Prophylactic Inferior Vena Cava Filters in High-Risk Bariatric Surgery

Background  

Bariatric patients are at significant risk for venous thromboembolism (VTE) and a subset may benefit from retrievable inferior vena cava filters (rIVCFs). Optimal VTE prophylaxis and a consensus on factors which make bariatric patients high risk have not been established. This study describes our experience with the use of rIVCFs in combination with chemoprophylaxis for high-risk bariatric surgery patients.     

The Impact of Surgical Complications as a Main Risk Factor for Venous Thromboembolism: A Multicenter Study

Background

Studies suggest that postoperative complications are a risk factor for venous thromboembolism (VTE) after bariatric surgery. Knowledge of factors associated with a higher risk of VTE after bariatric surgery may be essential to select patients who may benefit from either prolonged or intensified thrombosis prophylaxis. The aim of this study is to determine the relationship between postoperative complications and VTE after bariatric surgery and other classical risk factors.

Methods

A retrospective multicenter case-control study was performed in patients who had bariatric surgery between January 2008 and September 2011. VTE until 6 months after surgery was registered, and patients were contacted to ascertain the results. For every case of VTE after surgery, 6 control patients were selected who were matched for gender, age, participating center and type of surgery. Risk factors for VTE before and after surgery and postoperative complications were registered.

Results

A total of 2,064 surgeries were included. In 12 patients, VTE occurred within 6 months after bariatric surgery (incidence 0.58 %, 95 % confidence interval (CI)?=?0.25–0.93). There was a strong association of complications after surgery (cases 91.7 %, controls 15.3 %, odds ratio (OR) 61.0; 95 % CI?=?7.1–521.3) or intensive care admission (cases 50.0 %, controls 11.1 %, OR?=?8.0; 95 % CI?=?2.1–30.8) with VTE. The majority of postoperative complications were anastomotic leak, abdominal abscess, and infection. We could not detect an association between classical thrombosis risk factors and postoperative VTE.

Conclusions

The incidence of VTE is low after bariatric surgery using thrombosis prophylaxis. However, there is a strong association between postoperative complications and VTE. These patients may benefit from more intensive thrombosis prophylaxis.     

Incidence of Venous Thromboembolism After Bariatric Surgery: A Population-Based Cohort Study

Background

The incidence of venous thromboembolism (VTE) after bariatric surgery is uncertain.

Methods

Using the resources of the Rochester Epidemiology Project and the Mayo Bariatric Surgery Registry, we identified all residents of Olmsted County, Minnesota, with incident VTE after undergoing bariatric surgery from 1987 through 2005. Using the dates of bariatric surgery and VTE events, we determined the cumulative incidence of VTE after bariatric surgery by using the Kaplan–Meier estimator. Cox proportional hazards modeling was used to assess patient age, sex, weight, and body mass index as potential predictors of VTE after bariatric surgery.

Results

We identified 396 residents who underwent 402 bariatric operations. The most common operation was an open Roux-en-Y gastric bypass (n?=?228). Eight patients had VTE that developed within 6 months (7 within 1 month) after surgery; five events occurred after hospital discharge but within 1 month after bariatric surgery. The cumulative incidence of VTE at 7, 30, 90, and 180 days was 0.3, 1.9, 2.1, and 2.1 %, respectively (180-day 95 % confidence interval (CI), 0.7–3.6 %). Patient age was a predictor of postoperative VTE (hazard ratio, 1.89 per 10-year increase in age; 95 % CI, 1.01–3.55; P?=?0.05).

Conclusions

In our population-based study, bariatric surgery had a high risk of VTE, especially for older patients. Because most VTE events occurred after hospital discharge, a randomized controlled trial of extended outpatient thromboprophylaxis is warranted in patients undergoing open Roux-en-Y gastric bypass for medically complicated obesity.     

Practice patterns in high-risk bariatric venous thromboembolism prophylaxis

Background

In the morbidly obese population that undergoes bariatric surgery, venous thromboembolism (VTE) is the leading cause of morbidity and mortality. Certain factors place a patient at higher risk for VTE. No consensus exists on VTE screening or prophylaxis for the high-risk patient. This report describes the results of a survey on VTE screening and prophylaxis patterns in high-risk bariatric surgery.

Methods

Members of the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) were queried on factors that identified bariatric patients as high risk for VTE and on routine screening and prophylaxis practices. This included mechanical and chemical prophylaxis, duration of therapy, and use of inferior vena cava (IVC) filters.

Results

Of the 385 surgeons who responded to the survey, 81 % were bariatric surgeons, and the majority managed more than 50 cases annually. One or more of the following risk factors qualified patients as high risk: history of VTE, hypercoagulable status, body mass index (BMI) exceeding 55 kg/m², partial pressure of arterial oxygen (PaO₂) lower than 60 mmHg, and severe immobility. Preoperative screening of patients for VTE was practiced routinely by 56 % of the surgeons, and 92.4 % used preoperative chemoprophylaxis. The most common agent used preoperatively was heparin (48 %), and Lovenox was most commonly used postoperatively (49 %). Whereas 48 % of the patients discontinued chemoprophylaxis at discharge, 43 % continued chemoprophylaxis as outpatients, and 47 % routinely screened for VTE postoperatively. Use of IVC filters was routine for 28 % of the patients, who most commonly removed them after 1–3 months.

Conclusions

This study describes current practice patterns of VTE screening and prophylaxis in high-risk bariatric surgery. Nearly all surgeons agree on risk factors that qualify patients as high risk, but only half routinely screen patients preoperatively. Preoperative VTE chemoprophylaxis is used by nearly all surgeons, but the duration of therapy varies. Use of IVC filters is not routine, and postoperative screening was performed by less than half of the respondents. An understanding of current practice patterns yields insight into the rates of VTE and shows variability in the need for evidence-based prophylaxis and standardized screening.     

Risk of thrombosis and thromboembolic prophylaxis in obesity surgery: data analysis from the German Bariatric Surgery Registry

Background

Evidence-based data on optimal approach for prophylaxis of deep venous thrombosis (VTE) and pulmonary embolism (PE) in bariatric operations is discussed. Using antithrombotic prophylaxis, weight adjusted the risk of VTE and its complications have to be balanced with the increased bleeding risk.

Methods

Since 2005, the current situation for bariatric surgery has been examined by quality assurance study in Germany. As a prospective multicenter observational study, data on the type, regimen, and time course of VTE prophylaxis were documented. The incidences of clinically diagnosed VTE or PE were derived during the in-hospital course and follow up.

Results

Overall, 31,668 primary bariatric procedures were performed between January 2005 and December 2013. Most performed operations were 3999 gastric banding (GB); 13,722 Roux-en-Y-gastric bypass (RYGBP); and 11,840 sleeve gastrectomies (SG). Gender (p?=?0.945), surgical procedure (p?=?0.666), or administration of thromboembolic prophylaxis (p?=?0.272) had no statistical impact on the DVT incidence. By contrast, BMI (p?=?0.116) and the duration of thromboembolic prophylaxis (p?=?0.127) did impact the frequency of onset of DVT.

Conclusion

Age, BMI, male gender, and a previous history of VTE are the most important risk factors. The drug of choice for VTE is heparin. LMWH should be given preference over unfractionated heparins due to their improved pharmacological properties, i.e., better bioavailability and longer half-life as well as ease of use. Despite the low incidence of VTE and PE, there is a lack of evidence. Therefore, prospective randomized studies are necessary to determine the optimal VTE prophylaxis for bariatric surgical patients.

     

Which postoperative complications matter most after bariatric surgery? Prioritizing quality improvement efforts to improve national outcomes

Background

National quality programs have been implemented to decrease the burden of adverse events on key outcomes in bariatric surgery. However, it is not well understood which complications have the most impact on patient health.

Extended use of bemiparin as thromboprophylaxis during bariatric surgery: results of anti-factor Xa activity measurements

Background

The incidence of venous thromboembolism (VTE) in morbidly obese patients after obesity surgery is between .2% and 3.5%. Because there are a lack of prospective studies on the type of drug, the correct dosage, and the optimal duration, there are no specific recommendations found in the guidelines on thrombophylaxis.

Pulmonary Embolism and Deep Venous Thrombosis Following Bariatric Surgery

Background

The contribution of obesity to the thromboembolic risks of surgery suggests that patients undergoing bariatric surgery would have a particularly high risk of postoperative pulmonary embolism (PE) and/or deep venous thrombosis (DVT). This study aimed to assess the prevalence of in-hospital PE, DVT, and venous thromboembolism (VTE) following bariatric surgery in the USA from 2007 to 2009.

Methods

We used the database of the Nationwide Inpatient Sample.

Results

The prevalence of PE was 4,500 of 508,230 (0.9 %). The prevalence of DVT not accompanied by PE was 6,480 of 508,230 (1.3 %) and VTE (either PE or DVT) occurred in 10,980 of 508,230 (2.2 %). In-hospital death among patients with PE was 130 of 508,231 (0.03 %). Vena cava filters were inserted in 1,515 of 508,230 (0.3 %) patients who underwent bariatric surgery. Among patients who had VTE, filters were inserted in 1,150 of 10,980 (10.5 %). Among patients who had neither PE nor DVT, prophylactic vena cava filters were inserted in 365 of 497,250 (0.07 %). Among patients with PE, in-hospital mortality was 25 of 635 (3.9 %) with a filter compared with 105 of 3,865 (2.7 %) (NS) without a filter. However, among patients with DVT alone, in-hospital mortality was 0 of 510 (0 %) with a filter compared with 80 of 5,970 (1.3 %) (P?=?0.009) without a filter.

Conclusions

This investigation establishes a baseline for the incidence of venous thromboembolic complications following bariatric surgery in recent years. Determination of the present in-hospital rate of PE and DVT may contribute to antithrombotic prophylactic considerations.     

Prevalence of Thrombophilias in Patients Presenting for Bariatric Surgery

Background  The rise in bariatric surgery has driven an increased number of complications from venous thromboembolism (VTE). Evidence supports obesity as an independent risk factor for VTE, but the specific derangements underlying the hypercoagulability of obesity are not well defined. To better characterize VTE risk for the purpose of tailoring prophylactic strategies, we developed a protocol for thrombophilia screening in patients presenting for bariatric surgery at our institution. Methods  Between April 2004 and April 2006, 180 bariatric surgery candidates underwent serologic screening for inherited thrombophilias (Factor V-Leiden mutation, low Protein C activity, low Protein S activity, Free Protein S deficiency) and acquired thrombophilias (D-Dimer elevation, Fibrinogen elevation, elevation of coagulation factors VIII, IX, and XI, elevation of Lupus anticoagulants and homocysteine level, and Antithrombin III deficiency). Prevalence rate of each thrombophilia in the subject group was compared to the actual prevalence rate of the general population. Results  Most plasma markers of both inherited and acquired thrombophilias were identified in higher than expected proportions, including D-Dimer elevation in 31%, Fibrinogen elevation in 40%, Factor VIII elevation in 50%, Factor IX elevation in 64%, Factor XI elevation in 50%, and Lupus anticoagulant in 13%. Conclusions  Obesity is a well-described demographic risk factor for VTE. In bariatric surgery candidates routinely screened for serologic markers, both inherited and acquired thrombophilias occurred more frequently than in the general population, and may therefore prove to be useful for individualized VTE risk assessment and prophylaxis.     

Postoperative Venous Thromboembolism Rates Vary Significantly After Different Types of Major Abdominal Operations

Background  Venous thrombolism (VTE) is a significant cause of morbidity for surgical patients. Comparative risk across major procedures is unknown. Methods  Retrospective analysis of the Nationwide Inpatient Sample (2001–2005) was conducted. Eight surgeries were identified: bariatric surgery, colorectal surgery, esophagectomy, gastrectomy, hepatectomy, nephrectomy, pancreatectomy, splenectomy. Age < 18, patients with multiple major surgeries, and those admitted for treatment of VTE were excluded. Primary outcome was occurrence of VTE. Independent variables included age, gender, race, Charlson score, hospital teaching status, elective procedures, cancer/metastasis, trauma, and year. Results  Patients, 375,748, were identified, 5,773 (1.54%) with VTE. Overall death rate was 3.97%, but 13.34% after VTE. Unadjusted rate (0.35%) and adjusted risk for VTE were lowest among bariatric patients. On multivariate analysis, highest risk for VTE was splenectomy (odds ratio 2.69, 95% CI 2.03–3.56). Odds ratio of in-hospital mortality following VTE was 1.84 (1.65–2.05), associated with excess stay of 10.88days and $9,612 excess charges, translating into $55 million/year nationwide. Conclusion  Highest risk for VTE was associated with splenectomy, lowest risk with bariatric surgery. Since bariatric patients are known to have greater risk for this complication, these findings may reflect better awareness/prophylaxis. Further studies are necessary to quantify effect of best-practice guidelines on prevention of this costly complication. This paper was presented as a poster at the Digestive Disease Week conference in San Diego, California on Monday, May 19, 2008.     

Reduced Cardiovascular Risk Following Bariatric Surgeries is Related to a Partial Recovery from “Adiposopathy”

Background  

Altered cytokine secretion from dysfunctional adipose tissue or “adiposopathy” is implicated in obesity related inflammation and may mediate reduced cardiovascular disease (CVD) risk in response to weight loss after bariatric surgery. We hypothesized that bariatric surgery reduces CVD risk by favorably altering the pro-inflammatory profile of adipose tissue as a result of weight loss.     

Surgical Site Infections Following Bariatric Surgery in Community Hospitals: A Weighty Concern?

Background  

Although obesity is a well-known risk factor for surgical site infection (SSI), specific risk factors for SSI among obese patients undergoing bariatric surgery (BS) have not been well-defined.     

Symptomatic venous thromboembolism in Asian colorectal cancer surgery patients

Background  

The occurrence of venous thromboembolism (VTE), manifesting as deep vein thrombosis (DVT) or pulmonary embolism (PE), after colorectal cancer surgery in Asian patients remains poorly characterized. The present study was designed to investigate the incidence of symptomatic VTE in Korean colorectal cancer patients following surgery, and to identify the associated risk factors.     

The Effects of Bariatric Surgery on Asthma Severity

Background  

Excess body weight increases both the risk and severity of asthma. Several studies indicate that bariatric surgery decreases asthma severity, but either enrolled few patients or were not focused primarily on asthma. Furthermore, none compared the effects of different bariatric surgical procedures.     

Increased Serum Nitric Oxide Concentration After Bariatric Surgery—A Potential Mechanism for Cardiovascular Benefit

Background  

It is believed that endothelial dysfunction associated with obesity contributes to reduced vascular production of nitric oxide (NO). Weight reduction after bariatric surgery is known to decrease the risk of cardiovascular disease. The purpose of this study was to determine whether bariatric surgery leads to improvement of metabolic markers of endothelial function: serum NO and its precursor (arginine) concentrations in obese patients.     

Prevalence and Co-occurrence of Upper and Lower Functional Gastrointestinal Symptoms in Patients Eligible for Bariatric Surgery

Background  

Obesity is considered as a risk factor for many functional digestive disorders. The aim of the present study was to evaluate the prevalence and the association of functional digestive symptoms affecting the upper and the lower digestive tract in patients eligible for bariatric surgery.     

Intraoperative Fluid Replacement and Postoperative Creatine Phosphokinase Levels in Laparoscopic Bariatric Patients

Background  

Morbid obesity and bariatric surgery are both risk factors for the development of postoperative rhabdomyolysis (RML). RML results from injury to skeletal muscle, and a serum creatine phosphokinase (CK) level >1,000 IU/L is considered diagnostic of RML. The aim of this study was to determine if intraoperative intravenous fluid (IVF) volume affects postoperative CK levels following laparoscopic bariatric operations.     

Prospective randomized controlled trial on the effect of fondaparinux sodium for prevention of venous thromboembolism after hip fracture surgery

Background  

Hip fracture surgery (HFS) carries a high risk of venous thromboembolism (VTE) in the absence of thromboprophylactic treatment. Previous reports have suggested that fondaparinux sodium (FPX) administration decreases the incidence of VTE after HFS and total hip and knee arthroplasties. However, investigations of that effect in Japanese populations remain inadequate. We evaluated the efficacy of FPX after HFS in a prospective randomized controlled trial.     

Impact of bariatric surgery on outcomes of patients with nonalcoholic fatty liver disease: a nationwide inpatient sample analysis, 2004–2012

Background

Bariatric surgery in eligible morbidly obese individuals may improve liver steatosis, inflammation, and fibrosis; however, population-based data on the clinical benefits of bariatric surgery in patients with nonalcoholic fatty liver disease (NAFLD) are lacking.

Venous thromboembolism in women undergoing pelvic reconstructive surgery with mechanical prophylaxis alone

Introduction and hypothesis

The objective of this study was determine the frequency of symptomatic perioperative venous thromboembolism (VTE) and risk factor(s) associated with VTE occurrence in women undergoing elective pelvic reconstructive surgery using only intermittent pneumatic compression (IPC) for VTE prophylaxis.

Methods

A multi-center case–cohort retrospective review was conducted at six clinical sites over a 66-month period. All sites utilize IPC as standard VTE prophylaxis for urogynecological surgery. VTE cases occurring during the same hospitalization and up to 6 weeks postoperatively were identified by ICD9 code query. Four controls were temporally matched to each case. Information collected included demographics, medical history, route of surgery, operative time, and intraoperative characteristics. Univariate and multivariate backward stepwise logistic regression analyses were performed to identify potential risk factors for VTE.

Results

Symptomatic perioperative VTE was diagnosed in 27 subjects from a cohort of 10,627 women who underwent elective urogynecological surgery (0.25 %). Univariate analysis identified surgical route (laparotomy vs others), type of surgery (“major” vs “minor”), history of gynecological cancer, surgery time, and patient age as risk factors for VTE (P?<?0.05). Multivariate analysis identified increased frequency of VTE with laparotomy, age?≥?70, and surgery duration?≥?5 h.

Conclusions

In our study cohort, the frequency of symptomatic perioperative VTE was low. Laparotomy, age?≥?70 years, and surgery duration?≥?5 h were associated with VTE occurrence.