Impact of Change in Sizing Protocol on Outcome of Magnetic Sphincter Augmentation.

Abstract

To evaluate and compare magnetic sphincter augmentation (MSA) device sizing protocols on postoperative outcomes and dysphagia. Among predictors of dysphagia after MSA, device size is the only factor that may be modified. Many centers have adopted protocols to increase device size. However, there is limited data on the impact of MSA device upsizing protocols on the surgical outcomes. Patients who underwent MSA were implanted with 2 or 3-beads above the sizing device's pop-off point (POP). Clinical and objective outcomes >1-year after surgery were compared between patients implanted with POP+2-vs-POP+3 sizing protocols. Multiple subgroups were analyzed for benefit from upsizing. Pre- and postoperative characteristics were compared between size patients received, regardless of protocol. A total of 388 patients were implanted under POP+2 and 216 under POP+3. At a mean of 14.2(7.9) months pH normalization was 73.6% and 34.1% required dilation, 15.9% developed persistent dysphagia, and 4.0% required removal. Sizing protocol had no impact on persistent dysphagia ( P =0.908), pH normalization ( P =0.822), or need for dilation ( P =0.210) or removal ( P =0.191). Subgroup analysis found that upsizing reduced dysphagia in patients with <80 percent peristalsis (10.3-vs-31%, P =0.048) or DCI >5000 (0-vs-30.4%, P =0.034). Regardless of sizing protocol, as device size increased there was a stepwise increase in percent male sex ( P <0.0001), BMI>30 ( P <0.0001), and preoperative hiatal hernia>3cm ( P <0.0001), LA grade C/D esophagitis ( P <0.0001), and DeMeester score ( P <0.0001). Increased size was associated with decreased pH-normalization ( P <0.0001) and need for dilation ( P =0.043) or removal ( P =0.014). Upsizing from POP+2 to POP+3 does not reduce dysphagia or affect other MSA outcomes; however, patients with poor peristalsis or hypercontractile esophagus do benefit. Regardless of sizing protocol, preoperative clinical characteristics varied among device sizes, suggesting size is not a modifiable factor, but a surrogate for esophageal circumference.