79.Axial pattern flaps Flashcards
difference btwn axial pattern flap and sub dermal plexus flap
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)
survival rates of axial pattern flaps
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
advantages of axial pattern flap
–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
disadvantages of axial pattern flap
–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)
easiest and hardest direct cutaneous arteries to find
easiest–caudal superficial epigastricshardest–cranial cervical artery
T/Fdogs have a much higher density of tertiary and higher order blood vessels than cats (especially over the trunk)
TRUEless cutaneous perfusion to the uninjured skin in catscats heal slower and risk greater tissue necrosis with flapspreserve SQ fat in cats!
angularis oris flap
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)
superficial temporal flap
use: maxillofacial, eyelid defectsbase: zygomatic archrostral incision: along lateral orbital rimcaudal incision: rostral to ear baselength incision: middle of contralateral dorsal orbital rim
caudal auricular flap
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
superficial cervical branch of omocervical flap*
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
superficial brachial flap
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
thoracodorsal flap*
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
lateral thoracic flap
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)
cranial superficial epigastric flap
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
caudal superficial epigastric flap*
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
DORSAL deep circumflex iliac flap
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
VENTRAL deep circumflex iliac flap
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
lateral genicular flap
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
reverse saphenous conduit flap
saphenous artery and vein from femoral artery and veinrequires intact collateral circulation to distal extremityUse: tarsometatarsal defectsProximal incision: distal incision:length incision: variable;
T/Fthe presence of granulation tissue is required for axial flaps
FALSEgranulation tissue is NOT required for axial pattern flaps HOWEVER the recipient bed should be free of gross contamination
most robust and versatile axial pattern flaps
caudal superficial epigastricthoracodorsal
% survival and % partial tip necrosis seen with thoracodorsal flap
98% survival (but were not rotated)70% experience partial tip necrosis
maximum length of a caudal superficial epigastric flap
maximum gap length would include the second mammary gland
what muscle is in the caudal superficial epigastric flap
dissect below (in order to include) the supramammaruis muscledissect ABOVE external abdominal oblique
mean survival btwn cranial and caudal superficial epigastrics
95% caudal87% cranial
important structures near and under angularis oris flap
facial nerve branches (dorsal, ventral, auriculopalpebral)branches of auriculotemporal nerveparotid salivary ductfacial vein
survival rate of caudal auricular flap
85%
survival rate and degree of flap necrosis of genicular flap to cover tibial defects
89% survival10-30% necrosis
reverse saphenous conduit flap is dependent on what
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
outcome of reverse saphenous conduit flap
CONGESTION from reverse flow of blood through veins
latissimus dorsi myocutaneous flap
type V vascular pattern (single dominant vascular pedicle with segmental vascular pedicle)dorsally–thoracodorsal arteryventrally–lateral thoracic arterysome intercostal arteries (deep to lats)
location of latissimus dorsi myocutaneous flap
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
cause of necrosis of axial pattern flaps
** 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
monitor for flap survival
–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
T/Fflaps are partially denervated
TRUEthis flap thermoregulation and pain sensation may be disrupted making subjective assessment of flap survival difficult
salvage of failing flaps
- 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!
