Central dilemma in CSF pseudocyst – A case series and review of literature

Etiological aspects

There is no well-established etiology for the CSF pseudocyst in the literature. Long-standing subclinical abdominal infection,^[7,8] high-protein contents in CSF, recurrent abdominal surgeries, increased abdominal adhesions, and silicone allergy^[9] are some of the contributing factors for decreased CSF absorption, leading to CSF collection in the form of pseudocyst formation. A subclinical infection has been documented in 17–80% of cases.^[10] In addition, few pathogens have also been found quite commonly associated with pseudocyst which include Staphylococcus epidermis, Staphylococcus aureus, and Streptococcus.^[10,11] At times, the subclinical infection caused by shunt may not be diagnosed by single CSF culture and infection may remain latent.^[5,11] In our cases, cultures were all sterile presuming the role of subclinical infection.

Clinical manifestations

We noticed abdominal distension on presentation, which was insidious in onset and gradually progressive in all three cases [Figure 1] and case-wise details are mentioned in [Table 1]. Associated features of raised ICP such as headache, nausea, and vomiting may be seen especially in shunt-dependent cases (as in one of our cases) whereas abdominal distension with or without pain may be the only presenting symptom, especially in adult patients. Other less common features may be fever, anorexia, constipation, tenderness, palpable mass, and subphrenic abscess.^[10]

Management dilemma

Management of CSF pseudocyst should be tailored to individual patient as there is no standard/uniform management strategy defined for pseudocyst abdomen and is always a management dilemma [Figure 2]. The options discussed in the literature [Table 2] include open procedures such as laparotomy and cyst drainage/cyst wall excision or laparoscopic cyst drainage with repositioning of the abdominal catheter of the shunt.^[5,11-15] The laparoscopic method is considered a preferred method for pseudocyst abdomen management by many authors. Other options such as exteriorization of abdominal end with or without concomitant antibiotics and the alternate site or contralateral side for shunt catheter placement are suggested by many. Whereas few authors have advocated ventriculoatrial (VA), ventriculopleural (VPL), or endoscopic third ventriculostomy, especially when peritoneal cavity is not a suitable environment or infection free.^[11,16] A comparative evaluation of management is detailed in Table 2.^{[5,11-15,17-21]}

Open procedures such as laparotomy and excision of pseudocyst abdomen have been associated with multiple adhesion formation, obstruction, wound infections, etc. Such procedures are prone to recurrence of pseudocyst. Whereas, VPL shunt placement is a good alternative but it carries the risk of pleural effusion [Table 2], as in our Case 2. Most of the management options do not address the importance of clinical or subclinical infection, which may be a contributing factor. However, it is critically important that the presence or absence of subclinical or on-going infection as an infected assembly may continue to be a nidus.^[3,11] Laparoscopic excision of the cyst and repositioning of the catheter are a less morbid procedure but we have observed in shunt-independent/non-dependent cases, even such procedures can be avoided.

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Figure 2:

Exploratory laparotomy with collapsed pseudocyst abdomen and shunt tip (a-c). Development of pleural effusion following ventriculopleural shunt (d).

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Most of the studies have not taken into account of the role of CSF workup or other inflammatory markers (TLC, ESR, and CRP) before proceeding any intervention. These levels are necessary as they will guide whether to exteriorize the shunt or not. Similarly, antibiotics need to be started as per culture and sensitivity.^[22]

Role of shunt dependency – A key step

To the best of our knowledge, none of the studies has given any emphasis on shunt dependency. The “shunt dependency” has to be ruled out right at the beginning, especially when there are no signs of raised ICP and only complaint is abdominal distension. We can rule out “shunt dependency” by a simple and safe technique. One needs to tie the abdominal catheter of the shunt just below the clavicle by making a small skin incision (1 cm) over the shunt catheter and further dissection to locate shunt catheter. One needs to avoid any accidental cut in underlying catheter. The shunt is tied with nylon 2–0 suture [Figure 3a-c]. The patient should be observed for 2–3 days for any feature of raised ICP. Repeat Noncontrast computed tomography head should be done after a couple of days (after 48–72 h). If there are no features suggestive of raised ICP clinically as well as radiologically, then we consider him/her “shunt independent” and it makes management strategy simpler thereafter. We can simply remove the whole shunt assembly as an offending source to eliminate the possibility of latent or subclinical infection. CSF pseudocyst abdomen is further managed by a very simple, effective, and minimally invasive technique, that is, ultrasound-guided percutaneous drainage of the cyst (PIGTAIL drainage), as shown in algorithm in [Figure 4]. Furthermore, this technique may avoid many expected complications such as pleural effusion following VPL shunt, chances of infection following exteriorization of shunt end, and laparotomy-related complications. Gaskill and Marlin documented in their series that it is not mandatory to remove the walls of pseudocyst because pseudocysts solve spontaneously, once the catheter is taken off.^[23] In our cases, it has proven a successful modality and no recurrence is seen after 3-year follow-up.

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Figure 3:

Child showing collapsed pseudocyst lump size after PIGTAIL drainage (on the right lower abdomen shown by black arrow) and site of tying shunt catheter infraclavicular, right side – shown by black arrow (a). Noncontrast computed tomography (NCCT) head showing no ventriculomegaly after tying shunt (b). Before draining, pseudocyst abdomen with shunt tips lying anteriorly and inferiorly (c).

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Figure 4:

Proposed algorithm showing management strategies for shunt dependent and shunt non-dependent abdominal CSF pseudocyst.

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In the case of shunt-dependent patients, management is always challenging as there are possibilities of failure or recurrence of the pseudocyst. Again analysis of inflammatory markers (TLC, CRP, and CSF) beforehand is of utmost importance. In case of recurrence, we need to choose other options such as VPL or VA shunt placements. Some authors also suggest placement of the distal catheter in the gallbladder. For infected cases, we need to exteriorize the distal end or convert the proximal end of the catheter into EVD and start broad-spectrum/culture-based IV antibiotics for 2–3 weeks or till two cultures are sterile [Figure 4].

Statement of ethics

Written informed consent was obtained from the patients for publication of this case report and any accompanying images. Ethical approval was not required for this study in accordance with national guidelines.

Data availability statement

All data generated or analyzed during this study are included in this article. Further enquires can be directed to the corresponding author.