Biomedical subjects

M Tschabitscher

Publications and source records attributed to M Tschabitscher.

At least 19 recordsLinked to original sources

PubMed2005

Intraoperative imaging of the brachial plexus by high-resolution ultrasound.

The authors attempted to perform direct high resolution ultrasound imaging of the intraneural ultrastructure of the brachial plexus for intraoperative image guidance in brachial plexus surgery. The brachial plexuses of four fresh-frozen cadaver specimens were surgically exposed in a standard approach used in routine brachial plexus surgery to undergo direct ultrasound examination using a 15 MHz SonoCT scanhead. By placing the scanhead directly onto the epineurium, all components of the brachial plexus were directly visualized in an axial plane and compared with histologic findings. The internal neural structure at different levels could be visualized in high resolution, showing the specific fascicular pattern. The histologic processing revealed good correlation with the intraneural topography demonstrated on ultrasound. In the study, high resolution ultrasound examination of the brachial plexus showed substantial details of the ultrastructure of neural tissue, which may play a role in intraoperative image guidance in the surgical treatment of patients with brachial plexopathy.

Brachial Plexus↗

PubMed2003

Surgical anatomy of the puboprostatic complex with special reference to radical perineal prostatectomy.

OBJECTIVE: To investigate the retropubic space and attachments of the prostate and urethra, with special reference to radical perineal prostatectomy. MATERIALS AND METHODS: Anatomical relationships were assessed intraoperatively in 60 patients, and in five cadavers after preparing the dorsal vein complex with coloured latex. Cross-sections of the area of interest were evaluated by microscopy. RESULTS: The puboprostatic (pubovesical) ligaments could be clearly distinguished from the median part of the puboprostatic complex continuous with the urethral suspensory mechanism. The dorsal vein complex is integrated into this fibromuscular attachment of the prostate and male urethra. During the perineal approach, dissection in this region follows the so-called avascular plane. CONCLUSION: With this new insight into the anatomical relationships the nomenclature derived from radical retropubic prostatectomy could be mirrored. In radical perineal prostatectomy, both the urethral suspensory mechanism and the dorsal vein complex can be preserved.

Humans↗

PubMed2003

Thecaloscopy part III: first clinical application.

PURPOSE: We have already dealt with the technical and anatomical basics for thecaloscopy. The first results of clinical application are presented and the indications for its diagnostic and therapeutic use are described. The aetiology of aseptic arachnitis and the term "Wide spinal canal syndrome" are discussed. PATIENTS AND METHODS: Twelve patients who fulfilled the criteria for entry to the study were selected and the criteria were chosen according to German medical and legal rules. All patients underwent an endoscopic inspection and, if necessary, therapeutic manipulation under general anaesthesia. RESULTS: In all cases the procedure was safely and successfully performed. The pathomorphology of the arachnoid was detected and endoscopically treated in almost all cases. Arachnoid cysts were successfully fenestrated and an intraspinal meningocoele treated with endoscopic assistance. CONCLUSION: Thecaloscopy is a safe procedure if skilfully performed. It provides an opening for a wide range of new diagnostic and therapeutic options.

Adult↗

PubMed2002

Microsurgical anterior cervical foraminotomy (uncoforaminotomy) for unilateral radiculopathy: clinical results of a new technique.

BACKGROUND: The authors report the clinical application of a new microsurgical technique. The cervical anterior foraminotomy (uncoforaminotomy), which is used for the surgical treatment of unilateral cervical radiculopathy secondary to posterolateral disc herniations or spondylotic foraminal stenoses. METHOD: Between June 2000 and May 2001, 34 patients (16 men and 18 women with a mean age of 43.8 years, range 29 to 80 years) underwent anterior cervical foraminotomy (uncoforaminotomy) for the treatment of cervical radiculopathy at one or two adjacent levels in the Neurosurgical Department of the University of Vienna. This surgical technique was devised to accomplish direct anterior decompression of the affected nerve root by removing an offending posterolateral sponylotic spur or disc fragment. The nerve root is decompressed from its origin in the spinal cord to the point were it passes behind the vertebral artery laterally. The intervertebral disc of the affected level is maintained in its form and function. Thus, the functioning motion segment is preserved and fusion related sequelae, including graft related complications, graft site complications and the adjacent level disease, are avoided. Prior to its clinical application, anatomical features of the anterior cervical spine were reviewed, and an anatomical morphometric analysis and work-up of the technique was performed in 4 cervical specimens. FINDINGS: The follow-up period varied from two to 17 months with a mean of 8.2 months. The large majority (97%) of patients were pleased with the results of their operation. The relief of neck pain and redicular pain in the affected dermatome was immediate in all patients. Motor-weakness and sensory deficit improved dramatically immediately postoperatively, and improved to normalisation in the majority of patients within 3 to 6 months. Two of the patients sustained an incomplete transient recurrent laryngeal nerve palsy, which fully resolved within two to 4 weeks. One of the patients had a repeat herniation on the second postoperative day, but recovered completely after re-operation and continued to do well at the 6-month follow-up. No permanent surgery related morbidity or associated complications were encountered. INTERPRETATION: The results indicate that this new microsurgical technique is an attractive treatment option for adequate anterior decompression of the cervical nerve root via a minimized approach. It was associated with excellent clinical outcome and a less painful postoperative course, allowing patients an almost immediate return to unrestricted full activity.

Adult↗

PubMed2002

Endoscopic endonasal approach to the ventral cranio-cervical junction: anatomical study.

OBJECTIVE: In order to develop an endoscopic endonasal approach to the ventral cranio-cervical junction and odontoid process under the concept of a minimally invasive surgical strategy, a cadaver study was performed. METHODS: Sixteen artery-injected adult head specimens were used. Endonasal endoscopic approach was made through one- or two-nostril routes following the Jho's endonasal paraseptal technique. Rod-lens endoscopes, which were 2.7 or 4 mm in diameter, 18 cm in length with 0-, 30-, and 70-degree lenses, were used. RESULTS: Surgical landmarks leading to the craniocervical junction were the inferior margin of the middle turbinate, nasopharynx and Eustachian tube. The nasopharynx was readily identified following the inferior margin of the middle turbinate. The line drawn between the Eustachian tubes indicated the juncture between the clivus and atlas. With a midline mucosal incision, the ventral cranio-cervical junction was exposed. Odontoid resection was performed with removal of the anterior arch of the atlas. Clival resection can be performed as much rostral as required. Maneuverability of the surgical instruments was better with a two-nostril technique than with a one-nostril. Although the entire midline clivus was accessible rostrally, C-2 was the caudal limit through this endonasal route. A suturing device needed to be developed for mucosal or dural closure for live operations. CONCLUSION: This cadaver study demonstrates that an endoscopic endonasal approach to the ventral cranio-cervical junction and odontoid process can be a valid alternative to the conventional transoral approach.

Cranial Fossa, Posterior↗

PubMed2001

A computer-based method for calculation of orbital floor fractures from coronal computed tomography scans.

PURPOSE: A computer program recently developed for the calculation of the orbital floor and fracture areas from coronal computed tomography (CT) scans was used in a study to evaluate the accuracy and ability of this new method. MATERIAL AND METHODS: The size of orbital floors and fabricated fractures in 14 dried, anatomic specimens were measured in coronal CT scans by 3 independent observers. Based on this data set, the orbital floor and fracture regions were calculated with the newly developed computer program. These calculated regions were then compared with a direct measurement of the specimens that had been obtained by digital photography. The accuracy of the computer-based calculations was assessed using Lin's concordance correlation coefficient. RESULTS: The size of the orbital floor (mean +/- SD) was found to be 5.21 +/- 0.39 cm(2) by direct measurement of the specimens and 5.30 +/- 0.52 cm(2) by calculation with the computer program. The region of the fracture (mean +/- SD) was 1.05 +/- 0.64 cm(2) by direct measurement and 1.01 +/- 0.62 cm(2) by computer calculation. The between-method mean difference (direct measurement minus computer based calculation) was -0.09 cm(2) (or 1.7% of mean orbital floor region) for orbital floor region and 0.04 cm(2) (or 3.8% of mean fracture region) for fracture region. CONCLUSIONS: This accurate and time-saving method is practicable for determining the size and location of orbital floor fractures. This calculation program can be advantageously applied in the clinical management of blowout fractures of the orbit.

Algorithms↗

PubMed2001

Thecaloscopy: the endoscopy of the lumbar subarachnoid space, part I: historical review and own cadaver studies.

Since 1931 only a few efforts have been made for direct visualization of the neural structures of the spinal canal. Given current technologies and minimally invasive techniques it is now possible to effectively view these structures. We describe here a new technique for inspection of the subarachnoid space of the lumbar spinal canal by using a flexible endoscope in ten fresh post-mortem adult human cadavers. According to the anatomical structures, namely the thecal sac and its anatomical position, the procedure is called thecaloscopy and the instrument is a thecaloscope. It was proven that the procedure is safe and easy to perform.

Cadaver↗

PubMed2001

Thecaloscopy part II: anatomical landmarks.

Endoscopic anatomy differs from microsurgical anatomy. Topographical orientation as well as the proportion of objects, is different as they depend on the lens/object distance. Orientation under endoscopic conditions requires structures with defined positions or recognisable structures previously identified radiolologically. Structures are anatomical landmarks if the topographical relation to their surroundings is constant and they are easy and reliable to recognise. The contents of the dural sack are nerve roots with their supplying vessels, arachnoid trabeculars, filum terminale, and CSF. Safe navigation of a thecaloscope in relation to the bony structures is only possible with the simultaneous use of intraoperative fluoroscopy. To facilitate the navigation of scopes and instruments in the subarachnoid space we attempted to identify and describe reliable, and therefore constant recognisable anatomical landmarks.

Endoscopy↗

PubMed2000

Exposure to formaldehyde and phenol during an anatomy dissecting course: sensitizing potency of formaldehyde in medical students.

BACKGROUND: The sensitizing potency of formaldehyde and phenol during anatomy dissecting was investigated. The objective was to determine whether exposure induces specific IgE or IgG against formaldehyde-albumin or phenol-albumin. METHODS: In 27 medical students, specific IgE against formaldehyde-albumin by RAST plus ELISA and specific IgE against phenol-albumin by ELISA were assessed. In addition, specific IgG against formaldehyde-albumin was assessed in 23 students. Symptoms before and during dissecting were assessed, and indoor formaldehyde and phenol were measured. RESULTS: Mean indoor formaldehyde was 0.265 +/- 0.07 mg/m3, and mean indoor phenol was 4.65 +/- 2.96 mg/m3. Specific IgE/IgG against formaldehyde-albumin was not found at the beginning. Four students developed specific IgE against formaldehyde-albumin (RAST classes of > or =2.0), and all four also had specific IgE in the ELISA, but IgG against formaldehyde-albumin was not found. Specific IgE against phenol-albumin was not seen. Itch and paresthesia of the hands (P<0.00001), dizziness (P<0.008), burning eyes (P<0.01), headache, sneezing, epistaxis, gingival bleeding, oral or pharyngeal itch, and shortness of breath were experienced. CONCLUSIONS: Formaldehyde exposure during dissecting may induce specific IgE, but not IgG, against formaldehyde-albumin. Sensitization did not correlate with symptoms.

Adult↗

PubMed1999

Two-port endoscopy of the middle ear: endoscopic anatomy.

OBJECTIVES: To shed light on the endoscopic anatomy of the middle ear seen on 2-port endoscopy and to describe potential clinical applications. DESIGN: Anatomical structures were visualized by transmeatal or transtympanic rigid scopes of different angles and by a flexible scope in the eustachian tube. This arrangement ensured reciprocal guidance of the scopes and provided access to regions not seen otherwise. SETTING: The Department of Anatomy 1, University of Vienna, Vienna, Austria. MATERIALS: Forty tympanic cavities obtained from cadaver skulls without prior fixation were examined. Specimens did not show any abnormalities and were chosen without regard to age or sex. RESULTS: Depending on the angle of view, rigid transmeatal or transtympanic endoscopes provided a full view of the entire tympanic cavity except for the epitympanum, access to which was barred by the incudomallear joint, the mallear folds, and the tympanic chord, but the epitympanum was well visualized through the flexible, steerable, transtubal scope. CONCLUSIONS: Two-port endoscopy of the middle ear offers a full view of all structures in the tympanic cavity. The atraumatic transtubal approach to the tympanic cavity enhances the safety of transmeatal interventions and facilitates postoperative follow-up.

Cadaver↗

PubMed1999

Endoscopy of the middle ear through the eustachian tube: anatomic possibilities and limitations.

HYPOTHESIS: This anatomic study was designed to provide otosurgeons with a detailed description of the technique of transtubal middle ear endoscopy and anatomic landmarks facilitating orientation. To establish the role of transtubal endoscopy, its anatomical potentials and limitations were studied. BACKGROUND: Transtubal endoscopy has recently been described as an atraumatic tool for exploring the tympanic cavity. From the nasopharynx, a thin, flexible endoscope is advanced into the middle ear through the Eustachian tube. After the endoscope has been placed, it offers an anteroposterior view of the tympanic structures. METHODS: Temporal bone blocks and whole skulls of recently deceased persons were examined to define the average range of view obtained by transtubal endoscopy. Key structures in each region of the tympanic cavity were chosen for inspection, and positive identifications were noted. RESULTS: With a 0.8-mm, flexible, steerable scope, most mesotympanic structures (stapes suprastructure, incudostapedial joint, tympanic chord, and inner surface of the eardrum) were clearly defined. Areas of the posterior wall that were not accessible with the otomicroscope (lateral tympanic sinus, tympanic sinus, and facial recess) were also seen. Unlike with transtympanic endoscopy, the epitympanum (incudomalleal joint and malleus neck) was also evaluable. The stapes footplate was not seen well and the round window niche was unable to be inspected in the anteroposterior view inherent in the technique. Technical factors (poor illumination and small image size) and the unfamiliar anteroposterior view made orientation in the middle ear difficult. CONCLUSION: Transtubal middle ear endoscopy is a suitable method for exploring the tympanic cavity without traumatizing the eardrum.

Ear, Middle↗

PubMed1998

The lumbrical muscle flap: anatomic study and clinical application.

This article describes the anatomy and clinical application of the lumbrical muscle flap. Anatomic and radiologic studies were performed in 20 fresh human cadaver hands injected with latex-lead-oxide solution. Only the 2 radial lumbrical muscles were found suitable for flap transposition. The vascular supply of the first and second lumbrical muscles is from branches originating in the superficial palmar arch and from the common palmar digital artery, respectively. The dominant branches invariably enter the muscle bellies at the junction of their proximal and middle thirds. Pedicled on these vessels, the lumbrical muscles can be transposed to reach the entire palm, up to the wrist flexion crease. The clinical use of the first and second lumbrical muscle flaps in 2 patients demonstrated the value of these flaps for coverage of the median nerve and its palmar branches.

Cadaver↗

PubMed1998

Anatomic position of the asterion.

OBJECTIVE: The asterion is defined as the junction of the lambdoid, parietomastoid, and occipitomastoid sutures. The asterion has been used as a landmark in lateral approaches to the posterior fossa. However, its reliability as a landmark comes into question considering the apparent variability of its position. This study was performed to determine the reliability of the asterion as a surgical landmark. METHODS: One hundred dried skulls were obtained for study. A 2-mm drill hole was placed at the asterion on each side. The position of the drill hole on the inner surface of the skull was next determined and recorded. RESULTS: The asterion was located over the posterior fossa dura in 32% on the right and 25% on the left. Its position was over the transverse or sigmoid sinus complex in 61% on the right and 66% on the left. The landmark was located above the transverse-sigmoid sinus complex in 7% on the right and 9% on the left. CONCLUSIONS: The asterion is not a strictly reliable landmark in terms of locating the underlying posterior fossa dura. Its location is very often directly over the transverse-sigmoid sinus complex. Burr holes placed at the asterion may often open the bone directly over the sinus, leading to potential damage.

Anatomy, Artistic↗

PubMed1997

Epicardial branches of the coronary arteries and their distribution in the rabbit heart: the rabbit heart as a model of regional ischemia.

BACKGROUND: The rabbit heart has been frequently used to study regional ischemia, but there is hardly any detailed information on the epicardial branching of the coronary arteries. Therefore, we wanted to determine whether there is a constant branching pattern and how comparable this pattern is with the human heart. METHODS: We investigated epicardial branching of the coronary arteries in 30 adult rabbit hearts. For vessel visualisation, we used injections of Technovit, followed by corrosion. RESULTS: We found that there is not one constant pattern but rather a bifurcation or a trifurcation of the arteria coronaria sinistra (15 of 15 hearts). The left coronary artery is always the dominant artery; a vessel comparable to the human ramus interventricularis anterior is rarely found in the bifurcation type. The ramus circumflexus is a constant but minor branch of the posterior or posterolateral division and does not originate directly from the main stem of the left coronary artery, as it does in humans. As a consequence, ligation of the left ramus interventricularis anterior leads to severe ischemic injury only where trifurcation exists (50% of our population). A ligation of the ramus circumflexus proximal to its origin produces a large posterolateral infarction in the bifurcation type (50% of our population). CONCLUSIONS: Because a defined ischemic area is difficult to reproduce under these anatomical conditions, the rabbit heart may be a model only for regional ischemia if the investigator is knowledgeable about the distributions of the coronary arteries.

Animals↗

PubMed1997

The course of the prevertebral segment of the vertebral artery: anatomy and clinical significance.

BACKGROUND: The so called "pretransverse or prevertebral segment" of the vertebral artery is defined from its origin at the subclavian artery to its entry into the respective transverse foramen. In surgery, angiography, and in all noninvasive procedures it is of great importance to know the exact details of the course and the origin of this segment of the vessel as well as in which percentages real abnormalities can be found. METHODS: The VI segment of the vertebral artery was investigated both in anatomic preparations and clinical studies. A total of 402 vertebral arteries were evaluated (70 anatomic preparations in different forms, 181 patients, 95 angiographies of the aortic arch, and 86 color coded doppler sonographies). RESULTS: A contorted course was found in 157 (39%) cases. The plane of tortuosities demonstrated by the respective vessels was found to be horizontal in 40 (44.9%) cases, sagittal in 30 (33.7%) cases, and frontal in 19 (21.4%) cases. In 51 (32.5%) cases the contorted pathway was on the right side, and in 106 (68%) cases, on the left. A hypoplasia was found in 16 (10%) cases--11 (4.8%) right and 5 (2.2%) left. We further differentiated the convexity lying either medially or laterally in the transverse or frontal plane, or oriented dorsally or ventral in the sagittal plane. The exact location of the origin of the artery on the circumference of the subclavian artery (47% cranial, 44% dorsal, 3% ventral, 6% caudal) and also the average values of length and diameter are described. No significant differences between tortuous and nontortuous vessels were found with respect to length and diameter. A real abnormality of the origin of the vertebral artery was found in 8 (3.5%) cases. CONCLUSIONS: The described morphologic variations and frequencies of the VI segment of the vertebral artery have clinical applications in a wide field of pathologies in that region. To know about these findings seems to be very important not only in diagnosis (angiography, color coded doppler sonography) but also in their surgical and endovascular treatment.

Aorta, Thoracic↗

PubMed1997

Scarpa's fascia flap: anatomic studies and clinical application.

Fascia and fascia-subcutaneous flaps are thin, pliable, and well-vascularized tissue with aesthetic and functional advantages, particularly for the extremities and in the head and neck region. Although various donor sites have been used for these flaps, there is an occurrence of unsatisfactory donor-site defects that are often complicated by conspicuous, widened scars or alopecia. In addition, flap elevation is sometimes prolonged because of the demanding operative procedures as well as the impossibility of a two-team approach. In this anatomic and clinical study we present a new fascial flap that results in a minimal donor-site defect and a short and easy operative procedure. Scarpa's fascia, which can be used as both a free and a pedicled flap, is a well-defined single membranous sheet within the subcutaneous tissue layer at the lower abdominal wall. We studied its distribution, structure, and vascular supply in 27 fresh cadaver specimens. In addition, computed tomographic (CT) and ultrasound studies were performed in 13 healthy volunteers and in 3 cadavers before and after injection of diluted contrast material in the superficial epigastric artery. Finally, histologic examinations were done with hematoxylin and eosin or with reticulum and elastin. Our studies showed that Scarpa's fascia provides a thin, pliable, and well-vascularized flap pedicled on the superficial epigastric artery. After successful application of the Scarpa's fascia flap as a free flap in 3 patients and as a pedicled option in 1 patient, we can recommend this flap as a valuable tool for the reconstructive surgeon.

Abdominal Muscles↗

PubMed1997

The vertically based deep fascia turnover flap of the leg: anatomic studies and clinical applications.

Although fasciocutaneous turnover flaps are a simple and fast method for covering soft-tissue defects of the lower leg, many reconstructive surgeons have their doubts about them. They revolve around the lack of criteria for safely designing these random-pattern flaps and around the risk of donor site problems. A vertically based deep fascia turnover flap with a paratibial or parafibular pedicle is presented. Anatomic studies of 36 injected lower limbs showed the deep fascia to be supplied by a mean of 61 vessels. As musculofascial, septofascial, and periosteofascial branches, these contribute to a richly anastomosing vascular network within the deep fascia. Along the deep transverse septum at the medial tibial border, the anterior and posterior peroneal septa, and between the anterior tibial and extensor muscles, the fascia is supplied by segmental vessels in a clearly defined arrangement. Pedicled on these vessels, the deep fascia is a useful candidate tissue for transversely oriented turnover flaps. These are particularly well suited for covering pretibial or prefibular soft-tissue defects. Unlike adipofascial turnover flaps, the transversely oriented deep fascia turnover flap keeps its subcutaneous layer with its intact vascular plexus so that the overlying skin is adequately perfused even in patients with sizable flaps or an extremely thin skin. Clinical experience with the vertically based paratibial or parafibular deep fascia turnover flap in six patients confirmed its usefulness for covering small to medium-sized soft tissue defects of the lower leg.

Adult↗

PubMed1996

Endoscopic carpal tunnel release using a single-portal system.

In this prospective clinical study, we present our experience with a new single portal carpal tunnel release kit. The safety and efficacy of this new device was assessed and compared with a consecutive control group treated with conventional open carpal tunnel release. 126 patients were enrolled in this study, 64 of them were treated endoscopically (group 1) and 62 by open release of the carpal ligament (group 2). Follow-ups were conducted at 1, 3, 6, 12 and 24 weeks postoperatively. A serious intraoperative complication in group 1 was a transection injury of a branch of the superficial palmar arch. No intraoperative complications were noted in group 2. Postoperative evaluation revealed significantly less scar tenderness in group 1 at 1 week (P < 0.001), 3 weeks (P < 0.001) and 24 weeks (P < 0.05) compared to group 2. Functional status at 1 week was significantly (P < 0.05) better in group 1 than in group 2 but not at later times. Grip strength at 1 week (P < 0.001), 3 weeks (P < 0.05) and 12 weeks (P < 0.05), and pinch strength at 3 weeks (P < 0.001) were significantly higher in group 1. No significant differences between the groups were obtained regarding postoperative symptom severity. The new device provides a reliable tool for single portal carpal tunnel release, although the risk of inadvertent damage to the neurovascular structures always remains a possibility with the endoscopic carpal tunnel technique.

Activities of Daily Living↗