Robotic assistance improves intracorporeal suturing performance and safety in the operating room while decreasing operator workload.

BACKGROUND: Intracorporeal suturing is one of the most difficult laparoscopic tasks. The purpose of this study was to assess the impact of robotic assistance on novice suturing performance, safety, and workload in the operating room. METHODS: Medical students (n = 34), without prior laparoscopic suturing experience, were enrolled in an Institutional Review Board-approved, randomized protocol. After viewing an instructional video, subjects were tested in intracorporeal suturing on two identical, live, porcine Nissen fundoplication models; they placed three gastro-gastric sutures using conventional laparoscopic instruments in one model and using robotic assistance (da Vinci) in the other, in random order. Each knot was objectively scored based on time, accuracy, and security. Injuries to surrounding structures were recorded. Workload was assessed using the validated National Aeronautics and Space Administration (NASA) task load index (TLX) questionnaire, which measures the subjects' self-reported performance, effort, frustration, and mental, physical, and temporal demands of the task. Analysis was by paired t-test; p < 0.05 was considered significant. RESULTS: Compared with laparoscopy, robotic assistance enabled subjects to suture faster (595 +/- 22 s versus 459 +/- 137 s, respectively; p < 0.001), achieve higher overall scores (0 +/- 1 versus 95 +/- 128, respectively; p < 0.001), and commit fewer errors per knot (1.15 +/- 1.35 versus 0.05 +/- 0.26, respectively; p < 0.001). Subjects' overall score did not improve between the first and third attempt for laparoscopic suturing (0 +/- 0 versus 0 +/- 0; p = NS) but improved significantly for robotic suturing (49 +/- 100 versus 141 +/- 152; p < 0.001). Moreover, subjects indicated on the NASA-TLX scale that the task was more difficult to perform with laparoscopic instruments compared with robotic assistance (99 +/- 15 versus 57 +/- 23; p < 0.001). CONCLUSIONS: Compared with standard laparoscopy, robotic assistance significantly improved intracorporeal suturing performance and safety of novices in the operating room while decreasing their workload. Moreover, the robot significantly shortened the learning curve of this difficult task. Further study is needed to assess the value of robotic assistance for experienced surgeons, and validated robotic training curricula need to be developed.

Construct and face validity and task workload for laparoscopic camera navigation: virtual reality versus videotrainer systems at the SAGES Learning Center.

BACKGROUND: Laparoscopic camera navigation (LCN) training on simulators has demonstrated transferability to actual operations, but no comparative data exist. The objective of this study was to compare the construct and face validity, as well as workload, of two previously validated virtual reality (VR) and videotrainer (VT) systems. METHODS: Attendees (n = 90) of the SAGES 2005 Learning Center performed two repetitions on both VR (EndoTower) and VT (Tulane Trainer) LCN systems using 30 degrees laparoscopes and completed a questionnaire regarding demographics, simulator characteristics, and task workload. Construct validity was determined by comparing the performance scores of subjects with various levels of experience according to five parameters and face validity according to eight. The validated NASA-TLX questionnaire that rates the mental, physical, and temporal demand of a task as well as the performance, effort, and frustration of the subject was used for workload measurement. RESULTS: Construct validity was demonstrated for both simulators according to the number of basic laparoscopic cases (p = 0.005), number of advanced cases (p < 0.001), and frequency of angled scope use (p < 0.001), and only for VT according to training level (p < 0.001) and fellowship training (p = 0.008). Face validity ratings on a 1-20 scale averaged 15.4 +/- 3 for VR vs. 16 +/- 2.6 for VT (p = 0.04). Ninety-six percent of participants rated both simulators as valid educational tools. The NASA-TLX overall workload score was 69.5 +/- 24 for VR vs. 68.8 +/- 20.5 for VT (p = 0.31). CONCLUSIONS: This is the largest study to date that compares two validated LCN simulators. While subtle differences exist, both VR and VT simulators demonstrated excellent construct validity, good face validity, and acceptable workload parameters. These systems thus represent useful training devices and should be widely used to improve surgical performance.

Psychomotor testing predicts rate of skill acquisition for proficiency-based laparoscopic skills training.

BACKGROUND: Laparoscopic simulator training translates into improved operative performance. Proficiency-based curricula maximize efficiency by tailoring training to meet the needs of each individual; however, because rates of skill acquisition vary widely, such curricula may be difficult to implement. We hypothesized that psychomotor testing would predict baseline performance and training duration in a proficiency-based laparoscopic simulator curriculum. METHODS: Residents (R1, n = 20) were enrolled in an IRB-approved prospective study at the beginning of the academic year. All completed the following: a background information survey, a battery of 12 innate ability measures (5 motor, and 7 visual-spatial), and baseline testing on 3 validated simulators (5 videotrainer [VT] tasks, 12 virtual reality [minimally invasive surgical trainer-virtual reality, MIST-VR] tasks, and 2 laparoscopic camera navigation [LCN] tasks). Participants trained to proficiency, and training duration and number of repetitions were recorded. Baseline test scores were correlated to skill acquisition rate. Cutoff scores for each predictive test were calculated based on a receiver operator curve, and their sensitivity and specificity were determined in identifying slow learners. RESULTS: Only the Cards Rotation test correlated with baseline simulator ability on VT and LCN. Curriculum implementation required 347 man-hours (6-person team) and 795,000 dollars of capital equipment. With an attendance rate of 75%, 19 of 20 residents (95%) completed the curriculum by the end of the academic year. To complete training, a median of 12 hours (range, 5.5-21), and 325 repetitions (range, 171-782) were required. Simulator score improvement was 50%. Training duration and repetitions correlated with prior video game and billiard exposure, grooved pegboard, finger tap, map planning, Rey Figure Immediate Recall score, and baseline performance on VT and LCN. The map planning cutoff score proved most specific in identifying slow learners. CONCLUSIONS: Proficiency-based laparoscopic simulator training provides improvement in performance and can be effectively implemented as a routine part of resident education, but may require significant resources. Although psychomotor testing may be of limited value in the prediction of baseline laparoscopic performance, its importance may lie in the prediction of the rapidity of skill acquisition. These tests may be useful in optimizing curricular design by allowing the tailoring of training to individual needs.

Intensive continuing medical education course training on simulators results in proficiency for laparoscopic suturing.

BACKGROUND: The purpose of this study was to determine the feasibility and effectiveness of implementing a validated suturing curriculum as a free-standing continuing medical education (CME) course. METHODS: Eighteen participants (9 practicing surgeons, 9 surgery residents) attended a 4-hour laparoscopic suturing CME course. After viewing an instructional videotape all participants had their baseline performance measured on a fundamentals of laparoscopic surgery-type videotrainer suture model. Participants then practiced on the model with active instruction from 6 proctors until a previously reported proficiency level was achieved or until the course ended. Performance was scored objectively based on time and errors. Precourse and postcourse questionnaires were collected. RESULTS: Participants trained for 2.6 +/- .8 hours and performed 37 +/- 11 repetitions. Although no participant was proficient at baseline, 72% achieved the proficiency level by the end of the course. Participants showed 44% improvement in objective scores and 34% improvement according to subjective self-rating. CONCLUSIONS: Although 4 hours may be insufficient for some trainees, an intensive half-day CME course is feasible and effective in significantly improving performance and allowing the majority of participants to achieve proficiency.

Skill retention following proficiency-based laparoscopic simulator training.

BACKGROUND: Proficiency-based curricula using both virtual reality (VR) and videotrainer (VT) simulators have proven to be efficient and maximally effective, but little is known about the retention of acquired skills. The purpose of this study was to assess skill retention after completion of a validated laparoscopic skills curriculum. METHODS: Surgery residents (n=14) with no previous VR or VT experience were enrolled in an Institutional Review Board-approved protocol and sequentially practiced 12 Minimally Invasive Surgical Trainer-VR and 5 VT tasks until proficiency levels were achieved. One VR (manipulate diathermy) and 1 VT (bean drop) tasks were selected for assessment at baseline, after training completion (posttest), and at retention. RESULTS: All residents completed the curriculum. Posttest assessment occurred at 13.2 +/- 11.8 days and retention assessment at 7.0 +/- 4.0 months. After an early performance decrement at posttest (17%-45%), the acquired skill was maintained up to the end of the follow-up period. For VR, scores were 81.5 +/- 23.5 at baseline, 33.3 +/- 1.8 at proficiency, 48.4 +/- 9.2 at posttest, and 48.4 +/- 11.8 at retention. For VT, scores were 49.4 +/- 12.5 at baseline, 22.0 +/- 1.4 at proficiency, 25.6 +/- 3.6 at posttest, and 26.4 +/- 4.2 at retention. Skill retention was better for VT, compared with VR (P < .02). The extent of skill deterioration did not correlate with training duration or resident level. CONCLUSIONS: Although residents do not retain all acquired skills (more so for VR than for VT) according to simulator assessment, proficiency-based training on simulators results in durable skills. Additional studies are warranted to further optimize curriculum design, investigate simulator differences, and establish training methods that improve skill retention.

Simulator training for laparoscopic suturing using performance goals translates to the operating room.

BACKGROUND: The purpose of this study was to develop a performance-based laparoscopic suturing curriculum using simulators and to test the effectiveness (transferability) of the curriculum. STUDY DESIGN: Surgical residents (PGY1 to PGY5, n = 17) proficient in basic skills, but with minimal laparoscopic suturing experience, were enrolled in an IRB-approved, randomized controlled protocol. Subjects viewed an instructional video and were pretested on a live porcine laparoscopic Nissen fundoplication model by placing three gastrogastric sutures tied in an intracorporeal fashion. A blinded rater objectively scored each knot based on a previously published formula (600 minus completion time [sec] minus penalties for accuracy and knot integrity errors). Subjects were stratified according to pretest scores and randomized. The trained group practiced on a videotrainer suturing model until an expert-derived proficiency score (512) was achieved on 12 attempts. The control group received no training. Both the trained and control groups were posttested on the porcine Nissen model. RESULTS: For the training group, mean time to demonstrate simulator proficiency was 151 minutes (range 107 to 224 minutes) and mean number of attempts was 37 (range 24 to 51 attempts). Both the trained and control groups demonstrated significant improvement in overall score from baseline. But the trained group performed significantly better than the control group at posttesting (389 +/- 70 versus 217 +/- 140, p < 0.001), confirming curriculum effectiveness. CONCLUSIONS: These data suggest that training to a predetermined expert level on a videotrainer suture model provides trainees with skills that translate into improved operative performance. Such curricula should be further developed and implemented as a means of ensuring proficiency.

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.

Laparoscopic nonanatomic hepatic resection employing the LigaSure device.

BACKGROUND: Advancements in technology have allowed laparoscopic surgery to expand into advanced procedures such as liver resection; however, the value and safety of laparoscopic liver surgery is still a topic for debate. This study was designed to evaluate the feasibility and outcome of laparoscopic nonanatomic hepatectomy using the LigaSure device in a swine model. METHODS: Nonanatomic hepatic lobe resection was performed in 3 groups comparing the open finger-fracture method, the open method with the LigaSure device, and the laparoscopic method with the LigaSure device. The cut surfaces of the liver were evaluated for bleeding and biliary leakage at the time of the operation. The animals were inspected 48 hours later for hemorrhage and evaluated with cholescintigraphy (hepatobiliary iminodiacetic acid [HIDA] scan) for biliary leakage, in addition to histological evaluation of liver specimens. RESULTS: No hemorrhage or biliary leakage was noted in the groups where the LigaSure device was used, whereas 1 animal from the open finger-fracture method sustained a bile leak observed on HIDA scan. The operative blood loss was considerably less in the groups where the LigaSure device was used, and the shortest operative time was observed in the laparoscopic group. CONCLUSIONS: The LigaSure device can be safely and effectively used to perform a laparoscopic nonanatomic hepatectomy.

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.