Are scintiscans accurate in the selection of reflux patients for pyloroplasty?

Abstract

Background: Gastric emptying scintiscans are currently used to select reflux patients for added pyloroplasty at the time of fundoplication. The accuracy of this scan selection approach has been assumed. If preoperative scintiscans do not reliably predict postfundoplication gastric emptying, however, the decision to add pyloroplasty to the fundoplication operation may be inappropriate and even harmful.

Methods: The authors studied 27 children prospectively before and after gastric fundoplication. Gastric emptying at 60 minutes was measured by double isotopic labeling of liquid (111In) and solid (99mTc) phases of a test meal specifically designed for label fixation. The authors' question involved the accuracy of preoperative gastric scintiscans in predicting postfundoplication delay of gastric emptying (DGE). An evaluation of pyloroplasty as an effective treatment for DGE was not part of the study design. Pyloroplasty was performed as a secondary operation in three of the study children, however, because they persisted with unrelieved symptoms of retching, fullness, and abdominal discomfort. Scintiscan-documented postfundoplication delay in gastric emptying was present in all three patients at 18, 58, and 12 weeks, respectively. Additional scintiscans were performed in these patients after pyloroplasty.

Results: Gastric emptying of solids at 60 minutes did not show a significant change after a gastric fundoplication operation, although the trend was in the direction of a decrease (paired t test, P= .13). Liquid emptying at 60 minutes, however, was significantly increased (paired t test, P = .01). The variation in values between patients was wide, and the correlation between pre- and postoperative study results in the same patient was poor (r2 = 0.337 for solids and r2 = 0.116 for liquids). Most unexpectedly, scintiscans after postfundoplication pyloroplasty in the three patients with persistent symptoms showed no improvement in delayed gastric emptying on repeat scintiscan 42 to 117 weeks later.

Conclusions: The data suggest that preoperative scintiscan evidence for postfundoplication DGE is probably accurate for solid emptying but not for liquids, at least as measured by the double isotope methodology of our study. Preoperative scintiscans that use a liquid phase label only may be highly misleading for the prediction of postfundoplication DGE. Furthermore, pyloroplasty may not be useful as treatment even when postfundoplication delay in gastric emptying can be accurately anticipated or confirmed. A fundamental motility disorder of the gastric body seems to be more important than muscular resistance at the gastric outlet as a cause for postfundoplication DGE, and the most effective treatment approach remains unclear.