Primary prophylaxis for venous thromboembolism in patients undergoing cardiac or thoracic surgery

Medical Clinics of North America-Periprocedural Antithrombotics: Prophylaxis and Interruption

Anticoagulation management in the surgical patient requires clinical expertise and careful attention. For patients already receiving anticoagulation for a defined indication (ie, stroke prevention for atrial fibrillation, treatment of venous thromboembolism (VTE), or presence of a mechanical heart valve), understanding how to manage these agents by weighing the risks of thromboembolic events and bleeding is paramount. Additionally, prevention of VTE in the surgical patient involves the identification of patient-specific and procedure-specific risk factors for both VTE and bleeding. With this information, as well as familiarity with the several antithrombotic options available, an appropriate prophylaxis strategy can be employed.

Incidence of venous thromboembolism and bleeding after pulmonary lobectomy: evaluating the timing for thromboprophylaxis

Venous thromboembolism (VTE) is an important postoperative complication after major lung cancer resective surgery, such as lobectomy. It is recommended to start chemical thromboprophylaxis within the first 12 h following the procedure. Postoperative bleeding is also a relevant complication in patients with predisposing conditions. However, the criterion for classifying a patient as "high risk of bleeding" is not standardized and is left to the expertise of the attending physician or surgeon. We aim to describe the incidence and risk factors for postoperative VTE and hemorrhage after pulmonary lobectomy; and to assess the impact of the timing of thromboprophylaxis on the incidence of postoperative thrombotic or hemorrhagic events. A retrospective observational study of 358 lobectomies performed in a single center was performed, analyzing the rates of postoperative thrombotic and hemorrhagic events and predisposing factors, including postoperative thromboprophylaxis management. Cumulative incidence of VTE was 3.07% (95% CI 1.54-5.43), and early postoperative bleeding was 10.05% (95% CI 7.14-13.64). Underlying pulmonary disease was associated with VTE (p = 0.001) and open approach was associated with hemorrhagic events (p = 0.01). The use of thromboprophylaxis and timing of its initiation were not associated with a higher incidence of events. VTE and postoperative hemorrhage are relevant complications following pulmonary lobectomy. Compliance with VTE prophylaxis guidelines is essential. Even so, a case-by-case risk evaluation of VTE and bleeding remains preferable and safe in order to decide on the most suitable timing of thromboprophylaxis.

Efficacy and safety of thromboprophylaxis in cancer patients: a systematic review and meta-analysis

BACKGROUND

Thrombosis is a common complication in patients with cancer. Whether thromboprophylaxis could benefit patients with cancer is unclear. The aim of this systematic review was to determine the efficacy and safety of thromboprophylaxis in patients with cancer undergoing surgery or chemotherapy.

METHODS

We searched the Cochrane Library, EMBASE, MEDLINE, EBSCOhost, and Web of Science for studies published before May 2018 to investigate whether thromboprophylaxis measures were more effective than a placebo in patients with cancer.

RESULTS

In total, 33 trials with 11,942 patients with cancer were identified. In patients with cancer undergoing surgery, the administration of thromboprophylaxis was associated with decreasing trends in venous thromboembolism (VTE) [relative risk (RR) 0.51, 95% confidence interval (CI) 0.32-0.81] and DVT (RR 0.53, 95% CI 0.33-0.87). In patients with cancer undergoing chemotherapy, the administration of thromboprophylaxis reduced the incidences of VTE, DVT, and pulmonary embolism compared with no thromboprophylaxis (RR 0.54, 95% CI 0.40-0.73; RR 0.47, 95% CI 0.31-0.73; RR 0.51, 95% CI 0.32-0.81, respectively). The pooled results regarding major bleeding showed no significant difference between prophylaxis and no prophylaxis in either the surgical or the chemotherapy groups (RR 2.35, 95% CI 0.74-7.52, p = 0.1482, I2 = 0%; RR 1.30, 95% CI 0.93-1.83, p = 0.1274, I2 = 0%, respectively).

CONCLUSION

Thromboprophylaxis did not increase major bleeding events or the incidence of thrombocytopenia. All-cause mortality was not significantly different between those who received thromboprophylaxis and those who did not. This meta-analysis provides evidence that thromboprophylaxis can reduce the number of VTE and DVT events, with no apparent increase in the incidence of major bleeding in patients with cancer.

Benefits may not outweigh risks of low molecular weight heparin (LMWH) in early postoperative thromboprophylaxis following minimally invasive cardiac surgery: a propensity score-matched analysis

Background

Whether the benefits of early prophylactic anticoagulation by low molecular weight heparin (LMWH) would outweigh its possible harms in patients after minimally invasive cardiac surgery (MICS) remains contentious. The aims of this study were to define the incidence of venous thromboembolism (VTE) and to assess whether early prophylactic anticoagulation by LMWH postoperatively was indeed effective in reducing VTE without increasing risk of complications after MICS.

Methods

This investigation was a single-center, retrospective, propensity score-matched analysis study. A total of 473 patients underwent MICS, of whom 257 received prophylactic anticoagulation with LMWH (LMWH group) in the early postoperative period and 216 were not treated with LMWH (Control group). The main outcome measurements included the incidence of embolism events and major bleeding events, the volume of erythrocyte transfusion, the volume of drainage and the duration of drainage after MICS. In addition, the incidence of poor wound healing, the mechanical ventilation time, ICU stay time and postoperative hospitalization time were also documented.

Results

There were fewer embolic events (P=1.000) and a higher rate of major bleeding events (P=0.008) in the LMWH group than the Control group, and their magnitude and significance were maintained in the propensity matched analysis. In the matched cohorts, there was no significant difference in the total volume of red blood cell transfusion (P=0.552), assisted mechanical ventilation time (P=0.542), and the ICU stay time (P=0.166) between the two groups; while the volume of drainage (P<0.001) and the duration of drainage (P<0.001) in the LMWH group were significantly more than the Control group, and the incidence of poor wound healing (P=0.009) and the postoperative hospitalization time (P<0.001) were significantly increased in the LMWH group.

Conclusions

Early prophylactic anticoagulation with LMWH could not reduce the incidence of embolism events after MICS. Instead, it might increase postoperative major bleeding events and prolong drainage tube indwelling time and the length of hospital stay.

Preoperative Heparin for Lung Cancer Resection Increases Risk of Reoperation for Bleeding

Lung cancer patients are at risk for venous thromboembolism (VTE). Preoperative heparin administration may increase the risk of bleeding requiring reoperation. The purpose of this study was to evaluate preoperative heparin's effect on reoperation for bleeding. A retrospective review compared outcomes for patients undergoing pulmonary resection for primary lung cancer from January 2006 to April 2018. Preoperative heparin was administered at the discretion of the attending surgeon. Comparisons were performed between preoperative subcutaneous heparin (5000 U) and no heparin groups. A total of 3325 lung resections were reviewed, 1.4% (n = 48) required reoperation for bleeding. VTE occurred in 1.1% (n = 38). Four hundred sixty-four patients (14.0%) did not receive preoperative heparin. The preoperative heparin group had increased rates of prior thoracic surgery (5.1% [n = 146] vs 1.7% [n = 8], P < 0.001), minimally invasive approach (40.2% [n = 1150] vs 10.6% [n = 49], P < 0.001), and sublobar resections (17.7% [n = 506] vs 10.6% [n = 49], P < 0.001). There were no differences in blood loss/transfusions. Reoperation for bleeding was significantly increased in the preoperative heparin group (1.6% [n = 47] vs 0.2% [n = 1], P = 0.017). There were no differences in VTE (1.5% [n = 7] vs 1.1% [n = 31], P = 0.424). On logistic regression, preoperative heparin was independently associated with increased reoperation for bleeding (odds ratio 8.13, P = 0.039); however, preoperative heparin was not independently associated with VTE. Preoperative heparin was associated with increased reoperation for bleeding. VTE rates are low after pulmonary resection for lung cancer and are not decreased by preoperative heparin. Preoperative heparin use should be determined by risk factor stratification for VTE and reoperation for bleeding in patients undergoing lung cancer resection.

American Society of Hematology 2019 guidelines for management of venous thromboembolism: prevention of venous thromboembolism in surgical hospitalized patients

BACKGROUND

Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2).

CONCLUSIONS

For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.

Non-intubated anesthesia in patients undergoing video-assisted thoracoscopic surgery: A systematic review and meta-analysis

INTRODUCTION

Non-intubated anesthesia (NIA) has been proposed for video-assisted thoracoscopic surgery (VATS), although how the benefit-to-risk of NIA compares to that of intubated general anesthesia (IGA) for certain types of patients remains unclear. Therefore, the aim of the present meta-analysis was to understand whether NIA or IGA may be more beneficial for patients undergoing VATS.

METHODS

A systematic search of Cochrane Library, Pubmed and Embase databases from 1968 to April 2019 was performed using predefined criteria. Studies comparing the effects of NIA or IGA for adult VATS patients were considered. The primary outcome measure was hospital stay. Pooled data were meta-analyzed using a random-effects model to determine the standard mean difference (SMD) with 95% confidence intervals (CI).

RESULTS AND DISCUSSION

Twenty-eight studies with 2929 patients were included. The median age of participants was 56.8 years (range 21.9-76.4) and 1802 (61.5%) were male. Compared to IGA, NIA was associated with shorter hospital stay (SMD -0.57 days, 95%CI -0.78 to -0.36), lower estimated cost for hospitalization (SMD -2.83 US, 95% CI -4.33 to -1.34), shorter chest tube duration (SMD -0.32 days, 95% CI -0.47 to -0.17), and shorter postoperative fasting time (SMD, -2.76 days; 95% CI -2.98 to -2.54). NIA patients showed higher levels of total lymphocytes and natural killer cells and higher T helper/T suppressor cell ratio, but lower levels of interleukin (IL)-6, IL-8 and C-reactive protein (CRP). Moreover, NIA patients showed lower levels of fibrinogen, cortisol, procalcitonin and epinephrine.

CONCLUSIONS

NIA enhances the recovery from VATS through attenuation of stress and inflammatory responses and stimulation of cellular immune function.

Association of Acute Venous Thromboembolism With In-Hospital Outcomes of Coronary Artery Bypass Graft Surgery

Background

While venous thromboembolism (VTE) prophylaxis is a strong recommendation after most surgeries, it is controversial in cardiac surgeries such as coronary artery bypass grafting (CABG), because of perceived low VTE incidence and increased bleeding risk. Prior studies may not have been adequately powered to study outcomes of VTE in this population. We sought to investigate the postoperative incidence and outcomes of CABG patients using a large national inpatient database.

Methods and Results

We utilized the 2013 to 2014 National Inpatient Sample to identify all patients >18 years of age who underwent CABG (without concomitant valvular procedures), and had VTE during the hospital stay. We then compared clinically relevant outcomes in patients with and without VTE. We identified 331 950 CABG procedures. Of these, 1.3% (n=4205) had VTE. Patients with VTE were more likely to be older (mean 67.2±10.4 years versus 65.2±10.4 years, P<0.001). VTE was associated with higher incidence of inpatient mortality (6.8% versus 1.7%; adjusted odds ratio 1.92 [95% CI 1.40–2.65]; P<0.001) and complications. VTE was also associated with higher cost (mean±SE $81 995±$923 versus $48 909±$55) and longer length of stay (mean±SE 17.06±0.16 days versus 8.52±0.01 days).

Conclusions

Our analysis of >330 000 CABG procedures suggests that while postoperative VTE after CABG is rare, it is associated with increased morbidity and mortality. Randomized controlled trials are needed to identify optimal strategies for VTE prophylaxis in these patients.

Preoperative thromboprophylactic administration of low-molecular-weight-heparin significantly decreased the risk of intraoperative bleeding compared with heparin in patients undergoing video-assisted lobectomy for lung cancer

Background

Due to the threat from venous thromboembolism (VTE) after major thoracic surgery, especially for cancers, guidelines recommend either heparin sodium (unfractionated heparin) or low-molecular-weight-heparin (LMWH) for those patients at high risk of deep vein thrombosis (DVT). However, risk of bleeding remains a major concern for pre-operative administration of anti-coagulation agents. Therefore, this study aimed to compare the bleeding risk of preoperative administration of LMWH and heparin in patients undergoing video-assisted thoracic surgery (VATS) lobectomy for lung cancer.

Methods

A retrospective, single-center study was designed. A total of 130 patients diagnosed with lung cancer were included from August 2016 to January 2018. These patients were divided into two groups. The preoperative administration of heparin group (PH group) had received heparin 5,000 IU, BID (twice a day) both pre- and post-operatively. And the LMWH group (PL group) had received LMWH 4,000 IU, QD (once a day) both pre- and post-operatively. These anticoagulants would not be ceased until patient was discharged or 24-hour postoperative chest drainage volume exceeded 500 mL. Both preoperative and postoperative coagulation parameters including platelet count (PLT), hemoglobin value (HGB), international normalized ratio (INR), prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombin time (TT), postoperative drainage parameters and intraoperative bleeding volume were compared.

Results

A total of 62 patients were collected in PH group, while 68 patients comprised PL group. Preoperative coagulation parameters, hematologic data and demographic data were comparable. Preoperative duration of two agents (P=0.414), operation time (P=0.155), postoperative HGB (P=0.943), PLT (P=0.244), INR (P=0.469), PT (P=0.651), TT (P=0.407), FIB (P=0.151), drainage duration (P=0.800), duration of heparin and LMWH (P=0.778) were all comparable between the two groups. Compared with PL group, intraoperative bleeding volume (105.11 and 50.26, P<0.001) and postoperative mean drainage volume (251.52 and 216.90 mL, P=0.025) of PH group were significant more. Postoperative APTT (30.17 vs. 28.20 seconds, P=0.022) was significantly longer in PH group.

Conclusions

Compared with preoperative administration of heparin, preoperative thromboprophylactic administration of LMWH significantly decreased the risk of intraoperative bleeding in VATS lobectomy.

Critical Care after Lung Transplantation

Since the first successful lung transplantation in 1983, there have been many advances in the field. Nevertheless, the latest data from the International Society for Heart and Lung Transplantation revealed that the risk of death from transplantation is 9%. Various aspects of postoperative management, including mechanical ventilation, could affect intensive care unit stay, hospital stay, and immediate postoperative morbidity and mortality. Complications such as reperfusion injury, graft rejection, infection, and dehiscence of anastomosis increase fatal adverse side effects immediately after surgery. In this article, we review the possible immediate complications after lung transplantation and summarize current knowledge on prevention and treatment.

The influence of heparin on coagulation function of patients undergoing video-assisted major thoracic surgery

Background

Venous thromboembolism (VTE) remains a common complication after major thoracic surgery, especially resection of lung or esophagus cancer. This trial aims to explore the influence of preoperative usage of heparin on coagulation function of patients treated with video-assisted major thoracic surgery.

Methods

This prospective randomized control trial collected 91 patients who are diagnosed with lung or esophagus cancer intending to accept video-assisted neoplasm resection from June 2016 to May 2017 in West China Hospital, Sichuan University. After admission to hospital, the patients received heparin sodium (unfractionated heparin) 5,000 U twice a day before operation. The change of blood platelet count (PLT), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (FIB), international normalized ratio (INR) was collected and analyzed at the points of admission to hospital and post-operation.

Results

The mean value of all coagulation parameters (PLT, PT, APTT, TT, INR, FIB) were in normal range both before and after operation. Postoperative PLT and FIB were not significantly different from preoperative PLT and FIB respectively (P>0.05). Preoperative PT, APTT, and INR increased significantly compared to pre-operation respectively (P<0.05). Postoperative TT significantly decreased when compared to preoperative TT (P<0.05). Preoperative and postoperative abnormal rate of PT or APTT or TT or INR (number of abnormal cases/all cases) was not different significantly respectively (P>0.05). Postoperative mean drainage was 240 mL/d, mean time of hospital stay was 7.50 days, drainage tube was maintained for 4.22 days on average.

Conclusions

All patients underwent video-assisted major thoracic surgery with preoperative use of heparin, there were significant differences in coagulation function after operation. However, mean values of all coagulation parameters stayed normal range clinically. In a word, the method showed no influence on coagulation function clinically.

The safety profile of preoperative administration of heparin for thromboprophylaxis in Chinese patients intended for thoracoscopic major thoracic surgery: a pilot randomized controlled study

BACKGROUND

Patients undergoing major thoracic surgery especially for cancers are at a high risk of perioperative thromboembolism. Current guidelines recommended either heparin sodium (unfractionated heparin) or low-molecular-weight heparin (LMWH) for those patients at high risk of deep vein thrombosis (DVT). However, the rational timing of starting heparin has not yet been well established, because DVT can be caused by not only surgery but also comorbidities as well as prolonged hospital stay, and thoracic surgeons always concerned about heparin-related increased risk of intra- or post-operative bleeding. Therefore, this study aimed to establish the safety profile of preoperative administration of heparin for thromboprophylaxis in Chinese patients intended for thoracoscopic major thoracic surgery.

METHODS

From June to August 2016, patients intended for thoracoscopic lobectomy, esophagectomy, and thymectomy were randomly assigned into two groups: the case group (starting heparin sodium 5,000 U, bid preoperatively upon the admission into our department) and the control group (starting heparin sodium 5,000 U, bid postoperatively from postoperative day 1). The baseline data including demographic data and preoperative conditions were collected. The end points included operation time, intraoperative bleeding volume, postoperative chest tube drainage volume and duration as well as lab coagulation function data.

RESULTS

A total of 58 qualified patients were randomized into case group (29 patients) and control group (29 patients), and after excluding 6 conversion patients, the case group and control group each had 26 patients for analysis. The baseline data of the two groups were comparable. Operation time (P=0.368), intraoperative bleeding volume (P=0.231), postoperative drainage days (P=0.466), and mean drainage volume per day (P=0.108) were not significantly increased in case group compared with those of control group. Moreover, there were no significant differences of perioperative coagulation function between these two groups.

CONCLUSIONS

Preoperative administration of heparin for thromboprophylaxis in Chinese patients intended for thoracoscopic major thoracic surgery was safe and feasible.

TRIAL REGISTRATION

NCT02940444 (https://register.clinicaltrials.gov/).

Practice patterns in venous thromboembolism (VTE) prophylaxis in thoracic surgery: a comprehensive Canadian Delphi survey

BACKGROUND

The incidence of venous thromboembolic events (VTE) after resection of thoracic malignancies can reach 15%, but prophylaxis guidelines are yet to be established. We aimed to survey Canadian practitioners regarding perioperative risk factors for VTE, impact of those factors on extended prophylaxis selection, type of preferred prophylaxis, and timing of initiation and duration of thromboprophylaxis.

METHODS

A modified Delphi survey was undertaken over three rounds with thoracic surgeons, thoracic anesthesiologists and thrombosis experts across Canada. Participants were asked to rate each parameter on a ten-point scale. Agreement was determined a priori as an item reaching a coefficient of variation of ≤30% (0.3), with the item then discontinued from later rounds.

RESULTS

In total, 72, 57 and 50 respondents participated in three consecutive rounds, respectively. Consensus was reached on previous VTE, age, cancer diagnosis, thrombophilia, poor mobilization, extended resections, and pre-operative chemotherapy as risk factors. Consensus on risk factors impacting extended prophylaxis decisions was achieved on cancer diagnosis, obesity, previous VTE and poor mobilization. With respect to perioperative prophylaxis, once daily low-molecular-weight heparin (LMWH) was the only parameter that demonstrated agreement as a common practice pattern. No agreement was achieved regarding the role of mechanical prophylaxis, unfractionated heparin (UFH) or timing of initiation of peri-operative treatment. VTE prophylaxis until discharge reached agreement but there was substantial variability regarding the role of extended prophylaxis.

CONCLUSIONS

There is agreement between Canadian clinicians treating patients with thoracic malignancies regarding most risk factors for VTE, but there is no agreement on timing of initiation of prophylaxis, the agents used or factors mandating usage of extended prophylaxis.