Surgical Correction of a Sinus Venosus Atrial Septal Defect with Partial Anomalous Pulmonary Venous Connections Using Cardiac Computed Tomography Imaging and a 3D-Printed Model.

Sinus venosus atrial septal defects (SVASDs), concurrent with partial anomalous pulmonary venous connections (PAPVCs), are a rare congenital heart disease in dogs. Surgical correction is essential when clinical signs or significant hemodynamic changes are present. We aimed to report on the successful surgical correction of an SVASD with PAPVCs, using a computed tomography (CT)-based customized 3D cardiac model. A 10-month-old male poodle was referred for corrective surgery for an ASD. Echocardiography confirmed a hemodynamically significant left-to-right shunting flow through an interatrial septal defect and severe right-sided heart volume overload. For a comprehensive diagnosis, a CT scan was performed, which confirmed an SVASD with PAPVCs. A customized 3D cardiac model was used for preoperative decision-making and surgical rehearsal. The defect was repaired using an autologous pericardial patch under a cardiopulmonary bypass (CPB). Temporary pacing was applied for sinus bradycardia and third-degree atrioventricular block. The patient recovered from the anesthesia without further complications. The pacemaker was removed during hospitalization and the patient was discharged without complications 2 weeks post-surgery. At the three-month follow-up, there was no shunting flow in the interatrial septum and the right-sided volume overload had been resolved. The cardiac medications were discontinued, and there were no complications. This report indicates the validity of surgical correction under CPB for an SVASD with PAPVCs, and the advantages of utilizing a CT-based 3D cardiac model for preoperative planning to increase the surgical success rate.

Partial Venous Inflow Occlusion under Mild Hypothermia for Membranectomy in a Dog with Cor Triatriatum Dexter.

Cor triatriatum dexter (CTD) is an uncommon congenital cardiac anomaly in dogs. This case report describes successful membranectomy for CTD via partial venous inflow occlusion under mild hypothermia in a dog. A 7-month-old intact male mixed-breed dog weighing 20.5 kg presented with a history of abdominal distention, lethargy, and anorexia. Clinical examination, radiography, echocardiography, microbubble testing, and computed tomography revealed a remnant right atrium membrane obscuring the venous blood inflow from the vena cava. Considering the potential risk of re-stenosis following interventional treatment, curative resection involving surgical membranectomy via venous inflow occlusion was performed. By performing partial venous inflow occlusion under mild hypothermia (34.5 °C), sufficient time was obtained to explore the defect and resect the remnant membrane. The dog recovered without any complications, and the clinical signs were relieved. This case illustrates that partial venous inflow occlusion under mild hypothermia is feasible for achieving curative resection of cor triatriatum dexter in dogs.

Open-heart surgery using Del-Nido cardioplegia in two dogs: partial atrioventricular septal defect and mitral repair.

Del-Nido cardioplegia (DNc) is a single-dose cardioplegia that is widely used in human medicine because of its long duration. In this report, we describe two cases of open-heart surgery with cardiopulmonary bypass (CPB) using DNc. One dog was diagnosed with partial atrioventricular septal defect, and the other dog was diagnosed with myxomatous mitral valve disease stage D. Both dogs were treated with open-heart surgery with DNc to induce temporary cardiac arrest. No complications from DNc were observed, and the patients were discharged. Veterinary heart surgeons should consider DNc as an option for temporary cardiac arrest during open-heart surgery with CPB.

Granulomatous Inflammation and Pericarditis Induced by Silk Granuloma Related to Previous Surgical Ligation of Patent Ductus Arteriosus in a Dog.

Surgical ligation of a patent ductus arteriosus is regarded as a standard treatment approach with a low complication rate if performed by experienced surgeons, and it has been performed successfully for decades in dogs. However, there are no reports describing the clinical symptoms related to granulomatous inflammation after the surgical ligation of the patent ductus arteriosus. This report describes the clinical symptoms caused by granulomatous inflammation and subacute pericarditis in a dog that had undergone the surgical closure of a patent ductus arteriosus 2 years previously. Exploratory thoracotomy was performed for subtotal pericardiectomy, and a biopsy was performed to obtain specimens for histopathological examination and culture tests. The clinical symptoms were relieved after surgery. The persistent leukocytosis improved with steroid administration. This case illustrates that the granulomatous inflammatory response associated with silk suture granuloma is a rare postoperative complication of ductal ligation. In such cases, pericardiectomy can help relieve the clinical symptoms.

Retroperitoneal Metastatic Apocrine Gland Ductal Adenocarcinoma in a Beagle Dog.

Tumors of sweat glands usually originate from apocrine glands and can develop throughout the body but are rare in dogs. This report describes the retroperitoneal metastasis of primary cutaneous apocrine adenocarcinoma. An 8-year-old, spayed female beagle dog, weighing 11.7 kg, presented with a history of anorexia, hypodynamia, and weight loss. Clinical examination, radiography, ultrasonography, and computed tomography revealed a skin mass on the dorsum of the right metatarsal region, an enlarged ipsilateral popliteal lymph node, and a retroperitoneal mass. Fine-needle aspiration cytology of the popliteal lymph node suggested metastasis of an apocrine sweat gland tumor. Surgical excision of the skin mass, popliteal lymph node, and retroperitoneal mass was performed. The retroperitoneal mass was diagnosed as a metastasis of primary cutaneous apocrine adenocarcinoma. Immunohistochemistry revealed that the tumor cells were positive for cytokeratin 7 but negative for cytokeratin 20 and S100 proteins. There were no postoperative complications, except for temporary hindlimb edema, including local recurrence or metastasis, in the 6-month postoperative follow-up period. This case illustrates that although malignant apocrine gland tumors are rare in dogs, a wide resection of primary cutaneous apocrine gland adenocarcinomas is recommended because of the risk of local invasion or distant metastasis.

Successful mitral repair in dogs by mitral annuloplasty using Hegar dilator: two case reports.

Mitral regurgitation (MR) is the most common heart disease in small-breed dogs. Mitral repair, which comprise artificial chorda tendineae implantation and mitral annuloplasty, has become the mainstay of treatment in the veterinary field. We report on two small dogs who underwent mitral repair surgery for MR. A Hegar dilator was used during mitral annuloplasty for accurate and reproducible surgery. In both cases, mitral regurgitant flow almost disappeared after surgery, and clinical signs improved. The treatment regimen was terminated 3 months after the surgery. We concluded that using a Hegar dilator may facilitate mitral valve repair surgery.