Anatomical and Clinical Study of the Posterior Auricular Artery Angiosome: In Search of a Rescue Tool for Ear Reconstruction

Posterior auricular artery helix root free flap-part I: radio-anatomical study

Full-thickness defects of the distal nose are an ongoing surgical challenge. Among the available techniques, pre-auricular chondrocutaneous free flaps based on the superficial temporal artery (STA) have good aesthetic and functional outcomes. However they often require autologous venous grafts. The aim of this radio-anatomical study was to evaluate the feasibility of the helix root free flap based on the posterior auricular artery (PAA). Vascular lengths, diameters, and networks were investigated in flaps harvested from cadavers. The perfusion of the flaps was studied by injecting patent blue. Some flaps were also injected with contrast agent and studied by angiography and computed tomography. Ten flaps from seven fresh cadavers were dissected and analysed. The mean length of the PAA was 114.2 mm and the mean diameter was 2.2 mm. Perfusion was investigated in six flaps and considered good in three of these. The study results demonstrate the feasibility of PAA-based helix root free flaps. This alternative technique provides an 11 cm pedicle with vessels of appropriate calibre, facilitating any potential microsurgery. The scar is mostly hidden behind the ear. This PAA-based helix root free flap could be a reliable and promising single-stage procedure to repair complex defects of the alae nasi.

Reconstruction of Extensive Auricular Defects Using a Retroauricular Artery Perforator-Based Propeller Flap

BACKGROUND

Various local techniques have been successfully used for the reconstruction of auricular defects. However, most local techniques are not suitable for extensive auricular defects. The aim of this study is to investigate the utility of a retroauricular artery perforator-based propeller flap for the reconstruction of extensive auricular defects by evaluating aesthetic outcomes using objective and quantitative parameters.

METHODS

Twenty-one patients with extensive full-thickness and partial-thickness defects were treated with retroauricular artery perforator-based propeller flaps harvested from the mastoid and neck regions. The surgical procedures were performed using single-stage reconstruction in postauricular partial-thickness defects and 2-stage reconstruction in full-thickness auricular defects. Levels of final satisfaction and tissue matching as well as donor scar perception were evaluated by the patients and objective observers.

RESULTS

The original sizes and projections of the auricles were achieved. The color, texture, and thickness of the flaps matched well with the adjacent auricles. The vast majority of the patients and observers were very satisfied with the surgical outcome.

CONCLUSIONS

Retroauricular artery perforator-based propeller flaps may preserve the size and projection in both partial- and full-thickness extensive defects of the auricle. With this procedure, there was also excellent matching of the color, texture, and thickness of the flap with the adjacent tissue, as well as acceptable levels of donor scarring, thereby achieving satisfactory aesthetic outcomes.

Anatomical and Histological Evaluation of the Retroauricular Fascia Flap for Staged Auricular Reconstruction

OBJECTIVES

The retroauricular fascia flap (RFF) is one of the most commonly used vascularized linings for auriculocephalic sulcus reconstruction in staged total auricular reconstruction. This study aims to investigate the histomorphometric features regarding the retroauricular fascia.

METHODS

Histological evaluation included qualitative observation and quantitative analysis of sections of RFF stained with hematoxylin and eosin, Masson's trichrome, Elastica van Gieson, CD31, and Lyve-1. Ultrasonographic evaluation included measurement of the thickness of the superficial layer of the retroauricular fascia (RFF origin) at three different positions in microtia patients. P < 0.05 was considered statistically significant.

RESULTS

RFF was a thin, highly organized layer with mainly collagen fibers. From its superior to inferior portions, the percentage of collagen fibers differed significantly (superior 87.57 ± 10.85%, middle 68.29 ± 29.02%, inferior 53.31 ± 33.33%, p < 0.05). The percentages of elastic fibers in the superior (4.86 ± 5.17%) and middle (5.05 ± 5.37%) areas were higher than that in the inferior (2.14 ± 2.42%, p < 0.05). RFF blood vessel density (20× magnification) decreased significantly from the superior to inferior portions (superior 6.39 ± 1.18, middle 5.17 ± 1.15, inferior 2.67 ± 0.78, p < 0.05). Lymphatic vessel density (20× magnification) also decreased significantly from the superior to inferior regions (superior 6.80 ± 0.62, middle 5.26 ± 1.17, inferior 2.11 ± 0.46, p < 0.05). Thickness of the superficial layer of retroauricular fascia increased significantly from the superior to inferior regions (superior 0.29 ± 0.06 mm, middle 0.36 ± 0.09 mm, inferior 0.53 ± 0.14 mm, p < 0.001).

CONCLUSIONS

From cranial to caudal, the RFF became thicker, less elastic, and less vascularized, and contained fewer lymphatic vessels. Therefore, when the retroauricular fascia is large enough, the superior portion would be preferred for RFF in auriculocephalic sulcus reconstruction.

NO LEVEL ASSIGNED

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