CHAPTER 13: MICROSURGERY AND FLAPS Flashcards

Question

Name a classification for musculocutaneous (muscle) flaps

Answer 1

Mathes and Nahai 1981 PRS Type I - One dominant pedicle o TFL, Gastroc, Rectus Femoris, Abd Dig Min Type II - One dominant + minors o Gracilis, Soleus, Trapezius, Peronei, Biceps Fem, Semitend, Brachioradialis, Abductor Digit Quinti, Abductor Hallucis. - Delaying by ligating the dominant vessel improves survival. - A portion of muscle can be based on a minor pedicle but whole muscle will not survive. Type III - Two dominant pedicles o Pec Minor, Serratus, Rectus Abdominus, Temporalis, Gluteus maximus. - good for dividing up eg pec minor for facial reannimation (slips to orbit, slips to angle of mouth). TRAMS for breast. Type IV - Segmental o sartorius, Tib Ant, EDL, EHL, FDL, FHL. - Muscle survives if only proximal vessel divided (sartorius switch).  Type V - One dominant + segmental o L Dorsi, Pec Major. - Will survive if dominant pedicle divided but segmental supply preserved (Pec Major turnover flap for sternum)

Answer 2

Flap based on venous pedicle. Veins have small arteries within them. Type 1 = single venous pedicle Type 2 = venous flow through flaps supplied by a vein which enters one side of the flap and exits from the other. Type 3 = Arterialised venous flaps e.g. saphenous flap (short saphenous vein) for knee defects

Answer 3

Local = composed of tissue adjacent to the defect Regional = tissue from same region e.g. head and neck, upper limb Distant = Pedicle → remain attached to the distant part, can be transposed, waltzed or attached to a carrier (usually the wrist) to get into position. Free → completely detached and anastomosed.

Answer 4

By the method they are transferred into defect. Rotation flap Semicircular flap, rotates about pivot point through arc of rotation into adjacent defect e.g. buttock rotation flap Transposition Flap flap moves laterally about pivot point into adjacent defect. e.g. Z plasty, Limberg (Rhomboid), Bilobed, Post thigh flap (ischial sore). Defect closed directly/ SSG Hatchet flap = transposition + rotation Interpolation Flap moves laterally into defect not immediately adjacent. E.g. Nasolabial island flap to nasal tip, deltopectoral flap Advancement Flaps Flap moves forwards. Facilited by stretching, excision of Burrow’s triangles, V-Y advancement, Z plasty at base. Primary closed donor defect. V-Y, Y-V, Reiger flap on nasal dorsum, lip advancement techniques.

Answer 5

Technique transforms ungraftable bed → graftable Flap into defect → vascular ingrowth Superficial parts of flap raised again leaving segment of sc tissue that can take graft. Put superficial part of flap back.

Answer 6

Langer lines (1800's) Relaxed skin tension lines (Borges) Lines of maximal extensibility - perpendicular to above

Answer 7

Transposition of 2 adjacent triangular flaps Used for 1. ↑ length of area of tissue or scar 2. Break up a straight line scar 3. Realign a scar 4. Return structures to anatomical alignment

Answer 8

``` o 30° → 25% lengthening o 45° → 50% length o 60° → 75% length o 75% → 100% length o 90% → 125% ```

Answer 9

1. Z - plasty - from Z → S - Mark desired position - Draw central limb down existing scar - Lateral limb from one end of the scar to the new line - 2 patterns will be available → one wide angle and one narrow angle - Select pattern with the narrower angles 4 flap - ABCD → CADB 5 flap - ABCDE → BACED

Answer 10

Advancement → simple, modified, VY or bipedicled | Pivot → transposition, rotation, bilobed

Answer 11

Perforator is any innominate vessel in subcut tissue going to skin Nomenclature - musculocutaneous perforator - septocutaneous - direct cutaneous

Answer 12

a composite block of tissue that may be removed from a donor site to a distant recipient site where its circulation is restored by microvascular anastomosis

Answer 13

- thin layer of platelets at anastomosis (immediate → 72hrs) - pseudointima forms (5days) - new endothelium (1-2wks)

Answer 14

rough dissection, diathermy, prolonged vasospasm, dessication, clamps >30g/mm2, large needles, repeated stabs, partial thickness bites sutures too loose / tight, too many, unequally spaced

Answer 15

o Collagen exposed → trigger plt aggregation and degranulation (ADP and thromboxane). o Intrinsic → factor XII stimulated by collagen exposure. 12,11,9,8 o Extrinsic → factor VII stimulated by tissue factors e.g. lipoproteins from damaged cells. o Both converge at factor X o Coag and complement pathways initiated o X causes PT → Thrombin (Factor V & Ca2+) o Thrombin causes Fibrinogen → Fibrin o Thrombus propagates & traps red cells (white → red thrombus)

Answer 16

Intrinsic and extrinsic pathways

Answer 17

``` Christmas = F IX deficiency Haemophilia = F VIII deficiency ```

Answer 18

Heparin - ↑ amount of antithrombin III which inactivates thrombin, so reduction in amount of fibrinogen to fibrin. → ↓ platelet adherence. Aspirin - Inhibits platelet aggregation, mediated by cyclooxygenase pathway. Proteolytic enzymes - Streptokinase, urokinase and t-PA (salvage cases, repeated thrombosis) Dextran - polysaccharide, with antiplatelet & antifibrin properties Tranexamic Acid – Anti fibrinolysis – inhibits activation of plasminogen to plasmin

Answer 19

- Papaverine (adrenoceptor blockade) - Verapamil (calcium channel inhibitor) - Lignocaine (membrane stabilization by sodium channel blockade)

Answer 20

- Replace like with like - Types of tissue + volume - Sensate v non sensate - Donor site morbidity - Ease of raising / speed/ position - Length of pedicle

Answer 21

Equipment - Scope or loupes x6 → x 40 - Micro set - Single and double clamps closing pressure under 30g/mm2 - Sutures Monofilament 8-11/0 , atraumatic needles - 100 units/ml of heparin flush - antispasmodics

Answer 22

- Keep well filled - Hct 0.3 → 0.35 - Warm - Monitor Urine output - Muscle relaxation - Prevent pressure sores

Answer 23

- Surgical precision, vessel diameter, blood flow into anastomosis, tension,anticoagulation - Adequate access, dry field, position and secure flap, avoid kinks/twists, careful preparation, flush with heparin, limit distension with dilators, check forward flow, be happy with set up.

Answer 24

- well hydrated - pain free - Warm room, warming blanket - Urine output 1ml/kg/hr - Systolic BP over 100mmHg, MAP >60 - Hct 0.25 - 0.35

Answer 25

- Colour - Refill - Tissue turgor - Temperature (ΔT) (beware differences of more than 2°C between flap and core = ischaemia). Differential Thermography → esp. good for digital replants - Bleeding on pinprick

Answer 26

- Doppler pulse (art / vein) → may give false +ve due to sound transmission - Doppler coupler - Transcutaneous oxygen sat (digits) - Laser Doppler (1.5mm penetration) - Near Infrared spectroscopy → penetrates deeper - Impedance monitoring → measure impedance b/t 2 electrodes placed on flap - Plethysmography → measure changes in volume of flap ↑ readings = congestion - IV fluorescein fusion → demonstrated blood flow in flap→ test dose IV the followed by 15mg/kg, observe passage of fluorescein into flap with woods lamp and dark room.

Answer 27

Mechanical - Anastomosis (technical). - Pedicle (kinked, twisted, stretched, compressed) Hydrostatic - ↓ perfusion (hypovolaemia, spasm, ↓ temp) - ↓ drainage (small vein, dependent, shunting) Thrombogenic - Vessels in zone of injury - Trauma to pedicle during dissection - Hypercoagulable state - Ischaemia – reperfusion injury - Consider thrombolytics

Answer 28

- Described by Kerrigan 1993 (Microsurg) - cellular hypoxia → buildup of anaerobic metabolites (lactate) - membrane transport system disturbed → Ca influx into cells → inflammatory mediators Reperfusion - Occurs after re-establishment of circulation to flap - Neutrophils respiratory burst (xanthine oxidase) → Free radicals (superoxide O2 + Hydroxyl OH) → peroxide (H2O2). - free radicals accumulate when ischaemic - when blood supply reestablished get endothelial damage, swelling, ↑ cap permeability  Skin and s/c tissue → warm ischamia 6 hrs, cold 12 hrs  Muscle → 3hrs warm and 8 hrs cold

Answer 29

 Failure of a flap to perfuse after anastomosis  Possibly due to endothelial injury or platelet aggregation, swelling of the endothelium, leakage of intravascular fluid into interstitial space.

Answer 30

Chang 1996 J Recon Microsurg Thrombogenic state due to o Dermal vasculature o Blood circ o Vasoconstricting prostaglandins (nicotine → ↑ TXA2 and ↓ PGI2) o Carbon monoxide = COHb → tissue hypoxia and ↑ plt adhesiveness 1 cigarette → 42% ↓ blood flow velocity to hand for 1 hr Advise smoking cessation 3wks pre & post

Answer 31

Advantages - Large surface area and volume - Donor site closed directly - Well vascularised → combats infection - Muscle splitting allows customization - May retain motor function (reanimation) Disadvantages - Match size of donor and recipient nerves - Leave donor nerve short to minimize re-innervation time - Allow 50% loss of motor power after transfer - Match size and shape of donor muscle to available pocket.

Answer 32

Ponten 1981 length : breadth 3:1 thin, pliable, sensate less donor morbidity esp if d/c

Answer 33

Arterial supply from arteries supplying nerve ``` Sural nerve flap - sural nerve - short saphenous vein Cephalic flap - lateral cutaneous nerve of arm - cephalic vein ```

Answer 34

``` Bone flaps Toe and joint transfers GI flaps (omental, free jejunum) Specialised tissues - vascularised nerve and tendon ```

Answer 35

- Annelid worm - V-shaped mouth parts. Three jaws each with >100 teeth - Secrete hirudin in saliva → prevents fibrinogen → fibrin - Aeromonas hydrophilia in gut - Prophylactic Ciprofloxacin - Surrounding circle of paraffin to prevent migration

Answer 36

Temporoparietal fascial flap - superficial temporal artery - superficial to deep temporal fascia - continuous with galea & SMAS - can be raised with skin + / or deep temporal fascia - can include auriculotemporal nerve

Answer 37

Axillary artery → subscapular artery → circumflex scapular Through triangular space (borders = long head triceps (lat), teres major (inf), teres minor (sup) Transverse branch → scapular flap Descending branch → parascapular flap Scapular flap - b/t spinous processes & long head of triceps, over scapula Parascapular flap - ?larger Disadv - poor donor site scar

Answer 38

Lateral arm flap Medial arm flap Posterior arm flap Radial forearm flap Ulnar artery forearm flap Posterior interosseous artery flap

Answer 39

``` Groin flap (Type A) - sup circumflex iliac Lateral and medial thigh flap (Type B) - lat = perf br profunda femoris - med = sup femoral Anterolateral thigh flap (Type B/C) - SC / MC perforators of descending br of lat circ fem artery off profunda femoris - SC = b/t rectus femoris & vastus lateralis - MC = through RF Posterior / gluteal thigh flap - over biceps femoris - descending br of inf gluteal artery ```

Answer 40

``` Saphenous flap (Type A) - saphenous branch of descending genicular branch of superficial femoral artery ``` Anterior tibial artery flap (Type B) - anterolateral leg = b/t knee → lat malleolus - septocutaneous branches of anterior tibial a. Peroneal artery flap (Type B) - lateral leg = b/t fibula head → lat malleolus - SC branches of peroneal artery Posterior tibial artery flap (Type B) - medial leg = knee → med malleolus Sural artery flap (Type A) - sural artery direct cutaneous br of popliteal - b/t pop fossa & 2 heads of gastrocnemius Dorsalis pedis flap (Type B) - SC perforators of DP & 1st dorsal MT artery - dorsal 2/3 of foot Medial plantar artery flap (Type B) - instep of foot

CHAPTER 13: MICROSURGERY AND FLAPS Flashcards

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