We are closing this study due to the focus on other research projects and there is no time or personnel tofurther pursue the completion of this project

Surgical reconstruction of anatomical structures after head and neck cancer resection has made enormous strides in the past 20 years with advancing flap techniques and the usage of perforating vessels, but accurate and consistent identification of these perforators has remained a challenge due to the varying anatomy of vasculature in the donor region. Computed tomography angiography (CTA) has been used increasingly in preoperative free flap perforator mapping for breast reconstruction but has been limited in head and neck applications. In addition, indocyanine green (ICG) assisted NIR fluorescence angiography has been developed for intra-operative flap assessment. In this study, the investigators propose to assess a previously undocumented, multi-modal imaging technique with preoperative dual energy CTA to design and intraoperative ICG assisted NIR angiography to assess free flap in head and neck reconstruction.

CTA and NIR-assisted ICG angiography will be used in the mapping of the free flaps. CTA provides surgeons with preoperative information on the vascular anatomy and facilitates surgical planning for flap harvesting. The advantages of CTA are that it is noninvasive, rapid, and easy to read by the surgeon. Moreover, it provides information to help the surgeon decide which site to explore in the operation and reduces the rate of injuring or missing an optimal perforator.

This technique can help reduce the size of the incision needed for perforator exploration, which helps reduce the patient's postoperative discomfort. The operation time can be reduced by choosing suitable perforators in the preoperative stage, which can also help reduce the cost of hospitalization. NIR-assisted angiography gives live localization of the flap's dominant perforator perfusion zones while quantifying the relative tissue perfusion for immediate skin paddle design.

Inclusion Criteria:

• The study will include patients planned for free anterolateral thigh/fibula or scapula flap for Head&Neck cancer reconstruction.
• The patients should have a complete and detailed medical record.
• Subjects must be at least 18 years of age.
• Subjects must sign and be given a copy of the written Informed Consent Form.

Exclusion Criteria:

• Patients who are not able to consent by themselves or grasp the implication of the study.
• Subjects participating in any other clinical trial during the time of this clinical investigation and that may have an impact on this evaluation.
• Pregnant or potentially pregnant woman
• Lactation.
• Iodine, shellfish, cough mixture, betadine or ICG allergy
• The exclusion criteria for the IV contrast detailed in appendix 2.