Value of ultrasound for evaluation of postoperative vomiting as a complication of endoscopic sphincterotomy in the treatment of congenital hypertrophic pyloric stenosis

Abstract

Objective To investigate the value of ultrasound for evaluation of postoperative vomiting as a complication of endoscopic sphincterotomy in the treatment of congenital hypertrophic pyloric stenosis(CHPS).Methods A review of 30 pediatric cases of CHPS in our hospital from January 2006 to November 2009 was conducted on postoperative coffee-ground vomiting and related treatment.as well as study with ultrasound regarding the length and morphological characteristics of the pyloric canal,thickness of the mucous layer(including submucosa)and the muscular layer,and patency of the pyloric canal upon arrival of gastric peristaltic wave.Results Except for 4 children(group A),26 of the 30 children presented postoperative vomiting,of whom,17 experienced obvious relief or resolution with conventional conservative treatment (group B) , whereas the remaining 9 did not respond and subsequently needed a second operation (group C). Postoperative coffee-ground vomit was noted in a total of 16 patients from group B or C, which disappeared with conservative treatment. There was no statistical difference in thickness of raucous layer of children among the groups A, B and C before operation and one week after operation, nor was in length of pyloric canal between groups A and C, and in thickness of pyloric muscular layer between groups B and C. The pyloric muscular layer in group A or the length of pyloric canal in group B was significantly reduced at one week after operation as compared with before operation [group A:(9.03±2.67) mm vs (8.38±2.59) mm, group B:(18.70±3.90) mm vs(16.66±3.00) mm, all P＜0.05]. The patency of pyloric canal was well in group A, inadequate in group B (with minimal passage of fluids through pylorus) , and poor in group C (delayed emptying of the stomach with occasional opening of a slit-like pylorus). Only 2 of 16 patients with coffee-group vomiting from group B or C showed grooves at the mucosa of pylorus canal where incision was performed, as did only another 2 of the 10 patients who presented non coffee-group vomiting. Conclusions Ultrasound can identify the cause and guide the treatment of postoperative vomiting, but can not be useful for differentiating the cause of coffee-ground vomiting. Key words: Ultrasonography; Pyloric stenosis, hypertrophic; Vomiting; Gastroscopy; Sphincterotomy, endoscopic