Budd–Chiari-like syndrome in a dog with a chondrosarcoma of the thoracic wall

Objective: To describe a dog with Budd–Chiari‐like syndrome secondary to caudal vena cava compression from a thoracic wall chondrosarcoma. Case summary: A 9‐year‐old spayed female Shetland Sheepdog cross with a recent history of non‐productive cough developed severe abdominal distension and dyspnea. Marked ascites and enlarged hepatic veins were identified with ultrasonography. At surgery, a right thoracic wall mass was found to be compressing the caudal vena cava. Fluid analysis of the ascites revealed a modified transudate with elevated protein concentration, consistent with Budd–Chiari‐like syndrome. Clinical signs resolved following thoracotomy and complete resection of the mass. New or unique information provided: Obstruction of venous blood flow can result from compression exerted by a space‐occupying thoracic wall mass on the caudal vena cava. Clinical resolution can be achieved with return of adequate venous circulation by removal of the mass and alleviation of the external pressure.     

Kinking of the intrathoracic caudal vena cava in five dogs

Five dogs with kinking of the intrathoracic caudal vena cava (CVC) were studied. One dog had neither clinical nor laboratory abnormalities associated with the kinked CVC, and the cause was unknown. The other four dogs had evidence of post-sinusoidal obstruction of venous flow characterized by high protein ascites (modified transudate). Causes of the kinked CVC were automobile trauma (two dogs), cardiomegaly with ascites, and a large neoplastic lung mass. Surgical removal of the kinked caval segment was successful in the two dogs injured by automobiles. Medical therapy with a diuretic was associated with a decrease in ascites, straightening of the CVC, and improvement in clinical condition of the dog with cardiomegaly and ascites. Surgical removal of the neoplastic lung mass in one dog resulted in straightening of the CVC, but it later died of respiratory failure associated with pulmonary neoplasia.     

49-month survival following caval venectomy without nephrectomy in a dog with a pheochromocytoma

An 11 yr old spayed female Labrador retriever was diagnosed with a right adrenal tumor. At surgery, adhesions to the right kidney were dissected, allowing the right kidney to be preserved. The tumor showed extensive invasion into the suprarenal vena cava. It was felt that thrombus removal via venotomy could not be performed. Instead, the vena cava was ligated caudal to the liver and cranial to the right renal vein. The neoplastic gland was then excised en bloc together with the portion of the invaded caudal vena cava. Hind limb edema had developed preoperatively and increased transiently in the first days postoperatively. The animal was discharged 6 days postoperatively with no other clinical disorders, and hind limb edema resolved over time. Histopathology identified a pheochromocytoma. The dog died 49 mo later. A neoplastic thrombus of the vena cava may require venotomy to allow thrombus removal. Occasionally, removal of the thrombus by venotomy may prove impossible. In such a situation, en bloc removal of the concerned portion of the vena cava may be performed with a good long-term outcome provided that gradual occlusion of the vena cava by the thrombus has allowed time for collateral circulation to develop.     

Caudal vena cava kinking in dogs with ascites

A 9-year-old dog with spontaneous ascites was found to have hepatic vein distension and a tortuous vena cava on abdominal ultrasound. In right lateral recumbency, the caudal vena cava crossed the diaphragm and became kinked before entering into the right atrium. Following this observation, we performed an experimental study in a normal dog to determine whether kinking of the caudal vena cava could be the result and not the cause of ascites. Ascites was induced using warm saline injected through a needle inserted into the abdominal cavity. Venograms were collected from different body positions, under four conditions: before and after a total of one, two and 3 liters of saline had been injected. Caudal vena cava kinking was observed in the experimental dog after 2 liters of fluid had been injected. Vena cava obstruction may cause ascites, but we found that sometimes caudal vena cava kinking can be the result and not the cause of the peritoneal effusion.     

Extensive caudal vena cava thrombosis secondary to unilateral renal tubular cell carcinoma in a dog

A nine-year-old German shorthaired pointer cross was admitted because of partial anorexia, exercise intolerance and haematuria. On clinical examination, subcutaneous oedema, purpura and ascites were detected along with a palpable mass in the right craniodorsal abdomen. Laboratory findings included regenerative anaemia, leucocytosis, thrombocytopenia, azotaemia, increased blood serum alkaline phosphatase and proteinuria. Radiographic and ultrasonographic examinations revealed a large neoplasm involving the right kidney. Computed tomography further showed that the neoplastic tissue had spread into the lymph nodes, the wall of the caudal vena cava, the liver and lungs. The right renal vein, caudal vena cava and iliac veins appeared enlarged and secondarily thrombosed. A diagnosis was made of renal tubular cell carcinoma with secondary venous thrombosis. Gross postmortem examination confirmed the imaging findings, while light and electron microscopic examination revealed that the neoplasm was a solid carcinoma originating from the proximal convoluted renal tubules.     

Cushing's disease complicated with thrombosis in a dog

Thrombosis is a potential complication of hyperadrenocorticism (HAC) in dogs. An 8-year-old male Beagle diagnosed with pituitary-dependent HAC had complicated with thrombosis in the caudal vena cava and abdominal aorta, which was treated by hypophysectomy and antithrombotic therapy. After hypophysectomy, hypercortisolemia disappeared and the general condition was also significantly improved. Ultrasonography after hypophysectomy revealed that the thrombus remained in the abdominal aorta, but the thrombus in the caudal vena cava had disappeared. However 692 days after the hypophysectomy, the dog had an acute onset of dyspnea and died. Postmortem examination revealed the presence of thrombi in the abdominal aorta and the pulmonary artery. Observations from this case show that HAC dogs must be attention to thrombosis.     

Ultrasonographic findings in a cow with ascites due to thrombosis of the caudal vena cava.

This case report describes a three-year-old Swiss Braunvieh cow with ascites due to thrombosis of the caudal vena cava. Ultrasonography verified the ascites and revealed dilatation of the abdominal portion of the caudal vena cava (4.8 cm). It was presumed that the caudal vena cava was occluded by a thrombus or by perivenous compression cranial to the dilatation. Post mortem findings included: a massive accumulation of fluid in the abdominal cavity; a 15 cm long thrombus in the subphrenic region of the caudal vena cava; multiple pulmonary abscesses; severe thrombosis of the pulmonary vasculature; hepatic congestion; oedematous abomasal folds; and severe thrombophlebitis of the left jugular vein and both udder veins, due to poor intravenous injection technique. Ascites caused by thrombosis of the caudal vena cava is rare because collateral routes of venous return, including the udder veins, are usually established. It was therefore concluded that the ascites was attributable to bilateral thrombosis of the udder veins.     

Aortic to caudal vena cava ratio measurements using abdominal ultrasound are increased in dogs with confirmed systemic hypertension

Chronically sustained systemic hypertension in dogs can damage the kidneys, eye, brain, heart, and vessels. In human medicine, systemic hypertension has been implicated as the most common risk factor for aorta dilation, which can progress to an aneurysm. Abdominal ultrasound has been commonly used to monitor the size of the abdominal aorta in people with systemic hypertension. In this retrospective cross‐sectional abdominal ultrasound study, evaluation of the size of the abdominal aorta relative to the caudal vena cava was performed in 18 control dogs and 128 dogs with confirmed systemic hypertension. Preexisting conditions contributing to systemic hypertension in these dogs were renal disease, hyperadrenocorticism, diabetes mellitus, adrenal tumors, and previous administration of phenylpropanolamine or palladia. The abdominal aorta and caudal vena cava were assessed from longitudinal images cranial to the trifurcation with measurements made from outer border to outer border of the walls, being careful not to compress the caudal vena cava that would alter its size. Our hypothesis was the ratio of the diameter of the abdominal aorta to caudal vena cava would be higher in dogs with systemic hypertension compared to dogs with normal blood pressure. The mean abdominal aorta‐caudal vena cava ratio was 1.028 in control dogs with a normal blood pressure and 1.515 in dogs with systemic hypertension. In dogs with confirmed systemic hypertension, the abdominal aorta was dilated compared to the caudal vena cava in the caudal abdomen. An increase in the abdominal aorta‐caudal vena cava ratio in a dog should raise suspicion for the presence of systemic hypertension and prompt evaluation of blood pressure.     

Computed tomographic and magnetic resonance imaging features of canine segmental caudal vena cava aplasia

O bjective : To describe the computed tomographic and magnetic resonance imaging features of segmental caudal vena cava aplasia and associated vascular anomalies in dogs.
M ethods : A retrospective study was performed reviewing computed tomographic and magnetic resonance imaging archives of eight institutions for dogs with segmental caudal vena cava aplasia. Inclusion criteria included a computed tomographic or magnetic resonance imaging study and supportive diagnostic and follow-up information. Abdominal vessels were reviewed for size, shape, location and course (including tributaries and branches) and classified as normal, abnormal or shunt vessels.
R esults : Ten dogs with segmental caudal vena cava aplasia were identified. In all dogs, postrenal caval blood was shunted to either a right or a left azygos vein, with seven different angiographic patterns. Affected dogs were predominantly female (70 per cent) and young (mean 2·6 years). Additional portocaval and porto-azygos shunt vessels were identified in two cases each. Computed tomographic angiography and magnetic resonance angiography depicted details of abdominal vessels including thrombus formation in one dog.
C linical S ignificance : Segmental caudal vena cava aplasia is a vascular congenital anomaly in the dog that can be associated with thrombosis and portosystemic shunts. Computed tomographic angiography and magnetic resonance angiography are excellent tools to demonstrate the complex vascular anatomy and to guide treatment planning for portosystemic shunts and thrombolytic therapy.     

Extensive venous thrombosis and hind-limb edema associated with adrenocortical carcinoma in a dog.

A 10-year-old, spayed female, mixed-breed dog was referred for evaluation of bilateral hindlimb edema and weakness. Abdominal ultrasonography showed increased echogenicity of the lumen of the caudal vena cava from the level of the urinary bladder to the level of the cranial pole of the right kidney. Bilateral saphenous venograms displayed numerous filling defects in the caudal vena cava, right external iliac vein, right femoral vein, and the right common iliac vein. Extensive venous thrombosis was diagnosed, and the animal was euthanized. Necropsy confirmed the presence of venous thrombosis and revealed a right adrenocortical carcinoma that had invaded the caudal vena cava.     

Diagnosis by ultrasonography of congestion of the caudal vena cava secondary to thrombosis in 12 cows

This paper describes the clinical, ultrasonographic, radiographic and postmortem findings in 12 cows with thrombosis of the caudal vena cava. The principal clinical signs were chronic bronchopneumonia and fever in 11 cows; one cow had epistaxis and one cow bled from the mouth; eight cows had anaemia and leucocytosis, and the clotting time for the glutaraldehyde test was markedly decreased in all the cows; in nine of the cows the activity of gamma-glutamyltransferase was high, suggesting chronic hepatic congestion. The most important ultrasonographic finding was congestion of the caudal vena cava attributable to thrombosis of the vein. In all the cows the caudal vena cava was round to oval on cross-section, rather than the normal triangular shape. The hepatic, splenic and portal veins were dilated in five, three and one cow, respectively. The results of radiography and endoscopy supported a diagnosis of bronchopneumonia, but there were radiographic changes in the diaphragmatic lung lobes that supported a diagnosis of vena caval disease in only four cows. Postmortem there was a thrombosis of the caudal vena cava in all the cows, and the thrombi were located in the thoracic, subphrenic and abdominal part of the caudal vena cava at the level of the liver in four, one and seven cows, respectively. In three cows, the thrombus was situated where a hepatic abscess had broken into the caudal vena cava, and in one cow it was at the site of a diaphragmatic abscess. In another cow, there was a fistula between the major bronchus of the right diaphragmatic lung lobe and the caudal vena cava where the thrombus was situated. Three cows had liver abscesses that had not broken into the caudal vena cava. There was severe bronchopneumonia in 11 of the cows, some of which also had multiple pulmonary abscesses.     

Phaeochromocytoma treated by en bloc resection including the suprarenal caudal vena cava in a dog

A 10-year-old, neutered male Cairn terrier was examined after experiencing intermittent vomiting of several months' duration and sudden onset of acute depression. Abdominal ultrasound examination revealed an adrenal mass invading the suprarenal part of the caudal vena cava. The vascular invasion could not be corrected so en bloc ligation/excision of the adrenal neoplasm and the suprarenal part of the vena cava was performed. Microscopic examination identified an adrenal phaeochromocytoma. The dog recovered well and had no significant vascular or renal dysfunction at follow-up 20 months after surgery. To the authors' knowledge, this is the first report of a dog surviving long term after resection of the suprarenal caudal vena cava.     

Passive liver congestion associated with caudal vena caval compression due to oesophageal leiomyoma

A large caudodorsal mediastinal mass was identified in a dog which had been presented for vomiting and anorexia. A few weeks later, the dog developed ascites and hindlimb oedema. Radiography showed that the caudodorsal mediastinal mass was compressing the caudal vena cava, probably inducing passive congestion of the liver. At postmortem examination, the mass was diagnosed as a large oesophageal leiomyoma. To the authors' knowledge, an oesophageal tumour leading to compression of the caudal vena cava associated with passive congestion of the liver has not been described previously in dogs. Secondary signs relating to the oesophageal mass appeared to be more prominent than the digestive signs. Causes of passive congestion of the liver and the differential diagnoses for a caudodorsal mediastinal mass are discussed.     

Congenital Interruption of the Portal Vein and Caudal Vena Cava in Dogs: Six Case Reports and a Review of the Literature

Objective —To describe six dogs with congenital abnormalities involving the portal vein, caudal vena cava, or both.
Animals —Six client-owned dogs with congenital interruption of the portal vein or the caudal vena cava, or both.
Methods —Portal vein and caudal vena cava anatomy was evaluated by contrast radiography and visualization at surgery. Vascular casts or plastinated specimens were obtained in three animals.
Results —Portal blood shunted into the caudal vena cava in four dogs and the left hepatic vein in one. Two of these five dogs also had interruption of the caudal vena cava with continuation as azygous vein, as did an additional dog, in which the portal vein was normally formed. Portal vein interruption was present in 5 of 74 (6.8%) dogs with congenital portosystemic shunts evaluated at the Veterinary Teaching Hospital during the study period.
Conclusions —Serious malformations of the abdominal veins were present in more than 1 in 20 dogs with single congenital portosystemic shunts.
Clinical Relevance —Veterinarians involved in diagnosis and surgery for portosystemic shunts should be aware of these potential malformations, and portal vein continuity should be evaluated in all dogs before attempting shunt attenuation.     

ULTRASONOGRAPHIC LOCALIZATION OF A CAUDAL VENA CAVA THROMBUS IN A DOG WITH LEISHMANIASIS

A dog with visceral leishmaniasis developed rear limb edema, and distension of the caudal epigastric veins. Glomerular disease with nephrotic syndrome and hypercoagulable state was diagnosed. Sonographically there was massive thrombosis of the caudal vena cava.     

Surgical treatment of right-sided renal lymphoma with invasion of the caudal vena cava

An eight-year-old, male castrated basset hound presenting with a three-month history of lethargy was examined. Diagnostic tests including radiography and ultrasonography showed a right-sided renal mass. A 99mTc diethylenetriamine penta-acetic acid scan demonstrated that this kidney was non-functional. At surgery, invasion of the caudal vena cava was found, and the renal segment of the vena cava and the right kidney were resected. The left renal vein was anastomosed to the more proximal vena cava using a polytetrafluoroethylene graft, and the dog recovered well. Two days postsurgery, the dog suffered an acute episode of aspiration pneumonia and was euthanased. The renal mass was diagnosed as lymphoma on histopathology.     

Nephrotomography and ultrasonography for the localization of hyperfunctioning adrenocortical tumors in dogs

Nephrotomography and ultrasonography were used in 11 dogs with hyperadrenocroticism to assess the value of these techniques for the localization of biochemically diagnosed hyperfunctioning adrenocortical tumors. Both techniques enabled accurate localization of a unilateral adrenal mass in each of the dogs. Cross-sectional diameters of the masses ranged from 1 to 4 cm. In 1 dog, expansion of tumor into the caudal vena cava was revealed by caudal venacavography and ultrasonography. Mineralization in the tumor mass in 2 dogs was easily recognized by nephrotomography, but not by ultrasonography. Paracostal laparotomy confirmed the presence of an adrenocortical tumor in each dog, and expansion of tumor into the caudal vena cava in 1 dog. Cross-sectional diameters of the tumors ranged from 1.2 to 4.5 cm and corresponded well with cross-sectional measurements by nephrotomography and ultrasonography. It was concluded that nephrotomography and ultrasonography have similar diagnostic accuracies for the detection and localization of hyperfunctioning adrenocortical tumors.     

INTRAHEPATIC VENOUS COLLATERALS PREVENTING SUCCESSFUL STENT-SUPPORTED COIL EMBOLIZATION OF INTRAHEPATIC SHUNTS IN DOGS

The purpose of the following study was to evaluate stent-supported coil embolization of the hepatic vein in combination with antithrombotic treatment as a method for treatment of intrahepatic shunts, and to describe the complications associated with this procedure. Seven dogs with an intrahepatic shunt were included in a prospective clinical trial. A stepwise procedure was performed. First intervention: transjugular retrograde portography and stent implantation into caudal vena cava; second intervention: hepatic vein embolization combined with an antithrombotic treatment; third intervention in dogs with residual shunting: hepatic vein embolization without antithrombotic treatment. A right shunt was found in one dog and a left shunt in six dogs. Primary intrahepatic venous collaterals were found in one dog and hepatic vein embolization was not performed. Stent implantation into the caudal vena cava was performed in the other six dogs. There was no stent migration or thrombosis. Following the first coil intervention two dogs died due to vessel laceration while removing an oversized or migrated coil. On follow-up the shunt was completely closed in one dog. Secondary intrahepatic venous collaterals developed after the first or second coil intervention in two and one dog, respectively. In conclusion, stent-supported coil embolization of the hepatic vein in combination with an antithrombotic treatment was of limited success because primary or secondary intrahepatic venous collaterals tend to occur.     

Budd-Chiari-like syndrome associated with an adrenal phaeochromocytoma in a dog

A nine-year-old dog was presented with sudden-onset ascites and a history of two previous syncopal episodes. Diagnostic tests pointed to a Budd-Chiari-like syndrome, with obstruction of the caudal vena cava between the liver and heart. The ascites was refractory to treatment and the dog was euthanased. On postmortem examination, a phaeochromocytoma of the left adrenal gland was present, with contiguous invasions into the caudal vena cava, extending cranially as far as the cavoatrial junction. To the authors' knowledge, this is the first reported case of a Budd-Chiari-like syndrome associated with a phaeochromocytoma in a dog.     

Clinical findings and diagnosis of thrombosis of the caudal vena cava in cattle

This paper describes the causes, clinical findings and diagnosis of caudal vena caval thrombosis in cattle. Occlusion of the vein is caused by a 'white' thrombus, and typical clinical signs include chronic weight loss, poor general condition and intermittent fever. Most affected cattle have respiratory signs; in some, pulmonary haemorrhage, ascites and sudden death occur. Haematological analyses, endoscopy of the respiratory tract and ultrasonographic examination of the pleura, liver and abdomen should be carried out in cattle suspected of having thrombosis of the caudal vena cava. The most important diagnostic finding is dilatation of the caudal vena cava seen via ultrasonography. Normally, the caudal vena cava appears triangular in cross section but in cattle with thrombosis it is oval or circular. The prognosis is poor and there is no treatment.