Isolated Lower Esophageal Sphincter Relaxation as ``Wave-Suppressed' Secondary Peristalsis

Esophageal venting following air insufflation may occur by secondary peristalsis or by isolated transient lower esophageal sphincter relaxation (TLESR). To identify factors determining venting by these two mechanisms, we analyzed the responses to esophageal air insufflation in 4 infants and in 2 adults. We used a nine-lumen dual-Dent-sleeve manometric catheter with an air insufflation esophageal side hole, identifying swallowing by pharyngeal manometry or submental electromyography. The time from the venting lower esophageal sphincter relaxation (whether part of a secondary peristalsis or an isolated TLESR) to the next swallow (whether spontaneous, in the infants, or on command, in the adults) was characterized as ≥15 sec or <15 sec. Of the 25 evaluable trials, the subsequent swallow was ≥15 sec after the venting response in 9 instances and <15 sec afterward in 16 instances. Eight of the 9 trials with delayed swallows (≥15 sec) were vented by secondary peristalsis, whereas 11 of the 16 with early swallows (<15 sec) were vented by TLESR (X² p < 0.01). TLESRs may be induced by esophageal stimuli, in which case they may represent ``wave-suppressed' secondary peristaltic complexes.