Proximal Iliac Artery Stenosis in Allograft Renal Transplant, a Diagnostic beyond Echo-Doppler, Treatment Approach

Abstract

Background: Transplant Renal Artery Stenosis (TRAS) is a well-known vascular complication after a kidney transplant. It is associated with premature renal failure, uncontrolled hypertension, and allograft loss. However, Proximal Iliac Artery Stenosis to a Kidney Transplant (Prox-TRAS) is an uncommon cause of vascular graft complication leading to acute renal failure and refractory hypertension with a less incidence around and only a few cases reports have been described in the medical literature. Methods: We reviewed the medical record of kidney transplant recipients of the General Hospital of Ciudad Real, Spain, from March 2008 to March 2019. We identified all cases (260) with the diagnosis of renal vascular hypertension by imaging studies. Of those 260 renal vascular stenoses, five (5) were diagnosed with proximal iliac artery stenosis through Angio-CT and arteriography. We performed an analysis of clinical parameters and evolution. Results: Prox-TRAS was diagnosed in 5 of the 260 patients who presented acute or progressive allograft dysfunction with refractory hypertension, with an incidence rate of 1.4%. In 4 of them (1.1%), we had to resort to another imaging test, angio-CT, arteriography, as the echo-doppler was unable to identify the abnormalities. Hypertension was a constant finding along with impaired renal function (100%); with respect to Prox-TRAS, its onset was later (12 - 60 months) after transplantation. An increase in TA (140 ± 10 and 80.7 ± 7 to 160 ± 18 and 85 ± 7 mmHg, p-0.009) was observed. There was an increase in the use of hypotensive drugs (2.1 ± 1.1 and 4.3 ± 1, p-0.003). Similarly, in all cases, a worsening of basal creatinine from 0.9 to 0.1 ± to 1.2 ± (P × 0.004) was also observed. Prox-TRAS was a cause of the increase in both creatinine and TA (140 ± 10 and 80.7 ± 7 to 160 ± 18 and 85 ± 7 mmHg, P 0.009). All cases were treated by Percutaneous transluminal angioplasty with stent placement, N= 5. In the follow-up, improvement was obtained from the claudication clinic as well as renal function and blood pressure, CRB (from 2.7 ± 1.4 to 1.8 ± 0.4 mg/dL, P-0.02) and TA (160 ± 18/85 ± 7mmHg at 138 ± 7/82 ± 9, p 0.018). Kidney function, blood pressure remained unchanged during follow-up (130 ± 36 months). Conclusion: Through these cases review, we propose highlighting the importance of extending imaging studies to the iliac artery of the kidney graft in case of high suspected renal vascular hypertension; showing the role and safety of angioplasty as a reasonable and effective treatment in the identified cases. We assessed the possibility of the limited role of Duplex Sonography (DS) regarding clinical and angiographic. PTA is the appropriate initial treatment of Prox-TRAS, with low morbidity and mortality rates, achieving improvement of graft function and amelioration of hypertension.