Is subduro-peritoneal shunt surgery the first or last resort in managing subdural effusion developing after supratentorial tumor surgery in infancy?

Dear Sir,

Basaran et al. reported an interesting case of subdural effusion developing following desmoplastic infantile ganglioglioma managed with gross total excision with good outcome in a 9-month-old boy. He underwent frontotemporal craniotomy with aspiration of the cyst, followed by gross total resection of the tumor. Authors stated postoperative period was uneventful; however, a subdural-peritoneal shunt insertion was carried out on the third postoperative day for management of subdural hygroma formation, revealed on computed tomography (CT) scan causing squeezing of brain tissue and producing mass effect.[1] Is subduro-peritoneal shunt always needed to manage subdural effusion developing following intracranial microsurgical tumor resection in infancy, as early as on third postoperative period? Definitely not always, although occasionally it may be needed.[234]

Interestingly he had relatively large head circumference 47 cm, 90th percentile on clinical evaluation.[1] CT scans of the head also showed a cranial bony defect in his right parietal bone[1] which along with intra-operative ventricular opening, might have predisposed to the development of the effusion. Further infantile desmoplastic ganglioglioma carries a favorable prognosis after gross total resection despite being aggressive and infiltrating in nature.[5] VandenBerg et al. recommended against requirement of adjuvant therapy, even after incomplete resection.[2] However, for such lesion, additional subduro-peritoneal shunt was inserted, which carries associated complication. Was drastic shunt surgery warranted or was a trial of minimally invasive procedure like anterior frontanelle tapping, twist drill or burr hole drainage prudent.[34567]

Usually, the natural course of subdural effusion developing after intracranial surgery is self-limiting showing spontaneous resolution with passage of time leading to resolution of mass effect or very rarely may have slow progression requiring neurosurgical intervention.[13] Only very few reported cases needed surgical intervention Ban et al. analyzed 89 cases, undergoing decompressive craniectomy for traumatic brain injury, a total of 29 cases developed effusion, and all cases were managed conservatively and showed spontaneous resolution except for one, which needed surgical intervention for failure to resolve and showing progressive increasing mass effect.[8]

Treatment modalities of effusion are tapping of anterior fontanelle, single stage burr-hole, burr-holes with drains placed in the subdural space kept for few days, drain placement following simple twist drill, and a formal craniotomy.[2469] However, in cases requiring prolonged drainage, an Ommaya reservoir placement and repeated tapping under aseptic precautions are other useful alternatives. Subduro-peritoneal shunt is rarely advised, however, Miyake et al. strongly discourages use of subduro-peritoneal shunt and it cannot be recommended as first option for treatment of subdural effusion in most cases as procedure carries inherent long-term potential morbidity.[4] Further, it carries risk of shunt dependency and another surgery may be required for removal of the shunt. The best option would be one that has greatest chance of definitively treating the effusion with a single surgery with low complications risk and without placing a shunt.[5]

Arachnoid granulations become visible at 6 months of age and grow in size and number over the next years. This may lead to spontaneous resolution of subdural effusion making subduro-peritoneal shunt non-functional and a second surgery may be required for its removal.[7]

Mattei et al. observed that a temporary shunt for pseudomeningocele in infants can constitute a viable therapeutic alternative with favorable clinical outcomes and a low risk of shunt dependency similar to those of children with subdural hematoma, but second surgery is definitely required for shunt removal after 201 days for the pseudomeningocele group and 384 days for the subdural hematoma.[3] Hence, definitely subduroperitoneal shunt placement would require a second surgery for removal involving consumption of resources and depriving opportunity to other patients, as high patient load in a developing country with limited resources.

However, occasionally subduro-peritoneal shunt is advocated by Satyarthee et al., who reported a case, who despite burr-hole and ongoing conservative therapy developed progressive subdural hygroma under pressure with visual deterioration, which was managed successfully with placement of a subduro-peritoneal shunt.[5]

The subduro-peritoneal shunt still has a role in management of rare cases of subdural effusion, especially associated with raised intracranial pressure and showing further neurological deterioration or failure to other procedures like twist drill, burr hole or other simple procedures. However, other minimally invasive surgical procedures such as anterior fontanelle tapping, twist drill, or burr hole should be tried first.