Classification of flaps

Classification of flaps for Mch classes

1. CLASSIFICATION OF FLAPS Dr. Prabhu Dayal Sinwar Resident Plastic and Reconstructive Surgery

2. Introduction Flap consists of a tissue that is mobilized on the basis of its vascular anatomy. It may consists of simple skin tissue, muscle, fascia, bone. The purpose of classification is to understand the anatomy and features that each flap provides. It also provides easy communication with peers and patients to achieve a common goal of reconstruction.

3. Timeline of the development of flap surgery 600 BC Sushruta Samhita Pedicle flaps in the face and forehead for nasal reconstruction 1597 Tagliacozzi Nasal reconstruction by tubed pedicle flap from arm; described “delay” of pedicle flap 1896 Tansini Latissimus dorsi musculocutaneous flap for breast reconstruction (post- mastectomy) 1920 Gillies Tubed pedicle flap 1946 Stark Muscle flaps for osteomyelitis 1955 Owens Compound neck flap 1963 McGregor Temporalis flap 1965 Bakamjian Deltopectoral flap 1971 Ger Lower extremity musculocutaneous flap 1972 McGregor and Jackson Groin flap 1972 Orticochea Musculocutaneous flaps 1977 McCraw et al Musculocutaneous territories 1981 Mathes and Nahai Classification of muscle flaps based on vascular anatomy 1981 Ponten described fasciocutaneous flap

4. Atomic Classification of Tolhurst (Modified by Hallock ,2004) Conditioning Conformation Contiguity Construction Constituents Circulation

5. Basis for flap classification

6. * Pedicle usually drain single source( unipedicle ) and antegrade / orthograde flow

7. Fascial plexus : divided into 1) Subfascial plexus : plexus lying on the under surface of the fascia . relatively minor plexus . incapable of sustaining a fascial flap . 2) Prefascial plexus : dominant distribution system . 3) Subcutaneous Plexus • Network of vessels which divide subcutaneous fat into deep (loose) and superficial (dense) layers. • More developed in torso than in extremities. • Supplied by both septo -cutaneous and Musculo -cutaneous arteries .

8. 4) Sub dermal Plexus : • Located at junction between reticular dermis and subcutaneous fat. • Vessels have a continuous arterial muscular wall. • Primary blood supply to the skin. • Primarily distributor function. • Corresponds with “dermal bleeding” at the edge of the flap. 5) Dermal Plexus • Present at lower limits of dermal papillary ridge. • The Vessel in the plexus are arterioles and wall contains isolated muscular elements . • Primarily thermoregulatory function . 6) Sub epidermal Plexus • Located at dermoepidermal junction. • Consists mostly of capillaries having no muscle in their wall. • Therefore they serve to have primarily nutritive function .

9. RANDOM FLAP AXIAL FLAP • Based on the rich sub - dermal vascular plexus of the skin. • Derive their blood supply from a direct cutaneous artery or named blood vessel . • Most of the local flap are random flaps. E.g Bipedicle flap, VY advancement flaps, rotation or advancement flaps • Examples : Nasolabial flap (angular artery) , Forehead flap( supratrochlear artery). • Maximum length : breadth ratio of 1 : 1 in the lower extremity. Up to 3 : 1 in the face. • The surviving length of an axial pattern flap is entirely related to the length of the included artery.

10. Random flaps

11. Flap based on Constituents Muscle and Musculocutaneous flaps 1981, Mathes and Nahai classification Five vascular pattern

12. Advantages of muscle, musculocutaneous flap Vascular pedicle are specific and reliable. Vascular pedicle often located outside surgical defect. Muscle provide bulk for deep extensive defect and protective padding for exposed vital structure. Muscle is malleable and can be manipulated. Well vascularised muscle resistant to bacterial infection and inoculation. Often one stage procedure. Restoration of function possible with certain flap.

13. Disadvantages of muscle, musculocutaneous flap Donor defect may lose some degree of function. Donor defect may be aesthetically undesirable. May provide excessive bulk or may atrophy over time. May result in contour deformities at the donar site.

14. Fascia and Fasciocutaneous flaps Fascial flap consist of fascia detached from its normal origin or insertion and transposed to another location. Fasciocutaneous flap consist skin, subcutaneous tissue and underlying fascia. 1975, Schafer found three major vascular system for deep fascia Perforating arteries Subcutaneous arteries Subfacial arteries 1981, Ponten for lower extrimity reconstruction 1983,Tolhurst for trunk and axillary reconstruction.

15. MATHES AND NAHAI On the basis of the source of the pedicle Examples Groin fascio-cutaneous flap Superficial inferior epigastric flap Examples Scapular and para -scapular flap Lateral arm flap Examples Median forehead flap Antero-lateral thigh flap

16. CORMACK AND LAMBERTY Examples Lower leg flaps described by Ponten Examples Scapular and Parascapular flap Examples Radial forearm flap Lateral arm flap Also TYPE D flaps are osteomusculofasciocutaneous flaps with vascular supply similar to Type C

17. Nakajima classification

18. Advantages of fascia, fasciocutaneous flap Thin and pliable Blood supply is reliable and robust. Donor site morbidity is minimal. They are muscle sparing. Have ability to restore sensation. There are many potential donor site.

19. Disadvantages of fascia, fasciocutaneous flap Lack of bulk for deep defect. Technically more challenging. There are size limitation. Arc of rotation sometimes limited. (though often better than similar muscle flap.) Donor site may require skin graft closure.

20. Perforator flap ( Skin with fat and with or without fascia ) Skin flap with or without fascia based on single perforator. Evolved from musculo -cutaneous and fascio -cutaneous flap without the muscle and fascial carrier. Aiming to minimizing donor morbidity.

21. Perforasome theory Given by Saint-Cry Reported four major characteristic Each perforosome linked with adjacent perforosome. Flap design and skin paddle orientation should be based on direction of linking vessel. Filling of perforosome occur within perforosome of same source artery first. Mass vascularity of a perforator found adjacent to an articulation is directed away from the same articulation.

22. Types of perforator based on surgical dissection Type 1: Direct perforators perforate the deep fascia only Type 2: Indirect muscle perforator predominantly supply subcutaneous tissue. Type 3: Indirect perforator predominantly supply the muscle Type 4: Indirect perimyceal perforator Type 5: Indirect septal perforator

23. Propeller flap, an island flap is a type of perforator based local flap that reaches the recipient site via an axial rotation of upto 180 degrees around the perforator.

24. Advantages of perforator flap Reduced donor site morbidity Versatility of flap design Muscle sparing Improved post operative recovery of patient

25. Disadvantages of perforator flap Meticulous dissection needed Increased operative time Variability in size and position of perforator vessels Steep learning curve

26. Visceral flap Jejunum To reconstruct esophagus Colon / Jejunum Vaginal reconstruction Appendix Urethra and voice reconstruction Omentum To reconstruct a wide range of extraperitoneal defect Also have immunologic and angiogenic property

27. Bone flap ( Vascularised bone, osseous- periosteal flap) Flap Based on Fibula Peroneal Artery Iliac crest Deep circumflex iliac artery Scapula Circumflex scapula or thoraco -dorsal artery Radius Radial artery Calvarial osseous flap Superficial temporal artery or occipital artery Genicular osseous- periosteal flap ( Medial femoral condyl flap ) Articular branch of decending genicular artery

28. Nerve flap Sensory nerve supplied by extrinsic and intrinsic blood supply. Extrinsic blood supply : From arteria nervorum from perforating vessels. Intrinsic blood supply : From longitudinal oriented arteriole. Nerve flap can harvested from superficial located sensory nerve based on perforating vessels.

29. Nerve Based on Superficial radial nerve flap Radial artery and accompanying vein Saphanous nerve flap Femoral artery (proximally) Saphanous artery (distally) Sural nerve flap Superficial / medial sural artery * Lesser saphanous vein can be arterialised if perforator are missing.

30. Lymph node flap Offer a solution in Lymphoedema patient. Require supermicrosurgery technique for anastomosis extremly small vessels. Source vessels are superficial inferior epigastric artery, superficial circumflex iliac artery and supraclavicular artey .

31. Flap based on Contiguity (Destination) Flaps can be classified as Local flaps (Tissue adjacent to the flap) Regional flap (Tissue from the same region of the body as the defect) e.g. Radial forearm flap for a defect on the dorsum of hand. Distant flaps Pedicled from a distant part of the body staying attached to its original vasculature Free flaps are completely detached from the body and anastamosed to recipient vessels close to the defect

32. Flap based on construction / flow Unipedical flap: Pedicle usually drains into single source. Bipedical flap: Flap with dual pedicle. Random pattern skin flap to cover a defect on extremity, Transabdominal bipedicle flap to provide coverage on dorsum of hand.

33. Retrograde flow flap: When orthograde pedicle ligated proximally than flow of flap become reversed and flap based on distal part of major pedicle. First reported by Bostwick et al using a reverse flow temporal artery island flap. Other are Distally based radial forearm fasciocutaneous flap, posterior interosseous flap, Reversed first dorsal metacarpal artery flap used in hand reconstruction. Sural fasciocutaneous flap Lateral calcaneal flap Reverse flexor hallucis longus flap

34. Supercharged flap : In addition to its original vascular source, using an unrelated distant vascular source to anastomose to a flap may result in augmentation of either inflow or outflow. Superior unipedicled transverse rectus abdominis musculocutaneous flap.

35. Turbocharging : Using main vascular source to connect to an additional pedicle from same flap create a direct flow to vascular territory of the connected branch. Connecting ipsilateral and contralateral deep inferior epigastric vessel of TRAM flap to improve vascular supply of whole TRAM flap.

36. Venous flaps ( Arterialised venous flap): Using subcutaneous vein for arterial inflow and venous outflow. Does not require a donor site artery. Widely used for soft tissue repair on hands and fingers.

37. Woo’s classification of arterialised venous flap for hand and finger reconstruction based on presence of intervenous valve, venous network of donar site, location, number of vein at recipient site. Type I: Through and along valve Type II: Against valve Type III: Mixed pattern (through and against valve)

38. Flap based on conditioning 1. Delay “ preliminary surgical intervention wherein a portion of the vascular supply to a flap is divided before definitive elevation and transfer of the flap”. In 16 th century Tagliacozzi delayed his upper arm flap by making parallel incision. In 1921 Blair introduced the term ‘Delay transfer’. In 1965, Milton investigated four different method of delaying a flap (in pig model). Goal are to enhance flap circulation, ensuring flap servival after advancement, transposition, or transplantation to a defect site.

39. Two theories that describe potential mechanism by which delay phenomenon prevent skin necrosis. Delay acclimatizes flap to ischemia (tolerance) : vascular delay cause adaptive metabolic changes at cellular level within the tissue. Delay improve vascularity by increasing flow through preexisting vessels, reorganizing the pattern of blood flow to more ischemic area. *May result in part from sympatholytic state that result from cutting of sympathetic innervation and subsequent vasodilation .

40. 1.STANDARD DELAY : 2. STRATEGIC DELAY : With an incision at the periphery of the cutaneous territory or partial flap elevation. Flap is then elevated after 10-14 days. With division of selected pedicles to the flap to enhance perfusion through the remaining pedicle or pedicles . Flap elevation after 2 week period. Surgical flap delay is accomplished in two ways:

41. 2. TISSUE EXPANSION 1957 : Neumann is credited with the first modern report of this technique. 1976 : Radovan further described the use of this technique for breast reconstruction . Although immediate skin expansion is possible, delayed expansion is usually performed prior to flap elevation. During a selected time interval, usually 6 week to 3 months, expander is injected with saline at weekly interval till the desired amount of expander achieved. Advantages : 1. Reconstruction with tissue of a similar color, texture and contour. 2. Reconstruction with sensate skin containing skin appendages. 3. Limited donor-site deformity.

42. 3. Prelaminated and prefabricated flap Flap prelamination : Surgical manipulation of flap that requires partial or complete flap elevation and suturing of flap to form structure at the site of reconstruction. When these structure at donar site healed, flap transposition or transplantation performed. Commonly done in flap used in head and neck reconstruction.

43. Prefabrication: Provide a new dominant vascular pedicle to structure for subsequent transposition or transplantation. Large pedicle of adjacent muscle is selected and inset beneath the proposed flap site. In 6 weeks this flap based on new vascular pedicle is elevated and transposed or transplanted.

44. 4. Sensory flap Cutaneous nerves are incorporated in the flap base or senory nerves of the the flap may be coapted to the suitable nerve at the donor site to retain protective sensibility to hands, feet and other weight bearing areas Another common area in which sensate flap are used is oral cavity and this potentially improve postoperative intraoral function.

45. 5. Functional muscle flap For function to be preserved: Motor nerve must be preserved along with dominant vascular supply Muscle must be reattached to a new bone or tendon across a joint. Muscle must exert a direct force on its new point of attachment. Eg . Latissimus , gluteus maximus (segmental), gracilis , gastrochnemius and serratus muscle.

46. Flap based on conformation Conformation of flap frequently combine multiple flap. Tubed flaps – flaps rolled over to allow easy movement from one region to another e.g. facial reconstruction. Compound flaps consist of multiple tissue components linked together in a manner that allows their simultaneous transfer and consequent more effective reconstruction.

47. Compound flaps HALLOCK’S CLASSIFICATION Solitary Compound Flap – composite flaps based on a single source of circulation Combined compound Flap – compound flap with multiple sources and combined vascularisation 2a. Conjoined Flaps – At least two anatomically distinct territories each preserving their individual blood supply but joined by means of some common physical territory. Two subgroup- Perforator based or branch based(independent or common type). 2b. Chimeric Flaps – M ultiple otherwise independent flaps each having an independent blood supply but in turn all pedicles are linked to a large common source vessel. Three subclasses: perforator based, branch based and fabricated(sequential type or internal type).

48. THANKS