Comparison Among Different Closure Methods of the Appendicular Stump in Laparoscopic Appendectomy.

In view of the fact that appendectomy is the most common operation for an acute abdomen, laparoscopic appendectomy has evolved as the most frequently performed procedure. Hospitals, therefore, require at all times the expertise, technique, and staff to ensure a high quality of standard for appendectomies, which not only supports the requirements of the high caseload but also takes into consideration the socio-economical aspects. A critical step is the closure of the appendicular stump. The three most widely employed techniques are an endo-stapler, an endo-loop, or a clip. Although the endo-stapler is fairly expensive, it combines closing and transecting the appendix in one step, offers the possibility of a partial caecal resection, and can be used if the appendicular base is inflamed. Endo-loop and clip are equally cost-effective, but the clip appears to be simpler in handling than the endo-loop and, like the stapler, offers closing and cutting the appendix before dissecting the mesoappendix. However, only appendices up to 16 mm in diameter can be clipped, a disadvantage not shared with the loop.

Fas (CD95/APO-1) and Fas ligand expression in normal pancreas and pancreatic tumors. Implications for immune privilege and immune escape.

BACKGROUND: Fas (CD95/APO-1) and Fas ligand (FasL) play key roles in immunologic homeostasis and immune privilege and may regulate normal cell turnover. Earlier studies had suggested that FasL-positive pancreatic carcinoma cell lines can induce apoptosis in T cells, thereby evading host immune surveillance. In the current study the authors have characterized the expression of Fas and FasL in the normal pancreas and in pancreatic neoplasia. METHODS: Pancreatic resection specimens with ductal-type adenocarcinoma or intraductal dysplasia (n = 41), nonductal pancreatic neoplasms (n = 5), and chronic pancreatitis (n = 4) were examined for Fas and FasL expression by immunohistochemistry. The results in invasive adenocarcinoma were compared to those for benign ducts and intraductal dysplasia, and correlated with clinicopathologic features of the tumors and with patient survival. RESULTS: Fas was expressed in the normal pancreatic ducts and in intraductal dysplasia in a mixed membrane/cytoplasmic pattern. In all cases of invasive ductal-type adenocarcinoma, membranous Fas could not be detected; cytoplasmic Fas staining was reduced or completely lost. Loss of Fas expression in pancreatic ductal-type adenocarcinomas significantly correlated with poorer differentiation and extrapancreatic spread of the tumors and was associated with a shorter overall survival. FasL expression was present in the normal pancreatic ducts as well as in islet cells and was maintained in all pancreatic tumors. CONCLUSIONS: These results implicate the Fas pathway in the regulation of physiologic cell turnover and immune privilege in the normal pancreas and indicate that loss of Fas expression is correlated with malignant transformation and biologic aggressiveness in pancreatic adenocarcinomas. This may represent a mechanism by which pancreatic tumor cells become resistant to apoptosis and escape immune surveillance in vivo.