Biomedical subjects

Karl F Kothbauer

Publications and source records attributed to Karl F Kothbauer.

4 recordsLinked to original sources

PubMed2006

Clinical presentation and optimal management for intramedullary cavernous malformations.

OBJECT: Intramedullary cavernous malformations (CMs) account for approximately 5% of all intraspinal lesions. The purpose of this study was to define the spectrum of presentation for spinal intramedullary CMs and the results of microsurgery for these benign but clinically progressive lesions. METHODS: Retrospective chart review was performed in 26 patients with histologically diagnosed CMs. All patients had undergone preoperative magnetic resonance (MR) imaging studies. All patients were treated with a laminectomy and microsurgical resection of the malformation. CONCLUSIONS: The MR imaging findings are diagnostic for intramedullary CMs; these lesions abut a pial surface and have a characteristic imaging pattern. Spinal intramedullary CMs present with either an acute onset of neurological compromise or a slowly progressive neurological decline. Acute neurological decline occurs secondary to hemorrhage inside the spinal cord. Chronic progressive myelopathy occurs due to microhemorrhages and resulting gliotic reaction to blood products. Surgery and total removal of the lesion tends to halt progression of symptoms.

Adolescent↗

PubMed2005

Endoscopic third ventriculostomy.

The traditional treatment for all forms of hydrocephalus has been the implantation of ventricular shunt systems; however, these systems have inherent tendencies toward complications such as malfunction and infection. A significant advance in the treatment of hydrocephalus has been the evolution of endoscopy. The recent technological advances in this field have led to a renewed interest in endoscopic third ventriculostomy as the treatment of choice for obstructive hydrocephalus. Although several different endoscopes are available, the authors favor a rigid one to perform a blunt fenestration of the third ventricle floor. This description of the technique stresses the nuances for successful completion of this procedure.

Endoscopy↗

PubMed2004

Intraoperative monitoring for tethered cord surgery: an update.

OBJECT: Intraoperative neurophysiological recording techniques have found increasing use in neurosurgical practice. The development of new recording techniques feasible while the patient receives a general anesthetic have improved their practical use in a similar way to the use of digital recording, documentation, and video technology. This review intends to provide an update on the techniques used and their validity. METHODS: Two principal methods are used for intraoperative neurophysiological testing during tethered cord release. Mapping identifies functional neural structures, namely nerve roots, and monitoring provides continuous information on the functional integrity of motor and sensory pathways as well as reflex circuitry. Mapping is performed mostly by using direct electrical stimulation of a structure within the surgical field and recording at a distant site, usually a muscle. Sensory mapping can also be performed with peripheral stimulation and recording within the surgical site. Monitoring of the motor system is achieved with motor evoked potentials. These are evoked by transcranial electrical stimulation and recorded from limb muscles and the external anal sphincter. The presence or absence of muscle responses are the parameters monitored. Sensory potentials evoked by tibial or pudendal nerve stimulation and recorded from the dorsal columns via an epidurally inserted electrode and/or from the scalp as cortical responses are used to access the integrity of sensory pathways. Amplitudes and latencies of these responses are then interpreted. The bulbocavernosus reflex, with stimulation of the pudendal nerve and recording of muscle responses in the external anal sphincter, is used for continuous monitoring of the reflex circuitry. Presence or absence of this response is the pertinent parameter that is monitored. CONCLUSIONS: Intraoperative neurophysiology provides a wide and reliable set of techniques for intraoperative identification of neural structures and continuous monitoring of their functional integrity.

Anal Canal↗

PubMed2002

Contact laser microsurgery.

INTRODUCTION: Lasers are commonly understood as instruments that produce a freestanding light beam that can cut or vaporize tissue. In contrast, a contact laser is an instrument where the laser beam resides entirely within a coated sapphire crystal probe tip. The authors describe the use of the contact laser for a variety of intraspinal procedures. METHOD: The probe is mounted on a curved handpiece and can be used in the same way as any microsurgical instrument. The laser energy is delivered only at the probe tip and only on contact of the tip with tissue. Different probe sizes and shapes allow for sharp cutting or tissue vaporization with minimal tissue penetration. FINDINGS: We have used this laser in 95 operations for dysraphic conditions, and intradural (both intra- and extramedullary) spinal tumors. It was easy to use for the microsurgically trained neurosurgeon. It is safer than a freestanding, noncontact, laser beam. To lyse scar tissue, evaporate lipomatous tissue, perform a precise myelotomy, and dissect, cut and debulk firm and fibrous intradural spinal lesions this instrument is superior to microscissors, suction, or the ultrasonic aspirator. INTERPRETATION: The contact laser is a useful microsurgical instrument for use in neurosurgery. It combines the advantages of lasers with those of microinstruments and avoids most shortcomings of both.

Humans↗