VASCULAR ANATOMY OF THE NOSE AND THE EXTERNAL RHINOPLASTY APPROACH

Objective: To characterize the venous, lymphatic, and arterial blood s upply of the nose and determine the effect of the external rhinoplasty approach on this vasculature. We hypothesized that dissection in the areolar tissue plane below the musculoaponeurotic layer of the nose wi ll preserve the nasal vasculature and minimize postoperative nasal tip edema. Design: The study included preoperative and postoperative clin ical evaluation, cadaver dissection, and histologic examination. In th e clinical section, lymphoscintigraphy was performed before and after rhinoplasty using the endonasal (transnostril) or external (open) appr oach. Additionally, nasal tip edema was subjectively quantified at spe cified intervals after surgery. In the cadaver dissection section, 15 fresh cadavers were dissected to identify the venous and arterial vasc ulature. In the histology section, fresh nasal tissue was examined by light microscopy to verify the anatomy of arteries, veins, and lymphat ic vessels. Setting: Subjects for the clinical section of the study we re volunteers undergoing primary rhinoplasty surgery at the University of Illinois College of Medicine at Chicago. Patients: Lymphoscintigra phy was performed on nine patients who underwent rhinoplasty surgery. Seven of these patients underwent postoperative lymphoscintigraphy. In terventions: The rhinoplasty procedures included three different metho ds of exposure of the nasal structures. Two patients underwent an endo nasal (transnostril) nondelivery approach using a transcartilaginous i ncision. Five patients underwent the external approach with three rece iving dissection in the areolar tissue plane below the musculoaponeuro tic layer (preserving major nasal vasculature) and two undergoing diss ection above the musculoaponeurotic layer (disrupting nasal vasculatur e). Main Outcome Measures: In the clinical section of the study, the o utcome measures were tracer flow as seen on lymphoscintigraphy and tip edema scores subjectively quantitated on a scale from 1 (none) to 4 ( maximal). Results: Clinical Section: Lymphoscintigraphy revealed flow of tracer along the lateral aspect of the nose (cephalic to lateral cu ra) to the preparotid lymph nodes. Postoperative scans revealed preser vation of flow of tracer with the endonasal (transnostril) approach an d the external approach with submusculoaponeurotic areolar tissue plan e dissection. There was loss of normal flow of tracer with the externa l approach using dissection that disrupted the musculoaponeurotic laye r with supratip debulking. The nasal tip edema scores for the transnos tril and external approach using areolar plane dissection were signifi cantly lower than the external approach with disruption of the musculo aponeurotic layer. Cadaver Dissection Section: Other than the lateral nasal veins, the major arteries, veins, and lymphatic vessels ran supe rficial to the musculoaponeurotic layer of the nose. The lateral and d orsal nasal and the columellar arteries comprise an alar arcade that p rovides the majorblood supply to the flap elevated in the external rhi noplasty approach. Histologic Section: Light microscopy of plastic res in sections verified the lymphoscintigraphic and cadaver dissection fi ndings. The lymphatic vessels were located primarily in the reticular dermis above the muscle layer. Conclusions: The major arterial, venous , and lymphatic vasculature courses in or above the musculoaponeurotic layer of the nose. In the external rhinoplasty approach, dissection i n the areolar tissue plane below the musculoaponeurotic layer will min imize tip edema and protect against skin necrosis by preserving the ma jor vascular supply to the nasal tip.