Tomographic microtherapy.

Minimally invasive techniques using endoscopes for image-guided therapy are now common in the field of surgery. Fast real-time radiologic imaging should be integrated into the procedure for increased safety in access and guidance techniques for endoscopes and instruments. The transparency of computed tomography (CT) guidance, magnetic resonance imaging, and electron beam tomography scan techniques allows precise guidance of instruments and endoscopes while permitting their diameter to be minimized. This guarantees safe and transparent access into the body, especially in high-risk areas such as the spine and brain. Combining both technologies has the potential to reduce complications and offers significant advantages in microinvasive operative procedures such as biopsies; local tumor therapy with lasers, radio frequency, or drugs; and percutaneous diskectomies or implants. CT is the golden standard for microtherapeutic procedures because of its precise tip discrimination.

[Precision and comparison of CT-, MRI- and DL-controlled interventions exemplified by lumbar facet infiltration--an experimental study]. / Präzision und Vergleich von CT-, MR- und DL-gesteuerten Interventionen am Beispiel der lumbalen Facetteninfiltration--eine experimentelle Untersuchung.

We evaluated the accuracy of the needle tip representation by different imaging techniques for the guidance of facet infiltrations. For visualisation of the lumbar facet joints we used a high-field magnetic resonance tomograph (MRT) with a 2.0 Tesla field and 3.5 mm slice thickness, an open low-field magnetic resonance tomography (MRT) with an 0.064 Tesla field and 9 mm slice thickness, and IMATRON electron beam computed tomograph (EBCT) with a slice thickness of 6 mm, and a mobile C-arm fluoroscope. The study was performed on 4 human cadaveric lumber spine preparations, each of which had 8 facet joints. Under imaging control, special injection needles were placed as close as possible to the facet joint space. Following placement of he needle, all specimens were scanned with the electron beam tomograph using a slice thickness of 1.5 mm. The thin-slice study served as the gold standard. The distance between the tip of the needle and the facet joint was measured in all the images. Comparison of the different modalities with the gold standard revealed the following results: 1) median values of the absolute differences were 1.25 mm for high-field MRI, 1.35 mm for 6 mm EBCT, 2.05 mm for low-field MRI, and 2.30 mm for X-ray fluoroscopy. 2) While there was no statistically significant difference in the accuracy of tip localization between high-field MRI and 6" EBCT (p = 0.293), both systems were more precise than low-field MRI (p = 0.04) and X-ray fluoroscopy (p = 0.009). When choosing the best imaging technique, such additional factors as radiation, costs and time, must also be considered. Provided necessary radiological precautions are taken, and assuming careful pre-interventional planning, CT. EBCT and X-ray fluoroscopy are currently more effective than the expensive, time-consuming and costly magnetic resonance tomography.

[Possibilities of spinal endoscopy within the scope of minimal invasive intervention--an experimental study]. / Möglichkeiten der Spinaloskopie im Rahmen der minimal invasiven Intervention--eine experimentelle Untersuchung.

The purpose of the present study was to evaluate, in vitro, a newly designed spinaloscope with a diameter of 1.8 mm, with integrated portals for instruments and irrigation. The 0 degree optical system has a resolution of 6,000 pixels. The instrument portals can be used for surgical lasers, biopsy forceps or burrs. We carried out our evaluations on fresh (unfixed) human lumbar spine specimens. The position of the endoscope was documented by CT scans. The endoscope was introduced into the spinal canal via the hiatus sacralis using a blunt trocar. The various structures and tissues were clearly identifiable and included the dura, the lig. flavum, the lig. long. posterior, spinal nerves, small pieces of disc material and various fibrous bands. The usefulness of the biopsy forceps was also shown.

[Percutaneous vertebral augmentation (PVA) in osteoporosis of the vertebrae--an experimental study]. / Perkutane vertebrale Augmentation (PVA) bei osteoporotischen Wirbelkörpern--eine experimentelle Unterschung.

The present study was conducted with the aim of establishing whether minimally invasive percutaneous techniques used to stabilize osteoporotic vertebrae are technically feasible. Two different methods were investigated in human thoracolumbar cadaveric vertebrae. In the first technique, special titanium implants were placed via a postero-lateral approach. With the second method, the vertebrae were filled with different types of cement of different viscosities. After each procedure, the vertebrae were examined with conventional X-ray and CT scans. The first technique proved quite unsuccessful--the insertion of the titanium implants proving difficult despite the use of special instruments. The results achieved with the second method were much better. The use of low-viscosity bone cement produced the best results. Despite a single lateral point of entry, the vertebrae were almost completely filled right into the contralateral side. Lumbar vertebrae required an average volume of cement of 7 ml (range: 6.5-10 ml) and thoracic vertebrae 5.5 ml (range: 4-7 ml). Specially developed cement application devices made possible problem-free, controlled introduction of the cement.

CT-guided percutaneous laser disc decompression with Ceralas D, a diode laser with 980-nm wavelength and 200-microm fiber optics.

The aim of this study was to evaluate the compact, portable Ceralas-D diode laser (CeramOptec; 980 + 30 nm wavelength, 200-microm optical fiber) concerning clinical usefulness, handling, and clinical results in the CT-guided treatment of herniated lumbar discs. The positioning of the canula in intradiscal space, the placement of the laser fiber into the disc through the lying canula, and the vaporization itself were carried out under CT-guidance. Due to the thin fiber optic, it was possible to use a thin 23-gauge canula. The laser procedure was performed in 0.1- to 1-s shots with 1-s pulse pause and 4-W power output. A total of 1650-2300 J was applied on each percutaneous laser disc decompression (PLDD). Results in 26 patients were established with a visual-analogue scale (VAS). On the follow-up examinations, 46% of the patients were absolutely pain free ( > 85 % VAS) and fully active in everyday life after 4 postoperative weeks. Thirty-one percent of patients were relieved of the leg pain but had occasional back pain without sensorimotor impairment. Fifteen percent sensed a slight alleviation ( > 50% VAS) of the radiate pain. Eight percent did not experience radicular or pseudo-radicular pain alleviation (< 25% VAS). Cerales-D proves to be an efficient tool for CT-guided PLDD on non-sequestered herniated lumbar discs.

CT-guided percutaneous radiofrequency denervation of the sacroiliac joint.

Defining the origin of low back pain is a challenging task. Among a variety of factors the sacroiliac joint (SIJ) is a possible pain generator, although precise diagnosis is difficult. Joint blocks may reduce pain, but are, in cases, of only temporary effect. This study was conducted to evaluate CT-guided percutaneous radiofrequency denervation of the sacroiliac joint in patients with low back pain. The procedure was performed on 38 patients who only temporarily responded to CT-guided SIJ blocks. The denervation was carried out in the posterior interosseous sacroiliac ligaments and on the dorsal rami of the fifth spinal nerve. All interventions were carried out under CT guidance as out-patient therapies. Three months after the therapy, 13 patients (34.2%) were completely free of pain. Twelve patients (31.6%) reported on a substantial pain reduction, 7 patients (18.4%) had obtained a slight and 3 patients (7.9%) no pain reduction. The data of 3 patients (7.9%) was missing. There were no intra- or postoperative complications. Computed tomography-guided percutaneous radiofrequency denervation of the sacroiliac joint appears safe and effective. The procedure may be a useful therapeutic modality, especially in patients with chronic low back pain, who only temporarily respond to therapeutic blocks.

[Chronic non radicular cervicocephalic syndrome: CT-guided percutaneous RF-thermocoagulation of the zygapophysial joints]. / Chronisches, nichtradikuläres HWS-Syndrom. CT-gesteuerte perkutane Radiofrequenz-Thermokoagulation der zervikalen Zygapophysialgelenke--eine Pilotstudie.

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.

Image-guided percutaneous laser disk decompression for herniated lumbar disks: a 4-year follow-up in 200 patients.

OBJECTIVE: The purpose of this study was to describe the long-term effect of image-guided percutaneous laser disk decompression (PLDD). BACKGROUND DATA: PLDD has been reported to be an alternative method to treat herniated lumbar disks. It has proved to be effective on a short-term basis. Although the procedure has been used for several years, few articles report on the long-term effect of the intervention. MATERIALS AND METHODS: Two hundred patients, who were treated with image-guided PLDD for herniated lumbar disks, were observed over a period of 4 +/- 1.3 years. Treatments were carried out under CT/fluoroscopy guidance with local anesthesia on an outpatient basis with an Nd:YAG laser of 1064 nm. RESULTS: At follow-up, back pain was eliminated or reduced in 73% of the patients. Regarding sensorimotor impairment, PLDD did have a positive effect on 74% of the patients. In the majority of patients, the number of sick days and consumption of pain medication was reduced. In one patient, diskitis occurred as a complication of PLDD; 74% of the patients said they were satisfied with the outcome of the therapy; and 81.5% of the patients would have required another PLDD in cases of disk herniation. CONCLUSION: From our clinical results, we conclude that image-guided PLDD is an effective and secure method to treat contained herniated lumbar disks. Advantages of the procedure include the minimally invasive approach on an out-patient basis and the low complication rate.