Portosystemic shunt

 

svet penDr Svetoslav Penchev

United Veterinary Clinic

Varna, Bulgaria

 

Portosystemic shunts are anomalies that allow blood returning from the gastrointestinal systems to bypass the liver and pass directly into the systemic circulation. When this occurs, toxins from gastrointestinal tract that are normally cleared by the liver are shunted directly into the systemic circulation. This build-up of these toxins in the bloodstream leads to the clinical signs commonly seen in animals with these shunts. Three categories of clinical signs commonly are associated with the presence of these shunts: neurological, gastrointestinal and urinary. Neurological signs include seizures, head pressing, circling, lethargy and blindness among others- hepatic encephalopathy. Gastrointestinal signs include vomiting, anorexia, weight loss and a reduced rate of growth. Urinary tract signs, including stranguria, pollakiuria and hematuria are generally related to the development of urate cystoliths secondary to the presence of ammonium biurate crystals in the urine.

Case report:

Signalment: Dog, male, 4 months old, Yorkshire terrier

History: The owner noticed hypersalivation and abnormal behaviour of the dog.

Case presenting signs: Seizures, pacing, blindness, depressed mental state, hypersalivation

Clinical examination: Internal body temperature- 37.8; Normal respiratory and heart rate; Color of mucous membranes – pink; CRT – 1,5 sec.

Neurological examination:

Mentation- depressed Behaviour- abnormal Gait- compulsive walking

Cranial nerves – normal

There was no change in conscious proprioception and bladder function was normal. Spinal reflexes were normal.

Neuroanatomic localisation: Forebrain

Differential diagnosis: Idiopatic/Inflammatory/Trauma/ Metabolic/Neoplastic/Anomaly

 

Case work-up:

CBC:f 1

 

 

Biochemistry:f 2

 

 

 

Elevation of liver enzymes

 

 

Elevation of bile acidsf 9

 

 

 

 

 

 

 

 

 Abdominal ultrasound:

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Contrast CT study with 64 slice scanner was performed with i.v administration of iopamidol solution 370g/ml (contrast agent) in dosage 1ml/kg.

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CT findings: There is a abnormal communication between the portal vein and the caudal vena cava using the splenic vein. The portal vein decreases in diameter cranial to the shunt exit and splienic vein is enlarged. The both kidneys are too big and liver is too small.

Diagnosis:

Congenital extrahepatic splienocaval-caval shunt

The treatment consisted of medical and surgical approach. Ten days before the surgery the condition was managed with amoxicillin 12,5 mg/kg p.o q12h for 15, Lactose oral solution 67g/ 100ml in dosage 1ml/kg p.o q12h and hydrolyzed protein food.

The surgery was planned in great teamwork with d-r Kaloyan Voichev in Multidisciplinary Veterinary Clinic Bulgaria. The operation was performed with the kind assistance of the whole team. The operational approach consisted of midline celiotomy and isolation of the shunt from surrounding structures and placement of thin cellophane band surround the vessel.

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Max recovered well from the anesthesia and was discharged after 48 hours with amoxicillin 12,5 mg/kg p.o q12h for 10days, Lactose oral solution 67g/100ml in dosage 1ml/kg p.o q12h for 15 days and hydrolyzed protein food. In postoperative period Max was vomiting sporadic within one week, but with good appetite. The vomiting was stopped with maropitant 1mg/kg s.c q 24h for 3 days.

One month after the surgery Max doesn’t show any clinical signs.

Luba Gancheva