Flap and soft tissue recon, lip/mandible/eye recon

Question 1

List 5 advantages and 5 disadvantages of local flaps

Answer 1

Advantages:
1. Height and skin color match (donor match)
2. Easy wound care
3. Low donor site morbidity
4. One stage procedure in most cases
3. Shorter healing period

“HELOS”

Disadvantages:
1. Risk of deformation of adjacent structures due to donor site closure
2. Creates additional scars
3. May be technically challenging (e.g. limited length with random pattern blood supply)
4. Potential for greater reconstructive challenge if failure
5. Increased risk of bruising, swelling, trapdoor deformity
6. Not enough bulk for deep defects

“STReeT DuB”
S - additional Scars
T - Trapdoor deformity, more swelling bruising in surrounding areas
R - Re-reconstruction may be required if it fails
T - Technically challenging (esp. with random pattern blood supply, limits length)
D - Deformation of local adjacent structures depending on way it closes
B - Bulk may not be enough for deep defects

Question 2

√Describe the reconstructive ladder.

Answer 2

1. Healing by secondary intention (concave areas - nasolabial, medial canthus, periauricular, temporal, forehead - “concave and be brave”)
2. Primary closure
3. Delayed primary closure
4. Grafts (STSG, FTSG) - harvest from pre or post-auricular area, supraclavicular, or upper eye lid
5. Local flap
6. Regional flap
7. Free flap tissue transfer

Question 3

What is a trapdoor deformity?

Answer 3

A phenomenon of outward bulge of tissue centrally due to concentric retraction of a curved scar peripherally
(surrounding scar contracted down, middle is raised) - commonly seen in local/bilobed flaps

Question 4

Describe the flap classification schemes.

Answer 4

A. Location: Local, regional, distant
B. Vascular Supply: Random patterned or axial
C. Flap design and method of tissue movement
i. Pivotal flap
ii. Advancement flap
iii. Hinge flap

Question 5

What are 6 uses for flaps?

Answer 5

1. Replace tissue loss
2. Skin covering to future surgical site
3. Padding over bony prominence (also for protection from radiation)
4. Bringing in new blood supply to an area
5. Increase sensation
6. Specialized tissue for reconstruction

“I need RVSPS”
I - Increased sensation
R - Replace tissue loss
V - bring new Vascular supply to an area
S - Specialized tissue needed for reconstruction
P - Protection (ie. of underlying exposed bone, protection from radiation)
S - Surgical site - skin covering to a future surgical site

Question 6

Describe the flap classification based on design and method of tissue movements.

Answer 6

A. PIVOTAL FLAPS
- Flaps move toward the center of the wound by pivoting around a fixed point at the base of the flap pedicle
- Examples:
— Rotation flaps (curvilinear design)
— Transposition flaps (linear configuration): Rhomboid flap and bilobed flap are the main ones and Z plasty
— Interpolated flaps (base is not contiguous with defect; e.g. paramedian forehead flap. Requires secondary detachment)

B. ADVANCEMENT FLAPS
- Linear design and moved directly to defect
- Examples:
— Uni- or bi-pedicled advancement flaps
— V-Y or Y-V flaps
— Island advancement flaps

C. HINGE FLAPS
- Involve transfer of tissue by flipping it over into the desired position
- Usually used for internal lining purposes (e.g. nasal mucosal hinge flap)

Rhomboid flap: https://www.researchgate.net/profile/Abhishek-Vijayakumar-3/publication/311443764/figure/fig1/AS:436298457587712@1481033066035/Marking-of-rhomboid-flap.png

Bilobed flap: https://journals.sagepub.com/cms/10.1177/2732501621993908/asset/images/large/10.1177_2732501621993908-fig1.jpeg

Island advancement flap:
https://i0.wp.com/plasticsurgerykey.com/wp-content/uploads/2019/09/f147-006ac-9780702062759.jpg?w=960

V-Y flap:
https://entokey.com/wp-content/uploads/2016/07/DA1-DB5-DC3-C88-FF3.gif

Bipedicled advancement flap:
https://img.medscapestatic.com/pi/meds/ckb/49/8249tn.jpg

Question 7

Describe the classification of local skin flaps based on blood supply

Answer 7

A. Random Cutaneous
- No named vessels
- Rely on dermal and subdermal plexus vessels supplied by musculocutaneous arteries near the base of the flap

B. Axial pattern/Direct Cutaneous flap
- Incorporates a named subcutaneous artery running along length of the longitudinal axis of flap

C. Fasciocutaneous Flap
- Flap that includes skin, subcutaneous tissue and underlying fascia, based on the prefascial and subfascial plexuses

D. Musculocutaneous flap
- Encompasses skin, SC tissue, and muscle. Based on muscular perforations.

Vancouver page 340
Kevan FP page 13

Question 8

What are the 4 main types of local flaps?

Answer 8

1. Advancement
2. Rotation (single axis, curved scar)
3. Transposition (flap base is contiguous with the defect, straight scar generally)
4. Interpolation (compared to transposition, flap base is not contiguous with the defect) - e.g. paramedian forehead for nasal tip

Question 9

What are 4 common examples of advancement flaps?

Answer 9

1. Monopedicled
2. Bipedicled
3. T-plasty
4. V-Y plasty

Vancouver Pg 343

Question 10

Know how to draw at least 2 types of rotation flaps

Answer 10

Vancouver Pg 343

Question 11

What are 3 examples of transposition flaps?

Answer 11

1. Rhomboid/Limberg (angle must be 60 and 120 degrees from each other)
2. Dufourmental (narrower angles than a Limberg; can be < 60 degrees)
3. Bilobed
4. Z-plasty

Vancouver Pg 343
See Timmins Rhomboid Flap

Question 12

What are two examples of interpolation flaps?

Answer 12

1. Paramedian forehead flap (supratrochlear artery)
2. Melolabial interpolation flap

Question 13

What is the classification of musculovascular flaps based on pedicle type?

Answer 13

Mathes and Nahai Classification

Type 1:
- Single pedicle
- E.g. Tensor fascia Lata

Type 2:
- 1 dominant pedicle in the mid-belly of muscle
- 1 secondary pedicle (or several very minor distally)
- E.g. SCM, Trapezius, Gracilis, Platysma

Type 3:
- 2 dominant pedicles
- E.g. Rectus abdominus, gluteus maximus, orbicularis oris

Type 4:
- Multiple segmental pedicles of similar size along belly
- E.g. Sartorius flap

Type 5:
- Single dominant pedicle and multiple secondary segmental pedicles
- E.g. Pectoralis major, latissimus dorsi

See Kevan Page 13
Vancouver Pg 340

Question 14

Describe the ideal design of a rotational flap.

Answer 14

1. Arc of closure < 30 degrees
2. Radius of the arc = 2-3x diameter of defect
3. Length of arc = 4x diameter of defect

Question 15

√What is the Delay Phenomenon? Describe 6 mechanisms of how it works.

Answer 15

Delay Phenomenon: Improved survival of a flap occurs by delaying definitive transfer of a pedicled tissue flap, allowing improved blood flow to distal aspect of pedicle
- Procedure: Elevating flap and then placing it back into position without mobilizing it (partially incise and undermine flap) for 10-21 days. Re-evaluation and inset then occurs 3-4 weeks later.
- Effect lost after 3 weeks to 3 months

Mechanisms:
1. Closure of arteriovenous shunts (due to development of autonomous tone or regrowth of sympathetics along flap base, or increased sensitivity to circulating catecholamines)
2. Improved blood supply after recovery from hyperadrenergic state due to sympathetic denervation, causing change in sympathetic tone
3. Reorientation of vessels along axis of the flap
4. Increase in vessel caliber; dilation of choke vessels (vessels that connect between two vascular components) through hyperplasia and hypertrophy
5. Increase in vessel numbers
6. Conditioning of distal flap to ischemia

Question 16

√What is reperfusion injury? What is the main driver

Answer 16

Reperfusion injury = paradoxical exacerbation of cellular dysfunction and death, following restoration of blood flow to previously ischaemic tissues

Xanthine Oxidase:
- Major source of free radical in ischemic tissues
- Responsible for conversion of hypoxantine to uric acid after restoration of oxygen to hypoxic tissue, which produces superoxide ions (free radical) –> exacerbates tissue death

Question 17

√What is an oxygen free radical scavenger? List 5 examples.

Answer 17

A substance, such as an antioxidant, that helps protect cells from the damage caused by free radicals.

1. Allopurinol (xanthine oxidase inhibitors)
2. Superoxide dismutase
3. Vitamine A, C, E
4. Deferoxamine
5. Glutathione

“SAVe Damaged Goods”
S - Superoxide dismutase
A - Allopurinol (xanthine oxidase inhibitors)
Ve - Vitamin E, C, A
D - Deferoxamine
G - Glutathione

Question 18

√Define Stress in the context of flap physiology

Answer 18

Force applied across a cross-sectional area of tissue

Question 19

√Define Strain in the context of flap physiology

Answer 19

Change in length divided by the original length of the given tissue to which a force is applied. (Change in length relative to original length)

Measure of deformation.

Question 20

√Define creep in the context of flap physiology. What are the types of creep?

Answer 20

An increase in strain (change in length relative to original length) seen as a result of constant mechanical stress. Constant stress on a structure results in a change in length, and this PROCESS of increasing strain is called creep.

Types of Creep:
1. Mechanical Creep: Creep due to the stretching of collagen fibres. No new tissue formation
- Happens over minutes
- Migration of undermined tissue into field defect by stretching force
- Due to: (1) displacement/extrusion of fluid and MPS ground substance from the dermis, (2) breakdown of the dermal framework, (3) realignment of collagen, (4) Microfragmentation of elastin

2. Biologic Creep: Stimulation of new tissue growth
   - Happens over weeks
   - Gradual stress stretches skin, muscles, nerves, blood vessels, lymphatics
   - Due to: (1) increase in length by cell division, (2) collagen and elastin synthesis
   - Examples: (1) Pregnancy, (2) Lymphedema, (3) Morbid obesity

Short term effect of stress is mechanical creep. Over longer periods of time, you obtain biologic creep.

Question 21

√Define Stress Relaxation

Answer 21

The decrease in stress that occurs when skin is held under tension at a constant strain. This is caused by a change in skin physiology (increase in skin cellularity) over time by application of constant stress.

Question 22

√What is an angiosome?

Answer 22

Angiosome is an anatomic unit of tissue (consisting of skin, subcutaneous tissue, fascia, muscle, and bone) fed by a source artery and drained by specific veins
- Body can be divided into 40 angiosomes
- Adjacent angiosomes are connected by a vast compensatory collateral web of “choke vessels” (vessels that connect between two vascular components)

Question 23

Regarding Tissue expansion, discuss:
1. What is the goal
2. What are the principles of tissue expanders 4
3. How do different tissues respond to tissue expanders? What tolerates it well, which ones don’t?
4. What are the types of tissue expanders? 3
4. Contraindications 5
5. Complications and side effects? 9

Answer 23

Goal of expansion: To increase local tissue size to facilitate reconstruction. (Biological creep)

Principles of tissue expanders:
1. Base area of expander should be 2.5-3x as large as the area to be reconstructed/closed. Amount of flap advancement either half the base diameter of the expander, or half the diameter of the expansion dome.
2. Expansion should proceed until skin blanches or there is discomfort
3. Intervals between injections (to increase expansion) = 4-14 days (every 1-2 weeks)
4. Expansion starts ~3 weeks after implant insertion, 6-12 weeks to reach maximum expansion

Types of Tissues: Collagen fibers realign.
1. Nerve tissue tolerates expansion well
2. Adipose tissue is intolerant to tissue expansion

Types (match geometric shape of expander to the shape of expansion site/planned flap):
1. Rectangular
2. Crescent-shaped
3. Round

Contraindications:
1. Smokers
2. HTN
3. Diabetes
4. Poor nutrition
5. Chronic steroid use

Complications:
1. Dehiscence/Expander Exposure (most common)
2. Expander Rupture
3. Skin necrosis
4. Hematoma - truly emergent; return to OR for evacuation, stop bleeding, and possibly re-insert expander
5. Infection
6. Pain / discomfort
7. Extrusion
8. Bone remodelling/neurovascular compromise - remove expander or perform surgery ASAP
9. Alopecia

“I BENDHARD”
I - Infection
B - Bony remodelling underlying or vascular compromise
E - Extrusion
N - Necrosis of skin
D - Dehiscence
H - Hematoma
A - Alopecia
R - Rupture of expander
D - Discomfort / pain

Side effects:
1. Adverse cosmesis while expander in place
2. Pain and discomfrot

Question 24

Discuss 15 causes or risk factors of flap failure. 6 patient factors, 4 environmental, 7 flap reasons

Answer 24

“6 - 4 - 7”

Patient factors:
1. Hypercoagulability
2. Smoking
3. Vasoconstrictive agents (e.g. pressors, mint, chocolate)
4. Hypotension
5. Peripheral vascular disease
6. Diabetes

Environmental factors:
1. Irradiated field
2. Poor peripheral blood supply
3. Contaminated field
4. Cold (vasoconstriction)

Flap factors:
1. Long pedicle
2. Inadequate blood supply relative to tissue
3. Venous congestion
4. Arterial obstruction
5. Infection
6. Pedicle compression (hematoma, seroma)
7. Poor pedicle geometry (tension, axial length too long for vascular supply)

Question 25

What is the minimum blood flow for flap viability?

Answer 25

1-2mL/min per 100g
(Normal = 2mL/min per 100g)

Question 26

List 6 adjuncts that can improve flap viability and manage venous congestion

Answer 26

1. Hyperbaric Oxygen Therapy
2. Anticoagulants (e.g. Heparin)
3. VAC dressings
4. Avoidance of vasoconstrictive agents (e.g. pressors, nicotine)
5. Leeches
6. Temperature (keep flap warm!)

“HAVe A Tiny Leech”
H - Hyperbaric oxygen therapy
A - Avoid vasopressors or vasoconstrictive agents (e.g. nictoine, pressors)
V - VAC dressings
A - Anticoagulants (e.g. heparin)
T - Temperature (keep flap warm)
L - Leeches

Question 27

List 9 characteristics of an ideal free flap

Answer 27

1. Two team approach for resection and harvest of flap
2. Innervation with sensation and motor function feasible
3. Adequate length and caliber of vessels
4. Donor site previously unviolated
5. Minimal donor site morbidity
6. Potential for osseointegration
7. Tissue composition similar to that of defect
8. Bulk and color matched to that of defect
9. Excellent cosmetic potential

“LOOK, FEEL, MOVE, FUNCTION”:
Look (looks good for patient):
- Excellent cosmetic potential
- Bulk and color match to defect
- Tissue composition similar to defect

Feel (feels good for patient at defect and donor site)
- Donor site previous unviolated
- Minimal donor site morbidity
- Innervation with sensation and motor function feasible

Move (Flap characteristics - Moves good for surgeon):
- Two team approach for resection and harvest
- Adequate length and of vessel

Function (Functions good):
- Potential for osseointegration

Question 28

What are 6 characteristics of the ideal qualities of the bony component of a vascularized composite free tissue transfer?

Answer 28

1. Adequate length to restore a segmental defect of nearly any length
2. Natural shape or easy contourability to match the mandibular defect
3. Well vascularized
4. Vascular anatomy that is well preserved while contouring the graft
5. Sufficient height and width for reliable placement of endosteal dental implants for prosthetic rehabilitation
6. No significant functional or esthetic defects at the donor site after harvest

“LOOK, FEEL, MOVE, FUNCTION”
Look: (looks good for pt)
- Natural shape or easy contourability to match the mandibular defect

Feel: (feels good for pt at defect and donor site)
- No significant functional or esthetic defects at the donor site after harvest

Move: (Flap characteristics - moves good for surgeon in surgery):
- Adequate length to restore a segmental defect of nearly any length
- Well vascularized
- Vascular anatomy that is well preserved while contouring the graft

Function:
- Sufficient height and width for reliable placement of endosteal dental implants for prosthetic rehabilitation

Question 29

List 7 characteristics of the ideal qualities of the soft tissue component of a vascularized composite free tissue transfer

Answer 29

1. Accessible for a two-team approach
2. Well vascularized
3. Sensate
4. Thin and pliable
5. Mobile relative to bone
6. Minimal morbidity at the donor site
7. Lubricated

“LOOK, FEEL, MOVE, FUNCTION”

LOOK:
- Color and bulk match

FEEL:
- Minimal donor site morbidity
- Sensate

MOVE:
- Lubricated
- Accessible with two team approach
- Thin and pliable
- Mobile relative to bone
- Well vascularized

FUNCTION:
- None

Question 30

List 4 mechanisms that VAC dressing can improve flap viability

Answer 30

1. Reduces shear forces over flap
2. Reduces excess fluid
3. Ensures adequate tissue contact
4. Decreases bacterial buildup

“VAC Can Slurp Even Better”
C - improves CONTACT of tissues
S - reduces SHEAR forces over flap
E - reduces EDEMA of tissues (decrease excess fluid)
B - reduces BACTERIAL build up

Question 31

Describe 13 advantages (over local or regional) and 5 disadvantages of free flap reconstruction

Answer 31

ADVANTAGES
1. Improved functional outcomes
2. Improved cosmesis
3. Immediate reconstruction at the time of ablation (single stage)
4. Allows for 2 simultaneous operative teams
5. Can transfer healthy tissue to an unhealthy bed
6. Improved vascularity and healing
7. Potential for sensate, motor and secretory function
8. Large number of donor sites available
9. Unrestricted positioning and reach
10. Large amount of composite tissue
11. Can cover any defect (larger tumor free margins)
12. Low rate of resorption
13. Permits primary placement of osseointegrated implamts

Again, think: “Look, Feel, Move, Function”
Look:
- Better cosmesis
- Can cover any defect (larger tumor with free margins)
- Low rate of resorption (hence keeps its majority of bulk)

Feel:
- Transfers healthy tissue to healty bed
- Potential for motor, sensate, and secretory function
- Improved vascularity and healing

Move:
- Allows for 2 surgical teams and single stage surgery
- Large number of donor sites available
- Large amount of composite tissue available
- Unrestricted positioning and reach

Function:
- Improved functional outcomes
- Allows placement of osseointegrated implants

DISADVANTAGES
1. Technical difficulty
2. Increased risk of flap failure
3. Donor site morbidity (multiple surgical sites)
4. Surgical times
5. Most extensive post-operative management

Question 32

How do you manage donor-recipient vessel-caliber mismatch? List 3 ways

Answer 32

1. Dilate smaller vessel
2. Bevel smaller vessel
3. End to side anastomosis

Techniques:
- < 2:1 mismatch: uneven stitches end to end, or dilation
- 2-3:1 mismatch: beveled or spatulation (max angle of beveling is 30 degrees)
- > 3:1 mismatch: End to side anastomosis

Question 33

What is the maximum angle of anastomotic vessels that can be used for end to side anastomosis?

Answer 33

Less than 60 degrees

Question 34

What are 4 signs of microvascular trauma to a vessel during reconstruction?

Answer 34

1. Cobweb sign (thrombus forming)
2. Measles sign/sausage sign (vessel looks like sausages on a string)
3. Thrombus sign (low spurt test)
4. Telescope sign (thrombus)

Question 35

√Discuss the Perfusion Zones

Answer 35

4 Types

Zone I: Macrovascular System
- Cardiopulmonary system, arteries/veins, and lymphatics
- Flow in Zone I is non-nutritive in that there are no mechanisms for exchange between tissue and blood
- Essential for flap survival - supplies flap through musculocutaneous and septocutaneous branches
- Delay phenomenon is part of Zone I effect

Zone II: Capillary System
- Microcirculation, includes arterioles, venules, capillaries
- Site of nutrient exchange
- No-reflow phenomenon is part of Zone II (loss of nutritive blood flow in the presence of an adequate vascular supply)

Capillary circulation flow is controlled by:
- Precapillary & preshunt sphincters
- Precapillary sphincters under control by local hypoxia and metabolic by-products
- Preshunt sphincters under autonomic control (norepinephrine) for thermoregulation and systemic BP maintenace

Zone III: Interstitial System
- Interstital space
- Nutrient and waste removal occur via diffusion (down concentration gradient) and convection (bulk flow of plasma current)

Zone IV: Cellular System
- Final step to maintaining cell viability

Kevan Page 15

Question 36

√What is the “No-Reflow Phenomenon”? What is the pathophysiology? 2

Answer 36

Adequate Zone I perfusion but the absence of Zone II/III perfusion. Implies a period of iscehmia.

This suggests flap failure on a microcirculatory level, despite adequate large vessel flow.

Pathophysiology:
- When the critical ischemia time for a flap is exceeded (12 hours), endothelial & parenchymal swelling, intravascular stasis, and thrombosis lead to loss of nutritive flow
- Severity of this effect is correlated with ischemia time
- Microcirculatory failure may be related to showers of microemboli from the anastomosis

Question 37

What are the 5 main useful clinical signs for monitoring a cutaneous free flap?

Answer 37

1. Color
2. Temperature
3. Capillary refill
4. Palpable pulse
5. Needle stick scratch

Other:
1. Doppler pencil
2. Temperature probe
3. Laser doppler probe
4. Quantitative fluorometer
5. Implantable doppler
6. Near infra-red spectroscopy

Question 38

When are flaps at greatest risk of failure, and what is the most common mechanism of failure?

Answer 38

Highest risk of failure within the first 48-72 hours, and 15-20 minutes post-anastomosis.

Most common mechanism of failure is venous obstruction (venous anastomosis)

Question 39

List 3 mechanisms of flap thrombosis

Answer 39

Virchow’s Triad (same for DVTs)
1. Hypercoagulability
2. Endothelial Injury
3. Stasis

Question 40

Discuss 3 possible methods of flap salvage

Answer 40

1. Immediate re-exploration in the OR
2. Blood thinners (e.g. ASA, Heparin, Dextran)
3. Leeches

Question 41

Regarding anticoagulation in free flaps, discuss the mechanism of action, and dosing of:
1. Aspirin
2. Heparin
3. Dextran

Answer 41

ASPIRIN:
- Inhibits cyclooxygenase, interferes with PGH2 synthesis
- 81 or 325mg

HEPARIN:
- Binds and stimulates to antithrombin III, inactivated thrombin, other esterases
- Increases electronegative potential of endothelium, therefore decreases platelet ahdesiveness
- 50-400 units / hr

DEXTRAN:
- Antithrombin & antifribin effects
- Either 40cc of Dextran40 followed by 25cc/hr x 5 days; or 500cc followed by 500cc/d x 3 days

Question 42

Describe the mechanism of action of how leeches provide possible flap salvage. What considerations need to be made if using leeches?

Answer 42

Leeches secrete Hementin (fibrinogen lytic enzyme ie. inhibitor - inhibits thrombin - which inhibits fibrinogen to fibrin conversion causing anticoagulation) & Hirudin (anticoagulant)
- Hementin also has local anesthetic properties - only found in amazon giant leeches and not medical grade leeches
- Medicinal leeches secrete Hirudin, collagenases & proteases

Indication: venous congestion.

Risk: Aeromonas Hydrophilia (gram negative beta lactamase producing organism) - causes necrotic soft tissue flap infection 10-15%
- Cover prophylactically with leech use, with prophylactic Fluoroquinolone (Cipro) or Septra x 3-5 days
- Leeches should not be removed forcibly - can get their teeth stuck in wound and predispose to abscess formation

Question 43

What are the phases of Hyperbaric Oxygen Treatment and how it can improve flap viability?

Answer 43

1. LAG PHASE (Treatments 1-8)
   - Increase in capillary budding
   - Minimal clinical change
   - No change in O2 tension
2. LOG PHASE (Treatments 8-22)
   - Log increase in O2 tension (O in Log)
   - Angiogenesis, rapid response
3. PLATEAU PHASE (Treatments 22+)
   - O2 tension plateaus even with more treatments
   - No further clinical response

Question 44

What is the mechanism of action of hyperbaric oxygen? List 5

Answer 44

1. Increases oxygen tension (partial pressure of oxygen within interstitial space)
2. Increases neovascularization
3. Increases fibroblast proliferation
4. Increases oxidative killing
5. Increases distance O2 can dissolve in tissues

“FOND of Oxygen”
F - Fibroblast proliferation increases
O - Oxidative killing increases
N - Neovascularization increases
D - Distance that O2 can travel to tissue increases
O - Oxygen tension increases

Question 45

Define oxygen tension?

Answer 45

Tissue oxygen tension is the partial pressure of oxygen within the interstitial space of an organ bed. Represents a balance between local oxygen delivery and consumption at any given time.

Question 46

List 9 indications for hyperbaric oxygen treatment

Answer 46

1. Air embolus
2. SSNHL
3. Chronic wound
4. Flap salvage
5. Osteradionecrosis
6. Pre- and post-dental extractions in patients with prior radiotherapy
7. Decompression sickness
8. Malignant otitis externa
9. CO poisoning

“ELEMENTS: AIR, WATER, FIRE (burned/unhealthy/dead), EARTH (e. bugs/infection)”
Air:
- Air embolus
- CO poisoning

Water:
- Barotrauma / decompression sickness
- SSNHL (cochlea has water in it… best I could come up with.. also SSNHL hearing related to barotrauma)

Fire:
- Chronic wound
- Flap salvage
- Osteoradionecrosis
- Pre- and post- Dental extractions in patients with prior radiotherapy

Earth:
- Malignant otitis externa

Question 47

List 3 absolute contraindications and 5 relative contraindications for hyperbaric oxygen treatment

Answer 47

ABSOLUTE:
1. Active malignancy
2. Untreated pneumothorax
3. Certain medications (“BCD” doxorubicin due to risk of cardiotoxicity - need at least 3 days, bleomycin due to risk of pulmonary fibrosis, cisplatin)

RELATIVE:
1. Airway disease (e.g. asthma, COPD, bullous emphysema)
2. Seizure disorder
3. Claustrophobia
4. Pregnancy
5. Eustachian tube dysfunction

Question 48

Describe the Marx Grading classification of Mandibular ORN

Answer 48

Grade 1:
- Exposed bone without pathologic fracture
- Can be treated with antibiotics, HBO

Grade 2:
- Fails to respond to antibiotics or HBO
- Sequestrectomy (surgery) required / saucerization

Grade 3:
- Full thickness injury or pathologic fracture
- Usually requires complete resection and reconstruction with free tissue transfer

Question 49

Describe the Jewer Classification of Mandibular Bony Defects

Answer 49

Segments (HCL)
H: Hemimandibulectomy = lateral defects of any size INCLUDING condyle
C: Central = central defect, including both canines and 4 incisors
L: Lateral = lateral defects EXCLUDING condyle

This results in 8 possible causes of bony defects based on all combinations of the above:
1. H
2. C
3. L
4. HC
5. LC
6. LCL
7. HCH
8. LCH or HCL

Additional subscripts:
Boyd’s modified HCL classification:
- o = no mucosal or skin component
- m = mucosal defect
- s = skin defect

Kevan Page 17

Question 50

Describe the Urken Classification of Mandibular Defects

Answer 50

Comprehensive classification of composite oromandibular defects which includes neurological defects, in addition to bony and soft tissue defects

Way too complicated…

Bony Defects “CRBS”
1. C = Condyle
2. R = Ramus
3. B = Body
4. Sh = Symphysis (hemi) - superscript H
5. S = Symphysis (total)

Further Classifications:
Mucosal defects
Tongue defects
Cutaneous defects
Neurologic Defects

See photo for details

https://www.plarecon.com/wp-content/uploads/2017/08/Urken-CRBS-classification-e1502604643664.jpg

Question 51

Describe the Schultz Classification of Mandibular Defects (2015)

Answer 51

4 classes of defects based on increasing reconstructive complexity:

Type 1 = Unilateral dentoalveolar
Type 2 = Unilateral dentoalveolar + ramus
Type 3 = Bilateral dentoalveolar
Type 4 = Bilateral dentoalveolar and ≥ 1 ramus

Further divided into A/B based on presence of ipsilateral donor vessels:
A = Ipsilateral donor vessel present
B = Ipsilateral donor vessels absent

C = added represents condylar involvement

This classification provides an algorithm for microvascular reconstruction:
Type 1 A = Deep circumflex iliac artery (DCIA) Iliac flap or FOSC
Type 1 B = DCIA + vein graft or FOSC
Type 2 A = FOSC or DCIA
Type 2 Ac = FOSC
Type 2 B = FOSC or DCIA + VG
Type 2 Bc = FOSC
Type 3 A/B = Fibula osteoseptocutaneous flap (FOSC)
Type 4 A/B = Full length FOSC or multiple flaps

https://www.plarecon.com/wp-content/uploads/2017/08/Schultz-mandibular-defects-classification.jpg

Question 52

Name 4 types of non-vascularized bone grafts. Which one is best for osteogenesis?

Answer 52

1. Cortical = dense, compact bone, takes longer to revascularize
2. Cancellous (spongy) = trabecular, higher osteogenic properties, takes less time to revascularize
3. Cortico-cancellous
4. Particulate Cancellous bone marrow (best option for osteogenesis)

Question 53

List 10 goals of mandibular reconstruction

Answer 53

1. Oral competence
2. Occlusion
3. Cosmesis
4. Projection
5. Articulation
6. Mastication
7. Orocutaneous closure
8. Restore mandibular continuity
9. Maintain tongue mobility
10. Maintain or restore sensation

FUNCTION AND COSMESIS

Function:
1. Oral competence
2. Occlusion
3. Articulation
4. Mastication
5. Orocutaneous closure
6. Tongue mobility
7. Sensation maintain and restore

COSMESIS:
1. Cosmesis
2. Projection
3. Restore Mandibular continuity

Question 54

List 6 goals of maxillary reconstruction

Answer 54

1. Oronasal separation
2. Occlusion
3. Orbital floor
4. Nasolacrimal duct
5. Vertical buttresses
6. Normal facial dimensions (height, width, projection)

NO OVO N!@#$

Normal height and facial dimensions (cosmesis)
Oronasl closure
Occlusion
Vertical buttresses maintenance
Orbital floor protection / support
Nasolacrimal duct protection / support

Question 55

Describe the blood supply for the inferior turbinate flap. Describe 4 potential uses for the inferior turbinate flap.

Answer 55

Inferior turbinate branch of the posterolateral nasal artery (which arises from the sphenopalatine artery < from internal maxillary artery < from ECA)

Anterior = angular artery

Indications:
- Septal perforation repair
- Inner lining reconstruction in through-and-through nasal defect
- Anterior skull base repair
- Closure of palatal fistula

https://i2.wp.com/entokey.com/wp-content/uploads/2018/11/978-3-13-205391-5_c011_f002.eps_epub1.jpg?w=960

Question 56

Describe the blood supply to the Hadad-Bassagasteguy flap

Answer 56

Hadad-Bassagasteguy flap = Nasoseptal flap

Blood supply: Nasoseptal artery (branch of the posterior septal artery < from sphenopalatine artery)

Question 57

Describe 8 septal perforation treatment options

Answer 57

1. Observation
2. Septal button
3. Mucosal advancement flaps
4. Mucosal advancement flaps with interposed graft (fascia, cartilage, acellular dermal allograft)
5. Inferior turbinate flap
6. Nasal floor mucosal flap
7. Facial artery myomucosal flap
8. Pericranial flap

Think nearby structures then far away structures

Question 58

What is the blood supply to the paramedian forehead regional flap? What is the course of the blood supply?

Answer 58

Supratrochlear Artery
± Supraorbital artery

Terminal branch of ophthalmic artery (which is the first intracranial branch of internal carotid artery). After exiting the orbit, the vessel travels vertically (supratrochlear notch landmark), ascending to the forehead, approximately 2 cm from the midline.

https://img.medscapestatic.com/pi/meds/ckb/52/42352tn.jpg

Question 59

What is the blood supply to the Temporoparietal Fascia regional flap? What is the course of the blood supply?

Answer 59

Superficial temporal artery (terminal branch of external carotid artery)

Runs along the posterior margin of the condylar process of mandible, and crosses the posterior root of the zygomatic process of the temporal bone

https://www.ncbi.nlm.nih.gov/books/NBK555905/

https://ars.els-cdn.com/content/image/1-s2.0-S0165587617300216-gr1.jpg

Question 60

What is the blood supply of the temporalis muscle regional flap? Describe its course

Answer 60

Deep temporal artery

The temporalis muscle flap comprises the temporalis muscle, with or without the overlying temporalis fascia. It is an axial flap based on the anterior and posterior deep temporal arteries. Deep to the skin and subcutaneous tissues is the superficial temporal fascia, also known as the temporoparietal fascia.

Course -
External carotid branches to Superficial Temporal and Internal Maxillary Artery.
Internal Maxillary branches to anterior and posterior deep temporal artery

https://entokey.com/wp-content/uploads/2016/06/image00636.jpeg

Question 61

What is the blood supply to the post-auricular regional flap?

Answer 61

Posterior Auricular Artery (branch of external carotid)

https://ars.els-cdn.com/content/image/1-s2.0-S0196070917307068-gr1.jpg

Question 62

What is the blood supply of the nape of neck flap?

Answer 62

Occipital Artery

Question 63

What is the blood supply to the nasolabial regional flap? Describe its courses

Answer 63

https://i0.wp.com/pocketdentistry.com/wp-content/uploads/2020/03/gr5-21.jpg?fit=594%2C285&ssl=1

1. Superiorly based = Infratrochlear artery (ophthalmic artery)
2. Inferiorly based = Angular Artery (terminal branch of facial artery) – Perforation of levator labii superioris muscle
3. Transverse Facial Artery (Branch of superficial temporal artery that supplies lateral face)

Transverse facial, infraorbital, and ophthalmic arteries distal to facial artery in a retrograde flow also supply flap

Angular Artery: https://i0.wp.com/plasticsurgerykey.com/wp-content/uploads/2017/09/gr1-35.jpg?w=960

Transverse Facial Artery: https://www.researchgate.net/publication/364361661/figure/fig1/AS:11431281090821774@1666192667884/Illustration-demonstrating-the-tFa-which-branches-from-of-superficial-temporal-artery.jpg

Question 64

Describe the submental island flap. Describe the blood supply to the submental regional flap.
Contents 5
Describe its course.
Max pedicure length
What are an indications for submental flaps? 2

Answer 64

Submental island flap options:
- Unipedicled
- Bipedicled
- Free flap

Can be Fasciocutaneous, myocutaneous, or osteomyocutaneous, based on the inclusion of:
- Skin
- Platysma
- Anterior belly of digastric
- Mylohyoid muscle
- Bone from inferior mandibular borders

Artery:
- Submental Artery (branch of Facial Artery)
- Can be harvested either anterograde (from facial artery) or retrograde (ligate facial artery proximal to takeoff of submental artery, thus relying on retrograde from above)
- Maximum pedicle length is 8cm via an anterograde approach

Vein:
- Submental vein
- Drains into the facial vein, EJV, or both

Can be used for:
1. Intraoral reconstruction
2. Repair of cutaneous facial defects

https://media.springernature.com/lw685/springer-static/image/art%3A10.1186%2Fs13005-022-00343-0/MediaObjects/13005_2022_343_Fig1_HTML.png

Question 65

Describe the blood supply of the platysma regional flap - describe the dominant one and 4 additional contributors

Answer 65

The blood supply of the platysma myocutaneous flap is extensive with the primary supply coming from the submental artery which branches from the facial artery. Additional supplies come from the other vessels.

1. Submental Artery
2. Transverse cervical
3. Superior thyroid artery
4. Occipital artery
5. Posterior auricular artery

“POST” (SCM one plus submental artery)
- POsterior auricular
- Occipital
- Superior thyroid
- Transverse cervical

https://ars.els-cdn.com/content/image/1-s2.0-S1043181005000631-gr1a.jpg

Question 66

Describe the blood supply of the SCM regional flap

Answer 66

Dual blood supply from above and below, predominantly from above (Type 2 flap - 1 dominant pedicle, 1 secondary pedicle)

Dominant (above):
1. Occipital Artery (major blood supply)
2. Superior thyroid artery
3. Posterior auricular artery

Secondary (Below)
1. Transverse cervical artery

https://image.slidesharecdn.com/localandregionalflapsinheadandneckreconstruction-180217201716/85/local-and-regional-flaps-in-head-and-neck-reconstruction-57-320.jpg?cb=1665787051

Question 67

Describe the blood supply to the Trapezius regional flap. What is its course?

Answer 67

Type 2:

Transverse cervical artery (dominant vessel)
- The transverse cervical artery originates from the thyrocervical trunk, it passes through the posterior triangle of the neck to the anterior border of the levator scapulae muscle, where it divides into deep and superficial branches.

If using it as a free flap:
- Superior flap: occipital artery, paraspinous muscle perforators, only reliable choice following neck dissection
- Lateral island flap - transverse cervical artery
- Lower island flap (extended island) - descending branches of the transverse cervical artery and dorsal scapular artery

https://image.slidesharecdn.com/localandregionalflapsinheadandneckreconstruction-180217201716/85/local-and-regional-flaps-in-head-and-neck-reconstruction-57-320.jpg?cb=1665787051

https://o.quizlet.com/lHDxI51aECHh7E7Ct3LrpQ.png

Question 68

Describe the blood supply to the Deltopectorial regional flap. What is its course?

Answer 68

1st to 4th Internal mammary cutaneous perforators (branch from Axillary artery)

Kevan FP Page 19

https://www.semanticscholar.org/paper/Deltopectoral-Flap-Revisited-in-the-Microvascular-A-Andrews-McCulloch/e5b73a680fea62025c61bf86af558df030e16885

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTlyL-g2Lkw5eKUbEt1SYesvgUrjjzMhMhyT57jlseQ1UjKl5F_clRaiGppTO8E1bYrjQU&usqp=CAU

Question 69

Describe the blood supply of the Pectoralis Major regional flap. What is its course? 3
What are its innervations? 1

Answer 69

Type 5 (1 dominant, multiple segmental)
1. **Dominant artery: Pectoral branch of thoracoacromial artery (medial branch from axillary artery) **
2. Lateral thoracic artery (lateral branch from axillary artery)
3. Internal mammary artery perforators

Innervated by the lateral pectoral nerve, which must be divided to denervate the muscle flap.

The medial pectoral nerve innervates the pectoralis minor.

Kevan FP Page 19

https://pocketdentistry.com/wp-content/uploads/2016/06/f111-001-9781455753284.jpg

https://i0.wp.com/plasticsurgerykey.com/wp-content/uploads/2019/03/f034-001-9780323243223.jpg?w=960

Question 70

Describe the neurovascular supply to the radial forearm free flap (artery, vein, nerve, tendon). Describe the supply for the osseous composite component

Answer 70

Fasciocutaneous flap

Artery: Radial artery
- Perforators travel in lateral intermuscular septum (brachioradialis-flexor carpi radialis)
- 2-2.5mm diameter, 20cm length

Vein: Venae comitantes or cephalic vein

Nerve: Medial or Lateral antebrachial cutaneous nerve

Tendon: Palmaris longus, if present

Can also harvest part of the radius for an osteocutaneous flap, however too thin for dental implants
- Up to 10cm and 40% of radial circumference can be taken
- Not suitable for osseointegration

Question 71

Describe the neurovascular supply to the lateral arm free flap (artery, vein, nerve, tendon). Describe the supply for the osseous composite component.

Answer 71

Fasciocutaneous flap

Artery: Posterior radial collateral artery from the profunda brachii artery
Vein: Venous comitantes from Posterior radial collateral vein
Nerve: Posterior cutaneous nerve of the arm/forearm

Less commonly used, as many of its applications have been supplanted by the ALT flap

Can also be used as a osseous composite free flap:
- Vessels: Posterior radial collateral artery of Profunda Brachii artery
- Up to 10cm and 1/6th of humeral circumference can be taken

Kevan FP Page 20

Question 72

What are 2 reasons for hand ischemia after raising a forearm free flap

Answer 72

1. Lack of palmar arch
2. No connection between superficial and deep palmar arches

Question 73

Describe the neurovascular supply to the Lateral thigh free flap (artery, nerve)

Answer 73

Type: Fasciocutaneous flap

Artery: 3rd perforator of the profunda femoris (Deep femoral artery). Travels in intermuscular septum between the vastus lateralis and bicep femoris

Nerve: Lateral Femoral cutaneous nerve of the thigh

Question 74

Describe the neurovascular supply to the Anterolateral thigh (ALT) free flap (artery, vein, nerve, fascia)

Answer 74

Type: Musculocutaneous flap

Artery: Descending branch of the lateral circumflex artery
Vein: Venae comitantes
Fascia: Tensor fascia lata
Nerve: Anterior femoral cutaneous nerve, lateral femoral cutaneous nerve

Pedicle is between the vastus lateralis and rectus femoris.
Lateral thigh flap - pedicle is between the vastus lateralis and the biceps femoris.

Kevan FP Page 20

Question 75

Describe the neurovascular supply to the Temporoparietal free flap (artery, vein, nerve, tendon)

Answer 75

Can be taken as a pedicled or free flap

Artery: Superficial temporal artery
Vein: Superficial temporal vein

Flap is just below the subcutaneous layer:
- Skin
- Subcutaneous tissue
- Temporoparietal fascia = superficial temporal fascia
- Loose areolar tissue
- Deep temporal fascia (has both a superficial and deep layer)
- Temporalis muscle
- Pericranium
- Cranium

Kevan FP Page 21

Question 76

Describe the neurovascular supply to the Gracilis free flap (artery, vein, nerve)

Answer 76

Muscle free flap

Gracilis flap: Medial thigh muscle flap commonly used for facial reamination. Often part of a 2 stage procedure with a cross face sural graft

Artery: Terminal branch of the adductor artery <- profunda femoris artery (deep femoral artery)
Vein: Venae comitantes
Nerve: Motor supply from anterior branch of the obturator nerve

https://media.springernature.com/lw685/springer-static/image/chp%3A10.1007%2F978-3-030-74232-4_26/MediaObjects/498460_1_En_26_Fig2_HTML.png

Question 77

Describe the neurovascular supply to the Latissimus Dorsi free flap (artery, vein, nerve)

Answer 77

Type: Muscle or Musculocutaneous flap

Artery: Thoracodorsal artery (branch from subscapular artery < axillary artery < subclavian)
- Medial and lateral branches allow for 2 skin paddles
Vein: Thoracodorsal vein
Nerve: Thoracodorsal nerve

Kevan FP Page 21

https://images.squarespace-cdn.com/content/v1/5b3677595cfd79256009eb92/f9ffb400-8c5b-4ef2-ac61-9aa82a8d62ee/214BB838-4959-438B-BBD4-3C165DB6C5E0.JPEG

Question 78

Describe the neurovascular supply to the Rectus Abdominus free flap (artery, vein, nerve)

Answer 78

Type: Muscle or Musculocutaneous flap

Most common configuration is the transverse rectus abdominis musculocutaneous flap (TRAM flap)

Artery: Deep superior and deep inferior epigastric artery (inferior pedicle larger and provides musculocutaneous perforators supplying skin)
Vein: Deep superior and deep inferior epigastric vein
Nerve: Any of the intercostal nerves (lower six)

Note: MUST REAPPROXIMATE THE ARCUATE LINE

https://i0.wp.com/plasticsurgerykey.com/wp-content/uploads/2020/06/10-1055-b-006-163726_c055_f001.jpg?w=960

https://www.modeplasticsurgery.com.au/wp-content/uploads/2018/07/Untitled17-1.png

Question 79

Describe the neurovascular supply to the Fibula free flap (artery, vein, nerve, tendon). What are the principles of fibular free flap?

Answer 79

Type: Osteocutaneous (composite) flap

Artery: Peroneal artery (aka. fibular artery –> branch from tibial fibular trunk from popliteal) - perforators run in posterior intermuscular septum; take flexor hallicus longus and soleus to protect the pedicle
Vein: Peroneal vein (from posterior tibial vein)
Nerve: Lateral Sural cutaneous nerve (branch from tibial nerve)

Principles/key points:
- Up to 25cm of bone available, contourable due to segmental blood supply
- 8-10cm of remaining bone is required superior and inferior to bone cuts - maintains ankle and knee stability
- Sural nerve passes between 2 heads of gastrocnemius, and wraps around the lateral malleolus
- Poor perfusion of skin flap overall, around 5-10% risk of failure (not reliable skin blood supply)
- Skin paddle should be designed around the perforator
- A cuff of flexible hallicus longus and soleus should be included to protect perforators to the skin

Peroneal artery: https://upload.wikimedia.org/wikipedia/commons/3/36/Popliteal_branches_from_posterior_labeled.png

Peroneal vein: https://coreem.net/content/uploads/2016/10/Screen-Shot-2016-10-21-at-12.51.45-PM.png

Sural nerve: https://my.clevelandclinic.org/-/scassets/images/org/health/articles/22323-sural-nerve

Lateral lower leg muscular anatomy: https://i.pinimg.com/564x/05/32/25/053225fec092756ef02aec0bc7626a84.jpg

Question 80

Describe the neurovascular supply to the ilac crest free flap (artery, vein)
What are the main indications?

Answer 80

Type: Osseous, myoosseous, or osseomyocutaneous

Artery: Deep circumflex iliac artery (DCIA) –> external iliac artery (just above inguinal ligament)
Vein: Deep circumflex iliac vein

Natural shape conforms to native mandible (use ipsilateral hip)

Indications: Best for osseointegrated implants as it has the largest cross sectional area, however skin paddle is geometrically limited for soft tissue reconstruction. Due to soft tissue limitations and donor site morbidity, this is less frequently used

https://www.microsurgeon.org/dcia

Question 81

List 4 scapula free flap options. Discuss the neurovascular supply to the scapula flap and indications for the scapular flap. What are the main advantages?

Answer 81

Scapula flap is based on the subscapsular system. Subscapular artery is the largest branch off the axillary artery, that divides into:
1. Circumflex scapular artery, which divides into:
a. Transverse cutaneous branch –> Transverse scapula flap
b. Descending cutanous branch –> Parascapaular flap
2. Thoracodorsal artery, which divides into:
a. Angular branch –> Scapula tip
b. Transverse branch & vertical branch –> latissimus dorsi flap
c. Branch to serratus anterior muscle –> serratus muscle (with rib)

Terminal cutaneous branches - when following the pedicle follow it deep through the muscle

Flap Options:
1. Transverse Scapular Flap
- Skin paddle flap
- Artery: Transverse branch of circumflex scapular artery

2. Parascapular flap
   - Skin paddle flap
   - Artery: Descending branch of circumflex scapular artery
3. Scapular tip
   - Angular branch of thoracodorsal artery
   - AKA TDAST donor site (Thoracodorsal Artery Scapular Tip flap)
   - Can be combined with latissimus muscle or myocutaneous flap (also supplied by thoracodorsal)
4. Lattisimus dorsi flap
   - Thoracodorsal artery
5. Serratus (anterior) muscle flap
   - Branch to serratus artery from thoracodorsal artery

Vein: Venous comitans
Bone: 10-12cm length from inferior lateral aspect of bone
Not suitable for osseointegration

Key points/advantages on Scapula flaps:
- Desirable due to independent rotation of bone and soft tissue paddles, and pliability of soft tissue
- Circumflex scapular artery travels through the triangular space

Kevan FP Page 22

https://www.microsurgeon.org/scapulaflap

Question 82

What are the borders of the triangular space and its implication of the scapula free flap?

Answer 82

Borders:
1. Teres Major
2. Teres Minor
3. Long head of triceps

The apex of the scapular flap is centered over the triangular space, where the circumflex scapular artery provides the vessel to this flap after it travels through the triangular space.

https://www.microsurgeon.org/scapulaflap

Question 83

Name 5 flaps that derive from the subscapular artery system

Answer 83

CIRCUMFLEX SCAPULAR ARTERY:
1. Scapular flap - based on transverse cutaneous branch of circumflex scapular artery
2. Parascapular flap - based on descending cutaneous branch of circumflex scapular artery

THORACODORSAL ARTERY:
1. TDAST (thoracodorsal artery scapular tip) - based on angular branch of thoracodorsal artery to the scapular tip
2. Latissimus dorsi flap - based on thoracodorsal artery
3. Serratus muscle flap - based off branch to the serratus anterior muscle from the thoracodorsal artery

Question 84

Describe the Jejunal flap and neurovascular supply. What are the main indications and how does the procedure work?

Answer 84

Type: Visceral flap

Indications:
- Circumferential pharyngoesophageal defects

Procedure: A segment of jejunum is selected by transilluminating the mesentery and identifying an area fed by a single mesentery artery and vein branch. Typically, the second or third branch provides adequate pedicle length and length of jejunum to supply the flap.

Artery: Branch of superior mesenteric artery (usually the second arcade)
Vein: Branch of superior mesenteric vein
Nerve: Peristalsis is maintained by action of autonomic plexuses

https://www.microsurgeon.org/jejunum

Question 85

What is the one main key difference/disadvantage of the jejunal flap?

Answer 85

The flap does not grow blood vessels/neovascularize - therefore it will ALWAYS remain pedicle dependent!

Question 86

Describe the Gastro-omental flap. Describe its neurovascular supply.
What are its main indications in the head and neck?

Answer 86

Artery: Right or left gastroepiploic artery
Vein: Right or left gastroepigloic vein

Rarely used flap in the head/neck

Indications for head/neck:
- Severe cicatrical scarring (hair follicles destroyed) from radiation
- Coverage of extensive scalp defects

https://www.microsurgeon.org/omentum

Gastroepiploic artery: https://upload.wikimedia.org/wikipedia/commons/thumb/5/54/Stomach_blood_supply.svg/500px-Stomach_blood_supply.svg.png

Question 87

What is the neurovascular supply of the dorsalis pedis osseous composite free flaps?

Answer 87

Artery = dorsalis pedis artery
Nerve superficial peroneal nerve
- Thin sensate cutaneous flap from dorsal foot - 2nd metatarsal included for osseocutaneous flap

Question 88

What is the neurovascular supply of the rib osseous composite free flaps?

Answer 88

Intercostal vascular pedicle; marginal blood supply to skin

Question 89

What flap is used for dynamic facial reconstruction?

Answer 89

Gracilis

Question 90

List the 4 main categories of free flaps and 2-3 examples of each

Answer 90

1. FASCIAL & FASCIOCUTANEOUS FREE FLAPS
   a. Radial forearm free flap
   b. Lateral arm
   c. Anterolateral thigh
   d. Temporoparietal
2. MUSCLE & MYOCUTANEOUS FREE FLAPS
   a. Gracilis
   b. Rectus abdominis
   c. Latissimus Dorsi
3. COMPOSITE FLAPS
   a. Fibula free flap
   b. Iliac crest
   c. Scapula
4. VISCERAL FLAPS
   a. Jejunal
   b. Gastro-omental

Question 91

What test must you perform prior to radial forearm free flap harvest? What 2 anatomical variations can result in hand ischemia?

Answer 91

Allen’s test to assess for ulnar collateral flow (keep radial artery occluded to determine whether ulnar artery isolated can provide enough flow.

Greatest concern with RFFF is integrity of ulnar collateral flow through the palmar arches (superficial and deep)

2 Anatomic Variations:
1. Incomplete superficial palmar arch
2. Lack of communication between superficial and deep palmar arch (superficial arch communicates to deep palmar arch to supply it)

Thumb is supplied by Princeps pollicis artery (branch off the deep palmar arch). The presence of BOTH of the above puts the vascular supply of the thumb at risk.

Kevan FP Page 23

Question 92

What are the options for mandibular reconstruction based on the location of defect?

Answer 92

Posterolateral Defect:
1. No reconstruction (allow it to swing! Not a good option, poor function)
2. Plate reconstruction
3. Osteocutaneous free flap
4. Autologous bone graft

Lateral segment defect:
1. Plate reconstruction
2. Osteocutaneous free flap
3. Autologous bone graft

Anterior defect:
1. Osteocutaneous free flap
2. Autologous bone graft
*Plating is a poor option (80% extrusion at 2 years)

Question 93

For lip reconstruction, what are your reconstructive considerations? List 3 main considerations

Answer 93

1. Upper or lower lip
2. Size of defect (0 to 1/2, 1/2 to 2/3, or >2/3)
3. Partial thickness or full thickness

Question 94

What are the subunits of the lip?

Answer 94

Upper lip:
1. Alar-facial sulcus
2. Nasolabial crease
3. Nasal base
4. Upper lateral subunits (x2) - lateral to the philtrum
5. Philtrum
6. Philtrum columns (the lines that make the philstrum
7. Vermillion subunits (x2 - one upper, one lower)
8. Cupid’s bow (philtral groover or dimple at the top of the lip)
9. White roll (most distinct centrally)

Lower Lip:
10. Commissure
11. Lower subunit
12. Labiomandibular crease
13. Mentolabial crease (upper chin, makes the crease)
14. Chin

Question 95

What are the muscles contributing to the oral cavity sphincter? 6

Answer 95

UPPER:
1. Levator anguli oris (raises mouth)
2. Zygomaticus major (superolateral movement)

SIDE:
3. Buccinator (compresses cheeks against teeth (e.g. chewing, blowing, sucking)
4. Risorius (outward and upward)

DOWN:
5. Depressor Anguli Oris (corners of mouth downward)

OVERALL:
6. Orbicularis Oris (overall orofacial function)

Question 96

How many segments are there of the upper and lower lip?

Answer 96

Upper lip: Left, right, philtrum
Lower lip: Left, right

Question 97

What are the ideal goals for reconstruction of the lip?

Answer 97

1. Sensate
2. Intact sphincter function for control of watertight closure/seal
3. Sufficient opening for food, dentures, oral hygiene
4. Aesthetically acceptable

Question 98

What are reconstructive options for partial thickness lip defects? List 6. ie. post-vermillionectomy)

Answer 98

Vermillionectomy = lip shave

1. Labial buccal mucosa advancement flap or V-Y advancement flap
2. Ventral tongue flap (2 stage)
3. Cross lip mucosa flap (2 stage)
4. Bipedicle visor-type flaps (2stage)
5. FAMM flap (Facial artery myomucosal flap)
6. Mucosalization by secondary intention

https://oncohemakey.com/reconstruction-of-complex-lip-defects/

Question 99

What are the reconstructive options for full thickness lower lip defects? Classify based on size of defect. List 10 options.

Answer 99

0-1/2 of lip:
1. Primary Closure

1/2-2/3 of lip:
2. Abbe flap (if oral commissure is spared)
3. Estlander flap (if oral commissure is involved)
4. Karapandzic flap

> 2/3 of lip:
If adequate adjacent cheek tissue:
Midline defect:
5. Bernard repair with multiple modifications
- Webster modification includes burow triangles (triangular pieces of tissue that can be taken anywhere to increase scar length) with limbs within the melolabial fold.
- Width of base of triangle equals 1/2 of width of lip tissue excised

Lateral Defect:
6. Gilles fan flap
7. Full-thickness nasolabial transpositional flap

If inadequate adjacent cheek tissue:
8. Regional flap
9. Free flap
- Radial forearm most common
- ± Palmaris longus static sling
- ± Reinnervation from the lateral antebrachial cutaneous nerve to the mental or inferior alveolar nerve
10. Revascularized flap

Kevan FP Page 24

Question 100

Describe the Abbe Lip switch flap, indications, and vasculature

Answer 100

Indications: Defect < 1/3 of the lip + intact commissure
Benefit: muscle continuity, preserves landmarks (cupid’s bow, philtrum, modiolus)
Limitations: two-stage, insensate
Design: full thickness, half the defect width, based on ipsilateral labial artery
Tip: protect the labial artery with a cuff of muscle and ensure adequate mouth opening during the 2-week period between the first and second stages.

https://www.theplasticsfella.com/lip-reconstruction/

Question 101

Describe the Estlander flap, indications, and vasculature

Answer 101

Also called Abbe-estlander flap

Indications: defect < 2/3 of upper and lower lip + commissure affected
Benefit: single-stage is possible
Limitations: insensate, can distort oral animation as modiolus altered.
Design: full thickness, third-half defect width, contralateral labial artery
Tip: protect the labial artery with a cuff of muscle; it may require secondary commissuroplasty.

https://www.theplasticsfella.com/lip-reconstruction/
Contralateral artery: chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://cdn.mdedge.com/files/s3fs-public/CT107003144.PDF

Question 102

Describe the Karapandzic Flap, indications, and vasculature

Answer 102

The karapandzic flap is an orbicularis oris myocutaneous flap with an axial blood supply.

Indications: central defect < 2/3 of upper and lower lip
Benefit: single-stage, sensate, preserves oral competence and landmarks (philtrum and modioulus)
Limitations: can lead to microstomia
Design: rotational, circumoral flaps based on the bilateral labial arteries
Tip: preserve the vascular pedicles and buccal nerve branches by performing intramuscular dissection

Question 103

What are the reconstructive options for full thickness upper lip defects? Classify based on size of defect. List 10 options.

Answer 103

0-1/2 of lip:
1. Lateral defect: Primary Closure
2. Medial Defect: Perialar cheek crescent excisions + primary closure

1/2-2/3 lip:
1. If commissure spared: Abbe flap
2. If commissure involved: Estlander flap
3. Karapandzic flap

> 2/3 of lip:
If adequate adjacent cheek tissue:
4. Midline defect: Advancement flaps via method of Dieffenbach and Webster (similar to perialar cresentic areas to allow advancement and reduce tension)
5. Lateral defect: Nasolabial transposition flap; Gilles Fan Flap (looks like a one-sided karapandzic)

If inadequate adjacent cheek tissue:
6. Temporal forehead flap
7. Regional flap
8. Free flap

Question 104

Options for reconstruction of the buccal mucosa? 6

Answer 104

Small:
- Primary closure
- STSG
- Dermal graft

Moderate:
- Temporoparietal fascia flap (with STSG)

Larger/full thickness:
- Regional (pectoralis major or lat dorsi)
- Free flap

Question 105

Describe the FAMM flap. What type of flap is it?
Describe the course of the facial artery
What are the artery and vein associated?
What are the indications?

Answer 105

Facial Artery Myomucosal flap
Axial flap
Artery: Facial artery, either superior or inferior based
Vein: Facial venous plexus

Intraoral axial flap based on facial artery, which includes:
1. Mucosa
2. Submucosa
3. Buccinator and orbicularis oris muscles

The facial artery arises from the anterior surface of external carotid. It moves deep to the platysma, digastric and stylohyoid muscles. It then continues along the posterior surface of the submandibular gland. The artery curves upward over the body of the mandible and courses along the anteroinferior border of the masseter. The pulse of the facial artery is palpable as it crosses the mandible. The artery continues superiorly at an oblique angle across the cheek towards the oral commissure then ascends along the side of the nose terminating at the medial canthus of the eye as the angular artery.

Indications:
1. Hard palate
2. Alveolus
3. Nasal lining
4. Upper lip
5. Lower orbit
6. Lower lip
7. Floor of mouth

https://www.researchgate.net/publication/318406425/figure/fig1/AS:619865937309696@1524798964634/Design-of-the-FAMM-flap.png

https://i2.wp.com/entokey.com/wp-content/uploads/2018/11/978-3-13-205391-5_c018_f004.eps_epub1.jpg?w=960

Course of Facial Artery:
https://www.kenhub.com/en/library/anatomy/facial-artery
https://i.ytimg.com/vi/CBNIK2MpMzw/maxresdefault.jpg

Question 106

What are the goals for reconstruction of the floor of mouth?
What are the options?
What are the regional and free flap options?

Answer 106

Goals:
1. Reduce bulk
2. Reduce tethering post-operatively
3. Maintain articulation of speech
4. Maintain oral phase of swallowing

OPTIONS:
1. Secondary intention
2. Primary closure
3. Dermal graft
4. STSG (small defect)
5. Local flaps (e.g. Nasolabial flap - moderate defect)
6. Regional Flaps (moderate defects)
7. Free tissue transfer

REGIONAL FLAPS:
1. Forehead flao (superficial temporal artery)
2. Submental artery island flap (submental branch of facial artery)
3. Facial artery musculomucosal flap (FAMM - includes some buccinator and buccal fat)
4. Platysma flap
5. Deltopectoral flap (historical)
6. Pectoralis Major flap

FREE TISSUE TRANSFER:
1. Radial forearm
2. Lateral arm
3. Anterolateral thigh

Question 107

What are the options for reconstruction of anterior tongue depending on the size?

Answer 107

A. UP TO 50% RESECTION
1. No reconstruction (secondary intention)
2. Primary Closure
3. STSG or Dermal graft only

B. LARGER OR COMPOSITE RESECTION
1. Free radial forearm
2. Lateral arm flap
3. ALT for increased bulk

C. TOTAL GLOSSECTOMY RECONSTRUCTION
1. Pectoralis Major
2. Rectus abdominus
3. Latissimus Dorsi
4. ALT flap

Question 108

List the blood supply for the following flaps:
1. Melolabial flap
2. Dorsal nasal
3. Paramedian forehead
4. Forehead
5. Temporoparietal
6. Postauricular
7. Submental island
8. FAMM Flap
9. Palatal island
10. Inferior turbinate
11. SCM
12. Trapezius
13. Deltopectoral
14. Pectoralis major
15. Supraclavicular
16. Radial forearm
17. Lateral arm
18. Lateral thigh
19. Anterolateral thigh
20. Rectus abdominus
21. Latissimus Dorsi
22. Gracillis
23. Jejunum
24. Gastroomental
25. Fibula
26. Iliac crest
27. Scapula
28. Dorsalis pedis osseus
29. Rib

Answer 108

1. Melolabial flap
   - Inferiorly based: Angular artery
   - Superiorly based: Infratrochlear
   - Perforators through levator labii superioris muscle
2. Dorsal nasal - dorsal nasal artery
3. Paramedian forehead - supratrochlear, supraorbital
4. Forehead - Superficial temporal
5. Temporoparietal - Superficial temporal
6. Postauricular - Posterior auricular
7. Submental island - Submental branch of facial
8. FAMM Flap - Facial
9. Palatal island - Greater palatine
10. Inferior turbinate
    - Posterior: Descending branch of SPA
    - Anterior: Angular
11. SCM
    - Upper 1/3: occipital (main) and posterior auricular
    - Middle 1/3: Superior thyroid
    - Lower 1/3: Suprascapular or transverse cervical
12. Trapezius
    - Lateral island: transverse cervical
    - Superior island: occipital and paraspinous perforators
    - Inferior (lower) island: descending branches of transverse cervical and dorsal scapular
13. Deltopectoral - 1st to 4th perforators from internal mammary
14. Pectoralis major - Pectoralis branch of thoracoacromial artery, lateral thoracic, and internal mammary artery perforators
15. Supraclavicular - Supraclavicular
16. Radial forearm - Radial artery
17. Lateral arm - Posterior radial collateral from profundal brachii
18. Lateral thigh - 3rd perforator of the profundal femoris
19. Anterolateral thigh - Descending branch of lateral femoral circumflex
20. Rectus abdominus - Deep inferior epigastric
21. Latissimus Dorsi - Thoracodorsal
22. Gracillis - Terminal branch of adductor artery
23. Jejunum - Vascular arcade from SMA
24. Gastroomental - Right gastroepiploic
25. Fibula - Peroneal artery
26. Iliac crest - Deep circumflex iliac artery
27. Scapula - Circumflex scapular
28. Dorsalis pedis osseus - Dorsalis pedis
29. Rib - Intercostal vascular pedicle

Question 109

Describe the stages of wound healing and the predominant cell types in each.

Answer 109

1. Inflammation (Day 0-7)
   - Phase also includes hemostasis (sometimes referred to as the 4th stage)
   - Involves chemotaxis to site of injury
   - PMNs clear debris from wound
   - Macrophages follow and secrete cytokines and growth factors
   - PMNs are first cells to arrive within 24hr
   - Macrophages are key cell
2. Proliferation (Day 4-Week 3)
   - 3 Major components
   - a/ Angiogenesis = macrophages secrete TNF alpha
   - b/ Fibroplasia = fibroblasts form collagen (III>I)
   - c/ Epithelialization
   - Fibroblasts are key cell
3. Maturation (Week 3 - 1 year)
   - Achievement of collagen equilibrium
   - Where synthesis of collagen by fibroblasts = breakdown of collagen by matrix metalloproteinases
   - Type III collagen is replaced by Type I collagen until normal adult ratio of 4:1 is obtained
   - 2 major components: contraction (not the same as contracture which is a functional disability) and remodelling
   - Myofibroblasts are key cell

Mnemonic: HIP Mom
1. Hemostasis (Coagulation)
2. Inflammation
3. Proliferation
4. Maturation

Question 110

Describe the phases of skin graft take and their days

Answer 110

1. Plasmatic Imbibition (24-48h)
   - Skin graft “imbibes” (drinks) nutrients from donor site (absorption of nutrients from underlying recipient bed). Dependent on donor site for nutritional support
2. Inosculation
   - Osculate = kissing
   - Recipient and graft vessels “align” and kiss - growth of graft’s blood vessels to meet pre-existing blood vessels of recipient bed
3. Revascularization (48h-7d) - why we take casts off at 7d
   - Angiogenesis and vessel ingrowth into graft, bridges graft to underlying tissues.

Question 111

Differentiate between primary vs. secondary wound contracture

Answer 111

Primary contracture:
- Immediate contracture due to elastin, dehydration
- FTSG > STSG

Secondary contracture:
- Delayed contracture as part of maturation process of wound healing (recall, myofibroblast mediated)
- STSG > FTSG

Question 112

How do you harvest a split calvarial bone graft? What bone do you take?

Answer 112

• Parietal bone is the most appropriate source
• Stay 2cm from cranial suture lines
• Go through outer table down to diploic (marrow) layer. For instance with a drill
• Chisel out outer cortical layer
• Reconstruction is optional, but may fill with bone substitutes

Question 113

Regarding free flaps, what is the benefit of proximal flaps vs distal flaps?

Answer 113

Vasculature closer to the heart are generally less atherosclerotic than vasculature farther (eg. Pec vessels are better than leg). So proximal flap vessels are nicer than leg.

Question 114

In microvasculature re-anastomosis, if you have one atherosclerotic vessel and one not, how do you anastomose? Soft to hard or hard to soft?

Answer 114

Soft to hard.
If you go hard to soft, when you enter the hard vessel you may break off the atherosclerosis and tear the intima.
When you go soft to hard, then you’re entering the hard vessel through the intima and therefore won’t tear it.

Question 115

What are the reconstructive options for lower eyelid defects?

Answer 115

1. Primary closure
2. Lateral canthotomy with primary closure
3. Full thickness skin graft (good for anterior lamella only, or secondary intention)
4. Tenzel procedure - < 50 %
5. Hughes procedure - > 50%
6. Mustarde procedure - large
7. Free Tarsal graft
8. Laterally based upper lid graft

See handwritten notes

Question 116

What are the reconstructive options for upper eyelid defects?

Answer 116

1. Primary closure
2. Lateral cantholysis + primary closure
3. STSG
4. Tenzel
5. Cutler Beard
6. Tarsal-conjunctival sliding flap
7. Posterior lamellar graft with myocutaneous flap
8. Pedicled flap from lower lid

See handwritten notes

Question 117

What are the reconstructive options for full thickness eyelid defects?

Answer 117

• Under 25%
  1. Primary closure
  2. Secondary intention if possible
• 25-30%
  1. Lateral canthotomy with primary closure (gives an extra 5-10mm)

30-50%
1. Lower lid: Tenzel
2. Upper lid: Sliding tarsoconjunctival flap

50% or more
1. Free tarsoconjunctival graft with STSG or myocutaneous local flap
2. Upper lid: STSG, Cutler-Beard, Regional flaps (nasal, temporal)
3. Lower lid: Modified Hughes procedure, Mustarde, FTSG

Question 118

What are the methods to prevent lower lid contracture (ectropion, entropion) in a subciliary approach? 4

Answer 118

1. Frost stitch
2. Do not incise septum
3. Resuspend maxillary soft tissue
4. Lower lid massage