Virtual Reality Compared with Bench-Top Simulation in the Acquisition of Arthroscopic Skill: A Randomized Controlled Trial.

BACKGROUND: Work-hour restrictions as set forth by the Accreditation Council for Graduate Medical Education (ACGME) and other governing bodies have forced training programs to seek out new learning tools to accelerate acquisition of both medical skills and knowledge. As a result, competency-based training has become an important part of residency training. The purpose of this study was to directly compare arthroscopic skill acquisition in both high-fidelity and low-fidelity simulator models and to assess skill transfer from either modality to a cadaveric specimen, simulating intraoperative conditions. METHODS: Forty surgical novices (pre-clerkship-level medical students) voluntarily participated in this trial. Baseline demographic data, as well as data on arthroscopic knowledge and skill, were collected prior to training. Subjects were randomized to 5-week independent training sessions on a high-fidelity virtual reality arthroscopic simulator or on a bench-top arthroscopic setup, or to an untrained control group. Post-training, subjects were asked to perform a diagnostic arthroscopy on both simulators and in a simulated intraoperative environment on a cadaveric knee. A more difficult surprise task was also incorporated to evaluate skill transfer. Subjects were evaluated using the Global Rating Scale (GRS), the 14-point arthroscopic checklist, and a timer to determine procedural efficiency (time per task). Secondary outcomes focused on objective measures of virtual reality simulator motion analysis. RESULTS: Trainees on both simulators demonstrated a significant improvement (p < 0.05) in arthroscopic skills compared with baseline scores and untrained controls, both in and ex vivo. The virtual reality simulation group consistently outperformed the bench-top model group in the diagnostic arthroscopy crossover tests and in the simulated cadaveric setup. Furthermore, the virtual reality group demonstrated superior skill transfer in the surprise skill transfer task. CONCLUSIONS: Both high-fidelity and low-fidelity simulation trainings were effective in arthroscopic skill acquisition. High-fidelity virtual reality simulation was superior to bench-top simulation in the acquisition of arthroscopic skills, both in the laboratory and in vivo. Further clinical investigation is needed to interpret the importance of these results.

Global Rating Scales and Motion Analysis Are Valid Proficiency Metrics in Virtual and Benchtop Knee Arthroscopy Simulators.

BACKGROUND: Work-hour restrictions and fatigue management strategies in surgical training programs continue to evolve in an effort to improve the learning environment and promote safer patient care. In response, training programs must reevaluate how various teaching modalities such as simulation can augment the development of surgical competence in trainees. For surgical simulators to be most useful, it is important to determine whether surgical proficiency can be reliably differentiated using them. To our knowledge, performance on both virtual and benchtop arthroscopy simulators has not been concurrently assessed in the same subjects. QUESTIONS/PURPOSES: (1) Do global rating scales and procedure time differentiate arthroscopic expertise in virtual and benchtop knee models? (2) Can commercially available built-in motion analysis metrics differentiate arthroscopic expertise? (3) How well are performance measures on virtual and benchtop simulators correlated? (4) Are these metrics sensitive enough to differentiate by year of training? METHODS: A cross-sectional study of 19 subjects (four medical students, 12 residents, and three staff) were recruited and divided into 11 novice arthroscopists (student to Postgraduate Year [PGY] 3) and eight proficient arthroscopists (PGY 4 to staff) who completed a diagnostic arthroscopy and loose-body retrieval in both virtual and benchtop knee models. Global rating scales (GRS), procedure times, and motion analysis metrics were used to evaluate performance. RESULTS: The proficient group scored higher on virtual (14 ± 6 [95% confidence interval {CI}, 10-18] versus 36 ± 5 [95% CI, 32-40], p < 0.001) and benchtop (16 ± 8 [95% CI, 11-21] versus 36 ± 5 [95% CI, 31-40], p < 0.001) GRS scales. The proficient subjects completed nearly all tasks faster than novice subjects, including the virtual scope (579 ±169 [95% CI, 466-692] versus 358 ± 178 [95% CI, 210-507] seconds, p = 0.02) and benchtop knee scope + probe (480 ± 160 [95% CI, 373-588] versus 277 ± 64 [95% CI, 224-330] seconds, p = 0.002). The built-in motion analysis metrics also distinguished novices from proficient arthroscopists using the self-generated virtual loose body retrieval task scores (4 ± 1 [95% CI, 3-5] versus 6 ± 1 [95% CI, 5-7], p = 0.001). GRS scores between virtual and benchtop models were very strongly correlated (ρ = 0.93, p < 0.001). There was strong correlation between year of training and virtual GRS (ρ = 0.8, p < 0.001) and benchtop GRS (ρ = 0.87, p < 0.001) scores. CONCLUSIONS: To our knowledge, this is the first study to evaluate performance on both virtual and benchtop knee simulators. We have shown that subjective GRS scores and objective motion analysis metrics and procedure time are valid measures to distinguish arthroscopic skill on both virtual and benchtop modalities. Performance on both modalities is well correlated. We believe that training on artificial models allows acquisition of skills in a safe environment. Future work should compare different modalities in the efficiency of skill acquisition, retention, and transferability to the operating room.

Atrial thrombi detection prior to pulmonary vein isolation: diagnostic accuracy of cardiac computed tomography versus transesophageal echocardiography.

BACKGROUND: Patients routinely undergo transesophageal echocardiography (TEE) prior to pulmonary vein isolation (PVI) in order to rule out the presence of intra-atrial thrombi. Cardiac computed tomography (CCT) is also routinely conducted prior to the procedure to determine cardiac anatomy. Although it has been demonstrated that CCT can also rule out intra-atrial thrombi, the use of CCT for thrombi detection is controversial. The primary objective was to determine the utility of CCT for detection of atrial thrombi as compared to TEE. METHODS: Patients who underwent PVI between 2010 and 2011 with CTs and TEEs complet-ed within 3 days of each other were retrospectively identified. TEE reports were analyzed, while CCTs were interpreted by a cardiologist specializing in CCTs. Severe spontaneous echo contrast or thrombus detected on TEE were considered positive, as were filling defects found on CCT. RESULTS: A total of 51 patients undergoing PVI (mean age 59.4 ± 9.5 years; 75% male; ejection fraction 60 ± 12%) had both TEE and CCT in timely fashion. By TEE, 0 left atrial ap-pendage (LAA) thrombi were identified with mild to moderate spontaneous echo contrast in 4 patients. By CCT, 2 definite LAA thrombi were identified and thrombi in 4 patients could not be ruled out. Specificity, positive predictive value, and negative predictive value for CCT were 88%, 0%, and 100%, respectively. CONCLUSIONS: CCT is an effective tool in ruling out atrial thrombi prior to PVI. TEE should be completed only if CCT is positive.