Hugging balloons dilatation by noncompliant balloons to successfully dilate a stent refractory to routine peripheral transluminal renal angioplasty

A small proportion of lesions are refractory even when very high pressures are used to deploy the stent. Here, we report the case of a 7-year-old boy referred for evaluation of refractory hypertension. There was a bruit on auscultation on the back in the lumbar region. Renal angiogram revealed bilateral renal artery stenosis. Right and left renal arteries were stented with a 7 × 23 mm and a 7 × 19 mm Hippocampus bare metal stent (Medtronic, Minneapolis, MN, USA). Despite delivering the stent in the left renal artery at 10 atm pressure, it didn’t open up properly. We successfully attempted the technique of hugging balloons. This involved two noncompliant balloons of 4 × 10 mm each, inflated simultaneously side by side at 20 atm to successfully dilate the stent. This technique enables success as the geometry of two ‘kissing’ balloons is different from that of one balloon. This altered geometric configuration may be important in successfully dilating a stent refractory to standard dilating techniques. Higher pressures can be attained with two smaller balloons because the burst pressure is higher in smaller balloons compared to larger balloons.