DIGIT REPLANTATIONS FROM BIOMECHANICS TO ......insufficiency, New York, 1983 Flow recirculation as in: Hathcock, Arteriosclerosis, Thrombosis, and Vascular Biology 2006-> Risk of Thrombosis

Bruno Barbato

Urgences Mains Val de Seine78410 Aubergenville, France.

Anne Virginie Salsac

Laboratoire Biomécanique et Bioingénierie (UMR 7338), CNRS-Université de Technologie de Compiègne

Alliance Sorbonne Université, 60200 Compiègne, France.

DIGIT REPLANTATIONS

FROM BIOMECHANICS TO EFFICIENCY

Mapuche Indians led by chief Galvarino and enslaved by

the Spanish conquerors in the 16th century

LOSS OF A HAND OR DIGIT IS AN EXTREME HANDICAP

ORTHOPAEDIC

The 1970’s saw the rise of handtrauma centers

One-time procedure

PLASTIC

MICRO-SURGERY GEM

THE RISE OF HAND TRAUMA CENTERS

Teaching

Learning

Microsurgery Laboratory

SOS MAINS BOUCICAUT 1972

Le livre Blanc 2018 PMSI

EPIDEMIO CURRENT PRACTICE

In the USA, 12% of finger amputation injuries are treated

with replantation. Most microsurgeons perform less than

5 per year.

Payatakes and al. J Hand Surg Am 2007 Nishizuka and al. J Hand Sur Am 2015.

In France, 15% of finger amputation injuries are treated

with replantation.

In Japan, 29% of finger amputation injuries are treated

with replantation

Fluid biomechanics considerations

General principles of digital replantation

Consensual indications

The Thumb

Distal amputations

Multiple digit amputations

Transmetacarpal amputation

Ring fingers avulsion

SURGICAL EFFICIENCY FOR OPTIMIZED OUTCOMES IN DIGIT REPLANTATION

FLUID

BIOMECHANICS CONSIDERATIONS

∆𝑝 = 𝑄8𝜂𝐿

𝜋𝑅4

=RHProvides information on:

Blood flow behaviour in veins and in smallarteries (quasi-steady flows)

Hydraulic resistance RH induced in a vesselof radius R and length L because of bloodviscosity η.

POISEUILLE LAW

𝑅𝑒 =𝜌𝑈𝐷

𝜂> 2200When

Hardly occurs under physiologicalconditions in blood vessels

May occur in largely stenosed vessels

Risk of thrombosis

with density 𝜌, velocity U

i.e. at large blood flows

HIGHER RISK IF THERE IS ASYMMETRICAL SIZE MISMATCH IN ANASTOMOSIS

TURBULENT FLOW

Zarins, Gidens, Glagov. In: Cerebrovascular insufficiency, New York, 1983

Flow recirculation as in:

Hathcock, Arteriosclerosis, Thrombosis, and Vascular Biology 2006

-> Risk of Thrombosis

HEMODYNAMIC CONSEQUENCES IN ANASTOMOSIS

Unsteady Flow

Time evolution of the blood flow Q over one period T

Velocity profile at different time instances in the cardiac period

Systolic Peak

Diastolic Peak

Salsac et al. Journal of Fluid Mechanics 2006

BLOOD FLOW IN LARGE ARTERIES

Risk of thrombosis

Womersley Number

α = 𝑅𝜌𝜔

𝜂

Velocity Profiles at Systolic Peak

Quasi-steady flow when ⍺ < 3Strong effect of pulsatility

when ⍺ > 5

with density 𝜌, viscosity η

BLOOD FLOW IN LARGE ARTERIES

GENERAL PRINCIPLES OF REPLANTATION

Prior to patient arrival in Emergency Department

Special boxes with ID and details

No colored solutions

No tourniquet required

GENERAL PRINCIPLES

Operative room staff and anesthesia teams should be notified

Eliminate any potential life-threatening lesions or conditions: replantation should not risk the life of the patient

Examination of the hand and x-ray of patient and amputated part(s)

Check the parts are not stored in a freezer compartment

PATIENT ARRIVAL TO THE EMERGENCY DEPARTMENT

Type of injury crush or guillotine: importance of the debridement

Number of amputated parts with or without the Thumb: Priorities in replantation

Macroscopic conditions of amputated parts and hand: associated lesion requiring additional repair surgery

X-ray status: type of bone repair and osteosynthesis anticipation

Patient details and conditions: major influence on final decision

WHAT COULD BE DONE?

ANTICIPATION & EFFICIENCY IN WORKFLOWS AND PROCEDURES

Clinical aspect: blue ribbon sign with pulpecchymosis indicating severe shearing forcealong the neurovascular bundle

Arteries and nerves debridement accordingto the type of injury tagged using 9-0 nylon/veins location

Bone resection is made to avoid damage tothe vessels /skeletal shortening for tensionfree vessels and nerves

Bone synthesis preparation

Extensor and flexor tendons preparation

WHAT CAN BE DONE?

ANTICIPATION & EFFICIENCY IN WORKFLOWS AND PROCEDURES

Amputated part examination and status: backtable and magnifying loupe or microscope

Possible options:

Lengthy process with important functionality consequences

Patient approval

Confident emotional and moral relationship

Non surgical factors and patient details

Upper extremity block anethesia

WHAT WILL BE DONE!

EXPLAINING TO THE PATIENT

Crush injury

Psychiatric disorders

Peripheral vascular disease (Raynaud)

Electrolytes imbalances

In the elderly risk is not only by age but bynumber of comorbidities

Left hand

Tobacco

• Ma and al. J Hand Surg Eur 2015.• Van Adrichem and al. J hand Surg Am 1992.• Waikakul and al. Injury 2000.• Hustedt and al J Hand Surg Am 2016

EFFECTS OF NON-SURGICAL FACTORS

No significant differences between immediate versus overnight delayed Replantations < 15 H Cold ischemia.

• Cavadas and al. J Hand Surg Am 2018• Woo and al. J Hand Surg Am 2015

ISCHEMIA TIME < 12 H COLD OR 6 H WARM

Medical legal aspects +++

But it depends on:

ISCHEMIA TIME < 12 H COLD OR 6 H WARM

Tourniquet run

Debridement: experience dependant +++

Vessels and nerves: location and tagged

Venous graft pre-drawing

Out of tourniquet

Bone and tendon repair out of tourniquet run andvein location

Extensor repair

Flexor Digitorum Profundis FDP privileged(reparation of the FDS often foregone / finalfunction not improved)

TIME AND EFFICIENCY

GENERAL OPERATIVES PRINCIPLE OPERATIVE TIME

BONE REPAIR AND TENDONS REPAIR

Secure but fast out of tourniquet

Cup-and-ball (bilboquet) or internal screwsin transmetacarpal+

K-wires +++

Skeletal shortening

No external fixation

FDP Tsuge/ Kessler/ Mac Larnay

Extensor

Digit irrigation with heparine solution (40%of French surgeons according to FESUM)

24-gauge yellow catheter without cuttingextremity

Direct arterial anastomosis even crossed

9 or 10-0 Nylon interupted suture

Tamai’s disposable micro plastic clip

Dumont and al Chir Main 2010.

MICROSURGICAL TIME: ARTERIAL REPAIR

ARTERIAL REPAIR

Microsurgery is the safer anastomosispossible

Looping suture on the last 2 or 3 sutures inorder to leave the lumen open

Oblique cut in case of asymetrical sizemismatch

Forearm ++

Length in physiological tension to avoid« Kinking » phenomenon, origin ofturbulent flow and thrombosis

Tension free suture by 9-0 Nylon suture

This is a graft and not a bypass

Bypass

In case of extended arterial damages

MICROSURGICAL TIME: VENOUS GRAFT

Graft

Functionally important, however:

Time efficiency

Tension free neurorraphy ++ skeletal shortening

Nerve graft

Nerve guides? When synthetic, they causediscomfort and inflammatory reaction in thedigit area mostly in transmetacarpal

Vein conduits

Spare part fingers

Source: biotextiles2017blog

MICROSURGICAL TIME: NERVE REPAIR

The key to success

Vein patterns « Dorsal Ladder » CentralTerminal Dorsal Vein

11-0 Nylon

Tourniquet release vein distension andlocation

Lucas GL. J Hand Surg Am 1990. 10h

14h

Efficiency+++

MICROSURGICAL TIME: VENOUS REPAIR

TOURNIQUET RELEASE

Vessels anastomosis patency test

Vein graft condition

Papaverine and tepid serum

Digit coloration

SKIN CLOSURE AND DRESSING

This is the surgeon’s responsibility+++ andshould not delegated

Skin graft to avoid tension suture

Pulp free

Splint

POST-OPERATIVE CARE CONTROL

Trained nursing staff

Hourly (first 24 hrs), every two hrs (for thefollowing 72 hrs) (documented)

Pulp color / temperature / capillary refill

Rest in warm environment and no need forheating lamp

Tobacco exclusion

Psychological support as soon as possible

R. Vilain, Jeux De Mains, 1987

Personal relationship of trust betweenpatient and surgeon

Preferred interlocutor of the follow-up

Preferred interlocutor of salvatoryprocedures

PERSONALIZED POST-OPERATIVE CARE

PHARMACOLOGICAL SUPPORT

Use of anticoagulants vary widely amongmicrosurgeons

Arterial platelet aggregation is the underlyingcause of arterial thrombosis Aspirin

Fibrin clotting is the underlying cause of venousthrombosis Heparin

Dextran reduces erythrocyte aggregation andplatelet adhesiveness however, can cause acuterenal failure and cerebral oedema

Bleeding risks of antithrombotic therapy. Fitzmaurice. BMJ 2002

PGE-1 in replantation and free tissue transfer: early preliminary experience., Rodriguez and al. Microsurgery 2007

Effect of anticoagulation and inhibition of platelet aggregation on arterail versus, Venous microvascular thrombosis, Li and al. Ann Plast Surg 1995

Topical and systemic anticoagulation in the treatment of absent or compromised venous outflow In replanted fingers. Han and al. J Hand Surg Am 2000

Blood loss associated with anticoagulation in patients with replanted digits, Fumas and al. J Hand Surg Am 1992

No More Than Two

Aspirin 160 mg per day during 15 to 30 days

Low-molecular-weight heparin (LMWH) duringrecovery phase in prophylactic dosage

Anticoagulation therapy in microsurgery: a review. Askari and al. J Hand Surg Am 2006

Etude multicentrique sur la prévention de la thrombose en microchirurgie du membre supérieur. Enquête auprès de la Fesum, Dumont and al. Chir Main 2010

A phase II trial of intraluminal irrigation with RHTF pathway to prevent thrombosis in free flap surgery. Khoury and al. Plast reconstr Surg 2001

Anticoagulation following digital replantationBuckley and al. J Hand Surg Am 2011

PHARMACOLOGICAL SUPPORT

Leeches (Hirudo Medicinalis) up to three days

Bloodletting action

Hirudin >>>> Heparin

Aeromonas hydrophila

Not forcefully removed

COMPLICATIONS

Venous Thrombosis = First cause ofreplantation failure

Arterial thrombosis 3X> but the salvage rate ofdigital replantation complicated by arterialthrombosis is 30% whereas only 7% forvenous occlusion

Maximum risk during first 48 hrs

Speed Reaction < 24 -36 hrs

Removal of the dressing to release anyextrinsic compression

Return to the OR for anastomosis revision

Care should commence as soon as possibleonce vascular survival is confirmed.

Depends upon the strength of theosteosynthesis

Intrinsic part of the functional results

REHABILITATION CARE

www.materiel-pla-medical.fr

CONSENSUAL

INDICATIONS

Again--- many thanks for your recent letter and article. All I can say is congratulations; and I only wish I could have done it.

Successful replantation of a completely cut-off thumb. Komatsu and Tamai. Plastic Reconstr Surg 1968.

THE THUMB

Merle Classification

Merle and al. Chirurgie 1984.

The particularity of thehuman thumb positionmakes it uncomfortable forsurgery and even more sofor the microsurgery.

EVERYTHING MUST BE DONE DUE TO HIGH LEVEL OF HANDICAP

WHEN LOCAL ANASTOMOSIS IS POSSIBLE

WHEN LOCAL ANASTOMOSIS IS NOT POSSIBLE

When local anastomosis is difficult pre placement of venous interposition graft.

Proximal anastomosis at the snuff box.

30 year old man

Mixed crush and stripping injury

No dorsal vein available only dorsal collateraland ulnar palmar artery in the amputated part

PINCH TAKES PRIORITY OVER MOBILITY

EVEN IF IT SEEMS COMPLICATED…

Fukui and al. J Hand Surg Am 1990.

ARTERIO VENOUS SHUNT IN DIGIT REPLANTATION

Ulnar palmar artery anastomosed

Dorsal artery anastomosed with radial dorsal vein

Le lambeau cerf-volantFoucher. Ann Chir 1978.

VENOUS FLOW-THROUGH KITE FLAP

IN CASE OF DORSAL VEIN AND SKIN DEFECT

PRIMARY THUMB RECONSTRUCTION WITH SPARE FINGERS

When the thumb is missing

In case of multiple digit amputations

But not everything

WAIT AND SEE TO PRESERVE THE FUTURE

Delayed reconstruction by index stump pollicization wrapped with a partial great toe transfer

Barbato and al. J Hand Surg Eur 1998

DISTAL REPLANTATIONS

Good indications

Distal to FDS insertion

Simultaneous procedure on amputated part and hand

DIP Fusion and skeletal shortening

• Replantations digitales distales, Dautel and al. La Main 1997.• Fingertip replantation, Hatori and al. J Hand Surg Am 2007.• Distal and very distal digital replantations., Foucher. Br J Plast Surg 1992.• Twenty years’ experience of limb replantationreview of 293upper extremity

replants., Tamai S. J Hand Surg Am 1982.

ISHIKAWA CLASSIFICATION

Predetermines the possibility of repairing both an artery and a vein

From Zone 3 and above, the possibility of nerve, vein and artery repair

Nerve repair difficult above tuft zone

Suzuki and Ishikawa. Br J Plastic Surg 1993.

DISTAL ARTERY ANASTOMOSIS

Pulp central artery even more so with the detour of the arcade to permit length gain in case of artery defect and favor end-to-end anastomosis, in order to avoid a venous graft in this minute environment.

Ultra micro anastomosis 11-0 NYLON/50µm needle

First back wall repair: free clamp suture

Harris and al. Br J Past Surg 1981

WHEN VENOUS REPAIR IS POSSIBLE

Success rates of distal amputation to the DIP have been reported between 70 to 90%

Post-operative outcomes are favorable

Suzuki and al. Br J Plast Surg 1993.

Last Resort: Artery only replantation with controlled bleeding, leeches and AC therapy

3 or more anticoagulation agents increase the blood transfusion to 50%

Furnas and al. J Hand Surg Am 1992Buntic and al. J Hand Surg Am 2010

VENOUS REPAIR CAN BE DIFFICULT IN ZONES 2 AND 3

A-V fistula by anastomosing a second available artery to a palmar vein

SKIN CLOSURE IN DISTAL REPLANTATIONS

De-eperdimization of the stump skin, of the amputated part and the proximal digit bank, on 1-2mm closure is made then overlaying the two de-epidermized surfaces which increase the cutaneous surface contact and venous neoconnections

ZONE 3 REPLANTATION

MULTIPLE DIGIT AMPUTATIONS

Distal Multiple Digit Amputations

Attempts all digits with priority to the thumb

The Problems:

Proximal complex crush injury amputations

Multiple digit amputations and soft tissue loss

MULTIPLE DIGIT COMPLEX INJURY

Team concept for strategic decisions and multiple surgeons for simultaneous surgeries

Each patient is unique

Replantation priorities

Creative use of « spare parts bank » the most usable part in the most effective position with priority to the THUMB

Foucher. Ann Chir 1980.

MULTIPLE DIGIT COMPLEX INJURY

Additional procedure flap can lead to failure

Abdominal flap is uncomfortable

Local pedicle flap as forearm interrupts an artery flow

STRATEGIC DECISION MAKING IS THE MAIN POINT

Revascularisation attempt in the famous area up to the Flexor digitorum superficialis tendon insertion leads to poor functional outcome

This case can be discussed in other ways

USEFUL FUNCTION OF THE HAND

The number of digits useful for replantation drives the process along with the equilibrium for the most useful function of the hand

In any case the index postion is the one to be least considered

Rad

ial side fo

r pin

ch

Uln

ar side fo

r grasp

TRANSMETACARPAL AMPUTATION

This is a challenge in efficiency

Ischemia of the intrinsic muscles with resultant sclerosis and contracture

Vascularization of intrinsic muscles by palmar arcade

Resection of the involved intrinsic musculature and adequate metacarpal shortening (at least 12mm) should be considered

Meyer and alJ Bone Joint Surg Br 1976.

BLOOD FLOW RESTORATION

Direct VY vein graft

Direct arterial anastomosis when possible

or

VY venous graft

Foot dorsal arcade

Potency of one common digital vessel provides blood flow to all fingers through transverse and commissural skin arteries

Nakamura and al. J Microsurgery 1980.

Tonkin and al. J Hand Surg Br 1988.Salmon M, Masson 1936

BLOOD FLOW RESTORATION

TRANS METACARPAL REPLANTATION

RING FINGERS AVULSION

COMPLETE RING FINGER AVULSION

Challenging procedure

Controversial replantation

Undeserved badreputation

STAGE DESCRIPTION

I Circulation adequate with or without skeletal injury

II Circulation inadequate, no skeletal injury

IIA Arterial circulation inadequate only

IIB Venous circulation inadequate only

III Circulation inadequate with fracture or joint injury present

IIIA Arterial circulation inadequate only

IIIB Venous circulation inadequate only

IV Complete Amputation

IVd Amputation distal to the FDS* insertion

IVp Amputation proximal to the FDS insertion

* FDS: FlexorDigitalSuperficialis

• Urbaniak and al. J Hand Surg Am 1981• Kay et al. J Hand Sur Am 1989• Adani et al. J Reconstr Micro 1996

RING FINGER AMPUTATION

THE RECIPE

Short hemi-Bruner incision at DIP joint for artery location

No sheath splitting

Skeletal osteosynthesis using a needle cap as protection

The use of a vein graft increase the vascular success

Firstly: vein graft distally anastomosed

RING FINGER REPLANTATION

Subcutaneous passage of the venous graft and repositioning of the degloving part helped by sterile liquid vaseline

Proximal anastomosis close to the common palmar artery bifurcation

Dorsal veins anastomosis with Vilain flag cutaneous venous flap

Nerve repair difficult (stretching injury) the stretched nerve is inserted distal in the sheath in neurotization procedure

• Vilain. Plast Reconstr Surg 1973.

EARLY MOBILISATION OF THE UNINJURED PIP JOINT

Under medical care control

In order to avoid stiffness

LONG TERM RESULT

• TAM / 157• Hamouya and al. J Hansurg 2018

BECAUSE….

Young adults

Cold intolerance decrease with time

Stiffness is unusual if PIP joint useful

Low sensitivity does not affect function

Less than 10% of base metacarpal resections

Only one among replanted fingers

Even if primary resection has been recommended by few authors

In case of uninjured PIP. At least attempt replantation

SURGICAL EFFICIENCY FOR OPTIMIZED OUTCOMES IN DIGIT REPLANTATION

Basic Thumb Variation

Ring Finger Multi-digit and Transmetacarpal

1 Osteosynthesis 1 Arterial graft on amputated part

1 Arterial graft on amputated part

1 Osteosynthesis

2 Extensor tendon repair

2 Osteosynthesis 2 Osteosynthesis


3 Flexor tendon repair

3 Proximal arterial anastomosis


3 Vein repair/ Venous flap

4 Arterial repair/ reconstruction




5 Nerve repair/ reconstruction


5 Nerve repair or neurotization


6 Vein repair/ reconstruction




7 Skin Closure 7 Vein repair/ Venous flap

7 Skin Closure 7 Skin Closure

8 Dressing and splint

8 Skin Closure 8 Dressing and splint



: with or without tourniquet

Basic Thumb Variation

Ring Finger Multi-digit and Transmetacarpal

1 Osteosynthesis 1 Arterial graft on amputated part

1 Arterial graft on amputated part

1 Osteosynthesis


2 Osteosynthesis 2 Osteosynthesis












5 Nerve repair or neurotization


6 Vein repair/ reconstruction




7 Skin Closure 7 Vein repair/ Venous flap

7 Skin Closure 7 Skin Closure


8 Skin Closure 8 Dressing and splint



: with or without tourniquet

GUIDE TO WORKFLOW EFFICIENCY IN DIGIT REPLANTATION

1 o

r more

tourn

iquet ru

ns

CONCLUSION

EFFICIENCY DEPENDS ON LEARNING, TRAINING AND EXPERIENCE

+ =

SURVIVAL TISSUE DOES NOT EQUATE WITH FUNCTIONAL AND AESTHETIC OUTCOME

Documents

DIGIT REPLANTATIONS FROM BIOMECHANICS TO ......insufficiency, New York, 1983 Flow recirculation as in: Hathcock, Arteriosclerosis, Thrombosis, and Vascular Biology 2006-> Risk of Thrombosis