Treatment of hepatic encephalopathy by retrograde transcaval coil embolization of an ileal vein-to-right gonadal vein portosystemic shunt

Spontaneous portosystemic shunts in noncirrhotic patients presenting with encephalopathy

Portosystemic shunts (PSS) are common in patients with chronic liver disease and portal hypertension, however, their occurrence in noncirrhotic individuals is likely under appreciated. Patients may present with symptoms of hepatic encephalopathy and/or gastrointestinal bleeding and undergo extensive work up for liver disease to no avail. Often, these patients suffer for years with accruing medical expenses and numerous hospitalizations related to repeated episodes of encephalopathy. The underlying cause may go undiagnosed or misdiagnosed as occult hepatic dysfunction or even a neuropsychological disorder. In many cases, abdominal CT imaging demonstrates the abnormal portosystemic connection well before it is recognized as the cause of symptoms. In this brief report, we discuss three cases presenting with symptoms of encephalopathy and report successful management with endovascular occlusion of the portosystemic shunts.

Systematic review of congenital and acquired portal-systemic shunts in otherwise normal livers

BACKGROUND

Portal-systemic shunts (PSSs) are rarely seen in healthy individuals or patients with non-cirrhotic liver disease. They may play an important role in hepatic metabolism as well as in the spread of gastrointestinal metastatic tumours to specific organs. Small spontaneous PSSs may be more common than generally thought. However, epidemiological data are scarce and inconclusive. This systematic review examined the prevalence of reported PSSs and the associated detection methods.

METHODS

Literature up to 2011 was reviewed for adult patients with proven congenital or acquired PSSs. Only PSSs in normal livers were analysed for the methods of diagnosis. Eligible studies were identified by searching relevant databases, including PubMed, Embase, MEDLINE and the Cochrane Library. The selection of eligible articles was carried out using predefined inclusion criteria (adult, non-surgical PSS) and a set of search terms that were established before the articles were identified.

RESULTS

Eighty studies were included describing 112 patients with congenital or acquired PSSs. The majority were diagnosed incidentally using Doppler ultrasound imaging and CT.

CONCLUSION

Congenital and acquired PSSs are rare. They are usually clinically asymptomatic and discovered incidentally by radiological techniques. They may be clinically relevant owing to drug, tumour cell, metabolic and pathogen shunting.

Balloon occlusion retrograde transvenous obliteration for inferior mesenteric vein-systemic shunt

Two cases of portosystemic encephalopathy caused by an inferior mesenteric vein (IMV)-internal iliac vein shunt and an IMV-renal vein shunt are presented. IMV and systemic varicosity consisted of a first functional segment, a stagnant segment, and a second functional segment. Both patients underwent balloon occlusion retrograde transvenous obliteration (BRTO), using a microcatheter, to occlude the stagnant segment selectively. Although transient portal vein thrombosis was observed in case 1 and aggravation of esophageal varices was observed in case 2, these complications were tolerable. Following BRTO, the portosystemic encephalopathy in both cases resolved, and serum ammonia levels, although elevated, remained within the normal range.

Treatment of chronic portosystemic encephalopathy in cirrhotic patients by embolization of portosystemic shunts

AIMS/BACKGROUNDS: Large spontaneous portal-systemic shunts can occasionally be the cause of chronic and disabling encephalopathy in cirrhotic patients. Shunt embolization has been proposed, however the clinical relevance of this technique remains uncertain.

METHODS/RESULTS

We report our results in seven patients treated by shunt embolization. Although the procedure was achieved and technically successful in all patients, the clinical results were poor as long-term improvement was obtained in only one patient. Three patients died within 3 months after the procedure from cirrhoses' end stage complications.

CONCLUSION

We believe that optimal management of these patients with chronic spontaneous encephalopathy is liver transplantation.

Methods of Gradual Vascular Occlusion and Their Applications in Treatment of Congenital Portosystemic Shunts in Dogs: A Review

OBJECTIVE

To provide a comprehensive review of the experimental and clinical data related to gradual vascular occlusion of congenital portosystemic shunts (CPS) in dogs.

STUDY DESIGN

Literature review.

METHODS

PubMed literature search (1966-2004).

RESULTS

Surgical intervention and complete vascular occlusion have been recommended for CPS therapy in dogs; however, acute complete ligation of CPS is often associated with life-threatening portal hypertension. Recently, several investigators have attempted to reduce the risk of postoperative portal hypertension by using gradual vascular occlusion. Successful vascular occlusion has been achieved using partial ligation with silk suture, ameroid constrictors, cellophane bands, thrombogenic coils and hydraulic vascular occluders. Objective comparisons of the reliability and rate of vascular occlusion produced by each of these methods have been limited by differences in experimental models and a lack of definitive follow up evaluation in some clinical studies.

CONCLUSIONS

Gradual vascular occlusion is widely used in the clinical treatment of CPS in dogs. Objective evaluation of the experimental and clinical data on each of the techniques for gradual vascular occlusion is necessary for informed clinical practice and for the planning of future research into this important area.

CLINICAL RELEVANCE

Even from the limited data available, it is clear that the ideal method for gradual vascular occlusion of CPS has yet to be identified.

Oral glutamine challenge and magnetic resonance spectroscopy in three patients with congenital portosystemic shunts

BACKGROUND/AIMS

Congenital portosystemic shunts are rare abnormalities of liver vasculature that can cause neurological symptoms, probably secondarily to the effects of the metabolism of ammonia in the brain. Our aim was to investigate the relationship between capillary blood ammonia after oral glutamine challenge and magnetic resonance spectroscopy in three patients with congenital portosystemic shunts.

METHODS

Neuropsychological tests, oral glutamine challenge and magnetic resonance spectroscopy were performed at baseline and after 6 months of follow-up in three patients with congenital portosystemic shunts. The results were compared to those obtained in a group of six cirrhotic patients with prior episodes of hepatic encephalopathy and healthy controls.

RESULTS

Patients with congenital portosystemic shunts exhibited abnormalities of neuropsychological tests, magnetic resonance spectroscopy and a response to the oral glutamine challenge similar to those observed in patients with cirrhosis. The intensity of the rise of brain glutamine was correlated to the area under the curve of ammonia after the oral glutamine challenge (R=0.72).

CONCLUSIONS

Neurological manifestations of patients with congenital portosystemic shunts are mediated through similar mechanisms that are involved in the pathogenesis of hepatic encephalopathy. The area under the curve appears to be the better parameter that defines the response to the oral glutamine challenge.

Schizophrenia and liver dysfunction

It is suggested that a non-hepatocellular liver dysfunction, caused by the presence of a congenital or acquired portal-systemic shunt, constitutes a major predisposing factor in the pathogenesis of schizophrenia. In addition to the common occurrence of schizophrenic reactions observed in liver disease, this suggestion is supported by autoptic findings in addition to the fact that a considerable number of abnormal biochemical and biological phenomena are shared by patients suffering from schizophrenia and portal-systemic shunting. The frequency of abnormal portal-systemic shunts in schizophrenia is unknown. Recent advances in non-invasive Doppler-sonographic techniques should enable an elucidation of this question.

Intrahepatic portal-hepatic venous anastomosis: a portal-systemic shunt with neurological repercussions

Intrahepatic shunts are rarely diagnosed as a cause of neurocognitive abnormality. A complaint of fatigue led to the diagnosis of a right portal vein-hepatic vein aneurysmal communication in a 23-yr-old, otherwise healthy woman. Neuropsychological testing, imaging, and MR spectroscopy revealed changes similar to those described in patients with cirrhosis and subclinical hepatic encephalopathy. T1-weighted MRI showed a hyperintense globus pallidus, a feature seen in subjects with and without portal-encephalopathy. Portal-systemic shunting in the absence of parenchymal liver disease reproduces neurological features described in cirrhosis.