Use of pericardial patch graft reconstruction of the right atrium for treatment of hemangiosarcoma in a dog

Atrial mass resection is possible in a limited number of dogs with hemangiosarcoma in which only the right atrial appendage or atrial free wall is involved, A pericardial patch graft can be used to reconstruct the right atrium after resection of large atrial tumors. Tumor-free margins can be obtained by use of this technique.     

Pericardial effusion in a dog with rhabdomyosarcoma in the right ventricular wall

A seven-year-old male labrador retriever presented in right heart failure with weak femoral pulses, and pleural, abdominal and mild pericardial effusion. No diagnosis could be established initially. Two days later, the dog developed severe pericardial effusion causing cardiac tamponade. A tumour in the right ventricular wall was visualised on ultrasonographic examination. An exploratory thoracotomy was performed and biopsies of the mass submitted for histopathological examination. A diagnosis of rhabdomyosarcoma arising from the myocardium was established. Cardiac rhabdomyosarcoma has been reported in only two dogs. Neither report was associated with pericardial effusion.     

Echocardiographic results and clinical considerations in dogs with right atrial/auricular masses

The case records of 26 dogs with pericardial effusion were examined. Sixteen dogs with confirmed right atrial/auricular masses were found. Eighteen masses were identified, of which 16 were confirmed as hemangiosarcomas. Eleven dogs had an abnormal mass detected during the echocardiographic examination, and tumor location was correctly predicted in nine of the 11 dogs. Six of seven tumors, which were not detected during the echocardiogram, were located in the right auricle. Pericardial effusion was apparently not necessary for the echocardiographic detection of a right atrial/auricular mass. Of ten dogs with pericardial effusion due to causes other than a cardiac mass, one abnormal mass-like lesion was seen during echocardiographic examination.     

Pericardial effusion and cardiac tamponade caused by intrapericardial granulation tissue in a dog

Objective – To describe and report successful surgical management of pericardial effusion and cardiac tamponade in a dog caused by intrapericardial granulation tissue.
Case Summary – An 8-month-old, intact male, Greater Swiss Mountain Dog was referred for cardiac evaluation following 2 weeks of progressive lethargy, abdominal distention, and difficulty breathing. On the day of presentation, the dog had an episode of acute collapse. A 14-cm multilocular pericardial cystic lesion causing collapse of the right atrial free wall and resulting in pericardial tamponade was observed on echocardiogram. After the dog subsequently experienced two acute episodes of pericardial effusion, a subtotal pericardectomy was performed and clinical signs resolved. The histopathologic diagnosis of the mass was inflammation and granulation tissue, likely caused by a resolving hematoma or abscess.
New or Unique Information Provided – This is the first report of intrapericardial granulation tissue as the cause of pericardial effusion and cardiac tamponade.     

IMAGING DIAGNOSIS—INTRAPERICARDIAL RIGHT AURICLE ANEURYSM IN A DOG

An 11‐year‐old, male, Pekinese was examined because of a sporadic, nonresponsive, nonproductive cough. Radiographically there was cardiomegaly and a soft tissue mass in the cranial mediastinum. Echocardiographically, chronic degenerative valvular disease was diagnosed. Furthermore, a large anechoic structure located cranial to the right atrium was detected. Computed tomography was performed to define the mediastinal mass and a right auricle aneurysm was diagnosed. The dog died suddenly 1 day after the diagnostic imaging procedures. At necropsy, a right auricular aneurysm without discontinuity of the pericardial sac was confirmed. Intrapericardial right auricular aneurysm should be included in the differential diagnoses of cranial mediastinal masses.     

Partial Right Ventriculectomy Using the Incised Patch Technique to Treat Double Chambered Right Ventricle and Chylothorax in a Cat

Objective— To report successful surgical treatment of double chambered right ventricle (DCRV) in a cat.
Study Design— Clinical report.
Animals— Cat with DCRV.
Methods— DCRV was diagnosed in a 5-month-old male Maine Coon cat using echocardiography and angiocardiography. At 2 years, despite medical therapy, chylothorax developed. A section of the right ventricular free wall that spanned the fibromuscular obstruction was excised under total venous inflow occlusion (TVIO) using the incised pericardial patch technique.
Results— Short-term recovery was complicated by return of chylothorax but this resolved after thoracocentesis and diuretic therapy. Three years after surgery, the cat is free of clinical signs and no longer on any medical therapy.
Conclusions— Partial right ventriculectomy can be performed under TVIO through an incised pericardial patch.
Clinical Relevance— DCRV in cat can be successfully treated by partial right ventriculectomy performed under TVIO through an incised pericardial patch.     

Aneurysmal dilatation of the right auricle in two dogs

An 8-year-old sexually intact male Golden Retriever with a history of collapse during exercise underwent an examination during which tachydysrhythmia was identified. At another institution, a 12.5-year-old spayed female Lhasa Apso was referred because of a cough and for evaluation of a heart murmur. In the Golden Retriever, radiographic examination revealed bulging of the craniodorsal aspect of the cardiac silhouette and echocardiography revealed right atrial dilatation. In the Lhasa Apso, a cranial mediastinal mass was suspected on the basis of radiographic findings, but no abnormalities were detected echocardiographically. In both dogs, nonselective angiography and contrast-enhanced computed tomography revealed a markedly enlarged, thin-walled right auricle. Exploratory thoracotomy in the Golden Retriever revealed a defect in the pericardium through which the right auricle and part of the atrium had herniated. In dogs, a right auricular aneurysm should be considered in differential diagnoses of a cranial mediastinal mass (detected radiographically) adjacent to the cardiac silhouette.     

Pneumopericardium associated with a pulmonary-pericardial communication in a dog

A 6-year-old 18-kg (39-lb) spayed female Standard Poodle was referred for treatment of pneumopericardium. The dog did not have severe clinical signs relating to the pneumopericardium, and the diagnosis was made incidentally while investigating the cause of a cough. Computed tomography revealed an air-filled structure consistent with a bulla to the right of the heart base that appeared to communicate with the pericardial cavity Because spontaneous resolution of the pneumopericardium seemed unlikely and cardiac tamponade was a possibility, exploratory thoracotomy was performed. A lobulated bulla was found at the hilus of the right middle lung lobe adhered to the underlying pericardial sac, and a 4-cm-diameter communication from the pericardium to the pulmonary bulla was found. Right middle lung lobectomy was performed, and the pericardiotomy and pericardial opening were sutured. The dog recovered without complications. In previously reported cases of pneumopericardium involving a cat and a dog, the condition resolved spontaneously. In this dog, in contrast, surgical resection of the affected lung lobe with pericardial reconstruction was required for resolution of the pneumopericardium.     

Echocardiography and Surgery in a Dog With Left Atrial Rupture and Hemopericardium

Endocardial splitting and left atrial rupture were diagnosed in a dog with mitral regurgitation that experienced the sudden onset of collapsing episodes, weakness, depression, labored breathing, and weak pulses. Thoracic radiographs showed a rounded cardiac silhouette with prominent left atrium consistent with hemopericardium due to left atrial rupture. Two-dimensional echocardiography confirmed the presence of severe mitral valve disease, pericardial fluid, and a laminated blood clot caudal to the left ventricle. A sterile emergency thoracotomy was performed, the hemopericardium and blood clot were removed, and the rupture site in the left atrium was repaired with reinforced sutures. The dog recovered from surgery but died the next day, presumably from a ventricular arrhythmia.     

Canine cardiac mesothelioma with granular cell morphology

Cardiac mesothelioma with granular cell features was diagnosed in a 10-year-old Golden Retriever presenting with pericardial and abdominal effusions. The diagnosis was based on gross, morphologic, and immunohistochemical features. The immunohistochemical profile of the neoplasm was pancytokeratin positive, vimentin positive, and S-100 negative; most gross and morphologic features were consistent with both mesothelioma and granular cell tumor. To the authors' knowledge, the prognosis for either primary cardiac mesothelioma or granular cell tumor in the dog is unknown. At 4 months after thoracotomy, pericardectomy, and mass excision, this dog was alive and without clinical evidence of pericardial or abdominal effusions. We describe a granular morphologic variant of cardiac mesothelioma in a dog.     

Successful Management of Traumatic Right Atrial Rupture

A 2 year old male mixed breed dog presented with clinical signs of acute cardiac tamponade after being hit by a car. Echocardiography confirmed the presence of pericardial effusion. Pericardiocentesis revealed venous blood that clotted normally, suggestive of an acute lesion involving the right side of the heart. An emergency thoracotomy was performed, and a laceration of the right atrium was identified and repaired. Postoperatively, the dog developed traumatic myocarditis that improved with time and medical management. Six months after surgery, the dog was healthy with no adverse effects of the trauma. The importance of early recognition and the necessity for expeditious surgical management of traumatic right atrial rupture in the dog is illustrated in this report.     

Pericardial lipoma in a geriatric dog with an incidentally discovered thoracic mass

An intrathoracic mass was discovered as an incidental finding in a 14-year-old, spayed, female Rottweiler cross during evaluation of urinary incontinence. Computed tomography suggested a pericardial or pleural location and high adipose content of the mass. The mass was removed via lateral thoracotomy with partial pericardectomy and was diagnosed as a pericardial lipoma. The dog recovered well, and there was no evidence of recurrence approximately one year later. Adipose tumours of the heart and its associated structures are rare in dogs and have been associated with both successful and fatal outcomes.     

DETECTION OF CARDIAC MASSES IN DOGS BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY

From a two-year review of diagnostic two-dimensional real-time echocardiographic studies, a diagnosis of cardiac mass lesion was made in 18 dogs. Thirteen of 18 also had pericardial effusion. Three types of lesions were identified: (1) right atrial masses (7 dogs; 5 confirmed as hemangiosarcoma) originating from the wall of the right atrium of right auricle and projecting into the atrial lumen, pericardial space, or both; (2) large cavitary pericardial masses (2 dogs; both confirmed as abscesses) located over the right ventricle; (3) heartbase masses (9 dogs; 6 confirmed as neoplasms) attached to the ascending aorta, with varying degrees of infiltration of heartbase structures. Although extrapericardial portions of the masses were not outlined as well as intrapericardial portions, surgical accessibility was correctly predicted in most dogs. It was concluded that two-dimensional echocardiography (2DE), performed systematically using multiple imaging planes, allowed accurate detection and localization of cardiac and pericardial masses in dogs and was useful in predicting surgical accessibility of these lesions.     

Echocardiographic,thoracic ultrasonographic,and CTA diagnosis of pericardial neoplasia in a dog

A 12-year-old male neutered Yorkshire Terrier presented for coughing and respiratory distress. Transthoracic echocardiography initially misdiagnosed the patient with pericardial effusion; repeat echocardiography increased suspicion for neoplasia. A definitive diagnosis was not apparent. Findings on thoracic computed tomography and thoracic ultrasound were consistent with a diffusely thickened, heterogenous, hypoechoic soft tissue structure surrounding the heart. Fine needle aspirates were obtained using ultrasound guidance and routine cytology of the intrapericardial mass was consistent with neoplasia, with pericardial mesothelioma most likely. These novel findings highlight the importance of thoracic ultrasound and potential limitations of echocardiography in diagnosis of pericardial neoplasia.     

Right cranial lung lobe torsion after a diaphragmatic rupture repair in a Jack Russell terrier

A seven-year-old male Jack Russell terrier was presented with a history of coughing, generalised weakness and lethargy 10 days after an abdominal coeliotomy to repair a large diaphragmatic rupture. Thoracic radiographs demonstrated a soft tissue mass in the midcaudal right thoracic cavity. Ultrasonographic studies, bronchoscopy and subsequent exploratory thoracotomy confirmed a diagnosis of a right cranial lung lobe torsion (LLT), with an anomalous caudodorsal displacement of the affected lobe. LLT should be considered as a differential diagnosis for respiratory tract disease following diaphragmatic rupture repair.     

Constrictive pericarditis in a mare: attempted treatment by partial pericardiectomy.

Chronic constrictive pericarditis was diagnosed in a 6-year-old Thoroughbred mare based on the clinical findings of right congestive heart failure, hyperechoic pericardium without pericardial effusion, and a dip-and-plateau shape of the right ventricular pressure curve with equilibration of the diastolic pressures in all cardiac chambers. Treatment was attempted by partial pericardiectomy using a right lateral thoracotomy approach. Because of severe epicardial involvement recurrence of the constrictive pathology was noted 6 weeks after the surgical procedure. However, in selected cases in which the disease process is limited to the pericardium, partial pericardiectomy may offer a mode of therapy in horses suffering from constrictive pericarditis.     

Percutaneous balloon pericardiotomy for the management of malignant pericardial effusion in two dogs

Two dogs with signs of right-sided congestive cardiac failure, due to recurrent pericardial effusion secondary to the presence of intraperi-cardial neoplasia, were treated by percutaneous balloon pericardiotomy. The first patient was euthanased one month after the procedure while the second patient developed ascites as a result of obstruction of the caudal vena cava by the growing tumour and was euthanased 14 weeks after the procedure. In neither case was there a recurrence of a significant volume of the effusion. Percutaneous balloon pericardiotomy represents an effective means of relieving recurrent malignant pericardial effusion, without resorting to thoracotomy.     

Experimental study of materials for patch graft on right ventricular outflow tract under extracorporeal circulation in dogs--comparison between Denacol EX-313-treated bovine jugular vein graft and expanded polytetrafluoroethylene (EPTFE) graft

A comparison between a bovine jugular vein treated with a hydrophilic polyepoxy compound cross-linker (Denacol), and expanded polytetrafluoroethylene (EPTFE), an artificial material, as a patch graft for the reconstruction of the right ventricular outflow tract under extracorporeal circulation in dogs, as if they had pulmonic stenosis, was made. Hemodynamic and histological examinations were conducted two weeks after the transplantation. Hemodynamic problems were not observed in either the Denacol or EPTFE groups. Macroscopically, organization of new tissue on the graft surface was more marked in the EPTFE group than in the Denacol group, and newly-formed tissue was seen surrounding the border of the graft and burying it in the EPTFE group. In the Denacol group, microscopic findings revealed the presence of inflammatory cells and fibroblasts, and an invasion of the graft by collagen fibers and elastic fibers. In the EPTFE group, there was minimal cellular infiltration of the graft and a thick layer consisting of collagen fibers and fibroblasts was observed around the graft. These results indicated that two weeks after transplantation the graft was better assimilated and organized with blood vasculature in the patch graft in the Denacol group than in the EPTFE group.     

Macroscopic Anatomy of the Great Vessels and Structures Associated with the Heart of the Ringed Seal (Pusa hispida)

The ringed seal [Pusa (Phoca) hispida], as well as other seals, exhibits unique anatomical properties when compared to its terrestrial counterparts. In the ringed seal, the most conspicuous marine adaptation is the aortic bulb. This large dilatation of the ascending aorta is comparable to that found in other seal species and marine mammals. The branches of the ascending aorta (brachiocephalic trunk, left common carotid artery and left subclavian artery) are similar to those of higher primates and man. The peculiarities of the venous system are: three pulmonary veins, a pericardial venous plexus, a caval sphincter, a hepatic sinus with paired caudal vena cavae and a large extradural venous plexus. Generally, three common pulmonary veins (right, left and caudal) empty into the left atrium. The pericardial venous plexus lies deep to the mediastinal pericardial pleura (pleura pericardica) on the auricular (ventral) surface of the heart. The caval sphincter surrounds the caudal vena cava as it passes through the diaphragm. Caudal to the diaphragm, the vena cava is dilated (the hepatic sinus), and near the cranial extremity of the kidneys, it becomes biphid. The azygos vein is formed from the union of the right and left azygos veins at the level of the 5th thoracic vertebra. Cardiovascular physiological studies show some of these anatomical variations, especially of the venous system and the ascending aorta, to be modifications for diving. This investigation documents the large blood vessels associated with the heart and related structures in the ringed seal.