Alexandra Mignucci, MS, BS1, Virali Shah, BS, MBA1, Michael Tadros, MD, MPH, FACG2; 1Albany Medical College, Albany, NY; 2Albany Medical Center, Albany, NY
Introduction: HRM is the gold standard for assessing esophageal motility disorders. It can include multiple provocative tests, such as Multiple Rapid Swallows (MRS) and Apple Viscous Swallows (AVS). Few studies have directly compared these two tests, which are limited by patient tolerance. The study goal is to compare MRS and AVS to determine utility. Methods: This is a mixed retrospective study of 100 patients. 86 patients underwent MRS and/or AVS. Tolerance and added value from each test were analyzed. Added value from MRS was defined as weak peristaltic reserve (DCI ratio< 0.85), good peristaltic reserve (DCI ratio >1), or an abnormal motility/pressurization pattern. DCI ratio was defined as mean DCI of MRS/mean DCI of wet swallows. Added value from AVS was defined as presence of IEM ( >50% of swallows being ineffective) or an abnormal pattern. Results: 73 patients completed both tests. Added value was found to be greater for MRS than AVS (34% for MRS, 17% for AVS, p< 0.05). 88% of patients tolerated MRS (n=76), and 96% of patients tolerated AVS (n=83) (p< 0.05). From the 76 patients who completed MRS, 24 abnormal patterns were found (32%), including 14 hypercontractile, 5 spasm, 1 paradoxical LES response, 1 distal pressurization, and 1 panesophageal pressurization. MRS identified 22 patients with weak peristaltic reserve (29%) and 8 patients with good reserve (11%). Added value for MRS was 59% (n=45). From the 83 patients who completed AVS, 24 patients had IEM (29%) and 7 patients had abnormal patterns (8%), including 3 hypercontractile, 1 distal pressurization, and 3 spasms. Added value for AVS was estimated to be 48% (n=40). Both tests were comparable for diagnosing IEM (29% for MRS, 29% for AVS, p >0.05). However, 4 patients showed Absent peristalsis on AVS but passed MRS (5%). Discussion: This is the first study to demonstrate that MRS is better at identifying abnormal pathophysiology than AVS (p< 0.05). When patients underwent both tests, MRS provided significantly greater added value for diagnosing esophageal dysfunction (p< 0.05). Nevertheless, patients tolerated the AVS more than MRS (p< 0.05). When evaluating for IEM, AVS and MRS were equally effective (p >0.05). In 4 cases, AVS uniquely indicated severe forms of hypokinetic disorders. We recommend a tailored approach when choosing provocative measures. For patients with unclear diagnoses, MRS can be more clinically useful in detecting abnormal pathophysiology. For pre-operative anti-reflux surgery, both MRS and AVS are helpful.
Figure 1. Findings of wet swallow (1), apple viscous swallow (2), and multiple rapid swallow (3) tests performed on three different patients (A, B, and C). Patient A: A1. Weak contraction seen on wet swallow. A2. Failed swallow seen on AVS. A3. Patient able to augment contraction on MRS. [This suggests that a combination of AVS and MRS may be more useful in pre-operative assessment.] Patient B: B1. Fragmented contraction seen on wet swallow. B2. Repetitive spasm seen on AVS. B3. Significant paradoxical LES contractions seen on MRS. [Patient diagnosed with early achalasia.] Patient C: C1. No major abnormality seen on wet swallow. C2. No major abnormality seen on AVS. C3. Marked hypercontractile esophagus and loss of deglutitive inhibition on MRS. [MRS is more useful in detecting abnormal pathophysiology.]
Figure 2. Flowchart demonstrating subsets of patients included and excluded in this study, beginning with 100 patients.
Table 1. Comparative Analysis of MRS vs. AVS to Measure Significance of Tolerance, Added Value, Abnormal Patterns, and IEM.
Disclosures: Alexandra Mignucci indicated no relevant financial relationships. Virali Shah indicated no relevant financial relationships. Michael Tadros indicated no relevant financial relationships.