Nonsurgical filler rhinoplasty is among the fastest growing cosmetic procedures worldwide1 and is also the one with greatest risk of ocular complications.2 Although still rare, intravascular injections of the filler material can cause serious complications, culminating in amaurosis and skin necrosis.1, 3-6 Ischemic lesions result primarily from the insertion of the filler into the lumen of blood vessels, especially arterial ones, with subsequent vascular thrombosis. Blunt cannulas are suggested in high-risk regions in an attempt to reduce the possibility of vessel cannulation,7 as these require greater forces for intra-arterial penetration (especially large diameter ones) compared to similar-sized needles.8 In previous force assessments,9 22 gauge cannulas were unable to penetrate the angular branch of the facial artery. Altogether, this can induce a [false] perception of being risk-free merely by using a large—diameter cannula. Here, two rare cases are reported to exemplify and raise concern for severe vascular complications due to nonsurgical rhinoplasty using hyaluronic acid (HA) injected though 22 gauge cannulas. Case 1.A healthy 68-year-old male with a history of implantation of polymethylmethacrylate and polydioxanone threads, 10 and 6 years prior, respectively, was referred with nasal skin ulceration after HA injections 6 days ago. The injector stated that she used a 22 gauge cannula, entry point on the infratip of the nose, with serial bolus injections of no more than 0.1 mL, in the midline and in the lateral wall of the nasal dorsum, following aspiration. Hyaluronidase injection was performed 72 h post-procedure. Physical examination revealed a main ulcer with about 1.5 cm in diameter present on the lateral wall of the nose, among multiple small satellite ulcerations (Figure 1). Doppler ultrasound indicated that regular flow was restored in all main nasal arteries. The treatment was then directed to healing the ulcers through general wound care (Figure 2). Fortunately, only a discreet scar resulted on the site. Case 2.A healthy 30-year-old female with no prior treatments to the nose area was referred 5 days after having undergone HA injections in the nose, performed by a nonphysician injector. She reported having had immediate retro-orbital pain, exotropia, and total loss of vision in the right eye during the filling of the nasal tip with a 22 gauge cannula, entry point on the supratip. Physical examination identified erythema, livedo reticularis, and pustules along the course of the right lateral nasal, angular, dorsal nasal, and supratrochlear arteries, compatible with skin ischemia (Figure 3), in conjunction with exotropia and vision loss in the right eye. The patient had not yet received any hyaluronidase injections. Doppler ultrasound examination presented difficulty in identifying the main arteries on the right side of the nasal dorsum while also spotting some capsulated anechoic areas. Brain magnetic resonance angiography detected a small area of intracranial ischemia in the right middle frontal gyrus, corresponding to ischemic infarction of microembolic origin (Figure 4). The patient received pulsed injections of hyaluronidase into the affected region for 48 h and hyperbaric treatment for the next 5 days. There was a significant improvement in exotropia in the following month, as well as full recovery of the nasal skin. The blindness in the right eye showed no improvement. Forces needed to penetrate a blood vessel significantly increases with larger diameter needles and cannulas.8 As the cases reported here illustrate, although cannulas of greater than 22 gauge caliber are unlikely to perforate the nasal arteries Indeed, ultrasound-based measurements have revealed that those arteries can reach a diameter of up to 1.1 mm,10 while 22 gauge cannulas have an external diameter of about 0.7 mm (Figure 5). This implies that those arteries can be cannulated, which is also facilitated by their restricted mobility due to the minimal thickness and limited flexibility of the soft tissue of the nasal dorsum.11 Practitioners are thus urged to understand that the keys to safety are diverse and not confined to the injection apparatus: not just using blunt cannulas, but also targeting only the midline of the nose, with precise, low-pressure, low-volume, and deep-layer filler injections.12 A growing number of studies focusing on the nasal region demonstrate that injection into the supraperiosteal or supraperichondrial layers can significantly reduce the risk of complications.2, 13 Blunt by nature, cannulas can make it difficult to accurately determine the exact depth of product placement.14 Still, using a sharp needle can potentially result in arterial embolization, even when the needle is in constant contact with the periosteum.15 Regardless of the chosen device (cannula or needle), emphasis must be placed on proper injection techniques.16 If safety is defined as the diminished ability to penetrate the arterial vasculature, it can still be stated that large diameter cannulas are safer than needles and thinner cannulas. The application of the filler using cannulas presents greater injection precision in the chosen plane, since the material tends not to recede into the more superficial layers, thus reducing the risk of vascular events and unsightly defects.8 However, the cases reported here should alert injectors that choosing a safer injection instrument alone does not mean the procedure is exempt from intra-arterial filler deposition. The authors are grateful to Raisa Bento de Albuquerque, MD, for assistance with clinical case information that improved the article significantly. The authors received no financial support for the research, authorship, and publication of this article. Dr F.N. Magacho-Vieira is a regular speaker and participates in advisory boards for Galderma. A.P. Santana declares no potential conflict of interest in the subject matter or materials discussed in this article. No institutional approval was required for this publication. The authors confirm that the ethical policies of the journal, as noted on the journal's author guidelines page, have been adhered to. The patients in this article have given written informed consent to publication of their case details and photos. The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available due to privacy or ethical restrictions.