External-beam radiation therapy for improved dialysis access patency: feasibility and early safety.

Rectenwald, J. E., Pretus, H. A., Seeger, J. M., Huber, T. S., Mendenhall, N. P., Zlotecki, R. A., Palta, J. R., Li, Z. F., Hook, S. Y., Sarac, T. P., Welborn, M. B., Klingman, N. V., Abouhamze, Z. S. and Ozaki, C. K. External-Beam Radiation Therapy for Improved Dialysis Access Patency: Feasibility and Early Safety. Radiat. Res. 156, 53-60 (2001).Prosthetic dialysis access grafts fail secondary to neointimal hyperplasia at the venous anastomosis. We hypothesized that postoperative single-fraction external-beam radiation therapy to the venous anastomosis of hemodialysis grafts can be used safely in an effort to improve access patency. Dogs (n = 8) underwent placement of expanded polytetrafluoroethylene grafts from the right carotid artery to the left jugular vein. Five dogs received single-fraction external-beam photon irradiation (8 Gy) to the venous anastomosis after surgery. Controls were not irradiated. Shunt angiograms were completed 3 and 6 months postoperatively. Anastomoses, mid-graft, and the surrounding tissues were analyzed. Immunohistochemistry for smooth muscle cell alpha-actin, proliferating cellular nuclear antigen (PCNA), and apoptosis was performed. Incisions healed well, though all animals developed wound seromas. One control suffered graft thrombosis 4 months postoperatively. Angiography/histology confirmed severe neointimal hyperplasia at the venous anastomosis. The remaining seven dogs developed similar amounts of neointimal hyperplasia. PCNA studies showed no accelerated fibroproliferative response at irradiated anastomoses compared to controls. Skin incisions and soft tissues over irradiated anastomoses revealed no radiation-induced changes or increase in apoptosis. Thus we conclude that postoperative single-fraction external-beam irradiation of the venous anastomosis of a prosthetic arteriovenous graft that mimics the situation in humans is feasible and safe with regard to early wound healing.

Cytologic criteria for the brush diagnosis of gastric adenocarcinoma.

BACKGROUND: The cytologic diagnosis of gastric adenocarcinoma often is difficult, and the role of gastric brushing in the detection of gastric malignancy is controversial. The purpose of this study was to identify the key cytologic criteria that are most useful for establishing a diagnosis of adenocarcinoma in gastric brushing specimens. METHODS: One hundred gastric brushings were reviewed retrospectively. Fifty of the specimens were obtained from patients with histologically confirmed benign lesions. The other 50 specimens were obtained from patients with histologically confirmed gastric adenocarcinoma. All 100 brushing specimens were reviewed without knowledge of the histologic diagnosis. Each specimen was assessed for the presence or absence of 16 different cytologic features that have been identified in the published literature as being useful for separating benign conditions from malignancy. A multiple logistic linear regression analysis was performed to determine which combination of criteria was the most useful for diagnosing gastric adenocarcinoma. RESULTS: Three key cytologic criteria were identified as being the most useful for diagnosing gastric adenocarcinoma: single atypical cells with intact cytoplasm, eccentric nuclei, and atypical naked nuclei. When at least 2 of these cytologic criteria were present, the sensitivity and specificity for detecting adenocarcinoma were 88% and 100%, respectively. Two minor cytologic criteria also were identified: nuclear hyperchromasia and nuclear molding. CONCLUSIONS: Our statistical analysis demonstrates that gastric adenocarcinoma can be diagnosed with a high degree of accuracy using gastric brushing specimens when specific cytologic criteria are applied.