Biomedical subjects

R Seibel

Publications and source records attributed to R Seibel.

35 records · Page 2Linked to original sources

PubMed1996

Non-invasive visualization of coronary arteries with and without calcification by electron beam computed tomography.

Coronary artery disease (CAD) is one of the leading causes of mortality and morbidity in the western industrialized countries. Recent studies demonstrate the feasability of successful primary and secondary prevention. However, the detection of early stages of coronary artery disease is an unresolved issue. Whereas sensitivity and specificity of traditional risk factor assessment and stress tests are limited, the analysis of coronary calcification allows to obtain a direct sign of coronary atherosclerosis. This concept has been applied using fluoroscopy and conventional computed tomography (CT). However, the exact localization and quantification of coronary calcification only became possible with the advent of electron beam CT (EBCT). This new method showed a high prevalence of coronary calcification in the asymptomatic population. With the definition of a standardized "calcium score" the normal age-specific distribution and amount of coronary calcification was investigated. EBCT proved to be more sensitive in the diagnosis of both non-obstructive and obstructive coronary artery disease than risk factor analysis and stress testing, respectively. Obstructive coronary artery disease, however, cannot yet be predicted with high enough accuracy. A close correlation of EBCT coronary calcification was found to a) the total coronary plaque volume defined by histo-pathology, b) intracoronary ultrasound findings, c) the number of coronary risk factors, d) the coronary prognosis. Using EBCT, a reliable non-invasive identification of persons at risk was obtained for the first time. Guidelines for the use of EBCT in the early diagnosis and treatment of coronary artery disease are being developed.

Adult↗

PubMed1995

[Electron beam tomography in coronary disease. Prevalence and distribution of coronary calcifications and their relationship with coronary risk factors in 650 patients].

OBJECTIVE: The extent of coronary calcification demonstrated by electron beam tomography was correlated with the individual cardiac risk profile. PATIENTS AND METHODS: The possible presence of coronary calcifications was studied by electron beam tomography (EBT) in 650 patients (526 men, 124 women; mean age 54 +/- 10 [28-81] years) with known or suspected coronary heart disease. Depending on the degree of density and the size of the lesion a score was calculated according to an international standard. RESULTS: No calcification was shown to be present in 202 patients (score of 0). A score of more than 0 was calculated in 73.8% of men and 48.4% of women. The average score was 227.8 +/- 24.8 in men, compared with 65.3 +/- 26.5 in women (P < 0.001). There were significantly more calcifications in older patients: Men aged 71-75 years had the highest score, 859.4, while the lowest, 9.6, was in those aged 36 to 40 years. The most important variables for the presence of calcification were age (relative risk per age group: 1.6), male sex (relative risk: 4.3), hypertension (relative risk: 2.4) and nicotine consumption (relative risk: 1.8). The median point score in patients without known risk factors was 1.3, with one known factor it was 7.2, and with three it was 48.0. The vessel segment most affected with calcification was the anterior interventricular branch with an average score of 84. CONCLUSION: Together with an evaluation of the risk profile EBT provided a better assessment of individual risk than conventional examination.

Adult↗

PubMed1995

Ports, Trocars/Cannulae, and Access Techniques.

One of the keys to safe laparo-endoscopic surgery is an expeditious, reliable, and safe access to the operative field. Aside from appropriate surgical technique, the technology of trocars, cannulae, and other endoscopically guided insertion techniques plays a decisive role for safe identification of and access to the peritoneal cavity. This report takes a close look at critical features of trocar and cannula design for blind insertion with the focus on the biomechanical principles involved in traversing the abdominal wall. Particular attention has been paid to techniques minimizing the risk of accidental injury to major vessels, intestine, and other important structures. The principle of controlled visualized access led to several developments in the field of trocars, cannulae, and puncture techniques. Aside from blind and open access with the Veress needle, conventional trocars and cannulae, a selected variety of endoscopically assisted ports such as the optical Veress needle, optical trocars and optical scalpel, and a vacuum-supported access system are described in detail.

Journal Article↗

PubMed1995

[Microinvasive, CT-controlled periradicular therapy in treatment of chronic intervertebral disk-induced functional disorders].

The disease of the spinal column is number 2 of common diseases world-wide and leads to high business- and commerce-related losses as well as to high expenses for the health care systems. An effective treatment of this disease is given by the microinvasive. CT controlled periradicular therapy (micro PRT). Under visibility, the tip of a canula is led directly and high precisely in close neighbourhood to the prolaps, then locally NaCl and cristaline cortisone (40 mg Volon A) is instillated. The periradicular distribution and the distribution into the epidural space is documented via contrast medium. A retrospective study with 220 patients and a prospective randomized double blind study with 40 patients (10 mg vs. 40 mg Volon A) were carried out. The average age of the retrospective collective was 53.1 +/- 12.4 years, average treatment period 18.4 weeks, and the mean follow-up 17 months. The mean value of successful treatment of lumbal spine was at 60% (spine 88.5%) with protrusion, with prolaps at 75% (spine 94%), with sequester at 94%, and with stenoses at 69% (spine 60%). With 78.8% of the patients, the percentual result was constantly good at the time of questionnaire as to the end of the treatment. 7.7% still took analgesics, 5.9% were post-operated. 1.8% of the patients made a pension application. The average age of patients within the prospective randomized double-blind-study was 47.2 +/- 11.9 years. At 27.5% of the patients, the start of pain was about more than 5 years ago and goes back to about 23 years (72.5% had pain more than 1 year). The mean value of visits was 4 physicians per patient, and 5 months of follow-up. There is a high significant improvement in results within the group with 40 mg Volon A (p = 0.0351479). The entire improvement, subjectively estimated (visual analogical scale) within this group was at 90%. After end of therapy, 83.3% (n = 30) had stopped the taking of analgesics and the neurologic deficit decreased significantly. Furthermore, significant reduction of prolapses could be observed at 60% of the patients in both study groups (n = 156). The CT scopic micro PRT with 40 mg Volon A leads to a significant improvement of pain and neurologic symptoms caused by chronical disk herniation.

Adult↗

PubMed1995

[Noninvasive evaluation of the patency of coronary vessel stents using electron beam tomography segment images with administration of contrast media].

The implantation of intracoronary stents is increasingly employed in interventional cardiology. Even with high-resolution x-ray equipment the tiny struts of stainless steel stents can usually not be visualized. Coronary angiography is required to prove stent patency, and correct localization and deployment of the stent can only be assessed with intravascular ultrasound. In this setting a non-invasive diagnostic method would be of great advantage to document patency of the stented vessel segment. Herein we describe two patients with stent implantation in whom contrast-medium-enhanced electron beam tomographic scanning was applied to check for vessel patency. A pathological finding with reduced contrast enhancement could be distinguished from a normal finding, as was confirmed subsequently as a highly obstructed and a patent stented vessel segment by angiography. Thus, for the first time an alternative non-invasive diagnostic method may provide information on patency of stented vessel segments and may be useful for sequential follow-up investigations.

Angina Pectoris↗

PubMed1994

How reliable is lumbar nerve root sheath infiltration?

To determine the reliability of lumbar nerve root sheath infiltration, a prospective study was performed. Ninety-four patients were randomized into three groups. In the first group of 33 patients, 0.5 cc of dye (Telebrix N, 30 g) was applied at nerve root L4, in the second group of 30 patients, 1.0 cc, and in the third group of 31 patients, 2.0 cc. The infiltration was guided by computer tomography. The diffusion of the dye was documented with computed tomography of the affected segment L4-5. The images were evaluated by an unbiased observer. The results showed that in the first group the dye diffused to the adjacent ipsilateral nerve roots L3 and/or L5 in nine patients. In the second and third groups this diffusion was seen in 9 and 11 patients, respectively. A diffusion into the psoas muscle was documented in 4, 10 and 22 patients, respectively. These latter differences were statistically significant (P < 0.01). Diffusion into the psoas muscle is especially important because the nerve roots converge in this muscle to become a plexus, and they are no longer surrounded by their dural sheaths. Diagnostic lumbar nerve root sheath infiltration should be performed by an experienced examiner. To guarantee high reliability, the tip of the needle should be placed as near as possible to the affected nerve root. The amount of local anaesthetic should be as small as possible, 0.5 cc or preferably less.

Anesthetics, Local↗

PubMed1993

External fixation of severely comminuted and open tibial pilon fractures.

Twenty patients with severely comminuted fractures about the ankle, either severely comminuted pilon fractures or open pilon fractures (three Grade II, seven Grade III), were managed with the use of a Delta-framed external fixator across the ankle joint. All fractures had open reduction and internal fixation (ORIF) with either screw fixation or small plates to stabilize the articular surface with minimal soft-tissue dissection. Average external fixator time was 2.5 months, and the time to union averaged 4.5 months. All fractures healed. Three delayed unions required bone grafting and two had plate stabilization. No infection occurred in the 12 open fractures. There was no infection of the closed injuries, no skin sloughs, and only two minor pin tract infections. Follow-up analysis averaged 12 months (range, six to 30 months). Range of motion (ROM) at last follow-up observation was excellent in six patients, good in nine, fair in three, and poor in two. Two patients required ankle arthrodesis because of posttraumatic arthritis. The ROM and outcomes of the severely comminuted or open fractures of the distal intraarticular tibia were very good.

Adult↗

PubMed1992

Experience as a surgeon determines resident knowledge.

BACKGROUND: This is a prospective study that compares operative experience with performance on the American Board of Surgery Inservice Training Examination (ABSITE) to establish the primacy of procedural experience in the graduate training environment. METHODS: Operative experience was determined from a computerized log of surgical procedures. The Report D of the 1991 ABSITE was used to assign each test item to specific operative procedures and to determine the frequency of the correct response (Fcr) for each item. The fraction of operative procedures (Fs) was determined for each category of surgical procedures (Fs = Number of procedures as surgeon/Total number of procedures). The Fcr was compared to the Fs by use of the Pearson correlation coefficient with significance at 95% confidence. RESULTS: Forty-two residents reported doing 8357 surgical procedures as surgeon in 12 months. Report D contained 209 test items. Of these, 162 items could be assigned to 26 categories of surgical procedures. The Fcr correlated directly with the Fs (p = 0.002, r = 0.605). CONCLUSIONS: A significant correlation exists between the experience of surgical residents as surgeon and their performance on the ABSITE:

Clinical Competence↗

PubMed1987

The gut origin septic states in blunt multiple trauma (ISS = 40) in the ICU.

The association between support elements (ventilator days = Vd, enteral protein = EnP, number of antibiotics per day = AB/d) and the magnitude of the septic state (SSS) and its bacteriologic manifestations (bacti. log) in 66 patients with blunt multiple trauma (mean HTI-ISS = 40) over 1649 days have been studied retrospectively. SSS is measured by summing the standard deviation units of change in the septic direction for the 16 measurements taken every day in the intensive care unit. Increasing Vd is tightly associated with an increasing SSS (r = +0.52), after day 10 an increasing bacti. log (r = +0.21 to +0.32), and an increasing AB/d (r = +0.26) (all p less than 0.001, N = 1615 - 1626). The independent variables that best predicted Vd were delayed operations (DORS), day of rising EnP, and total positive blood cultures (TPC) (adj. R sq. = 0.84, F = 104, dF = 3/59). An increasing AB/d was associated with an increasing SSS (r = +0.38), increasing Vd (r = +0.26), and an increased bacti. log (r = +0.14 to +0.18) (all p less than 0.001, N = 1615). Only an increased EnP was consistently associated with a reduced SSS (r = -0.38) and a reduction in bacti. log (r = -0.10 to -0.21) (all p less than 0.001, N = 1626-1636). The independent variables Vd, EnP, AB/d, and TPC best predicted SSS for all surviving patients (adj. R sq. = 0.42, F = 268, dF = 4/1496). The patients who died of sepsis were not different in terms of bacti. log from those with equal Vd but were distinguished by zero EnP, high AB/d, and persistent ventilatory support. In conclusion, DORS is tightly associated with increased Vd, SSS, AB/d, and zero EnP. If Vd exceeds 10, there is an increasing bacti. log and evidence of infection probably from the gut. This responds only to increased EnP and not to AB/d. Death due to sepsis is not associated with increased bacti. log but with zero EnP and high AB/d and their consequences.

Adolescent↗

PubMed1985

Blunt multiple trauma (ISS 36), femur traction, and the pulmonary failure-septic state.

Fifty-six blunt multiple trauma patients (HTI-ISS 22-57) were studied for the effects of immediate versus delayed internal fixation of a femur or acetabular fracture on the pulmonary failure septic state. The pulmonary failure septic state may be defined as an alveolar arterial oxygen tension difference greater than 100, plus fever and leukocytosis. These patients were divided into four groups. Group I (N = 20) had immediate internal fixation, postoperative ventilatory support, and was sitting up at 30 hours. Group II (N = 20) had 10 days of femur traction and postoperative ventilatory support. Group III (N = 9) was immediately extubated after surgery and had 30 days of femur traction. Group IV (N = 7) had special circumstances that should increase the duration of the pulmonary failure septic state. These four groups of patients were statistically identical by 20 different criteria on admission except that Group I had more recognized chest injuries than Group II (12 vs. 9). Group I required 3.4 +/- 2.6 days of ventilator support and 7.5 +/- 3.8 intensive care unit (ICU) days; they had 12 +/- 8.8 elevated white counts, 3.8 +/- 4 febrile days, 0.05 positive blood cultures per patient, four fracture complications out of 93 fractures, 59 injections of narcotics, and 23 +/- 8.6 acute care days. Ten days of femur traction doubled the duration of the pulmonary failure septic state relative to Group I at a statistically significant level for nine out of 10 criteria, while increasing the number of positive blood cultures by a factor of 10, the number of fracture complications by a factor of 3.5, and the use of injectable narcotics by a factor of 2. Thirty days of femur traction increased the duration of the pulmonary failure septic state relative to Group I by a factor of 3 to 5 for all criteria at a statistically significant level, while increasing fracture complications by a factor of 17, positive blood cultures by a factor of 74, and the use of narcotics by a factor of 2. Group IV, which had four out of seven immediate internal fixations, behaved similarly to Group II. Femoral shaft traction should be avoided in the blunt multiple trauma patients because it greatly increases the cost of care and the risk of multiple systems organ failure.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetabulum↗

PubMed1982