Portal vein resection and reconstruction

Very often, patients with pancreatic cancer are found to have unresectable disease at the time of diagnosis. This is because of two reasons mainly:

1. In many patients, the cancer has already moved to (metastasized) to the liver. This means that cancer cells have moved out of the pancreas (where the origin of the tumor is), gained access to the bloodstream, and eventually were implanted within the liver where they have started growing. This process translates to a generalized disease that is not amenable to surgical treatment.

2. In several patients, the tumor has grown a lot, does not have metastases, but extends around the pancreas. In doing so, it grows into a large crucial vein that goes behind the pancreas (portal vein). Involvement of the portal vein is a very common reason that cancers of the pancreas are deemed unresectable.

Traditionally, patients with portal vein involvement are considered by definition incurable by surgery and are sent for chemotherapy. This way, every year in the whole world thousands of patients are not even given the chance of surgical treatment, even though they have no metastatic disease, simply because it is extremely technically challenging for these patients to undergo a safe and successful operation. However, the resection of the portal vein that is involved with cancer is technically feasible and safe, when it is performed in a planned and prepared fashion. It is important to emphasize that here we are not describing a situation where the tumor was thought to be resectable and during the operation the surgeon realized that there was some small attachment of the tumor to the portal vein, in which case a sliver of the vein wall may be removed and the portal vein over sewn. On the contrary, we are describing patients in whom portal vein involvement is already known preoperatively and portal vein resection is intentionally planned in advance.

We have been performing this operation over the last few years with very good results. What we do is that we mobilize the pancreas very extensively, along with the portal vein and its contributing branches, and then we take out the whole area of the tumor along with the portion of the portal vein or superior mesenteric vein, which is infiltrated by the cancer. This way, we are able to remove all the tumor-bearing area with wide clearance and leave only healthy tissue behind. Then, the missing part of the vein is replaced with a graft, which may be either a vein of the same patient taken from another location, or an artificial piece of vein. The precise way that the reconstitution or replacement of the portal vein is performed, depends on many factors, but mainly on the length of the portal vein removed.

It goes without saying that this operation is very advanced and technically very demanding. It has to be performed by true pancreatic surgeons who know very well all the possible variations of the anatomy of the vessels in and around the pancreas, have become very facile with pancreatic surgery techniques, and have a long track record on pancreatic surgery. This is why such an operation is performed only in a very limited number of centers worldwide. However it is worth it because it signifies the difference between unresectable and resectable/resected cancer, with all the consequences of each.