title: A novel resorbable embolization microsphere for transient uterine artery occlusion: a comparative study with trisacryl-gelatin microspheres in the sheep model.
abstract: OBJECTIVE
  To evaluate angiographic recanalization, inflammatory reaction, and uterine damage after sheep uterine artery embolization (UAE) with a novel calibrated resorbable embolization microsphere (REM) and compare the results with control nonresorbable microspheres.
  
  
  METHODS
  Six hormonally artificially cycled sheep underwent bilateral UAE until stasis with either REM or trisacryl-gelatin microspheres (TGMS). At 7 days, control angiograms were obtained to assess the residual vascularization at arterial and parenchymal phases. The animals were then sacrificed for analysis of the presence of microspheres, inflammatory foreign body reaction, and surface areas of uterine damage.
  
  
  RESULTS
  Mean volume of microspheres injected per uterine artery (UA) or per animal did not differ between groups. At day 7, the flow was normal for six of six UAs that received embolization with REM versus only three of six UAs with TGMS (P = .0455, χ(2) test). Uterine parenchymography showed no defects in six UAs in the REM group versus five defects in six UAs in the TGMS group (P = .0060, χ(2) test). No REM or residual fragments of microspheres were observed on histologic analysis. TGMS were observed in tissues and accompanied by a mild inflammatory response. Necrosis rates were not significantly different between the two products, either in endometrium (REM 23.5% ± 28.8% [median 8.1%] vs TGMS 21.8% ± 23.7% [median 14.6%]) or in myometrium (REM 8.2% ± 22.7% [median 0.0%] vs TGMS 8.8% ± 20.8% [median 0.9%]). Endometrium alteration rate was lower with REM than with TGMS (39.7% ± 25.7% [median 34%] vs 60.6% ± 27.1% [median 71%]; P = .0060, Mann-Whitney test). Myometrium alteration rates were not significantly different between REM (45.7% ± 37.1% [median 63.0%]) and TGMS (37.8% ± 34.0% [median 19.1%]).
  
  
  CONCLUSIONS
  At 1 week after sheep UAE with REM, the recanalization was complete, the microspheres were completely degraded, and there was no remnant inflammatory response.
authors.affiliation: Occlugel SAS, Jouy en Josas.
authors.forename: Valentin
authors.initials: V
authors.lastname: Verret
authors.affiliation: Department of Radiology, Centre Hospitalier Universitaire de Caen, Caen.
authors.forename: Jean Pierre
authors.initials: JP
authors.lastname: Pelage
authors.affiliation: Department of Pathology, APHP, Hôpital Lariboisière, 2 rue Ambroise Paré, 75010 Paris, France; Université René Diderot, Paris.
authors.forename: Michel
authors.initials: M
authors.lastname: Wassef
authors.affiliation: Occlugel SAS, Jouy en Josas.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Louguet
authors.affiliation: Occlugel SAS, Jouy en Josas.
authors.forename: Emeline
authors.initials: E
authors.lastname: Servais
authors.affiliation: Occlugel SAS, Jouy en Josas.
authors.forename: Laurent
authors.initials: L
authors.lastname: Bédouet
authors.affiliation: Occlugel SAS, Jouy en Josas.
authors.forename: Thomas
authors.initials: T
authors.lastname: Beaulieu
authors.affiliation: UMR CNRS 8612 Institut Galien Paris-Sud, Chatenay Malabry.
authors.forename: Laurence
authors.initials: L
authors.lastname: Moine
authors.affiliation: Department of Interventional Neuroradiology, APHP, Hôpital Lariboisière, 2 rue Ambroise Paré, 75010 Paris, France; Université René Diderot, Paris; Laboratoire MSC, Paris, France.. Electronic address: dr.alex.laurent@gmail.com.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Laurent
mesh_terms: D000180:Acrylic Resins / Q000627:therapeutic use*; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000628:therapy*; D004195:Disease Models, Animal; D005780:Gelatin / Q000627:therapeutic use*; D008863:Microspheres; D012756:Sheep; D016896:Treatment Outcome; D055357:Uterine Artery Embolization / Q000379:methods*
chemical_list: D000180:Acrylic Resins; C496735:trisacryl gelatin microspheres; D005780:Gelatin