Milk intolerance following gastric operations with special reference to lactase deficiency

Weight loss and dietary intake after vertical banded gastroplasty and Roux-en-Y gastric bypass

OBJECTIVE

The purpose of this study was to learn whether preoperative eating habits can be used to predict outcome after vertical banded gastroplasty (VBG) and Roux-en-Y gastric bypass (RYGB). BACKGROUND SUMMARY: Several independent randomized and sequential studies have reported significantly greater weight loss after RYGB in comparison with VBG. Although the mechanism responsible for weight loss after both procedures is restriction of intake rather than malabsorption, the relationships between calorie intake, food preferences, and postoperative weight loss are not well defined.

METHODS

During the past 5 years, 138 patients were prospectively selected for either VBG or RYGB, based on their preoperative eating habits. All patients were screened by a dietitian who determined total calorie intake and diet composition before recommending VBG or RYGB. Thirty patients were selected for VBG; the remaining 108 patients were classified as "sweets eaters" or "snackers" and had RYGB. Detailed recall diet histories also were performed at each postoperative visit.

RESULTS

Early morbidity rate was zero after VBG versus 3% after RYGB. There were no deaths. Mean follow-up was 39 +/- 11 months after VBG and 38 +/- 14 months after RYGB. Mean weight loss peaked at 74 +/- 23 lb at 12 months after VBG and 99 +/- 24 lb at 16 months after RYGB (p < or = 0.001). Twelve of 30 VBG patients lost > or = 50% of their excess weight versus 100 of 108 RYGB patients (p < or = 0.0001). Milk/ice cream intake was significantly greater postoperatively in patients who underwent VBG versus patients who underwent RYGB after 6 months (p < or = 0.003), whereas solid sweets intake was significantly greater after VBG during the first 18 months postoperatively (p < or = 0.004). Revision of VBG was performed in 6 of 30 patients (20%) for complications or poor weight loss, whereas only 2 of 108 patients who underwent RYGB required surgical revisions (p < or = 0.001).

CONCLUSIONS

These data show that VBG adversely alters postoperative eating behavior toward soft, high-calorie foods, resulting in problematic postoperative weight loss. Conversely, RYGB patients had significantly greater weight loss despite inferior preoperative eating habits. The high rate of surgical revision in conjunction with inconsistent postoperative weight loss has led us to no longer recommend VBG as treatment for morbid obesity.

Difference in calcium metabolism following Billroth-I and Billroth-II procedures for gastric and duodenal ulcers

There have been 7 patients with postoperative osteomalacia in our series of 500 patients who had a gastrectomy for gastric or duodenal ulcers. All seven of these patients had a Billroth-II type gastrojejunostomy or esophagojejunostomy which caused food to bypass the duodenum and the upper part of the jejunum, and six of these patients showed milk intolerance and had diarrhea on food other than cow's milk. From this finding, it may be surmised that patients are predisposed to osteopenia after gastrectomy due to disorder in the process of calcium absorption and they develop osteomalacia when treated with the Billroth-II procedure, showing milk intolerance and diarrhea on food other than cow's milk.

Disaccharidase levels in the small intestine in patients with diarrhoea following vagotomy and pyloroplasty

Diarrhoea is a common sequel to vagotomy and pyloroplasty but its cause is unknown. One of our patients who developed this complication had an abnormal lactose barium meal and responded well to a lactose-free diet. This led us to make a systematic study of disaccharidase activity in the small intestine in patients with diarrhoea following vagotomy and pyloroplasty. The small-intestinal disaccharidases have been estimated in jejunal biopsy specimens taken from 23 patients suffering from persistent diarrhoea, either continuous or episodic, after vagotomy and pyloroplasty. The disaccharidase values were normal in all but one of these patients. This patient showed hypolactasia but the sucrase and maltase levels were normal. The jejunal biopsy specimen taken from this patient showed a convoluted pattern under the dissecting microscope and severe partial villous atrophy under the light microscope. A repeat jejunal biopsy taken 20 cm beyond the duodeno-jejunal flexure showed similar appearances and also had a low level of lactase. However, two lactose tolerance tests and a lactose barium meal yielded normal results, suggesting that the low level of lactase in the upper jejunum was not a limiting factor in lactose absorption. The finding of one example of a low lactase level among 23 postvagotomy patients corresponds with what is being found in a study of normal subjects at present in progress. In effect, almost all patients with persistent diarrhoea after vagotomy and pyloroplasty have normal small-intestinal disaccharidase activity.