Surgical outcomes in 31 patients with craniopharyngiomas extending outside the suprasellar cistern: an evaluation of the frontobasal interhemispheric approach.

Abstract

Craniopharyngiomas frequently grow from remnants of the Rathke pouch, which is located on the cisternal surface of the hypothalamic region. These lesions can also extend elsewhere in the infundibulohypophyseal axis. The aim of this study was to establish the usefulness of the frontobasal approach made through a relatively small craniotomy window for the removal of tumors protruding from the sellar-suprasellar region into the third and basal cistern. Thirty-one patients who were surgically treated for craniopharyngiomas extending outside the sellar-suprasellar region were evaluated. The diagnoses were established in all cases by using magnetic resonance and computerized tomography imaging. The initial symptoms and signs were increased intracranial pressure in eight, vision impairment or visual field defect in 16, hypopituitarism in 17, and psychological disturbances in three cases. All patients underwent surgery via the frontobasal interhemispheric approach, and the average follow-up period was 30 months. Total removal of the lesion was achieved in 22 cases, six patients underwent subtotal resection, and three underwent partial removal due to tumor recurrence after previous surgeries performed with or without adjunctive radiotherapy. Major complications, including impairment of the cranial nerves, were not observed in the immediate postoperative period. One patient exhibited transient memory disturbance due to infarction of the perforating vessels; after 3 months this symptom was ameliorated. None of the patients died during long-term follow up; however, four of the 22 who underwent total removal and six of the nine patients who underwent subtotal or partial removal suffered recurrence. Of the 10 patients with recurrence, six experienced a small recurrence of the lesion (average 3 months postsurgery); after gamma knife surgery (GKS), the size of two of the lesions was unchanged and in four reoperation was performed due to tumor enlargement during the follow-up period. Ultimately, a total of eight patients (four with recurrence and four who had been treated with GKS) underwent reoperation, with gross-total removal via the same approach or combined with the orbitozygomatic approach in patients with very short optic nerves. In no patient was deterioration of visual acuity and visual field observed after surgery. Although all patients except four children and one adult were receiving some form of hormone replacement therapy, their endocrine status was stably controllable. In the authors' experience, the frontobasal interhemispheric approach, even made through a small craniotomy window, is a valid choice for the removal of craniopharyngiomas extending outside the sellar-suprasellar region. Via this approach, tumors can be removed without significant sequelae related to the surgical method, due to ease of preservation of the pituitary stalk, hypothalamic structures, and perforating vessels. This approach offers a safe and minimally invasive means of treating craniopharyngiomas.