Incidence of venous obstruction following insertion of an implantable cardioverter defibrillator. A study of systematic contrast venography on patients presenting for their first elective ICD generator replacement.

AIMS The number of implantable cardioverter defibrillator (ICD) implantations, as well as follow-up procedures such as generator exchanges, lead revisions and lead system upgrades, is ever-increasing. Lead revisions and implantation of additional leads require venous access at the site of the previous ICD implantation. The aim of our study was therefore to evaluate the incidence of venous obstruction after chronic transvenous ICD system implantation. METHODS AND RESULTS One hundred and five consecutive patients admitted for their first elective ICD generator replacement were included. All patients underwent bilateral contrast venography and the images were analyzed by two attending radiologists. Venous obstruction was classified as moderate stenosis (50-75% diameter reduction), severe stenosis (>75%) or total occlusion. Venous obstruction of various degrees was found in 25% of the patients. Complete occlusion was found in 9%, severe stenosis in 6% and moderate stenosis in 10% of the patients. The incidence of venous obstruction was increased in patients with a pacemaker prior to the initial ICD system implantation (67%). No difference was found in patients with a single defibrillator lead compared with patients who had an additional superior vena cava (SVC) shocking coil. However, the presence of a second shocking coil in the SVC incorporated in a single ICD lead was associated with an increased incidence of venous obstruction. No difference was found between silicone and polyurethane insulated leads. CONCLUSION This study shows that venous obstruction occurs relatively frequently after ICD implantation. Therefore, contrast venography should always be obtained if malfunction of a preexistent lead is suspected or a system upgrade is considered.