Intra-operative heparin release during lung surgery

Area of Science:

• Pulmonary Medicine
• Surgical Oncology
• Hematology

Background:

• Heparin, a key anticoagulant, is traditionally believed to be synthesized and stored in mast cells within the lungs and gastrointestinal tract.
• Mast cell degranulation, triggered by inflammation or trauma, leads to heparin release into circulation.

Purpose of the Study:

• To investigate whether operative trauma during lung mobilization in thoracotomies enhances heparin release.
• To assess heparin levels in both pulmonary and systemic circulations following lung surgery.

Main Methods:

• A prospective study involving 34 patients undergoing elective thoracotomies (19 with inflammatory disease, 15 with lung carcinoma).
• Blood samples were collected pre-operatively, intra-operatively (pulmonary vein and radial artery), and post-operatively.
• Heparin levels were quantified using high-performance liquid chromatography (HPLC).

Main Results:

• Intraoperative serum heparin levels were significantly higher (P = 0.0016, P = 0.0014) compared to pre-operative levels.
• No significant difference was observed between heparin levels in the pulmonary versus systemic circulation intraoperatively (P = 0.6508).
• Patients with inflammatory lung diseases showed higher mean heparin levels compared to lung carcinoma patients.

Conclusions:

• Operative trauma during lung surgery appears to enhance heparin release, possibly via pulmonary mast cell degranulation.
• This episodic anticoagulant effect may contribute to excessive bleeding and reduced thromboembolic complications observed in thoracic surgery.
• Elevated heparin release should be considered a potential cause for unexplained bleeding during thoracotomies.