A Guide To Using Bilobed Flaps In Lower Extremity Surgery
Bilobed flaps can preserve tissue and facilitate primary closure in various surgical procedures as the flaps do not require skin grafts and have predictable long-term reproducibility and functional outcomes. Accordingly, this author presents his own experience with bilobed flaps and discusses how they can have an impact in closing lower extremity defects.
The bilobed flap presents many advantages for closure of a defect of the lower extremity. These flaps typically do not require skin grafting and allow for primary closure. The bilobed flap redistributes and redirects tension from the primary defect to the donor site. Bilobed flaps typically extend beyond the defect, which allows for adequate length and primary closure.
The bilobed flap is a local cutaneous skin flap, a mass or tongue of tissue for transplantation. A local flap includes the epidermis, dermis and subcutaneous tissue. The blood supply to the bilobed flap is made up of a source artery and vein that is based upon a local angiosome.1
Muscular vessels form extensive networks of subdermal and dermal plexuses. The cutaneous vessels create an anastomotic region to form a continuous vascular network that is quite extensive and allows for the survival of this type of random local flap. The vascular supply to the skin is based upon the musculocutaneous and cutaneous arteries that perforate subcutaneous tissue.
The bilobed flap is a transposition flap that is made up of two flaps that are separated by an angle and share a common pedicle.2 This flap is tongue-like in shape and has a slightly narrower base.
What You Should Know About The Evolution Of Bilobed Flaps
Sir Harold Delf Gillies was a London-based otolaryngologist who was widely considered as the father of plastic surgery. He has stated that the best skin for flaps is the nearest skin and most definitively describes the significant advantages of a bilobed flap.3 Gillies noted that the use of bilobed flaps reduces both the number of surgical procedures for the patient and shortened hospital stays.
Esser originally described the bilobed flap in 1918.4 Zimany revised the flap in 1953 and popularized the flap with two lobes.5 Bouché, McGregor and their respective colleagues also described applications of the bilobed flap.6,7 These applications include painful plantar skin lesions of the foot that are not amenable to simple excisional procedures.
The bilobed flap was designed to move additional skin over a larger distance than is available with a single lobe flap. This type of flap works well where there is appropriate skin mobility. These flaps utilize the laxity of adjacent tissue and transpose it to the region of poor inelastic tissue or skin. The bilobed flap is extremely versatile for closure of defects throughout the entire lower extremity. One can utilize this flap for the closure of excised pigmented lesions, tissue lesions, cystic masses, traumatic wounds and diabetic foot ulcerations.
The bilobed flap uses adjacent donor sites for closure of the defect.7 The first lobe closes the original defect and the second lobe closes the first flap donor site. The surgeon would then close the second flap donor site primarily. Each lobe is typically 90 degrees from the defect and 90 degrees from the other lobe. There are many variations of the bilobed flap design but the most common presentation is a 90 degree angle. The rotation of this flap consists of a 360 degree circle for rotation on an axis point. The most common lobe design is 75 percent of the size of the original defect and the secondary lobe is typically 50 percent of that same defect. There are variations as to the width of the primary and secondary lobe depending upon angular design.