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.

   Closure of the bilobed flap can occur with suturing of the primary lobe to the first frenulum and suturing the secondary lobe to the second frenulum with circumferential sutures in the periphery of each lobe. One would suture these lobes with 4.0 nylon in a simple interrupted suture mattress. Corner stitches and deep sutures are not recommended as they can lead to necrosis and dehiscence of the flap. Closure of the adjacent lobes with respect to the defect can lead to a small dog ear formation, which one should not back cut or excise as this can compromise the base of the flap and lead to necrosis. The dog ear formation typically resolves spontaneously over several weeks without resection or risk to the flap.

   There are numerous advantages of the bilobed flap for closure of defects of the lower extremity. This flap allows for recruitment of large amounts of tissues, which rotate from different areas in a tangential design. The bilobed flap allows for preservation of tissue, reduction of scar formation, mobility of tension lines and the ability to close defects in a variety of anatomic locations.

How To Create a Bilobed Flap

The technique for creating a bilobed flap includes an initial excision of the lesion with a number 15 blade. One would completely excise the lesion’s full thickness through the subcutaneous tissue to the level of the deeper structures. After fully excising the lesion, assess the lines of maximal extensibility and the relaxed skin tension lines. The pinch test allows one to determine how supple the tissue is within the region, which will ultimately determine the rotation of the axis from mobility to immobility.

   Design the flaps after completing the excision of the lesion. Carefully dissect the flaps utilizing skin hooks and atraumatic techniques. Rotate the flap and elevate it from the deeper levels in order to allow for subcutaneous adipose tissue to remain within the flap. Utilizing dissecting scissors, one can carefully undermine the peripheral region from which each of the flaps had been elevated. Undermining this region will produce laxity within the region. Rotate the primary lobe into the adjacent defect and then inset the second lobe into the primary flap site. Tourniquet use can be acceptable based upon assessment of the patient. When it comes to tourniquet use, it should be deflated and one should achieve appropriate hemostasis. A Colorado tip and a bipolar cautery can prevent collateral damage as these flaps are extremely delicate.

   The bilobed flap can provide coverage for a diabetic foot wound but surgeons must take many additional steps prior to considering this flap for closure of a defect. As with many indications for this flap with respect to pigmented lesions and soft tissue mass excisions, one must excise the defect as the initial step. More often than not, a diabetic foot wound requires some form of bone realignment, bone debridement or bone resection.8 These wounds are considered contaminated and one should treat them as such. One should excise the wound’s full thickness including any underlying subcutaneous tissue, possible bursa and bone in the region. Creation and mobilization of the bilobed flap can occur at the same point.

   After addressing the bone pathology and carefully dissecting the flap, the surgeon should pulse irrigate the entire area with at least 4 liters of normal saline. A separate closure table should be available. When lavage of the surgical site is complete, redrape the area with uncontaminated linens. At this point, a glove and gown change would be appropriate in order to reduce any previous contamination from the open wound and possibly exposed bone. One should avoid using any previous equipment that had entered the field with respect to the chronic wound. Then inset the flap again and suture it with nylon as stated above. Surgeons should always avoid using any deep sutures in this region.

   The conclusion of the procedure will include the appropriate management with minimal compression and the incorporation of immobilization. One can evaluate the flaps at one-week intervals and remove sutures at three to four weeks.

A Closer Look At The Research On Bilobed Flaps

Yetkin and colleagues in 2003 described the utilization of bilobed flaps for non-healing ulcer treatment.9 The average size of the ulcers treated was approximately 1.6 cm. There was a minimal follow-up period of one year with an average of 19.5 months. The authors concluded that one can treat non-healing foot ulcers with a bilobed skin flap of healthy tissues rotated from non-weightbearing parts of the sole.

   My colleagues and I described the use of a bilobed flap for excision of recurrent digital mucoid cysts in 2005.10 This retrospective review described the utility of a bilobed flap in conjunction with resection of the head of the middle phalanx for mucoid cyst pathology. In our study, there were no recurrences, flap failures or significant complications with this technique. The bilobed flap allowed for greater exposure than traditional semi-elliptical incisions while providing a template for wide excision of the defect and primary closure.

   Jager and coworkers published on the Zitelli design for bilobed flaps.11 The retrospective review examined the application of bilobed flaps on skin defects after digital mucoid cyst excision. The authors also described the unique indication in the geometric design, which allows for fast wound healing and excellent outcomes. The design is easy, safe and reproducible.

   My colleagues and I also published another retrospective study evaluating single-stage surgical treatment of non-infected diabetic foot ulcers, which did include bilobed flap reconstruction.12 This single-stage approach consisted of total excision of the ulcer with broad exposure, correction of the underlying osseous deformity and immediate primary closure with a local random flap. We analyzed 400 cases of pedal ulcers via chart review. Of those cases, 67 cases had a single-stage surgical treatment and we analyzed them for length of hospital stay, postoperative complications, time to heal, recurrence of the ulcer and post-procedure ambulatory status. The age of the ulcers before surgery was 12 ± 12 months with a range of one to 60 months. The median perioperative hospital stay was 5 ± 7.6 days. We followed all patients until the wounds were healed or to amputation.

   The median total time to heal was 30.8 ± 40 days.12 Ninety-seven percent of the wounds healed. The recurrence rate of ulceration was 10.4 percent (seven of 67) over a time span of up to six years. All but one patient returned to previous levels of ambulation and many patients had improved levels of ambulation. The single-stage approach eliminated the need for additional surgical procedures with their associated costs and risks. In addition, healing times were significantly shorter, resulting in decreased hospital stays and subsequent costs, and providing the patient with an expedient return to footwear so surgeons could restore bipedal function. Most importantly, by addressing the underlying bony pathologic findings, surgeons saw dramatically lower recurrence rates.

In Conclusion

Bilobed flap reconstruction for lower extremity reconstruction is a viable option for foot and ankle surgeons. The geometric construct of the bilobed flap allows for superb versatility. A bilobed flap should be included in the reconstructive ladder as an option for defect closure and reconstruction.13 The long-term reproducibility and functional outcome of the bilobed flap are quite predictable. This flap does not typically require additional skin grafting and allows for primary closure. In addition, the advantage of the bilobed flap is that it will also reduce the typical hospitalization that occurs with many of these complex wounds. Surgeons can also use local anesthesia for bilobed flaps, therefore reducing morbidity and mortality.

   Dr. Blume is an Assistant Clinical Professor of Surgery in the Department of Surgery and an Assistant Clinical Professor of Orthopaedics and Rehabilitation in the Department of Orthopaedics, Section of Podiatric Surgery at the Yale University School of Medicine in New Haven, Ct. Dr. Blume is a Fellow of the American College of Foot and Ankle Surgeons.

References
1. Attinger CE, Evans KK, Bulan E, Blume P, Cooper P. Angiosomes of the foot and ankle and clinical implications for limb salvage: reconstruction, incisions, and revascularization. Plast Reconstr Surg. 2006; 117(7 Suppl):261S-293S.
2. Sanchez-Conejo-Mir J, Buneo Montes J, Moreno Giminez JC, Camacho-Martinez F. The bilobed flap in sole surgery. J Dermatol Surg Oncol. 1985; 11(9):913-7.
3. Gillies HD. The design of direct pedicle flaps. Br Med J. 1932; 2(3752):1008.
4. Esser JFS. Gestielte loakle Nasenplastik mit zweizipfligen Lappen, Deckung des sekundaren Defektes vom ersten Zipfel durch den Zweiten. Dtsch Zschr Chir. 1918;143:385.
5. Zimany A. The bi-lobed flap. Plast Reconstr Surg (1946). 1953; 11(6):424-34.
6. Bouché RT, Christensen JC, Hale DS. Unilobed and bilobed skin flaps. Detailed surgical technique for plantar lesions. J Am Podiatr Med Assoc. 1995; 85(1):41-8.
7. McGregor JC, Soutar DS. A critical assessment of the bilobed flap. Br J Plast Surg. 1981; 34(2):197-205.
8. Blume PA, Key JJ. Skin Grafts. In: Dockery GL, Crawford ME (eds.) Lower Extremity Soft Tissue and Cutaneous Plastic Surgery. Saunders/Elsevier, Philadelphia, 2006, pp. 151-171.
9. Yetkin H. Bilobed flaps for nonhealing ulcer treatment. Foot Ankle Int. 2003; 24(9):685-9.
10. Blume PA, Moore JC, Novicki DC. Digital mucoid cyst excision by using the bilobed flap technique and arthroplastic resection. J Foot Ankle Surg. 2005; 44(1):44-8.
11. Jager T, Vogels J, Dautel G. The Zitelli design for bilobed flap applied on skin defects after digital mucous cyst excision. A review of 9 cases. Tech Hand Up Extrem Surg. 2012; 16(3):124-6.
12. Blume PA, Paragas LK, Sumpio BE, Attinger CE. Single-stage surgical treatment of noninfected diabetic foot ulcers. Plast Reconstr Surg. 2002 Feb; 109(2):601-5.
13. Janis JE, Kwon RK, Attinger CE. The new reconstructive ladder: modifications to the traditional model. Plast Reconstr Surg. 2011; 127(Suppl 1):205S-212S.

   For further reading, see “A Closer Look At Plastic Surgery Techniques” in the March 2003 issue of Podiatry Today. To access the archives, visit www.podiatrytoday.com.