Guidewire entrapment in the Chiari network during the insertion of a hemodialysis catheter: a case report.

BACKGROUND: The Chiari network, a remnant of fetal anatomy, consists of a mesh-like structure within the right atrium. With advancements in cardiac interventions, complications associated with the Chiari network have increasingly been reported. However, there are few reports about guidewire or catheter entrapment in the Chiari network during the insertion of a dialysis catheter. CASE PRESENTATION: A 46-year-old male with end-stage renal disease was hospitalized and underwent a digital subtraction angiography-assisted catheterization of the right internal jugular vein tunnel-cuffed dialysis catheter. When the guide wire entered a depth of about 20 cm, it was difficult to advance, manifested as resistance when twisting the guide wire and inability to enter the inferior vena cava. After the peelable sheath was inserted, it was difficult to pull out the guide wire. After repeated attempts to rotate the guide wire, the guide wire was finally pulled out. A fibrous tissue was wrapped around the tip of the guide wire. Its length was 6 cm, with a smooth surface and tough texture. We considered that the tissue we pulled out was most likely a part of a Chiari network. CONCLUSIONS: This case highlights the potential for the Chiari network to complicate surgical procedures, including difficulty with guidewire and catheter manipulation. Attention should be paid to Chiari networks. Echocardiography can be used to identify the Chiari network. During the surgery, forcefully pulling out a stuck guidewire is not suggested, to avoid the risk of tearing the atrial wall and causing pericardial tamponade. An urgent consultation with ultrasound doctors and cardiac surgeons might be helpful in such cases.

Chiari network as a cause of neonatal hypoxemia.

The Chiari network is an embryonic remnant of the right venosus, consisting of a thin, mobile structure connected to the right atrium. Neonates with the Chiari network may present with hypoxemia. We report a case of a neonate with persistent hypoxemia despite improvement in respiratory distress symptoms and increased supplemental oxygen that was diagnosed using real-time telemedicine.

Prominent prolapsing Chiari network: presentation and prognosis in paediatric patients.

Chiari network is an infrequently visualized web-like structure in the right atrium that is usually thin and small. Rarely, it can be prominent and elongated with protrusion into the right ventricle during diastole and complications have been reported. Thirty-eight patients (median age 2.5 years) with prolapsing Chiari network were identified and associated cardiac abnormalities documented. Echocardiographic right and left heart parameters were measured and compared to normative data. At presentation, the extent of Chiari network prolapse below the tricuspid annulus was 9.1 ± 3.5 mm (mean ± standard deviation), mean pulmonary valve annulus diameter z-value was reduced (-0.91 ± 0.64), and mean aortic valve z-value was enlarged (+0.97 ± 0.87). Fourteen patients exhibited no other cardiac abnormality. Eight were noted to have atrial septal defects, eight demonstrated supraventricular dysrhythmias, six had mild to moderate tricuspid valve regurgitation, and one patient each had an atrial septal aneurysm, severe pulmonic valve stenosis, small perimembranous ventricular septal defect, bicuspid aortic valve, and mild right upper pulmonary vein stenosis. Fourteen patients (37%) were seen in follow-up from 1 to 8.5 years later (median 3.2 years). During that time, the magnitude of prolapse across the tricuspid valve decreased by up to 7 mm (median 2 mm). Interventions were required in three patients, but many associated cardiac abnormalities resolved spontaneously with growth. Thus, the presence of a prolapsing Chiari network has a substantial risk of associated CHDs. However, the extent of Chiari network prolapse gradually decreases and many related abnormalities resolve during growth.

P-Wave Changes Associated with Chiari Network in the Right Atrium.

The Chiari network (CN) is a mobile, net-like structure occasionally present in the right atrium, near the opening of the inferior vena cava and coronary sinus. While typically asymptomatic, it may contribute to thromboembolism or right atrial pathologies. Here, we hypothesized that existing differences in P-wave morphology on electrocardiograms (ECG) may be associated with atrial conduction changes. Seventy-one children with a CN were recruited and matched to 60 healthy controls. P-wave duration, P-wave amplitude, P dispersion (Pd), QRS, PR, QT, and QTc (calculated with Bazett formula) intervals were measured and compared. Between the control and the patient groups, the mean P-wave duration was 78.1 ms and 88.7 ms, P amplitude was 1.3 mm and 1.1 mm, and Pd was 18.9 and 35.5 ms, respectively. These differences were statistically significant across all measurements (p < 0.05). Atrial conduction may be affected in patients with CN, and these patients may then develop atrial arrhythmia.

Chiari Network Associated with Hypoxemia in a Neonate: Case Report and Review of the Literature.

Chiari network is an embryonic remnant of the right sinus venosus. It appears as a thin, fenestrated membrane attached to two or more regions within the right atrium. Usually, a Chiari network has a benign course; however, rare complications associated with a Chiari network have been reported. We present the case of a neonate with hypoxemia and a Chiari network protruding into the right ventricular inflow tract associated with right-to-left shunting across the patent foramen ovale throughout the cardiac cycle. We noted spontaneous improvement after 3 weeks of life.

Catheter entrapment in Chiari network: Extraction with radiofrequency.

We report a challenging case of a duodecapolar mapping catheter entrapment in Chiari network and its release by radiofrequency energy application with an ablation catheter.

Entrapment of a Pacing Lead within a Chiari Network: Utility of Intracardiac Echo and a Laser Sheath.

Although rare, Chiari networks are elaborate embryological remnants that can pose distinct challenges for catheter and pacing lead manipulation within the right atrium. Device entrapment may require open thoracotomy for removal, with significant morbidity. We report an unusual case of pacing lead entanglement within this structure, followed by prompt intracardiac echocardiographic identification and laser sheath removal.

Topographic anatomy of the fetal inferior vena cava, coronary sinus, and pulmonary veins: Variations in Chiari's network.

To understand anomalies in Chiari's network better, we assessed the topographical anatomy of the fetal inferior vena cava (IVC), coronary sinus, and atria. We examined sagittal serial paraffin sections of 15 human fetuses of crown-rump length 24-36 mm, corresponding to a gestational age of 8 weeks. Although their outflow tract morphologies were similar, these 15 specimens could be classified into two groups. In eight specimens, the left common cardinal vein reached the body wall, whereas in the other seven the vein was obliterated near the left pulmonary vein. Irrespective of the group in which the specimen was included, the anteroposterior arrangement of the coronary sinus, the sinus septum (septum), and the right sinus valve (right valve) could be classified into three types: the right valve-septum-coronary sinus arrangement in seven specimens; the right valve-coronary sinus-septum arrangement in five; and the coronary sinus-right valve-septum arrangement in three. Depending on differences in topographical anatomy, the sinus septum separated the coronary sinus opening from either the right or the left atrium. Likewise, the coronary sinus opening was either adjacent to or distant from the IVC terminal. Rather than the counter-side position of the right valve being at the IVC terminal, the left sinus valve protruded leftward, forming an incomplete interatrial septum. Fetal variations seemed to be closely connected with individual variations and a high frequency of Chiari's network anomalies in adults.

Death due to coronary artery anomaly with coexistence of Chiari network.

Coronary artery anomalies rarely detected in autopsy series and angiograms can be a component of complex malformations, besides, can be also associated with sudden cardiac death. Presented case was 22-year-old male, who had suddenly fainted during a football match played on artificial turf, he was transferred into the hospital, however had died during intensive care therapy. He had been evaluated by local prosecutor, and sent to our center for autopsy. At autopsy, internal macroscopic examination revealed absence of the right coronary artery. A total of two coronary artery ostia were observed. One of them originated from the left aortic sinus, and the other one stemmed from 8 mm above the sinotubular line. Besides, Chiari network formation was seen in the right atrium. This case with coronary artery anomaly associated with formation of Chiari network was discussed from the perspective of forensic medicine in the light of the literature information.

Co-occurrence of patent foramen ovale and Chiari network in a diabetic patient.

INTRODUCTION: The coexistence of congenital cardiovascular anomalies provides valuable insights into the intricate nature of human cardiac anatomy and its potential interactions with underlying health conditions. This case report presents an autopsy analysis of a diabetic patient manifesting both a patent foramen ovale and a Chiari network. CASE PRESENTATION: A 26-year-old male with a history of type 2 diabetes mellitus was admitted with post cardiac arrest. He died despite resuscitative efforts. Autopsy revealed notable findings including a patent foramen ovale and a Chiari network. Post-mortem biochemical markers indicated elevated HbA1c level and hyperglycaemia. The absence of cryptogenic strokes or paradoxical embolism prompted exploration into potential relationships between these anomalies and metabolic disturbances, and prompts a discussion about whether the observed anatomical variations could potentially serve as risk factors contributing to the patient's death due to complications of diabetes. CONCLUSION: The co-occurrence of a patent foramen ovale and a Chiari network within a diabetic patient, accompanied by elevated HbA1c level and hyperglycaemia, offers a unique perspective on the convergence of congenital cardiovascular variation and metabolic health. The juxtaposition of these anomalies with biochemical markers underscores the intricate interplay between cardiac morphology and metabolic conditions.

Unresponsiveness to Chiari Malformation Type I Surgery Can Be Related to the Accompanying Chiari Network.

Surgical treatment is indicated for Chiari malformation type 1 (CMI) with tonsillar descent (TD) of >5 mm and other clinical manifestations. However, some patients remain unresponsive to surgery; this is an active topic of discussion. A patient presented to the emergency department with dizziness and an impaired gait. He had a history of hypertension. Magnetic resonance investigations revealed a 9-mm TD and cervical syringomyelia. There was no evidence of interatrial septum pathology on transthoracic echocardiography performed preoperatively. Although his complaints were attributed to CMI and surgery was performed, his symptoms remained persistent. Two years later, when the patient's dizziness increased, a posterior fossa transient ischemic attack (TIA) was suspected. A large patent foramen ovale (PFO) and Chiari network (CN) were also detected on transesophageal echocardiography. His complaints were resolved following PFO closure. Our case suggests that neurosurgeons should be informed about the results of the companionship of a PFO and CN. Before deciding on CMI surgery for patients with only dizziness complaints, a detailed investigation of accompanying cardiac pathologies is paramount to ensure accurate diagnosis and treatment.

A Triad of Intricacies: An Exploration of Concomitant Codominant Coronary Artery Pattern, Patent Foramen Ovale, and Chiari Network in a Cadaveric Study.

Although findings related to codominant coronary artery circulation, patent foramen ovale (PFO), and Chiari network (CN) have been documented in isolation, there is a gap in literature detailing the unique case with the presence of all three cardiac anomalies concomitantly present in a single heart. The purpose of this case report is to detail a unique cadaveric heart case, to serve as reference to provide useful data for interventionalists and clinicians. This observational cadaveric study assessed a single donor heart obtained through the University of Houston College of Medicine's Willed Donor Program. After meticulous dissection, relevant heart surface structures were isolated and identified. Morphometric analysis and measurements were obtained via a digital vernier caliper. The donor heart exhibited a typical codominant coronary arterial scheme, in that the posterior interventricular artery arose as a merger between the right coronary and the circumflex on the postero-inferior surface of the heart when placed in the valentine orientation. Interestingly, the antero-lateral surface of the heart was supplied via a left marginal artery (LMA) and an accessory left anterior interventricular artery.Contribution to the existing knowledge base of unique concomitant cardiac anomalies, may prove to be a beneficial future reference for interventionalists in hopes that an expanded knowledge base may lead to comprehensive and safe implementation of a wide variety of procedures.

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

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.

Case Report: Right atrial mass arising from the Eustachian valve.

A mass in the right atrium (RA) is an unusual finding that warrants further investigation. We report the case of a 72-year-old male patient who underwent a Bentall operation with a biological composite graft and closure of patent foramen ovale 18 months prior to his presentation with an incidental new RA mass during follow-up echocardiography. Transesophageal echocardiography and thoracic CT angiography confirmed a right atrial mass attached to the Eustachian valve and additionally revealed a non-occlusive pulmonary embolism in the inferior lobar artery of the left lung. Despite 2 months of anticoagulation treatment, the size of the mass did not decrease. Further MRI imaging showed a central mass enhancement which raised concerns about a tumoral lesion. Following a discussion with the local Heart Team, management with surgical treatment was decided. The intraoperative findings revealed a 2.5 cm × 2.1 cm mass arising from the Eustachian valve and a non-diagnosed Chiari network in the RA. Both were resected and sent for a frozen section procedure which excluded a malignancy. The final histopathological analysis described fibrotic tissues compatible with an organized thrombus. The patient was discharged on postoperative day 7 without any complications. Although imaging studies are useful for the initial and differential diagnosis of RA masses, it is not always possible to get the final diagnosis without surgery. In case of a suspicion of a potentially malignant pathology, surgical exploration and resection are necessary.

Thrombosis of Chiari's network in the setting of non-bacterial thrombotic endocarditis occurring under non-vitamin K antagonist oral anticoagulation: a case report.

Background: Non-bacterial thrombotic endocarditis (NBTE) is a rare condition characterized by sterile thrombi on undamaged valves. We herein report a case of NBTE involving the Chiari's network and the mitral valve, related to a metastatic cancer, and occurring under non-vitamin K antagonist oral anticoagulant (NOAC). Case summary: A 74-year-old patient with metastatic pulmonary cancer was diagnosed with a right atrium mass during pre-treatment cardiovascular check-up. Transoesophageal echocardiography and cardiac magnetic resonance concluded that the mass was a Chiari's network. Two months later, the patient was admitted for a pulmonary embolism and started rivaroxaban. At 1-month follow-up, the patient underwent a new echocardiography, which showed an increased size of the right atrium mass and the presence of two new masses on the mitral valve. She suffered an ischaemic stroke. Infectious work-up was negative. Coagulation factor VIII was 419%. A NBTE with Chiari's network thrombosis and mitral valve involvement was suspected in the setting of a hypercoagulable state related to the active cancer, and intravenous heparin was started, bridged to vitamin K antagonist (VKA) after 3 weeks. All the lesions were fully resolved on follow-up echocardiography at 6 weeks. Discussion: This case highlights an atypical association of thrombosis on right and left heart chamber with systemic and pulmonary embolism, related to a hypercoagulable state. Chiari's network is an embryonic remnant with no clinical significance and is exceptionally thrombosed. Failure of treatment by NOAC highlights the complexity of cancer-related thrombosis, particularly in NBTE, and the necessity of heparin and VKA in our case.

Huge Chiari Network in the Right Atrium Diagnosed as Thrombosis - Case Report and a Brief Review.

The Chiari network is a common benign finding usually found incidentally in the right atrium (RA). This lesion frequently coexists with patent foramen ovale (PFO). Although the Chiari network is diagnosed easily and has no clinical importance, sometimes, the accurate diagnosis becomes hard and the lesion itself, or with PFO, can lead to clinical events. Accordingly, cardiologists should consider the Chiari network and its differential diagnosis in the evaluation of RA masses.

Three-dimensional echocardiographic assessment of Chiari's network relationship with the left ventricular false tendon.

BACKGROUND: Left ventricular false tendon (LVFT) is a fibromuscular band crossing the left ventricular cavity. And Chiari's network (CN) is a highly mobile, mesh-like, echogenic structure in right atrium. In this study, we aimed to evaluate the coexistence of LVFT in patients with CN. CN patients were examined with live/real-time three-dimensional transthoracic echocardiography (TTE) for visualization of LVFT. RESULTS: This is a single-center prospective study of 49 patients with CN. In literature studies, the average ratios of LVFT were 22% in the normal population. In our study, an increased ratio of LVFT (n = 31, 63.3%) was found in CN patients evaluated with a three-dimensional TTE (63.3% versus 22%) (p = 0.01). The interatrial septal aneurysm was found in 31 (63.3%) patients with CN. And, the positive contrast echocardiography examination was determined in 22 (61.1%) patients with CN. CONCLUSIONS: Our study reveals that CN is associated with LVFT and is also associated with cardiac anomalies like an interatrial septal aneurysm, and atrial septal defect. And LVFT can be evaluated better with three-dimensional TTE than with traditional two-dimensional TTE. Patients with CN should be evaluated more carefully by three-dimensional echocardiography as they can be in synergy in terms of the cardiac pathologies they accompany.

Pitfalls of Using Imaging Technique in the Presence of Eustachian Valve or Chiari Network: Effects on Right-to-Left Shunt and Related Influencing Factors.

When patent foramen ovale (PFO) combines with the prominent Eustachian valve or Chiari network (EV/CN), contrast transthoracic echocardiography (cTTE) may miss the diagnosis of PFO. We sought to determine the characteristics of right-to-left shunt (RLS) in PFO patients with prominent EV/CN on cTTE and identify the causal factors of missed diagnosis. We consecutively enrolled 98 patients who suffered from PFO-related stroke and with prominent EV/CN. All patients were divided into the delayed and non-delayed groups according to the characteristics of RLS on cTTE. The characteristics of RLS were compared with those of 42 intrapulmonary shunt patients. The anatomical characteristics of PFO and EV/CN were analyzed in the 98 PFO patients. Upon cTTE, significantly delayed occurrence and longer duration of the RLS in the delayed group were found both at rest and during the Valsalva maneuver, similar to the intrapulmonary shunt. Multivariate logistic analysis revealed that the length of EV/CN (>19 mm) and the diameter of PFO at the left atrium aspect (<1.2 mm) were high-risk factors for missed diagnosis. In conclusion, RLS showed delayed emergence and disappearance in some of the PFO patients with prominent EV/CN. The length of EV/CN and the diameter of PFO may have been related to the missed diagnosis of PFO.