Posterior Fossa Tumors: Clinical Outcome of Surgery without Cerebrospinal Fluid Diversion

Abstract

Objective. To present the results of surgery for posterior fossa tumors
without CSF diversion and describe the patients who may require
permanent CSF diversion post op.
Methods. We analyzed data of 72 patients with posterior fossa
tumors and hydrocephalus who were treated surgically through a
suboccipital craniotomy/craniectomy and tumor excision without CSF
diversion. All of the patients were operated on by the authors and the
surgical technique standardized as follows: suboccipital craniotomy/
craniectomy, early access of the cisterna magna and evacuation of CSF
until the posterior fossa compartment is relaxed, then tumor excision.
Data underwent statistical tests for significance for the variables age,
tumor type, tumor location, degree of hydrocephalus and extent of
tumor excision using Mantel-Haenszel estimates and p values.
Results. The mean age of patients was 36.15 years. The most common
tumor type was schwannoma. Eighty-six percent (86%) of patients
had moderate to severe hydrocephalus. Eighty-one percent (81%)
had total tumor excision. No patient required any other form of CSF
drainage or diversion intra-op. The complication rate was 4.2%, with
pseudomeningocoele being the most common complication. Four
patients required a permanent VP shunt post tumor excision.
Conclusion. The good clinical outcome and low postoperative shunt
insertion rate in our series led us to believe that posterior fossa tumor
surgery without CSF diversion is a safe and effective treatment plan for
posterior fossa tumors with hydrocephalus, and routine CSF diversion
for posterior fossa tumor surgery may not be entirely justified. Factors
such as age, tumor type, tumor location, degree of hydrocephalus and
extent of excision, which showed a statistically significant association
with the postoperative shunt requirement in our study, should be
considered when the decision regarding CSF diversion is made.