Persistent portosystemic shunts after liver transplantation causing episodic hepatic encephalopathy

Imaging and Intervention in the Management of Vascular Complications Following Liver Transplantation

Liver transplantation is the treatment of choice in majority of the patients with end stage liver disease. Vascular complication following liver transplantation is seen in around 7-13% of the patients and is associated with graft dysfunction and high morbidity and mortality. Early diagnosis and prompt treatment are crucial in management of these patients. Advances in interventional radiology have significantly improved the management of vascular complications using minimally invasive percutaneous approach. Endovascular management is preferred in patients with late hepatic artery thrombosis, or stenosis, whereas retransplantation, surgical revision, or endovascular management can be considered in patients with early hepatic artery thrombosis or stenosis. Hepatic artery pseudoaneurysm, arterioportal fistula, and splenic artery steal syndrome are often treated by endovascular means. Endovascular management is also preferred in patients with symptomatic portal vein stenosis, early portal vein thrombosis, and symptomatic late portal vein thrombosis, whereas surgical revision or retransplantation is preferred in patients with perioperative portal vein thrombosis occurring within 3 days of transplantation. Venoplasty with or without stent placement can be considered in patients with hepatic venous outflow tract or inferior vena cava obstruction. Transjugular intrahepatic portosystemic shunt (TIPS) may be required in transplant recipients who develop cirrhosis, often, secondary to disease recurrence, or chronic rejection. Indications for TIPS remain same in the transplant patients; however, major difference is altered vascular anatomy, for which adjunct techniques may be required to create TIPS.

Spontaneous portosystemic shunt embolization in liver transplant recipients with recurrent hepatic encephalopathy

INTRODUCTION AND OBJECTIVES

Spontaneous portosystemic shunts (SPSS) are a common cause of recurrent hepatic encephalopathy (HE). Shunt occlusion is an effective and safe procedure when performed in patients with cirrhosis and preserved liver function. We aimed to describe our experience with SPSS embolization after liver transplantation (LT).

PATIENTS

We identified five patients who underwent SPSS embolization after LT. Clinical, biochemical and technical procedure data were collected.

RESULTS

At presentation, all patients had developed graft cirrhosis and HE after LT. Median Model for End-stage Liver Disease (MELD) at embolization was 9 (range 7-12), median Child-Pugh was 8 (range 7-9). Splenorenal and mesocaval shunt were the most frequent types of SPSS found. Three patients have been completely free of HE. Of the two patients who had HE recurrence after embolization, one patient had two episodes of HE which was controlled well with medications. The other patient required three embolizations because of recurrent HE. Median follow-up was 4.4 years (range 1.0-5.0) and MELD score at last follow up was 13 (range 10-18) and median Child-Pugh score B, 7 points (range 5-12).

CONCLUSIONS

SPSS can be considered as a cause of HE after LT. SPSS embolization is feasible and safe in LT recipients.

Undifferentiated non-hepatic hyperammonemia in the ICU: Diagnosis and management

Hyperammonemia occurs frequently in the critically ill but is largely confined to patients with hepatic dysfunction or failure. Non-hepatic hyperammonemia (NHHA) is far less common but can be a harbinger of life-threatening diagnoses that warrant timely identification and, sometimes, empiric therapy to prevent seizures, status epilepticus, cerebral edema, coma and death; in children, permanent cognitive impairment can result. Subsets of patients are at particular risk for developing NHHA, including the organ transplant recipient. Unique etiologies include rare infections, such as with Ureaplasma species, and unmasked inborn errors of metabolism, like urea cycle disorders, must be considered in the critically ill. Early recognition and empiric therapy, including directed therapies towards these rare etiologies, is crucial to prevent catastrophic demise. We review the etiologies of NHHA and highlight the first presentation of it associated with a concurrent Ureaplasma urealyticum and Mycoplasma hominis infection in a previously healthy individual with polytrauma. Based on this clinical review, a diagnostic and treatment algorithm to identify and manage NHHA is proposed.

Management of Large, Spontaneous Portosystemic Shunts in Liver Transplantation: Case Report and Review of Literature

BACKGROUND

The presence of collateral circulation in liver cirrhosis patients with portal hypertension is quite frequent due to re-permeabilization of closed embryonic channels. In some cases, these shunts could measure over 1 cm wide, therefore, containing a significative blood flow. Its management during liver transplantation could be challenging due to possible complications resulting from either ligation of the shunts or from ignoring them. We present the case of a patient with recurrent hepatic encephalopathy (HE) and a large spontaneous portosystemic shunt (SPSS) who submitted to liver transplant and review the literature identifying options, complications, and outcomes with the aim of facilitating decision making.

MATERIAL AND METHODS

A 68-year-old, Spanish man diagnosed with liver cirrhosis with portal hypertension and recurrent episodes of HE is proposed for LT. The patient's Child-Pugh score was A6-B7, and the Model for End-stage Liver Disease score was 12. Preoperatively, a computed tomography scan showed a large SPSS running to the inferior cava vein. During the surgery, a small-sized portal vein and a large shunt measuring almost 3 cm wide were identified. After reperfusion, portal vein flow was 1000 to 1100 mL/min. Owing to the previous HE and the risk of low portal flow, the shunt was closed increasing the portal flow to 1800 mL/min. The patient was discharged without any complications.

CONCLUSIONS

The presence of large SPSSs are frequent during LT. Decision making intraoperatively can be challenging due to possible complications derived from ligation of the SPSS or from ignoring it. Either preoperative assessment of a further HE risk or portal vein flow measurement after reperfusion are essential to achieve a correct resolution.

Pathophysiology and Management of Hyperammonemia in Organ Transplant Patients

Neurologic complications are common after solid-organ transplantation, occurring in one-third of patients. Immunosuppression-related neurotoxicity (involving calcineurin inhibitors and corticosteroids), opportunistic central nervous system infections, seizures, and delirium are some of the causes of neurologic symptoms following solid-organ transplantation. An uncommon often missed complication posttransplantation involves buildup of ammonia levels that can lead to rapid clinical deterioration even when treated. Ammonia levels are not routinely checked due to the myriad of other explanations for encephalopathy in a transplant recipient. A treatment of choice for severe hyperammonemia involves renal replacement therapy (RRT), but there are no guidelines on the mode or parameters of RRT for reducing ammonia levels. Hyperammonemia in a transplant recipient poses specific challenges beyond the actual condition because the treatment (RRT) involves significant hemodynamic fluctuations that may affect the graft. In this review, we describe a patient with posttransplantation hyperammonemia and discuss the pathways of ammonia metabolism, potential factors underlying the development of hyperammonemia posttransplantation, and choice of appropriate therapeutic options in these patients.

Hepatic Encephalopathy: An Update on the Pathophysiology and Therapeutic Options

Hepatic encephalopathy is a spectrum of reversible neuropsychiatric abnormalities, seen in patients with liver dysfunction and/or portosystemic shunting. One of the most debilitating complications of cirrhosis, encephalopathy affects 30-45% of cirrhotics. In addition to significantly affecting the lives of patients and their caregivers, it is also associated with increased morbidity and mortality as well as significant utilization of health care resources. In this paper, we provide an overview on the pathophysiology, diagnosis, management and newer therapies of hepatic encephalopathy.

Embolization of portosystemic shunt for treatment of recurrent hepatic encephalopathy

Hepatic encephalopathy in the setting of advanced chronic liver disease, occurs following a precipitating factor and generally responds to correction of the precipitating factor and anticoma measures. We report the case of a lady with Child A cirrhosis who presented with frequent episodes of hepatic encephalopathy without any precipitating factors. She was found to be having a large portosystemic shunt. The shunt was obliterated by coil embolotherapy following which there was no further episodes of encephalopathy.