Histopathological evaluation of 0-h biopsy specimens of donor kidney procured by laparoscopic donor nephrectomy

Effects of pneumoperitoneum with carbon dioxide on renal and hepatic functions in rats

Introduction

Laparoscopic surgery is a preferred method based on its many benefits. However, increasing abdominal pressure by CO₂ insufflation during the implementation of this technique poses challenges.

Aim

To determine the degree of renal and liver injury that occurs in a pneumoperitoneum (PP) model of prolonged CO₂ insufflation.

Material and methods

Twenty-one female Sprague Dawley rats were separated randomly into three groups. Group 1 was the control group and given anesthesia for 3 h. In group 2, PP was administered under anesthesia for 1 h. In the last group, PP was administered under anesthesia to animals for 3 h. We measured renal and liver injury biomarkers and made a histopathological evaluation to estimate the degree of injury and assessed the correlation of biomarkers including kidney injury molecule-1 (KIM-1) with histopathological findings.

Results

Histopathological analysis according to the kidney ischemia tubular damage score showed a statistically significant difference between the 3 groups (p < 0.001). There was an increase in KIM-1 levels in the groups, although it was not statistically significant (p = 0.062, p = 0.156, p = 0.350 respectively). According to the correlation test in this research, KIM-1 results had a statistically significant association with creatinine, urea, aspartate aminotransferase and alanine aminotransferase levels in all control and study groups.

Conclusions

According to our results, the increase in KIM-1 was correlated with Cr levels and compatible with histopathological analysis. Moreover, intra-abdominal pressure statistically significantly increased the degree of kidney injury and there was not a significant increase in the levels of KIM-1. There was no difference in liver damage between groups.

Effects of low versus standard pressure pneumoperitoneum on renal syndecan-1 shedding and VEGF receptor-2 expression in living-donor nephrectomy: a randomized controlled study

Background

Laparoscopic nephrectomy is a preferred technique for living kidney donation. However, positive-pressure pneumoperitoneum may have an unfavorable effect on the remaining kidney and other distant organs due to inflamed vascular endothelium and renal tubular cell injury in response to increased systemic inflammation. Early detection of vascular endothelial and renal tubular response is needed to prevent further kidney injury due to increased intraabdominal pressure induced by pneumoperitoneum. Transperitoneal laparoscopic living donor nephrectomy represented a human model of mild increasing intraabdominal pressure. This study aimed to assess the effect of increased intraabdominal pressure on vascular endothelium and renal tubular cells by comparing the effects of low and standard pressure pneumoperitoneum on vascular endothelial growth factor receptor-2 (VEGFR-2) expression and the shedding of syndecan-1 as the early markers to a systemic inflammation.

Methods

We conducted a prospective randomized study on 44 patients undergoing laparoscopic donor nephrectomy. Subjects were assigned to standard (12 mmHg) or low pressure (8 mmHg) groups. Baseline, intraoperative, and postoperative plasma interleukin-6, syndecan-1, and sVEGFR-2 were quantified by ELISA. Syndecan-1 and VEGFR-2 expression were assessed immunohistochemically in renal cortex tissue. Renal tubule and peritubular capillary ultrastructures were examined using electron microscopy. Perioperative hemodynamic changes, end-tidal CO₂, serum creatinine, blood urea nitrogen, and urinary KIM-1 were recorded.

Results

The low pressure group showed lower intra- and postoperative heart rate, intraoperative plasma IL-6, sVEGFR-2 levels and plasma syndecan-1 than standard pressure group. Proximal tubule syndecan-1 expression was higher in the low pressure group. Proximal-distal tubules and peritubular capillary endothelium VEGFR-2 expression were lower in low pressure group. The low pressure group showed renal tubule and peritubular capillary ultrastructure with intact cell membranes, clear cell boundaries, and intact brush borders, while standard pressure group showed swollen nuclei, tenuous cell membrane, distant boundaries, vacuolizations, and detached brush borders.

Conclusion

The low pressure pneumoperitoneum attenuated the inflammatory response and resulted in reduction of syndecan-1 shedding and VEGFR-2 expression as the renal tubular and vascular endothelial proinflammatory markers to injury due to a systemic inflammation in laparoscopic nephrectomy.

Trial registration

ClinicalTrials.gov NCT:03219398, prospectively registered on July 17th, 2017.

The effects of prolonged CO2 insufflation on kidney function in a rat pneumoperitoneum model

INTRODUCTION

Pneumoperitoneum (PP) is known to cause ischemia in kidneys and other intra-abdominal organs because of decreased splanchnic blood flow.

AIM

We aimed to determine the degree of renal injury that occurs due to a PP and prolonged PP. We measured renal injury biomarkers and made a histopathological evaluation to estimate the degree of injury and assessed the correlation of biomarkers with histopathological findings.

MATERIAL AND METHODS

Twenty-one female Sprague Dawley rats were separated randomly into three groups. Group 1 was the control group and was given anesthesia for 3 h. In group 2, a PP was administered under anesthesia for 1 h. A pneumoperitoneum was administered under anesthesia to animals in group 3 for 3 h.

RESULTS

Pathological analysis showed a significant statistical difference between the 3 groups. In particular, neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C (Cys C) levels at the 24^th h and preoperative mean urea levels showed a significant difference between the groups. The 24^th-hour NGAL level in group 3 was significantly higher than that of group 1. The preoperative Cys C level was higher in group 1 than in either group 2 or 3. Cys C was decreased significantly in group 1 and increased significantly in both groups 2 and 3.

CONCLUSIONS

The increase in NGAL and Cys C levels directly correlated with the duration of PP and intra-abdominal pressure, and they are therefore good biomarkers in diagnosing acute renal injury in the early phase. Serum creatinine level is not a good biomarker in the early phase of renal injury.

Influence of preoperative anti-HLA antibodies on short- and long-term graft survival in recipients with or without rituximab treatment

We investigated the relationship between preoperative anti-HLA antibodies (donor-specific antibody, DSA) and the graft survival rate in recipients who had or had not received rituximab (Rit) treatment. The subjects were categorized into four groups as follows: DSA+Rit-, n = 39; DSA-Rit-, n = 121; DSA+Rit+, n = 74; and DSA-Rit+, n = 47. We examined the influence of preoperative DSA on the incidence of graft rejection and the survival rate of recipients who had or who had not received rituximab before transplantation. The 6-month acute rejection rates based on graft biopsies were 39%, 19%, 15%, and 0% for the DSA+Rit-, DSA-Rit-, DSA+Rit+, and DSA-Rit+ groups. The rates of chronic antibody-mediated rejection after more than 6 months were 50%, 22%, 18%, and 0%. The 5-year graft survival rate was significantly lower in the DSA+Rit- group (84%) than in the other groups (95% for DSA-Rit-, 98% for DSA+Rit+, and 91% for DSA-Rit+). The rate of the appearance of de novo anti-HLA antibodies was higher in the groups that did not receive rituximab treatment. The rate of graft loss associated with chronic antibody-mediated rejection was also higher in the DSA+Rit- group than in the other groups (P = 0.01). The presence of DSA and the administration of rituximab had strong impacts on not only short-term graft rejection, but also long-term graft rejection and its association with the graft survival time.

Carbon dioxide insufflation causes upper urinary tract injury in the early period of an experimental vesicoureteral reflux model

PURPOSE

Ureteral reimplantation via pneumovesicum is a new aspect of vesicoureteral reflux management. We aimed to determine the effects of carbon dioxide (CO2) insufflation on the upper urinary tract in an experimental model.

MATERIALS AND METHODS

Thirty New Zealand rabbits were allocated into five groups of six rabbits each. Right ureters were cannulated for CO2 insufflation in four groups. The pressures and durations of CO2 insufflation in the respective groups were as follows: Group A (10 mm Hg, 2 h); B (12 mm Hg, 2 h); C (10 mm Hg, 4 h); and D (12 mm Hg, 4 h) and control (E). Blood gas analysis, urea and creatinine levels were measured from renal veins and aorta. Histopathological evaluation of the renal parenchyma and ureters was scored.

RESULTS

Significant histopathological changes were detected in the ipsilateral ureter and renal parenchyma exposed to CO2 insufflation, predominantly observed in groups insufflated for longer durations, p < 0.05. Blood gases drawn separately from renal veins were significantly more acidotic, and serum urea and creatinine levels were increased in all the groups, p < 0.05.

CONCLUSIONS

CO2 causes significant histopathological and biochemical changes in the early period. Long-term results are required to determine whether permanent renal injury occurs.

Protective response in renal transplantation: no clinical or molecular differences between open and laparoscopic donor nephrectomy

OBJECTIVE

Prolonged warm ischemia time and increased intra-abdominal pressure caused by pneumoperitoneum during a laparoscopic donor nephrectomy could enhance renal ischemia reperfusion injury. For this reason, laparoscopic donor nephrectomy may be associated with a slower graft function recovery. However, an adequate protective response may balance the ischemia reperfusion damage. This study investigated whether laparoscopic donor nephrectomy modified the protective response of renal tissue during kidney transplantation.

METHODS

Patients undergoing live renal transplantation were prospectively analyzed and divided into two groups based on the donor nephrectomy approach used: 1) the control group, recipients of open donor nephrectomy (n = 29), and 2) the study group, recipients of laparoscopic donor nephrectomy (n = 26). Graft biopsies were obtained at two time points: T-1 = after warm ischemia time and T+1 = 45 minutes after kidney reperfusion. The samples were analyzed by immunohistochemistry for the Bcl-2 and HO-1 proteins and by real-time polymerase chain reaction for the mRNA expression of Bcl-2, HO-1 and vascular endothelial growth factor.

RESULTS

The area under the curve for creatinine and delayed graft function were similar in both the laparoscopic and open groups. There was no difference in the protective gene expression between the laparoscopic donor nephrectomy and open donor nephrectomy groups. The protein expression of HO-1 and Bcl-2 were similar between the open and laparoscopic groups. Furthermore, the gene expression of B-cell lymphoma 2 correlated with the warm ischemia time in the open group (p = 0.047) and that of vascular endothelial growth factor with the area under the curve for creatinine in the laparoscopic group (p = 0.01).

CONCLUSION

The postoperative renal function and protective factor expression were similar between laparoscopic donor nephrectomy and open donor nephrectomy. These findings ensure laparoscopic donor nephrectomy utilization in renal transplantation.

Oxidants as important determinants of renal apoptosis during pneumoperitoneum: a study in an isolated perfused rat kidney model

INTRODUCTION

Pneumoperitoneum-associated ischemia-reperfusion (IR) may initiate renal dysfunction. Whether oxidants are responsible for renal structural damage, such as cell apoptosis, has not yet been evaluated. We investigated such eventuality in an isolated rat kidney model.

METHODS

Thirty-five rat kidneys with their vessels and ureter were harvested and perfused within a closed environment at flow of 15 ml min(-1). After stabilization, kidneys were assigned to one of five groups (n = 7 per group): CO(2)-induced intrachamber pressure of 8, 12, or 0 mmHg (control), and 8 or 12 mmHg pressure applied to kidneys from rats treated pre-experimentally with tungsten for 14 days. Pressurization lasted 60 min.

RESULTS

Organ perfusion pressure raised as intrachamber pressure increased. Urinary output decreased in the two pressurized nonpretreated groups. Intrachamber pressure was directly associated with an increase in postexperimental xanthine oxidase tissue levels. Twofold apoptosis was documented (p < 0.05) in cortex of nonpretreated kidney in the 12 mmHg group compared with the 8 or 0 mmHg groups. Tungsten pretreatment significantly (p < 0.05) attenuated the abnormalities documented in the 12 mmHg group, but less so in the 8 mmHg pressurized nontreated counterparts.

CONCLUSIONS

Pneumoperitoneal pressure applied to isolated perfused kidney is associated with renal apoptosis. This rapidly induced structural renal damage is oxidant dependent and can be attenuated by antioxidants. Further studies may shed more light on the role of antioxidants in preventing pneumoperitoneum-induced kidney dysfunction.

The detrimental effect of poor early graft function after laparoscopic live donor nephrectomy on graft outcomes

We undertook this study to assess the rate of poor early graft function (EGF) after laparoscopic live donor nephrectomy (lapNx) and to determine whether poor EGF is associated with diminished long-term graft survival. The study population consisted of 946 consecutive lapNx donors/recipient pairs at our center. Poor EGF was defined as receiving hemodialysis on postoperative day (POD) 1 through POD 7 (delayed graft function [DGF]) or serum creatinine >/= 3.0 mg/dL at POD 5 without need for hemodialysis (slow graft function [SGF]). The incidence of poor EGF was 16.3% (DGF 5.8%, SGF 10.5%), and it was stable in chronologic tertiles. Poor EGF was independently associated with worse death-censored graft survival (adjusted hazard ratio (HR) 2.15, 95% confidence interval (CI) 1.34-3.47, p = 0.001), worse overall graft survival (HR 1.62, 95% CI 1.10-2.37, p = 0.014), worse acute rejection-free survival (HR 2.75, 95% CI 1.92-3.94, p < 0.001) and worse 1-year renal function (p = 0.002). Even SGF independently predicted worse renal allograft survival (HR 2.54, 95% CI 1.44-4.44, p = 0.001). Risk factors for poor DGF included advanced donor age, high recipient BMI, sirolimus use and prolonged warm ischemia time. In conclusion, poor EGF following lapNx has a deleterious effect on long-term graft function and survival.

Renal apoptosis following carbon dioxide pneumoperitoneum in a rat model

PURPOSE

Laparoscopically recruited kidneys regain normal function more slowly than laparotomy harvested organs for several possible reasons. We investigated the effects of CO(2) induced pneumoperitoneum on kidney function, as reflected by blood and urine creatinine levels, and its relation with renal cell apoptosis.

MATERIALS AND METHODS

CO(2) pneumoperitoneum was established in anesthetized Wistar male rats that were randomly allocated at 6 per group into 1 of 6 groups with an intraperitoneal pressure of 0 (control), 5, 8, 12, 15 or 18 mm Hg. Pressure was maintained for 60 minutes in all groups. Three additional groups were subjected to 30-minute pneumoperitoneum at 0, 12 and 18 mm Hg, respectively. The rats were kept alive for the ensuing 24 hours, after which blood and urine creatinine were analyzed and the abdominal organs were harvested. Various areas of the organs were analyzed for apoptotic cells using the TUNEL method. Cells were randomly counted in 10 eyeshots in 3 sections each using an ocular micrometer.

RESULTS

Creatinine levels in blood and urine changed as pressure and pneumoperitoneum duration progressed. Isolated TUNEL positive nuclei were detected in the outer medulla and the cortex of control kidneys. There was a significantly higher number of TUNEL positive nuclei in the cortex and the medulla of all pressurized kidneys (p <0.05), which increased in parallel with increasing intraperitoneal pressure and pneumoperitoneum exposure time.

CONCLUSIONS

The CO(2) pneumoperitoneum gradient and its duration affect renal function and induce apoptosis. This could be a mechanism involved in renal delayed graft dysfunction in recipients of laparoscopically harvested kidneys.

Early and late histopathological changes in renal allografts procured by laparoscopic donor nephrectomy

INTRODUCTION

Subcapsular cortical damage (SCCD) is a characteristic pathological change, which is seen in renal allograft biopsy specimen obtained immediately after laparoscopic donor nephrectomy (LDN). In this study we evaluated the early and late histopathological effect of SCCD examining renal allograft biopsy specimens obtained after kidney transplantation.

MATERIALS AND METHODS

Laparoscopic donor nephrectomy was performed on 250 donors between July 2000 and September 2004 in our institution. Allograft biopsy of all 250 kidneys was performed immediately after LDN (zero hour biopsy). Of 250 biopsy specimens, 105 were diagnosed as SCCD and the allograft biopsy specimens obtained from 105 recipients after transplantation were enrolled in this study. All specimens were routinely examined by using light microscopy and immunofluorescence.

RESULTS

In 87 patients 256 allograft biopsy specimens did not show post-pathological changes of SCCD. Twenty biopsy specimens obtained from 18 recipients showed tubular necrosis and a partly tubular regeneration and patchy interstitial hemorrhage, which seemed to be caused by SCCD. Ten allograft biopsy specimens from nine recipients demonstrated residual pathologic changes in SCCD early after transplantation. The other 10 specimens from nine recipients had abnormal histopathologic changes including interstitial edema and fibrosis, tubular atrophy and glomerular sclerosis in the subcapsular cortex late after transplantation.

CONCLUSION

The early change of SCCD after transplantation remained intact and partial regeneration and the late showed subcapsular fibrosis with glomerular sclerosis. The incidence of the subcapsular lesions due to SCCD after transplantation was 17% in 105 allografts.