Successful treatment by percutaneous transvenous coil embolization in a small-breed dog with intrahepatic portosystemic shunt

A Miniature Dachshund, 3-month-old, 3.1 kg, was diagnosed as an intrahepatic portosystemic shunt (PSS) with the shunting vessel in 6-mm diameter. Percutaneous transvenous coil embolization (PTCE) was performed with a stainless steel coil in 8-mm diameter. Intraoperative portal pressure elevated about 2.5 times after one-stage coil occlusion. Two weeks after the PTCE, serum bile acid levels reduced within the normal range. The portogram showed complete occlusion of the shunting vessel 4 months after the PTCE. Approximately 3 years after the PTCE, the patient has shown no clinical signs. PTCE could be performed more easily and less invasively in a small-breed dog. It is therefore suggested that PTCE is a promising therapeutic technique in canine intrahepatic PSS.     

Splenocaval Shunting for Alleviation of Portal Hypertension in a Dog: A Case Report

Objective —To describe the construction and use of a splenocaval shunt to prevent portal hypertension in a dog with iatrogenic rupture and subsequent complete occlusion of an intrahepatic portosystemic shunt (IPSS).
Study Design —Case report describing a single, client-owned animal.
Results —During dissection, the back wall of an IPSS was torn. Complete shunt occlusion was required to control the hemorrhage. This resulted in the development of life-threatening portal hypertension. Emergency splenocaval shunt construction reduced the portal pressure from 47 to 20 cm H₂0. The dog experienced minimal postoperative complications. A second surgical procedure was performed a month later to completely ligate the splenocaval shunt.
Conclusions —A splenocaval shunt can be used to divert blood from the portal to the systemic circulation to control portal hypertension. In this dog, it resulted in a successful outcome with few complications.
Clinical Relevance —The splenocaval shunt could be constructed before the dissection of a difficult IPSS if problems arise as occurred in the dog described in this report. Complete IPSS occlusion can be performed without development of portal hypertension.     

Transjugular coil embolization of an intrahepatic portosystemic shunt in a cat

A 4-month-old male domestic shorthair cat was evaluated for intermittent tremors, ptyalism, and signs of depression. The cat was small, thin, and unthrifty. Clinically important serum biochemical abnormalities included low blood urea nitrogen concentration and high baseline bile acids concentration. Abdominal ultrasonography and jejunal portography identified an intrahepatic portosystemic shunt. The cat was anesthetized, and a transjugular approach was used for percutaneous coil embolization of the shunt. Guidewires, catheters, and coils were inserted under fluoroscopic guidance to locate the shunt and define its anatomy, measure portal vein pressures before and after temporary balloon occlusion, and place thrombogenic coils to completely attenuate the anomalous vessel. The cat recovered without complications and was weaned from medical management. Ten weeks following the procedure, clinical signs had completely resolved, and baseline bile acids concentration was near reference range. Results in this cat illustrate that interventional radiology techniques can be safely used in small animals and may reduce the morbidity and mortality rates associated with traditional surgical procedures.     

Intravascular Occlusion for the Correction of Extrahepatic Portosystemic Shunts in Dogs

Background: Congential extrahepatic portosystemic shunts (EHPSS) are common in dogs. An effective minimally invasive technique for correction of EHPSS could result in reduced morbidity, reduced costs, and reduced hospitalization times. Hypothesis: Use of an intravascular occlusion device can effectively and safely result in acute complete occlusion of EHPSS in dogs. Animals: Seven dogs with naturally occurring EHPSS that presented to the Purdue University Veterinary Teaching Hospital. Methods: Prospective, clinical trial. The 7 dogs were consecutively enrolled over a 2‐year period. Results of serum biochemistry, total serum bile acids, fasting plasma ammonia, abdominal radiography, and ultrasonography suggested the diagnosis of portosystemic shunts in all dogs. Definitive diagnosis of EHPSS was achieved with cranial mesenteric arterial portography and acute occlusion was attempted by the deployment of the Amplatzer vascular plug (AVP). Results: EHPSS were identified in all dogs consisting of 5 portocaval and 2 portoazygous variants; 1/7 dogs (14%) were intolerant to temporary complete occlusion of the EHPSS. Of the remaining 6 dogs, 5 (83%) had complete occlusion of the EHPSS by the AVP. There were no complications and resolution of abnormal clinical signs and laboratory values was achieved in 4/5 (80%) dogs with complete occlusion. Conclusions and Clinical Importance: Intravascular correction of EHPSS by the AVP is a viable option to surgical correction while larger studies will be required to determine the clinical applicability of this procedure in the broader portosystemic shunt population.     

Portovenogram findings in cases of elevated bile acid concentrations following correction of portosystemic shunts.

The case records of 36 cats and dogs undergoing surgical correction of a single extrahepatic portosystemic shunt were reviewed. In 12 animals, the shunt was fully ligated during the first surgical procedure, while, in the remaining 24, the shunting vessel could only be partially ligated. Assessment of serum bile acid concentrations demonstrated complete shunt occlusion in 15 of these latter 24 animals (63 per cent) between one and six months postoperatively. Ten animals (28 per cent) had persistently high serum bile acid concentrations postoperatively. Portovenogram findings in these individuals revealed six that demonstrated shunting solely through the original vessel; In five of these, full shunt attenuation was achieved at second surgery. Further shunt manipulation was not possible in the sixth case due to extensive adhesion formation. In the remaining four animals with raised bile acid concentrations, the portovenogram demonstrated shunting through the original vessel as well as the development of multiple acquired shunts.     

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.     

Outcome associated with use of a percutaneously controlled hydraulic occluder for treatment of dogs with intrahepatic portosystemic shunts

OBJECTIVE: To evaluate efficacy of a hydraulic occluder (HO) used for treatment of dogs with an intrahepatic portosystemic shunt (IHPSS). DESIGN: Prospective study. ANIMALS: 10 dogs with an IHPSS. PROCEDURES: Serum biochemical and postprandial bile acids (PPBA) analyses and transcolonic scintigraphy were performed before surgery. Laparotomy was performed, and an uninflated HO was placed around the portal vein branch leading to the IHPSS. After surgery, 0.9% NaCl solution was injected into subcutaneous injection ports at 2, 4, 6, and 8 weeks to achieve staged occlusion of the HO. Serum biochemical analyses, PPBA analysis, and scintigraphy were performed 2 weeks after occlusion. Serum biochemical analyses were repeated 1 year after surgery. RESULTS: Implant revision was required in 3 dogs because of rupture of the HO (n = 2) or detachment of the actuating tubing (1). Serum biochemical values and clinical signs improved in all dogs after surgery. Six of 10 dogs had PPBA concentration within reference range 2 weeks after occlusion, and 2 additional dogs had concentrations within reference range at 1 year. Only 5 of 10 dogs had complete resolution of portosystemic shunting 2 weeks after occlusion. Two dogs were lost to follow-up, and 8 dogs remained alive with no recurrence of clinical signs at a median of 22 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE: Use of the HO appeared to be an effective method for surgical treatment for dogs with IHPSS, although problems with implant reliability indicate a need for modifications in design and manufacturing.     

Use of Ursodeoxycholic Acids in a Dog With Chronic Hepatitis: Effects on Serum Hepatic Tests and Endogenous Bile Acid Composition

A dog with severe cholestasis secondary to chronic hepatitis was treated with ursodeoxycholic acid (UDCA1 PO. After 2 weeks of daily treatment, the dog was more active and had an improved appetite. Monthly serum biochemical determinations and analysis of individual bile acid profiles documented improvement in hepatobiliary tests and a marked reduction in the concentrations of potentially hepatotoxic endogenous bile acids. These effects were maintained for approximately 6 months- The findings in this dog are similar to those reported for human patients treated with UDCA and provide preliminary evidence in support of its continued evaluation in the treatment of cholestatic liver disease in the dog.     

A Syndrome Resembling Idiopathic Noncirrhotic Portal Hypertension in 4 Young Doberman Pinschers

We describe 4 young male Doberman Pinschers (3 littermates and 1 unrelated dog) with a syndrome resembling idiopathic or noncirrhotic portal hypertension of humans. Each dog was evaluated for a hepatopathy resulting in portal hypertension, development of portosystemic collateral vessels, and hepatic encephalopathy. These dogs differ from previous reports of young dogs with hepatic insufficiency associated with portal hypertension and acquired portal systemic shunting by their lack of intrahepatic arteriovenous fistulae, portal vein atresia, or intrahepatic fibrosis. Clinicopathologic features included erythrocyte microcytosis, normal to mildly increased liver enzyme activities, increased concentrations of serum bile acids, reduced plasma indocyanine green clearance, and normal total bilirubin concentration. Abdominal ultrasonography disclosed a small liver and portosystemic collateral vessels. Radiographic imaging studies confirmed hepatofugal portal circulation and discounted hepatic arteriovenous fistulae. Histopathologic features in liver tissue from each dog were similar and consistent in all sections examined. Common findings included increased cross-sectional views of hepatic arterioles; hepatic lobular atrophy; scanty increase in connective tissue around some large portal triads; and absence of inflammation, disturbed lobular architecture, bile duct proliferation, or intrahepatic cholestasis.     

Effect of oral ursodeoxycholic acid on bile acids tolerance tests in healthy dogs

OBJECTIVE: To determine whether oral administration of ursodeoxycholic acid (UDCA) to healthy dogs alters the results of the bile acids tolerance test. METHODS: UDCA (15 mg/kg once daily) was administered to 16 healthy dogs for 7 days. Health of the dogs was assessed by clinical examination, haematology, serum biochemistry and a bile acids tolerance test. Normal liver structure was confirmed by histopathology at the end of the study. Bile acids tolerance tests were performed before and at the end of the treatment period, with each dog serving as its own control. For the posttreatment bile acids tolerance test, UDCA was administered at the time of feeding. RESULTS: Pretreatment, the fasted serum total bile acid concentrations ranged between 0 and 9 micromol/L. In the majority of dogs, the postprandial total bile acid concentration was greater than the preprandial value, with a range of 0 to 16 micromol/L. The fasted total bile acid concentration was 0 micromol/L in most dogs (93.75%) after treatment with UDCA. Postprandial serum bile acids also remained within the reference range for the majority of dogs (93.75%) after UDCA treatment. A single dog had a postprandial bile acid concentration above the reference range, but the concentration was within the reference range when the assay was repeated the following day without concurrent administration of UDCA. The pre- and postprandial total serum bile acid concentrations were not significantly affected by UDCA treatment. CONCLUSION: The administration of UDCA does not alter the bile acids tolerance test of normal healthy dogs.     

CONTRAST‐ENHANCED PORTAL MAGNETIC RESONANCE ANGIOGRAPHY IN DOGS WITH SUSPECTED CONGENITAL PORTAL VASCULAR ANOMALIES

Contrast‐enhanced multiphase magnetic resonance angiography (CE‐MRA) was used in 17 dogs with a suspected congenital portal vascular anomaly. Portal vascular anomalies were identified in 16 of the 17 dogs. Eleven had a single intrahepatic portocaval shunt (two central divisional, three right divisional, and six left divisional), one dog had a double intrahepatic portocaval shunt, one dog had a hepatic arteriovenous malformation, one dog had a complex intrahepatic porto‐caval shunt. Two dogs had an extrahepatic portosystemic shunt and no shunt was identified in one dog. Total imaging time was <10 min and image quality was good to excellent in all dogs. Portal CE‐MRA is a feasible, fast and non invasive technique to diagnose portal vascular anomalies in dogs, with a large field‐of‐view and good anatomic depiction of the abnormal vessels. Based on these results, CE‐MRA is an efficient imaging technique for the diagnosis of portal vascular anomalies in dogs.     

Percutaneous transcatheter coil embolization of a ventricular septal defect in a dog

A 4-month-old male French Bulldog weighing 5.0 kg (11 lb) was referred for a heart murmur. A grade 3/6 systolic murmur was detected at the left heart base and a grade 4/6 systolic murmur was detected at the right heart base. By use of color-flow Doppler ultrasonography and cardiac catheterization, a diagnosis of supracristal ventricular septal defect (VSD) with accompanying aortic regurgitation was made. Percutaneous transcatheter coil embolization was used to close the VSD. Because residual shunt was detected via echocardiography after coil implantation, the residual shunt was followed periodically via echocardiography to detect spontaneous closure of the VSD. Volume overload in the left ventricle was detected in the dog 131 days after admission. Additional coils were placed 137 days after admission. Hemolysis resulting in hemoglobinuria was detected, but this complication was mild. In the dog of this report, results of coil occlusion for correction of VSD were promising. Thus, coil occlusion should be considered as an alternative treatment for VSD in dogs.     

Gradual Occlusion of Extrahepatic Portosystemic Shunts in Dogs and Cats Using the Ameroid Constrictor

Gradual occlusion of the splenic vein, using a specialized device (ameroid constrictor), was evaluated experimentally in three normal beagle dogs. Splenoportograms were used to verify that total occlusion of the splenic vein had occurred in all dogs within 4 to 5 weeks after application of the device. The ameroid constrictor (AC) was also evaluated as a method of gradual vascular occlusion in 12 dogs and two cats with single, extrahepatic, portosystemic shunts (PSS). Serum bile acid (SBA) concentrations were measured and portal scintigraphy (PS) was performed on all 14 animals preoperatively and 10, 20, 30, and 60 days postoperatively. Two dogs (14%) died from portal hypertension in the early postoperative period. One dog and one cat developed multiple acquired PSS, confirmed by mesenteric portography 90 days after the operation. Portal scintigraphy confirmed total occlusion of the primary shunt in the other 10 animals. Shunt fractions (SF), as measured by PS on postoperative days 30 and 60, declined significantly from preoperative values. Significant decreases were noted between preoperative and postoperative values for preprandial SBA on postoperative day 60 and for postprandial SBA on postoperative day 30. SBA concentrations did not correlate with SF. Based on this study, gradual vascular occlusion using the AC is recommended as a method for treatment of single, extrahepatic, PSS.     

Vertebral physitis with epiphyseal sequestration and a portosystemic shunt in a Pekingese dog

Vertebral physitis with bone sequestration and a portosystemic shunt were diagnosed in an 18-month-old female Pekingese dog. The latter was determined by the presence of low blood urea nitrogen, elevated serum bile acids, microhepatica and an increased portosystemic shunt fraction. It was managed with a home-cooked low protein diet. Vertebral physitis and bone sequestration was diagnosed by the presence of thoracolumbar hyperaesthesia, radiographic and scintigraphic changes, isolation of Staphylococcus intermedius from blood and the third lumbar vertebra, and histopathological examination of a surgical biopsy. A partial sequestrectomy was performed and a six-month course of amoxycillin-clavulanate was prescribed. The dog was pain-free and showed partial resolution of the radiographic signs four months after the discontinuation of antibiotics.     

Association of portovenographic findings with outcome in dogs receiving surgical treatment for single congenital portosystemic shunts: 45 cases (2000-2004)

OBJECTIVE: To determine whether hepatic portal vascularity, as assessed by intraoperative mesenteric portovenography (IMP), is related to outcome in dogs undergoing attenuation of single congenital portosystemic shunts (CPSSs). DESIGN: Retrospective case series. ANIMALS: 45 dogs, each with a single CPSS, in which IMP was performed before and after temporary complete occlusion of the shunting vessel and that underwent complete (17 dogs) or partial (28 dogs) CPSS attenuation (surgery 1). PROCEDURES: Medical records were reviewed for signalment, clinical history, and bile acids stimulation test results. Intrahepatic portal vessel (IPV) opacification in pre- and postocclusion portovenograms was graded to determine whether the degree of opacification was correlated with the degree of shunt attenuation, clinical or biochemical factors, or long-term clinical outcome. In 17 of 28 dogs that had partial CPSS attenuation, these procedures were subsequently repeated (surgery 2) to achieve complete (14 dogs) or further partial (3 dogs) CPSS attenuation. RESULTS: Compared with preattenuation findings, IPV opacification increased significantly after partial or complete CPSS attenuation. The degree of IPV opacification before and after CPSS occlusion (surgery 1) was greater in dogs that tolerated complete versus partial CPSS attenuation and was correlated positively with age. The degree of IPV opacification following CPSS occlusion (surgery 1) was maximal in all dogs without encephalopathy and was correlated negatively with follow-up preprandial serum bile acids concentrations and positively with clinical improvement. CONCLUSIONS AND CLINICAL RELEVANCE: Data suggest that IMP can be used to assess changes in IPV blood flow and help predict outcome following attenuation of single CPSSs in dogs.     

Long-Term Results of Complete and Partial Ligation of Congenital Portosystemic Shunts in Dogs

The medical records of 65 dogs that underwent complete or partial ligation of a single congenital portosystemic shunt (CPSS) were reviewed to determine the long-term clinical results. Information retrieved from the records included age at surgery, preligation (baseline) portal pressure, postligation portal pressure, change in portal pressure from baseline, complete or partial occlusion of the shunting vessel and fasting, and 2-hour postprandial bile acids from the preoperative, early postoperative (PO), and greater than 1 year PO time periods. A clinical rating score derived from a follow-up examination greater than 1 year PO was assigned to each dog. Of the 56 dogs that survived the perioperative period, 29 (52%) had complete and 27 (48%) had partial ligations. Age at surgery, pre- and postligation portal pressure, change in portal pressure from baseline and serum bile acid concentrations were not related to long-term clinical outcome. Clinical rating scores were significantly greater for dogs with partial CPSS ligations compared with dogs with complete ligations, indicating a less favorable clinical outcome for partial ligations. Fasting and 2-hour postprandial bile acid values at both PO time intervals were significantly greater in partial versus complete ligation groups. Follow-up information for more than 1 year was available on 18 of 29 dogs (62%) with complete ligations. All were clinically normal. Of 27 dogs with partial ligations, 11 dogs (41%) developed recurrence of clinical signs resulting in presentation to the university or referring veterinarian for additional surgery, medical management, or euthanasia. Only three dogs with partial CPSS ligation (11%) were clinically normal. Another nine dogs (33%) were operated on again before the possible development of clinical signs and four dogs (15%) were unavailable for follow-up. It was concluded that partial ligation of CPSS is associated with a greater recurrance of clinical signs and patient morbidity than complete ligation.     

Clinical outcome of congenital extrahepatic portosystemic shunt attenuation in dogs aged five years and older: 17 cases (1992-2005)

OBJECTIVE: To assess the outcome of extrahepatic portosystemic shunt (EHPSS) treatment in dogs aged 5 years and older. DESIGN: Retrospective case series. ANIMALS: 17 client-owned dogs. PROCEDURES: Medical records for dogs (> or = 5 years old) that underwent surgical attenuation of an EHPSS (1992 through 2005) were evaluated; data, including clinical signs, clinicopathologic findings, surgical procedure, and outcome, were recorded. Follow-up information was obtained via patient examination or telephone interview with veterinarians and owners. RESULTS: Dogs (5 to 9 years old [median age, 6.6 years]) had neurologic (n = 12), urinary tract (8), and gastrointestinal tract (6) EHPSS-associated clinical signs. Serum bile acids and ammonia concentrations were abnormal in all evaluated dogs. Treatment of EHPSSs included complete (n = 6 dogs) or partial (2) suture attenuation or ameroid constrictor placement (9). Two dogs died following surgery. Follow-up information (6 to 120 months) was available for 13 dogs. Deaths were attributable to heart failure (n = 1), bacterial hepatitis (2; with pyelonephritis in 1 dog), and unknown causes (3). At a median of 23 and 25 months, serum bile acids concentrations had almost normalized in 5 of 8 dogs and ammonia concentrations were within reference limits in 3 of 5 dogs, respectively; dogs with abnormal liver function test results had no associated clinical signs. Median long-term survival time was 72 months. CONCLUSIONS AND CLINICAL RELEVANCE: Attenuation of EHPSS in > or = 5-year-old dogs ameliorated signs of liver dysfunction in surviving dogs, although return of normal liver function occurred less frequently than expected.     

Surgical repair of a complete endocardial cushion defect in a dog

Objective: To describe surgical repair of a complete endocardial cushion defect (ECD) in a dog. Study Design: Clinical report. Animal: A 5‐month‐old, 9.2 kg male Shetland sheepdog. Methods: Echocardiographic examination revealed an ostium primum atrial septal defect (ASD), an inlet ventricular septal defect (VSD), mitral regurgitation (MR) and tricuspid regurgitation (TR), and a complete ECD was diagnosed. Surgical correction was performed using cardiopulmonary bypass (CPB) via right atriotomy. A polytetrafluoroethylene (PTFE) patch was secured along the margin of the inlet VSD using simple continuous suture, then the cleft in the septal mitral leaflet was sutured. Similarly, the cleft in the septal tricuspid leaflets was sutured. To complete inlet VSD closure, the VSD patch was secured to these sutured leaflets by simple continuous suture. Another PTFE patch was used to close the ostium primum ASD. Result: After surgery, MR, TR, and interventricular shunting were decreased. The dog was alive 6 years and 5 months after the surgery with no evidence of an interventricular shunt, TR, or other clinical signs. Conclusions: Complete ECD in a dog was corrected using a 2‐patch technique under CPB.     

Re-evaluation of a portocaval venograft without an ameroid constrictor as a method for controlling portal hypertension after occlusion of intrahepatic portocaval shunts in dogs

OBJECTIVE: To evaluate the use of a portocaval venograft without an ameroid constrictor in the surgical management of intrahepatic portosystemic shunts (PSS). STUDY DESIGN: Prospective clinical study. ANIMALS: Seven dogs with intrahepatic PSS. METHODS: Portal pressure was measured after temporary suture occlusion of the intrahepatic PSS. In dogs with an increase in portal pressure > or =8 mm Hg or signs of portal hypertension, a single extrahepatic portocaval shunt was created using a jugular vein. Clinical outcome and complications were recorded. RESULTS: The mean (+/-SD) portal pressure increased from 5.9+/-1.6 to 17.9+/-4.1 mm Hg with PSS occlusion. There were no intraoperative complications and, after creation of the portocaval shunt, the intrahepatic PSS could be completely ligated in all dogs. The final portal pressure was 9.6+/-1.9 mm Hg. Complications developed during postoperative hospitalization in 5 dogs and included incisional discharge (4 dogs), ascites (3), ventricular premature contractions (2), and melena, bloody diarrhea, neurologic signs, coagulopathy, and aspiration pneumonia (each in 1 dog). Six dogs died or were euthanatized with clinical signs related to depression, inappetance, abdominal pain, vomiting, melena, and abdominal distention, with a median survival of 82 days (range, 20-990 days). One dog was clinically normal at 33 months after surgery. CONCLUSIONS: Clinical signs observed in 6 dogs after surgery were consistent with portal hypertension. Use of a portocaval venograft without an ameroid constrictor may reduce the likelihood of hepatic vascular development, thereby increasing the risk of life-threatening portal hypertension should the venograft suddenly occlude. CLINICAL RELEVANCE: Use of a portocaval venograft without an ameroid constrictor to control portal hypertension after ligation of an intrahepatic PSS cannot be recommended.