Auricular Reconstruction in Adult Patients With Unprepared Congenital Microtia: A Single Institution's Experience

A Feasibility Study of HoloLens Ear Image Guidance for Ear Reconstruction

BACKGROUND

An ideal 3D cartilage framework and accurate anatomical location are the most important factors to carry out a satisfactory reconstruction of the ear. To streamline this process, we developed an augmented reality assistance system, HoloLens Ear Image Guidance, which is based on computed tomography (CT) data, tailor-made navigation kits to guide reconstruction, data processing software, and HoloLens hardware. The objective of this study is to verify its feasibility in a clinical setting.

METHODS

This study first validated our system in healthy controls and then extrapolated data to test on patients with microtia. First, three healthy volunteers were recruited, and reconstructive navigation kits were made using 3D printing. CT data were collected for the head and neck and imported into the HoloLens Ear Image Guidance Application to generate a personalized 3D virtual ear image. Volunteers then wore the navigation kits while researchers observed them through the HoloLens to check accuracy, track delay, and view the ear image guide.Ten patients with unilateral microtia were recruited and CT data were collected, and reconstructive navigation kits were made to assist with surgery. The procedure was monitored to record the surgeon's experience wearing the HoloLens, the patients' complications associated with wearing navigation kit, and to measure the symmetry between the reconstructed ear and the reference counterpart.

RESULTS

In control patients, the deviation between the virtual image and the real ear was less than 2.4% (±0.22%); the tracking delay was less than 1.26 s (±0.09 s), the display effect was good, and surgeons did not report discomfort or dizziness while wearing the HoloLens. Volunteers did not report any pain from holding the navigation reference in their mouth during the test. Following validation, the HoloLens-assisted procedures were not associated with surgeon discomfort or dizziness. No complications were noted in patients including injury to the oral mucosa. Symmetry between the reconstructed ear and the contralateral ear was noted to be satisfactory in HoloLens-assisted surgery.

CONCLUSIONS

The HoloLens Ear Image Guidance initially met clinical demands in registration accuracy, tracking speed, and subjective user experience, which can be used as the basis for continual software improvements and clinical application.

Modified Technique for Auricular Helical Rim Reconstruction in Adult Patients with Subtotal Helical Rim Defects

BACKGROUND

In adults, the volume of costal cartilage is enough for reconstruction, but floating cartilage is hard, brittle, and easily broken due to calcification, in addition to being short, making it unsuitable for helical rim reconstruction in such age groups.

AIM OF STUDY

This study describes a novel technique in which adult patients underwent 2-stage helical rim reconstruction using the syncytium of sixth and seventh costal cartilage.

MATERIAL AND METHODS

A single-arm clinical trial involves 35 adults with total and subtotal helical rim defects, either congenital, post-traumatic, postburn, or postvascular malformation excision. Twenty-nine unilateral and 6 bilateral cases. The age of patients ranged between 19 and 40 years. In the period between April 2021 and April 2023. Follow-up was 6 months.

RESULTS

There were no technique-related complications, such as broken helix. In most cases, scars were invisible, with the normal contour of helical rim. Among the 35 patients, 19 were graded as excellent, 13 as good, and 3 as fair. In objective photographic evaluation, all patients were evaluated with high (3 or 4) ratings; the score was 3 in 19 patients and 4 in 16 patients. All patients were satisfied with the size, contour, position and details of the new helix.

CONCLUSION

Using the syncytium of the sixth and seventh costal cartilage to fabricate the helical rim in adult patients gives a suitable volume of cartilage graft as regards the length and width, which suits the reconstruction of the helical rim, and shows a good configuration with satisfactory surgical results.