Iliac Artery Stenosis Causing Post-Renal Transplant Hypertension: Successful Management by Percutaneous Angioplasty and Stent Im
- Volume 14 - Issue 4 - April, 2002
- Posted on: 8/1/08
- 0 Comments
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Renal transplantation offers the potential for complete rehabilitation in end-stage renal disease (ESRD).1 However, as renal transplant recipients survive longer and become an increasingly more elderly population, occlusive atherosclerosis leading to ischemic heart disease and/or peripheral vascular complications is becoming a force with which to reckon. Atherosclerotic occlusion involving the aorto-iliac system can mimic renovascular hypertension in renal transplant recipients and is an important cause of renal dysfunction in this population.2 Poorly controlled hypertension after renal transplantation should therefore raise the question of functional stenosis either in the aorto-iliac vessels or renal arteries.3 Percutaneous transluminal angioplasty (PTA) in the above condition has been reported to have a more favorable outcome when compared to surgical intervention.4,5
This report discusses the case of a kidney transplant recipient with coronary artery disease and bilateral iliac stenoses who presented with hypertensive urgency and was successfully managed with PTA and stenting of the iliac arteries.
Case Report. A 61-year-old male presented to our Emergency Unit with a history of transient episodes of giddiness and slurring of speech. He also complained of progressive angina for the past 4 months. Four years earlier, he had received an allograft from a living relative for ESRD. On physical examination, he was alert and cooperative. His blood pressure was 200/120 mmHg and pulse rate was 70 beats per minute. Bilateral femoral pulses were feeble, but there was no bruit. Neurological examination was unremarkable. Laboratory investigations revealed adequate renal function with serum creatinine of 1.0 mg/dl and blood urea of 40 mg/dl. The electrocardiogram revealed T-wave inversions in the inferior leads and transthoracic echocardiogram showed normal ventricular function with mildly calcified aortic valve. The patient was managed as a case of hypertensive urgency. On the third day of admission, the patient was subjected to an abdominal aortogram, which revealed 60–70% stenosis of the right common iliac artery and 70% stenosis of the left common iliac artery (Figure 1). The renal allograft was seen filling from the right external iliac artery. Coronary angiogram showed single-vessel disease with 99% eccentric stenosis of the dominant right coronary artery (RCA).
In view of his severe hypertension, it was decided to treat bilateral iliac artery lesions by PTA. PTA was performed via the ipsilateral, retrograde femoral approach. The lesion in the right common iliac artery was crossed using a 7 French, long sheath (Arrow International Inc., Reading, Pennsylvania) and a 0.035´´ x 260 cm Teflon guidewire (Medtronic AVE, Santa Rosa, California). A 10 x 40 mm Smart stent (Cordis Endovascular, Warren, New Jersey) was directly deployed across the diseased segment and intra-stent dilatation was done using an 8 x 40 mm Powerflex Plus balloon (Cordis Endovascular). A 9 x 80 mm Smart stent was deployed in the left iliac artery via the ipsilateral retrograde approach. Final angiogram showed good antegrade flow in both iliac arteries with no residual stenosis or dissection (Figure 2).
Percutaneous transluminal angioplasty and stenting of the RCA was done in the same sitting. At 1-month follow-up, the blood pressure was under good control with diastolic pressure of less than 90 mmHg on minimal antihypertensive medication.
Discussion. Post-transplant hypertension is one of the common complications seen in renal transplant recipients.1,3,6 The causative factors include chronic graft rejection, cyclosporin-induced hypertension and vascular complications such as in-flow stenosis or dissections involving renal arteries or native aorto-iliac vessels.7 Renovascular hypertension due to transplant renal artery stenosis is well recognized, variably reported in 2–25% of allografts.5,8 Most stenoses occur at or near the site of surgical anastomosis. Intimal hyperplasia, probably due to both rejection and endothelial trauma, is considered the most common cause.
Iliac artery stenosis is a rare cause of renal dysfunction in renal allograft recipients and can mimic renovascular hypertension.2 The diminished femoral pulses and low ankle-brachial index should lead to suspicion of iliac artery stenosis. Duplex Doppler sonography and femoral artery Doppler wave form analysis may resolve questionable cases.9 Angiographic examination is indicated when the hypertension is not readily controlled by drugs or there is continuous deterioration in the renal functions. Lacombe10 classified arterial stenosis in renal transplant recipients into the following categories: Type I) stenosis of the recipient iliac artery due to atheroma; Type II) a localized stenosis of the suture line between recipient and donor vessels due to faulty suture technique or improper positioning of the kidney/vessel during the procedure; and Type III) a more diffuse stenosis of the donor renal artery or its branches.
The presence of bilateral iliac artery stenoses with co-existing coronary artery disease, as in our case, brings into focus the major risk factors in the transplant population, i.e., hypertension and hyperlipidemia. As older patients are accepted as transplantation candidates and as the recipient population ages, ischemic heart disease and cerebrovascular disease have become the major cause of death after transplantation.1 The constant erosive effect of cardiovascular disease on the otherwise steady improvement in renal allograft success has generated a counteroffensive in the renal transplant population, with the usage of drugs like cyclosporin and other glucocorticoids contributing to the above risk factors.11 Therefore, it is imperative that transplantation candidates are screened for the same, both before surgery and during the follow-up period.
Since renal transplant recipients are more prone to accelerated atherosclerosis, iliac artery stenosis can occur as a late complication. Surgical interventions, such as vein patch or bypass, involve significant risk of kidney loss. Reported experience with iliac artery angioplasty shows an initial success rate of 90–95% with a 3–5 year patency rate of 75–90%.12 These results, along with the lower morbidity and mortality rates, make angioplasty the appropriate initial treatment for iliac artery stenoses that cause post-transplant hypertension.