Detection of transplant renal artery stenosis with contrast-enhanced ultrasound

Abstract

Transplant renal artery stenosis (TRAS) is a vascular complication occurring during the first 2 years after kidney transplantation, with an incidence and a prevalence ranging from 1% to 23%, and from 1.5% to 4%, respectively. Detection of TRAS is the key, since most stenoses may progress to renal graft loss, however it may be difficult to detect due to its nonspecific clinical manifestations. Although Doppler ultrasound has become a primary imaging technique, digital subtraction angiography (DSA) remains the gold standard for diagnosing TRAS. We present a case of delayed graft function following kidney transplantation complicated by a lateral by-pass with prosthesis upstream and downstream of renal anastomosis, TRAS criteria were unclear using Doppler ultrasound, contrast-enhanced computed tomography-scan, and DSA. Only contrast-enhanced ultrasound (CE-US), observing a delayed and pulsating contest impregnation of renal parenchyma, supported the hypothesis of TRAS that was confirmed by the measurement of trans-anastomosis pressure gradient during DSA.

Diagnosis and Treatment of Renal Artery Stenosis in China in the Era of Donation After Cardiac Death

“…TRAS is a common vascular complication after renal transplantation and is an important factor leading to renal failure and postoperative hypertension [1][2][3]. According to reports, the incidence of TRAS varies greatly depending on the diagnostic method, ranging from 1% to 23% [4][5][6]. Most studies on TRAS are single-center retrospective studies.…”

“…It can cause refractory hypertension and renal dysfunction, and can even progress to graft failure, which ultimately may reduce the survival rate of grafted kidneys [1][2][3]. The incidence of TRAS varies greatly depending on the diagnostic method used, ranging from 1% to 23% [4][5][6]. At present, the main source of organ donation in China has been completely transformed from traditional judicial channels to DCD, which is different from traditional judicial channels for kidney supply in terms of donor risk, donation procedure, organ function quality assessment, organ harvesting and preservation, and perioperative management of recipients [7][8][9][10][11].…”

Contrast-Enhanced Ultrasound Assessment of Renal Parenchymal Perfusion in Patients with Atherosclerotic Renal Artery Stenosis to Predict Renal Function Improvement After Revascularization

“…10,11 Because more than 50% of ARAS patients present renal cortical ischemia, the assessment of renal parenchymal perfusion is a useful supplement to evaluate the degree of renal ischemia, identify patients with potential benefits after PTRAS, and guide the treatment of ARAS. 12,13 Cheung et al 14 utilized MRI to identify kidneys with hibernating parenchyma and help predict the outcome of renal function after PTRAS. Compared with MRI, contrast-enhanced ultrasonography (CEUS) does not require the administration of a gadoliniumbased contrast agent, and is capable of assessing the degree of ARAS and renal parenchymal perfusion simultaneously.…”