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PubMed1997

Determination of the learning curve of the AESOP robot.

BACKGROUND: As the variety of procedures performed with laparoscopic technology increases, the skill levels and equipment demands also increase. Laparoscopic appendectomy, hernia repair, colon resection, and Nissen fundoplication all require someone whose only responsibility is to control the laparoscope and therefore the operative field. This is usually the most inexperienced person on the operating team. The Automated Endoscope System for Optimal Positioning (AESOP) robot provides a means to eliminate the need for the camera person, returns control of the camera and operative field to the operating surgeon, and enhances human performance. The purpose of this study was to evaluate the acquisition of skills to control the laparoscope in a satisfactory fashion. METHODS: We selected medical students as our study group because they have no prior experience in laparoscopic procedures. They performed a readily reproducible task in a pelvic trainer with hand control and with the AESOP robot. Their initial times are compared, as is the improvement in their times after 10 min of practice with the AESOP robot. RESULTS: These data show that in this study group use of the AESOP robot was not as fast as hand control but the skill to use it was learned as quickly. Additional features of the robut such as a steady view and the ability to acquire images and return to them reliably are other advantages. CONCLUSION: The AESOP robotic arm provides a stable support for the laparoscope during laparoscopic procedures which can be manipulated by the surgeon. We found that the time required to learn control of the laparoscope manually and with the AESOP robot is equal.

Clinical Competence↗
PubMed2002

A comparison of learning curves in natural and synthesized speech comprehension.

This study examined the effect of listening practice on the ability of young adults to comprehend natural speech and DECtalk synthesized speech by having them perform a sentence verification task over a 5-day period. Results showed that response latencies of participants shortened in a similar fashion to sentences presented in both types of speech across the 5-day period, with latencies remaining significantly longer in response to DECtalk than to natural speech across the days. These results suggest that high-quality synthesized speech, such as DECtalk, can be useful in many human factors applications.

Adolescent↗
PubMedDate not supplied

Lymphoscintigraphy in the sentinel lymph node technique for breast tumor: value of early and late images for the learning curve.

As the performance of early (H+1 to H+4) and late (D1) lymphoscintigraphic images raises organizational problems in outpatient surgery for breast cancer, only early images are generally obtained. The present study evaluated whether two series of images are better than one and defined the advantages of both methodologies. One hundred and eighteen patients with infiltrating breast carcinoma (T(0), T(1) and T(2)) were included in the study: 87 in group A (early and late images) and 31 in group B (only early images). All patients received two peritumoral injections of (99m)Tc-sulfur colloid, 15-18 MBq (group A) and <15 MBq (group B). During the operation, the patent blue bye technique was associated with radioactivity detection. The two groups were comparable for histological type and tumor size and localization. Successful localization of sentinel nodes on early lymphoscintigraphic images was significantly greater for group B. The identification of a sentinel node focus on early lymphoscintigraphy increased by 10% during the study. Sentinel node detection by the isotopic method alone, or the two methods combined, was comparable for both groups. In radioactivity detection, the count rate for sentinel nodes versus background (contralateral breast) was similar for the two groups. During the learning phase, two series of images gave a definite advantage. Subsequently, lymphoscintigraphy performed at +2 h was sufficient (the results for the two groups became indistinguishable).

Adult↗
PubMed1999

Acquisition of competence in colonoscopy: the learning curve of trainees.

BACKGROUND AND STUDY AIMS: Most official training programs in colonoscopy recommend that trainees should carry out a minimum of 100 procedures, but limited data exist on the technical progress of trainees. The aim of our study was to estimate the number of supervised procedures required for obtaining competence in colonoscopy. MATERIALS AND METHODS: Between 1990 and 1997 we have prospectively evaluated the performance of eight consecutive trainees in colonoscopy. The extent of intubated colon was recorded after each endoscopic procedure. Regression analysis was used to study the effect on the trainees' success rates on the number of colonoscopies which they had done. RESULTS: Out of 2,255 colonoscopies carried out over an 8-year period 1,408 were suitable for evaluation, fulfilling the training criteria for diagnostic colonoscopy. Senior staff (n=2) did 430 colonoscopies with a success rate of 91%, which was significantly reduced to 79% (344/434 colonoscopies; X2=20.67, df=l, P<0.001), when taking over colonoscopies which trainees had failed to complete. Regression analysis of trainees' data (y=88.97-(2185/x), r=0.74, F1,21=23.43, P<0.001) showed success rates of 67 % (95 % CI, 59 to 75 %) and 77 % (95 % CI, 66 to 88 %), when 100 and 180 procedures, respectively, had been done. These figures had been attained by the end of the second and third year of training in colonoscopy. CONCLUSIONS: Our regression analysis model shows the technical progress of trainees over a 3-year period as they learned how to carry out colonoscopy. Depending on individual skill, between 100-180 procedures, done over a 2-3-year period, are required before trainees can be considered competent in colonoscopy.

Clinical Competence↗
PubMed1991

Laparoscopic cholecystectomy. The learning curve: report of 50 patients.

Laparoscopic cholecystectomy was first performed at Saint John Hospital in November 1989. This is a study of the first 50 patients operated on between November 1989 and March 1990. This new technique, which requires different eye-hand coordination and deals with new instruments, prompted an analysis of the first 25 patients (Group 1) vs the second 25 patients (Group 2) for complications, hospital stay, and operating time. All patients were candidates for elective cholecystectomy. There were 32 women and 18 men with an average age of 51 years (range of 20-72 years). There was an average weight of 174 lb (range of 107-265 lb). Group 1 had three minor complications: bile drainage (1), nausea (1), and pain (1). Group 2 only had one minor complication: nausea. Group 1 had four major complications: bile leak from the cystic duct (1), conversion to open cholecystectomy for bleeding (1), reoperation for control of liver oozing in an unsuspected cirrhotic (1), and common duct injury (1). Group 2 had no major complications. The hospital stay was 2.33 days (range of 1-13 days) and 1.04 days (range of 1-3 days) and the operating time was 134 minutes (range of 75-200 min) and 78 minutes (range of 50-150 min) for Group 1 and Group 2, respectively. Sixteen Group 1 patients (64%) and 24 Group 2 patients (96%) were outpatients. Significantly fewer complications, shorter hospital stay, and decreased operating time in Group 2 emphasize the importance of the learning experience.

Adult↗
PubMed2001

The tail of the learning curve for laparoscopic cholecystectomy.

BACKGROUND: This study estimates the number of laparoscopic cholecystectomies required until improvement ceases, assesses the magnitude of such improvement, and provides some insight into the mechanism by which it takes place. METHODS: Data from 500 consecutive laparoscopic cholecystectomies were analyzed from a prospective data base for number of short and long operations and operative time. RESULTS: There was a 40% decrease (P <0.05) in average operative time over the first 200 operations. Significant decrease in the number of longer operations, increase of shorter cases, and decrease in the range of operative time were noted. The major contributor was a marked shortening of longer cases, without much increased speed of shorter operations. CONCLUSIONS: For laparoscopic cholecystectomy, improvement persists for about 200 operations, resulting in a 40% reduction in operative time. The primary mechanism of improvement seems to be an ability to deal more effectively with difficult cases.

Cholecystectomy, Laparoscopic↗
PubMed2003

Audit-derived guidelines for training in endoscopic sinonasal surgery (ESS)--protecting patients during the learning curve.

The objective of the present study is to propose guidelines to ensure safe practice in teaching centres while allowing endoscopic sinonasal surgery (ESS) training to proceed. A prospective complications audit of ESS procedures was undertaken over a 5-year period (January 1996-December 2000). The results have been used to form specific guidelines for safe and effective ESS training. A total of 500 patients underwent ESS during the 5-year period. The senior author was the main surgeon in 55% of cases with the trainee observing or assisting. A supervised trainee was the main surgeon in 45% of cases. The overall complication rate was 1.2% (n = 6) (i.e. 0.7% for the 815 procedures performed). These were all minor complications. We encountered no major complications in 500 patients over the 5-year period. This audit shows that training need not compromise patient safety provided it is phased and structured. We propose appropriate phases and suggest the minimum requirements for units involved in ESS training.

Endoscopy↗
PubMed2002

Virtual reality as a metric for the assessment of laparoscopic psychomotor skills. Learning curves and reliability measures.

BACKGROUND: The objective assessment of the psychomotor skills of surgeons is now a priority; however, this is a difficult task because of measurement difficulties associated with the assessment of surgery in vivo. In this study, virtual reality (VR) was used to overcome these problems. METHODS: Twelve experienced (>50 minimal-access procedures), 12 inexperienced laparoscopic surgeons (<10 minimal-access procedures), and 12 laparoscopic novices participated in the study. Each subject completed 10 trials on the Minimally Invasive Surgical Trainer; Virtual Reality (MIST VR). RESULTS: Experienced laparoscopic surgeons performed the tasks significantly (p < 0.01) faster, with less error, more economy in the movement of instruments and the use of diathermy, and with greater consistency in performance. The standardized coefficient alpha for performance measures ranged from a = 0.89 to 0.98, showing high internal measurement consistency. Test-retest reliability ranged from r = 0.96 to r = 0.5. CONCLUSION: VR is a useful tool for evaluating the psychomotor skills needed to perform laparoscopic surgery.

Adult↗
PubMed2002

The operative learning curve for vestibular schwannoma excision via the retrosigmoid approach.

The results of 127 operations for vestibular schwannomata via the retrosigmoid approach performed by a single surgeon over a 24-year period are examined. Facial nerve preservation and function, morbidity and mortality were recorded prospectively for three consecutive 8-year periods to assess the effect of increasing surgical experience on outcome. Rates of facial nerve preservation and good function (House grade I & II) improved over the study period. This reached statistical significance for medium-sized tumours, indicating that the effect was independent of tumour size, whose distribution varied through the series. Improvements occurred independently in the ability to preserve the nerve and its function. Analysis of the percentage of good facial nerve outcomes achieved over time indicated that the improvements occurred mainly between the 40th and 100th cases. Overall mortality was 3% and there were no deaths in the final time period. The implications of these findings for patient care and surgical training are discussed.

Adolescent↗
PubMed1999

Focused abdominal sonogram for trauma: the learning curve of nonradiologist clinicians in detecting hemoperitoneum.

BACKGROUND: The focused abdominal sonogram for trauma (FAST) has been used by surgeons and emergency physicians (CLIN) to screen reliably for hemoperitoneum after trauma. Despite recommendations for "appropriate training," ranging from 50 to 400 proctored examinations, there are no supporting data. METHODS: We prospectively examined the initial FAST experience of CLIN in detecting hemoperitoneum by using diagnostic peritoneal lavage, computed tomography, and clinical findings as the diagnostic "gold standard." RESULTS: 241 patients had FAST performed by 12 CLIN (average, 20/CLIN; range, 2-43); 51 patients (21.2%) had hemoperitoneum and 17 patients (7.1%) required laparotomy. Initial experience with FAST by CLIN produced 35 true positives, 180 true negatives, 16 false negatives, and 3 false positives; sensitivity, 68%; specificity, 98%. Initial error rate was 17%, which fell to 5% after 10 examinations (chi2; p < 0.05). CONCLUSION: Previous recommendations for the number of proctored examinations for individual nonradiologist clinician sonographers to develop competence are excessive.

Abdominal Injuries↗
PubMed1998

Learning curve in the use of the radial artery as vascular access in the performance of percutaneous transluminal coronary angioplasty.

Radial artery access for coronary artery angioplasty is a cost-effective alternative to other vascular entry sites. The initial series of patients using the radial artery site for an operator without experience in using arm access for coronary artery angioplasty was evaluated. Clinical success was achieved via the radial artery in 87% of 32 lesions and 84% of 27 patients. The major feature limiting success via the arm was radial/brachial artery spasm, which occurred in 30% of cases (clinical success: 50% with spasm vs. 95% without spasm, P < 0.05). Spasm was more common in patients with peripheral vascular disease and in hypertensive patients not treated with calcium channel blockers prior to angioplasty. Coronary angioplasty via the radial artery may be successfully performed even by the interventionalist inexperienced in arm access. Vascular spasm is an important feature that limits the ability successfully to complete coronary angioplasty via the radial artery.

Angioplasty, Balloon, Coronary↗
PubMed2005

The learning curve for EMR with circumferential mucosal incision in treating intramucosal gastric neoplasm.

BACKGROUND: EMR with circumferential mucosal incision facilitates en bloc resection, which is the most important predictor for complete resection in the treatment of intramucosal gastric neoplasm. The objective of the study was to evaluate the efficacy and the safety of EMR with circumferential mucosal incision in relation to the endoscopist's experience. METHODS: In this retrospective study, we analyzed the outcome of 80 EMR procedures performed by a single endoscopist at the National Cancer Center, Goyang, Korea. The EMR procedure with circumferential mucosal incision was performed with a conventional needle knife. We compared the en bloc resection rate, the complete resection rate, the duration of the procedure time, and the associated complications by quartiles. RESULTS: From the first to the last quartile, en bloc resection rates were 55%, 45%, 85%, and 85% (p = 0.006), and complete resection rates were 65%, 60%, 90%, and 85% (p = 0.039). The increase in the mean en bloc and complete resection rates between the first two quartiles and the second two quartiles was significant (p = 0.002 and p = 0.019, respectively). Three perforations (15%) were reported in the first quartile and only one (1.7%) in the remaining 3 quartiles (p = 0.046). The procedure time also decreased after the first 20 cases (p = 0.004). CONCLUSIONS: For an experienced endoscopist, EMR with circumferential mucosal incision could be performed effectively and safely after the experience of 40 cases.

Adenocarcinoma↗
PubMed1998

Learning curve for oesophageal cancer surgery.

BACKGROUND: Surgical training and experience are frequently claimed to influence early and late outcome measures. The aim of this study was to examine any improvement in an individual surgeon's performance in one operation over a period of 7 years from initial appointment to date. METHODS: Patients undergoing Ivor Lewis subtotal oesophagectomy performed by a single surgeon between April 1990 and December 1996 were identified from a prospectively compiled oesophageal cancer database. Operating time (abdominal, thoracic and 'one-lung time'), blood loss, transfusion requirements (intraoperative and total), extent of lymphadenectomy (number of lymph nodes sampled), intensive treatment unit (ITU) stay, hospital stay, postoperative morbidity and mortality, pathological stage, grade and survival were recorded. RESULTS: The records of 150 patients were identified for analysis. The cohort was split into five groups, each of 30 patients operated on consecutively. Each of the groups was comparable for age, sex, smoking history, preoperative haemoglobin and creatinine levels, weight loss, American Society of Anesthesiologists' grade, and histological stage and grade of disease. Analysis of the variables pertaining to operation revealed a significant improvement with time including reduced single-lung operating time (P=0.01), reduced blood loss (P=0.03), reduced transfusion requirement (P < 0.0001), reduced ITU stay (P< 0.0001), reduced inpatient stay (P< 0.0001) and an increased yield of lymph nodes (P < 0.0001). CONCLUSION: This study showed a continuing improvement in a surgeon's performance over a 7-year period. With the current trend to shorter training periods there is a case for continuing supervision of the 'fully trained' surgeon within highly specialist units.

Blood Loss, Surgical↗
PubMed2006

Day case laparoscopic herniorraphy. A NICE procedure with a long learning curve.

BACKGROUND: The aim of this study was to evaluate day case laparoscopic herniorraphy (LH) and to ascertain the impact of trainee surgeons on its performance. METHODS: We performed a prospective study of ambulatory laparoscopic transabdominal preperitoneal herniorraphies performed in a dedicated day surgical unit between March 1996 and October 2003. RESULTS: A total of 840 herniorraphies were performed in 706 consecutive patients. Surgery was performed by 15 higher surgical trainees and three consultant surgeons. The mean operating times for trainees were longer for unilateral (48.4 +/- 0.98 vs 41.4 +/- 0.87 min, p < 0.05) and bilateral (69.0 +/- 3.24 vs 53.0 +/- 1.68 min, p < 0.05) repairs than for consultants. Subgroup analysis demonstrated that after an experience of 40 procedures, trainee times approached those of the consultants (41.39 +/- 1.17 vs 41.4 +/- 0.87 min, p= 0.31). LH repair was well tolerated and associated with minimal postoperative pain and nausea. Mean pain scores postoperatively and at 24 h were 2.69 +/- 0.11 and 2.07 +/- 0.09, respectively. Mean nausea scores postoperatively and at 24 h were 0.34 +/- 0.06 and 0.22 +/- 0.06, respectively. Ninety-three percent of patients (n = 657) were discharged within 8 h. There were two conversions to an open procedure (0.1%) and two significant complications (0.1%). Ninety-five percent of patients who responded to our questionnaire (n = 398/419) were satisfied with surgery and would undergo day case laparoscopic herniorraphy again. CONCLUSIONS: Laparoscopic herniorraphy is a safe technique suitable for day case surgery. Operator experience dictates duration of surgery. Trainees' operating times approach those of consultants after 40 procedures. Prolonged operating times and increased cost are not justifiable reasons for not recommending LH.

Adolescent↗
PubMed2001

Learning curves and breast cancer lymphatic mapping: institutional volume index.

INTRODUCTION: To date, studies of breast cancer lymphatic mapping (LM) have analyzed success with respect to individual surgeons. However, LM and sentinel lymph node biopsy (SLNBx) are procedures that require institutional multidisciplinary cooperation between the departments of radiology, pathology, and surgery. Thus, it is important to evaluate these procedures with respect to the institution. This study examines 30 institutions to clarify the value of the institutional volume index (IVI) (cases/month) to the outcome of LM and SLNBx in breast cancer. METHODS: From July 1997 to July 1999, 30 institutions participated in the Department of Defense national breast LM trial. All participants underwent a 2-day training course for surgeons, nuclear medicine physicians, and pathologists. The records for each institution were prospectively accrued and submitted to a database. The false negatives, failure rates, and IVI were calculated for each institution. A logistic regression model plots the relationship between IVI and institutional failure rate. Using a multivariate analysis, mapping failure was analyzed as a function of case number with respect to the individual surgeon and the institution as a whole. RESULTS: False negative results were demonstrated in only 5 (4%) cases among all institutions and were excluded from further analysis due to small numbers. Mapping failures were found in all but 7 of the 30 institutions whose data were complete. There were 71 mapping failures among 74 surgeons over 555 cases, which yielded an overall failure rate of 12.79% (71 555). The logistic regression model revealed an inverse relationship between IVI and institutional failure rate. However, the multivariate analysis revealed that the individual surgeon performance was the most significant factor in determining institutional mapping success. CONCLUSION: Failure to map can be a function of multiple factors including surgical skill, surgical volume index, and injection method of the SLN patient, all under the quality control of an institution. The surgical failure rate on the other hand is a function of surgical skill, surgical volume, and injection methods. While differences in mapping success exist across institutions, this disparity is not due to factors associated with the institution as a whole, but lie with the individual surgeon.

Breast Neoplasms↗