In the previous part of this blog (Preparatory work to resect a hilar cholangiocarcinoma-biliary drainage and volumetry) I described the initial stages of working up a patient with a Bismuth Type 3A hilar cholangiocarcinoma in whom it is planned to perform an extended right hepatectomy and caudate excision. The pre-operative volumetry based on CT imaging suggested that the future liver remnant would constitute only 15% of the functional liver volume and this is too small and would pose a very serious risk of post-operative liver failure. Drainage of the future liver remnant itself will act as a stimulus for hepatic regeneration of the future liver remnant but this is a relatively slow process. To accelerate regeneration in the future liver remnant we can selectively block the branches to the part of the liver that is to be surgically resected. In this case this means occluding the right portal vein and the segment 4 branches of the left portal vein.
In the vascular lab, under local anaesthesia and sometimes sedation, the radiologist inserts a needle to identify a right portal vein branch by direct puncture through the right side of the abdomen under ultrasound guidance and using screening with contrast. Using image intensification the portal tree can be easily identified. A catheter (blue) arrow is then fed into the right portal vein. The previously placed biliary drain lying in the segment 3 duct (red arrow) can clearly be seen.
Using PVA particles and coils the segment four branches of the portal venous system are occluded by placing the portal catheter into the left portal vein. The coils occluding the segment 4 branches are indicated by the yellow arrows. If these segment 4 branches are not occluded then segment 4 will also hypertrophy and as a consequence hypertrophy of the future liver remnant, in this case segments 2 and 3, will be smaller than it would be if segment 4 branches are blocked.
After blocking the segment 4 branches the catheter is moved to the right portal vein branch and the segmental branches sequentially blocked again with PVA, gelfoam and coils
The last branch to be occluded is the one which was initially punctured with the catheter and the image below shows the completed portal vein embolization with the catheter ready to be removed.
We keep patients overnight after portal vein embolization as a precaution but complications are very uncommon and patients barely notice that the procedure has been done.
Cross sectional imaging should be repeated at 4-6 weeks after PVE. In this particular case CT scan was done at 4 weeks and there was a degree of hypertrophy with new measurements being:
Total liver vol 1945ml Seg II/III 446 ml Ratio 22%
We decided to leave a little longer for hypertrophy and repeated the CT scan in a further 4 weeks. This time the measurements were as follows
8 weeks Total liver volume 2150ml
Seg II/III 546 ml Ratio 27.3%
We repeated the tubogram to check the appearance of the bile ducts which remained unchanged. here you can see the cholangiogram and the PVE coils plus the external biliary drain lying as before.
A recent study from Thomas van Gulik’s group at the Amsterdam Medical Centre reported that functional recovery of the liver after PVE precedes volume changes and this raises the interesting question of whether it is strictly necessary to wait for liver volume increase in the future liver remnant before embarking on resectional surgery. Part of the reason for performing PVE in my opinion is to test the regenerative capacity of the future liver remnant and if there is no change in size I would not proceed to resection. I am therefore quite cautious with PVE in hilar cholangiocarcinoma and prefer to see volume change before I commit the patient to surgery.
This patient is now all ready for surgery and now that the difficult bit has been done I will write another blog with some considerations about how to approach the surgery itself.