Transplant Renal Artery Stenosis

A Case Report of Concurrent Transplant Renal Artery Stenosis, Renal Cell Carcinoma, and Papillary Thyroid Cancer After Renal Transplantation: A Literature Review

BACKGROUND

Kidney transplantation is the preferred treatment option for eligible patients with end-stage renal disease. With advanced transplantation technology and novel immunosuppressive agents, kidney transplant recipients survive significantly longer. However, the chance of developing malignant tumors has increased, posing a serious challenge to the survival of transplanted kidneys and patients.

CASE PRESENTATION

We report a male patient (the patient's informed consent has been obtained) who underwent kidney transplantation 23 years ago. Subsequently, he developed transplant renal artery stenosis, primary renal clear cell carcinoma, and papillary thyroid cancer. The narrowed blood vessels were dilated through percutaneous transluminal angioplasty, and the malignant tumor was removed surgically. Currently, antirejection drugs are regularly taken, and the transplanted kidney function is good. The patient is satisfied with his living conditions.

CONCLUSIONS

Hypertension that is difficult to control after kidney transplantation should be suspected as a possibility of graft vascular stenosis. When B-ultrasound cannot accurately diagnose it, magnetic resonance angiography should be used as early as possible to clarify the diagnosis and relieve the stenosis before graft dysfunction. Transplantation patients have a high incidence of malignant tumors after surgery, and the risk increases with the prolongation of the disease course. The focus should be on symptomatic treatment of related diseases, and antirejection drugs can be reduced or not reduced as appropriate.

Percutaneous transluminal angioplasty with stenting for transplant renal artery stenosis at the anastomosis site in a young female patient: A case report

INTRODUCTION

Transplant renal artery stenosis (TRAS) is one of the major vascular complications and is mostly reported within six months following kidney transplant.

CASE PRESENTATION

The present case was a 16-year-old female whose blood urea nitrogen (BUN) and creatinine rose seven days after a kidney transplant. Ultrasound investigation revealed well-prefusion with a 90-degree angle anastomosis, apparent narrowing, and peak systolic velocity of 300 cm/s. Fourteen days after the transplant, with pre-and post-intervention hemodialysis and well hydration, an angiography with diluted iodinated contrast was done for the patient, which revealed >80 % narrowing at the anastomosis site. Percutaneous transluminal angioplasty (PTAS) with stenting was carried out for the patient, resulting in normal levels of BUN, creatinine, and urinary output.

CLINICAL DISCUSSION

While the patient did not have any risk factors for TRAS and was young, an early stenosis occurred in her left internal iliac artery one week after the kidney transplant. Due to the lower accuracy of CO2 angiography, diluted iodinated contrast angiography with well hydration and pre- and post-intervention dialysis was preferred. Endovascular treatment was preferred by the patient and attending physician due to possible adhesion and complications of open surgery and the possibility of arterial rupture.

CONCLUSION

Performing PTAS two weeks after the renal transplantation at the anastomosis site can be a treatment in patients with early TRAS. However, due to the higher risk of rupture at the anastomosis site, it should be carried out carefully and with consideration of the need for open surgery.

Perfusion and oxygenation in allografts with transplant renal artery stenosis: Evaluation with functional magnetic resonance imaging

BACKGROUND

Transplant renal artery stenosis (TRAS) has been shown to reduce kidney perfusion leading to post-operative hypertension. We aimed to measure the perfusion and oxygenation changes in TRAS with arterial spin labeling (ASL) and blood oxygen level-dependent (BOLD) imaging, respectively.

METHODS

In this single-center prospective study, a total of seven patients with TRAS and seven age- and sex-matched normal kidney transplant recipients underwent both ASL and BOLD imaging. Moreover, measurements of ASL and BOLD were also performed in five patients after successful angioplasty for TRAS.

RESULTS

Allograft cortical perfusion as measured by ASL in the TRAS group was significantly decreased as compared with normal control group (129.9 ± 46.6 ml/100 g vs. 202.4 ± 47.7 ml/100 g, P = .01). Interestingly, allograft oxygenation as indicated by R2* derived from BOLD in both the cortex (16.42 ± 1.90 Hz vs. 18.25 ± 4.34 Hz, P = .33) and the medulla (30.34 ± 2.35 Hz vs. 30.43 ± 6.85 Hz, P = .97) showed no statistical difference between the TRAS and normal control group. In addition, both cortical and medullary oxygenation remained unchanged despite significantly improved cortical perfusion in those undergone successful angioplasty.

CONCLUSION

Cortical and medullary oxygenation were preserved in the presence of reduced allograft perfusion in clinically significant TRAS. Prospective larger studies are needed to conclusively establish perfusion and oxygenation changes in TRAS.

Kidney Transplantation and Diagnostic Imaging: The Early Days and Future Advancements of Transplant Surgery

The first steps for modern organ transplantation were taken by Emerich Ullmann (Vienne, Austria) in 1902, with a dog-to-dog kidney transplant, and ultimate success was achieved by Joseph Murray in 1954, with the Boston twin brothers. In the same time period, the ground-breaking work of Wilhelm C. Röntgen (1895) and Maria Sklodowska-Curie (1903), on X-rays and radioactivity, enabled the introduction of diagnostic imaging. In the years thereafter, kidney transplantation and diagnostic imaging followed a synergistic path for their development, with key discoveries in transplant rejection pathways, immunosuppressive therapies, and the integration of diagnostic imaging in transplant programs. The first image of a transplanted kidney, a urogram with intravenous contrast, was shown to the public in 1956, and the first recommendations for transplantation diagnostic imaging were published in 1958. Transplant surgeons were eager to use innovative diagnostic modalities, with renal scintigraphy in the 1960s, as well as ultrasound and computed tomography in the 1970s. The use of innovative diagnostic modalities has had a great impact on the reduction of post-operative complications in kidney transplantation, making it one of the key factors for successful transplantation. For the new generation of transplant surgeons, the historical alignment between transplant surgery and diagnostic imaging can be a motivator for future innovations.