title: Late neointimal proliferation following implantation of stents for relief of pulmonary arterial stenosis.
abstract: On the assumption that the diameter of the reference vessel might determine the thickness of neointimal coverage of stents placed in the pulmonary arteries, we analyzed the angiograms of 28 lesions in 17 patients who underwent follow-up cardiac catheterization. Excluding 2 lesions where late stenosis was determined mainly by recoil of greater than 30%, we investigated the neointimal thickness of 26 lesions in 16 patients. Several factors that might contribute to late re-stenosis were also analyzed. Age and body weight at implantation ranged from 0.8 to 20 years, with a median of 6 years, and from 6.8 to 77.5 kg, with a median of 17.6 kg. Follow-up interval was from 6 to 15 months, with a median of 6 months. There was a significant increase in diameter, as well as a reduction in pressure gradient, immediately after the implantation of stents. Although there was no significant difference between the achieved diameter and the diameter of the stent at follow-up, the diameter of the lesion at follow-up was significantly smaller than the diameter achieved by stenting. The increase in the pressure gradient at follow-up was slightly greater in 4 lesions where the late reduction in diameter was greater than 30% than in the 18 lesions where this was less than 30% (p = 0.05). The diameter of the reference vessel, and the diameter by stenting correlated with the late reduction in diameter. All lesions with diameter reduced greater than 30% had a reference diameter of less than 6.1 mm, and a diameter achieved by stenting of less than 6.5 mm. Late loss in luminal diameter directly correlated with the thickness of the neointimal coverage. In conclusion, close observation should be mandatory following implantation of stents in small pulmonary arteries.
authors.affiliation: Department of Pediatrics, National Cardiovascular Center, Suita, Osaka, Japan. tomitah@hsp.ncvc.go.jp
authors.forename: Hideshi
authors.initials: H
authors.lastname: Tomita
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yazaki
authors.forename: Kohji
authors.initials: K
authors.lastname: Kimura
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ono
authors.forename: Toshikatsu
authors.initials: T
authors.lastname: Yagihara
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Echigo
mesh_terms: D000293:Adolescent; D000328:Adult; D000792:Angiography / Q000379:methods; D006328:Cardiac Catheterization / Q000379:methods; D002404:Catheterization / Q000009:adverse effects / Q000379:methods*; D002455:Cell Division / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D011668:Pulmonary Veno-Occlusive Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D015607:Stents; D013997:Time Factors; D017539:Tunica Intima / Q000166:cytology* / Q000473:pathology*; D014654:Vascular Patency / Q000502:physiology