Transparent optical neurosurgical instruments

1984 ◽  
Vol 60 (1) ◽  
pp. 208-210 ◽  
Author(s):  
Walter J. Levy

✓ Neurosurgical instrumentation over the last two decades has improved with the increasing use of the operating microscope and has provided much better visualization and lighting of the surgical field. During this time, dissecting instruments have become smaller, but they sacrifice some of the microscopic gains because they are made of opaque metal. This has the disadvantage of hiding from the surgeon the area of the surgical field being worked on. This paper reports the development of transparent instruments that are strong enough to be used in dissection and yet do not sacrifice part of the improved visualization and lighting gained with the operating microscope. Made of a high-strength plastic, these instruments can be used for dissection in surgical procedures and allow the surgeon to look through them and observe the tissues underneath. He can watch the condition of blood vessels and nervous tissues with an improved visibility that can help to avoid damage to delicate structures. Furthermore, as hidden structures such as small vessels come into view they are identified earlier. These instruments can also incorporate jeweled cutting edges and use their optical properties to improve further visualization of the surgical field.

1985 ◽  
Vol 62 (4) ◽  
pp. 610-611 ◽  
Author(s):  
Kenichiro Sugita ◽  
Yohji Ohohigashi ◽  
Shigeaki Kobayashi

✓ A new and simple method of stereoscopic television imaging of surgical procedures performed under an operating microscope has been developed. Two television cameras of the same type, two television monitors of the same size, and a mirror box for fusion of the two visual objects on the two television monitors are used. No significant modifications of available components are necessary. The method can be applied to all operating microscopes with a beam splitter.


1984 ◽  
Vol 60 (2) ◽  
pp. 287-295 ◽  
Author(s):  
Peter C. Haines ◽  
R. M. Peardon Donaghy

✓ Poor patency results in the surgery of small vessels operated on between 1959 to 1964 was demonstrated to be in part due to the long period of occlusion of the operated vessel during surgery and the presence of a foreign body (suture) in the lumen of the vessel postoperatively. New suture techniques and T-tube bypass were introduced at that time. New experimental data have not been extensively sought since that time. To provide further current data regarding the above observations, 110 arterial vessels (60 carotid arteries 1.1 to 1.3 mm in outside diameter (OD) and 50 femoral arteries 0.6 to 0.7 mm OD) were operated on in rats to compare the bypass versus non-bypass and vein patch closure techniques. In 1-mm vessels, patency rates 1 month after surgery were 100% regardless of the use of bypass or type of closure. Improved visualization, better suture material, and improved surgical skill were probably chiefly responsible for this success. The success rate was not as encouraging, however, in vessels of 0.6 mm OD. The following points are brought out: 1) The presence of the bypass causes damage to the intima in 0.6 mm OD vessels and should not be used. Smaller bypasses do not conduct blood well. 2) Bypass is not required in 1-mm vessels as the patency rate is satisfactory and not altered by its use. 3) The major indication for T-tube bypass is in vessels of 1 mm OD and larger, that nourish tissue which would be damaged by vascular occlusion for 20 to 40 minutes. 4) Foreign body (suture) in the lumen is poorly tolerated in 0.6 mm vessels, but can be tolerated more easily in larger vessels. 5) Techniques that limit the amount of suture material in the lumen are indicated in 0.6-mm vessels. 6) After 1 month, suture material has an epithelial covering and if patency has been maintained for that period of time it is likely to remain.


1976 ◽  
Vol 44 (5) ◽  
pp. 642-643 ◽  
Author(s):  
Eugene H. Holly

✓ An inexpensive mouth guide is described, which increases the mobility of the operating microscope and effectively shortens operating time.


1977 ◽  
Vol 46 (5) ◽  
pp. 596-600 ◽  
Author(s):  
Ivan Ciric

✓ Observations under the operating microscope confirming the presence of a pituitary capsule are reported. This capsule envelops the anterior lobe of the pituitary, the neurohypophysis, and the pituitary stalk. It merges along the stalk with the intracranial pia mater. The origin and nature of this capsule are discussed in light of the known facts of development of the pituitary gland and surrounding structures. It is concluded that the pituitary gland capsule is a derivative of the primitive pia mater.


2000 ◽  
Vol 92 (6) ◽  
pp. 1053-1055 ◽  
Author(s):  
Tetsuhiro Nishihara ◽  
Akira Teraoka ◽  
Akio Morita ◽  
Keisuke Ueki ◽  
Keisuke Takai ◽  
...  

✓ The authors advocate the use of a transparent sheath for guiding an endoscope, a simple and unique tool for endoscopic surgery, and describe preliminary results of its application in the evacuation of hypertensive intracerebral hematomas. This sheath is a 10-cm-long tube made of clear acrylic plastic, which greatly improves visualization of the surgical field through a 2.7-mm nonangled endoscope inserted within. Between April 1997 and December 1998, the authors performed endoscopic evacuation of intracerebral hematomas by using this sheath inserted into the patients' heads through a burr hole. In nine consecutive cases in which the hematoma was larger than 40 ml in volume, nearly complete evacuation (86–100%) of the lesion was achieved without complication. Excellent visualization of the border between the brain parenchyma and the hematoma facilitated accurate intraoperative orientation, and also allowed easy identification of the bleeding point. Thus, this combination of sheath and endoscope achieves both minimal invasiveness and the maximum extent of hematoma removal with secure hemostasis. This tool will reduce the inherent disadvantage of endoscopic procedures and may expand their application in other areas of neurosurgical management.


1988 ◽  
Vol 69 (2) ◽  
pp. 276-282 ◽  
Author(s):  
David S. Nicholas ◽  
Roy O. Weller

✓ The fine anatomy of the human spinal meninges was examined in five postmortem spinal cords taken within 12 hours after death from patients aged 15 months to 46 years. Specimens of spinal cord were viewed in transverse section and from the dorsal and ventral aspects by scanning electron microscopy. Transverse sections of spinal cord and meninges were also examined by light microscopy. The arachnoid mater was seen to be closely applied to the inner aspect of the dura. An intermediate fenestrated leptomeningeal layer was observed attached to the inner aspect of the arachnoid mater and was reflected ventrally to form a series of dorsal septa. As it arborized laterally over the surface of the cord to surround nerves and blood vessels, the intermediate layer became highly fenestrated but remained distinct from the pia and arachnoid mater. The pia mater appeared to form a continuous layer which was reflected off the surface of the cord to coat blood vessels within the subarachnoid space in a manner similar to that described in the leptomeninges over the human cerebral cortex. Each dentate ligament consisted of a collagenous core which was continuous with the subpial connective tissue and was attached at intervals to the dura; pia-arachnoid cells coated the surface of the dentate ligaments. The present study suggests that the fine anatomy of the human spinal meninges differs significantly from that described in other mammals.


1978 ◽  
Vol 49 (1) ◽  
pp. 143-145 ◽  
Author(s):  
John I. Moseley ◽  
Robert W. Rand

✓ A technique is outlined for retraction of tumors under the operating microscope using the microcryoprobe. The method depends on temperature settings in the −20° to −30° C range to produce a small ice bond uniting tumor and cryoprobe. No attempt is made to create a solid frozen tumor. The locally avascular field and retraction provided ideal circumstances for microdissection. Examples of this approach are outlined with case summaries for spinal cord ependymoma and hemangioblastoma.


1976 ◽  
Vol 44 (6) ◽  
pp. 757-758 ◽  
Author(s):  
Sanford J. Wright

✓ A small microvascular occluder termed a “microblock” is described. It has the advantages of controlled gentle occlusion and small size.


1987 ◽  
Vol 67 (5) ◽  
pp. 710-716 ◽  
Author(s):  
Hisashi Aikawa ◽  
Kinuko Suzuki

✓ A new experimental model of chronic subdural hematoma in mice is described. A single intraperitoneal injection of 6-aminonicotinamide (25 mg/kg body weight) on the 5th postnatal day induced hydrocephalus in mice with almost 100% success. Approximately 60% of the mice spontaneously developed intracranial hemorrhage 20 days after the injection. About 1 week after the hemorrhage, a lens-shaped or spherical subdural hematoma was observed, accompanied by marked dilatation of the lateral ventricles and intraventricular hemorrhage. Histological examination revealed that the hematoma contained well-organized outer and inner membranes. Fresh hemorrhage surrounded by many hemosiderin-laden macrophages was seen at the margin of the hematoma adjacent to the organizing outer membrane, in which many fibroblasts and blood vessels were noted. The inner membrane of the hematoma was made up of several tiers of flattened cells with thin-walled blood vessels. The gross morphology and histology of these hematomas closely resembled those of human chronic subdural hematoma.


1977 ◽  
Vol 47 (6) ◽  
pp. 861-863 ◽  
Author(s):  
Theodore Kurze ◽  
Michael L. J. Apuzzo ◽  
Martin H. Weiss ◽  
James S. Heiden

✓ Experiments were conducted to assess the feasibility of both paraformaldehyde and ethylene oxide gas sterilization of the operating microscope. From these experiments and practical experience, it is concluded that ethylene oxide sterilization of the operating microscope is a feasible and desirable alternative to cumbersome draping techniques.


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