Renal allograft artery stenosis: results of medical treatment and intervention. A retrospective analysis

Transplant renal artery stenosis: The impact of endovascular management and their outcomes

Introduction:

Transplant renal artery stenosis (TRAS) is a well-known vascular complication of renal transplantation. The aim of this analysis was to assess the short and midterm outcomes of endovascular therapy to salvage transplant kidney.

Methods:

We retrospectively analyzed our transplant database from 2000 to 2015. Percutaneous transluminal angioplasty/stenting was done in 24 patients (22 men and two women) with significant TRAS. The mean age was 59 ± 12 years. The parameters analyzed were: Technical success, pre- and post-treatment serum creatinine and number of antihypertensive drugs before and after treatment and vessel patency on Doppler ultrasonography at 3 and 6 months.

Results:

Overall incidence of TRAS in this study was 5.06%. Incidence of TRAS following live donor transplantation was 4.68% while that in deceased donors was 11.5%. Technical success was 100%. There were no periprocedural deaths. Renal function was improved from 2.32 ± 0.5 mg/dL to 1.72 ± 0.3 mg/dL (P < 0.001) and number of antihypertensive medications after the procedure was reduced from 2.9 ± 0.7 to 2 ± 0.6 (P < 0.001) at 6 months follow-up. One patient developed restenosis within 5 months (4.2%). Clinical success at 6 months follow-up was 79.2%.

Conclusions:

Endovascular treatment of TRAS has high technical success with minimal complications. It also provides satisfactory clinical success with improvement in overall transplant renal function and renovascular hypertension in early follow-up.

Transplant renal artery stenosis: clinical manifestations, diagnosis and therapy

Transplant renal artery stenosis (TRAS) is a well-recognized vascular complication after kidney transplant. It occurs most frequently in the first 6 months after kidney transplant, and is one of the major causes of graft loss and premature death in transplant recipients. Renal hypoperfusion occurring in TRAS results in activation of the renin–angiotensin–aldosterone system; patients usually present with worsening or refractory hypertension, fluid retention and often allograft dysfunction. Flash pulmonary edema can develop in patients with critical bilateral renal artery stenosis or renal artery stenosis in a solitary kidney, and this unique clinical entity has been named Pickering Syndrome. Prompt diagnosis and treatment of TRAS can prevent allograft damage and systemic sequelae. Duplex sonography is the most commonly used screening tool, whereas angiography provides the definitive diagnosis. Percutaneous transluminal angioplasty with stent placement can be performed during angiography if a lesion is identified, and it is generally the first-line therapy for TRAS. However, there is no randomized controlled trial examining the efficacy and safety of percutaneous transluminal angioplasty compared with medical therapy alone or surgical intervention.

Management of transplant renal artery stenosis

Transplant renal artery stenosis is the most frequent vascular complication of transplantation. Early detection and correction reduce patients' morbidity and allograft dysfunction. Although noninvasive imaging can detect an underlying stenosis, angiography with subsequent angioplasty or stenting, or both, provides definitive diagnosis and treatment. With the introduction of alternative contrast agents and newer catheter and stent technology, these procedures can be performed safely with little risk of contrast-induced nephropathy or allograft loss.

Duplex-Doppler Long-term Follow-up of Renal Transplant Artery Stenosis: Case Controlled Study

The aim of this retrospective clinical study was to assess a long-term course of renal transplant artery stenosis with duplex-Doppler ultrasound, and its influence upon serum creatinine, hemoglobin concentration and hypertension, as well as to investigate a possible association between stenosis and the number of acute rejections. Thirty-four renal transplant recipients, aged 43 +/- 13 years, with significant (>50%) renal transplant artery stenosis as seen on Doppler ultrasound were compared with 34 renal transplant recipients without stenosis (excluded by Doppler). Patients of both groups were matched by age, sex, time of transplantation, type of renal transplant, and number of previous transplantations. We analyzed peak systolic velocity (PSV) in the renal transplant artery, resistance index (RI) at the level of intra-renal arteries, serum creatinine, hemoglobin concentration, blood pressure, the number of antihypertensive medications, and the number of acute rejections on a yearly basis. In the stenosis group, PSV was 2.1 +/- 0.5 m/s at 1 year after transplantation (controls 1.1 +/- 0.4), 1.9 +/- 0.5 at 2 years (0.9 +/- 0.4), 1.9 +/- 0.5 at 3 years (0.9 +/- 0.4); RI was 62 +/- 10% at 1 year (controls 68 +/- 7), 65 +/- 9 at 2 years (67 +/- 7), 63 +/- 9 at 3 years (67 +/- 7); serum creatinine was 128 +/- 58 micromol/L at 1 year (controls 129 +/- 43), 119 +/- 47 at 2 years (121 +/- 33), 125 +/- 54 at 3 years (127 +/- 32). Long-term course of renal transplant artery stenosis (>50%), treated medically or interventionally, seems to be stable and non-progressive (during a 3-year follow up). Spontaneous regression of stenosis to non-significant level is possible. No difference in graft function, blood pressure or the number of acute rejections was observed comparing the stenotic and non-stenotic groups.

Recommendations for the outpatient surveillance of renal transplant recipients. American Society of Transplantation

Many complications after renal transplantation can be prevented if they are detected early. Guidelines have been developed for the prevention of diseases in the general population, but there are no comprehensive guidelines for the prevention of diseases and complications after renal transplantation. Therefore, the Clinical Practice Guidelines Committee of the American Society of Transplantation developed these guidelines to help physicians and other health care workers provide optimal care for renal transplant recipients. The guidelines are also intended to indirectly help patients receive the access to care that they need to ensure long-term allograft survival, by attempting to systematically define what that care encompasses. The guidelines are applicable to all adult and pediatric renal transplant recipients, and they cover the outpatient screening for and prevention of diseases and complications that commonly occur after renal transplantation. They do not cover the diagnosis and treatment of diseases and complications after they become manifest, and they do not cover the pretransplant evaluation of renal transplant candidates. The guidelines are comprehensive, but they do not pretend to cover every aspect of care. As much as possible, the guidelines are evidence-based, and each recommendation has been given a subjective grade to indicate the strength of evidence that supports the recommendation. It is hoped that these guidelines will provide a framework for additional discussion and research that will improve the care of renal transplant recipients.