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Biomedical subjects

V A Fasano

Publications and source records attributed to V A Fasano.

At least 19 recordsLinked to original sources
PubMed1992

[Postoperative complications in neurosurgery].

Hemorrhage, ischemia and ischemic edema are among the complications which may occur following neurosurgery and they represent the most frequent cause of neurological deterioration. The mechanisms predisposing vascular complications (hemorrhage, ischemia) are described and discussed in relation to systemic alterations associated with surgery and anesthesia. In addition, the physiopathology of these complications is discussed in the various pathologies: cancer, vascular malformations, trauma and the intra-operative diagnostic possibilities which prevent their onset.

Brain↗
PubMed1989

[Surgical indications for the treatment of cervico-spinal cord injuries].

The surgical treatment of cervico-medullary traumas is indicated, in unstable lesions, in large lesions of the mobile rachidic segment in the presence of neurological complications or following worsening of prior neurological symptomatology. The purpose of the operation is at least three-fold: to obtain alignment of vertebral structures and decompression of the bone marrow due to bone or disc compression, stabilise the vertebral segment involved, attain early mobilisation of the patient. The conventional radiological examinations allows to detect osteous and artro-ligamentous lesions. The Computed Tomography shows the consequences of the lesions on the roots and the spinal cord. The Nuclear Magnetic Resonance directly shows the oedema, the haemorrhages, the compression and the section of the spinal cord. It gives useful indications for the surgical treatment of the spinal lesions. An immediate and careful assistance at the seat of the accident, during the transport and during the diagnostic steps is essential to avoid the worsening of the primitive spinal cord lesions.

Cervical Vertebrae↗
PubMed1988

Intraoperative use of laser Doppler in the study of cerebral microvascular circulation.

Laser Doppler (LD) flowmetry has been used for evaluation of microcirculatory flow in a variety of human tissues, including skin, muscle, retina and recently the brain. In the present paper, intraoperative Laser Doppler recordings have been performed in 72 cases, in basal conditions and after stimulation. The morphology of basal recordings obtained from normal cortical areas were analyzed and three different rhythmical variations were identified; these rhythmical variations are described and explained. Several kinds of stimulation have been used: hypotensive drugs, mannitol, nimodipine, eupaverine, hypercapnia, decompressive manoeuvres and temporary occlusion of the ICA in the neck. Laser Doppler recordings obtained during and after these stimulations are reported and explained. The results have been evaluated in order to verify the reliability and the reproducibility of this technique in the study of the cerebral microvascular circulation intraoperatively.

Adult↗
PubMed1988

Intraoperative electrical stimulation for functional posterior rhizotomy.

Intraoperative electrical stimulation of dorsal spinal roots from L1 to S1 bilaterally was performed in 80 patients affected by cerebral palsy, in whom spasticity was the main symptom. Clinical examination and EMG recordings showed three main features of reflex responses. We know that they indicate respectively a normal presence, a defect or an excess of inhibitory activity within the spinal circuits examined. Only those roots or rootlets involved in circuits where normal inhibitory processes are reduced or absent are surgically sectioned. Therefore these circuits are interrupted. The theoretical bases and long-term results indicate that this method is a useful and correct approach to the neurosurgical therapy of spasticity. It allows us to utilize a new important criterion to identify the roots or rootlets to be sectioned, based not on the anatomic, but on the functional selection.

Cerebral Palsy↗
PubMed1987

Cryoanalgesia. Ultrastructural study on cryolytic lesion of sciatic nerve in rat and rabbit.

The sciatic nerve was exposed to cryoinjury at different freezing patterns in albino rats and rabbits and the frozen nerves were serially examined with electron microscopy from the time of cryolitic lesion (--60 degrees C for 3 minutes) for up to 28 days. The cryolesion was characterized by a total degeneration of the myelin fibers, while non-myelin fibers and vessels seemed less affected. Regeneration began 8 days after cryolysis. A peculiar pattern was the absence of Schwann cells, while the basal membrane around regenerating axons remained intact. The hypothesis that the basal membrane might play a role is discussed.

Animals↗
PubMed1986

Effects at the periphery of the laser lesion in human brain and its tumors after CO2, Nd:YAG, and CO2 high-peak pulsed radiation.

The histological changes in various tissues irradiated with lasers are well known. Our own previous observations with the optical microscope confirm those already reported in the laser literature. If tissue is treated with various laser sources, the results are similar, with the characteristic three layers from the outside toward the inside of carbonization, coagulative necrosis, and edema. Otherwise, only the shapes and sizes of the lesions differ, with craters of different depths. In this paper, we report an ultrastructural study of the changes occurring in the periphery of the laser lesions in both normal human brain and neoplastic tissues (gliomas and meningiomas). Continuous-wave CO2 and Nd:YAG lasers were used at different exposure times and powers and the effects of high-peak pulsed CO2 laser radiation has also been investigated. The study, performed during neurosurgical procedures was mostly focused on microcirculation at 1.5-3 mm outside the area of coagulative necrosis, at the level of the edema zone. Only lesions of the blood brain barrier are produced in normal brain by CO2 radiation (power ranging from 40 to 80 W; exposure time from 3 to 10 seconds). The same results were achieved by Nd:YAG radiation of short duration (3 seconds) regardless of the power used (40 and 80 W). Long-duration Nd:YAG radiation (10 sec; power: 40-80 W) produces endoluminal phenomena leading to the complete occlusion of the capillaries. In neoplastic brain tissues, microcirculation does not seem to be impaired by CO2 radiation. More marked lesions are produced in tumors even after Nd:YAG short-time radiation. Endoluminal obliteration is observed in meningiomas and perivascular hemorrhage occurs in highly vascularized gliomas. According to these results, the risk of delayed post-operative hemorrhages, noticed in some patients with glioblastoma operated on by Nd:YAG lasers, suggests that residual tumor in the cavity should be treated by CO2 laser because of its minimal damage of microcirculation.

Astrocytoma↗
PubMed1986

The effects of new technologies on the surgical management of brainstem tumors.

Nuclear magnetic resonance, real-time and A-scan ultrasonography, and computerized CO2 lasers were recently introduced for diagnosis and surgical treatment of brainstem tumors. These new technologies offer many advantages: safe but aggressive surgery on the brainstem, the possibility of performing a correct histologic diagnosis, and an exact indication for radiotherapy. Eleven tumors were operated on in our series: seven were intrinsic and four protruded out from the axis. Patients with high-grade malignant tumors died from 5 to 12 months after treatment, whereas those with pilocytic astrocytoma are still alive and leading useful lives.

Adult↗
PubMed1984

Treatment of cerebral arterio-venous malformations with laser.

The surgical application of the laser in the treatment of vascular diseases of the brain is based on its characteristic to perform an immediate or delayed modification of the vessel wall either by shrinking the collagenous fibres or by intraluminal thrombosis. Personal researches have been carried out to study the histological modifications of the vessel wall in normal arteries following laser irradiation with Nd:YAG. On this basis we have treated arterio-venous malformations (AVMs) in man. The laser enables radical surgery with a complete preservation of the healthy tissue surrounding the lesion because of reduced manipulation and the absence of intraoperative haemorrhage. Doppler technique and real-time ultrasonography are mostly suitable in the identification of the small deep-seated AVMs localizing the site of the malformation and the reactive glial tissue surrounding the lesion. The main indications are small AVMs located in critical areas of the brain.

Adult↗
PubMed1983

Observations on the use of three laser sources in sequence (CO2-Argon-Nd: YAG) in neurosurgery.

In neurosurgical practice the laser can be considered an additional instrument to improve conventional techniques, or even a new method of treatment of some cerebral lesions. A complete laser surgery requires the association of three laser sources in combination. The CO2 laser is useful for cutting small lesions in important brain areas. Nd: YAG is particularly suitable for tumor surgery--allowing a deeper destruction with predictable effects associated with a more complete hemostasis. The combination Nd: YAG-Argon has clear indications for irradiation of the vessels.

Argon↗
PubMed1983

Effects of laser sources (argon, Nd:YAG, CO2) on the elastic resistance of the vessel wall: histological and physical study.

The function of elastic elements of the vessel wall is to produce a tension suitable to resist the distension strength made by blood pressure. By producing a modification in the morphologic and structural configuration of such elastic elements, it is possible to obtain changes of the elastic resistance of the wall. The paper reports the histological and physical modifications of blood vessel walls irradiated with different laser sources.

Animals↗
PubMed1983

Preliminary experiences with "real-time" intraoperative ultrasonography associated to the laser and the ultrasonic aspirator in neurosurgery.

Twelve cerebral lesions were operated upon with various laser sources (carbon dioxide, neodymium-yttrium-argon-garnet, and argon) and with an ultrasonic aspirator utilizing the intraoperative "real-time" ultrasonography. With the last method, the tumor was imaged just as well through the intact dura mater as on the brain surface itself, allowing a precise localization of deep intracranial lesions. A sharp selectivity on the healthy tissues is, in this way, achievable to reach the tumor, which is successively removed with the laser and ultrasonic aspirator checking the surgical maneuvers on the visual control of the ultrasonograph.

Adult↗
PubMed1983

Preliminary experiences with the use of three lasers (CO2, Nd: YAG, Argon) in some posterior fossa tumors in childhood.

The authors present 5 cases of posterior fossa tumors in childhood operated on using three laser sources: CO2, Nd: YAG and Argon. Each laser source is used as required during the different steps of the operation: CO2 for cutting and vaporizing, Nd: YAG for shrinking the tumoral mass and deep coagulation and Argon for selective cutting and superficial coagulation of small vessels. The main advantages of multiple laser surgery are: (1) a more radical surgery with less side effects (edema); (2) the possibility of operating near high functional structures with great accuracy, and (3) reduction of blood loss.

Adolescent↗
PubMed1982

[Headache].

Explore the source record for details and available documents.

Brain↗
PubMed1982

Observations on the simultaneous use of CO2 and Nd:YAG lasers in neurosurgery.

Seven cases of cerebral tumors (four deep-seated sovratentorial gliomas located in motor area, occipital region, parietal region and frontal region; one deep-seated cystic cerebellar spongioblastoma; one sphenoidal wing meningioma, and one spinal cord intradural tumor) were simultaneously irradiated in the same area with two sources (CO2 and Nd:YAG). Using CO2 and Nd:YAG simultaneously, a larger and deeper lesion was obtained. The main bulk was irradiated with two sources free hand. The implant with the two sources was connected to the operating microscope. The rise in temperature, 3 mm from the border of the lesion, was similar to that obtained with Nd:YAG alone. Hemostasis was not impaired. In comparison with the single sources, this method allows a more rapid demolition of the tumor without additional damage to the surrounding tissues.

Adult↗
PubMed1982

Photocoagulation of cerebral arteriovenous malformations and arterial aneurysms with the neodymium: yttrium-aluminum-garnet or argon laser: preliminary results in twelve patients.

Six arteriovenous malformations (AVMs) and five arterial aneurysms (AAs) were treated with either argon or neodymium:yttrium-aluminum-garnet laser irradiation; one AVM was treated with both. All AVMs were occluded completely, leaving adjacent tissue untouched and preserving the regional vascularization. Photocoagulation produced varying effects on AAs: in one case an intraoperative rupture was sealed, in two cases the volume of an ectasia was reduced when the bleeding and thinner areas were coagulated, and in one case a saccular aneurysm was progressively and completely obliterated while the patency of the parent artery was preserved. These preliminary results are satisfactory; more experience will indicate how and when these new techniques can replace traditional ones or be used in combination with them.

Adolescent↗