Emel Avci

Risky anatomic variations of sphenoid sinus for surgery

We searched for the surgically risky anatomic variations of sphenoid sinus and aimed to compare axial and coronal tomography in detection of these variations. Fifty-six paranasal tomography images (112 sides) were evaluated for coronal, axial and both coronal and axial images. Tomographic findings including bony septum extending to optic canal or internal carotid artery; protrusions and dehiscences of the walls of internal carotid artery, optic nerve, maxillary nerve and vidian nerve; extreme medial course of internal carotid artery; patterns of aeration of the anterior clinoid process; and Onodi cells were evaluated. The results were classified as “present, absent, suspicious-thin (only for dehiscence) or no-consensus”. The results of each plane were compared with that of the result of the both planes together. Kappa coefficient and Chi-square tests were used to compare both planes. Twelve cadaveric dissections were performed to reveal the proximity of sphenoid sinus to surgically risky anatomic structures. Endoscopy was applied to five cadavers. 18 evaluations were classified as ‘no-consensus’. We detected 34, 35, 34 and 40 protrusions of internal carotid artery, optic nerve, maxillary nerve, vidian nerve, respectively. Dehiscences were present in 6, 9, 4 and 8, and suspicious-thin in 8, 10, 16 and 25 in canals of internal carotid artery, optic nerve, maxillary nerve and vidian nerve, respectively. Bony septum to internal carotid artery and optic nerve was observed in 30 and 22 cases. We observed 9 extreme medial courses of internal carotid artery, 27 aerated clinoid process and 9 Onodi cells. Axial images were superior in detection of bony septum to internal carotid artery and Onodi cells; while the coronal images were more successful in detection of protrusion of optic nerve and vidian nerve, and dehiscense of maxillary nerve and vidian nerve (P<0.05). In cadaveric dissections, the septa were inserted into the bony covering of the carotid arteries in two sinuses (8.3%). Detailed preoperative analysis of the anatomy of the sphenoid sinus and its boundaries is crucial in facilitating entry to the pituitary fossa and reducing intraoperative complications. Coronal tomography more successfully detects the sphenoid sinus anatomic variations.

Posterior cranial fossa morphometry in symptomatic adult Chiari I malformation patients: comparative clinical and anatomical study.

BACKGROUND AND OBJECTIVES The cerebellar tonsillar herniation occurring in Chiari malformation Type I (CMI) mainly results from overcrowding of a normally developing hindbrain within a primary small posterior cranial fossa (PCF) due to an anomaly in the embryological development of the occipital bone. In the present study, the lengths of PCF parameters were studied in adult CMI patients. PATIENTS AND METHODS The authors retrospectively examined 15 adult patients with CMI. Multiple measurements were made on magnetic resonance images (MRIs). The results were compared with the findings in 25 controls and 30 dry skulls. RESULTS Length of the neural structures did not significantly differ between the CMI and the control groups. The average length of the basiocciput was significantly shorter in the CMI group as compared with the control group. The mean length of the supraocciput was significantly shorter and the average diameter of the foramen magnum was significantly longer in the CMI group when compared to the control group and dry skulls. CONCLUSIONS The morphometric data suggest that, in CMI, a hypoplastic occipital bone, possibly due to the paraxial mesodermal defect of the parachordal plate, causes overcrowding in PCF, which contains the normally developed neural structures.

Anatomical variations of the foramen magnum, occipital condyle and jugular tubercle.

AIM The foramen magnum (FM) is a unique and complex anatomical region. The occipital condyle (OC) and jugular tubercle (JT) are the main bony structures which obscure the anterolaterally situated lesions of the FM.The aim of this study was to revisit the anatomy of the FM region and assess variations of the surrounding structures. MATERIAL AND METHODS Observations, on thirty dry skulls (dried specimens, 60 sides) and ten formalin-fixed cadaveric heads with perfused vessels, were carried out to define the microsurgical anatomy of the FM region. Morphometric analysis and variations of the FM, OC, JT and hypoglossal canal (HC) were noted. Radiological assessment (3D-computed tomography) of the OC, JT, HC were also conducted on dry skulls. RESULTS The short and long OC were demonstrated in 5% and 33% of the specimens, respectively. Flat formation of the JT was determined in 10% and tall JT was found in 23% of the specimens. The comparison of the anatomical measurements and the correspondent radiological mean values did not achieve statistical significance. CONCLUSION The OC and JT are the main bony prominences obstructing the anterolateral surface of the brainstem. Neurosurgeons should be familiar with variations of the structures surrounding the FM in order to perform the safest and widest exposure possible.

Sorption of alpha and beta hydrophobic endosulfan in a Vertisol from southeast region of Turkey

Endosulfan has been applied to control numerous insects in a variety of food and non-food crops. Limited information is available on dynamics of this pesticide in the soil. The objective of this research was to determine the adsorption-desorption behavior of the alpha (alpha) and beta (beta) endosulfan in a Vertisol from the southeast region of Turkey, where cotton is the main crop in the large irrigated lowlands. The alpha and beta endosulfan were adsorbed considerably and Freundlich adsorption-desorption isotherms fitted the alpha and beta endosulfan data (R(2)>0.98). Freundlich adsorption coefficients (K(f)) for the alpha endosulfan ranged between 21.63 and 16.33 while for the beta endosulfan they were between 14.01 and 17.98 for the Ap and Bw2 horizons. The difference of K(f) values of alpha and beta endosulfan for two horizons were explained with the slight difference in the amount of organic matter and clay, but considerable difference in Fe contents of the two horizons. Alpha and beta endosulfan K(fd) values were 118.03 and 45.81 for the Ap and 48.08 and 68.71 for the Bw2 horizons. Higher adsorption and desorption behavior of the endosulfan isomers for the same horizon was attributed to poor physical bonding between the endosulfan molecule and the surfaces of fundamental soil particles. This fact is thought to increase the effective use of endosulfan in agriculture with a possibility of its movement to the surface and groundwater in the Vertisol studied.

Intraoperative perineural infiltration of lidocaine for acute postlaminectomy pain: preemptive analgesia in spinal surgery.

Study Design Prospective, cohort, and clinical study. Summary of Background Data It was proven that effective control of postoperative pain in lumbar disk surgery improves the patients recovery. Despite the many advances in surgical and nonsurgical techniques, the most accurate approach in pain relief is still under debate. Objective In this study, our aim was to determine whether neural root blockade before the onset of noxious stimuli could inhibit the production of pain. Methods Forty-five patients undergoing unilateral 1 spinal level (lumbar 5) hemipartial laminectomy were included in the study. In 20 of the patients (group 2), 0.5 mL 2% lidocaine was infiltrated onto the neural root immediately after the exposure; the 25 patients in the control group (group 1) were not injected. All patients were monitored regarding pain determination using a visual analog scale, and the exact time of analgesic requirement during the first postoperative day was noted. Total analgesic dose given during the first postoperative day was also recorded. Results Perineural lidocaine infiltration extended the early postoperative analgesic period. Although the pain was not completely suppressed, the lidocaine infiltration helped to manage the postoperative pain more effectively. The patients (group 2) who received lidocaine infiltration intraoperatively onto the neural root had a statistically significant longer time before analgesia requested (P<0.001) and also required significantly less analgesic when compared with the control group (P<0.001). Conclusions For preemptive analgesia for acute postoperative pain in laminectomy surgery, which remains a major concern, we suggest that lidocaine infiltration onto the dorsal neural sheath immediately before retraction of the root may extend the time before analgesia requested and the total analgesic drug consumption.

Microsurgical anatomy of the vein of Labbé

ObjectiveVenous drainage of the temporal lobe is of great importance in various neurosurgical and combined skull base approaches. The most significant draining vein of the temporal lobe is the inferior anastomotic vein (vein of Labbé). The purpose of this study was to examine the detailed anatomy and variations of the vein of Labbé (VL) from microsurgical perspective.MethodsFourteen fixed human cadaver heads (28 sides) with perfused vessels were included to define microsurgical anatomy and variations of the VL.ResultsThe main findings of the present study were as follows: (1) drainage pattern of the VL was found to be very variable in cadaveric dissections; (2) VL drained around the sinus confluence at the tentorium in one specimen (3.5%), into the large meningeal vein in the occipital dura mater in another specimen (3.5%). The VL rarely (7%) drains into the superior petrosal sinus (SPS) which may make combined skull base approaches very difficult or impossible.ConclusionResults of this study suggest that careful and thorough evaluation of the VL is of great importance, especially in surgeries combining a subtemporal route with petrosal approaches by sectioning the SPS and the tentorium.

Level I to III craniofacial approaches based on Barrow classification for treatment of skull base meningiomas: surgical technique, microsurgical anatomy, and case illustrations

OBJECT Although craniofacial approaches to the midline skull base have been defined and surgical results have been published, clear descriptions of these complex approaches in a step-wise manner are lacking. The objective of this study is to demonstrate the surgical technique of craniofacial approaches based on Barrow classification (Levels I-III) and to study the microsurgical anatomy pertinent to these complex craniofacial approaches. METHODS Ten adult cadaveric heads perfused with colored silicone and 24 dry human skulls were used to study the microsurgical anatomy and to demonstrate craniofacial approaches in a step-wise manner. In addition to cadaveric studies, case illustrations of anterior skull base meningiomas were presented to demonstrate the clinical application of the first 3 (Levels I-III) approaches. RESULTS Cadaveric head dissection was performed in 10 heads using craniofacial approaches. Ethmoid and sphenoid sinuses, cribriform plate, orbit, planum sphenoidale, clivus, sellar, and parasellar regions were shown at Levels I, II, and III. In 24 human dry skulls (48 sides), a supraorbital notch (85.4%) was observed more frequently than the supraorbital foramen (14.6%). The mean distance between the supraorbital foramen notch to the midline was 21.9 mm on the right side and 21.8 mm on the left. By accepting the middle point of the nasofrontal suture as a landmark, the mean distances to the anterior ethmoidal foramen from the middle point of this suture were 32 mm on the right side and 34 mm on the left. The mean distance between the anterior and posterior ethmoidal foramina was 12.3 mm on both sides; the mean distance between the posterior ethmoidal foramen and distal opening of the optic canal was 7.1 mm on the right side and 7.3 mm on the left. CONCLUSIONS Barrow classification is a simple and stepwise system to better understand the surgical anatomy and refine the techniques in performing these complex craniofacial approaches. On the other hand, thorough anatomical knowledge of the midline skull base and variations of the neurovascular structures is crucial to perform successful craniofacial approaches.

Unusual Location of Hydatid Cysts in Pediatric Patients

Objective/Aims: To emphasize the importance of diagnosis and treatment of unusually localized hydatid cysts in pediatric cases. Methods: Hydatid cyst patients of two departments were listed who had undergone surgery between January 2001 and December 2008. Of the 7 pediatric patients, 3 were chosen as the ones with unusual localization. Cyst removal with Dowling’s technique was performed in 2 cases and total removal of the cyst wall was achieved after cyst aspiration in the other patient. Results: Two patients did not show any signs of recurrence. Some of the cranial multiple cysts of the patient who had undergone her first surgery in another clinic with cyst rupture were successfully removed in our clinic. Six months later, she was admitted with spinal seedings. Conclusion: Hydatid cyst removal without rupture should be the surgical goal in all cases. Radiological evaluation is of utmost importance for differential diagnosis. When a cystic lesion is found in the central nervous system on radiological evaluation, hydatid disease must be considered in countries where the disease is endemic and surgery is to be planned emergently especially for pediatric cases with increased intracranial pressure. The study focuses on the strategy for the correct diagnosis and the appropriate treatment of unusually localized hydatid cysts.

Microsurgical anatomy and variations of the anterior clinoid process.

AIM The aim of this study was to better define the microsurgical anatomy of the supra/parasellar region and describe variations of the anterior clinoid process (ACP). MATERIAL AND METHODS Fifteen formalin-fixed cadaver heads and 25 dry skulls were used to define the microsurgical anatomy of the ACP and related structures. The presence of the caroticoclinoid foramen (CaCF) as well as other relevant measurements were all noted. Radiological examination of the CaCF was also demonstrated on dry skulls. RESULTS Interosseous bridges, which form between the anterior and middle clinoid processes or connect all three (anterior, middle and posterior) clinoid processes, were found in 30% of the specimens. The average basal width, length and thickness of the ACP were 7.3 mm, 9.7 mm and 5.4 mm, respectively. Length of the optic nerve (ON) up to the falciform ligament (FL) was 10.9 mm; length of the ON under the FL was 2.7 mm; length of ON after removal of the ACP and unroofing the optic canal was 21.1 mm. CONCLUSION This study contributes to the relationship of important vascular, neural, bone and dural layers of this region and also demonstrates the variations of ACP by means of microsurgical dissections and radiological examinations.

Intraoperative supratentorial epidural haematoma during removal of a huge posterior fossa dermoid cyst.

Epidural haematomas may occur following cranial operations, and most of them are located near the craniotomy or burr-hole areas. There are very few cases of supratentorial epidural haematoma following the resection of giant tumours located in the posterior fossa. In this case report, we present a patient who developed an acute left temporoparietal epidural haematoma in the perioperative period during the excision of a huge dermoid cyst in the posterior fossa.