Right heart catheterization via hemiazygos-azygos collaterals in the setting of inferior vena cava stenosis

Abstract

Background

In cases of inferior vena cava (IVC) obstruction, venous collaterals involving the hemiazygos and azygos veins can provide venous return to the right atrium. This can lead to procedural challenges in right heart catheterization (RHC).

Case presentation

A 54-year-old male with end stage renal disease and severe aortic regurgitation underwent RHC for valve replacement planning. Swan Ganz catheter, via left femoral vein, would not advance beyond the distal IVC despite an inflated balloon. It was advanced over a V18 wire, taking a tortuous path to the right ventricle. Imaging revealed infrarenal IVC stenosis due to a dialysis catheter, with venous return through a dilated lumbar vein and hemiazygos and azygos collaterals.

Conclusion

When catheter advancement fails, IVC stenosis and collateral pathways should be considered. Wire-guided navigation allows completion of RHC in these settings. Familiarity with venous anatomy enables successful RHC despite IVC obstruction. Early recognition and guidewire use can prevent procedural delays.

Background

Right heart catheterization (RHC) is a well established procedure that can be performed through femoral vein access allowing direct passage to the inferior vena cava into the right atrium.[1] However, cases of anatomical or acquired IVC obstruction in patients with a history of end-stage renal disease and long-term dialysis catheter use may lead to development of alternative venous pathways leading to the right atrium.

In this case, IVC stenosis secondary to an infrarenal chronic dialysis catheter disrupted the expected course of the Swan-Ganz catheter advancing through the IVC into the right atrium. This led to a redirection of venous return through dilated lumbar, hemiazygos, and azygos veins. Although clinically significant collateral circulation through these veins is uncommon in adults, they can serve as a significant alternate pathway in situations where central venous flow is impeded. The catheter’s abnormal posterior and midline course on fluoroscopy raised suspicion for an alternate venous route, which was later confirmed with venography and cross sectional imaging. Previous case reports have documented cases of IVC interruption with azygous continuation have complicated the diagnosis of pulmonary embolism or caused unexpected catheter positioning during RHC. [2] These findings highlight how collateral venous anatomy may remain clinically silent until exposed by procedural imaging or complication during procedures. Fig. 1.

Fig. 1.

Fluoroscopy: Femoral Access Showing Collateral Entry. A. Right side large bore femoral dialysis catheter, which is going past the area of IVC narrowing (above the field of view). The cardiac catheter enters from a left femoral approach, goes to the IVC, then curves into a left lumbar vein at the area of narrowing. B. Fluoroscopy: Right Heart Catheter in Azygos System. B. Right heart catheter goes through the SVC into the azygous vein. C. Venography: Lumbar Collateral and Infrarenal IVC Stenosis. C. Left popliteal venogram showing infrarenal IVC stenosis around the catheter. Additional large lumbar vein through which the cardiac catheter advanced. D. CT Angiography: Hemiazygos-to-Azygos Collateral Drainage. D. CT scan showing the dilated hemiazygos vein crossing to the right side, joining the azygos vein, and draining into the SVC. This is believed to be the path the cardiac catheter took

Case presentation

The patient is a 54-year-old male who presented to the hospital for aortic valve replacement planning while complaining of orthopnea, dyspnea upon exertion, and bilateral leg edema. Patient denied palpitations, syncope, or abdominal fullness. Upon arrival, the patient’s EKG showed normal sinus rhythm with a heart rate of 75 beats per minute and no ST changes or T-wave inversions. Chest X-ray revealed right pleural effusion with mild pulmonary vascular congestion. The patient’s BNP elevated to 4437 pg/m with negative troponin/lactate levels. He also has impaired kidney function as indicated by an elevated creatinine of 7.56 mg/dL. Other laboratory values include sodium of 134 mmol/L, potassium of 5.1 mmol/L, and slightly reduced hemoglobin of 10.0 g/dL.

The past medical history significant for end stage renal disease on hemodialysis with right lower extremity tunneled dialysis catheter, severe aortic regurgitation secondary to methicillin-sensitive Staphylococcus aureus (MSSA) infective endocarditis, hypertension, prior COVID-19 infection, chronic left jugular deep vein thrombosis. Patient smokes ¼ pack of cigarettes daily for the past 25 years with no current alcohol abuse. Current medications include albuterol, apixaban, carvedilol, isosorbide mononitrate, losartan, sevelamer, amlodipine, hydralazine, and clonidine. Fig. 2.

Fig. 2.

Fluoroscopy: Wire Path Deviating from IVC Course. This X-ray shows wire (red dashed line) during sheath insertion took a course that is not identical to the right femoral vein dialysis catheter, implying the wire is not in IVC

Differential diagnosis included congestive heart failure secondary to volume overload, inadequate dialysis in treatment of end-stage renal disease, pleural effusion, acute coronary syndrome (ACS), pneumonia, sepsis, and cardiac dysrhythmia.

Under ultrasound guidance, access was obtained using a micro-puncture needle and modified Seldinger technique. A 5 French sheath was inserted into the left femoral artery and 7 French sheath into the left femoral vein, however, the wire advanced through the femoral venous sheath through a tortuous route. Right heart catheterization was performed using a 7 French Swan-Ganz catheter (SGC) over a V18 wire. Wire and catheter advancement similarly took a tortuous route to reach the right ventricle (Fig. 3A). After pressure measurements and obtaining PA saturation, the SGC was removed intact and coronary angiography performed using 5 French WRP and 4 French JL 4 catheters. Both were removed and exchanged over a J-wire. Hemostasis was obtained by manual pressure at the end of the procedure. CT and venogram imaging demonstrated dialysis catheter causing infrarenal IVC stenosis with a dilated lumbar vein, and hemiazygos and azygous vein collaterals correlating with the course of SGC. SGC passing through the accessory hemiazygos system was likely due to chronic DVT and preferential enlargement of the accessory hemiazygos system.

Fig. 3.

Fluoroscopy: Catheter Route Through Hemiazygos and Right Heart. This X-ray shows the catheter, from the hemiazygous vein (red arrow), enters SVC (yellow arrow), and from there on took an usual course through RA (blue), RV (green), PA (purple), and wedge position (brown).

Discussion and conclusion

Our case found that guidewire support was key to procedural success. After the balloon tipped catheter failed to advance, a V18 wire was used to navigate a tortuous venous path through the collaterals aforementioned. This strategy demonstrates the benefit of wire-assisted catheterization when encountering resistance amongst patients susceptible to venous anomalies Previous literature supports guidewire-assisted techniques, which improve success rates for repositioning malpositioned catheters during central venous access. [3] Additionally, although routine imaging before RHC is not necessary and common, it should be considered in patients with central venous disease, repeated catheter placement, or challenging venous anatomies. Early use of venography or CT may improve planning and procedural efficiency.

Overall, this case reinforces the importance of recognizing abnormal catheter trajectories and adapting through knowledge of alternative venous pathways to prevent delays or procedural failures.

This case highlights how IVC stenosis from long-term dialysis access can alter venous return and complicate right heart catheterization. Central venous obstruction has been a well-established complication in hemodialysis patients, [4] and collateral access through the azygos system has also been reported as a viable strategy. [5] The use of guidewire assistance and recognizing catheter deviation is essential for procedural success in this high-risk population. Additionally, early imaging and adaptable procedural planning will be increasingly important when treating patients with risk factors for the central venous stenosis or abnormal venous anatomy. Table 1.

Table 1.

Timeline of patient admission and catheterization

Timeline	Pertinent Information
Previous Admission	● MSSA bacteremia, GAS bacteremia, moderate aortic regurgitation, coronary cusp calcification
ED Presentation / Day of Admission	● 54-year-old male with end-stage renal disease and severe aortic regurgitation presented for valve replacement planning ● Reported orthopnea, exertional dyspnea, and bilateral leg edema, suggesting acute decompensated heart failure
Twelve Days after Admission	● TEE completed, demonstrating normal LV systolic function, LVH, severe AI with ruptured coronary sinus and abscess, severe TR, and small pericardial effusion
Fourteen Days after Admission	● RHC planned to assess for AV replacement ● Attempted via left femoral vein ● Swan-Ganz catheter failed to advance past distal IVC despite balloon inflation ● Catheter advanced over V18 wire, which followed a tortuous path to the right heart ● CT and venogram revealed infrarenal IVC stenosis from chronic dialysis catheter, with collateral drainage via dilated lumbar, hemiazygos, and azygos veins ● Procedure completed successfully with wire guidance ● Patient remained hemodynamically stable and tolerated procedure without complication
Following Procedure	● Remained hemodynamically stable, vancomycin continued for endocarditis, CTS consulted for AV replacement
Subsequent Action	● Continued management with CTS and vascular surgery, HeRO graft placement

Abbreviations

RHC

Right Heart Catheterization

IVC

Inferior Vena Cava

SGC

Swan–Ganz Catheter

CT

Computed Tomography

TEE

Transesophageal Echocardiography

LV

Left Ventricle

RA

Right Atrium

RV

Right Ventricle

MSSA

Methicillin–Sensitive Staphylococcus aureus

DVT

Deep Vein Thrombosis

Authors’ contributions

Concept and design: AS, VP, PJ, NC, TQ, RS, CLAcquisition of case: RS, CLAnalysis and interpretation of data: AS, RP, AB, BP Drafting of the manuscript: AS, RP, AB, BP Critical revision of the paper for important intellectual content: All Obtaining funding: N/A Supervision: CL.

Funding

None.

Data availability

All data supporting the findings of this study are available within the paper and its Supplementary Information.

Declarations

Ethics approval and consent to participate

Informed consent was obtained.

Consent for publication

Written informed consent for publication was not obtained because the patient is deceased. There was no identified next of kin. No identifying information is included in this report.

Competing interests

The authors declare no competing interests.