Ultrasound Examination Protocol for Patients with Suspected Traumatic Arteriovenous Fistulas when Direct Scanning is Unfeasible

Combat extremity trauma is characterized by multiple injuries — wounds of the skin, soft tissues, bones, vessels, and nerves. The implementation of diagnostic assistance is often associated with the injury zone features, and ultrasound (US) examination of the damaged area in the presence of a wound or an external fixation device is challenging for a detailed assessment of the arteries and veins in the target segment. Objective. To develop an algorithm for suspected traumatic arteriovenous fistula based on specific US patterns when direct scanning of the injury zone is not feasible, using remote intact segments. Material and methods. The analysis included 15.000 US examinations of patients with extremity injuries. A total of 574 cases of limb arteriovenous fistula were verified. The following parameters were analyzed: traumatic damage to the walls of veins/arteries; presence of venous/arterial (traumatic) thrombosis; concomitant arterial pathology (significant atherosclerosis). Results. Based on the diagnostic US examinations performed in patients with wounds, we developed an algorithm to verify suspected arteriovenous fistulas using specific US patterns when direct scanning of the injury zone is impossible. The application of this algorithm in routine practice provides a highly reliable diagnosis of traumatic arteriovenous fistulas located distal to the scanned area. Conclusion. An understanding of specific US patterns that suggest an arteriovenous fistula in an intact (remote) area, as well as the use of linear and convex transducers during the examination, is helpful in significantly accelerating diagnosis, injury verification, and treatment planning for patients with a history of shrapnel and blast injuries of the extremities.