Ultrasonographic Diagnosis of Portal Vein Thrombosis in Four Dogs

Abstract

Ante mortem diagnosis of portal vein thrombosis was determined ultrasonographically in four dogs. In each dog the thrombus was visible in two‐dimensional, grey‐scale images of the portal vein obtained through a right intercostal window. Duplex‐Doppler measurements and color‐Doppler images provided information about the effects of thrombosis on portal blood flow. Reduced portal blood flow compatible with portal hypertension was detected in three dogs. A hypercoagulable state was probably involved in the pathogenesis of portal vein thrombosis in two dogs, one with pancreatitis and gastrointestinal blood loss and another with protein‐losing nephropathy and probable immune‐mediated anemia. The third dog had chronic ehrlichiosis; thrombosis was probably secondary to vasculitis. The remaining dog had thrombosis secondary to invasion of the portal vein by a recurrent duodenal neoplasm. This dog was euthanized because the tumor was considered inoperable. The dog with pancreatitis developed acute portal hypertension due to obstruction of the portal vein by the thrombus and was euthanized. The dogs with protein‐losing nephropathy and ehrlichiosis were treated medically and recovered. Although portal vein thrombosis is uncommon, this complication should be considered in dogs with a variety of abdominal or systemic disorders. Ultrasonography is a practical method for diagnosis of portal vein thrombosis and detection of the underlying cause.

Ultrasonographic diagnosis of unusual portal vascular abnormalities in two cats

“…Portal vein occlusion may be caused by stenosis, thrombosis, tumour invasion or extraluminal compression (Johnson 1987). Portal vein thrombosis has been reported in the dog but not in the cat (Lamb and others 1996). Reported causes in the dog include immune‐mediated haemolytic anaemia, following surgery to ligate portosystemic shunts and for pancreatitis, renal amyloidosis, ehrlichiosis and retrograde growth of hepatic tumours (Van Winkle and Bruce 1993, Lamb and others 1996).…”

ACVIM consensus statement on the diagnosis and treatment of chronic hepatitis in dogs

“…Ultrasonographic evidence of PH may accompany late‐stage CH (Table ). These signs include the presence of ascites, APSS, edema in the gallbladder wall, gastrointestinal wall or pancreatic region, decreased portal blood flow velocity (mean velocity < 10 cm/s), hepatofugal blood flow or both . Acquired portosystemic shunts usually appear as plexuses of tiny tortuous vessels located caudal to the kidneys, or as a splenorenal anastomosis flowing from the splenic vein to the plexus, the left renal vein, caudal vena cava, or aberrant vessels in the mesentery; all best seen with color or power Doppler .…”

Pulsed Doppler Ultrasonographic Evaluation of Portal Blood Flow in Dogs with Experimental Portal Vein Branch Ligation.

“…Doppler ultrasound examinations were performed one week before and then after left portal vein branch ligation (3,5,7,9,11,15, 21 days after ligation).…”

“…Preliminary studies in man have compared Doppler blood flow measurements in normal and various disease states, and the results show promise for establishing this technique as an important clinical and research tool [2,8,17]. Some reports of portal hypertension in dogs indicate that Doppler ultrasonography is one of the most useful methods in the diagnosis of portal hypertension [3,4,7].…”