Approximately one out of every 10 women and men in the United States will have a kidney stone at least once in their lifetime. Kidney stones are solidified clumps of minerals, acids, and salts that form inside your kidneys and may sometimes get stuck in your ureters, causing tremendous pain.
Obesity is one of the factors that’s strongly associated with kidney stones. So, you might think that bariatric surgery — which helps you shed excess weight — would lead to a reduced risk. It doesn’t always. In fact, in some cases, this kind of surgery may raise your risk.
Caring and experienced urologist, Alex Lesani, MD, diagnoses and treats kidney stones at our Las Vegas, Nevada, office. If you’re considering bariatric surgery, you should learn about the risks of associated kidney stones.
Why does some bariatric surgery raise your risk for kidney stones? Read on to find out why specific procedures may result in more stones.
Your kidneys are fist-sized organs — on either side of your spine — that filter about half a cup of your blood every minute. During this process, they remove wastes, minerals, and excess water to create urine.
Even though your kidneys filter about 150 quarts of blood per day, they only produce about 1-2 quarts of urine. If you eat a diet high in certain minerals, or if you don’t drink enough water, the minerals and other chemicals may harden into clumps called kidney stones.
Small stones may remain in your kidneys and not cause any problems. Larger stones can pass through the ureters, the tubes that connect your kidneys to your bladder. If they get stuck, they can produce excruciating pain.
Before you undergo bariatric surgery, you’re at increased risk for kidney stones. Obesity causes system-wide inflammation and oxidative stress, which raises the risk for stone formation. Obesity is also associated with low urine pH, which in turn is related to the formation of uric acid stones.
Weight loss through diet modification and exercise decreases the risk of stone formation. However, certain aids to weight loss — including a type of bariatric surgery called malabsorptive bariatric surgery — raise the risk.
A malabsorptive procedure changes the way your digestive system works. Your food is rerouted to bypass a large portion of the stomach and some of the small intestines. Your digestive system, therefore, isn’t able to absorb many of the nutrients from the food.
The most common type of malabsorptive procedure is the gastric bypass, including the Roux-en-Y and sleeve gastrectomy procedures. Your surgeon may even remove some portion of your stomach.
Unfortunately, when food bypasses the lining of your stomach and intestines, the composition of your urine changes. Less absorption raises the level of oxalate in your urine while lowering the level of citrate as well as the volume of fluids.
If you have a history of kidney stones or if they run in your family, you may want to avoid gastric bypass and other malabsorptive bariatric surgeries. Instead, opt for restrictive bariatric surgery.
During a restrictive procedure, your stomach is stapled to minimize its size so that you eat far less food. In restrictive bariatric surgery, your digestive system functions normally, allowing your (smaller) stomach and intestines to absorb the nutrients and minerals your body needs.
The downside to a restrictive procedure is that you lose less weight than you would with a gastric bypass. The upside is that your body absorbs minerals, acids, and salts before they get to the urine, which decreases your risk for stone formation.
Even if you’ve undergone malabsorptive bariatric surgery, you can minimize your risk for kidney stones by adopting new habits, such as:
If you develop stones, we can help dissolve them or break them up using medications or other treatments, including shockwave therapy.
Have you had, or do you want to have, bariatric surgery? Contact us for kidney stone prevention or treatment by phoning us at 702-470-2579 today. You can also book your appointment online.
