Geometric Analysis of the Bilobed Flap for Nasal Reconstruction Surgery

Background: Reconstruction of the nose can be difficult due to its complex anatomical features. In 1989, Zitelli described a modified version of the bilobed flap design technique using 45° and 90° angles to improve nasal reconstructions. While the bilobed flap is still frequently referenced in scholarly literature, there seems to be inconsistency in preoperative flap design; these deviations can lead to suboptimal outcomes. The authors aim to illustrate the variability in bilobed flap execution and provide guidelines in preoperative design to improve consistency. Methods: A geometrically-based approach was used to characterize the inconsistency of bilobed repair technique. The pre-operative design images from fifteen scholarly articles were analyzed via a series of measurements and computations to quantify the angle of rotation and dimensions for the primary and secondary lobes. The “Error Quotient” was a calculated ratio that objectively measured the extent to which a bilobed design deviated from Zitelli’s specifications. Results: There was a noticeable variability in the design of both the primary and secondary lobes. Bilobed designs with smaller angles of rotation, particularly of the first lobe, were associated with higher Error Quotients and greater amounts of deviation from Zitelli’s design. Designs with the smallest Error Quotients had a primary lobe rotation that approached 45°. Conclusion: Consistency of application of the bilobed flap should be established to allow for optimal results, particularly with emphasis on design of the primary lobe. This can be accomplished by including a disposable protractor and marker in their sterile kit to measure a 45° rotation.

Technique for Reconstruction of Nasal Alar Defects in Asian Patients with a Modified Bilobed Nasolabial Flap

Introduction: The Oriental nose differs from the Caucasian nose in terms of size, subunit definition, texture, and thickness of the skin [1]. Zitelli’s bilobed flap enables aesthetic reconstruction in Caucasian noses but in smaller Oriental noses the outcomes are less desirable with nasal alar retraction commonly seen [2]. Hence, we describe a modification of Zitelli’s bilobed flap incorporating nasolabial skin for a single stage nasal reconstruction with reduced nasal alar retraction [3]. Methods: We modified the bilobed flap based on Zitelli’s bilobed flap and the aesthetic subunit principle, as modified for Orientals by Yotsuyanagi in 2000 [4]. The primary lobe was located between the defect and the cheek and the second lobe was located on the cheek, above the nasolabial fold. The modification of the bilobed flap was designed to have a primary lobe that was 10% longer than the length of the distal defect edge from the flap’s pivot point, and the width of the primary lobe was equal to the width of the defect. The length of the secondary lobe was 130% of the length of the distal defect edge to the flap’s pivot point, and the width of the secondary lobe was two-thirds the width of the primary lobe. Results: Satisfactory alar reconstruction was achieved from the viewpoint of the patient and surgeon. There was good nasal contour and appropriate symmetry of the nasal tip with reduced nasal alar retraction. Conclusion: The modification of Zitelli’s bilobed flap to have a longer primary lobe and include nasolabial skin, results in reduced nasal alar retraction.