Prospective study of the incidence and risk factors of postsplenectomy thrombosis of the portal, mesenteric, and splenic veins.

HYPOTHESIS: Splenectomy is recognized as a cause of portal, mesenteric, and splenic vein thrombosis. The exact incidence of the complication and its predisposing factors are not known. DESIGN: Prospective observational cohort study. The median follow-up time of the patients was 22.6 months. SETTING: University surgical clinic in a teaching hospital. PATIENTS: A total of 147 consecutive patients who underwent splenectomy in a 4-year period were enrolled in the study. INTERVENTIONS: Preoperative and postoperative evaluation included ultrasonography with color Doppler flow imaging of the portal system, results of blood coagulation tests, fibrinogen levels, D-dimer levels, and complete blood counts. Operative sheets were recorded and reviewed. When portal system thrombosis (PST) was diagnosed, a complete control for acquired and congenital thrombophilia disorders was obtained. MAIN OUTCOME MEASURES: Primary end points of the study were the assessment of the incidence of postsplenectomy PST and the identification of risk factors for its occurrence. RESULTS: Portal system thrombosis occurred in 7 (4.79%) of 146 patients who underwent splenectomy. The age, sex, type or length of the operation, and use of preoperative and postoperative thromboprophylaxis with low molecular weight heparin did not prove to be significant factors in the occurrence of PST. Platelet count of more than 650 x 10(3)/microL and greater spleen weight (>650 g) was associated with the development of PST (P = .01, P = .03). Normal D-dimer levels on diagnosis of the complication showed a negative predictive value of 98%. Two of the affected patients were diagnosed with thrombophilia disorders. In a median follow-up period of 22.6 months, no other case of PST was recorded. CONCLUSIONS: Postsplenectomy PST occurs in approximately 5% of patients. Possible risk factors are thrombocytosis, splenomegaly, and congenital thrombophilia disorders.

Risk estimation for breast cancer development; a clinical perspective.

Breast cancer is the commonest cancer among women and the second highest cause of cancer death. It remains a significant health problem and represents a significant worry for many women and their physician. During the last years, intensive research has been focused on accurate risk estimation for breast cancer development. The aim of these efforts is to identify the "high-risk" group of women for breast cancer development. Preventive strategies (including intensive surveillance, chemoprevention, or prophylactic mastectomy) may be applied for the women at high risk for breast cancer development. Given the many management options, it seems reasonable that management of the high-risk woman be tailored to the level of risk she is willing to accept. In estimating the risk for breast cancer development, several factors should be taken into account (including age, reproductive factors, such as age at menarche and age at menopause or pregnancy and age at first live birth, history of benign breast lesions or breast cancer in situ [LCIS/DCIS], prior history of breast cancer, history of familiar or hereditary breast cancer, and environmental and lifestyle factors). Recently, quantitative risk estimation is possible by combining multiple risk factors into a comprehensible risk expression; this is of significant clinical importance, since it will reduce the considerable variation in management among health care providers. The Gail and the Claus model are the most widely used models for quantitative risk estimation. However, the clinician should understand that all models have some limitations that should be recalled as they are applied. It should be emphasized that risk assessment is a serious undertaking and should only be performed by those who have in-depth knowledge about risk factors, family pedigree analysis, comparative statistics, genetics susceptibility testing and the science of probability.