Case 12: Bilobe flap for mandibular border reconstruction after BCC excision
Authors:Anna Louise Norling (MD), Linn Anna Fiehn (stud. med.)
86-year-old well-preserved and active male with a medical history of AFib, hypertension, and hypercholesterolemia and medicated with acetylsalicylate. He was referred to the dep. of plastic surgery at SUH, Roskilde by his local dermatologist with a biopsy verified nodular and infiltrating basal cell carcinoma (BCC) on the jaw.
Before and after
Patient examination
Highly active male with a good general health condition. At the right side of the jaw, crossing the inferior border of the mandibular, a 25 x 25 mm elevated and mobile tumor presents itself with an irregular border and a central ulceration. No lymphadenopathy at the head, neck or peri clavicular.
Pre-Operative Considerations
It’s a quite large tumor placed at the jawline with no clear border and a biopsy, which shows an invasive component of basal cell carcinoma. The tumor seems mobile and therefore not thought to be invasive to the deeper structures. Because of the invasive component, the excision margin needs to be 5 mm [1], leaving a defect of approx. 35×35 mm in an area with hair growth. A skin graft would be quite obvious in the middle of the beard. Therefore, a local flap involving hair-bearing skin to cover the defect would be preferable. A big bilobe flap from the neck seemed to be the best option in this case [2]. Before a reconstruction with a flap, the border and bottom of the defect must be cleared. To do the procedure with excision and reconstruction in one step, an intraoperative histopathological examination must be planned. In the area of this tumor, there are some precious structures that, if possible, need to be spared. The marginal branch of the facial nerve lies under the deep facial fascia together with the facial artery and vein, whereas the cervical branch of the facial nerve lies on the deep surface of the platysma. The cervical branch is more likely to be damaged due to its more superficial position. Damage to either nerve will lead to some asymmetric mimics of the mouth, but damage to the marginal branch will also lead to difficulty in controlling the lower ipsilateral part of the lip and may lead to difficulty in chewing and swelling food, and drooling. At the neck, even more valuable structures are placed but these structures lie under the platysma and are therefore not directly at risk. Excision to deeper than the platysma must be performed with great caution and raising the flap should be superficial of the platysma.
Step 1: BCC excision and flap definition
The tumor is excised at a 5 mm margin including a minor part of the subdermal tissue. When the borders are cleared by the pathologist, the bilobe flap is drawn on the neck with a size that fits the defect.
Step 2: Flap elevation and inset
The flap is raised superficially to the platysma. The defect and donor site are then closed. The tip of both lobes seems a bit pale, which could indicate a compromised blood supply. Sutures are dressed with Micropore and dry gauze.
Step 3: Follow-up 8 days postoperative
8 days after surgery. The flap is vital, with some defects at the tip of the lobes. A bit of redness and swelling and some pus from the defects indicate a post-operative infection. A test for wound culture showed s. aureus, which was treated with dicloxacillin 1g x 4.
Post-Operative Plan
To minimize the risk of bleeding the head should be kept elevated and hot drinks and food should be avoided together with food that needs chewing for a couple of days. If necessary, 1 g acetaminophen PN maximum 4 times a day, is recommended as painkillers. Exercises and other physical activities should be avoided until the stitches are removed which are planned for removal at the outpatient-clinic 8 days postoperative.
- A well-designed bilobe flap is a great way to use skin from local areas with excess skin.
- By using directly adjacent skin, the outcome appears more natural when the defect is closed with a local flap from a hair-bearing area.
- The tumor could infiltrate deeper structures and excision might lead to nerve and vessel damage
- It’s a quite large random flap, which relies on the blood flow from the subdermal plexuses. This potentially leads to necrosis of part of the reconstruction. And with a defect the risk of infection increases.
- Although there is a good amount of excess skin on the neck, if the flap is too big, the skin at the neck will be tight and could affect the movement and the posture of head and neck.
References
- Krammer, C.W., et al., Treatment algorithm for non-melanoma skin cancer. Ugeskr Læger, 2018. 180:V01180044
- Salgarelli AC, Cangiano A, Sartorelli F, Bellini P, Collini M. The bilobed flap in skin cancer of the face: our experience on 285 cases. J Craniomaxillofac Surg. 2010 Sep;38(6):460-4. doi: 10.1016/j.jcms.2009.10.022. Epub 2009 Nov 24. PMID: 19939690.