Redilation of endovascular stents in congenital heart disease: Factors implicated in the development of restenosis and neointimal proliferation

OBJECTIVES We sought to determine the incidence of and risk factors for the development of restenosis and neointimal proliferation after endovascular stunt implantation for congenital heart disease {CHD). BACKGROUND Risk Factors for the development of restenosis and neointimal pr oliferation are poorly understood. METHODS This was a retrospective review of patients who underwent endovascu lar stent redilation between September 1989 and February 2000. RESULTS Of 368 patients who had 752 scents implanted, 220 were recatheteriz ed. Of those 220 patients, 103 underwent stent redilation. Patients were cl assified into three groups: 1) those with pulmonary artery stenosis (n = 94 ), tetralogy of Fallot/pulmonary atresia {n = 72), congenital branch pulmon ary stenosis (n = 9), status post-Fontan operation (n = 6), status post-art erial switch operation (n = 7); 2) those with iliofemoral venous obstructio n (n = 6); and 3) those with miscellaneous disorders (n = 3). The patients' median age was 9.9 years (range 0.5 to 39.8); their mean follow-up duratio n was 3.8 years (range 0.1 to 10). Indications for stent redilation include d somatic growth (n = 67), serial dilation (n = 27) and development of neoi ntimal proliferation or restenosis, or both (n = 9). There was a low incide nce of neointimal proliferation (1.8%) and restenosis (2%). There were no d eaths. Complications included pulmonary edema (n = 1), hemoptysis (n = 1) a nd contralateral stem compression (n = 2). CONCLUSIONS Redilation or further dilation of endovascular stems for CHD is effective as late as 10 years. The risk of neointimal proliferation {1.8%) and restenosis (2 10) is low and possibly avoidable. Awareness of specific risk factors and modification of the scent implantation technique, includi ng avoidance of minimal scent overlap and sharp angulation of the scent to the vessel wall and avoidance of overdilation, have helped to reduce the in cidence of restenosis. (J Am Cull Cardiol 2001;38:521-6) (C) 2001 by the Am erican College of Cardiology.