Plastic Surgery · Supplementary · from Plastic Surgery
Case 2: Free Flap Reconstruction After Mandibulectomy
Patient Presentation
Demographics: 58-year-old male construction worker
Chief Complaint: "I noticed a painful sore in my mouth that won't heal for the past 3 months"
History of Present Illness: This 58-year-old male construction worker presents with a 3-month history of a non-healing ulcer on the right side of his lower gum. He initially attributed it to trauma from a rough tooth edge but became concerned when it continued to grow despite dental extraction of the adjacent molar 6 weeks ago. The ulcer is now approximately 3 cm in diameter and causes constant dull pain rated 5/10, worsened by eating. He reports a 15-pound unintentional weight loss over the past 2 months and difficulty opening his mouth fully.
He has a 40-pack-year smoking history and drinks 4-6 beers daily. He reports no prior history of head and neck cancers. He was referred by his dentist after an incisional biopsy revealed moderately differentiated squamous cell carcinoma of the mandibular gingiva. CT and MRI imaging demonstrated tumor invasion into the mandibular body with no radiographic evidence of distant metastases but a suspicious 2.5 cm right level IB lymph node.
PET-CT confirmed FDG-avid primary tumor and the right level IB lymph node. After multidisciplinary tumor board discussion, the recommended treatment plan is segmental mandibulectomy with right selective neck dissection followed by fibula free flap reconstruction and adjuvant radiation therapy.
Past Medical History:
- Hypertension
- Type 2 diabetes mellitus (HbA1c 7.2%)
- Chronic obstructive pulmonary disease (moderate, FEV1 62% predicted)
- Peripheral vascular disease (ankle-brachial index 0.9 bilaterally)
- Dental caries with multiple extractions
Medications:
- Lisinopril 20 mg daily
- Metformin 1000 mg twice daily
- Tiotropium inhaler daily
- Albuterol inhaler as needed
- Ibuprofen 600 mg as needed for pain
Social History:
- 40-pack-year smoking history, currently smoking 1 pack/day
- Alcohol: 4-6 beers daily for 30 years
- Construction worker
- Married with two adult children
- No illicit drug use
Family History:
- Father died of lung cancer at age 67
- Mother alive with hypertension
- Brother with oral cancer diagnosed at age 62
Physical Examination
- Vital Signs: BP 148/88 mmHg, HR 78 bpm, RR 16/min, Temp 37.0°C, SpO2 95% on room air, BMI 24.1
- General: Thin-appearing male, appears older than stated age
- Head/Neck: 3 cm ulcerative, indurated mass of the right mandibular gingiva extending from the first premolar region to the retromolar trigone. Lesion is fixed to underlying bone. Trismus present with maximum interincisal opening of 28 mm. Palpable 2.5 cm firm, fixed lymph node in the right submandibular triangle (level IB). No contralateral lymphadenopathy
- Oral Cavity: Poor dentition, leukoplakia of the right buccal mucosa. Tongue mobility preserved
- Cranial Nerves: Intact including mental nerve sensation bilaterally
- Lower Extremities: Bilateral pedal pulses 2+, no significant varicosities. Fibula palpable with adequate length bilaterally
- Cardiac: Regular rate and rhythm, no murmurs
- Lungs: Diminished breath sounds bilaterally with scattered expiratory wheezes
Workup and Results
Laboratory Studies:
| Test | Result | Reference Range |
|---|---|---|
| Hemoglobin | 12.1 g/dL | 13.5-17.5 g/dL |
| WBC | 8,400/μL | 4,500-11,000/μL |
| Platelets | 245,000/μL | 150,000-400,000/μL |
| Albumin | 3.2 g/dL | 3.5-5.0 g/dL |
| Prealbumin | 15 mg/dL | 20-40 mg/dL |
| HbA1c | 7.2% | <7.0% |
| Creatinine | 1.0 mg/dL | 0.7-1.3 mg/dL |
| AST | 38 U/L | 10-40 U/L |
| ALT | 42 U/L | 7-56 U/L |
| INR | 1.0 | 0.8-1.2 |
| Calcium | 9.4 mg/dL | 8.5-10.5 mg/dL |
Imaging/Additional Studies:
- CT Neck with contrast: 3.2 cm enhancing mass of right mandibular gingiva with cortical erosion and invasion of the mandibular body. 2.5 cm right level IB lymph node with central necrosis
- MRI Face/Neck: Tumor invasion through buccal and lingual cortices of the mandible with marrow involvement over a 4 cm segment. No perineural invasion along the inferior alveolar nerve
- PET-CT: FDG-avid primary tumor (SUV max 12.4) and right level IB node (SUV max 8.7). No distant metastases
- CT Angiography of lower extremities: Patent peroneal arteries bilaterally, adequate three-vessel runoff to both feet
- Biopsy: Moderately differentiated squamous cell carcinoma, p16-negative
- Staging: T4aN1M0, Stage IVA
Clinical Image
Diagram illustrating fibula free flap harvest and transfer for mandibular reconstruction, showing vascular anastomosis and reconstruction plate fixation. Source: Educational illustration.
Diagnosis
Squamous Cell Carcinoma of the Mandibular Gingiva, Stage IVA (T4aN1M0), Requiring Segmental Mandibulectomy with Fibula Free Flap Reconstruction
Key Diagnostic Criteria:
- Biopsy-proven moderately differentiated squamous cell carcinoma
- Cortical erosion and invasion of the mandibular body (T4a)
- Ipsilateral lymph node metastasis <3 cm (N1)
- No distant metastases (M0)
Treatment Plan
- Preoperative optimization: Smoking cessation (minimum 2-4 weeks preoperatively), nutritional supplementation with high-protein oral supplements, glycemic optimization targeting glucose <180 mg/dL perioperatively, pulmonary function optimization with bronchodilators
- Surgical procedure: Right segmental mandibulectomy with 1.5 cm bony margins, right selective neck dissection (levels I-IV), fibula free flap reconstruction with titanium reconstruction plate, microvascular anastomosis of peroneal artery and vein to facial artery and vein
- Perioperative care: Free flap monitoring with hourly Doppler checks for 72 hours, nasogastric tube feeding initiated postoperative day 1, tracheostomy for airway protection
- Adjuvant therapy: Concurrent chemoradiation (cisplatin 100 mg/m² every 3 weeks with 66 Gy in 33 fractions) given positive lymph node and close/positive margins
- Rehabilitation: Speech-language pathology for swallowing rehabilitation, prosthetic dental rehabilitation after radiation, physical therapy for lower extremity donor site
- Surveillance: Clinical examination and imaging per NCCN guidelines every 1-3 months for the first year
Key Learning Points
- The fibula free flap is the workhorse flap for mandibular reconstruction due to its adequate bone stock (up to 25 cm), reliable pedicle (peroneal artery and venae comitantes), and ability to be osteotomized for contouring
- Preoperative CT angiography of the lower extremities is mandatory to confirm three-vessel runoff to the foot before fibula harvest
- Nutritional optimization (albumin >3.0, prealbumin >15) is critical for wound healing and flap survival; consider preoperative nutritional supplementation
- Free flap success rates exceed 95% in experienced centers, but risk factors for failure include atherosclerosis, diabetes, prior radiation, and tobacco use
- Dental rehabilitation with osseointegrated implants in the fibula can be performed 6-12 months after completion of radiation therapy to restore masticatory function