Keywords
ventriculoperitoneal shunt - cerebrospinal fluid pseudocyst - hepatic cyst
Palavras-chave
derivação ventriculoperitoneal - pseudocisto de líquido cefalorraquidiano - cisto hepático
Introduction
Ventriculoperitoneal (VP) shunt remains the most used technique for the treatment of hydrocephalus.[1] With the increased survival of patients undergoing the procedure, we can identify some complications, such as abdominal cysts of cerebrospinal fluid (CSF). These are rare complications of VP shunt, accounting for only 0.25% of all cases with abdominal disorders.[2]
[3]
This article aims to report a case of hepatic CSF pseudocyst, an even more unusual example of abdominal complications after a VPS procedure, in which there was perforation of a massive organ. The literature review performed was based on PubMed, using the keywords and Boolean operators VP shunt complications OR ventriculoperitoneal shunt AND hepatic pseudocyst OR CSF pseudocyst OR intrahepatic cyst, restricting the search to articles in the English language. No other limitations were included, and less than 50 cases reporting this condition in the past 20 years were found.
Case Report
TJC, male, 18 years old, with VPS since childhood due to hydrocephalus of idiopathic etiology, with history of revision of the valve in adolescence, presented to the neurology service of Hospital da Restauração, in Recife, Brazil, in August 2020. The patient complained of severe temporal headache associated with visual turbidity for approximately 3 months. He brought a recent brain computed tomography (CT) scan with no abnormalities. Despite this, the examination of the eye fundus already showed papilledema, with visual acuity of 20/20 bilaterally.
In a detailed investigation, it was evidenced that the patient had visual turbidity associated with abdominal pain. Therefore, a new brain CT scan without contrast was requested, which did not show lesions or signs of hydrocephalus and, additionally, a brain magnetic resonance imaging (MRI) was performed, which showed no signs of aqueduct stenosis ([Fig. 1]). For better investigation, the patient underwent abdominal CT and evaluation by the ophthalmology and general surgery teams. On the abdominal CT scan, the presence of an intrahepatic abdominal catheter was observed, forming a hepatic pseudocyst of intracapsular CSF, due to the probable entry of the distal VPS catheter through the hepatic capsule ([Fig. 2]).
Fig. 1 Brain computed tomography scan without contrast showing no lesions or signs of hydrocephalus (upper). Brain magnetic resonance imaging showing no fossa posterior.
Fig. 2 Abdominal computed tomography scan showing an hepatic pseudocyst of intracapsular cerebrospinal fluid, due to the probable entry of the distal ventriculoperitoneal shutn catheter through the hepatic capsule
The surgical management of the patient was performed with removal of the catheter from the liver capsule and repositioning of the catheter, intraperitoneally, in another site at the same surgical time, due to the absence of signs of infection in surgery. Venous antibiotic therapy (vancomycin and ceftriaxone) was performed for 14 days. The patient evolved with stability and a positive prognosis. Control abdominal CT was performed 8 days after the surgery, showing resorption of more than 70% of the hepatic cyst without need for further interventions ([Fig. 3]). The patient stayed in the hospital for 20 days, and was dismissed without any complications.
Fig. 3 Control abdominal computed tomography scan showing resorption of more than 70% of the hepatic cyst
Discussion
The set of abdominal cysts are a well-recognized but uncommon complications of the VPS procedure.[4] However, the hepatic CSF pseudocyst is an even less frequent condition classified into intraaxial or extraaxial cases. Intraaxial cysts happen when the tip of the shunt is lodged in the liver and causes the cyst to grow within the organ parenchyma.[5] Similar to the case reported, extraaxial cysts develop when there is a migration of the distal catheter through the Glisson capsule, resulting in the subcapsular accumulation of CSF.[6] In addition, a case report described a cyst whose smaller part was inside the parenchyma and the largest part outside, configuring a case of juxtahepatic CSF cyst.[7]
There are several etiologies for the development of hepatic CSF pseudocysts. Among the possible etiologies, sterile or infected inflammatory processes, such as peritonitis, reactions against foreign bodies, and irritation of the peritoneum due to continuous exposure to CSF,[8] were considered the most common phenomena that could cause this condition by destabilizing the capsular structure of the liver.[9] Furthermore, intraperitoneal fibrosis has a great role in the perforation process as it promotes the fixation of the tip of the distal catheter and the continued mechanical irritation of the organ's periphery. Among other causes, multiple revisions of the shunt in the abdomen as well as prior surgeries in that location, CSF malabsorption, and history of intracranial tumor are factors that predispose the formation of abdominal and hepatic pseudocysts.[10]
[11]
Image findings are essential for the diagnosis of this condition. Ultrasound examination, because it is simple, economical, and provides satisfactory diagnosis results, is the most advisable method for the first evaluation in most cases. In contrast, abdominal CT ensures an accurate diagnosis, especially when the CSF cyst grows to the point of deforming the normal internal configuration of the abdomen[12]
[13] or its growth is extraaxial, in which the liver tissue cannot be identified in the periphery of the cyst. With the CT exam, it is possible to make differential diagnoses of conditions that mimic the hepatic CSF pseudocyst symptoms (to exemplify, appendicitis, diverticulitis, volvulos, among others). Finally, it is emphasized that the efficient interpretation of the neurological deficits presented by the patient is indispensable.
Various types of treatment approaches have been reported in the analyzed literature; however, only one case has experienced recurrence.[8] Due to the scarcity of cases and the fact that the treatment depends on the patient's particular characteristics as well as on the surgeon's experience and findings during the procedure, there is no consensus in the treatment of the hepatic CSF pseudocyst. After the possible infection is treated,[14] the most common procedures include 6 main categories (1) removal of the primary shunt, placement of external ventricular shunt (EVD) followed by VP shunt insertion[15]
[16]; (2) removal of the primary shunt, placement of the EVD, followed by the insertion of a ventriculoatrial shunt (VAS)[17]
[18]; (3) removal of the primary shunt and conversion to VAS[19]; (4) repositioning of the distal catheter to the opposite side of the peritoneum[18]
[20]; (5) exploratory laparotomy, removal of the primary shunt, EVD followed by VAS or VPS[17]
[21]; (6) other treatment modalities, such as aspiration, paracentesis or excision of the pseudocyst.[22]
[23]
[24] In the case demonstrated in this report, due to the absence of infection and spontaneous resorption of > 70% of the CSF pseudocyst, the management was repositioning the distal catheter on the opposite site of the peritoneum.
Conclusion
The present case report describes a rare complication of the VPS technique. Hepatic CSF pseudocysts should be suspected in patients with a history of surgery for shunt placement for hydrocephalus treatment, and the diagnostic approach should be based on ultrasound and abdominal CT scans. In the reported case, after confirming the absence of infection and the natural resorption of the cyst, the surgical procedure chosen was to reposition the catheter on the opposite side of the peritoneum.
