The purpose of this study is to evaluate the performance of the EchoMark and EchoSure (both FDA approved devices) as an ultrasound-based method of monitoring the viability of free flaps and patency of at-risk vessels. The implant and ultrasound will be used per IFU. The primary purpose of the study is to collect data on patient outcomes in cases where the surgeon has chosen it as the appropriate method of monitoring.

You may be eligible for this study if you meet the following criteria:

• Conditions: Free Flap Transfer Malignant Neoplasm
• Age: 99 years or below
• Gender: All