Spontaneous intrahepatic portosystemic shunt managed by laparoscopic hepatic vein closure.

Intrahepatic portosystemic shunt (IPSS) is uncommon and usually follows trauma or iatrogenic injury, but spontaneous shunts may also occur, in patients without the evidence of chronic liver disease. Although interventional endovascular management of the shunts is the treatment of choice, a surgical approach can be used when the percutaneous approach fails. We report here a case of symptomatic spontaneous IPSS between the posteroinferior branch of right portal vein and the right inferior hepatic vein, which was successfully managed with laparoscopic closure of the hepatic vein. To the best of our knowledge, this is the first case report of laparoscopic management of spontaneous IPSS.

INTRODUCTION

Spontaneous intrahepatic portosystemic shunt (IPSS) is uncommon, but when it occurs it can cause symptoms mimicking hepatic encephalopathy.[12] When symptoms are mild, the patients can be managed conservatively, with medication and dietary control.[2] However, in intractable cases, surgical removal of the IPSS or shunt disconnection should be considered.[3] In recent times, less invasive percutaneous interventional treatment has been widely adopted instead of open surgery.[45] In addition, a laparoscopic approach can be an attractive option in cases when interventional procedures are considered unlikely to be successful, although the reported experience with these procedures is extremely limited and confined to cases of extrahepatic portosystemic shunts.[678] We report here a case of symptomatic spontaneous IPSS successfully managed by laparoscopic closure of the right inferior hepatic vein.

CASE REPORT

A 62-year-old woman, with a history of hypertension and diabetes, presented with recurrent episodes of the reduced level of consciousness and the altered mentality, which lasted for 2 months. A computed tomography (CT) and magnetic resonance imaging of the brain revealed no abnormalities. She was managed conservatively under the impression of metabolic encephalopathy, only to suffer from repeated attacks of encephalopathy. She denied any history of liver trauma, biopsy, disease, including cirrhosis, or abdominal surgery.

On admission, her blood chemistry tests revealed elevated values of serum ammonia (146 μg/dL; normal <75 μg/dL), aspartate aminotransferase (AST, 112 U/L; normal 7-38 U/L) and alanine aminotransferase (ALT, 152 U/L; normal 4-43 U/L). Her serum magnesium and ionised calcium concentrations were normal. An abdominal CT scan showed a vascular lesion in segment six of the liver, which was measured about 4.7 cm in diameter, without evidence of ascites or splenomegaly [Figure 1a]. Transhepatic portography and inferior venacavography were performed simultaneously, which revealed aneurysmal dilatation of the right portal vein, and a large high-flow fistula draining into the retrohepatic inferior vena cava (IVC) [Figure 1b]. The maximum diameters of the inflow vein, shunt, and outflow vein were 18.6 mm, 30.4 mm, and 18.7 mm, respectively. Interventional coil embolisation for occlusion of the shunt was considered, but it was deemed unlikely to be successful because of the very short neck of the shunt, the high-flow of the outlet, and the possibility of coil migration. Therefore, laparoscopic surgery was performed.

Figure 1

(a) An abdominal computed tomography shows a lobulated, enhancing vascular structure in segment six of the liver (arrow), with intact right hepatic vein (arrow head). (b) Transhepatic portography and inferior venacavography performed simultaneously. The diameters of the inflow (arrow), shunt (double arrow), and outflow (arrowhead) were measured

Under general anaesthesia, the patient was placed in the left decubitus position. An 11-mm trocar was introduced through an open approach at the mid-clavicular line along the right subcostal margin, to be used as the camera port. After carbon dioxide insufflation, a 5-mm trocar was inserted at the midaxillary line under laparoscopic vision to retract the liver. A 12-mm trocar was inserted at the subxyphoid area, and blunt and sharp dissection was performed at the peritoneal reflection between the liver and the parietal peritoneum. Upon dissecting the right triangular ligament and retracting the liver with a snake liver retractor, a lobulated, bulging vascular mass was seen. Otherwise, the surrounding liver parenchyma looked healthy. After identifying the direct communication between the aneurysm and the IVC, the dilated accessory right inferior hepatic vein was dissected circumferentially through the retrohepatic space. A 60-mm Echelon FlexTM Endopath® Stapler (Ethicon Endo-Surgery Inc., Ohio, USA) with a white cartridge was introduced, and the dissected communicating accessory vein was clamped and cut [Figure 2]. A closed suction drain was inserted, and the trocar sites were closed. The operation took 120 min, and the estimated blood loss was 100 mL.

Figure 2

Illustration of the laparoscopic view of the operative field. Note that the right inferior hepatic vein is dissected circumferentially and ready to be cut. GB indicates gallbladder, and IVC indicates inferior vena cava

The patient's postoperative recovery was uneventful. Her mental status improved immediately on recovering from the anaesthesia. Her serum ammonia levels on the 1st and 3rd postoperative days were 55 μg/dL and 57 μg/dL, respectively. The AST level had declined to 45 U/L, and the ALT to 89 U/L, by the 3rd postoperative day. She was discharged from the hospital on the 4th postoperative day. Her symptoms had not recurred in the ensuing months, and no further management was necessary. An abdominal CT scan at 8 months after surgery showed that the shunt was no longer present and the distribution of portal blood flow throughout the liver parenchyma was normal [Figure 3].

Figure 3

An abdominal computed tomography at 8 postoperative months demonstrates the disappearance of the shunt (arrow). The right hepatic venous drainage is well preserved (arrow head)

DISCUSSION

When a portosystemic venous shunt is found in a patient without liver disease or a history of trauma, it is presumed to be spontaneous or congenital in origin.[2] The outcome of our patient may have implications regarding the causal relationship between intrahepatic portal venous aneurysm and shunt formation. In contrast to the speculations that an aneurysm might have ruptured into the hepatic vein to form an aneurysmal IPSS, the disappearance of aneurysm after outflow occlusion prefers the explanation that a preexisting shunt caused progressive aneurysmal dilatation of IPSS.[9]

The symptomatic IPSS patients can be managed conservatively if the symptoms are mild.[12] However, a shunt disconnection should be considered when the conservative measures fail.[3] In recent times, percutaneous endovascular techniques have been widely adopted for the management of IPSS.[5] Although minimally invasive, an endovascular shunt occlusion is not always possible due to anatomical difficulties and problems with the occlusive devices.[458] When percutaneous endovascular techniques are considered to be unsuccessful, conventional open or laparoscopic surgery can be used. The laparoscopic approach is preferred to open surgery, because the latter is associated with higher rates of morbidity and mortality,[8] which may be attributed to the intraoperative bleeding in patients with already compromised liver function. Whatever obliterative method is used, the blockade may be placed at one of three sites: The inflow, the shunt per se, or the outflow.[5] To our knowledge, the present case is the first report of outflow occlusion of IPSS performed laparoscopically, although there are reports of laparoscopic outflow disconnection of extrahepatic portosystemic shunt.[678]

CONCLUSION

Spontaneous IPSS can be managed by outflow occlusion, and rapid restoration of hepatic function and resolution of encephalopathic symptoms may result. In selected patients, the laparoscopic approach is feasible and safe, and can be a valid option when interventional endovascular procedures are deemed unlikely to be successful.