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.

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.

The use of laser in neurosurgery.

In the neurosurgical practice the laser can be considered an additional instrument to improve the conventional techniques, or even a new method of treatment of some cerebral lesions. The laser surgery requires the association of three laser sources in combination. The CO2 offers the possibility of a precise cutting and of shrinking by vaporization which makes the removal of the lesion more complete without touching the surrounding 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 coagulation. The laser is very useful in high risk cases and in combination with the operating microscope in a restricted field near the critical areas of the brain and in the spinal cord. The association Argon-Nd: YAG is a new method for coagulation. In all cases of AAV malformation a complete exclusion was obtained and in 2 cases out of 7 reduced damage were registered. In saccular aneurysm in no case additional damage was registered, reduced damage was noticed in 2 out of 5 cases.

Ultrasonic aspiration in the surgical treatment of intracranial tumors.

The CUSATM (Cavitron Corporation - Stamford, Conn., USA) has been used for aspiration and ultrasonic fragmentation in 52 cases of intracranial tumors: 24 meningiomas, 20 gliomas, 5 acoustic neurinomas, 1 cerebral metastasis, 1 pinealoma, 1 pituitary adenoma in our Clinic, since January 1979. Several advantages of the CUSA were found as compared to conventional techniques: it provides good visibility of the operating field: pathologic tissue can be removed from the surface to the deep structures and only one instrument is present in the surgical cavity; its use reduces manipulation, traction and thermic effects on nearby tissue; it selectively spares major vessels and has a hemostatic effect on those less than 1 mm in diameter. The rapidity of the action of the CUSA is relative to the consistency of the tissue. Tumors of high consistency are very slowly removed by the CUSA, and its use is not worthwhile. In our cases no damage to the surrounding structures was evident. Preliminary experimental data suggest that the use of the CUSA be avoided near the brain stem or within the spinal cord. However, in a cervical ependymoma of our series, the CUSA provided complete removal of the mass without complications. This result was achieved by using lower vibratory power: we were thus able to remove pathologic soft tissue without clinically evident damage to the surrounding structures. In some particular situations the volume and the shape of the instrument can be a hindrance, and some modifications are suggested: a bayonet shape and longer tip would facilitate the reaching of deep structures and permit its use in transphenoidal surgery; incorporation of a cautery in the tip, so that contemporary hemostasis can be accomplished. Our experience indicates that the use in transphenoidal surgery; incorporation of a cautery in the tip, so that contemporary hemostasis can be accomplished. Our experience indicates that the use of the CUSA is better indicated in deep tumors: meningiomas of the base of the skull, acoustic neurinomas, pinealomas, pituitary adenomas. In gliomas it is very useful in the selective removal of the neoplastic tissue in functionally important areas.

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.

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.

[Diagnostic and therapeutic studies using the cryoprobe in various forms of facial pain, not of the migraine or trigeminal type]. / Ricerche diagnostiche e trattamento mediante criosonda di alcune forme di dolore facciale, non di tipo emicranico nè trigeminale

The application of cold in neurosurgery (cryosurgery) has already clearly shown that it acts on the nervous structures in two opposite directions, depending on the temperature: i.e., at temperature from 0 degrees to --10 degrees, it stimulates the nervous fibres, and, at lower temperatures (below--80 degrees), it causes their destruction. On these bases we started our diagnostic researches and the treatment of certain forms of non-migraine nor trigeminal facial pain.

[Functional posterior radiculotomy, in the treatment of cerebral spasticity. peroperative electric stimulation of posterior roots and its use in the choice of the roots to be sectioned]. / La radicotomie postérieure fonctionnelle dans le traitement de la spasticité cérébrale Premieres observations sur la stimulation électrique peropératoire des racines postérieures, et leur utilisation dans le choix des racines ã sectionner

The authors present a modification of Foerster's Rhizotomy for the treatment of spasticity in cerebral palsy: functional posterior rhizotomy. The selection of the roots/rootlesses to be sectioned, is accomplished on functional data, based upon the analysis of the reflex responses to the intraoperative lumbar dorsal roots stimulation. With this method it is possible to selectively interfere with the pathological circuits responsible for hypertonia, saving proprioceptive afferences necessary for motor reeducation. The clinical results on hypertonia are the same as for total or partial rhizotomies, but sides effects (ataxia, hypotonia) are considerably reduced.