title: Subintimal recanalization of occluded stents: the substent technique.
abstract: OBJECTIVE
  Application of metal stents is complicated by neointimal hyperplasia leading to vessel restenosis and reocclusion. Treatment options in cases presenting with complete occlusion of the stented segment and recurrent critical limb ischemia (CLI) are limited. We present the option of the subintimal/substent technique in dealing with occluded stents.
  
  
  METHODS
  The study included patients presenting with recurrent CLI due to impaired blood flow as a result of complete occlusion of previously inserted metal stents and unsuccessful intraluminal crossing of the lesion via either the antegrade or retrograde approach. In these cases, crossing the occlusion through the subintimal/substent plane was attempted. Primary end points included technical success, safety of the procedure, clinical improvement, and limb salvage, while secondary end points were patient survival, primary patency, and vessel restenosis rates at 1-year follow-up. Study end points were calculated by Kaplan-Meier survival analysis.
  
  
  RESULTS
  Between July 2006 and October 2011, a total of 14 patients (mean age 69.14 ± 12.59 years, 12 men) were treated with the substent technique and included in the analysis. Technical success rate was 85.71% (12 of 14), with a total lesion length of 193.57 ± 90.78 mm. The mean occluded stented segment length was 90.21 ± 44.34 mm. In 10 (83.33%) of 12 cases, a new stent had to be placed by the side of the old occluded one, while the remaining two cases (16.67%) were treated only with balloon angioplasty. No serious adverse events were noted during the immediate postprocedural period. All successfully treated patients improved clinically. Estimated limb salvage was 90.9%, and patient survival rate was 90.0% at 1 year's follow-up. Primary patency was 45.50% and vessel restenosis 77.30%.
  
  
  CONCLUSIONS
  Subintimal recanalization of occluded metal stents through the substent plane is a valuable alternative treatment option, especially in patients with recurrent CLI with few alternatives.
authors.affiliation: Department of Interventional Radiology, School of Medicine, Patras University Hospital, 26504, Rion, Patras, Greece. adiamant@upatras.gr
authors.forename: Athanasios
authors.initials: A
authors.lastname: Diamantopoulos
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Katsanos
authors.forename: Stavros
authors.initials: S
authors.lastname: Spiliopoulos
authors.forename: Dimitris
authors.initials: D
authors.lastname: Karnabatidis
authors.forename: Dimitris
authors.initials: D
authors.lastname: Siablis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000800:Angioplasty, Balloon / Q000009:adverse effects* / Q000379:methods / Q000401:mortality; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D005263:Femoral Artery / Q000000981:diagnostic imaging / Q000601:surgery; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D023821:Limb Salvage / Q000379:methods; D008297:Male; D008670:Metals; D008875:Middle Aged; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging / Q000401:mortality / Q000628:therapy*; D011150:Popliteal Artery / Q000000981:diagnostic imaging / Q000601:surgery; D011379:Prognosis; D011475:Prosthesis Failure; D011673:Pulsatile Flow / Q000502:physiology; D011859:Radiography; D018570:Risk Assessment; D015607:Stents; D015996:Survival Rate; D016896:Treatment Outcome; D017539:Tunica Intima; D014654:Vascular Patency / Q000502:physiology
chemical_list: D008670:Metals