Belly Pain After Bypass: Internal Hernias

We are fortunate to have a new PA in the practice we are training these days.  Even more fortunate for us that she comes with a surgical background. I am looking forward to getting her up to speed in the Bariatric world as she adjusts to the likely newfound 'intimacy'of the Family Practice-style setting we enjoy, as compared to her most recent position in the Surgical house staff at an area hospital, seeing many patients and usually hoping not to see them back again.

Bariatric Surgery really is a little different.  It has the typical aspects of any surgical practice, but we also continue to follow patients for at least a year after surgery, as well as seeing them weekly for weight loss and MD visits prior to surgery.  Hard not to get 'attached' to them in a more intimate way as they journey through the weight loss process.  Reminds me in certain aspects of my Family Practice days..

So, as my teaching often goes, when a patient you have known for a while through regular followups, comes in with abdominal pain, whether severe or subacute, current or recent in temporal history, take notice.  As seen with the last Blog post on abdominal pain, pain is not 'normal' after bypass (or sleeve or Band for that matter), and requires a thoughtful history to sort out.

Internal Hernias after Gastric Bypass can present with pain from intermittent / nuisance quality, or severe, as well as that of dead bowel if neglected long enough.  Their abdominal pain comes from the bowel obstruction that happens internally, not the hernia space itself.

From ScienceDirect.com

At the time of the Bypass surgery, in order to reposition the mid-small intestine to link up with the newly-formed gastric pouch, and then distally create the "Y", where biliopancreatic secretions enter the ingested food 'downstream' (think malabsorption), the mesentery that attaches to the small intestine must be transected.  At the time of the surgery, care is taken to close these hernia spaces.  The tissue we close is mainly fatty, and although it can initially hold sutures fairly well, over time and with resultant weight loss, the spaces can reopen and cause a Partial Small Bowel Obstruction, or even a more acute situation with a bowel obstruction or strangulation.

Internal Hernias and their associated bowel obstructions occur after Bypass at a rate of about 9%.

We usually say "100# lost / 1 year out of surgery" as a rough guide, although we have seen patients present earlier, and certainly later, and with less weight loss.  The majority do generally seem to follow this rule.

Symptoms are variable, but often a high index of suspicion will lead us to the OR for a diagnostic laparoscopy rather than a CT scan.

The pain is often Left sided, intermittent, and not related to eating or activities.  There may be mild / vague associated intermittent obstructive complaints (nausea, emesis, BM habit changes), but not always. As stated earlier, with an acute presentation, they may look like an SBO, or even sicker if incarcerated for a while (hours to days).
 

So, if they fit the rough criteria as above, and their pain both is consistent with what we usually see with this complication, as well as not sounding like any other pattern of either a Bariatric or non-Bariatric cause of abdominal pain, we may be going to the OR, either as an elective or an emergent case.  CT scans often do not show anything specific, unless there is an acute nature to the PSBO or SBO, however a 'mesenteric swirl sign' is diagnostic, but infrequently seen.  Of course, a CT may show another cause of the pain, but best practice is to just give us a call to evaluate the patient and expedite their care.

And just so you are clear, because the patients often are not...

Abdominal wall hernias (Ventral) are very common after open Gastric Bypass (which we very rarely do), whereas they are relatively rare after laparoscopic surgery.  Again, this defect causing the more common variety PSBO and its attendant pain after Bypass is "internal", rather than external as with an abdominal wall hernia.

And further, it is actually thought that due to reduced internal inflammation with the laparoscopic approach than the open approach, internal hernia rates are higher than that of the open surgical approach for that reason.

That's enough for today.

Let's be careful out there.