PEG-Based Sealants — CoSeal and Related Products
Polyethylene glycol (PEG) hydrogel sealants are synthetic two-component sealants that cure within seconds into a soft, elastic, resorbable hydrogel. They fill a niche distinct from fibrin sealants — providing a non-biologic, non-thrombogenic seal that works on surfaces where fibrin-based agents are contraindicated or suboptimal, and in patients with religious or immunologic objections to blood-product-derived agents.[1]
Products
| Product | Manufacturer | Primary role |
|---|---|---|
| CoSeal | Baxter | Vascular suture line sealing; cardiac/vascular surgery |
| DuraSeal | Integra | Dural closure (neurosurgery) |
| Progel | NeoMend/Davol | Pulmonary pneumostasis |
| FocalSeal-L | (historical) | Light-activated pulmonary sealant (withdrawn) |
CoSeal is the most relevant for GU use.
Composition and Mechanism
- Component 1: PEG polymer with electrophilic end-groups
- Component 2: PEG polymer with nucleophilic end-groups (or a thiol-amine crosslinker)
- Mixed through a dual-syringe spray applicator
- Crosslink within 3–5 seconds via covalent bonding at tissue surface
- Forms a soft elastic hydrogel that conforms to tissue contour
- Swells ~4× volume as it absorbs tissue fluid
- Resorbs via hydrolysis over ~30 days — cleared renally
GU Applications (Selective)
PEG sealants are not standard workhorses in GU reconstruction — fibrin sealants and collagen-fibrinogen patches dominate for most sealing applications. CoSeal finds niche use:
1. Urinary-tract suture line reinforcement (investigational)
- Ureteroenteric anastomosis — limited evidence for reducing leak rate
- Cystotomy closure — alternative to fibrin sealant in specific populations
2. Pelvic dead space / presacral bleeding
- Non-hemostatic surface sealing after exenteration or APR where fibrin sealant is contraindicated or not available
- Typically combined with mechanical hemostasis (clips, cautery) for bleeding control
3. Religious / immunologic alternative
- Jehovah's Witness patients refusing blood-product-derived agents
- Severe human plasma product allergy
- Bovine / porcine dietary objections
4. Cardiac / vascular suture lines at GU-overlap boundaries
- CoSeal was originally developed for vascular anastomoses
- Occasionally relevant in renal vein reconstruction during complex urologic cases with vascular involvement (renal cell carcinoma with IVC thrombus — outside primary scope)
Advantages
- Fully synthetic — no blood products, no animal sources
- Rapid cure (3–5 seconds) — faster than fibrin sealant
- Elastic hydrogel — tolerates distension and physiologic movement
- Renal hydrolysis clearance — complete absorption within ~30 days
Limitations
- Swelling — 4× volume expansion can compress adjacent structures in confined spaces
- Not hemostatic — no thrombin component; purely a sealant, not a hemostatic agent
- Cost — comparable to fibrin sealants
- Limited GU evidence base — most data are from cardiac, vascular, pulmonary, and neurosurgical applications
- Spinal canal / CSF restrictions — not for use in areas where 4× swelling could compress neural structures (dedicated formulations like DuraSeal exist for dural applications)
Technique
- Prepare — reconstitute and connect dual-syringe spray applicator
- Dry the field
- Spray both components simultaneously onto the target surface
- Hold 30 seconds while the hydrogel cures
- Avoid over-applying — excess produces mass effect from swelling
CoSeal vs. Fibrin Sealants
| Feature | CoSeal (PEG) | Fibrin sealant (Tisseel/Evicel) |
|---|---|---|
| Source | Fully synthetic | Human plasma-derived |
| Cure time | 3–5 sec | ~10 sec |
| Hemostatic | No | Yes (mild) |
| Swelling | 4× | Minimal |
| Resorption | ~30 days | ~10–14 days |
| Religious objections | None | Plasma-derived |
| GU evidence base | Limited | Extensive |
| Typical GU role | Niche / alternative | First-line sealant |
Practical Take
In contemporary GU reconstruction:
- Fibrin sealants dominate for soft-tissue, anastomotic, and urinary-tract sealing applications
- TachoSil/Evarrest patches dominate for focal tunical and parenchymal sealing
- CoSeal and related PEG sealants are reserved for specific alternative indications — the Jehovah's Witness patient, severe plasma-allergic patient, or surgeon preference in cardiac/vascular overlap cases
The surgeon should be aware of PEG sealants as an option but does not need one on routine GU reconstruction trays.
See Also
References
1. Spotnitz WD, Burks S. Hemostats, sealants, and adhesives: components of the surgical toolbox. Transfusion. 2008;48(7):1502–16. doi:10.1111/j.1537-2995.2008.01703.x