Simone Peraio

Hydrocephalus and Chiari type I malformation

IntoductionHydrocephalus has been related to Chiari type I malformation (CIM) for a long time. The pathogenesis of this association is complex and still debated.DiscussionA supratentorial hypertensive hydrocephalus may cause CIM, exerting pressure from above. Another pathogenetic hypothesis is based on the clinical and radiological data from patients affected by complex craniosynostosis, in which this association is more commonly observed as the consequence of a “cephalo-cranial disproportion” ultimately leading to a secondary hydrocephalus. In some cases, the concomitant presence of a stenosis of the jugular foramina would determine a condition of upward venous hypertension, resulting in the development of CIM and an associated hydrocephalus due to cerebellar parenchyma turgor.ConclusionsThe radiological association of ventricular enlargement and hindbrain herniation would be the result of heterogeneous pathogenetic mechanisms which would then require specific therapeutic approaches. In this context, the endoscopic third ventricle-cisternostomy is gaining an increasing interest because of its more physiologic correction of the altered CSF dynamics and its minor interference on the developmental processes responsible for the association of hydrocephalus and CIM.

Antiangiogenic therapy for high-grade gliomas: current concepts and limitations

Glioblastoma (GBM) is associated with a high degree of angiogenesis. Therefore, antiangiogenic therapy could have a role in the treatment of this tumor. The currently available treatment approaches acting against angiogenesis are mainly directed toward three pathways: VEGF pathway, VEGF-independent pathways and inhibition of vascular endothelial cell migration. It has been demonstrated that antiangiogenic therapy can produce a rapid radiological response and a decrease of brain edema, without significantly influencing survival. Future studies should consider that: animal models are inadequate and cells used for animal models (mainly U87) are deeply different from patient GBM cells; GBM cells may become resistant to antiangiogenic therapy and some cells may be resistant to antiangiogenic therapy ab initio; and angiogenesis in the peritumor tissue has been poorly investigated. Therefore, the ideal target of angiogenesis is probably yet to be identified.

History of Chiari type I malformation

Chiari type I malformation (CIM) was first described in the late 19th Century. However, it still raises a great interest among the scientific Community because of the increasing number of diagnosed cases, the still unclear pathogenesis and natural history and the different options in the surgical management. The present review aims at analyzing the centenary history of CIM, starting from the first description done by Hans Chiari to the more recent classification, in order to introduce such a complex disease and to show the way followed for its assessment over the time.

Section of the filum terminale: is it worthwhile in Chiari type I malformation?

A section of the filum terminale (SFT) is used for the surgical treatment of isolated tethered cord or that resulting from neurulation disorders. More recently, it has been proposed for the management of the occult tethered cord syndrome (OTCS), though it is still under debate. Even more controversial appears to be the use of SFT in patients with Chiari type I malformation (CIM), which is based on the possible presence of OTCS. This review shows that: (1) there are issues both in favor and against the occurrence of OTCS, (2) there is no significant correlation between CIM and tethered cord, the old “caudal traction theory” being not supported by clinical or experimental evidences. On these grounds, a relationship between CIM and OTCS is hard to be demonstrated, (3) a subgroup of patients with CIM suffering from OTCS may exist and benefit from SFT.

Problems of reconstructive cranioplasty after traumatic brain injury in children

Cranial repair after traumatic brain injury in children is still burdened by unsolved problems and controversial issues, mainly due to the high rate of resorption of autologous bone as well as the absence of valid alternative material to replace the autologous bone. Indeed, inert biomaterials are associated to satisfactory results in the short period but bear the continuous risk of complications related to the lack of osteointegration capacity. Biomimetic materials claiming osteoconductive properties that could balance their mechanical limits seem to allow good cranial bone reconstruction. However, these results should be confirmed in the long term and in larger series. Further complicating factors that may affect cranial reconstruction after head injury should be identified in the possible associated alterations of CSF dynamics and in difficulties to manage the traumatic skin lesion and the surgical wound, which also might impact on the cranioplasty outcome. All the abovementioned considerations should be taken into account when dealing with the cranial reconstruction after decompressive craniectomy in children.

From above or from below? That is the question. Comparison of the supraorbital approach with the endonasal approach. A cadaveric study

Abstract Background: Nowadays the endoscopic endonasal approach is increasingly being used to remove craniopharyngiomas, tuberculum sellae meningiomas and other presellar and parasellar lesions and its value in anterior skull base surgery is undisputed. Herein, we assess the relative advantages, disadvantages and feasibility of the keyhole eyebrow approach and the endonasal endoscopic approach in four cadaveric heads for the removal of presellar and parasellar lesions. Methods: We used four cadaveric heads for 12 surgical dissections. The specimens were embalmed with two different techniques. Two bilateral supraorbital endoscopic assisted approaches and one transnasal expanded endonasal approach were performed for each head. We evaluated the feasibility, maneuverability and safety of each approach. We measured the operating room obtained with each approach and the distance from the main structures we reached. Results: The technical feasibility of the endoscopic endonasal transphenoidal approach and the supraorbital eyebrow approach was reproduced in all four cadaveric heads. The transnasal approach gave us a good operating field medial to the two optic nerves and the two carotid arteries anteriorly until the frontal sinus and, posteriorly, the basilar artery, the emergence of the superior cerebellar arteries and posterior cerebral arteries. After performing the supraorbital approach, we viewed a wider field of the anterior skull base and we were able to reach the ipsilateral carotid artery, the optico-carotid recess, the pituitary stalk, the lamina terminalis until the contra lateral optic nerve and carotid artery, keeping a wider angle of maneuverability. Conclusions: Although the endoscopic transnasal approach has developed in leaps and bounds in the last decade, other transcranial approaches maintain their value. The supraorbital endoscopic approach is a minimally invasive approach and seems to be optimal for those lesions wider than 2 cm in the lateral extension and for all the paramedian lesions.