Ihsan Anik

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.

Fluorescein sodium-guided surgery in glioblastoma multiforme: a prospective evaluation

We have evaluated the influence of fluorescein-guided resection on gross total resection (GTR) and survival in a series of patients with GBM. Group 1 consisted of 47 patients given fluorescein and group 2 comprised 33 patients, on whom fluorescein was not used. Median survival time was 43.9 weeks in the patients given fluorescein and was 41.8 weeks in the non-fluorescein group. There was no statistically significant difference in survival between the two groups. However, the extent of resection had a powerful influence on the median survival time. Survival was 34.3 weeks after partial resection and 46.5 after GTR. Our data shows that the use of fluorescein injection is a simple procedure, which allows a significant increase in the number of patients having GTR (83 vs. 55%). Our findings are similar to a recently published multicentre Phase III randomized trial in which 5-aminolevulinic acid was used to facilitate resection of malignant glioma.

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.

Spinal Hydatid Cyst Mimicking Arachnoid Cyst on Magnetic Resonance Imaging

Abstract Background: Primary spinal hydatid cysts are uncommon and account for 1% of all cases of hydatid disease. Echinococcus granulosus is most often responsible for the cyst hydatid. Intradural, extramedullary involvement is rare. When the cysts do not demonstrate typical magnetic resonance imaging findings, the differential diagnosis is more complex. Method: Case report. Findings: An isolated primary hydatid cyst of the spine in a 35-year-old man that appeared to be an arachnoid cyst on preoperative radiographic examination. Conclusion: Hydatid cysts that lack the typical radiographic appearance may be mistaken for arachnoid cysts. Misdiagnosis has serious implications for surgical intervention and long-term care.

Apparent Diffusion Coefficient and Cerebrospinal Fluid Flow Measurements in Patients With Hydrocephalus

Objective: To evaluate the efficacy of diffusion magnetic resonance imaging and compare with cerebrospinal fluid (CSF) flow imaging in patients with hydrocephalus before and after treatment. Methods: Twenty patients with hydrocephalus (group 1, pediatric, with primary aqueductal stenosis, n = 10; group 2, adult, with normal-pressure hydrocephalus, n = 10) and 20 age-matched healthy subjects that served as controls were examined. Cerebrospinal fluid flow velocity interval was calculated as the mean absolute values of the peak craniocaudal velocity and caudocranial velocity on CSF flow measurements. On diffusion magnetic resonance imaging, apparent diffusion coefficient (ADC) values from 8 regions were evaluated. Results: The decrease in ADC values after treatment was significant in both groups (P < 0.001 for both). Preoperative mean CSF flow velocity interval value was significantly lower in group 1 and significantly higher than postoperative and control group values in group 2 (P < 0.001 for all). Conclusion: The ADC values increase in hydrocephalus and decrease significantly after treatment. Preoperative ADC value may serve as baseline, and the change in ADC may be an indicator of response to treatment and CSF flow measurements.

Surgical outcomes of the brachial plexus lesions caused by gunshot wounds in adults

Background The management of brachial plexus injuries due to gunshot wounds is a surgical challenge. Better surgical strategies based on clinical and electrophysiological patterns are needed. The aim of this study is to clarify the factors which may influence the surgical technique and outcome of the brachial plexus lesions caused by gunshot injuries. Methods Two hundred and sixty five patients who had brachial plexus lesions caused by gunshot injuries were included in this study. All of them were male with a mean age of 22 years. Twenty-three patients were improved with conservative treatment while the others underwent surgical treatment. The patients were classified and managed according to the locations, clinical and electrophysiological findings, and coexisting lesions. Results The wounding agent was shrapnel in 106 patients and bullet in 159 patients. Surgical procedures were performed from 6 weeks to 10 months after the injury. The majority of the lesions were repaired within 4 months were improved successfully. Good results were obtained in upper trunk and lateral cord lesions. The outcome was satisfactory if the nerve was intact and only compressed by fibrosis or the nerve was in-contunuity with neuroma or fibrosis. Conclusion Appropriate surgical techniques help the recovery from the lesions, especially in patients with complete functional loss. Intraoperative nerve status and the type of surgery significantly affect the final clinical outcome of the patients.

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.

Role of Interpeduncular and Prepontine Cistern Cerebrospinal Fluid Flow Measurements in Prediction of Endoscopic Third Ventriculostomy Success in Pediatric Triventricular Hydrocephalus

Aim: The aim of the present study was to evaluate the correlation of the clinical success of the endoscopic third ventriculostomy (ETV) procedure with the measurements of cerebrospinal fluid (CSF) flow through the interpeduncular and prepontine cisterns in pediatric triventricular hydrocephalus. Methods: 51 children (age range: 25–201 months; mean: 55.3 months) with primary aqueductal stenosis who have been treated with ETV were included in the study. All patients were analyzed by conventional and cine magnetic resonance imaging (MRI) before and after endoscopic treatment. Both the stroke volume and the flow velocity of CSF in the interpeduncular and prepontine cisterns were evaluated. The MRI findings were correlated with clinical outcome. Simple descriptive and independent t tests were used for statistical analyses, and receiver operating characteristic curve analysis was used for the cutoff value of the ‘flow index’ (FI). Results: Among the 51 patients, 37 patients (72.5%) responded to ETV clinically during long-term follow-up. A further analysis was made for the prediction of who would respond to ETV, using the formula (stroke volume of prepontine cistern/stroke volume of interpeduncular cistern) ×100, which was defined as the FI. Early postoperative FI values of over 40% were significantly correlated with ETV success. Conclusion: Our results suggest that ETV success can be predicted by the ratio of early CSF stroke volume values of the interpeduncular and prepontine cisterns.

Microsurgical anatomy of membranous layers of the pituitary gland and the expression of extracellular matrix collagenous proteins

BackgroundThere are several reports about the microanatomical and histological features of sellar and parasellar membranous structures and clinical studies about MMP proteinase as a predictive factor. However, studies on collagen contents of sellar and parasellar membranous structures are limited. We demonstrated the membranous structures surrounding the pituitary gland and defined extracellular matrix (ECM) collagenous proteins, collagen I-IV expression patterns of sellar and parasellar connective tissues.MethodsThe study was carried out on ten fresh postmortem human bodies at the Forensic Medicine Institution. Cavernous sinuses were resected with sellar structures and were stored at −80°C liquid nitrogen tanks. Medial wall of the cavernous sinus, pituitary capsule and pituitary tissue samples were obtained for RT-PCR. Opposite side specimens were used for histological and immune staining studies. Collagens I-IV were studied by immunohistochemical and reverse transcription polymerase chain reaction (RT-PCR) methods.FindingsThe pituitary capsule and medial wall were identified as two different structures. The fibrous membrane, as the third membrane, was identified as staying whole in eight of ten specimens. Increased type IV collagen was determined in the pituitary gland, medial wall and pituitary capsule, respectively, in both RT-PCR and immunhistochemical studies. Immunhistochemical studies revealed that collagen I was strongly expressed in both the medial wall and pituitary gland.ConclusionIncreased type IV collagen was detected especially in pituitary tissue, the medial wall and the pituitary capsule by immune staining and RT-PCR. Type IV collagen was considered to be an important factor in the progression of adenoma and invasion.

Extradural giant multiloculated arachnoid cyst causing spinal cord compression in a child.

Abstract Background: Spinal extradural arachnoid cysts are rare expanding lesions in the spinal canal. Enlargement may cause progressive signs and symptoms caused by spinal cord compression. They are associated with trauma, surgery, arachnoiditis, and neural tube defects. Most nontraumatic spinal extradural arachnoid cysts are thought to be congenital. Design: Case report and literature review. Findings: A 9-year-old boy with mild paraparesis was found to have an extradural multiloculated arachnoid cyst with fibrous septa at T4-L3 levels and anterior compression and displacement of the spinal cord. Conclusions: Definitive treatment of arachnoid cyst entails radical cyst removal and dura cleft repair. Formation of a postoperative cerebrospinal fluid fistula may require external lumbar drainage.