Motor Response to Multiple Rapid Swallows (mrs) Can Predict Dysphagia in Patients Scheduled for Laparoscopic Antireflux Surgery

Nathaniel Stoikes, MD, Jesse Drapekin, RA, Anisa Shaker, MD, Vladimir Kushnir, MD, L. Michael Brunt, MD, C. Prakash Gyawali, MD. Division of Gastroenterology and Section of Minimally Invasive Surgery, Washington University School of Medicine, St. Louis

INTRODUCTION:  When multiple swallows (MRS) are rapidly administered, esophageal peristalsis is inhibited, and pronounced lower esophageal sphincter (LES) relaxation ensues.  After the last swallow of the series, a robust contraction sequence results.  Abnormal responses include incomplete inhibition or suboptimal contraction after MRS.  We speculate that MRS has value in predicting esophageal transit symptoms in patients undergoing laparoscopic anti-reflux surgery (LARS).

METHODS AND PROCEDURES:  Records of patients undergoing esophageal high resolution manometry (HRM, Sierra Scientific/Given Imaging, Los Angeles, CA) before LARS were evaluated.  Inclusion criteria included symptom score sheets evaluating esophageal symptoms (dysphagia, heartburn, regurgitation, chest pain) before and after LARS, completion of MRS procedure (5 rapid swallows of 2 mL water 3-5 seconds apart) during HRM, and an adequate HRM study without artifacts.  MRS was evaluated for adequate inhibitory response during swallows, and contraction pattern following MRS. Contraction patterns were evaluated separately in proximal (S2) and distal (S3) smooth muscle contraction segments on HRM.  Abnormal MRS responses included the following: incomplete inhibition, abnormal contraction (S2, S3 or both) or presence of an intersegmental trough (IST) of >3 cm between skeletal and smooth muscle contraction segments when peristalsis was intact.

RESULTS:  Sixty-three patients (mean age 60.3±1.7 yrs, 48 F) undergoing HRM prior to LARS successfully performed MRS (median 5 swallows, longest interval 3.2 ±0.1s between swallows).  At presentation, all patients had heartburn or regurgitation; 28 subjects (44.4%) reported some degree of dysphagia to solids or liquids.  Mean LES end-expiratory pressure was low (11.2 ±1.3 mmHg); 16 patients had values <5 mmHg. On HRM wet swallows, patients had a mean of 84.5% transmitted sequences; 8 had at least moderate esophageal body hypomotility (of which 6 had ≥80% peristaltic failure).  After MRS, 14 patients (22.2%) had an intact peristaltic sequence. Of the remainder, 29 patients (46.0%) had segmental failure (complete failure=19; failure of S2=10); 18 (28.6%) had incomplete inhibition; and 14 (22.2%) had an IST; some had overlapping abnormalities.  When stratified by presence or absence of dysphagia, 46.2% of subjects without dysphagia had a normal MRS response; 76.9% had formation of peristaltic segments following MRS.  In contrast, only 16.0% of subjects with dysphagia (10.7% with preoperative dysphagia and 22.7% with postoperative dysphagia) had a normal MRS response (p≤0.03 compared to subjects with no dysphagia).  Of patients with pre-LARS dysphagia who had worsening dysphagia following LARS, 62.5% had an abnormal MRS response.  Incomplete inhibition during MRS (39.3%) was the predominant pattern with pre-LARS dysphagia, while absent peristalsis after MRS (36.4%) dominated in subjects with post-LARS dysphagia.

CONCLUSIONS:  High resolution manometry with multiple rapid swallows helps predict dysphagia in subjects undergoing preoperative esophageal function testing prior to LARS.  Our results suggest differing pathophysiologic mechanisms for pre- and post-LARS dysphagia.