DIAPHRAGM REPLACEMENT - AN EXPERIMENTAL A NIMAL STUDY

Background: Only a few indications exist for diaphragm replacement: ap lasias, tumours and accidents. The defect may be so extensive that it is impossible to close the gap. Allogenic and autologous materials are proposed for replacement of the diaphragm. The disadvantages of allog enic materials are recurrence rates of up to 20% and a high rate of ma lalignment of thoracic muscles and bones; the implication of autologou s materials requires a longer operation time and no long-term results exist. To avoid these disadvantages, we have tested a material from bo vine serosa, which is absorbable for a short time, for diaphragm repla cement. Methods: The merits of four methods of diaphragmatic hernia re pair were evaluated in animals. One hundred Spraque-Dawley rats underw ent laparotomy. The control group had an incision in the diaphragm wit h primary repair. The other four groups underwent partial resection of the left hemidiaphragm. The defects were repaired in 20 rats with lyo philized dura, in 20 with polytetrafluoroethylene (PTFE), in 20 with a utologous transversus muscle and in another 20 with absorbable serosa from a cow. The animals were followed up by electromyography (EMG) and post-mortem physical and histological examinations after 3 and 6 mont hs. Results: Eighty-nine animals survived the operations. The EMG show ed normal function for the absorbable material and the transversus mus cle. Only scanty physiological waves were recorded in the PTFE group. The examination for stretching and stress showed good results for all materials tested. The histological examinations showed strong foreign body reactions in the dura and PTFE groups. The absorbable bovine sero sa had vanished after 3 months postoperatively. Conclusion: We conclud e that bovine serosa can be recommended for the treatment of diaphragm atic defects.