Review of post bariatric surgery effects on common genitourinary physiology

Abstract

Background: Obesity is a worldwide challenging health problem. Weight loss through medical management of obesity has not always been successful, thus, giving rise to the need for surgical intervention. Bariatric surgery has been shown to be helpful for morbidly obese patients. However, studies have also shown the effect of surgery on stone formation, fertility and erectile function. This review summarizes the main findings of several studies that analyze stone formation and fertility in men as well as erectile function post bariatric surgery. The underlying pathophysiologic alterations post bariatric surgery include increased absorption of oxalate leading to hyperoxaluria, hypocitraturia and increased urinary calcium oxalate supersaturation. Contradicting data exist on the effect of bariatric surgery on fertility and erectile function. Further studies are needed to analyze the mechanisms.

Bariatric Surgery and Risk of Urolithiasis: A Review

“…This leaves behind increased intestinal quantities of unbound oxalates with subsequent colonic absorption and secretion into the urine. 47,48 In a study by Nelson et al, 49 21 of their 23 patients presented with a symptomatic stone resulting from enteric hyperoxaluria following RYGB. 48 Furthermore, several studies have implied that patients undergoing RYGB are at higher risk for nephrolithiasis post-surgery than pre-surgery.…”

“…47,48 In a study by Nelson et al, 49 21 of their 23 patients presented with a symptomatic stone resulting from enteric hyperoxaluria following RYGB. 48 Furthermore, several studies have implied that patients undergoing RYGB are at higher risk for nephrolithiasis post-surgery than pre-surgery. 26,50,[51][52][53] An even greater concern was the occurrence of oxalate nephropathy and renal failure in a small subset of patients, an additional consideration for those with high urinary oxalate excretion.…”

“…This metabolic derangement is commonly observed in acidotic states as renal citrate reabsorption increases and urinary citrate excretion is reduced. 45,55 Penniston et al 48 after evaluating post-operative 24-hour urine specimens, have demonstrated that patients who have had RYGB have higher urinary oxalate and lower urinary citrate levels when compared to gastric banding patients. 8 While urine volume was low in both groups, it was postulated that the observed hypocitraturia in the patients who have had RYGB was a result of increased bicarbonate losses from the gastrointestinal tract.…”

“…8 While urine volume was low in both groups, it was postulated that the observed hypocitraturia in the patients who have had RYGB was a result of increased bicarbonate losses from the gastrointestinal tract. 48…”