Microsurgery involves surgery performed under magnification using specialized small instruments. It requires precise hand movements and suturing of small tissues and blood vessels. Proper equipment, techniques, and magnification are essential for achieving successful microsurgical reconstructions. The document outlines the principles, history, equipment, positioning, and technical aspects of microsurgery.

1. D R G AV I N A S H R A O
F E L L O W I N H A N D &
M I C R O S U R G E RY
S K I M S , S R I N A G A R
PRINCIPLES OF

2. Microsurgery
 Definition
 Surgery utilizing
magnification and
small, handheld
instruments and
sutures to correct
defects in small &/or
delicate tissues

3. INTRODUCTION
 Two main purposes of microsurgery are to transplant tissue from one
part of the body to another and to reattach amputated parts.
 It is incorrect to state that microsugery is simply a general term for
surgery requiring an operating microscope
 It is based on the fact that the human hand, by appropriate training, is
capable of performing finer movements than the naked eye is able to see.
 Magnification is a tool to lessen the effects of compromise in treatment
modalities
 The term MICROVASCULAR SURGERY was coined by JACOBSON

4. Microsurgical techniques include nerve and blood vessel repairs
and grafts, free tissue transfers, limb replantation, and composite
tissue allotransplantation.
Technical expertise, Preoperative planning and Post-Operative
monitoring are also critical in achieving a successful microsurgical
reconstruction.

5. HISTORY
► 1590- Invention of compound microscope by Zacharia
Janseen
► 1889- First successful end-to-end arterial anastomosis by
Jassinowski in sheep.
► 1897- First vascular anastomosis by J.B.Murphy in
humans
► 1902- End to end anastomosis by 3-stay suture technique by
Alexis Carrel.
► 1965- First digital replantation by Tamai
► 1968- First successful toe to thumb transfer by Cobbett

6. ► Guthrie and Carrel - inclusion of the INTIMA in repair laid the
foundations for standardization of anastomotic techniques.
► 1912 - Carrel – (Nobel Prize in Medicine and Physiology), First
described the technique of placing triangulating sutures to
ensure equal traction on the blood vessels being anastomosed.
► 1968- First free flap in Bombay,India by Antia and Buch (Use of
dermatolipomatous groin flap to fill a facial defect).
► 1970- First completely successful free flap operation in
Oakland,California by Mclean and Buncke.
► 1973- First composite flap (groin flap) by Daniel.

7. PRINCIPLES OF MICROSURGERY
 As a treatment philosophy, microsurgery incorporates three
important principles:
1.Improvement of motor skills, thereby enhancing surgical ability.
2.An emphasis on passive wound closure with exact primary
apposition of the wound edge.
3.The application of microsurgical instrumentation and suturing to
reduce tissue trauma.

8. MICROSURGICAL TRIAD

9. To do a job….you need the right tools

10. Microsurgery
 Differs from traditional surgery
in:
 Surgeon position
 Magnification
 Specialized
instrumentation
 Suture and needle size

11. EQUIPMENT FOR MICROSURGERY
 Good quality instruments – prefer own instruments
 Old wornout, battered instruments – not even
suitable for Lab training.
 Spring tension – appropriate.
Weak – closes early – hold the instrument gently with
tips 1-2mm apart and pronate forearm such that
instrument is upside down – falls down.
Firm – fatigue of thumb muscles – hold the instrument
gently closed for 10 min.

13. Jewellers forceps
 Straight pointed no.3 – non dominant hand for
tissue handling and suture tying.
 Tip precision – 1/1000 = diameter of 10.0
Nylon.
 Jaws should meet over 3mm (not only at tip)–
easy thread pickup

14. Angled jewellers forceps
 Reaching under vessel, tying knots, doing
patency test.
 Rest same as straight jewellers.

15. Needle holder
 Round handled, fine, fully curved jaws with a lock.
 Look for open gap at the at the point jaws closes
completely – thread traps.

17. Vessel dilator
 Modified jewellers forceps
 Slender, smoothly polished, non-tapering tip.
 Used for dilating vessel, counter pressure for
suturing.

18. Dissecting scissors
 Spring handled with gently curved blades, lightly
round at the tips.
 Rounded tips are important – enable to dissect
closely along a vessel with out perforating it,

19. Adventitia scissors
 Trimming adventitia off the vessel end.
 A pair of Fine straight, sharp pointed tip
microscissors.

20. Vessel clamps
 Collection of clamps required.
 One comparatively large sliding approximator clamp with built in
suture holding frame.
 A smaller plain approximator clamp
 Two small single clamps – small gentle jaws.
Larger – 11mm – harmless on vessels between 1.5 and 0.7 mm
diameter
Smaller – 8mm – less closing force for vessels between 1.0 and
0.4mm.
 Clamp applicator forceps.

21. Closing pressure (gms), area of vessel wall compressed by clamp
(mm2)
 Good clamp – Recommended closing pressure – 5-10gm/mm2 – large
vessels and 15-20 gm/mm2 on smaller vessels.
 For every vessel there will be two suitable clamp sizes – smaller clamp is
recommended to use.
0
2
4
6
8
10
12
B1 B2 B3 HD RD
5gm/mm2
10gm/mm
2
15gm/mm
2

22. Non microsurgical instruments.
 Autoclavable Instrument case.
 Hemolytic emzyme solution – contact time of 30 min - best to
clean microinstruments.
 Small fine flat jawed pliers – minor adjustments tip of jewellers.
 Instrument demagnetizer – simple hollow electric coil connected
to the regular AC supply – place instrument inside – swith on
current – slowly withdraw till it is 60cm away- then swit
 Sutures – flat bodied microvascular needles on 10.0 nylon. ch
off current.
100 microns needle – basic exercise.
75 microns needle for advanced exercise.
AVOID round bodied needles – difficult to control.

23. Magnification
 OPERATING MICROSCOPE
 MAGNIFICATION LOUPES-

24. Microscope
 Zeiss – Good Optics.
 Best focal length for objective lens is 200mm for
normal height, 300mm for very tall persons for
better working position
 Best eyepiece magnification is 12.5X.
 200mm + 12.5X gives magnification range between
4 to 20.
 Full floor column, adjustable supprt arm, foot
controls, inclinable eyepiece – in newer scopes –
required.
 Floor mounted / Ceiling mounted / Table mounted /
Portable

25. Care of microscope
 Clean outer glass surface of eyepiece and objective
lens each time – with lens tissue.
 Cover after use.
 Careful handling while moving.

26. Optical head has
 Primary surgeon
 Beam splitter
 Assistant surgeon
 Video attachment

27. OPERATING MICROSCOPE - Features
 Coaxial illumination.
 variable magnification
 motorized continuous zoom
 motorized focus
 motorized X-Y axis
 Foot controls adjust light, magnification, zoom, focus and X-Y
axis
 Allow multiple surgeons
 Floor, table or ceiling mount
 Additional attachments

28.  Operating Microscope
 magnification from 5-40x
 magnification of 5-20x is generally
sufficient.
 Increased cost and maintenance
 longer surgical setup time
 less intraoperative positioning flexibility
 less portability

29.  Center the X-Y axis
 Lowest magnification, Zero the fine focus.
 Adjust the gross focus manually
 Adjust the interpupillary distance
 Adjust the chair and table height
 Ensure the surgeons view and the video view are both in focus Verify at the
highest magnification to be used.
 Position all foot pedals where they can be reached
 Microscope pedal goes to the non- dominant foot
 Know Where All The Foot Pedal Controls Are Before Starting Surgery
 When seated, adjust gross focus by hand, not foot pedal.
Prior to surgery

30.  Surgeon is seated comfortably
 Feet reach the pedals
 Back is straight
 Arms at 90 degrees
 Lean slightly forward
 Arms on armrests
 Hands positioned and supported
 Rest on the ball of the hand or extend 5th finger for support
 Turn off room light and on microscope light
AT THE START OF SURGERY

31. Adjust table height
Adjust chair height
 Adjust microscope height
Adjust chair arm rest position
Set microscope fine focus to neutral Center X-Y axis
Adjust microscope tilt
Adjust interpupillary distance
Set microscope to highest magnification to be used
Adjust focus of oculars
Ensure video and assistant images are also in focus
Return microscope to low magnification Place foot pedals to be comfortably accessible
PREOP CHECK LIST

32. Surgeon Position
 Surgical Position
 Seated
 Specialized chairs with
armrests
 Arms resting on armrest
 Essential for fine motor control

33.  Surgical Position
 Seated
 Specialized chairs with
armrests
 Arms resting on table
or armrest
 Essential for fine motor
control
 Able to adjust height

35. Positioning of hand
 Arm - Rested, Elbow, Wrist, Ulnar border of
hand on table, forearm supinated a little.
 Three digit grip – IF, THUMB, MF.
 MF – rest firmly on the working surface either
directly or via RF.
PULP TO PULP PINCH

36.  Instrument Handling
 Delicate, precise
movements
 Finger movements only
 Pencil grip
 Arms on arm rests
 Elbows and wrists
locked

37. Simple Loupes
 one pair of positive meniscus lenses
 limited by spherical aberration and color fringing
 plastic construction
 fixed interpupillary distance
 very short working distance
 poor surgeon body and arm position
 strain on the surgeon’s neck and back.
 POOR CHOICE

38.  up to 2.5x magnification
 multiple lenses to offer magnification
and are generally lightweight and less
expensive
 adjustable interpupillary distance
 working distance varies
Galilean Loupes

39.  up to 8.0x magnification
 ≥5.0x a microscope is preferred
 highest optical quality
 series of lenses and prisms to magnify the subject
 similar in principle to low-power telescopes
 greater magnification
 sharp resolution
 greater depth of field
 heavier and more expensive
Prismatic Loupes
As magnification increases
 they become long and
heavy
 Shallow depth of field
 Head movements
make use difficult
(>5X)

40.  Provide an improved view of the tissues
of concern
Will vary by tissue of interest
 Allow a comfortable working distance
for the surgeon
Back straight, arms at 90 degrees
 Facilitate adjustment of the
interpupillary distance to suit the
surgeon
 Permit a wide field of view
Magnification – purpose:

41. AS MAGNIFICATION INCREASES
 The field of view and depth of field decrease
 At 3.5X - field of view is 50mm and depth of field is
2.6mm
 At 20X - field of view is 10mm and depth of field is
0.4mm

42.  Magnification
 Beginning surgeons should
start with magnification
early as part of their basic
training
 Will improve their tissue
handling and appreciation
for tissue trauma and wound
apposition

43. FIRST THING FIRST – PRECONDITIONS FOR
SUCCESS
 Uninteruppted Surgical training.
 Adequate sleep.
 Diengage from Clock and Telephone.
 NO MAGIC for success – dedicated Practice – as
Margin of error is measured in thousandths of an
inch.
 If Some thing is wrong – Donot Struggle ON –
Figureout First and then Proceed.
 Avoid Cigarette Smoking, Coffee before Surgery,
Strenous manual exertion like weight lifting / playing
tennis etc (Causes tremors).

44.  Surgeons must have a plan to achieve the goal, But must also
be adaptable and familiar with more than one technique, so that
obstacles encountered during the surgical procedure may be
overcome.

45.  Not all surgeries proceed according to the plan.
 We may all travel a different route and method.
 We get there in various ways, BUT…..we all get to the SAME
DESTINATION

46. Regardless of our individual variations, we
must all follow the BASIC RULES:
 To Use Appropriate Magnification And Instrumentation
 To Be Efficient And Precise
 To Ensure Minimal Tissue Trauma
 To Minimize Surgical Time
 To Obtain Excellent Tissue Wound Apposition With The
Smallest And Most Appropriate Suture Materials
 To Achieve A Successful, Comfortable, Cosmetic Outcome

47. EXIT PUPIL – OPTICAL AXIS

48. Exit pupil
 Lies in mid air at short distance of 15mm from eye piece.
 Diameter of exit pupil is 2mm and pupil in normal light
condition is 3mm.
 The exit pupil must sit right in the middle of the hole in iris, that
is pupil – for circular field of vision.
 Movements even by a millimeter changes circular field to
eclipse.
 Position eyepiece at 500 angle to the horizontal for better
longterm comfort. (very tall near to 60, very small near to 40)

49. Handling needle holder and
suture
 Lift thread with forceps in left hand till the needle dangles and
just rest on surface – rotate thread accordingly to position
needle direction.
 Needle is to be setup at 900 to the needle holder tip.
 Needle tip should point horizontally not up / not down – hold at
the middle of needle.
 Needle holder is held with tip pointing away – towards left for
right handed.

51. Passing Needle through the
tissue
 Needle should pass perpendicular to tissue surface.
 Evert tissue edge before passing needle – place
forceps underneath, near to the needle placement
and evert tissue – never grab full thickness.
 Needle should come out of the other side
perpendicularly – counter press to the needle is
given from outside side with forceps near the exit
point.
 Width of bite from tissue edge – 3 times the
thickness of needle.
 Pull thread in straight line, drop the needle.
 Short end of thread should be at least 3mm.

53. Knot tying
 Pick the long thread with left hand forceps.
 Turning it into loop over needle holder.
 Now Picking up short end.
 Completing first half knot
 Then second half knot
 Use third extra half knot also for safety.
 Cut short end first and discard it.
 Then hold long end and cut it after needle come in
view.
 Surgeons knot with a double throw – overcomes

56. MICROVASCULAR
SURGERY
1. Gentle handling of
tissues
*Avoid grasping the
ends of the vessels to be
anastomosed
*Grasp only a small
quantity of loose
periadventitia

57. 2. ADEQUATE DEBRIDEMENT
► Inspect under high
power for signs of
damage
► Debride until no signs of
vessel damage
► Strong pulsatile flow of blood
after adequate debridement

58. 3.SPASM
► Trauma is blamed for the reason of spasm
► Two main factors for spasm
- cold
- contact of outside wall of vessel with freshly shed blood

59. RELIEF OF SPASM
► Mechanical dilatation
► Hydrodistention of the vein graft
► Moist gauge soaked in warm saline
► 1% lignocaine spray – contact time 3 min – after dilation wash
with RL

60. 4. SIMILAR DIAMETER OF
VESSELS
Vessels with dissimilar
diameter of upto 50%
can be anastamosed
satisfactorily

61. ► Small vessel is dilated
and divided obliquely
(not >300 to give
adequate symmetry
► When the size
discrepancy is much
greater, an
interposing vein graft
is used

62. 5. TENSION-FREE
ANASTOMOSIS
► Apply an adjustable approximating clamp to bring the vessel
end together for convenient suturing
► Never apply clamp with excess tension
► Avoid any kinking or twisting of the vessels distal to the
anastomosis
► Avoid inverting cut end of vessel wall during anastamosis -
THROMBOGENIC

63. 6. CORRECT SUTURE TENSION
► Not too tight or too loose sutures
► Too tight sutures
Avoided by a
small “suture
circle” at the end
of three ties.

64. 7. APPROPRIATE SUTURE SPACING:
-Goal is to achieve an ultimately leak - free
anastomosis with as few sutures as possible
8. RECHEK OF ANASTOMOSIS:
-All anastomosis are rechecked prior to the final skin
closure

65. 8 CHOICE OF RECIPIENT
VESSELS
► Use of healthy vessel of reasonable size with good outflow is
the key for success
► Pre-operative assessment - caliber and injury during dissection.
► Mobilisation of vessels – for tension free repair.

66. DISSECTION TECHNIQUES
► Hemostasis – must
*Torniquet
*Vascular clips
*Bipolar coagulator
► Avoid perivascular hematoma
► Irrigation – moisten tissue every few minutes with RL, mop
excess with sponge.

67. Avoid damage – on dissection
 DONOT - work in a field obscured by blood.
- work out of focus.
- cut when you cant see.
- hold scissors at wrong angle.
- grab full thickness of vessel wall.
 Grab vessel with its outer layer – adventitia
 Divide adhesions b/w adventitia and vessel wall – tease the adventitia before
cutting with round microscissors – to see cut end of tunica media.
 Cauterize any branching of vessel with bipolar at a distance away from main
vessel.

68. Preparing the vessel ends
 Get the blood out – RL Flushes
 Remove the adventitia – to see media.
 Dilate vessel ends – relieve spasm. And to
handle
easily during repair.
This will determine the quality of anastamosis to
a larger extent

69. Background –
1mm Grid Lines - Provides an accurate measuring tool for the
surgeon
Available in Blue, Green or Yellow - Best contrast
Non-Reflective Surface - Eliminates glare from OR lighting
Radiopaque Silicone Material - Can be seen under X-Ray if
needed

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

71. Demonstration of forward pulsatile flow prior to clamping

72. 2. Clamping of vessels:
-With double approximating
clamp leaving generous length
of vessel end for ease of
working
-Tips of the jaws should project
just beyond the vessel for
maximal grip

73. Incorrect vertical position

74. Incorrect horizontal position

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

76. 4. Final Preparation of vessel
ends:
nd
► Resect sufficient periadventitia,
flush with the underlying vessel
to expose 2-3 mm of the vessel
wall for suturing

77. ► If the lumen is small
or in spasm, gently
dilate it with vessel
dilator
dr sumer yadav (mch nd nstructive

78. ► Irrigate the lumen with
solution of heparinized
saline (1000 units per 100
ml).

79. 5. SUTURING
► End to end / End to side - depending on type of anastamosis
► Full thickness of wall
► Size of the suture material – 10.0 Nylon
► Number of sutures – 8 stiches for 0.7 – 2 mm vessel diameter
sufficient
► Distance between sutures – equidistant – good enough to
prevent leak.
► Arteries- more sutures than veins

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

85. ► Make sure that the posterior wall is not accidentally cought
► For last 2-3 sutures: Modified Harashina technique

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

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

88. 6.RELEASE OF CLAMPS
► The distal clamp is released first
► If any major leak, reapply the clamp, irrigate and insert
additional superficial thickness sutures
► Now release both the clamps- usually small amount of blood
leaks from anastomosis, but stops after a few min. with the
application of sponges

89. VENOUS ANASTOMOSIS
► Veins are thinner, flatter and more difficult to anastomose
► Use ringer’s solution to float or irrigate the vessel
► Deeper bites
► More sutures

90. ALTERNATIVE ANASTOMOSIS
TECHNIQUES
1. BACK-WALL FIRST (ONE-
WAY UP) TECHNIQUE
-This technique is safest
because the entire inside of
the anastomosis can be
visualized until the very last
few sutures are placed

91. 2. FLIPPING TECHNIQUE
When free flap, digit or vein graft is fixed fo mobile vessel, it can
be flipped to expose the back-wall for repair, as rotation is not
possible

92. 3. CONTINUOUS SUTURING
► Acceptable patency rates ( 92% for arteries, 84% for veins)
comparable with interrupted sutures
► Advantages: Quicker and more hemostatic
► Disadvantages:
* Potential for creating purse-string constriction at the site of
anastomosis
* Entrapment of the suture material in the clamp
* Breakage of the suture
► So less favourable

93. 4. SLEEVE ANASTOMOSIS
► Microanastomosis of
vessels in 1 mm external
diameter range can be
accomplished by means of
invaginating technique
with fewer sutures than the
end to end method of
closure

94. ► Advantages:
- Quicker
- Less intraluminal suture exposure
- Less vessel trauma owing to fewer sutures
► Disadvantages:
- Patency rate is significantly less than that achieved
by the conventional end to end method, so it is not
superior in clinical situations

95. END TO SIDE ANASTOMOSIS
► Indications:
*To preserve patency of the recipient vessel in lower
limb,esp. in elderly patients, where sacrifice of a major
vessel can have a serious effect on the distal blood flow
*Considerable size or wall thickness, mismatch between
the vessels

96. Steps of end to side anastomosis

98. ► Advantages:
- Search for recipient arteries is simplified
- No. of possible sites to which free flaps can be transferred
is greatly increased

99. Signs of Patency
 Expansile pulsations – increase and decrease in diameter of
vessel distally with each pulsation – patent
 Wriggling – change in curvature of vessel distally with each
beat – patent
 Longitudinal pulsations – conentrared over particular point –
along long axis – hammering against a partial / complete block
 False wriggling can be seen with longitudinal pulsations – lift
anastamotic site with suture thread.

100. PATENCY
► Return of colour
► Capillary oozing and venous bleeding from the
revascularized tissue
► Direct inspection under the microscope
► Uplift test & Empty and Refill test

101. Uplift test

102. Empty & Refill
test
► This is traumatic and is performed as gently and infrequently as
possible

104. Modified Uplift test – Vein
patency
 Curved forceps beneath vein distal to anastamosis – lift it up till
occluded – move it along proximal in downstream direction –
going past anastamotic site.
 Patent – vessel fills up behind moving instrument.
 Blocked – distally dilated with negative filling test & with time
blood in vein becomes dark.

105. Practical points on blood.
 Undamaged vessel wall secretes anticoagulants – so
uncontaminated blood in undamaged vessel remain liquid for several
hours.
 Blood inside a vessel will not clot unless – the vessel is damaged /
blood contaminated with thromboplastins
 Blood that is in open contact with the wound should never be allowed
to stand still in a vessel unless heparinized irrigation fluid is present.
 Wise to leave the vessel alone and run for 20 min – after dissection &
20 min after anastamosis.

106. ANASTOMOTIC FAILURE
A) TECHNICAL ERRORS:
1. Tearing
2. Leaking
3. Narrowing
4. Through-stitching
5. Inclusion of adventitia
B) Poor flow from proximal vessel due to undetected damage
more proximally or vasospasm

107. C) A clot or thrombus at the anastomotic site or in an area where
a clamp was applied
-
Damage to endothelium from
+ Excessive clamp pressure
+ Poor technique or
+ Contamination
 Prevention:
+ Flushing of the suture line with heparinized solution
+ Systemic heparin (40 u/kg before completion of anastomosis
and release of clamps)

108. REVISION OF THE FAILED
ANASTOMOSIS
► If the patency test reveals slow filling of the distal vessel,
revise the anastomosis, carefully keeping original
problem in mind
► Insert a vein graft, if the vessel length is insufficient

109. *Poor proximal flow that does not respond to local vasodilator
and warming may require:
Proximal exploration of the vessel
Dilatation along a proximal length of vessel sufficient to relieve
vasospasm

110. FACTORS INFLUENCING
FAILURE OF
ANASTOMOSIS
A. TECHNICAL:
► Both walls sutured together
► Traumatic vessel handling
► Apposition of vessel edges
► Disproportional vessel size
► Tension at suture line
► Excessive clamp pressure
► Kinking of vessels

111. B. REPERFUSION FAILURE:
► Blood turbulence
► Spasm
► Hypercoagulability
► Acidosis
► Cold
► Hypovolemia
► Vasoconstrictors

112. C. POSTOPERATIVE CARE:
► Infection
► Acidosis
► Cold
► Limb position
► Environmental factors

113. POST-OPERATIVE MEASURES
► Oxygen administation
► Bed rest or limited movements for 3 to 5 days
► Warm room
► Limb elevation to decrease the venous congestion
► Fluid administration
► Pharmaotherapy – anticoagulants

114. ► Adequate analgesia
► Limitation of visitors and telephone calls to decrease the
emotional stress
► Prohibition of smoking, caffeine and chocolate
because they may cause vasoconstriction