What are the causes of post-surgical hemorrhage (postoperative bleeding)?

From the Guidelines

Post-surgical hemorrhage (postoperative bleeding) is primarily caused by a combination of patient-related factors, surgical factors, and perioperative management of antithrombotic therapy.

Causes of Post-Surgical Hemorrhage

• Patient-related factors: patient co-morbidities (e.g. renal insufficiency), associated conditions (e.g. angiodysplasia), and concomitant therapies (e.g. oral anticoagulation, anti-platelet agents) 1
• Surgical factors: type of surgery, with high-risk procedures including major cardiovascular surgery, orthopedic surgery, head and neck cancer surgery, urologic surgery, and surgeries lasting ≥ 45 minutes 1
• Perioperative management of antithrombotic therapy: use of anticoagulants, such as heparin bridging, which can increase the risk of bleeding complications 1

High-Risk Surgical Procedures

• Urologic surgery and procedures (e.g. transurethral prostate resection, bladder resection, or tumor ablation) 1
• Pacemaker or implantable cardioverter-defibrillator device implantation 1
• Colonic polyp resection, especially of large sessile polyps 1
• Surgery and procedures in highly vascular organs (e.g. kidney, liver, and spleen) 1
• Bowel resection, with bleeding risk at the bowel anastomosis site 1
• Major surgery with extensive tissue injury (e.g. cancer surgery, joint arthroplasty, reconstructive plastic surgery) 1
• Cardiac, intracranial, or spinal surgery, with even small bleeds having serious clinical consequences 1

Bleeding Risk Assessment

• A patient’s previous history of bleeding and use of concomitant antiplatelet and nonsteroidal anti-inflammatory medications are important determinants in assessing surgical bleeding risk 1
• Estimated perioperative major bleeding risk with periprocedural anticoagulants is 2%-4% for major surgery and 0%-2% for nonmajor surgery or minor procedures 1

From the Research

Causes of Post-Surgical Hemorrhage

The causes of post-surgical hemorrhage (postoperative bleeding) can be attributed to various factors, including:

• Technical factors, which account for approximately 75% to 90% of intraoperative and early postoperative bleeding 2
• Acquired or congenital coagulopathies, which may favor or directly cause surgical hemorrhage 2
• Pre-existing medical comorbidities, such as hypertension, coagulopathies, and haematological abnormalities 3
• Intraoperative hypertension and blood loss 3
• Certain lesion pathologies, including tumors, chronic subdural hematomas, and deficiencies in hemostasis 3
• Endogenous heparin-like substances, which can be present in certain cases and contribute to postoperative bleeding 4

Risk Factors

Several risk factors can increase the likelihood of postoperative bleeding, including:

• Preoperative risk assessments and developments in surgical and anaesthetic techniques, which can help identify potential causes of coagulopathy 5, 6
• Inadequate management of coagulopathy, both pre- and post-operatively 6
• The type of surgical procedure, with certain procedures such as elective vascular surgery and major surgery for liver diseases carrying a higher risk of bleeding 2

Pathophysiology

The pathophysiology of postoperative bleeding involves a complex interplay of factors, including:

• Hemodilution, hypothermia, consumption of clotting factors, and acidosis, which can worsen the clotting process and exacerbate the problem 2
• A vicious cycle of bleeding, where uncontrolled bleeding leads to further clotting disorders and increased bleeding 2