Partial cardiomyectomy--an animal model of gastro-oesophageal reflux

Various procedures have been adopted to provide experimental models of gastro-oesophageal reflux. Although some procedures have produced better results than others, previous literature does not assert that experimental gastro-oesophageal reflux can be produced reliably in all animals. This study attempts to compare two procedures to produce a working model of gastro-oesophageal reflux in the rabbit: (i) cardiomyotomy and (ii) cardiomyectomy. The animals underwent intraoesophageal pH monitoring one week before and one week following surgery. The mean changes in % reflux time from preoperative to one week postoperative were compared. The cardiomyotomy group did not demonstrate significant gastro-oesophageal reflux (p > 0.2, p < 0.5), the mean change in % reflux time was 10.5 +/- 14.11%, whereas the cardiomyectomy group did demonstrate significant reflux (p < 0.001) with a mean change in % reflux time of 22.35 +/- 3.05%. A further study investigated the cardiomyectomy procedure in ten rabbits. Animals underwent preoperative, one-week and four-week postoperative intraoesophageal manometry and pH studies. The mean change in values from preoperative to four weeks postoperative were compared. There was a significant increase in mean % reflux time from a preoperative value of 3.05 +/- 2.29% to 42.08 +/- 12.05% at four weeks after surgery (p < 0.001). There was also a significant decrease in mean basal LOS pressure from a preoperative value of 15.00 +/- 5.49 mmHg to 4.45 +/- 1.90 mmHg four weeks following surgery (p < 0.001). This study showed that cardiomyectomy alone produces effective gastro-oesophageal reflux in the rabbit, and thus provides an experimental model to test the effectiveness of antireflux procedures.