Overview
Definition:
Fibrin sealants are topical hemostatic agents derived from human plasma proteins, primarily fibrinogen and thrombin
They mimic the final stage of the coagulation cascade to promote rapid clot formation and tissue adhesion, thereby reducing bleeding and sealing tissue surfaces.
Epidemiology:
The use of hemostatic agents is widespread across various surgical specialties
While specific epidemiological data for fibrin sealant use is not extensively published, their application is common in complex surgeries where bleeding control is paramount, including cardiovascular, neurosurgery, and general surgery.
Clinical Significance:
Effective bleeding control is crucial for patient outcomes, reducing operative time, minimizing blood loss, decreasing transfusion requirements, and preventing postoperative complications such as hematoma formation and anastomotic leaks
Fibrin sealants offer a valuable adjunct to conventional hemostatic techniques.
Indications
General Indications:
Used as an adjunct to conventional hemostasis when conventional methods are impractical or insufficient
Applied to control capillary, arteriolar, and venous bleeding
Indicated for sealing surfaces and reinforcing friable tissues.
Cardiovascular Surgery:
Suturing of vascular grafts to minimize oozing
Sealing of suture lines in coronary artery bypass grafting
Hemostasis in procedures on the great vessels and heart chambers
Reinforcement of atrial or ventricular septal defect repairs.
Neurosurgery:
Control of intraoperative bleeding from dural tears or brain surfaces
Sealing of cerebrospinal fluid (CSF) leaks
Hemostasis in vascular neurosurgery, such as aneurysm clipping or arteriovenous malformation (AVM) resection.
General And Abdominal Surgery:
Sealing of liver or spleen surfaces after resection
Hemostasis in bowel surgery, particularly in patients with coagulopathy or friable tissues
Reinforcement of gastrointestinal anastomoses
Management of bleeding from paragangliomas or adrenal tumors.
Orthopedic Surgery:
Control of bleeding in bone marrow cavities during joint replacement or spinal surgery
Sealing of cancellous bone surfaces
Hemostasis in procedures involving extensive soft tissue dissection.
Urology And Gynecology:
Control of bleeding during nephrectomy or prostatectomy
Sealing of pelvic tissues in gynecological procedures, such as hysterectomy or myomectomy
Management of bleeding from the vaginal cuff.
Thoracic Surgery:
Sealing of lung fissures after wedge resection
Hemostasis on pleural surfaces
Reinforcement of bronchial or vascular anastomoses.
Plastic And Reconstructive Surgery:
Hemostasis in extensive flap elevation or grafting procedures
Sealing of recipient vessels in microvascular surgery.
Contraindications
Absolute Contraindications:
Known hypersensitivity to bovine proteins or any component of the sealant
Not for intravenous administration
Should not be used as a parenchymal sealant in extensive liver resection where major vascular structures are not controlled.
Relative Contraindications:
Patients with severe coagulopathy where the sealant may not achieve adequate hemostasis
Use with caution in pregnant or lactating women, as safety has not been fully established
Patients with a history of severe allergic reactions.
Mechanism Of Action
Coagulation Cascade Mimicry:
Fibrinogen is converted to fibrin by thrombin, forming a stable clot
Factor XIII, also present in the sealant, cross-links the fibrin strands, enhancing clot strength and stability.
Tissue Adhesion:
The fibrin clot acts as a scaffold and adhesive, binding to tissue surfaces and promoting cell migration and tissue regeneration
This provides a physical barrier and promotes healing.
Application Technique
Preparation:
The sealant is typically prepared by mixing the fibrinogen and thrombin components according to manufacturer instructions
It is often applied using a double-barreled syringe and applicator tip to ensure proper mixing and delivery.
Delivery Methods:
Can be applied as a liquid spray, by direct application with a sponge, or by a brushing technique
The method of application depends on the surgical site, the type of bleeding, and the desired outcome (hemostasis vs
adhesion).
Surface Application:
Applied directly to bleeding surfaces as a thin, uniform layer
Excessive application should be avoided to prevent potential complications like tissue compression or delayed healing.
Complications
Allergic Reactions:
Rare, but can range from mild skin reactions to anaphylaxis, especially in patients with bovine protein sensitivity.
Thrombosis:
Theoretical risk if delivered intravascularly, though not a common complication with topical use.
Delayed Wound Healing:
Can occur if the sealant forms a thick barrier that impedes tissue ingrowth or if applied to infected wounds.
Infection:
Risk is low, but as with any foreign material, it can serve as a nidus for infection if applied to a contaminated field without adequate antimicrobial prophylaxis.
Air Embolism:
A rare but serious complication associated with spray application under high pressure, particularly in laparoscopic procedures
Proper technique and pressure control are essential.
Key Points
Exam Focus:
Understand the primary indications for fibrin sealants across different surgical specialties
Recognize contraindications and potential complications
Differentiate between hemostasis and adhesion applications
Know that fibrin sealants are adjuncts to, not replacements for, conventional surgical techniques.
Clinical Pearls:
Always ensure the surgical field is relatively dry before application for optimal adherence
Avoid excessive application
Consider the type of bleeding and tissue friability when choosing an application method
Document the use of hemostatic agents in the operative report.
Common Mistakes:
Using fibrin sealants as a primary hemostatic method for major arterial or venous bleeding
Applying the sealant intravascularly
Inadequate preparation leading to poor clot formation
Over-application leading to tissue compression.