Factors associated with incomplete resection:
(1) firm adherence of the tumor to the hypothalamus, especially when bilateral
(2) obstruction of the neurosurgeon's view of the tumor and operative field (inadequate visualization)
(3) presence of major calcifications (> 10%, page 243 Fahlbusch et al)
(4) adherence of the tumor to perforating and/or major blood vessels
(5) high blood loss during surgery (from a coexisting aneurysm, other sources)
(6) advanced age of the patient
(7) severe bradycardia or other arrhythmia during the surgery
(8) very thin capsule to the tumor
(9) tumor within the third ventricle
(10) presence of hydrocephalus
(11) proximity to the optic pathways, including the optic chiasm
Factors that alone do not affect extent of resection:
(1) size of the tumor
Modern imaging techniques can help determine the extent of tumor before and after surgery.
