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Biomedical subjects

M Samii

Publications and source records attributed to M Samii.

At least 37 records · Page 2Linked to original sources
PubMed1989

Surgical treatment of myeloradiculopathy in cervical spondylosis. A report on 438 operations.

In the past eleven years we have performed 438 microsurgical ventral discectomies with bilateral foraminotomy followed by fusion with palacos in the cervical spine in our clinic. An analysis of the preoperative symptoms shows a great variability and overlapping of the various segments. To determine the right level for the operation it is crucial that the results of the clinical and the radiological examinations be evaluated. The results of ascending myelography and CT scans are of great value. In cases of cervical myelopathy a multisegmental operation is often necessary to obtain good results. The complication rate was small in our patients and a second operation was only necessary in a few cases. We had very good postoperative results in radicular pain and muscle weakness. In patients with symptoms of cervical myelopathy we achieved considerable improvement.

Cervical Vertebrae↗
PubMed1989

Chronic epidural hematoma--report on eight cases and review of the literature.

The authors report eight cases of chronic epidural hematoma, classified according to macroscopical operative findings and histological studies of the hematomas. Clinical, radiological, and pathological findings are described. A review of 63 cases of the literature is presented, and the accepted concepts for classification and management of these lesions are discussed.

Adolescent↗
PubMed1989

Surgery of petroclival meningiomas: report of 24 cases.

Twenty-four patients with petroclival meningiomas were operated upon at the neurosurgical clinic of the City Hospital of Hannover between 1978 and 1987. Seventeen were women and seven men; the mean age was 45 years. Symptoms were usually present for more than 2 years before the diagnosis was made. The most common symptom was disturbance of gait; the most common preoperative sign was cranial nerve deficit, mainly of the 7th and 8th nerves. Preoperative neuroradiological evaluation included computed tomography and four-vessel cerebral angiography. Fifteen patients (62%) had a tumor larger than 2.5 cm in its major diameter. The surgical approaches used were the retromastoid, pterional, subtemporal, and combined retromastoid-subtemporal. We developed a modification of the retromastoid-subtemporal approach with preservation of the transverse sinus and used this in the last 2 patients. There was no postoperative death; 11 patients (46%) suffered postoperative complications, mainly in the form of cranial nerve deficits, often reversible. "Total" tumor removal was achieved in 17 patients (71%). Twenty patients (83%) were independent at the time of discharge from the hospital. With accurate neuroradiological evaluation, careful choice of the surgical approach, and sound application of microsurgical techniques, petroclival meningiomas may be "totally" and safely resected in a significant number of patients.

Adult↗
PubMed1989

[Surgical treatment of malignant tumors of the paranasal sinuses with involvement of the base of the skull].

After 18 years of close cooperation between ORL and neurosurgery in the treatment of the base of the skull, the authors present their surgical conception and technique for the treatment of malignant tumors of the paranasal sinuses involving the base of the skull. Three basically different surgical procedures are possible: 1. Extracranial partial resection of the anterior base of the skull sparing the contents of the orbit. 2. Radical revision of superior maxilla, ethmoid bone, and base of the skull including exenteratio orbitae. 3. Combined intra-extracranial approach. An interdisciplinary cooperation and the combination of macro- and microsurgery will be more successful with respect to survival chances, functional and esthetic results.

Adenocarcinoma↗
PubMed1988

The combined supra-infratentorial pre-sigmoid sinus avenue to the petro-clival region. Surgical technique and clinical applications.

Nine patients with tumours located at the petro-clival region were operated upon from June 1985 to June 1988 using a combined supra- and infratentorial approach anterior to the sigmoid sinus. Two patients had petroclival meningiomas. 4 foramen jugulare neurinomas and 3 glomus jugulare tumours. There was no mortality. Total tumour removal was accomplished in all the patients. All patients remained independent postoperatively. The surgical approach used involves a temporal craniotomy, a suboccipital craniectomy, an extensive mastoidectomy and petrous pyramid drilling without entering the bony labyrinth, the middle ear or the Fallopian canal. The dura is incised supratentorially over the posterior temporal lobe and infratentorially in front of the sigmoid sinus. The temporal lobe is retracted superiorly and the cerebellum and the sigmoid sinus medially. This approach makes use of a very short distance to the petroclival area, offers a multiangled exposure, preserves the dural sinuses, does not iatrogenically impair hearing and minimizes temporal lobe retraction. This exposure is particularly useful in large tumours.

Adult↗
PubMed1988

Improvement of global cerebral blood flow after STA-MCA bypass in a patient with bilateral occlusion of the internal carotid artery: effect of surgery or natural course?

A xenon-CT examination was performed on a patient who had received a STA-MCA bypass. Evaluation of cerebral blood flow (CBF) pre- and postoperatively shows a post-operative increase of about 60%. During manual compression of STA, a decrease of 20% was observed so that one third of the total CBF increase could be attributed to anastomosis. The remaining two thirds may originate from the natural collateral circulation.

Arterial Occlusive Diseases↗
PubMed1988

Revascularization of nerve grafts: an experimental study.

The time course of revascularization of grafted nerves, and the possible dependence of this revascularization on the length of the graft are two related questions that are addressed. Survival of Schwann cells in the nerve graft and a timely revascularization must be seen as a precondition for an optimal regeneration process. The revascularization process after different postoperative intervals is demonstrated in the sciatic nerve of rabbits by the use of microangiography, with Roentgen-positive water-soluble contrast medium. The third postoperative day is the earliest point in time for revascularization of the autologous graft from surrounding tissues. On the fourth postoperative day, a hyperemia with extension to all sides of the intraneural vessel system exists that still persists on the fifth and sixth days. In one experimental group, revascularization was allowed to occur only in a longitudinal direction. Revascularization under these conditions proved to be poor, slow, and obviously dependent on the length of the graft. Survival and subsequent function of free autologous nerve grafts may depend on the diameter of the grafts and the quality of the recipient site, but not on the length of the grafts, when timely revascularization from the surrounding tissues is present.

Animals↗
PubMed1988

Bone imaging as an aid for the diagnosis of osteopoikilosis.

An unusual case of osteopoikilosis was found in a 52-year-old black woman. The rather large diffuse focal increased densities involving the ribs, spine, and pelvis as seen in the roentgenograms were believed to represent metastatic bone lesions. The normal nuclide bone images helped revise the diagnosis to osteopoikilosis. Early recognition of osteopoikilosis would have prevented the patient's apprehension and the extensive work-up for the primary tumor.

Bone Neoplasms↗
PubMed1987

Stable-xenon-CT: effects of xenon inhalation on EEG and cardio-respiratory parameters in the human.

The effects of inhalation of a 33% Xenon-O2 mixture over a period of 5 minutes on EEG and cardio-respiratory parameters were studied in 18 human volunteers. This dosage is similar to that used clinically in Xenon-CT studies. In 4 cases no EEG power change was observed during the study. In the 14 other subjects EEG variations were seen. The most prominent change was an increase in beta EEG power. No change was observed in theta and delta EEG power. The findings seem to correlate with the early induction (excitation) phase of an anaesthetic. Hyperventilation was observed before the study and increased during the Xenon inhalation. Blood pressure remained stable while the heart rate tended to decrease a little. All these changes disappeared rapidly following the termination of the Xenon inhalation. The effects are minimal and should not reduce the clinical value of CBF measurement using the Xenon-CT method.

Administration, Inhalation↗
PubMed1987

EEG changes during five minutes of inhalation of a 33% xenon-O2 mixture.

The effects on the EEG of inhalation of a 33% Xenon O2 mixture over a period of 5 minutes were studied in 18 human volunteers. This dosage is similar to that used in xenon CT studies. In 4 subjects no EEG changes were observed during the study. In the 14 other subjects, EEG variations were detected, the most prominent of which was an increase in beta power. No change was observed in theta and delta power. These findings seem to support an early induction (excitation) phase of anaesthetics. All changes disappeared rapidly following the termination of xenon inhalation. The effects reported are minimal and should not impair the clinical value of CBF measurements using the xenon CT method.

Administration, Inhalation↗
PubMed1986

[Experience with the inhalation of a 33% xenon-(stable-)oxygen mixture in relation to a new method of measuring local cerebral circulation].

We describe a new non-invasive method for measuring local blood flow in the brain. Xenon (stable)-nl CBF-CT-method has been used in our clinic for the first time in Europe. It is superior to all other methods, such as 133Xenon, SPECT and PET in terms of anatomical accuracy and its resolution. We describe the method and its side effects. Inhalation of Xenon in sub-narcotic doses (33% for five minutes) produced no significant complications. Of 95 examinations, 74 were free of any incidents. The most common side effect was euphoria. The method appears to be suitable for general clinical use.

Cerebrovascular Circulation↗
PubMed1985

Possibility of the excision of aneurysms in the vertebrobasilar system followed by end-to-end anastomosis for the maintenance of circulation.

Microsurgical techniques have revolutionized the perspectives of neurosurgery. Vascular neurosurgery in particular has only shown real progress since the evolution of such techniques. The management of large fusiform aneurysms had always been more problematic than that of the usual aneurysms. Clipping was either insufficient to occlude the whole neck or too extensive to include a significant part of the parent vessel and its important branches. Several alternative methods were therefore developed to redress the problem and included proximal occlusion, coating and wrapping, induction of intralaminal thrombosis with a variety of substances, and balloon catheter occlusions; however, they have all proved to have limited success. Aneurysmorrhaphy (excision of the aneurysm and reconstruction of the vessel wall) has also been described. In 1978 Dolenc reported excision of a fusiform aneurysm along with the adjacent vessel wall and an end-to-end anastomosis, either directly or by interposing a short arterial graft, in two cases of peripheral middle cerebral aneurysms, and in one aneurysm arising from PICA. This communication deals with two cases of large fusiform aneurysms of the vertebrobasillar territory, one from PICA and another from P2P3 Segment of the posterior cerebral arteries. These aneurysms were excised and the parent vessel reanastomosed to restore its continuity as seen at surgery and on postoperative angiography. The results have been favourable. The technique is recommended for the elimination of a large fusiform aneurysm that cannot be safely or successfully clipped, provided the parent vessel is lax or mobile enough to permit direct reanastomosis despite the slight shortening of vessel length.

Adult↗
PubMed1979

[Neurosurgical aspects of the treatment of acoustic neurinoma with special consideration of the facial nerve (author's transl)].

The decisive progress in the field of surgical treatment of acoustic neurinomas has occured after the introduction of the operating microscope. This is a survey of the microsurgical treatment of cerebellopontine angle tumors with special emphasis of the facial nerve and demonstration of individual cases. Moreover, the technique of the dissection and preservation of the continuity of the facial nerve during removal of a tumor is analysed. The possibilities of reconstructive surgery of an end-to-end suture or nerve graft in case of facial nerve lesions after removal of a tumor are discussed.

Cranial Nerve Neoplasms↗
PubMed1978

[Indication and treatment of frontobasal rhinoliquorrhoea from the ent-surgical and neurosurgical point of view (author's transl)].

This paper deals with some special questions based on joint neuro-rhinosurgical diagnostic and treatment of frontobasal injuries with rhinoliquorrhoea. The indications of the rhinosurgical transfronto-orbital approach with debridement of paranasal sinuses in the same stage are defined. Detailed technical instructions are given for treatment of "midline fractures". The transfrontal intradural approach of the neurosurgeon should be prefered: 1. If there is rhinoliquorrhoea combined with an extensive fracture of anterior skull base. 2. In cases of frontobasal liquor fistual--no matter of localisation and extension--with increasing spaceoccupation should the intracranial decompression be combined with duraplasty. Cerebral lesions with no progressive intracranial pressure should be treated first of all conservatively. The operative treatment of paranasal sinuses is not necessary in every case after transfrontal intradural surgery. X-ray controls have shown the spontaneous healing.

Cerebrospinal Fluid Rhinorrhea↗