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Biomedical subjects

D B Witzke

Publications and source records attributed to D B Witzke.

At least 19 recordsLinked to original sources
PubMed2004

Development of a valid, cost-effective laparoscopic training program.

BACKGROUND: Practical programs for training and evaluating surgeons in laparoscopy are needed to keep pace with demand for minimally invasive surgery. METHODS: At the University of Kentucky five inexpensive simulations have been developed to train and assess surgical residents. Residents are videotaped performing laparoscopic procedures on models. Five surgeons assess the taped performances on 4 global skills. RESULTS: Creating mechanical models reduces training costs. Trainees agreed procedures were well represented by the simulations. Blinded assessment of performances showed high interrater agreement and correlated with the trainees' level of experience. Nonclinician evaluations on checklists correlated with evaluations by surgeons. CONCLUSIONS: Inexpensive simulations of laparoscopic appendectomy, cholecystectomy, inguinal herniorrhaphy, bowel enterotomy, and splenectomy enable surgical residents to practice laparoscopic skills safely. Obtaining masked, objective, and independent evaluations of basic skills in laparoscopic surgery can assist in reliable assessment of surgical trainees. The simulations described can anchor an innovative educational program during residency for training and assessment.

Education, Medical↗
PubMed2003

Determinants of competency judgments by experienced laparoscopic surgeons.

BACKGROUND: The definitive criteria for assessing competence remain elusive. In our study, we aimed to identify the determinants of competence assessment used by individual laparoscopic surgeons. METHODS: In a blinded fashion, five laparoscopic surgeons rated 27 subjects on three laparoscopic simulations in four skill categories: clinical judgment, dexterity, serial/simultaneous complexity, and spatial orientation. The raters then assessed overall subject competence for each procedure. Point-biserial correlational analyses and cluster analyses were performed to ascertain the relationships among the various scales. RESULTS: All of the correlations between the skills' ratings and competence judgments were statistically significant ( p <.05). No skill rating was consistently more highly correlated with the competence rating. There were no distinct patterns of correlations for each rater or each procedure. One factor emerged from each cluster analysis of the skills measures. CONCLUSIONS: The results suggest that the four skills scored in the study are highly correlated with each other and are important in determining competence. The cluster analyses revealed that the surgeon raters shared a common perception of competence.

Adult↗
PubMed2003

Evaluating minimally invasive surgery training using low-cost mechanical simulations.

BACKGROUND: The goal of this study was to develop, test, and validate the efficacy of inexpensive mechanical minimally invasive surgery (MIS) model simulations for training faculty, residents, and medical students. We sought to demonstrate that trained and experienced MIS surgeon raters could reliably rate the MIS skills acquired during these simulations. METHODS: We developed three renewable models that represent difficult or challenging segments of laparoscopic procedures; laparoscopic appendectomy (LA), laparoscopic cholecystectomy (LC), and laparoscopic inguinal hernia (LH). We videotaped 10 students, 12 surgical residents, and 1 surgeon receiving training on each of the models and again during their posttraining evaluation session. Five MIS surgeons then assessed the evaluation session performance. For each simulation, we asked them to rate overall competence (COM) and four skills: clinical judgment (respect for tissue) (CJ), dexterity (economy of movement) (DEX), serial/simultaneous complexity (SSC), and spatial orientation (SO). We computed intraclass correlation (ICC) coefficients to determine the extent of agreement (i.e., reliability) among ratings. RESULTS: We obtained ICC values of 0.74, 0.84, and 0.81 for COM ratings on LH, LC, and LA, respectively. We also obtained the following ICC values for the same three models: CJ, 0.75, 0.83, and 0.89; DEX, 0.88, 0.86, and 0.89; SSC, 0.82, 0.82, and 0.82; and SO, 0.86, 0.86, and 0.87, respectively. CONCLUSIONS: We obtained very high reliability of performance ratings for competence and surgical skills using a mechanical simulator. Typically, faculty evaluations of residents in the operating room are much less reliable. In contrast, when faculty members observe residents in a controlled, standardized environment, their ratings can be very reliable.

Clinical Competence↗
PubMed2002

Using semi-automated image processing and desktop systems to incorporate actual patient volumetric data in immersive surgical planning and viewing systems for multiple patients.

This paper describes how patient specific volumetric data are managed from image acquisition through final processing for the purposes of creating a 3D VR rendering of user selected and manipulated 3D models. The system described here allows for the development of quick, inexpensive, and clinician manipulated patient-specific models. The utility of this process is demonstrated by being able to move VRML models to desktop or immersive environments for both pre-operative planning and patient-specific surgical and anatomical training.

Computer Simulation↗
PubMed2001

Obesity and laparoscopic repair of ventral hernias.

BACKGROUND: Laparoscopic ventral hernia repair (LVHR) is gaining acceptance and compares favorably with open repair. Patients who are morbidly obese (MO) traditionally have been considered poor surgical candidates for ventral hernia repair because of their associated comorbidities and risk of postoperative wound infection and hernia recurrence. In this study we evaluated our experience with LVHR in patients who are obese and those who are morbidly obese. METHODS: All 64 patients undergoing LVHR at the University of Kentucky between September 1997 and October 2000, representing 66 hernias, were entered prospectively into a database. Data before, during, and after surgery were collected as well as follow-up data. Patients were divided into three groups on the basis of body mass index (BMI): normal to overweight (BMI < or = 29); obese (BMI 30-39), and MO (BMI > or = 40). RESULTS: There were 16 patients in the MO group, most of them women. The mean BMI was 43.9 (range, 40-60), and the mean age was 45.6 years (range, 25-68 years). The location of defects was similar among the groups, as were the number of prior repairs. The operative time and length of stay for the MO group tended to be longer than for the other two groups. Five minor complications occurred in the MO group. During a follow-up period ranging from 1 to 35 months, there were no recurrences. CONCLUSION: Laparoscopic repair of ventral hernias in patients who are morbidly obese is both safe and feasible, and can be performed with minimal morbidity. At this writing, there have been no recurrences, but long-term follow-up evaluation is required.

Adult↗
PubMed2001

Transfer of training in acquiring laparoscopic skills.

BACKGROUND: Building on skills already learned in acquiring more complex or related skills is termed transfer of training (TOT). This study examined the TOT effects of previous open and laparoscopic surgical experience on a laparoscopic training module. STUDY DESIGN: Intracorporeal knot tying was chosen for evaluating TOT among three groups of surgical residents: interns (n = 11) with limited open and laparoscopic surgical experience, junior residents (n = 9) with recent and ongoing open and laparoscopic surgical experience, and senior residents (n = 8) with remote and limited laparoscopic experience but ongoing open surgical experience. After receiving a lecture, demonstration, and written instructions on three knot-tying techniques, residents rotated through three performance stations, one for each technique, over 2 days. After 15 minutes of practice, the residents were videotaped completing a test knot. Time to completion and economy of motion were recorded and analyzed. RESULTS: Junior residents had fewer performance errors than senior residents (reported as mean +/- standard error of the mean) and were significantly faster than interns. No significant differences between interns and senior residents for mean time or error performance were observed. Senior residents did not demonstrate TOT from open surgical experience to laparoscopic knot tying. No significant differences were obtained across the three sessions for errors or for time. CONCLUSION: No evidence was found for TOT from open surgical experience to newly introduced laparoscopic knot-tying techniques or from one skill training session to a different skill session at least 4 hours later. This study indicates that specific minimally invasive surgery training is needed to develop laparoscopic surgery skills.

Clinical Competence↗
PubMed2001

Immersive virtual reality used as a platform for perioperative training for surgical residents.

Perioperative preparations such as operating room setup, patient and equipment positioning, and operating port placement are essential to operative success in minimally invasive surgery. We developed an immersive virtual reality-based training system (REMIS) to provide residents (and other health professionals) with training and evaluation in these perioperative skills. Our program uses the qualities of immersive VR that are available today for inclusion in an ongoing training curriculum for surgical residents. The current application consists of a primary platform for patient positioning for a laparoscopic cholecystectomy. Having completed this module we can create many different simulated problems for other procedures. As a part of the simulation, we have devised a computer-driven real-time data collection system to help us in evaluating trainees and providing feedback during the simulation. The REMIS program trains and evaluates surgical residents and obviates the need to use expensive operating room and surgeon time. It also allows residents to train based on their schedule and does not put patients at increased risk. The method is standardized, allows for repetition if needed, evaluates individual performance, provides the possible complications of incorrect choices, provides training in 3-D environment, and has the capability of being used for various scenarios and professions.

Cholecystectomy, Laparoscopic↗
PubMed2000

A pilot study of new approaches to teaching anatomy and pathology.

PURPOSE: Minimally Invasive Surgery (MIS) has impacted patient care as well as medical training. New medical education opportunities have emerged with MIS. In this pilot study we explore the role of live, interactive MIS to augment and strengthen specific segments of the undergraduate medical curriculum. METHODS: Laparoscopic cholecystectomy (LC) was selected to demonstrate upper abdominal anatomy and pathology. Second year medical students (n=100) in the course of their GI pathology classes attended live LC telesurgery-the telesurgery student group (TSG). Because of technical difficulties, a second class of medical students (n=90) was shown the tape of the MIS procedure one year later instead of the live surgery-the videotape surgery group (VSG). Background clinical information was provided by the program director and the durgeon. During the live and taped LC broadcast living anatomy was demonstrated and a diseased gallbladder was resected. TSG students were able to ask questions of the program director and the surgeon and vice versa using telesurgery technology. After the procedure, the surgeon met with the students for further discussion. VSG students were able to ask questions of the program director during and after the program. Both groups of students completed a pre- and posttest using remote audience responders. Students' responses from the two groups were compared for selected test and evaluation items. RESULTS: Pre-test (Cronbach's alpha=.10) and post-test (Cronbach's alpha =.28) data were obtained from 73 students in the TSG and.22 and.54 respectively from 69 students in the VSG. A significant increase in laparoscopic anatomy knowledge was observed from pretest to posttest for the VSG (31-55%) and from the TSG (30-61%). The majority of VSG students (68%) indicated the method used to teach was outstanding, and 87% indicated that the program was outstanding in keeping their interest. This is contrasted with only 24% of the TSG group responding that the teaching method was outstanding, and 41% indicated that the program was outstanding in keeping their interest. CONCLUSIONS: Medical students can productively be exposed to surgical methods and living anatomy using telesurgery. The high regard the TSG students had for this program suggests that it can be used effectively to teach and inspire medical students. The positive results have encouraged us to have a backup instructional method such as a tape of the MIS procedure, it apparently does not have the positive impact of live surgery.

Anatomy↗
PubMed2000

Laparoscopic splenectomy: outcomes and lessons learned from over 200 cases.

BACKGROUND: In this study of laparoscopic splenectomy (LS), we evaluate prospectively gathered perioperative patient data and review lessons learned in the evolution of this procedure. METHODS: At 2 university medical centers between November 1993 and March 2000, there were 203 patients (122 female patients and 81 male patients) who underwent LS after preoperative evaluation. RESULTS: LS was successfully completed in 197 patients (97%). The mean operative time was 145.5 minutes and the length of stay averaged 2.7 days with 143 (70.4%) staying less than 48 hours. The most common indication was idiopathic thrombocytopenic purpura (ITP). Six patients required conversion to open splenectomy (OS), with only 2 conversions in the last 163 cases. No deaths were attributed to the procedure. Complications occurred in 19 patients (9.3%). Thirty accessory spleens were identified in 25 patients (12.3%). Seventeen patients (8.4%) underwent concomitant procedures, most commonly cholecystectomy. CONCLUSIONS: LS by the lateral approach is both safe and feasible in patients of all ages.

Adolescent↗
PubMed1999

Cancer survivors as standardized patients: an innovative program integrating cancer survivors into structured clinical teaching.

BACKGROUND: Increasingly, standardized patients are involved in medical education; however, reports of cancer survivors functioning as standardized patients have not been available. This study describes the participation of cancer survivors as standardized patients in structured clinical teaching. METHODS: Forty-two cancer survivors, 354 trainees, and 54 faculty members took part in the structured clinical instruction modules (SCIMs) at five academic institutions. After completing the SCIMs, the cancer survivors answered evaluation questionnaire items concerning their perceptions of the course, and all participants (cancer survivors, faculty members, medical students, and residents) rated the benefit of the participation of cancer survivors. The evaluation items were rated on a five-point scale ranging from 1 = "strongly disagree" to 5 = "strongly agree. RESULTS: The evaluation responses were very positive, and the cancer survivors expressed a strong willingness to participate in future courses. Faculty members, residents, and medical students all rated the benefit of using cancer survivors highly. CONCLUSIONS: The participation of cancer survivors in structured clinical teaching was considered beneficial not only by the cancer survivors themselves, but also by the faculty members, residents, and medical students who were involved in the educational program. The role of cancer survivors in the education of physicians needs to be expanded.

Adult↗
PubMed1998

The relationship between medical students' academic achievement and patterns of initial postgraduate placement.

PURPOSE: To explore the relationship between various levels of academic achievement and the spectrum of initial specialty placements for graduates. METHOD: The authors studied the initial specialty placements of all 1984-1994 graduates of the University of Kentucky College of Medicine. Statistical analyses were used to determine the nature and strength of the relationships between initial specialty selection and students' achievement indicators and changes in that relationship over time. RESULTS: Students tended to aggregate across time into discernible levels of achievement. The relationships between academic achievement levels and initial specialty placements were highly variable. CONCLUSION: Although students with higher levels of achievement had broader choices available to them, graduates at every level of achievement entered a wide variety of specialties. Thus, the authors believe that academic achievement should not be used to the exclusion of other performance characteristics in determining how students and residencies should be matched.

Career Choice↗
PubMed1998

Faculty development: a field of dreams.

This chapter describes the faculty development efforts of the eight schools that participated in The Robert Wood Johnson Foundation's "Preparing Physicians for the Future: Program in Medical Education." The authors define "faculty development" as the "enhancement of educational knowledge and skill of faculty members so that their educational contributions can extend to advancing the educational program rather than just teaching within it." Faculty development programs varied widely among the schools. Some schools had active programs in place, others initiated programs at the start of the project. This chapter explores the faculty development topics and methods, both shared and unique, among the eight schools. It then looks at the ways the schools motivated their faculties to participate in their programs. Finally, it describes some of the outcome measures that were used to gauge the effectiveness of the faculty development programs. The authors conclude that the eight schools' approaches and levels of commitment to their faculty development programs varied. They present lessons learned from the successes and failures of the various programs.

Curriculum↗
PubMed1998

The RSNA-AUR-ARRS introduction to research program for 2nd year radiology residents: effect on career choice and early academic performance. Radiological Society of North America. Association of University Radiologists. American Roentgen Ray Society.

PURPOSE: To evaluate graduates of the first 5 years of the Introduction to Research program, sponsored by the Radiological Society of North America, Association of University Radiologists, and American Roentgen Ray Society, to determine if they more frequently entered and demonstrated early success in academic careers than did nonparticipants. MATERIALS AND METHODS: In 1997, the authors surveyed all 396 program participants for the 1990-1995 period and 2,047 nonparticipants who were in the same residencies as the participants during that period. Career plans, research participation, and academic achievements were compared. RESULTS: The survey was completed by 321 participants (81%) and 1,153 nonparticipants (56%). More than a third of participants thought the program had a strong effect on their initial career decision. Forty-one percent of participants who completed training (n = 192) were currently in academia versus 26% of nonparticipants (n = 676; P = .001). Of the 321 participants, 35% believed they would spend most of their careers in academia and 15% thought research would be their major focus versus 19% and 8% for the 1,153 nonparticipants (P < .001). Participants had higher levels of academic achievement earlier in their careers than did nonparticipants. CONCLUSION: The Introduction to Research program is encouraging the development of successful research careers. However, the results may be influenced by the self- or departmental selection of participants who were oriented toward research independent of program participation.

Achievement↗
PubMed1998

Assessing residents' clinical performance: cumulative results of a four-year study with the Objective Structured Clinical Examination.

BACKGROUND: The Objective Structural Clinical Examination (OSCE) is an objective method for assessing clinical skills and can be used to identify deficits in clinical skill. During the past 5 years, we have administered 4 OSCEs to all general surgery residents and interns. METHODS: Two OSCEs (1993 and 1994) were used as broad-based examinations of the core areas of general surgery; subsequent OSCEs (1995 and 1997) were used as needs assessments. For each year, the reliability of the entire examination was calculated with Cronbach's alpha. A reliability-based minimal competence score (MCS) was defined as the mean performance (in percent) minus the standard error of measurement for each group in 1997 (interns, junior residents, and senior residents). RESULTS: The reliability of each OSCE was acceptable, ranging from 0.63 to 0.91. The MCS during the 4-year period ranged from 45% to 65%. In 1997, 4 interns, 2 junior residents, and 2 senior residents scored below their group's MCS. MCS for the groups increased across training levels in developmental fashion (P < .05). CONCLUSIONS: Given the relatively stable findings observed, we conclude (1) the OSCE can be used to identify group and individual differences reliably in clinical skills, and (2) we continue to use this method to develop appropriate curricular remediation for deficits in both individuals and groups.

Clinical Competence↗
PubMed1997

The development and evaluation of a geriatric emergency medicine curriculum. The SAEM Geriatric Emergency Medicine Task Force.

OBJECTIVE: To summarize the processes used to develop a curriculum and model of care for the emergency medical treatment of elder patients and to assess the efficacy of the teaching material in a pilot course. METHODS: A survey of emergency medicine (EM) residency directors and geriatric fellowship directors was used to identify key topics for inclusion in the didactic material. An interdisciplinary consensus process was used to develop didactic as well as teaching material in geriatric EM. Pretests and posttests were administered to 46 participants in the initial course to assess knowledge gain. Subjective course evaluations were also done. RESULTS: Test scores significantly increased from 54% correct on the pretest to 77% correct on the posttest (p < 0.001). Significant improvement in knowledge as judged by pretest and posttest results occurred in 6 of the 7 teaching modules. Subjective evaluations demonstrated good to excellent ratings for each module as well as the overall workshop. CONCLUSIONS: The process of developing a curriculum for geriatric EM is described. The initial training of instructors was effective in improving participants' knowledge of geriatric issues in EM. Participants considered the training to be effective. The effect of the training on the emergency care of elder persons remains to be determined.

Aged↗
PubMed1996

Patient perceptions of stereotaxic large-core breast biopsy.

RATIONALE AND OBJECTIVES: The authors evaluated the perceptions of patients who underwent stereotaxic core breast biopsy before and after the procedure. METHODS: By using a standard questionnaire, 58 patients undergoing stereotaxic core breast biopsy with a 14-gauge needle were interviewed immediately before, immediately after, and 24 hours and 5 days after the procedure. RESULTS: Discomfort recorded by patients 24 hours after core biopsy correlated with the amount of time needed before normal activities were resumed (P = .001). Only five patients (9%) indicated severe discomfort during the procedure. Patient age, number of core biopsy samples taken, and lesion depth did not correlate with level of discomfort. Fifty-five patients (95%) resumed normal activities within 24 hours. However, 41 patients (71%) had some breast bruising as many as 5 days after the procedure. Overall, patient satisfaction with care was high; 56 patients (97%) stated they would return for another biopsy in the future. CONCLUSION: The morbidity associated with stereotaxic core breast biopsy is low, although the majority of patients in this series experienced bruising lasting as long as 5 days after the procedure. Despite this, almost all patients would return for a core breast biopsy in the future, if indicated.

Activities of Daily Living↗
PubMed1994

Factors influencing the safety of colostomy closure in the elderly.

Although colostomy closure is a commonly performed surgical procedure, there remains concern that the attendant risks may be misjudged, especially in the elderly. The purpose of this study was to evaluate the safety of performing colostomy closure and to define the factors that may influence morbidity and mortality in patients over the age of 70. Three hundred seven patients (178 males, 129 females) underwent colostomy closure over a 5-year period. The mean age was 52 years and 84 (27%) of the patients were 70 years or older. The indications for colostomy included diverticulitis, 115 (38%); malignancy, 47 (15%); perforation 35 (11%); trauma, 34 (11%); congenital anomalies, 26 (8%); obstruction, 13 (4%); bleeding, 6 (2%); colovesical fistulae, 6 (2%); polyps, 2 (0.7%); and miscellaneous, 23 (8%). An end colostomy was performed in 193 (63%) patients and a transverse loop colostomy in the remaining 114 (37%). There were no deaths. Complications occurred in 27 (9%) patients: 17 were directly related to colostomy closure (8 wound infections, 3 intraabdominal abscesses, 3 small bowel obstructions, 2 anastomotic strictures, and 1 anastomotic leak) while 10 were nonsurgical. Risk factors statistically associated with increased morbidity included age > 70 years (13% versus 5%), end versus loop colostomy (10% versus 2%), an operative time > 2 hr, and estimated blood loss > or = 500 ml (P < 0.05). ASA classification was only predicative of postoperative complications in patients over 70 years of age. We conclude that although colostomy closure can be performed without mortality, the increased morbidity associated with this procedure in patients 70 years or older necessitates careful preoperative assessment.

Adolescent↗