Venous thromboembolism prophylaxis in patients undergoing abdominal or pelvic surgery for cancer – A real-world, prospective, observational French study: PRéOBS

A Prospective Observational Study to Determine Rate of Thromboprophylaxis in Oncology Patients Undergoing Abdominal or Pelvic Surgery

Venous thromboembolism (VTE) is common in patients with cancer and is a leading cause of death. In addition to the hypercoagulable state associated with malignancy, cancer-related surgery and subsequent immobilization further increase the risk of VTE. Guidelines suggest extended prophylaxis up to 4 weeks with low-molecular-weight heparin (LMWH) in such patients. This study is conducted to determine the proportion of patients receiving thromboprophylaxis among those undergoing surgery for malignant abdominal or pelvic tumor. This prospective, multicenter, observational study included 300 patients (217 [72.3%] were women). Mean age and duration of cancer were 53.2 and 1.2 years, respectively. A total of 162 (54%) patients received thromboprophylaxis of which only pharmacological in 78 [48.1%], only mechanical in 27 [16.7%], and both pharmacological and mechanical in 57 [35.2%] patients. LMWH (128, 79.0%) and graduated compression stockings (74, 45.7%) were the commonly used modalities. VTE prophylaxis was given in only half of the patients. Physician education to increase adherence to international guidelines is very important. Trial Registration No. CTRI/2013/05/003617.

Dual mechanical and pharmacological thromboprophylaxis decreases risk of pulmonary embolus after laparotomy for gynecologic malignancies

OBJECTIVES

Patients with gynecologic malignancies have high rates of post-operative venous thromboembolism. Currently, there is no consensus for peri-operative thromboprophylaxis specific to gynecologic oncology. We aimed to compare rates of symptomatic pulmonary embolus within 30 days post-operatively, and to identify risk factors for pulmonary embolus.

METHODS

The Division of Gynecologic Oncology at Sunnybrook Health Sciences Centre implemented dual thromboprophylaxis for laparotomies in December 2017. We conducted a prospective study of laparotomies for gynecologic malignancies from December 2017 to October 2018, with comparison to historical cohort from January 2016 to November 2017 using the institutional National Surgical Quality Improvement Program database (NSQIP). Pre-intervention, patients received low molecular weight heparin during admission and extended 28-day prophylaxis was continued at the surgeon's discretion. Post-intervention, all patients received both mechanical thromboprophylaxis with sequential compression devices during admission and 28-day prophylaxis with low molecular weight heparin.

RESULTS

There were 371 and 163 laparotomies pre- and post-intervention, respectively. Patient characteristics (age, body mass index, diabetes, smoking, tumor stage), rate of malignant cases, operative blood loss and duration, and length of stay were similar between groups. After implementation, pulmonary emboli rates decreased from 5.1% to 0% (p=0.001). There were more cytoreductive procedures pre-intervention (p≤0.0001) but surgical complexity scores were similar (p=0.82). Univariate analysis revealed that surgery pre-intervention (OR 4.25, 95% CI 1.04 to 17.43, p=0.04), length of stay ≥5 days (OR 11.94, 95% CI 2.65 to 53.92, p=0.002), and operative blood loss ≥500 mL (OR 2.85, 95% CI 1.05 to 7.8, p=0.04) increased risk of pulmonary embolus. On multivariable analysis, surgery pre-intervention remained associated with more pulmonary emboli (OR 4.16, 95% CI 1.03 to 16.79, p=0.045), when adjusting for operative blood loss.

CONCLUSION

Dual thromboprophylaxis after laparotomy significantly reduced rates of pulmonary embolus in this high-risk patient population.

Hyperthermic intraperitoneal chemotherapy enhances blood coagulation perioperatively evaluated by thromboelastography: a pilot study

Background and Objectives: Postoperative thromboembolism is a significant cause of prolonged recovery in patients undergoing cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Thromboelastography (TEG) can detect hypercoagulable states and predict thromboembolic complications after surgery. This study assessed the impact of CRS and HIPEC on TEG values.Methods: TEG parameters reaction time (R), kinetics time (K), angle (α), maximum amplitude (MA), and lysis percent at 60 min (LY60) were determined preoperatively, and at the end of CRS, during HIPEC, and at the end of the operation using blood samples from 15 HIPEC patients. Platelets, P-TT, and aPTT were also determined before and after CRS.Results: A total of 75 samples were analyzed. During CRS, there was a significant reduction in the mean MA (3.06 mm, p = 0.001). The mean P-TT declined by 32% (p < 0.001) and mean platelets by 55 × 10⁹/L (p < 0.001). During HIPEC, the mean R and K shortened by 1.04 min (p = 0.015) and 0.18 min (p = 0.018), respectively, whereas α increased by 2.48° (p = 0.005).Conclusions: During CRS, both TEG and conventional laboratory tests indicated hypocoagulation. During HIPEC, however, the initiation of coagulation and the kinetics of thrombin formation were accelerated.

Extended versus inpatient thromboprophylaxis with heparins following major open abdominopelvic surgery for malignancy: a systematic review of efficacy and safety

Background

Patients undergoing open abdominopelvic procedures for malignancy are at high risk of postoperative venous thromboembolism (VTE). This risk can be mitigated with prophylaxis; however, optimum duration in this population remains unknown. Our objective was to conduct a systematic review of contemporary literature on the use of heparin thromboprophylaxis following major open pelvic surgery for malignancy, comparing the efficacy and safety of extended duration to inpatient treatment.

Methods

A study protocol describing search strategy and inclusion and exclusion criteria was developed and registered with PROSPERO. A literature review was conducted in accordance with the protocol.

Results

Literature review identified only 4 studies directly comparing extended and inpatient duration prophylaxis, with a combined population of 3198 and 3135 patients for VTE rate and bleeding events, respectively. Despite many studies reporting lower VTE rates in patients receiving extended prophylaxis, no statistically significant difference in rates of postoperative VTE (p = 0.18) or bleeding complications (p = 0.43) was identified between patients receiving extended duration prophylaxis and those receiving inpatient only prophylaxis.

Conclusion

On the review of contemporary literature, no significant difference was found in rates of postoperative VTE or bleeding complications between patients receiving extended duration heparin VTE prophylaxis and those receiving inpatient prophylaxis after open abdominopelvic surgery for malignancy.

This raises the question of how extended duration prophylaxis has become common practice in this population, and whether this needs to be re-evaluated.

The role of extended venous thromboembolism prophylaxis for major urological cancer operations

OBJECTIVES

Venous thromboembolism (VTE), consisting of both pulmonary embolism (PE) and deep vein thromboses (DVT), remains a well-recognised complication of major urological cancer surgery. Several international guidelines recommend extended thromboprophylaxis (ETP) with LMWH, whereby the period of delivery is extended to the post-discharge period, where the majority of VTE occurs. In this literature review we investigate whether ETP should be indicated for all patients undergoing major urological cancer surgery, as well procedure specific data that may influence a clinician's decision.

METHODS

We performed a search of six databases (PubMed, Cochrane, EMBASE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycINFO, and British Nursing Index (BNI)) from inception to June 2019, for studies looking at adult patients who received VTE prophylaxis after surgery for a major urological malignancy.

RESULTS

Eighteen studies were analysed. VTE risk is highest in open and robotic Radical Cystectomy (RC) (2.6-11.6%) and ETP demonstrates a significant reduction in risk of VTE, but not a significant difference in Pulmonary Embolism (PE) or mortality. Risk of VTE in open Radical Prostatectomy (RP) (0.8-15.7%) is comparable to RC, but robotic RP (0.2-0.9%), open partial/radical nephrectomy (1.0-4.4%) and robotic partial/radical nephrectomy (0.7-3.9%) were lower risk. It has not been shown that ETP reduces VTE risk specifically for RP or nephrectomy.

CONCLUSION

The decision to use ETP is a fine balance between variables such as VTE incidence, bleeding risk and perioperative morbidity/mortality. This balance should be assessed for each specific procedure type. While ETP still remains of net benefit for open RP as well as open and robotic RC, the balance is closer for minimally invasive RP as well as radical and partial nephrectomy. Due to a lack of procedure specific evidence for the use of ETP, adherence with national guidelines remains poor. Therefore, we advocate further studies directly comparing ETP vs standard prophylaxis, for specific procedure types, in order to allow clinicians to make a more informed decision in future.

Patients' experience and compliance with extended low molecular weight heparin prophylaxis post-surgery for gynecological cancer: a prospective observational study

OBJECTIVE

Gynaecological cancer patients have a high risk of developing venous thromboembolism (VTE). There is limited information on patient experience and compliance with an extended low molecular weight heparin prophylaxis in this setting. The aim of this study was to assess patient compliance, satisfaction and experience with the extended low molecular weight heparin prophylaxis after major surgery for gynaecological cancer.

METHODS

This was a prospective observational study conducted in a large tertiary center for gynaecological cancer between July 2017-March 2018. Consecutive patients undergoing surgery for gynaecological cancer who received low molecular weight heparin prophylaxis for four weeks following surgery were recruited. All participants received a log book to record all injections, side effects, and questionnaire to be completed at the end of the study.

RESULTS

A total of 106 patients completed and returned the VTE prophylaxis logbook and questionnaire. Sixty-six (62%) patients received low molecular weight heparin for 28 days, twenty-five (24%) for 26-27 days, and 15 (14%) for less than 26 days. The median number of days of therapy was 28 days (range; 12-28 days). Reasons for missed or stopped injections included: forgetfulness(n=12), medical procedures (n=6), pain (n=5), incorrect prescription (n=4), patient choice (n=3), cost (n=2), physician request (n=2), non-availability of person administering the injections (n=1) or unknown (n=5). Sixty-one (58%) patients self-administered the injections. Patients who had the injection performed by a third person were twice as likely to experience pain compared to patients who self-administered (OR 2.81, p=0.003). Eighty-nine (84%) patients self-reported side effects during low molecular weight heparin prophylaxis including: bruising (75%), pain after injections (49%), itchiness (9%), swelling (9%) or other (8%). Although 83 (78%) patients were satisfied with injections, 91 (86%) admitted they would much prefer a tablet form.

CONCLUSIONS

Compliance with standard recommended regimen of 28-days prophylaxis was completed by 62% of patients. Majority of patients (86%) reported a preference for a tablet form, if one was available.

Extended venous thromboembolism prophylaxis after abdominopelvic cancer surgery: a retrospective review

Objective

Extended prophylaxis against venous thromboembolism (vte) after abdominal or pelvic cancer surgery with low molecular weight heparin (lmwh) is recommended by multiple guidelines. The primary objective of the present study was to assess adherence to that guideline recommendation at tertiary care centres within Hamilton Health Sciences (hhs).

Methods

Given that an estimated 70% of the study population would be expected to receive extended prophylaxis, a sample size of 105 patients was calculated. Patients who had undergone abdominal or pelvic surgery for cancer from March 2012 to December 2015 were identified, and data were collected from electronic health records. The primary outcome was prescription of extended vte prophylaxis.

Results

Of 105 patients, only 3 received extended vte prophylaxis. Those 3 patients had serous carcinoma of the uterus, transitional cell carcinoma of the bladder, and cecal cancer. Of the 3 patients, 2 were followed by the thrombosis service while in hospital; none of the other 102 patients received any form of extended vte prophylaxis.

Conclusions

Based on multiple randomized controlled trials, guidelines suggest lmwh prophylaxis for up to 4 weeks after major abdominal or pelvic cancer surgery. Despite those recommendations, postoperative extended vte prophylaxis is not commonly prescribed at hhs facilities. Next steps will include identification of barriers and an examination of how those barriers could be addressed. Failure to use prophylaxis is not consistent with evidence-based guidelines and is placing patients at risk of vte.

Prophylactic enoxaparin doses may be inadequate in patients undergoing abdominal cancer surgery

BACKGROUND

The incidence of venous thromboembolism has increased in patients following cancer surgery despite the increased use of prophylactic anticoagulants, suggesting standard doses may be inadequate. We sought to determine the adequacy of enoxaparin prophylaxis in patients undergoing abdominal cancer surgery.

METHODS

Peak and trough anti-Xa levels were measured in patients receiving enoxaparin thromboprophylaxis (40 mg daily or 30 mg twice daily, at the surgeon's discretion) after undergoing open abdominal cancer surgery at a single institution.

RESULTS

Fifty-five patients received enoxaparin 40 mg daily (group 1), 18 received 30 mg twice daily (group 2; total n = 73). There were no significant differences in gender, age, body mass index, creatinine clearance, diagnosis, or procedure between the two groups. Thirty-nine patients (53.4%) had inadequate peak anti-Xa levels (<0.2 IU/mL) and 69 patients (94.5%) had inadequate trough levels (≤0.1 IU/mL). Group 2 had lower mean peak levels (0.14 ± 0.02 IU/mL) than group 1 (0.22 ± 0.01, P = 0.003), and higher mean trough levels (0.06 ± 0.017) than group 1 (0.02 ± 0.004, P = 0.033). Group 2 had lower incidence of adequate peak anti-Xa levels than group 1 when adjusting for gender, age, body mass index, and preoperative creatinine clearance (OR 0.23, P = 0.039).

CONCLUSIONS

The majority of patients had inadequate anti-Xa levels following abdominal cancer surgery, calling into question standard prophylactic enoxaparin dosing.

Who Should Get Extended Thromboprophylaxis After Bariatric Surgery?: A Risk Assessment Tool to Guide Indications for Post-discharge Pharmacoprophylaxis

OBJECTIVE

To determine the risk factors for 30-day postdischarge venous thromboembolism (VTE) after bariatric surgery and to identify potential indications for extended pharmacoprophylaxis.

BACKGROUND

VTE is among most common causes of death after bariatric surgery. Most VTEs occur after hospital stay; still a few patients receive extended pharmacoprophylaxis postdischarge.

METHODS

From American College of Surgeons-National Surgical Quality Improvement Program, we identified 91,963 patients, who underwent elective primary and revisional bariatric surgery between 2007 and 2012. Regression-based techniques were used to create a risk assessment tool to predict risk of postdischarge VTE. The model was validated using the 2013 American College of Surgeons-National Surgical Quality Improvement Program dataset (N = 20,575). Significant risk factors were used to create a user-friendly online risk calculator.

RESULTS

The overall 30-day incidence of postdischarge VTE was 0.29% (N = 269). In those experiencing a postdischarge VTE, mortality increased about 28-fold (2.60% vs 0.09%; P < 0.001). Among 45 examined variables, the final risk-assessment model contained 10 categorical variables including congestive heart failure, paraplegia, reoperation, dyspnea at rest, nongastric band surgery, age ≥60 years, male sex, BMI ≥50 kg/m, postoperative hospital stay ≥3 days, and operative time ≥3 hours. The model demonstrated good calibration (Hosmer-Lemeshow goodness-of-fit test, P = 0.71) and discrimination (c-statistic = 0.74). Nearly 2.5% of patients had a predicted postdischarge VTE risk >1%.

CONCLUSIONS

More than 80% of post-bariatric surgery VTE events occurred post-discharge. Congestive heart failure, paraplegia, dyspnea at rest, and reoperation are associated with the highest risk of post-discharge VTE. Routine post-discharge pharmacoprophylaxis can be considered for high-risk patients (ie, VTE risk >0.4%).

Effects of Long-Term Low-Molecular-Weight Heparin on Fractures and Bone Density in Non-Pregnant Adults: A Systematic Review With Meta-Analysis

BACKGROUND

Adults who require long-term anticoagulation with low-molecular-weight heparin (LMWH) such as cancer patients or the elderly may be at increased risk of fractures.

OBJECTIVE

To determine the effects of LMWH therapy of at least 3 months' duration on fractures and bone mineral density (BMD) in non-pregnant adult populations.

METHODS

We systematically reviewed electronic databases (e.g., MEDLINE, EMBASE), conferences and bibliographies until June 2015 and included comparative studies in non-pregnant adult populations that examined the effects of LMWH (≥3 months) on fractures and BMD. We synthesized evidence qualitatively and used random-effects meta-analysis to quantify the effect of LMWH on fractures.

RESULTS

Sixteen articles reporting 14 studies were included: 10 clinical trials (n = 4865 participants) and four observational cohort studies (3 prospective, n = 221; 1 retrospective, n = 30). BMD and fractures were secondary outcomes in the majority of trials, while they were primary outcomes in the majority of observational studies. In participants with venous thromboembolism and underlying cardiovascular disease or cancer (5 RCTs, n = 2280), LMWH for 3-6 months did not increase the relative risk of all fractures at 6-12 months compared to unfractionated heparin, oral vitamin K antagonists or placebo [pooled risk ratio (RR) = 0.58, 95 % CI: 0.23-1.43; I(2) = 12.5 %]. No statistically significant increase in the risk of fractures at 6-12 months was found for cancer patients (RR = 1.08, 95 % CI: 0.31-3.75; I(2) = 4.4 %). Based on the data from two prospective cohort studies (n = 166), LMWH for 3-24 months decreased mean BMD by 2.8-4.8 % (depending on the BMD site) compared to mean BMD decreases of 1.2-2.5 % with oral vitamin K antagonists.

CONCLUSIONS

LMWH for 3-6 months may not increase the risk of fractures, but longer exposure for up to 24 months may adversely affect BMD. Clinicians should consider monitoring BMD in adults on long-term LMWH who are at increased risk of bone loss or fracture.

Preoperative dosing of low-molecular-weight heparin in hepatopancreatobiliary surgery

BACKGROUND

Venous thromboembolism is a common cause of morbidity. Guidelines recommend perioperative thromboprophylaxis, but clinicians remain cautious of bleeding after major oncologic resections.

METHODS

Retrospective analysis of a single institution's prospective hepatopancreatobiliary database was performed for patients undergoing surgery between January 2010 and February 2013. A total of 223 patients received postoperative thromboprophylaxis and 93 patients were dosed with low-molecular-weight heparin (LMWH) preoperatively.

RESULTS

Two hundred twenty-three patients were analyzed; 50.6% underwent pancreatic and 49.3% underwent liver resection. There were no differences in previous venous thromboembolism (3.8% vs 3.3%; P = .56) or preoperative venous thromboembolism scores (5.74 vs 5.67; P = .82). Estimated blood loss (537 mL vs 592 mL; P = .54), transfusions (25.4% vs 30.4%; P = .25), and complications (52.3% vs 43.5%; P = .12) were equivalent. Incidence of thromboembolic events was lower (6.1% vs 1.1%; P = .05); however, bleeding requiring intervention was increased in the preoperative LMWH group (10.9% vs 3.1%; P = .026).

CONCLUSIONS

Caution must be exercised when using LMWH, as bleeding remains a concern for oncologic hepatopancreatobiliary surgery.