gms | German Medical Science

Objectives: Free vascularised toe transfer is one of the reconstructive options in congenital absence, underdevelopment and traumatic complete or partial loss of the thumb and fingers. Preoperative imaging is rarely performed and Doppler examination is often the only tool being used to localise the presence and position of the dorsalis pedis artery (DPA). Whether the toe flap is based on the dorsal or plantar system has implications on operating time, pedicle length and donor site morbidity. Nevertheless, direct visualization of the arterial system during dissection from is often the final method to appreciate the exact vascular pattern, whether dorsal or plantar dominant. We wanted to find out if Colour Doppler Ultrasound could help in the preoperative planning in free vascularised toe transfers, aiding in determining the vascularity pattern and localising the vessels, thus facilitating dissection.

Method: In this preliminary study, we used the mobile ultrasound machines from the anaesthetic department, which are commonly used in the preoperative setup and easily available in the anaesthetic bay. We scanned the feet of 10 consecutive paediatric patients undergoing elective surgery. The ultrasounds were performed by the first author who is trained and certified as a sonographer, using the time during the anaesthetic setup in order not to delay the time to surgery. Two of these patients underwent free vascularised toe-to-hand transfers which allowed to use the ultrasound for marking and correlate the results with the intraoperative findings.

Results: Using a 13-6 MHz hockey stick probe we could easily identify the location, course, diameter and interconnections of the dorsal and plantar system in these 10 paediatric patients. Nine patients had a dorsal dominant blood supply to the first and second to via the dorsalis pedis artery (DPA) and first dorsal metatarsal artery (FDMA). One patient had no identifiable FDMA but a well-developed plantar system. In both patients undergoing free vascularised second toe transfer the exact course, calibre and branching pattern of the DPA, FDMA and dorsal veins could be precisely determined, marked and exactly correlated to the intraoperative findings.

Conclusion: Colour Doppler Ultrasound is a simple and valuable tool for preoperative planning and marking in free vascularised toe transfers, potentially reducing dissection time. The procedure is simple and quick and can be done during the pre-surgical setup without any delay on the surgery.