A reassessment of needs and practice patterns in pharmacologic prophylaxis of venous thromboembolism following elective major surgery

Should all patients receive the same prophylaxis? Racial variation in the risk of venous thromboembolism after major abdominal operations

BACKGROUND

Whether prevention strategy for postoperative venous thromboembolism (VTE) should be tailored across racial groups remains unknown.

METHODS

Patients who underwent major abdominal operation in the Nationwide Inpatient Sample (NIS) were examined. Our primary outcome was postoperative VTE, and the secondary outcome was postoperative bleeding. Multivariable logistic regression analyses were performed and validated with the National Surgical Quality Improvement Program (NSQIP) database.

RESULTS

781,888 patients from NIS were analyzed. Overall VTE rate was 2.0%. Compared to White patients, Hispanic (OR 0.85, 95% CI 0.78-0.93, p < 0.01) and Asian patients (OR 0.49, 95% CI 0.40-0.61, p < 0.01) had significantly lower risks for VTE. In contrast, Asian patients had a significantly higher risk of bleeding (OR 1.39, 95% CI 1.24-1.56, p < 0.01). Similar trends were observed in NSQIP.

CONCLUSIONS

The risk-benefit ratio of postoperative VTE prophylaxis for Asian patients is roughly three times higher than that for White patients, suggesting a tailored approach is necessary.

Impact of pulmonary embolism on morbidity and mortality in patients undergoing pancreatic surgery

PURPOSE

Postoperative pulmonary embolism (PE) after pancreatic surgery is a potentially life-threatening complication. However, the magnitude of morbidity and mortality of PE is still uncertain. The present study aims to assess the incidence of PE after pancreatic surgery and analyze its impact on the outcome.

METHODS

We conducted a retrospective study including all patients who underwent pancreatic resections between 2005 and 2017. The development of PE was analyzed for a 90-day period following surgery. Risk factors were evaluated using regression models.

RESULTS

The study investigated 947 patients undergoing pancreatic surgery. Overall, 26 (2.7%) patients developed PE. The median body mass index (BMI) of patients with PE was significantly higher (28.1 kg/m² [24.7-31.8] vs. 24.8 kg/m² [22.4-27.8], p < 0.001). Patients with PE had a significantly increased duration of the operation and more often underwent multivisceral resections. The lowest incidence of PE was found after distal or total pancreatectomy (2%). In median, PE occurred on the fifth postoperative day (interquartile range: 3-9). Increased BMI, duration of operation, and postoperative deep venous thrombosis were found to be multivariate risk factors for the development of PE. Importantly, postoperative complications (53.8% vs. 15.1%, p < 0.001) and the 30-day mortality rate were significantly increased in the PE group (19.2% vs. 3.3%, p < 0.001).

CONCLUSIONS

Patients with increased BMI, a history of deep venous thrombosis, and multivisceral resections are a high-risk group for PE after pancreatic surgery. While the absolute incidence and related mortality of PE after pancreatic surgery is low, it is associated with severe sequelae.

Does preoperative pharmacologic prophylaxis reduce the rate of venous thromboembolism in pancreatectomy patients?

BACKGROUND

Whether the risk of venous thromboembolism (VTE) may be reduced by preoperative administration of prophylactic heparin is unknown. We hypothesized that timing of heparin administration does not significantly alter the incidence of VTE in pancreatic surgery.

METHODS

An analysis was conducted using data from Massachusetts General Hospital's National Surgical Quality Improvement Program from 2012 to 2017. All patients admitted for elective pancreatic resection were included. The primary outcome was development of VTE. Multivariable regression was performed, adjusting for patient demographics and various clinical factors.

RESULTS

In total, 1448 patients were analyzed, of whom 1062 received preoperative heparin (73.3%). Overall, 36 (2.5%) patients developed VTE. On unadjusted analysis, there was no statistically significant difference between patients who received preoperative heparin compared with those who did not (2.6% vs. 1.3%, respectively; p = 0.079). On adjusted analysis, there was an association with increased VTE rates among patients who received preoperative heparin (OR 2.93, 95% CI 1.10-7.81; p = 0.031).

CONCLUSION

There was an association between preoperative heparin administration and increased incidence of VTE on adjusted analysis, possibly reflecting appropriate surgical judgment in patient selection for prophylaxis. These data question the inclusion of preoperative VTE pharmacologic prophylaxis as a reliable quality indicator.

Extended thromboprophylaxis following colorectal surgery in patients with inflammatory bowel disease: a comprehensive systematic clinical review

AIM

Patients with inflammatory bowel disease (IBD) are at increased risk of postoperative venous thromboembolism (VTE) following major abdominal surgery. The pathogenesis is multifactorial and not fully understood. A combination of pathophysiology, patient and surgical risk factors increase the risk of postoperative VTE in these patients. Despite being at increased risk, IBD patients are not regularly prescribed extended pharmacological thromboprophylaxis following colorectal surgery. Currently, there is a paucity of evidence-based guidelines. Thus, the aim of this review is to evaluate the role of extended pharmacological thromboprophylaxis in IBD patients undergoing colorectal surgery.

METHOD

A search of Ovid Medline, EMBASE and PubMed databases was performed. A qualitative analysis was performed using 10 clinical questions developed by colorectal surgeons and a thrombosis haematologist. The Newcastle-Ottawa Scale was utilized to assess the quality of evidence.

RESULTS

A total of 1229 studies were identified, 38 of which met the final inclusion criteria (37 retrospective, one case-control). Rates of postoperative VTE ranged between 0.6% and 8.9%. Patient-specific risk factors for postoperative VTE included ulcerative colitis, increased age and obesity. Surgery-specific risk factors for postoperative VTE included open surgery, emergent surgery and ileostomy creation. Patients with IBD were more frequently at increased risk in the included studies for postoperative VTE than patients with colorectal cancer. The risk of bias assessment demonstrated low risk of bias in patient selection and comparability, with variable risk of bias in reported outcomes.

CONCLUSION

There is a lack of evidence regarding the use of extended pharmacological thromboprophylaxis in patients with IBD following colorectal surgery. As these patients are at heightened risk of postoperative VTE, future study and consideration of the use of extended pharmacological thromboprophylaxis is warranted.

Pulmonary embolism: specific risk factor after pancreas resection?

OBJECTIVE

Pulmonary embolism (PE) after major abdominal surgery is a serious and potentially lethal complication. The purpose of the present study was to identify risk factors for postoperative PE after pancreas resection.

METHODS

Our prospective database for pancreatic surgery was retrospectively analyzed for patients treated between January 2006 and August 2012 in a tertiary care Swiss hospital. Risk factors for PE were identified in univariate and multivariate analyses that included preoperative, intraoperative, and postoperative variables.

RESULTS

Among 251 patients, 187 underwent pancreato-duodenectomy (PD), 62 underwent distal pancreatectomy, and 2 underwent other types of pancreas resections. PE was diagnosed in 13 patients (7.0%) after PD and none after other procedures. Compared with the non-PE group, the PE group had higher body mass indices (≥25 kg/m, P = 0.04), longer median operation times (P = 0.009), higher rates of severe abdominal complications (P < 0.001), longer median intensive care unit stays (P = 0.003), and longer hospital stays (P = 0.01). Multivariate analyses identified the following independent predictors for PE: a history of thromboembolic events (odds ratio [OR], 22.3), prolonged operation time (OR, 5.76), and major abdominal complications (OR, 10.8).

CONCLUSIONS

Prolonged operation times and major postoperative abdominal complications were strong risk factors for PE after PD, in both univariate and multivariate analyses.

The risk of venous thromboembolism, myocardial infarction, stroke, major bleeding and death in patients undergoing total hip and knee replacement: a 15-year retrospective cohort study of routine clinical practice

We examined the risk of thrombotic and major bleeding events in patients undergoing total hip and knee replacement (THR and TKR) treated with thromboprophylaxis, using nationwide population-based databases. We identified 83 756 primary procedures performed between 1997 and 2011. The outcomes were symptomatic venous thromboembolism (VTE), myocardial infarction (MI), stroke, death and major bleeding requiring hospitalisation within 90 days of surgery. A total of 1114 (1.3%) and 483 (0.6%) patients experienced VTE and bleeding, respectively. The annual risk of VTE varied between 0.9% and 1.6%, and of bleeding between 0.4% and 0.8%. The risk of VTE and bleeding was unchanged over a 15-year period. A total of 0.7% of patients died within 90 days, with a decrease from 1% in 1997 to 0.6% in 2011 (p < 0.001). A high level of comorbidity and general anaesthesia were strong risk factors for both VTE and bleeding, with no difference between THR and TKR patients. The risk of both MI and stroke was 0.5%, which remained unchanged during the study period. In this cohort study of patients undergoing THR and TKR patients in routine clinical practice, approximately 3% experienced VTE, MI, stroke or bleeding. These risks did not decline during the 15-year study period, but the risk of dying fell substantially.

Thromboprophylaxis only during hospitalisation in fast-track hip and knee arthroplasty, a prospective cohort study

OBJECTIVES

International guidelines recommend thrombosis prophylaxis after total hip arthroplasty (THA) and total knee arthroplasty (TKA) for up to 35 days. However, previous studies often have hospital stays (length of stay; LOS) of 8-12 days and not considering early mobilisation, which may reduce incidence of venous thromboembolic events (VTE). We investigated the incidence of any symptomatic thromboembolic events (TEEs) with only in-hospital prophylaxis if LOS ≤5 days after fast-track THA and TKA.

DESIGN

A prospective descriptive multicentre cohort study in fast-track THA and TKA from February 2010 to December 2011, with complete 90-day follow-up through the Danish National Patient Registry and patient files.

SETTING

6 Danish high-volume centres with a similar standardised fast-track setup, including spinal anaesthesia, opioid-sparing analgesia, early mobilisation, functional discharge criteria and discharge to own home.

PARTICIPANTS

4924 consecutive unselected unilateral primary THA and TKAs in patients ≥18 years with no preoperative use of continuous 'potent' anticoagulative therapy (vitamin K antagonists).

EXPOSURE

Prophylaxis with low-molecular-weight heparin or factor Xa-inhibitors only during hospitalisation when LOS ≤5 days.

OUTCOMES

Incidence of symptomatic TEE-related, VTE-related and VTE-related mortality ≤90 days postoperatively.

RESULTS

LOS ≤5 days and thromboprophylaxis only during hospitalisation occurred in 4659 procedures (94.6% of total). Median LOS and prophylaxis duration was 2 days (IQR 2-3) with 0.84% (95% CI 0.62% to 1.15%) TEE and 0.41% (0.26% to 0.64%) VTE during 90-day follow-up. VTE consisted of five pulmonary embolisms (0.11% (0.05% to 0.25%)) and 14 deep venous thrombosis (0.30% (0.18% to 0.50%)). There were four (0.09% (0.04% to 0.23%)) surgery-related deaths, of which 1 (0.02% (0.00% to 0.12%)) was due to pulmonary embolism, and 6 (0.13% (0.06% to 0.28%)) deaths of unknown causes after discharge.

CONCLUSIONS

The low incidence of TEE and VTE suggests that in-hospital prophylaxis only, is safe in fast-track THA and TKA patients with LOS of ≤5 days. Guidelines on thromboprophylaxis may need reconsideration in fast-track elective surgery.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01557725.

Procedure-specific venous thromboembolism prophylaxis: a paradigm from colectomy surgery

BACKGROUND

Colectomy patients are at high-risk for venous thromboembolism (VTE), but associated risk factors and best prophylaxis in this defined population are only generalized.

METHODS

Fifteen hospitals prospectively collected pre-, peri-, and postoperative variables related to VTE and prophylaxis, in addition to the variables defined by the National Surgical Quality Improvement Program between 2008 and 2009 concerning open and laparoscopic colectomy patients with 30-day outcomes. Symptomatic VTE was the primary outcome, and risk factors were tested for association with VTE using multiple logistic regression.

RESULTS

The cohort included 3,464 patients with a mean age of 65; 53% were female. Overall, the 30d incidence of VTE was 2.2%. VTE prophylaxis included sequential compression devices (SCDs, 11%) alone; pharmacologic prophylaxis alone (15%); and both SCDs and pharmacologic prophylaxis (combined prophylaxis, 74%). VTE was associated with each additional year of age (OR, 1.05; 95% CI 1.02-1.06, P < .001); increased body mass index (OR 1.03; CI 1.01-1.05; P = .02); preoperative anemia (OR 2.4; CI 1.2-4.8; P = .011); contaminated wound (OR 3.4; CI 1.6-7.3; P < .01); postoperative surgical site infection (OR 2.5; CI 1.2-5.2; P < .011); and postoperative sepsis/pneumonia (OR 3.6;CI 1.9-6.7; P < .01). Postoperative factors alone accounted for 32% of VTE risk. When controlling for all other factors, only combination prophylaxis was protective against VTE (OR 0.48; CI 0.27-0.9; P = .02). Operative time, presence of disseminated malignancy, anastomotic leak, transfusion, urinary tract infection, and laparoscopic procedure were not significantly associated with VTE. Propensity matching showed that unfractionated heparin was equivalent to low molecular weight heparin, and the transfusion rate was not increased with pharmacologic prophylaxis compared to SCDs alone.

CONCLUSION

Regardless of preoperative factors, VTE prophylaxis using a combination of SCDs and chemoprophylaxis was associated with significant reduction in VTE and should be standard care for patients after colectomy.

Pulmonary embolism after elective liver resection: a prospective analysis of risk factors

BACKGROUND & AIMS

Impairment of clotting factors after liver resection (LR) is considered to protect from the risk of pulmonary embolism (PE). We aimed at formally investigating the risk of PE after elective LR.

METHODS

From 2007 to 2009, 410 consecutive patients were prospectively analyzed to assess the risk of postoperative PE after LR with a thoracic CT scan, with or without a CT pulmonary angiography (CTPA). All patients were on a standardized thromboprophylaxis regimen.

RESULTS

PE was diagnosed in 24 (6%) patients within the first 10 postoperative days. Comparison between the PE group (n=24) and the non-PE group (n=386) showed a similar rate of metastatic liver disease (25 vs. 31%, p=0.308) but higher rates of BMI ≥ 25 kg/m(2) (75 vs. 46%, p=0.006), major LR (79 vs. 45%, p=0.003) and normal or minimally fibrotic liver parenchyma (92 vs. 73%, p=0.05). No patients with PE had inherited or acquired coagulation disorders. The 90-day mortality rate was similar in the two groups (4% vs. 3%, p=0.77), but the median hospital stay was longer in the PE group (20(IQR 16-27) vs. 11(IQR 8-16) days, p=0.001). On multivariate analysis, the independent predictors for PE were a BMI ≥ 25 kg/m(2) (adj. OR 5.27), major LR (adj. OR 3.13) and normal or minimally fibrotic liver parenchyma (adj. OR 4.21).

CONCLUSIONS

In addition to patient characteristics (high BMI), major resection and normal liver parenchyma increase the risk of PE after LR. This suggests that specific thromboembolic mechanisms are involved in liver regeneration and advocates more aggressive thromboprophylaxis in the high-risk groups.

Perioperative pharmacologic prophylaxis for venous thromboembolism in colorectal surgery

BACKGROUND

To determine the effectiveness of pharmacologic prophylaxis in preventing clinically relevant venous thromboembolic (VTE) events and deaths after surgery. The Surgical Care Improvement Project recommends that VTE pharmacologic prophylaxis be given within 24 hours of the operation. The bulk of evidence supporting this recommendation uses radiographic end points.

STUDY DESIGN

The Surgical Care and Outcomes Assessment Program is a Washington State quality improvement initiative with data linked to hospital admission/discharge and vital status records. We compared the rates of death, clinically relevant VTE, and a composite adverse event (CAE) in the 90 days after elective, colon/rectal resections, based on receipt of pharmacologic prophylaxis (within 24 hours of surgery) at 36 Surgical Care and Outcomes Assessment Program hospitals (2005-2009).

RESULTS

Of 4,195 (mean age 61.1 ± 15.6 years; 54.1% women) patients, 56.5% received pharmacologic prophylaxis. Ninety-day death (2.5% vs 1.6%; p = 0.03), VTE (1.8% vs 1.1%; p = 0.04), and CAE (4.2% vs 2.5%; p = .002) were lower in those who received pharmacologic prophylaxis. After adjustment for patient and procedure characteristics, the odds were 36% lower for CAE (odds ratio = 0.64; 95% CI, 0.44-0.93) with pharmacologic prophylaxis. In any given quarter, hospitals where patients more often received pharmacologic prophylaxis (highest tertile of use) had the lowest rates of CAE (2.3% vs 3.6%; p = 0.05) compared with hospitals in the lowest tertile.

CONCLUSIONS

Using clinical end points, this study demonstrates the effectiveness of VTE pharmacologic prophylaxis in patients having elective colorectal surgery. Hospitals that used pharmacologic prophylaxis more often had the lowest rates of adverse events.