3D modeling better visualizes perianal Crohn's fistula

Last Updated: 2018-01-03

By Will Boggs MD

NEW YORK (Reuters Health) - Three-dimensional (3D) models based on MRI can aid in the understanding of complex anatomical relationships in patients with perianal Crohn's fistula, according to a brief clinical report.

"The best modality for 3D modeling remains un-evaluated," Dr. Kapil Sahnan from Imperial College London told Reuters Health by email. "This open-source (free) technology could be easily translated to other pathologies and fields."

Dr. Sahnan's team constructed 3D models for inter-sphincteric and trans-sphincteric fistulas, with the various segments displayed in different colors (red for the fistula tract, green for the external anal sphincter and levator plate, and blue for the internal anal sphincter and rectum).

The models were then uploaded into an app, with which the operator can manipulate the models and remove the surrounding structures, the team explains in Annals of Surgery, online December 11.

Dr. Sahnan suggested that such models could be used for surgical planning, medical education, and patient understanding (e.g., during informed consent for surgery).

"The technique to create segmentations is reproducible and generalizable," the researchers write. "Accuracy is dependent on the expertise of the radiologist. Therefore, this technique might initially be most appropriate for use in high-volume centers by specialist gastrointestinal radiologists, or to have tertiary sites performing the reconstructions remotely and interacting in a virtual multi-disciplinary team."

Dr. Jose Carlos Gallego from Complexo Hospitalario Universitario de Ferrol, in Spain, who recently reviewed the role of MRI in the management of perianal Crohn's disease, told Reuters Health by email, "Undoubtedly, this 3D modeling allows for a better understanding of fistula anatomy by the surgeon, and so it can be advantageous to preoperative planning. Conversely, it seems to be laborious and time-consuming. On the other hand, as patients with Crohn's disease are often demanding information, it can also improve the clinician-patient relationship."

"In my opinion, it can be a very useful tool for the interdisciplinary team who deal with inflammatory bowel disease," said Dr. Gallego, who was not involved in the new work. "We must keep in mind that, nowadays, this type of patients must be treated by interdisciplinary units composed of gastroenterologists, surgeons, radiologists, and other specialists; any tool that allows a more accurate perception of the disease by the team will yield a better outcome for the patient."

SOURCE: http://bit.ly/2lQVhTh

Ann Surg 2017.