nondiabetic donors in the 7 years before the development of DM was ?0.08 mL/min/year; p = 0.51. After DM development, the difference was ?1.10 mL/min/year for diabetic donors with hypertension and proteinuria, p < 0.001; ?0.19 for diabetic donors with hypertension but no proteinuria, p = 0.29; ?0.75 mL/min/year for diabetic donors with proteinuria but no hypertension, p = 0.19; and ?0.09 mL/min/year for diabetic donors without proteinuria or hypertension, p = 0.63. When DM was considered as a time‐dependent covariate, it was associated with the development of proteinuria (hazard ratio [HR] 2.65, 95% confidence interval [CI] 1.89–3.70; p < 0.001) and hypertension (HR 2.19, 95% CI 1.74–2.75; p < 0.001). It was not, however, associated with ESRD. eGFR decline after DM development exceeds that of nondiabetic donors only in diabetic donors with concomitant proteinuria and hypertension.     

Risks of Living Donor Nephrectomy

Introduction

There is good evidence that long-term graft survival is superior when living donors are used for kidney transplantation. Nevertheless, an assessment of potential risks associated with living donation is of particular interest.

Patients and Methods

In this single-center study, we evaluated the renal function of 31 kidney living donors (1997-2003) at 2-13.2 years after nephrectomy. The purpose of this study was to evaluate perioperative complications, renal function, new-onset proteinuria, and hypertension.

Results

Living related donation was performed in all cases. The average time after donation was 5.7 ± 2.4 years. The mean age at nephrectomy was 46.3 ± 9.0 years (range, 25-64), and 26 (83.9%) donors were females. Twelve patients (29%) were older than 50 years. The left kidney was used in 25 patients (80.6%). Surgical complications occurred in 2 patients. Glomerular filtration rate (GFR) decreased from 116.9 ± 23 to 77.7 ± 19.2 mL/min/1.73 m² (P < .001). Five patients (16.1%) developed a postdonation GFR between 50 and 60 mL/min/1.73 m². Patients with lower GFR values after uninephrectomy showed lower predonation values (P < .05). Older patients (>50 years) displayed lower postdonation GFR than younger ones. We did not observe an increased prevalence of low postdonation GFR over time nor significant differences in protein excretion and blood pressure.

Conclusions

Living donor nephrectomy appears to be an acceptably safe intervention. Despite a reduction in GFR, the postdonation incidence of hypertension was low and proteinuria was not observed in any donor, even among previously hypertensive patients. Rigorous donor follow-up is recommended to identify persons at risk.