Comparative Study Of Modified Pyloromyotomy And H-M Pyloroplasty In Radical Proximal Gastrectomy

ObjectiveEsophagogastrostomy after proximal gastrectomy(PG-EG)is one of the most commonly used surgical methods for adenocarcinoma of esophageal-gastric junction(AEJ).The cutting of vagus nerve during operation leads to a constant spasm of the pyloric sphincter,resulting in the gastric emptying disorder.Clinically,H-M pyloroplasty(Heineke-Mikuliez pyloroplasty)is often operated after PG-EG to prevent delayed gastric emptying,but this operation causes more serious bile reflux,which could aggravate gastroesophageal reflux and seriously affect the quality of life of patients after operation.The modified pyloromyotomy only cuts the seromuscular layer of the pyloric ring and retains the mucosal layer.The operation has the advantages of small injury,simple operation,no increase in the tension of residual gastric esophageal anastomosis,less anastomotic leakage and no increase in the risk of abdominal infection.The purpose of this study is to compare the effects of modified pyloromyotomy and H-M pyloroplasty on relieving gastric emptying disorder,controlling bile reflux and improving quality of life after proximal gastrectomy.Methods1.In the clinical study,we retrospectively analyzed the clinical data of 73 patients with AEJ from January 2016 to August 2020,including 39 patients who underwent proximal gastrectomy with H-M pyloroplasty(HM group)and 34 patients who underwent proximal gastrectomy with modified pyloromyotomy(PM group).The Intraoperative short-term and long-term postoperative variables were compared between the two surgical methods in alleviating gastric emptying,controlling bile reflux and improving quality of life.The observation indexes included: operation time,estimated blood loss,hospital stay time;the incidence of postoperative complications: anastomotic leakage,anastomotic bleeding,gastric emptying disorder and abdominal infection;gastroscopy,quality of life score,use of anti gastric acid drugs.2.In the animal experiment,the animal model of gastric emptying disorder was established by cutting off the vagus nerve of SD rats.48 SD rats were randomly divided into four groups(n = 12): simple vagotomy group(V group),vagotomy + Heineke-Mikulicz pyloroplasty group(HM group),vagotomy + Modified pylorus myotomy group(PM group)and control group(O group).The effects of modified pyloromyotomy and H-M pyloroplasty on improving gastric emptying and controlling bile reflux were recorded and compared respectively,and histopathological examination of the healed pylorus ring was did to find how gastric emptying disoeder and bile reflux was control.The observation indexes included: gastric emptying rate,postoperative eating and weight changes,mucosal bile acid concentration gradient in different parts,gastric mucosal pathology,and postoperative pyloric section pathology.Results1.In the retrospective clinical study,there was no significant difference in operation time and bleeding volume between the patients with proximal gastrectomy and esophagogastrostomy combined with modified pylorus myotomy(PM group)and the patients with H-M pyloroplasty(HM group)(P values were 0.287,0.485respectively);There was no significant difference in short-term postoperative complications(gastric emptying disorder,anastomotic fistula,etc.)(P values were 1.00and 0.422 respectively);In terms of long-term complications,the incidence of bile reflux was lower than that in H-M pyloroplasty group(P=0.017);In terms of quality of life score,PM group scored higher than HM group in heartburn,abdominal distension after meals and the number of meals(P values were 0.042,0.025 and0.045respectively).2.In the animal experiment,the circumference of pyloric ring after operation in HM group and PM group was significantly greater than that before operation(P values were less than0.001),but there was no significant change in V group and O group(P values were 0.459 and0.767,respectively);The half-hour gastric emptying rate(%)in HM group and PM group was higher than that in V group(P values were 0.037 and 0.021 respectively),but there was no significant difference between HM group and PM group(P value was 0.681);The bile acid concentration of gastric mucosa in HM group was significantly higher than that in PM group,V group and O group(P<0.001).3.The pathological study showed that the gastric mucosa in HM group was yellow stained in the antrum,with inflammatory cell infiltration.The surface of gastric mucosa in PM group was smooth without obvious congestion ulcer.In group V,the mucosa was thinner and the wrinkled wall was reduced.The surface of gastric mucosa in group O was smooth and light red,without congestion,erosion and ulcer.The pyloric anatomical structure was completely destroyed and the mucosal layer was interrupted in HM group,while in PM group,the mucosal layer was continuous,the muscle layer healed regularly,and the scar tissue filled the defect of pyloric ring to make the pyloric ring continuous.Conclusion1.The modified pyloromyotomy is safe and effective.It can reduce the incidence of gastric emptying disorder after proximal gastrectomy and residual gastroesophageal anastomosis.The effect is equivalent to that of Heineke Mikulicz pyloroplasty.2.Compared with Heineke Mikulicz pyloroplasty,modified pyloromyotomy can reduce the incidence of bile reflux after proximal gastrectomy and residual gastroesophageal anastomosis to a certain extent,and can reduce postoperative heartburn,abdominal distension.3.The anti-bile reflux function of modified pyloromyotomy is related to the fact that the pyloromyotomy preserves the intact mucosal muscle layer of the pyloric ring and the contractile function of the pyloric ring muscle after scar healing.