Shunts In Dogs Research Articles

Evaluation of the Characteristics of Congenital Portosystemic Shunts in Dogs and Cats Using Computerised Tomography Angiography and Brain Magnetic Resonance Imaging

Evaluation of the Characteristics of Congenital Portosystemic Shunts in Dogs and Cats Using Computerised Tomography Angiography and Brain Magnetic Resonance Imaging

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.

Repeated specific canine pancreatic lipase measurements do not identify multiple acquired portosystemic shunts in dogs after extrahepatic portosystemic shunt attenuation.

In dogs with portal hypertension (PH), spec cPL is suggested to be increased despite normal pancreatic histology. After attenuation of congenital extrahepatic portosystemic shunts (cEHPSS), multiple acquired portosystemic shunt (MAPSS) can develop as consequence of sustained PH. Presence of MAPSS affects future therapeutic options and prognosis. Evaluate if spec cPL concentrations increase postoperatively in dogs that develop MAPSS and can thus serve as an indicator of PH. Twenty-four dogs with cEHPSS. Dogs classified according to surgical outcome after cEHPSS attenuation (8 with MAPSS [group M], 9 with closed cEHPSS [group C] and 7 with patent blood flow through the original cEHPSS, without evidence of MAPSS [group P]). Spec cPL was measured in preoperative samples (T0), 4 days (T1) and 1 (T2) and 3- to 6-months (T3) after surgery. Spec cPL was within reference interval (<200 μg/L) at all timepoints except at T1. At T1, 2 dogs in group M (321 and >2000 μg/L) and also 1 in group C (688 μg/L) and 1 in group P (839 μg/L) had increased spec cPL concentrations. No differences in spec cPL concentrations between groups or changes over time were identified. Spec cPL is not consistently increased in dogs that develop MAPSS after cEHPSS attenuation and has no potential as a biomarker for the identification of MAPSS after cEHPSS attenuation.

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.

Evaluation of Overshunting between Low and Medium Pressure Ventriculoperitoneal Shunts in Dogs with Severe Hydrocephalus Using Frameless Stereotactic Ventricular Shunt Placement

Hydrocephalus is a neurological disorder characterized by an abnormal accumulation of cerebrospinal fluid (CSF) within the ventricular system of the brain, leading to cerebral ventricular dilation, brain parenchyma compression, and neuronal cell loss. Surgery is an effective method of draining excessive amounts of CSF. Ventriculoperitoneal shunt (VPS) allows excess CSF to divert into the abdomen; this device is the most commonly used in the treatment of hydrocephalus both in veterinary and human patients. This study aims to describe the application of two types of VPS, low-pressure valve and medium-pressure valve, using a frameless stereotactic neuronavigational system in eight severe hydrocephalus in dogs and, in particular, analyze the prevalence of postoperative overshunting. Non-communicating hydrocephalus was found in seven dogs, whereas the rest of them had communicating hydrocephalus caused by traumatic brain injury with a skull fracture. The criteria for pressure valve selection depended on the intraoperative intraventricular pressure (IVP) that was determined by the adaptive manometer, according to the human protocol. Low-pressure valve placement was performed in five dogs, and the others received medium-pressure valve placement. The follow-up period was 2 weeks, 4–12 weeks, and 12 weeks to 12 months. Pre- and postoperative information including neurological signs, CT-Scan or MRI, medical treatment, complications, and ventricular volume were compared in all dogs. Seven dogs showed neurological improvement within 2 weeks after surgery. Overshunting was seen in four dogs who received low-pressure valve placement. Three of them had shunt infections within 4 to 6 weeks after surgery. One dog underwent shunt revision from a low-pressure valve to a medium-pressure valve caused by severe overshunting and progressive neurological signs. In addition, cognitive and learning improvements were evaluated based on the owners’ feedback, and neurological signs were examined during the follow-up period in two dogs that received low-pressure valve placement. We conclude that a medium-pressure valve is recommended for overshunting prevention. However, low-pressure valve placement seems to improve cognitive function and learning ability, which is related to an increase in the brain parenchyma observed during long-term monitoring. Moreover, we also report our experience and surgical procedure for frameless stereotactic ventricular shunt placement (FSVSP) in VPS surgery in dogs affected by hydrocephalus.

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.

Short- and long-term outcomes of polyethylene band attenuation of congenital extrahepatic portosystemic shunts in dogs: 60 cases (2010-2020).

To report the short- and long-term outcomes following attenuation of congenital extrahepatic portosystemic shunts in dogs using a novel polyethylene band. Records were retrospectively reviewed for dogs that underwent congenital extrahepatic portosystemic shunt attenuation by a polyethylene banding technique, at a single institution between 2010 and 2020. Short-term outcome data were collected from peri-operative clinical records with follow-up examinations, scheduled at 6 and 18 weeks post-operatively, and post-operative imaging when performed. Long-term follow-up was collected by validated owner questionnaire, telephone interview or medical records. Long-term outcomes were categorised by "excellent", "good" or "poor". Sixty dogs were included. Post-operative complications occurred in 10 of 60 dogs (16.7%), four major and six minor, with a peri-operative mortality of 6.7%. Persistent shunting was identified in nine of 53 dogs (17%) available for follow-up examination and four dogs underwent a revision surgery. Long-term follow-up was available for 44 dogs at a median of 75 months post-operatively (range 7 to 128). Long-term outcomes were "excellent" (26) or "good" (8) in 81.8% of dogs and "poor" (8) in 18.2%. At the time of follow-up, 30 of 44 (68.2%) dogs were not receiving any medical treatment and 27 of 28 (96.4%) questionnaire respondents were satisfied with the response to surgery. Polyethylene band attenuation of congenital extrahepatic portosystemic shunts provides comparable outcomes to cellophane. The material used in this study is widely available and consistent while being pre-sterilised and pre-folded makes it easy to use.

Total lipid concentration of hairs increases after successful attenuation of extrahepatic portosystemic shunts in dogs.

Skin and coat quality can reflect nutritional deficiencies in humans and dogs with liver diseases. Determine skin and coat quality based on a scoring protocol and skin biopsies in dogs with an extrahepatic portosystemic shunt (EHPSS), and determine total lipid concentrations in hairs of dogs at time of surgery and 3 months after successful shunt closure. Ten client-owned dogs that underwent successful gradual attenuation of EHPSS, as defined by transsplenic portal scintigraphy, were included. A prospective cohort study was performed. All dogs underwent gradual attenuation of the EHPSS. Skin and coat scoring was performed at diagnosis, surgery, and 1 and 3 months postoperatively. Hair was plucked from the lumbar region for total lipid analysis and an 8 mm punch skin biopsy was taken at time of surgery and 3 months postoperatively, when the dogs underwent transsplenic portal scintigraphy to determine EHPSS closure. No significant differences were observed in skin and coat scoring over time. Total lipid concentrations of hairs increased significantly from surgery to 3 months postoperatively [30 μg/mg hair (13-56 μg/mg hair) to 47 μg/mg hair (25-63 μg/mg hair); p= 0.005]. Skin biopsies showed the presence of significantly more scales 3 months postoperatively (p= 0.018). A significant increase in total lipid concentrations in hairs suggests that successful surgical attenuation of EHPSS improves either intestinal absorption of lipids, fat metabolism in the liver, or a combination of both.

Use of an ameroid constrictor ring for gradual occlusion in canine congenital extrahepatic portosystemic shunts: Review

Congenital extrahepatic portosystemic shunts may be caused by embryological failure and are related to normal abdominal vascular development. They are noteworthy due to the higher prevalence of portosystemic vascular shunts and small to miniature breeds are the most affected. In this literature review, we carefully compiled in international articles in the field on the use of the ameroid constrictor ring in surgery for the gradual occlusion of unique congenital extrahepatic portosystemic shunts in dogs. In this sense, aspects of pathophysiology, etiopathogenesis, clinical symptoms and technical aspects regarding the surgical area were addressed. It is concluded that the use of the constrictor ring becomes a safe and highly recommended method, resulting in low rates of morbidity and mortality and prolonged postoperative survival in dogs.

Does surgical or medical management of extrahepatic portosystemic shunts in dogs carry a better prognosis for the resolution and reduction of neurological dysfunction?

PICO question&#x0D; In dogs with congenital extrahepatic portosystemic shunts that are treated with surgical attenuation what is the persistency, frequency, severity and outcome of neurological signs when compared to dogs that are treated medically?&#x0D; &#x0D; Clinical bottom line&#x0D; Category of research question&#x0D; Prognosis&#x0D; The number and type of study designs reviewed&#x0D; Ten papers were critically reviewed&#x0D; Strength of evidence&#x0D; Weak&#x0D; Outcomes reported&#x0D; For short-term success, owners reported an overall decrease in neurological signs associated with neurological dysfunction and an increase in quality of life after the initiation of either medical management or surgical management. Surgical management has a weak association with higher mortality or severe neurological signs in the immediate postoperative period&#x0D; Conclusion&#x0D; It is challenging to make a direct comparison between medical and surgical management but, overall, both strategies seemed to decrease neurological signs in the short term. There was a lack of evidence and available data about the efficacy of each for long-term control of neurological signs&#x0D; &#x0D; How to apply this evidence in practice&#x0D; The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.&#x0D; Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.&#x0D; &#x0D;

Persistent hypercobalaminemia three months after successful gradual attenuation of extrahepatic shunts in dogs: a prospective cohort study

BackgroundDeficiencies in vitamin A and D and disorders in the vitamin B complex are often present in people with chronic liver diseases. So far, the serum concentrations of these vitamins have not yet been studied in dogs with congenital extrahepatic portosystemic shunts (EHPSS), who also have some degree of liver dysfunction. The objective was to assess serum vitamin concentrations in dogs with EHPSS from diagnosis to complete closure. A prospective cohort study was performed using ten client-owned dogs with EHPSS, closed after gradual surgical attenuation. Serum concentrations of vitamin A, 25-hydroxyvitamin D, folic acid, cobalamin and methylmalonic acid (MMA) were measured at diagnosis prior to institution of medical therapy, prior to surgery, and three months after gradual attenuation and complete closure of the EHPSS.ResultsAt diagnosis, median serum concentrations of vitamin A, 25-hydroxyvitamin D and folic acid were 18.2 μg/dL (8.8 - 79.5 μg/dL), 51.8 ng/mL (19.4 - 109.0 ng/mL), and 8.1 μg/L (5.2 - 14.5 μg/L), respectively, which increased significantly postoperatively (88.3 μg/dL (51.6 - 182.2 μg/dL, P=0.005), 89.6 ng/mL (49.3 - >150.0 ng/mL, P =0.005), and 14.8 μg/L (11.5 - 17.7 μg/L, P <0.001), respectively). Median serum cobalamin concentrations were 735.5 ng/L (470 - 1388 ng/L) at diagnosis and did not significantly decrease postoperatively (P =0.122). Both at diagnosis and three months postoperatively 7/10 dogs had hypercobalaminemia.ConclusionsSerum concentrations of vitamin A, 25-hydroxyvitamin D and folic acid significantly increase after surgical attenuation. Nevertheless, persistent hypercobalaminemia is suggestive of ongoing liver dysfunction, despite successful surgery.

Morphometric and cytological disturbances of pancreatic islets evoked by congenital portosystemic shunt in dogs.

In 46 dogs with congenital portosystemic shunt (cPSS) histopathological examination of the pancreas, including measuring of the islet area, was performed, and the results were compared with those obtained in 6 control dogs without cPSS. Pancreatic islets were found in 43 (94%) dogs with cPSS and in all control animals. Mean area of the pancreatic islets was significantly lower in cPSS patients (median of 2219.4 μm2, interquartile range [IQR] from 1559.0 to 3146.2 μm2, range from 485.4 to 10333.4 μm2) than in control dogs (median of 8705.5 μm2, IQR from 8284.4 to 9329.2 μm2, range from 7689.9 to 9624.2 μm2) (p⟨0.001). The area of pancreatic islets was weakly, but significantly, positively correlated with the body weight of dogs (r=0.32, p=0.026), but not with the age or sex. Vacuoles were found in the cytoplasm of pancreatic islet cells in 37 (87%) dogs with cPSS and in none of the control animals (p⟨0.001). Their presence was not linked to the sex, breed, age or body weight. Extracellular homogenous eosinophilic masses were present in pancreatic islets in 5 (12%) cPSS patients and in none of control animals. Connective tissue hyperplasia was found in pancreatic islets of 4 (9%) dogs with cPSS and in none of the control dogs. These results indicate that cPSS severely affects the pancreas, as shown by significantly reduced area of the islets, and the presence of eosinophilic masses in the pancreas and/or intracellular vacuoles.

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.

Palliative ventriculoperitoneal shunting in dogs with obstructive hydrocephalus caused by tumors affecting the third ventricle.

BackgroundHypertensive or obstructive hydrocephalus is a common complication in dogs with tumors affecting the third ventricle for which few therapeutic options are available.ObjectivesTo describe signalment, neurological status, and pre‐ and postsurgical findings, complications and survival time in 4 dogs with obstructive hydrocephalus caused by third ventricle tumors that were palliatively treated using ventriculoperitoneal shunting (VPS).AnimalsFour client‐owned dogs with obstructive hydrocephalus caused by tumors affecting the third ventricle.MethodsMedical records were reviewed for dogs diagnosed with third ventricular tumors. Inclusion criteria were complete medical record, advanced diagnostic imaging for review, and VPS as sole surgical treatment.ResultsAt the time of diagnosis, all patients displayed acute onset and rapidly progressive diffuse intracranial clinical signs. On advanced imaging, all dogs had a homogeneously enhancing mass occupying or collapsing the third ventricle as well as obstructive hydrocephalus. All of the dogs underwent VPS of the most dilated lateral ventricle. In 2 of the patients, intracranial hypertension followed by normotension after VPS placement was confirmed intraoperatively by means of direct intracranial pressure monitoring. Excellent clinical improvement was observed in all dogs immediately after surgery. Three patients required a second VPS in the contralateral lateral ventricle 3, 7 and 11 months after the first surgery, all of them with renewed improvement in clinical signs.Conclusion and Clinical ImportanceVentriculoperitoneal shunting is a rapid and effective treatment for patients with obstructive (hypertensive) hydrocephalus caused by tumors located within the third ventricle.

Appraisal of the ‘penumbra effect’ using lingual pulse oximetry in anaesthetized dogs and cats

ObjectiveFactors described as contributors to the ‘penumbra effect’ in relation to pulse oximetry include optical shunting, circulatory anastomoses and probe parallelity. This study aimed to clarify the main underlying mechanism involved. Study designProspective clinical trial. AnimalsA total of 30 dogs and 15 cats (client-owned). MethodsIn anaesthetized dogs and cats, a pulse oximeter probe was placed on the tongue to measure haemoglobin oxygen saturation (SpO2) and perfusion index. In 15 dogs, the probe was positioned at the root (baseline) of the tongue, then at 0.5 and 1 cm rostral to it, to investigate the effect of circulatory anastomoses on SpO2 values. In cats (which do not have lingual arteriovenous anastomoses), the probe was positioned at the root and apex of the tongue. To assess the effect of probe parallelity on SpO2 values in dogs, two lines were drawn parallel to the planes of the light-emitting diode and the detector surfaces and the intersection angle calculated using ImageMeter Pro, Google Play. In a further 15 dogs, the probe was placed at the tongue edge (0% optical shunt), with 50% optical shunt, then with the 50% optical shunt shielded. Data were analysed using Friedman’s test, Student t test and Pearson’s correlation coefficient (p < 0.05). ResultsIn dogs, SpO2 values were significantly higher at 1.0 cm than at baseline (p < 0.0001). In cats, there were no significant differences in SpO2 values at each location. There was no significant difference in SpO2 between 0% and 50% optical shunt in dogs. SpO2 had a moderate negative correlation with tongue thickness and negligible correlation with intersection angle. Conclusions and Clinical relevanceCirculatory anastomoses are probably responsible for observed changes in SpO2 as the probe is placed towards an extremity, rather than optical shunting or probe parallelity.

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

BackgroundThe 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...

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.

Congenital portosystemic shunt in dogs: review

Portosystemic shunt is a condition commonly seen in dogs. This disease is a vascular anomaly that makes communication between the systemic circulation and the portal circulation. Because of this anomalous vascular communication, portal blood from the drainage of organs such as the stomach, intestine, pancreas and spleen, passes directly into the systemic circulation, diverting from the liver that is responsible for detoxification of various substances. Therefore, the patient will manifest numerous clinical signs with possible neurological or systemic involvement only due to the accumulation of toxins in the blood. The treatment of choice for the portosystemic shunt is the ligation of the anomalous vessel, to which the ameroid constricting ring will be the most approached in this article.

Treatment of congenital extrahepatic portosystemic shunts in dogs: A systematic review and meta-analysis.

BackgroundSeveral options have been proposed for the treatment of congenital extrahepatic portosystemic shunts (cEHPSS) in dogs, but formal comparisons among different treatment options are currently unavailable. A previous evidence‐based review (2012) found low quality of evidence for papers assessing the treatment of cEHPSS in dogs.ObjectivesTo assess the quality of evidence available in the treatment of cEHPSS, summarize the current state of knowledge with respect to outcome after cEHPSS management, and compare different treatment techniques.AnimalsNot used.MethodsA bibliographic search was performed without date or language restrictions. Studies were assessed for quality of evidence (study design, study group sizes, subject enrollment quality, and overall risk of bias) and outcome measures reported (perioperative outcome, clinical outcome, and surgical or interventional outcome), all reported with 95% confidence intervals. A network meta‐analysis was performed.ResultsForty‐eight studies were included. Six retrospective studies (grade 4b) compared 2 techniques and 7 were abstracts (grade 5). The quality of evidence was low and risk of bias high. Regarding surgical outcome, statistically significant superiority of ameroid constrictor over thin film band was observed (P = .003). No other comparisons were statistically significant.Conclusions and Clinical ImportanceThe evidence base of choice of treatment of cEHPSS in dogs remains weak despite recent publications on the subject. Ameroid is superior to thin film band in causing EHPSS closure. Blinded randomized studies comparing different treatment modalities, which routinely include postoperative imaging to assess cEHPSS closure and acquired portosystemic shunt development are essential.