Chiari network for the interventional cardiologist: A hidden enemy at the heart gate - A systematic review of the literature

Int J Cardiol. 2023 Mar 15:375:23-28. doi: 10.1016/j.ijcard.2022.12.046. Epub 2022 Dec 29.


Background: This study aimed to collect and analyze the literature data regarding Chiari network (CN) and other right atrium (RA) remnants comprising the Eustachian and Thebesian valves (EV, ThV) as a potential entrapment site during different percutaneous cardiac procedures (PCP).

Methods and results: A systematic search was conducted using Pubmed and Embase databases following the PRISMA guidelines to obtain available data concerning PCP associated with entrapment of inserted materials within CN-EV-ThV. The final analysis included 41 patients who underwent PCP with reported material entrapment within these RA remnants. The PCP was atrial septal defect (ASD)/patent foramen ovale (PFO) closure, catheter ablation, and pacemaker/defibrillator implantation in 44%, 22%, and 17% of patients, respectively. The entrapped materials were ASD/PFO devices, multipolar electrophysiology catheters, passive-fixation pacing leads, and J-guidewires in about 30%, 20%, 15%, and 10% of patients, respectively. Intraprocedural transthoracic, transoesophageal and intracardiac echocardiography showed sensitivity to reveal these structures of 20%, ∼95%, and 100%, respectively. A percutaneous approach successfully managed 70% of patients, while cardiovascular surgery was required in 20% and three patients died (7.3%).

Conclusions: CN and other RA remnants may cause entrapment of various devices or catheters during PCP requiring right heart access. The percutaneous approach, guided by intraprocedural imaging, appears safe and effective in managing most patients. Prevention includes recognizing these anatomical structures at baseline cardiac imaging and intraprocedural precautions. Further studies are needed to analyze the actual incidence of this condition, its clinical impact and appropriate management.

Keywords: Chiari network; Entrapment; Eustachian valve; Interventional cardiology; Percutaneous.

Publication types

  • Systematic Review
  • Review

MeSH terms

  • Cardiac Catheterization / methods
  • Cardiologists*
  • Foramen Ovale, Patent* / diagnostic imaging
  • Foramen Ovale, Patent* / epidemiology
  • Foramen Ovale, Patent* / surgery
  • Heart Atria / diagnostic imaging
  • Heart Atria / surgery
  • Heart Septal Defects, Atrial* / diagnostic imaging
  • Heart Septal Defects, Atrial* / epidemiology
  • Humans
  • Prostheses and Implants
  • Treatment Outcome