Intercostal thoracotomy for surgical attenuation of portoazygos extrahepatic portosystemic shunts in three dogs: surgical technique and short-term outcomes

CASE HISTORIES

The medical records of three dogs, presenting to the surgery department at a tertiary private referral hospital (Cork, Republic of Ireland), were retrospectively reviewed. The patients presented for investigation of a 3-day history of progressive lethargy, decreased appetite and hindlimb weakness (Case 1); brachycephalic obstructive airway syndrome and the development of abnormal licking behaviours (Case 2); and a 2-month history of increased thirst with elevated alanine aminotransferase in serum (Case 3).

CLINICAL FINDINGS

Case 1 presented with tachycardia, hindlimb paraparesis and neck pain, while Case 2 presented with facial conformation abnormalities consistent with brachycephalic obstructive airway syndrome. General physical examination and neurological assessment were within normal limits for Case 3. Baseline serum biochemistry measurements, in all three patients, indicated elevated activities of alanine aminotransferase and alkaline phosphatase, as well as elevated concentrations of resting bile acids (BA), suggestive of an extrahepatic portosystemic shunt. Abdominal computed tomography (CT) angiography was performed, for each dog, which revealed the presence of a portoazygous shunt (PAS) with final insertion into the caudal azygos vein within the thorax.

TREATMENT AND OUTCOME

Abdominal CT angiography images were used for surgical planning and a right-sided intercostal thoracotomy was performed. The location of the thoracotomy was patient-specific and located cranial to the diaphragm, either at the point of PAS insertion into the azygos vein or one rib-space caudal to the insertion, as determined by pre-operative CT images. The intercostal thoracotomy provided good visualisation of the PAS and an appropriate surgical field for placement of a thin film band around the PAS. No surgical complications or post-attenuation seizures were observed. All patients appeared comfortable on oral analgesia and were discharged from the hospital by 48 hours after surgery. All patients demonstrated a clinical improvement when reassessed 6-8 weeks after surgery, and Cases 2 and 3 demonstrated a reduction of resting BA concentrations to within normal limits. The third patient (Case 1) had a considerable reduction in the concentration of resting BA from >140 µmol/L to 20 µmol/L (reference range 0-10 µmol/L) 6-8 weeks after surgery.

CLINICAL RELEVANCE

A right-sided intercostal thoracotomy can be considered for surgical management of PAS in dogs. While both intraoperative and short-term results appear promising, further prospective studies are required before this approach can be recommended as the preferred approach for PAS attenuation.

An Adult Case of Congenital Extrahepatic Portosystemic Shunt Successfully Treated with Balloon-occluded Retrograde Transvenous Obliteration

A 42-year-old woman visited our hospital due to syncope. Contrast-enhanced CT revealed portosystemic shunt, portal vein hypoplasia, and multiple liver nodules. The histological examination of a liver biopsy specimen exhibited portal vein hypoplasia and revealed that the liver tumor was positive for glutamine synthetase. The patient was therefore diagnosed with congenital extrahepatic portosystemic shunt type II, and with focal nodular hyperplasia (FNH)-like nodules. She had the complication of severe portopulmonary hypertension and underwent complete shunt closure by balloon-occluded retrograde transvenous obliteration (B-RTO). The intrahepatic portal vein was well developed at 1 year after B-RTO, and multiple liver nodules completely regressed. Her pulmonary hypertension also improved.

Case Report: Membranoproliferative Glomerulonephritis, a Rare Clinical Manifestation of Abernethy Malformation Type II

This report describes an 8-year-old male who presented with clinical manifestations including systemic edema, heavy proteinuria, hypoproteinemia, and persistent hypocomplementemia. Arachnoid cysts and focal nodular hyperplasia were also detected. Imaging examination and renal biopsy were performed, and Abernethy malformation type II with immune complex-mediated membranoproliferative glomerulonephritis was considered the diagnosis. Due to the persistence of embryonic vessels, Abernethy malformation is a rare congenital vascular malformation of the splanchnic venous system, which can be classified as type I (end-to-side shunt) and type II (side-to-side shunt). Abernethy malformation with glomerulonephritis remains extremely rare. In the patient described, glomerulonephritis mediated by immune complex with "full-house" positive immunohistochemistry was confirmed on renal biopsy. In addition, he was treated with glucocorticoids and tacrolimus. Whether surgical treatment is necessary should be determined according to the state of the disease in the later stages. The present case reflects the association between the congenital portosystemic shunt and the renal region and, to the authors' knowledge, may be the first report to describe arachnoid cysts as a symptom of Abernethy malformation.

Case Report: Hepatic Adenoma in a Child With a Congenital Extrahepatic Portosystemic Shunt

Congenital extrahepatic portosystemic shunts (CEPS), previously also described as Abernethy malformations, are rare malformations in which the extrahepatic portal system directly communicates with the vena cava inferior, thereby bypassing the liver. A hypoplastic portal vein (PV) exists in most cases. CEPS have been associated with the development of liver nodules, ranging from mostly focal nodular hyperplasia (FNH) to hepatic adenoma (HA) and even hepatocellular carcinoma (HCC). Tumor development in CEPS may be due to changes in perfusion pressures, oxygen supply or endocrine imbalances. It is important to rule out CEPS in children with liver tumors, because resection could impede future shunt occlusion procedures, and benign masses may regress after shunt occlusion. Here, we review the case of a 9-years-old male with CEPS and hepatic nuclear Factor 1-alpha (HNF-1-alpha) inactivated HA to raise awareness of this condition and review histopathological changes in the liver of CEPS.

Pulmonary arterial hypertension combined with a high cardiac output state: Three remarkable cases

A congenital extrahepatic portosystemic venous shunt (CEPVS), also known as an Abernethy malformation, is a rare cause of pulmonary arterial hypertension (PAH). In this case series, we describe three male patients of 30, 23, and 27 years of age with PAH due to a CEPVS. In all three patients, a right heart catheterization revealed a high cardiac output. The aim of this case series is to make pulmonary hypertension physicians aware of the possibility of a CEPVS when PAH is accompanied with a high cardiac output state.