Roux-en-Y Surgery May Increase Kidney Stone Risk

A recent study made by the Johns Hopkins University School of Medicine revealed that patients who underwent the most popular gastric bypass surgery developed kidney stones at a rate that almost doubles the rate of obese patients who didn't have the operation. During many years, doctors have thought that the Roux-en-Y procedure did not decrease calcium absorption, but this study has shown different results. The aim of this study is not to send the message that bariatric surgery is a bad thing because patients are twice as likely to get a kidney stone, but it is for doctors to recognize that proper counseling should be given. Considering that rates of morbid obesity have climbed in recent years and so has the popularity of various weight-loss operations, this study should not be considered "an indictment" of the Roux-en-Y procedure, says Dr. Brian Matlaga, M.D., because the long-term health benefits for obese patients are significant. As it is known, weight loss surgery can help reduce diabetes, back pain, heart diseases, sleep apnea and pregnancy problems, amongst others. Study Results After comparing 4,639 patients who had undergone the procedure with a second set of people with similar characteristics but who had not undergone surgery, researchers found that the overall risk remains at about 8 percent, compared to 5 percent of kidney stone development in similar patients who didn't have weight loss surgery. The Roux-en-Y procedure is the most common type of bariatric surgery and the first to be performed in the U.S and consists of a small stomach pouch created by stapling part of the stomach together or by vertical banding, limiting the food intake. The Y-shaped section of the small intestine is attached to the pouch to allow food to bypass the duodenum as well as the first portion of the jejunum, causing reduced calorie and nutrient absorption. Mineral deposits that harden over time form kidney stones. They begin as microscopic particles or crystals and develop into stones over time. The kidneys filter waste products, but when they do not dissolve completely, crystals and kidney stones may form. Our kidneys must maintain an adequate amount of water in the urine to dissolve all the removed waste products. If dehydration occurs, high levels of substances that do not dissolve completely (e.g., calcium, oxalate, uric acid) may form kidney stones. Therefore it is advised that patients drink at least six to eight glasses of fluids a day, cut down on salt and animal protein and reduce consumption of foods like black tea, nuts, okra and some leafy vegetables that are high in oxalates, which can form into kidney stones. Patients should know that the Roux-en-Y surgery might reduce the amount of calcium that patients absorb, contributing to kidney stone formation. Therefore, it is important that they ask their doctors for calcium supplements or other ways to help reduce the possibility of kidney stones development.