Biomedical subjects

S Kazan

Publications and source records attributed to S Kazan.

12 recordsLinked to original sources

PubMed2000

Anatomical evaluation of the groove for the vertebral artery in the axis vertebrae for atlanto-axial transarticular screw fixation technique.

Anatomical measurements were studied on 40 dry axis vertebrae to determine the suitability of the groove for the vertebral artery for atlanto-axial transarticular screw fixation technique. We measured 13 parameters including three angular and 10 linear dimensions related to the groove of the vertebral artery, pedicle, and pars interarticularis and evaluated 80 measurements for each parameter. All measurements were done after placing a Kischner guide wire through the pedicle. We found that differences between measurements on the left and right sides of each vertebra were nonsignificant. In spite of the variability in measurements such as height, width, and median angle of the pedicle, the decline angle for instrumentation, the depth of the groove for the vertebral artery, and the internal height of the pars interarticularis, all of these had good symmetry. However, there were statistically significant differences between the sides in measurements for both the width (P=0.05) and the angle (P<0.02) of the pedicle allowing instrumentation and they did not show good symmetry. The risk of vertebral artery injury was found to be 22.5% per specimen, or 16.25% per screw inserted because the internal height of the pars interarticularis at point of fixation was </= 2.1 mm. In addition, we found that the pedicle width allowing instrumentation was not suitable in 12.5% of screws inserted because their values were </= 6 mm. When the width of the pedicle for instrumentation and the internal height of the pars interarticularis were both evaluated together, we also found that this technique would be extremely dangerous in 7.5% of specimens. In conclusion, the internal height of the pars interarticularis and the width of the pedicle for instrumentation should be evaluated together in thin CT sections preoperatively, because of the risk of vertebral artery injury in patients upon which atlanto-axial transarticular screw fixation is to be performed.

Atlanto-Axial Joint↗

PubMed2000

Proof of the patent subcutaneous fibrous tract in children with V-P shunt malfunction.

A connective tissue sheath that forms around the peritoneal catheter of silicone ventriculo-peritoneal (V-P) shunt tubing is quite often observed in children with V-P shunts. However, proof of the passage of cerebrospinal fluid (CSF) through these sheaths has been reported in only one published study to date. We present four cases associated with chronic malfunction of the V-P shunt peritoneal catheter. In these cases, CSF passage through the subcutaneous fibrous tract, which had a pericatheter connective tissue sheath, was demonstrated around the V-P shunt peritoneal catheter. In the first case the patient suffered intermittent headache attacks over a long period of time; abdominal migration of the peritoneal catheter was detected. The second patient, who had been asymptomatic in the follow-up period with an outgrown peritoneal catheter, was admitted with acute hydrocephalus symptoms. A peritoneal catheter disconnection was detected in another patient, who had had multiple shunt revisions previously. In the last case, an obstruction of the peritoneal catheter was detected. The existence of the subcutaneous fibrous tract and its function were demonstrated by radio-opaque shuntogram in two cases and radionuclide shuntogram in the other two cases. In all four cases V-P shunt revision was performed. Within this study, the possible passage of CSF through a fibrous tract in cases of migration, outgrowth, disconnection or obstruction of the peritoneal shunt catheter was demonstrated. In conclusion, patients with shunt malfunction with a well-grown pericatheter fibrous sheath who are either asymptomatic or minimally symptomatic and show no evidence of active ventricular dilatation on their cranial CT scan should not be regarded as having arrested hydrocephalus until radio-opaque or radionuclide shuntogram studies have been done.

Adolescent↗

PubMed2000

Spinal canal stenosis at the level of axis.

We describe a rare case of marked segmental stenosis of the axis secondary to developmental hypertrophy of the posterior neural arch causing severe neck pain and headache in the occipital region. The patient made a remarkable recovery following decompressive laminectomy and foraminal decompression.

Axis, Cervical Vertebra↗

PubMed2000

Bilateral cerebellopontine angle arachnoid cysts: case report.

OBJECTIVE AND IMPORTANCE: A rare case of bilateral cerebellopontine angle (CPA) arachnoid cysts (ACs), accompanied by cerebellar tonsillar displacement toward the foramen magnum, is presented. CLINICAL PRESENTATION: A 45-year-old woman presented with progressive dysphagia, vertigo, and truncal ataxia. Magnetic resonance imaging revealed bilateral CPA ACs and cerebellar tonsillar displacement. INTERVENTION: The right CPA AC was excised via a suboccipital approach. Decompression of the foramen magnum and duraplasty were also performed. CONCLUSION: The case reported here is the first case of bilateral CPA ACs. Decompression of the foramen magnum and excision of the cyst resulted in complete relief of symptoms.

Arachnoid Cysts↗

PubMed1999

Percutaneous anterior odontoid screw fixation technique. A new instrument and a cadaveric study.

We describe a new instrument and a percutaneous technique for closed anterior fixation of odontoid fracture. The instrument which we developed consists of a telescopic tube system. This new instrument and closed fixation technique was used in six cadavers with type II odontoid fractures and to two cadavers with an intact odontoid process. Each cadaver underwent satisfactory placement of the screw to the odontoid with this technique under biplanar scopy control. After this procedure, no serious injury was found in the parapharyngeal and neurovascular areas of the necks of the cadavers, in which anatomical dissection along the track of this instrument was performed. The instrumentation and the technique as a whole is seen as reliably applicable for odontoid fracture fixation. Also, we expect to reduce operating time and hospital costs because this system is simple, easily applicable and minimally invasive.

Bone Screws↗

PubMed1999

The effect of mild hypothermia, mannitol and insulin-induced hypoglycaemia on ischaemic infarct volume in the early period after permanent middle cerebral artery occlusion in the rat.

We investigated the effect of mild hypothermia (32-34 degrees C), mannitol and insulin - induced hypoglycaemia on the ischaemic infarct volume on permanent middle cerebral artery occlusion with bilateral carotid artery ligation in rats. Temporalis muscle temperature as an indicator of brain temperature was monitored throughout the experiment in all rats, which were randomly divided into seven groups. During ischaemia, control rats received intravenous saline in a normothermic condition; treated rats had hypothermia and intravenous saline, hypothermia and mannitol, normothermia and mannitol, normothermia and insulin, normothermia, insulin and glucose, and hypothermia and insulin applied. After the experiment, the animals were killed, and brain sections were stained with haematoxylin and eosin. Images of infarct areas were determined using a camera attached to the microscope, and analysed by image analysis software. The total volume of infarcted tissue, right hemispheric volume, and the percentage of infarction were determined at the end of the image analysis investigation. The infarct volume on the control group was found to be 128.16+/-6.67 mm(3). Infarct volumes in hypothermic groups were significantly smaller than those of the control group (p<0.05). There were no significant differences between infarct volumes in the hypothermic groups. However, we found that hypothermia plus mannitol have the greatest neuro-protective effect. In normothermic rats, the infarct volume decreased proportionally but not statistically (p>0.05) whether mannitol or insulin was given. Our results also demonstrate that pre-, and post-ischaemic serum glucose concentrations influence the volume of infarction. Rats that had had pre-ischaemic high serum glucose concentrations had a higher volume of infarct than the hypothermic rats (p<0.05), while rats with post-ischaemic low serum glucose concentrations had a lower volume of infarct than the control rats.

Animals↗

PubMed1999

Spinal intradural arachnoid cysts located anterior to the cervical spinal cord. Report of two cases and review of the literature.

The authors describe two rare occurrences of radiographically, surgically, and pathologically confirmed spinal intradural arachnoid cysts (not associated with additional pathological entities) that were located anterior to the cervical spinal cord. These lesions have been reported previously in only eight patients. The patients described in this report were young adults who presented with progressive spastic tetraparesis shortly after sustaining mild cervical trauma and in whom no neurological deficit or bone fracture was demonstrated. The presence of an intradural arachnoid cyst was detected on postcontrast computerized tomography (CT) myelography and on magnetic resonance imaging; both diagnostic tools correctly characterized the cystic nature of the lesion. Plain radiography, plain tomography, and contrast-enhanced CT scans were not diagnostic. In both cases a laminectomy was performed, and the wall of the cyst was excised and fenestrated with subarachnoid space. Postoperatively, the patients made complete neurological recoveries. Based on a review of the literature, arachnoid cysts of the spinal canal may be classified as either extra- or intradural. Intradural arachnoid cysts usually arise posterior to the spinal cord in the thoracic spine region; however, these cysts very rarely develop in the cervical region. The pathogenesis of arachnoid cysts is unclear, although congenital, traumatic and inflammatory causes have been postulated. The authors believe that the formation of an arachnoid cyst cannot be explained by simply one mechanism because, in some reported cases, there has been accidental or iatrogenic trauma in association with congenital lesions. They also note that an intradural arachnoid cyst located anterior to the cervical spinal cord is an extremely rare disorder that may cause progressive myelopathy; however, the postoperative prognosis is good.

Adolescent↗

PubMed1998

Effects of intra-arterial papaverine on the chronic period of cerebral arterial vasospasm in rats.

OBJECTIVES: The effect of intra-arterial papaverine (IAP) on the basilar artery (BA) and cerebral perfusion pressure (CPP) during the chronic period of the cerebral arterial vasospasm in rats was investigated. MATERIAL AND METHODS: The study was carried out on male, Swiss-Albino rats, the weight of each varied between 200-340 g. A large volume (0.3 cc) of nonheparinized, autolog blood was utilized in order to cause a subarachnoid haemorrhage. For the measurement of the changes in BA diameter, the angiograms were made prior to the subarachnoid haemorrhage, 48 h after the subarachnoid haemorrhage, and in 1, 15, 30, and 60 min after papaverine infusion into the vertebral artery. The BA vascular index was found separately for each angiogram. At each stage of the procedure mean arterial blood pressure (MAP) and intracranial pressure (ICP) were monitored. RESULTS: BA diameter measurements were found to be 226+/-32 microm in pre-haemorrhage angiograms and 145+/-44 microm in angiograms 48 h after the subarachnoid haemorrhage. In the angiograms immediately after IAP, it was found that the BA diameter reached about 92% (206+/-41 microm) of control values. But, in the angiograms 15 min after IAP, it was observed that BA underwent a spasm again. CONCLUSION: The dilatator effect of IAP on BA was temporary. Additionally, in the chronic vasospasm period when cerebral autoregulation mechanisms are impaired and CPP decreased significantly, IAP has adversely affected CPP decreasing MAP.

Animals↗

PubMed1997

Post-traumatic bilateral diffuse cerebral swelling.

This study confirms that bilateral diffuse cerebral swelling with or without parenchymal haemorrhages (< 15 cc) is a more common occurrence in the paediatric patients with severe head injury as compared with adults, since the analysed sample represented 42.55% and 20.43% of all paediatric and adult patients with severe head injury recorded in our clinic at the time of the study, respectively. The incidence of patients with diffuse cerebral swelling without parenchymal haemorrhages was found to be 27.65% of paediatric patients and 5.37% of adult patients with severe head injury. Secondary neurological deterioration occurred only in 5 (12.5%) paediatric patients and in 4 (10.5%) adult patients with diffuse cerebral swelling and was not to be found associated with parenchymal haemorrhages. A better outcome was seen in paediatric patients. Mortality rates were 12.5% in paediatric patients and 34.21% in adult patients. Our data also suggest that the mortality rate between paediatric and adult patients with diffuse cerebral swelling without parenchymal haemorrhages was similar (15.38% and 20% in paediatric and adult group, respectively), while the adult patients with diffuse cerebral swelling associated with small intraparenchymal haemorrhages have a worse prognosis than paediatric patients.

Adolescent↗

PubMed1997

Conservative management of extradural haematomas: effects of skull fractures on resorption rate.

In conservative management of extradural haematomas (EDH), several mechanisms were described to explain the resorption of the haematoma. One of these was the transfer of the clot into the epicranial space through the skull fracture. In this study, the effects of skull fracture and associated intracranial lesions in the conservative management of EDH were investigated. Skull fracture and associated intracranial lesions were found in 71.11% and 51.1% of the patients, respectively. Resorption rate was calculated using an original formula and it was 0.548 +/- 0.227 in patients with skull fracture and 0.507 +/- 0.170 in patients with both skull fractures and additional intracranial lesions. These rates were found to be significantly higher than in the patients without fracture. In conclusion, in the patients with EDH planned to be managed conservatively, skull fracture and additional intracranial lesions must not be thought as risk factors, on the contrary, resorption of the clot might be earlier than in the others.

Absorption↗

PubMed1997

The effect of condylectomy on extreme lateral transcondylar approach to the anterior foramen magnum.

The dorsolateral, suboccipital, transcondylar technique was used in this cadaveric study. The angle and distance measurements in the corridors were taken intradurally both superior and inferior of the foramen magnum level. In the first stage of this study, the findings which were gained from the standard lateral suboccipital approach were compared with the findings after condyle and lateral atlantal mass removal. After condylectomy, the approach to anterior foramen magnum via both corridors was found to be shorter and the lateral angle of the exposure of the anterior foramen magnum was found to be wider. The considerable shortening of the distances to the anterior foramen magnum, especially in the superior corridor, emphasises the necessity of combining standard approaches with condylectomy. In addition, it was found that after condylectomy, considerable widening of both transverse and longitudinal planes in the inferior corridor allows the surgeon greater access to work on lesions. Furthermore, the freed space between the superior corridor and the interior corridor, which was gained by condylectomy, shows that condylectomy provides a combined approach to the inferior and superior parts of the foramen magnum anteriorly.

Cadaver↗

PubMed1993

Conservative management of epidural haematomas. Prospective study of 15 cases.

Conservative management of epidural haematoma (EDH) depends on a balance between expansion and resorption rate of the clot. 15 patients with EDH whose CT scans demonstrated a small EDH and were asymptomatic or with minor symptoms or with a delayed diagnosis were treated conservatively. The thickness of haematoma ranged between 4.9-40.8 mm. In two patients, the haematoma extended from the posterior fossa to the supratentorial region. In 7 patients, additional intracranial pathology was detected. None of the patients had neurological deterioration on follow up. The second CT was performed on second day at the earliest, in fourth week at the latest. We conclude that the patients with EDH who are neurologically stable during the first 24 hours after trauma, with small EDH and with minor or no symptoms or signs, might be candidates for conservative management. An absolute precondition for conservative management is close supervision of the patient.

Adolescent↗