ISOLATED LOWER ESOPHAGEAL SPHINCTER RELAXATION AS WAVE-SUPPRESSED SECONDARY PERISTALSIS

Esophageal venting following air insufflation may occur by secondary p eristalsis or by isolated transient lower esophageal sphincter relaxat ion (TLESR). To identify factors determining venting by these two mech anisms, we analyzed the responses to esophageal air insufflation in 4 infants and in 2 adults. We used a nine-lumen dual-Dent-sleeve manomet ric catheter with an air insufflation esophageal side hole, identifyin g swallowing by pharyngeal manometry or submental electromyography. Th e time from the venting lower esophageal sphincter relaxation (whether part of a secondary peristalsis or an isolated TLESR) to the next swa llow (whether spontaneous, in the infants, or on command, in the adult s) was characterized as greater than or equal to 15 sec or <15 sec. Of the 25 evaluable trials, the subsequent swallow was greater than or e qual to 15 sec after the venting response in 9 instances and <15 sec a fterward in 16 instances. Eight of the 9 trials with delayed swallows (greater than or equal to 15 sec) were vented by secondary peristalsis , whereas 11 of the 16 with early swallows (<15 sec) were vented by TL ESR (X-2 P < 0.01). TLESRs may be induced by esophageal stimuli, in wh ich case they may represent ''wave-suppressed'' secondary peristaltic complexes.