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FloSeal — Flowable Gelatin-Thrombin Hemostatic Matrix

FloSeal is a flowable hemostatic matrix that combines bovine-derived cross-linked gelatin granules with a thrombin component to deliver a hybrid passive-plus-active hemostatic in a single syringe-based product. It is an adjunct for diffuse oozing on irregular surfaces — the renal bed after partial nephrectomy, the pelvic sidewall after lymphadenectomy, the retropubic space after complex reconstruction — particularly in patients with impaired clotting capacity (heparinization, coagulopathy).[1][2]

Composition and Mechanism​

ComponentRole
Gelatin matrix (bovine)Passive mechanical scaffold; contact-activates platelets; swells to fill irregular cavities
Thrombin (current US product includes recombinant Recothrom; older kits used plasma-derived human thrombin)Converts fibrinogen → fibrin directly; bypasses the intrinsic/extrinsic coagulation cascade
Combined effectPassive matrix + active thrombin = local clot formation that still requires available fibrinogen; not treatment for systemic coagulopathy

Mechanism sequence​

  1. Syringe delivers flowable gel onto the bleeding surface
  2. Gelatin granules swell (up to 20%) as they absorb blood and tissue fluid
  3. Thrombin converts local fibrinogen → fibrin immediately, catalyzing clot formation
  4. Mechanical tamponade of the bleeding surface as the gel conforms to irregular anatomy
  5. Matrix resorbs over 6–8 weeks

GU Reconstruction Applications​

1. Partial nephrectomy renal bed​

The highest-yield application:[1][2]

  • Combined with sliding-clip renorrhaphy (suture hemostasis of the parenchymal bed)
  • FloSeal fills the tumor excision defect, controlling diffuse parenchymal oozing after tumor removal
  • May assist focal oozing control; routine reductions in warm ischemia time or transfusion are not established by the limited GU evidence cited here
  • Used in both open and robotic partial nephrectomy — the syringe tip is trocar-compatible

2. Pelvic sidewall / lymphadenectomy​

  • After pelvic lymph node dissection during radical cystectomy, prostatectomy, or deep endometriosis resection
  • Controls capillary and small-venous oozing without cautery near iliac vessels or obturator nerve

3. Retropubic space​

  • After complex bladder-neck reconstruction (Y-V plasty, complex pelvic fistula repair)
  • After radical prostatectomy when anterior urethral / puboprostatic ligament dissection has created a raw surface

4. Deep pelvic dissection​

  • Presacral venous plexus bleeding
  • Pelvic sidewall after extensive dissection
  • Post-exenteration bleeding

5. High-risk patient populations​

  • Heparinized patients — topical thrombin may assist local control, but anticoagulant effects are not universally bypassed
  • Coagulopathic patients — local adjunct only; correct clinically important systemic coagulopathy in parallel
  • Radiated tissue — where tissue quality is poor and standard suturing is unreliable

Preparation and Application​

Preparation and application​

Follow the specific kit IFU: current US FloSeal uses Recothrom (recombinant topical thrombin), while older product instructions describe plasma-derived human thrombin. Reconstitution and mixing instructions must match the supplied kit.[1][3]

Apply to the active bleeding site with gentle approximation as directed, then remove material outside the clot with gentle irrigation. Do not inject/compress into vessels, use prophylactically on a nonbleeding surface, or apply where absent blood flow/negative venous pressure could permit intravascular clotting or entry. Do not use in infection. Consider the matrix's expansion near confined structures.[1]

Volume​

  • Standard kit: 5 mL, 10 mL sizes
  • Typical GU application: 2–5 mL covers a moderate renal bed or pelvic sidewall
  • Large irregular cavities may require 10 mL or repeat application

Advantages​

  • Active + passive combined — effective even in coagulopathic / heparinized patients where passive matrices underperform
  • Conforms to irregular surfaces — flowable delivery reaches crevices inaccessible to sheet products
  • Trocar-compatible — direct laparoscopic / robotic application
  • Excellent for parenchymal surfaces (renal bed, liver in GU-adjacent trauma)
  • Evidence and labeled precautions depend on the operation; urologic routine-benefit claims need stronger comparative evidence

Limitations​

  • Cost — FloSeal is substantially more expensive than Surgicel or Arista (~$200–500/kit)
  • Swelling — 20% expansion; can compress nerves or narrow spaces (use sparingly in spinal canal, pelvic sidewall near nerves)
  • Bovine gelatin origin — rare anaphylaxis reported; contraindicated in patients with known bovine allergy; Recothrom also has hamster-protein and component hypersensitivity contraindications
  • Not for intravascular use — thrombin can cause pulmonary embolism if injected into a vessel
  • Preparation time — reconstitution takes a few minutes; not instantly available if unanticipated bleeding
  • Urinary-tract collecting-system contact — as with other hemostatic matrices, avoid direct contact with the urinary collecting system (stone nidus concern); do not leave it in the renal pelvis or ureters

Evidence Base​

FloSeal has been reported in partial-nephrectomy series, but the manufacturer states that safety and effectiveness in urologic procedures have not been established through randomized clinical studies. The older BioGlue study formerly cited here concerns a different product and cannot support FloSeal-specific outcome claims. Do not infer routine transfusion, ischemia-time or reconstruction benefits from other surgical specialties.[1][2]

See Also​

References​

1. Baxter. FloSeal current US product information and important risk information. Accessed September 11, 2026.

2. Msezane LP, Katz MH, Gofrit ON, Shalhav AL, Zorn KC. Use of novel hemostatic agents in robotic laparoscopic partial nephrectomy. Can Urol Assoc J. 2009;3(4):324–30.

3. Baxter. FloSeal with Recothrom product information. Formulation, preparation and safety restrictions.