Microvascular Free Tissue TransferMicrovascular Free Tissue Transfer

Plastic SurgeryPlastic Surgery

Taipei Veterans General HospitalTaipei Veterans General Hospital

HistoryHistory• 1899 – Dorfler advocated use of all layers of vessels 1899 – Dorfler advocated use of all layers of vessels

in repairin repair• 1907 – (Carrel) “The Surgery of Blood Vessels” 1907 – (Carrel) “The Surgery of Blood Vessels” ((JH JH

Hospital Bull.Hospital Bull.))• 11stst replantation of canine limbs replantation of canine limbs• 11stst esophageal-intestinal interposition esophageal-intestinal interposition

• 1959 – (Seidenberg) human esophageal-intestinal 1959 – (Seidenberg) human esophageal-intestinal interpositioninterposition

• 1960 – (Jacobson/Suarez) operating microscope 1960 – (Jacobson/Suarez) operating microscope introduced (1 mm vessels)introduced (1 mm vessels)

• 1966 – (Antia/Buch) fasciocutaneous transfer1966 – (Antia/Buch) fasciocutaneous transfer• 1972 – (McLean/Buncke) omental flap to scalp1972 – (McLean/Buncke) omental flap to scalp

Advantages of free tissue transferAdvantages of free tissue transfer

• 2 team approach2 team approach• Improved vascularity and Improved vascularity and

wound healingwound healing• Low rate of resorptionLow rate of resorption• Defect size of little Defect size of little

consequenceconsequence• Potential for sensory and Potential for sensory and

motor innervationmotor innervation• Use of osseointegrated Use of osseointegrated

implantsimplants

Blood Flow RegulationBlood Flow Regulation• Skin blood flowSkin blood flow

• Varies constantlyVaries constantly• Maximal flow = 20x constricted flowMaximal flow = 20x constricted flow

• Extrinsic (Extrinsic ( receptors) receptors)• Sympathetics Sympathetics NE NE• Circulating catecholamines Circulating catecholamines NE & E NE & E

• shunt sphincters shunt sphincters extremely sensitive extremely sensitive to catecholsto catechols• Intrinsic Intrinsic

• Tissue metabolitesTissue metabolites• CO2, NO, lactate CO2, NO, lactate dilation dilation• potassium potassium constriction constriction

• Kinins, histamine, serotoninKinins, histamine, serotonin• ProstaglandinsProstaglandins

Free Flap PhysiologyFree Flap Physiology• Responses to IschemiaResponses to Ischemia

• SkinSkin• AnaerobicAnaerobic metabolism preferred (glycolysis) metabolism preferred (glycolysis)

• temperature regulation?temperature regulation?• allows prolonged periods of anoxiaallows prolonged periods of anoxia

• MuscleMuscle• AerobicAerobic metabolism essential (TCA cycle) metabolism essential (TCA cycle)

• 2 hr anoxia – immediate recovery2 hr anoxia – immediate recovery• 4 hr anoxia – prolonged recovery (edema)4 hr anoxia – prolonged recovery (edema)• 6 hr anoxia – no recovery (necrosis/infection)6 hr anoxia – no recovery (necrosis/infection)

• little histololgic change until little histololgic change until reperfusionreperfusion• Bone/CartilageBone/Cartilage

• Needs dependent on activity of constituent cellsNeeds dependent on activity of constituent cells• Poor studiesPoor studies

Microcirculatory Response to IschemiaMicrocirculatory Response to Ischemia

• Endothelial responseEndothelial response• AerobicAerobic metabolism metabolism extremely importantextremely important

• irreversibleirreversible injury in 2.5 min of anoxia injury in 2.5 min of anoxia• endothelial swelling narrows lumenendothelial swelling narrows lumen• complete regeneration in 7 – 10 days complete regeneration in 7 – 10 days

(monocytes/pleuropotential myoepithelial cells)(monocytes/pleuropotential myoepithelial cells)• Erythrocyte sludgingErythrocyte sludging

• stiff walls with low pHstiff walls with low pH• reduced with hematocrit below 30%reduced with hematocrit below 30%

• Leukocyte adherenceLeukocyte adherence• Interstitial swellingInterstitial swelling

• increases capillary pressureincreases capillary pressure

Consequences of Vascular InjuryConsequences of Vascular Injury• EndotheliumEndothelium

• Actively produces PGIActively produces PGI22• vasodilatorvasodilator• acts on distal arteriolesacts on distal arterioles

• Basement membraneBasement membrane• Exposed following Exposed following

endothelial lossendothelial loss• Potent activator of plateletsPotent activator of platelets• Rapid growth of clot (TxARapid growth of clot (TxA22))

• vasoconstrictionvasoconstriction• vascular occlusionvascular occlusion

• Muscularis and adventitiaMuscularis and adventitia• Heals with scar depositionHeals with scar deposition• Extensive injury leads to Extensive injury leads to

patency and aneurysmpatency and aneurysm

Principles of MicrosurgeryPrinciples of Microsurgery

• Macrocirculation of Macrocirculation of Composite TissueComposite Tissue• Segmental vasculature Segmental vasculature

(axial flaps)(axial flaps)• skin/fasciaskin/fascia• skin/fascia & muscleskin/fascia & muscle• skin/fascia & bone +/- skin/fascia & bone +/-

musclemuscle

• Vessels 0.8 to 4 mm Vessels 0.8 to 4 mm appropriate for transferappropriate for transfer

Factors Affecting Anastomosis Factors Affecting Anastomosis PatencyPatency

• TechnicalTechnical• Flow factorsFlow factors

• TurbulenceTurbulence• Smaller vessels more sensitiveSmaller vessels more sensitive

• Coagulation FactorsCoagulation Factors• PGIPGI22 vasodilation vasodilation• TxATxA22 vasoconstriction vasoconstriction

• SpasmSpasm• Vessel handlingVessel handling• Blood, temperature, desiccationBlood, temperature, desiccation• Circulating catecholaminesCirculating catecholamines

• smokingsmoking• sympathetic activity sympathetic activity

stress/exogenous stress/exogenous -agonists-agonists

Advantages of free tissue transferAdvantages of free tissue transfer

• Wide variety of available tissue Wide variety of available tissue typestypes

• Large amount of composite Large amount of composite tissue tissue

• Tailored to match defectTailored to match defect• Wide range of skin Wide range of skin

characteristicscharacteristics• More efficient use of harvested More efficient use of harvested

tissuetissue• Immediate reconstructionImmediate reconstruction

Recipient vesselsRecipient vessels• ArteriesArteries

• Superficial temporal system Superficial temporal system –scalp –scalp and upper faceand upper face

• Facial artery—midface and Facial artery—midface and cervical region cervical region (atherosclerosis common)(atherosclerosis common)

• Superior thyroid or lingual Superior thyroid or lingual artery—lower cervical artery—lower cervical regionregion

• Other: thyrocervical trunk, Other: thyrocervical trunk, external carotid, common external carotid, common carotidcarotid

Recipient vesselsRecipient vessels• VeinsVeins

• External jugularExternal jugular• Branches of internal Branches of internal

jugular (common facial)jugular (common facial)• Internal jugularInternal jugular• Retrograde (superficial Retrograde (superficial

temporal, thyroid)temporal, thyroid)• Transverse cervical, Transverse cervical,

occipital (very small)occipital (very small)

Recipient vessels after previous neck Recipient vessels after previous neck dissectiondissection

• Gold standard: Angiogram (short-term Gold standard: Angiogram (short-term injury to endothelium reported)injury to endothelium reported)

• Operative reportsOperative reports• Long-pedicled flapsLong-pedicled flaps• Thyrocervical trunk (transverse Thyrocervical trunk (transverse

cervical), Occipital vessels, retrograde cervical), Occipital vessels, retrograde drainage (thyroid veins, superficial drainage (thyroid veins, superficial temporal), external carotid artery temporal), external carotid artery

• Contralateral vessels (recipient or graft)Contralateral vessels (recipient or graft)• End-to-side anastomoses with large End-to-side anastomoses with large

vessels vessels • Vein graftsVein grafts• Arteriovenous loop (poorer results)Arteriovenous loop (poorer results)

Vessel selectionVessel selection

• Size Size • Arterial vs.VenousArterial vs.Venous

• Atherosclerosis Atherosclerosis • XRT-related changesXRT-related changes• Vessel geometry Vessel geometry

(location and (location and orientation)orientation)

• Vessel lengthVessel length

Vessel preparationVessel preparation

• Arteries need to have strong pulsatile flow—Arteries need to have strong pulsatile flow—cut until it flows. cut until it flows.

• Cut back beyond branches or ligate them if Cut back beyond branches or ligate them if sufficiently distant from the anastomosis site.sufficiently distant from the anastomosis site.

• AtherosclerosisAtherosclerosis• Intimal inspectionIntimal inspection• DilationDilation• Removing the adventitiaRemoving the adventitia

Irradiated vesselsIrradiated vessels• Technically more difficult—effects appear specific to Technically more difficult—effects appear specific to

arteriesarteries• Higher incidence of atherosclerosisHigher incidence of atherosclerosis• Vessel wall fibrosis, increased wall thickness, more Vessel wall fibrosis, increased wall thickness, more

intimal dehiscenceintimal dehiscence• No reported difference in outcome of microvascular No reported difference in outcome of microvascular

anastomoses anastomoses (Nahabedian MY, et al., 2004, Kroll SS, et al 1998)(Nahabedian MY, et al., 2004, Kroll SS, et al 1998)• Microvascular anastomoses tolerate XRT well long-Microvascular anastomoses tolerate XRT well long-

term term (Foote RL., et al., 1994)(Foote RL., et al., 1994)• Require careful handling, cut off clot (teasing thrombi Require careful handling, cut off clot (teasing thrombi

may denude vessel wall—”sticky” walls), smaller may denude vessel wall—”sticky” walls), smaller suture, needle introduced from lumen to outside wall suture, needle introduced from lumen to outside wall (to pin intima to wall)(to pin intima to wall)

Microvascular AnastomosisMicrovascular Anastomosis• Prepare vesselsPrepare vessels

• Evaluate vessel geometryEvaluate vessel geometry• Trim, irrigate, dilateTrim, irrigate, dilate

• Partial flap insetting (bony Partial flap insetting (bony cuts and plating done at cuts and plating done at donor bed, if necessary)donor bed, if necessary)

• Arterial vs. venous Arterial vs. venous anastomosis first with early anastomosis first with early or delayed unclamping of or delayed unclamping of first vessel showed no first vessel showed no difference. difference. (Braun, et al., 2003(Braun, et al., 2003))

• Anastomosis of remaining Anastomosis of remaining vesselvessel

• Complete flap insettingComplete flap insetting

Microvascular surgical techniqueMicrovascular surgical technique

• Trim adventitiaTrim adventitia• 2-3mm2-3mm• Gentle handling (no full-Gentle handling (no full-

thickness)thickness)• Trim free edge, if neededTrim free edge, if needed• Dissect vessels from Dissect vessels from

surrounding tissuessurrounding tissues• Irrigate and dilateIrrigate and dilate

• Heparinized salineHeparinized saline• Mechanical dilation (1 ½ times Mechanical dilation (1 ½ times

normal –paralyses smooth normal –paralyses smooth muscle)muscle)

• Chemical dilation, if necessaryChemical dilation, if necessary• SuturingSuturing

Microvascular suture techniqueMicrovascular suture technique• 3 guide sutures (120 3 guide sutures (120

degrees apart)degrees apart)• Perpendicular piercingPerpendicular piercing• Entry point 2x thickness of Entry point 2x thickness of

vessel from cut endvessel from cut end• Equal bites on either sideEqual bites on either side• Microforceps in lumen vs. Microforceps in lumen vs.

retracting adventitiaretracting adventitia• Pull needle through in Pull needle through in

circular motioncircular motion• Surgeon’s knot with guide Surgeon’s knot with guide

sutures, simple for otherssutures, simple for others• Avoid backwalling—2 Avoid backwalling—2

bites/irrigationbites/irrigation

3 suture technique3 suture technique

Vessel size mismatchVessel size mismatch

• Laminar flow vs. turbulent flowLaminar flow vs. turbulent flow• <2:1 – dilation, suture technique<2:1 – dilation, suture technique• >2:1, <3:1 – beveling or spatulation (no more than 30 >2:1, <3:1 – beveling or spatulation (no more than 30

degrees to avoid turbulence)degrees to avoid turbulence)• >3:1 – end-to-side>3:1 – end-to-side

End-to-end vs. End-to-sideEnd-to-end vs. End-to-side

• Recent reports indicate end-to-side without Recent reports indicate end-to-side without increase in flap loss or blood flow rate.increase in flap loss or blood flow rate.

• End-to-side overcomes size discrepancy, End-to-side overcomes size discrepancy, avoids vessel retraction, and IJ may act as avoids vessel retraction, and IJ may act as venous siphon.venous siphon.

• End-to-side felt best when angle is less than 60 End-to-side felt best when angle is less than 60 degrees (minimize turbulence)degrees (minimize turbulence)

• Vessel incision should be elliptical, not slitVessel incision should be elliptical, not slit• Can use continuous suture techniqueCan use continuous suture technique

End-to-side AnastomosisEnd-to-side Anastomosis

Continuous suture techniqueContinuous suture technique

• May significantly narrow anastomosisMay significantly narrow anastomosis• May be used on vessels >2.5 mmMay be used on vessels >2.5 mm• Decreases anastomosis time by up to Decreases anastomosis time by up to

50%50%• Decreases anastomosis leakageDecreases anastomosis leakage• Most commonly used for end-to-side Most commonly used for end-to-side

anastomoses with large vesselsanastomoses with large vessels

Mechanical anastomosisMechanical anastomosis• DevicesDevices

• ClipsClips• CouplerCoupler• LaserLaser

• ResultsResults• Increased efficiency and Increased efficiency and

speed, use in difficult areasspeed, use in difficult areas• Patency rates at least equal Patency rates at least equal

to hand-sewn to hand-sewn (Shindo, et al (Shindo, et al 1996, De Lorenzi, et al 2002)1996, De Lorenzi, et al 2002)

• Can be used for end-to-end Can be used for end-to-end or end-to-side or end-to-side (DeLacure, et al (DeLacure, et al 1999)1999)

• Poorer outcome with arterial Poorer outcome with arterial anastomosis—20-25% failure anastomosis—20-25% failure (Shindo, et al 1996, Ahn, et al (Shindo, et al 1996, Ahn, et al 1994)1994)

Vein graftsVein grafts• Used in situation where pedicle is not long enough for Used in situation where pedicle is not long enough for

tension-free anastomosistension-free anastomosis• Usually harvested from lower extremity (saphenous Usually harvested from lower extremity (saphenous

system)system)• Valve orientation is necessaryValve orientation is necessary• Avoid anastomosis at level of vein valveAvoid anastomosis at level of vein valve• Keep clamps in place until both anastomoses sewnKeep clamps in place until both anastomoses sewn• Prognosis for success controversial Prognosis for success controversial (Jones NF, et al., (Jones NF, et al.,

1996, German, et al. 1996)1996, German, et al. 1996)• Recent literature Recent literature

Microvascular Hints & HelpsMicrovascular Hints & Helps• Use background to help Use background to help

visualize suturevisualize suture• Demagnetize instruments, if Demagnetize instruments, if

neededneeded• May reclamp vessels for May reclamp vessels for

repair after 15 minutes of repair after 15 minutes of flowflow

• Reclamp both arterial and Reclamp both arterial and venous vessels when venous vessels when revising venous anastomosisrevising venous anastomosis

• Support your hands and hold Support your hands and hold instruments like a pencilinstruments like a pencil

Ischemia Ischemia • Primary and secondaryPrimary and secondary

• Primary: 2.25-6 hoursPrimary: 2.25-6 hours• Secondary: 1-12 hours Secondary: 1-12 hours • Interrelation Interrelation • No flow phenomenonNo flow phenomenon

• Cold vs. normothermic Cold vs. normothermic • In vitro studies show benefit to cooling of flapsIn vitro studies show benefit to cooling of flaps• In vivo studies show surface cooling (<4hr ischemia time) In vivo studies show surface cooling (<4hr ischemia time)

does not adversely effect flap success does not adversely effect flap success (Shaw W. et al 1996)(Shaw W. et al 1996)• Tissue specific critical ischemia timesTissue specific critical ischemia times

• Metobolic rate dependentMetobolic rate dependent• Perfusates (UW, tissusol, Viaspan, Heparin)Perfusates (UW, tissusol, Viaspan, Heparin)

• Literature unclearLiterature unclear

Anastomotic failureAnastomotic failure• 93-95% success rate expected93-95% success rate expected• Venous thrombosis:Arterial thrombosis 4:1, ateriovenous loop, Venous thrombosis:Arterial thrombosis 4:1, ateriovenous loop,

tobacco use significant factors tobacco use significant factors (Nahabedian M., et al, 2004)(Nahabedian M., et al, 2004) Other Other literature indicates 9/10 thromboses secondary to venous literature indicates 9/10 thromboses secondary to venous thrombusthrombus

• Tobacco use as contribution controversial (4/5 failures in Tobacco use as contribution controversial (4/5 failures in Nahabedian study - venous thrombosis)Nahabedian study - venous thrombosis)

• Venous occlusion, Delayed reconstruction, Hematoma Venous occlusion, Delayed reconstruction, Hematoma significant factors in breast free tissue recon. significant factors in breast free tissue recon. (Nahabedian M., et al, (Nahabedian M., et al, 2004)2004)

• Salvage 50% in breast reconstructionSalvage 50% in breast reconstruction• Age, prior irradiation, DM (well-controlled), method of Age, prior irradiation, DM (well-controlled), method of

anastomosis, timing, vein graft, and specific arteries/veins not anastomosis, timing, vein graft, and specific arteries/veins not felt to contribute to failure ratefelt to contribute to failure rate

Anastomotic Failure--timelineAnastomotic Failure--timeline

• 15-20 minutes15-20 minutes• <72 hours<72 hours• 5-7 days5-7 days• >8 days >8 days

• Thin vs. thick flapsThin vs. thick flaps

Thrombus formationThrombus formation• Injury to endothelium and media of vesselInjury to endothelium and media of vessel

• Mechanical vs. thermalMechanical vs. thermal• Error in suture placementError in suture placement

• Backwall or loose suturesBackwall or loose sutures• Edges not well-aligned (most common in veins—most common Edges not well-aligned (most common in veins—most common

site of thrombus)site of thrombus)• Intimal discontinuity with exposure of mediaIntimal discontinuity with exposure of media

• Oblique sutures, large needles, tight knotsOblique sutures, large needles, tight knots• InfectionInfection• Hypovolemia and low flow statesHypovolemia and low flow states

• Nitroprusside at dose to decrease arterial pressure by 30% Nitroprusside at dose to decrease arterial pressure by 30% causes severe reduction in flap blood flow (40%) causes severe reduction in flap blood flow (40%) (Banic, et al. (Banic, et al. 2003)2003)

• Vessel geometry (kinking, tension)Vessel geometry (kinking, tension)

Vessel spasmVessel spasm• CausesCauses• TraumaTrauma• Contact with bloodContact with blood• Vasoconstrictive drugs Vasoconstrictive drugs

• Phenylephrine--dose causing 30% increase in arterial Phenylephrine--dose causing 30% increase in arterial pressure shows no effect on flap circulation pressure shows no effect on flap circulation (Banic A, et al., (Banic A, et al., 1999) 1999)

• NicotineNicotine• Temperature, dryingTemperature, drying

• TreatmentTreatment• WarmthWarmth• XylocaineXylocaine• Papavarine, thorazinePapavarine, thorazine• Volume repletionVolume repletion

Treatement for anastomotic failureTreatement for anastomotic failure

• Revision of anastomosesRevision of anastomoses• Exploration of woundExploration of wound• Streptokinase, urokinase, rt-PA Streptokinase, urokinase, rt-PA (Atiyeh BS, et al 1999)(Atiyeh BS, et al 1999)• Leech therapyLeech therapy• Wound careWound care• StatisticsStatistics

• Revisions successful in 50%Revisions successful in 50%• Revisions less successful after first 24-48hrRevisions less successful after first 24-48hr• >6 hrs of ischemia leads to poor survival>6 hrs of ischemia leads to poor survival• 12 hrs of ischemia leads to “no-flow” phenomenon12 hrs of ischemia leads to “no-flow” phenomenon• After 5 days almost all flaps in rabbit model survived with loss After 5 days almost all flaps in rabbit model survived with loss

of artery or vein (but not both)—this is rational for other of artery or vein (but not both)—this is rational for other modalities after 48 hoursmodalities after 48 hours

Post-operative carePost-operative care• AnticoagulationAnticoagulation• Attention to wound careAttention to wound care• Flap monitoring Flap monitoring • Nothing around neck that Nothing around neck that

might compress pediclemight compress pedicle• Antibiotics Antibiotics • Hemoglobin/intravascular Hemoglobin/intravascular

volume—literature unclear volume—literature unclear (Velanovich V., et al 1988, Quinlan (Velanovich V., et al 1988, Quinlan 2003) 2003)

• No pressors/nicotine/cooling No pressors/nicotine/cooling of flap (literature unclear)of flap (literature unclear)

AnticoagulationAnticoagulation• RheologyRheology

• RBC concentrationRBC concentration• Plasma viscosityPlasma viscosity• RBC aggregationRBC aggregation• RBC deformability RBC deformability • Other (platelets, thrombogenic mediators)Other (platelets, thrombogenic mediators)

• AgentsAgents• AspirinAspirin• HeparinHeparin• DextranDextran• OtherOther

• IndicationsIndications• Hypercoagulable state Hypercoagulable state (Friedman G, et al, 2001)(Friedman G, et al, 2001)• Excessive vessel traumaExcessive vessel trauma

• ComplicationsComplications

DextranDextran• Macromolecule which is a compound of glucose subunitMacromolecule which is a compound of glucose subunit• Thought to improve RBC flexibility, increase electronegativity of Thought to improve RBC flexibility, increase electronegativity of

vessel wall (which decreases platelet adhesion), act as vessel wall (which decreases platelet adhesion), act as intravascular volume expander, decrease RBC aggregationintravascular volume expander, decrease RBC aggregation

• Shown to decrease clotting secondary to exposed collagen in Shown to decrease clotting secondary to exposed collagen in rabbit arteries. Little effect on platelet, rather inhibits fibrin rabbit arteries. Little effect on platelet, rather inhibits fibrin stabilization of thrombi stabilization of thrombi (Weislander, JB, et al., 1986)(Weislander, JB, et al., 1986)

• No effect on overall flap survival when compared with aspirin. No effect on overall flap survival when compared with aspirin. Systemic complications 3.9-7.2 times more common with Systemic complications 3.9-7.2 times more common with dextran infusion dextran infusion (Disa J., et al, 2001)(Disa J., et al, 2001)

• Complications can include renal damage, anaphylactic shock, Complications can include renal damage, anaphylactic shock, congestive heart failure, MI, pulmonary edema, pleural effusion, congestive heart failure, MI, pulmonary edema, pleural effusion, pneumoniapneumonia

AspirinAspirin• Prevent platelet thrombosisPrevent platelet thrombosis• Inhibits arachidonic acid to prostaglandin synthesis Inhibits arachidonic acid to prostaglandin synthesis

on the platelet—prevents release of platelet on the platelet—prevents release of platelet granuoles that cause platelet aggregation. granuoles that cause platelet aggregation. Mechanism is biphasic and dose-dependantMechanism is biphasic and dose-dependant

• High doses of aspirin can have negative effect on High doses of aspirin can have negative effect on endothelial production of prostacyclin which endothelial production of prostacyclin which prevents platelet accumulation on exposed prevents platelet accumulation on exposed collagen and dilates vessels.collagen and dilates vessels.

• ASA PR qd x several weeks (often given at ASA PR qd x several weeks (often given at beginning of case)—5 grains (325 mg)beginning of case)—5 grains (325 mg)

• No good studies to confirm benefit of useNo good studies to confirm benefit of use• Hematoma formationHematoma formation

HeparinHeparin• Naturally occuring glycosoaminoglycan which interrupts clotting Naturally occuring glycosoaminoglycan which interrupts clotting

cascadecascade• Prevents transformation of prothrombin to thrombin, fibrinogen to fibrinPrevents transformation of prothrombin to thrombin, fibrinogen to fibrin• Does not lyse existing thrombiDoes not lyse existing thrombi

• Strongly adheres to endotheliumStrongly adheres to endothelium• Concentration on endothelium 100x serumConcentration on endothelium 100x serum

• ½ life = 90 minutes½ life = 90 minutes• Given at time of first quarter of arterial anastomoses vs. at time of Given at time of first quarter of arterial anastomoses vs. at time of

unclamping (bolus only vs. bolus with drip x 3 days)unclamping (bolus only vs. bolus with drip x 3 days)• Literature unconvincing, although it may increase microvascular Literature unconvincing, although it may increase microvascular

perfusion after ischemiaperfusion after ischemia• Hematoma formationHematoma formation• Used as irrigation solutionUsed as irrigation solution• Local infusion may possibly be beneficialLocal infusion may possibly be beneficial

Low molecular weight heparinLow molecular weight heparin• Appears to decrease vessel thrombosis in renal Appears to decrease vessel thrombosis in renal

transplants transplants

• Broyer M, et al.,1991, Alkhunaizi AM, et al, 1998Broyer M, et al.,1991, Alkhunaizi AM, et al, 1998

Flap monitoringFlap monitoring• Clinical –”flap checks”Clinical –”flap checks”

• Most commonly usedMost commonly used• WarmthWarmth• ColorColor• Pin prickPin prick• Wound monitoring (hematoma, fistula)Wound monitoring (hematoma, fistula)• Frequency Frequency

• MechanicalMechanical• Doppler Doppler

• Implanted vs. external vs. color flowImplanted vs. external vs. color flow• OtherOther

Clinical flap monitoringClinical flap monitoring• Normal exam:Normal exam:

• Warm, good color, CRT 2-3 seconds, pinprick Warm, good color, CRT 2-3 seconds, pinprick slightly delayed with bright red bloodslightly delayed with bright red blood

• Venous occlusion (delayed):Venous occlusion (delayed):• Edema, mottled/purple/petechiae, tenseEdema, mottled/purple/petechiae, tense• CRT decreasedCRT decreased• Pinprick – immediate dark blood, won’t stopPinprick – immediate dark blood, won’t stop

• Arterial occlusion (usually <72hr):Arterial occlusion (usually <72hr):• Prolonged CRT, temperature, turgorProlonged CRT, temperature, turgor• PalePale• Pinprick—little bleeding, very delayedPinprick—little bleeding, very delayed

Mechanical flap monitoringMechanical flap monitoring

• DopplerDoppler• ExternalExternal• ImplantedImplanted

• Buried flapsBuried flaps• 80-100% salvage 80-100% salvage

(Disa J, et (Disa J, et al 1999)al 1999)

• Color flowColor flow• OtherOther

AntibioticsAntibiotics• 8-20% of patients undergoing free tissue 8-20% of patients undergoing free tissue

transfer will develop an infection despite transfer will develop an infection despite intravenous antibiotic coverageintravenous antibiotic coverage.(Cloke DJ., et al, .(Cloke DJ., et al, 2004)2004)

• 1 day vs. 5 day course of Clindamycin 1 day vs. 5 day course of Clindamycin showed no significant difference in free flap showed no significant difference in free flap survival survival (Carroll WR., et al., 2003)(Carroll WR., et al., 2003)

• Topical antibiotics in combination with Topical antibiotics in combination with intervenous antibiotics did not show a intervenous antibiotics did not show a significant difference in post-operative significant difference in post-operative complications after free tissue transfer complications after free tissue transfer (Simons (Simons JP, et al., 2001)JP, et al., 2001)

Free flap reconstructionFree flap reconstruction

• Longer ICU stay, Longer ICU stay, • More expensive, More expensive, • Longer OR time Longer OR time