Savas Ceylan

Endoscopic endonasal transsphenoidal approach for pituitary adenomas invading the cavernous sinus.

OBJECT In this report, the authors describe their experience with surgical access to the cavernous sinus via a fully transnasal endoscopic approach in 20 cases. Clinical and endocrinological follow-up are discussed. METHODS The authors used an endoscopic transsphenoidal approach in 192 patients with pituitary adenomas between September 1997 and January 2008, adding a cavernous sinus approach in 20 patients with invasive tumors during the last 5 years of this period [corrected]. Parasellar extension of the tumor was measured according to the Knosp Scale. Radical tumor removal was achieved in 13 (65%) of 20 patients, and subtotal removal in 7 (35%). The authors used recently defined cavernous sinus approaches in the first 14 cases, including the paraseptal approach in 6, middle turbinectomy in 7, and contralateral middle turbinectomy in 1 case. Combined approaches rather than defined standard cavernous sinus approaches were used in 4 cases and an extended approach in 2. RESULTS The tumors included nonsecretory adenomas in 5 cases (25%), growth hormone-secreting adenomas in 7 (35%), prolactin-secreting adenomas in 4 (20%), and adrenocorticotropic hormone-secreting adenomas in 4 cases (20%). Normal growth hormone and insulin-like growth factor 1 levels were achieved in 4 patients (57%) with growth hormone adenomas, and remission criteria were obtained in 3 patients with prolactinomas and 3 patients with adrenocorticotropic hormone-secreting adenomas. CONCLUSIONS Compared with transcranial and microscopic transsphenoidal surgery, endoscopic transsphenoidal surgery offers a wide exposure for cavernous sinus medial wall adenomas that enables removal of the adenoma from the medial cavernous sinus wall. Because of the necessity for multidisciplinary treatment to achieve satisfactory results, Gamma Knife surgery and medical therapy should be supplementary treatment options after endoscopic transsphenoidal surgery.

The learning curve in endoscopic pituitary surgery and our experience

Experience is the important point in reduction of the complications and in the effectiveness of the surgical procedure in pituitary surgery. Endoscopic pituitary surgery differs from microscopic surgery, since it requires a steep learning curve for endoscopic skills. In this article, we evaluate our learning curve in two groups, as early and late experience. Purely endoscopic transsphenoidal operations were performed on 78 patients, which were retrospectively reviewed and grouped as early and late experience groups. We used the purely endoscopic endonasal approach to the sella that was performed via an anterior sphenoidotomy, without the use of a transsphenoidal retractor. All patients with adenomas were evaluated considering operation time, endocrinology, ophthalmology, total removal and, especially, modifications of standard technique. On the basis of the experience gained with the use of the endoscope in transphenoidal surgery over the years, modifications can be performed on the different phases of the endoscopic approach. Reviewing our cases in two groups of period due to our experience showed that the effectiveness of endoscopic surgery increases and operation time decreases. In our study, we identified a learning curve in endoscopic pituitary surgery.

Success of endoscopic third ventriculostomy in children less than 2 years of age

Current literature reveals different opinions about the effectiveness of endoscopic third ventriculostomy in the treatment of hydrocephalus in children less than 2 years of age. Performing a retrospective evaluation of our own experience in this age group, we aimed to contribute to the growing data on the controversial issues related to this procedure in children. In a series of 97 endoscopic third ventriculostomy procedures, 25 were performed in children less than 2 years of age as an initial treatment for hydrocephalus. A retrospective analysis of our data revealed that the overall success rate of endoscopic third ventriculostomy in this age group was 56%. However, analysis of the results in subgroups with different etiologies of hydrocephalus showed that the success rate of the procedure was 83% in patients with defined anatomic obstruction, 66.6% in post-hemorrhagic hydrocephalus, 50% in infection related hydrocephalus and 41.6% in hydrocephalus accompanied by myelomeningocele. This article considers our data and the features of endoscopic third ventriculostomy procedure in this age group, with a detailed review of the literature. In our experience, the success of endoscopic third ventriculostomy is etiology related rather than age-dependent. We suggest that there are no grounds for denying children younger than 2 years this chance for a shunt-free life.

Intraventricular meningioma of the fourth ventricle

A rare case of meningioma of the fourth ventricle is reported. A review of the literature revealed only 24 reported cases of this type of tumor.

Topical application of mitomycin C prevents epineural scar formation in rats

The role of topically applied mitomycin C in preventing postoperative perineural fibrosis was examined by gross anatomical dissection and histological analysis in rats. The sciatic nerve was exposed bilaterally in 24 Wistar adult male rats, and an abrasion injury was produced on the exposed surface of the biceps femoris muscle in all animals. In the experimental group, cotton pads soaked with mitomycin C (0.5 mg/ml) were placed around the nerves for 5 min, whereas cotton pads soaked with saline were applied to the control group. Four weeks after surgery, the neurolysis sites were evaluated by blinded surgical dissection. Perineural adhesions were graded using a numerical grading scheme. The scar tissue formation index was also calculated, and a grading was made according to the number of fibroblasts/fibrocytes counted around the epineurium in histological evaluation. Mitomycin C-treated nerves showed significantly less perineural adhesions than controls. Quantification of the dense connective tissue surrounding the nerves revealed a statistically significant reduction around nerves treated with mitomycin C, and the number of fibroblast/fibrocytes was also significantly reduced. Application of topical mitomycin C might be effective in preventing epineural scar formation after neurolysis of peripheral nerves.

Reconstruction of the middle cerebral artery after excision of a giant fusiform aneurysm

A patient with a giant fusiform aneurysm of the left inferior trunkus of the middle cerebral artery (MCA) is presented. The size of the aneurysm was 5 cm at its largest diameter. Retrograde flow was well developed. After the application of temporary clips the aneurysm was excised and microsurgical reconstructions were undertaken. Adequate flow in the reconstructed MCA trunkus was maintained. This rare case is discussed in the light of the literature.

Glossopharyngeal neuralgia: a study of 6 cases.

Glossopharyngeal neuralgia is a rare disease. In this report; six cases of glossopharyngeal neuralgia have been studied. At first, drug therapy was used in all of the 6 cases. In 2 of the 6 cases which were resistant to medical therapy intracranial section of the 9th nerve as well as the upper two rootlets of the 10th nerve were performed. This resolved the symptoms completely. One of these two cases, had, in addition to pain paroxyms, hypotension, bradycardia and syncope, which were controlled by temporary cardiac pacemaker.In the other 4 cases, drug therapy was able to control the paroxysms of pain. In addition, two patients with weight loss and one patient with bradycardia rapidly responded to drug therapy as well. Reviewing the literature, we discuss the medical and surgical treatment of glossopharyngeal neuralgia and possible mechanisms of associated cardiovascular disturbances.

Microsurgical and endoscopic anatomy of Liliequist's membrane and the prepontine membranes: cadaveric study and clinical implications.

BackgroundLiliequist’s membrane is mostly described as having a diencephalic leaf, mesencephalic leaf, and diencephalic-mesencephalic leaves in the literature. Also different descriptions of the prepontine membranes were reported. In this study, we visualized the regular structural forms of membranes without disturbing any attachments and defined infrachiasmatic and prepontine safety zones. We discussed the clinical significance of these structures.Materials and methodsThe study was carried out on 24 adult human cadavers at the Morgue Specialization Department of the Forensic Medicine Institution following the initial autopsy examination. Liliequists membrane and the prepontine membranes were explored after retraction of the frontal lobes. Dissections were performed under the operative microscope. A 0- and 30-degree, 2.7-mm angled rigid endoscope (Aesculap, Tuttlingen, Germany) was advanced through the prepontine cistern from the natural holes of membranes, or small holes were opened without damaging the surrounding structures.ResultsThe basal arachnoid membrane (BAM) continued as Liliequists membrane (LM) without any distinct separation in all specimens. The LM coursed over the posterior clinoids and split into two leaves as the diencephalic leaf (DL) and mesencephalic leaf (ML) in 18 specimens; the medial pontomesencephalic membrane (MPMM) coursed anterolaterally as a continuation of the ML and attached to the medial surfaces of the fifth and sixth nerves, joining with the lateral pontomesencephalic membrane (LPMM), which was also a posterolateral continuation of the ML in all specimens. The medial pontomedullar membrane (MPMdM) and lateral pontomedullar membrane (LPMdM) were observed in 21 specimens. The MPMdM membrane was a continuation of the MPMM, and the LPMdM was a continuation of the LPMM in all 21 specimens.ConclusionWe observed that the LM is a borderless continuation of the BAM. The MPMM and LPMM split from the ML without any interruptions. The MPMdM and LPMdM were a single membrane continuing from the MPMM and LPMM. We determined infrachiasmatic and prepontine areas that can be important for inferior surgical approaches.

Risk of strabismus and ambylopia in children with hydrocephalus.

ObjectivesThe present study was undertaken to determine the risk of strabismus and ambylopia in children who underwent operation for hydrocephalus and to compare our results with those in previous studies.MethodsFull orthoptic and ophthalmological examinations, including cycloplegic refraction, were performed in all subjects.ResultsTen of 25 patients (40%) were found to have manifest squint. Four of these had esotropia and six had exotropia. No paretic squint or alphabetic pattern strabismus was determined. Refraction measurements revealed amblyogenic refractive errors (significant refractive errors that cause amblyopia) in five of the 25 (20%) patients in this study. Strabismus and the risk of amblyopia were found to be significantly higher in patients who experienced shunt revision than those who had not (P<0.05).ConclusionAmblyopia, strabismus, and other acquired defects in the visual system related to hydrocephalus should be closely monitored and treated when indicated. Regular ophthalmic supervision will provide and help to maintain the best possible standard of vision in children with hydrocephalus.

Valproic acid sodium-induced spina bifida occulta in the rat

Abstract The antiepileptic drug valproic acid is a well-known teratogenic agent; its main target organ is the neuroepithelium neural tube, although skeletal malformations have also been described. The goal of our investigations was to determine whether there is a direct relationship between high doses of valproic acid and vertebral arch openings. On day 9 of gestation, rats were treated with either 0.3 ml physiologic saline or 600 mg/kg valproic acid (VA) given once in the morning and once in the evening (7 h between doses) for a total of 1200 mg/kg. For the teratological investigations, fetuses were examined at 21 days of gestation. Spina bifida occulta was demonstrated in double-stained fetal skeletons by measuring the distance between the cartilaginous ends of each vertebral arch. The most important finding was the very high rate of spina bifida occulta observed with this application regimen. Spina bifida aperta was not observed in our study. A low rate of exencephaly was observed in the treated group (3%). The difference between the control and treated groups was statistically highly significant from the first thoracic to fifth sacral level. The effects of VA are most pronounced from thoracic 9 to the upper lumbar region. The largest gap in vertebral arches was found in the first and second lumbar vertebrae in the VA-treated group. These findings suggest that the peak concentration of VA in the maternal plasma and high bolus administration of VA may be more important for spina bifida occulta than the total dose and infusion of VA.