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TachoSil and Evarrest — Collagen-Fibrinogen Sealing Patches

TachoSil and Evarrest are solid-phase fibrin sealants — pre-formed patches of equine or human collagen bonded with fibrinogen and thrombin. When the yellow active side of the patch contacts blood or tissue fluid, the fibrinogen and thrombin release and react locally to form a fibrin clot that bonds the patch to the underlying tissue. The collagen carrier provides mechanical substrate during healing and resorbs over 3–6 months.[1][2]

TachoSil has become the workhorse patch for tunical defect sealing in Peyronie's surgery — the Hatzichristodoulou sealing technique and the PICS technique both depend on it — and is widely used in partial nephrectomy and complex reconstructive applications.

Composition​

LayerMaterialRole
Passive side (white)Equine collagen (TachoSil) or polyglactin (Evarrest)Mechanical carrier; handling surface
Active side (yellow)Human fibrinogen + human thrombinForms fibrin on contact with blood/fluid
  • Fibrinogen: ~5.5 mg/cm² (TachoSil)
  • Thrombin: ~2 IU/cm² (TachoSil)
  • Collagen carrier: ~4 mg/cm²

Versions​

ProductCarrierNotes
TachoSilEquine collagenBaxter; the original and most widely used
EvarrestPolyglactin-910 meshEthicon; synthetic carrier, no animal component

Mechanism​

  1. Contact with blood or fluid activates the fibrinogen/thrombin layer
  2. Fibrin forms within ~3 minutes at the patch-tissue interface
  3. The patch adheres to the tissue by the fibrin bond — no sutures required
  4. The collagen (or polyglactin) carrier resorbs over 3–6 months, leaving a thin fibrous scar at the application site

GU Reconstruction Applications​

1. Peyronie's disease — tunical defect sealing​

The defining GU application. After partial plaque excision or relaxing incision on the concave side of the tunica albuginea, the tunical defect is sealed with a TachoSil patch rather than sutured graft fixation:[3][4]

  • Hatzichristodoulou sealing technique (319 patients): median operative time 79.8 min, 93.7% immediate straightness, 91.2% durable straightness at 47 months, mean penile length gain 1.1 cm
  • PICS technique (Penile Implant with Collagen Sealing): TachoSil is applied over the tunical defect after IPP insertion in severe Peyronie's; 84% complete straightening in complex PD cases (Falcone multicenter, 37 patients)
  • See Peyronie's — plaque incision/grafting and Peyronie's — prosthesis with straightening

2. Partial nephrectomy — collecting system / parenchymal sealing​

  • Placed over the collecting system repair after tumor excision
  • Reduces urinary leak rate and provides hemostatic backup
  • Comparable or superior to pericardium in head-to-head comparisons[5]

3. Urinary diversion anastomosis reinforcement​

  • Ileal conduit ureteroenteric anastomosis reinforcement
  • Neobladder afferent / efferent limb reinforcement
  • Reduces anastomotic leak in selected high-risk cases

4. Pelvic dead space after exenteration​

  • Applied to raw surfaces in the pelvic basin
  • Combined with omental flap when available

5. IPP — PICS technique​

  • Covered in the Peyronie's prosthesis article
  • Patches applied over tunical defects after relaxing incisions in severely curved IPP recipients

6. Liver and splenic bleeding (GU-adjacent trauma)​

  • In GU trauma where concurrent hepatic or splenic injury is present
  • Standard of care in hepatic and splenic surface bleeding outside the primary GU scope

Application Technique​

Standard steps​

  1. Prepare the surgical field — dry the target surface as much as possible
  2. Select patch size — product available in multiple sizes (1.3×3 cm, 3×3 cm, 4.8×4.8 cm, 9.5×4.8 cm)
  3. Orient the patch with the yellow active side against the tissue
  4. Apply with gentle manual compression for 3–5 minutes using moistened gauze
  5. Do not move the patch once positioned — the bond forms during the 3-minute contact
  6. Check adherence — a properly placed patch is firmly bonded; if it lifts, re-apply pressure

Robotic / laparoscopic application​

  • Trocar-compatible sizes (1.3×3 cm fits through a 12 mm trocar when rolled)
  • Introduce rolled; unroll in the abdomen with instrument assistance
  • Position over the defect; apply gentle sustained pressure with a blunt instrument or rolled gauze through a second port

Advantages​

  • Sutureless sealing — no suture placement required for graft fixation
  • Fast — 3–5 minute hands-on application
  • Strong immediate bond — resistant to irrigation and low-pressure fluid challenge within minutes
  • Hemostatic + sealing combined — one product serves both roles
  • Preserves length in Peyronie's — grafting without the long operative time of sutured grafts
  • Compatible with IPP cylinders — the PICS technique depends on this property

Limitations​

  • Expensive — $700–1500 per patch depending on size
  • Single-use — no reapplication if initial placement fails
  • Requires a dry field for optimal adhesion
  • Bovine or equine collagen (TachoSil) — rare allergy; Evarrest uses synthetic carrier
  • Human plasma-derived fibrinogen/thrombin — small theoretical risk of blood-borne pathogen transmission (extensively screened)
  • Not for intravascular use

TachoSil vs. Fibrin Sealant vs. Sutured Graft​

OptionBest for
TachoSil patchFocal tunical defect (Peyronie's); collecting system sealing; fast sutureless coverage
Fibrin sealant liquidBroad surfaces; anastomotic reinforcement; under-graft inosculation
Sutured graft (bovine pericardium, BMG, dermis)Large or high-tension defects requiring tensile strength beyond what sealant provides
Combination — fibrin sealant under a sutured graftEnhanced inosculation and reduced shear at the graft-bed interface

See Also​

References​

1. Rickenbacher A, Breitenstein S, Lesurtel M, Frilling A. Efficacy of TachoSil a fibrin-based haemostat in different fields of surgery — a systematic review. Expert Opin Biol Ther. 2009;9(7):897–907. doi:10.1517/14712590903029172

2. Öllinger R, Mihaljevic AL, Schuhmacher C, et al. A multicentre, randomized clinical trial comparing the Veriset haemostatic patch with fibrin sealant for the management of bleeding during hepatic surgery. HPB (Oxford). 2013;15(7):548–58.

3. Hatzichristodoulou G, Fiechtner S, Pyrgidis N, et al. Suture-free sealing of tunical defect with collagen fleece after partial plaque excision in 319 consecutive patients with Peyronie's disease: the sealing technique. J Urol. 2021;206(5):1276–1282. doi:10.1097/JU.0000000000001933

4. Falcone M, Preto M, Peretti F, et al. The use of collagen fleece to correct residual curvature during inflatable penile prosthesis implantation (PICS technique) in patients with complex Peyronie disease: a multicenter study. J Sex Med. 2023;20(2):229–235. doi:10.1093/jsxmed/qdac003

5. Farrell MR, Abdelsayed GA, Ziegelmann MJ, Levine LA. A comparison of hemostatic patches versus pericardium allograft for the treatment of complex Peyronie's disease with penile prosthesis and plaque incision. Urology. 2019;129:113–118. doi:10.1016/j.urology.2019.03.008