Single Extrahepatic Portosystemic Shunts Research Articles

Diagnosis and classification of portosystemic shunts: a machine learning retrospective case-control study.

Diagnosis of portosystemic shunts (PSS) in dogs often requires multiple diagnostic tests, and available clinicopathologic tests have limitations in sensitivity and specificity. The objective of this study was to train and validate a machine learning model (MLM) that can accurately predict the presence of a PSS utilizing routinely collected demographic data and clinicopathologic features. Dogs diagnosed with PSS or control dogs tested for PSS but had the condition ruled out (non-PSS) were identified. Dogs were included if a complete blood count and serum chemistry panel were available from PSS diagnostic testing. Dogs with a PSS were subcategorized as having a single intrahepatic PSS, a single extrahepatic PSS, or multiple extrahepatic PSS. An extreme gradient boosting (XGboost) MLM was trained with data from 70% of the cases, and MLM performance was determined on the test set, comprising the remaining 30% of the case data. Two MLMs were created. The first was designed to predict the presence of any PSS (PSS MLM), and the second to predict the PSS subcategory (PSS SubCat MLM). The trained PSS MLM had a sensitivity of 94.3% (95% CI 90.1-96.8%) and specificity of 90.5% (95% CI 85.32-94.0%) for dogs in the test set. The area under the receiver operator characteristic curve (AUC) was 0.976 (95% CI; 0.964-0.989). The mean corpuscular hemoglobin, lymphocyte count, and serum globulin concentration were most important in prediction classification. The PSS SubCat MLM had an accuracy of 85.7% in determining the subtype of PSS of dogs in the test set, with variable sensitivity and specificity depending on PSS subtype. These MLMs have a high accuracy for diagnosing PSS; however, the prediction of PSS subclassification is less accurate. The MLMs can be used as a screening tool to increase or decrease the index of suspicion for PSS before confirmatory diagnostics such as advanced imaging are pursued.

Percutaneous transvenous coil embolization (PTCE) for treatment of single extrahepatic portosystemic shunt in dogs

BackgroundThere is limited information regarding percutaneous transvenous coil embolization (PTCE) for single extrahepatic portosystemic shunt (PSS). This study aimed to describe the procedure and outcome of PTCE in dogs with a single extrahepatic PSS. Forty-two privately owned dogs were included in this study. All dogs were diagnosed with extrahepatic PSS by computed tomography (CT). Preoperative CT images were used to evaluate the diameter of the PSS for coil placement. A multipurpose balloon catheter was percutaneously inserted into the PSS via the jugular vein, and transvenous retrograde portography (TRP) and measurement of blood pressure in the PSS (pPSS) were performed during balloon inflation; one or more embolization coils were implanted via the catheter.ResultsIn most cases, preoperative median fasting and postprandial serum total bile acid (TBA) concentrations were high (fasting, 86.5 μmol/L [ 3.7–250.0 μmol/L]; postprandial, 165.5 μmol/L [ 1.5–565.0 μmol/L]). CT revealed that 30 dogs had left gastrophrenic shunt; eight had left gastroazygos shunt; and one each had left gastrocaval, splenocaval, splenophrenic, and left colocaval shunt. TRP revealed that intrahepatic portal vascularity was clearly detectable in all dogs. The median values of pPSS before and during the balloon occlusion were 4.8 mmHg [2.0–13.0 mmHg] and 8.6 mmHg [5.0–18.0 mmHg], respectively. The median number and diameter of coils used were 2 coils [1 – 5 coils] and 8.0 mm [4.0 – 12.0 mm], respectively. The median times of irradiation and PTCE were 9 min [4–26 min] and 40 min [23–75 min], respectively. The median fasting and postprandial TBAs significantly decreased to 8.2 μmol/L [0.3–45.1 μmol/L, n = 38, p = 0.0028] and 19.8 μmol/L [0.3–106.7 μmol/L, n = 38, p = 0.0018], respectively, approximately 1 month after PTCE. The clinical success rate of PTCE without requirement for a second surgery was 95.2% (40/42 dogs). During revision surgery, one dog underwent surgical ligation and, in another dog, an ameroid constrictor was placed.ConclusionsPTCE was clinically effective in treating single extrahepatic PSS in dogs. Preoperative CT and TRP prior to PTCE might be clinically valuable for choosing the size of embolization coils, deciding the appropriate location of coil implantation, and estimating the number of coils to be implanted. PTCE is a promising alternative to conventional surgical procedures for single extrahepatic PSS in dogs.

Quantitative analysis of contrast-enhanced ultrasound estimates intrahepatic portal vascularity in dogs with single extrahepatic portosystemic shunt.

To evaluate the clinical impact on quantitative analysis of contrast-enhanced ultrasound (CEUS) on single extrahepatic portosystemic shunt (PSS) in dogs. 21 client-owned dogs with single extrahepatic PSS and 5 healthy Beagles. In all dogs, CEUS was performed to calculate the rising time (RT), rising rate (RR), and portal vein-to-hepatic parenchyma transit time (ΔHP-PV) from the time-intensity curve obtained in the hepatic parenchyma and portal vein. All dogs in the PSS group underwent preoperative CT angiography (CTA) and surgery. The CEUS variables in the PSS group were compared with those in the healthy dogs (control group) and were analyzed for shunt types and grades of intrahepatic portal venous branches based on CTA findings, intraoperative portal pressure, and surgical procedures. All 3 CEUS variables showed no significant differences between the PSS and control groups. The RT and ΔHP-PV in the left gastrophrenic shunt group were significantly longer than in the other shunt types. In the intrahepatic portal vascularity, the RT in grade 1 was significantly shorter than in grades 3 and 4, and the RR in grade 1 was significantly higher than in grade 4. The RT and ΔHP-PV were significantly correlated with portal pressure variables. The RT in dogs with partial ligation was significantly shorter than in dogs with complete ligation and percutaneous transvenous coil embolization. Quantitative assessments of CEUS may be useful for estimating intrahepatic portal vascularity in dogs with single extrahepatic PSS.

The effectiveness of intraoperative mesenteric portography for preventing misdiagnosis of congenital absence of the portal vein in dog with extrahepatic portosystemic shunt: a case report

A 5-month-old mixed-breed dog and a 10-month-old Welsh corgi dog were presented for evaluation with signs of congenital portosystemic shunt. In both dogs, computed tomography angiography revealed a single extrahepatic portosystemic shunt with the absence of the portal vein cranial to the shunt origin. Intraoperative mesenteric portography (IOMP) was performed after temporary complete occlusion of the shunt, revealing the portal branches faintly opacified with contrast medium. A cellophane band was applied around the shunt vessel without intraoperative attenuation. Postoperatively, both the dogs showed significant clinical improvement and the portal veins, not observed on preoperative ultrasonography, were visualized on postoperative ultrasonography. This study suggests the efficacy of IOMP, enabling the appropriate surgical procedure to be determined.

Clinical and laboratory outcome after surgical treatment of single congenital extrahepatic portosystemic shunt using ameroid constrictor in 25 dogs

The objective of the study was to evaluate the clinical and laboratory outcome after the surgical treatment of a single congenital extrahepatic portosystemic shunt using an ameroid constrictor. Patient medical records were reviewed in retrospect. Data on the signalment, clinical signs, preoperative bile acid stimulation test and ammonia concentration were recorded. The surgical treatment success rate was evaluated by mortality in the perioperative and short-term postoperative period and by the long-term clinical outcome. Bile acid stimulation test and ammonia concentration were also analysed 2–3 days, 4–6 weeks, and 6–8 weeks postoperatively. No patient died in the selected periods. The long-term clinical outcome was excellent in 15 out of 20 patients, good in 3 out of 20 patients and poor in 2 out of 20 patients. Preprandial bile acid concentration was elevated in 96.00%, postprandial bile acid concentration in 100.00% and ammonia concentration in 80.95% of patients preoperatively. A significant decrease was found in postprandial bile acid and ammonia 2–3 days postoperatively and in preprandial bile acid 4–6 weeks postoperatively. A significant decrease in liver function parameters in days post operation indicates a rapid restoration of hepatic function. The surgical treatment of a single extrahepatic portosystemic shunt using an ameroid constrictor is a successful method of treatment for this type of portosystemic shunt, with as much as 75.00% of the patients having an excellent long-term clinical outcome.

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

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). 36 client-owned dogs with EPSS. 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. 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. 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.

Outcomes of dogs treated for extrahepatic congenital portosystemic shunts with thin film banding or ameroid ring constrictor.

To compare the outcomes of dogs treated at a single institution for single extrahepatic congenital portosystemic shunts (CPSS) by thin film banding (TFB) or by placement of an ameroid constrictor (AC). Retrospective case series. Seventy-six client-owned dogs with CPSS treated with TFB (n = 53) or AC (n = 23). Records were reviewed for signalment, preoperative, intraoperative, and postoperative management and short-term outcomes. Data on second surgeries were reviewed. Long-term outcomes were obtained via an owner-directed health-related quality of life questionnaire. The rates of complications, mortality, and revision surgery were compared between the treatment groups. Postoperative complications occurred in 15 (28%) dogs with TFB (9% mortality, n = 5) and 8 (35%) dogs with an AC (4% mortality, n = 1). Long-term follow-up was available in 41 of 56 dogs at a median of 55 months (range, 15-89). Revision surgery for persistent shunting was performed in 14 (29%) dogs treated initially with TFB and in no dogs treated initially with AC (P = .007). Median long-term outcome scores were good in both groups; nine of 14 revision surgeries led to favorable outcomes. Persistent shunting requiring revision surgery was more common when CPSS were treated with TFB than with an AC, but both treatments achieved favorable long-term outcomes. Treatment of CPPS by placement of an AC rather than TFB seems more reliable for shunt attenuation and prevention of revision surgeries.

Long‐term outcome after surgical ameroid ring constrictor placement for treatment of single extrahepatic portosystemic shunts in dogs

To report long-term clinical outcome in dogs treated for single congenital extrahepatic portosystemic shunt (CEHPSS) with a ameroid ring constrictor (ARC) and to identify perioperative variables associated with outcome. Retrospective, multi-institutional study. Dogs (n = 206) with CEHPSS. Medical records of dogs with CEHPSS treated by ARC were reviewed for perioperative and short-term (<1 month) data. Long-term follow-up information was obtained by telephone interview with referring veterinarians and/or owners. Kaplan-Meier analysis was used to estimate median survival time. Factors associated with short-term survival, outcome grade, and total survival time were identified. Fifteen dogs died <1 month after ARC placement. Follow-up data were obtained for 112 of 191 dogs that survived >1 month; median follow was 54 months (range, 1-175 months) and 103 (92%) dogs had no clinical signs. Estimated median survival time was 152 months. Variables significantly associated with short-term survival included being intact and a low total white blood cell (WBC) count. Variables significantly associated with a successful outcome included having surgery later in the study period and negative postoperative nuclear scintigraphy. In the long-term survival analyses, intact dogs and those with higher WBC counts and occlusion pressures and lower bile acid concentrations were more likely to survive. Dogs with CEHPSS treated by ARC generally have a good prognosis and prolonged postoperative survival.

Association of increased erythrocyte osmotic resistance with haematological and histopathological findings in dogs with a congenital extrahepatic portosystemic shunt

The aim of the study was to investigate changes in erythrocyte osmotic resistance in relation to haematological and histological changes in dogs with a congenital portosystemic shunt. Osmotic fragility tests with complete blood counts and liver histological examinations were performed in 12 dogs with single extrahepatic portosystemic shunt confirmed by surgical exploration. Laboratory results were compared with those from 30 healthy dogs. Dogs with portosystemic shunt had a significantly increased erythrocyte osmotic resistance (P&lt; 0.01) with 5%, 50% and 90% haemolysis corresponding to 0.45%, 0.35% and 0.30% NaCl solution, respectively. Statistical analyses revealed no correlation between haematological indicators and the osmotic fragility test results. Increased osmotic resistance was significantly associated with hepatic lipogranulomas. Based on these results, dogs with a congenital portosystemic shunt have a significantly increased erythrocyte osmotic resistance suggesting impaired red blood cell deformability. Osmotic resistance test that until now was not studied in canine hepatopathies seems to be independent of routinely performed haematological tests.

Intraoperative contrast echocardiography to verify the surgical occlusion of a single extrahepatic portosystemic shunt in a dog

This report details a bubble echocardiographic study carried out during the surgical treatment of a congenital single extrahepatic portosystemic shunt (PSS) in a Labrador Retriever. After celiotomy, agitated saline was injected through a jejunal vein and microbubbles appeared rapidly in the right cardiac chambers. The test confirmed the presence of a PSS, helping the surgeon to identify the vessel concerned and to rule out a second shunt. Successively, portography confirmed what the exploratory celiotomy had revealed before with the aid of the bubble study: a single shunt was located between the portal vein and the right renal vein. It was completely ligated, as all the criteria for this solution were met. Intraoperative contrast echocardiography (ICE) was easy to perform, helpful and undemanding. It is proposed here as an intraoperative ancillary test to diagnose all PSS and to confirm successful treatment when complete shunt closure is possible.

Outcome from status epilepticus after portosystemic shunt attenuation in 3 dogs treated with propofol and phenobarbital

To describe outcome of treatment with propofol and phenobarbital for status epilepticus (SE) after portosystemic shunt (PSS) attenuation. Three dogs without preceding seizure activity, were diagnosed with a single extrahepatic PSS. Following standard preoperative medical therapy, an ameroid constrictor was placed surgically. Recovery was uneventful until spontaneous SE developed 46-96 hours after surgery. After unsuccessful seizure control with benzodiazepines, dogs were treated with a bolus of propofol followed by a propofol constant rate infusion. Phenobarbital was concurrently administered and supportive care was optimized. All dogs recovered uneventfully over the next 7-9 days. Over the following months phenobarbital was slowly tapered. All dogs have been free from antiepileptic drugs for several months, without recurrence of neurologic signs. In this case series, we describe the treatment of 3 dogs with propofol and phenobarbital for refractory SE following attenuation of a single congenital PSS. After weaning of the propofol constant rate infusion, and tapering and discontinuation of phenobarbital over the following months, all dogs experienced a complete recovery. This study provides evidence that use of propofol in combination with phenobarbital may be efficacious for management of SE in dogs after PSS surgery.

Complex extrahepatic portocaval shunt with unusual caval features in a cat: computed tomographic characterisation

A two-year-old, neutered male domestic shorthair cat was evaluated for a history of urate calculi, and neurologic signs. Diagnostic imaging revealed an elongated and tortuous single extrahepatic portosystemic shunt which appeared to receive normal tributaries of the caudal vena cava. Surgical correction of the shunt was carried out using cellophane banding. Eight months following surgery, clinical signs had resolved. Computed tomographic angiography allows thorough, rapid imaging of complex vascular anomalies to aid proper surgical correction. Errors in the formation of the portal vein and caudal vena cava can produce complex anomalies of the abdominal vasculature. Persistence of the embryologic left subcardinal vein is proposed to account for the lesion.

In vitro expansion patterns of ameroid ring constrictors

To evaluate and quantify in vitro dimensional changes of ameroid ring constrictors (ARCs) with and without the outer stainless steel ring in place over time. 12 ARCs (5.0-mm diameter). 6 ARCs were immersed in canine plasma baths for 34 days without the stainless steel outer ring in place (group N), and 6 ARCs were immersed in canine plasma baths with the stainless steel outer ring in place (group R). The ARCs were digitally imaged at day 0, daily for the first 10 days, then on days 14, 20, 27, and 34. Inner diameter, outer diameter, luminal area, and height were measured for each time point. Volume and weight of rings were obtained at the start and completion of the study. The inner diameter, outer diameter, and luminal area were significantly different between the 2 groups over the course of 34 days. The inner diameter and luminal area of the R-group constructs did not change significantly, while the inner diameter, outer diameter, luminal area, and height of N-group constructs all significantly increased over the course of the study. R-group constructs had insignificant centripetal swelling without ring closure, whereas N-group constructs had significant generalized centrifugal expansion. Results of this study indicated that the outer stainless steel ring of an ARC may not be necessary for attenuation and closure of some single extrahepatic portosystemic shunts.

Use of transcolonic portal scintigraphy to evaluate efficacy of cellophane banding of congenital extrahepatic portosystemic shunts in 16 dogs

To evaluate the efficacy of cellophane banding of single congenital extrahepatic portosystemic shunts in dogs using transcolonic portal scintigraphy. To investigate the portal circulation of those dogs with elevated postoperative shunt fractions to determine the cause of the persistent shunting. Further, to evaluate whether presenting signs, clinical pathology findings and liver histopathology are predictive of outcome. Prospective study of 16 dogs presenting with single congenital extrahepatic portosystemic shunts. Dogs with single extrahepatic portosystemic shunts attenuated by cellophane banding underwent portal scintigraphy and bile acids tolerance testing pre- and post-operatively. Dogs identified with elevated shunt fractions at 10 weeks post-operatively underwent mesenteric portovenography. Qualitative hepatic histopathology from all dogs was reviewed by a veterinary pathologist and assigned a semi-quantitative score to identify any abnormalities that may predict surgical outcome. At 10 weeks post cellophane banding, 10 of 16 cases (63%) had normal shunt fractions, whilst six dogs (37%) had increased shunt fractions and seven dogs (44%) had increased serum bile acids. Of these dogs, mesenteric portovenography revealed incomplete closure of the shunt in three dogs (18.6%) and multiple acquired shunts in three dogs (18.6%). Liver histopathology findings were similar for all dogs, regardless of outcome. Cellophane banding is an efficacious method for complete gradual occlusion of single extrahepatic shunts when the shunt vessel is attenuated to < or = 3 mm. Transcolonic portal scintigraphy is a reliable method for assessment of shunt attenuation and, unlike serum bile acids, is not influenced by other causes of liver dysfunction.

Evaluation of ameroid ring constrictors for treatment for single extrahepatic portosystemic shunts in dogs: 168 cases (1995–2001)

To evaluate use of an ameroid ring constrictor (ARC) for treatment for single extrahepatic portosystemic shunts (PSSs) and identify factors associated with postoperative death, continued portosystemic shunting, and long-term outcome in dogs. Retrospective study. 168 dogs with a single extrahepatic PSS. Medical records of dogs that had a single extrahepatic PSS and were treated with an ARC were reviewed. Signalment, history, clinical signs, results of preoperative blood analyses and portal pressure measurements, PSS location, ARC size, postoperative complications, and postoperative scintigraphy results were recorded. Owners were interviewed 6 months to 6 years after surgery. Results-Postoperative complications developed in 10% of dogs. Postoperative mortality rate was 7.1%. Predictive factors for postoperative death included high preoperative WBC count and postoperative complications. Twenty-one percent of dogs in which portal scintigraphy was performed 6 to 10 weeks after surgery had continued shunting. Predictive factors for persistent shunting included low preoperative plasma albumin concentration, high portal pressure after complete occlusion, and high portal pressure difference (postocclusion minus baseline). Clinical outcome in 108 dogs was classified as excellent (80%), good (14%), or poor (6%). Predictive factors for excellent long-term clinical outcome included high preoperative plasma albumin concentration, low preoperative leukocytosis, low portal pressure after complete occlusion, absence of postoperative seizures, and absence of continued shunting. Use of an ARC for treatment for a single extrahepatic PSS resulted in low morbidity and mortality rates. Certain preoperative factors were associated with increased risk of postoperative death, continued portosystemic shunting, and long-term outcome.

Simultaneous congenital and acquired extrahepatic portosystemic shunts in two dogs.

Two dogs with simultaneous congenital and acquired portosystemic shunts are reported. The first dog was an eight-month-old, male Golden Retriever with a history of peritoneal effusion, polyuria/polydipsia, and stunted growth. The dog had a microcytic, hypochromic anemia, a mildly elevated AST, and a moderate to severely elevated preprandial and postprandial serum bile acids. Transcolonic portal scintigraphy confirmed the presence of a portosystemic shunt. An intraoperative mesenteric portogram was performed. Two conjoined congenital extrahepatic portosystemic shunts and multiple acquired extrahepatic portosystemic shunts were identified. The second dog was a five-month-old, mixed breed with two week history of peritoneal effusion. Abdominal ultrasound and transcolonic scintigraphy were used to diagnose a portosystemic shunt. A single extrahepatic portosystemic shunt, portal hypertension, and multiple acquired collateral shunts were identified at surgery. The histologic alterations observed in these dogs were consistent with a portosystemic shunt. In these dogs, the presence of congenital and acquired portosystemic shunts and histopathologic findings are considered to represent a combination of congenital portosystemic shunts and noncirrhotic portal hypertension or portal vein hypoplasia.

Portosystemic Shunts: Diagnosis, Prognosis, and Treatment of 64 Cases (1993–2001)

Cases diagnosed with portosystemic shunting between the years 1993 and 2001 were reviewed. Sensitivities of screening tests and abdominal ultrasonographic evaluation for the detection of portosystemic shunting were evaluated. Prognosis for surgically treated shunts was also evaluated. Results indicated that both paired serum bile acids and blood ammonia levels were useful screening tests for portosystemic shunting. However, paired bile acid tests were significantly more sensitive than blood ammonia levels. Overall postoperative mortality rates for extrahepatic shunts and intrahepatic shunts were 8.7% and 20%, respectively. Postoperative mortality rates were slightly higher for animals treated with partial ligation when compared to those treated with ameroid ring placement, although this did not reach statistical significance. Long-term complication rates for animals with single extrahepatic portosystemic shunts treated with complete ligation, ameroid ring placement, and partial ligation alone were 9%, 15.4%, and 42%, respectively. Animals >2 years of age with extrahepatic shunts had almost identical postoperative mortality and long-term complication rates as animals < or = 2 years of age. No animal in this study had paired bile acid samples within the reference range postoperatively, indicating continued abnormal liver function after surgery.

Transvenous retrograde portography for identification and characterization of portosystemic shunts in dogs.

Transvenous retrograde portography for identification and characterization of portosystemic shunts in dogs A method for transvenous retrograde portography (TRP) in dogs suspected to have a portosystemic shunt (PSS) and results in 20 dogs are described. For TRP, dogs were anesthetized and positioned in left lateral recumbency A dual-lumen balloon-tipped catheter was inserted into the right jugular vein and advanced into the azygos vein. The balloon was inflated to occlude the azygos vein, and contrast material was injected during fluoroscopic evaluation. The catheter was then positioned in the caudal vena cava just cranial to the diaphragm. The balloon was again inflated to occlude the vena cava, and contrast material was again injected. Once a shunt was identified, selective catheterization was attempted with a guide wire and angled catheter. A PSS was identified in 18 of the 20 dogs. In 10 of the 18, the shunt vessel could be selectively catheterized, allowing measurement of portal pressures while the shunt was occluded with the balloon. In 1 dog, results of TRP were normal, but subsequent exploratory celiotomy revealed a single extrahepatic PSS, which was surgically attenuated. The other dog in which results of TRP were normal did not have a macroscopic PSS. In dogs suspected to have a PSS, TRP may be a useful adjunctive diagnostic test that is less invasive than operative mesenteric vein portography and allows measurement of portal pressures before and after temporary shunt occlusion.

Evaluation of ameroid ring constrictors for the management of single extrahepatic portosystemic shunts in cats: 23 cases (1996–2001)

To document the signalment; history; clinical signs; clinicopathologic, diagnostic imaging, and surgical findings; perioperative complications; and long-term clinical results of ameroid ring constrictor (ARC) placement on single extrahepatic portosystemic shunts (PSS) in cats. Retrospective study. 23 cats treated with an ARC on a single extrahepatic PSS. An ARC was placed surgically around the PSS. Portal pressure was measured prior to ARC placement, with complete temporary PSS occlusion, and after ARC placement. Cats were scheduled for recheck transcolonic portal scintigraphy 8 to 10 weeks after surgery. Follow-up information was obtained by telephone interview with the owners. An ARC was successfully placed in 22 of 23 cats. Intraoperative complications, consisting of PSS hemorrhage, occurred in 2 cats. Mean (+/- SD) portal pressure (n = 15) was 6.7+/-2.9 mm Hg before PSS manipulation, 18.6+/-7.7 mm Hg with complete temporary PSS occlusion, and 6.9+/-2.7 mm Hg after ARC placement. Postoperative complications developed in 77% (17 of 22) of cats after ARC placement, and included central blindness, hyperthermia, frantic behavior, and generalized motor seizures. Perioperative mortality rate was 4.3% (1 of 23). Persistent shunting was identified in 8 of 14 cats. Overall, 75% (15 of 20) of cats had an excellent long-term outcome. Placement of an ARC on single extrahepatic PSS in cats resulted in low surgical complication and perioperative mortality rates, but most cats did have substantial postoperative complications. Persistent shunting was common, although many cats with persistent shunting were clinically normal.

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.