The Prospective Peri-operative Enoxaparin Cohort Trial (PROSPECT)

Reference: Dunn AS, Spyropoulos AC, Turpie AG. Bridging therapy in patients on long-term oral anticoagulants who require surgery: the Prospective Peri-operative Enoxaparin Cohort Trial (PROSPECT). Journal of Thrombosis and Haemostasis. 2007 Nov;5(11):2211-2218.

Summary: Due to limited data on the incidence of peri-operative thromboemobolic and bleeding during bridge therapy, there is no agreement on optimal peri-operative management of patients on oral anticoagulants (OACs). Dunn et al sought to “examine the incidence of major bleeding of a peri-operative strategy using once-daily therapeutic-dose enoxaparin administered primarily at home, and the effect, if any, of the extensiveness of the procedure on the risk of bleeding during bridge therapy” (p.2211-2212).

The study involved 24 sites in North America between January 2002 and August 2003. The figure below shows the study’s peri-operative management protocol (p.2212): periop mgmt2

 

Safety outcomes:

  • Incidence of major bleeding while on enoxaparin or in the 24 hours following cessation of enoxaparin treatment
    • Occurred in 3.5% (95% CI: 1.6-6.5)
    • Invasive procedures: 1.4%
    • Minor surgery: 0%
    • Major surgery:  27.5%
  • Rate of minor bleeding while on enoxaparin, or within 24 hours of discontinuation
    • Occurred in 108 patients (41.5%, 95% CI:35.7-47.6)
    • Invasive procedures: 44.6%
    • Minor surgery: 47.2%
    • Major surgery: 20.0%

Efficacy outcomes:

  • Incidence of arterial thromboembolic events for patients with afib
    • 4 events out of 176 patients (2.3%, 95% CI: 0.6-5.7)
    • 2 TIAs, 0 strokes, 2 patients had peripheral arterial thromboembolic events
  • Incidence of venous thromboembolic events for patients with a history of DVT.
    • 1 event out of 96 patients (1.0%, 95% CI: 0.03-5.7)
    • None fatal

Bleeding risk is high when bridging therapy is done peri-operatively in major surgery. In this study, there were 8 instances of major bleeding among 40 total patients in major surgery. Out of 220 invasive procedures or minor surgery, there was only 1 major bleeding event.

The value of diverting loop ileostomy to prevent low pelvic anastomotic leak

One discussion this week focused on the impact of diverting ileostomy on low rectal anastamoses.

Reference: Matthiessen P, Hallbook O, Rutegard J, Simert G, et al. Defunctioning Stoma Reduces Symptomatic Anastomotic Leakage After Low Anterior Resection of the Rectum for Cancer: A Randomized Multicenter Trial. Annals of Surgery. 2007 Aug;246(2):2017-214. doi:10.1097/SLA.0b013e3180603024

Summary: Anastomotic leakage is a feared complication of rectal resections, reportedly occuring in 1-24% and increasing postoperative morbidity from 1-8% to 6-22% (Matthiessen et al, 2007). In a randomized multicenter trial of 234 patients (no easy feat for surgical technique studies), Matthiessen et al (2007) found “patients without diverting stoma leaked in 28.0%, compared to 10.3% of those with diverting stomas (OR = 3.4; 95% CI, 1.6-6.9; P < 0.001), a result not previously demonstrated in any randomized trial” (p.207).

surgmm_leakage

Among patients randomized for diverting ostomy, surgeons demonstrated a preference for loop ileostomy vs transverse colostomy (112/116) and in all 25 urgent diverting stomas. In 97% of the patients (227/234), surgeons chose to use pelvic drainage. All anastomotoses were made with a stapling device, none were handsewn.

The authors conclude that their trial accurately demonstrates a decreased rate of symptomatic ansatomotic leakage in diverted patients in low anterior resection. This is the first randomized trial to illustrate this result and, therefore, they recommend the use of a diverting stoma in low anterior resection of the rectum.

(Matthiessen et al, 2007, p.210)

Additional reading: Hanna MH, Vinci A, Pigazzi A. Diverting Ileostomy in Colorectal Surgery: When is it Necessary? Langenbeck’s Archives of Surgery. 2015 Feb;400(2):145-152. doi:10.1007/s00423-015-1275-1.