With the technique of foraminoplasty, a stent is placed endoscopically into the foramen of Monro with the purpose of CSF diversion, when intraventricular craniopharyngiomas cause obstructive hydrocephalus.

The endoscopic foraminoplasty technique should be considered as an optional treatment for patients who present with obstructive hydrocephalus caused by a tumor that occludes both foramina of Monro, when shunt placement or endoscopic third ventriculostomy is not practicable [14]. Depending on tumor size, this procedure could require a partial resection of the tumor to provide sufficient space for endoscopic stent placement and an endoscopic septostomy [20].

Several adjuvant therapies for cystic craniopharyngiomas require the placement of Ommaya reservoir systems [11]. Ommaya reservoirs could make it easier to reduce cystic volume prior to radiotherapy as the final procedure and may also be used for instillation of chemotherapeutic agents and for repeated aspirations, making the achievement of cystic control more likely.

The catheter can be safely placed under endoscopic guidance with a parallel insertion technique using a transparent ventricular sheath for the endoscope through one burr hole [21].

The burr hole is made in the right frontal region on the pupillary line anterior to the coronal suture and then the transparent peel-away sheath is inserted into the right lateral ventricle directed to the right foramen of Monro. The neuroendoscopic system is introduced into the peel-away sheath while the Ommaya reservoir catheter with a stylet is inserted running over the outer surface of the sheath itself. Its transparency allows to follow the catheter insertion under endoscopic visual control in the sheath. The catheter is introduced in the right lateral ventricle and then into the cystic tumor under endoscopic view. The catheter is then connected to a subcutaneous Ommaya reservoir; the sheath is peeled away, leaving the endoscope in the lateral ventricle, in order to enable the observation of the tip of the catheter even after sheath removal.

The advantages of using endoscopic guidance are safe fenestration of the cystic capsule under visual control, conversion of multicystic craniopharyngiomas in uniloculated cyst, avoidance of the need for multiple catheters, and the possibility of performing other neuroendoscopic procedures. Large fenestration of the cyst walls should not be performed, in order to avoid leak of neurotoxic drugs into the CSF pathways.

Nicolato et al. [22] recommend performing positive contrast CT cystography prior to administration of intracavitary drugs to exclude leakage of the contrast agent from the cyst cavity.

Only a minority of small (<2 cm), cystic, purely intraventricular, noncalcified craniopharyngiomas are amenable to endoscopic resection [19, 23, 24].

Often, the solid portions arise outside the third ventricle, usually in the suprasellar area, and show an intimate relationship with the hypothalamus, optic pathway, major vessels, and perforating vessels of the cranial base; they cannot be removed without the risk of uncontrollable damage to these neurovascular structures [16]. The solid remnants, in these cases, should be later considered for microsurgery or radiation therapy [12, 14, 22].

In literature, the experience is limited and the results do not always seem to be satisfactory [15].

Marsupialization of the cystic portion of the craniopharyngiomas is often followed by additional treatments on the solid parts [11, 13, 18, 22].

Endoscopic cyst decompression and resolution of hydrocephalus before craniopharyngioma removal usually permit a delayed intervention in better clinical and technical conditions [16]. The endoscopic procedure can be performed in emergency in patients with severe and progressive visual loss or hypothalamic disorders. In most cases symptoms and signs improve and a reduced risk of the subsequent surgical tumor removal can also be anticipated, with less surgical trauma on suffering structures.