A Comparative Study of Graft Materials in the Treatment of Paraesophageal Hernia in Dogs
Abstracts
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Background: Paraesophageal hernia (PEH) repair is associated with a radiological recurrence rate of 33%. Recurrence is thought to occur partly as a result of undue tension on the crural repair. Reducing tension on the crural repair through the use of mesh may result in reduction of hernia recurrence. Methods: Twenty-four mongrel dogs (mean weight 23.6 kg.) underwent resection of a 1 x 2 cm segment from each crus; the crural arch was left intact. Animals then underwent immediate repair using one of the following techniques: primary repair (n = 6), polypropylene mesh (n = 5), porcine small intestinal submucosa (SIS) biograft (n = 8), or dual-surface ePTFE (n = 5). Animals were survived for 6 weeks, and a contrast esophogram was carried out just prior to euthanasia. Not all animals survived 6 weeks. At necropsy, the presence of hernia and severity of adhesions to the mesh (0=3, 3= severe) was determined. Results: Animals undergoing primary repair had a 50% rate of subsequent hernia and only 2 animals survived the full 6 weeks. There were no recurrences in the polypropylene group, and only 1 in the ePTFE group (20%). In the 8 dogs undergoing SIS, 5 developed recurrent hernias (62.5%). In all SIS recurrences, the patch was found to have markedly contracted, pulling well away from the esophageal surface with enlargement of the neoesophageal hiatus. Compared to the other groups, the hernia rate with SIS was significantly higher (p<0.05, Fisher exact test). With respect to adhesions, the animals in the ePTFE group exhibited the least amount of adhesions (median = 1, range 0-1) when compared to SIS (median 3, range 2-3) and polypropylene (median 2, range 1-2, p<0.005). Esophograms demonstrated stenosis in one SIS animal and in one polypropylene animal. Conclusions: Primary cruroplasty in dogs is associated with a high incidence of recurrence. Improved outcomes can be achieved by using graft materials. Of the materials assessed in this study, polypropylene and ePTFE provided the best results, with ePTFE carrying the additional advantage of the fewest adhesions. |
