Ch09. Recon Surgery Flashcards
1
Q
How much bone can you get from fibula?
A
Up to 40 cm
2
Q
Disadvantages of using fibular free flap?
A
Variable and tenuous blood supply to skin paddle
Septocutaneous perforators make for a precarious skin island
Skin graft may be required at donor site for osseocutaneous harvest (skin paddle >6 cm)
3
Q
Artery, vein, nerve for fibular free flap?
A
Peroneal (fibular) artery
Peroneal vein
Lateral cutaneous branch of peroneal nerve
4
Q
Normal occlusion in Angle’s classification
A
The mesiobuccal cusp of the upper first molar occludes with the buccal groove of the lower first molar. If anterior to buccal groove then class II (retrognathic); if posterior then class III (prognathic)
5
Q
What is the epidermis?
A
Outer layer, predominant cell is the keratinocyte (epidermis rarely referred to as cuticle)
6
Q
Epidermis layers
A
Crazy layers give skin bulk
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
7
Q
What is stratum corneum?
A
Most superficial, dead cells (no nucleus), loosens then desquamates
8
Q
What is stratum lucidum?
A
Second most superficial, absent in thin skin
9
Q
What is stratum granulosum?
A
Middle layer. 3-5 layers thick, flattened, keratohyalin granules
10
Q
What is stratum spinosum?
A
4th layer (prickle layer) initiates keratin synthesis, basophilic cells
11
Q
What is stratum basale?
A
single layer of cuboidal cells above basal lamina; continuously divide to renew outer layers
12
Q
How are cells connected?
A
Desmosomes form cell-to-cell
Hemidesmosomes form cell-to-basal lamina
13
Q
What is epidermal-dermal junction?
A
“blueprint” for overlying skin, must be re-established in repair
14
Q
What are epidermal-dermal junction elements?
A
- Rete pegs: epidermal projections into dermal layer
2. Papillae: dermal, vascularized projections into epidermal layer
15
Q
What is the dermis?
A
Inner layer, predominant cell is the fibroblast (dermis rarely referred to as subcuticle, as in subcuticular stitch, which is simply intradermal)
16
Q
What are the dermal layers?
A
- Papillary
2. Reticular
17
Q
What is the papillary layer?
A
Lies immediately deep to the epidermis, made of loose connective tissue, contains small blood vessels and nerve endings
18
Q
What is the reticular layer?
A
Made of dense connective tissue; contains blood vessels, hair follicles, sweat glands, nerves and sebaceous glands
19
Q
What is Fitzpatrick scale?
A
a numerical classification schema for human skin color developed by Thomas Fitzpatrick
20
Q
What is hypodermis?
A
The subcutaneous layer deep to skin and contains fat and fibrous tissue
21
Q
What are the methods of wound closure?
A
- Primary (first intention)
- Secondary (second intention)
- Tertiary (third intention, delayed primary)
22
Q
What is the primary/first intention wound closure?
A
Skin edges are approximated within hours, optimal cosmesis, typically for clean wounds
23
Q
What is the secondary/second intention wound closure?
A
Wound is left open, wound bed granulates, contracts -> increased scar, typically for contaminated or very small wounds
24
Q
What is the tertiary/third intention/delayed primary?
A
Delayed closure after initial secondary healing (and possible debridement)
25
What is the definition of chronic wounds?
>4-6 weeks old
26
What are the stages of cutaneous wound healing?
1. Inflammatory/Substrate Phase
2. Proliferative Phase
3. Remodeling (maturation) phase
27
What are the steps of inflammatory/substrate phase of cutaneous wound healing?
1. Hemostasis
| 2. Inflammatory (cellular)
28
What is the first step of hemostasis in the inflammatory/substrate phase of cutaneous wound healing?
Initial vasoconstriction for 10-15 minutes (thromboxane A2) followed by vasodilation (histamine, serotonin [platelets], and nitric oxide [endothelium])
29
What is the second step of hemostasis in the inflammatory/substrate phase of cutaneous wound healing?
Endothelial cells contract
- > expose collagen, fibronectin, and laminin
- > forms platelet plug with fibrin from coagulation cascade
30
What is the third step of hemostasis in the inflammatory/substrate phase of cutaneous wound healing?
The coagulation and complement cascades, along with activated platelets, release biologically active substances including prostaglandins, growth factors, and cytokines (chemotactic and proliferative factors), which active their target cells
31
What are the roles of neutrophils (PMNs) in inflammatory/substrate phase of cutaneous wound healing?
Appear by 6 hours, maximum cellular influx at 24-48 hours (not critical for wound healing); clean wound for debris and bacteria by phagocytosis
32
What are the roles of macrophages in inflammatory/substrate of cutaneous wound healing?
Essential for wound healing (regulatory function); predominant cell type by 48-96 hours; attracted by PDGF; transition wound into stage of repair; attract fibroblasts via PDGF; secrete TNF-alpha, TNF-beta, IGF-1, and IL-1
33
What are the roles of fibroblasts in inflammatory/substrate of cutaneous wound healing?
Appear by 48 hours, maximum cells at 15 days; predominant producer of collagen, elastin, and fibronectin (differentiate into myofibroblasts, which are important for wound contraction, disappear by apoptosis once a scar is formed)
34
What are the steps in the proliferative phase of cutaneous wound healing?
1. Reepithelialization
2. Neovascularization
3. Collagen deposition
35
What is the first step in reepithelilization of proliferative phase of cutaneous wound healing?
Begins within hours with basal epithelial cell differentiation and separation from basement membrane (may be stimulated by epidermal growth factor), collagenease and plasmin begin dissolution of eschar matrix, matrix metalloproteinases also imporatant for degradation and remodeling
36
What is the second step in reepithelization of proliferative phase of cutanoeus wound healing?
Initial cellular detachment from loss of desmosomes, pseudopod formation, and migration of fibroblast from dermis into woudn bed
37
What is the third step in reepithelization of proliferative phase of cutaneous wound healing?
Migration in "leap frog" pattern with fibronectin and others at 12-21 micron/hr (moist environment aids in migration)
38
What is the first step in neovascularization of proliferative phase of cutnaneous wound healing?
Granulation tissue begins to form ~day 4. Scaffold for cell migration made of fibrin, fibronectin, and hyaluronic acid in matrix.
39
What is the second step in neovascularization of proliferative phase of cutaneous wound healing?
Angiogenesis involving migration of epithelial cells into perivascular spaces, forms channels, and capillary buds
40
What is the third step in neovascualization of prolifeative phase of cutaneous wound healing?
Increases delivery of neutrophils, macrophages, and fibroblasts
41
What is the fourth step in neovasculaization of proliferative phase of cutaneous wound healing?
Modulated via vascular endothelial growth factor (VEGF)
42
What is are the types of collgen deposited in collagen deposition during collagen deposition of proliferative phase of cutaneous wound healing?
Initial deposition of type III collagen, later forms type I collagen
43
What is the maximum deposition of collagen duration?
Maximum deposition at 2-3 weeks
44
Describe collagen synthesis pathway during collagen deposition during proliferative phase of cutaneous wound healing
Polypeptide chains -> hydroxylation of proline and lysine (requires vit C and iron) -> combine into a helix -> glycosylation -> secreted by fibroblasts as procollagen -> cleavage to tropocollagen -> aggregates into fibrils -> combines into collagen fiber
45
What increases local tissue strength during collagen deposition during proliferative phase of cutaneous wound healing?
Collagen fiber cross-linking
46
When does the tensile strength increase during collagen deposition during proliferative phase of cutaneous wound healing
tensile strength begins to increase at 4-5 days
47
Describe the collagen types
I. most common, bone ("b-one"), tendon, late scar, fascia, skin
II. articular and hyaline cartilage ("car-two-lage")
III. skin, uterus, arteries, early scar
IV. basement membrane ("four under the floor")
48
Describe the timing and mediators of wound contraction during wound contraction phase during proliferative phase of cutaneous wound healing?
Wound contraction is mediated by myofibroblasts
- maximal at 12-15 days
- contracts at 0.6-0.75mm/day
49
What happens in the remodeling (maturation) phase?
Increase in type I collagen and more parallel alignment of collagen fibers results in increased tensile strength with decreased scar dimensions (4:1 ratio of type III to type I)
50
Tell me the strengths at 3 weeks, 6 weeks, and 6 months
3 weeks: 15% original tensile strength (highest level of collagen)
6 weeks: 60% original tensile strength
6 months: 70-80% original tensile strength (maximum achieved)
51
What are unique about fetal skin?
Does not form scars (due to decreased TGF-beta and increased MMP)
52
What are some categories of causes for compromised wound healing?
Local factors
Medications
Medical conditions
Technical factors
53
What are local factors that cause compromised wound healing?
Infection, irradiated tissue, contamination, hematoma, neoplasm, wound desiccation, hypoxia, ischemia
54
What are medications that cause compromised wound healing?
Corticosteroids, NSAIDs, chemotherapy, immunosuppressants
55
What are medical conditions that cause compromised wound healing?
Diabetes, obesity, severe malnutrition (specifically protein or loss of 20% lean body mass), cofactor deficiency (vitamin A, B12, C, zinc, folate, iron, selenium), smoking, peripheral vascular disease, hypothyroidism, connective tissue disorders (Ehlers-Danlos syndrome, osteogenesis imperfecta), immunodeficiency (Cancer, HIV, transplant), and fibroproliferative disorders (keloids, hypertrophic scars)
56
What are technical factors that cause compromised wound healing?
Traumatic handling of tissues, poor incision design, closure tension, poor hemostasis
57
What are four options in management of compromised wound healing?
Assess medical condition
Address infection
Local wound care
Hyperbaric oxygen (HBO)
58
What should we do for assessing medical condition to manage compromised wound healing?
Assess nutrition (albumin and prealbumin, total lymphocyte count, transferrin, nitrogen balance)
Dietary modifications with protein and micronutrient supplementation, consider parenteral nutrition
Assess diabetes (fasting glucose) and hypothyroidism (TSH, T4)
The catabolic state induced by stress (trauma, surgery) leads to excess protein metabolism
59
What should we do for addressing infection to manage compromised wound healing?
Culture and sensitivities with appropriate antibiotics (oral vs parenteral)
Defined as 10^5 bacterial colonies per gram of tissue
Topical antibiotics (oist environment aids in reepithelization)
Silver-based dressings prophylactic against antibiotic resistance and superinfections
60
What should we do for local wound care to manage compromised wound healing?
Debridement and irrigation (healthy tissue bleeds)
Occlusive wound dressing changes (wet-to-dry for debridement)
Consider hydrogen peroxide, sodium hypohrlotie (Dakin's solution), or povidone-iodine (Betadine) dressings to aid in local debridement and decrease bacterial load
Negative pressure dressing
Skin subsitutes
61
Tell us about negative pressure dressing that can be used for local wound care to manage compromised wound healing?
aka Wound VAC (vacuum-assisted closure)
Promotes angiogenesis, actively debrides, faster healing, use to bolster STSG (eg, burns) or save distal pedicle flap necrosis (eg, scalp), helps promote granulation tissue over exposed bone, may decrease bacterial load, not indicated over exposed dura, may be painful
62
Tell us about skin subsitutes that can be used for local wound care to manage compromised wound healing?
For larger areas, stimulate woudn bed to granulate, prevent fluid loss, contracture.
Options include cadaver versus bovine (neither for permanent use) or autologous skin grafts consisting of dermal and epidermal components
63
How is hyperbaric oxygen used in management of compromised wound healing?
For poorly healing tissue secondary to hypoxia
Creates a steep oxygenation gradient that aids in oxygen delivery
Reduces edema, activates fibroblasts and macrophages, stimulates collagen synthesis/angiogenesis, bacteriostatic/bacteriocidal
Complications?
64
What are complications of hyperbaric oxygen used in management of compromised wound healing?
Generally rare, but pneumothorax, lung toxicity (ARDS), seizures, middle ear barotrauma (may require myringotomy prior to initiating HBO)
65
What are absolute contraindications of hyperbaric oxygen used in management of compromised wound healing?
Untreated pneumothorax, select medications (eg, cisplatin, doxorubicin, disulfiram, mefenamic acid, steroids)
66
What are relative contraindications of hyperbaric oxygen used in management of compromised wound healing?
Emphysematous blebs, eustachian tube dysfunction, sinusitis, seizure disorder, history of thoracic surgery, pregnancy
67
Tell me about the reconstructive ladder
Each option for wound closure is considerd before moving to the next, more complicated option, based on the complete clinical picture
Concerns for defect analysis include size of defect, available tissue and type needed, type of injury (burn, cancer, trauma), patient comorbidities (chronic disease, infection, previous surgery, trauma, radiation, future treatments), functional status, cosmesis
68
List the reconstructive ladder
1. Second intention: best in concave areas
2. Primary closure (first intention)
3. Skin grafts: STSG, FTSG, dermal grafts
4. Local (pedicled) skin flaps (advancement, rotational)
5. Tissue expansion
6. Regional pedicled flaps
7. Free tissue transfer (free flap)
69
What are the two theories of the vascular anatomy of the skin?
Angiosome theory
| Fasciocutaneous plexus theory
70
What is the angiosome theory?
40 distinct regions of body consisting of skin paddle adn underlying tissue supplied by a named artery
71
What is fasciocutaneous plexus theory?
6 distinctive types of deep fascia perforators (can be considered direct or indirect)
1. direct cutaneous branch of a muscular artery
2. septocutaneous perforator (direct)
3. direct cutaneous perforator
4. direct septocutaneous artery
5. musculocutaneous perforator (indirect)
6. perforating cutaneous branch of a muscular vessel (indirect)
72
What are musculocutaneous vessels?
#5 of fasciocutaneous plexus theory
Dominant blood supply to skin
Ubiquitous
Small variable size of perfusion area
Run perpendicular to skin
Basis of random flaps (blood supply from dermal/subdermal plexus; most local facial skin flaps)
Based off subdermal plexus, limited 3:1 length-width ratio
73
What are direct cutaneous vessels?
```
#3 of fasciocutaneous plexus theory
Supplementary blood supply to skin
Limited number
Larger size of perfusion area
Run parallel to skin
Associated with a vein
Basis of axial (blood supply from named vesels) and island flaps (eg, paramedian forehead flap)
```
74
What are types of flaps (by tissue type?)
1. Skin flaps
2. Muscular flaps
3. Visceral flaps
4. Osseous flaps
5. innervated flaps
75
What are examples of skin flaps?
Cutaneous, fasciocutaneous, adipofascial, septocutaneous, musculocutaneous
76
What are types of muscular flaps?
1. Perforator flaps
| 2. Musculocutaneous flaps
77
What are the advantages and disadvantages of perforator flaps?
Indirect muscle perforator, indirect septal perforator, direct cutaneous perforator
Advantages: able to incorporate muscle, bone, fat; decreased donor site morbidity
Disadvantages: tedious, variable, fat necrosis
78
What are advantages of musculocutanous flaps?
```
#2 of musuclar flaps
Advnatages: compared to fasciocutaneous flap, better ability to obliterate dead space, reduce infection, and increase collagen deposition
```
79
What are the types of musculocutaneous flap types?
Classified based on vascular pedicle, types I, III, and V are most reliable
Type I: 1 dominant pedicle (eg tensor fascia lata flap)
Type II: 1 dominant + 1 or more minor (eg, gracilis flap)
Type III: 2 dominant (eg, gluteus maximus flap)
Type IV: multiple segmental (eg, sartorius flap)
Type V: 1 dominant, multiple segmental (eg, latissimus flap)
80
What are examples of visceral flaps?
Examples: omentum, colon, jejunum
| Used as free tissue transfer for pharyngoesophageal reconstruction
81
What are examples of osseous flaps?
Examples: fibula, humerus, radius, iliac crest, scapula
82
What are examples of innervated flaps?
Innervation can occur spontaneously, however, innervated flaps produce better results; almost any flap can be innervated
83
How would you innervate the following flaps?
Sural nerve: for facial reanimation
Radial forearm: for oral sensation (lateral antebrachial cutaneous nerve)
Lateral arm: allows sensation to face and/or movement of face/tongue (lower lateral brachial cutaneous nerve and/or motor to triceps)
Anterolateral thigh: for partial glossectomy (cutaneous nerve below inguinal ligament to lingual nerve)
Rectus abdominus: for partial glossectomy (anterior cutaneous branches of the intercostal nerves to lingual nerve)
84
What is another name for local (pedicled) skin flaps?
Adjacent tissue transfer
85
What are some considerations in local (pedicled) skin flaps?
Underlying disease (tumor, wound healing problems)
Smoking (increases risk of flap necrosis)
Size, depth, quality of skin
Adjacent structures, function (movement, sensation)
Cosmesis (color match, potential scarring, relaxed skin tension lines, anatomic subunits)
86
What is the basic technique of local (pedicled) skin flaps?
Undermine, orient to relaxed skin tension lines (RSTLs),
4:1 ratio of length to width for elliptical excision, avoid dog ears (eg, empoy Burow's triangles)
Develop flap, tack sutures, evaluate for anatomic distortion, reduce tension on closure
May consider allowing some areas to heal by secondary intention
87
What is the estimated length-width ratio of local flaps, and when are random and axial flaps used in H&N?
Estimated length-width ratio of local flaps is 4:1 in the face and 2:1 in the neck
- Almost all local flaps in the H&N have an element of random pattern vascular supply based on the subdermal lexus
- Axial flaps are based on a septocutaneous artery with associated venae comitantes (eg, forehead)
88
What is the difference between advancement flap and rotational flap?
They are both local skin flaps but defined by the direction of tissue movement
Advancement flap is linear
Rotational flap is radial
89
How is advancement flap characterized?
It is characterized by linear movement
90
What is a single advancement flap?
Placed over defect, long axis oriented parallel to RSTLs (relaxed skin tension lines), should not be longer than 2-3 times the width
91
What is a bilateral advancement flap?
Flaps begin on opposing ends of defect (for larger defects)
92
What is T-plasty in local skin advnacement flaps?
Converts triangular or circular defect into inverted-T scar (upper lip, forehead)
93
What are dog ears and how to prevent them?
Typically requires Burow's triangles to prevent dog ear (standing cone deformity)
94
What is V-Y plasty?
Versatile technique, can provide lengthening of some structures, V-shaped flap witih udnerlying tissue advanced into defect (good for lip and columella)
95
What are advantages, disadvantages and common uses of advancement flap?
Advantages: simple, avoids unwanted or secondary movement, avoids deformity of facial structures by favorably orienting incisions (eg, brow, lateral canthus)
Disadvantages: restricted flexibility
Common uses: forehead, chin/mentum
96
How is rotational flap characterized?
Semicircular flap, raised in subdermal plane, radial pattern of movement along a defined arc with a fixed pivot point, shares a common side with the defect
97
What is the ideal length-width ratio?
Length-width ratio is ideally 2:1
98
What is the relationship between the effective length and angle of rotation?
The effective length decreases with increased angle of rotation
99
Can you get dog ears with rotational flap?
Yes. May use Burow's triangle or a back cut to facilitate
100
What are advantages, disadvantages, and common uses of rotational flap?
Advantages: allows closure of large lesions by recruiting lax skin
Disadvantages: requires a wider base than the advancement flap, requires extensive undermining and long peripheral incision (4-5x dimaeter of the defect)
Comon uses: cheek defect using lax neck skin
101
What are transpositional flaps?
Raised from a donor site and rotated over adjacent tissue to be placed in the defect site
Base is contiguous with the defect (different from interpolated flap)
3:1 length-width ratio
Most important principles are to minimize tension and develop a wide flap base
102
What are three types of transposition flaps?
Classic rhomboid flap (Limberg)
Bilobed flap
Z-plasty and W-plasty
103
How are classic rhomboid flaps created?
Classic rhomboid flap (Limberg) is a transposition flap constructed typically from equal length segments around two 120 and two 60 angles
104
What is dufourmentel flap?
Defect diamond is created simiarly, however, the extending semgents are constructed with more acute angles (<120 and <60 angles)
Allows improved bllod supply to flap base and shares closing tensions
105
What are advantages, disadvantages, and common uses of classic rhomboid flaps?
Advantages: better distribution of tension (tension is away from defect), reliable, may be designed so the final closure will be parallel to the RSTLs
Disdvantages: forces a facial defect into an arbitrary design
Common uses: cheek, temple
106
What is a bilobed flap?
A transposition flap that recruits lax tissue (secondary flap) from a nearby site that allows primary flap to effect closure of the defect
107
Tell me about the size of bilobed flaps
Primary flap should be slightly smaller than the defect, secondary flap should be 1/2-3/4 the width of the primary flap (except on nasal tip where defect:primary flap = 1:1)
108
What are the advantages, disadvantages, and common uses of bilobed flaps?
Advantages: distributes tension evenly
Disadvantages: risk of pincuishioning, lengthy incision that rarely exploits ideal RSTLs
Common uses: nasal tip/dorsum (medial lesions generally employ laterally based flaps, lateral lesions generally employ medially based flaps), lateral cheek
109
What does Z-plsty and W-plasty achieve?
Break up scar profiles into smaller, irregular units
| Useful for scar revision.
110
Define Z-plasty
Versatile method for excising lesion or scar, reorienting and lengthening new incision
Relies on health of adjacent skin
May not be optimal for burn contractures
111
Define W-plasty
Preplanned excision with alternating angle which can be interdigitated, does not provide increase in length but can camouflage scar profile
112
What is an interpolated flap?
A flap passed over or under a bridge of skin, separated by donor site from defect (eg, subcutaneous island flap, paramedian forehead flap)
Useful in ear and nose defects
113
What are advantages and disadvantages of interpolated flaps?
Advantages: healthy vascular supply, fills deep defects
Disadvantages: requires second procedure to divide pedicle, trapdoor effect from excess donor skin
114
What is trapdoor deformity?
trapdoor deformity is characterized by the development of a protuberant, globular-appearing flap, and the deformity is likely due to the centrifugal contraction of plate-like scar tissue under the nascent repair
115
What are paramedian forehead flaps?
An interpolated flap based on supratrochlear artery, similar to a regional flap.
Great for extensive nasal defects; pedicle is divided at 3-4 weeks after inset and nasal defect healing
2 or 3 stages can be used, based on when to thin the underlying frontalis muscle and subcutaneous tissue
Forehead defect can close by secondary intention if large flap taken
