Ihsan Dogan

New practical landmarks to determine sigmoid sinus free zones for suboccipital approaches: an anatomical study.

Abstract Literature defines the landmarks to identify the courses and locations of the transverse and sigmoid sinuses on the outer surface of the skull and inner surface of the scalp. These natural landmarks may only be helpful after skin incision and are inadequate to determine the length and size of the skin incision. Still, there is a need to identify palpable landmarks easily to determine the ideal location to open the initial burr hole before an operation. Twenty-eight dried adult human skulls and 2 cadavers were evaluated. The zygomatic root, the inion, and the mastoid process were identified on the external, and the grooves for sigmoid and transverse sinuses, on the internal surfaces. The distances between the 3 landmarks and the midpoints, and the shortest distances of the midpoints to the border of the groove for sigmoid sinus and groove for transverse sinus were measured. Statistically significant differences were evaluated for both sides. Based on the measurements, the defined “artificial landmarks” can be considered safe points that involve no vascular structures and may be used to perform the initial burr hole during posterolateral approaches. Identification of the midpoints and palpation of the defined landmarks easily before the operation render the study feasible and practical unlike with natural landmarks. To avoid venous injury, the midpoints of mastoid-inion line and zygomatic root-inion line can be used safely in skin incision during posterior fossa approaches and craniotomy.

Surgical Management of Supratentorial Intracerebral Hemorrhages: Endoscopic Versus Open Surgery

OBJECTIVE Intracerebral hemorrhage continues to be a major global problem. No standard treatment or surgical procedure has been identified for intracerebral hemorrhages. High morbidity and mortality rates caused by conventional approaches and the disease itself have necessitated more-invasive treatment methods. The endoscopic approach is a more minimally invasive method than craniotomy, which is another alternative surgical treatment. METHODS We compared intracerebral hematoma drainage in 2 groups of 17 patients each, treated with minimally invasive endoscopic method versus craniotomy. All the patients were treated for supratentorial spontaneous hemorrhage between December 2013 and February 2017 at the Neurosurgery Clinic of Ankara University Faculty of Medicine. RESULTS We retrospectively evaluated 34 patients surgically treated between December 2013 and February 2017. All patients underwent surgery within the first 24 hours. Patients in the early surgery group had better surgical outcomes. In the neuroendoscopic group, Glasgow Coma Scale increased from 6 to 11 at 1 week postoperatively compared with 5 to 9 in the craniotomy group. CONCLUSIONS Minimally invasive endoscopic hematoma evacuation may be a good alternative surgical method for treating supratentorial spontaneous cerebral hematomas.

Is a Unilateral Surgical Approach Effective in Patients with Bilateral Leg Pain with Unilateral Lumbar Disc Herniation? A Prospective Nonrandomized Clinical and Surgical Study

OBJECTIVE To examine the surgical results of unilateral lumbar discectomy in patients with bilateral leg pain and discuss short- and long-term outcomes within the limits of lumbar decompression. METHODS We analyzed 60 patients with unilateral disc herniation who underwent unilateral lumbar discectomy and hemipartial laminectomy between 2014 and 2017. Group 1 (30 patients) had bilateral leg pain and unilateral lumbar disc herniation. Pain lateralization was determined radiologically. Group 2 (30 patients) had unilateral leg pain and unilateral lumbar disc herniation. Pain scores were preoperatively evaluated with visual analog scale (VAS) for both legs and Oswestry Disability Index (ODI) for overall life quality. In both groups, surgery was performed on the ipsilateral side of the herniated disc. Scores were repeated on postoperative day 1 and 1, 3, 6, 12, and 24 months later. VAS score differences for pain lateralization and disc levels were compared in group 1. ODI score differences were compared between both groups. Results were statistically analyzed. RESULTS VAS score differences were statistically significant at all follow-up time points in patients with ipsilateral and contralateral pain. VAS score differences between L4-L5 and L5-S1 level discopathies were statistically insignificant for all time points in both groups. All postoperative ODI score decreases for all time points were statistically significant (P < 0.001) for both groups, whereas the differences between groups 1 and 2 were statistically insignificant. CONCLUSIONS Conventional lumbar disc surgery alone is sufficient for the ipsilateral side of radiologically demonstrated disc herniation in patients with bilateral leg pain.

Effect of Riluzole on Spinal Cord Regeneration with Hemisection Method Before Injury

OBJECTIVE The pathophysiology of spinal cord injury (SCI) with the information obtained to date has not been elucidated fully. A safe drug or treatment protocol that results in cell regeneration for SCI remains unknown. Neuroprotective and neuroregenerative effects of riluzole, administered after a SCI, have been shown in experimental studies. This study aimed to investigate the effect of riluzole on neural regeneration in a rat SCI model. METHODS Thirty-two rats were divided into 8 groups, with 4 rats in each group. Hemisection method was performed after T7-T9 laminectomy. Rats were intraperitoneally aministered with riluzole (6 mg/kg). Locomotor recovery of the rats was assessed at 1 day, and 1, 2, 3, and 4 weeks after the 21-point Basso, Beattie, and Bresnahan test. Subsequently, the spinal cords of the rats were scored according to a semiquantitative grading system using a light microscope, and the numbers of myelinated axons, neurons, and glial cells were calculated. RESULTS Basso, Beattie, and Bresnahan test changes were statistically significant when groups 4-6 and 8 were compared with the other groups (P < 0.05, P < 0.00625). The results of the numbers of neurons, glial cells, and myelinated axons were statistically significant. Especially group 8, in which riluzole was administered 5 days before injury, more positive clinical and histopathologic results were obtained. CONCLUSIONS Riluzole treatment is more effective when provided before injury. Riluzole may contribute to functional recovery when used in the preoperative period in patients who are at a high risk for permanent neurologic deficit.

Usefulness and radiological evaluation of accuracy of innovative “smart” hand technique for pedicle screw placement: an anatomical study

AIM To use a smartphone application (app) during pedicle screw placement navigation and examine the accuracy of this application on an anatomical dry vertebrae model. MATERIAL AND METHODS Seventy-six dry vertebrae were used for this study, and pedicle entry points and projections of pedicle screw trajectory lines in the lateral and superior aspects of the vertebral body were identified and drawn for each vertebra bilaterally. In each position, all angulations were measured directly before the procedure manually. One hundred and fifty two pedicle screws were inserted as a simulation of screw placement with the guidance of the angle-meter smart app. Accuracy of the method was tested according to the occurrence of bone penetration while the angular deviation of the inserted screws was evaluated in computed tomography images. RESULTS The mean deviation for 76 pedicle screws on the right side was 2.30°±1.78° in the horizontal plane and 2.17°±1.57° in the sagittal plane; and on the left side, 3.01°±1.83° in the horizontal plane and 2.38°±1.68° in the sagittal plane. No bone penetration occurred during 152 pedicle screw placements. According to the t-test results, there were significant differences between the two groups in the craniocaudal direction of the right side pedicle screws and in the craniocaudal direction of left sided pedicle screws. CONCLUSION The free smartphone app presented here as an angle-meter is a safe digital device for spinal instrumentation procedures. As a prototype of future pedicle screw fixation systems, it should be improved in terms of its feasibility and compatibility with screw probes. This may lead to a useful mobile digital angle-meter for spinal procedures.

Preoperative Exposure of Sigmoid Sinus Trajectory in Posterolateral Cranial Base Approaches Using a New Landmark Through a Neurosurgical Perspective

Abstract The location of burr holes in posterolateral cranial base approaches should be appropriate to provide an adequate operative field, and surgical freedom is crucial for bone window opening. The aim of this study was to search for more convenient and easily detectable landmarks in comparison with current landmarks in posterolateral cranial base surgery. Twenty 3-dimensional reconstructed head and neck computed tomography angiography images (group 1) and 20 cadaver heads (group 2) were evaluated. An imaginary line connecting the angle of the mandible and the mastoid tip was extended upward. A second line passing through the lateral edge of the zygomatic arch was also extended posteriorly. The authors examined if the first line met with the sigmoid sinus throughout its course and determined the location of the intersection point of these 2 lines relative to the sigmoid-transverse sinus junction. The intersection point did not correspond to the sinus region in 3 images from group 1 and 4 specimens from group 2. The matching of the mandibula-mastoid line trajectory with the sigmoid sinus course was unacceptable in 4 images and 5 cadavers. For venous anatomy preservation and anatomic skull base fossa orientation during posterolateral cranial base approaches, upward extension of the mandibula-mastoid line can be a proper landmark for surgical planning in this region. The authors’ proposed superficial anatomical line and intersection point over the skull could be used as a reliable indicator for the external projection of the sigmoid sinus and an appropriate initial burr-hole location.

Fatal rupture of dissecting anterior inferior cerebellar artery aneurysm as an unexpected complication after anterior skull base surgery: a case report

Aneurysm of the anterior inferior cerebellar artery (AICA) is a very rare entity and the manifestation and manipulation of such aneurysms remain contentious. In this paper, we report a case where a successful surgery for an olfactory groove meningioma was performed and the patient discharged but readmitted to hospital with loss of consciousness and subsequently passed away three hours after re-admission. The patient was diagnosed with subarachnoid hemorrhage. The cause of the fatal subarachnoid hemorrhage was rupture of a new onsetting AICA dissecting aneurysm which had provided neither clinical nor radiological signs before the operation. We discuss the possible causes of the formation of such aneurysm.

Diagnostic importance and surgical usefulness of three dimensional movie like images created by using free Osirix software in cerebral aneurysm surgery

Purpose: To examine the diagnostic accuracy of movie images created by using free Osirix software in a 3 dimensional virtual reality environment showing aneurysm and arterial vasculature through the surgeon’s operative vision by comparing with the real operation images and to discuss the benefits of these images to sugery. Materials and methods:Thin brain computed tomography angiography images of 10 patients with intracerebral aneurysm operated in our clinic between January 2013December 2015 were processed by Osirix software. Three dimensional pictures in movie format of these radiological images similar with surgical view were created. These reconstructed iamges were compared according to the surgical video images in terms of arterial vasculature’s and aneurysm’ s morphologic features’ similiarity. Results: Three dimensional images of 5 anterior communicating artery aneurysm, 4 middle cerebral artery aneurysm and 1 internal carotid artery aneurysm were included in our study. The dome of aneurysm were shown in all patients radiologically. The neck of aneurysm in 2 patients, hypoplastic contralateral A1 in 2 patients, presence of blister aneurysm in 4 patients and relationship of a parent artery with aneurysm in 1 patient were not shown in these images. Conclusion: Radiological movie images created by Osirix software are showing similarities with surgical observations. These images are thought not only have diagnostic importance also provide surgeon’s familiarity to surgical procedure. Concomitant usage of this program with 3 dimensional digital subtraction angiography images will improve the accuracy of this software. doi: 10.5505/ptd.2016.10846

Subcutaneous schwannoma in the head region

Schwannoma is a benign neural tumor derived from Schwann cells surrounding the nerves. It occurs primarily in subcutaneous tissues and muscles with a tendency for distal extremities, head, and neck area. Treatment of schwannoma is surgical excision. Lipomas are the most common soft-tissue lesions. A case is presented to increase awareness on differential diagnosis of head and neck subcutaneous masses.