Cardia yield pressure measurement in an infant porcine model: a novel technique to evaluate the quality of laparoscopic fundoplication.

Background: Cardia yield pressure (CYP) has been described as a measure of the combined effect of all antireflux mechanisms and not simply as another test of lower esophageal sphincter pressure. In this paper, we present a simple technique for the measurement of CYP before and after fundoplication through laparoscopic gastrostomy in an experimental pig model.

Materials And Methods: Twelve 8-week-old female pigs with a mean weight of 8.7 +/- 0.7 kg underwent laparoscopic gastrostomy placement and Nissen fundoplication under general anesthesia. CYP was determined before and after the fundoplication by filling the stomach with water until reaching the pressure at which the cardia opened and became incompetent. Pre- and postoperative CYP was compared by using the Student's t-test for paired samples.

Results: Laparoscopic Nissen fundoplication and gastrostomy was completed in all pigs. CYP increased in all subjects after fundoplication, from a mean of 20 +/- 8 to a mean of 63 +/- 13 cm of H(2)O (p < 0.001). The lowest increase in yield pressure of 17.5 cm was recorded after the first operation. Work-flow analysis revealed that this particular procedure took the longest, that bleeding from the liver was encountered, and shorter sutures than those used on all subsequent fundoplications may have compromised knot tying.

Conclusions: CYP increases consistently after laparoscopic Nissen Fundoplication in young pigs. This parameter may be a good indicator of antireflux efficacy and functional quality of the result. Yield pressure measured through laparoscopic gastrostomy offers a new, feasible, and effective technique for the evaluation of antireflux surgery in an experimental setting. Moreover, this minimally invasive technique may become a simple investigative tool for other antireflux procedures.