Sukru Caglar

Surgical Anatomic Evaluation of the Cervical Pedicle and Adjacent Neural Structures

OBJECTIVEAlthough several clinical applications of transpedicular screw fixation in the cervical spine have been documented recently, few anatomic studies concerning the cervical pedicle are available. This study was designed to evaluate the anatomy and adjacent neural relationships of the middle and lower cervical pedicle (C3–C7). The main objective is to provide accurate information for transpedicular screw fixation in the cervical region and to minimize complications by providing a three-dimensional orientation. METHODSTwenty cadavers were used to observe the cervical pedicle and its relationships. After removal of the posterior bony elements, including spinous processes, laminae, lateral masses, and inferior and superior facets, the isthmus of the pedicle was exposed. Pedicle width, pedicle height, interpedicular distance, pedicle-inferior nerve root distance, pedicle-superior nerve root distance, pedicle-dural sac distance, medial pedicle-dural sac distance, mean angle of the pedicle, root exit angle, and nerve root diameter were measured. RESULTSThe results indicate that there was no distance between the pedicle and the superior nerve root and between the pedicle and the dural sac in 16 specimens, whereas there was a slight distance in the lower cervical region in the 4 other specimens. The mean distance between the pedicle and the inferior nerve root for all specimens ranged from 1.0 to 2.5 mm. The mean distance between the medial pedicle and the dural sac increased consistently from 2.4 to 3.1 mm. At C3–C7, the mean pedicle height ranged from 5.2 to 8.5 mm, and the mean pedicle width ranged from 3.7 to 6.5 mm. Interpedicular distance ranged from 21.2 to 23.2 mm. The mean root exit angle ranged from 69 to 104 degrees, with the largest angle at C3 and the smallest at C6. The mean angle of the pedicle ranged from 38 to 48 degrees. The nerve root diameter increased consistently from 2.7 mm at C3 to 3.8 mm at C6 and then decreased to 3.7 mm at the C7 level. Differences in measurements were considered statistically significant at levels ranging from P < 0.05 to P < 0.01. CONCLUSIONThis study indicates that improper placement of the pedicle screw medially and superiorly in the middle and lower cervical spine should be avoided and that the anatomic variations between individuals should be established by measurement.

The effect of intrathecal sodium nitroprusside on severe chronic vasospasm

The efficacy of sodium nitroprusside in resolving cerebral vasospasm was evaluated with multicisternal injections. Twelve animals received fresh, unheparinized arterial blood via three injections (15 ml total) into the cisterna magna. Selective vertebral arteriography was performed on Day 0, and blood injections were performed on the second and third days after the first injection. On the seventh day selective arteriography was performed to evaluate the diameter of the basilar artery. In the sodium nitroprusside group, intrathecal injections of the drug were started on Day 4 and continued for two days (25 micrograms/kg/day). The diameter of the basilar artery was reduced 72.98 +/- 11.07% in control experiments. For the animals treated with intrathecal sodium nitroprusside, the mean diameter of the basilar artery was reduced 29.25 +/- 4.54%. The effect of intrathecal sodium nitroprusside on intracranial pressure (ICP), blood pressure (BP) and electrocardiogram (ECG) was also evaluated in 14 animals. There were no prominent changes in ICP, BP, or ECG when sodium nitroprusside was given intrathecally, but BP decreased and ICP and heart rate increased with intravenous doses of sodium nitroprusside. These results support the hypothesis that sodium nitroprusside administered intrathecally is an effective treatment for cerebral vasospasm.

CT-guided trigeminal tractotomy

SummaryTrigeminal tractotomy is an effective procedure in denervating pain areas of 5th, 7th, 9th and 10th nerves. The classical imaging technique is the x-ray method which visualizes the target electrode relation indirectly. The method of CT-guided trigeminal tractotomy demonstrates the target electrode relation directly.

Extraforaminal lumbar arterial anatomy

BACKGROUND There are few studies carried out to reveal lumbar arterial anatomy. The studies of vascular anatomy of the lumbar zone are usually based on the angiographic imaging methods and barium injected radiographic sections of human specimens. METHODS Upon the recent breakthroughs in the microscopic anatomic dissections, the vascular structure of this zone is examined in 16 cadavers. Arterial anatomies of the extraforaminal zones of 80 lumbar vertebral objects were studied. RESULTS In each segment, lumbar artery, extraforaminal branches of the lumbar artery and the spinal (foraminal) branch were described. The spinal branch is originated from lumbar artery and extends as the dorsal branch. The dorsal branch is divided into 4 branches: ganglionic, transverse, ascending, and descending. Diameters of the lumbar artery, spinal, dorsal, and ganglionic branches were measured at each stage. The mean diameter of the lumbar artery was 2.7 mm, the dorsal branch was 2.0 mm, the foraminal branch was 1.9 mm, and the ganglionic branch was 1.0 mm, respectively. CONCLUSION Knowledge of lumbar arterial anatomy is needed for carrying out a successful surgical operation and reducing complications.

Microsurgical anatomy of the dorsal cervical rootlets and dorsal root entry zones

SummaryBackground. Detailed anatomical knowledge of the dorsal cervical rootlets and dorsal root entry zones (DREZ) is important for the diagnosis and treatment of cervical myeloradiculopathy and surgical management of pain. There are far fewer micro-anatomical studies of this area than gross anatomical studies. This study presents several anatomical points regarding the dorsal cervical rootlets and dorsal root entry zones.Method. Fifteen adult formalin-fixed cadaveric spines from C1 to T1 were used to observe the posterior structures. They were studied under the surgical microscope following en bloc laminectomy and foraminotomy. The morphological features of the dorsal root entry zones and dorsal rootlets were determined. The distance from the midline to the DREZ, the longitudinal length of the DREZ in the spinal canal, the length of the dorsal rootlets, the number of dorsal rootlets and the intersegmental anastomoses between the dorsal rootlets were measured.Findings. The distance from the midline to the DREZ ranged from 1.1 to 4.7 mm. Longitudinal length of the dorsal rootlets ranged 4.3–17.7 mm. The shortest length of the dorsal rootlets ranged between 5–28 mm, and longest lengths of the dorsal rootlets ranged 6.8–30.3 mm. The number of dorsal rootlets ranged from 2–13. Between the C2–T1 dorsal rootlets, 142 connections out of 30 intersegments were noted.Conclusions. The distance from the midline to the DREZ decreased in the lower cervical spine. The longest longitudinal length of the DREZ was at the C5 level. The length of the dorsal rootlets was increased in the lower cervical spine. The average number of dorsal rootlets tended to increase in the lower cervical spine. Anastomoses were most often found between C6–7 and C5–6 dorsal rootlets. Knowledge of the anatomical features of dorsal cervical rootlets and dorsal root entry zones is essential for a surgeon to avoid injuring the neural structures. This knowledge is a must not only to avoid complications but also for the success, safety and effectiveness of microsurgical operations of the pathological conditions like posterior myeloradiculopathy and pain treatment such as DREZ operations.

Transclival Approach to Rabbit Basilar Artery for Experimental Induction of Chronic Vasospasm

SummaryAn experimental technique for producing delayed cerebral vasospasm in a rabbit model is described. The basilar artery is punctured via the transclival route and angiographic verification is illustrated.

Correlation of matrix metalloproteinase-3 expression with patient age, magnetic resonance imaging and histopathological grade in lumbar disc degeneration.

AIM The purpose of the present study is to analyze the expression of matrix metalloproteinase-3 (MMP-3), magnetic resonance imaging (MRI) grading and histopathological alterations of the intervertebral disc (IVD) for correlations with each other and with the age, gender and low back pain duration of the patients who had undergone operations for lumbar disc herniation (LDH). MATERIAL AND METHODS Forty-two patients were admitted to our clinic with signs of LDH and underwent surgery for LDH at 48 IVD levels. In all cases, specimens for histological and immunohistochemical analyses were removed from the IVD space. Lumbar IVD degeneration on MRI of the 48 IVDs from which surgical specimens had been obtained was classified into five grades using the Pfirrmann classification. RESULTS In the degenerated IVD, the expression of MMP-3, MRI grading and histopathological alterations of the IVD displayed significant correlation. Increased age is closely related with aforementioned alterations. There was no correlation between MMP-3 expression and age, gender and duration of the pain. CONCLUSION For evaluating and treating IVD degeneration, MRI is a good and non-invasive diagnostic tool to determine the severity of degeneration. MMP-3 may be a therapeutic target of the degenerated IVD.

The lumbar roots and pedicles: a morphometric analysis and anatomical features.

The objective of this study was to conduct a morphometric analysis of the lumbar nerve roots and surrounding structures. In this investigation, the lumbar roots were studied in 14 cadavers (70 lumbar vertebrae). Lumbar pedicle heights and widths were measured at every level of the lumbar vertebrae. The largest mean root diameter was 5.6 mm (L5 root) and the smallest 3.5 mm (L1 root). With regard to the root-dura exit angle, the widest was measured at L1 as 26.2+/-1.6 degrees and the narrowest at L5 as 16.3+/-2.4 degrees. The widest lumbar pedicle was measured at L5 as 17.1+/-4.2 mm and the narrowest at L1 as 8.4+/-1.8 mm. The longest lumbar pedicle was measured at L2 as 15.3+/-2.2 mm and the shortest at L4 as 13.8+/-2.3 mm. Quantitative measurements of lumbar root diameters, their exit angles from the dura, and lumbar pedicle heights and widths in anatomical dissection models may help us to gain a deeper understanding of the pathologies of this region and positively influence the success of surgical interventions.

Infection-related atlantoaxial subluxation in two adults: Grisel syndrome or not?

Summary. Grisels syndrome involves the subluxation of the atlanto-axial joint from inflammatory ligamantous laxity following an infectious process in the head or neck. It is a rare disease usually affecting children, but infrequent adult cases do occur. Today, due to the widened use of antibiotics and availability of MR imaging, some cases presenting with neck pain, resulting from the infectious inflammation of C1 and C2 but without pronounced subluxation, can be a challenging problem for most neurosurgeons. Several theories have been proposed to explain the pathogenesis of inflammatory subluxation. The primary treatment of Grisels syndrome is medical. The underlying infectious organism must be isolated and appropriate antibiotics must be prescribed. The subluxation is reduced in holter or skeletal traction. This paper reports two cases of infection-related atlanto-axial subluxation in two adults. The literature on this subject is briefly reviewed.

Comparative Analysis of Vertebroplasty and Kyphoplasty for Osteoporotic Vertebral Compression Fractures

Study Design A retrospective study. Purpose The aim of this study is to compare the efficacy and outcome of vertebroplasty compared with unipedicular and bipedicular kyphoplasty for the treatment of osteoporotic vertebral compression fractures in terms of pain, functional capacity and height restoration rates. Overview of Literature The vertebroplasty procedure was first performed in 1984 for the treatment of a hemangioma at the C2 vertebra. Kyphoplasty was first performed in 1998 and includes vertebral height restoration in addition to using inflation balloons and high-viscosity cement. Both are efficacious, safe and long-lasting procedures. However, controversy still exists about pain relief, improvement in functional capacity, quality of life and height restoration the superiority of these procedures and assessment of appropriate and specific indications of one over the other remains undefined. Methods Between 2004 and 2011, 296 patients suffering from osteoporotic vertebral compression fracture underwent 433 vertebroplasty and kyphoplasty procedures. Visual analogue scale (VAS), the Oswestry Disability Index (ODI) and height restoration rates were used to evaluate the results. Results Mean height restoration rate was 24.16%±1.27% in the vertebroplasty group, 24.25%±1.28% in the unipedicular kyphoplasty group and 37.05%±1.21% in the bipedicular kyphoplasty group. VAS and ODI scores improved all of the groups. Conclusions Vertebroplasty and kyphoplasty are both effective in providing pain relief and improvement in functional capacity and quality of life after the procedure, but the bipedicular kyphoplasty procedure has a further advantage in terms of height restoration when compared to unipedicular kyphoplasty and vertebroplasty procedures.