Jeffrey Barkun

Development of a Model for Training and Evaluation of Laparoscopic Skills

BACKGROUND Interest in the training and evaluation of laparoscopic skills is extending beyond the realm of the operating room to the use of laparoscopic simulators. The purpose of this study was to develop a series of structured tasks to objectively measure laparoscopic skills. This model was then used to test for the effects of level of training and practice on performance. METHODS Forty-two subjects (6 each of surgical residents PGY1 to PGY5, 6 surgeons who practice laparoscopy and 6 who do not) were evaluated. Each subject viewed a 20-minute introductory video, then was tested performing 7 laparoscopic tasks (peg transfers, pattern cutting, clip and divide, endolooping, mesh placement and fixation, suturing with intracorporeal or extracorporeal knots). Performance was measured using a scoring system rewarding precision and speed. Each candidate repeated all 7 tasks and was rescored. Data were analyzed by linear regression to assess the relationship of performance with level of residency training for each task, and by ANOVA with repeated measures to test for effects of level of training, of repetition, and of the interaction between level of training and repetition on overall performance. Students t test was used to evaluate differences between laparoscopic and nonlaparoscopic surgeons and between each of these groups and the PGY 5 level of surgical residents. RESULTS Significant predictors of overall performance were (a) level of training (P = 0.002), (b) repetition (P < 0.0001), and (c) interaction between level of training and practice (P = 0.001). There was also a significant interaction between level of training and the specific task on performance scores (P = 0.006). When each task was evaluated individually for the 30 residents, 4 of the 7 tasks (tasks 1, 2, 6, 7) showed significant correlation between PGY level and score. A significant difference in performance scores between laparoscopic and nonlaparoscopic surgeons was seen for tasks 1, 2, and 6. CONCLUSIONS A model was developed to evaluate laparoscopic skills. Construct validity was demonstrated by measuring significant improvement in performance with increasing residency training, and with practice. Further validation will require correlation of performance in the model with skill in vivo.

Randomised controlled trial of laparoscopic versus mini cholecystectomy

Laparoscopic cholecystectomy (LC) has gained wide acceptance for treatment of cholelithiasis in preference to open cholecystectomy, though it has not been formally compared with mini cholecystectomy (MC). We have compared these two techniques in a randomised trial. 70 patients with ultrasound-proven cholelithiasis were randomly allocated LC (38) or MC (32); 37 and 25, respectively, underwent the assigned procedure. The mean hospital stay (including 1 preoperative day) was significantly shorter in the LC than the MC group (median 3 [interquartile range 2-3] vs 4 [3-5], p = 0.001) as was duration of convalescence (mean 11.9 [SD 9.1] vs 20.2 [16.5] days, p = 0.04). The rate of return to normal activities was 1.77 times greater in the LC group than in the MC group (95% confidence interval 1.01-3.11, p = 0.03). In regression analysis, the type of cholecystectomy done was the only variable significantly associated with the duration of convalescence. Although there was significant postoperative improvement in all of three quality of life scores in both groups, LC patients improved more quickly than did MC patients. This randomised trial shows the superior effectiveness of LC over MC in treating cholelithiasis.

Evaluation and stages of surgical innovations

Surgical innovation is an important part of surgical practice. Its assessment is complex because of idiosyncrasies related to surgical practice, but necessary so that introduction and adoption of surgical innovations can derive from evidence-based principles rather than trial and error. A regulatory framework is also desirable to protect patients against the potential harms of any novel procedure. In this first of three Series papers on surgical innovation and evaluation, we propose a five-stage paradigm to describe the development of innovative surgical procedures.

Useful predictors of bile duct stones in patients undergoing laparoscopic cholecystectomy

ObjectiveThe authors determined the most useful predictors of common bile duct (CBD) stones as diagnosed by endoscopic retrograde cholangiopancreatography (ERCP) in patients who underwent laparoscopic cholecystectomy (LC). MethodsProspective and retrospective collection of historical, biochemical and ultrasonographic data was used. Receiver operating characteristics curve analysis was used to determine optimal biochemical cut-off values. Multivariate analysis using logistic regression with generation of the best model identifying independent predictors of CBD stones also was employed. Prospective validation of the model was performed on an independent group of patients. ResultsEndoscopic retrograde cholangiopancreatographies were performed before LC in 106 patients, and after LC in 33. Only four of ten clinical variables evaluated independently predicted the presence of CBD stones. The optimal model predicted a 94% probability of CBD stones in a patient older than 55 years of age who presented with an elevated biliubin (over 30 μmol/L) and positive ultrasound findings (a dilated CBD, and a CBD stone seen on ultrasound). This model was validated prospectively in a subsequent series of 49 patients in which the probability of CBD stone was only 8% when all four predictors were absent. ConclusionsThe identified independent clinical predictors of a CBD stone helps select a population of symptomatic gallstone bearers who benefit most from cholangiographic assessment.

The Comprehensive Complication Index: A Novel Continuous Scale to Measure Surgical Morbidity.

Objective:To develop and validate a comprehensive complication index (CCI) that integrates all events with their respective severity. Background:Reporting of surgical complications is inconsistent and often incomplete. Most studies fail to provide information about the severity of complications, or inform only on the most severe event, ignoring events of lesser severity. Methods:We used an established classification of complications, adopting methods from operation risk index analysis in marketing research to develop a formula that considers all complications that may occur in a patient. The weights of each grade of complication, defined as median reference values, were obtained from 472 participants, who rated 30 different complications. Validation to assess sensitivity to treatment effects and validity of the CCI was performed by 4 different approaches, based on 1299 patients. Results:The CCI is calculated as the sum of all complications that are weighted for their severity (multiplication of the median reference values from patients and physicians). The final formula yields a continuous scale to rank the severity of any combination of complications from 0 to 100 in a single patient. The CCI was highly sensitive in detecting treatment effect differences in the context of a randomized trial (effect size detected by CCI vs conventional standardized morbidity outcomes). It also showed a negative correlation with postoperative health status (r = −0.24, P = 0.002), and high correlation with the results of patient-rated single and multiple complications on conjoint analysis (r = 0.94, P < 0.001). Conclusions:The CCI summarizes all postoperative complications and is more sensitive than existing morbidity endpoints. It may serve as a standardized and widely applicable primary endpoint in surgical trials and other interventional fields of medicine. The CCI can be readily computed on the basis of tabulated complications according to the Clavien-Dindo classification (available at www.assessurgery.com).

Factors determining conversion to laparotomy in patients undergoing laparoscopic cholecystectomy

Laparoscopic cholecystectomy (LC) has been performed increasingly in an outpatient setting. Conversion from LC to open cholecystectomy (OC) is sometimes required. To predict conversion to OC, a single institutional study of 1,676 consecutive patients in whom LC was attempted was performed. Factors evaluated were age, sex, history of acute cholecystitis, pancreatitis, or jaundice, previous abdominal surgery, abnormalities of liver function tests, thickened gallbladder wall identified by preoperative ultrasound, obesity or morbid obesity, and cumulative institutional experience in LC. Conversion to OC was required in 90 of 1,676 (5.4%) patients. Significant preoperative predictors of conversion were acute cholecystitis, increasing age, male sex, obesity, and thickened gallbladder wall found by ultrasound. Nonobese women younger than age 65 years with symptoms of biliary colic and normal gallbladder wall thickness found by preoperative ultrasound required conversion only 1.9% of the time. These predictors may be useful in planning a program of ambulatory or short stay surgical units for patients undergoing LC and for comparing data between series.

Comparison of neoral dose monitoring with cyclosporine through levels versus 2-hr postdose levels in stable liver transplant patients.

BACKGROUND We reported that cyclosporine 2-hr postdose levels (C2) correlate better with the AUC0-4 hr than trough levels (C0) in heart transplant patients receiving Neoral. METHODS We compared Neoral dose adjustment with C0 (group 1: 100-200 ng/ml) vs. C2 (group 2: 700-1000 ng/ml; group 3: 300-600 ng/ml) in 35 stable adult patients >1 year after liver transplantation. The AUC0-4hr was calculated, and simultaneous blood samples were obtained to measure calcineurin inhibition. Clinical benefit was defined as the absence of rejection and no increase in serum creatinine at the 7-month follow-up. RESULTS C2 correlated better with the AUC0-4 hr than C0 (r=0.92 vs. r=0.40). Neoral dose increased by 17% and 39% in groups 1 and 2, and decreased by 18% in group 3 (P=0.002 vs. group 1 and P=0.0004 vs. group 2). Serum creatinine increased by 2.1% and 16% in groups 1 and 2, and decreased by 5.1% in group 3 (P=0.006 vs. group 2). A clinical benefit was observed in 37.5%, 23%, and 82% of patients in groups 1, 2, and 3 (P=0.03 vs. group 1 and P=0.01 vs. group 2). Calcineurin inhibition was similar in all groups at 2-hr (44+/-17%, 39+/-30%, and 44+/-35%), in spite of different Neoral doses (2.9+/-0.9, 4.0+/-1.8, and 2.6+/-1.3 mg/kg/day) and C2 (857+/-226, 922+/-274, and 588+/-274 ng/ml). CONCLUSIONS C2 correlated better with the AUC0-4 hr than C0. Neoral dose monitoring with a C2 range of 300-600 ng/ml resulted in a lower dose and greater clinical benefit compared to C0 or a higher C2 in stable liver transplant patients. The correlation between calcineurin inhibition and clinical events deserves further research.

Postcholecystectomy biliary leaks in the laparoscopic era: risk factors, presentation, and management

BACKGROUND The management of bile leaks has evolved in the laparoscopic era. This study characterizes risk factors for their developmental and their clinical course and management. METHODS Data on a cohort of patients who developed bile leaks after cholecystectomy in the laparoscopic era were gathered prospectively and retrospectively from an ongoing surgical database and following a review of hospital charts. RESULTS Sixty-four patients (mean age 56 +/- 17.1 years, 72% women) were included over a 5-year study period. The incidence of leaks was 1.1% among patients entered in a laparoscopic cholecystectomy database. Intraoperative complications were encountered in 36%. Rates of intraoperative complication and conversion to open surgery were greater among patients who developed leaks (5.2% vs 0.6% and 33% vs 6.3%, respectively, p < 0.00001). Patients presented 5.3 +/- 4.2 days following surgery with abdominal pain (89%), fever (74%), and tenderness (81%). Ultrasound diagnosed a suspected leak in 73%, which ERCP showed as originating from the cystic duct stump in 77%. Biliary obstruction was noted in 20 (31%) patients (14 with stones). Treatments included percutaneous (13%), endoscopic (28%), primary or secondary operative procedures (14%), or a combination thereof (45%). CONCLUSION A complication at laparoscopic cholecystectomy increases the likelihood of a subsequent bile leak. Most patients present early with a patent cystic duct stump in the absence of biliary obstruction. Endoscopic therapy is successful in the majority of cases, but otherwise percutaneous or operative procedures may be needed.

Measuring postoperative complications in general surgery patients using an outcomes-based strategy: Comparison with complications presented at morbidity and mortality rounds

BACKGROUND This study was undertaken to compare the incidence of adverse postoperative outcomes recorded in a prospective general surgery database with that identified through weekly morbidity and mortality (M&M) rounds and to measure the impact of feedback of information to the providers of care. METHODS Data were collected on patients admitted to one general surgery service between October 1, 1995, and May 15, 1996, and recorded in a computer database. Postoperative complications were graded in severity from I (minor) to IV (mortality). RESULTS Of 479 admissions entered into the database during the study period, 325 (311 patients) led to operations and were further analyzed. Admissions resulting in complications were associated with longer hospital stays, regardless of complication grade, compared to uncomplicated admissions (p < 0.01). A total of 29 of 106 patients with postoperative complications were presented at M&Ms (27.4%). Whereas 15.4% of database patients with grade I complications were presented at M&Ms, this proportion increased to 22.2% for grade IIa, 34.8% for grade IIb, 33.3% for grade III, and 87.5% for grade IV. (p < 0.05 for grade I, IIa, and IIb compared to grade IV). A total of 58 of 142 patients in the first part of the study period developed complications (40.8%), compared to 53 of 183 patients in the second part of the study (29%, p = 0.034). CONCLUSIONS Although most severe complications are recorded at M&M rounds, a large proportion of complications remain unreported. Monitoring of outcomes may contribute to improvements in quality of care.

Evaluation of renal function in liver transplant recipients receiving daclizumab (Zenapax), mycophenolate mofetil, and a delayed, low-dose tacrolimus regimen vs. a standard-dose tacrolimus and mycophenolate mofetil regimen: A multicenter randomized clinical trial

Posttransplant chronic renal failure, secondary to calcineurin inhibitor agents, is emerging as a major problem in liver transplantation. We report a randomized clinical trial comparing daclizumab, delayed low‐dose tacrolimus (target trough level 4‐8 ng/mL, starting day 4‐6), Investigational Arm (n = 72), to standard tacrolimus induction/maintenance dosing, Standard Arm (n = 76), with mycophenolate mofetil and tapering corticosteroids in both study arms. The end‐points were renal function indicated by the Modification of Diet in Renal Disease (MDRD). There was no significant difference in patient survival (86.6% Investigational Arm vs. 92.9% Standard Arm; P = 0.21) or acute rejection (23.2% vs. 27.7%, respectively; P = 0.68). Statistically significant differences in median glomerular filtration rate (GFR) were found in favor of the Investigational Arm. With the CG equation, the GFR at the end of the first week was 110.7 vs. 89.6 mL/min (P = 0.019) without significant differences thereafter. With the MDRD, statistically significant differences extended to the first posttransplant month (86.8 vs. 70.1 mL/min/1.73 m2; P < 0.001) with and was seen at month 6 (75.4 vs. 69.5 mL/min/1.73 m2; P = 0.038). In conclusion, delayed low‐dose tacrolimus, in combination with daclizumab and mycophenolate mofetil, preserves early renal function post–liver transplantation without the cost of increased acute rejection. (Liver Transpl 2005;11:1064–1072.)