79.Axial pattern flaps

Question 1

difference btwn axial pattern flap and sub dermal plexus flap

Answer 1

axial pattern flap relies on blood supply from a direct cutaneous artery and vein incorporated into the flap—allows for a larger flap with increased survivalcan be rotated 180 degreepenninsula vs island flapcan also come as composite flaps (can include underlying muscle, bone or cartilage)

Question 2

survival rates of axial pattern flaps

Answer 2

87-100%the tips of the flap are most prone to necrosis but mean survival of an axial pattern flap is at least 50% greater than fro sub dermal plexus flap

Question 3

advantages of axial pattern flap

Answer 3

–larger–cover bigger defects–rely on direct cutaneous vessel–more consistent blood supply, does not require delay phenomenon–can cover bone, tendon, ligaments–more consistent survival

Question 4

disadvantages of axial pattern flap

Answer 4

–cosmesis (unwanted hair, mammae)–may be of limited use for distal extremities–regional anatomy may be variable (rely on US or doppler to find artery)

Question 5

easiest and hardest direct cutaneous arteries to find

Answer 5

easiest–caudal superficial epigastricshardest–cranial cervical artery

Question 6

T/Fdogs have a much higher density of tertiary and higher order blood vessels than cats (especially over the trunk)

Answer 6

TRUEless cutaneous perfusion to the uninjured skin in catscats heal slower and risk greater tissue necrosis with flapspreserve SQ fat in cats!

Question 7

angularis oris flap

Answer 7

use: facial, nasal, palatal defectbase: labial commissuredorsal incision: ventral aspect zygomatic archventral incision: ventral mandibular ramuslength incision: to vertical ear canal(branch of facial artery)

Question 8

superficial temporal flap

Answer 8

use: maxillofacial, eyelid defectsbase: zygomatic archrostral incision: along lateral orbital rimcaudal incision: rostral to ear baselength incision: middle of contralateral dorsal orbital rim

Question 9

caudal auricular flap

Answer 9

use: neck, facial, ear, dorsal head defectsbase: depression btwn wing of atlas and vertical ear canaldorsal incision: parallel from base, centered over lateral neckventral incision: parallel from base, centered over lateral necklength incision: spine of scapula

Question 10

superficial cervical branch of omocervical flap*

Answer 10

use: facial, ear, cervical shoulder, axillary defectscranial incision: parallel to caudal incision and equidistant to cranial scapular spinecaudal incision: acromion to dorsally over scapular spinelength incision: variable; contralateral shoulder

Question 11

superficial brachial flap

Answer 11

use: antebrachial, elbow defectsbase: centered over dorsal third of elbow’s flexor surfacelateral and medial incisions: parallel from base, taper togetherlength incision: distal to greater tubercle humerus

Question 12

thoracodorsal flap*

Answer 12

use: thoracic, shoulder, forelimb, axillary defectscranial incision: from acromion dorsally over scapular spinecaudal incision: parallel to cranial incision and equidistant to caudal scapular spinelength incision: variable; contralateral shoulder

Question 13

lateral thoracic flap

Answer 13

use: elbow, axillary, upper extremity defectsbase: axillary skin foldventral incision: parallel to dorsal border of deep pectoral muscledorsal incision: below origin of thoracodorsal artery (near acromion)length incision: terminates at/before costal chondral arch (second teat NOT included)

Question 14

cranial superficial epigastric flap

Answer 14

use: sternal defectsbase: caudal to thoracic cage on either side of midlinemedial incision: abdominal midlinelateral incision: parallel to medial incision and equidistant to teatslength incision: includes glands 3,4

Question 15

caudal superficial epigastric flap*

Answer 15

use: caudal abdominal, flank, inguinal, preputial, perineal, thigh, stifle defectsmedial incision: abdominal midlinelateral incision: parallel to medial incision and equidistant to teatslength incision: may include glands 2-5

Question 16

DORSAL deep circumflex iliac flap

Answer 16

DORSAL Use: ipsilateral flank, lateral lumbar, pelvic, lateromedial thigh, greater trochanter defectsbase: cranioventral edge of wing of iliumcaudal incision: midway btwn greater trochanter and ilium extending dorsallycranial incision: parallel to caudal incision and equidistant to the iliac winglength incision: dorsal to contralateral flank fold

Question 17

VENTRAL deep circumflex iliac flap

Answer 17

VENTRALUse: lateral abdominal wall, pelvic and sacral defectsbase: cranioventral edge of wing of iliumcaudal incision: midway btwn greater trochanter and ilium extending ventrally cranial to femur shaftcranial incision: parallel to caudal incisionlength incision: proximal to patella

Question 18

lateral genicular flap

Answer 18

Use: medial stifle or tibial defectsbase: 1 cm proximal to patella and 1.5 cm distal to TT (laterally)dorsal and ventral incisions: parallel from base extending caudodorsally along femoral shaft length incision: distal to greater trochanter

Question 19

reverse saphenous conduit flap

Answer 19

saphenous artery and vein from femoral artery and veinrequires intact collateral circulation to distal extremityUse: tarsometatarsal defectsProximal incision: distal incision:length incision: variable;

Question 20

T/Fthe presence of granulation tissue is required for axial flaps

Answer 20

FALSEgranulation tissue is NOT required for axial pattern flaps HOWEVER the recipient bed should be free of gross contamination

Question 21

most robust and versatile axial pattern flaps

Answer 21

caudal superficial epigastricthoracodorsal

Question 22

% survival and % partial tip necrosis seen with thoracodorsal flap

Answer 22

98% survival (but were not rotated)70% experience partial tip necrosis

Question 23

maximum length of a caudal superficial epigastric flap

Answer 23

maximum gap length would include the second mammary gland

Question 24

what muscle is in the caudal superficial epigastric flap

Answer 24

dissect below (in order to include) the supramammaruis muscledissect ABOVE external abdominal oblique

Question 25

mean survival btwn cranial and caudal superficial epigastrics

Answer 25

95% caudal87% cranial

Question 26

important structures near and under angularis oris flap

Answer 26

facial nerve branches (dorsal, ventral, auriculopalpebral)branches of auriculotemporal nerveparotid salivary ductfacial vein

Question 27

survival rate of caudal auricular flap

Answer 27

85%

Question 28

survival rate and degree of flap necrosis of genicular flap to cover tibial defects

Answer 28

89% survival10-30% necrosis

Question 29

reverse saphenous conduit flap is dependent on what

Answer 29

dependent on REVERSE flow through the vascular anastomoses btwn branches of the cranial tibial and saphenous arteries and btwn branches of the medial and lateral saphenous veinsrequires intact collateral circulation in order to achieve reverse flow

Question 30

outcome of reverse saphenous conduit flap

Answer 30

CONGESTION from reverse flow of blood through veins

Question 31

latissimus dorsi myocutaneous flap

Answer 31

type V vascular pattern (single dominant vascular pedicle with segmental vascular pedicle)dorsally–thoracodorsal arteryventrally–lateral thoracic arterysome intercostal arteries (deep to lats)

Question 32

location of latissimus dorsi myocutaneous flap

Answer 32

craniodorsal point is at the level just ventral to acromion and caudal to triceps ventral point is lower 1/3 of humerusincised caudodorsally to the level of the 13th rib

Question 33

cause of necrosis of axial pattern flaps

Answer 33

** inadequate blood perfusion **—-flap elevation will decr perfusion—-rotation can cause vascular obstruction—-tension compromises vasculature —-hematoma or seroma formation increases interstitial P and vascular compromise—-poor surgical technique

Question 34

monitor for flap survival

Answer 34

–color (may be hard if pigmented, devoid artery (pale), devoid vein (congested)–warmth–bleeding (prick center)–laser doppler–fluorescein (has not correlated with sup.temp.flaps)most flaps will declare themselves by the end of 6 days

Question 35

T/Fflaps are partially denervated

Answer 35

TRUEthis flap thermoregulation and pain sensation may be disrupted making subjective assessment of flap survival difficult

Question 36

salvage of failing flaps

Answer 36

1. if partial tip necrosis—heal by second intention2. if too much tension–release borders3. pentoxifylline, vasodilators, Ca channel blockers4. hyperbaric oxygen5. VACstudies on efficacy are conflicting!