Quote from "The SAGES Manual of Pediatric Minimally Invasive Surgery" by Danielle S. Walsh, Todd A. Ponsky, Nicholas E. Bruns -
"The advantages of this technique are preservation of the pylorus, which prevents the dumping syndrome prevalent in bypass, reduced malabsorption (although nutritional deficiencies remain a challenge), relative simplicity and shorter operative time versus bypass, and fewer postoperative complications than bypass, as there is only one staple line and no new spaces are created for internal hernia. Although weight loss is slightly less than that after bypass, a sleeve can later be converted to bypass if the malabsorptive component is later necessary or if post-sleeve reflux is refractory."
"The advantages of this technique are preservation of the pylorus, which prevents the dumping syndrome prevalent in bypass, reduced malabsorption (although nutritional deficiencies remain a challenge), relative simplicity and shorter operative time versus bypass, and fewer postoperative complications than bypass, as there is only one staple line and no new spaces are created for internal hernia. Although weight loss is slightly less than that after bypass, a sleeve can later be converted to bypass if the malabsorptive component is later necessary or if post-sleeve reflux is refractory."