[Effects of diaphragmatic plication in the antireflux barrier in rats].

INTRODUCTION

There is increasing evidence of frequent occurrence of gastroesophageal reflux (GER) in patients surviving operations for congenital diaphragmatic hernia (CDH) and diaphragmatic eventration (DE). The murine model allows to study the behavior of the components of antireflux barrier.

AIM

To study the changes introduced in esophageal-gastric junction by DE due to cervical transection of the left phrenic nerve and subsequent plication of the paralyzed diaphragm.

MATERIAL AND METHODS

Adult male Wistar rats were divided into two groups: in one we measured the pressure conditions before and after phrenic nerve section (PNS) and in the other we evaluated such conditions in PNS rats before and after diaphragmatic plication (DP).

RESULTS

Phrenic transection significantly lowered inspiratory pressure gradient (IPG), (2.79 +/- 1.05 vs 4.43 +/- 1.03, p < 0.05), without changes in expiratory pressure gradient (EPG) (0.31 +/- 1.03 vs 0.25 +/- 1, p > 0.05), or lower esophageal sphincter pressure (LESP) (20.88 +/- 7.73 vs 15.88 +/- 9.25, p > 0.05). Plication of the diaphragm reestablished normal IPG (4.04 +/- 0.75 vs 2.58 +/- 0.51, p < 0.05) while increased EPG (1 +/- 0.75 vs -0.32 +/- 1.05, p < 0.05) and decreased LESP (10.59 +/- 5.74 vs 17.15 +/- 5.59, p < 0.05).

CONCLUSION

Paralyzed diaphragmatic eventration lowered inspiratory gradient pressure; diaphragmatic plication reestablished this gradient, but decreased LESP and increased expiratory gradient pressure. These modifications may contribute to induce GER.