DS vs RNY statistics

Top Abstract Introduction Long-Term Effect of RYGB... Mechanisms for Weight Regain Effect of Bariatric Surgery... Recommendations References

Deficiency of iron, vitamin B12, folate, calcium, and vitamin D has been frequently observed after RYGB surgery. Deficiency of vitamin A has also been observed, although less frequently. Nutrient deficiencies after GB surgery are less common because it does not have a malabsorptive component, and an adult multiple vitamin and mineral supplement is considered sufficient to prevent these problems (64). Reviewed below are the studies that have reported nutritional deficiencies in RYGB surgery patients (Table 2). The majority of these studies were uncontrolled case series, and so it is important to note that the studies may have somewhat overestimated the effect of surgery on nutritional status, especially given that nutritional deficiencies have been noted in severely obese subjects before surgery (65) and that many of the patients are menstruating women who are more likely to have poor iron status.

View larger version (31K): [in this window] [in a new window]   FIG. 2. Schematic representation of the normal gastrointestinal tract (A) and its perturbations in the two common bariatric surgery procedures, RYGB (B) and adjustable GB (C). A, Major sites of micronutrient absorption and gastrointestinal hormone production. Absorption of iron and other minerals such as calcium and magnesium occur mostly from the duodenum and proximal jejunum. Whereas the absorption of dietary fats and concomitantly the fat-soluble vitamins such as vitamins A and D occurs in the distal small intestine, it is facilitated by the action of pancreatic enzymes and bile salts released into the duodenum. Water-soluble vitamins are absorbed throughout the small intestine. Among the gastrointestinal hormones, ghrelin is secreted predominantly from the gastric fundus. Glucose-dependent insulinotropic peptide (GIP) and cholecystokinin (CCK) are secreted mostly from the proximal small intestine, whereas the distal intestines are the primary site of production of the satiety-inducing hormones, GLP-1 and PYY. B, In RYGB, the stomach is divided into a small proximal pouch, excluding much of the ghrelin-secreting regions, and a larger distal segment. The pouch is anastomosed with the proximal jejunum through a narrow end to side anastomosis, whereas the distal segment along with the duodenum and part of the jejunum are attached to the distal jejunum. This surgery combines restrictive and malabsorptive procedures. C, GB is a purely restrictive procedure in which the prosthetic band divides the stomach into a small proximal segment and a larger distal segment. The band aperture between the two segments can be adjusted by changing the volume of the saline reservoir, which has a sc port.

Serum folate deficiency has been reported to be as high 38% after RYGB surgery (67). Brolin et al. (74) reported that a supplement containing 400 µg of folate per day consistently corrected low folate levels in patients who underwent RYGB surgery, although 1000 µg/d have been recommended by others (64). Primary reason for folate deficiency is decreased folate intake. Malabsorption may not play a big role, even though folate is preferentially absorbed in the proximal part of the small intestine, because absorption can occur along the entire part of the small intestine with adaptation after surgery (76). Maintaining adequate folate levels is important, however, because of the possibility of megaloblastic anemia. Also, there have been reports of neural tube defects in infants born to mothers who underwent RYGB surgery (77, 78).

Calcium and vitamin D deficiency may occur in patients who undergo RYGB surgery, and a deficiency rate of 10% for serum calcium and 51% for serum 25-hydroxy vitamin D levels has been reported (66). PTH levels, however, were not reported (66). Possible contributors to calcium deficiency in the RYGB patients include malabsorption of calcium because of bypassing the duodenum and proximal jejunum in which calcium is mostly absorbed; intolerance to rich sources of calcium such as milk; and defective absorption of vitamin D because of fat malabsorption. Fat malabsorption is due to the short common channel and delayed mixing of fat with pancreatic enzymes and bile salts as a result of bypassing the duodenum. Deficiency of calcium is not always apparent, however, because of release of calcium from bone. Coates et al. (79) and von Mach et al. (80), who followed subjects for 9 and 24 months, respectively, reported elevated markers of bone turnover and/or decreased bone mass in patients who underwent RYGB surgery, compared with patients who underwent GB surgery (80) or the matched obese controls (79, 80). The higher bone turnover in the RYGB patients, however, may be partly due to the increased weight loss in these patients, compared with the other patients. PTH levels were not different between the RYGB and obese control groups (80) nor did they change over time after surgery (79). Nevertheless, to prevent metabolic bone disease, 1200–1500 mg/d of calcium and 400 IU/d of vitamin D supplements are recommended (64, 65). These amounts, however, may not suppress serum PTH or bone resorption, and increased supplementation may need to be considered (81). Because of reduced stomach acid content, calcium citrate rather than calcium carbonate is recommended because the latter requires acid for absorption (64, 65). Regular monitoring of markers of bone resorption such as urinary N-telopeptide level and markers of bone formation such as serum osteocalcin level may also be necessary.

Serum vitamin A deficiency has been reported in 10% of RYGB patients (66, 67). Whereas symptoms of vitamin A deficiency are rare in this population, a case study reported xerophthalmia and nyctalopia in a patient after a duodenal switch gastric bypass surgery due to inadequate vitamin A supplementation (82). A contributing factor to vitamin A deficiency in RYGB patients is fat malabsorption. Careful monitoring of serum vitamin A status and supplementation as needed is necessary to avoid a deficiency.

Despite the evidence of nutritional deficiencies, many surgeons do not recommend adequate supplements or evaluate serum nutrient levels (83), and most patients do not comply with the recommended supplement regimen (70). Education of both the physicians and patients is thus necessary to prevent malnutrition after RYGB surgery.

Macronutrient deficiency and intolerance

Protein deficiency, assessed by serum albumin levels, is less common than most other nutrient deficiencies (Table 2) (66, 67, 68, 69). To consume enough protein, patients should be advised to consume fish, which is better tolerated than meat.

Simple sugar intake, especially added sugars (64), has been reported to cause dumping syndrome in as many as 76% (84) of the RYGB patients. The food rapidly enters the small intestine causing an osmotic load, which leads to movement of fluid from the blood into the intestine (85, 86). Rapid food entry into the jejunum also stimulates a substantial release of peptide hormones (85, 86). Clinical manifestations of the dumping syndrome include gastrointestinal symptoms such as early satiety, nausea, cramps, and explosive diarrhea and vasomotor symptoms such as sweating, flushing, palpitations, dizziness, and an intense desire to lie down (85). The insulin response is exaggerated and causes hypoglycemia (85, 86). To prevent dumping syndrome, patients should avoid consuming fruit juices and foods and drinks with added sugar (64); consume frequent, small, dry meals because water can make the food more soluble; include dietary fiber; increase dietary protein (especially fish and chicken); and modestly increase dietary fat (to delay gastric emptying) (86).  ^{*************************************} Nobody is trying to make post-ops feel badly about their surgery choice.  The DSers postings are aimed at pre-ops and potential revisions, to make sure they know about the DS BEFORE they choose which surgery to have.  I'm sorry if that's how our postings make them feel, but that is not our intent. 

We DSers also want people to know that we can help people with insurance issues, as most insurance companies can be FORCED to pay for the DS if the patient wants it and is willing to jump through the hoops to appeal -- one of the major independent medical reviewers in the country (used by many insurance companies and the federal government) TOTALLY supports the DS over the RNY when the IMRs are sent to them.  Medicare changed their rules in 2006 (in no small part in response to a letter-writing campaign by us DSers!) to include the DS as a covered surgery.  As more and more people stand up for their rights to have the surgery of their CHOICE, the insurance companies, one by one, are giving in and making the DS equally available, which is one of our major goals.