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Michael Koller

Publications and source records attributed to Michael Koller.

At least 19 recordsLinked to original sources
PubMed2006

Improvement of surgical skills after a three-day practical course for laparoscopic surgery.

OBJECTIVES: Currently, skills labs are becoming increasingly important in the field of medical education. This study aims to objectively assess psychomotor skills acquisition of residents attending a three-day laparoscopic course. MATERIALS AND METHODS: 44 participants (test group) of the sixth practical course for Visceral Surgery of German surgical societies (Deutsche Gesellschaft für Chirurgie; DGCH and Berufsverband Deutscher Chirurgen; BDC) in Warnemuende with various degree of experience in laparoscopic surgery (18 advanced residents performing more than 50 laparoscopic operations and 26 novices performing less than 10 laparoscopic operations) and 6 consultants attending as tutors of the course (gold standard) were recruited as subjects. 20 medical students in their final year (camera holder) were chosen as a second control group (naive). Both control groups had no training during the practical course. The virtual reality simulator LapSim was used to assess laparoscopic skills of participants before and after the course. Time to complete the tasks, error score, and economy of motion parameters (path length and angular path) were analysed. RESULTS: After the practical course the advanced participants of the test group completed the task significantly faster (p = 0.019), with smaller error score (p = 0.023), and more economy of motion [path length (p = 0.014) and angular path (p = 0.049)] than before the course. The novices of the test group and both control groups showed no significant improvement of their performance parameters (p >0.05). CONCLUSION: A three-day practical course for laparoscopic surgery improved laparoscopic skills of residents. However, advanced residents benefit most from the course.

Adult↗
PubMed2006

Supervised surgical trainees perform thyroid surgery for Graves' disease safely.

BACKGROUND: There is little information about the effect of operative experience and supervision of trainees on long-term outcomes after thyroid resection for Graves' disease (GD). The aim of this study was to compare the morbidity rate after thyroid resection performed by trainees vs consultant surgeons. METHODS: Based on a cross-sectional design analysis with a median follow-up of 96 months (range, 12-216 months), long-term outcomes for 111 patients operated on by consultants were compared with those of 42 patients operated on by supervised trainees in an academic teaching hospital between 1987 and 2002. RESULTS: Of the 111 patients operated on by the consultants, there were 25 (21.6%) cases of transient and 12 (10.8%) cases of permanent hypocalcemia and 10 (9.0%) cases of transient and 1 (0.9%) case of permanent recurrent laryngeal nerve (RLN) palsy. Of the 42 patients operated upon by the supervised trainees, there were 8 (21.4%) cases of transient and no permanent hypocalcemia, 3 (7.1%) cases of transient, and 1 (2.3%) case of permanent RLN palsy. Permanent complication rate of the entire group was low, and the grade of the primary surgeon made no difference in the occurrence of complications (P>0.05). CONCLUSION: Supervised trainees can perform thyroid surgery for GD safely if a standardized surgical teaching program is available.

Adolescent↗
PubMed2006

Keratocyte density in the retroablation area after LASEK for the correction of myopia.

PURPOSE: During excimer laser photoablation keratocyte cell death is induced in the retroablation area. Afterwards this area is repopulated by keratocyte mitosis and migration from the adjacent stroma. The aim of this study was to investigate keratocyte density in the retroablation area and in the posterior stroma during the first year after LASEK for the correction of myopia. METHODS: In a prospective study LASEK surgery was performed in 17 eyes of 10 consecutive patients for the correction of myopia (-2.25 D to -9.0 D, mean -5.0 D). Confocal microscopy (Nidek Confoscan 2) was performed before surgery and 1 month, 3 months, 6 months and 12 months after LASEK. Keratocyte density was assessed in the anterior retroablation area at depths of 5 mum and 25 mum and in the posterior stroma at distances of 5 mum and 100 mum from the corneal endothelium and compared with the corresponding area before surgery. RESULTS: Keratocyte density was statistically significant reduced in the retroablation area at all timepoints after LASEK. At a depth of 5 mum, cell densities were decreased by 64%, 47%, 43%, and 28% at 1 month, 3 months, 6 months and 12 months after LASEK compared with preoperative values. At a depth of 25 mum, cell densities were decreased by 51%, 32%, 28%, and 18% at 1 month, 3 months, 6 months and 12 months after LASEK compared with preoperative values. In the posterior stroma no significant change in keratocyte density was observed at any time after LASEK. CONCLUSIONS: Keratocyte density in the anterior retroablation area recovers during the first year after LASEK for the correction of myopia, but does not go back to preoperative values.

Adult↗
PubMed2006

Early self-reported impairments in arm functioning of primary breast cancer patients predict late side effects of axillary lymph node dissection: results from a population-based cohort study.

OBJECTIVES: Improvements in the life expectancy of women with breast cancer raise important questions how to improve quality of life (QoL) for women sustaining complications and side effects of cancer treatment. The presented study examined the prevalence of arm morbidity in a cohort of primary breast cancer patients over time as a result of the extent of axillary lymph node dissection. Of particular interest is the question of using a recognized QoL assessment instrument at defined assessment points as an endpoint criteria of oncological treatment. METHODS: A prospective, population-based, longitudinal cohort study of patients with primary breast cancer was performed (n = 389). QoL data (EORTC QLQ C30 + BR23) and clinical data were assessed at designated time points. Primary endpoint of this analysis was patient reported arm morbidity assessed with the three-idem scale in the BR 23 (swelling, moving, pain). RESULTS: 20% of the patients evidenced considerable impairments in arm functioning. Arm morbidity was significantly related to the number of lymph nodes dissected (P < 0.002 entire cohort, P < 0.001 lymph node negatives) and was independent of age, stage of the disease, kind of breast surgery and radiation treatment. Early impairments in arm functioning (below 50 score values) assessed within 6 months after axillary surgery was a good predictor for late arm morbidity at 12 months RR 11.5 (CI 95% 4.7-28.4), 24 months RR 6.0 (CI95% 2.8-13.3) and 36 months RR 3.8 (CI 95% 1.8-7.9). CONCLUSIONS: Arm morbidity after axillary surgery is a severe and chronic condition affecting many breast cancer patients. The recognized QoL assessment instrument depict patients with severe impairments in arm functioning after axillary lymph node dissection and predict late arm morbidity. To increase patients' quality of life it thus may serve as a valid assessment tool for screening, allowing early referral for treatment and monitoring.

Aged↗
PubMed2006

Novices in surgery are the target group of a virtual reality training laboratory.

BACKGROUND: This study aims to establish which physicians represent the suitable target group of a virtual training laboratory. METHODS: Novices (48 physicians with fewer than 10 laparoscopic operations) and intermediate trainees (19 physicians who performed 30-50 laparoscopic operations) participated in this study. Each participant performed the basic module 'clip application' at the beginning and after a 1-hour short training course on the LapSim. The course consisted of the tasks coordination, lift and grasp, clip application, cutting with diathermy and fine dissection at increasing difficulty levels. The time taken to complete the tasks, number of errors, and economy of motion parameters (path length and angular path) were analyzed. RESULTS: Following training with the simulator, novices completed the task significantly faster (p = 0.001), demonstrated a greater economy of motion [path length (p = 0.04) and angular path (p = 0.01)]. In contrast, the intermediate trainees showed a reduction of their errors, but without reaching statistical significance. They showed no improvement in economy of motion and completed the task significantly slower (p = 0.03). CONCLUSION: Novices, in comparison to intermediate trainees, tend to benefit most during their first exposure to a laparoscopy simulator.

Adult↗
PubMed2006

Preoperative information for ICU patients to reduce anxiety during and after the ICU-stay: protocol of a randomized controlled trial [NCT00151554].

BACKGROUND: According to current evidence and psychological theorizing proper information giving seems to be a promising way to reduce patient anxiety. In the case of surgical patients, admission to the intensive care unit (ICU) is strongly associated with uncertainty, unpredictability and anxiety for the patient. Thus, ICU specific information could have a high clinical impact. This study investigates the potential benefits of a specifically designed ICU-related information program for patients who undergo elective cardiac, abdominal or thoracic surgery and are scheduled for ICU stay. METHODS/DESIGN: The trial is designed as a prospective randomized controlled trial including an intervention and a control group. The control group receives the standard preparation currently conducted by surgeons and anesthetists. The intervention group additionally receives a standardized information program with specific procedural, sensory and coping information about the ICU.A measurable clinical relevant difference regarding anxiety will be expected after discharge from ICU. Power calculation (alpha = 0.05; beta = 0.20; Delta = 8.50 score points) resulted in a required sample size of N = 120 cardiac surgical patients (n = 60 vs. n = 60). Furthermore, N = 20 abdominal or thoracic surgical patients will be recruited (n = 10 vs. n = 10) to gain insight to a possible generalization to other patient groups. Additionally the moderating effect of specific patient attributes (need for cognition, high trait anxiety) will be investigated to identify certain patient groups which benefit most. DISCUSSION: The proposed study promises to strengthen evidence on effects of a specific, concise information program that addresses the information needs of patients scheduled for ICU stay.

Journal Article↗
PubMed2006

Evaluation of the McPeek postoperative outcome score in three trials.

BACKGROUND: Postoperative outcome of patients is determined by recovery characteristics and self-reported quality of life. The first can be assessed with the McPeek score which values three aspects of recovery: mortality, postoperative critical care and duration of hospitalization. MATERIALS AND METHODS: We calculated the McPeek score of 669 patients in three trials: (1) colorectal cancer surgery, (2) antihistamine/volume loading in various operations, and (3) cholecystectomy. Beforehand, the average of intensive care unit treatment and duration of hospitalization were determined for the different operations to define McPeek score points. The score was tested on reliability, validity, and sensitivity. In addition, clinical applicability was assessed in a survey. RESULTS: The score was reliable with similarly distributed score points in the three trials at different institutions. Inter-rater reliability was high (97% overlap). Validity was proven by moderate high correlation to convergent criteria such as complications (trial I to III r=0.43, r=0.38, r=0.60), preoperative American Society of Anesthesiologists class (ASA) (r=0.24, r=0.28, r=0.57), and age (r=0.23, r=0.32, r=0.31). The score was different between patients with and without neoplasms (P<0.001, trial II) and between elective or emergency patients (P<0.001, trial III). In a survey, investigators reported that the score was easy to assess and more comprehensive than four other scores. CONCLUSIONS: The McPeek score values the postoperative outcome on a nonlinear scale. A priori, the average duration of hospitalization and critical care for a specific operation has to be defined. Our validation suggests that it is a reliable, valid, sensitive, and practical instrument for outcome analysis after anesthesia and surgery.

Adult↗
PubMed2006

[Diagnosis and therapy of illness-related quality of life in breast cancer patients. Protocol of a randomized clinical trial at the Regensburg Tumour Centre].

BACKGROUND: The project conducted at the Tumour Centre in Regensburg aims to integrate quality of life (QL) diagnostics with the therapy of breast cancer patients and to evaluate the efficacy of QL diagnostics in the context of a randomized clinical trial. METHODS: The Regensburg Tumour Centre provides the infrastructure of the present project (telemedicine, project groups, quality circle). The treatment of breast cancer patients is based on the recent national breast cancer therapy guideline, including assorted QL-enhancing therapy options such as pain therapy, physiotherapy and lymphatic drainage, psychotherapy, social counselling and rehabilitation, nutrition and sports. During an implementation phase a new method of QL diagnostics has been developed. Five experts with varying professional background use the individual patient's QL profile and clinical and socio-demographic information in order to generate a QL report including a treatment recommendation. The study is designed as a two- arm randomized clinical trial with one test group (communication of the QL findings to the co-ordinating physician) and a control group (no communication). Patients with newly diagnosed breast cancer who are treated in the study region by one of the co-ordinating doctors will be included in this randomized study. At designated points in time QL assessments (EORTC QLQ-C30 plus BR23) will be conducted over a 12-months period. EXPECTED RESULTS: We expect that patients in the test group will experience a lower amount of QL deficits at the end of the study period (M = 1, SD = 2) than patients in the control group (M = 2, SD = 2). The statistical confirmation of this expected effect requires a total sample size of N = 200 (n = 100 vs. n = 100, alpha = 5% [two-tailed], beta = 10%). CONCLUSIONS: This is the first study to evaluate a new form of QL diagnostics in the complexity of a real patient care environment, and it promises to make the inclusion of the quality of life concept into the current breast cancer treatment guideline more tangible.

Breast Neoplasms↗
PubMed2005

Octreotide versus octreotide plus interferon-alpha in endocrine gastroenteropancreatic tumors: a randomized trial.

BACKGROUND & AIMS: The effect of octreotide plus interferon-alpha versus octreotide monotherapy on the primary study end points of time to treatment failure (progression, death, stop of study treatment) and long-term survival was investigated in patients with progressive metastatic neuroendocrine foregut (mainly pancreatic) and midgut tumors. METHODS: One hundred nine of 125 registered patients were randomized starting in January 1995, and 105 patients (51 monotherapy, 54 combination treatment) were finally analyzed in March 2000. Tumor growth was assessed at 3-month intervals by computed tomography or magnetic resonance imaging. Long-term survival was studied up to April 2004 in all analyzed patients and in 9 patients not randomized because of stable disease. RESULTS: Partial tumor regression occurred in 2.9%, 1.9%, and 5.7% and stabilization of tumor growth in 44.8%, 27.6%, and 15.2% at 3, 6, and 12 months, respectively, with no significant differences between both treatment arms. In March 2000, 9.5% of patients were in treatment. Time to treatment failure and long-term survival did not differ significantly between the 2 groups, with a median survival of 32 and 54 months for the octreotide and the combination groups, respectively. Survival was longer in patients not randomized because of stable disease (median, 68 months) and in those with low nuclear Ki-67. A trend toward longer survival was shown for patients with slow spontaneous tumor growth before randomization. Patients responding to treatment lived longer than unresponsive patients. CONCLUSIONS: Combination treatment was not superior to monotherapy concerning progression-free and long-term survival. Patients responding to treatment and those with slow spontaneous tumor growth had a survival advantage.

Adolescent↗
PubMed2004

Integrated outcome assessment after anterior cervical discectomy and fusion: myelocompression but not adjacent instability affect patient-reported quality of life and cervical spine symptoms.

STUDY DESIGN: The authors conducted a cross-sectional study. OBJECTIVE: Integrated assessment of adjacent instability (AI), myelocompression (MC), magnetic resonance imaging (MRI) signs of myelopathy (MRISM), physician-assessed clinical signs and symptoms, including clinical signs of myelopathy (CSM), patients' self-reported symptoms and quality of life after anterior cervical discectomy and fusion (ACDF). MATERIALS AND METHODS: Fifty-four patients who had ACDF between 1986 and 1995 received MRI scans, conventional and flexion/extension radiographs to assess myelocompression, MRISM, fusion, and AI. Clinical outcome was assessed using signs and symptoms based on selected items of Odom's criteria, Oswestry low back pain disability questionnaire, and the neck disability index. Patients reported their quality of life (QL) on a standardized instrument (Profiles of QL of Chronically Ill [PLC]) and by a specific validated Cervical Spine Symptom Scale (CSSS). RESULTS: Myelocompression was found more frequently than expected (24%). MRISM were seen in 2 patients (4%). One of the 2 patients developed CSM. Fusion was achieved in 94% (with kyphosis in 17%). AI was found in 30%. However, only myelocompression but not AI was associated with statistically significant decreases in most QL scores (i.e., everyday capabilities, positive mood) and high cervical spine symptom burden (all P's < 0.05). CONCLUSIONS: The study results underline the need for a better understanding of the biomechanical changes in the adjacent unfused segments. Consensus is needed on postoperative follow-up guidelines, including pain management strategies. Future studies on the outcome of ACDF will profit from an integrated outcome approach, including assessments based on imaging, physicians, and patients.

Adult↗
PubMed2004

Comprehensive Geriatric Assessment (CGA) in general practice: results from a pilot study in Vorarlberg, Austria.

BACKGROUND: Most comprehensive geriatric assessment (CGA) programs refer to hospital-based settings. However the body of geriatric healthcare is provided by general practitioners in their office. Structured geriatric problem detection by means of assessment instruments is crucial for efficient geriatric care giving in the community. METHODS: We developed and pilot tested a German language geriatric assessment instrument adapted for general practice. Nine general practices in a rural region of Austria participated in this cross-sectional study and consecutively enrolled 115 persons aged over 75 years. The prevalence of specific geriatric problems was assessed, as well as the frequency of initiated procedures following positive and negative tests. Whether findings were new to the physician was studied exemplarily for the items visual and hearing impairment and depression. The acceptability was recorded by means of self-administered questionnaires. RESULTS: On average, each patient reported 6.4 of 14 possible geriatric problems and further consequences resulted in 43.7% (27.5% to 59.8%) of each problem. The items with either the highest prevalence and/or the highest number of initiated actions by the GPs were osteoporosis risk, urinary incontinence, decreased hearing acuity, missing pneumococcal vaccination and fall risk. Visual impairment was newly detected in only 18% whereas hearing impairment and depression was new to the physician in 74.1% and 76.5%, respectively.A substantial number of interventions were initiated not only following positive tests (43.7% per item; 95% CI 27.5% to 59.8%), but also as a consequence of negative test results (11.3% per item; 95% CI 1.7% to 20.9%). The mean time expenditure to accomplish the assessment was 31 minutes (SD 10 min). Patients (89%) and all physicians confirmed the CGA to provide new information in general on the patient's health status. All physicians judged the CGA to be feasible in everyday practice. CONCLUSION: This adapted CGA was feasible and well accepted in the general practice sample. High frequencies of geriatric problems were detected prompting high numbers of problem-solving initiatives. But a substantial number of actions of the physicians following negative tests point to the risks of too aggressive treatment of elderly patients with possibly subsequent negative effects.

Journal Article↗
PubMed2004

[A concept for the implementation and evaluation of the guideline "Early Detection of Breast Cancer in Germany"].

Systematically developed, evidence- and consensus-based guidelines are important tools for improving health care services. The effectiveness of a guideline does not only relate to its methodological quality but also to the implementation strategy used. The following paper describes the systematic development of a strategy for implementing and evaluating the guideline "Early Detection of Breast Cancer in Germany" as part of a national project. A multi-faceted systematic implementation strategy has been developed addressing existing barriers and building on projects that have recently been introduced in Germany to improve the early detection and management of breast cancer. The aim is to induce behavioural changes in women as healthcare recipients and physicians as healthcare providers, both involved in the medical decision-making process within the scope of the guideline. Furthermore, it supports organisational changes to assure compliance with the guideline by means of quality assurance and quality management. To ensure evaluation of the implementation process a set of quality indicators have been identified for the baseline assessment of structures, provider performance and outcomes. Both the effectiveness of the implementation process and the effectiveness of the guideline itself will be measured by using the same set of indicators for reevaluation within a pre-defined time interval of 18 months. The quasi-experimental design of this uncontrolled before and after implementation study outlined in the present paper allows the assessment of clinically relevant changes using quality indicators that measure the effectiveness of the guideline on a national level.

Breast Neoplasms↗
PubMed2004

[Short version of the guideline "Early Detection of Breast Cancer in Germany"].

The aim of this evidence-, consensus- and outcome-based good clinical practice guideline is to help physicians, and women in making appropriate healthcare decisions about the early detection of breast cancer. The principle of early detection of breast cancer comprises the detection and diagnosis of pre-malignant breast tumours (UICC stage 0, carcinoma in situ) with a possible cancer risk reduction and the detection and diagnosis of breast cancer at an early stage (UICC stage 1) with a scientifically proven 90% chance of cure. By establishing a nation-wide comprehensive quality assurance program for the early detection of breast cancer this guideline lays the foundation for a timely reduction of breast cancer mortality and achievement of cure with less impairment of patient's quality of life. It would appear that this guideline makes major improvements in women's healthcare feasible.

Algorithms↗
PubMed2003

Relation between severe illness and non-completion of quality-of-life questionnaires by patients with rectal cancer.

Quality of life (QoL) is an important outcome measure in clinical studies, but interpretation is hindered by incompleteness of data. We addressed this issue in a population-based cohort study of 146 patients with newly diagnosed rectal cancer. QoL was assessed by means of European Organization for the Research and Treatment of Cancer questionnaires at discharge from hospital after primary treatment and then every 3 months for 2 years. In parallel, objective clinical data were documented. Analyses were conducted in three steps: participants versus non-participants with QoL-assessment; poor compliers who filled in only one or two questionnaires (n=20) versus good compliers who filled in all or nearly all questionnaires (n=18); and the proportion of missing forms and critical (very poor) QoL scores in risk patients versus non-risk patients over the course of 2 years. Non-participants and poor compliers were older, were more likely to receive palliative (rather than curative) treatment, and had worse scores for physical status. Tumour progression and therapeutic interventions were more frequent in poor compliers than in good-compliers. Patients with risk factors (age 475 years, poor physical status, palliative treatment) were more likely to have missing questionnaires and critical QoL scores in respect of physical functioning and global quality of life over the course of 2 years. Missing values for QoL have clinical as well as methodological implications, because QoL scores can enhance a clinician's insight. Unwillingness to fill in a questionnaire is an indicator of serious illness. Studies that report sample statistics without specifying compliance rates and the characteristics of non-compliers will give a misleadingly positive picture.

Adult↗
PubMed2002

Communicating accuracy of tests to general practitioners: a controlled study.

OBJECTIVE: To assess the extent to which different forms of summarising diagnostic test information influence general practitioners' ability to estimate disease probabilities. DESIGN: Controlled questionnaire study. SETTING: Three Swiss conferences in continuous medical education. PARTICIPANTS: 263 general practitioners. INTERVENTION: Questionnaire with multiple choice questions about terms of test accuracy and a clinical vignette with the results of a diagnostic test described in three different ways (test result only, test result plus test sensitivity and specificity, test result plus the positive likelihood ratio presented in plain language). MAIN OUTCOME MEASURES: Doctors' knowledge and application of terms of test accuracy and estimation of disease probability in the clinical vignette. RESULTS: The correct definitions for sensitivity and predictive value were chosen by 76% and 61% of the doctors respectively, but only 22% chose the correct answer for the post-test probability of a positive screening test. In the clinical vignette doctors given the test result only overestimated its diagnostic value (median attributed likelihood ratio (aLR)=9.0, against 2.54 reported in the literature). Providing the scan's sensitivity and specificity reduced the overestimation (median aLR=6.0) but to a lesser extent than simple wording of the likelihood ratio (median aLR=3.0). CONCLUSION: Most general practitioners recognised the correct definitions for sensitivity and positive predictive value but did not apply them correctly. Conveying test accuracy information in simple, non-technical language improved their ability to estimate disease probabilities accurately.

Aged↗
PubMedDate not supplied

Outcome and quality of life in medicine: a conceptual framework to put quality of life research into practice.

It is rather counterproductive to get caught up in never ending discussions on what quality of life (QOL) is and whether it can be assessed. This article is based on the idea that it is much more important to improve the conceptual frameworks that allow the use of the QOL concept in clinical practice. Survival of the QOL concept within the medical community will depend on its contributions to a better understanding of patients and to improving patient care. It is important to accept that QOL should not be viewed in isolation but in synopsis, with other psychologic concepts and clinical data. We propose a profile format that presents QOL data in a way that is easily accessible for clinicians, allowing action to be taken immediately. QOL profiles are never a substitute but a starting point for a patient-doctor interaction. A profile driven interaction has the potential to be structured, efficient, and leading to action.

Biomedical Research↗