It’s our experience that people considering weight-loss surgery have a number of questions (a good thing!). One of the questions we hear relates to procedures. Specifically, what is the difference between gastric bypass and gastric sleeve? The short answer is that laparoscopic gastric bypass and laparoscopic sleeve gastrectomy are both effective surgical procedures for weight loss, but procedures, mechanisms and outcomes vary for each. Let’s take a closer look.
Gastric Bypass Vs Sleeve Gastrectomy: The Procedure
With gastric bypass, a small pouch is created at the top of the stomach using staples. This pouch is then connected directly to the small intestine, bypassing a portion of the stomach and the upper part of the small intestine. There is a surgical term in there, called a Roux limb, or bypass limb, that describes the part of the intestine brought up and connected to the stomach pouch. (Good ol’ Cesar Roux was a Swiss surgeon who came up with this method.) Patients who undergo gastric bypass need to be vigilant about nutritional deficiencies due to malabsorption. They usually require lifelong supplementation of vitamins and minerals, including vitamin B12, D, iron, calcium and folate.
Sleeve gastrectomy involves removing a large portion of the outer stomach, leaving behind a banana-shaped stomach that looks more like a tube or the sleeve of one’s jacket. Unlike gastric bypass, sleeve gastrectomy does not involve rerouting the intestines. While the sleeve does not involve much malabsorption since the intestine (where we absorb all the nutrients) in unaffected, patients still need to follow a nutrient-dense diet and may require supplements, especially in the initial post-operative period.
So, how exactly do these procedures bring about weight loss? Both cause weight loss primarily by changing the hormones in the blood stream. The key hormones that regulate body weight, blood sugar, fat storage and metabolism are mostly produced in the stomach and intestines. The smaller stomach pouch restricts the amount of food that can be consumed, so this might play a small role in losing weight early after the bypass. Gastric bypass also affects gut hormones like ghrelin, GLP-1, PYY, and many others which regulates fat storage, body weight, blood sugar, and hunger. By bypassing a portion of the stomach and intestines, gastric bypass leads to decreased ghrelin levels, which reduces appetite and body weight.
The sleeve procedure causes weight loss and reduction of blood sugar by changing the hormone profile in the blood stream for the long term. Removal of the outer stomach results in removal of the glands or factories that produce some key hormones, profoundly influencing the body weight “set point.” The reduced stomach size also limits the amount of food that can be eaten, so again there may be some “restrictive component” that plays a minor role. The sleeve also affects levels of a similar list of key hormones, especially ghrelin, GLP-1, leptin, and PYY, causing the body to receive a different signal on body weight “set point,” lowering fat storage, hunger, and blood sugar.
Gastric Bypass Vs Sleeve Gastrectomy: Long-Term Results
Gastric bypass typically results in slightly greater weight loss compared to sleeve gastrectomy in the short term. It also tends to have somewhat higher rates of resolution or improvement in conditions like type 2 diabetes and high blood pressure. But over the long term, there are also more complications such reoperations, blockages, malabsorption, hypoglycemia, and vitamin deficiency.
The sleeve, however, is simpler to perform and has a lower risk of complications compared to gastric bypass. While weight loss may be slightly lower, the sleeve still leads to significant and sustainable weight loss in the vast majority of patients and has lower long- and short-term complications. If a sleeve procedure fails, it can be revised with excellent success. Overall, studies indicate that patients with obesity live the longest lives after the sleeve, followed by gastric bypass, and both live much longer than people who did not undergo a surgical procedure.
The Takeaway
While both gastric bypass and the sleeve are effective weight loss procedures, they take a different approach that impacts complexity, vitamin considerations and long-term outcomes. So which is right for you? The choice between the two procedures largely depends on various factors including your medical history, preferences and the recommendations of your healthcare provider. If you’re ready to learn more about bariatric surgery and whether you might be a candidate, the team here at Nevada Surgical is happy to answer your questions. Contact us today to learn more.
