Tag: Bowel obstruction
We are all aware of the arterial and venous systems. Arteries take the oxygenated blood from the heart to the organs and the veins take the blood back to the lungs to unload the carbon dioxide and reload oxygen to be taken back to the organs. In addition to the arterial and venous vascular systems, we also have the lymphatic channels that flow into the lymphatic system.
The Lymphatic channels and system may be new to some, however, it is the third vascular network that is much less defined. The Lymphatic system collects fluids that has left the artierial/venous vascular system along their travel outlined above and take it back to the venous system. The lymphatic vessels transport this fluid to the lymph nodes throughout the body where the nodes filter the fluid of bacteria and harmful substances. Eventually, the fluid makes it way back to the venous system via the Superior Vena Cava. Additionally, Lymphatics collect the lipids within the GI tract and transport them to the venous system for metabolism. Most of the time these serosal lymphatic vessels are very small and hard to notice on the bowel.
Example of Lymphatic channels
The following image is in a patient who had small bowel obstruction. The obstruction had resulted in vascular congestion at the base of the mesentery. The congestion had effected the low pressure system of the veins and the lymphatics disproportionately more that the arterial system. The white-milky tubular structures are the lymphatic channels filled with lipids.
There are three layers to the small intestinal lymphatic system, in the villi, submucosal and serosal layers and has the unique ability to transport absorbed intra-lumenal nutrients. There is a need for further research in the areas of health, obesity and disease in regards to the lymphatic system.
Whenever there is a bowel resection with anastomosis made there will be a defect in the mesentery (the tissue that holds the blood supply and the nerves etc going to and from the bowel) that needs to be closed. In this particular case, the stitches that were used to close the defect were intact and yet the tissue had separated from it. The result is an internal hernia. This can cause bowel obstruction, where by a loop of the bowel can go through the defect and kink the bowel causing the blockage. In some cases, the internal hernia may reduce itself with intermittent symptoms of the bowel obstruction and in other cases it may require immediate emergent surgery. A CAT scan with oral and IV contrast is needed after Duodenal Switch to visualize the alimentary and bioliopancreatic limbs.
Symptoms may include but are not limited to:
- abdominal bloating
- abdominal tenderness
- cramping abdominal pain
- diarrhea, constipation
- feeling of inability to completely empty bowels
- severe abdominal pain.
One of the potential complications of any abdominal surgery is Bowel Obstruction. If the treating physician (usually the primary care, or the emergency room doctor) is not absolutely clear of the anatomy of a patent post duodenal Switch or the Gastric bypass surgeries this will pose a diagnostic dilemma. In intact anatomy the GI tract start at the mouth and ends up at the rectum as a long tube. After the Duodenal Switch the small bowel has two parallel limbs, the alimentary limb brings the food down from the stomach, and the biliopancreatic limb brings down the biliopancreatic secretions. These two limbs join and form the common channel.
In normal anatomy, bowel obstruction may present with nausea, vomiting, abdominal cramps, inability to pass gas, and/or have bowel movements. In this case, the X-ray will also show dilated loops of bowel and if oral contrast is given with the X-ray, there will be no contrast past the obstruction. Think of it as a garden hose that has been kinked and no water is going thru.
In this upper GI- the contrast travels down the small bowel and the entire small bowel is the same caliber. This is normal study with no evidence of obstruction. In a patient with the DS, the patient my have the biliopancreaitc limb obstruction, with an identical X-ray as above, since the oral contrast given will never get to the biliopancreatic limb and it will not show if it is dilated or not.
In duodenal switch operation, a patient may have complete obstruction of the alimentary limb, with nausea, vomiting and abdominal pain, and yet have bowel movements because the content of the biliopancreatic limb is getting to the common channel. Similarly, a patient with biliopancreatic limb may have nausea, but no vomiting, because the obstructed biliopancreatic limb is not connected to the stomach and the content can’t not be expelled from the stomach.
The images of fluid filled loops of bowel are highly suspicious.
It is critical to make sure that a patient with a suspected bowel obstruction after the DS, is evaluated with the understanding that the common signs and symptoms, and the diagnostic workup will not provide an accurate picture. A patient with the DS or RNY, can have bowel obstruction and still have bowel movement, and no vomiting.
A patient with suspected bowel obstruction should have CT scan of the Abdomen with oral and IV contrast. The cardinal findings will be “dilated loops of bowel with no contrast within the lumen of the bowel”. This is highly suspicious for bowel obstruction after DS, where the regular x ray will not pick this up. Additionally, abnormal liver function test may suggest biliopancreatic limb obstruction.