The portal vein has numerous anatomical variations, with many different branches that can be difficult to distinguish one from another on 2D fluoroscopic images. Sometimes, two branches – one anterior and one posterior – may project at almost the same location in the fluoro image.The objective is to embolize only those branches that correspond to the part of the liver that will be resected.To do this with confidence, the clinician must understand exactly where we are in the anatomy and control in real-time the embolization phase in real-time.
Courtesy of Dr. T. De Baère, IGR – Villejuif, France.
Patient History
A 57-year-old man suffered from right liver metastases that had decreased after six courses chemotherapy with Irinotecan. The volume of the left lobe, which was the future remnant liver volume, was too small (below 25%) to allow for a safe post-operative course after an extended hepatectomy. Consequently, it has been decided to embolize the right liver lobe, which would be resected. The procedure was performed to redirect the portal flow toward the left lobe of the liver, which would hypertrophy.
Procedure
At the beginning of the exam, after the puncture of the portal vein, an Innova 3D acquisition was performed at 40°/s. This helps us to depict the full portal vein system and select the branches to be embolized before the resection. (Figs. 1 .2 and 3)
Volume rendering of Portal Vein system: Posterior-Anterior (Fig. 1) – 45°LAO (Fig. 2) – Right (Fig. 3)
The segmented portal vein system was then incorporated into Innova Vision and was used to help guide the intervention.
The 3D information was automatically registered and overlaid on the real-time fluoroscopy, allowing a quick centering and orientation for an enhanced branch selection. (Figs. 4 and 5).
Innova Vision compensates for table position and gantry rotation to help obtain centering and orientation for the embolization.
During the intervention, Innova Vision was used not only to guide the micro-catheter placement at the right injection point but also during the embolization phase to help control, in real-time, the displacement of the embolization material and to control where the glue was going. (Figs. 6 and 7)
Innova Vision helps improve the transparency of the volume overlaid on the fluoroscopy, and allows zooming and centering on the region of interest
At the end of the procedure, a Subtracted 3D acquisition was performed to help ensure that all the targeted branches had been embolized. Two rotational acquisitions, one without contrast, one with contrast, produced three sets of 3D images – one to see the glue alone (Fig. 8), one to see boththe glue and the vessels (Fig. 9) and one the patent vessels alone (Fig. 10).
Subtracted 3D after the treatment: Thick oblique views of Mask (Fig. 8), Opacified (Fig. 9), Subtracted (Fig. 10) volumes
The 3D information correlates very well with the corresponding Digital Subtracted Angiography acquisitions. (Figs. 11 and 12)
A complete embolization of all the portal branches feeding the right liver lobe was obtained, with redirection of the portal towards the left lobe. One month later, left liver lobe was hypertrophied by 87% and surgery was safely performed with an uneventful post-operative course.
DSA of Portal Vein system: Before (Fig. 11) and after (Fig. 12) the embolization.
Conclusion
Using the Innova Vision application gives us more confidence with less stress.
Thanks to excellent visualization of the 3D model in fluoro, we have a better understanding of the 3D anatomy and where we are going – we have the potential to see where we are at all times. It takes less time to inject the glue, and the procedure goes more quickly and smoothly.
We also use less contrast, since we don’t need to keep injecting contrast as we do with a 2D fluoroscopy image. Innova Vision also helps show us where the glue is going as it’s injected. If the glue doesn’t go where we want it to, we can react immediately to stop the injection.
The clinical case above is displayed only for educational purpose and for the benefit of healthcare student and professional
