Mark A. Carlson, MD

Department of SurgeryUniversity of Nebraska Medical Center

Omaha VA Medical CenterOmaha, Nebraska

USA

Next Generation Hemostatic Devices

UNMC Surgical Grand Rounds, March 10, 2010

Disclosures:None

Disclaimer:Not a trauma surgeon

Not a vascular surgeon

Content available: www.nebraskasurgicalresearch.com

Overview

• Currently available hemostatic aids & devices

• Description of Univ Nebr hemostasis research

• And, a completely unrelated topic in General Surgery

The Military Experience

• 15-20% of combat deaths are potentially preventable

• Rapid battlefield evacuation has resulted in more soldiers dying atmedical treatment facilities

• About half of the deaths from penetrating trauma are due to hemorrhage

• Hemorrhage is the #1 cause of preventable death

Impetus to improve treatment of exsanguinating hemorrhage

Clinical Problem:exsanguinating hemorrhage

Ann Surg 2007; 245: 986-991

J Trauma 2003; 54: S13-S19

Distinction:

*locally-applied (topical)* vs. systemic agents

NovoSeven(Novo Nordisk)Dry Fibrin Sealant Dressing

(American Red Cross)

Current Hemostatic Devices

The Ideal Hemostatic Device

1. *Efficacy*

2. Biocompatibility3. Safety4. Pliability5. Simplicity6. Stability7. Affordability8. Scalability9. FDA compatibility

State of the Art:Locally-Applied Hemostatic Devices

1. Occlusion/tamponade agents2. Scaffolding agents3. Chitin-based agents4. Mineral agents5. Thrombin-based agents6. Sealants7. Experimental treatments

Categories

…a Growth Industry

1. Occlusion & Tamponade Agents

limited to bone;local effects?

rapid; not dependenton patient; slowly

eliminated

occlusion &tamponade

alkylene oxidecopolymer

Ostene (Ceremed)

nonabsorbable;inhibits union;limited to bone

cheap; rapid; notdependent on patient

occlusion &tamponade

beeswax, paraffinBone wax (Ethicon)

disadvantagesadvantagesmechanismcompositionAgent

Indication: bleeding from cut surface of bone

Sternotomies

2. Scaffolding Agents

swelling brings risk ofcompression

biodegradable; pHneutrality; combinable

with thrombin

clotting scaffold;tamponade

gelatin foam(hydrolyzed collagen)

GelFoam (Pharmacia& Upjohn)

acidic degradation;possible long-term

complications

absorbable; pliable;versatile; antimicrobial

clotting scaffoldoxidized regeneratedcellulose (wood pulp)

Surgicel (Ethicon)

less effective withthrombocytopenia;handling issue with

powder form

biodegradable; pHneutrality; versatility;no effect by heparin;

no swelling

clotting scaffold;platelet activation

microfibrillar collagen(multiple formulations)

Avitene (Davol)Helistat (Integra)Instat (Ethicon)

disadvantagesadvantagesmechanismcompositionAgent

Indication: raw surface bleeding; small vessel/orifice bleeding

GelFoam in tumor bed Surgicel on liver bed

3. Chitin-based agents

HemCon(HemCon MedicalTechnologies)

modified Rapid DeploymentHemostat, mRDH (MarinePolymer Technologies)

TraumaStat (Ore-Medix)

allergy risk; relies onpatient’s clottingcascade; gauze-

based products arenonabsorbable

absorbable;antimicrobial;

versatile; stable;gauze-based productsare more efficaciousthan regular gauze

scaffolding agent;vasoconstrictor;

clotting activation

polymers ofN-acetyl-

glucosamine(chitin, chitosan)

Celox (Celox Medical)

disadvantagesadvantagesmechanismcompositionAgent

Indication: severe traumatic injuries; field use; elective procedures

HemCon Celox

4. Mineral agents

foreign body; relies onpatient; *Army halted

use in 2009

field use; simple; noexothermia

tamponade; sealant;scaffold

clay (silicate) -basedgranules (bentonite,

kaolin, smectite)

WoundStat(TraumaCure)

exothermic reaction;foreign body reaction& fibrosis; relies on

patient’s clotting

field use; simple;newer bandage forms

available withprehydration

absorbent; increaseslocal concentration of

patient's clottingfactors

mineral zeolite(microporous

aluminosilicate

QuickClot, CombatGauze (Z-Medica)

disadvantagesadvantagesmechanismcompositionAgent

Indication: severe traumatic injuries; field use

clay(aka dirt)

"The risk inherent in WS (WoundStat) use outweighs its benefits asa back-up hemostatic agent to combat gauze.

"CG (combat gauze) remains the recommended hemostatic agentfor current combat operations."

All Army Activity Message, 17 April 2009:

WoundStat

J Trauma 2010; 68: 269-278

5. Thrombin agents

requires patientclotting factors;plasma-derived

human plasma-derived thrombin

Evithrom (Ethicon)

requires patientclotting factors

human recombinantthrombin

Recothrom(Zymogenetics)

requires patientclotting factors;plasma-derived;risk of swellingcomplications

swelling + scaffoldeffect

activated thrombin +scaffold

human plasma-derived thrombin +

gelatin

FloSeal (Baxter)

requires patientclotting factors;

allergenic

simple to useactivated thrombin

bovine thrombinThrombin JMI (KingPharmaceuticals)

disadvantagesadvantagesmechanismcompositionAgent

Indication: treatment of raw surface ooze; low pressure/small orificebleeding (scaffold combinations)

6. Sealants

scaffold; fibrin sealant;platelet gel

possible swelling riskcross-links to tissue;rapid effect; minimal

inflammation

wound attachment;sealant

polyethylene glycolpolymers

Coseal (Baxter)

not dependent onpatient’s clottingtrue fibrin sealant

human plasma-derived fibrinogen

and thrombin +plasminogen inhibitor

Crosseal (Ethicon)

plasma-derived; notuseful in the field norfor arterial bleeding;very little Factor XIIIhuman plasma-

derived fibrinogenand thrombin

Evicel (Ethicon)

Tisseel (Baxter)

complex preparationincludes harvest of

patient plasma

combines fibrinsealant & platelet

activities

microfibrillar collagen+ plasma-derivedthrombin + patient’splasma

Vitagel (Orthovita)

risk of local nervecomplications

cross-links to tissue;rapid effect; not

affected bytemperature or liquid

wound attachment;sealant; clot scaffold

glutaraldehyde-crosslinked albumin

BioGlue (CryoLife)

disadvantagesadvantagesmechanismcompositionAgent

Indication: sealing of raw surface ooze and/or small orifice bleeding; tissue “welding”

7. Experimental Treatments

plasma-derived;minimal Factor XIII

activity

collagen sponge +fibrinogen +

thrombin

Tachosil (Nycomed)

complexmost likely the fastest& strongest clotting;no dependence onpatient factors; fully

recombinant;absorbable; pliable;

versatile; optimizable

formation of cross-linked human clot in

an absorbablescaffold

recombinanthuman fibrinogen,

thrombin, andFactor XIII; ±

polylactide mesh

Recombinant HemostaticDevices

(University of Nebraska)

expensive; brittlehandling; plasma-derived; minimal

Factor XIII activity

little dependence onhuman factors;

anecdotal battlefieldsuccess stories

(DFSD); absorbable

formation of humanclot in an absorbable

scaffold

freeze driedfibrinogen +thrombin on

polyglactin mesh

Dry Fibrin SealantDressing, DFSD

(American Red Cross)

disadvantagesadvantagesmechanismcompositionAgent

Indication: varied, including exsanguinatingtrauma in the field

DFSDTachosil

(on vascular graft)

8. Others

1. Hemostase (CryoLife): plant protein; scaffold/activation mechanism

2. Haempatch (Venomics): prothrombinase (Factor Xa mimetic) fromsnake venom in a collagen scaffold (compare to FloSeal, thrombin-soaked GelFoam)

3. Amylopectin powder (Hemostasis LLC)

4. Arista AH; TraumaDex (Medafor): microporous polysaccharide spheres

Hemostasis Research at the University of Nebraska:

Recombinant clotting factors in a variety of formulations

Why is our research “Next Generation”?

1. Recombinant source of all clotting proteins2. Factor XIII3. Biodegradable, nanoengineered matrix4. Treatment can be optimized/configured

1. Efficacy2. Biocompatibility3. Safety4. Pliability5. Simplicity6. Stability7. Affordability8. Scalability9. FDA compatibility

and

10. Versatility

Ideal hemostatic device:

fibrinogen (Factor I)

fibrin monomer

fibrin polymer

fibrin clot

thrombin(Factor II)

Factor XIII(crosslinking factor)

Some have access to this

Everyone has access to this

*Only NU has access to this*

RECOMBINANT VERSION:

Simplified Coagulation Cascade

Expression of Human Proteins in Animal Vectors

Bos taurus

Sus scrofa domesticus

Pichia pastorisN

ational Geographic 1999; 196, N

o. 4

Nature Biotechnol 1997; 15: 971-975

insert gene + mammary specific-promoter into embryo

screen offspring for gene insertion

harvest milk, extract/purify protein product

fibrinogen, thrombin, Factors VII, VIII, IX, XIII,and more

Thromboelastography (TEG)

0 600 1200 1800

seconds

80

60

40

20

0

ampl

itude

(mm

)

normal human blood

high [fibrinogen] + IIa + XIIIa

low [fibrinogen] + IIa + XIIIa

in vitro performance ofrecombinant clotting factors

(clot “strength,”not adherence)

Polylactic acid (PLA) polymer

(or gelatin, chitosan, elastin, composites, etc.)

macroporous

microporousmass production at LNK Chemsolutions (Lincoln, NE)

Absorbable Scaffold

Preclinical Studies

• Swine (~35 kg)

• Femoral arteriotomy (4-6 mm)

• Stellate liver injury, central region

• Major hepatic resection

Endpoints:a) hemostasisb) blood lossc) survivald) vessel patencye) long-term effects

B

C

FA

PLA

M L

prox

dist

PLAM

L

prox

dist

FAL

M

prox

dist

A

PLA

Figure 4: the swine femoral arteriotomy model.(A) The femoral artery (FA) is exposed through agroin incision (right side shown), and controlled withvessel loops. A 4 mm arteriotomy is made with apunch instrument between the loops. A dressing(microporous PLA in this image) then is applied,finger pressure is held for 5 min, and then the site isinspected for bleeding. (B) Hemostatic result afterapplication of microporous PLA in 2 plies, containingthrombin and recombinant Factor XIII in the inner ply,and recombinant fibrinogen in the outer ply. Dopplerflow was present in the distal artery. L = lateral; M =medial; prox = proximal; dist = distal. (C) Hemostaticresult after application of the macroporous (“woolly”)PLA in 2 layers with the same distribution of clottingfactors as in B. Doppler flow was present in the distalartery. (D) Appearance of a macroporous PLA ban-dage containing all 3 clotting factors post-removalfrom an arteriotomy site. Note formation of a prom-inent vessel groove (arrowheads) in the dressingmaterial. This used bandage was quite firm to thetouch.

D

Femoral Arteriotomy

Treatment of femoral arteriotomy with microporous PLAwet with recombinant fibrinogen, thrombin, and XIIIa

[go to video file “Vid1_microporous.mov”]

Treatment of femoral arteriotomy with macroporous PLAwet with recombinant fibrinogen, thrombin, and XIIIa

[go to video file “Vid2_macroporous.mov”]

Blood-letting through femoral arteriotomy withflash of proximal clamp (MAP > 100 mm Hg)

[go to video file “Vid3_bloodletting.mov”]

liver injury clamp

Treatment of central liver injurywith soluble recombinant factors

(fibrinogen, thrombin, XIIIa)

IVC

treatment of central liver injury with liquid recombinant factors (fibrinogen, thrombin, XIIIa)

delivered with aerosol propulsion

[go to video file “Vid4_centralinjury.mov”]

Hemostasis of majorhepatic resections with

recombinant clotting factorsR L

d

gb

Major liver resection treated with recombinant fibrinogen, thrombin, and XIIIa

[go to video file “Vid5_majorresection.mov”]

Quantification of efficacy:

Aerosolized clotting factors& small hepatic wedge cuts

Hemostasis obtained with[fibrinogen] < 10% of that

contained in Tisseel

Application of recombinant factors with dual-reservoir aerosol gun

Small hepatic wedge excisions treated withaerosolized fibrinogen, thrombin, and XIIIa

[go to video file “Vid6_wedgeresection.mov”]

Planned Experiments in Swine

1. Trial of our hemostatic bandage vs. competitor bandage in swine femoralarteriotomy and/or aortotomy models

2. Trial of our fibrin sealant vs. competitor fibrin sealant in a swine liver resectionmodel (normothermic/noncoagulopathic)

3. Trial of our fibrin sealant vs. competitor fibrin sealant in a swine liver injurymodel (hypothermic/coagulopathic)

4. Investigational studies of recombinant factors as systemic adjunctivetreatment of coagulopathic hemorrhage (e.g., treatment of liver fracture incold/coagulopathic swine with intravenous recombinant fibrinogen)

5. Investigational studies of recombinant factors + absorbable scaffold fortreatment of incompressible hemorrhagic injuries

Opinions

Wait, Ground Rounds is not over yet….

1. Variety of topical hemostatic agents with reasonable efficacy

2. Treatment options for exsanguinating hemorrhage in the fieldhave improved, but still need to be better

3. Hemostatic devices composed of recombinant fibrinogen,thrombin, and Factor XIIIa have great potential