The Effect of a Combination of Vibration and External Cold on Pain Caused during Vaccine Injection in Infants: A Randomized Clinical Trial.

Aim: This study was conducted to determine the effect of combining vibration and external cold on pain caused by vaccine injection among six-month-old infants. Design: Randomized controlled trial. Methods: In this clinical trial, 80 eligible infants were selected from the infants referred to a health center as per the inclusion criteria. The infants were assigned to either a control group or an intervention group by block randomization. In the intervention group, a vibrating and cold device was placed above the injection site from one minute before to 15 seconds after the pentavalent vaccine injection. In the control group, no intervention was performed, and they were vaccinated according to the routine procedure. The pain status in the two groups was measured using the Modified Behavioral Pain Scale (MBPS) 15 seconds after the injection, and the crying duration was assessed from the injection of the vaccine till the end of it. Data were analyzed in SPSS 23 software using Mann-Whitney, t, Spearman, and chi-square tests. The level of significance was set to p < 0.05. Results: Most participants in the control (55%) and intervention (55%) groups were girls. Statistical data analysis of 80 infants showed that the mean pain intensity (p = 0.032) and duration of crying (p = 0.0001) in the intervention group (6.1 ± 1.8, 32.47 ± 16.78) were lower than those of the control group (7.2 ± 0.1, 51.02 ± 25.9), respectively. Conclusion: Because the intensity of pain, especially the duration of crying, was lower in the intervention group than in the control group, we may suggest that nurses use simple pain relief solutions in vaccination centers, such as a combination of vibration and cold. This trial is registered with IRCT201207157130N2.

Injections of the Hip and Knee.

Hip and knee injections are useful diagnostic and therapeutic tools for family physicians. This article reviews anatomic landmark-guided and ultrasound-guided injections and aspiration techniques for greater trochanteric pain syndrome, the hip joint, the knee joint, the pes anserine bursa, and the iliotibial band. Indications for injections include acute and chronic inflammatory conditions, such as rheumatoid arthritis; osteoarthritis; overuse; and traumas. Joint aspirations may be performed to aid in the diagnosis of unexplained effusions and to relieve pain. Technique, injectant, and follow-up timing depend on the physician's comfort, experience, and preference. Infections of the skin or soft tissue are the primary contraindications to injections. The most common complications are local inflammatory reactions to the injectant. These reactions usually cause soreness for 24 to 48 hours, then spontaneously resolve. Follow-up after injections is usually scheduled within two to six weeks.

[Effectiveness and interest of retrobulbar hyaluronidase injections in the treatment of blindness complicating facial hyaluronic acid injections: A literature review]. / Efficacité et intérêt des injections rétrobulbaires de hyaluronidase dans le traitement des cécités compliquant une injection faciale d'acide hyaluronique : revue de la littérature.

INTRODUCTION: Hyaluronic acid injections are becoming increasingly common among both the general public and the medical community, but they are not without risks. The occurrence of blindness, although rare, is a tragic event for both the patient and the practitioner. One of the treatments proposed in the literature is to inject hyaluronidase as close as possible to the site of ischemia, retrobulbarly. The aim of our study is to evaluate the effectiveness and potential benefits of retrobulbar hyaluronidase injections. MATERIALS AND METHODS: A literature review was conducted using the PubMed database. Only articles addressing retrobulbar hyaluronidase injections for the treatment of blindness following hyaluronic acid injections were included. RESULTS: We identified 12 case reports or series, comprising a total of 16 patients. Among these 16 patients, 3 regained their vision. Hyaluronidase was injected between 20minutes and 7days after the onset of the complication, with injected doses ranging from 3×150IU to 3×1500IU. DISCUSSION: Literature reveals only 3 cases of successful treatment out of the 16 reported injections. The time interval before retrobulbar injection, as well as the dose and the experience of the injecting practitioner, may influence the success rate of this treatment. Other treatments, such as intravascular hyaluronidase injections, remain to be explored.

Vessel infiltration with microcannula during filler injection: a rare but consequential occurrence.

Serious complications of cosmetic filler injections include vascular necrosis if the filler is injected into an artery. The use of a microcannula for filler injection has been reported to be safer with lower rates of vascular occlusion. We report a case of vessel infiltration that was noted prior to injection with microcannula which identifies an additional safety step for injectors. This case highlights the potential for devastating vascular occlusion with microcannula use while also demonstrating methods to identify vascular infiltration prior to filler injection. The purpose of this report is to educate and encourage injectors to inspect the introducer needle prior to any filler injection in order to avoid vascular occlusion during filler injection.

The Use of Botulinum Toxin in Raynaud Phenomenon: A Comprehensive Literature Review.

BACKGROUND: Raynaud phenomenon (RP) is a vasospastic condition of the digits that can be primary or secondary to systemic disease. Symptoms are triggered by cold or stress and can cause pain and skin color changes. The chronic ischemia may lead to necrosis, ulceration, and amputation. There are no Food and Drug Administration-approved treatments and cases refractory to pharmacologic and surgical treatments are difficult to control. Local botulinum toxin injections have been increasingly used in the treatment of Raynaud disease and have shown promising results. AIM OF THE STUDY: To examine the outcomes, techniques, and complications of botulinum toxin use for the treatment of Raynaud disease. METHODS: The PubMed database was queried using "botulinum toxin" AND "Raynaud phenomenon" as title key words. Preferred reporting items for systematic reviews and meta-analysis criteria were used. Additional articles were selected while reviewing the references of the articles from PubMed. No time restrictions were followed. Articles of all languages were included. Articles were analyzed for study type, demographics, diagnosis/inclusion criteria, treatment methods, outcome measures, length of follow-up, results, and complications. A positive outcome was defined as subjective improvement in symptoms and/or improvement in the outcome measures. A poor outcome was defined as harm done to the patient by the injection that would not have occurred otherwise. RESULTS: Forty-two clinical studies describing the use of botulinum toxin for Raynaud's phenomenon were found. A total of 425 patients with primary or secondary Raynaud's were treated, with ages ranging from 14 to 91 years. There were 342 women and 81 men, with a female-to-male ratio of 38:9. Outcomes were positive in 96.2% of patients. There were 14.2% of the studies that reported 3.5% of all patients showing no subjective improvement. A single study reported a poor outcome for 1 patient. There were 40.5% of the studies that reported complications, affecting 20.2% of all patients. The most frequently reported complication was transient hand weakness, affecting 44.2% of patients with complications and 8.9% of total patients. Weakness resolved in hours to months after injection. Pain at the injection site lasting minutes to days was reported in 40.7% of patients with complications, and 8.2% of total patients. CONCLUSIONS: Botulinum toxin treatment for RP is effective. Complications are minor and self-limiting.

Safety of Botulinum Toxin A Injections for Facial Rejuvenation: A Meta-Analysis of 9,669 Patients.

PURPOSE: To quantitatively evaluate safety profile for botulinum toxin A (BTX-A) injections among patients undergoing treatment for cosmetic indications is produced, with special attention to clinically relevant covariates and their relative impact on safety. METHODS: A systematic literature search was performed using PubMed (1996-January 2020) and Embase (1947-January 2020) to identify all randomized controlled trials (RCTs) that reported safety data for patients receiving BTX-A for cosmetic indications compared to placebo. A meta-analysis was performed to determine pooled risk ratios (RR) for treatment-related adverse events (TRAEs) and for specific adverse events. Meta-regression and additional analyses were performed for significant and/or clinically relevant covariates. RESULTS: Following the review of 8,690 studies, 32 RCTs involving 9,669 patients were included. The pooled RR of any TRAE occurring after BTX-A injection compared to placebo injection was 1.53 (95% CI, 1.33-1.77; p < 0.001). Statistically significant covariates included individual injection volume and total injection volume. The type of BTX-A formulation, treatment site, total BTX-A units, and BTX-A units per injection were not significant. Specific adverse events more likely to occur following BTX-A injection rather than placebo injection included eyelid/eyebrow malposition (RR 3.55; p < 0.001), facial paresis (RR 2.42; p = 0.316), and headache (RR 1.45; p = 0.003). Injection site reactions and injection site bruising occurred at similar rates in both groups. CONCLUSIONS: The overall safety profile of BTX-A is acceptable and consistent with previous publications. The authors' additional analyses provide a relative comparison of the impact of various treatment parameters on safety.

Death from Pulmonary Embolism Caused by Vaginal Injection of Hyaluronic Acid: a Case Report and a Literature Review.

A 40-year-old woman underwent vaginoplasty with intramural injection of fillers from an illegal medical practitioner. Approximately 2 h after the injection, she developed lower abdominal pain. The patient was taken to the hospital approximately 5 h later due to worsening pain. When the patient was admitted for physical examination, she suddenly experienced cardiac and respiratory arrest. She was resuscitated but remained in a coma. Unfortunately, the patient died approximately 12 h after being admitted to the hospital. The forensic autopsy revealed extensive amorphous basophilic emboli in the small interstitial vascular lumen of both lungs, and a large amount of the same type of substances were also found in the vaginal wall. Hyaluronidase digestion and Alcian blue staining confirmed that most components of the injection were hyaluronic acid (HA). HA is widely used as a cosmetic filler in the field of plastic surgery and is generally considered to have few adverse effects. This paper reports the first anatomical case of fatal pulmonary embolism caused by vaginal injection of HA. LEVEL OF EVIDENCE V: 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 .

High-pressure injection hand injury: What lies beneath?

ABSTRACT: High-pressure injection injuries are true emergencies that require prompt treatment to avoid devastating complications. This article describes the presentation and management of these injuries and provides clear and concise recommendations for intervention by the ED clinician.

[What's new in the management of systemic sclerosis]. / Nouveautés dans la prise en charge de la sclérodermie systémique.

This review of the literature highlights the results of the recent randomized controlled trials about the management of systemic sclerosis (SSc) and its complications. The latest randomized studies have failed to demonstrate the utility against placebo of the injections of botulinum toxin A to achieve a better control of Raynaud's phenomenon and the efficacy of the adipose-derived cell transplantation for the treatment of hand dysfunction. Rituximab allows a significant improvement of cutaneous induration. The injections of mesenchymal stromal cells are well tolerated and should encourage future randomized trials to evaluate their efficacy. Finally, nintedanib and tocilizumab allow a reduction in the rate of decline of lung function, as well as a possible stabilization with tocilizumab.

Cet article expose les résultats des essais randomisés et contrôlés récents concernant la prise en charge de la sclérodermie systémique (SSc) et ses complications. Les études discutent l'utilité des injections de la toxine botulinique pour le contrôle du phénomène de Raynaud, et des injections de cellules dérivées du tissu adipeux pour améliorer la fonctionnalité de la main. Le rituximab permet une amélioration significative de l'induration cutanée, et les injections de cellules stromales mésenchymateuses, en plus d'être bien tolérées, ouvrent la voie à d'éventuels essais randomisés en vue d'évaluer leur efficacité. Finalement, le nintédanib et le tocilizumab permettent une réduction du taux de déclin de la fonction pulmonaire, jusqu'à une éventuelle stabilisation de cette dernière observée avec le tocilizumab.

Painful Purulent Nodules Caused by Mycobacterium at Site of Lipodissolve Injections.

ABSTRACT: "Lipodissolve" (LD) is a non-FDA-approved solution of phosphatidylcholine in deoxycholate that was developed around 2004. A study of its safety reported minor and uncommon side effects including pain, tender nodules, pigmentary alterations, and ulceration at the site of injection. We present a 53-year-old woman who received LD injections bilaterally to her proximal arms. One week later, she developed painful nodules at each injection site. She was treated with a 10-day course of trimethoprim/sulfamethoxazole without improvement. An incisional biopsy was performed and showed deep dermal suppurative inflammation with numerous neutrophils and granulomas. Stains for bacteria, fungus, and acid-fast organisms were negative. Cultures for acid-fast bacilli grew Mycobacterium abscessus, sensitive to amikacin and clarithromycin. The patient was subsequently treated with intravenous amikacin, azithromycin, and bedaquiline with symptom resolution. Investigation revealed 3 similar infections linked to LD injections originating from the same physician's office. The most common organism implicated in injection infections is Staphylococcus aureus. Infections at injection sites caused by atypical mycobacteria have been reported to occur after tattooing, other types of injections, and implants. Of atypical mycobacteria, M. abscessus accounts for the greatest number of postinjection or iatrogenic infections. Common antitubercular drugs are not effective for treating atypical mycobacteria, making species identification and sensitivity testing imperative for treatment. This case highlights an unusual infection caused by cosmetic injections of LD, previously reported to be associated with minimal side effects, and the importance of examination for acid-fast bacilli and follow-up with culture, even in the absence of organisms identified on stained sections.

Clinical Management of Complications Following Filler Injection.

AIM: Dermal fillers have been progressively used for cosmetic procedures. Concurrently, the rates of filler complications have also increased. The aim of this study is to describe the clinical management and treatment we performed in patients with complications occurred after filler injection. METHODS: From March 2000 to February 2020, 197 patients have been evaluated for complications due to filler injection. For each patient type of material, symptoms and signs were recorded. Ultrasound evaluation was used to obtain information about the type, amount and location of the injected material. Magnetic Resonance Imaging was performed in those patients who were candidate for surgery. Based on the clinical manifestations, we performed a targeted therapy. RESULTS: The local and systemic medical therapy allowed us a complete remission of the clinical signs and symptoms in all patients presented with edema and erythema. We obtained optimal results with surgery, where a complete removal of the injected material was possible. In all the cases in which the complete removal of the infiltrated area could have led to functional impairments, we performed partial removal with poor outcomes. CONCLUSION: We observed complex clinical manifestations in the patients subjected to permanent fillers. An accurate knowledge upon the effects of the materials on tissues, a specific instrumental evaluation and a targeted therapy are crucial. We suggest the use of absorbable fillers. Patient should be subjected to filler implant in authorized structures by an expert specialist with experience in filler injection and with a thorough knowledge of the anatomical structures. 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 .

Long-term Infective Endocarditis Mortality Associated With Injection Opioid Use in the United States: A Modeling Study.

BACKGROUND: The expansion of the US opioid epidemic has led to significant increases in infections, such as infective endocarditis (IE), which is tied to injection behaviors. We aimed to estimate the population-level IE mortality rate among people who inject opioids and compare the risk of IE death against the risks of death from other causes. METHODS: We developed a microsimulation model of the natural history of injection opioid use. We defined injection behavior profiles by both injection frequency and injection techniques. We accounted for competing risks of death and populated the model with primary and published data. We modeled cohorts of 1 million individuals with different injection behavior profiles until age 60 years. We combined model-generated estimates with published data to project the total expected number of IE deaths in the United States by 2030. RESULTS: The probabilities of death from IE by age 60 years for 20-, 30-, and 40-year-old men with high-frequency use with higher infection risk techniques compared to lower risk techniques for IE were 53.8% versus 3.7%, 51.4% versus 3.1%, and 44.5% versus 2.2%, respectively. The predicted population-level attributable fraction of 10-year mortality from IE among all risk groups was 20%. We estimated that approximately 257 800 people are expected to die from IE by 2030. CONCLUSIONS: The expected burden of IE among people who inject opioids in the United States is large. Adopting a harm reduction approach, including through expansion of syringe service programs, to address injection behaviors could have a major impact on decreasing the mortality rate associated with the opioid epidemic.

Multi-Electrode Array of Sensory Neurons as an In Vitro Platform to Identify the Nociceptive Response to Pharmaceutical Buffer Systems of Injectable Biologics.

PURPOSE: Pharmaceutical buffer systems, especially for injectable biologics such as monoclonal antibodies, are an important component of successful FDA-approved medications. Clinical studies indicate that buffer components may be contributing factors for increased injection site pain. METHODS: To determine the potential nociceptive effects of clinically relevant buffer systems, we developed an in vitro multi-electrode array (MEA) based recording system of rodent dorsal root ganglia (DRG) sensory neuron cell culture. This system monitors sensory neuron activity/firing as a surrogate of nociception when challenged with buffer components used in formulating monoclonal antibodies and other injectable biologics. RESULTS: We show that citrate salt and citrate mannitol buffer systems cause an increase in mean firing rate, burst frequency, and burst duration in DRG sensory neurons, unlike histidine or saline buffer systems at the same pH value. Lowering the concentration of citrate leads to a lower firing intensity of DRG sensory neurons. CONCLUSION: Increased activity/firing of DRG sensory neurons has been suggested as a key feature underlying nociception. Our results support the utility of an in vitro MEA assay with cultured DRG sensory neurons to probe the nociceptive potential of clinically relevant buffer components used in injectable biologics.

Different Doses of Oxycodone for Endoscopic Injection Sclerotherapy of Esophageal Varices.

BACKGROUND The aim of the present study was to evaluate the effects of different doses of oxycodone during endoscopic injection sclerotherapy (EIS) for esophageal varices with painless sclerosing agents. MATERIAL AND METHODS A total of 119 patients were randomly divided into 3 groups: Group A, midazolam and 0.075 mg/kg oxycodone (n=40); Group B, midazolam and 0.1 mg/kg oxycodone (n=40); and Group C, midazolam and 0.125 mg/kg oxycodone (n=39). The main observation index was the incidence of body movement during the perioperative period. The secondary indices were additional propofol usage; postoperative analgesic usage; other adverse effects, such as hypoxia, myoclonus, and cough; and satisfaction scores for surgeons and patients. RESULTS The incidence rates for body movement during the perioperative period in groups A, B, and C were 33%, 13%, and 0, respectively (P<0.001). The satisfaction scores for surgeons and patients were highest in Group C (0.125 mg/kg oxycodone). The incidence rates for hypoxia before EIS were 15%, 8%, and 33% (P=0.026) and during EIS were 23%, 3%, and 0% (P<0.001), respectively. There were no significant between-group differences with respect to other adverse effects. CONCLUSIONS The ideal dose of oxycodone for perioperative analgesia during EIS for esophageal varices is 0.125 mg/kg.

Techniques to Relieve Pain Associated With Botulinum Injections for Palmar and Plantar Hyperhidrosis.

BACKGROUND: Palmar and plantar hyperhidrosis (HH) is a common condition characterized by excessive sweating of the palms and soles. Botulinum neurotoxin (BTX) is a very effective and safe treatment. However, the associated intense injection pain is a major limiting factor deterring patients from selecting this treatment. OBJECTIVE: The aim of this study was to review the numerous techniques used to minimize pain accompanying injections for palmoplantar HH. Additionally, the advantages and limitations of each modality will be discussed. MATERIALS AND METHODS: The authors performed a comprehensive literature search in PubMed/MEDLINE, Embase, Cochrane Central, and Google Scholar on randomized controlled trials, cohort studies, and case series on techniques to relieve pain of BTX injections for treatment of palmar and plantar HH. RESULTS: Current available techniques in reducing botulinum injection with merits and drawbacks are nerve blocks, Bier blocks, cryoanalgesia, needle-free anesthesia, topical anesthetics, and vibration anesthesia. CONCLUSION: Topical anesthesia, ice, and vibration are the safest and most convenient noninvasive available methods to relieve pain associated with botulinum injection. Nerve blocks, Bier block, and needle-free anesthesia provide better anesthesia but are limited by the need for training and equipment.

Effectiveness of Pre-administered Natural Sweet-tasting Solution for Decreasing Pain Associated with Dental Injections in Children: A Split-mouth Randomized Controlled Trial.

AIM: This study aimed to discern if a prior intake of a natural sweet remedy (honey) impacted pain perception during intraoral injections. MATERIALS AND METHODS: One hundred healthy children who needed the same treatment bilaterally in either arch which required local anesthetic administration (infiltration in maxillary arch and inferior alveolar nerve block in mandibular arch) were recruited. The patients' demographic details were recorded. Local anesthesia was administered after taking 5 mL of honey solution on the test side and 5 mL of sterile water on the control side. Subjective pain perception during injection was measured using Wong-Baker Faces Pain Rating Scale and objective pain by sound, eye, body movement (SEM) rating scale. The parametric data were analyzed using a paired Student's t-test (p <0.05). Level of consensus between the two scales was assessed using Pearson's correlation. RESULTS: The test side yielded lower mean Wong-Baker Faces Pain Rating Scale (3.72 ± 1.80) and SEM (4.12 ± 1.04) scores than the control side (6.00 ± 2.06 and 5.00 ± 1.45 respectively). This was statistically significant. CONCLUSION: The administering of a natural sweet solution such as honey before dental injections in children tends to reduce the discomfort and pain associated with the procedure. CLINICAL SIGNIFICANCE: Pain management is of utmost importance in dentistry, especially among children. The consumption of natural foods such as honey helps in decreasing injection pain perception, making the child cooperative, and thereby allowing the dentist to provide the best dental care.

Left-sided infective endocarditis in persons who inject drugs.

PURPOSE: The purpose of this study was to describe left-sided infective endocarditis (LSIE) in persons who inject drugs (PWID) and compare that group to PWID with non-LSIE and to non-PWID with LSIE. METHODS: Retrospective single-center study of adult IE patients from 2011 to 2018. RESULTS: Of the 333 patients in our cohort, 54 were PWID with LSIE, 75 were PWID with non-LSIE, and 204 were non-PWID with LSIE. When comparing LSIE vs non-LSIE in PWID, the LSIE group was older (median age 35 vs 28.5, p < 0.01), had fewer S. aureus infections (59% vs 92%, p < 0.01), was more likely to have cardiac surgery (31% vs 13%, p < 0.01), and had a higher 10-week mortality (22% vs 5%, p < 0.01). When comparing PWID with LSIE to non-PWID with LSIE, the PWID group were younger (median age 35 vs 46, p < 0.01); had more frequent multi-valve involvement (33% vs 19%, p = 0.04), Staphylococcus aureus infections (54% vs 27%, p < 0.01), and previous IE (24% vs 8%, p < 0.01); and experienced more strokes (54% vs 31%, p < 0.01). Ten-week mortality was similar for LSIE in both PWID and non-PWID (24% vs 20%, p = 0.47). CONCLUSIONS: LSIE in PWID is not uncommon. Compared to non-LSIE in PWID, valve surgery is more common and mortality is higher. For reasons that are unclear, stroke is more frequent in LSIE in PWID than in non-PWID with LSIE but mortality is no different.

Does asymptomatic bacteriuria increase the risk of adverse events or modify the efficacy of intradetrusor onabotulinumtoxinA injections?

AIM: To assess the impact of asymptomatic bacteriuria (ASB) on the safety and efficacy of intradetrusor onabotulinumtoxinA injections in patients with overactive bladder and neurogenic detrusor overactivity. METHODS: We reviewed the medical records of patients who had received onabotulinumtoxinA between 2009 and 2014. Safety analysis was based on the appearance of urinary tract infections (UTIs), hematuria, and need for hospitalization because of related adverse event(s) in the month after injection. Patients who underwent urodynamic study before and 3 months after the first onabotulinumtoxinA treatment were included in efficacy analysis. Changes in maximal cystometric capacity (MCC), bladder compliance (BC), maximal detrusor pressure at maximal involuntary detrusor contraction (Pdetmax), and detrusor leak point pressure (DLPP) were assessed. RESULTS: Totally, 183 patients underwent 457 injection sessions. ASB was found in 38.8% (185) of urine cultures taken before injections. After treatment, 49 patients (with or without ASB) developed UTI. Urosepsis did not occur. The odds ratio of UTI in patients with ASB was 16.48. The efficacy cohort, consisting of 83 patients, showed that ASB had no significant effect on any of the efficacy parameters (MCC-risk ratio [RR]: 0.93, 95% confidence interval [CI]: 0.72-1.21; BC-RR: 0.88, 95% CI: 0.62-1.24; Pdetmax-RR: 0.9, 95% CI: 0.69-1.21; DLPP-RR: 1.69, 95% CI: 0.72-3.97). CONCLUSIONS: ASB is common among patients who are candidates for intradetrusor onabotulinumtoxinA treatment. ASB increases the risk of UTI, but does not heighten the risk of urosepsis, hospitalization, or therapy failure. This study should lead to the reconsideration of current recommendations.

Pain and Bruising Levels After Lip Augmentation: A Comparison of Anterograde and Retrograde Techniques Using an Automated Motorized Injection Device. A Blinded, Prospective, Randomized, Parallel Within-Subject Trial.

BACKGROUND: Dermal fillers for lip augmentation can be injected using various techniques. Although all seem to provide acceptable results, it is not clear which technique is safer, less painful, and provides greater patient comfort. OBJECTIVE: To compare patients' self-reported pain intensity during the injection of hyaluronic acid dermal filler for lip augmentation, with 2 different techniques, anterograde versus retrograde. METHODS AND MATERIALS: Prospective, single-center, within-subject, single-blinded, randomized controlled trial. All subjects received injections in the lip with hyaluronic acid-based filler, each side using the anterograde or retrograde injection technique. An automated motorized injection device was used to ensure a homogeneous deposition flow of the product injected and reduce operator bias. Pain intensity was self-assessed using a 100-mm visual analog scale. Presence and severity of bruising were recorded. RESULTS: Forty-four women (mean age 30.3 years) were randomized. Mean self-reported pain score was 53.1% lower with the anterograde technique than with the retrograde (p < .0001). The anterograde technique had lower rates of site reactions, showed a faster recovery time, and 68.2% of patients favored this technique. CONCLUSION: This study demonstrated that the anterograde technique was less painful, and led to fewer bruising and site reactions than the retrograde technique when using an automated device. LEVEL OF EVIDENCE: I.

The Force Required to Inject a Column of Filler Through Facial Arteries.

BACKGROUND: Injectable fillers have become an integral part of facial rejuvenation, but vascular occlusion is a dreaded complication of such injections. OBJECTIVE: To determine the force required by the fingertip onto the plunger of the syringe to cause retrograde migration. METHODS: In this cadaver study, twelve 2-cm arterial segments and 4 fillers were tested. Injection pressure required to force a column of filler for 1 cm was measured. Five oculoplastics specialists were subsequently recruited and asked to inject the filler at a typical injection pressure. RESULTS: The nonhyaluronic acid filler required significantly more pressure to cause propagation of the material compared with all other fillers (p < .01). None of the other fillers differed significantly from each other. Typical injection pressures generated by experienced injectors were significantly lower than that required to cause propagation of filler at the desired velocity and significantly lower than mean arterial pressure. Measured pressure required to cause filler propagation was well within the normal range of the finger strength that can be generated by humans. CONCLUSION: Typical injection pressures from fingertip to plunger are lower than required to cause propagation of filler intravascularly.