[Clinical study on responses of the upper esophageal sphincter after subtotal esophagectomy for esophageal cancer].

Responses of the upper esophageal sphincter (UES) to distention of the esophageal wall by use of a balloon catheter were measured in 30 patients after subtotal esophagectomy for esophageal cancer and 33 volunteers with unrelated disorders (control group). Patients were divided into extended dissection group and non-extended dissection group according to the width of lymph node dissection, or palsy group and non-palsy group according to recurrent-laryngeal nerve palsy. The resting upper esophageal sphincter pressure (UESP) and the upper esophageal sphincter contraction (UESC) following UES induced by swallowing were measured after esophageal distention. Neither of UESP nor UESC without distention was significantly different among each group. But those of the extended dissection group and palsy group after esophageal distention were significantly lower values than those of control group. These findings suggest that responses of the UES to distention of esophageal wall are decreased, thus protection against aspiration is probably decreased.