title: Paradoxical embolism after declotting of hemodialysis fistulae/grafts in patients with patent foramen ovale.
abstract: OBJECTIVE
  The safety of percutaneous endovascular declotting procedures for thrombosed hemodialysis fistulae/grafts is well described in the general population; however, its safety in the presence of a patent foramen ovale (PFO) is not known. The objective of this study is to assess the incidence of symptomatic paradoxical embolic events associated with declotting procedure of thrombosed arteriovenous (AV) graft or fistula in patients with documented PFO.
  
  
  METHODS
  This was a retrospective study in a hospital-based, academic practice. It included 23 patients (10 men; mean age, 65) with PFO and thrombosed hemodialysis graft/fistula who underwent a standardized declotting procedure with 2 mg of Alteplase and balloon thrombectomy. Twenty patients (87%) had AV grafts, and three (13%) had AV fistulae. The PFO shunt was right to left in two (9%), left to right in eight (34%), and bidirectional in ten (44%). The shunt direction was not specified in three patients (13%). The technical success of the declotting procedure and the frequency of clinically manifested paradoxical embolic events in this patient population were calculated.
  
  
  RESULTS
  Fifty declotting procedures were performed on 23 patients with a technical success rate of 96% (48 of 50, 96%). No symptomatic paradoxical embolic events were found in any of the 23 patients with PFO.
  
  
  CONCLUSIONS
  Symptomatic paradoxical embolic events after percutaneous endovascular declotting procedures of thrombosed AV grafts and fistulae in patients with documented PFO are rare. This procedure appears to be safe in patients with a PFO.
authors.affiliation: Section of Interventional Nephrology, Division of Nephrology, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA. wu.steven@mgh.harvard.edu
authors.forename: Steven
authors.initials: S
authors.lastname: Wu
authors.forename: Iftikhar
authors.initials: I
authors.lastname: Ahmad
authors.forename: Sohail
authors.initials: S
authors.lastname: Qayyum
authors.forename: Stephan
authors.initials: S
authors.lastname: Wicky
authors.forename: Sanjeeva P
authors.initials: SP
authors.lastname: Kalva
mesh_terms: D000368:Aged; D000800:Angioplasty, Balloon / Q000009:adverse effects; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D001900:Boston; D015150:Echocardiography, Doppler; D019320:Embolism, Paradoxical / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects; D054092:Foramen Ovale, Patent / Q000150:complications* / Q000000981:diagnostic imaging; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000628:therapy*; D006801:Humans; D007674:Kidney Diseases / Q000150:complications / Q000628:therapy*; D008297:Male; D006435:Renal Dialysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D017131:Thrombectomy / Q000009:adverse effects; D015912:Thrombolytic Therapy / Q000009:adverse effects; D013927:Thrombosis / Q000209:etiology / Q000628:therapy*; D010959:Tissue Plasminogen Activator / Q000009:adverse effects
chemical_list: D005343:Fibrinolytic Agents; D010959:Tissue Plasminogen Activator