Effects of ischemia-reperfusion injury in kidney transplantation: risk factors and early and long-term outcomes in a single center

INTRODUCTION

Ischemia-reperfusion injury (IRI) causes a high rate of delayed graft function (DGF), the most frequent complication in the immediate postoperative period after cadaveric donor kidney transplantation. Herein we evaluated the impact of donor and recipient characteristics on DGF development in terms of the incidence of acute rejection episodes, hospital stay, renal function, and long-term graft and patient survivals.

MATERIALS AND METHODS

Between February 1998 and July 2011, 761 patients underwent cadaveric donor kidney transplantations. DGF was defined as the need for dialysis in the first week. Patients were subdivided according to initial graft function as immediate graft function (IGF) or DGF.

RESULTS

DGF observed in 241 patients (31.6%) was associated independently with expanded criteria donors, extended cold ischemia time, Karpinsky histological score, and prior dialysis duration both univariate and multivariate analysis. The incidence of acute rejection episodes was 18.1% among the DGF group versus 1.3% in the IGF group (P < .01). DGF significantly reduced both graft and patient survivals at 6, 12, 36, and 60 months.

CONCLUSION

DGF was responsible for a longer hospital stay, worse early and long-term renal function, a higher incidence of acute rejection episodes as well as reduced graft and patient survivals.

Advanced age is not an exclusion criterion for kidney transplantation

INTRODUCTION

Renal transplantation in patients older than 60 years has long been regarded with skepticism owing to the increased risk of complications although, as compared with dialysis treatment, a graft seems to improve not only the quality of life but also long-term patient survival. This study sought to analyze the impact of recipient age older than 60 years on patient and graft outcomes.

MATERIALS AND METHODS

We retrospectively investigated the outcomes of 761 kidney transplant recipients from cadaveric donors performed between February 1998 and July 2011. While 69 subjects were at least 60 years of age (group A), 692 were younger than 60 years (group B) at the time of transplantation.

RESULT

Mean follow-up was 60.1 ± 38.5 months. Delayed graft function (DGF) requiring dialysis was observed in 36 group A (52.1%) and 205 group B (29.6%) subjects (P = .001). However, there were also significant differences between group A and group B in terms of mean donor age (60.3 vs 44.6 years; P < .001) and mean donor estimated creatinine clearance (57.8 vs 83.4 mL/min; P < .001). There were no significant differences in death-censored graft survival between the two groups, but elderly patients experienced worse survival (P = .0005). The most common causes of patient death were myocardial infarction, other cardiovascular complications, and tumors.

CONCLUSION

Kidney transplantation is a good option for elderly recipients with end-stage renal disease, providing long graft survival and a good quality of life, although these patients are more likely to develop cancer or cardiovascular disease. Our findings suggested that older patients should not be excluded a priori from transplantation, but meticulous screening for cancer and heart disease should be always be performed to improve outcomes.

Middle and long-term outcomes of dual kidney transplant: a multicenter experience

INTRODUCTION

Dual kidney transplantation (DKTx) to reduce the disparity between demand and supply of organs was evaluated in two Italian centers (Bari and Novara).

MATERIALS AND METHODS

Between October 2000 and October 2011, we performed 97 DKT (26 ipsilateral/71 bilateral) following routine biopsy of all kidneys obtained from expanded criteria donors by Remuzzi-Karpinsky scores. The reference group was 379 single grafts from donors older than 60 years single kidney transplantation ([SKT] × > 60).

RESULTS

Good postoperative renal function was observed in 56 DKTx (57.7%); whereas acute tubular necrosis requiring dialysis was observed in 41 (42.3%) patients. After a mean follow-up of 60 months, DKTx graft survivals were 96%, 93%, and 90% and patient survivals, 96%, 91%, and 91% at 1, 3, and 5 years, respectively. Complications in expanded criteria donor kidney transplantations included a high rate of cytomegalovirus (CMV) disease especially dual kidney cases. DKTx represented the only independent risk factor for CMV disease upon multivariate analysis (odds ratio [OR] 2.33, 95% confidence interval [CI] 1.28-4.2; P = .006). We did not observe any significant difference in graft or patient survival between DKTx and SKTx > 60 years.

CONCLUSIONS

We observed good outcomes up to 5 years after transplantation in terms of graft and patient survival despite the use of inferior grafts. Comparing DKTx and SKT > 60, we noted that the mean Karpinski score for SKTx was significantly better than DKTx, although patient and graft survivals were similar. This trend confirms that the use of a biopsy to allocate expanded criteria donor kidneys may be too protective; therefore, the criteria to select DKTx require further refinement.

Obesity in kidney transplantation affects renal function but not graft and patient survival

INTRODUCTION

The number of overweight and obese patients undergoing renal transplantation has increased dramatically over the past two decades. Studies on graft survival and posttransplantation complications have often yielded conflicting results. Some authors have reported similar results for graft and patient survivals between obese and normal weight patients, but with a marginally increased rate of postoperative complications. In contrast, other reports note higher percentage of graft losses as well as increased mortality. In our study, we analyzed early- and long-term outcomes among obese versus nonobese kidney transplant recipients.

PATIENTS AND METHODS

Between January 2000 and December 2008, we performed 563 cadaveric kidney transplantations. Recipients were classified in 1 of 5 groups based on their body mass index (BMI) at the time of transplantation: group A (n = 68; BMI < 18.5); group B (n = 310; 18.6 < BMI < 24.9); group C (n = 143; 25 < BMI < 29.9); group D (n = 32; 30 < BMI < 34.9); and group E (n = 10; BMI ≥ 35). The comparative analysis included patient and graft survivals, postoperative complications, onset of delayed graft function (DGF), acute rejection episodes, hospital stay, and serum creatinine values in the first 3 years posttransplantation.

RESULTS

At a mean follow-up of 53 months (range, 3-112 months), DGF was observed in 20 patients in group A (29.4%), 82 in group B (26.4%), 43 in group C (30%), 16 in group D (50%), and 4 in group E (40%). Nevertheless, obese patients (groups D and E) showed higher mean serum creatinine values and worse renal function at 6 months (P = .001), 1 year (P < .001), and 3 years (P = .001). Moreover, they were at increased risk of an acute rejection episode (P = .01) and more susceptible to cardiovascular and metabolic complications (P = .01). Morbidly obese patients displayed a higher incidence of postsurgical complications (P = .002). There were no differences in the incidences of chronic allograft nephropathy (CAN) or infectious complications. Despite the differences in morbidity among the 5 groups, we failed to observe significant differences in patient or graft survivals at 6, 12, 36, or 60 months.

CONCLUSION

Our findings suggested that obese patients should not be discriminated against simply based on the BMI. At our center, obese (BMI >35) transplantation candidates undergo a thorough cardiac evaluation, as well as pulmonary, endocrine, and nutritional counseling seeking to minimize medical and surgical complications and improve survival and quality of life.