Manual graphic roadmap for transarterial coil embolization of guttural pouch arteries in horses: A technical note.

Manual graphic roadmap (MGR) technique was used to assist fluoroscopic guidance during transarterial coil embolization (TACE) for treating guttural pouch artery bleeding in horses. This approach helped improve anatomical orientation and catheter navigation during the procedure.

Background and Purpose

• Transarterial coil embolization (TACE) is a minimally invasive procedure used to treat arterial hemorrhage in the guttural pouch of horses.
• Fluoroscopic guidance is crucial for navigating catheters and placing coils accurately within target vessels during TACE.
• Typically, advanced fluoroscopy systems provide roadmap technology, which overlays vessel images to guide catheter advancement.
• The study addresses the challenge of performing TACE in facilities lacking fluoroscopy with built-in roadmap technology.
• The authors describe a manual graphic roadmap (MGR) technique to assist catheter navigation and coil placement during fluoroscopy-guided TACE.

Methods

• Horses with guttural pouch arterial hemorrhage underwent TACE at the Equine Clinic, Free University of Berlin, from 2012 to 2024.
• The procedure was performed under general anesthesia with fluoroscopic imaging guidance.
• Initially, an angiogram (contrast injection with X-ray) was conducted to visualize the vascular anatomy of the target arteries.
• A transparent foil was then secured over the fluoroscopy monitor screen.
• An assistant traced the vascular anatomy visible on the fluoroscopic image onto the transparent foil using a waterproof marker, creating the manual graphic roadmap.
• This MGR served as a fixed visual reference during subsequent catheter navigation and coil deployment.
• The MGR aided continuous anatomical orientation without the need for additional contrast injections except for confirming vessel occlusion after coil placement.
• The technique was consistently applied in all TACE procedures performed at the authors’ institution during the study period.

Results and Observations

• The manual graphic roadmap provided a helpful and practical guide for catheter advancement.
• Operators could maintain spatial orientation inside complex vascular structures more easily.
• Use of MGR reduced the need for repeated contrast injections, thereby potentially lowering contrast agent usage and radiation exposure.
• The technique proved feasible and efficient in clinical settings without advanced fluoroscopy roadmap software.

Implications and Future Directions

• The MGR technique offers a low-cost, accessible means to improve anatomical orientation during TACE when fluoroscopy roadmap software is unavailable.
• This manual approach could enhance procedural safety and efficiency by reducing contrast media volume and radiation dose.
• Further research is recommended to quantitatively evaluate the benefits of MGR regarding procedural parameters such as:
• Contrast agent usage
• Radiation exposure
• Overall procedural time and efficiency
• Standardized study models and case series could validate the technique’s effectiveness and reproducibility.
• Potential integration with other visualization tools or training protocols could be explored.

Conclusion

• The authors present a simple yet effective manual graphic roadmap technique to assist fluoroscopic guidance in equine TACE procedures.
• This approach supports catheter navigation and coil embolization in guttural pouch arterial hemorrhage without requiring advanced fluoroscopic roadmap technology.
• The technique provides continuous anatomical orientation, minimizes contrast use, and may improve procedural efficiency in resource-limited settings.