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Farhoodimoghadam M, Reagan KL, Zwingenberger AL. Diagnosis and classification of portosystemic shunts: a machine learning retrospective case-control study. Front Vet Sci 2024; 11:1291318. [PMID: 38638645 PMCID: PMC11024426 DOI: 10.3389/fvets.2024.1291318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 03/21/2024] [Indexed: 04/20/2024] Open
Abstract
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.
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Affiliation(s)
- Makan Farhoodimoghadam
- Department of Computer Science, University of California, Davis, Davis, CA, United States
| | - Krystle L. Reagan
- Department of Veterinary Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Allison L. Zwingenberger
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
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Konstantinidis AO, Patsikas MN, Papazoglou LG, Adamama-Moraitou KK. Congenital Portosystemic Shunts in Dogs and Cats: Classification, Pathophysiology, Clinical Presentation and Diagnosis. Vet Sci 2023; 10:vetsci10020160. [PMID: 36851464 PMCID: PMC9961057 DOI: 10.3390/vetsci10020160] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/07/2023] [Accepted: 02/14/2023] [Indexed: 02/19/2023] Open
Abstract
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.
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Affiliation(s)
- Alexandros O. Konstantinidis
- Companion Animal Clinic (Medicine Unit), School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece
- Correspondence:
| | - Michail N. Patsikas
- Laboratory of Diagnostic Imaging, School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece
| | - Lysimachos G. Papazoglou
- Companion Animal Clinic (Surgery and Obstetrics Unit), School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece
| | - Katerina K. Adamama-Moraitou
- Companion Animal Clinic (Medicine Unit), School of Veterinary Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, 54627 Thessaloniki, Greece
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Nilsson CH, Svensson MBT, Säve SJM, Van Meervenne SAE. Transient hyperammonaemia following epileptic seizures in cats. J Feline Med Surg 2021; 23:534-539. [PMID: 33034248 PMCID: PMC10741304 DOI: 10.1177/1098612x20962747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The aim of this study was to determine whether transient postictal hyperammonaemia exists in cats. METHODS The medical records of all feline patients that presented at a Swedish veterinary hospital between 2008 and 2018 were retrospectively reviewed to find those that had a recent or ongoing epileptic seizure. To qualify for inclusion, the medical record had to include information on at least one ammonia value taken in close proximity to, or during, an active seizure, the cat must have exceeded the normal upper limit of blood ammonia concentration on initial testing (reference interval 0-95 μmol/l), and there needed to be a follow-up ammonia value available within a maximum of 3 days. RESULTS Five cats were included in the study, and they had blood ammonia concentrations on initial testing ranging from 146 to 195 µmol/l. They were all retested within a period of 2 h to 3 days of the original reading. All five cats had a spontaneous decrease in ammonia levels without any specific treatment for hyperammonaemia. CONCLUSIONS AND RELEVANCE Pursuant to the findings of this retrospective study, transient hyperammonaemia may be noted after epileptic seizure in cats. Consequently, a differential diagnostic list in feline patients with hyperammonaemia could, depending on the context, include non-hepatic-related pathologies, such as epileptic seizures.
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Devriendt N, Serrano G, Paepe D, de Rooster H. Liver function tests in dogs with congenital portosystemic shunts and their potential to determine persistent shunting after surgical attenuation. Vet J 2020; 261:105478. [PMID: 32741493 DOI: 10.1016/j.tvjl.2020.105478] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 05/24/2020] [Accepted: 05/29/2020] [Indexed: 02/03/2023]
Abstract
Portosystemic shunts (PSS) are congenital or acquired vascular anomalies that cause blood to bypass the liver. Liver function tests, such as fasting ammonia, ammonia tolerance test, and (paired) serum bile acids, are reliable for the diagnosis of PSS in dogs. Surgical attenuation is a common treatment for congenital PSS. Following surgical attenuation, it is useful to evaluate shunt closure. In this critical review, the ability of liver function tests to determine the presence and degree of residual shunting following surgical attenuation of canine PSS is discussed. Despite the availability of several liver function tests, a single rapid, simple, cost-effective, sensitive and specific test to evaluate surgical attenuation of PSS is not available.
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Affiliation(s)
- Nausikaa Devriendt
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium.
| | - Gonçalo Serrano
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Dominique Paepe
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Hilde de Rooster
- Small Animal Department, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820 Merelbeke, Belgium
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Saline is as effective as nitrogen scavengers for treatment of hyperammonemia. Sci Rep 2017; 7:13112. [PMID: 29030642 PMCID: PMC5640627 DOI: 10.1038/s41598-017-12686-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Accepted: 09/14/2017] [Indexed: 12/22/2022] Open
Abstract
Urea cycle enzyme deficiency (UCED) patients with hyperammonemia are treated with sodium benzoate (SB) and sodium phenylacetate (SPA) to induce alternative pathways of nitrogen excretion. The suggested guidelines supporting their use in the management of hyperammonemia are primarily based on non-analytic studies such as case reports and case series. Canine congenital portosystemic shunting (CPSS) is a naturally occurring model for hyperammonemia. Here, we performed cross-over, randomized, placebo-controlled studies in healthy dogs to assess safety and pharmacokinetics of SB and SPA (phase I). As follow-up safety and efficacy of SB was evaluated in CPSS-dogs with hyperammonemia (phase II). Pharmacokinetics of SB and SPA were comparable to those reported in humans. Treatment with SB and SPA was safe and both nitrogen scavengers were converted into their respective metabolites hippuric acid and phenylacetylglutamine or phenylacetylglycine, with a preference for phenylacetylglycine. In CPSS-dogs, treatment with SB resulted in the same effect on plasma ammonia as the control treatment (i.e. saline infusion) suggesting that the decrease is a result of volume expansion and/or forced diuresis rather than increased production of nitrogenous waste. Consequentially, treatment of hyperammonemia justifies additional/placebo-controlled trials in human medicine.
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Grobelna AP, Honkavaara J, Restitutti F, Huuskonen V, Sakka SG, Spillmann T. Evaluation of a transcutaneous method to assess canine liver function by indocyanine green plasma disappearance rate in healthy adult Beagle dogs. Vet J 2015; 209:169-73. [PMID: 26831155 DOI: 10.1016/j.tvjl.2015.10.053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 10/23/2015] [Accepted: 10/26/2015] [Indexed: 11/29/2022]
Abstract
A non-invasive, transcutaneous method using near infrared spectroscopy to assess indocyanine green plasma disappearance rate (ICG-PDR) in healthy dogs subjected to different conditions was evaluated in eight healthy purpose-bred Beagles under isoflurane-anaesthesia (Trial 1) and when they had initially recovered from anaesthesia (Trial 2). Plasma ICG concentrations (0, 5, 10, 15, 30 min after rapid ICG injection (0.5 mg/kg) into a peripheral vein were determined by high-performance liquid chromatography in parallel with transcutaneous measurements. ICG clearance (mL/min/kg) and retention rate after 15 min (R15, %) were calculated from plasma concentrations to be 3.09 ± 0.83 (mean ± SD) and 30.6 ± 8.3 in anaesthetised dogs and 3.63 ± 0.88 and 28.1 ± 7.3 in recovering dogs, respectively. ICG-PDR (%/min) and R15 (%) obtained using the transcutaneous method were 7.11 ± 3.18 and 34.6 ± 12.4 (Trial 1) and 7.79 ± 3.33 and 32.3 ± 9.2 (Trial 2). The coefficients of determination (r(2)) for ICG clearance and ICG-PDR were 0.14 (Trial 1) and 0.81 (Trial 2) and 0.47 (Trial 1) and 0.29 (Trial 2) for R15, respectively. The mean bias (lower, upper limit of agreement) for R15 were 5.6 (-12.3, 23.5) (Trial 1) and 3.9 (-12.4, 20.1) (Trial 2). The results suggest good agreement between the two methods in dogs recovering from isoflurane-anaesthesia and the transcutaneous method might be useful in real-time assessment of liver function in conscious dogs.
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Affiliation(s)
- A P Grobelna
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, PO Box 59 (Viikintie 49), 00014 Helsinki, Finland
| | - J Honkavaara
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, PO Box 59 (Viikintie 49), 00014 Helsinki, Finland
| | - F Restitutti
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, PO Box 59 (Viikintie 49), 00014 Helsinki, Finland
| | - V Huuskonen
- UCD Veterinary Hospital, School of Veterinary Medicine, University College Dublin, Belfield, Dublin, Ireland
| | - S G Sakka
- Department of Anesthesiology and Operative Intensive Care Medicine, Cologne-Merheim Medical Center (CMMC),Witten/Herdecke University, Witten, Germany
| | - T Spillmann
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, Helsinki University, PO Box 59 (Viikintie 49), 00014 Helsinki, Finland.
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van Straten G, Spee B, Rothuizen J, van Straten M, Favier RP. Diagnostic value of the rectal ammonia tolerance test, fasting plasma ammonia and fasting plasma bile acids for canine portosystemic shunting. Vet J 2015; 204:282-6. [PMID: 25959128 DOI: 10.1016/j.tvjl.2015.04.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 01/29/2015] [Accepted: 04/10/2015] [Indexed: 11/19/2022]
Abstract
Portosystemic shunting (PSS) often results in hyperammonaemia and, consequently, hepatic encephalopathy. This retrospective study evaluated the sensitivity, specificity, positive and negative predictive values (PPV and NPV, respectively) and other test performance metrics for the ammonia tolerance test (ATT), serum fasting bile acids (FBA), serum fasting ammonia concentration (FA), and combinations of these tests for their association with PSS in dogs. Medical records of 271 dogs suspect for PSS (symptomatic group) and 53 dogs returning for evaluation after surgical closure of a congenital PSS (CPSS post-surgical control group) were analysed. In the symptomatic group, ATT at 40 min (T40), and the FBA had the highest sensitivity (100% and 98%, respectively) and NPV (100% and 96%, respectively) for PSS. The combination of increased FBA and FA had the highest specificity (97%), with a PPV of 97%, and a positive likelihood ratio of 29. In the CPSS post-surgical control group, the specificity and PPV of FA and the combination of increased FBA/FA were both 100%. In purebred populations, the NPV of all tests was 100%. Consequently, PSS would be ruled out in a symptomatic dog with normal FBA or ATT (T40) and would be highly probable when both FBA and FA are increased. Increased FA was conclusive for PSS in dogs evaluated for post-surgical closure of a CPSS. FBA was the most suitable test for screening purposes.
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Affiliation(s)
- G van Straten
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
| | - B Spee
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - J Rothuizen
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - M van Straten
- 'Hachaklait', Mutual Society for Veterinary Services, P.O.B. 3039, Caesarea Industrial Park 38900, Israel; Koret School of Veterinary Medicine, Faculty of Agriculture, Hebrew University of Jerusalem, P.O.B. 12, Rechovot 76100, Israel
| | - R P Favier
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
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Carrera I, Kircher PR, Meier D, Richter H, Beckman K, Dennler M. In vivo proton magnetic resonance spectroscopy for the evaluation of hepatic encephalopathy in dogs. Am J Vet Res 2014; 75:818-27. [DOI: 10.2460/ajvr.75.9.818] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Liver. CANINE AND FELINE GASTROENTEROLOGY 2013. [PMCID: PMC7161409 DOI: 10.1016/b978-1-4160-3661-6.00061-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
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Silva S, Wyse C, Goodfellow M, Yam P, Preston T, Papasouliotis K, Hall E. Assessment of liver function in dogs using the 13C-galactose breath test. Vet J 2010; 185:152-6. [DOI: 10.1016/j.tvjl.2009.05.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Revised: 05/20/2009] [Accepted: 05/23/2009] [Indexed: 10/20/2022]
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Ruland K, Fischer A, Hartmann K. Sensitivity and specificity of fasting ammonia and serum bile acids in the diagnosis of portosystemic shunts in dogs and cats. Vet Clin Pathol 2010; 39:57-64. [DOI: 10.1111/j.1939-165x.2009.00178.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Goggs R, Serrano S, Szladovits B, Keir I, Ong R, Hughes D. Clinical investigation of a point-of-care blood ammonia analyzer. Vet Clin Pathol 2008; 37:198-206. [PMID: 18533920 DOI: 10.1111/j.1939-165x.2008.00024.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Hyperammonemia has frequently been implicated in the pathogenesis of hepatic encephalopathy. Blood ammonia determination requires minimal delay between sampling and analysis for accurate results. OBJECTIVES The aim of this study was to investigate the PocketChem BA, a new point-of-care (POC) blood ammonia analyzer for clinical use by determining machine precision, linearity, repeatability, and accuracy. METHODS Coefficients of variation were determined by repeated measurement of 2 control solutions. Linearity was investigated by testing serial dilutions of a stock solution. For accuracy, samples from clinical cases were used to compare the results on the PocketChem BA with those obtained using an enzymatic reference method for canine plasma. Canine and feline patients were consecutively enrolled if blood ammonia was assayed and samples could be analyzed shortly after collection. Classification of results (as normal or high, using 100 micromol/L as a cutoff value), Bland-Altman and Deming regression plots, and intraclass correlation coefficients were used to compare the methods. Stability of samples and test strips also was assessed over time. RESULTS Coefficients of variation were 10.6% and 4.8% for low and high controls, respectively. Concentrations of ammonia in diluted stock solutions correlated positively with mean measured concentrations (Pearson coefficient 0.988, P<.001). Of the 54 samples obtained from 38 dogs and 4 cats, 41 had ammonia concentrations within the readable range. Results from the POC analyzer and the reference method were correlated positively (intraclass coefficient 0.800, 95% confidence interval 0.655-0.888), with the POC analyzer having negative constant and proportional biases. The methods agreed in the classification of 45/54 (83.3%) samples, with 7 false negative results on the POC analyzer. Results of repeated sample and strip analyses at 1 and 24 hours were significantly different (P<.05) from those at 0 hour. CONCLUSIONS The PocketChem BA has acceptable precision, adequate linearity, and satisfactory agreement with a reference method, but negative constant and proportional biases. The POC analyzer may be suitable for clinical use in patients suspected of having hepatic encephalopathy, using a lower reference limit of 60 mumol/L to decrease false negative results.
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Affiliation(s)
- Robert Goggs
- Department of Veterinary Clinical Sciences, The Royal Veterinary College, University of London, London, UK.
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Gerritzen-Bruning M, Ingh T, Rothuizen J. Diagnostic Value of Fasting Plasma Ammonia and Bile Acid Concentrations in the Identification of Portosystemic Shunting in Dogs. J Vet Intern Med 2006. [DOI: 10.1111/j.1939-1676.2006.tb02818.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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