principles of microvascular surgery

PRINCIPLES OF PRINCIPLES OF MICROVASCULAMICROVASCULA

R SURGERYR SURGERY-Dr.sumer yadav-Dr.sumer yadav

dr sumer yadav (mch plastic and reconstructive surgery); [email protected]

INTRODUCTIONINTRODUCTION►MICROSCOPEMICROSCOPEMICROSURGERYMICROSURGERYMICROVASCULAR SURGERYMICROVASCULAR SURGERYRECONSTRUCTIVE RECONSTRUCTIVE

MICROSURGERYMICROSURGERY


HISTORYHISTORY►1590- Invention of compound 1590- Invention of compound

microscope by Zacharia Janseenmicroscope by Zacharia Janseen►1897- First vascular anastomosis by 1897- First vascular anastomosis by

J.B.MurphyJ.B.Murphy►1902- End to end anastomosis by 3-stay 1902- End to end anastomosis by 3-stay

suture technique by Alexis Carrelsuture technique by Alexis Carrel►1965- First digital replantation by Tamai1965- First digital replantation by Tamai►1968- First successful toe to thumb 1968- First successful toe to thumb

transfer by Cobbetttransfer by Cobbettdr sumer yadav (mch plastic and reconstructive

surgery); [email protected]

►1968- First free flap in Bombay,India by 1968- First free flap in Bombay,India by Antia and Buch(Use of Antia and Buch(Use of dermatolipomatous groin flap to fill a dermatolipomatous groin flap to fill a facial defect)facial defect)

►1970- First completely successful free 1970- First completely successful free flap operation in Oakland,California by flap operation in Oakland,California by Mclean and BunckeMclean and Buncke

►1973- First composite flap (groin flap) 1973- First composite flap (groin flap) by Danielby Daniel


TOOLS IN MICROSURGERYTOOLS IN MICROSURGERY1. SURGICAL MICROSCOPE:1. SURGICAL MICROSCOPE:

- 4 to 40x magnification- 4 to 40x magnification- Double-headed system- Double-headed system

- Foot control of focus - Foot control of focus and zoomand zoom - Interchangeable - Interchangeable eyepieceeyepiece - Fiber-optic - Fiber-optic light source light source


2. MAGNIFYING LOUPES2. MAGNIFYING LOUPES *Types:*Types: a. compound loupesa. compound loupes b. b.

prismatic loupes (wide-angle prismatic loupes (wide-angle loupes)loupes) - For hand surgery and - For hand surgery and dissection of dissection of flaps : 2.5x flaps : 2.5x magnification magnification -- For anastomosis : 3.5x or 4.5x For anastomosis : 3.5x or 4.5x magnification-- Working distance : 25 magnification-- Working distance : 25 to 50 cmto 50 cm


3. MICROINSTRUMENTS3. MICROINSTRUMENTS►ScissorsScissors►Needle holdersNeedle holders►ForcepsForceps►ClampsClamps►Bipolar CoagulatorBipolar Coagulator


PULP TO PULP PINCHPULP TO PULP PINCHdr sumer yadav (mch plastic and reconstructive


4. MICROSUTURES4. MICROSUTURES►Most commonly used- Nylon and Most commonly used- Nylon and

ProleneProlene►Size: 7-0 to 12-0Size: 7-0 to 12-0►MICRONEEDLES: 3/8 circle taper-MICRONEEDLES: 3/8 circle taper-

pointed needles with a diameter range pointed needles with a diameter range of 30 to 150 micron are preferredof 30 to 150 micron are preferred

►When not in use the needle can be When not in use the needle can be placed in the foam in an inclined placed in the foam in an inclined position ready for easy lifting position ready for easy lifting


PREREQUISITES FOR PREREQUISITES FOR MICROSURGEYMICROSURGEY

►COMFORTABLE POSITIONCOMFORTABLE POSITION

►PATIENCEPATIENCE

►GOOD PLANNINGGOOD PLANNING

►ADEQUATE EXPOSUREADEQUATE EXPOSUREdr sumer yadav (mch plastic and reconstructive


BASIC PRINCIPLES OF BASIC PRINCIPLES OF MICROSURGERYMICROSURGERY

1. Gentle handling of 1. Gentle handling of tissuestissues*Avoid grasping the *Avoid grasping the ends of the vessels ends of the vessels to be anastomosedto be anastomosed *Grasp only a small *Grasp only a small quntity of loose quntity of loose periadventitiaperiadventitia


2. ADEQUATE DEBRIDEMENT2. ADEQUATE DEBRIDEMENT► Inspect under high Inspect under high

power for signs of power for signs of damagedamage

► Debride until no Debride until no signs of vessel signs of vessel damagedamage

► Strong pulsatile flow Strong pulsatile flow of blood after of blood after adequate adequate debridementdebridement


3.RELIEF OF SPASM3.RELIEF OF SPASM►Mechanical dilatationMechanical dilatation

►Hydrodistention of the vein graftHydrodistention of the vein graft

►Pharmacologic measures Pharmacologic measures

► Moist gauge soaked in warm saline Moist gauge soaked in warm saline dr sumer yadav (mch plastic and reconstructive


4. SIMILAR DIAMETER OF 4. SIMILAR DIAMETER OF VESSELSVESSELS

Vessels with dissimilar diameter Vessels with dissimilar diameter upto 50% can be anastomosed upto 50% can be anastomosed satisfactorilysatisfactorily


►Small vessel is Small vessel is dilated and dilated and divided obliquely divided obliquely to give adequate to give adequate symmetrysymmetry

►When the size When the size discrepancy is discrepancy is much greater, an much greater, an interposing vein interposing vein graft is usedgraft is used


5. TENSION-FREE 5. TENSION-FREE ANASTOMOSISANASTOMOSIS

►Apply an adjustable approximating Apply an adjustable approximating clamp to bring the vessel end together clamp to bring the vessel end together for convenient suturingfor convenient suturing

►Never apply clamp with excess tensionNever apply clamp with excess tension►Avoid any kinking or twisting of the Avoid any kinking or twisting of the

vessels distal to the anastomosisvessels distal to the anastomosis


6. CORRECT SUTURE 6. CORRECT SUTURE TENSIONTENSION

►Not too tight or too loose suturesNot too tight or too loose sutures►Too tight sutures- Avoided by a small Too tight sutures- Avoided by a small

“suture circle” at the “suture circle” at the end of three tiesend of three ties


7. APPROPRIATE SUTURE SPACING:7. APPROPRIATE SUTURE SPACING:-Goal is to achieve an ultimately -Goal is to achieve an ultimately

leak-leak- free anastomosis with as free anastomosis with as few sutures few sutures as possibleas possible

8. RECHEK OF ANASTOMOSIS:8. RECHEK OF ANASTOMOSIS:-All anastomosis are rechecked -All anastomosis are rechecked

prior to prior to the final skin closurethe final skin closure


CHOICE OF RECIPIENT CHOICE OF RECIPIENT VESSELSVESSELS

►Use of healthy vessel of reasonable Use of healthy vessel of reasonable size with good outflow is the key for size with good outflow is the key for successsuccess

►Pre-operative assessmentPre-operative assessment

Mobilisation of vsselsMobilisation of vssels


DISSECTION TECHNIQUESDISSECTION TECHNIQUES►Hemostasis - must Hemostasis - must

*Vascular clips*Vascular clips*Bipolar coagulator*Bipolar coagulator

*Torniquet*Torniquet

►Avoid perivascular hematomaAvoid perivascular hematoma

► IrrigationIrrigation


PREPARATION OF VESSELSPREPARATION OF VESSELS►Plane of dissectionPlane of dissection►Retract the sheath by gentle Retract the sheath by gentle

pulling and remove itpulling and remove it►Vessels branchesVessels branches►BackgroundBackground►Moist fieldMoist field


TECHNIQUE OF TECHNIQUE OF ANASTOMOSIS ANASTOMOSIS

1.Resection to normal 1.Resection to normal vessels:vessels: - Resect - Resect proximal to areas proximal to areas with microscopic with microscopic signs of vessel signs of vessel damage with fine, damage with fine, straight, sharp straight, sharp scissors in a single scissors in a single motionmotion


Demonstration of forward pulsatile Demonstration of forward pulsatile flow prior to clampingflow prior to clamping


2.Clamping of 2.Clamping of vessels:vessels: - With - With double double approximating approximating clamp leaving clamp leaving generous length of generous length of vessel end for ease vessel end for ease of workingof working - - Tips of the jaws Tips of the jaws should project just should project just beyond the vessel beyond the vessel for maximal grip for maximal grip dr sumer yadav (mch plastic and reconstructive


Incorrect vertical positionIncorrect vertical positiondr sumer yadav (mch plastic and reconstructive


Incorrect horizontal positionIncorrect horizontal positiondr sumer yadav (mch plastic and reconstructive


3. Positioning: -Correct position of the clamp is 3. Positioning: -Correct position of the clamp is horizontal and parallel to the operatorhorizontal and parallel to the operator


4. Final Preparation of vessel 4. Final Preparation of vessel ends:ends:

► Resect sufficient Resect sufficient periadventitia, flush periadventitia, flush with the underlying with the underlying end to expose 2-3 end to expose 2-3 mm of the vessel mm of the vessel wall for suturing wall for suturing


►If the lumen is If the lumen is small or in small or in spasm, gently spasm, gently dilate it with dilate it with vessel dilatorvessel dilator


► Irrigate the lumen Irrigate the lumen with solution of with solution of heparinizedheparinized saline (1000 units saline (1000 units per 100 ml)per 100 ml)


5. SUTURING5. SUTURING►End to end / End to sideEnd to end / End to side►Full thickness of wallFull thickness of wall►Size of the suture materialSize of the suture material►Number of suturesNumber of sutures►Distance between suturesDistance between sutures►Arteries- more sutures than veinsArteries- more sutures than veins


► Pass the needle at Pass the needle at right angles to the right angles to the wall at a distance wall at a distance from the margin from the margin slightly greater( 1-slightly greater( 1-2 times for 2 times for arteries, 2-3 times arteries, 2-3 times for veins) than the for veins) than the thickness of the thickness of the vessel wallvessel wall


►Make sure that Make sure that the posterior wall the posterior wall is not accidentally is not accidentally coughtcought

►For last 2-3 For last 2-3 sutures:sutures: Modified Modified

HarshinaHarshinatechniquetechnique


► For thick walled For thick walled arteries and large arteries and large diameter collapsible diameter collapsible veins- use 180 veins- use 180 degree halving degree halving method ( first method ( first suture at 150 suture at 150 degree position and degree position and second suture at -second suture at -30 degree 30 degree


For thin walled For thin walled vessels, use 120 vessels, use 120 degree triangulating degree triangulating method for key method for key sutures( First suture sutures( First suture at 150 degree at 150 degree position and second position and second suture at +30 suture at +30 degree position)degree position)


VENOUS ANASTOMOSISVENOUS ANASTOMOSIS► Veins are thinner, Veins are thinner,

flatter and more flatter and more difficult to difficult to anastomoseanastomose

► Use ringer’s solution Use ringer’s solution to float or irrigate to float or irrigate the vesselthe vessel

► Deeper bitesDeeper bites► More suturesMore sutures


6.RELEASE OF CLAMPS6.RELEASE OF CLAMPS►The distal clamp is released firstThe distal clamp is released first► If any major leak, reapply the clamp, If any major leak, reapply the clamp,

irrigate and insert additional irrigate and insert additional superficial thickness sutures superficial thickness sutures

►Now release both the clamps- usually Now release both the clamps- usually small amount of blood leaks from small amount of blood leaks from anastomosis, but stops after a few anastomosis, but stops after a few min. with the application of sponges min. with the application of sponges


ALTERNATIVE ANASTOMOSIS ALTERNATIVE ANASTOMOSIS TECHNIQUESTECHNIQUES

1. BACK-WALL FIRST 1. BACK-WALL FIRST ( ONE-WAY UP) ( ONE-WAY UP) TECHNIQUE TECHNIQUE

-This technique is -This technique is safest because the safest because the entire inside of the entire inside of the anastomosis can anastomosis can be visualized until be visualized until the very last few the very last few sutures are placed sutures are placed


2. FLIPPING TECHNIQUE2. FLIPPING TECHNIQUE

When free flap, digit or vein graft is fixed fo mobile When free flap, digit or vein graft is fixed fo mobile vessel, it can be flipped to expose the back-wall vessel, it can be flipped to expose the back-wall for repair, as rotation is not possiblefor repair, as rotation is not possibledr sumer yadav (mch plastic and reconstructive


3. CONTINUOUS SUTURING3. CONTINUOUS SUTURING► Acceptable patency rates ( 92% for arteries, Acceptable patency rates ( 92% for arteries,

84% for veins) comparable with interrupted 84% for veins) comparable with interrupted suturessutures

► Advantages: Quicker and more hemostaticAdvantages: Quicker and more hemostatic► Disadvantages: Disadvantages: * Potential for creating * Potential for creating

purse-string constriction at the site of purse-string constriction at the site of anastomosisanastomosis * Entrapment of the suture * Entrapment of the suture material in the clampmaterial in the clamp * Breakage of the * Breakage of the suturesuture

► So less favourableSo less favourable


4. SLEEVE ANASTOMOSIS4. SLEEVE ANASTOMOSIS► Microanastomosis of Microanastomosis of

vessels in 1 mm vessels in 1 mm external diameter external diameter range can be range can be accomplished by accomplished by means of means of invaginating invaginating technique with fewer technique with fewer sutures than the end sutures than the end to end method of to end method of closureclosure


►Advantages:Advantages:- Quicker- Quicker

- Less intraluminal suture - Less intraluminal suture exposureexposure - Less vessel - Less vessel trauma owing to fewer trauma owing to fewer sutures sutures

►Disadvantages:Disadvantages:- Patency rate is significantly - Patency rate is significantly

less than that achieved by the less than that achieved by the conventional end to end method, so conventional end to end method, so it is not superior in clinical situationsit is not superior in clinical situations


END TO SIDE ANASTOMOSISEND TO SIDE ANASTOMOSIS► Indications: Indications:

*To preserve patency of the *To preserve patency of the recipient vessel in lower limb,esp. in recipient vessel in lower limb,esp. in elderly patients, where sacrifice of a elderly patients, where sacrifice of a major vessel can have a serious effect major vessel can have a serious effect on the distal blood flowon the distal blood flow*Considerable size or wall thickness *Considerable size or wall thickness mismatch between the vesselsmismatch between the vessels


Steps of end to side anastomosisSteps of end to side anastomosisdr sumer yadav (mch plastic and reconstructive surgery); [email protected]

An optional end to side anastomosisAn optional end to side anastomosisdr sumer yadav (mch plastic and reconstructive surgery); [email protected]

►Advantages:Advantages:- Search for recipient arteries is - Search for recipient arteries is

simplifiedsimplified- No. of possible sites to which - No. of possible sites to which

free flaps can be transferred is free flaps can be transferred is greatly increasedgreatly increased


PATENCYPATENCY►Return of colour Return of colour

►Capillary oozing and venous bleeding Capillary oozing and venous bleeding from the revascularized tissue from the revascularized tissue

►Direct inspection under the microscopeDirect inspection under the microscope ►Uplift testUplift test


PATENCY TESTPATENCY TEST► This is traumatic This is traumatic

and is performed as and is performed as gently and gently and infrequently as infrequently as possiblepossible


ANASTOMOTIC FAILUREANASTOMOTIC FAILUREA) TECHNICAL ERRORS:A) TECHNICAL ERRORS:1.1. TearingTearing2.2. LeakingLeaking3.3. NarrowingNarrowing4.4. Through-stitchingThrough-stitching5.5. Inclusion of adventitiaInclusion of adventitiaB) Poor flow from proximal vessel due to B) Poor flow from proximal vessel due to

undetected damage more proximally or undetected damage more proximally or vasospasmvasospasm


C) A clot or thrombus at the anastomotic site C) A clot or thrombus at the anastomotic site or in an area where a clamp was appliedor in an area where a clamp was applied

- Damage to endothelium fromDamage to endothelium from + Excessive clamp pressure+ Excessive clamp pressure

+ Poor technique or+ Poor technique or+ Contamination+ Contamination

- Prevention:Prevention:+ Flushing of the suture line with + Flushing of the suture line with

heparinized solutionheparinized solution+ Systemic heparin (40 u/kg before + Systemic heparin (40 u/kg before

completion of anastomosis and release of completion of anastomosis and release of clamps)clamps)


REVISION OF THE FAILED REVISION OF THE FAILED ANASTOMOSISANASTOMOSIS

►If the patency test reveals slow If the patency test reveals slow filling of the distal vessel, revise filling of the distal vessel, revise the anastomosis, carefully keeping the anastomosis, carefully keeping original problem in mindoriginal problem in mind

►Insert a vein graft, if the vessel Insert a vein graft, if the vessel length is insufficientlength is insufficient


*Poor proximal flow that does not *Poor proximal flow that does not respond to local vasodilator and respond to local vasodilator and warming may require:warming may require:

- Proximal exploration of the vesselProximal exploration of the vessel

- Dilatation along a proximal length Dilatation along a proximal length of vessel sufficient to relieve of vessel sufficient to relieve vasospasmvasospasm


FACTORS INFLUENCING FAILURE FACTORS INFLUENCING FAILURE OF ANASTOMOSISOF ANASTOMOSIS

A. TECHNICAL:A. TECHNICAL:► Both walls sutured togetherBoth walls sutured together► Traumatic vessel handlingTraumatic vessel handling► Apposition of vessel edgesApposition of vessel edges► Disproportional vessel sizeDisproportional vessel size► Tension at suture lineTension at suture line► Excessive clamp pressureExcessive clamp pressure► Kinking of vesselsKinking of vessels


B. REPERFUSION FAILURE:B. REPERFUSION FAILURE:

►Blood turbulenceBlood turbulence►SpasmSpasm►HypercoagulabilityHypercoagulability►AcidosisAcidosis►ColdCold►HypovolemiaHypovolemia►VasoconstrictorsVasoconstrictors


C. POSTOPERATIVE CARE:C. POSTOPERATIVE CARE:► InfectionInfection

►AcidosisAcidosis

►ColdCold

►Limb positionLimb position

►Environmental factorsEnvironmental factorsdr sumer yadav (mch plastic and reconstructive


POST-OPERATIVE MEASURESPOST-OPERATIVE MEASURES►Oxygen administationOxygen administation►Bed rest or limited movements for 3 to Bed rest or limited movements for 3 to

5 days5 days►Warm roomWarm room►Limb elevation to decrease the venous Limb elevation to decrease the venous

congestioncongestion►Fluid administrationFluid administration


►Adequate analgesiaAdequate analgesia►Limitation of visitors and telephone Limitation of visitors and telephone

calls to decrease the emotional stresscalls to decrease the emotional stress►Prohibition of smoking, caffeine and Prohibition of smoking, caffeine and

chocolate because they may cause chocolate because they may cause vasoconstrictionvasoconstriction


principles of microvascular surgery

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