Surgical technique and evaluation of the incidence of intraoperative and postoperative complications following surgical management of Porto Azygos Shunt attenuation in Thoracoscopy

Congenital extrahepatic portosystemic shunts (CEPSS) frequently occur in small breed dogs, approximately 25% of CEPSS cases terminate on the azygos vein within the thoracic cavity, known as portoazygos (PA) shunts. They are conventionally attenuated intra-abdominally. The aim of this study is to evaluate the PA shunt attenuation by cellophane band using thoracoscopic approach in twelve dogs.The patients were positioned in sternal position, and three incisions were made, with 11 out of 12 cases having incisions at the levels T9, T10, and T11 on the right side, while in 1 case, incisions were made at T7, T8, and T9 on the left side. In all instances, the shunts were secured using a 4mm cellophane band. Thoracoscopic exploration allowed to identify the PA shunt close to the azygos vein. The aberrant vessel was dissected and isolated for at least 2 cm. A 4-mm-wide triple-layer cellophane band previously prepared was placed around the vessel using a right-angled forceps. Two clips were applied in an alternating manner from both sides of the cellophane aiming to achieve the shunt correct attenuation. After thoracoscopic procedure in 3 of 12 cases were done laparoscopic liver biopsy. The patient was changed position, it was in dorsal recumbency, optica of 5 mm 30° was positioned in preumbelical site and forceps for biopsy in right position. In 12 dogs, no intraoperative or postoperative complications were observed. The average surgical duration was 45 minutes (range: 26-90 minutes) for 9/12 cases, while the surgical duration time was 45, 50, 60 minutes for the 3/12 cases were the laparoscopic liver biopsy was associated. In one case, a follow-up total body CT scan revealed shunt patency, prompting subsequent surgical ligation of the shunt.The mean follow-up period was 389 days (range: 14-820 days). At the conclusion of the follow-up, all patients were alive and exhibited no sign associated with the PA shuntThoracoscopy offers a direct path to the terminal PA shunt with minimal soft tissue dissection. Cellophane bands application to the PA shunt using thoracoscopic approach appears to be feasible.