Biomedical subjects

D H Groenemeyer

Publications and source records attributed to D H Groenemeyer.

4 recordsLinked to original sources

PubMed2001

[Chronic non radicular cervicocephalic syndrome: CT-guided percutaneous RF-thermocoagulation of the zygapophysial joints].

PURPOSE: The objective of this study was to evaluate the clinical outcome of CT-guided radiofrequency- (RF-)thermocoagulation of cervical zygapophysial joints for chronic non radicular cervical pain syndrome using an improved posterior approach. METHODS: 169 patients were treated with CT-guided pericapsular drug instillation of steroids and local anaesthesia on the symptomatic and adjoining segments. 46 patients experienced an only short term pain relief after repeated CT-guided blocks and were therefore treated with CT-guided RF-neurolysis. For the microtherapeutic procedure the patients were placed on the CT-table in prone-position. A 23-gauge isolated aspiration canula (Leibinger) was placed vertically, under CT-guidance lateral to the zygapophysial joint to coagulate the capsular nerve endings. The probe was then repositioned to coagulate the medial and lateral branches of the corresponding segment-nerves' dorsal branches. The thermocoagulation was applied 3-4 times with 90 s. duration and a coagulation temperature of 70 degrees C. The coagulation-probe was drawn back 3-5 mm each time. No sedation or general anaesthesia was required. The treatments were carried out on out patient basis in local anaesthesia. Statistical data on pain sensation was acquired with the help of a standardized visual analogue pain scale (VAS) and by a questionnaire on treatment satisfaction and every day activities. Patients were examined and questioned on the 2nd, 7th, 30th and 90th day after the operation. RESULTS: After 90 days, 26 (56,5%) patients had experienced a definite pain reduction of >75% (VAS). 13 (28,3%) patients obtained alleviation of <50% (VAS), within the first three postoperative months. Seven (15,2%) patients reported <25% (VAS) pain relief. No intra- and postoperative complications were reported. CONCLUSIONS: CT-guided radiofrequency thermocoagulation is an effective, precise and secure, minimally invasive treatment for non radicular cervical pain that is caused by zygapophysial joint arthropathy, when CT-guided, lateral drug instillation does not cause a lasting improvement.

Electrocoagulation↗

PubMed1998

Electron-beam CT in the noninvasive assessment of coronary stent patency.

RATIONALE AND OBJECTIVES: Coronary artery stents reduce the rate of restenosis in patients who have undergone balloon angioplasty; therefore, the implantation of coronary stents represents an important method in the treatment of coronary stenoses. The authors' purpose was to investigate the usefulness of electron-beam computed tomography (CT) as a noninvasive means of assessing the patency of coronary artery stents in patients who had undergone balloon angioplasty and stent placement. MATERIALS AND METHODS: Electron-beam CT was used to assess stent patency in 177 patients with 285 stents. Contrast material-enhanced multisection flow studies were performed, and the images were evaluated by three investigators and compared with the findings of coronary angiography. RESULTS: Cine loop evaluations and time-attenuation curve analysis led to the correct diagnosis in 167 (94.3%) patients, as confirmed with coronary angiography. Stenoses had occurred in 18 of the 194 vessels with stents, and 14 of these were detected with electron-beam CT. CONCLUSION: Electron-beam CT appears to be a valuable imaging modality in the noninvasive assessment of stent patency in coronary arteries.

Adult↗

PubMed1995

Image-guided access techniques.

For increasing safety in access and guidance of endoscopes and instruments, fast real-time radiologic imaging should be integrated. Open designed Magnetic Resonance Imaging (MRI), Computer Tomography (CT), and Electron Beam Tomography (EBT) scanners permit adequate transparency of the operative field. CT and EBT as hybrid scanners can be combined with fluoroscopy. MRI avoids X-ray exposure and entails the possibility of 3D localisation, while open access and keyhole imaging allows nearly real-time guidance of instruments. EBT has the largest gantry (90 cm) for using long instruments, and the image acquisition requires only 50 msec (34 images/sec at 8 levels). However, computed reconstruction of the data takes about 3 times longer than conventional CT. Until EBT can be accelerated, CT will be the golden standard of guidance-techniques in high risk areas, because the tips of the instruments can be precisely visualised within +/- 0.5 mm (MRI: 3.5 mm). MRI-guidance can be used for low risk access techniques. This safe interactive transparent guidance technique has the potential to reduce complications, and it adds significant advantages to micro-invasive operative procedures such as percutaneous diskectomies, pain and cancer therapy with ethanol, or gene-technology implants in the new field of "surgical tomography".

Diagnostic Imaging↗

PubMedDate not supplied

Technique for CT guided microendoscopic dissection of the spine.

The indications for percutaneous nucleotomy techniques are limited to disk herniation without dislocated free fragments. In cases with free fragments we have developed a new technique for percutaneous sequestrectomy. Under CT and fluoroscopic guidance spinal endoscopy was performed. In the past, percutaneous diskectomies were X-ray-guided with or without endoscopy. In this paper we describe the combination of CT-scanning, fluoroscopy and microendoscopy for guidance of nucleotomes, lasers, microendoscopes and micro-instruments. The technique was performed on 20 patients (17 outpatients) with chronic back pain. To date no major complications occurred. The method offers an effective outpatient treatment of small free fragments and scar tissue in the spinal canal and the foramen.

Adult↗