Case Competition 2023 Case 4 Extensive scalp reconstruction using a free myocutaneus lattisimus dorsi flap
Authors: Felix Strübing, Resident, BG Ludwigshafen, Germany
A 57-year-old male patient presented with an ambiguous lesion on his scalp. Sixteen years prior, he had sustained a work-related scalping injury when his long hair became entangled in a machine. Although a replantation of the scalp was attempted, it ultimately failed. A soft tissue defect measuring approximately 25 x 6 cm resulted, and reconstruction was performed using split-thickness skin grafting. In the years following the procedure, the skin graft area progressively thinned, leading to an increased susceptibility to superficial lesions. Furthermore, an ulcer developed on the parietal scalp, raising concerns about potential malignancy.
Before and after
Large parts of the scalp have been reconstructed using split thickness skin grafts. The skin was extremely thin and non-pliable. On the parietal aspect of the scalp, centrally located in the skin grafted area, a hypergranulating ulcer five centimeters in diameter was found.
Skin lesions, such as the grafted area in this patient or actinic keratosis commonly observed in elderly individuals, have the potential to develop into squamous cell carcinomas (SCCs) at multiple sites. Consequently, it is imperative to discuss the complete removal of the lesion and soft-tissue reconstruction employing a large flap.
- Proposed treatment plan:
- 1. Excise the suspicious lesion and obtain histological confirmation, ensuring clear surgical margins.
- 2. In the event of malignancy, excise the entire area at risk of developing further SCCs and apply temporary negative pressure wound therapy.
- 3. Reconstruct the scalp using an expansive free myocutaneous latissimus dorsi flap.
- 4. If the free myocutaneous latissimus dorsi flap would not suffice for a complete reconstruction, a conjoined free myocutaneous latissimus dorsi and anterior lateral thigh flap would be backuo strategy. The entire planning had been discussed with the patient, including the possible extension of the surgery.
- Patient information: Risk of partial or total free flap loss, donor-site complications (seroma, hematoma, wound breakdown, loss of strength), hourly monitoring of the flap for 48 hours. The reconstruction might be bulky at first but will thin due to denervation of the muscle.
Step 1: Operation 1: Tumor resection
In the initial procedure, the suspicious lesion was excised, and suture marking is employed to delineate the margins. We advise incorporating a diagram to accurately represent the surgical specimen’s orientation for the pathologist’s reference. Temporary closure is achieved using negative pressure wound therapy (NPWT).
Step 2: Operation 1: Tumor resection
We performed a complete excision of the tumor, including the periosteum in the specimen.
Step 3: Operation 2: Complete resection of the skin grafted area
The pathology report identified a squamous cell carcinoma (TNM: pT2, L0, V0, pM0, G3, R1) with incomplete surgical margins. Together with the patient, we decided to excise the entire skin-grafted area. After the resection, a soft tissue defect measuring 27 x 28 cm remained. NPWT was employed for temporary wound closure.
Step 4: Operation 2: Diagram for the Pathologist
Again, we suggest drawing a precise diagram of the specimen and its orientation for the pathologist and including it in the pathology report. (The intraoperative sketch shown here was later redrawn for the pathology report)
Step 5: Step 3: Operation 3: Soft-tissue reconstruction
The patient is put in the lateral decubitus position. We used a two team approach with one team raising the flap, while the other team was preparing the recipient site. First, the outer table of the skull in the previous tumor bed was resected together with the neurosurgery service for improved oncologic safety.
Step 6: Operation 3: Preparation of recipient vessels
The superficial temporal vessels were meticulously dissected, with special attention given to preventing injury to the facial nerve within the preauricular space. A minimum of 2 to 3 cm of the vessels should be prepared for anastomosis (black arrow points at the superficial temporal vessels). Owing to the abundant blood supply in the facial region, the vessels can be sacrificed to facilitate end-to-end anastomosis.
Step 7: Operation 3: Marking the flap
The challenge was to address the extensive soft-tissue defect using one flap. In order to exhaust the maximum size of the myocutaneus latissimus dorsi flap, the anterior border of the muscle was precisely identified using sonography. The skin paddle was than designed critically extending the anterior border of the muscle. It was planned to use the myocutaneus flap part for reconstruction of the occipital and nuchal area.
Step 8: Operation 3: Raising the flap
The flap was elevated based on the thoracodorsal vessels, with particular care taken to include the entire muscle. Intraoperative indocyanine green fluorescence angiography indicated hypoperfusion in the distal portion of the flap (see 9 and 10). The designated resection area, visible in the congested distal region of the flap, is illustrated above in the broken white surrounding. This area was resected prior to flap transfer.
Step 9: Operation 3: ICG angiography
The intraoperative ICG angiography reveals optimal perfusion in the proximal parts of the flap (left is proximal, right is distal).
Step 10: Operation 3: ICG angiography
The most distal part of the skin flap incorpated in the lattisimus dorsi myocutaneous free flap showed an insufficient perfusion in the ICG angiography. It was marked and resected prior to flap transfer.
- In our experience, intraoperative ICG angiography is an extremely reliable procedure and may prevent partial flap loss.
Step 11: Operation 3: Flap Inset
We were able to realize the flap inset as planned. The flap is then anastomosed in an end-to-end fashion the temporal vessels. A venous coupler of 3.0 mm diameter is used for the venous anastomosis.
Step 12: Operation 3: Skin grafting
The muscle portion of the flap is covered with 0.2 mm-thick split-thickness skin grafts obtained from the thigh and meshed at a 1:1.5 ratio. Skin staples are utilized to secure the skin grafts in place.
Hourly flap monitoring using clinical evaluation for at least 48 hours.
- Daily low molecular weight heparin 30mg twice daily for five days and 40mg daily afterwards until discharge.
- Compression garment for six weeks to prevent seroma formation.
- Precise preoperative planning can ease the operative flow and save operating time.
- A skin paddle extending anteriorly beyond the muscle may be raised to extend the lattisimus dorsi flap.
- Intraoperative ICG angiography may prevent partial flap loss due to hypoperfusion of distal parts of the flap.
- Place large drains at the donor site and remove only if
- If possible, delay the reconstruction until clear surgical margins have been confirmed.
- Meticulous dissection of the recipient vessels is crucial.