C. Daniel Smith

Virtual reality simulation for the operating room: proficiency-based training as a paradigm shift in surgical skills training.

Summary Background Data:To inform surgeons about the practical issues to be considered for successful integration of virtual reality simulation into a surgical training program. The learning and practice of minimally invasive surgery (MIS) makes unique demands on surgical training programs. A decade ago Satava proposed virtual reality (VR) surgical simulation as a solution for this problem. Only recently have robust scientific studies supported that vision Methods:A review of the surgical education, human-factor, and psychology literature to identify important factors which will impinge on the successful integration of VR training into a surgical training program. Results:VR is more likely to be successful if it is systematically integrated into a well-thought-out education and training program which objectively assesses technical skills improvement proximate to the learning experience. Validated performance metrics should be relevant to the surgical task being trained but in general will require trainees to reach an objectively determined proficiency criterion, based on tightly defined metrics and perform at this level consistently. VR training is more likely to be successful if the training schedule takes place on an interval basis rather than massed into a short period of extensive practice. High-fidelity VR simulations will confer the greatest skills transfer to the in vivo surgical situation, but less expensive VR trainers will also lead to considerably improved skills generalizations. Conclusions:VR for improved performance of MIS is now a reality. However, VR is only a training tool that must be thoughtfully introduced into a surgical training curriculum for it to successfully improve surgical technical skills.

Bile Duct Injury During Laparoscopic Cholecystectomy: Results of a National Survey

ObjectiveTo determine whether surgical residency training has influenced the occurrence of common bile duct injuries during laparoscopic cholecystectomy, and to asses the anatomic and technical details of bile duct injuries from the practices of surgeons trained in laparoscopic cholecystectomy after residency versus surgeons trained in laparoscopic cholecystectomy during residency. Summary Background DataShortly after the introduction of laparoscopic cholecystectomy, the rate of injury to the common bile duct increased to 0.5%, and injuries were more commonly reported early in each surgeon’s experience. It is not known whether learning laparoscopic cholecystectomy during surgery residency influences this pattern. MethodsAn anonymous questionnaire was mailed to 3,657 surgeons across the United States who completed an Accreditation Council for Graduate Medical Education (ACGME)-approved residency between 1980 and 1990 (group A) or 1992 and 1998 (group B). All surgeons in group A learned laparoscopic cholecystectomy after residency, and all those in group B learned laparoscopic cholecystectomy during residency. Information obtained included practice description, number of laparoscopic cholecystectomies completed since residency, postgraduate training in laparoscopy, and annual volume of laparoscopic cholecystectomy in the surgeon’s hospital. In addition, technical details queried included the completion of a cholangiogram, the interval between injury and identification, the method of repair, and the site of definitive treatment. The primary endpoint was the occurrence of a major bile duct injury during laparoscopic cholecystectomy (bile leaks without a major bile duct injury were not tabulated). ResultsForty-five percent (n = 1,661) of the questionnaires were completed and returned. Mean practice experience was 13.6 years for group A and 5.4 years for group B. At least one injury occurrence was reported by 422 surgeons (37.6%) in group A and 143 surgeons (26.5%) in group B. Forty percent of the injuries in group A occurred during the first 50 cases compared with 22% in group B. Thirty percent of bile duct injuries in group A and 32.9% of all injuries in group B occurred after a surgeon had performed more than 200 laparoscopic cholecystectomies. Independent of the number of laparoscopic cholecystectomies completed since residency, group A surgeons were 39% more likely to report one or more biliary injuries and 58% more likely to report two or more injuries than their counterparts in group B.Bile duct injuries were more likely to be discovered during surgery if a cholangiogram was completed than if cholangiography was omitted (80.9% vs. 45.1%). Sixty-four percent of all major bile duct injuries required biliary reconstruction, and most injuries were definitively treated at the hospital where the injury occurred. Only 14.7% of injuries were referred to another center for repair. ConclusionsAccepting that the survey bias underestimates the true frequency of bile duct injuries, residency training decreases the likelihood of injuring a bile duct, but only by decreasing the frequency of early “learning curve” injuries. If one accepts a liberal definition of the learning curve (200 cases), it appears that at least one third of injuries are not related to inexperience but may reflect fundamental errors in the technique of laparoscopic cholecystectomy as practiced by a broad population of surgeons in the United States. Intraoperative cholangiography is helpful for intraoperative discovery of injuries when they occur. Most injuries are repaired in the hospital where they occur and are not universally referred to tertiary care centers.

Endoscopic Therapy for Achalasia Before Heller Myotomy Results in Worse Outcomes Than Heller Myotomy Alone

Objective:Heller myotomy has been shown to be an effective primary treatment of achalasia. However, many physicians treating patients with achalasia continue to offer endoscopic therapies before recommending operative myotomy. Herein we report outcomes in 209 patients undergoing Heller myotomy with the majority (74%) undergoing myotomy as secondary treatment of achalasia. Methods:Data on all patients undergoing operative management of achalasia are collected prospectively. Over a 9-year period (1994–2003), 209 patients underwent Heller myotomy for achalasia. Of these, 154 had undergone either Botox injection and/or pneumatic dilation preoperatively. Preoperative, operative, and long-term outcome data were analyzed. Statistical analysis was performed with multiple χ2 and Mann-Whitney U analyses, as well as ANOVA. Results:Among the 209 patients undergoing Heller myotomy for achalasia, 154 received endoscopic therapy before being referred for surgery (100 dilation only, 33 Botox only, 21 both). The groups were matched for preoperative demographics and symptom scores for dysphagia, regurgitation, and chest pain. Intraoperative complications were more common in the endoscopically treated group with GI perforations being the most common complication (9.7% versus 3.6%). Postoperative complications, primarily severe dysphagia, and pulmonary complications were more common after endoscopic treatment (10.4% versus 5.4%). Failure of myotomy as defined by persistent or recurrent severe symptoms, or need for additionally therapy including redo myotomy or esophagectomy was higher in the endoscopically treated group (19.5% versus 10.1%). Conclusion:Use of preoperative endoscopic therapy remains common and has resulted in more intraoperative complications, primarily perforation, more postoperative complications, and a higher rate of failure than when no preoperative therapy was used. Endoscopic therapy for achalasia should not be used unless patients are not candidates for surgery.

Esophageal sphincter device for gastroesophageal reflux disease.

BACKGROUND Patients with gastroesophageal reflux disease who have a partial response to proton-pump inhibitors often seek alternative therapy. We evaluated the safety and effectiveness of a new magnetic device to augment the lower esophageal sphincter. METHODS We prospectively assessed 100 patients with gastroesophageal reflux disease before and after sphincter augmentation. The study did not include a concurrent control group. The primary outcome measure was normalization of esophageal acid exposure or a 50% or greater reduction in exposure at 1 year. Secondary outcomes were 50% or greater improvement in quality of life related to gastroesophageal reflux disease and a 50% or greater reduction in the use of proton-pump inhibitors at 1 year. For each outcome, the prespecified definition of successful treatment was achievement of the outcome in at least 60% of the patients. The 3-year results of a 5-year study are reported. RESULTS The primary outcome was achieved in 64% of patients (95% confidence interval [CI], 54 to 73). For the secondary outcomes, a reduction of 50% or more in the use of proton-pump inhibitors occurred in 93% of patients, and there was improvement of 50% or more in quality-of-life scores in 92%, as compared with scores for patients assessed at baseline while they were not taking proton-pump inhibitors. The most frequent adverse event was dysphagia (in 68% of patients postoperatively, in 11% at 1 year, and in 4% at 3 years). Serious adverse events occurred in six patients, and in six patients the device was removed. CONCLUSIONS In this single-group evaluation of 100 patients before and after sphincter augmentation with a magnetic device, exposure to esophageal acid decreased, reflux symptoms improved, and use of proton-pump inhibitors decreased. Follow-up studies are needed to assess long-term safety. (Funded by Torax Medical; ClinicalTrials.gov number, NCT00776997.).

When fundoplication fails: redo?

Objective:The largest series in the literature dealing with redo fundoplication was presented and published in 1999 and included 100 patients. Herein we update this initial series of 100, with 207 additional patients who have undergone redo fundoplication (n = 307). Summary Background Data:Increasing numbers of patients are failing esophagogastric fundoplication and requiring redo procedures. Data regarding the nature of these failures have been scant. Methods:Data on all patients undergoing foregut surgery are collected prospectively. Between 1991 and 2004, 307 patients underwent redo fundoplication for the management of anatomic complications or recurrent GERD. Statistical analysis was performed with multiple χ2 and Mann-Whitney U analyses, as well as ANOVA. Results:Between 1991 and 2004, 1892 patients underwent primary fundoplication for GERD (1734) or paraesophageal hernia (158). Of these, 54 required redo fundoplication (2.8%). The majority of failures (73%) were managed within 2 years of the initial operation (P = 0.0001). The mechanism of failure was transdiaphragmatic wrap herniation in 33 of 54 (61%). In the 231 patients who underwent fundoplication elsewhere, 109 had transdiaphragmatic herniation (47%, P = NS). In this group of 285 patients, 22 (8%) required another redo (P = NS). The majority of the procedures were initiated laparoscopically (240/307, 78%), with 20 converted (8%). Overall mortality was 0.3%. Conclusions:Failure of fundoplication is unusual in experienced hands. Most are managed within 2 years of the initial operation. Wrap herniation has now become the most common mechanism of failure requiring redo. Redo fundoplication was successful in 93% of patients, and most could be safely handled laparoscopically.

Who will fail laparoscopic Nissen fundoplication? Preoperative prediction of long-term outcomes

BackgroundA small but significant percentage of patients are considered failures after laparoscopic Nissen fundoplication (LNF). We sought to identify preoperative predictors of failure in a cohort of patients who underwent LNF more than 10 years ago.MethodsOf 312 consecutive patients undergoing primary LNF between 1992 and 1995, recent follow-up was obtained from 166 patients at a mean of 11.0 ± 1.2 years. Eight additional patients who underwent reoperation were lost to follow-up but are included. Failure is broadly defined as any reoperation, lack of satisfaction, or any severe symptoms at follow-up. Potential predictors evaluated included sex, age, body-mass index (BMI), response to acid reducing medications (ARM), psychiatric history, typical versus atypical symptoms, manometry, esophageal pH, and others. Logistic regression was used to assess significance of predictors in univariate analysis.ResultsOf 174 known outcomes, 131 were classified as successful (75.3%), while 43 were failures (24.7%): 26 reoperations, 13 unsatisfied, and 13 with severe symptoms. Response and lack of response to ARM were associated with 77.1% and 56.0% success rates respectively (P = 0.035). Eighty five percent of patients with typical symptoms had a successful outcome, compared to only 41% with atypical symptoms (P < 0.001). Preoperative morbid obesity (BMI > 35 kg/m2) was associated with failure (P = 0.036), while obesity (BMI 30–34.9 kg/m2) was not. A history of psychiatric illness trended toward significance (P = 0.06).ConclusionsIn a cohort with 11 years follow-up after LNF, factors predictive of a successful outcome include preoperative response to ARM, typical symptoms, and BMI < 35 kg/m2. Patients with atypical symptoms, no response to ARM, or morbid obesity should be informed of their higher risk of failure. Some patients in these groups do have successful outcomes, and further research may clarify which of these patients can benefit from LNF.

Assessing laparoscopic manipulative skills

BACKGROUND The rapid emergence of laparoscopic surgery over the past decade has highlighted the need for teaching and assessing laparoscopic manipulative skills. Most analyses consist of a measurement of the time to complete a specified task and a subjective assessment by an observer. Objective assessments of accuracy in the performance of manipulative skills have been lacking. To quantify both speed and accuracy during laparoscopic skill performance, we have developed a skills assessment device (SAD) using a laparoscopic simulator platform and computer-based skills assessment software that precisely measures an instruments movement during performance of timed laparoscopic manipulations. STUDY DESIGN The SAD device measures the time necessary for an operator to complete a task, and the movements of the working end of laparoscopic instruments in three dimensions. Ten nonsurgeons performed 10 repetitions of a standardized laparoscopic manipulation. Data were captured in real time for both hands on a personal computer. Accuracy was determined by calculating the sum of all distances traveled. Duration was measured in seconds. Results are group means. RESULTS The time necessary to perform defined laparoscopic manipulative skills improved dramatically during the first 3 repetitions and then stabilized. However, accuracy of manipulations continued to improve over all 10 repetitions. CONCLUSIONS When untrained subjects are learning a laparoscopic manipulative task, measurement of time alone fails to account for the more protracted learning curve for accuracy. Therefore, devices and training programs that fail to consider objective assessments of accuracy may overestimate laparoscopic proficiency.

Prospective, Randomized, Double-Blind Trial of Curriculum-Based Training for Intracorporeal Suturing and Knot Tying

BACKGROUND Advanced surgical skills such as laparoscopic suturing are difficult to learn in an operating room environment. The use of simulation within a defined skills-training curriculum is attractive for instructor, trainee, and patient. This study examined the impact of a curriculum-based approach to laparoscopic suturing and knot tying. STUDY DESIGN Senior surgery residents in a university-based general surgery residency program were prospectively enrolled and randomized to receive either a simulation-based laparoscopic suturing curriculum (TR group, n=11) or standard clinical training (NR group, n=11). During a laparoscopic Nissen fundoplication, placement of two consecutive intracorporeally knotted sutures was video recorded for analysis. Operative performance was assessed by two reviewers blinded to subject training status using a validated, error-based system to an interrater agreement of >or=80%. Performance measures assessed were time, errors, and needle manipulations, and comparisons between groups were made using an unpaired t-test. RESULTS Compared with NR subjects, TR subjects performed significantly faster (total time, 526+/-189 seconds versus 790+/-171 seconds; p < 0.004), made significantly fewer errors (total errors, 25.6+/-9.3 versus 37.1+/-10.2; p < 0.01), and had 35% fewer excess needle manipulations (18.5+/-10.5 versus 27.3+/-8.6; p < 0.05). CONCLUSIONS Subjects who receive simulation-based training demonstrate superior intraoperative performance of a highly complex surgical skill. Integration of such skills training should become standard in a surgical residencys skills curriculum.

Relationship Between Tissue Ingrowth and Mesh Contraction

Contraction is a well-documented phenomenon occurring within two months of mesh implantation. Its etiology is unknown, but it is suggested to occur as a result of inadequate tissue ingrowth into the mesh and has been associated with hernia recurrence. In continuation of our previous studies, we compared tissue ingrowth characteristics of large patches of polyester (PE) and heavyweight polypropylene (PP) and their effect on mesh contraction. The materials used were eight PE and eight PP meshes measuring 10 × 10 cm2. After random assignment to the implantation sites, the meshes were fixed to the abdominal wall fascia of swine using interrupted polypropylene sutures. A necropsy was performed three months after surgery for evaluation of mesh contraction/shrinkage. Using a tensiometer, tissue ingrowth was assessed by measuring the force necessary to detach the mesh from the fascia. Histologic analysis included inflammatory and fibroblastic reactions, scored on a 0–4 point scale. One swine developed a severe wound infection that involved two PP meshes and was therefore excluded from the study. The mean area covered by the PE meshes (87 ± 7 cm2) was significantly larger than the area covered by the PP meshes (67 ± 14 cm2) (p = 0.006). Tissue ingrowth force of the PE meshes (194 ± 37 N) had a trend toward being higher than that of the PP meshes (159 ± 43 N), although it did not reach statistical significance. There was no difference in histologic inflammatory and fibroblastic reactions between mesh types. There was a significant correlation between tissue ingrowth force and mesh size (p = 0.03, 95% CI: 0.05–0.84). Our results confirm those from previous studies in that mesh materials undergo significant contraction after suture fixation to the fascia. PE resulted in less contraction than polypropylene. A strong integration of the mesh into the tissue helps prevent this phenomenon, which is evidenced by a significant correlation between tissue ingrowth force and mesh size.

Objective psychomotor skills assessment of experienced and novice flexible endoscopists with a virtual reality simulator

The objective of this study was to determine whether the GI Mentor II virtual reality simulator can distinguish the psychomotor skills of intermediately experienced endoscopists from those of novices, and do so with a high level of consistency and reliability. A total of five intermediate and nine novice endoscopists were evaluated using the EndoBubble abstract psychomotor task. Each subject performed three repetitions of the task. Performance and error data were recorded for each trial. The intermediate group performed better than the novice group in each trial. The differences were significant in trial 1 for balloons popped (P = .001), completion time (P = .04), and errors (P = .03). Trial 2 showed significance only for balloons popped (P = .002). Trial 3 showed significance for balloons popped (P = .004) and errors (P = .008). The novice group showed significant improvement between trials 1 and 3 (P < 0.05). No improvement was noted in the intermediate group. Measures of consistency and reliability were greater than 0.8 in both groups with the exception of novice completion time where test-retest reliability was 0.74. The GI Mentor II simulator can distinguish between novice and intermediate endoscopists. The simulator assesses skills with levels of consistency and reliability required for high-stakes assessment.