A study from Michigan Medicine published in the American Journal of Neuroradiology reports that early postoperative CT scans and MRIs can help predict whether a “free ﬂap” in head and neck cancer patients who have surgery to remove the tumor will fail, which could allow surgeons to intervene earlier. These patients often need reconstructive surgery in the form of a “free ﬂap,” which is skin and tissue taken from a different part of the body and connected to the blood vessels of the wound in need of repair. This free ﬂap method, called microvascular reconstruction, carries around a 10-40% risk of wound complications, with 10% of cases requiring another surgery.
“All patients who have this procedure can be investigated with non-invasive post-operative CT or MRI perfusion, and these two methods show a lot of promise as accurate biomarkers of predicting free ﬂap viability,” said Ashok Srinivasan, MD, FACR, senior author of the paper and neuroradiologist at University of Michigan Health.
“By seeing how much blood is ﬂowing in and out of the tissue, we may be able to predict if the ﬂap will succeed and if the patient can be discharged earlier, or it may be able to tell us sooner that surgical intervention is needed to repair the ﬂap. Radiologists have used CT and MRI perfusion with contrast to look at blood perfusion in brain imaging for a stroke or tumor, but no studies have used them to look at free ﬂaps early after a procedure.”
The U-M Head and Neck Oncology Program performs approximately 300 free ﬂaps a year, with each of these patients staying approximately one week in the hospital after surgery. The ability to predict which patients are safe for an earlier discharge would have signiﬁcant and immediate cost savings, says Matthew Spector, MD, co-author of the paper and otolaryngologist at U-M Health.
Currently, most surgeons use ultrasound to assess viability for free ﬂap reconstruction with techniques known as doppler and skin paddle. Those methods often are unable to evaluate deeper aspects of the ﬂap, or air and blood products cause interference in visualization, which affects how well clinicians can analyze a ﬂap’s viability, says Srinivasan, who is also a clinical professor of radiology at U-M Medical School.
The team of researchers analyzed 19 patients who had successful free ﬂap reconstruction, as well as ﬁve who had wound failure, at U-M Health between January 2016 to mid-2018. They found that both CT and MRI perfusion techniques showed signiﬁcant differences between the two patient groups.
Researchers were not able to compare the two methods to ultrasound techniques or each other due to the small sample size. They hope to accomplish those comparisons through a larger future trial.
“This pilot research shows us that these models work, as all areas of the ﬂap can be assessed using CT and MRI, unlike doppler and skin paddle where some areas may be blind to evaluation,” said Yoshiaki Ota, MD, lead author of the paper and a neuroradiology fellow at University of Michigan Health. “We know that using CT and MRI could help shorten a patient’s hospital stay or avoid a prolonged hospitalization, and now we need to look further at which is more effective and cost-effective.”Back To Top
Post-Op CT and MRI Predict Flap Failure in Head and Neck Cancer Surgery Patients. Appl Rad Oncol.