Complete Microsurgical Resection of Large Retrochiasmatic Hypothalamic Craniopharyngioma by Transpetrosal Approach: 2-Dimensional Operative Video

This two-dimensional video shows the technical nuances of complete microsurgical resection of a hypothalamic craniopharyngioma located in the retrochiasmatic region by the transpetrosal approach. This 49-yr-old man presented with progressive fatigue, excessive sleepiness, and difficulty in vision in both eyes. He was found to have right CN 3 paralysis and bitemporal hemianopsia on neurological examination. Further workup revealed panhypopituitarism. Brain magnetic resonance imaging (MRI) demonstrated a large solid retrochiasmatic hypothalamic lesion with homogeneous contrast enhancement, measuring 2.1 × 2.6 × 2.4 cm. Optic chiasm was prefixed, and the tumor was just posterior to the pituitary stalk area. The preoperative differential diagnosis included hypothalamic astrocytoma, craniopharyngioma, germinoma, and histiocytosis. Because of the prefixed chiasm, a presigmoid, transpetrosal approach was performed. Our initial plan was a large biopsy, but based on frozen section histology, we decided to excise the tumor completely. The tumor had a pseudocapsule, which was firm and yellowish. It was debulked, dissected from the surrounding hypothalamus, and removed completely. The pituitary stalk was found at the anterior and inferior ends of the tumor and was preserved. Postoperatively, the patient developed diabetes insipidus and requires desmopressin replacement, which was gradually tapered. For panhypopituitarism, he is receiving thyroxine, hydrocortisone, and testosterone. Postoperatively, patient had an improvement in vision in his left eye and ptosis was improving in the right eye with mRs 1- at 10-wk follow-up. An informed consent was obtained from the patient prior to the surgery, which included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.

Endoscopic endonasal transplanum transtuberculum approach for resection of retrochiasmatic craniopharyngioma

Retrochiasmatic craniopharyngiomas are formidable cranial base tumors to resect because of their intimate relationship with neighboring critical neurovascular structures, particularly the undersurface of the optic chiasm and hypothalamus. Radical resection offers the best chance of minimizing tumor recurrence, although this may be associated with significant surgical morbidity. Although various transcranial approaches have been utilized (transbasal subfrontal, frontobasal interhemispheric, pterional, orbitozygomatic, and petrosal) for resection of retrochiasmatic craniopharyngiomas, each is associated with some degree of brain retraction, and direct visualization of the retrochiasmatic region is often incomplete, therefore resulting in blind dissection. The endoscopic endonasal transplanum transtuberculum approach provides the most direct route to the retrochiasmatic region while affording unmatched visualization of the undersurface of the optic chiasm, third ventricle, and hypothalamus. This advantage allows for direct bimanual tumor dissection off of these critical structures by using microsurgical principles. The endonasal route also has the advantage of avoiding brain retraction and risk of cerebral edema that can be associated with transcranial approaches. In this operative video atlas report, the authors demonstrate their step-by-step techniques for resection of a suprasellar retrochiasmatic craniopharyngioma using a purely endoscopic endonasal transplanum transtuberculum approach. They describe and illustrate the operative nuances and surgical pearls to safely and efficiently perform the approach, tumor resection, and multilayered reconstruction of the cranial base defect. The video can be found here: http://youtu.be/ZIbJvAyRxYU.

Interleukin-1 mediates endothelin-1-induced fever and prostaglandin production in the preoptic area of rats

The intracerebroventricular injection of endothelin-1 (ET-1) induces fever and increases PG levels in the cerebrospinal fluid of rats. Likewise, the injection of IL-1 into the preoptic area (POA) of the rat hypothalamus causes both fever and increased PG production. In this study, we conducted in vivo and in vitro experiments in the rat to investigate 1) the hypothalamic region involved in ET-1-induced fever and PG biosynthesis and 2) whether hypothalamic IL-1 plays a role as a mediator of the above ET-1 activities. One hundred femtomoles of ET-1 increased body temperature when injected in the POA of conscious Wistar rats; this effect was significantly counteracted by the coinjection of 600 pmol IL-1 receptor antagonist (IL-1ra). In experiments on rat hypothalamic explants, 100 nM ET-1 caused a significant increase in PGE2production and release from the whole hypothalamus and from the isolated POA, but not from the retrochiasmatic region, in 1-h incubations. Six nanomoles of IL-1ra or 10 nM of a cell-permeable interleukin-1 converting enzyme inhibitor completely counteracted the effect of ET-1 on PGE2release from the POA. One hundred nanomoles ET-1 also caused a significant increase in IL-1β immunoreactivity released into the bath solution of hypothalamic explants after 1 h of incubation, although during such time ET-1 failed to modify the gene expression of IL-1β and other pyrogenic cytokines within the hypothalamus. In conclusion, our results show that ET-1 increases IL-1 production in the POA, and this effect appears to be correlated to ET-1-induced fever in vivo, as well as to PG production in vitro.

Lipoma of the infundibulum

✓ Lipomas of the infundibulum are extremely rare and may not be recognized radiologically, even on computerized tomography (CT) scanning, if the tumor is less than 20 mm in diameter. A questionable CT diagnosis in the presence of endocrinological symptoms may justify an operation by microsurgical technique on the retrochiasmatic region. In the case reported, microsurgical removal of a small infundibular lipoma was successfully accomplished.