Free Chimeric Scapular with Latissimus Dorsi Myocutaneous Flap as a Third Free Flap for Reconstruction of Metachronous Mandibular Defects―A Rare Case Report

Abstract

This is a rare case report in which a third free flap was used to restore metachronous mandibular defects. Significant functional and aesthetic losses may result from segmental mandibular excision in cases of oral cancer. The fibula flap is the gold standard for reconstructing these defects, which is essential for regaining shape and function. Reconstruction attempts become more complex when individuals experience metachronous malignancies or recurrence. We present a rare instance in which a third free flap was required for restoration following 2 metachronous mandibular defects. Mandibular continuity was effectively restored using a free chimeric scapular with latissimus dorsi myocutaneous flap, yielding positive functional and cosmetic results. This case report shows that even after prior reconstruction, patients can successfully undergo an additional free flap procedure, improving their quality of life. It further underscores the adaptability and effectiveness of this reconstructive technique in correcting complex mandibular defects.

Introduction

One of the most common cancers to affect the head and neck region is oral cancer. Long-term survival for head and neck malignancies has increased with multimodality treatment that includes chemotherapy, surgery, and/or radiation. Due to either direct tumor invasion or significant soft-tissue disease adjacent to the mandible, patients frequently require segmental resection to achieve “complete” excision of the main tumor¹⁾. Mandible excision has serious, long-lasting functional and cosmetic aftereffects.

Vascularized bone grafts, bridge plates with soft-tissue flaps, and non-vascularized bone grafts are the available reconstructive methods for a segmental mandibular defect^2,3). Because of its length, bone stock, dependable pedicle, ability to support dental implants, and low donor-site morbidity, the fibula flap is regarded as the gold standard of choice⁴⁾.

However, a significant percentage of patients who undergo segmental mandibulectomy will experience a recurrence of their first cancer or develop a second primary head and neck tumor. Metachronous second primary head and neck lesions occur at a rate of 4% per year, whereas recurrence rates vary from 12% to 48%⁵⁾. Although the use of consecutive osseous free flaps for reconstructing the mandible following cancer recurrence has been previously reported⁶⁾, there have only been a few case reports and short case series detailing this particular clinical scenario.

Free tissue transfer is the primary restorative technique used following both the initial and subsequent resections. As a result, reports have described the technical aspects and success rates of second head and neck free flaps.

In this instance, we present a rare case report of a third free flap in a patient with recurrence followed by a second primary.

Case Report

A 61-year-old male was admitted for carcinoma lower alveolus. In 2018, he underwent 3 cycles of neo-adjuvant chemotherapy. That same year, a left free fibula flap was used for reconstruction after a mid-segmental mandibulectomy (right 1st premolar to left 2nd premolar) with neck dissection.

The vessels used for anastomosis were the left facial artery and a tributary of the left internal jugular vein.

He received adjuvant chemotherapy in 2018 (60 Gy/30# of RT and 3 cycles of chemotherapy), and remained disease-free for 4 years.

In 2022, due to recurrence, he again underwent right segmental mandibulectomy (right 2^nd premolar and right body of the previously placed left fibula) and reconstruction with a right free fibula flap. The vessels used for anastomosis were the right facial artery and the right internal jugular vein. The disease-free interval continued for 2 years.

In 2024, after presenting with a new lesion in the left buccal mucosa, he was planned for a left segmental mandibulectomy (anterior 1/3^rd of the left fibula bone including the central segment and left body, extending posteriorly to just above the angle of the mandible), along with left buccal mucosa wide local excision, skin excision and neck dissection (Figure 1).

Figure 1.

A 61-year-old man who had 2 segmental mandibulectomy surgeries with sequential bilateral free fibula reconstruction is scheduled for a third segmental mandibulectomy with skin and buccal mucosa and a third free flap procedure. a-c, showing pre-operative profile of the patient. d, showing lesion (recurrence) in reconstructed left fibula surrounding dental implants and in left buccal mucosa. The extent of resection is also marked with dotted lines representing bony cuts, and soft tissue resection includes the left buccal mucosa surrounding the lesion.

The decision to proceed with a third free flap was made due to the presence of an 8 cm bone defect crossing the midline, associated soft-tissue loss, skin excision, as well as the patient's characteristics (no co-morbidity). A free scapular-parascapular flap was planned because 2 fibulas had already been used for repair (Figure 2).

Figure 2.

a, showing the design of the scapular-parascapular flap; however, due to intra-operative perforator injury to the parascapular paddle, the plan was changed to take the LDMC paddle with scapula bone. Design in red shows the future LDMC paddle. b, intraoperative defect showing segmental mandibulectomy with skin excision and buccal mucosa wide local excision, and at the bottom left shows the resected specimen. c, showing schematic presentation of the reconstruction using a free chimeric scapular flap with LDMC in relation to the previous fibula and native mandible.

LMDC: latissimus dorsi myocutaneous

Following primary resection, the free scapular-parascapular flap was harvested in the lateral position.

A handheld Doppler was used to mark the perforators. The 17 × 5 cm flap is marked. The circumflex scapular artery and its scapular branch were seen after a lateral incision was made. The circumflex scapular artery was dissected up to its origin, and the thoracodorsal pedicle was dissected up to its common origin. The branch to the latissimus dorsi muscle (LDMC) was clipped. The angular branch was identified and dissected. While completing the posterior incision of the parascapular skin paddle, the perforator got injured, necessitating a change in approach. The LDMC flap was utilized. First, the clipped portion of the LDMC pedicle was anastomosed on-table to the thoracodorsal pedicle. The scapular bone was harvested along with the scapular tip based on the angular branch. The lateral border of the scapula was used for the body, and the tip of the scapula for the central segment. Screws and miniplates were used for fixation (Figure 3).

Figure 3.

Chimeric Free Scapular Flap with LDMC Flap showing on the table anastomosis done with the clipped part of the LDMC pedicle (marked in red circle) and the close-up view of the anastomotic site at the bottom left corner.

LMDC: latissimus dorsi myocutaneous

The latissimus dorsi muscle was used to cover the intraoral defect, and the skin paddle was used for the mucosal defect along with the skin defect.

The left internal jugular vein and left superior thyroid artery served as the recipient vessels for the anastomosis.

Complete flap survival was noted, and the postoperative course remained uneventful (Figure 4).

Figure 4.

Immediate post-operative result.

Two weeks following the repair, there was no donor-site morbidity, and the flap appeared to be well-settled.

Seven days after the procedure, the donor site began to heal, and 3 weeks later, the patient had no difficulty using his left shoulder for everyday tasks.

The patient was able to tolerate oral liquids at 1 month.

The postoperative speech and swallowing functions were evaluated using 7 clinical parameters, which included 1) OSME⁷⁾ (Oral Speech Mechanism screening Examination) 2) FOIS⁸⁾ (Functional Oral Intake Scale) 3) PSS HNC⁹⁾ (Performance Status Scale for Head and Neck Cancer) 4) Airway/breathing 5) 100 mL water swallow test⁸⁾ 6) Leipzig and Pearson scale¹⁰⁾ 7) Aspiration risk. The objective data using these parameters in the postoperative period is shown in Table 1.

Table 1.

Postoperative Date of Objective Evaluation of Speech and Swallowing Function Showing Functional Gain after the Third Free Flap Surgery.

No.	Clinical parameters	November 2024	March 2025	June 2025
1)	Oral Speech Mechanism Screening Examination (OSME)
a)	Mouth Opening	1 Finger	1 Finger	1 Finger
b)	Tongue Range of Motion	Mild to Moderate impairment	Mild impairment	Improved
c)	Oral Seal	Intact	Intact	Intact
2)	Functional Oral Intake Scale (FOIS)	3	5	5
3)	Performance Status Scale for Head and Neck Cancer (PSS HNC)
a)	Diet	40	40	40
b)	Speech	75	100	100
4)	Airway/breathing	Good	Good	Good
5)	100 ml water swallow test
a)	Able to swallow well	Yes	Yes	Yes
b)	Laryngeal elevation noted	Yes	Yes	Yes
c)	Pre and post-swallow voice	Good, no cough	Good, no cough	Good, no cough
6)	Leipzig and Pearson scale	01	01	01
7)	Aspiration risk	Low	Low	Low

The patient has good mouth opening and is receiving oral liquids and semi-solids at 6 months (Figure 5). The postoperative orthopantomogram shows the reconstructed area (Figure 6).

Figure 5.

Follow-up after 6 months with good form and function (mouth opening).

Figure 6.

Postoperative OPG (orthopantomogram) showing the reconstructed area with markings and also the relation with previous surgeries and the remaining mandible.

Discussion

Longer periods of disease-free survival have been made possible by improvements in perioperative care and surgical procedures. Additionally, immediate free flap repair has improved the functional and aesthetic outcomes after radical excision of head and neck cancer¹¹⁾. Nevertheless, patients may survive only to present later with a second or third metachronous tumor or a recurrence of their original tumor.

Available reconstructive methods for segmental mandibular defects include free osteocutaneous flaps, soft-tissue flaps with reconstruction plates, or pedicled flaps. For mandibular reconstruction, the free fibula flap is currently considered the gold standard. However, in the absence of a fibula, another option is the free scapular flap.

The free scapula flap has various benefits―decreased donor-site morbidity, providing an osseous component with fewer osteotomies¹²⁾.

After multiple segmental mandibulectomies, a number of parameters must be taken into account. These include the recipient vessels chosen, the location of the defect, the involved structures, the altered anatomic relationships, the surgical fitness and illness status of the patient, and additional side effects of prior radiation therapy.

Although there have been reports of consecutive free tissue osseous reconstructions in the past, this is a unique instance of a third sequential free flap for mandibular restoration in a metachronous mandibular defect.

Due to special difficulties such as the effect of radiation pretreatment, the large defect size following recurrent tumor resections, and the complexity of composite tissue restoration, second free flap reconstruction after tumor ablation becomes more complicated.

The intrinsic benefits of the free osteocutaneous flap in repeated mandible reconstructions must be carefully weighed against the existing defect. Therefore, central segment defects are the strongest indication for a second fibula flap in mandibular repair, as the presence of solid support prevents issues with breathing, drooling, swallowing, and poor cosmesis that are associated with the Andy Gump deformity^6,13). Apart from bony support, the extent of the muscle groups involved in mastication and swallowing during each surgery also plays an important role in postoperative swallowing function. In our case, the first surgery was a mid-segmental mandibulectomy where the genioglossus and geniohyoid muscles were divided at the mental tubercle, along with resection of the mylohyoid and masticatory muscles (both anterior bellies of the digastric muscles and some attachments of the masseter). Following the second surgery, which involved a right segmental mandibulectomy, some attachments of the right masseter were divided. During the third surgery, which involved a left segmental mandibulectomy, fibers of the left masseter and left medial pterygoid were divided. However, since the remaining masticatory muscles were preserved during all 3 surgeries, and the temporomandibular joint remained intact, the patient's mastication improved with bony reconstruction. Additionally, the tongue was preserved with an intact hypoglossal nerve, which also contributed to good swallowing function, so no special measures were required to preserve swallowing ability. Nevertheless, considering all of the aforementioned factors, we encountered significant challenges in reconstructing the third mandible defect. Reconstructing the mandible for a third time with a free osteocutaneous flap is very challenging. These challenges include recipient vessel selection in a vessel-depleted neck, achieving a functional outcome in terms of swallowing and speech, no dependency on tracheostomy tube, higher chances of flap failure, additional donor-site morbidity, and providing an acceptable cosmetic outcome for the patient. However, these challenges can be overcome by proper preoperative planning, joint discussion with the head and neck, medical and radiation oncology team, and pre-surgical counselling with the patients and their family. Given the functional deficit and subpar result expected in the absence of bony support, a third free flap was planned. However, the initial plan was a free scapular-parascapular flap, but due to intraoperative perforator injury while raising the parascapular skin paddle, the decision to use the LDMC paddle was made. As mentioned previously, the LDMC pedicle was clipped (since the parascapular flap was planned), so on-table anastomosis of the clipped portion was done with the thoracodorsal pedicle, thereby finally utilizing a chimeric free scapular flap with LDMC flap. The advantage of adding skin and soft tissue is provided by the LDMC without increasing morbidity and still allowing primary closure of the entire donor site. Also, the on-table anastomosis to the thoracodorsal pedicle avoids the need for separate sets of anastomoses in the vessel-depleted neck, especially in this case, where 2 previous free flaps had been done. Based on our experience, it is therefore wise to preserve the LDMC pedicle before committing to parascapular harvest in cases of scapular-parascapular flaps. Although a bridging plate and a soft-tissue flap (pedicled or free) are also options, we believe that osseous support plays the primary role in restoring swallowing abilities. Additionally, a large soft-tissue flap often functions as a static component that impairs swallowing effectiveness.

The concavity of the scapula can be used to replicate long pedicle lengths, soft curvatures, and chimeric alternatives (such as the LDMC)¹⁴⁾. Based mainly on soft-tissue requirements, Hasan et al. proposed an algorithm for lateral/anterior mandibular defects. This algorithm suggests that a chimeric scapula with latissimus dorsi muscle should be used to reconstruct larger complex defects or mobile soft-tissue areas, while a scapula osseous flap could be used to reconstruct smaller osseous defects in fixed mucosal areas¹⁵⁾.

As previously mentioned in the case report, we also experienced an iatrogenic perforator injury, which was managed by applying microvascular principles.

To the best of our knowledge, this is the first instance of a third sequential free flap after 2 fibulas for metachronous mandibular lesions, while other publications have documented the restoration of oncologic defects with consecutive bilateral free fibular flaps.

Conclusions

Patients can successfully undergo additional reconstructive treatments to restore their function, appearance, and quality of life despite prior multiple resections with complex microvascular reconstruction. Even after 2 fibulas, a free scapula flap can provide sufficient bone for mandible reconstruction.

Author Contributions: D.G. drafted the initial manuscript. V.K. reviewed and undertook final editing. V.K. and V.K.S. critically reviewed the manuscript for important intellectual content. V.K. is the surgeon in charge of this patient. All Authors read and approved the final manuscript.

Conflicts of Interest: There are no conflicts of interest.

Ethical Approval: No ethical approval is required for the mentioned case report.

Consent to Participate: The patient provided their written informed consent to participate.

Consent for Publication: Written informed consent for publication of images and/or information about the patient was obtained.