Importance and limits of ischemia in renal partial surgery: experimental and clinical research

A comparison of pre- and post-operative outcomes in living donors undergoing transperitoneal laparoscopic nephrectomy and open nephrectomy: a retrospective single-center study

BACKGROUND

Kidney transplantation is often regarded as the preferred therapy for end-stage renal disease. Several surgical procedures have been developed to reduce postoperative donor complications, while maintaining kidney quality.

OBJECTIVE

This study aimed to compare the preoperative and postoperative outcomes of living kidney donors who underwent either transperitoneal laparoscopic nephrectomy or open nephrectomy.

DESIGN AND SETTING

Retrospective study conducted in Istanbul, Turkey.

METHODS

Fifty-five living-related kidney donors underwent nephrectomy and were retrospectively divided into two groups: 21 donors who underwent open nephrectomy (Group 1) and 34 donors who underwent transperitoneal laparoscopic nephrectomy (Group 2).

RESULTS

In comparison to the donors who underwent open nephrectomy, those who underwent transperitoneal laparoscopic nephrectomy had significantly shorter postoperative hospital stays (2.3 ± 0.2 versus 3.8 ± 0.8 days, P = 0.003), duration of urinary catheterization (1.2 ± 0.8 days versus 2.0 ± 0.7 days, P = 0.0001), operating times (210 ± 27 minutes versus 185 ± 24 minutes, P = 0.02), and less blood loss (86 ml versus 142 ml, P = 0.048). There was no statistically significant difference between the two groups with regard to the estimated blood transfusion and warm ischemia time. The preoperative week, first postoperative week, and 1-month postoperative serum creatinine levels were comparable between the groups.

CONCLUSIONS

Laparoscopic donor nephrectomy can be safely performed at centers with expertise in laparoscopic surgery. Laparoscopic donor nephrectomy has better outcomes than open donor nephrectomy in terms of length of hospital stay, duration of urinary catheterization, operating time, and blood loss.

The role of warm ischemia time on functional outcomes after robotic partial nephrectomy: a radionuclide renal scan study from the clock randomized trial

PURPOSE

To evaluate the relationship between warm ischemia time (WIT) duration and renal function after robot-assisted partial nephrectomy (RAPN).

METHODS

The CLOCK trial is a phase 3 randomized controlled trial comparing on- vs off-clamp RAPN. All patients underwent pre- and postoperative renal scintigraphy. Six-month absolute variation of eGFR (AV-GFR), rate of relative variation in eGFR over 25% (RV-GFR > 25), absolute variation of split renal function (SRF) at scintigraphy (AV-SRF). The relationships WIT/outcomes were assessed by correlation graphs and then modeled by uni- and multivariable regression.

RESULTS

324 patients were included (206 on-clamp, 118 off-clamp RAPN). Correlation graphs showed a threshold on WIT equal to 10 min. The differences in outcome measures between cases with WIT < vs ≥ 10 min were: AV-GFR - 3.7 vs - 7.5 ml/min (p < 0.001); AV-SRF - 1% vs - 3.6% (p < 0.001); RV-GFR > 25 9.3% vs 17.8% (p = 0.008). Multivariable models found that AV-GFR was related to WIT ≥ 10 min (regression coefficient [RC] - 0.52, p = 0.019), age (RC - 0.35, p = 0.001) and baseline eGFR (RC - 0.30, p < 0.001); RV-GFR > 25 to WIT ≥ 10 min (odds ratio [OR] 1.11, p = 0.007) and acute kidney injury defined as > 50% increase in serum creatinine (OR 19.7, p = 0.009); AV-SRF to WIT ≥ 10 min (RC - 0.30, p = 0.018), baseline SRF (RC - 0.76, p < 0.001) and RENAL score (RC - 0.60. p = 0.028). The main limitation was that the CLOCK trial was designed on a different endpoint and therefore the present analysis could be underpowered.

CONCLUSIONS

Up to 10 min WIT had no consequences on functional outcomes. Above the 10-min threshold, a statistically significant, but clinically negligible impact was found.

Protective effect of sacubitril/valsartan (Entresto) on kidney function and filtration barrier injury in a porcine model of partial nephrectomy

Kidney surgery often includes organ ischaemia with a risk of acute kidney injury. The present study tested if treatment with the combined angiotensin II-angiotensin II receptor type 1 and neprilysin blocker Entresto (LCZ696, sacubitril/valsartan) protects filtration barrier and kidney function after ischaemia and partial nephrectomy (PN) in pigs. Single kidney glomerular filtration rate (GFR) by technetium-99m diethylene-triamine-pentaacetate clearance was validated (n = 6). Next, four groups of pigs were followed for 15 days (n = 24) after PN (one-third right kidney, 60 min ischaemia) + Entresto (49/51 mg/day; n = 8), PN + vehicle (n = 8), sham + Entresto (49/51 mg/day; n = 4) and sham + vehicle (n = 4). GFR, diuresis and urinary albumin were measured at baseline and from each kidney after 15 days. The sum of single-kidney GFR (right 25 ± 6 mL/min, left 31 ± 7 mL/min) accounted for the total GFR (56 ± 14 mL/min). Entresto had no effect on baseline blood pressure, p-creatinine, mid-regional pro-atrial natriuretic peptide (MR-proANP), heart rate and diuresis. After 15 days, Entresto increased GFR in the uninjured kidney (+23 ± 6 mL/min, P < .05) and reduced albuminuria from both kidneys. In the sham group, plasma MR-proANP was not altered by Entresto; it increased to similar levels 2 h after surgery with and without Entresto. Fractional sodium excretion increased with Entresto. Kidney histology and kidney injury molecule-1 in cortex tissue were not different. In conclusion, Entresto protects the filtration barrier and increases the functional adaptive response of the uninjured kidney.

Impact of Blood Loss on Renal Function and Interaction with Ischemia Duration after Nephron-Sparing Surgery

OBJECTIVES

Nephron-sparing surgery (NSS) exposes the kidney to ischemia-reperfusion injury. Blood loss and hypotension are also associated with kidney injury. We aimed to test the hypothesis that, during NSS, both ischemia duration and blood loss significantly affect postoperative renal function and that their effects interact.

METHODS

Consecutive patients undergoing NSS were enrolled. The primary endpoint was renal function expressed as the absolute delta between preoperative and postoperative peak creatinine. We developed a generalized linear model with the ischemia duration and absolute hemoglobin difference as independent variables, their interaction term, and the RENAL score. The model was than expanded to include a history of hypertension (as a proxy for hypotension susceptibility) and related interaction terms. Further, we described the perioperative and mid-term oncological outcomes.

RESULTS

A total of 478 patients underwent NSS, and 209 (43.7%) required ischemia for a mean of 10.9 min (SD 8). Both the ischemia duration (partial eta 0.842, p = 0.006) and hemoglobin difference (partial eta 0.933, p = 0.029) significantly affected postoperative renal function, albeit without evidence of a significant interaction (p = 0.525). The RENAL score also significantly influenced postoperative renal function (p = 0.023). After the addition of a previous history of hypertension, the effects persisted, with a significant interaction between blood loss and a history of hypertension (p = 0.02).

CONCLUSIONS

Ischemia duration and blood loss had a similar impact on postoperative renal function, albeit without potentiating each other. While the surgical technique and ischemia minimization remain crucial to postoperative kidney function, increased awareness of conscious hemodynamic management appears warranted.

Functional, oncological outcomes and safety of laparoscopic partial nephrectomy versus open partial nephrectomy in localized renal cell carcinoma patients with high anatomical complexity

PURPOSE

Partial nephrectomy (PN) is the main treatment strategy for localized renal cell carcinoma (RCC). However, for RCC with high anatomical complexity, PN remains a challenge for urologists. Therefore, this study aimed to evaluate the functional oncological outcomes and safety of laparoscopic partial nephrectomy (LPN) versus open partial nephrectomy (OPN) in localized RCC patients with highly anatomical complexity (R.E.N.A.L. score ≥ 10).

PATIENTS AND METHODS

We retrospectively studied 575 patients who underwent PN at our center between January 2007 and December 2017. After propensity score-matching (PSM), 137 patients treated with LPN and 54 patients treated with OPN were balanced into 97 and 44 pairs. Patient demographics, and extensive perioperative and prognostic data were recorded and compared.

RESULTS

In the matched group, the OPN group had significantly less eGFR loss than the LPN group (2.57 ml/min/1.73 m² vs. 31.59 ml/min/1.73 m², P < 0.001). The recurrence-free survival (P = 0.287), overall survival (P = 0.296), cancer-specific survival (P = 0.664), and cardiocerebrovascular disease-specific survival (P = 0.341) were equivalent between groups. The rates of minor (P = 0.621) and major (P = 0.647) complications were also similar between groups.

CONCLUSIONS

This PSM cohort study showed that OPN resulted in better renal function preservation than LPN in localized RCC patients with high anatomical complexity, and had comparable oncological and safety outcomes after long-term follow-up. These findings may help improve clinical decision-making for localized RCC patients with high anatomical complexity.

The Effect of Antioxidant Added to Preservation Solution on the Protection of Kidneys before Transplantation

Ischemia–reperfusion injury is a key clinical problem of transplantology. Current achievements in optimizing organ rinse solutions and storage techniques have significantly influenced the degree of graft damage and its survival after transplantation. In recent years, intensive research has been carried out to maintain the viability of tissues and organs outside the integral environment of the body. Innovative solutions for improving the biochemical functions of the stored organ have been developed. The article discusses directions for modifying preservation solutions with antioxidants. Clinical and experimental studies aimed at optimizing these fluids, as well as perfusion and organ preservation techniques, are presented.

Trimetazidine an emerging paradigm in renal therapeutics: Preclinical and clinical insights

Trimetazidine (TMZ) is a well-known anti-ischemic agent used for the treatment of angina pectoris. In the past decades, the efficacy of this drug has been tested in a wide range of kidney injuries, including drug-induced nephrotoxicity (DIN), radio-contrast agent-induced nephropathy, and surgically induced renal ischemic injury. TMZhas renoprotective effects by attenuating oxidative stress, inflammatory cytokine release, maintaining oxygen and energy balance. Moreover, TMZ administration prevented kidney graft rejection in the porcine model by suppressing the infiltration of mononuclear cells, preserving mitochondrial functions, and maintaining Ca+ homeostasis. In DIN and diabetic kidney diseases,TMZ treatment prevents renal injury by inactivating immune cells, attenuating renal fibrosis, inflammation, apoptosis, and histological abnormalities. Interestingly, the clinical therapeutic efficacy of TMZ has also been documented in pre-existing kidney disease patients undergoing contrast exposure for diagnostic intervention. However, the mechanistic insights into the TMZ mediated renoprotective effects in other forms of renal injuries, including type-2 diabetes, drug-induced nephrotoxicity, and hypertension-induced chronic kidney diseases, remain uninvestigated and incomplete. Moreover, the clinical utility of TMZ as a renoprotective agent in radio-contrast-induced nephrotoxicity needs to be tested in a large patient population. Nevertheless, the available pieces of evidence suggest that TMZ is a promising and emerging renal therapy for the treatment and management of kidney diseases of variable etiologies. This review discusses the various pre-clinical and clinical findings and provides mechanistic insights into the TMZ mediated beneficial effects in various kidney diseases.

Effect of unilateral renal ischemia on the contralateral kidney assessed by Caspase 3 expression

Background

Studies have demonstrated with histological analysis and Doppler flow measurement analysis that unilateral renal ischemia, which is performed in some surgeries, interfered with the contralateral kidney, identifying the phenomenon of kidney-kidney crosstalk.

Objectives

To identify the effects on the ischemic and contralateral kidney of renal ischemia induced by two types of clamping technique by analyzing the volume of kidney cells positive for Caspase 3.

Methods

Sixteen pigs were divided into 2 groups, as follows: A (n = 8) – clamping of left renal artery only and AV (n = 8) – clamping of left renal artery and vein. Immunohistochemical analyses (anti Caspase 3) were conducted with biopsy specimens collected from the ischemic and contralateral kidney at 0, 30, 60, and 90 minutes of ischemia and morphometric analysis was performed, taking the mean to represent the volume of the Caspase 3 positive area (%).

Results

Morphometric analysis of specimens collected at 30, 60, and 90 minutes of ischemia showed that the mean area marked for Caspase 3 was statistically larger in the contralateral kidney than the ischemic kidney in both groups: clamped renal artery (A) and clamped renal artery and vein (AV). Comparing the ischemic and contralateral kidney, there was no statistically significant difference in the area marked for Caspase 3 between the two types of clamping.

Conclusions

In the experimental model of unilateral renal ischemia, the non-ischemic kidney exhibited cell damage, demonstrated by Caspase 3 expression. The type of hilum clamping does not appear to influence the area marked for Caspase 3.

Nephroprotective effect of methanol extract of Moringa oleifera leaves on acute kidney injury induced by ischemia-reperfusion in rats

BACKGROUND

Moringa oleifera is known to exhibit protection against oxidative damage due to its rich content of compounds with antioxidant activity. This study investigated the protective effect of the methanol extract of Moringa oleifera (MO) in a rat model of renal ischemia-reperfusion (IR) injury.

METHODS

Forty two wistar rats were randomly assigned to six groups of seven rats each, as follows: A, control group; B, sham-operated group; C, IR group; D, IR + low dose (200 mg/kg) MO; E, IR + high dose (400 mg/kg) MO and F, IR + Vitamin C (200 mg/kg). Unilateral ischaemia was induced by occluding the left renal artery for 45 minutes followed by reperfusion up to 24 hours.

RESULTS

Moringa oleifera significantly (p<0.05) ameliorated IR-induced increases in malondialdehyde (MDA), protein carbonyls (PC) and advanced oxidation protein products (AOPP), while also decreasing serum BUN and Creatinine levels. Moreover, the low dose of MO caused reductions in renal NO and H2O2 levels, while increasing renal GPx and GST activities. Histopathology revealed marked improvement of tissue alterations induced by IR with both doses of MO.

CONCLUSION

Overall, the methanol extract of M. oleifera effectively attenuated the deleterious effects of renal IR via alleviation of tissue oxidative stress.

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.

Comparison of Hilar Clamping Techniques in Partial Nephrectomy: Is Artery Only Clamping Beneficial?

Hilar clamping is widely adopted in open partial nephrectomy, which is a treatment option for small renal cancer to reduce blood loss and improve surgical exposure, but whether to clamp either only artery or both artery and vein remains controversial. The purpose of this study is to determine whether artery only (AO) clamping is more beneficial than en bloc clamping by comparing perioperative variables in patients who underwent partial nephrectomy with either AO clamping or en bloc clamping. Eighty-eight patients with T1 renal tumor who underwent open partial nephrectomy with either AO or en bloc clamping between 2015 and 2018 at our institution were enrolled. They were randomly divided into two groups: AO group (n = 43) and artery and vein (AV) group (n = 45). Renal function was evaluated by serum creatinine (SCr) and differential renal function as determined by mercaptoacetyltriglycine renogram. AO clamping was associated with less total renal functional decrease until postoperative 7th day (P < 0.05). After postoperative 15th day, however, there was no significant difference in total renal functional impairment between AO and AV groups. There was also no significant difference in differential renal function change. Furthermore, AO clamping caused more blood loss and hemoglobin (Hb) decrease than en bloc clamping (P < 0.05). AO clamping is no more beneficial than en bloc clamping in partial nephrectomy, presenting with not significantly better long-term postoperative renal function than en bloc clamping.

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.

Predicting intra-operative and postoperative consequential events using machine-learning techniques in patients undergoing robot-assisted partial nephrectomy: a Vattikuti Collective Quality Initiative database study

OBJECTIVE

To predict intra-operative (IOEs) and postoperative events (POEs) consequential to the derailment of the ideal clinical course of patient recovery.

MATERIALS AND METHODS

The Vattikuti Collective Quality Initiative is a multi-institutional dataset of patients who underwent robot-assisted partial nephectomy for kidney tumours. Machine-learning (ML) models were constructed to predict IOEs and POEs using logistic regression, random forest and neural networks. The models to predict IOEs used patient demographics and preoperative data. In addition to these, intra-operative data were used to predict POEs. Performance on the test dataset was assessed using area under the receiver-operating characteristic curve (AUC-ROC) and area under the precision-recall curve (PR-AUC).

RESULTS

The rates of IOEs and POEs were 5.62% and 20.98%, respectively. Models for predicting IOEs were constructed using data from 1690 patients and 38 variables; the best model had an AUC-ROC of 0.858 (95% confidence interval [CI] 0.762, 0.936) and a PR-AUC of 0.590 (95% CI 0.400, 0.759). Models for predicting POEs were trained using data from 1406 patients and 59 variables; the best model had an AUC-ROC of 0.875 (95% CI 0.834, 0.913) and a PR-AUC 0.706 (95% CI, 0.610, 0.790).

CONCLUSIONS

The performance of the ML models in the present study was encouraging. Further validation in a multi-institutional clinical setting with larger datasets would be necessary to establish their clinical value. ML models can be used to predict significant events during and after surgery with good accuracy, paving the way for application in clinical practice to predict and intervene at an opportune time to avert complications and improve patient outcomes.

Matching Human Unilateral AKI, a Reverse Translational Approach to Investigate Kidney Recovery after Ischemia

BACKGROUND

The duration of renal ischemia that is associated with (or leads to) renal injury in patients is uncertain, and a reverse translational research approach has been proposed to improve animal models of AKI to facilitate clinical translatability. We developed a two murine models of unilateral renal ischemia to match a recently published human study that investigated renal injury after unilateral renal ischemia during partial nephrectomy.

METHODS

Eight 10-week-old C57BL/6 male mice underwent left UiAKI or sham procedure, with or without intra-operative ice packs. Functional, histological, and biomarker outcomes were followed at 2, 6 and 24 hours, or 14 or 28 days later. The 14 and 28 day cohorts were duplicated such that contralateral nephrectomy could be performed 3 days prior to sacrifice with functional measurements obtained to isolate the glomerular filtration rate of the injured kidney.

RESULTS

The short-term outcomes correlated with the human study findings with urine and serum biomarkers of injury peaking around 24 hours and then normalizing, and reassuring immediate histological outcomes. Functional and histological outcomes at the later time-points (14 and 28 days) demonstrate an increase in fibrosis markers, and a reduction in glomerular filtration rate in the injured kidney, corresponding to the duration of ischemia, while serum and urine biomarkers remained reassuring.

CONCLUSIONS

Our findings suggest that clinically available biomarkers of renal function are falsely reassuring against long-term injury following UiAKI, and that the duration of ischemia correlates with impaired function and increased fibrosis.

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.

Organ protection during aortic cross-clamping

Open surgical repair of an aortic aneurysm requires aortic cross-clamping, resulting in temporary ischemia of all organs and tissues supplied by the aorta distal to the clamp. Major complications of open aneurysm repair due to aortic cross-clamping include renal ischemia-reperfusion injury and postoperative colonic ischemia in case of supra- and infrarenal aortic aneurysm repair. Ischemia-reperfusion injury results in excessive production of reactive oxygen species and in oxidative stress, which can lead to multiple organ failure. Several perioperative protective strategies have been suggested to preserve renal function during aortic cross-clamping, such as pharmacotherapy and therapeutic hypothermia of the kidneys. In this chapter, we will briefly discuss the pathophysiology of ischemia-reperfusion injury and the preventative measures that can be taken to avoid abdominal organ injury. Finally, techniques to minimize the risk of complications during and after open aneurysm repair will be presented.

Identification of patients at risk for renal impairment after living donor kidney transplantation

PURPOSE

Outcome after living donor kidney transplantation is highly relevant, since recipient and donor were exposed to notable harm. Reliable identification of risk factors is necessary.

METHODS

Three hundred sixty-six living donor kidney transplants were included in this observational retrospective study. Relevant risk factors for renal impairment 1 year after transplantation and delayed graft function were identified with univariable and multivariable binary logistic regression and ordinal regression analysis.

RESULTS

Eighty-four patients (26.6 %) suffered from renal impairment KDIGO stage ≥4 1 year post-transplant; median estimated glomerular filtration rate was 35.3 ml/min. In multivariable ordinal regression, male recipient sex (p < 0.001), recipient body mass index (p = 0.006), donor age (p = 0.002) and high percentages of panel reactive antibodies (p = 0.021) were revealed as independent risk factors for higher KDIGO stages. After adjustment for post-transplant data, recipient male sex (p < 0.001), donor age (p = 0.026) and decreased early renal function at the first post-transplant outpatient visit (p < 0.001) were identified as independent risk factors. Delayed graft function was independently associated with long stay on the waiting list (p = 0.011), high donor body mass index (p = 0.043), prolonged warm ischemic time (p = 0.016) and the presence of preformed donor-specific antibodies (p = 0.043).

CONCLUSIONS

Broadening the donor pool with non-blood related donors seems to be legitimate, although with respect to careful medical selection, since donor age in combination with male recipient sex were shown to be risk factors for decreased graft function. Warm ischemic time and waiting time need to be kept as short as possible to avoid delayed graft function. Transplantation across HLA and ABO borders did not affect outcome significantly.

Predictors of postoperative renal functional damage after nephron-sparing surgery

BACKGROUND

Although nephron-sparing surgery has been reported not to affect total renal function, it is a non-negligible fact that functional damage of the operated kidney usually results, for various reasons. This study aimed to explore the effects of preoperative baseline characteristics, tumor characteristics, and function protection methods on postoperative renal damage.

METHODS

This study was a retrospective review of 51 patients who underwent open nephron-sparing surgery. The mean age of the patients (39 men, 12 women) was 54.2 ± 13.9 years, range 32 to 71 years. The glomerular filtration rate (GFR) was measured preoperatively and 6th months after the operation. Univariate analysis was used to screen indicators with significant differences in different levels of renal function damage. All variables found to be significant on univariate analysis were entered into a multiple logistic regression model to predict risk factors for renal function damage.

RESULTS

Univariate analysis showed that there was a significant difference in age, GFR of operated kidney, tumor diameter, tumor depth, and ischemic protection type between patients with little damage and those with heavy damage (P < 0.05). Forward stepwise logistic regression analysis suggested that age (odds ratio, 3.08; 95% confidence interval 1.78 to 7.04; P = 0.037), preoperative GFR of operated kidney (odds ratio, 0.51; 95% confidence interval 0.11 to 0.73; P = 0.033), and tumor diameter (odds ratio, 5.49; 95% confidence interval 2.14 to 7.88; P = 0.012) and depth (odds ratio, 5.82; 95% confidence interval 2.66 to 8.06; P = 0.010) were independent risk factors for postoperative renal function damage.

CONCLUSIONS

Patients with older age, poor renal function, and large tumor diameter and depth might be at higher risk of renal function damage after nephron-sparing surgery.

The second short-term warm ischemia after vascular anastomosis did not affect early renal function recovery in renal transplantation: a case report

Ischemic postconditioning was defined as rapid intermittent interruptions of blood flow in the early phase of reperfusion, which has been found to be protective against renal ischemia-reperfusion injury (IRI) in animal models but not in clinical trials.We describe a case that the allograft renal vein was twisted because of the surgeon's mistake, which caused the warm ischemia of allograft after reperfusion. The allograft restored blood flow without second reperfusion and cold preservation after 9 min of warm ischemia. The patient was followed up for 3 months and the allograft worked well without complications.

The suffocating kidney: tubulointerstitial hypoxia in end-stage renal disease

Chronic kidney disease (CKD) is characterized by irreversible pathological processes that result in the development of end-stage renal disease (ESRD). Accumulating evidence has emphasized the important role of chronic hypoxia in the tubulointerstitium in the final common pathway that leads to development of ESRD. The causes of chronic hypoxia in the tubulointerstitium are multifactorial and include mechanisms such as hemodynamic changes and disturbed oxygen metabolism of resident kidney cells. Epidemiological studies have revealed an association between CKD and systemically hypoxic conditions, such as chronic obstructive pulmonary disease and sleep apnea syndrome. In addition to tubulointerstitial hypoxia, glomerular hypoxia can occur and is a crucial factor in the development of glomerular disorders. Chemical compounds, polarographic sensors, and radiographical methods can be used to detect hypoxia. Therapeutic approaches that target chronic hypoxia in the kidney should be effective against a broad range of kidney diseases. Amelioration of hypoxia is one mechanism of inhibiting the renin-angiotensin system, the current gold standard of CKD therapy. Future therapeutic approaches include protection of the vascular endothelium and appropriate activation of hypoxia-inducible factor, a key transcription factor involved in adaptive responses against hypoxia.