Abstract
Introduction The treatment of esophageal atresia (OA) is challenging. The main goal is to achieve
primary anastomosis. We have previously demonstrated in a pig model that intramural
injection of botulinum toxin type A (BTX-A) resulted in significant elongation of
the esophagus during tensioning until bursting point. The objectives of the present
study were to investigate the influence of different amounts of intramural BTX-A on
the stretch–tension characteristics and histological changes of the esophagus in piglets.
Materials and Methods A total of 52 piglets were randomized to four groups receiving 2, 4, or 8 units/kg
of BTX-A or isotonic saline (placebo). After a 1-hour of rest the esophagus was harvested
and subjected to a stretch–tension test and histological examination to assess changes
in the density of presynaptic vesicles in the nerve cells.
Results Overall, 9 of the 52 animals were excluded from analysis due to problems with the
stretch–tension test or death from anesthesia. The maximum loads were higher in the
BTX-A groups (2 units/kg: +2.1 N; 4 units/kg: +1.3 N; 8 units/kg: +1.9 N) than the
placebo (p = 0.046). There were no significant differences in percentage elongation, or histology.
Conclusions This study demonstrated that injection of 2 units/kg BTX-A into a nonanastomosed
esophageal wall resulted in a modest increase in the maximum load achieved before
bursting; this may be due to the muscle-relaxant effect of BTX-A. BTX-A injection
produced no significant effects on elongation or esophageal histology. The clinical
usefulness of BTX-A in treatment of OA is still unclear.
Keywords
botulinum toxin type A - esophageal atresia - synaptophysin
