A, Unmarked facial depiction. B, Vertical line through the oral commissure. C, Intersecting line through the nasolabial sulcus. The point of intersection marks the deep course of the angular artery. Reprinted with permission of the Cleveland Clinic Center for Medical Art & Photography, copyright 2013-2014.
A, Marked facial depiction showing the course of the angular artery. B, Facial depiction showing the nasolabial fold incision in addition to the course of the angular artery. Reprinted with permission of the Cleveland Clinic Center for Medical Art & Photography, copyright 2013-2014.
A, Depiction of the angular artery and vein (black hash marks) coursing deep to the zygomaticus muscle (ZM) complex. B, The vein is identified 1.5 cm superior to the artery (black hash marks indicate vessel locations) along the lateral border of the ZM. C, Fat and fascia bluntly dissected deep to identify the vessels, which can then be circumferentially dissected and mobilized as needed for microvascular anastomosis. Reprinted with permission of the Cleveland Clinic Center for Medical Art & Photography, copyright 2013-2014.
A and B, Cadaveric images show the external landmarks used to locate the angular vessels. C, Image shows the course of the artery within the nasolabial sulcus.
A, Dissection exposes the distal facial artery and its terminal branch (angular artery) coursing deep to the zygomaticus muscle complex. B, The angular vein courses 1.5 cm superior and deep to the angular artery.
Haffey TM, McBride JM, Fritz MA. Use of Angular Vessels in Head and Neck Free-Tissue TransferA Comprehensive Preclinical Evaluation. JAMA Facial Plast Surg. 2014;16(5):348-351. doi:10.1001/jamafacial.2014.249
The angular artery, its perforating branches, and their zones of tissue perfusion have been described extensively for facial reconstruction. Various cutaneous and mucosal flaps with either anterograde or retrograde perfusion play an important role in facial and oral reconstruction. However, these flaps share the limitations of pedicled nature and donor-site intolerance. Free-tissue transfer (FTT) has transformed capabilities and outcomes in head and neck reconstruction. While less constrained by tissue volume and subtype, FTT has its own limitations, including pedicle reach for anastomosis to inflow and outflow vasculature in upper face reconstruction. The angular vessels, owing to their relatively high central location and accessibility via a camouflaged nasolabial fold incision, may have value in midface and nasal reconstruction.
To detail a technique for consistently locating the angular vessels while preserving the integrity of adjacent neuromuscular structures and to evaluate the caliber and consistency of the angular artery and vein for their usability in microvascular anastomosis.
Design and Setting
We conducted a PubMed literature search for the terms angular artery, melolabial flap, nasolabial flap, retroangular flap, and any associations with FTT. We also performed 26 anatomic cadaveric dissections on 13 fresh cadavers to evaluate the angular arteries and veins.
Main Outcomes and Measures
Vessel caliber, length, and variability were analyzed and utility for use in FTT was assessed. A total of 26 angular arteries and 26 angular veins were included in the analysis. Anatomic relationships were used to develop a surgical schema for dissection and isolation of the angular vessels specifically for FTT.
The angular vessels have consistent anatomic relationships facilitating localization and have a consistent caliber amenable to use in microvascular FTT. The mean (SD) artery diameter was 2.34 (0.67) mm prior to dilation and 3.21 (0.87) mm after dilation. The diameters of the vein before and after dilation were 3.57 (0.53) mm and 6.40 (0.81) mm, respectively. There was no statistical difference between the vessels on the right and left sides.
Conclusions and Relevance
We describe for the first time the anatomic cadaveric dissection and analysis of the angular arteries and veins specifically to determine compatibility with regard to FTT. We found good FTT compatibility.
Level of Evidence
The use of the terminal branch of the facial artery, the angular artery, has been described extensively in facial plastic surgery literature in local flaps for the reconstruction of cutaneous and mucosal defects.1- 7 However, there are limitations inherent to any rotational or pedicled flap. Namely, the pedicle length, and therefore reach, is determined by the donor vessel. There are also limitations in the size of the defect that can be repaired as well as the type of tissue that can be used for reconstruction. Free-tissue transfer provides solutions to some of these limitations, which is in part why this technique has gained so much favor in recent years.
Despite these benefits, oral, nasal, and facial defects present a unique challenge to the microvascular surgeon because pedicle length and geometry can still limit flap selection owing to proximity (or lack thereof) of recipient vessels. Typically, the facial artery and vein or the superficial temporal artery and deep temporal vein are the recipient vessels in oral-facial microvascular reconstruction. It is our experience that these vessels have an adequate and consistent caliber for microvascular anastomosis, but they require considerable pedicle length, which can be limiting in certain situations such as palatomaxillary, orbital, and nasal reconstruction.
An ideal solution for the reconstruction of oral, nasal, and facial defects would be to identify a reliable set of donor vessels in the vicinity of the defect that have adequate caliber for microvascular anastomosis. We had 2 objectives in performing this study: (1) to describe and detail a technique for consistently locating these vessels while preserving the integrity of adjacent neuromuscular structures; and (2) to assess the caliber and consistency of the angular artery and vein for suitability in microvascular anastomosis.
We conducted a PubMed literature search for the terms angular artery, melolabial flap, nasolabial flap, retroangular flap, and any associations with free-tissue transfer. To our knowledge, no similar study has been published to date.
We performed 26 anatomic cadaveric dissections on 13 fresh unfixed cadavers to evaluate the angular arteries and veins. The course of the vessels and pertinent anatomic relationships were noted, and the vessel caliber was measured before and after dilation and recorded.
A total of 26 angular arteries and 26 angular veins from 13 cadavers were included in the analysis. In 1 cadaver (2 arteries), the superior labial branch was the terminal branch, and the angular artery could not be found in the nasofacial sulcus. Anatomic relationships were evaluated to develop a surgical schema for dissection of the angular vessels specifically for free-tissue transfer (Figures 1, 2, and 3).
Once identified, the angular artery and vein were sharply transected at the medial border of the zygomaticus major/minor (ZM) complex. A caliper was used to measure the vessel diameter. Then a microsurgical vessel dilator was applied, and the diameter measured again. The mean (SD) artery diameter was 2.34 (0.67) mm prior to dilation and 3.21 (0.87) mm after dilation. The diameters of the vein before and after dilation were 3.57 (0.53) mm and 6.40 (0.81) mm, respectively. There was no statistical difference between the vessels on the right and left sides.
The nasolabial fold was marked with a line, and a vertical line was drawn through the oral commissure (Figure 1). The point of intersection of these lines identifies the location of the angular artery as it runs within the nasolabial sulcus toward the nasofacial sulcus (Figure 2).
An incision was made in the nasolabial fold, and subcutaneous tissues were dissected bluntly to identify the angular artery. Once identified, the artery was followed laterally (toward the oral commissure). The ZM muscle complex was identified as the artery coursed deep to them. Often, the superior labial branch was identified coming off of the distal facial artery at or underneath the ZM (Figure 3).
The lateral border of the ZM muscle complex was then identified, and the lateral border of the muscle was followed superiorly toward its origin on the zygoma. The point 1.5 cm superior to the artery along the lateral border of the ZM was identified, and the fat and fascia were bluntly dissected deep to identify the vessels (Figure 3). The artery and vein can then be circumferentially dissected and mobilized as needed for microvascular anastomosis (Figure 3).
The angular artery consistently runs deep to the intersection point of the nasolabial fold and a vertical line drawn through the oral commissure (Figure 4). Both the artery and the vein course deep to the ZM muscle complex. The vein consistently runs in a plane deeper than the artery 1.5 cm superior to the artery along the lateral border of the ZM muscle complex (Figure 5).
Through this cadaveric study, we were able to determine the angular vessels can be reliably dissected using known and consistent anatomic landmarks and can be accessed through a cosmetically acceptable incision in the nasolabial sulcus. They also have an adequate caliber for microvascular anastomosis and can allow for shorter pedicle lengths when reconstructing defects of the nose, midface, and oral cavity, depending on the geometry of the inset. We have used the angular artery and vein in multiple microvascular cases, which will be described separately in a follow-up study. Anecdotally, we have found the vessels to be of adequate caliber and the shortened pedicle reach to be favorable.
The angular vessels are likely best suited for use in reconstructing defects involving the nose and nasal lining (eg, free anterolateral thigh fascia lata free flap for nasal lining8), midface (eg, fibula for midface9), and palate and upper oral cavity owing to the close proximity. The results of the present study show that the angular artery diameter is comparable to that found in anatomic studies evaluating other vessels used in head and neck microvascular surgery, such as the superficial temporal artery.10 The angular vessels provide the reconstructive surgeon another tool with which to manage challenging facial defects in specific clinical situations.
It should be noted that the angular artery is the terminal branch of the facial artery and is therefore not a reconstructive option in patients who have had the facial artery transected in the neck as part of their extirpative procedure. There is theoretically a retrograde blood flow through the rich vascular plexus between the angular artery and the supraorbital artery,6,7 but it is unknown whether there is sufficient nutrient flow to sustain free-tissue transfer.
The angular artery has a diverse history of use in rotational, pedicled, and interpolated flaps in both nasal and facial reconstruction. Inherent to all pedicled flaps are limitations, which can potentially be circumvented with the use of free-tissue transfer. We describe for the first time to our knowledge the anatomic cadaveric dissection and analysis of the angular artery and vein specifically for use as recipient vessels in free-tissue transfer. We found that the vessels have consistent anatomic relationships and calibers sufficient for microvascular anastomosis.
Corresponding Author: Michael A. Fritz, MD, Cleveland Clinic Foundation, A71, 9500 Euclid Ave, Cleveland, OH 44195 (firstname.lastname@example.org).
Accepted for Publication: February 6, 2014.
Published Online: June 12, 2014. doi:10.1001/jamafacial.2014.249.
Author Contributions: Drs Haffey and Fritz had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Haffey, Fritz.
Acquisition, analysis, or interpretation of data: Haffey, McBride, Fritz.
Drafting of the manuscript: Haffey, Fritz.
Critical revision of the manuscript for important intellectual content: Haffey, McBride, Fritz.
Statistical analysis: Haffey, Fritz.
Administrative, technical, or material support: Haffey, McBride, Fritz.
Study supervision: Haffey, Fritz.
Conflict of Interest Disclosures: None reported.
Previous Presentation: This research was presented at the American Academy of Facial Plastic and Reconstructive Surgery Annual Fall Meeting; September 5-8, 2012; Washington, DC.