Rare Surgery Brings More Weight Loss & Risk
September 7, 2011 by staff
Rare Surgery Brings More Weight Loss & Risk, A less common form of obesity surgery may cause more weight loss than more popular cousin, gastric bypass – but at the expense of greater long-term risk, researchers said on Tuesday.
The study, published in the Annals of Internal Medicine, followed 60 morbidly obese patients who were randomized to gastric bypass surgery or a more extensive procedure known as duodenal switch.
Two years after surgery, duodenal switch patients had lost more weight around 50 pounds on average.
People lose a substantial amount of weight with any type of surgery. Gastric bypass patients an average cut of 111 pounds, while duodenal switch patients dropped about 162.
But those extra kilos came with almost twice the rate of complications.
Of the 29 patients duodenal switch, 62 percent had problems such as abdominal pain, vomiting, diarrhea and intestinal obstruction. And several long-term malnutrition suffered – something not seen in the group of gastric bypass.
Duodenal switch procedure is not popular. In a 2008 study, they represented only 1 percent of weight loss or bariatric surgeries performed in the U.S. and 5 percent in Europe.
The technique is often reserved for “super obese” patients with a body mass index (BMI) of 50 or more – although some surgeons who perform the less severely obese patients as well, said Dr. T. Torgeir Sovik, University of Oslo in Norway, the principal investigator of the new study.
“As a duodenal switch may be associated with more adverse effects, this procedure should only be performed in carefully selected patients by a dedicated bariatric,” he told Reuters Health in an email Sovik. “And close monitoring after surgery is necessary after such procedures.”
However, one expert not involved in the study went further.
“This is an operation that should probably go away,” said Dr. Edward H. Livingston, professor and surgeon at the University of Texas Southwestern Medical Center at Dallas.
The average weight loss seen with either gastric bypass or duodenal switch will improve or reverse obesity-related diseases such as diabetes, sleep apnea and arthritis of the knee, according to Livingston, who wrote an editorial accompanying the study.
So for those medical problems, it may not matter if a person loses 100 pounds or 150 pounds over two years.
BMI is a measure of weight relative to height. A BMI between 18.5 and 24.9 is considered normal weight, and above 30 is obese.
Patients in this study were a fairly healthy despite having a BMI of 50 or more.
After two years, who had a duodenal switch showed greater improvement in their cholesterol levels. However, these levels were nearly normal (both groups), for one, said Livingston.
That begs the question, he said, that extra weight loss “really accomplished anything.”
“The answer is ‘no’,” said Livingston.
In the U.S., where about 220,000 people underwent weight loss surgery in 2009, gastric bypass is the most common choice.
During gastric bypass, the upper stomach with staples to create a small pouch that restricts the amount of food a person can eat at the same time. The surgeon also creates a bypass in the rest of the stomach and a portion of the small intestine, which limits the absorption of food.
Duodenal Switch is broader. The surgeon removes part of the stomach and the rest of “manga” as the stomach is attached to the end of the small intestine, which further limits the absorption of calories and nutrients.
Both surgeries carry the risk of long-term nutritional deficiencies, and people need to take supplements and carefully monitor your diet for life thereafter.
But the risks of nutrient deficiencies are greater with duodenal switch, and include some not seen with gastric bypass, Livingston said.
Some people, for example, can have severe vitamin D and calcium leading to loss of weak and brittle bones. Other problems include severe protein deficiency and night blindness caused by vitamin A deficiency (which is also reversible with vitamin A supplementation of treatment).
In this study, three of 29 patients developed duodenal switch protein malnutrition, two developed night blindness, and one had a severe iron deficiency should be treated with infusions of iron.
Livingston said his advice to people considering bariatric surgery is to prevent duodenal switch. “It’s not just a good operation,” he said.
But he also questioned the value of weight loss surgery in general for people with morbid obesity who have no medical conditions that stand to improve or resolve after surgery.
In general, experts say that surgery could be an option for anyone with a BMI of 40 or higher, which translates roughly to a man who is at least 100 pounds overweight or a woman who is 80 pounds overweight.
Livingston said he believes that more caution is in order when a person is very obese otherwise healthy.
Along with the risks of surgery, he said, there is still uncertainty about whether they really lengthens life of people. Some studies have suggested that it might, but not all.
In a study recently published in the Journal of the American Medical Association, Livingston and colleagues found no survival advantage in patients with morbid obesity who had undergone weight loss surgery versus those who do not.
The study included 850 U.S. veterans undergoing any type of surgery to lose weight, average age about 50, and more than 41,000 veterans who had only non-surgical care. There was no evidence that surgery improves longevity in the next seven years.
“I really do not know if there is a survival benefit,” said Livingston.
That, he said, makes the risk of duodenal switch seem even less worthwhile.
But according to Sovik, duodenal switch may be appropriate for some patients super obese.
In the U.S., he said, one of three candidates for surgery to lose weight have a BMI of 50 or higher. And studies suggest that a significant percentage of those people will have a BMI greater than 40 after a gastric bypass.
In this study, a quarter of the gastric bypass patients still had a BMI higher than two years after surgery – compared to none of the patients duodenal switch.
A more extensive surveillance after duodenal switch, Sovik said, can help detect and manage side effects.
He noted, however, that large, long-term studies are still needed to show whether the loss of extra weight with duodenal switch ultimately improves the severely obese patient’s health and extend their lives.
Please feel free to send if you have any questions regarding this post , you can contact on
Disclaimer: The views expressed on this site are that of the authors and not necessarily that of U.S.S.POST.