Application of a novel straight leg raise test during high-resolution manometry can predict esophageal contractile reserve in patients with gastroesophageal reflux disease

Background/aim: Increased intra-abdominal pressure from abdominal compression augments esophageal peristalsis during high-resolution manometry (HRM), and straight leg raise (SLR) while supine increases intra-abdominal pressure. We determined if water swallows performed during SLR can mimic contraction reserve seen with multiple rapid swallows (MRS). Methods: Consecutive patients evaluated for GERD symptoms completed validated GERD questionnaires, esophageal HRM, and upper endoscopy. Distal contractile integral (DCI) was analyzed during single water swallows (10 × 5 mL), MRS (5 × 2 mL), and during SLR (5x5 mL). Peristaltic breaks were measured using software tools with a 20 mm Hg isobaric contour. Univariate correlational analyses were performed to compare esophageal motor patterns and DCI values during single water swallows, MRS, and SLR. Results: Of 103 study patients (mean age: 46.7 ± 12.3 years, 56.3% female), 50 (48.5%) had ineffective esophageal motility (IEM). Contraction reserve was observed on MRS in 62% with IEM, and 35.8% with normal motility (p = 0.008). DCI was significantly higher during SLR compared to mean single swallow DCI in both IEM and normal motility patients (p < 0.001 for each comparison). In IEM patients, SLR significantly reduced swallows with peristaltic breaks (6.1 ± 3.7 vs 3.6 ± 3.6; p < 0.001) and shortened the length of the largest break (4.8 ± 3.4 vs 3.0 ± 3.0 cm; p < 0.001). DCI response following MRS correlated with DCI with swallows during SLR, with a correlational coefficient (Pearson's r) of 0.70 (p < 0.001). Conclusions: Swallowing against the resistance of increased intra-abdominal pressure from SLR improves esophageal body peristaltic performance and predicts esophageal body contraction reserve.