Effects of gastric bypass surgery on kidney stone disease
Obesity is associated with comorbidities like type II diabetes, heart disease, hypertension, pregnancy complications and other health problems. While dietary changes and physical exercises are prescribed for weight reduction, morbidly obese patients are often advised to undergo bariatric (weight-loss) surgery. Currently weight-loss surgery is the only therapy that results in a sustained and significant weight loss in the majority of the morbidly obese patients.
Jejunoileal (JI) bypass, an early form of gastric bypass surgery was banned as it led to serious postoperative consequences such as osteomalacia (softening of bone due to loss of mineral from bone), nephrolithiasis (process of forming a stone in the kidney) and kidney failure. The Roux-en-Y gastric bypass (RYGB) overcame many of the problems associated with JI bypass. In the RYGB surgery, the stomach is made smaller and a length of small intestine is bypassed. This reduces the absorptive surface area and oral intake of calories leading to malabsorption and weight loss. However, malabsorption of fat soluble vitamins and calcium may lead to increased absorption of dietary oxalate (chemical that combines with calcium to create the most common type of kidney stone) which may lead to severe hyperoxaluria (too much oxalate is present in the urine) and kidney stones.
The Matlaga BR et al study evaluated the risk of kidney stone disease following RYGB procedure in more than 4000 patients. The likelihood of occurrence of kidney stones following RYGB surgery was compared with a set of obese patients who did not undergo RYGB procedure. It was noted that about 7.65% of the individuals who underwent the gastric bypass surgery developed kidney stones. More patients in the RYGB group underwent shock wave lithotripsy and ureteroscopy (stone removal procedures) compared with the control group.
These findings suggest that gastric bypass surgery procedures are associated with an increased risk of hyperoxaluria which can result in formation of kidney stones in the postoperative period. Further studies are required to evaluate the exact cause of this risk to prevent the occurrence of kidney stones in individuals undergoing gastric bypass surgery.
Written by: healthplus24.com team
Date last updated: December 07, 2014