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Biomedical subjects

W Hassler

Publications and source records attributed to W Hassler.

At least 37 records · Page 2Linked to original sources
PubMed1998

Nine cases of nontraumatic spinal epidural hematoma.

Nontraumatic spinal epidural hematoma (NSEH) is a rare but potentially serious spinal disease, which progresses inexorably to a catastrophic neurological situation if left untreated. Nine patients (5 males and 4 females, mean age 59.8 years) with NSEH were admitted to our hospital between 1987 and 1997. Clinical data, imaging, and operative results of these patients were analyzed retrospectively. Multilaminectomy was performed to decompress the affected levels. Postoperative neurological evaluation revealed functional improvement in five patients and no significant change in four patients. The most important factors influencing postoperative recovery were the preoperative neurological condition of the patient and the interval from onset of deficit until the operation. Magnetic resonance imaging allows non-invasive and specific diagnosis of NSEH, except in the first 24 hours. Computed tomography myelography with sagittal reconstructions provides specific diagnosis in this period. Combination of these diagnostic imaging modalities allows early diagnosis. Surgical decompression within 24 hours of complete sensorimotor deficit or within 48 hours of incomplete sensorimotor deficit will achieve the optimum outcome.

Adult↗
PubMed1998

Giant basilar artery aneurysms encorporating the posterior cerebral artery: bypass surgery and coil occlusion--two case reports.

Giant aneurysms of the basilar artery are rare. With a diameter of 25 mm or more they are often partially thrombosed and show atheromatous plaques. There are some problems in the treatment especially when the aneurysm is broadbased with bulbous origin encorporating the origin of the posterior cerebral artery (PCA). In many of these cases neither operative clipping alone nor coil embolization alone will be practical without causing an ischemia in the depending brain areas. We will report about two patients with giant aneurysms of the basilar artery involving the origin of the PCA and a combined surgical and interventional neuroradiological approach. Preoperatively both patients showed only mild neurological symptoms (slight left hemiparesis, incomplete hemianopsia). We anastomosed the superficial temporal artery as an extracranial-intracranial bypass end-to-side to the PCA followed by clipping the PCA out of the aneurysm. Next day embolization of the aneurysm with Guglielmi ditachable coils was done. Both patients recovered without complications. An angiographic control showed no more filling of the aneurysm and a free running bypass feeding the PCA. In our opinion this combined approach is an effective method to treat giant aneurysms of the basilar artery which involve the origin of the PCA when clipping alone is impossible.

Adult↗
PubMed1998

Complications of angioma surgery--personal experience in 191 patients with cerebral angiomas.

In the last years, treatment decisions of arteriovenous malformations (AVMs) were influenced by the improvement of stereotactic radiosurgery and were revolutionized by development of embolization techniques. The aim of this report was to examine the results, effectiveness, and complications associated with angioma surgery. 191 patients with AVMs were operated by the first author between 1981 and 1996. Angioma localization was distributed as follows: frontal 51 (26.7%), temporal 44 (23%), parietal 45 (23.6%), and occipital 24 (12.6%). Twelve (6.3%) AVMs were located in the cerebellum and 15 (7.9%) in other deep regions. Twenty-nine (15.2%) AVMs were associated with single or multiple aneurysms. The preoperative symptoms were hemorrhage (50.3%), seizure (33.5%), headache (23.0%), focal neurological deficits (12.6%), and other minor symptoms. In 9.9%, the disease remains preoperatively asymptomatic. Based on the Spetzler/Martin scale (S/M), 38 patients were grade I, 39 grade II, 52 grade III, 39 grade IV, and 23 grade V. The following severe complications were observed: postoperative hemorrhage in 13 (6.8%), infection in six (3.1%), infarction in two (1.0%), and death in three (1.6%). The risk for postoperative complications was related to the preoperative S/M grade of the AVM. Severe complications only occurred in AVM grades IV and V. In 62 patients with grade IV and V AVM, three patients died (4.8%) and 12 showed neurological deterioration (19.4%). Only 3/129 (2.3%) patients with grade I-III AVM deteriorated postoperatively. No severe complications were observed in preembolized and recently operated patients. Microsurgical management of cerebral AVMs seems to be a reasonably safe procedure especially in grade I-III AVMs, with a mortality of less than 2%. With enough experience and exact attention to detail, the experienced neurosurgeon can remove many of these AVMs with a minimum of risk to the affected patient. Although hemorrhage from an AVM can be disabling or deadly, the course in many nonoperated high-grade AVMs (S/M grades IV and V) can be quite benign, if compared with their surgical risk. This may justify conservative treatment or treatment with radiosurgery in some high-grade (S/M grades IV and V) angiomas, especially in elderly patients.

Adolescent↗
PubMed1997

Multiple intracranial tuberculomas with atypical response to tuberculostatic chemotherapy: literature review and a case report.

Approximately 34 cases of intracranial tuberculomas with paradoxical response to antituberculous chemotherapy have been documented worldwide. In most of the previously reported cases of this entity an associated tuberculous meningitis has been reported. The majority of these patients were children or young adults, who had inoperably located intracranial tuberculomas in high risk regions developing a few weeks or months after the start of appropriate chemotherapy. 53% of them recovered completely, 37% improved with mild neurological deficits and 10% died. It is interesting that these intracranial tuberculomas developed or enlarged at a stage when systemic tuberculosis was being treated successfully. We report our recent experience with these potentially curable tumours of the central nervous system. The literature is reviewed and diagnostic and therapeutic considerations are discussed. The possible immunological mechanisms of this phenomenon are analysed. In conclusion, patients, who are suspected to be suffering from CNS-tuberculosis should receive a prolonged (12-30 months) course of effective antituberculous therapy. Evidence of new intracranial tuberculomas or the expansion of older existing lesions require no change in the antituberculous drug programme. In such cases systemic dexamethasone as adjuvant therapy for 4 to 8 weeks is worthwhile and effective. Surgical intervention may be necessary in situations with acute complications of CNS tuberculosis such as shunting procedures for the treatment of hydrocephalus. When the diagnosis is not firm and there is no response to therapy within 8 weeks, a stereotactic biopsy of a suspected tuberculoma should be performed. If the largest lesion is not located in high risk deep regions of the brain, it should be total removed surgically. With this combined management, a satisfactory outcome can be obtained in the majority of cases.

Adult↗
PubMed1997

The transconjunctival microsurgical approach to the orbit: recent experience in 22 cases.

We report a 5-year follow-up of 22 consecutive patients, who underwent transconjunctival management of their orbital lesions without muscle dissection. The presentation, natural history, management, surgical appraisal of the transconjunctival approach and its indications are discussed. At follow-up, 21 of the patients showed excellent cosmetic and functional results. Our experience suggests that this approach remains a useful modality, with good intraoperative visibility and minimal postoperative scar formation, for managing selected patients with space-occupying lesions located in the inferior medial and basal compartment of the orbit. Not suitable for the transconjunctival approach are deep intraconal lesions (in the orbital apex) and extraconal superior lesions. Rare complications of transconjunctival approach have included temporary eye muscle injury with ophthalmoplegia postoperatively. More recently, the use of the transconjunctival approach has allowed surgeons to reduce cosmetic failures, functional deficits and deformities of the orbit. Because of its low risks, the absence of postoperative bleeding, and the limited hospitalization and immobilization of the patients, the transconjunctival approach is a successful procedure especially in elderly patients with intercurrent disease.

Adolescent↗
PubMed1996

Typical and atypical fractures of the odontoid process in young children. Report of two cases and a review of the literature.

The most common injury to the odontoid process in children under the age of seven years is a fracture through the synchondrosis with or without anterior displacement of the odontoid process, but this is not the only type of fracture of the odontoid process in this age-group. Fractures above and below the synchondrosis and fractures with posterior displacement were described. Typical clinical features of these fractures are: (1) major and blunt trauma, (2) neck pain and resistance to active and passive head movements; and (3) no or only slight neurological deficits. Conservative treatment had excellent results in the majority of cases. Nevertheless, there are a few specific indications for surgery.

Child, Preschool↗
PubMed1996

Cerebral vasospasm after subarachnoid haemorrhage of unknown aetiology: a clinical and transcranial Doppler study.

Sixteen patients (6 women, 10 men; mean age: 52.5 years) suffering from spontaneous subarachnoid haemorrhage (SAH) of unknown origin underwent a protocol of initial and then weekly computed tomography (CT), initial four-vessel digital subtraction angiography (DSA) and at least one control pancerebral DSA. Fourteen patients had magnetic resonance imaging before undergoing first control DSA. All patients had calcium-antagonists (Nimodipine) via a central venous catheter, were kept on the neurosurgical intensive care unit and followed daily with transcranial Doppler ultrasonography (TCD). One patient (6.3%) developed moderate and 5 (31.1%) developed severe cerebral vasospasm as documented with TCD and exhibited deterioration of their level of consciousness. These 6 patients were treated with induced hypertension, hypervolaemia and haemodilution. Their blood flow velocities were elevated for a mean of 8 (5-17) days with a peak after 12.5 (9-17) days following SAH. No complications due to treatment were noted. One patient of the non-vasospastic group died of pulmonary embolism, another patient had an ischaemic incident during angiography, which has led to permanent disability. On follow-up 2-24 months after SAH 14 patients had returned to their premorbid state. It is concluded that patients suffering from SAH of unknown origin should undergo repeated angiographic investigation and subsequent daily monitoring of their neurologic status including daily TCD recordings so that haemodynamic treatment can be established in the event of cerebral vasospasm, which may occur in up to one third of these patients.

Adult↗
PubMed1996

Microsurgical management of lateral lumbar disc herniations: combined lateral and interlaminar approach.

Seventy-three patients presenting either with biradicular symptoms caused by involvement of the upper and lower root or with monoradicular symptoms caused by affection of the upper root were treated between January 1993 and July 1995 in our department. An interlaminar and lateral access was used to decompress both the upper and lower root by combining the conventional interlaminar approach and a lateral partial facetectomy. With this technique, satisfactory to excellent results were obtained in 92% of the patients. The advantages of the combined approach are (i) optimized visualization of the disc and surrounding anatomical structures, (ii) improved exposure of the lateral foramen and thorough removal of disc material, (iii) minimal risk of root injury by improved visualization, (iv) preservation of a functional facet joint and thereby reduction of postoperative instability with persistent back pain. Since occasionally lateral disc herniations are poorly visualized by computed tomography or magnetic resonance imaging, the decision to use the combined approach should be guided by the patient's clinical presentation rather than by radiological findings.

Female↗
PubMed1996

[Microsurgical transconjunctival approach to the orbits. Initial retrospective analysis of experiences with the transconjunctival approach in 15 patients. Clinical and surgical aspects].

The authors report 4-year follow-up results for their first 15 consecutive tumor patients, who underwent transconjunctival surgery of their orbital lesions without muscle dissection. Presentation, natural history, management, surgical appraisal of the transconjunctival approach and its indications are discussed. At follow-up, 14 of the patients showed excellent cosmetic and functional results. Our experience with the transconjunctival approach in the past 4 years suggests that this approach remains a useful modality, with good intraoperative visibility and minimal postoperative scar formation, for managing selected patients with space-occupying lesions located in the inferior medial and basal compartment of the orbit. Not suitable for the transconjunctival approach are deep intraconal lesions (orbital apex) and extraconal superior lesions. The rare problems with the transconjunctival approach have included temporary eye muscle injury with ophthalmoplegia postoperatively. More recently, the use of the transconjunctival approach has allowed surgeons to reduce cosmetic failures, functional deficits and deformities of the orbit. Because of its low risks, the absence of postoperative bleeding, and the absence of prolongation of hospitalization or immobilization of the patients, the transconjunctival approach is a successful procedure, especially in elderly multimorbid patients.

Adolescent↗
PubMed1995

The combined pterional and orbitocygomatic approach to extensive tumours of the lateral and latero-basal orbit and orbital apex.

Using standardized transcranial (pterional, subfrontal, fronto-orbital) approaches, complete removal of tumours located in the latero-basal aspect of the orbit and the lateral orbital apex with or without extension to the temporal fossa is not possible or can only be achieved if excessive traction is applied to the contents of the orbit and the brain. In contrast, the combined pterional and orbitocygomatic approach provides unhindered access to the superior, lateral and latero-basal orbit, superior and inferior orbital fissure and, if required, to the temporal fossa including the foramina ovale and rotundum. Six patients with extensive orbital lesions underwent surgery using this technique with good operative results.

Adult↗
PubMed1995

The C-reactive protein for detection of early infections after lumbar microdiscectomy.

The tendency for short hospitalization after lumbar microdiscectomy implies the need for early confirmation or disapproval of serious postoperative infections such as spondylodiscitis or deep wound infections. The C-reactive protein (CRP) is a well-known screening parameter for monitoring postoperative infectious complications in other fields. Our objective was to establish the diagnostic significance of CRP-in comparison with ESR and WBC-for monitoring infectious complications after lumbar microdiscectomy. Over a 15 months period we studied prospectively a homogeneous group of N = 400 patients with lumbar disc herniations who were operated on a single level for the first time. CRP, ESR and WBC values were determined in all patients pre-operatively, and on postoperative days 1 and 5. Clinical and laboratory findings were correlated and the diagnostic significance of CRP, ESR and WBC calculated. N = 385 (96%) patients had an uneventful postoperative course. N = 15 (4%) patients developed infectious complications, of which N = 6 (1.5%) were unrelated and N = 9 (2.5%) related to surgery. Evaluation of the laboratory values showed: The CRP baseline is a very individual value of no prognostic relevance. A high postaggression peak is typical and essential as a reference value for only the future time course will disclose any infection. We found 0% false negative and 4% false positive results on day 5. The sensitivity for serial CRP testing was calculated as 100% and specificity as 95.8%. ESR (sensitivity: 78.1%/specificity: 38.1%) and WBC (sensitivity: 21.4%/specificity: 76.8%) both failed to reach such distinct diagnostic significance on day 5. The C-reactive protein has thus proved to be a reliable, simple and economical screening test for infectious complications after lumbar microdiscectomy, superior to classical laboratory parameters.

Adolescent↗
PubMed1995

Amount of subarachnoid blood and vasospasm: current aspects. A transcranial Doppler study.

Subsequent to admission after aneurysmal subarachnoid haemorrhage (SAH), 120 patients (74 women and 46 men) underwent microsurgical clipping of a total of 158 cerebral aneurysms within 96 hours after the bleed. Their mean age was 46 (20-91) years. Computed tomography (CT) findings were graded according to the modified Fisher scale and all patients had daily transcranial doppler (TCD) recordings of their basal cerebral arteries. In 19% of SAH was grade I on CT, in 44% grade II and in 37% grade III. The rate of patients who developed severe vasospasm as documented by TCD (mean blood flow velocities exceeding 160 cm/s on 2 or more consecutive days) was 39% for grade I patients, 26% for grade II patients and 34% for patients with SAH grade III on the initial CT. There was no difference in the rate of occurrence of severe vasospasm, when the patients were split into 2 groups according to the time of performance of the initial CT scan-within 24 hours, and 48-80 hours after SAH, respectively. It is concluded that the amount of subarachnoid blood on the initial CT scan should no longer be used as the indicator for occurrence and severity of the multifactorial entity vasospasm.

Adult↗
PubMed1995

Stereotactic puncture and lysis of spontaneous intracerebral hemorrhage using recombinant tissue-plasminogen activator.

We have tested a treatment protocol for intracerebral hemorrhage (ICH), consisting of stereotactic insertion of a catheter into the clot, hematoma lysis by the injection of a fibrinolytic agent, recombinant tissue-plasminogen activator (rt-PA), and closed system drainage of the liquefied clot. Fourteen patients underwent computed tomographically guided stereotactic hematoma puncture and silicone tube insertion within 72 hours of intracerebral hemorrhage. The majority (nine patients) suffered from ganglionic ICH, and the size of the hematoma ranged between 3 x 3 x 4 cm and 7 x 7 x 4 cm (mean, 5.2 x 4 x 3.6 cm). All patients had major neurological deficits with or without an impaired level of consciousness, but without signs of transtentorial herniation. The initial, then daily, dose (in milligrams) of rt-PA administered via the silicone tube equalled the maximal diameter (in centimeters) of the original and remaining clot as measured initially, then daily, by computed tomographic scan. The number of rt-PA injections was four in one patient, three in eight patients, two in four patients, and one in one patient, and the total dose of rt-PA required ranged from 5 to 16 mg (mean, 9.9 mg). After rt-PA injection, the tubing was clamped for 2 hours and then opened to drain spontaneously through a closed system against 0 cm of pressure. At follow-up 6.6 months (mean) after treatment (ranging from 3 to 13 months) and according to the Glasgow outcome score, one patient was Grade V, four were Grade IV, five were Grade III, two were Grade II, and two had died.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Local thrombolytic treatment of spontaneous intracerebral hemorrhage with plasminogen activator (rt-PA). Indications and limits].

Twenty patients underwent a regimen of stereotactic puncture and consecutive local lysis with recombinant tissue plasminogen activator (rt-PA) for their spontaneous intracerebral hemorrhage (ICH). Rt-PA was administered via a stereotactically placed silicone catheter according to a hematoma-size-related formula. There was no extensive intraoperative hematoma aspiration so that the capacity of rt-PA for blood-clot lysis could be investigated. Fifteen patients were somnolent/stuporous on admission and 5 comatose, the hematoma-size ranging from 3 x 3 x 4 cm up to 7 x 4 x 4 cm (mean: 5.1 x 3.9 x 3.5 cm). Control computed tomography (CT) was performed on a daily basis, and in 19 patients the hematoma showed complete or almost complete resolution on CT within 4 days. The rt-PA dosage necessary ranged from 5 to 14 (mean: 8.5) mg. Rt-PA application was performed once in 1 patients, twice in 7, three times in 11 and four times in 1 patient. On follow-up after a mean of 7.2 months 3 patients had died (Glasgow Outcome Score--GOS I). Another was GOS II, 10 GOS III, 5 GOS IV and 1 had made an excellent recovery (GOS V). Patients who were somnolent or stuporous on admission or who exhibited secondary deterioration of their level of consciousness benefitted from the treatment protocol. Early postoperative mobilization and thereby reduction of secondary complications during the patient's stay in the intensive care unit appear to be possible. Comatose patients did not benefit from this treatment and those should be treated conservatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Flow velocity and pressure measurements in spinal dural arteriovenous fistulas.

During ten operations for spinal dural arterio-venous fistulas (AVF), intraoperative measurement of flow velocity and intravascular pressure was performed. Flow velocities were recorded using a miniaturized Doppler probe. Intravascular pressure changes in the draining veins before and after AVF removal was measured with small needles. Varying the pCO2 between 20 mm Hg and 60 mm Hg, the flow velocities in arteries supplying the spinal cord were investigated so that the vasomotoric reactivity of the peripheral vessel wall in cord tissue was investigated before and after AVF occlusion. The flow velocities in dural AVF feeders were not as high as those known from cerebral angioma feeders. In addition, they often showed lowered end-diastolic flow velocity as a sign of increased vascular resistance, thus proving impaired venous outflow from the spinal canal. After excision of the local fistula, the vessels supplying and draining the spinal cord showed improved circulation. In the former recipient veins, no further flow could be recorded. The venous pressure in dural AVF was about 70% of the systemic arterial pressure. Fistulas presenting a high shunt volume on angiography showed only moderately increased venous pressure and a more pronounced pressure drop after fistula occlusion as compared with low-volume fistulas. The CO2 reactivity of vessels supplying the spinal cord was normal before and after AFV removal.

Aged↗
PubMed1994

Percutaneous needle trephination. Experience in 200 cases.

For many years percutaneous needle and classic burr-hole trephination with insertion of plastic catheters for external ventricular drainage are in use. The shortcomings of the conventional puncture needles were compensated for by the development of a modified instrument in recent years. In this prospective study we tried to define advantages and disadvantages of percutaneous ventriculostomy with this modified needle in a large number of patients. We treated and followed a total number of 200 patients with external ventricular drainage for various reasons (42% obstructive hydrocephalus, 27% haematocephalus, 11% malresorptive hydrocephalus, 11% elevated ICP and 9% infections). The ventriculostomy is performed--after percutaneous trephination with a 1.5 mm drill and 1.2 mm needle under local anaesthesia as a bedside procedure. The modified blunt needle is provided with markings and a set screw which allows insertion to a prefixed depth and a sharp guide which is withdrawn after penetration of the dura. It is then bent rostrally and fixed by a plaster cast. The mean duration of drainage was 9 days (1-30 days). Mean operating time for the whole procedure including fixation and connection to the drainage system was 20 minutes. Overall complication rate was 13% (N = 26). Two intracerebral haemorrhages (1%) occurred, of which one was caused by overdrainage. Five (3%) infections in primarily not infectious cases (N = 182) were seen. Only one case of infection occurred without loosening of the needle on day 17. In 19 patients (10%) the needles had loosened. Fifteen times this complication was repaired in time and no infection occurred.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

The extreme lateral transcondylar approach to aneurysms of the vertebrobasilar junction, the vertebral artery, and the posterior inferior cerebellar artery.

The unilateral suboccipital craniotomy is the commonly performed approach to aneurysms of the vertebrobasilar junction, the vertebral artery, and the posterior inferior cerebellar artery (PICA). Many of these aneurysms are placed anterior or anterolateral to the brain stem, necessitating brain stem retraction for adequate exposure. Small dorsolateral enlargement of the foramen magnum, partial resection of the occipital condyle, and removal of the jugular tubercle allow access to the neurovascular structures ventral to the medulla without retraction of the neuroaxis. This extreme lateral transcondylar approach was performed in 20 patients with aneurysms of the vertebrobasilar junction, the vertebral artery, and the PICA; intraoperatively, two suspected aneurysms proved to be vascular malformations. Occlusion of the aneurysm and vascular malformation was successfully performed in 16 patients, resection of the vascular malformation was achieved in 1 patient, and the vertebral artery was clipped in 3 patients with fusiform aneurysms without complications related to the extreme lateral transcondylar approach. Unobstructed exposure of the aneurysm, parent artery, and neural structures without retraction of the sensitive lower brain stem are the major advantages of the extreme lateral transcondylar approach.

Journal Article↗