Teaching and evaluation of basic surgical techniques: the University of British Columbia experience.

Surgical technical education has traditionally followed an apprenticeship format. The need for innovative undergraduate programs using dry and wet labs prior to clinical exposure continues to be an area of debate. Specific programs have been described to improve surgical skills; however, an accepted platform for training and evaluation of surgical skills programs has not been recognized. Therefore, introduction of specific programs to teach undergraduate medical students surgical skills is essential. This article describes the Basic Surgical Technique (BST) program taught at the University of British Columbia and reports the effectiveness of this program in improving the practical skills of undergraduate medical students. The program includes BST I for third-year students performed in a dry lab setting, and BST II for medical student interns (MSI) performed at the animal laboratories using female domestic swine as subjects. A total of 87 students participated in the study. The program is designed using Piaget's and Vygotsky's pedagogical philosophy of "learning by doing." A semiquantitative method is used to measure and analyze the outcome of this project. Data were validated using student self-evaluation tests and by quantitative evaluation by surgical staff from the surgical wards. Results of this prospective project indicated that the BST program significantly (p < .05) improved the surgical performance of undergraduate students, and that the time lapse between BST I and II has had a negative impact in retention of acquired surgical skills. This study concludes that the BST program taught at the University of British Columbia significantly improves the surgical skills of medical students and improves their self-confidence during their internship.

An animal model of benign bile-duct stricture, sclerosing cholangitis and cholangiocarcinoma and the role of epidermal growth factor receptor in ductal proliferation.

OBJECTIVE: To adapt an animal model of benign bile-duct stricture, sclerosing cholangitis and cholangiocarcinoma in order to determine if the expression of epidermal growth factor receptor (EGFr) could be used to differentiate these lesions. DESIGN: A prospective control study with blinded interpretation of liver biopsy histology and immunohistochemical staining as the criterion standards. SETTING: A university-affiliated research centre. SUBJECTS: Male Syrian Golden hamsters (40 for benign duct stricture, 29 for sclerosing cholangitis and 27 for cholangiocarcinoma). INTERVENTIONS: Ligation of the common bile duct with 6-0 catgut for benign duct stricture; injection of the biliary tree with 0.15 mL of formalin for sclerosing cholangitis; and weekly subcutaneous injections of 500 mg/kg of di-isopropanolnitrosamine for 10 weeks followed by ligation of the common bile duct with 6-0 catgut for cholangiocarcinoma. Routine histologic preparation of liver biopsies obtained at autopsy 10 weeks postoperatively then immunohistochemical staining of specimens for EGFr. MAIN OUTCOME MEASURES: The development of benign or atypical biliary ductal proliferation, including adenoma and carcinoma formation. The presence or absence of immunohistochemical staining for EGFr. RESULTS: Benign ductal proliferation without atypia was seen in 15 of 21 animals in the bile-duct-stricture group that were sacrificed, in 15 of 24 animals in the sclerosing cholangitis group and in 17 of 18 animals in the cholangiocarcinoma group. Atypical proliferation was seen in 13 of 18 animals with cholangiocarcinoma but not in the other two groups. The differential occurrence of atypical ductal proliferation was statistically significant (p < 0.00001) for both groups. No evidence of EGFr expression was found in any group. CONCLUSION: Although the animal model was valid histologically for comparing benign and malignant biliary disease, EGFr does not play a role in biliary ductal proliferation and so cannot be used to differentiate between benign and malignant lesions.

Differentiation of thyroid neoplasms by evaluating epithelial membrane antigen, Leu-7 antigen, epidermal growth factor receptor, and DNA content.

The expression of epithelial membrane antigen (EMA), Leu-7 antigen, epidermal growth factor receptor (EGFr), and deoxyribonucleic acid (DNA) content in 40 thyroid nodules was investigated to identify those factors that might differentiate these lesions or correlate to their prognosis. There were 22 carcinomas (16 papillary, 4 follicular, 1 anaplastic, 1 medullary) and 18 benign lesions prospectively obtained between 1989 and 1993. Patients' charts were reviewed to establish a database of known clinical prognostic indicators. Expression of EMA and Leu-7 was significant in malignant lesions when compared to benign lesions (P < 0.02 and P < 0.001). EMA was expressed significantly more frequently by follicular carcinomas than by follicular adenomas (P < 0.03). Leu-7 antigen was expressed by all papillary carcinomas. Neither of these antigens showed any association with known clinical prognostic indicators. EGFr expression neither differentiated benign from malignant lesions nor correlated with prognostic factors. The presence of aneuploidy correlated with poor tumor differentiation (P < 0.02), but did not distinguish benign from malignant lesions. These results suggest that EMA expression may be useful for confirming malignancy in follicular neoplasms and that the expression of Leu-7 antigen can assist in distinguishing papillary carcinoma from benign lesions with pseudopapillae.