title: Preoperative Computed Tomography Angiography for Evaluation of Feasibility of Free Flaps in Difficult Reconstruction of Head and Neck.
abstract: BACKGROUND
  Free tissue transfer has been advocated for anatomic and functional reconstruction of soft tissue defects after surgical removal of an extensive recurrent tumor and/or arising from previous irradiation in the head and neck. We report a case series of difficult reconstruction in the head and neck in which preoperative computed tomography (CT) angiography was utilized to evaluate the feasibility of free flap reconstruction. The preoperative radiological evaluation was performed to determine the availability of reliable vessels for anastomosis in free flap reconstruction. If none was found, regional pedicle flap or palliative treatment was applied instead. The use of CT angiography allows the clinical surgeon to perform precise surgical planning with greater confidence. This may improve surgical results, thereby potentially reducing perioperative morbidity.
  
  
  METHODS
  Twenty CT angiograms were obtained from 20 patients. All patients were men with a mean age of 57.2 years (range, 42-72 years) and were scheduled to undergo difficult reconstruction in the head and neck. All patients (20/20 [100%]) suffered from oral squamous cell carcinoma. They had all received extensive operations and radiation therapy. Eighteen patients (18/20 [90%]) had completed a course of perioperative irradiation. The CT angiography reports were used to perform detailed preoperative surgical planning accordingly. The findings of CT angiography were classified into 3 groups: group I: normal CT angiography (patent recipient arteries) (Fig. 3); group II: abnormal CT angiography (recipient vessels were present but stenosis or atherosclerotic lesions were noted) (Fig. 4); group III: abnormal CT angiography with no patent recipient arteries in bilateral sides of the neck (Fig. 5); CT angiography results were correlated to the operative findings.
  
  
  RESULTS
  The patients were classified into 3 groups based on the angiographic findings. Six patients (6/20 [30%]) were assigned to group I, 8 patients (8/20 [40%]) to group II, and 6 patients (6/20 [30%]) to group III. In groups I and III, all patients (12/12 [100%]) underwent the treatment according to the original preoperative detailed planning. No flap failure was noted in these 2 groups. In group II, 4 patients' recipient vessels (4/8 [50%]) possessed adequate blood flow intraoperatively; hence, microvascular free flaps were transplanted. Venous congestion in 1 case (1/4 [25%]) was noted. The remaining patients in this group (4/8 [50%]) underwent reconstruction with pedicle flaps rather than free flaps because of the lack of suitable target vessels intraoperatively. All flaps (4/4 [100%]) survived. Among the patients who were treated surgically, intraoperative findings were in accordance with those predicted by CT angiography. The total abnormality rate of CT angiography was 70%. Vascular abnormalities detected as a result of preoperative CT angiography led to changes in the operative plan in 50% (10/20) of the patients.
  
  
  CONCLUSIONS
  The use of CT angiography should be considered for difficult microsurgical reconstructions in the head and neck. When an abnormality in vascular anatomy is detected by CT angiography, the surgeon is advised to consider altering the operative plan accordingly. This allows precise operation, thereby maximizing the possibility of an optimal outcome. Changing the operative plan based on results of CT angiography may also help to avoid the difficult situation in which the surgeon finds that there are no suitable recipient vessels for free flap reconstruction during the operation. In addition, CT angiography enables surgeons to conduct the preoperative surgical planning with greater confidence, thereby potentially enhancing the success rate of difficult reconstructions in the head and neck, which in turn would tend to improve the perioperative course for the patient and consequently to improve results by decreasing vascular complication rates.
authors.affiliation: From the *Division of Plastic and Reconstructive Surgery, Department of Surgery, Taichung Veterans General Hospital; †Institute of Medicine, Chung Shan Medical University; ‡Department of Radiology, Taichung Veterans General Hospital; and §Department of Medical Imaging and Radiological Sciences, College of Heath Sciences, Central Taiwan University of Science and Technology, Taichung, Taiwan.
authors.forename: Yen-Wei
authors.initials: YW
authors.lastname: Chen
authors.forename: Jung-Hsing
authors.initials: JH
authors.lastname: Yen
authors.forename: Wen-Hsien
authors.initials: WH
authors.lastname: Chen
authors.forename: I-Chen
authors.initials: IC
authors.lastname: Chen
authors.forename: Chih-Sheng
authors.initials: CS
authors.lastname: Lai
authors.forename: Chun-Te
authors.initials: CT
authors.lastname: Lu
authors.forename: Ding-Yu
authors.initials: DY
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000601:surgery*; D005240:Feasibility Studies; D058752:Free Tissue Flaps / Q000098:blood supply* / Q000637:transplantation; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000601:surgery*; D061330:Multidetector Computed Tomography; D009333:Neck / Q000098:blood supply* / Q000601:surgery; D011300:Preoperative Care / Q000379:methods*; D019651:Plastic Surgery Procedures / Q000379:methods*