Multicenter construct validity for southwestern laparoscopic videotrainer stations.

BACKGROUND: The "Southwestern" videotrainer stations have demonstrated concurrent validity (transferability to the operating room). The purpose of this study was to evaluate the Southwestern stations for construct validity (the ability to discriminate between subjects at different levels of experience). MATERIALS AND METHODS: From two surgical training programs, Institutional Review Board approved protocol data were collected from 142 subjects, including novice (medical students and R1, n = 66), intermediate (R2-R4, n = 67), and advanced (R5 and expert surgeons, n = 9) groups. All participants performed three repetitions on each of five stations. Completion time was scored for each task. Laparoscopic experience was determined from residency case log databases and from expert surgeon personal case logs. Results for the three groups were compared using one-way ANOVA, including relevant pair-wise comparisons. Correlations between number of laparoscopic cases performed and task scores were determined by Pearson's and Spearman's rho-correlation coefficients. RESULTS: The mean number of laparoscopic cases performed prior to completing the five tasks was 0 for novices, 9 for intermediates, and 431 for the advanced group. Significant differences (P < 0.001) were noted between groups for all five tasks and composite score. Task scores and composite scores significantly correlated with laparoscopic experience (P < 0.01). CONCLUSION: These data suggest that differences in laparoscopic ability are detected by performance on the videotrainer; thus, construct validity is demonstrated. Moreover, scores accurately reflect laparoscopic experience. Further validation may allow such simulators to be used for testing and credentialing purposes.

Determining standards for laparoscopic proficiency using virtual reality.

Laparoscopic training using virtual reality has proven effective, but rates of skill acquisition vary widely. We hypothesize that training to predetermined expert levels may more efficiently establish proficiency. Our purpose was to determine expert levels for performance-based training. Four surgeons established as laparoscopic experts performed 11 repetitions of 12 tasks. One surgeon (EXP-1) had extensive Minimally Invasive Surgical Trainer-Virtual Reality (MIST VR) exposure and formal laparoscopic fellowship training. Trimmed mean scores for each were determined as expert levels. A composite score (EXP-C) was defined as the average of all four expert levels. Thirty-seven surgery residents without prior MIST VR exposure and two research residents with extensive MIST VR exposure completed three repetitions of each task to determine baseline performance. Scores for EXP-1 and EXP-C were plotted against the best score of each participant. On average, the EXP-C level was reached or exceeded by 7 of the 37 (19%) residents. In contrast, the EXP-1 level was reached or exceeded by 1 of 37 (3%) residents and both research residents on all tasks. These data suggest the EXP-C level may be too lenient, whereas the EXP-1 level is more challenging and should result in adequate skill acquisition. Such standards should be further developed and integrated into surgical education.

Developing and testing competency levels for laparoscopic skills training.

HYPOTHESIS: Expert levels can be developed for use as training end points for a basic video-trainer skills curriculum, and the levels developed will be suitable for training. DESIGN: Fifty subjects with minimal prior simulator exposure were enrolled using an institutional review board-approved protocol. As a measure of baseline performance, medical students (n = 11) and surgery residents (n = 39) completed 3 trials on each of 5 validated video-trainer tasks. Four board-certified surgeons established as laparoscopic experts (with more than 250 basic and more than 50 advanced cases) performed 11 trials on each of the 5 tasks. The mean score was determined and outliers (>2 SDs) were trimmed; the trimmed mean was used as the competency level. Baseline performance of each subject was compared with the competency level for each task. SETTING: All research was performed in a laparoscopic skills training and simulation laboratory. PARTICIPANTS: Medical students, surgical residents, and board-certified surgeons. MAIN OUTCOME MEASURES: Expert scores based on completion time and the number of subjects achieving these scores at baseline testing. RESULTS: For all tasks combined, the competency level was reached by 6% of subjects by the third trial; 73% of these subjects were chief residents, and none were medical students. CONCLUSIONS: These data suggest that the competency level is suitably challenging for novices but is achievable for subjects with more experience. Implementation of this performance criterion may allow trainees to reliably achieve maximal benefit while minimizing unnecessary training.

Laparoscopic virtual reality training: are 30 repetitions enough?

BACKGROUND: Current literature suggests that novices reach a plateau after two to seven trials when training on the MIST VR laparoscopic virtual reality system. We hypothesize that significant benefit may be gained through additional training. MATERIALS AND METHODS: Second-year medical students (n = 12) voluntarily enrolled under an IRB-approved protocol for MIST VR training. All subjects completed pre- and posttraining questionnaires and performed 30 repetitions of 12 tasks. Performance data were automatically recorded for each trial. Learning curves for each task were generated by fitting spline curves to the mean overall scores for each repetition. Scores were assessed for plateaus by repeated measures, slope, and best score. RESULTS: On average, subjects completed training in 7.1 h. (range, 5.9-9.2). Two to seven performance plateaus were identified for each of the 12 MIST VR tasks. Initial plateaus were found for all tasks by the 8th repetition; however, ultimate plateaus were not reached until 21-29 repetitions. Overall best score was reached between 20 and 30 repetitions and occurred beyond the ultimate plateau for 9 tasks. CONCLUSIONS: These data indicate that a lengthy learning curve exists for novices and may be seen throughout 30 repetitions and possibly beyond. Performance plateaus may not reliably determine training endpoints. We conclude that a significant and variable amount of training may be required to achieve maximal benefit. Neither a predetermined training duration nor an arbitrary number of repetitions may be adequate to ensure laparoscopic proficiency following simulator training. Standards which define performance-based endpoints should be established.

Laparoscopic marsupialization of a giant posttraumatic splenic cyst.

BACKGROUND AND OBJECTIVE: Nonparasitic cysts are rare clinical lesions of the spleen. Causes include congenital malformations and trauma. Historically, management has entailed partial or total splenectomy using an open approach. Recently, laparoscopic approaches have been developed. In this report, we describe laparoscopic marsupialization of a giant splenic cyst (diameter > 15 cm). METHODS: A 25-year-old African-American man presented with a 9-month history of early satiety, constipation, and left upper quadrant pain. Additionally, he reported blunt trauma to the abdomen 2 years earlier. Physical examination revealed a large, fixed, nontender left upper quadrant mass. Computed tomography scan confirmed a simple cyst within the spleen, measuring 20 x 25 cm. Echinococcus and Entamoeba histolytica serologies were negative. Laparoscopic exploration was performed. Four liters of brown fluid were aspirated and intraoperative cytology confirmed a nonparasitic cyst. The cyst wall was excised and the cavity was packed with omentum. RESULTS: The patient's recovery was uneventful, and he was discharged to home tolerating a regular diet on postoperative day 3. At 6-month follow-up, the patient was asymptomatic and showed no evidence of recurrence. CONCLUSION: Nonparasitic splenic cysts are rare lesions. Laparoscopic marsupialization is safe and effective for giant nonparasitic splenic cysts and should be considered the treatment of choice.