Extended endoscopic endonasal approach to the pterygopalatine fossa: anatomic study.

AIM: Our aim in this study was to recognize the endoscopic anatomy of the pterygopalatine fossa (PPF) and the anatomic variations of the related neurovascular structures, to define the endoscopic endonasal approach to this region. METHODS: Six fresh adult cadavers were studied (N=6) by endoscopic endonasal approach. To reach the pterygopalatine fossa endonasally, we performed the middle meatus transpalatine approach in 2 cadavers, the middle meatus transnasal approach in 2 cadavers and the inferior turbinatectomy transnasal approach in 2 cadavers. The superior and posterior walls of the maxillary sinus were defined and studied. The sphenopalatine foramen is widened by drilling the orbital process of the foramen and the sphenopalatine artery was exposed. The posterior wall of maxillary sinus was opened to expose the pterygopalatine fossa and its neurovascular contents, which were studied and documented. RESULTS: The PPF was easily approached by endoscopic transnasal transmaxillary approach. The PPF region was best exposed by the middle meatus tranasal approach. In the PPF; infraorbital nerve, vidian nerve, major palatine nerve, the infraorbital artery, internal maxillary artery, sphenopalatine artery, descending palatine artery, posterior superior alveolar artery and buccal artery were exposed. According Morton and Khan morphologic classification of the third portion of the internal maxillary artery we found intermediate type in 2 cadavers (33.3%), M' type in 2 cadavers (33.3%), T' type in 1 cadaver (16.7%) and Y' type in 1 cadaver (16.7%). Also, according to Chio and Park classification of the branching type of the infraorbital artery, posterior superior alveolar artery and deep palatine artery, we found type I in 4 cadavers (66%) and type II in 2 cadavers (33%). CONCLUSIONS: During the endoscopic transnasal transmaxillary approach to the PPF, it is possible to face wide range of variations in every phase of the approach. Understanding the anatomy of this region and the neurovascular relations from the endoscopic view by cadaver dissections will help us to performed more controlled and safe surgery.

Rotational compression of the vertebral artery at the point of dural penetration. Case report.

Vertebrobasilar insufficiency (VBI) due to vertebral artery (VA) compression occurs in a significant number of patients. Rotational compression of the VA usually occurs below C-2, where the artery is pinched during head rotation, leading to thrombus formation and subsequent cerebellar infarction. Although this problem has been reported to occur at the atlantooccipital levels, a review of the literature revealed no published cases of VA compression at the point of dural penetration, which is located above the atlantooccipital membrane. The authors report the case of a 30-year-old woman who presented with signs and symptoms of VBI. Dynamic angiography demonstrated left-sided VA compression at the site at which dural penetration had occurred, proximal to the posterior inferior cerebellar artery. Surgical decompression of the left VA at the point of dural penetration relieved the symptoms, and postoperative dynamic angiography demonstrated complete resolution of the positional compression of the left VA. Because of these findings, an additional possible location for rotational compression of the VA is described, namely, the point of dural penetration. The authors suggest a method of surgically treating rotational VA compression at this site.

Chiasmatic low-grade glioma presenting with sacral intradural spinal metastasis.

Leptomeningeal metastasis of low-grade gliomas in children has been documented in several series, both at the time of diagnosis and at relapse. The authors report a unique case of chiasmatic low-grade astrocytoma presenting with signs and symptoms related to the metastatic site rather than the primary site. In this respect, the possibility of appearance of symptoms and signs related to leptomeningeal dissemination preceding the signs and symptoms belonging to the primary site should be considered in this type of benign tumours.

Idiopathic granulomatous hypophysitis: are there reliable, constant radiological and clinical diagnostic criterias?

Idiopathic granulomatous hypophysitis is a rare inflammatory disease of unknown aetiology; few cases are reported. We review the clinical presentation and radiological characteristics of these cases and our own experience with three new surgical cases, to determine diagnostic criteria. MRI of three cases revealed sellar lesions extending into the chiasmatic cistern. Their shape varied, from dumbbell to spherical and elliptical. All were isointense with the brain on T1-weighted images and gave heterogeneously high signal on T2-weighted images. Contrast enhancement was homogeneous in one case and heterogeneous in another. The pituitary stalk could not be identified. There was no dural enhancement. The sphenoid sinus mucosa was thickened in two cases and normal in one.

Extradural balloon obliteration of the empty sella report of three cases (intrasellar balloon obliteration).

Empty sella syndrome is an anatomical and clinical entity composed of intrasellar reposition of the CSF and compression of the pituitary tissue, resulting in a clinical picture of headache, visual field defect, CSF rhinorrhea and some mild endocrinological disturbances. While some cases are primary with no appreciable aetiology, secondary cases are associated with prior operation or radiotherapy of the region. In our series, 3 patients with primary empty sella syndrome were treated by the current approach of extradural filling of the sellar cavity. This technique was first described by Guiot and widely accepted thereafter. We used a detachable silicon balloon filled with HEMA or liquid silicone for obliteration of the sellar cavity and obtained clinically satisfactory results without complications. Visual symptoms regressed and headache disappeared. But at long term follow-up all the balloons were found to be deflated. Despite the facility and efficacy of the technique we do not recommend it in the treatment of the empty sella because the filling of the sella is only transient and relapses may occur.

A new aneurysm wrapping material: polyglactin 910 + fibrin sealant.

Aneurysms experimentally induced by using the silver nitrate coagulation method in 10 Wistar Albino rats are wrapped with Polyglactin 910 and Fibrin Sealant. 6 weeks later the rats are sacrificed and compared with the control group. In the group in which Polyglactin 910 and Fibrin Sealant were used as the wrapping material, non-specific inflammatory granulation tissue development around the aneurysms is observed. We suggest that a Polyglactin 910 and Fibrin Sealant combination can be used as a wrapping material in the treatment of aneurysms where clipping is not possible.

Microvascular anatomy of the anterior surface of the medulla oblongata and olive.

The arterial supply and the microanatomy of the anterior surface of the medulla oblongata and olive were studied in 11 cadaveric specimens, with investigation of the size, course, and length of the arteries. Two distinct anatomical entities divide the vascular supply in this region: 1) the pyramid, which is the anterior surface of the medulla; and 2) the olive, which is adjacent to the lateral aspect of the pyramid. Primary vascularization of the pyramid was via small branches of the anterior spinal artery, a branch of the vertebral artery. Minute perforators from the anterior spinal artery were found in all specimens. Arterial supply to the olive varied by location: its anterior aspect was primarily supplied by the anterior spinal artery; the upper portion of the posterior aspect of the olive was supplied by the vertebral artery, the anterior inferior cerebellar artery, and the basilar artery; and the middle and lower portions of the posterior aspect were fed by the vertebral artery and posterior inferior cerebellar artery. These arteries supplied the medulla through the small branches directed toward the olive. The authors observed a wide anastomotic net connecting the small arteries in this area. These patterns of microvascular supply of the pyramid and olive may deepen the understanding of clinical and pathological conditions resulting from arterial occlusion. The existence of an anastomotic net may account for the rare incidence of medullary infarction in the olive region.

Microsurgical anatomy of the intracranial part of the vertebral artery.

We studied the intracranial portion of the vertebral artery and its branches in 11 cadaveric specimens. We evaluated the course of vessels and their dimensions (external diameter and length), as well as relationships between each of them. The vertebral artery was larger on the left side in two cases, on the right in five cases, and equal on both sides in four cases. The right and left vertebral arteries joined each other forming the basilar artery at the level of the pontomedullary junction in four cases, 2 mm below it in one case, and 1 to 7 mm above it in six cases. We divided all branches of the intracranial vertebral artery into two groups: the medial branches and the lateral branches. Two major types of medial branches were observed: the anterior spinal artery and the branches of the foramen caecum. The origin of the anterior spinal artery was located 6.5 mm (5-11 mm) proximal to vertebrobasilar junction on the right and 8.5 mm (6-17 mm) on the left. The anterior spinal artery was absent on the right in two cases and on the left in one. Branches arising from the vertebral artery to the foramen caecum were found in four brains. Lateral branches originated from the posterolateral or lateral aspect of vertebral artery. The posterior inferior cerebellar artery, the largest branch of the vertebral artery, was included in this group. Other branches were mostly located between the origin of the posterior inferior cerebellar artery and the vertebrobasilar junction. Forty-six lateral branches originating from the vertebral artery were found in 11 brains (26 on the right and 20 on the left). Lateral branches widely anastomosed with perforators from the basilar artery, posterior inferior cerebral artery, and the anterior inferior cerebellar artery.

Warburg syndrome.

The case of a newborn who had ocular, cerebral and cerebellar dysgenesis with hydrocephalus, which represents very rarely occurring Warburg syndrome, is described. Clinical, radiographic, and histopathological features are detailed.