Table 2.

Intraluminal pressure gradients across the hiatus during ampullary emptying

	Circumferentially Averaged Pressure at Each Axial Locus, mmHg				Nadir Radial Pressure at Each Axial Locus, mmHg
	Distance from the hiatal center			EGJ pressure gradient	Distance from the hiatal center			EGJ pressure gradient
Time Landmark	15 mm Above	0 ± 7.5 mm	15 mm Below		15 mm Above	0 ± 7.5 mm	15 mm Below
Onset ampullary emptying	19 (13–23)	26 (14–33)	14 (10–23)	3 (−2 to 12)	14* (8–19)	14* (7–19)	7* (5–15)	5 (1–9)
25% Emptying time	19 (14–39)	29 (18–42)	13 (9–24)	4 (−2 to 27)	14* (9–24)	14* (7–25)	7* (2–15)	7 (1–15)
50% Emptying time	22 (16–30)	29 (21–39)	14 (10–24)	5 (1–16)	15* (11–24)	18* (10–23)	8* (4–16)	7 (3-14)
75% Emptying time	25 (17–43)	27 (19–56)	16 (9–27)	7 (0–26)	17* (10–31)	18* (8–29)	8* (4–16)	9 (2-22)

Comparison of pressure values obtained with circumferential averaging (top) and based on selecting the nadir radial pressure at each axial locus (bottom). Values are given as median (5th–95th percentile).

EGJ, esophagogastric junction.

^*P < 0.01 vs. circumferentially averaged pressure.