Reinterventions for nonocclusive iliofemoral venous stent malfunctions

Background Percutaneous iliofemoral venous stenting has been shown to be effective, safe, and durable in both nonthrombotic iliac vein lesion (NIVL) and postthrombotic disease. A small fraction of stented limbs require reintervention to correct stent malfunction. This manuscript examines the reasons for reintervention, types of procedures performed, and outcome. Methods Femoro-ilio-caval stenting was performed in 1085 limbs over a 10 year period from 1997 to 2007 (NIVL/postthrombotic limb ratio 1:1). Reinterventions were required in 137 limbs (13%) for non-occlusive stent malfunction. Results Median time of reintervention after the initial procedure was 15 months. Primary indication for reintervention was stent abnormalities discovered on routine surveillance imaging in 31% of the limbs and residual/recurrent symptoms after initial stenting in 69% of the limbs. Prevalent symptoms before reintervention were swelling (45%), pain (18%), combination of pain and swelling (33%), and venous dermatitis/ulcer (15%). Seventy-seven percent of limbs required only a single reintervention and 23% required two or more interventions. The type of reintervention could be broadly categorized into four types: (1) cephalad stent extension to correct stent outflow problems; (2) caudad stent extension to correct inflow problems; (3) balloon dilatation of stent stenoses; and (4) combinations. The types of stent inflow/outflow lesions encountered were different in NIVL and postthrombotic limbs. In both groups, the external iliac vein segment had a greater incidence of pathology than other stented venous segments during reintervention. A denovo stenotic lesion of uncertain aetiology that occurred below an existing stent was also exclusive to the external iliac vein segment. Instent restenosis (ISR) occurred in both subsets. Two types of ISR were encountered: (1) a ‘soft’ lesion probably due to reduced flow channel lined by thrombus within the stent from inflow/outflow problems and (2) a ‘hard’ lesion that occurred independently, was resistant to dilatation and tended to recur unlike the ‘soft’ lesion. Cumulative improvement in pain and swelling at 18 months following intervention was 67% and 72%, respectively. Complete cumulative healing of venous dermatitis/ulcer was 90% at 12 months post reintervention. Conclusion Venous stenting for chronic venous disease is largely trouble-free with only a small fraction of the stented limbs requiring reinterventions. Reinterventions were perfo