Epidemiology And Risk Factor Of Postoperative Venous Thromboembolism

Background and ObjectiveVenous thromboembolism (VTE) encompasses deep venous thrombosis (DVT) and plumonary thromboembolism (PTE), which results from the obsturction of vein, and may lead to circulation disorder and organ dysfunction. Since lack of specific clinical signs and symptoms, VTE may escape prompt diagnosis. Due to investigation, VTE has become one of the most important cause of death in hospital. The causes of VTE can be divided into two groups:hereditary and acquired, and among the numerous risk factors, surgery is one that should not be overlooked. Postoperative VTE not only leads to prolonged hospitalization and increazed cost, but also results in death and disability. VTE is now one of the most common cause for unpredictable death in surgery patients. And since more and more clinical studies have proved the effectiveness and safety for anticoagulant agents being used in surgery patients, VTE is also a preventable disease for surgery patients. Therefore, taking reasonable precautions or early detection is quite meaningful.In our study, we retrospectively analyzed the epidemiology and characteristics of postoperative VTE patients which were collected in Sir Run Run Shaw hospital from January1995to March2015. Then we discussed the risk factors of postoperative VTE by matched case-control study (in the ratio of1:4). So as to offer some suggestion for the recognition, early dectetion and prophylaxis within high-risk group of postoperative VTE.MethodsWe screened the hospitalized surgery patients in Sir Run Run Shaw hospital electronic medical datebase within January1995-March2015, and selected patients with VTE (patients who diagnosed with VTE before operation were excluded), and got94patients at last. we chose376non-peroperative VTE patients in the same period matched with the operation code (be in the ratio of1:4) as control. And the clinical characteristic was collected, including manifestation, underlying diseases, surgery-related information, laboratory index et al. Then we calculated the diagnostic rate and investgated the risk factors of postoperative VTE.Results1. There were94patients clarified as VTE after operation in Sir Run Run Shaw hosipital from Juanary1995to March2015, and the cumulative diagnostic rate from2005to2014was0.378%o. Among2005-2009,2010,2011,2012,2013and2014, the diagnostic rate was0.0468%o,0.128%o,0.410%o,0.547%,0.827%o and1.191%respectively.2. Among1995-2004,2005-2009,2010,2011,2012,2013and2014, the proportion of high-risk group PTE was66.67%,50%,25%,22.22%,7.69%,4.35%and11.76%; the proportion of DVT was0%,0%,0%,33.33%,38.46%,68.86%and41.42%; the death rate was66.67%,25%,25%,0%,7.69%,4.35%and0%respectively.3. For the94patients, average age was62.23±14.45years old, BMI was 24.45±3.47kg/m2, Caprini score was6.01±2.05. There were42patients combined with malignancy; the proportion of patients with gastro-intestinal malignancies and lung cancer were33.33%and14.29%;66.67%of them were adenocarcinoma; most of them were diagnosed at late stage.4. There were42PTE patients,39DVT patients, and11patients coexist with PTE and DVT. VTE was diagnosed after11.20±15.87days of surgery, and54.26%of them was diagnosed within1week.5. By matched case-control study, we found that age≥65years, BMI>25kg/m2, combined with hypertention, coronary heart disease, malignancy, operation time≥120min, intraoperatve blood soss≥200ml, D-dimer level>lug/ml, albumin≤35g/l, haematocrit (HCT)≤38%were different between the two group (P<0.05). And age≥65years, operation time≥120min, albumin<3.5mg/dl were the independent risk factors of postoperative VTE.ConclusionThe diagnostic rate of postoperative VTE in Sir Run Run Shaw hospital rise year by year, but the proportion of high-risk group PTE and the death rate of the postoperative VTE declined gradually. When patients with a Caprini score≥5-7receive operation, VTE is quite easy to occur, espeacially those with malignancy. So appropriate prophylaxis is important for those patients. Age≥65years, operation time≥120min, albumin<3.5mg/dl is independent risk factors for surgery patients, early detection is vital for those patients.