Anterolateral thigh flap.pptx

Anterolateral thigh flap

1. Anterolateral thigh flap E knath.J Resident FNB,Hand and Microsurgery

2. Introduction In 1984 , Song and colleagues introduced the anterolateral thigh flap based on septocutaneous branches of the descending branch of the lateral circumflex femoral artery. O riginally described as a type B fasciocutaneous flap but more recently shown to be mostly a type C fasciocutaneous flap. Can provide muscle, fascia, skin, or any of these in combination. Early anatomic dissections on cadavers noted that the vascular anatomy was variable and that the majority of skin vessels were septocutaneous compared with musculocutaneous in nature.

3. Introduction R ecent studies and series indicate the skin vessels are predominantly musculocutaneous perforators and less commonly septocutaneous vessels. Flap has been extensively reported in the literature and has become a workhorse flap for reconstruction of small or large defects, both simple and complex, with excellent results and minimal morbidity at the donor site.

4. Anatomy

5. Anatomy

6. Anatomy ARTERIAL SUPPLY . E ither septocutaneous vessels or musculocutaneous perforators that usually arise from the descending branch of the LCFA. P rimarily based on musculocutaneous perforators vs septocutaneous ones (87% vs 13%). Less commonly, the perforators may originate from other sources such as the transverse branch of the LCFA.

7. Anatomy - LCFA Descending branch of the LCFA courses obliquely along the intermuscular septum between the rectus femoris and vastus lateralis muscles. It terminates by anastomosing with Sup.Lat Genicular artery

8. Anatomy Perforators ‘B’-most reliable and present on 90% ‘A’-located 5 cm proximal to ‘B’ and is present in 50% ‘C’-located 5 cm distal to ‘B’ and is present in 60%

9. Anatomy Septocutaneous perforators Perforators run between the rectus femoris and vastus lateralis and traverse the fascia to supply the skin of the anterolateral thigh. Moreno MA. Video-Assisted Harvesting of Anterolateral Thigh Free Flap: Technique Validation and Initial Results. Otolaryngology–Head and Neck Surgery. 2013;149(2):219-225. doi:10.1177/0194599813487490

10. Anatomy Musculocutaneous perforators musculocutaneous perforators traverse through the vastus lateralis muscle, giving off numerous intramuscular branches before piercing through the fascia and supplying the skin. Moreno MA. Video-Assisted Harvesting of Anterolateral Thigh Free Flap: Technique Validation and Initial Results. Otolaryngology–Head and Neck Surgery. 2013;149(2):219-225. doi:10.1177/0194599813487490

11. Anatomy 30% of cases, the descending branch will divide into a medial and lateral branch, with the latter giving rise to the skin vessels. 2% of cases there may be an absence of any skin vessels, either septocutaneous or musculocutaneous, or the perforator may be too small in diameter Artery may also course without the venae comitantes along its side and turn back at a more proximal point to join the course of the vein.

12. Anatomy Dominant :  branches of the descending branch of the LCFA Length: 12 cm (range 8–16 cm) Diameter: 2.1 mm (range 2–2.5 mm) Minor :  perforator of transverse branch of LCFA Length: 11 cm (range 9–13 cm) Diameter: 2.1 mm (range 1.5–2.5 mm)

13. Anatomy VENOUS DRAINAGE OF THE FLAP venae comitantes of the lateral circumflex femoral vessel and its branches Length: 12 cm (range 8–16 cm) Diameter: 2.3 mm (range 1.8–3.3 mm) “ In rare instances, there may be no existing veins with the perforator pedicle.”

14. Anatomy FLAP INNERVATION Motor vastus lateralis is innervated by a branch of the posterior division of the femoral nerve. accompanies the descending branch of the lateral femoral circumflex artery Sensory lateral femoral cutaneous nerve pierce the muscle fascia 10 cm below the inguinal ligament, medial to the tensor fascia lata.

15. FLAP COMPONENTS Cutaneous flap (skin and subcutaneous tissue based on either a septocutaneous vessel or musculocutaneous perforator)

16. FLAP COMPONENTS Composite flap fascia-only muscular (vastus lateralis myocutaneous anterolateral thigh flap) component

17. FLAP COMPONENTS Composite flap fascial (fasciocutaneous anterolateral thigh flap) muscular (vastus lateralis myocutaneous anterolateral thigh flap) component

18. FLAP COMPONENTS Combined flaps/ Chimeric flaps

19. FLAP COMPONENTS Combined flaps/ Chimeric flaps

20. FLAP COMPONENTS Combined flaps/ Chimeric flaps

21. INDICATIONS PEDICLED Lower abdominal wall Groin Suprapubic Perineum and penis Trochanteric and lateral gluteal area Knee.

22. INDICATIONS FREE FLAP Head and neck Esophagus Trunk Abdominal wall Breast reconstruction Penile reconstruction Upper extremity Lower extremity

23. PREOPERATIVE PREPARATION Any previous scars? history of previous injuries/Surgery to thigh Quadriceps function Thickness of the thigh tissue Presecnce of Hair?? Atherosclerotic disease?

24. FLAP DESIGN ANATOMIC LANDMARKS ASIS Patella (Superolateral Border)

25. FLAP DESIGN 35 x 25 cm on a single perforator Limiting the width of the flap to 7–9 cm allows for primary closure of the donor site without the need for a skin graft. Not necessary to design the flap with the skin vessel at the center. In areas requiring a thin flap, ALT can be elevated as a cutaneous flap as thin as 5 mm in thickness When extensive soft tissue coverage is needed, and muscle is believed to be necessary, the anterolateral thigh flap can be harvested with vastus lateralis muscle as a myocutaneous flap or rectus femoris muscle as a chimeric flap

26. FLAP DIMENSIONS Skin Island Dimensions Length 4-35cm Width 4-25cm, Max to close primarily being 9cm (centre) Muscle Dimensions Length: from 2 cm (cuff) to 20 cm (entire muscle)

27. FLAP HARVEST

28. FLAP HARVEST

29. FLAP HARVEST

30. FLAP HARVEST

31. FLAP HARVEST

32. Video assisted ALT harvest

33. Video assisted ALT harvest

34. Video assisted ALT harvest

35. Video assisted ALT harvest

36. Video assisted ALT harvest

37. Video assisted ALT harvest

38. Video assisted ALT harvest

39. FLAP MODIFICATION THIN FLAP WHEN BULK IS REQUIRED ADIPOFASCIAL FLAP USE OF MUSCLE COMPONENT ONLY INNERVATED FLAP FLOW-THROUGH FLAP

40. FLAP MODIFICATIONS Thinned ALT Flap defects of the face and neck, axilla and forearm, anterior tibia and ankle, and dorsum of the foot and hand Preservation of at least a 2 cm radius of tissue around the pedicle is recommended Defatting before vessel ligation allows for continuous monitoring of flap perfusion can be thinned up to the dermal plexus without compromise to the blood supply, provided that the flap is within 9 cm around the perforator.

41. FLAP MODIFICATIONS When Bulk is required larger flap harvest, partially de-depithilalised part used to add bulk to defect Add Vastus lateralis to add bulk Chimeric flaps (TFL,other skin flaps) Inclusion of thigh fat

42. FLAP MODIFICATIONS Adipofascial Flap a thin flap that does not require skin is desired for covering exposed tendons, providing a gliding surface, and allowing for easy closure of the overlying skin and intraoral defects, such as for tongue repair. fascia is exposed and incised, a subfascial dissection is performed until the perforator is located. A minimum of 3 mm of fat should be preserved over the fascia

43. FLAP MODIFICATIONS Innervated Flap lateral femoral cutaneous nerve pierces the fascia approximately 10 cm caudad to the anterior superior iliac spine & divides into two or three branches. Inclusion of the motor nerve to the vastus lateralis can provide motor function to a myocutaneous flap

44. FLAP MODIFICATIONS FLOW-THROUGH FLAP The pedicle can be used to bridge a vascular gap in the extremity or the distal end can serve as the blood supply to another free flap.

45. Advantages • Ease of harvest with relatively constant anatomy • Long length and large pedicle • Versatility in design with variable thickness and incorporation of various tissue components • Ability to provide sensory innervation • Lack of significant donor site morbidity • Decreased operative time with two-team approach.

46. Disadvantages Color mismatch in some patients for facial reconstruction • Presence of hair in some patients • Skin graft requirement at donor site if >8 cm or 9 cm width of harvested tissue. • Lack of vessels with reasonable size in rare cases.

47. Thank You