Biomedical subjects

T A Kopitnik

Publications and source records attributed to T A Kopitnik.

21 records · Page 2Linked to original sources

PubMed1987

Technique of stereotactic biopsy of two cranial target employing spherical coordinates to define a single trajectory.

A 'spherical coordinate system' has been developed to allow either stereotactic biopsy of two intracranial lesions using a single predetermined trajectory or biopsy of a single lesion through an existing burr hole. By means of the Gildenberg technique, the CT coordinates of the targets (or target and burr hole) are obtained. These are employed in three simple trigonometric equations to give three coordinates-two angles for the probe carrier (theta and alpha) and the radius (T) of a sphere, defined by one target as the center and the other target on the surface. These can be utilized in the Todd-Wells stereotactic frame. This system was evaluated using hollow skulls and crossed 30-gauge wire for phantom targets. The system was tried on ten different target combinations, and eight successful trajectories were obtained to within 3 mm. Two target combinations were inaccessible because of technical limitations of the Todd-Wells frame. This 'spherical coordinate system' can decrease the time to localize multiple targets as well as minimize the number of passes.

Biopsy↗

PubMed1986

Target fibers in multiple sclerosis: implications for pathogenesis.

Target fibers are generally considered a specific indicator of denervating disease. We found large numbers of target fibers in a biceps biopsy from a patient with MS and spastic quadriparesis. There was no evidence of denervation. Target fibers are not seen only in denervation.

Adult↗

PubMedDate not supplied

Posterior flank approach to the peritoneum for ventriculoperitoneal shunting.

We report a technique for insertion of a distal shunt catheter into the peritoneal cavity through a posterior incision. This has been helpful in patients with impaired access anteriorly. It may also be useful in elective situations. We have performed this procedure on 3 infants where the traditional anterior approaches would have been difficult due to subcutaneous scar tissue, ostomy sites and anterior intra-abdominal adhesions. This technique was safe and provided easy access to the peritoneal cavity. Complications would be similar to those for the standard ventriculoperitoneal shunts including bowel perforation, damage to the kidney or liver, infection and occasionally posterior cervical webbing that may cause pain locally or pull the head into an extended position.

Cerebrospinal Fluid Shunts↗