Principles of Microsurgery Flashcards
There is no difference in patency rate based on suture technique (simple interrupted versus continuous) or anastomotic technique (end-to-end versus end-to-side)
T
Routine use of antithrombotic agents in the postoperative
period is mandatory
F Routine use of antithrombotic agents in the postoperative
period is optional.
Routine use of antithrombotic agents in the postoperative
period is optional.
T
Platelets do not adhere to undamaged endothelium
T
collagen within the subendothelium is highly thrombogenic.
If the intima is damaged, exposed collagen within the media triggers platelet adhesion to the vessel wall
T
Dextran has been shown to have no
effect on flap survival
T
Heparin and aspirin continue to be commonly used
T
Cooling prolongs tolerance to ischemia for all types
of tissues
T
Skin and subcutaneous tissue remain viable for approximately 6 hours.
F 24 hours
Muscle is less tolerant; irreversible damage to the microcirculation occurs at
approximately 6 hours without blood flow.
T
What is the no-reflow phenomenon
The low flow state triggers
intravascular thrombosis and flap ischemia. The process is termed
the no-reflow phenomenon
Low magnification (6-12x)
may be used for suture placement
F Low magnification (6-12x)
may be used for vessel preparation and suture tying;
medium magnification (I0-15x) is used for suture placement
T
high magnification (>15x) is helpful in performing small-caliber anastomosis and for careful inspection at the completion of the procedure.
T
Generally, 3.Sx or higher
magnification is recommended for microsurgery
T
Loupes-only microsurgery reduces operative time
T microscope setup is eliminated
couplers Patency rates are lower than hand sewn anastomoses
F Patency rates of couplers are equivalent
to hand-sewn anastomoses.
Cou[pler can be used when vessel size mismatch is present and used on soft-walled arteries over 1 mm in diameter
T
Coupler should not be used on irradiated vessels
T
Preoperative angiography (traditional or image-based) is mandatory at the defect or donor site
F Preoperative angiography (traditional or image-based) is sometimes required at the defect or donor site
Age alone is not a contraindication for microsurgical reconstruction.
T
Macrovascular and ,microvascular considred contraindications for the microsurgery
F no difference in the rate of flap failur
Obesity is a known risk factor for flap and donor site complications
T
Free flaps in obese patients are twice as likely to fail
T
Smoking effect the anastomosis patency
F smoking does not reduce anastomotic
patency but does affect wound healing, skin graft take over flaps,
infection risk, flap necrosis, hernia formation, and length of hospital
stay
Adventitia and periadventitial tissue is
sharply excised to prevent it from becoming interposed between the
donor and recipient vessels, which is highly thrombogenic
T
Interrupted sutures are preferred when there is significant vessel
size discrepancy
T
Continuous sutures require less knot tying and are
more time efficient
T
End-to-side anastomosis may be necessary in
limb reconstruction to maintain distal perfusion, or when significant
size mismatch exists
T
The proximal arterial clamp is removed last
T
The saphenous veins are often used when
large-diameter vessels are required
T
Vien Grafts should be harvested at
least 35% longer than the measured gap to accommodate for contraction
T
Long-term patency
rates for vein grafts approach 100%, regardless of the length of
the graft required
T
Bisecting interrupted sutures are placed 180° apart,
useful when there is a vessel size mismatch
T
Triangulating interrupted sutures are placed 120° apart, dividing the vessel circumference into thirds. This technique helps prevent inadvertent inclusion ofthe opposite wall ofthe vessel in the remaining suture
T
vasopressors are avoided in microsurgery
T
Anesthesia Benefits
supporting circulatory volume
avoiding peripheral vasoconstriction
maintaining normal body temperature
It is thought that the rise in blood pressure overcomes
any vasospastic effect of the medication
T
postoperative antithrombotic use of any type offers no protection from microvascular
thrombosis and increases complication rates
T
The most common antithrombotic
agents used in routine postoperative care are aspirin and heparin.
T
Thrombosis is most common within 24 hours ofsurgery
T
Early failure
is often related to venous thrombosis
F Early failure
is often related to anastomotic imperfections or pedicle positioning.
approximately 50% of failing free flaps can
be salvaged
T
Doppler signals may
persist for several hours despite venous thrombosis.
T
A thrombolytic agent (streptokinase, urokinase, or tissue plasminogen activator) is infused while the flap is occluded from
systemic circulation
t
There is no indication for routine anticoagulation when conditions are optimal
T
ocal fibrinolytic therapy and postoperative anticoagulation may be indicated in situations where mechanical and vascular
factors are unfavorable
T
Leeches are a useful adjunct for flaps with signs of venous congestion
in case of venous anastomosis is not patent
F Leeches are a useful adjunct for flaps with signs of venous congestion
despite a patent venous anastomosis
Prophylaxis against
Aeromonas hydrophila is necessary why?
because this organism routinely
inhabits the digestive tract of leeches
Skin and fascia flaps can be derived from any perforating blood
vessel using the angiosome concept
T
Vascularized bone autografts are superior to nonvascularized bone graft in defects over 5 centimeters in regard to early
incorporation, bone hypertrophy, mechanical strength, and osseous
mass retention
T
Dissipation of platelets in the vessel lumen and
formation of the pseudointima correlates clinically with the critical
period of thrombus formation within the first 3 to 5 days
T
Continuous sutures have the added advantage
of equally distributing tension along the suture line, providing less
opportunity for leakage
T
Synthetic grafts are not common in microsurgery
T
fibrous polyurethane (PU) and microporous polytetrafluoroethylene (PTFE) grafts show adequate early patency in high-flow,43
short segment conduits, but long-term anastomotic narrowing due to
neointimal hyperplasia.” Significant thrombosis and occlusion occur
early in low-flow flaps
T
