Fluoroscopy-guided catheter tip positioning optimization: 10–30 mm beyond landmarks is associated with reduced intrathoracic central venous stenosis risk in hemodialysis patients

Introduction: The 2019 KDOQI guidelines recommend fluoroscopy-guided placement of tunneled cuffed catheter tips within the right atrium. However, fluoroscopy may misidentify the cavoatrial junction. This study quantified the discrepancy between digital subtraction angiography and fluoroscopy in locating the cavoatrial junction and assessed its impact on intrathoracic central venous stenosis risk. Methods: This retrospective cohort study analyzed 90 patients with right internal jugular tunneled cuffed catheters who underwent DSA at our hospital between June 2023 and May 2025; digital subtraction angiography and fluoroscopy were compared in locating the cavoatrial junction. Catheter tips were classified by DSA-defined location: superior vena cava upper segment (Group A), lower segment (Group B), or right atrium (Group C). Intrathoracic central venous stenosis risks were analyzed using logistic regression. Results: The DSA-defined cavoatrial junction was consistently 21.64 ± 7.23 mm caudal to fluoroscopic landmarks. The incidence of central venous stenosis was 34.4%. Intrathoracic central venous stenosis incidence was significantly higher in Group A versus C ( p < 0.0167) and Group B versus C ( p < 0.0167). Catheter tip location within the superior vena cava was associated with 5.78-fold higher odds of intrathoracic central venous stenosis compared to placement within the right atrium (OR = 5.78, 95% CI: 1.75–19.06; p = 0.004). Conclusion: Fluoroscopy overestimates the cavoatrial junction position. Given that right atrium placement reduces intrathoracic central venous stenosis risk, advancing the catheter tip 10–30 mm beyond fluoroscopically guided landmarks constitutes a key maneuver for achieving accurate positioning. Implementation of this optimization strategy is associated with a 5.78-fold reduction in odds of intrathoracic central venous stenosis, providing actionable optimization for hemodialysis access management.