PubMed Health⌕ Search

Biomedical subjects

P Niggemann

Publications and source records attributed to P Niggemann.

5 recordsLinked to original sources
PubMed2006

Magnetic versus manual guidewire manipulation in neuroradiology: in vitro results.

INTRODUCTION: Standard microguidewires used in interventional neuroradiology have a predefined shape of the tip that cannot be changed while the guidewire is in the vessel. We evaluated a novel magnetic navigation system (MNS) that generates a magnetic field to control the deflection of a microguidewire that can be used to reshape the guidewire tip in vivo without removing the wire from the body, thereby potentially facilitating navigation along tortuous paths or multiple acute curves. METHOD: The MNS consists of two permanent magnets positioned on either side of the fluoroscopy table that create a constant precisely controlled magnetic field in the defined region of interest. This field enables omnidirectional rotation of a 0.014-inch magnetic microguidewire (MG). Speed of navigation, accuracy in a tortuous vessel anatomy and the potential for navigating into in vitro aneurysms were tested by four investigators with differing experience in neurointervention and compared to navigation with a standard, manually controlled microguidewire (SG). RESULTS: Navigation using MG was faster (P=0.0056) and more accurate (0.2 mistakes per trial vs. 2.6 mistakes per trial) only in less-experienced investigators. There were no statistically significant differences between the MG and the SG in the hands of experienced investigators. One aneurysm with an acute angulation from the carrier vessel could be navigated only with the MG while the SG failed, even after multiple reshaping manoeuvres. CONCLUSION: Our findings suggest that magnetic navigation seems to be easier, more accurate and faster in the hands of less-experienced investigators. We consider that the features of the MNS may improve the efficacy and safety of challenging neurointerventional procedures.

Catheterization↗
PubMed2005

Fifteen-year follow-up of a patient with beta thalassaemia and extramedullary haematopoietic tissue compressing the spinal cord.

A long-term follow-up of a patient with beta thalassaemia with intra- and extraspinal extramedullary haematopoietic tissue compressing the spinal cord is presented. Extramedullary haematopoietic nodules are a rare cause of spinal cord compression and should be included in the differential diagnosis, especially in patients from Mediterranean countries. Treatment with radiation therapy solely failed, giving rise to the need of surgical intervention. Surgical decompression of the spine and the removal of the culprit lesion compressing the spine were performed. Postinterventional radiation therapy was applied to the spine. A relapse had to be treated again by surgical means combined with postinterventional radiation therapy. A complete relief of the symptoms and control of the lesion could be obtained.

Adult↗
PubMed2003

Venocutaneous fistula.

This is the first description of venocutaneous fistula, a late complication of elective laparoscopic cholecystectomy that arose 18 months after the initial operation. Postoperatively, the patient twice developed an abscess in the abdominal wall at the former site of the umbilical trocar. The first abscess occurred on the 6th postoperative day; the second, after 14 months. After an additional 4 months, a fistula opening appeared just below the umbilicus. Fistulography revealed a connection with the venous system of the omentum majus. During subsequent resection of the fistula, a pigment gallstone was retrieved from the base of the fistula.

Abdominal Abscess↗
PubMed2000

Peripheral directional atherectomy evaluated with a rotational digital angiography system.

BACKGROUND: One of the factors that affect the recurrence rate after peripheral directional atherectomy (DA) is the degree of residual stenosis. A new method of peripheral DA to reduce residual stenoses was evaluated with a rotational digital angiography (RDA) system that provides both angiography and fluoroscopy at multiple projections within 360 degrees. PATIENTS AND METHODS: Between March 1995 and July 1999, severe short segmental stenoses of six iliac arteries and two superficial femoral arteries (SFA) in eight patients were treated with the Simpson DA catheter under RDA system guidance. After pre-procedural RDA evaluation, the first series of DA were performed under ordinary PA fluoroscopic guidance. The residual stenoses were evaluated with RDA. If the residual stenoses exceeded 30%, a second series of DA were performed covering the residual plaque with the cutter window of the DA catheter. To this purpose the fluoroscopy of the RDA system was fixed in the direction in which the residual stenoses were largest and most eccentric. The end point was defined to be a residual stenosis of less than 30% evaluated with the RDA system, and the procedures were repeated until the end point was achieved. RESULTS: Five of six iliac artery lesions were curved at the pre-procedural RDA evaluation. After the first series of DA, only two of six iliac lesions but all SFA lesions achieved the end point. Among the four other iliac lesions, three achieved the end point with one or two additional series of DA using the RDA system guidance to control the selective cuts of the residual plaques. One patient had a residual stenosis of 50% because the procedure could not be completed by balloon rupture of the DA catheter. In the patients with iliac stenoses, there was no final residual stenosis in one, and the range was from 20% to 25% in the four patients. The residual stenoses were located on the greater curvature side of the curved artery in three of these four patients. CONCLUSION: The RDA system is a valuable tool in aiding reduction of the residual stenoses during peripheral DA. Minimal stenoses often remain on the greater curvature side of the wall because the rigid and straight metallic capsule (cylindrical housing) of the Simpson DA catheter does not completely fit the curved wall. This phenomenon was thought to be a mechanical limitation of this device.

Aged↗