Establishment of an acute rejection model by transplanting both renal grafts into two different rats using a modified method of ureterovesical anastomosis

Administration of adipose stromal vascular fraction attenuates acute rejection in donation after circulatory death rat renal transplantation

OBJECTIVE

Stem cell therapy represents a new approach to induce immune tolerance in solid organ transplantation. However, the time-consuming process of stem cell expending limits the range of stem cell treatment. Uncultured adipose stromal vascular fraction is considered an attractive cell source for cell-based therapy. This study aimed to evaluate the effect of stromal vascular fraction on the immune system in donation after circulatory death rat renal transplantation.

METHODS

Stromal vascular fraction cells and splenocytes were co-cultured to evaluate the effect of stromal vascular fraction on splenocyte proliferation and viability. Sprague-Dawley rats were used as donors. and Wistar rats as recipients to establish a donation after a circulatory death rat renal transplantation model. Warm ischemia time was 5 min. Stromal vascular fraction was administered in the rat model following the intra-arterial route. The spleens and grafts of recipients were harvested on days 1, 3 and 7 post-transplantation for assessing acute rejection, infiltration of inflammatory cells, indoleamine 2, 3-dioxygenase expression and T-cell frequency in the spleen.

RESULTS

Stromal vascular fraction could inhibit proliferation and induce apoptosis of splenocytes in vitro (P < 0.05). The administration of stromal vascular fraction could significantly reduce acute rejection and infiltration of CD8⁺ T cells and mononuclear macrophages in grafts, and increase indoleamine 2, 3-dioxygenase expression (P < 0.05). The frequency of CD8⁺ T cells decreased, and the frequency of CD25⁺ Foxp3⁺ regulatory T cells increased in the spleen of the acute rejection + stromal vascular fraction group on day 7 post-transplantation (P < 0.05).

CONCLUSION

Administration of the adipose stromal vascular fraction could attenuate acute rejection in donation after circulatory death renal transplantation by increasing the ratio of regulatory T cells and enhancing indoleamine 2, 3-dioxygenase expression.

Complications and Their Prevention in Experimental Renal Transplantation in Rats

OBJECTIVES

Experimental rat models of renal transplant have played a pivotal role in renal transplant research. Both intraoperative and postoperative complications during donor nephrectomy and implantation in the recipient can be associated with significant morbidity and mortality. The aim of this paper is to discuss the incidence, pathophysiology, and prevention of complications that occurred in the process of establishment of a rat model of chronic allograft injury at our institution.

MATERIALS AND METHODS

The complications observed while performing 67 consecutive donor nephrectomies and 61 renal transplants were recorded prospectively, and appropriate measures were taken to prevent these complications in the subsequent transplant procedures.

RESULTS

Donor-related complications included failure of the kidney to clear of blood by the kidney perfusion solution and intraoperative deaths. The recipient-related complications included intraoperative hemorrhage, inadequately perfused kidneys with dusky appearance, congested and paralyzed hind limbs, urine leak, necrosis of the kidneys, renal and bladder calculi formation, and death during and after kidney transplant.

CONCLUSIONS

Complications during donor nephrectomy and renal transplant can lead to significant loss of kidneys and animals. Proper recognition can allow appropriate measures to be taken to prevent these complications, thus achieving high-quality transplants and prolonged graft and animal survival.

Orthotopic Kidney Transplantation in the Rat With the Use of a Sleeve Arterial Anastomosis Method and a Modified Stenting Technique for Renal Veins

BACKGROUND

We describe a simple and reliable orthotopic kidney transplantation method in rats with the use of sleeve arterial anastomosis and a modified stenting technique for anastomosis of the renal vein (RV).

METHODS

Male Fischer and Lewis rats were used as kidney donors and recipients, respectively, and their left kidneys were harvested in situ. In the control rats (n = 30), the renal artery (RA) and RV anastomoses were performed end-to-end with interrupted sutures by means of the conventional technique. In the experimental animals (n = 30), revascularization of the RA was fashioned end-in-end with the use of a modified sleeve anastomosis, the RV was anastomosed end-to-end with the use of a modified stenting technique and interrupted sutures, and the ureter was anastomosed with the use of the end-to-end interrupted suture technique.

RESULTS

The arterial anastomosis time in the control group was 8.52 ± 1.1 minutes, and that in the experimental group was 4.7 ± 0.6 minutes (P < .05). The venous anastomosis time in the experimental group was 9.2 ± 1.3 minutes, which also was less than in the control group (11.19 ± 0.78 minutes; P < .05). The warm ischemia time decreased from 26.8 ± 1.3 minutes in the control group to 20.7 ± 0.5 minutes in the experimental group (P < .05). The success rate of 93% at 21 days after grafting was identical in the experimental and control groups.

CONCLUSIONS

We developed a modified model of orthotopic kidney transplantation that can significantly reduce the warm ischemia time.

Review of Surgical Techniques of Experimental Renal Transplantation in Rats

Microvascular surgical techniques of renal transplant in rats have evolved over the past 5 decades to achieve successful rat renal transplant; these modifications have included surgical techniques to address the anatomic variations in the renal blood vessels and those to reduce ischemic and operation durations. Here, we review the surgical techniques of renal transplant in rats and evaluate the advantages and disadvantages of individual techniques of vascular and ureteric anastomoses. For this review, we performed a systematic literature search using relevant medical subject heading terms and included appropriate publications in the review. Since the first description of a rat model of renal transplant by Bernard Fisher and his colleagues in 1965, which used end-to-side anastomosis between the renal vein and renal artery to the recipient inferior vena cava and aorta, several vascular and ureteric anastomosis techniques have been modified. Vascular anastomosis techniques now include end-to-end anastomosis, use of donor aortic and inferior vena cava conduits, sleeve and cuff anastomoses, and application of fibrin glue. Likewise, restoration of the urinary tract can now be achieved by direct anastomosis of the donor ureter to the recipient bladder, end-to-end anastomosis between the donor and recipient ureters, and donor bladder cuff to the recipient bladder. There are advantages and disadvantages attributable to individual techniques. The range of vascular and ureteric anastomosis techniques that has emerged reflects the need for mastering more than one technique to suit the vascular anatomy of individual animals and to reduce operating time for achieving successful outcomes after renal transplant.