Iliac artery stenosis proximal to a kidney transplant: clinical findings, duplex-sonographic criteria, treatment, and outcome.

BACKGROUND

Stenosis of the iliac segment proximal to the transplant renal artery (Prox-TRAS) is an uncommon cause of graft dysfunction and hypertension. We assessed the role of duplex sonography (DS) in regard to clinical and angiographic findings and followed the patients after percutaneous transluminal angioplasty (PTA), PTA stenting (PTAS), or surgery.

METHODS

From January 1988 to August 2001, 97 of 1,064 kidney recipients underwent angiography for clinical or Doppler-sonographic suspicion of vascular problems. Kidney function, blood pressure, medication, and DS findings after renal transplantation (RTx) at the time of diagnosis of Prox-TRAS and after treatment were evaluated.

RESULTS

Prox-TRAS was diagnosed in 16 patients (1.5%) (49.6+/-6.9 years). Four patients demonstrated early presentation of Prox-TRAS 1 to 7 days after RTx (group A), leading to acute renal failure but without hypertension. In all patients, DS revealed pulsus parvus et tardus, low pulsatility index (PI) (<1.0), and a pathologic flow profile in the iliac artery proximal and distal to the graft. After treatment (surgery in two patients, PTA in one patient, PTAS in one patient), all patients developed good renal function (creatinine 1.7+/-0.9 mg/dL). PI increased from 0.9+/-0.1 to 1.2+/-0.1 (P=0.04), and flow profile within the iliac artery distal to the graft normalized. Late presentation (3-209 months after RTx) of Prox-TRAS was observed in 12 patients (group B), causing an increase of creatinine in 11 patients (two patients receiving dialysis treatments), impairment of blood pressure (141+/-15 and 80.7+/-7 to 160+/-18 and 85+/-7 mm Hg, P=0.009), and an increase in antihypertensive drugs (2.1+/-1.1 and 4.3+/-1, P=0.003) in all patients. The PI was decreased when compared with values early after RTx (1.6+/-0.4 to 1.2+/-0.3, P=0.007), and flow profile in the iliac artery was pathologic. All patients except one were managed by surgery (n=6), PTA (n=1), or PTAS (n=4). Creatinine (2.7+/-1.4 to 1.8+/-0.4 mg/dL, P=0.02) and blood pressure (160+/-18/85+/-7 mm Hg to 138+/-7/82+/-9, P=0.018) improved. Antihypertensive drugs were reduced to 2.8+/-0.8 (P=0.01). PI increased from 1.2+/-0.3 to 1.9+/-0.5 (P=0.01). Flow profile within the iliac artery distal to the graft anastomosis normalized. Kidney function, blood pressure, and PI remained unchanged during follow-up (82+/-69.9 months) in both groups.

CONCLUSIONS

Prox-TRAS is rare. Because clinical symptoms are similar to those of transplant renal artery stenosis, DS is a valuable tool for diagnosis and follow-up for this type of vascular lesion. Selective treatment with PTA, PTAS, or surgery improves kidney function and hypertension.