title: Hydrodynamic boost: a novel re-entry technique in subintimal angioplasty of below-the-knee vessels.
abstract: OBJECTIVE
  To describe the hydrodynamic boost (HB) technique and report our preliminary results with this technique in the subintimal angioplasty of below-the-knee vessels.
  
  
  METHODS
  HB was used in 23 cases (14 males, mean age 73 ± 12 years) of critical limb ischemia, with long chronic total occlusion of tibial arteries extended to the ankle level. The operator performs a manual injection of diluted contrast dye through a 4 F catheter into the subintimal space, close to the patent true distal lumen, in order to achieve a tear in the intimal flap and a connection with the true lumen.
  
  
  RESULTS
  In 19/23 (83 %) cases, the HB was effective in creating a connection between the subintimal space and the true distal lumen and it was possible to advance a wire and to conclude the procedure. In 4/23 (17 %) lesions, the HB failed and the procedure was successfully completed by retrograde approach. No major complications occurred. Mean length between catheter tip and re-entry point was 8 ± 5 mm.
  
  
  CONCLUSIONS
  HB seems to be a feasible, safe and effective re-entry technique in distal below-the-knee vessels. This method represents an easy option for re-entry that extends the possibility of antegrade approach to obtain a successful revascularization.
  
  
  CONCLUSIONS
  • In subintimal angioplasty of below-the-knee vessel re-entry can represent a challenge. • Inability to re-enter may determine the failure of the revascularization procedure. • HB is a novel re-entry technique feasible in distal below-the-knee vessels. • HB may increase the success rate of antegrade approach. • In case of failure, retrograde approach remains feasible.
authors.affiliation: Peripheral Interventional Unit, Humanitas Gavazzeni, Via Mauro Gavazzeni, 21, Bergamo, Italy. ferraresi.md@gmail.com.
authors.forename: Roberto
authors.initials: R
authors.lastname: Ferraresi
authors.affiliation: Unit of Vascular Surgery, Humanitas Gavazzeni, Via Mauro Gavazzeni, 21, Bergamo, Italy.
authors.forename: Meneme
authors.initials: M
authors.lastname: Hamade
authors.affiliation: Unit of Vascular Surgery, Humanitas Gavazzeni, Via Mauro Gavazzeni, 21, Bergamo, Italy.
authors.forename: Vito
authors.initials: V
authors.lastname: Gallicchio
authors.affiliation: Vascular and Endovascular Surgery Unit, San Giovanni di Dio Hospital, P.zza Santa Maria Nuova, 1, Florence, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Troisi
authors.affiliation: Radiology Unit, IRCCS Policlinico San Donato, San Donato Milanese, , P.zza Edmondo Malan 1, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Mauri
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000379:methods*; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000628:therapy*; D002404:Catheterization / Q000379:methods; D002908:Chronic Disease; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D057446:Hydrodynamics; D007511:Ischemia / Q000000981:diagnostic imaging / Q000628:therapy; D008297:Male; D008875:Middle Aged; D016909:Tibial Arteries / Q000000981:diagnostic imaging
chemical_list: D003287:Contrast Media
keywords: Below-the-knee vessel; Critical limb ischemia; Hydrodynamic boost; Re-entry technique; Subintimal angioplasty