Prospective Study on Preoperative Versus Postoperative Venous Thromboprophylaxis in Patients Undergoing Major Colorectal Surgery

Phase 3

Completed

Conditions: Venous Thromboembolism

Interventions: Drug: Heparin

Registration Number: NCT01976988

Lead Sponsor: Cedars-Sinai Medical Center

Brief Summary: Patients undergoing major colorectal surgery are at increased risk for VTE (deep venous thrombosis) compared with patients undergoing other general surgical procedures (Bergqvist et al. Dis. Col. Rectum. 2006; 49: 1620-1628.)

The reported incidence of symptomatic VTE after colorectal surgery is approximately 4% (Monn, F. et al. JACS. 216; 2013: 395-401). However, the reported incidence of VTE after colorectal surgery in prospectively followed patients managed with perioperative venous thromboprophylaxis undergoing screening venography prior to hospital discharge ranges from 9 to 20% (Bergovist et al. NEJM 346; 2002: 975-980; McLeod et al. Ann. Surg. 233; 2000: 438-444; ENOXACAN Study group. Brit. J. Surg. 84; 1997: 1099-1103.

The Surgical Care Improvement Project (SCIP) and the American College of Chest Physician (ACCP) guidelines recommend that venous thromboprophylaxis be initiated within 24 hours of surgery. However, it is believed that deep venous thrombosis occurs during surgery, rather than in the postoperative period, justifying preoperative initiation of venous thromboprophylaxis. This practice is accompanied with a theoretically higher risk of bleeding complications.

Currently there is no consensus on the precise timing of VTE prophylaxis after major colorectal surgery, as demonstrated by the vague guidelines established by the ACCP and SCIP. Current studies on VTE prophylaxis report preoperative initiation of VTE prophylaxis. However, majority of surgeons at our institution begin heparin postoperatively given concern for bleeding complications with preoperative dosing of heparin.

The purpose of this study is to prospectively evaluate the incidence of VTE and major bleeding complications in patients undergoing major colorectal surgery who are treated with preoperative or postoperative venous thromboprophylaxis and to help establish more stringent guidelines on the optimal timing of VTE prophylaxis.

Detailed Description: Not available

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 410

Inclusion Criteria

Able to freely give written informed consent to participate in the study and have signed the Informed Consent Form;
Males or females, age 18 and older at the time of study screening;
American Society of Anesthesiologists (ASA) Class I-III (Appendix III);
Due to undergo major colorectal surgery via laparotomy or laparoscopy

Exclusion Criteria

Mentally incompetent or unable or unwilling to provide informed consent or comply with study procedures;
American Society of Anesthesiologists (ASA) Class IV or V;
Children <18
Pregnant patients
Current/Active DVT
Patients on therapeutic anticoagulation for DVT or PE at time of surgery
Patients on anticoagulation for other medical problem (Heart Valve/atrial fibrillation) at the time of surgery
Patients with IVC filter
History of allergy to heparin products
History of heparin induced thrombocytopenia (HIT)
Patients with recent or active hemorrhage (GI/intracranial, etc) felt by the attending surgeon to be a contraindication to heparin thromboprophylaxis
Patients with Epidural analgesia

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Post-op Heparin	Heparin	Postoperative venous thromboprophylaxis (Control Arm/current standard practice: subcutaneous Heparin 5000 units started 23 hours after the end of surgery and continued every 8 hours for the remainder of the patients hospital course
Pre-op Heparin	Heparin	Treatment arm: subcutaneous Heparin 5000 Units given in the preoperative area one hour prior to surgery and continued every 8 hours for the remainder of the patients hospital course

Primary Outcome Measures

Name	Time	Method
Number of Participants With Postoperative VTE Within 48 Hours After Surgery	48 hour postop period	Number of participants with postoperative VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE) as demonstrated by duplex sonography or high probability on ventilation-perfusion scan or CT chest angiography within 48 hour postop period

Secondary Outcome Measures

Name	Time	Method
Number of Participants With VTE Within 30-day After Surgery	30 day postop period	any VTE occuring within 30-days after surgery - clinical or asymptomatic - detected by venous duplex ultrasound, vq scan or ct pulmonary angiogram.
Number of Participants With Surgical Complications	30 day postop period	Major or minor medical and surgical complications
Hospital Stay	30 day postop period	Length of postoperative hospital stay
Number of Participants With Bleeding Complications	30 day postop period	1. Major bleeding defined as any intracranial or intraocular hemorrhage or bleeding from any site associated with \>2g/dL drop in hemoglobin or transfusion of \>2 unit packed RBCs (including operative site bleeding, unexpected upper or lower gastrointestinal hemorrhage, or retroperitoneal hemorrhage) or any hemorrhage needing surgical intervention/reoperation or leading to death. 2. Minor bleeding defined as wound hematoma, ecchymosis \>10 cm, epistaxis of more than 2 minute duration, macroscopic hematuria, unexpected upper or lower GI hemorrhage associated with \<2g/dL drop in hemoglobin or \<2 unit packed RBC transfusion
Number of Participants With Postoperative Thrombocytopenia	30 day postop period	Thrombocytopenia defined as \>50% or greater drop in platelet count