Analysis of the relationship of extrahepatic portosystemic shunt morphology with clinical variables in dogs: 53 cases (2009-2012)

Serum Amino Acid Profiles in Dogs with a Congenital Portosystemic Shunt

Background/Objectives: A functional liver is vital for normal protein metabolism. Alterations of circulating amino acid (AA) concentrations have previously been reported in dogs with hepatocellular carcinoma, chronic hepatitis, and hepatocutaneous syndrome. The purpose of this study was to compare serum AA profiles between dogs with a congenital portosystemic shunt (CPSS) and healthy control dogs. Methods: Serum samples were collected from 50 dogs with an extrahepatic congenital portosystemic shunt (eCPSS) and 10 dogs with an intrahepatic congenital portosystemic shunt (iCPSS) at time of surgical intervention and from 21 healthy control dogs. Serum AA and other nitrogenous compounds were measured with a dedicated amino acid analyzer. The concentration of each AA was compared between groups using a Kruskal-Wallis test followed by Dunn's multiple comparisons tests, as appropriate. The Benjamini-Hochberg procedure was used to control for false discovery. Significance was set at q < 0.05. Results: Compared to healthy controls, dogs with a CPSS had significantly increased serum concentrations of ammonia, asparagine, glutamic acid, histidine, phenylalanine, serine, and tyrosine and had significantly decreased concentrations of isoleucine, leucine, threonine, urea, and valine. There were no significant differences in serum AA concentrations between dogs with an eCPSS and dogs with an iCPSS. Conclusions: Dogs with a CPSS had altered serum AA concentrations compared to healthy control dogs, including decreased branched-chain amino acids (BCAAs) and increased aromatic amino acids (AAAs). In summary, serum AA profiles can differentiate dogs with a CPSS from healthy dogs but not dogs with an eCPSS from dogs with an iCPSS.

Outcome of 21 dogs treated for the portocaval subtype of extrahepatic portosystemic shunts

OBJECTIVE

To assess outcomes of dogs with side-to-side portocaval extrahepatic portosystemic shunts (PC-EHPSS) and poor portal perfusion to the liver treated with medical management alone (MM) or surgical attenuation (SA).

STUDY DESIGN

Multi-institutional retrospective study.

ANIMALS

A total of 21 dogs with PC-EHPSS (14/21 MM and 7/21 SA).

METHODS

Medical records were reviewed, and data was collected on dogs <12 kg with PC-EHPSS treated with MM or SA between June 2008 to June 2021. Signalment, clinical signs, postoperative complications, bloodwork values, long-term clinical outcome, survival, and owner reported quality of life were recorded.

RESULTS

Of 21 dogs included, 10 were mixed breeds and 14 were females. Median age at time of presenting clinical signs was 163 days. At final follow-up examination (median 1119 days), all SA and 6/14 MM dogs were alive, with a median survival time of 2138 days following treatment onset. In surviving MM dogs, outcome was fair in 3/6 and poor in 3/6. In SA dogs with long-term follow-up, outcome was fair in 5/6, and poor in 1/6. A greater proportion of SA dogs had improved bloodwork parameter values at final follow-up examination, and the mean relative change in final bloodwork values was higher when compared to MM dogs.

CONCLUSION

These findings demonstrate that SA has improved clinical outcomes to MM for PC-EHPSS; however, SA clinical outcomes appear worse than those previously reported for other EHPSS.

CLINICAL SIGNIFICANCE

This information may have implications for expected outcomes in other EHPSS subtypes associated with severely diminished portal perfusion.

Computed tomographic evaluation of portal vein indices in cats with the extrahepatic portosystemic shunts

IMPORTANCE

The portal vein to aorta (PV/Ao) ratio is used to assess the clinical significance of extrahepatic portosystemic shunt (EHPSS). Previous studies using computed tomography (CT) were conducted in dogs but not in cats.

OBJECTIVE

This study aimed to establish normal reference values for PV indices (PV/Ao ratio and PV diameter) in cats and determine the usefulness of these for predicting symptomatic EHPSS.

METHODS

This study included 95 dogs and 114 cats that underwent abdominal CT. The canine normal (CN) group included dogs without EHPSS. The cats were classified into feline normal (FN, 88/114), feline asymptomatic (FA, 16/114), and feline symptomatic (FS, 10/114) groups. The PV and Ao diameters were measured in axial cross-sections.

RESULTS

The group FN had a higher PV/Ao ratio than the group CN (p < 0.001). Within the feline groups, the PV indices were in the order FN > FA > FS (both p < 0.001). The mean PV diameter and PV/Ao ratio for group FN were 5.23 ± 0.77 mm and 1.46 ± 0.19, respectively. The cutoff values between groups FN and FS were 4.115 mm for PV diameter (sensitivity, 100%; specificity, 97.7%) and 1.170 for PV/Ao ratio (90%, 92.1%). The cutoff values between group FA and FS were 3.835 mm (90%, 93.8%) and 1.010 (70%, 100%), respectively.

CONCLUSIONS AND RELEVANCE

The results demonstrated significant differences in PV indices between dogs and cats. In cats, the PV/Ao ratio demonstrated high diagnostic performance for symptomatic EHPSS. The PV diameter also performed well, in contrast to dogs.

Enlargement of the hepatic artery is present in dogs with a congenital extrahepatic portosystemic shunt and is independent of shunt insertion into the systemic circulation

The accurate diagnosis of portovascular anomalies has been facilitated by improvements in diagnostic imaging technology. In humans, hepatic arterial blood flow changes in response to the reduction in portal blood flow. The hepatic arterial buffer response characterizes an intrinsic regulatory mechanism in response to reduced portal venous blood flow, which results in hepatic arterial enlargement. At the authors' institution, enlargement of the hepatic artery has been anecdotally observed in a population of dogs with extrahepatic portosystemic shunting, consistent with previous literature that documents variability in hepatic arterial size. In this retrospective, blinded, analytical study, a hepatic artery:aorta (Ha:Ao) ratio was assessed on CT studies from 112 dogs, with (n = 43) and without (n = 69) an extrahepatic congenital portosystemic shunt in order to compare the hepatic artery size independent of body weight between the two populations. A significant increase in the Ha:Ao ratio was documented in dogs with an extrahepatic portosystemic shunt (EHPSS) compared with those dogs with no EHPSS independent of the location of shunt insertion into the systemic circulation (P < .001). Three cases had repeat CT after surgery, and all had Ha:Ao ratio reductions following treatment. The authors propose that this may be an additional imaging feature observed in dogs with an EHPSS.

Regional cerebral blood flow in dogs with congenital extrahepatic portosystemic shunts before surgery and six months after successful closure

Previous studies both in humans and dogs with chronic liver diseases have shown that regional cerebral brain flow (rCBF) is altered. The current study aimed to assess abnormalities in rCBF in dogs with congenital extrahepatic portosystemic shunts (cEHPSS), both at diagnosis and after successful surgical attenuation. Furthermore, the influence of age at diagnosis, severity of hepatic encephalopathy (HE) and type of cEHPSS on rCBF were explored as a base for future research. Single photon emission computed tomography (SPECT) with 99mtechnetium-hexamethylpropylene amine oxime tracer was performed before surgical attenuation and six months postoperatively. Twenty-four dogs with cEHPSS had SPECT at time of diagnosis and 13 dogs with a confirmed closed cEHPSS had a second SPECT six months postoperatively. At diagnosis, dogs with cEHPSS had an altered rCBF distribution compared to healthy dogs. This altered rCBF distribution seemed to be most apparent in dogs ≥ one year and in dogs with overt HE at diagnosis. Six months postoperatively, only the rCBF distribution in the subcortical region decreased compared to pre-operatively. In conclusion, all dogs with cEHPSS had altered rCBF which did not seem to normalize completely six months after successful surgical attenuation. Dogs diagnosed at an older age seemed to have more distinct abnormalities in rCBF compared to younger dogs.

Computed tomographic measures of renomegaly vary among dogs with different types of congenital portosystemic shunts

Renomegaly has been reported in dogs with congenital portosystemic shunts (PSS). However, no study has objectively evaluated the degree of renomegaly in dogs with different types of PSS. The purpose of this retrospective, analytical, cross-sectional study was to determine kidney size (renal length-to-L2 vertebral body ratio; RL/L2 ratio) using CT in dogs with different types of PSS and correlate with clinical information. A medical record search for dogs with a PSS diagnosed using CT between 2016 and 2020 was conducted. Breed, age, sex, body weight, and biochemistry results were recorded. Kidney and L2 vertebral body lengths were measured using multiplanar reformatted CT images, and the RL/L2 ratio was calculated. Dogs were categorized into four groups based on PSS morphology for comparisons: intrahepatic (IH; n = 19), extrahepatic portocaval (EHPC; n = 20), extrahepatic portoazygos (EHPA; n = 7), or extrahepatic portophrenic (EHPP, n = 7). The RL/L2 ratio (mean ± SD) was largest in IH (3.55 ± 0.38) and EHPC (3.55 ± 0.38), followed by EHPP (3.10 ± 0.23), and EHPA (2.78 ± 0.18). RL/L2 ratio was significantly larger in EHPC and IH (vs. EHPA and EHPP [P < .01]). Significant correlations between kidney size and creatinine, alkaline phosphatase, albumin, total protein, and ammonia were present. Renomegaly was observed in 86.8% of dogs with PSS overall, but it was uncommon in dogs with EHPA and less common in dogs with EHPP, as these two groups showed clinical signs later in life, made evident by older age at presentation. The authors suggest that the severity of hepatic dysfunction and the shunted blood volume may influence the development of renomegaly in dogs with PSS.

Prospective Study Comparing Outcome following Complete Polypropylene Suture Ligation versus Partial Thin Film Band Attenuation of Congenital Portosystemic Shunts in Dogs

The main objective was to conduct a prospective study reporting the outcome for dogs with an extrahepatic congenital portosystemic shunt (CPSS) treated with a 'complete ligation where possible' philosophy. The second aim was to compare the outcomes following complete (C) polypropylene suture ligation versus partial thin film band (TFB) attenuation of a CPSS in dogs. Dogs that could not tolerate acute complete shunt ligation at surgery received partial shunt attenuation with TFB. Peri-operative complications, mortality, follow-up imaging findings, pre- and post-operative bile acid stimulation test results and details of any revision surgery performed were recorded. A follow-up health-related quality of life questionnaire enabled the calculation of a postoperative clinical shunt score, a quality of life score, and determined if any dogs were still on a hepatic diet and/or other medical management at a minimum of 6 months after surgery. Of the 110 dogs enrolled, 57 received complete ligation and 53 received partial TFB attenuation. Peri-operative mortality, the occurrence of post-attenuation neurological complications, the occurrence of multiple acquired shunts, the postoperative clinical shunt score and quality of life score were not significantly different between the two groups. Dogs in the C group were older, heavier and demonstrated a greater number of shunt classifications where the entry into the systemic circulation was the phrenic vein or azygous vein. Dogs in the TFB group had a greater number of unchanged bile acid concentrations after surgery, were more likely to remain on the hepatic diet and/or medical management after surgery and underwent a greater number of revision surgeries. There was variability in the precision of both ultrasound and computed tomographic angiography follow-up imaging compared to intra-operative mesenteric portovenography findings at revision surgery. Overall, dogs with an extrahepatic portosystemic shunt receiving either complete acute shunt ligation or partial TFB shunt attenuation are expected to have an excellent long-term clinical outcome and there is no reason to suggest that a dog able to tolerate complete acute shunt closure should be denied the benefit of this.

Intramural esophageal location of a portosystemic shunt in a dog with two congenital portosystemic shunts on CT angiography

A 5-year-old male neutered pug with hematuria was presented to a referral hospital after identification of an extrahepatic portosystemic shunt (EHPSS) during abdominal ultrasonography. Computed tomographic-angiography revealed two anomalous blood vessels (left gastroazygous and left gastrophrenic). The left gastroazygous vessel followed an atypical path within the dorsolateral esophageal wall before entering the azygous vein. The morphology of this highly unusual vessel has not, based on the authors' review of the literature, been previously reported. In combination with a second anomalous vessel, this resulted in a unique presentation of an EHPSS. Computed tomography-angiography was essential for diagnosis and surgical planning in this case.

Congenital Portosystemic Shunts in Dogs and Cats: Treatment, Complications and Prognosis

Congenital portosystemic shunts (CPSS) are a common vascular anomaly of the liver in dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise the clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests and diagnostic imaging. The aim of this article is to review the management, both medical and surgical, complications, and prognosis of CPSS in dogs and cats. Attenuation of the CPSS is the treatment of choice and may be performed by open surgical intervention using ameroid ring constrictors, thin film banding, and partial or complete suture ligation or by percutaneous transvenous coil embolization. There is no strong evidence to recommend one surgical technique over another. Medical treatment strategies include administration of non-absorbable disaccharides (i.e., lactulose), antibiotics, and dietary changes, and are indicated for pre-surgical stabilization or when surgical intervention is not feasible. After CPSS attenuation, short- and long-term post-surgical complications may be seen, such as post-operative seizures and recurrence of clinical signs, respectively. Prognosis after surgical attenuation of CPSS is generally favorable for dogs and fair for cats.

Congenital Portosystemic Shunts in Dogs and Cats: Classification, Pathophysiology, Clinical Presentation and Diagnosis

Congenital portosystemic shunts (CPSS) are abnormal vascular communications between the portal and the systemic circulation, bypassing the hepatic parenchyma and resulting in liver hypoplasia and hepatic insufficiency. Such connections develop in utero and persist postnatally. CPSS are among the two most common congenital vascular anomalies of the liver in small animals, along with primary hypoplasia of the portal vein without portal hypertension (PHPV without PH). CPSS can be extrahepatic (ECPSS), most commonly diagnosed in small and toy breed dogs and cats, or intrahepatic (ICPSS), most commonly seen in large breed dogs. Single ECPSS is the most common type encountered in both dogs and cats. Clinical signs of CPSS are non-specific and may wax and wane, while laboratory findings can raise clinical suspicion for CPSS, but they are also not specific. Definitive diagnosis will be established by evaluation of liver function tests, such as determination of fasting plasma ammonia (FA) levels, and pre- and postprandial serum bile acids concentrations, and diagnostic imaging. The purpose of this article is to review the definition, classification, pathogenesis, clinical presentation, and diagnosis of CPSS in dogs and cats, highlighted by the authors' clinical experience.

Congenital portopulmonary shunt in a cat

A 9-year-old spayed female crossbreed cat with chief complaints of anorexia and hypersalivation had high serum concentrations of ammonia and fasting and postprandial total bile acid. Therefore, she was referred to our hospital. On the first evaluation, haematology, serum chemistry, radiography and ultrasonography findings suggested that she had a congenital portosystemic shunt. CT revealed a shunt vessel from the left gastric vein to the left pulmonary vein. During median celiotomy and sternotomy, gross findings and mesenteric portography revealed abnormal vessel shunting from the left gastric vein to the left pulmonary vein. Complete ligation of the shunt vessel was achieved. She recovered without any complications. Postoperative serum chemistry revealed that ammonia and total bile acid levels decreased to within the reference intervals. This report is the first to describe the clinical features and surgical outcome of a cat with a congenital portopulmonary shunt.

Postattenuation neurologic signs after surgical attenuation of congenital portosystemic shunts in dogs: A review

The development of postattenuation neurologic signs (PANS) is a poorly understood and potentially devastating complication after surgical attenuation of congenital portosystemic shunts in dogs. Postattenuation neurologic signs include seizures but also more subtle neurologic signs such as depression, behavioral changes, tremors, and twitching. They most commonly occur within 7 days postoperatively and are typically unrelated to hyperammonemia, hypoglycemia, or electrolyte disturbances. This narrative review summarizes the findings of 50 publications from 1988-2020 that report occurrence of PANS. While most published reports included only dogs affected by postattenuation seizures (PAS), others included dogs with any form of PANS. Overall, PANS (including PAS) affected 1.6%-27.3% of dogs, whereas incidence of PAS ranged from 0%-18.2%. The etiology of PANS remains unknown; however, several theories have been proposed. Risk factors include preoperative hepatic encephalopathy, increasing age, and possibly certain breeds and extrahepatic shunt morphology. There is increasing evidence that prophylactic antiepileptic drugs do not prevent PANS. Treatment is centered around controlling neurologic signs with antiepileptic drugs and providing supportive intensive care. The 30-day survival rate in studies that included a minimum of four dogs affected by PANS was 0%-100% (median, 50.0%) and 0%-75.0% (median, 37.5%) for those with PAS. Mortality associated with PANS was typically related to occurrence of generalized seizure activity. Prognostic factors positively associated with short-term survival included having a history of preoperative seizures and development of focal seizures only. If affected dogs survived to discharge, survival for several years was possible, and the majority of neurologic signs manifested as part of the phenomenon of PANS appeared to resolve.

Risk factors for urinary bacterial growth in dogs with congenital portosystemic shunts: 66 cases (1997-2019)

OBJECTIVE

To identify risk factors for urinary bacterial growth in dogs with confirmed congenital portosystemic shunts on which a quantitative urine culture was performed.

MATERIALS AND METHODS

Sixty-six dogs were included in this retrospective cross-sectional study. Medical records were reviewed from 1997 through 2019. Variables of interest included age, sex and sexual status, clinical signs for a urinary tract infection, blood urea concentration, urinalysis abnormalities, ultrasound abnormalities of the urinary tract, and previous treatment. Univariable and multivariable analyses were performed.

RESULTS

The median age of the dogs was one year (range: 0.2-11.0 years). Urinary tract ultrasound abnormalities (cystic calculi and cystic debris) were reported in 50 dogs (75.7%). Abnormalities on urinalysis included pyuria in nine dogs (13.6%), bacteriuria in 13 dogs (19.7%), and haematuria in 26 dogs (39.4%). The median urine specific gravity was 1.021 (range: 1.004-1.052). Sixteen dogs (24.2%) had a positive quantitative urine culture. Based on multivariable analysis, bacteriuria (Odds ratio, 116; 95% CI, 9.6-1393; P = < 0.001) was the only variable significantly associated with a significantly increased odds for a positive quantitative urine culture.

CLINICAL SIGNIFICANCE

Clinical and subclinical bacteriuria can occur in dogs with congenital portosystemic shunts. In this group of dogs, bacteriuria was a risk factor for urinary bacterial growth.

Classification of portosystemic shunts entering the caudal vena cava at the omental foramen in dogs

OBJECTIVE

To re-evaluate the anatomy and classification of congenital extrahepatic portosystemic shunts entering the caudal vena cava at the level of the omental foramen.

MATERIAL AND METHODS

A retrospective review of a consecutive series of dogs undergoing CT angiography as part of the diagnostic work-up for a congenital extrahepatic portosystemic shunt.

RESULTS

In total, 53 dogs met the inclusion criteria revealing four anatomically distinct omental foramen shunt types; one of which (32 of 53 dogs) showed no shunting blood flow through the right gastric vein and three of which (21 of 53 dogs) involved shunting flow through this vessel. The anatomy of these four distinct shunt types, as defined by CT angiography, was found to be highly consistent. In all cases, regardless of the tributary vessels, the left gastric vein was the final vessel that communicated with the caudal vena cava. Using these findings, a more accurate naming classification for congenital portosystemic shunts entering the caudal vena cava at the level of the omental foramen was proposed.

CLINICAL SIGNIFICANCE

A precise pre-treatment anatomical classification of congenital extrahepatic portosystemic shunts entering the caudal vena cava at the level of the omental foramen is important for a more complete understanding of the severity of clinical signs and prognosis, and for the better communication between clinicians and researchers in this clinical field.

Computed tomographic-derived measurements of shunt fraction and hepatic perfusion in dogs with a single extrahepatic portosystemic shunt in a clinical setting

OBJECTIVE

To evaluate the clinical feasibility and usefulness of measuring shunt fraction (SF) and hepatic perfusion with CT in dogs with a single extrahepatic portosystemic shunt (EPSS).

ANIMALS

36 client-owned dogs with EPSS.

PROCEDURES

Dogs with EPSS referred for treatment between February 2016 and May 2017 were eligible for the clinical trial. Shunt type, SF, and hepatic perfusion were determined in each dog with a 320-row multidetector CT scanner, and surgical treatment was performed by a single veterinary surgeon. Differences in results between dogs grouped according to age (< 3 years vs ≥ 3 years), shunt type, and subgroups (eg, clinical signs and surgical procedure) were analyzed, and correlations between the SF and hepatic perfusion variables were evaluated.

RESULTS

The median SF was higher in dogs < 3 years old (74.6%; n = 18) versus dogs ≥ 3 years old (35.1%; 18). Correlations were identified between SF and hepatic perfusion variables, and differences in results for SF and hepatic perfusion variables were detected between dogs grouped according to shunt type.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that CT-derived measurements of SF and hepatic perfusion variables in dogs with EPSS were feasible and could be useful (eg, estimating EPSS condition status and planning treatment) in clinical settings. In addition, our findings suggested that perfusion CT could be useful for distinguishing hemodynamic characteristics among different types of portosystemic shunts in dogs.

Abramov P, M. Abdelhamid F. Clinical Characteristics, Serum Biochemical Changes, and Expression Profile of Serum Cfa-miRNAs in Dogs Confirmed to Have Congenital Portosystemic Shunts Accompanied by Liver Pathologies

Computed tomography angiography (CTA) and biochemical parameters cannot specify liver pathologies in dogs with congenital portosystemic shunts (CPSS) that are easily determined by invasive histopathology. This study aims to assess the possibility of using circulating serum canine familiaris (cfa) microRNAs (miRNAs) as novel non-invasive serum-based fingerprints for liver injuries associated with various morphologies of extrahepatic and intrahepatic portosystemic shunts (EHPSS and IHPSS). Data were obtained from 12 healthy dogs and 84 dogs confirmed to have EHPSS (splenocaval, splenophrenic, splenoazygos, right gastrocaval (RGC), right gastrocaval with caudal loop (RGC-CL)) and IHPSS (right divisional and left divisional) using CTA. Hepatic pathologies were determined by histopathology. Serum expression of miRNAs was assessed by real-time polymerase chain reaction. Based on the nature of liver injuries in each shunt type, cfa-miR-122 was significantly upregulated in all CPSS groups. Meanwhile, serums cfa-miR-34a and 21 were not significantly expressed in splenophrenic or splenoazygos groups, but they were extensively upregulated in splenocaval, RGC, RGC-CL groups and less frequently in right or left divisional groups. Also, serum cfa-miR126 was significantly upregulated in both IHPSS groups but less significantly expressed in RGC, RGC-CL, and splenocaval groups. Overall, estimated cfa-miRNAs could serve as novel biomarkers to mirror the histopathological and molecular events within the liver in each shunt type.

Diagnostic value of blood variables following attenuation of congenital extrahepatic portosystemic shunt in dogs

BACKGROUND

The aims of this study were to determine if extrahepatic portosystemic shunt (EHPSS) postoperative closure could be predicted based on preoperative blood analyses and to determine the accuracy of blood variables to evaluate persistence of portosystemic shunting postoperatively (multiple acquired portosystemic shunts (MAPSS) or persistent EHPSS).

METHODS

Retrospectively, 62 dogs treated surgically for congenital EHPSS that underwent postoperative trans-splenic portal scintigraphy or CT angiography three to six months postoperatively were included.

RESULTS

None of the studied preoperative blood variables could unambiguously predict surgical outcome. Elevated postoperative fasting venous ammonia (FA) concentration always indicated surgical failure (persistent shunting or MAPSS), but normal FA did not provide any information on the postoperative shunting status. Paired serum bile acids (SBA) were not reliable enough to confirm or exclude postoperative shunting. In the presence of low normal postoperative FA levels, elevated preprandial SBA was more likely in dogs with persistent shunting (sensitivity of 0.79, specificity of 0.83), whereas postprandial SBA below reference limit was more often observed in case of surgical success (sensitivity of 0.93, specificity of 0.67).

CONCLUSION

Blood variables, and more specifically the combination of FA and SBA, are not a valuable alternative to advanced medical imaging to reliably assess the surgical outcome after EHPSS surgery.

Washout Ratio in the Hepatic Vein Measured by Contrast-Enhanced Ultrasonography to Distinguish Between Inflammatory and Noninflammatory Hepatic Disorders in Dogs

Background

Perflubutane microbubbles, a second‐generation ultrasound contrast agent, are phagocytized by Kupffer cells. This characteristic may be useful to differentiate diffuse hepatic diseases in dogs.

Hypothesis/objectives

To determine whether the washout ratio in the hepatic vein (HV) measured by contrast‐enhanced ultrasonography (CEUS) can distinguish between inflammatory and noninflammatory hepatic disorders in dogs.

Animals

Forty‐one client‐owned dogs with hepatic disorders including 14 with hepatitis, 7 with primary hypoplasia of the portal vein (PHPV), 9 with congenital portosystemic shunt (cPSS), and 11 with other hepatopathy were enrolled. Six dogs without hepatic disease also were evaluated as healthy controls.

Methods

Dogs with hepatic disorders were prospectively included. Contrast‐enhanced ultrasonography of the HV was performed for 2 minutes. Washout ratio was defined as the attenuation rate from peak intensity to the intensity at the end of the CEUS study.

Results

Washout ratio in the hepatitis group (median, 18.0%; range, 2.0–37.0%) was significantly lower than that of the PHPV (median, 52.2%; range, 11.5–86.3%), cPSS (median, 60.0%; range, 28.6–77.4%), other hepatopathy (median, 70.5%; range, 26.6–88.4%), and normal (median, 78.0%; range, 60.7–91.7%) groups. The area under the receiver operating characteristic curve for hepatitis was 0.960, with a 95% confidence interval (CI) of 0.853–0.990. Washout ratio ≤37.1% resulted in a sensitivity of 100% (95% CI, 78.5–100%) and specificity of 85.2% (95% CI, 67.5–94.1%) for the prediction of hepatitis.

Conclusions and Clinical Importance

Washout ratio can distinguish hepatitis from the other noninflammatory disorders with high accuracy. This result might reflect impaired Kupffer cell phagocytosis in dogs with hepatitis.

Splenophrenic portosystemic shunt in dogs with and without portal hypertension: can acquired and congenital porto-caval connections coexist?

The possible existence of the same pattern of porto-caval connection in dogs having a single congenital portosystemic shunt (CPSS) and in dogs having multiple acquired portosystemic shunt (MAPSS) secondary to portal hypertension (PH) was evaluated. Retrospective evaluation of all CT examinations of patients having portosystemic shunt (PSS) was performed in a 4-year time period. All anomalous porto-caval connections were assessed for anatomical pattern and compared with published veterinary literature. Records of 25 dogs were reviewed. 16 dogs had a single CPSS (CPSS group), and 9 dogs had multiple acquired PSS secondary to PH (APSS group). The splenophrenic shunt pattern was found in 3 dogs of the CPSS group as a single congenital anomaly without PH and in 2 dogs of the APSS group associated with MAPSS and ascites due to different hepatic diseases causing PH. These findings corroborate two hypotheses: 1) Splenophrenic PSS should be considered as a classical CPSS but if this is not sufficient to alleviate a PH developed after birth because of eventual hepatic or portal diseases, in this case ascites and acquired portal collaterals may develop. In this case, MAPSS and CPSS may coexist. 2) The pattern of splenophrenic PSS, classically described among CPSS, may develop as acquired portal collateral in dogs with PH and it should also be included in the category of APSS. These preliminary findings may be helpful in reconsidering the classical haemodynamics of porto-caval diseases, enrich the classification of APSS in dogs and refine the imaging evaluation of patients with PH.

Emphysematous pyonephrosis associated with extrahepatic portosystemic shunt in a dog

A 16-month-old intact female Maltese dog was referred for examination of depression and vomiting. Ultrasonography revealed dilated right renal pelvis containing echogenic fluid with free gas. A hyperechoic material suspected of urolith was identified in the right ureter. Computed tomography revealed emphysematous change of the right kidney associated with ureteral obstruction and extrahepatic portosystemic shunt (EHPSS). Ureteronephrectomy and surgical correction were performed for the EHPSS. Escherichia coli was isolated from pus from the right kidney. Quantitative analysis revealed that the urolith was an ammonium urate stone. After 5 months follow-up, no complication was observed. This is the first report of emphysematous pyonephrosis associated with EHPSS in a dog.