Vascular mapping of the face: B-mode and doppler ultrasonography study

Segmental vitiligo distribution follows the underlying arterial blood supply territory: a hypothesis based on anatomo-clinical, pathological and physio-pathological studies

Background

Segmental vitiligo (SV) is a subset of vitiligo typically characterized by its unilateral distribution. The pathogenesis of SV remains unclear, and until now the two main patterns proposed for SV have lacked biological support. This calls for a new approach.

Objectives

Use data obtained from anatomo-clinical, pathological, and physio-pathological studies to formulate a new hypothesis on segmental vitiligo distribution and its pathogenesis.

Methods

Using transparent templates of local arterial blood supply, we evaluated anatomical correspondence (AC) in 140 SV lesions according to the number of SV lesions that fit within the corresponding arterial blood-supply areas. SV lesions were graded as 1 (moderate: AC < 50%), 2 (good: AC > 50%), or 3 (excellent: AC of all lesions). To support this anatomical investigation, we searched for complementary assessments according to the activity of SV lesions. Arterial and periarterial network impairment and inflammatory infiltration were histologically studied using nerve growth factor (NGF) and CD4 and CD8 monoclonal antibodies. Increased blood flow of the underlying arteries was also investigated using thermography and ultrasonography.

Results

We recruited 140 patients with a sex ratio of 0.8 and mean age 26.13 years. Localizations: head and neck 84.28%; trunk 6.42%; upper limb 5%; genital areas 2.14%; lower limb 1.42%. The AC of each SV lesion with the underlying artery blood supply territory was rated as 72% excellent; 16% good; and 12% moderate. Histologically (40 patients), we found some periarterial network impairments. Thermal asymmetry was significantly associated with active SV (p < 0.001).

Conclusion

We hypothesized that SV distribution corresponds to the underlying artery blood-supply territory.

Ultrasonography in the management of lip complications caused by hyaluronic acid

Ultrasonography is highly accurate for evaluating soft tissues. Given that minimally invasive aesthetic procedures are on the rise, complications have become more prevalent. Thus, ultrasonography holds promise for assisting in the diagnosis and management of complications arising from these interventions. This report highlights the importance of ultrasonography in the treatment of complications caused by hyaluronic acid injection. A patient visited a dental office 24 hours after hyaluronic acid application, presenting pain and bruising in the middle and inferior thirds of the face on the right side. To evaluate blood vessels, the surgeon used Doppler-mode ultrasonography, which enabled the precise application of hyaluronidase to reestablish blood perfusion and preserve adjacent structures. Therefore, to avoid severe outcomes, such as necrosis or even amaurosis, the use of ultrasonography is suggested, improving the precision and safety of these procedures.

"Filler-Associated Acute Stroke Syndrome": Classification, Predictive Modelling of Hyaluronidase Efficacy, and Updated Case Review on Neurological and Visual Complications

INTRODUCTION

The rising use of soft tissue fillers for aesthetic procedures has seen an increase in complications, including vascular occlusions and neurological symptoms that resemble stroke. This study synthesizes information on central nervous system (CNS) complications post-filler injections and evaluates the effectiveness of hyaluronidase (HYAL) treatment.

METHODS

A thorough search of multiple databases, including PubMed, EMBASE, Scopus, Web of Science, Google Scholar, and Cochrane, focused on publications from January 2014 to January 2024. Criteria for inclusion covered reviews and case reports that documented CNS complications related to soft tissue fillers. Advanced statistical and computational techniques, including logistic regression, machine learning, and Bayesian analysis, were utilized to dissect the factors influencing therapeutic outcomes.

RESULTS

The analysis integrated findings from 20 reviews and systematic analyses, with 379 cases reported since 2018. Hyaluronic acid (HA) was the most commonly used filler, particularly in nasal region injections. The average age of patients was 38, with a notable increase in case reports in 2020. Initial presentation data revealed that 60.9% of patients experienced no light perception, while ptosis and ophthalmoplegia were present in 54.3 and 42.7% of cases, respectively. The statistical and machine learning analyses did not establish a significant linkage between the HYAL dosage and patient recovery; however, the injection site emerged as a critical determinant.

CONCLUSION

The study concludes that HYAL treatment, while vital for managing complications, varies in effectiveness based on the injection site and the timing of administration. The non-Newtonian characteristics of HA fillers may also affect the incidence of complications. The findings advocate for tailored treatment strategies incorporating individual patient variables, emphasizing prompt and precise intervention to mitigate the adverse effects of soft tissue fillers.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The Safety of Injections in the Infraorbital Region

BACKGROUND

 Infraorbital filler injection is a commonly used minimally invasive cosmetic procedure on the face, which can cause vascular complications.

OBJECTIVE

 In this study, we aimed to explore the anatomical structure of the infraorbital vasculature and to establish an accurate protocol for infraorbital filler injection.

METHODS

 The vascular structure of the infraorbital region was evaluated in 84 hemifacial specimens using computed tomography. Four segments (P1-P4) and five sections (C1-C5) were considered. We recorded the number of identified arteries in each slice and at each location and the number of deep arteries. Furthermore, we also measured the infraorbital artery (IOA) distribution.

RESULTS

 At P1-P4, the lowest number of arteries was detected in segment P4, with a 317/1727 (18.4%) and 65/338 (2.3%) probability of total and deep arterial identification, respectively. The probabilities of encountering an identified artery at the five designated locations (C1-C5) were 277/1727 (16%), 318/1727 (18.4%), 410/1727 (23.7%), 397/1727 (23%), and 325/1727 (18.8%), respectively. The probability of an IOA being identified at C2 was 68/84 (81%).

CONCLUSION

 We described an effective filler injection technique in the infraorbital region to minimize the associated risks.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Novel assessment of lip redness and microcirculation using optical coherence tomography after dermal filler injection

OBJECTIVES

Lip filler injections are one of the most popular procedures in esthetic dermatology. In this study, we used three-dimensional colorimetric photography to assess lip color and optical coherence tomography-angiography (OCT-A), a noninvasive alternative to histopathology, to evaluate microcirculation after hyaluronic acid (HA) injection. The pain of the injection procedure was also assessed.

METHODS

An average of 0.85cc of the total volume of HA with lidocaine was injected into the upper and lower lip of eighteen young (<30yo) and nine postmenopausal healthy women. OCT-A, two-dimensional, and three-dimensional images were acquired immediately before (visit 1) and 15 days after injection (visit 2). Custom-made software was used to analyze the imaging data to detect vessel morphology and redness changes. The Wong-Baker FACES pain rating scale (0-10) was used to score the subject procedural pain.

RESULTS

For young and old subjects, three-dimensional lip volume was greater than the injected volume. OCT-A images of the lips showed higher vessel density and thickness, reaching statistical significance in the younger cohort. The overall trend of increased redness assessed by three-dimensional colorimetric imaging and increased vascularity evaluated by OCT-A imaging were similar. However, the correlation was not statistically significant for standard two-dimensional digital photography. The average pain score after the first needle insertion and overall procedure were 2.9 and 3.5, respectively.

CONCLUSIONS

The results suggest an increased microvasculature network observed in OCT-A images in young females. The increased blood vessel density and thickness observed by OCT-A after HA lip filler injection is associated with increased lip redness and volume as assessed by colorimetric three-dimensional photography; however, more research is needed to confirm these findings. This study presents OCT-A as a novel noninvasive tool to investigate changes in lip microvascularity after HA filler injection and indicates that HA filler procedures may affect lip vascularity.

Multiple Retinal Emboli and Medial Canthal Swelling Following Injection of Acellular Porcine Urinary Bladder Matrix for Hair Restoration

Acellular porcine urinary bladder matrix promotes wound healing and is also used to stimulate hair growth. A 64-year-old female presented with acute-onset OD pain and decreased visual acuity after subcutaneous injection of acellular porcine urinary bladder matrix at the hairline. Fundus examination revealed multiple emboli at retinal arcade branch points, and fluorescein angiography demonstrated corresponding areas of peripheral nonperfusion. Two weeks later, external examination revealed new swelling of the right medial canthus without erythema or fluctuance, which was felt to possibly represent recruitment of vessels after occlusion in the facial vasculature. At 1-month follow up, visual acuity of the OD improved with resolution of right medial canthal swelling. Fundus examination was normal with no visible emboli. Herein, the authors present a case of retinal occlusion and medial canthal swelling following injection of acellular porcine urinary bladder matrix for hair restoration, which to the authors knowledge has not been previously reported.

TFOS Lifestyle: Impact of cosmetics on the ocular surface

In this report the use of eye cosmetic products and procedures and how this represents a lifestyle challenge that may exacerbate or promote the development of ocular surface and adnexal disease is discussed. Multiple aspects of eye cosmetics are addressed, including their history and market value, psychological and social impacts, possible problems associated with cosmetic ingredients, products, and procedures, and regulations for eye cosmetic use. In addition, a systematic review that critically appraises randomized controlled trial evidence concerning the ocular effects of eyelash growth products is included. The findings of this systematic review highlight the evidence gaps and indicate future directions for research to focus on ocular surface outcomes associated with eyelash growth products.

The Assessment of the Anatomical Risk in the Perioral Region

Introduction:Safe and effective procedures in the perioral region rely on a clear understanding of the facial anatomy, as insufficient knowledge of this aspect can lead to severe complications. Materials and methods:We performed thorough layer-by-layer dissections of the perioral region on 11 freshly formalinized cadaver heads. Dissections were performed between 2020 and 2022 in the dissection laboratory of the Anatomy Department, where the ethical conducts were regulated by "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania, and fall under its jurisdiction. Dissections were digitally photographed and edited without altering the scientific content. By performing minute dissections, a considerable amount of attention has been paid to the trajectory and diameter of the superior and inferior labial arteries and their relations with the surrounding structures. Results:We demonstrated the presence of the fibro-muscular compartment above the philtrum, where the superior labial artery passes and gives off the columellar and septal branches, and where it can be compressed in case of either the migration of the filler or quick bolus injections of substance. We also emphasized the importance of the labial salivary glands as risk elements in the perioral region. The depth of the inferior labial artery varied between 4.1-5.4 mm and that of the superior labial artery between 4.8-5.6 mm. Discussion: Safe and complication-free procedures require an exact knowledge of the anatomy of the main neurovascular bundle of each facial region and their anatomical variability should be highlighted. Conclusion:The clinically relevant anatomical observations and descriptions of landmarks presented in our research serves as crucial information for plastic, reconstructive and aesthetic surgeons and dentists. Doppler ultrasound imaging has a considerable potential for both diminishing the risk and facilitating the prompt treatment of complications, especially because it is an affordable, repeatable, quick and reliable procedure. Cadaveric dissection for anatomy training provides an unparalleled opportunity to precisely understand the structure of actual human tissue and the clinical and structural relationships between the multitude of anatomical risk elements.

Dynamic region of interest selection in remote photoplethysmography: proof of principle (Preprint)

BACKGROUND

Remote photoplethysmography (rPPG) can record vital signs (VSs) by detecting subtle changes in the light reflected from the skin. Lifelight (Xim Ltd) is a novel software being developed as a medical device for the contactless measurement of VSs using rPPG via integral cameras on smart devices. Research to date has focused on extracting the pulsatile VS from the raw signal, which can be influenced by factors such as ambient light, skin thickness, facial movements, and skin tone.

OBJECTIVE

This preliminary proof-of-concept study outlines a dynamic approach to rPPG signal processing wherein green channel signals from the most relevant areas of the face (the midface, comprising the cheeks, nose, and top of the lip) are optimized for each subject using tiling and aggregation (T&A) algorithms.

METHODS

High-resolution 60-second videos were recorded during the VISION-MD study. The midface was divided into 62 tiles of 20×20 pixels, and the signals from multiple tiles were evaluated using bespoke algorithms through weighting according to signal-to-noise ratio in the frequency domain (SNR-F) score or segmentation. Midface signals before and after T&A were categorized by a trained observer blinded to the data processing as 0 (high quality, suitable for algorithm training), 1 (suitable for algorithm testing), or 2 (inadequate quality). On secondary analysis, observer categories were compared for signals predicted to improve categories following T&A based on the SNR-F score. Observer ratings and SNR-F scores were also compared before and after T&A for Fitzpatrick skin tones 5 and 6, wherein rPPG is hampered by light absorption by melanin.

RESULTS

The analysis used 4310 videos recorded from 1315 participants. Category 2 and 1 signals had lower mean SNR-F scores than category 0 signals. T&A improved the mean SNR-F score using all algorithms. Depending on the algorithm, 18% (763/4212) to 31% (1306/4212) of signals improved by at least one category, with up to 10% (438/4212) improving into category 0, and 67% (2834/4212) to 79% (3337/4212) remaining in the same category. Importantly, 9% (396/4212) to 21% (875/4212) improved from category 2 (not usable) into category 1. All algorithms showed improvements. No more than 3% (137/4212) of signals were assigned to a lower-quality category following T&A. On secondary analysis, 62% of signals (32/52) were recategorized, as predicted from the SNR-F score. T&A improved SNR-F scores in darker skin tones; 41% of signals (151/369) improved from category 2 to 1 and 12% (44/369) from category 1 to 0.

CONCLUSIONS

The T&A approach to dynamic region of interest selection improved signal quality, including in dark skin tones. The method was verified by comparison with a trained observer's rating. T&A could overcome factors that compromise whole-face rPPG. This method's performance in estimating VS is currently being assessed.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04763746; https://clinicaltrials.gov/ct2/show/NCT04763746.

An illustrated anatomical approach to reducing vascular risk during facial soft tissue filler administration – a review

Vascular complications from soft tissue fillers can have catastrophic consequences for patients. Adverse events are rare, but they are increasing, and their appearance may be the result of intravascular injection. A comprehensive understanding of the 2-dimensional anatomy (distribution) and 3-dimensional anatomy (depth) of the facial vasculature is fundamental for the safe delivery of nonsurgical cosmetic procedures. The purpose of this review is to provide an illustrated approach to examine surgical anatomy specific to the facial vascular system and the anatomical considerations clinicians need to give in specific danger during injectable cosmetic procedures. A grounding in safety and anatomy will help the new injector to mitigate the risk of vascular complications.

Identifying the course of the greater palatine artery using intraoral ultrasonography: cohort study

AIMS

The greater palatine artery (GPA) is one of the most important anatomical structure for free gingival grafts or connective-tissue grafts during soft tissue surgery for dental implants. Several studies have identified the approximate location of the GPA, but it is impossible to detect its exact location during surgery due to large variability between individuals. The authors, therefore, investigated the course of the GPA using intraoral ultrasonography to determine the feasibility of using real-time nonionizing ultrasonography for implant surgery.

MATERIALS AND METHODS

This study included 40 healthy young participants. The courses of the GPA were identified using intraoral ultrasound probes from the first premolar to the second molar. The distance from the gingival margin to the GPA (GM-GPA) and the depth of the palatal gingiva from the GPA (PG-GPA) were measured by two independent examiners. Measurements were analyzed statistically, and interexaminer reliability was determined.

RESULTS

The distance of the GM-GPA and the mean depth of the PG-GPA were 14.8 ± 1.6 mm and 4.10 ± 0.51 mm (mean ± SD), respectively. GM-GPA decreased when the GPA ran from the second molar to the first molar, and GM-GPA was significantly shorter in females (P < 0.05). PG-GPA increased when the GPA ran to the posterior teeth. Interexaminer measurement agreements were excellent, with intraclass correlation coefficient values of 0.983 and 0.918 for GM-GPA and PG-GPA, respectively.

CONCLUSIONS

Using an intraoral ultrasound probe, real-time GPA tracking is possible, which is expected to help reduce the possibility of bleeding during surgery.

Sudden vision loss and neurological deficits after facial hyaluronic acid filler injection

BACKGROUND

The ongoing expansion of the cosmetic armamentarium of facial rejuvenation fails to uncover the inherent risks of cosmetic interventions. Informed consent to all risks of cosmetic filler injections and potential sequelae, including ocular and neurological complications, should be carefully ensured. We present two cases of complications following facial hyaluronic acid filler injections.

CASE PRESENTATIONS

Case 1: A 43-year-old woman presented with monocular vision loss of the left eye, associated ptosis, ophthalmoplegia, periocular pain and nausea, cutaneous changes of the glabella region and forehead, and sensory impairment in the left maxillary branch dermatome (V2) after receiving a hyaluronic acid (HA) filler injection into the left glabellar area. On ophthalmological examination, an ophthalmic artery occlusion (OAO) was diagnosed upon identification of a "cherry-red spot". Magnetic resonance imaging (MRI) revealed a left ischemic optic neuropathy. Supportive therapy and hyaluronidase injections were initiated. A follow-up MRI of the head performed two months after presentation corresponded to stable MRI findings. The patient had irreversible and complete vision loss of the left eye, however, the ptosis resolved. Case 2: A 29-year-old woman was admitted to hospital a few hours after a rhinoplasty and cheek augmentation with hyaluronic acid, presenting with acute monocular vision loss in the right eye, retrobulbar pain, fatigue and vomiting. In addition, the patient presented a harbinger of impending skin necrosis and a complete oculomotor nerve palsy on the right side, choroidal ischemia and vision impairment. Supportive treatment and hyaluronidase injections into the ischemic tissue were initiated. A small scar at the tip of the nose, vision impairment and an irregular pupillary margin on the right side persisted at follow-up.

CONCLUSION

These two case reports and the literature review emphasize the pathophysiological mechanisms leading to potentially devastating complications. In order to reduce the risk of vision loss secondary to cosmetic filler injections, practitioners should possess a thorough knowledge of anatomy and preventive strategies.

Ultrasonographic evaluation of the effect of splint therapy on masseter muscle and blood flow in patients with bruxism

OBJECTIVE

To investigate the effect of splint therapy on masseter muscle and blood flow in patients with bruxism using ultrasonography (USG).

METHODS

Twenty female patients with bruxism receiving splint treatment were studied. Masseter thickness and elasticity were assessed using gray-scale USG and shear-wave elastography (kPa) at rest and maximum clenching. Blood flow parameters of external carotid artery (ECA), maxillary, facial, mental artery were examined using Doppler USG before and after splint application.

RESULTS

Thickness and elasticity of masseter muscle was statistically significantly decreased at rest after splint therapy (p < 0.05). Significant difference was determined only in some parameters of ECA and maxillary artery in Doppler USG before and after splint (p < 0.05); there was no difference for facial and mental artery (p > 0.05).

CONCLUSION

Thickness and elasticity of masseter muscle were significantly decreased after splint therapy. USG can measure muscle activity and blood flow in bruxism patients.

Case Report: Peri-oral Vascular Compromise Due to Calcium Hydroxyapatite

The increasing popularity of nonsurgical cosmetic treatments with the use of hyaluronic acid and calcium hydroxyapatite shows how effective and versatile these treatments can be. However, this is very likely to increase the number of complications that occur. Treatment protocols exist for vascular complications due to injections with hyaluronic acids. However, protocols for such events due to injections with calcium hydroxylapatite are less defined. The author suggests an exemplified protocol for the basis of managing such life-changing complications of impending necrosis after injections with calcium hydroxyapatite.

Movement of the Syringe During Filler Aspiration: An Ultrasound Study

BACKGROUND

Aspiration prior to hyaluronic acid filler injection is often taught as a safety maneuver to minimize the risk of intravascular injection. Its validity in aesthetic practice is being increasingly challenged. One key assumption underpinning the validity of the aspiration test is that the needle tip does not move during the aspiration and subsequent injection of filler.

OBJECTIVES

To visualize and measure in real-time needle tip movement during aspiration and injection of filler. Secondary objectives were to assess the impact of double-handed versus single-handed aspiration technique, and injector experience in maintaining stability of the syringe.

METHODS

Under real-time ultrasound visualization, 3 injectors of different experience level injected hyaluronic acid filler into pork belly tissue utilizing both double-handed and single-handed aspiration techniques. Needle-tip movements were recorded and measured on ultrasound and video.

RESULTS

The aspiration maneuvers is associated with retrograde movement of the needle tip in all cases ranging from 1.1mm to 5.3mm (mean 2.9mm), while injection leads to anterograde movement ranging from 0.6mm to 4.1mm (mean 1.9mm). Double-handed aspiration is associated with less needle tip movement compared with single-handed aspiration (p=0.037). Greater experience is also associated less movement of the needle-tip (p<0.0001).

CONCLUSIONS

In all cases, the aspiration and injecting maneuver is associated with micro-movements of the needle tip, of a magnitude consistently significant relative to the typical size of facial vessels. While needle tip movement is but a single factor that limit the usefulness of the aspiration test, the results of this study suggest that it is not advisable to solely rely on aspiration as a method of preventing intravascular injection.

Aspiration Before Tissue Filler-An Exercise in Futility and Unsafe Practice

BACKGROUND

Aesthetic physicians rely on certain anecdotal beliefs regarding the safe practice of filler injections. These include a presumed safety advantage of bolus injection after a negative aspiration.

OBJECTIVES

The authors sought to review and summarize the published literature on inadvertent intravascular injection of hyaluronic acid and to investigate whether the technique of aspiration confers any safety to the practitioner and the patient.

METHODS

Pertinent literature was analyzed and the current understanding of the safety of negative and positive aspiration outlined.

RESULTS

The available studies demonstrate that aspiration cannot be relied on and should not be employed as a safety measure. It is safer to adopt injection techniques that avoid injecting an intravascular volume with embolic potential than utilize an unreliable test to permit a risky injection.

CONCLUSIONS

To prevent intravascular injection, understanding "injection anatomy" and injection plane and techniques such as slow, low-pressure injection are important safety measures. Assurance of safety when delivering a bolus after negative aspiration does not appear to be borne out by the available literature. If there is any doubt about the sensitivity or reliability of a negative aspiration, there is no role for its utilization. Achieving a positive aspiration would just defer the risk to the next injection location where a negative aspiration would then be relied on.

LEVEL OF EVIDENCE: 4

A Guide to Doppler Ultrasound Analysis of the Face in Cosmetic Medicine. Part 2: Vascular Mapping

Duplex mode ultrasound imaging can detect the course of the main vascular structures in the face, which are known to be subject to variation. Once duplex mapping has been performed, measures can be taken to prevent injection into an artery, thereby avoiding skin necrosis or, worse, vision loss. For this reason, in particular, we predict that in the coming years sonography will become standard equipment in the offices of cosmetic doctors. We discuss the basics of vascular imaging by Doppler ultrasound, both in normal and pathologic situations. Starting from the 7 basic positions for the ultrasound probe, all facial arteries relevant in cosmetic medicine can be found.

Reverse blood flow in cervicofacial veins after venous ligations: Potential implications in microsurgery

INTRODUCTION

The consequences on the cervicofacial venous circulation of major cervicofacial vein ligations are poorly known. We aimed to highlight by using Doppler Ultrasound flow differences in the cervicofacial venous network in the case of unilateral or bilateral ligation of main venous collector trunks (external jugular vein [EJV] and internal jugular vein [IJV]) METHODS: A Doppler ultrasound was performed on 10 healthy volunteers, 8 patients with previous bilateral ligation of the EJV, 8 with a unilateral ligation of the EJV, and 8 with a unilateral ligation of the EJV and IJV, after modified radical neck dissection. The diameter, the flow direction and the peak systolic velocity (PSV) of the superficial temporal vein, the facial vein (FV) and the IJV were measured.

RESULTS

Healthy patients had a similar right and left PSV for all the veins studied, with always antegrade flows. Patients with previous ligations had some significant right/left differences and retrograde flows.

CONCLUSION

A redistribution of venous blood flow on the contralateral side of the face and neck seems to take place in the case of unilateral ligation of the EJV and/or IJV. Retrograde flows are sometimes observed in the case of previous ligation of the EJV and/or IJV and might compromise the success of venous microanastomoses.

Real-Time, Intraoperative, Ultrasound-Assisted Transoral Robotic Surgery for Obstructive Sleep Apnea

OBJECTIVES/HYPOTHESIS

To investigate the lingual artery (LA) position in the tongue base through intraoperative ultrasound (IOU) imaging during transoral robotic surgery (TORS) and evaluate bleeding complications with or without the assistance of IOU.

STUDY DESIGN

Cohort study with historical control.

METHODS

Patients with obstructive sleep apnea (OSA) who underwent TORS for tongue base resection were recruited since 2016. During surgery, ultrasound imaging was employed to identify anatomic parameters of the LA in the tongue base, including distance to the midline and arterial depth and diameter.

RESULTS

Ninety-three OSA patients (82 men, 88.2%) were analyzed. Mean age was 42.2 ± 10.0 years and body mass index was 29.2 ± 4.5 kg/m² . Average apnea-hypopnea index (AHI) was 58.1 ± 21.4 events/hour. Overall, 70 patients who underwent TORS with IOU had a shorter operation time (191.7 ± 3.8 vs. 220.1 ± 6.6 minutes), lower total blood loss (11.3 ± 10.8 vs. 19.6 ± 26.7 mL), and higher tongue base reduction volume (7.1 ± 2.5 vs. 3.9 ± 1.6 mL) than 23 patients who underwent TORS without IOU. Significant predictors of arterial depth included higher AHI level during the rapid eye movement sleep (P = .038), larger tonsil size (P = .034), and more elevated Friedman tongue position (P = .012). Postoperative complications associated with LA injury were not found in patients subjected to IOU.

CONCLUSIONS

With the assistance of IOU, surgeons can confidently determine LA position. The use of IOU can maximize efficiency and minimize catastrophic bleeding complications when OSA patients undergo TORS for tongue base resection.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E1383-E1390, 2021.

Targeted Endodontic Microsurgery: Implications of the Greater Palatine Artery

INTRODUCTION

Targeted Endodontic Microsurgery (TEMS) combines trephine burs and 3D-printed guides to make flapless maxillary palatal root-end surgery possible. This study assessed the location of the greater palatine artery (GPA), the relationship of the GPA to maxillary molar root ends, and the feasibility of flapless palatal-approach TEMS.

METHODS

Three endodontists analyzed 250 cone-beam computed tomographic images of maxillary molars for (1) transition morphology between the hard palate and the alveolar process adjacent to first and second molars as an indication of the most likely location of the GPA, (2) the superior-inferior relationship between the GPA and root ends, and (3) the feasibility of palatal-approach TEMS.

RESULTS

Palatal transition morphology included 20% Spine, 72% Bridge, and 8% Smooth. GPA position as related to palatal root ends was classified as 34% superior, 40% adjacent, and 21% inferior. Five percent of classifications were undefined. TEMS was deemed feasible for 47% of maxillary first molars and 52% of second molars, and was significantly more feasible with GPAs superior to palatal root ends. Reasons for infeasibility included GPA proximity and unfavorable resection angle or level. Maxillary first molar palatal roots were 11.13 ± 2.68 mm from the greater palatine foramen (GPF) and 2.37 ± 1.46 mm from the GPA. Second molar palatal roots were 4.94 ± 2.55 mm from the GPF and 2.53 ± 1.77 mm from the GPA.

CONCLUSIONS

Palatal transition morphology and GPA position adjacent to maxillary molars, as manifested in cone-beam computed tomographic coronal views, suggested maxillary palatal root TEMS could be accomplished with a 2-mm safety margin in 47% of first molars and 52% of second molars. Historical paradigms that do not consider flapless palatal surgical approaches may need to be revised.

Age-related changes in the vasculature of the dermis of the upper lip vermilion

Lip redness is unique to humans and creates an important facial impression, but this redness decreases with age. Here, using histological and immunohistological staining of human upper lip vermilion from donors of different ages, we investigated blood vessels in the upper lip dermis and age-dependent histological changes. We found that both total vessel area in the dermis and vessel number in the upper dermis decreased with aging. Moreover, vessel number in the upper dermis correlated positively with development of rete ridges, which flattened with age, despite no significant change in the thickness of the stratified squamous epithelium. These findings suggest that age-related reductions in lip redness result from a decrease of blood vessels, which in turn leads to a flattening of the epithelium caused by the loss of rete ridges. This is the first study to histologically demonstrate age-related reductions in blood vessels in the lip. Our results provide an opportunity for enhancing blood flow/vascularization to improve the aesthetic appearance of the lips in the elderly.

Vision Loss Associated with Hyaluronic Acid Fillers: A Systematic Review of Literature

BACKGROUND

With the global increase in the use of injectable fillers, more cases with serious adverse events such as skin ischemia and vision loss are being reported. This article aims to review the role of HA fillers, as a subgroup separate from fat graft and non-HA fillers, in causing vision loss and to elucidate various features and outcomes of post-HA filler vision loss.

METHODS

The preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were used to report this review. A total of 29 articles presenting 60 unique cases of post-HA filler vision loss were identified in the literature. Based on various inclusion and exclusion criteria, 26 articles with details of 44 cases were included in this study.

RESULTS

The majority of cases were seen in women and in the 20-40 years age group. The maximum number of cases was reported from Korea, followed by China. Nearly half of the cases reported after HA filler-related visual complications had partial loss of sight, hence 'partial vision loss' and 'complete vision loss' were used as differentiating descriptive terms to the degree of 'blindness.' Nearly all the cases were unilateral, with immediate onset of visual signs and symptoms. The nose, glabella, and forehead were the most commonly implicated areas, while no cases of post-HA filler vision loss were reported from lower face anatomical areas, including the chin, jawline, and lips. Partial vision loss after HA filler has a better prognosis than complete vision loss. HA filler volumes as low as 0.2 ml can cause permanent, complete vision loss, which is suggestive of the embolic nature of HA filler blockage. Ophthalmic artery occlusion (OAO) and central retinal artery occlusion (CRAO) were the two most commonly involved arterial obstruction patterns followed by branch retinal artery occlusion (BRAO). BRAO is the most favorable involved arterial pattern for a chance of recovery after HA filler-related vision loss while CRAO and OAO patterns carry a very poor prognosis.

CONCLUSION

Post-HA filler vision loss is nearly always of immediate onset. Partial vision loss after HA filler injection with the involvement of smaller branches of the retina, other than central retinal artery or ophthalmic artery, has more favorable visual outcomes.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Infrared Thermally Enhanced 3-Dimensional Time of Flight Magnetic Resonance Angiography Imaging for the Visualization of the Arteries of the Face

Background

The face is known for its extreme variation in vascular anatomy. Furthermore, the rapidly increasing number of filler treatments leads to an increase in severe filler-associated complications (such as skin necrosis and blindness) due to intra-arterial injection. Visualizing a patient’s individual complete facial arterial anatomy in a contrast- and radiation-free way has not been published before. This innovative imaging technique could, therefore, enhance the safety of minimally invasive surgical procedures as it provides a harmless way to map the arteries of the face.

Objectives

Evaluate a newly developed imaging technique to visualize the arteries of the face in a noninvasive and radiation-free manner.

Methods

The individual arterial facial anatomy of 20 volunteers was studied by an imaging technique, combining infrared (IR) facial warming and 3-dimensional (3D) time of flight (TOF) magnetic resonance angiography (MRA). The source and maximum intensity projection images were assessed by 2 investigators, familiar with the anatomy of the face.

Results

The MRA technique visualized most of the main facial arteries, albeit in a variable way. The main facial branches of the external carotid artery (facial, angular, supralabial, and superficial temporal arteries) were illustrated well, whereas the visualization of the internal carotid branches (supratrochlear and supraorbital arteries) and nasal branches (dorsal nasal and lateral nasal arteries) was less consistent.

Conclusions

The combination of IR “heat-induced enhancement” and a 3D-TOF MRA sequence may actually be an important step toward the visualization of the variable facial vascular anatomy in a noninvasive, radiation-free, and contrast-free manner.

Perivascular Hyaluronidase With Alteplase as Treatment for Hyaluronic Acid Thrombosis

BACKGROUND

Hyaluronic acid fillers are the second-most commonly performed nonsurgical procedure. Arterial thrombosis is their most devastating complication. Recent research shows that along hyaluronic acid thrombi, a platelet/fibrin thrombus forms in the site of injection. This is not addressed by current management protocols, which focus on perivascular hyaluronidase plus adjuvant strategies to increase blood flow. We experimented with an animal model utilizing both hyaluronidase and a thrombolytic agent for treatment of occlusion.

OBJECTIVES

The authors sought to evaluate the efficacy of a combined treatment of hyaluronidase with a thrombolytic agent applied perivascularly to an artery occluded with hyaluronic acid.

METHODS

After direct intravascular injection into the femoral artery, rats were randomized to receive one of the following perivascular solutions: saline, hyaluronidase, alteplase, or hyaluronidase + alteplase. Reperfusion, distal bleeding, and microscopic findings were evaluated 4 hours after intervention.

RESULTS

None of the subjects in the control group showed signs of reperfusion. In the hyaluronidase group, 60% reperfused, 10% completely, the rest only partially. In the alteplase group, 50% reperfused partially. In the hyaluronidase + alteplase group, 50% had partial and 50% complete prepermeabilization. Kruskal-Wallis test showed a P < 0.0001 favoring hyaluronidase + alteplase. Microscopic findings were compatible with bleeding rates.

CONCLUSIONS

Both hyaluronic acid and red thrombi play a role in the occluded vessel. Perivascular application of hyaluronidase with a thrombolytic agent seems to achieve greater reperfusion rates than either one alone. If proven safe in humans, this strategy could make treatment more effective while still being suitable for an outpatient setting.

Proposal of a Noninvasive Method to Reduce Injection-Related Bruising in Aesthetic Medicine: Transillumination

BACKGROUND

Hyaluronic acid (HA) injections involve a risk of vascular complications. Transillumination (TL) is a noninvasive technique that appears to allow preliminary detection of superficial vascular structures of the face to avoid intravascular HA injection. The purpose of our study was to test the efficacy of TL in terms of its sensitivity to locate vessels in the areas undergoing treatment and to reduce post-injection vascular complications.

MATERIAL AND METHODS

We conducted a prospective study enrolling 72 patients who consulted for HA injections to treat facial wrinkles. We used TL on one side of the face to obtain a vascular mapping of the face. The area undergoing testing was randomized for the TL technique. The primary study endpoint was sensitivity for identifying subcutaneous veins and the differences in complication rates between the side of the face where TL was used to guide the injection and the side of the face where no vascular exploration method was used.

RESULTS

TL sensitivity for locating the superficial temporal vein was 100%, 91% for the supratrochlear, supraorbital and infraorbital veins, and 95% for the dorsal nasal veins (p < 0.01). The complication rate was higher on the side of the face where no vascular exploration method was used (22.2% vs 2.7%; p = 0.010046).

CONCLUSIONS

Our preliminary findings validate our hypothesis concerning the advantage of using TL to identify superficial veins before performing injections. This method is simple and affordable, and the learning curve is small.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Ultrasonographic assessment of the maxillary artery and middle meningeal artery in the infratemporal fossa

PURPOSE

To investigate with Doppler ultrasonography the maxillary and middle meningeal arteries in the infratemporal fossa, and describe their hemodynamic characteristics.

METHODS

We included 24 female and 11 male volunteers without vascular diseases, with a median age of 43 years. We used the acoustic window, enlarged by subjects half-opening their mouth, located below the zygomatic arch, in front of temporo-mandibular joint, to reach the maxillary and middle meningeal arteries.

RESULTS

In the 35 subjects, 112 arteries were visualized successfully: 60 maxillary (85.7%), and 52 middle meningeal arteries (74.3%), at a depth of 2.40 and 2.50 cm, respectively. Their blood flow was directed anteriorly and away from the probe. While all the measured hemodynamic characteristics differed significantly between the maxillary and the middle meningeal artery (P < 0.001), there was no significant difference between male and female subjects, nor between the left or the right side.

CONCLUSIONS

The maxillary and middle meningeal arteries can be insonated in the infratemporal fossa through the easily accessible acoustic window below the zygomatic arch, when the patient holds his mouth half open. They can be differentiated by their ultrasonographic characteristics and blood flow features.

High frequency ultrasound imaging as a "potential" way of evaluation modality in side effects of lip augmentation - case report

Lip augmentation is a popular procedure performed by esthetic medicine doctors, however, it is associated with a significant number of side effects. High frequency ultrasound imaging helps with diagnosis of side effects.The patient was 43-year-old healthy female, 8 months after lip augmentation.The examination showed a variety of delayed side effects of lip augemntation. Ultrasound imaging revealed an increased echogenicity of lip soft tissue, too deep filler injection, occlusion of the inferior labial artery.

Managing Complications of Submental Artery Involvement after Hyaluronic Acid Filler Injection in Chin Region

Hyaluronic acid dermal fillers are becoming popular all over the world, but due to the presence of many blood vessels in the face, there is always a small possibility of vascular complications. We present a case with the ischemic involvement of chin and neck skin after accidental submental artery involvement after hyaluronic acid filler injection for chin region. Impending skin necrosis on the chin and upper neck on the right side was diagnosed quickly by observing the skin changes in the immediate postfiller phase. Pain in the mandible and in the muscles during swallowing due to possible ischemia of muscles supplied by submental artery was another crucial diagnostic feature. All parts of the affected zone were treated with high-dose pulsed hyaluronidase protocol using 4 pulses of hyaluronidase injection in first 24 hours after filler injection. Complete resolution of cutaneous ischemic changes and painful swallowing was achieved within days after treatment. Knowledge of presenting features of postfiller vascular complications and the extent of vascular territory of the involved artery is quite helpful in quickly instituting treatment leading to the near-complete recovery with minimal sequelae.

Facing the Worst Risk: Confronting the Dorsal Nasal Artery, Implication for Non-surgical Procedures of Nasal Augmentation

BACKGROUND

The nose is a dangerous site for filler injection. This study investigated the anatomy of the dorsal nasal artery at the upper part of the nose to clarify how ocular complications occur.

METHODS

Dissections were performed in 50 noses of the embalmed cadavers. Either the soft embalming or formaldehyde embalming processes were used.

RESULTS

The dorsal nasal artery is not a constant artery. The artery traveled in the subcutaneous tissue layer of the nasal dorsum on the transverse nasalis muscle and its midline nasal aponeurosis which connected the muscles on both sides. Bilateral dorsal nasal arteries existed only in 34%. In 28% of the specimens, a single and large dorsal nasal artery was presented. The diameter was 0.4 ± 0.2 mm when bilateral dorsal nasal arteries were present and 0.7 ± 0.3 mm in a single artery. The largest artery was 1.2 mm. The artery usually crossed the midline at the middle third part of the nose over the upper lateral cartilages to form an anastomosis with the contralateral lateral nasal artery as the oblique nasal artery in 14%. The artery might descend and communicate with the ipsilateral lateral nasal artery in 6% or descended as a midline artery and form the nasal tip plexus in 8%. In 38% of the specimens, the arteries became small, formed a subcutaneous plexus and randomly distributed on the superficial layer of the subcutaneous tissue in the upper two-thirds of the nose.

CONCLUSION

During the injections at the upper (bony) and middle (cartilaginous) part of the nose for nasal dorsal augmentation, the injector has to make sure the cannula tip is in the preperiosteal plane by reinsertion of the cannula if needed, due to the chance of encountering the large single dorsal nasal artery at the midline.

NO LEVEL ASSIGNED

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Ultrasound evaluation of intra-osseous cavity: A preliminary study in pig mandibles

AIMS

To assess the role of ultrasonography as a possible tool for diagnosis of intra-osseous lesions.

METHODS

Our sample comprised five macerated pig jaws. The regions of bony crypts of third molars were examined on both sides, totaling 10 examinations. The degrees of difficulty for both ultrasound image visualization and bone translucency were rated by two groups of evaluators (i.e. dental radiologists and physician ultrasonographers).

RESULTS

Our results showed that it is possible to detect images of the intra-osseous cavity at a low-degree difficulty by using both radiographic and ultrasonic techniques (46.6% and 43.3%, respectively). However, the crypts were not fully detected by both groups (16.6% and 13.3%, respectively).

CONCLUSIONS

We concluded that ultrasonography is a useful method for evaluation of intra-osseous lesions in jaws, provided that the cortical bone is thin enough to allow ultrasound waves to pass through.