Abstract
A case of squamous cell carcinoma (SCC) of the head and neck that developed thrombosis inside the flap during the surgery and subendocardial infarction after the surgery is presented. An 82-year-old man was referred to our hospital because of nonhealing of a tooth extraction socket. The patient’s medical history was unremarkable, with no ischemic heart disease. The preoperative blood tests and the physiological and imaging findings were also unremarkable other than an elevated hemoglobin A1c (HbA1c; 6.6%). He was diagnosed with SCC of the lower gingiva on biopsy. After intensive insulin therapy for glycemic control, tumor resection including mandibular segmental resection and neck dissection, followed by reconstruction with a vascularized fibular flap, was performed. Although there was visible thrombosis inside the fibular veins of the flap during the surgery, microvascular anastomosis and reconstruction were done without any complications after irrigation with heparin saline. Subendocardial infarction developed 10 hours after the surgery in the intensive care unit, but circulatory dynamics recovered after percutaneous coronary intervention. Two years after the surgery, the patient has had no decrease in basic activities of daily living, no local tumor recurrence, and no distant metastasis.
Highlights
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Vasucularized free fibular flap is useful for mandibular reconstruction in gingival cancer.
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Complications after free flap transfer include thrombosis, and it let the flap necrosis.
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A case of thurombosis at collection of the fibula flap and postoperative subendocardial infraction is presented.
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Diabetes mellitus might be risk for thrombosis, as in the present case.
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Surgeons need to keep in mind the possibitiry of thrombosis and share the relevant information with appropireate depatments.
1
Introduction
Mandibular reconstruction by a vascularized free fibular flap is useful for reconstruction for a wide defect of the mandible in gingival cancer [ , ]. Complications after free flap transfer include thrombosis, hematoma, and flap necrosis [ ]. People with cancer are known to be at increased risk of thromboembolism [ ], with chemoradiotherapy [ ], diabetes mellitus [ ], intraoperative bleeding [ ], and Trousseau syndrome [ ] among the risk factors. Moreover, it has been reported that tourniquet-induced ischemia is also thought to be a risk factor for thrombosis [ ]. The thrombus at the anastomotic vessel should be removed as early as possible to avoid flap necrosis [ ]. A case of carcinoma of the lower gingiva with thrombosis in the flap at collection of the vascularized fibular flap and postoperative subendocardial infarction is presented.
2
Presentation of case
An 82-year-old Japanese man (height, 164.0 cm; weight, 63.0 kg) with a chief complaint of nonhealing of a tooth extraction socket was referred to our department. His personal and family medical histories were unremarkable. There was no difference in thickness between the left and right sides of the lower limbs, and no tenderness or development of collateral circulation along the distribution of superficial veins was observed.
On extraoral examination, one elastic hard, mobile, tender-free, lymph node was palpated in the left submandibular area. No hypoesthesia was found in the left mental nerve innervation area. Intraoral findings showed an ulcerative lesion (31 × 23 mm 2 ) in the mandibular gingival mucosa ( Fig. 1 ). The lesion with induration bled easily and had associated spontaneous pain and tenderness. On computed tomography (CT), osteolysis was seen from the left mandibular first molar to the mandibular ramus ( Fig. 2 A and B), and there was disappearance of the upper wall of the mandibular canal ( Fig. 2 C and D). Contrast-enhanced CT showed one swollen lymph node in the left submandibular area ( Fig. 3 ). Fine needle aspiration cytopathology showed that the lymph node had only a few mildly atypical cells. No nodular lesions suspected of metastasis were found in the bilateral lung fields, and no deep vein thrombosis was found. A chest radiograph showed a cardiothoracic ratio of 43% ( Fig. 4 ). Preoperative blood tests showed no abnormalities in the coagulation system, including plasma D-dimer, and hemoglobin A1c was increased to 6.6%. Electrocardiographic findings showed only sinus tachycardia. On echocardiography, the left ventricular ejection fraction was 61%. The lesion was biopsied, and the clinical diagnosis was squamous cell carcinoma of the lower gingiva (cT4aN0M0, Stage IVA). He was hospitalized for preoperative intensive insulin therapy for type II diabetes mellitus and surgery for the gingival cancer. Segmental resection of the left mandible, ipsilateral conservative neck dissection (Level I – III), and reconstruction with a vascularized fibular flap were planned. The operation was started with left supra-omohyoid neck dissection that preserved the sternocleidomastoid muscle, internal jugular vein, and accessory nerve. When the incision for the carotid artery sheath, dissection of the surrounding tissues of the carotid artery, internal jugular vein, and vagus nerve was performed, no abnormality on the ECG and stable hemodynamics were observed. Then, segmental resection of the left mandible with a 10-mm safety margin from the lesion and left fibular flap collection using a tourniquet were started at the same time. A perforator was identified in the posterior crural intermuscular septum, and a skin paddle was collected that corresponded to the oral mucosal defect. After excision of the interosseous membrane and osteotomy of the fibula were performed, ligating the peripheral side of the peroneal artery and vein and excision of the muscle body and the central side of the peroneal artery and vein were performed. That time, a dark purple thrombus flowed out after dissection of the peroneal vein ( Fig. 5 A). The duration of tourniquet application was 1 hour and 19 minutes. The inside of the perforator was thoroughly irrigated with heparinized saline to remove the thrombus. Intravenous systemic administration of 5000 U heparin was performed and extended activated clotting time (ACT) to 240 seconds was confirmed. Finally, vascular anastomosis was performed under the microscope, and osteosynthesis of the residual mandible and fibula was performed with a titanium reconstruction plate (MatrixMANDIBLETM PLATING SYSTEM, Johnson & Johnson, Tokyo, Japan; Fig. 5 B). The duration of operation was 12 hours and 47 minutes, and total blood loss was 520 ml. After the tracheostomy, management with positive pressure ventilation, and intravenous sedation was performed in the intensive care unit (ICU). ST depression was suddenly observed in V4–V6 on the electrocardiogram 10 hours after the operation. A cardiologist made the diagnosis of subendocardial infarction and performed coronary angiography, percutaneous coronary angioplasty, and placement of a drug-eluting stent. No complications, such as flap necrosis or hematoma, were observed, and hemodynamics were stable after coronary angioplasty. His activities of daily living (ADL) did not decrease, cardiac function was stable, and no local recurrence or distant metastasis was observed 2 years after the operation ( Fig. 6 ).
