We can survive without a gallbladder, but clearly it is a useful, functioning organ, and we are better off to keep it if we can. There are times when things can go wrong such as gallstones, sludge and blocked ducts, and then it may need to be removed. However……even though there wasn’t really anything wrong with my gallbladder in 2010/2011, I was convinced it had to go.

You may have read previously that I receive a monthly injection of Somatuline Autogel (Lanreotide) which keeps me well.  The Lanreotide patient leaflet clearly states “Lanreotide may reduce gallbladder motility and lead to gallstone formation. Therefore, patients may need to be monitored periodically. There have been post–marketing reports of gallstones resulting in complications, including cholecystitis, cholangitis, and pancreatitis, requiring cholecystectomy in patients taking lanreotide. Fairly certain I could find a similar statement on the Octreotide leaflet.

I also searched for studies and found this issue in technical papers (including for Acromegaly, the other condition treated by somatostatin analogues (SSA)). All the papers confirmed a risk of “Biliary stone disease” as a common side effect of SSAs.  One study said the frequency ranged from 10% to 63%.  The study also suggested that “patients with primary GI NET or undergoing abdominal surgery should be considered for prophylactic cholecystectomy” (gallbladder removal) – but they added that “no conclusion could be drawn on the indication of prophylactic cholecystectomy in patients with primary pancreatic or thoracic NET for whom abdominal surgery is not planned”.  Study can be read here. 

Gallstones can not only be very painful, but they can potentially be life threatening. On top of what I had already endured, future surgery to treat gallstones or to remove my gallbladder could be riskier than it might normally have been, so it was conveniently removed during a second major operation on my liver (the gallbladder is located very close).  Worth noting that these risks are in addition to the normal risks associated with gallstone formation – read about that here.

One fairly recent set of guidelines (2017) for Small Intestine NETs talks about gallbladder removal during surgery – read more here. 

What does the gallbladder actually do? 

The gallbladder serves as a bridge between the liver and the small intestine, where digestion occurs. The liver produces bile (or bile acid) necessary for the digestion of fats, the gallbladder stores the bile and parcels it out as needed. If the gallbladder is removed, it doesn’t impair the production of needed bile, only its concentration and timed release into the small intestine. Bile now flows down the bile ducts directly from my liver into my duodenum. Clearly this isn’t as efficient as using the gallbladder with ‘on-demand’ bile and so produces its own side effects of fat absorption impairment.  In my own experience, this can be offset to a certain degree by making minor adjustments to diet.

Related issues for NETs

If the patient has also had a right hemicolectomy/terminal ileum resection, another ‘bile’ risk is Bile Acids Malabsorption (BAM) (sometimes known as Bile Salts Malabsorption and some texts described the resultant diarrhea as ‘Bile Acid Diarrhea”).  Following a terminal ileum resection which includes a right hemicolectomy, there is a risk that excess bile acids will leak into the large intestine (colon) via the anastomosis (the new joint between small and large intestines). Previously, the now removed ileocecal valve (junction of terminal ileum and cecum) would take care of this problem. This leakage can lead to increased motility, shortening the colonic transit time, and so producing watery diarrhea (or exacerbating an existing condition) – this can often be confused with carcinoid syndrome induced diarrhea resulting in the wrong therapeutic approach. It can also be confused with pancreatic enzyme deficiency related issues (although the therapy for this might help).  Removal of the gallbladder on top of a right hemicolectomy just has the potential to exacerbate the issue.   The treatment for this sort of malabsorption is normally some form of bile acid sequestrants (cholestyramine (Questran, Prevalite), colestipol (Colestid, Flavored Colestid ), and colesevelam (Welchol).  The trick is working out what is causing the issue and for that you need expert advice – testing is not an exact science.   

This should not be considered advice in your own case.  If you are concerned about your gallbladder situation or any of these associated issues, you should seek advice from your NET team.