title: Treatment of in-stent restenosis with excimer laser coronary angioplasty: mechanisms and results compared with PTCA alone.
abstract: BACKGROUND
  This study determined the clinical safety, mechanisms, and 6-month results of excimer laser angioplasty (ELCA)+adjunct PTCA for the treatment of in-stent restenosis and (via lesion matching) compared the results of ELCA+PTCA to PTCA alone.
  
  
  RESULTS
  Using quantitative angiography (QCA) and intravascular ultrasound (IVUS), we studied 107 restenotic previously stented lesions in 98 patients before and after intervention. QCA measurements included minimum lumen diameter (MLD) and diameter stenosis (DS). IVUS measurements included stent, lumen, and intimal hyperplasia (IH=stent-lumen) cross-sectional areas (CSA) and volumes. In the 54 lesions treated with ELCA+PTCA, the MLD increased from 0.73+/-0.38 mm before ELCA to 2.10+/-0.47 mm after ELCA+PTCA (P<.0001); the DS decreased from 70+/-14% to 25+/-12% (P<.0001). By IVUS, the minimum lumen CSA increased from 1.58+/-0.78 mm2 before ELCA to 6.34+/-1.75 mm2 after ELCA+PTCA (P<.0001) as a result of an increase in minimum stent CSA from 7.70+/-2.41 to 9.10+/-2.60 mm2 (P<.0001) and a decrease in IH CSA from 5.25+/-2.84 to 2.63+/-1.41 mm2 (P<.0001). Volumetric analysis showed that tissue ablation (during ELCA) contributed 29+/-15%, tissue extrusion (during adjunct PTCA) contributed 31+/-14%, and additional stent expansion (during adjunct PTCA) contributed 40+/-16% to the overall lumen gain. There were no ELCA-related complications. Matched to lesions treated with PTCA alone, ELCA+PTCA resulted in greater lumen gain, more IH ablation/extrusion, larger final lumen CSA (IVUS), and a tendency for less frequent need for subsequent target vessel revascularization (TVR, 21% versus 38%, P=.0823).
  
  
  CONCLUSIONS
  ELCA safely and effectively ablates in-stent neointimal tissue. Adjunct PTCA extrudes neointimal tissue out of the stent and also further expands the stent. Compared with PTCA alone, ELCA+PTCA achieves better short-term and, potentially, better long-term results.
authors.affiliation: Intravascular Ultrasound Imaging and Cardiac Catheterization Laboratories, Washington Hospital Center, DC, USA.
authors.forename: R
authors.initials: R
authors.lastname: Mehran
authors.forename: G S
authors.initials: GS
authors.lastname: Mintz
authors.forename: L F
authors.initials: LF
authors.lastname: Satler
authors.forename: A D
authors.initials: AD
authors.lastname: Pichard
authors.forename: K M
authors.initials: KM
authors.lastname: Kent
authors.forename: T A
authors.initials: TA
authors.lastname: Bucher
authors.forename: J J
authors.initials: JJ
authors.lastname: Popma
authors.forename: M B
authors.initials: MB
authors.lastname: Leon
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D017222:Angioplasty, Balloon, Laser-Assisted; D003131:Combined Modality Therapy; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000628:therapy*; D003925:Diabetic Angiopathies / Q000000981:diagnostic imaging / Q000628:therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D015607:Stents; D013997:Time Factors; D018084:Ultrasonography, Interventional