Identification of Factors Associated With Acute Tubular Necrosis Following Kidney Transplant in Northern Mexico: Increased Risk With Cold Ischemia After 8 Hours

Renal Transplant Anastomotic Pseudoaneurysm and Stenosis at the Proximal Transplant Renal Artery and Worse Renal Blood Flow After Stent Placement

ABSTRACT

A 60-year-old man with a history of end-stage renal disease received renal transplant and had decreasing renal function 4 months later. Nuclear medicine renal flow and functional study showed severely decreased blood flow and decreased function of the right renal allograft. There was focal increased radiotracer uptake at blood flow phase around the anastomosis of the renal allograft artery and the right external iliac artery. CT angiogram revealed right external iliac artery pseudoaneurysm. Interventional radiology angiography reconfirmed the pseudoaneurysm and revealed stenosis at the proximal transplant renal artery. After stent placement, however, there was worse renal allograft blood flow.

Up-regulation of VSIG4 alleviates kidney transplantation-associated acute kidney injury through suppressing inflammation and ROS via regulation of AKT signaling

Prolonged cold ischemia (CI) is a risk factor for acute kidney injury (AKI) after kidney transplantation (KT). AKI is an abrupt and rapid reduction in renal function due to multi-factors, including inflammation, oxidative stress and apoptosis. V-set immunoglobulin-domain-containing 4 (VSIG4) is a B7 family-related protein and specifically expressed in resting tissue-resident macrophages to mediate various cellular events. In the study, we attempted to explore the effects of VSIG4 on CI/KT-induced AKI in a mouse model. Our results showed that VSIG4 expression was markedly down-regulated in serum of kidney transplant recipients with acute rejection, and in renal tissues of cold ischemia-reperfusion (IR)-operated mice with AKI, which was confirmed in murine macrophages stimulated by oxygen glucose deprivation/reoxygenation (OGD/R). We then found that exogenous VSIG4 markedly ameliorated histological changes in kidney of CI/KT mice by suppressing inflammation and apoptosis through restraining nuclear factor-κB (NF-κB) and Caspase-3 activation, respectively. Oxidative stress and reactive oxygen species (ROS) accumulation in renal tissues were also mitigated by exogenous VSIG4 in CI/KT mice through improving nuclear factor-erythroid 2 related factor 2 (Nrf2) nuclear expression. The inhibitory effects of VSIG4 on inflammation, ROS generation and cell death were confirmed in OGD/R-treated macrophages, which further ameliorated oxidative damage and apoptosis in podocytes. More in vivo and in vitro studies showed that CI/KT- and OGD/R-induced AKI was further accelerated by VSIG4 knockdown. Mechanistically, VSIG4 directly interacted with AKT, and AKT activation was necessary for VSIG4 to govern all these above mentioned cellular processes. Collectively, our findings demonstrated that VSIG4 could mitigate AKI in a CI/KT mouse model, and we identified VSIG4/AKT axis as a promising therapeutic target for the treatment of the disease.

Description and Outcomes of Three Different End-to-Side Microsurgical Techniques for the Anastomosis of Accessory Renal Artery With the Dominant Renal Artery in Kidney Transplantation

BACKGROUND

In this study, we compared the outcomes of three different surgical microscope-assisted end-to-side anastomosis techniques between the dominant and accessory renal arteries during living donor kidney transplant.

METHODS

The demographics, serum creatinine levels, warm and cold ischemia times, rate of complications, and incidence of delayed graft function of 135 kidney recipients were analyzed according to the type of arterial anastomosis. Group A (n = 98) had one dominant renal artery (DRA) with one end-to-side anastomosis to the external iliac artery (EIA) using a surgical microscope. Group B (n = 17) had one DRA plus one accessory renal artery (ARA) with two separate end-to-side anastomoses to the EIA using a surgical microscope. Group C (n = 20) had one DRA with end-to-side anastomosis to the EIA and one ARA with an ex vivo on-bench end-to-side anastomosis to the DRA using a surgical microscope.

RESULTS

Compared with groups A and B, the cold ischemia time and the rate of delayed graft function were significantly higher in group C (P ≤ .001). At 6 months after transplant, group B demonstrated a higher creatinine value (2.40 ± 3.41 mg/dL) than group A and group B (P = .032). Also, the decrease in creatinine at postoperative month 6 was limited in group B as compared with groups A and C.

CONCLUSIONS

An end-to-side anastomosis between ARA (group B) and DRA (group A) of the kidney graft using a surgical microscope on the bench ex vivo results in superior outcomes. Single arterial anastomosis techniques are associated with a better function in a 6-month follow-up than two separate arterial anastomoses.