Risk assessment of China's Eastern Route of the South-to-north Water Diversion Project from the perspective of Phthalate Esters occurrence in the impounded lakes.

Phthalate esters (PAEs) are widely utilized and can accumulate in lacustrine ecosystems, posing significant ecological and human health hazards. Most studies on PAEs focus on individual lakes, lacking a comprehensive and systematic perspective. In response, we have focused our investigation on characteristic lakes situated along the Eastern Route of the South-to-north Water Diversion Project (SNWDP-ER) in China. We have detected 16 PAE compounds in the impounded lakes of the SNWDP-ER by collecting surface water samples using solid-phase extraction followed by gas chromatography analysis. The concentration of PAEs were found to between 0.80 to 12.92 µg L-1. Among them, Bis (2-ethylhexyl) phthalate (DEHP) was the most prevalent, with mean concentration of 1.56 ±â€¯0.62 µg L-1 (48.44%), followed by Diisobutyl phthalate (DIBP), 0.64 ±â€¯1.40 µg L-1 (19.87%). Spatial distribution showed an increasing trend in the direction of water flow. Retention of DEHP and DIBP has led to increased environmental risks. DEHP, Dimethyl phthalate (DMP) etc. determined by agriculture and human activities. Additionally, Dibutyl phthalate (DBP) and DIBP mainly related to the use of agricultural products. To mitigate the PAEs risk, focusing on integrated management of the lakes, along with the implementation of stringent regulations to control the use of plasticizes in products.

Proportioning optimization of transparent rock-like specimens with different fracture structures.

Clarifying the principles of proportioning optimization for brittle transparent rock-like specimens with differential fracture structures is crucial for the visualization study of the internal fracture and seepage evolution mechanisms in rock masses. This study, utilizing orthogonal experimental methods, uncovers the influence mechanisms, extents, and patterns by which the ratios of resin, hardener, and accelerator, along with the freezing duration, impact the mechanical characteristics of transparent rock-like specimens. Notably, it was observed that as the accelerator ratio and freezing time are increased, there's a general decline in the uniaxial compressive strength, tensile strength, and elastic modulus of the specimens. In contrast, an increase in the hardener ratio initially leads to an enhancement in these mechanical properties, followed by a subsequent decrease. Under uniaxial compressive loading, the specimens exhibit four typical modes of failure: bursting failure, splitting failure, single inclined plane failure, and bulging failure. As the hardener and accelerator ratios increase, the mode of failure gradually shifts from bulging to bursting, with freezing time having a minor overall impact on the evolution of failure modes. The study proposes a method for inducing random three-dimensional closed fractures within the specimens and further clarifies the principles for optimizing the proportions of specimens with different fracture structures, such as intact, embedded regular, and random three-dimensional fractures. This research facilitates the in-depth application of transparent rock-like materials in various scenarios and provides theoretical guidance and technical support for visualizing the evolution of fracture and seepage characteristics within the fractured rock mass.

Estimating the Change in Facial Subunits During Positive and Negative Facial Expression Using Three-Dimensional Stereophotogrammetry Facial Analysis.

Background: A more refined and clinically related facial expression analysis is required for patients who wish to be perceived more emotionally positive. Objective: To measure the change in skin vector and volume in facial subunits when expressing positive expression (happiness) compared with negative expressions (sadness, fear, disgust, and anger), using three-dimensional (3D) stereophotogrammetry analysis. Methods: This study took 3D photographs of 20 volunteers' face at rest and during positive and negative expression. The directions of skin vector and volume changes in each facial subregion were recorded and calculated. Results: In the positive expression, 78.3% (95% confidence interval [CI] 66.8-89.9) of the medial midfacial subregions presented superolateral vector and volume increase, whereas volume decrease in 82.5% (95% CI 78.5-86.5) of the lip subregions could be observed. In the negative expression, the vector changes were predominantly inferomedial in 26.0% (95% CI 15.4-36.5) of the forehead and 36.8% (95% CI 33.2-40.3) of the upper eyelid subregions, whereas volume increases in 34.0% (95% CI 30.4-37.7) of the upper eyelid subregions were observed. Conclusions: This 3D stereophotogrammetry analysis presents the morphological difference between the positive and negative expression.

GKT137831 in combination with adipose-derived stem cells alleviates high glucose-induced inflamm-aging and improves diabetic wound healing.

Adipose stem cells (ADSCs) have been proven to promote healing in diabetic wounds, which are one of the most serious chronic refractory wounds. However, reactive oxygen species (ROS) induced by high glucose (HG) lead to oxidative stress and aging in ADSCs, which limits the therapeutic effect of ADSCs. In this study, we investigated the role of GKT137831, a NOX1/4 inhibitor that can reduce ROS production, in protecting ADSCs from hyperglycemia and in diabetic wound healing. In vitro, ROS levels and NOX4 expression were increased after HG treatment of ADSCs, while the oxidative stress marker malondialdehyde (MDA) was increased, mitochondrial membrane potential (MMP) was decreased, inflammatory aging-related indicators such as p16, p21, MMP1, MMP3, IL6 and ß-GAL were increased, and migration was weakened. In vivo, we constructed a diabetic mouse wound model and found that the combination of ADSCs and GKT137831 synergistically promoted the 21-day wound healing rate, increased the expression of collagen and hydroxyproline, increased the number of blood vessels and the expression of CD31, and reduced the expression of IL6, MMP1, MMP3, and p21. These results suggest that GKT137831 could protect ADSCs from oxidative stress and aging induced by HG and enhance the therapeutic effect of ADSCs on diabetic wounds.

Retrospective Study of Vascular Complications Caused by Hyaluronic Acid Injection.

BACKGROUND: Complications from intravascular embolization of hyaluronic acid (HA) are not only no longer uncommon but also devastating. This study aimed to examine clinical aspects of patients referred to our hospital for care following complications from intravascular filler embolization. METHODS: We retrospectively reviewed data from all patients referred to our medical center for the management of complications associated with intravascular embolization of HA fillers including demographics, medical history, clinical features, and treatment between November 2013 and June 2022. RESULTS: A total of 116 patients with vascular complications (27 cases with vision loss and 89 cases with skin necrosis) were assessed. The highest risk injection sites for skin necrosis included the nasal region (58/115, 50.4%), temple (16/115, 13.9%), and forehead (11/115, 9.6%) and for vision loss included the nasal region (18/30, 60.0%) and forehead (7/30, 23.3%). In skin necrosis cases, a needle (60/89, 67.4%) carried a higher risk than that of a cannula (29/89, 32.6%), whereas in vision loss cases, nasal dorsum injections using a cannula (16/27, 59.3%) carried a higher risk than that observed using a needle (11/27, 40.7%). No treatment was completely successful in reversing these complications. CONCLUSION: Intravascular embolization of HA filler is a serious complication. Although some combination treatments have been proposed, there is no standard protocol for treating severe complications. 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 http://www.springer.com/00266 .

Age-Related Changes of the Zygomatic Ligament: An Experimental Animal Study.

BACKGROUND: Facial aging is a multifactorial process involving the skin, fat, muscles, bones, and ligaments. The role of facial ligaments in the facial aging process remains elusive. OBJECTIVES: The aim of this study was to identify whether age-related changes in facial ligaments exist and how to best quantify such changes when investigating the zygomatic ligament in the rat. METHODS: A total of 30 male Sprague-Dawley rats (10 young, 10 middle-aged, 10 mature) were investigated to visualize the zygomatic ligament. Samples of the ligaments spanning the zygomatic arch and the skin were taken and histologically examined with hematoxylin-eosin, Masson, Verhoeff's elastic, and picrosirius red staining. Quantification of the Type I/III collagen ratio and collagen content was performed by color deconvolution and electron microscopic imaging. RESULTS: With increasing age, collagen fibers inside of the examined ligaments appeared thicker and more closely arranged. The Type I/III collagen ratio was measured to be 1.74 in young animals, 3.93 in middle-aged animals, and 5.58 in mature animals. The ultra-microstructure of the ligament was less coordinated in direction and orientation in young and middle-aged animals than in mature animals, in which collagen fibers were bundled together in a strong and oriented mesh. CONCLUSIONS: Ligaments appeared thinner, transparent, more elastic, and less robust in young animals, whereas ligaments in mature animals appeared thicker, more fascia-like, less elastic, and more robust. An increase in the Type I/III collagen ratio, indicating greater stiffness and reduced elasticity, was observed with higher age of the investigated animals. These findings indicate that ligaments might increase in stiffness and rigidity with age.

Histopathologic analysis of hyaluronic acid composite solution following intravascular injection: Variability and safety.

BACKGROUND: Although a composite solution of non-crosslinked hyaluronic acid is generally considered safe, few studies have investigated its safety after intravascular injection. METHODS: Male Sprague-Dawley rats were administered 0.05 mL of a non-crosslinked hyaluronic acid composite solution via intravascular injection into bilateral inferior epigastric arteries (IEA). Artery samples were obtained at multiple time points for histopathologic analysis. Bilateral abdominal flaps supplied by the IEA were lifted and the same dose of solution was injected into the artery, and flap survival was analyzed. RESULTS: Histopathologic analysis showed that the non-crosslinked hyaluronic acid composite solution remained temporarily in the artery lumen following intravascular injection. With continuous blood flow, the filler gradually disintegrated and the artery became recanalized. At 24 h, no filler remained in the lumen. At 7 days after the filler was injected into the IEA feeding the flap, there was no significant difference between the experimental and control groups with respect to flap survival rate. CONCLUSIONS: Non-crosslinked hyaluronic acid composite solution is relatively safe when a minimal volume is administered by intravascular injection. The filler will remain in the vessel for a short time, after which the vessel recanalizes.

Effects of different colors of film mulch on soil temperature and rice growth in a non-flooded condition.

BACKGROUND: Rice cultivation under film mulching with no flooding is widely used as an effective water-saving technology. Different colors of film mulch have different effects on the soil hydrothermal environment and crop growth because of their different optical properties. However, the effects of different colors of film mulch on soil temperature and rice physiological growth are not clearly understood. RESULTS: Field experiments were conducted in 2019 and 2020 to investigate the effects of different color mulches on soil temperature and rice growth in a non-flooded condition. Transparent film (TM), black film (BM), two-color film (BWM, silver on the front and black on the back), and no film (NM) in a non-flooded condition were designed. Soil temperature variation at different soil depths of 0-0.25 m and rice plant height, stem thickness, dry matter, yield and quality were monitored. The results showed that compared to no mulching, the mulching treatment effectively increased the average soil temperature during the whole rice growth stage with the soil temperature ranked TM > BM > BWM. Compared with NM, the BM and BWM treatments increased rice yield by 12.1-17.7% and 6.4-14.4% in 2019 and 2020, respectively. The BWM had 18.2% and 6.8% greater gel consistency than NM in 2019 and 2020, respectively. CONCLUSION: Transparent film should be applied with care because of the high soil temperature stress. Black film and two-color film (silver on the front and black on the back) could be better option for rice yield, increasing and quality improving in a non-flooded condition. © 2023 Society of Chemical Industry.

A Computed Tomographic Investigation of the Ophthalmic Artery Volume and Its Relevance to Soft Tissue Filler Injections.

BACKGROUND: The measured intraarterial volume of cadaveric ophthalmic arteries was utilized for safety recommendations during facial soft tissue filler injections. However, its clinical practicability and model applicability have become questionable. OBJECTIVES: To measure the volume of the ophthalmic artery in living individuals by utilizing computed tomography (CT) imaging technology. METHODS: A total of 40 Chinese patients (23 males, 17 females) were included in this study with a mean age of 61.0 (14.2) years and a mean body mass index of 23.7 (3.3) kg/m2. Patients were investigated with CT imaging technology to evaluate the length, diameter, and volume of the bilateral ophthalmic arteries as well as the length of the bony orbits, resulting in a total of 80 investigated ophthalmic arteries and orbits. RESULTS: Independent of gender, the average length of the ophthalmic artery was 80.6 (18.7) mm, the calculated volume of the ophthalmic artery was 0.16 (0.05) mL and the minimal and maximal internal diameter of the ophthalmic artery were 0.50 (0.05) mm and 1.06 (0.1) mm, respectively. CONCLUSIONS: Based on the results obtained from the investigation of 80 ophthalmic arteries it must be concluded that current safety recommendations should be reevaluated. The volume of the ophthalmic artery appears to be 0.2 mL rather than 0.1 mL as previously reported. In addition, it appears impractical to limit the volume of soft tissue filler bolus injections to 0.1 mL due to the aesthetic requirements of each individual patient and treatment plan.

A Two-Center, Prospective, Randomized Controlled Trial to Evaluate the Efficacy and Safety of and Satisfaction with Different Methods of ART FILLER® UNIVERSAL Injection for Correcting Moderate to Severe Nasolabial Folds in Chinese Individuals.

BACKGROUND: Hyaluronic acid is the most popular dermal filler in the treatment of nasolabial folds. Injection methods vary among physicians. METHODS: A randomized, two-center, double-blind, intraindividual trial was designed to compare a new method of injecting ART FILLER® UNIVERSAL using the retaining ligament with the traditional method (linear threading and bolus injection) in moderate to severe nasolabial folds. Forty patients with moderate to severe nasolabial folds were randomized into groups A and B. Group A received injections via the traditional method on the left side and the ligament method on the right side, while group B received the reverse. Clinical efficacy and patient safety were independently assessed by a blinded evaluator, the injector, using the Wrinkle Severity Rating Scale (WSRS), the Global Aesthetic Improvement Scale (GAIS), and the Medicis Midface Volume Scale (MMVS) at 4 weeks (before and after the touch-up injection), 8 weeks, 12 weeks, and 24 weeks after the baseline injection. RESULTS: From the perspective of the blinded evaluator, the improvements in WSRS scores from baseline did not differ significantly between the ligament method (0.73 ± 0.61) and the traditional method (0.89 ± 0.61) at week 24 (p > 0.05). The mean GAIS score at week 24 was 1.41 ± 0.49 for the traditional method and 1.32 ± 0.47 for the ligament method (p > 0.05). CONCLUSIONS: The efficacy and safety of the ligament method for the management of nasolabial folds are comparable to those of the traditional method in terms of WSRS and GAIS score improvement in the long run. The ligament method is superior to the traditional method in that it improves midface deficits with fewer adverse events. LEVEL OF EVIDENCE II: 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 . CLINICAL TRIAL REGISTRATION: This study was registered with the Chinese Clinical Trial Registry under the registration number ChiCTR2100041702.

Three-dimensional Evaluation of Results After Dual-Plane Breast Augmentation with and Without Internal Suture Mastopexy.

BACKGROUND: In patients with breast atrophy and ptosis, it is necessary to correct both problems simultaneously. This study aimed to analyze breast morphological changes with a three-dimensional (3D) scanning technique to demonstrate the improvement effect of dual-plane breast augmentation combined with internal suture mastopexy. METHODS: 3D breast surface scans were performed preoperatively and postoperatively in 24 patients (n = 35 breasts) undergoing internal suture mastopexy combined with prosthetic augmentation through the periareolar approach and 24 patients (48 breasts) undergoing simple dual-plane breast augmentation. Changes in linear distance, breast volume and volume distribution, breast projection, and nipple position were analyzed to assess the breast morphology. RESULTS: Compared with simple breast augmentation, augmentation combined with internal suture mastopexy was associated with a higher upper pole volume increase and greater medial and upward nipple displacement. After the surgery, the upper pole volume increased by an average of 10.6% in combined augmentation group and decreased by an average of 2.2% in the simple breast augmentation group. The measured breast projections were 24.8 ± 2.2% lower than expected in the combined group and 23.1 ± 4.1% lower than expected in the simple group, based on implant parameters recorded by the manufacturer. The nipple moved 0.2 ± 0.5 cm laterally, 1.6 ± 0.6 cm upward, and 2.8 ± 0.7 cm anteriorly in the combined group and 0.9 ± 0.5 cm laterally, 0.7 ± 0.6 cm upward, and 3.0 ± 0.6 cm anteriorly in the simple group. CONCLUSIONS: Dual-plane breast augmentation in addition to internal suture mastopexy appears to reposition breast tissue from the lower pole to fill in the deficient upper breast, pull the nipple medially and superiorly, and ultimately correct mild to moderate breast ptosis. 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 .

Biofilm formation is a risk factor for late and delayed complications of filler injection.

Introduction: Biofilm formation is a major cause of delayed-graft complications. Similarly to implants, dermal fillers carry the risk of biofilm formation, which can lead to the development of nodules, chronic inflammatory reactions, abscesses and other complications. In this study, we investigated the late or delayed complications associated with biofilm formation on dermal fillers. Methods: In this retrospective analysis, we analyzed all cases of complications caused by filler injections at a single center between January 2017 and December 2022, the majority of which comprised nodule formation and chronic persistent inflammatory reactions. The risk of biofilm formation with fillers was summarized and analyzed based on the results of bacterial culture and pathological examination. Results: Sixty-one patients were enrolled, including 42 cases of nodule formation, 15 of chronic inflammatory reactions, and 4 of active infection. Bacterial culture of the tissue samples obtained from seven patients after surgical treatment were positive, and comprised four cases of Staphylococcus aureus, one case of Staphylococcus epidermidis, one case of Staphylococcus saprophyticus and one case of Mycobacterium abscessus. The corresponding histopathological results indicated extensive mononuclear lymphocyte infiltration, with a giant cell reaction in the fibrous connective tissue. Conclusion: The results of this study suggest that biofilm formation is a significant risk factor for late and delayed complications following filler injection, and is caused by the contamination of resident bacteria and recessive infection at the injection site.

Three-Body Abrasive Wear Behavior of WC-10Cr3C2-12Ni Coating for Ball Mill Liner Application.

Carbide coatings are frequently used to improve the wear resistance of industrial components in various wear environments. In this research, aiming at the service characteristics of easy wear and short service life of ball mill liners, WC-10Cr3C2-12Ni coatings were prepared by supersonic flame spraying technology (HVOF). The reciprocating sliding tests were conducted under four different WC particle size conditions, and the differences in the tribological behavior of the coatings and three-body abrasive wear mechanism were obtained. The findings reveal that the average nanohardness of the WC-Cr3C2-Ni coating is nearly five times greater than that of the steel substance. The COF of tribo-pairs decreases and then increases as the particle size increases. In the case of no particles, the surface of the coating is slightly worn, with fatigue and oxidative wear being the primary wear mechanisms. Small particles (1.5 µm and 4 µm) are crushed and coated on the coating surface, in which the extremely fine particles are plasticized to form friction layers that have a protective effect on the coatings. The protective effect of the particles disappears as the particle size increases and is replaced by a powerful chiseling effect on the coatings, resulting in serious material loss. The particle size has a direct relationship with coating wear.

Upper Facial Anastomoses Between the External and Internal Carotid Vascular Territories - A 3D Computed Tomographic Investigation.

BACKGROUND: Facial regions with a high risk for causing injection-related visual comprise are dual-supply vascular areas such as the nose, glabella, and forehead. These regions have in common that they receive arterial blood supply both by branches of the internal (ICA) and the external carotid artery (ECA). OBJECTIVE: The authors sought to investigate the anastomotic pathways between ICA and ECA branches in the upper face. METHODS: Postmortem computed tomographic angiographic scans of n = 38 Chinese non-embalmed hemifaces (25 males, 13 females; mean age, 37.79 [11.8] years; mean BMI, 21.90 [2.3] kg/m2) were conducted. Data analysis relied on the calculation of depth, distances, and pathways of forehead and temporal arteries to investigate the number of anastomotic connections, the connecting branches, and the layer of connection between ICA and ECA territories. RESULTS: Between ICA and ECA territories, only 1 connection in 57.9%, 2 connections in 31.6%, 3 connections in 5.3%, and 4 and 5 connections in 2.6% each were identified. A superficial connection was observed in 15.8% whereas in 84.2% the anastomotic connection was identified to be both superficial and deep. CONCLUSIONS: Adverse events following facial minimally invasive soft-tissue filler injections for aesthetic purposes are not frequent but devastating if they occur. Anatomic knowledge as presented in this study can help to increase awareness of 3-dimensional vascular anastomotic pathways and identify safer injection zones and safer fascial planes. Evidence-based injection techniques should be followed, and safety aspects should be placed over the aesthetic outcome.

Comparison of the Intestinal Structure and Intestinal Microbiome between Two Geographically Isolated Populations of Culter alburnus.

Geographical populations of Culter alburnus inhabiting different regions of China present substantial differences in their reproduction and development characters. This study compared the intestinal structures, digestive enzyme activities, and intestinal microbiomes in the Xingkai (XK) Lake and the Dianshan (DS) Lake populations of C. alburnus collected in two isolated and contrasting river systems. We wanted to discover whether the intestinal structure and functional divergence were formed in the two populations due to adaptive evolution caused by geographical isolation. Our study indicated that higher intestinal villi, thicker intestinal mucosa layer and intestinal muscle layer, and significantly higher activity of α-amylase were identified in the XK population. Moreover, quite different intestinal microbiomes were presented in the two populations, with the higher abundance of Bacteroidetes and Firmicutes in the XK population. The significantly different intestinal microbiome in the XK population was functionally enriched in carbohydrate, lipid, and amino acid metabolism by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Our findings indicated that substantial adaptative divergence in the intestinal structures and intestine microbiomes was formed in the two populations due to long-term geographical isolation, which may have strongly affected the digestion and absorption ability of the XK population compared with the DS population.

Intention to consume news via personal social media network and political trust among young people: The evidence from Hong Kong.

Introduction: Assessing the effect of different media sources on political trust provides an overall picture of the role of the current media landscape in influencing the legitimacy of political institutions. Methods: A cross-lagged model was developed and tested by applying it to a three-wave dataset obtained by surveying young people in Hong Kong in order to evaluate the unique impact of intention to consume news via personal social media network on political trust. Results: After controlling for the impact of other news channels and respondents' prior political interest, we found their political trust was most significantly affected by information intentionally obtained from friends and family through their personal social media network. Discussion: Media exhibits a relatively weak effect on political trust, which is primarily influenced by selection, indicating that policymakers do not have to be concerned with online exchange of information that is critical of the government. Moreover, this evidence from Hong Kong suggests that, when it comes to developing political trust throughout the society, conflicts resulting from opposing views are better than ignorance.

Proper Skin Management in Breast Augmentation with a Periareolar Incision Prevents Implant Contamination and Biofilm-Related Capsular Contracture.

BACKGROUND: Capsular contracture (CC) is a significant complication and major reason for revision in breast augmentation. Many studies indicate that most bacteria found in contracted capsules originate from the skin, especially that of the nipple-areolar complex (NAC). To prevent implant contamination, protocols without a periareolar incision have been proposed and have become a limitation for breast augmentation. We sought to propose a strategy of proper skin management for periareolar incisions to prevent implant contamination and biofilm-related CC. METHODS: The analyses in this study are based on data collected from February 2017 to July 2020. A total of 129 patients were included, and they were randomized into two groups. The control group was subjected to no skin treatment before the surgery, and the treatment group underwent preoperative cleaning and disinfection of the NAC. We collected bacteriologic swabs used to rub the skin of the NAC and chest after draping and suturing from the control and treatment groups. We assessed the potential risk of detecting bacteria or fungi in the swabs, and we analyzed the data. The relationship between the positive culture rate and complication rate indicated the effectiveness of our strategy. RESULTS: Initially, 774 swabs were obtained. In the control group, 6 swabs tested positive for pathogens, including 2 NAC swabs positive for Staphylococcus epidermidis (S. epidermidis) after draping and 3 and 1 NAC swabs positive for S. epidermidis and Staphylococcus aureus (S. aureus) after suturing, respectively. All the other samples in the control and treatment groups were negative for bacteria or fungi. All patients had at least 16 months of follow-up. No CC (Baker grades II-IV) was recorded during the follow-up, and the treatment group experienced a better outcome associated with a lower rate of minor complications. CONCLUSIONS: Proper preoperative skin management helps keep the field pristine and potentially prevents implant contamination and even biofilm-related CC. With this strategy, breast augmentation using a periareolar incision or any other approach, even other surgery, could be a safe procedure. 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 .

Experimentally Induced Arterial Embolism by Hyaluronic Acid Injection: Clinicopathologic Observations and Treatment.

BACKGROUND: Although major complications of hyaluronic acid injection rarely occur, with the rapidly growing number of procedures performed and their expanding applications, such complications warrant greater attention. Our study was designed to explore optimal treatment methods for hyaluronic acid-related vascular occlusion. METHODS: In the first part of the study, 60 rats were given intraarterial hyaluronic acid injected into the bilateral inferior epigastric arteries to establish an animal model, and were euthanized at different postinjection time points. The inferior epigastric artery was retrieved for pathologic examination. In the second part of the study, bilateral abdominal flaps supplied by the inferior epigastric artery were elevated in six groups of rats, and hyaluronic acid was injected into the right side, with each group receiving a different intervention. The flap survival rate was calculated and analyzed. RESULTS: In the first part of the study, pathologic examination revealed that the composition of the emboli caused by arterial hyaluronic acid-induced occlusion changed from pure hyaluronic acid to a hyaluronic acid-thrombus mixture. In the second part of the study, flap survival rates (mean percentages) were as follows: group A, 43.29 ± 9.28 percent; group B, 54.17 ± 10.86 percent; group C, 59.27 ± 13.40 percent; group D, 64.37 ± 8.61 percent; group E, 71.92 ± 19.06 percent; and group F, 57.47 ± 13.64 percent. Group A differed significantly from groups B, C, D, and E (p < 0.001). No significant difference was observed between groups A and F (p > 0.05). CONCLUSIONS: The combined use of intravenous or subcutaneous hyaluronidase and urokinase was most effective in treating hyaluronic acid injection-related arterial embolism after 45 minutes and 24 hours. This treatment may be ineffective after 48 hours.