Tag: gastric bypass
Vitamin A is one of the 4 fat soluble vitamins along with vitamin D, Vitamin E and Vitamin K. It is multifunctional and essential which means that it is not produced by the body. In this article we will touch on aspects of Vitamin A absorption and it’s effect on wound healing as well as its metabolism.
We often think of Vitamin A as the critical vitamin for vision, however it has several other roles that related to immune function, protein synthesis, and cellular communication. Vitamin A deficiency is a concern world wide because of the natural of the side effects. Vitamin A deficiency is the leading cause of preventable childhood blindness in the world according to UNICEF and sometimes it may be undetected until there is irreversible damage.
There are 2 chemical forms of vitamin A in diet:
Retinoids (Preformed vitamin A) This group include retinol, retinyl esters, and retinal they are mostly found in animal sources like liver, egg yolk or fish oils.
Carotenoids (Provitamin A) This group includes beta-carotene, alpha-carotene and lycopene, mainly found in plant sources like leafy vegetables or yellow/orange vegetables and fruits.
1.- Ingested food is digested in the stomach where retinyl palmitates (esters) are released from proteins. Retinol and beta-carotene are absorbed directly into the small intestine where retinyl esters and betacarotene are transformed into retinol . Retinol is the most easily absorbed form of vitamin A.
2.-That retinol absorbed by the enterocytes in the ileum (small intestine) along with bile is then transported to the liver with the help of chylomicrons a protein that transports fat.
3.-Fifty to 80% of the vitamin A is stored in the liver and the remaining is deposited into adipose tissue, lungs and kidneys.
4.-When stored retinol is released from the liver into the circulation to target organs, it is bound to plasma retinol-binding protein (RBP4) a transporting protein produced by the liver that requires ZINC, which is synthesized by the liver; This complex is stabilized by transthyretin (TTR), which reduces renal excretion.
Retinol is a crucial component for reproduction, embryological development, cellular differentiation, growth, protein synthesis, and immunity in the form of retinoic acid and vision in the form of retinal.
One of Vitamin A additional roles is in epithelial health of skin and mucous membranes. It increases epithelial turnover which is crucial during would healing. It also has anti-oxidative effects which prevent cell damage and can prevent or reverse the effects of other damaging agents. In addition to these benefits it has also been associated with increasing collagen, fibronectin, keratinocytes and fibroblast, all important in wound tissue structure. There have been some studies that suggest giving higher doses of Vitamin A in patients with non or slow healing wounds.
It is important to remember that we have documents delayed diagnosis of adult vitamin A deficiency leading to significant night blindness in adults. It is critical that the patients and their primary care physicians are acutely aware of this possibility. In majority of the patients with low vitamin A, post weight loss surgery, aggressive supplementations, including injections need to be considered as a part of the treatment regimen.
We would like to thank Miguel Rosado, MD for his significant contribution provided for this Blog.
Recently there has been some research and concern regarding sunscreen and the chemicals within them. This has led to findings that can be concerning but that need further research.
Post weight loss surgical patients, and in general patients who suffer with obesity, before or after weight loss surgery, have low vitamin D level. This may be caused by a number of factors. One such factor may be the reluctance to get skin exposed to sunlight in order for the bodies natural Vitamin D pathways functioning.
The recommendations are for daily exposure to sun. This not only is critical to the vitamin D metabolic pathways, but also help with bone health, immune function, mood, counteracting depression.
In a recently published online article, concerns were raised that some of the ingredients of some of few sunscreens are absorbed in the blood stream. This is a small study, and as the results indicates, it is not recommending to stop using the sun screens. Be aware of your sun exposure, timing exposure, and the ingredients in your sunscreen.
You can find past blog posts on Vitamin D, Bone health, etc here
Question : “Do I have to take higher dose of thyroid medication after the duodenal switch? ”
Answer : “Maybe”
With all weight loss surgical procedures, there may be changes to absorption of medications. It is easily understood why duodenal switch may results in decreased absorption of fat-soluble medication. What is not as clear is the reduction in absorption of other medication with procedures that do not explicitly change the absorption at the level of the small bowel directly.
The research data is all over on this topic. There is published literature that shows improvement in the thyroid function after gastric bypass and the sleeve gastrectomy. However, the exact mechanism is not completely understood.
There is research that reports “…decreased postoperative levothyroxine requirements.” Other have shows no correlation between the length of the bowel distal to duodenum to absorption of thyroid medication.
With all this confusing data, the best course would be to always “treat the patient and not the lab results.”
If a patients who has been on medications with stable number and symptoms, suddenly presents with complaints of hypothyroidism after weight loss surgery, it’s possible the medications should be up adjusted even if the thyroid lab values may not be as defining.
Treatment options should be approached is a global and systemic fashion. It is critical that the nutritional status is at its best possible and optimized for important healthy bone vitamins and minerals. Low protein needs to be corrected. Special attention should be given to nutrients, minerals and vitamins. These include Protein, Calcium, Magnesium, Vitamin D, and Vitamin K1/K2to name a few.
Healthy bones require ongoing and routine force in the form of exercise to remain health. Just as exercise improves muscle strength, it also improves bone health. Exercise is also critical in improving bone structure and density. Ideally, exercise should be weight bearing and resistance. Examples include: hiking, walking, jogging, climbing stairs, playing tennis, and dancing. Resistance type exercise is weight lifting and resistance bands. These exercise work by creating a pull or force on the bone either by gravity, movement or weight. Always check with your physician before beginning an exercise routine, start slowly and building up to longer periods of time. The ideal goal would be at least 30 minutes a day, every day, if you are able.
We frequently see patients immediately started on osteoporosis medications without checking or improving some of the nutritional markers noted above or without looking at exercise history. In some case, the medication recommended are contraindicated due to nutritional status.
The medications can be grouped in to those that help with new bone formation (Anabolic agents) or those that help by suppressing the bone breakdown phase (Antiresorptive agents).
National Osteoporosis Foundation has an exhaustive list (below) of medications for treatment of Osteoporosis.
The table below outlines the side effects and mechanism of the actions of the common medications used for treatment of osteoporosis which was published by the University Health News Publication on August of 2014.
With all this information, the few points to remember is that the most important factors in healthy bone structure are the nutritional status Protein, Calcium, Magnesium, Vitamin D, and Vitamin K1 levels.
This is an animation of normal bone Metabolism. It shows how bone structures is taken down and rebuilt continuously. This allows for a healthy bone maintainence as we age. The key is the balance of breakdown (osteoclast) and the build up (osteoblast) activity is regulated. Osteoporosis develops when there is more breakdown that build up.
With permission of Dr. Susan Ott of University of Washington.
Additional information available on her site.
Past blogs on Bone Health.
Adhesions are fibrous bands of scar tissue that form during the healing process. Following surgery, many people live normally with this scar tissue. However, they are also the cause of bowel obstruction when the adhesions form in such a way that causes a segment of the bowel to either get trapped, or form a “knot”. In both of those cases, the end result is a partial narrowing or a complete blockage of the intestines. This is called bowel obstruction.
Without treatment, the blocked parts of the intestine can die, leading to serious issues. However, with prompt medical care, intestinal obstruction often can be successfully treated.
Other causes of bowel obstruction:
- In children, the most common cause of intestinal obstruction is telescoping of the intestine (intussusception).
- Intussusception telescoping of the interstine
- Hernias — portions of intestine that protrude into another part of your body
- Inflammatory bowel diseases, such as Crohn’s disease
- Diverticulitis — a condition in which small, bulging pouches (diverticula) in the digestive tract become inflamed or infected
- Twisting of the colon (volvulus)
- Impacted feces
- Colon Cancer
In patients who haven’t Bariatric / weight loss surgery or an untouched GI track, bowel obstruction may manifest itself by symptoms of loss of appetite, constipation, nausea, vomiting, enlarged abdomen, abdominal pain, cramping, with no passage of gas or bowel movements.
However, patients who have had a weight loss surgery (Duodenal Switch, or the Gastric Bypass) because of the parallel limbs of the small bowel, the symptoms outlined above may not present. The diagnosis of a bowel obstruction, when suspected, should be identified with CT scan of the abdomen and pelvis with Oral and IV contrast. A CT scan with no oral contrast or water instead of oral contrast is inadequate and may lead to a delay in diagnosis and surgical intervention. Examples of Bowel Obstruction CT findings were discussed previously.
The treatment for an internal hernia and adhesions causing a bowel obstruction depending on the severity may range from observation to surgical intervention in order to release the small bowel from the constraints of the adhesions.
Gastrointestinal (GI) Bleed following weight loss surgery is rare but does require knowledge of the particular bariatric surgical procedure the patients has and how to proceed with diagnostics to fully evaluate the situation. Acute or chronic gastrointestinal bleeding can cause anemia in patients. However, Anemia may also be caused by nutritional deficiencies (iron, vitamin , minerals), Kidney disease, bone marrow disease and others. The work-up for anemia following weight loss surgery follows a routine protocol. If there is an evidence of bleeding from intestine (bloody emesis, bloody bowel movement, “tar” like black bowel movements) then the diagnostic work up would include an upper and lower endoscopy.
Upper endoscopy Esophagogastroduodenoscopy (EGD): evaluates the esophagus, stomach and a limited area of the duodenum past pyloric valve.
Lower endoscopy Colonoscopy or coloscopy: evaluates the rectus and the entire colon.
Between these two tests, there is still a considerable amount of the small bowel that is not accessible or visualized with endoscopic procedures. For the small bowel, examination Capsule endoscopy is an option in an intact GI tract. Patients who have had Gastric bypass RNY or the Duodenal Switch, the large segments of the small bowel can not be visualized or examined with capsule endoscopy.
Patients who have had Duodenal Switch, Gastric Bypass and SADI – S would need a tagged red cell scan or CT angiography if GI bleed is suspected in areas of the small intestine that are inaccessible by endoscopic procedures.
There are differing opinions, based on a broad set of scientific publication, wether or not gallbladder should be removed at the time of weight loss surgery. Obviously, Cholecystectomy is a stand alone general surgical procedure that is often performed due to gallstones and/or gallbladder disease with a variety of symptoms. However, the focus of this blog will deal with Bariatric Surgery and Cholecystectomy.
Rapid weight loss can increase a patients chance of forming gallstones. This rapid weight loss can be as little as 3-5 pounds per week. Weight loss surgery can increase your risk for gallstone formation. Several of the common thought processes the mechanism of this is, obesity may be linked to higher cholesterol in the bile, larger gallbladders, high fat diet and larger abdominal girth.
When a patient is having the Duodenal Switch (DS) Bariatric operation, or having a revision of a failed gastric bypass to the DS, I always remove the gallbladder. This is because there isn’t an anatomical route to utilize endoscopic procedure for an ERCP should the need rise.
In the case of a patient undergoing Vertical Sleeve Gastrectomy, if there are any indications or complaints of abdominal pain then an ultrasound is done. If there are findings of gallstones or other disease of the gallbladder, then a cholecystectomy is performed at the same time as the Sleeve Gastrectomy.
In my opinion, every patient having the Gastric Bypass (RNY) should also have the gallbladder removed because of the anatomical limitations after surgery that prevents the use of ERCP if needed. Some clinicians will place the patient on a long term medications to reduce the chance of gladstone formation after surgery, which themselves have side effects limiting the compliance in most patients.
Further information on Common Bile Duct Dilatation and ERCP
A Parathyroid scan or Sestamibi scan may be needed if the typical weight loss surgical reasons for elevated PTH levels have been addressed. Sestamibi is a small protein which is labeled with the radio-pharmaceutical technetium-99. This very mild and safe radioactive agent is injected into the veins of a patient with overactive parathyroid and is absorbed by the overactive parathyroid gland. If the parathyroid is normal it will not absorb the agent. The scan below shows the uptake of the agent.
Calcium, Vitamin D and Parathyroid hormone are routinely measured on yearly follow up for most post weight loss surgical (WLS) patients. Elevated parathyroid hormone (PTH) may be caused by Vitamin D deficiency or calcium deficiency (most common in post WLS) or by over active parathyroid gland(s). In the latter case, if one of the four glands is overactive then this is knows as a parathyroid Adenoma. If all 4 are over active and are secreting too much PTH, this is known as hyperplasia. Ultrasound of the neck, may identify an enraged parathyroid gland (adenoma) which is located behind the thyroid gland. Given the large area where the parathyroid gland may be located, additional tests are needed to not only identify the location of the gland(s) but also to distinguish between single gland (adenoma) or multiple glands (hyperplasia) cause for the elevated PTH. It is important to investigate all avenues and testing in parathyroid hormone elevation and in some cases, not to rely on one test for your diagnosis. It is also imperative that weight loss surgical patients take their supplements routinely and consistently and have their laboratory studies followed at least yearly.
One of the findings following Gastric Bypass is a Candy Cane Gastric Bypass. Nausea and vomiting , upper abdominal pain is a common complaint of patient who have had the Gastric Bypass RNY operation. This is in addition to the high incidence of patients who experience the complications of weight regain and or dumping syndrome.
Quite frequently the symptoms of nausea, vomiting and upper abdominal pain of a patient with history of gastric bypass is evaluated by a primary care, referred to a gastroenterologist. The “routine” work up recommended is X-ray of the abdomen, maybe contrast study (Ct scan or upper GI) and for sure and upper endoscopy. The result quite frequently reported as “…nothing wrong”.
A typical upper GI in a Candy Cane Gastric Bypass situation may look like this:
A common and underreported problem may be a Candy Cane finding. The “blind” end of the small bowel anastomosis is too long and this results in food settling in the hook of the candy cane. The symptoms of the nausea, vomiting and upper abdominal pain may be from the residual food and liquids that do not drain from this area.
Candy Cane Gastric Bypass finding
Candy Cane Gastric Bypass cases will require surgical intervention to shorten the length of the blind segment of the small bowel to improve symptoms.
It is my recommendations that any patient with history of weight loss surgery who is having any persistent gastrointestinal symptoms be evaluated by weight loss surgeon.
Weight loss surgical procedures have different long term results and some procedures have more dramatic weight loss than others. Some procedures also result in much more sustained and long term weight loss. Unfortunately, what may be not obvious is that the patient has very little control over the outcome of the surgery in most cases. IT is very easy to blame the patient for weight regain after weight loss surgery. However, it is important to remind ourselves that the long term data reporting outcomes of the surgical procedures in most cases, includes all patient population. All these studies include the most compliant and not so compliant patients. Comparison chart of outcomes of weight loss surgical procedures.
A larger percentage of gastric bypass patients will require revision for weight regain, or other problems. There is no evidence that the size of the pouch or the anastomosis between the pouch and the small bowel changes the weight regain outcomes. Yet, quite frequently I will see patient who have had gastric bypass revision for weight regain, by reducing the size of the pouch or the anastomosis. Here are some publications that support the notion that other than extreme dilation, the size of the pouch and the size anastomosis does not predict the outcome of the surgery. There is some correlation with the site of the pouch, anatsmosis and weight loss, but there is no correlation between the size of the pooch, the opening and the failure rate. This means that patient with smaller pouch do not have better long term outcome that the ones with larger pouch, only that the patient with smaller pouch or anatsmaosis will loose more weight.
Weight regain after RNY Gastric Bypass may also be caused by a Gastro-gastric fistula, which is a new connection between the pouch and the remnant stomach. Here is further information on Weight Loss Surgery Revisions.
When considering a primary weight loss surgical procedure, be informed. Investigate all your options and consider the long term outcomes. This may mean investigating different weight loss surgical procedures on your own.