title: Patients prone to recurrence after endovascular treatment: periprocedural results of the PRET randomized trial on large and recurrent aneurysms.
abstract: OBJECTIVE
  Some patients with large or recurrent aneurysms may be at increased risk of recurrence postcoiling. The Patients Prone to Recurrence after Endovascular Treatment (PRET) trial was designed to assess whether hydrogel coils were superior to platinum coils in these high-risk patients. This article reports periprocedural safety and operator-assessed angiographic results from the PRET trial.
  
  
  METHODS
  PRET was a pragmatic, multicenter, randomized controlled trial. Patients had ≥10-mm aneurysms (PRET-1) or a major recurrence after coiling of an aneurysm of any size (PRET-2). Patients were randomly allocated to hydrogel or control arms (any platinum coil) by using concealed allocation with minimization. Assist devices could be used as clinically required. Aneurysms could be unruptured or recently ruptured. Analyses were on an intent-to-treat basis.
  
  
  RESULTS
  Four hundred forty-seven patients were recruited (250 PRET-1; 197 PRET-2). Aneurysms were recently ruptured in 29% of PRET-1 and 4% of PRET-2 patients. Aneurysms were ≥10 mm in all PRET-1 and in 50% of PRET-2 patients. They were wide-neck (≥4 mm) in 70% and in the posterior circulation in 24% of patients. Stents were used in 28% of patients (35% in PRET-2). Coiling was successful in 98%. Adverse events occurred in 28 patients with hydrogel and 23 with platinum coils. Mortality (n=2, unrelated to treatment) and morbidity (defined as mRS>2 at 1 month) occurred in 25 patients (5.6%; 12 hydrogel, 13 platinum), related to treatment in 10 (4 hydrogel; 6 platinum) (or 2.3% of 444 treated patients). No difference was seen between hydrogel and platinum for any of the indices used to assess safety up to at least 30 days after treatment. At 1 month, 95% of patients were home with a good outcome (mRS≤2 or unchanged). Operator-assessed angiographic outcomes were satisfactory (complete occlusion or residual neck) in 339 of 447 or 76.4% of patients, with no significant difference between groups.
  
  
  CONCLUSIONS
  Endovascular treatment of large and recurrent aneurysms can be performed safely with platinum or hydrogel coils.
authors.affiliation: From the Department of Radiology (J.R., A.W., F.G., D.R.), Centre Hospitalier de l'Université de Montréal Laboratory of Interventional Neuroradiology (J.R., R.K.), Centre de recherche du Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital, Montreal, Quebec, Canada jean.raymond@umontreal.ca.
authors.forename: J
authors.initials: J
authors.lastname: Raymond
authors.affiliation: Laboratory of Interventional Neuroradiology (J.R., R.K.), Centre de recherche du Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital, Montreal, Quebec, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Klink
authors.affiliation: Département de mathématiques et de statistique (M.C.), Université de Montréal, Montreal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Chagnon
authors.affiliation: Department of Neurological Surgery (S.L.B.), Oregon Health & Science University, Portland, Oregon.
authors.forename: S L
authors.initials: SL
authors.lastname: Barnwell
authors.affiliation: Department of Radiology and Medical Imaging (A.J.E.), University of Virginia Health System, Charlottesville, Virginia.
authors.forename: A J
authors.initials: AJ
authors.lastname: Evans
authors.affiliation: Department of Neurosurgery (J.M., B.L.H.), University of Florida, Gainesville, Florida.
authors.forename: J
authors.initials: J
authors.lastname: Mocco
authors.affiliation: Department of Neurosurgery (J.M., B.L.H.), University of Florida, Gainesville, Florida.
authors.forename: B L
authors.initials: BL
authors.lastname: Hoh
authors.affiliation: Departments of Radiology and Neurosurgery (A.S.T., R.D.T.), Medical University of South Carolina, Charleston, South Carolina.
authors.forename: A S
authors.initials: AS
authors.lastname: Turk
authors.affiliation: Departments of Radiology and Neurosurgery (A.S.T., R.D.T.), Medical University of South Carolina, Charleston, South Carolina.
authors.forename: R D
authors.initials: RD
authors.lastname: Turner
authors.affiliation: Service de Neuroradiologie Diagnostique et Interventionnelle (H.D.), Centre Hospitalier Universitaire de Nantes, Nantes, France.
authors.forename: H
authors.initials: H
authors.lastname: Desal
authors.affiliation: Department of Neurological Surgery (D.F.), Stony Brook University Medical Center, Stony Brook, New York.
authors.forename: D
authors.initials: D
authors.lastname: Fiorella
authors.affiliation: Département de Neuroradiologie Diagnostique et Interventionnelle (S.B.), Centre Hospitalier Universitaire de Nancy, Nancy, France.
authors.forename: S
authors.initials: S
authors.lastname: Bracard
authors.affiliation: From the Department of Radiology (J.R., A.W., F.G., D.R.), Centre Hospitalier de l'Université de Montréal.
authors.forename: A
authors.initials: A
authors.lastname: Weill
authors.affiliation: From the Department of Radiology (J.R., A.W., F.G., D.R.), Centre Hospitalier de l'Université de Montréal.
authors.forename: F
authors.initials: F
authors.lastname: Guilbert
authors.affiliation: From the Department of Radiology (J.R., A.W., F.G., D.R.), Centre Hospitalier de l'Université de Montréal.
authors.forename: D
authors.initials: D
authors.lastname: Roy
mesh_terms: D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000628:therapy; D001807:Blood Vessel Prosthesis; D004621:Embolization, Therapeutic / Q000295:instrumentation / Q000379:methods; D057510:Endovascular Procedures / Q000295:instrumentation / Q000379:methods; D005260:Female; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000627:therapeutic use; D002532:Intracranial Aneurysm / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010984:Platinum; D012008:Recurrence; D016896:Treatment Outcome
chemical_list: D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D010984:Platinum