Reconstruction of a partial esophageal defect using tunica vaginalis and buccal mucosa autograft: an experimental study in mongrel dogs

In veterinary clinics, esophageal reconstruction is essential in many clinical situations. In this study, two autografts, the tunica vaginalis (TV) and the buccal mucosa (BM), were proposed to reconstruct a semi-circumferential cervical esophageal defect in dogs. This study aimed to verify whether these two grafts could successfully patch esophageal defects. Twelve male mongrel dogs were divided into two groups. Following cervical esophagoplasty, the defective area was patched with either a TV or a BM graft. Comprehensive clinical, serum biochemical, and histological analyses were performed to evaluate the two grafts. Throughout the study (120 days), the dogs survived the procedure well with minor complications. The lumen of the patched areas was covered with mucosa, with slight scar retraction. Compared with that of the natural esophagus, the average relative luminal diameter was not significantly decreased. Importantly, the measured cortisol and inflammatory marker levels returned to the preoperative levels after 14 days. Although histological examination revealed that both grafts repaired the esophageal defect with complete re-epithelialization, the BM graft showed a histological structure similar to that of the natural esophagus. Both grafts effectively repaired the esophageal defect with minor complications; therefore, both are recommended as promising low-cost clinical alternatives for cervical esophagoplasty in dogs.

Reconstruction of thoracic esophagus with pediculated diaphragmatic flap in dogs

PURPOSE

To verify whether pediculated diaphragmatic flaps were suitable to correct iatrogenic wounds in dog's esophagus injuries.

METHODS

Seven dogs were submitted to resection of a segment of the esophageal wall, which was then corrected by suturing a pediculated diaphragm flap. Endoscopic evaluation of the esophageal wall was done forty days after the surgical procedure.

RESULTS

Three animals died, one due to implant ischemia, caused by strangulation of the phrenic artery; other due to wound infection; and the last, due to mediastinitis. Scar retraction was observed, however, there was no stenosis, allowing the passage of a 9,8 mm probe with no difficulty. The limits between the implants and the native esophagus were indistinguishable, and the implant was covered by esophageal mucosa.

CONCLUSION

The diaphragmatic flaps are suitable on the restoring of continuity in dog's thoracic esophagus.

Surgical reconstruction of partial circumferential esophageal defect in the dog

Partial circumferential reconstruction of the cervical esophagus was evaluated in the dog. An esophageal defect 5.85 +/- 1.15 cm in length involving one-half of the circumference was repaired by direct closure (group I), using longus colli muscle patch grafts (group II), and using grafts of longus colli muscle lined with buccal mucosa (group III). The incidence of leakage, fistula formation, luminal stricture, peristalsis disturbance, lining loss, the quality of surface restoration, bursting strength, and wound healing were evaluated. No fistula formation or leakage was observed in any animal. Direct closure of the defect was easier to perform, led to less inflammatory reaction, and resulted in the highest bursting strength. However, this method was associated with luminal stricture and swallowing difficulties. The longus colli muscle patch grafts (group II) were associated with a slight to moderate luminal stricture, but had more inflammatory reaction and graft surface area contraction (62%) compared to group III. The longus colli muscle lined with buccal mucosa caused no stricture and slight surface area contraction (8%). Mucosal grafts remained viable and no lining loss was observed. Despite the loss of peristalsis at the level of the graft in 25% of the group III dogs, no clinical signs or swallowing difficulties were observed.