Cutaneous Flaps

Author Credentials 

G. Nina Lu, MD
Assistant Professor
Division of Otolaryngology-Head and Neck Surgery
University of Washington
Seattle, WA

 

Module Summary

A variety of cutaneous flaps are at the disposal of the trained otolaryngologist to repair cutaneous defects of the head and neck. The classification and design of cutaneous flaps are critical to understand in order to optimize patient outcomes and avoid complications. Orientation along RSTLs, vectors of tension, and relationship to vital structures are vital in flap design. Patient factors and patient preference are essential in determining the best treatment plan. This module specifically discusses cutaneous flaps. Unit reconstruction (e.g. eyelid, lip, nose) are covered elsewhere in OTOSource’s modules. 

Module Learning Objectives 
  1. Describe the classifications of cutaneous flaps.
  2. Compare and contrast advantages and disadvantages between the design of various cutaneous flaps.
  3. Discuss indications for cutaneous flaps based on patient factors, defect size, facial subunit, and aesthetic outcomes.
  4. Explain complications that can arise from cutaneous flaps and describe treatment options.

 

Anatomy

Learning Objectives 
  1. Describe the anatomic layers and components of the skin.
  • Epidermis: 
    • Cornified layer, Granular layer, Spinous Layer, Basal Layer. Predominant cell is keratinocyte.
    • Melanocytes: Confined to basal layer of epidermis
    • Langerhans Cells: Antigen-processing and presenting cells found within suprabasal epidermal layers
    • Merkel Cells: Neuroendocrine cells functioning as slow-adapting mechanoreceptos related to touch sensation. Found in basal keratinocytes. 
  • Epidermal Appendages:
    • Hair Follicle, Sebaceous glands, Eccrine sweat glands and Apocrine sweat glands
    • Pilosebaceous unit: Hair shaft, sebaceous gland, arrector poli muscle, and sensory end organ.
  • Dermis (Papillary and reticular)
    • Integrated connective tissue system between epidermis and subcutaneous adipose tissue. 
    • Ranges in thickness significantly depending on location.
    • 1 mm on the eyelid to more than 4 mm on the back
    • Principal component is collagen
  • Subcutaneous adipose tissue
  1. Explain the vascular anatomy as it relates to design of common local skin flaps.
  • Blood vessels supply the skin via two main routes: musculocutaneous and septocutaneous arteries. Musculocutaneous arteries pass through muscle to which they provide nutrition and supply a smaller region of skin. Septocutaneous arteries run parallel to the skin surface providing nutrition to a large area of skin. 
  • Both septocutaneous and musculocutaneous arteries end in a diffuse dermal and subdermal plexus. This diffuse, interconnecting network provides a redundancy in vascular supply in the skin.

Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014. Chapter 1-2.

  • Random cutaneous: The blood supply is derived from musculocutaneous arteries near the base of the flap and delivered to the distal aspect via interconnecting subdermal plexus.
  • Arterial Cutaneous Flap (axial pattern flap): A septocutaneous artery is included in the longitudinal axis of the flap. Presence of a septocutaneous artery allows for increased flap length.
  1. Recognize skin biomechanics when planning and designing local flaps.
  • Skin without tension has collagen fibers distributed throughout the dermis in a diffuse multidirectional array. During initial deformation of skin, randomly oriented collagen and elastic fibers stretch in the direction of applied force. As deformation progresses, more collagen fibers transition to load-carrying roles and resistance rises. At maximal deformation, all collagen fibers are aligned in the direction of the applied force and no further deformation is possible. 
  1. Summarize the theory by which delay improves flap vasculature.
  • When a flap is delayed, existing blood vessels within the flap will dilate at the level of “choke” vessels. Sympathetic denervation after initial flap creation may cause depletion of norepinephrine within the flap and increase blood flow to a delayed flap. 

 

 

References 
  1. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014. Chapter 1-2.
  2. Lucas, JB. The Physiology and Biomechanics of Skin Flaps. Facial Plast Surg Clin North Am. 2017 Aug;25(3):303-311
  3. Larrabee WF Jr, Holloway GA Jr, Sutton D. Wound tension and blood flow in skin flaps. Ann Otol Rhinol Laryngol. 1984 Mar-Apr;93(2 Pt 1):112-5 
  4. Myers, EN, Snyderman CH. Operative Otolaryngology: Head and Neck Surgery. Third edition. Philadelphia: Elsevier; 2018. P. 163, 1134-1148.e1

 

Patient Evaluation

Learning Objectives 
  1. Evaluate facial defects and understand the indications for choosing a cutaneous local flap within the context of the reconstructive ladder.
  • Cutaneous flaps are most suited to defects that involve cutaneous defects without a large contribution from deeper layers.
  • Reconstructive ladder includes healing via secondary intention, primary closure, skin grafts, local cutaneous flaps, regional soft tissue flaps, or free tissue transfers. Choice of reconstruction will depend on size and location of the defect, pliability or availability of surrounding soft tissue, and patient specific factors. 
  1. Identify the relaxed skin tension lines of the face and their importance in cutaneous flap design.
  • The degree of tension in the skin is greatest parallel to the relaxed skin tension lines. This depends on interaction between collagen and elastin and collagen attachments to each other. 
  • Elliptical excisions should be performed parallel to the RSTLs to place maximum closure tension parallel to the lines of maximal extensibility.

 

References 
  1. Wang CY, et al. Association of Smoking and Other Factors With the Outcome of Mohs Reconstruction Using Flaps or Grafts. JAMA Facial Plast Surg. 2019 Jun 13
  2. Johnson JT, et al. Bailey's Head and Neck Surgery--Otolaryngology. Fifth edition. Baltimore: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2014. Volume 2, Chapter 173. 
  3. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014, Chapter 5.

 

Treatment

Learning Objectives 
  1. Describe the classification different cutaneous flaps based on tissue movement. 
  • Pivotal: flaps that move around a fixed point at the base of the pedicle
    • Rotation- curvilinear configuration designed immediately adjacent to the defect, one border of the defect shared with the flap
    • Transposition- Linear configuration with the base of the flap contiguous with the defect. Flap may or may not share a border with the defect. 
      • Ex: Rhombic, Bilobe
    • Interpolated—Linear configuration similar to transposition flap but base of flap is not contiguous with the defect. Pedicle crosses over or under intervening tissue.
      • Ex: Paramedian forehead flap, melolabial flap
    • Island—An interpolated flap whose pedicle is de-epithelialized and buried to allow single-stage reconstruction. 
  • Advancement: Linear configuration and moved by sliding toward the defect. Can be unipedicled, bipedicled, V-Y, Y-V flaps
  • Hinge flaps (trap door, turn-in, or turn-down): ma be linear or curvilinear with the pedicle based on one border of the primary defect and epithelial surface turned downwards. Most often used to provide internal lining. 
  1. Describe how and when to avoid tension on surrounding structures when raising a local flap. 
  • Eyelid margin
  • Medial/Lateral Canthus
  • Nostril margin
  • Oral commissure
  • Hairline
References 
  1. Starkman SJ. et al. Flap Basics I: Rotation and Transposition Flaps. Facial Plast Surg Clin North Am 25(3): 313-321
  2. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014. Chapter 6
  3. Larrabee, WF Jr. Design of local skin flaps. Otolaryngol Clin North Am. 1990 Oct;23(5):899-923

 

Surgical Therapies

Learning Objectives 
  1. Describe indications, advantages, and disadvantages of Bilobe flaps.
  • Advantage: recruit skin for construction from areas of increased redundancy that are not adjacent to the defect. Second lobe of transposition reduces overall wound closure tension and provides greater distribution of wound closure tension. 
  • Disadvantages: Flap design does not typically follow subunit principle or RSTLs, trap door deformity can occur cur to curvilinear incisions. 
  1. Describe indications, advantages, and disadvantages of Rhombic flaps.
  • Advantages: Multiple variations to flap design but underlying design is simple and reliable. Scars from transfer are predictable and minimize distortion of surrounding structures
  • Limitations: Excess wound tension at base of flap, need for rhombic-shaped defect, standing cutaneous deformity may occur.
  • Variations: Limberg (original description), Dufourmental and Webster modifications, bilateral rhombic flaps
  1. Describe indications, advantages, and disadvantages of Paramedian forehead flaps.
  • Advantages: Able to transfer a large amount of skin with good color and texture match to facial skin, reliable anatomy, narrower pedicle with greater degree of freedom around pivot point.
  • Disadvantage: donor site scar, two-staged procedure, transfer of hair in low hairline, inability to wear glasses before pedicle division, increased wound care required post-operatively
  1. Describe indications, advantages, and disadvantages of Melolabial flaps.
  • Advantage: Recruits skin from redundant melolabial fold, donor site scar typically well hidden, decreased standing cutaneous deformity compared with transposition flaps
  • Disadvantage: Two staged procedure, limited reach with greater pivoting requiring longer flap design.
  1. Describe indications, advantages, and disadvantages of Cervicofacial advancement flaps.
  • Advantages: Good skin texture and color match, ability to repair larger defects, wound tension is typically horizontal around the eyelid.
  • Disadvantages: standing cutaneous deformity medially requiring excision, random pattern flap, need for full thickness skin graft of donor site.

 

 

References 
  1. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014. Chapter 10-13.
  2. Chu EA, PJ. Byrne. Local flaps I: bilobed, rhombic, and cervicofacial. Facial Plast Surg Clin North Am. 2009 Aug;17(3):349-60
  3. Ricks M, Cook J. Extranasal applications of the bilobed flap. Dermatol Surg. 2005 Aug;31(8 Pt 1):941-8
  4. Gado SK, et al. Interpolated Flaps. Facial Plast Surg. 2017 Feb;33(1):34-42
  5. Shew M, et al. Flap Basics II: Advancement Flaps. Facial Plast Surg Clin North Am. 2017 Aug;25(3):323-335

 

Case Studies

  1. A 42-year-old female patient develops a basal cell carcinoma of the left superior cheek. She is referred to the Mohs surgeon and after undergoing Mohs excision, she has a skin-only defect that is 3 cm wide x 3 cm tall of her superior, lateral cheek, about 1 cm away from her lateral canthus. You check that all margins were clear on the final pathology report. What patient factors do you consider for reconstruction of this defect? What reconstructive options exist?
  • With any facial defect, consider the anatomic components necessitating repair. In this case this is a skin-only defect but especially in the lateral forehead and jawline, make sure to assess facial nerve function for deeper defects. Perform a complete head and neck exam on every patient.
  • Proximity of the defect to structures such as the eyelids, eyebrows, lateral/medial canthus and oral commissure are important considerations for tensions and vectors of force. Scar contracture and points of maximal tension resulting from cutaneous flaps can cause ectropion, especially near the lower eyelid.
  • Patient factors such as age, skin laxity, Fitzpatrick classification, history of scarring/existing scars, overall health, future skin cancer risk, and patient preference are important to consider in deciding reconstruction. 
  • Describe the options along the reconstructive ladder to the patient. In this case you might consider healing by secondary intention, full thickness skin graft, and local cutaneous flap. Regional and distal flaps are not indicated for this sized defect.
  • You choose an inferiorly and laterally based rhombic flap that is about 75% of the defect size. Describe the point of maximal tension in rhombic flaps. Describe the variations of the Rhombic flap.
  • There is pallor of the distal portion of the flap indicating ischemia due to excessive wound closure tension. The majority of the pallor was related to the vasoconstrictive effects of injected anesthetics and resolves. However, a small portion of the distal flap suffers necrosis causing an eschar over the malar eminence. Describe the options for treatment of this complication (skin necrosis).
  • Minimal secondary tissue movement is expected over the malar eminence due to strong zygomatic cutaneous ligament attachments. Transposition flaps in this area must be designed with the same surface area as the defect to minimize wound tension.
  • The eschar can be conservatively debrided and the wound allowed to heal via secondary intention.
  1. A patient presents from the Mohs surgeon with an 8mm skin-only, circular defect of the nasal supratip.

 

  • What should you always ensure to check prior to closure of facial defects? Why is this important?
  • Always check that the final pathology report has clear margins. If margins are positive, then local flaps can transfer positive margins to different locations confusing the treatment picture and leading to larger than necessary re-resections.
  • What patient factors do you consider for reconstruction of a nasal defect? What reconstructive options exist for this patient?
  • Nasal subunits affected, size/percentage of subunit affected, location adjacent to the nostril margin, prior scars on the nose, history of multiple or recurrent skin cancers, laxity of surrounding skin, history of poor scarring, and patient preference are a few considerations in nasal reconstruction. These affect the reconstructive options presented to the patient.
  • You decide on a modified zitelli bilobe flap. What is the geometry of a bilobe flap and the point of maximal tension?
  • The patient heals uneventfully but after 4 weeks is unhappy with the appearance of their scar. What options would you offer this patient? How long should you wait prior to scar revision?
  • There are multiple methods for scar revision with one of the most common being Dermabrasion. Dermabrasion is best performed 6-8 weeks post-surgery and is best suited for Fitzpatrick types 1-3 due to the risk of post-abrasion dyspigmentation.
References 
  1. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014. Chapter 26.
  2. Flint PW, et al. Cummings Otolaryngology: Head & Neck Surgery. Sixth ed. Philadelphia: Elsevier/Saunders; 2015. Chapter 21, 298-306.e2
  3. Chu EA, Byrne PJ. Local flaps I: bilobed, rhombic, and cervicofacial. Facial Plast Surg Clin North Am. 2009 Aug;17(3):349-60
  4. Lu GN, et al. Local Cutaneous Flaps in Nasal Reconstruction. Facial Plast Surg. 2017 Feb;33(1):27-33

 

Complications

Learning Objectives 
  1. Recognize the major and minor complications that can arise from cutaneous flap surgery.
  2. Summarize the treatment options for complications.

 

References 
  1. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014. Chapter 26.
  2. Woodard CR. Complications in facial flap surgery. Facial Plast Surg Clin North Am. 2013 Nov;21(4):599-604

 

Review

Review Questions 
  1. What are the basic classifications of cutaneous flaps?
  2. What factors are important to consider in choosing cutaneous flaps?
  3. What are the location and vectors of maximal tension in cutaneous flaps?
  4. What are the potential complications of cutaneous flaps and how area they treated?

 

References 
  1. Baker R. Local Flaps in Facial Reconstruction. Third edition. Philadelphia: Elsevier/Saunders; 2014.
Resources 

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