Sitting Position Craniotomy for Posterior Fossa Tumor Resection in a Patient with Fontan Circulation

Background: Pineal body tumors constitute approximately 1% of all solid brain neoplasia. This tumor group has a particular bad prognosis, thus requiring aggressive therapy.

The Fontan Procedure is the correction of choice for cardiac malformations not compatible with biventricular repair. This procedure leads to passive pulmonary blood flow that is dependent on high central venous pressure (CVP) and low pulmonary vascular resistance.

The sitting position is of value when it comes to posterior fossa tumor resection, allowing better exposure and lower bleeding. However, compared with prone position it has a higher risk of venous air embolism, reduced cardiac preload and limited patient access.

Case report: A 17 year old male with Fontan circulation complicated by protein loosing enteropathy, was diagnosed with a posterior fossa tumor - pienoblastoma. The patient needed preoperative hospitalization for correction of his nutritional status and related electrolyte imbalance.

Intraoperative management included precordial Doppler, fenestrated central venous catheter and military anti shock trousers. Total IV anesthesia was maintained by remifentanil and propofol infusions. The patient was maintained with a normal–high CVP, by judicious administration of 5% Albumin. Low PEEP and PIP provided excellent oxygenation and ventilation. Following an uneventful surgery, extubation performed in the OR. Six units of cryoprecipitate were given in PICU, based on laboratory results.

Conclusion: This case demonstrates that the sitting position for a craniotomy is possible and might be beneficial in patients with Fontan circulation, despite potential risks. The benefits were improved surgical access, reduced bleeding and better V/Q matching.