Published online Jul 28, 2019. doi: 10.4329/wjr.v11.i7.102
Peer-review started: May 10, 2019
First decision: June 6, 2019
Revised: July 3, 2019
Accepted: July 25, 2019
Article in press: July 25, 2019
Published online: July 28, 2019
Radioembolization with Yttrium-90 (90Y) microspheres is commonly used for treatment of primary or secondary liver tumors. It is generally a well-tolerated treatment with few side effects, however non-target embolization of 90Y microspheres to the gastrointestinal tract is a severe potential complication. The risk for non-target embolization is very low in patients with a normal hepatic arterial anatomy. However, around 45% of patients have some form of variant hepatic arterial anatomy and patients with aberrant hepatic arteries might have a higher risk for reflux and non-target embolization of 90Y microspheres due to the close proximity between hepatic and enteric vessel branches.
So far, no study has specifically evaluated the safety of 90Y-Radioembolization in patients with a variant hepatic arterial anatomy. Therefore, this study aimed to evaluate whether there is an increased risk for non-target embolization during 90Y Radioembolization in this specific patient population.
To evaluate the safety of 90Y Radioembolization with resin microspheres in patients with one of the two most common hepatic arterial variants: A right hepatic artery (RHA) originating from the superior mesenteric artery (SMA) or a left hepatic artery (LHA) originating from the left gastric artery (LGA).
For this study, electronic medical records and imaging studies of 24 patients who had been treated with Radioembolization via an aberrant hepatic artery were retrospectively reviewed regarding clinical and imaging evidence of non-target embolization of 90Y-resin microspheres to the GI tract. 11 patients who underwent 90Y Radioembolization via an LHA originating from the LGA and 13 patients who underwent 90Y Radioembolization via an RHA originating from the SMA were included. Positioning of the tip of the microcatheter in relationship to the last hepatoenteric side branch was retrospectively analyzed using angiographic images, cone-beam CT and pre-interventional CT-angiograms.
None of the 24 patients developed clinical symptoms indicating a potential non-target embolization to the GI tract within the first month after 90Y-RE and there was no imaging evidence of non-target embolization on the postinterventional 90Y-bremsstrahlung images and/or 90Y-PETs in any of the patients. The distance between the tip of the microcatheter and the last enteric side branch was substantially shorter in patients with an aberrant LHA originating from a LGA (mean distance of 3.2 cm (range: 1.9-5 cm) than in those patients with an aberrant RHA originating from the SMA (mean distance of 5.2 cm (range: 2.9-7.7 cm). However even a minimum distance of 1.9 cm was sufficient to avoid reflux and non-target embolization of 90Y microspheres.
This study suggests that 90Y Radioembolization may be safely performed in patients with aberrant hepatic arteries. A minimum distance of 1.9 cm between the tip of the microcatheter and the last enteric side branch in combination with slow, manual infusion of the 90Y microspheres was sufficient to avoid reflux of microspheres and non-target embolization in this study.
Although this study provides clinical evidence that patients with aberrant hepatic arteries can generally be safely treated with 90Y Radioembolization, further studies with standardized infusion rates and catheter positions would be desirable to systematically determine exact cut-off values at which reflux and non-target embolization of 90Y microspheres occurs.