Cumhur Kilincer

Factors affecting the outcome of decompressive craniectomy for large hemispheric infarctions: a prospective cohort study

SummaryBackground. Although surgical decompression of large hemispheric infarction is often a life-saving procedure, many patients remain functionally dependent. The aims of this study were to identify specific factors that can be used to predict functional outcome, thus establish predictive criteria to reduce poor surgical results.Method. In this non-randomized prospective study, we performed decompressive craniectomy in 32 patients (age range, 27 to 77 years) with large hemispheric infarctions. Based on their modified Rankin Score (RS), which was calculated 6 months postoperatively, patients were divided into two functional groups: good (RS 0–3, n = 7) and poor (RS 4–6, n = 25). The characteristics of the two groups were compared using statistical analysis.Findings. One-month mortality was 31%. However, most of the surviving patients were severely disabled (RS 4 or 5), and 6-month total mortality reached 50%. Increased age (≥60 years) (P = 0.010), preoperative midline shift greater than 10 mm (P = 0.008), low preoperative Glasgow Coma Score (GCS≤7) (P = 0.002), presence of preoperative anisocoria (P = 0.032), early (within the first three days of the stroke) clinical deterioration (P = 0.032), and an internal carotid artery infarct (P = 0.069) were the positive predictors of a poor outcome.Interpretation. We view decompressive craniectomy for space-occupying large hemispheric infarction as a life-sparing procedure that sometimes yields good functional outcomes. A dominant hemispheric infarction should not be an exclusion criterion when deciding to perform this operation. Early operation and careful patient selection based on the above-mentioned factors may improve the functional outcome of surgical management for large hemispheric infarction.

Nocardial brain abscess: Review of clinical management

Nocardiosis has become a significant opportunistic infection over the last two decades as the number of immunocompromised individuals has grown worldwide. We present two patients with nocardial brain abscess. The first patient was a 39-year-old woman with systemic lupus erythematosus. A left temporoparietal abscess was detected and aspirated through a burr-hole. Nocardia farcinica infection was diagnosed. The patient had an accompanying pulmonary infection and was thus treated with imipenem and amikacine for 3 weeks. She received oral minocycline for 1 year. The second patient was a 43-year-old man who was being treated with corticosteroids for glomerulonephritis. He was diagnosed with a ring-enhancing multiloculated abscess in the left cerebellar hemisphere, with an additional two small supratentorial lesions and triventricular hydrocephalus. Gross total excision of the cerebellar abscess was performed via a left suboccipital craniectomy. Culture revealed Nocardia asteroides, and the patient was successfully treated with intravenous ceftriaxone, then oral trimethoprime-sulfamethoxazole for 1 year. The clinical course, radiological findings, and management of nocardial brain abscess are discussed in light of the relevant literature, and current clinical management is reviewed through examination of the cases presented here.

Contralateral subdural effusion after aneurysm surgery and decompressive craniectomy: case report and review of the literature.

We report a complication of decompressive craniectomy in the treatment of aneurismal subarachnoid hemorrhage (SAH) and accompanying middle cerebral artery (MCA) infarction. A 56-year-old man presented with subarachnoid hemorrhage and right sylvian hematoma. He was diagnosed with high-grade SAH and medical therapy was employed. He showed rapid clinical deterioration on day 9 of his admission. Computed tomographic scans showed right MCA infarction and prominent midline shift. Because of the patients rapidly worsening condition, further evaluation to find origin of SAH could not be obtained, and decompressive right hemicraniectomy was performed. During sylvian dissection, right middle cerebral and posterior communicant artery aneurysms were detected and clipped. One week after operation, a contralateral frontoparietal subdural effusion and left to right midline shift was detected and drained through a burr-hole. Through successive percutaneous aspirations, effusion recurred and complete resolution was achieved after cranioplasty and subduroperitoneal shunt procedures. Decompressive craniectomy is generally accepted as a technically simple operation with a low incidence of complications. In the light of this current case, we hypothesize that a large craniectomy may facilitate the accumulation of recurrent effusion on contralateral side creating a resistance gradient between two hemispheres. This point may be especially true for subarachnoid hemorrhage cases requiring aneurysm surgery. We conclusively suggest that subdural effusions may be resistant to simple drainage techniques if a large contralateral craniectomy does exist, and early cranioplasty may be required for treatment in addition to drainage procedures.

CERVICAL SPONDYLOTIC MYELOPATHY TREATED BY OBLIQUE CORPECTOMY : A PROSPECTIVE STUDY. Commentary

OBJECTIVEAnterolateral partial oblique corpectomy (OC) aims to decompress the cervical spinal cord without subsequent fusion and saves the patient from graft-, instrument-, and fusion-related complications. Although it is a promising technique, there are few studies dealing with its efficacy and safety. METHODSIn this prospective study, 40 consecutive patients underwent an OC (one to four levels from C3 to C7) for cervical spondylotic myelopathy; they ranged in age from 43 to 78 years (mean, 55 yr). The average follow-up period was 59 months (range, 24–98 mo). Clinical and radiological data were analyzed to assess the results and find possible factors related to outcomes. RESULTSThirty-seven (92.5%) of the 40 patients improved by the 6-month follow-up examination according to the Japanese Orthopedic Association score. The improvement was the most prominent in lower extremity dysfunction. Recovery was positively correlated with the preoperative Japanese Orthopedic Association score (r = 0.37, P = 0.018). Permanent Horners syndrome developed in four patients (10%). During the long-term follow-up period, neurological improvement was maintained and there were no signs of postoperative instability, posture change, or axial pain. CONCLUSIONOC for treating multilevel cervical spondylotic myelopathy achieved good results with a low morbidity rate. The results of the current study suggest that OC is a good alternative to conventional median corpectomy and fusion techniques in selected cases.

Cortex of the pedicle of the vertebral arch. Part II: microstructure

OBJECT Although the gross anatomy of the pedicle in the human spine has been investigated in great detail, knowledge of the microanatomy of trabecular and cortical structures of the pedicle is limited. An understanding of the mechanical properties and structure of the pedicle bone is essential for improving the quality of pedicle screw placement. To enhance this understanding, the authors examined human cadaveric lumbar vertebrae. METHODS In this study, the authors obtained seven human cadaveric lumbar vertebrae. The lateral and medial cortices of these pedicle specimens were sectioned and embedded in polymethylmethacrylate. Cross-sectional slices of cortex were obtained from each specimen and imaged with the aid of a high-resolution light microscope. Assessments of osteonal orientation, determinations of relative dimensions, and histomorphometric studies were performed. RESULTS The cortex of the pedicle in each human lumbar vertebra had an osteonal structure with haversian canals laid down mainly in the anteroposterior (longitudinal) direction. The organization of osteons across the transverse cross-section was not homogeneous. The layer of lamellar bone that typically envelops cortical bone structures (such as in long bones) was not observed, and the lateral cortex was significantly thinner than the medial cortex (p < 0.05). CONCLUSIONS The cortical bone surrounding the pedicle differed from bone in other anatomical regions such as the anterior vertebral body and femur. The osteonal orientation and lack of a lamellar sheath may account for the unique deformation characteristics of the pedicle cortex seen during pedicle screw placement.

Large intradiploic growing skull fracture of the posterior fossa

Growing skull fractures (GSFs) are rare complications of head injury and mostly occur in infancy and early childhood. Location in the posterior fossa and intradiploic development of a GSF is very uncommon. We report a 7-year-old boy with a large, 9×7×4-cm, occipital intradiploic GSF. The lesion developed progressively over a period of 5 years following a documented occipital linear fracture. This case of a GSF developing from a known occipital linear fracture demonstrates that a GSF may reach a considerable size and, although uncommon, intradiploic development and occipital localization of a GSF is possible.

Paraplegia due to spinal subdural hematoma as a complication of posterior fossa surgery: Case report and review of the literature

Although blood contamination of cerebrospinal fluid (CSF) after an intracranial operation is possible, development of a symptomatic spinal hematoma after a posterior fossa surgery has never been reported. A 43-year-old woman underwent a posterior fossa tumor removal in the prone position with no intraoperative difficulty. On the second postoperative day, she complained of severe epigastric pain and developed a rapid onset of paraplegia with anesthesia below the thoracic 5 spinal level. The emergency cranial and spinal MRIs revealed a spinal extramedullary hemorrhage spreading to the whole spinal regions, just sparing the cauda equina area. There was a prominent localized hematoma formation surrounding and compressing the spinal cord at the upper thoracic levels, which was evacuated via an urgent laminectomy. The patient showed partial neurological recovery after the decompression. Development of the spinal hematoma was explained by the movement of blood from the tumor bed into the spinal canal under the effect of gravity, during or after the operation. A 30 degrees head elevation might facilitate the accumulation of blood. Localization of the hematoma formation may be caused by the fact that the upper thoracic levels constitute the apex of the kyphosis. We conclusively suggest that a spinal hematoma should be taken into consideration as a rare but potentially severe complication of a posterior fossa surgery. Meticulous hemostasis and isolation of the surgical area from the spinal spaces are essential. Overdrainage of CSF should be abandoned. Postoperatively, patients should be monitored for spinal findings as well as cranial signs.

Effects of angle and laminectomy on triangulated pedicle screws

We aimed to demonstrate the effect of angle and laminectomy on paired pedicle screws to determine whether a 90 degrees screw angle is optimal as has been previously suggested. According to the angle between right and left screws, 28 calf vertebrae were divided into three groups and instrumented as follows: Group I: 60 degrees screw angle; Group II: 90 degrees angle; Group III: 60 degrees angle with laminectomy. The screws were connected using rods and cross-fixators and tested to peak pullout force. Triangulated pedicle screws provided 76.5% more pullout strength than single screws. Most of the specimens failed through loss of convergence angle (toggling of screws on the rods) and subsequent uni- or bilateral screw pullout. Mean+/-SD peak loads were: Group I: 2071+/-622 N; Group II: 1753+/-497 N; Group III: 2186+/-587 N. The differences were not significant (p>0.05). 90 degrees triangulation was not associated with a superior pullout performance versus conventional 60 degrees triangulation, suggesting that achieving additional triangulation angle is not necessary to obtain increased pullout strength. Laminectomy did not alter the effect of triangulation on fixation strength.

Giant cervicothoracic extradural arachnoid cyst: case report

The pathogenesis, etiology, and treatment of the spinal arachnoid cyst have not been well established because of its rarity. A 57-year-old male was presented with spastic quadriparesis predominantly on the left side. His radiological examination showed widening of the cervical spinal canal and left neural foramina due to a cerebrospinal fluid - filled extradural cyst that extended from C2 to T2 level. The cyst was located left anterolaterally, compressing the spinal cord. Through a C4–T2 laminotomy, the cyst was excised totally and the dural defect was repaired. Several features of the reported case, such as cyst size, location, and clinical features make it extremely unusual. The case is discussed in light of the relevant literature.

Sizes of the transverse foramina correlate with blood flow and dominance of vertebral arteries

BACKGROUND CONTEXT Knowing the side of the dominant vertebral artery (VA) may be of utmost importance if the VAs are at risk during spine surgery. Determination of the size of VAs is obtained by using Doppler ultrasonography or angiography. Because VA is the main anatomic structure occupying the transverse foramina (TF), it may be assumed that size of TF and blood flow of VAs should be proportional. PURPOSE To investigate if there is a correlation between the sizes of TF and the flow of VAs and determine the diagnostic accuracy of measuring TF to predict dominant side of VA. The specific hypothesis was that the larger side of TF corresponds to the side of the dominant VA. STUDY DESIGN This is a morphologically based, prospectively designed, single-center study. Thirty patients (14 male, 16 female) who were treated for degenerative spinal pathologies were included. Patients with cervical fractures, occluded VA, prominent degenerative changes affecting TF, deformity, or previous cervical instrumentation were excluded from the study. OUTCOME MEASURES In all patients, computed tomography of the cervical spine and Doppler ultrasonography of VAs were obtained for morphometric analysis. METHODS Axial computed tomography cuts at the C6 vertebral level were taken. Two measurements were performed for each foramen: its right to left width and its anteroposterior depth. Blood flow volumes of bilateral VAs were measured using color Doppler. RESULTS Diameters of TF ranged between 2.2 and 7 mm, and its width was generally slightly larger than the depth. Transverse foramina were always asymmetric, with no right or left side preference. There was a strong correlation between TF diameters and blood flow of VAs. Between TF width and VA blood flow, the Pearson correlation coefficient was 0.59 (p=.001) for right side and 0.72 for left side (p<.0001). The side of the larger TF matched with the side of dominant VA in 28 of 30 cases (93.3%) (p<.0001). The agreement between the dominant VA and the larger side of TF was almost perfect (Kappa=0.087, p<.0001). CONCLUSIONS There was strong correlation between TF diameters and VA blood volume. Our results suggest that TF diameter of C6 level can be used to predict the side of the dominant VA reliably.