Endovascular stenting with a drug-eluting stent of transplanted renal artery stenosis in a dual kidney transplanted patient / Tratamento endovascular com stent farmacológico em estenose de artéria renal transplantada de paciente com transplante renal duplo

Abstract Renal transplant remains the preferred therapy for end-stage renal disease (ESRD). Given the shortage of suitable donor kidneys, use of an expanded criteria donor (ECD) allows marginal kidneys to be transplanted; albeit at risk of increased graft failure due to lower nephron mass. To reduce the risk of graft failure, double kidney transplant (DKT) is advocated, with favorable outcomes. Transplant renal artery stenosis (TRAS) is one of the most common vascular complications following renal transplant. Unlike single kidney transplants, where TRAS usually presents with fluid overload, uncontrolled hypertension, and worsening kidney functions; it may be clinically silent in DKT patients since they have two functional transplanted kidneys. We hereby report a case of TRAS in a DKT patient who had 2 years of favorable clinical outcomes following successful endovascular stenting. He however recently died of COVID-19 associated pneumonitis.

Resumo O transplante renal continua sendo a terapia preferida para doenças renais em fase terminal. Dada a escassez de rins de doadores adequados, o doador com critérios expandidos permite que rins marginais sejam transplantados, embora haja um maior risco de falha do enxerto devido à diminuição da massa nefrótica. Para diminuir o risco de falha do enxerto, recomenda-se o transplante renal duplo (TRD), com resultados favoráveis. A estenose de artéria renal transplantada (EART) é uma das complicações vasculares mais comuns após o transplante renal. Ao contrário dos transplantes de rim simples, nos quais a EART geralmente se manifesta como sobrecarga de fluido, hipertensão descontrolada e piora das funções renais, ela pode ser clinicamente silenciosa em pacientes com TRD, pois eles têm dois rins funcionais transplantados. Relatamos aqui um caso de EART em um paciente com TRD que teve resultados clínicos favoráveis por dois anos após o sucesso do implante de stent endovascular. No entanto, ele morreu recentemente de pneumonite associada à covid-19.

Successful Renal Autotransplantation for the Treatment of Severe Renovascular Hypertension in a 14-year-old Boy

Percutaneous transluminal renal angioplasty (PTRA) is the current treatment of choice for renal artery revascularization, but renal autotransplantation has been an alternative treatment for complex cases. Here we report a 14-year-old boy with severe hypertension successfully treated with PTRA and renal autotransplantation. Doppler ultrasonography and computed tomography (CT) angiography revealed slight narrowing in the right renal artery ostium and complete obstruction in the left renal artery ostium with multiple collaterals. PTRA with stent insertion was performed for the treatment of the right renal artery, but it was impossible for the left renal artery due to the total obstruction. Therefore, left nephrectomy for autotransplantation was done with the peritoneal approach and the left kidney was autotransplanted to the ipsilateral iliac fossa. Postoperatively, Doppler ultrasonography and mercapto-acetyl-triglycine (MAG-3) renogram were performed, which showed normal renal artery blood flow and kidney function. Blood pressure was normalized and anti-hypertensive drugs were gradually tapered. Fibromuscular dysplasia was suspected to be responsible for the renal artery stenosis based on clinical aspects. In conclusion, renal autotransplantation is also a good treatment option for children with severe renovascular hypertension when endovascular treatment has failed or is not possible.

A Case of Renovascular Hypertension Controlled by Percutaneous Transluminal Renal Angioplasty with Balloon Dilatatio

Renovascular hypertension results from a lesion that impairs blood flow to a part of or all, of one or both kidneys. Renal artery stenosis is the major cause of renovascular hypertension and the most common cause of treatable secondary hypertension. Recently, percutaneous transluminal renal angioplasty(PTRA) with or without stent placement, has become the preferred choice for correcting symptomatic renal artery stenosis since it is less invasive than surgical reconstruction. PTRA with balloons designed for the dilatation of the coronary artery can be tried in small sized renal artery stenosis. We report a case of renovascular hypertension in a 13-year-old male who had small sized renal artery stenosis. Hypertension was controlled by PTRA with balloon dilatation.