Sleeve Gastrotomy: A Paradigm Change

This ongoing column is dedicated to sharing with readers the life and experiences of Dr. Edward Mason.

Column Editor: Tracy Martinez, RN, BSN, CBN
Ms. Martinez is the Program Director for Wittgrove Bariatric Center in La Jolla, California.

This month: Sleeve Gastrotomy: A Paradigm Change

Bariatric Times. 2014;11(4):10–11.

Submit Your Questions for Dr. Mason
To submit a question for “Ed Mason at Large,” e-mail Angela Hayes at [email protected]. Include “Mason at Large” in the subject line of your e-mail. All questions are reviewed by the editors and are selected based upon interest, timeliness, and pertinence, as determined by the editors. There is no guarantee a submitted question will be published or answered. Published questions are edited and may be shortened.

Is type 2 diabetes a gastro-duodenal motility disorder?

Dr. Mason: Yes, type 2 diabetes (T2D) is a motility disorder in which the stomach no longer empties with an initial gush to overflow the duodenum and expose jejunum to hypertonic contents, which stimulate a flush to distal bowel, where L cells sense glucose and secrete glucagon-like peptide-1 (GLP-1), which is required to decrease insulin resistance in order to prevent and resolve T2D. Normally, gastric emptying is regulated by a large capacity stomach, receptors in the duodenum, and L cells in the distal bowel. Normal regulation requires a stomach that gushes and squirts as directed by the duodenal receptors. When obesity and/or age increase, the regulatory system may fail. How this system fails is not clear to me and probably needs study. I would appreciate help from anyone who has an explanation of the mechanisms of this failure. It is interesting that to restore stimulation of L cells, we remove or inactivate the ballooning portion of the stomach, leaving only the thick walled lesser curvature sleeve which provides unregulated passage of content between esophagus and stomach. Nature requires a stomach of varying capacity for normal regulation while surgeons remove or inactivate the expandable stomach for an unregulated stimulation of secretion of GLP-1 to treat severe obesity and resolve T2D.

What do you think about an operation called gastric fundus invagination (GFI)? I recently had a rat model study published, which demonstrates the effectiveness and superiority of this new procedure compared to gastric plication.[1]

Editor’s Note: Dr. Darido’s article was published in Obesity Surgery. The article abstract is as follows:
Background: Gastric fundus invagination (GFI) is a novel weight loss procedure. The gastric fundus is invaginated inside the gastric lumen and anastomosed to the gastric antrum. In gastric plication (GP), the greater curvature is plicated inside the gastric lumen leaving a narrow gastric channel for food passage. This study compares GFI to GP in a diet-induced obesity rat model. Methods: Twenty Long-Evans male rats were fed a 60 percent high fat diet for six weeks. At 14 weeks of age, the rats underwent either GFI (N=10) or GP (N=10) surgery. Body weight and food intake were measured for six weeks. Serum adipokines and ghrelin hormone were assayed. Six weeks after surgery, all rats were euthanized and the stomachs examined. The two sample t test was used to compare the results between the two groups. Results: All GFI rats had an intact fundus invagination at six weeks following surgery. The greater curvature plication unfurled in 3 out of 10 GP rats. Part of the fundus herniated through the plication suture line in one GP rat. There was no significant difference between the mean percent weight change for the GFI (4.2±4.1%) and GP (8.8±6.0%) groups. There was no difference in food intake between both groups. GFI was associated with a significant lower fasting ghrelin levels (101.1±13.1 versus 137.3±27.4; p=0.044) compared with GP. Conclusions: GFI offers a more effective and more durable surgical alternative for weight loss than GP.

Dr. Mason: I like the concept of fundus invagination because it is simple and reversible, which was what I was looking for when I developed gastric bypass. GFI is an incision in the antrum through which a long grasping instrument is used to pull the fundus through the stomach and out the opening in the antrum. An anastomosis is performed between fundus and antrum. Only a small portion of fundus is removed. The anastomosis is an internal gastropexy for both inverted fundus and antrum. The stretchable portion of the stomach no longer provides large meal accommodation and regulated emptying into the duodenum is disrupted.

You demonstrated in your rodent study that this invagination succeeded while gastric plication failed. Most importantly, you have shown that GFI induced weight loss and was not associated with a compensatory increase in serum ghrelin level when compared with gastric plication.

“Sleeve gastrotomy” would be a short name and fit current bariatric surgical verbiage. Your operation preserves the lesser curvature sleeve for flow of ingested nutrients from esophagus to duodenum. Unregulated duodenal mixing with bile and pancreatic juice is inadequate for providing isotonic content for the jejunum. T2D is probably prevented or eliminated by GFI. You need plasma GLP-1 analysis to determine this in future study. Natural thickness of lesser curvature stomach wall probably adjusts sleeve diameter and eliminates any need for an indwelling tube or bougie during the operation. This should decrease leaks, obstruction, and pseudo-diverticula, which may occur after a sleeve gastrectomy. “Sleeve gastrotomy” could probably replace sleeve gastrectomy just as I replaced Billroth II gastrectomy with gastric bypass. The anatomical result is a three-part stomach; the vertical lesser curvature sleeve, the horizontal inversion, lined with mucosa and covered with peritoneum, and a small greater curvature segment inadequate for a gourmand, who could become a gourmet.

This has been déjà vu for me. I have frequently been asked how I discovered an operation for obesity. In fact, my goal was to simplify Billroth II gastrectomy by bypassing rather than removing stomach. I did not even consider treatment of obesity until after we had determined in the animal laboratory that gastric bypass would suppress gastrin secretion and not cause duodenal and stomal ulcers. Two simultaneous clinical studies of effect upon duodenal ulcer and also upon obesity were begun in the hope that gastric bypass would have a use if the bypass failed to resolve acid peptic ulceration. One patient out of eight with ulcer symptoms was also severely obese. He was the only patient whose ulcer healed while losing weight at the same time. It turned out that obesity (and T2D) warranted continued study, as you know. Understanding the mechanism of action of gastric bypass and sleeve gastrectomy in flushing hypertonic contents containing glucose and other nonabsorbed stimulants of GLP-1 secretion, we should be able to use poorly absorbed glucose mimetics to replace bariatric surgery and decrease the T2D pandemic. This will require study and data in order to obtain approval. GLP-1 secretion should also help decrease weight in patients who are not severely overweight.

Since early in the history of gastric bypass, attempts have been made to reduce the capacity of the stomach by plication without success. The plication sutures pull through, just as occurred in Darido and Moore’s rodent comparison of plication with fundus invagination. I performed vertical banded gastroplasty in swine and when the animals were sacrificed, there was no evidence that the operation had been performed. You did have enough retention of fundus invagination in swine to support use in other mammals including humans.[2] In the swine study, a circular stapler was used to perform the fundus anastomosis to antrum. Invagination could become the preferred procedure for obesity and diabetes if it receives the interest and study that it deserves.

References
1. Darido E, Moore JR. Comparison of gastric fundus invagination and gastric greater curvature plication for weight loss in a rat model of diet-induced obesity. Obes Surg. 2014 Jan 19 [Epub ahead of print]
2. Darido E, Overby W, Brownley KA, et al. Evaluation of gastric fundus invagination for weight loss in a porcine model. Obes Surg. 2012; 22: 1293–1297.

Tags: sleeve gastrotomy

Category: Ed Mason at Large, Past Articles