2 that there is a high risk of deep venous thrombosis (VTE) and pulmonary embolism (PE) for patients who undergo bariatric surgery. An even higher risk for the development of a thrombosis is reported by the German AWMFguidelines [6]. International guidelines refer to an independent risk for the occurrence of fulminate pulmonary embolism in obese patients. Current “ASBMS” guidelines recommend local compressions and anticoagulation [7]. Actually, the optimal approach for prophylaxis of VTE in bariatric operations as well as obese patients is unknown. The risk of VTE and its complications has to be balanced with the increased bleeding risk. In the literature, there have been no randomized studies examining the correlation between VTE, pulmonary embolism (PE), and the various options for VTE prophylaxis in bariatric surgery [8]. Recent published meta-analysis show the relatively low risk with standard regimen for antithrombotic prophylaxis, but an increasing bleeding risk, when weight-adjusted dose of heparin were used [9]. The aim of this study evaluating the data of the German Nationwide Survey on Bariatric Surgery was to investigate the speciﬁc complications of thrombosis and pulmonary embolism in the perioperative course in Germany and to compare our ﬁndings with data from the literature. 2. Patients and Methods Data from the Study for quality assurance in bariatric surgery in Germany have been prospectively obtained from January 1, 2005 [10] using an online data registry. For current evaluation, data from 2005 to 2010 were analyzed. Inci- dence and risk of VTE for the most performed metabolic procedures gastric banding (GB), sleeve gastrectomy (SG), and Roux-en-Y-gastric bypass (RYGBP) have been evaluated. Peri-interventional characteristics and parameters, such as BMI as well as the frequency, type, application mode, and duration of medication in VTE and PE, were determined in connection to the operative procedure. Follow-up data, which are available for 63.8% of patients, were used to elucidate the incidence of VTE and PE after discharge. To appropriately interpret the results, a literature search was initiated. 3. Results 3.1. Operations. Since 2005 the number of primary metabol- ic operations has been increasing, rapidly. We reporting on 12, 296 primary bariatric procedures including 668 implantations of gastric balloons (BIB), 2730 GB, 4901 RYGBP, 3042 SG, 120 biliopancreatic diver- sion (BPD), and 163 duodenal switch (DS) and 211 other procedures. 3.2. Demographic Data. In total 72.5% female patients and 27.5% male patients were operated between 2005 and 2010. Mean age for all patients was 42.2 years (range 11–79 years) and mean BMI 48.8 kg/m2 (range 23.7–115 kg/m2). Mean age for women (40.9 years, range 11–79 years) was signiﬁcantly lower than for men (43.6 years, range Table 1: Incidence of comorbidities. Hypertension Skeleton disease Sleep apnoea Noninsulin dependent diabetes Pulmonary disease Without GERD Cardiac disease Nicotin abuse LE in medical history (n) 7042 5366 2380 2347 2153 2001 1836 1193 275 108 Thrombosis Total (%) 57.3 43.6 19.4 19.1 17.5 16.3 14.9 9.7 2.2 0.9 14–79 years) (P > 0.001). Mean BMI was for women 48.1 kg/m2 (range 23.7–115.0 kg/m2) and 50.1 kg/m2 (range 27.4–10.2 kg/m2) for men. 3.3. Comorbidities. For risk analysis the incidence of comor- bidities is important. In German Nationwide Survey on Bariatric Surgery the incidence of comorbidities is high. At the diﬀerent periods from 2005 to 2010 the incidence on comorbidities did not change. 57.3% of patients suf- fering on hypertension, 17.5% on pulmonary diseases, 9.7% on cardiac comorbidities, 14.9% on gastroesophageal reﬂux disease, and 43.6% on skeleton disease. Incidence on patients with insulin-dependent diabetes is 10.0% and with noninsulin-dependent diabetes is 19.1% (P < 0.001) (Table 1). 3.4. Operation and Thromboembolic Prophylaxis. Prophy- laxis of VTE and PE depends on the kind of operation. Through the observation period from 2005 to 2010, a signiﬁcant reduction of patients undergoing GB procedure and who had previously undergone prophylaxis for throm- boembolism with medication was found (P < 0.001), respec- tively (Table 2). In cases of complex surgical interventions like biliopancreatic diversion (BPD) and duodenal switch (DS), prophylactic medication was given to all patients. The duration of prophylaxis of thromboembolism cor- related signiﬁcantly with the length of hospital stay, which ranged from 6 to 8 days (P < 0.001) (Table 3). LMWH was used for prophylaxis in 98.5% of the pa- tients; only in 1.5% of patients were unfractionated heparin used for prophylaxis. No prophylaxis with cava ﬁlters is reported to German Nationwide Survey. In 2005, there was no association between BMI and the frequency of prophylaxis administration for thromboem- bolism. In contrast, there was a tendency to administer low- molecular-weight heparin twice a day during the following years. Patients who received two administrations showed a higher BMI (once a day, BMI = 48.5 kg/m2; twice a day, BMI = 51.5 kg/m2 (P < 0.001). Therefore, patients with two applications for thromboembolism prophylaxis showed a signiﬁcantly higher BMI through the whole study period (Table 4).