The impact of age on outcomes after breast reduction surgery - A multi-institutional data analysis of 40,958 cases.

BACKGROUND: Reduction mammoplasty is popular among people of various age groups, yet the impact of age on postoperative outcomes remains debated. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (2008-2021) was queried to identify adult female patients who underwent reduction mammoplasty. Patients were categorized into 10-year age brackets (i.e., 18-29, 30-39, 40-49, 50-59, 60-69, and >70 years). We compared age-dependent 30-day outcomes via confounder-adjusted multivariate analyses. RESULTS: 40,958 female patients (mean age: 41 ± 14 years and mean body mass index: 31 ± 6.1 kg/m²) were identified. Complications occurred in 6.4% (n = 2635) of cases, with 770 (1.9%) and 483 (1.2%) patients requiring reoperation and readmission, respectively. 1706 (4.2%) women experienced surgical complications, whereas medical complications were generally rare (n = 289; 0.7%). Compared with women aged 18-29 years, risks of any, surgical, and medical complications were higher for patients aged 30-39 years (OR: 1.22, p < 0.01; OR: 1.05, p = 0.51; OR: 1.84, p < 0.01), 40-49 years (OR: 1.34, p < 0.01; OR: 1.17, p = 0.04; OR: 1.54, p = 0.03), 50-59 years (OR: 1.45, p < 0.01; OR: 1.31, p < 0.01; OR: 1.78, p < 0.01), 60-69 years (OR: 1.38 years, p < 0.01; OR: 1.29, p = 0.01; OR: 1.71, p < 0.01), and >70 years (OR: 1.25, p = 0.18; OR: 1.01, p = 0.98; OR: 1.86, p = 0.14). Patients aged >30 years were also more likely to require readmissions and reoperations. CONCLUSION: Patient age significantly affects outcomes after reduction mammoplasty, with the lowest risk in patients aged <30 years. Importantly, the association between age and postoperative morbidity was not linear. These findings can help guide informed decisions, recognizing that while age is a factor, it is not the sole determinant of risk.

In-depth analysis of ChatGPT's performance based on specific signaling words and phrases in the question stem of 2377 USMLE step 1 style questions.

ChatGPT has garnered attention as a multifaceted AI chatbot with potential applications in medicine. Despite intriguing preliminary findings in areas such as clinical management and patient education, there remains a substantial knowledge gap in comprehensively understanding the chances and limitations of ChatGPT's capabilities, especially in medical test-taking and education. A total of n = 2,729 USMLE Step 1 practice questions were extracted from the Amboss question bank. After excluding 352 image-based questions, a total of 2,377 text-based questions were further categorized and entered manually into ChatGPT, and its responses were recorded. ChatGPT's overall performance was analyzed based on question difficulty, category, and content with regards to specific signal words and phrases. ChatGPT achieved an overall accuracy rate of 55.8% in a total number of n = 2,377 USMLE Step 1 preparation questions obtained from the Amboss online question bank. It demonstrated a significant inverse correlation between question difficulty and performance with rs = -0.306; p < 0.001, maintaining comparable accuracy to the human user peer group across different levels of question difficulty. Notably, ChatGPT outperformed in serology-related questions (61.1% vs. 53.8%; p = 0.005) but struggled with ECG-related content (42.9% vs. 55.6%; p = 0.021). ChatGPT achieved statistically significant worse performances in pathophysiology-related question stems. (Signal phrase = "what is the most likely/probable cause"). ChatGPT performed consistent across various question categories and difficulty levels. These findings emphasize the need for further investigations to explore the potential and limitations of ChatGPT in medical examination and education.

Biocompatibility of Synechococcus sp. PCC 7002 with Human Dermal Cells In Vitro.

Being the green gold of the future, cyanobacteria have recently attracted considerable interest worldwide. This study investigates the adaptability and biocompatibility of the cyanobacterial strain Synechococcus sp. PCC 7002 with human dermal cells, focusing on its potential application in biomedical contexts. First, we investigated the adaptability of Synechococcus PCC 7002 bacteria to human cell culture conditions. Next, we evaluated the biocompatibility of cyanobacteria with common dermal cells, like 3T3 fibroblasts and HaCaT keratinocytes. Therefore, cells were directly and indirectly cocultured with the corresponding cells, and we measured metabolic activity (AlamarBlue assay) and proliferation (cell count and PicoGreen assay). The lactate dehydrogenase (LDH) assay was performed to determine the cytotoxic effect of cyanobacteria and their nutrition medium on human dermal cells. The cyanobacteria exhibited exponential growth under conventional human cell culture conditions, with the temperature and medium composition not affecting their viability. In addition, the effect of illumination on the proliferation capacity was investigated, showing a significant impact of light exposure on bacterial growth. The measured oxygen production under hypoxic conditions demonstrated a sufficient oxygen supply for further tissue engineering approaches depending on the number of bacteria. There were no significant adverse effects on human cell viability and growth under coculture conditions, whereas the LDH assay assessed signs of cytotoxicity regarding 3T3 fibroblasts after 2 days of coculturing. These negative effects were dismissed after 4 days. The findings highlight the potential of Synechococcus sp. PCC 7002 for integration into biomedical approaches. We found no cytotoxicity of cyanobacteria on 3T3 fibroblasts and HaCaT keratinocytes, thus paving the way for further in vivo studies to assess long-term effects and systemic reactions.

Gynecomastia Surgery in 4996 Male Patients Over 14 Years: A Retrospective Analysis of Surgical Trends, Predictive Risk Factors, and Short-Term Outcomes.

BACKGROUND: The high prevalence of benign male breast tissue enlargement (gynecomastia) has resulted in a marked increase of gynecomastia cases. While about one third of male adults experience some form of gynecomastia, gynecomastia surgery (GS) outcome research is limited to small study populations and single-center/-surgeon databases. In this study, we aimed to access the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to identify preoperative risk factors for complications and investigate postoperative outcomes of GS. METHODS: In this retrospective study, we queried the ACS-NSQIP database from 2008 to 2021 to identify male adult patients who underwent GS. Postoperative outcomes involved the occurrence of any, surgical and medical complications, as well as reoperation, readmission, and mortality within a 30-day postoperative time period. Univariable and multivariable assessment were performed to identify risk factors for complications while adjusting for possible confounders. RESULTS: The study included 4,996 GS patients with a mean age of 33.7 ± 15 years and BMI of 28.2 ± 5.1 kg/m2. White patients constituted 54% (n = 2713) of the cohort, and 27% (n = 1346) were obese. Except for 2020, there was a steady increase in GS cases over the study period. Outpatient surgeries were most common at 95% (n = 4730), while general surgeons performed the majority of GS (n = 3580; 72%). Postoperatively, 91% (n = 4538) of patients were discharged home; 4.4% (n = 222) experienced any complications. Multivariable analysis identified inpatient setting (p < 0.001), BMI (p = 0.023), prior sepsis (p = 0.018), and bleeding disorders (p = 0.047) as independent risk factors for complications. CONCLUSION: In this study, we analyzed 4996 male adult GS patients from the ACS-NSQIP database, revealing an increased caseload and significant general surgeon involvement. Risk factors like bleeding disorders, inpatient status, and prior sepsis were linked to postoperative complications, while BMI was crucial for predicting adverse events. Overall, our findings may aid in enhancing patient care through advanced preoperative screening and closer perioperative management. 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 .

Development of a photosynthetic hydrogel as potential wound dressing for the local delivery of oxygen and bioactive molecules.

The development of biomaterials to improve wound healing is a critical clinical challenge and an active field of research. As it is well described that oxygen plays a critical role in almost each step of the wound healing process, in this work, an oxygen producing photosynthetic biomaterial was generated, characterized, and further modified to additionally release other bioactive molecules. Here, alginate hydrogels were loaded with the photosynthetic microalgae Chlamydomonas reinhardtii, showing high integration as well as immediate oxygen release upon illumination. Moreover, the photosynthetic hydrogel showed high biocompatibility in vitro and in vivo, and the capacity to sustain the metabolic oxygen requirements of zebrafish larvae and skin explants. In addition, the photosynthetic dressings were evaluated in 20 healthy human volunteers following the ISO-10993-10-2010 showing no skin irritation, mechanical stability of the dressings, and survival of the photosynthetic microalgae. Finally, hydrogels were also loaded with genetically engineered microalgae to release human VEGF, or pre-loaded with antibiotics, showing sustained release of both bioactive molecules. Overall, this work shows that photosynthetic hydrogels represent a feasible approach for the local delivery of oxygen and other bioactive molecules to promote wound healing. STATEMENT OF SIGNIFICANCE: As oxygen plays a key role in almost every step of the tissue regeneration process, the development of oxygen delivering therapies represents an active field of research, where photosynthetic biomaterials have risen as a promising approach for wound healing. Therefore, in this work a photosynthetic alginate hydrogel-based wound dressing containing C. reinhardtii microalgae was developed and validated in healthy skin of human volunteers. Moreover, hydrogels were modified to additionally release other bioactive molecules such as recombinant VEGF or antibiotics. The present study provides key scientific data to support the use of photosynthetic hydrogels as customizable dressings to promote wound healing.

Artificial Intelligence in Dermatology Image Analysis: Current Developments and Future Trends.

BACKGROUND: Thanks to the rapid development of computer-based systems and deep-learning-based algorithms, artificial intelligence (AI) has long been integrated into the healthcare field. AI is also particularly helpful in image recognition, surgical assistance and basic research. Due to the unique nature of dermatology, AI-aided dermatological diagnosis based on image recognition has become a modern focus and future trend. Key scientific concepts of review: The use of 3D imaging systems allows clinicians to screen and label skin pigmented lesions and distributed disorders, which can provide an objective assessment and image documentation of lesion sites. Dermatoscopes combined with intelligent software help the dermatologist to easily correlate each close-up image with the corresponding marked lesion in the 3D body map. In addition, AI in the field of prosthetics can assist in the rehabilitation of patients and help to restore limb function after amputation in patients with skin tumors. THE AIM OF THE STUDY: For the benefit of patients, dermatologists have an obligation to explore the opportunities, risks and limitations of AI applications. This study focuses on the application of emerging AI in dermatology to aid clinical diagnosis and treatment, analyzes the current state of the field and summarizes its future trends and prospects so as to help dermatologists realize the impact of new technological innovations on traditional practices so that they can embrace and use AI-based medical approaches more quickly.

Five-point liquid rhinoplasty: Results from a retrospective analysis of a novel standardized technique and considerations on safety.

BACKGROUND: Nonsurgical aesthetic improvement of the nose with hyaluronic acid (HA) fillers is becoming increasingly popular but comes with important safety considerations. AIMS: To assess the safety and effectiveness of the standardized "five-point liquid rhinoplasty" approach. METHODS: This was a retrospective, single-center analysis of consecutive adult patients undergoing nonsurgical aesthetic treatment of the nose. All had one of the three main indications (insufficient nasal projection, nasal hump, or deep glabella) and were injected using HA fillers with high elastic modulus. Treatments were given using some or all of the injection points of the "five-point liquid rhinoplasty" technique: P1 (nasal tip, 0.2-0.3 ml supracartilaginous); P2 (nasal root, 0.1-0.2 ml supraperiostal); P3 (cartilaginous dorsum, 0.1-0.2 ml supracartilaginous/supraperiostal); P4 (subnasal, 0.1-0.2 ml supraperiostal); and P5 (nasal alar, 0.1-0.2 ml per side supraperiostal). The risk of complications was minimized by injecting deep and staying in the midline as far as possible. RESULTS: Twenty patients were enrolled (n = 15 female [75%]; mean age: 37.8 ± 11.7 years). The mean volume of filler used was 0.66 ± 0.35 ml per patient. Nineteen subjects (95%) said they were "very satisfied" with results, and the physician was also "very satisfied" with outcomes in 19 patients (95%). Two individuals experienced hematoma, which was managed conservatively; there were no other significant complications. CONCLUSIONS: The "five-point liquid rhinoplasty" is a simple and effective method designed to maximize safety. It offers a good alternative to surgery in selected patients.

Nonsubjective Assessment of Shape, Volume and Symmetry during Breast Augmentation with Handheld 3D Device.

Three-dimensional Surface Imaging (3DSI) has become a valuable tool for planning and documenting surgical procedures. Although surface scanners have allowed for a better understanding of breast shape, size, and asymmetry during patient consultation, its use has not been included in intraoperative assessment so far. Validation of the reliability of the intraoperative use of a portable handheld 3DSI equipment as a tool to evaluate morphological changes during breast augmentation surgery. The patients who underwent bilateral subpectoral breast augmentation through an inframammary incision were included in this study. Intraoperative 3DSI was performed with the Artec Eva device, allowing for visualization of the surgical area before incision, after use of breast sizers and implant, and after wound closure. Intraoperatively manual measurements of breast distances and volume changes due to known sizer and implant volumes were in comparison with digital measurements calculated from 3DSI of the surgical area. Bilateral breasts of 40 patients were 3D photographed before incision and after suture successfully. A further 108 implant sizer uses were digitally documented. There was no significant difference between manual tape measurement and digital breast distance measurement. Pre- to postoperative 3D volume change showed no significant difference to the known sizer and implant volume.

Investigating the Reliability of Novel Nasal Anthropometry Using Advanced Three-Dimensional Digital Stereophotogrammetry.

Three-dimensional surface imaging systems (3DSI) provide an effective and applicable approach for the quantification of facial morphology. Several researchers have implemented 3D techniques for nasal anthropometry; however, they only included limited classic nasal facial landmarks and parameters. In our clinical routines, we have identified a considerable number of novel facial landmarks and nasal anthropometric parameters, which could be of great benefit to personalized rhinoplasty. Our aim is to verify their reliability, thus laying the foundation for the comprehensive application of 3DSI in personalized rhinoplasty. We determined 46 facial landmarks and 57 anthropometric parameters. A total of 110 volunteers were recruited, and the intra-assessor, inter-assessor, and intra-method reliability of nasal anthropometry were assessed through 3DSI. Our results displayed the high intra-assessor reliability of MAD (0.012-0.29, 0.003-0.758 mm), REM (0.008-1.958%), TEM (0-0.06), rTEM (0.001-0.155%), and ICC (0.77-0.995); inter-assessor reliability of 0.216-1.476, 0.003-2.013 mm; 0.01-7.552%, 0-0.161, and 0.001-1.481%, 0.732-0.985, respectively; and intra-method reliability of 0.006-0.598°, 0-0.379 mm; 0 0.984%, 0-0.047, and 0-0.078%, 0.996-0.998, respectively. This study provides conclusive evidence for the high reliability of novel facial landmarks and anthropometric parameters for comprehensive nasal measurements using the 3DSI system. Considering this, the proposed landmarks and parameters could be widely used for digital planning and evaluation in personalized rhinoplasty, otorhinolaryngology, and oral and maxillofacial surgery.

Reproducibility of Novel Soft-Tissue Landmarks on Three-Dimensional Human Facial Scan Images in Caucasian and Asian.

BACKGROUND: Three-dimensional surface imaging is established in many disciplines for objective facial acquisition regarding anthropometry. Former studies addressed the validation of landmark-based measurements for single race. In order to distinguish racial difference, the reproducibility of the landmark measurements must first be validated. OBJECTIVES: Our purpose is to validate the reproducibility of 46 facial soft-tissue landmarks on x, y, z axes to prove their reliability as 3D reference points. METHODS: The study included 80 European Caucasian and 80 Chinese volunteers. Standardized 3D surface imaging was performed using Vectra 3D system. Two raters identified and defined 46 landmarks (138 coordinates), then repeatedly 3D-imaged volunteers' facial region in separate sessions. Coordinates' reproducibility of landmarks is divided into three categories (< 0.5 mm, < 1 mm, and >1 mm) for intra- and inter-rater reproducibility assessments. RESULTS: Coordinates' reproducibility of 160 samples was distributed as follows: Intra-rater: < 0.5 mm (45%), < 1 mm (42%), >1 mm (13%); inter-rater: < 0.5 mm (31.2%), < 1 mm (42%), > 1 mm (26.8%). The reproducibility of landmarks in nasal tip region differs slightly between Caucasians and Asians. Compared to females, males typically have higher landmark reproducibility in lip and chin region. However, there were no differences in the reproducibility ranking of landmarks by gender. CONCLUSION: The majority of the 46 landmarks in the 3D plane are reproducible to 1 mm, which is clinically acceptable. All selected landmarks showed strong consistency across race and gender, suggesting their potential use as reference points in prospective clinical practice. 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 .

Evaluation of the Usability of a Low-Cost 3D Printer in a Tissue Engineering Approach for External Ear Reconstruction.

The use of alloplastic materials instead of autologous cartilage grafts offers a new perspective in craniofacial reconstructive surgery. Particularly for regenerative approaches, customized implants enable the surgeon to restore the cartilaginous framework of the ear without donor site morbidity. However, high development and production costs of commercially available implants impede clinical translation. For this reason, the usability of a low-cost 3D printer (Ultimaker 2+) as an inhouse-production tool for cheap surgical implants was investigated. The open software architecture of the 3D printer was modified in order to enable printing of biocompatible and biologically degradable polycaprolactone (PCL). Firstly, the printing accuracy and limitations of a PCL implant were compared to reference materials acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA). Then the self-made PCL-scaffold was seeded with adipose-tissue derived stem cells (ASCs), and biocompatibility was compared to a commercially available PCL-scaffold using a cell viability staining (FDA/PI) and a dsDNA quantification assay (PicoGreen). Secondly, porous and solid patient-customized ear constructs were manufactured from mirrored CT-imagining data using a computer-assisted design (CAD) and computer-assisted manufacturing (CAM) approach to evaluate printing accuracy and reproducibility. The results show that printing of a porous PCL scaffolds was possible, with an accuracy equivalent to the reference materials at an edge length of 10 mm and a pore size of 0.67 mm. Cell viability, adhesion, and proliferation of the ASCs were equivalent on self-made and the commercially available PCL-scaffolds. Patient-customized ear constructs could be produced well in solid form and with limited accuracy in porous form from all three thermoplastic materials. Printing dimensions and quality of the modified low-cost 3D printer are sufficient for selected tissue engineering applications, and the manufacturing of personalized ear models for surgical simulation at manufacturing costs of EUR 0.04 per cell culture scaffold and EUR 0.90 (0.56) per solid (porous) ear construct made from PCL. Therefore, in-house production of PCL-based tissue engineering scaffolds and surgical implants should be further investigated to facilitate the use of new materials and 3D printing in daily clinical routine.

Digital Leg Volume Quantification: Precision Assessment of a Novel Workflow Based on Single Capture Three-dimensional Whole-Body Surface Imaging.

Whole-body three-dimensional surface imaging (3DSI) offers the ability to monitor morphologic changes in multiple areas without the need to individually scan every anatomical region of interest. One area of application is the digital quantification of leg volume. Certain types of morphology do not permit complete circumferential scan of the leg surface. A workflow capable of precisely estimating the missing data is therefore required. We thus aimed to describe and apply a novel workflow to collect bilateral leg volume measurements from whole-body 3D surface scans regardless of leg morphology and to assess workflow precision. For each study participant, whole-body 3DSI was conducted twice successively in a single session with subject repositioning between scans. Paired samples of bilateral leg volume were calculated from the 3D surface data, with workflow variations for complete and limited leg surface visibility. Workflow precision was assessed by calculating the relative percent differences between repeated leg volumes. A total of 82 subjects were included in this study. The mean relative differences between paired left and right leg volumes were 0.73 ± 0.62% and 0.82 ± 0.65%. The workflow variations for completely and partially visible leg surfaces yielded similarly low values. The workflow examined in this study provides a precise method to digitally monitor leg volume regardless of leg morphology. It could aid in objectively comparing medical treatment options of the leg in a clinical setting. Whole-body scans acquired using the described 3DSI routine may allow simultaneous assessment of other changes in body morphology after further validation.

Zone-Dependent Architecture and Biochemical Composition of Decellularized Porcine Nasal Cartilage Modulate the Activity of Adipose Tissue-Derived Stem Cells in Cartilage Regeneration.

Previous anatomical studies have shown different functional zones in human nasal septal cartilage (NC). These zones differ in respect to histological architecture and biochemical composition. The aim of this study was to investigate the influence of these zones on the fate of stem cells from a regenerative perspective. Therefore, decellularized porcine septal cartilage was prepared and subjected to histological assessment to demonstrate its equivalence to human cartilage. Decellularized porcine NC (DPNC) exposed distinct surfaces depending on two different histological zones: the outer surface (OS), which is equivalent to the superficial zone, and the inner surface (IS), which is equivalent to the central zone. Human adipose tissue-derived stem cells (ASCs) were isolated from the abdominal fat tissue of five female patients and were seeded on the IS and OS of DPNC, respectively. Cell seeding efficiency (CSE), vitality, proliferation, migration, the production of sulfated glycosaminoglycans (sGAG) and chondrogenic differentiation capacity were evaluated by histological staining (DAPI, Phalloidin, Live-Dead), biochemical assays (alamarBlue®, PicoGreen®, DMMB) and the quantification of gene expression (qPCR). Results show that cell vitality and CSE were not influenced by DPNC zones. ASCs, however, showed a significantly higher proliferation and elevated expression of early chondrogenic differentiation, as well as fibrocartilage markers, on the OS. On the contrary, there was a significantly higher upregulation of hypertrophy marker MMP13 (p < 0.0001) and GAG production (p = 0.0105) on the IS, whereas cell invasion into the three-dimensional DPNC was higher in comparison to the OS. We conclude that the zonal-dependent distinct architecture and composition of NC modulates activities of ASCs seeded on DPNC. These findings might be used for engineering of cartilage substitutes needed in facial reconstructive surgery that yield an equivalent histological and functional structure, such as native NC.

Anatomy behind the Paramedian Platysmal Band: A Combined Cadaveric and Computed Tomographic Study.

BACKGROUND: The muscular hypothesis explanation of the pathophysiology behind paramedian platysmal bands does not seem to provide a sufficient explanation for the clinical presentation of these platysmal bands in aged individuals with cervical soft-tissue laxity. The purpose of this study was to investigate the fascial relationships of the anterior neck to enhance appropriate surgical treatment. METHODS: Retrospective analysis of computed tomographic scans of 50 Caucasian individuals (mean age, 55.84 ± 17.5 years) and anatomical dissections of 20 Caucasian and 10 Asian body donors (mean age, 75.88 ± 10.6 years) were conducted. Fascial adhesions were classified according to platysma fusion types, and platysma mobility was tested during dissection procedures. RESULTS: Fusion between the left and right platysma muscles occurred in 64 percent in the suprahyoid region and in 20 percent at the thyroid cartilage, and in 16 percent, the platysma attached to the mandible without fusion. In the absence of muscular fibers, a fascial adhesion zone with limited mobility was observed where the superficial cervical fascia fused with the investing layer of the deep cervical fascia. CONCLUSIONS: Muscular contraction of the platysma results in elevation of the most medial platysma muscle fibers, which are not attached in the fascial adhesion zone. The presence of a fatty layer deep to the platysma enables platysmal movement and anterior and inferior gliding of the skin and platysma when cervical soft-tissue laxity exists. Surgical treatments should include transection of the fascial adhesion; this could potentially prevent the recurrence of paramedian platysmal bands.

Artificial decellularized extracellular matrix improves the regenerative capacity of adipose tissue derived stem cells on 3D printed polycaprolactone scaffolds.

Ideal tissue engineering frameworks should be both an optimal biological microenvironment and a shape and stability providing framework. In this study we tried to combine the advantages of cell-derived artificial extracellular matrix (ECM) with those of 3D printed polycaprolactone (PCL) scaffolds. In Part A, both chondrogenic and osteogenic ECMs were produced by human adipose derived stem cells (hASCs) on 3D-printed PCL scaffolds and then decellularized to create cell free functionalized PCL scaffolds, named acPCL and aoPCL respectively. The decellularization resulted in a significant reduction of the DNA content as well as the removal of nuclei while the ECM was largely preserved. In Part B the bioactivation and the effect of the ac/aoPCL scaffolds on the proliferation, differentiation, and gene expression of hASCs was investigated. The ac/aoPCL scaffolds were found to be non-toxic and allow good adhesion, but do not affect proliferation. In the in vitro investigation of cartilage regeneration, biochemical analysis showed that acPCL scaffolds have an additional effect on chondrogenic differentiation as gene expression analysis showed markers of cartilage hypertrophy. The aoPCL showed a large influence on the differentiation of hASCs. In control medium they were able to stimulate hASCs to produce calcium alone and all genes relevant investigated for osteogenesis were significantly higher expressed on aoPCL than on unmodified PCL. Therefore, we believe that ac/aoPCL scaffolds have a high potential to improve regenerative capacity of unmodified PCL scaffolds and should be further investigated.

Influence of Rheological Properties and Needle Size on Extrusion Forces of Hyaluronic Acid Based Soft Tissue Fillers.

BACKGROUND: To date no precise data are available for extrusion forces related to the G-prime and G-double-prime of fillers in combination with different 27G and 30G needles. Therefore, the objective of this study was to analyze extrusion forces of various product-needle-combinations containing two different 27G and two different 30G needles in combination with fillers of a wide range of elastic moduli starting from 2.0 – 166.0 Pa. MATERIAL AND METHODS: Four different fillers with the following elastic moduli 1.87, 11.65, 61.80, 165.50 Pa were combined with four different needles: 27G ½”, internal diameter: 0.300 μm; 27G ½”, internal diameter: 0.241 μm; 30G ½”, internal diameter: 0.241 μm and 30G ½“, internal diameter: 0.240 μm. Product-needle-combination were subjected to uni-axial mechanical testing and the respective extrusion force was measured. RESULTS: The results of this study revealed that the G-prime and the G-double-prime of a product are statistically significantly related to their extrusion force, with higher G-prime/G-double-prime products requiring higher extrusion forces. The results additionally revealed that whether the size of the needle was described as 27G or 30G by the respective manufacturer statistically significant differences between the measured extrusion forces were detected. CONCLUSION: Injectors need to be aware that not every 27G/30G needle has the same extrusion force even though the external diameter is similar (27G or 30G); this might additionally influence the ability to withdraw blood during a pre-injection aspiration manoeuvre. J Drugs Dermatol. 20(5): doi:10.36849/JDD.5237.

[The frequency of performing vascular anastomoses determines the learning curve in a retrospective analysis of 212 participants of the Munich course of microsurgery]. / Die Häufigkeit der Durchführung einer Gefäßanastomose ist der entscheidende Faktor auf den Lernerfolg in einer retrospektiven Analyse von 212 Teilnehmern des Münchner Mikrochirurgiekurses.

OBJECTIVE: Microsurgical courses are a widely accepted and common method of acquiring microsurgical skills outside of the operation theatre. In-vivo models are often used to prepare surgeons for vascular microsurgery in patients. Although microsurgical courses are commonly offered and attended, the learning curve acquired in such courses remains elusive. MATERIAL AND METHODS: The patency of end-to-end anastomoses performed by a total of 212 participants with different education levels and from different specialist fields were assessed in models of living rats. Participants attended the annually held microsurgical course at the Department for Hand, Plastic and Aesthetic Surgery, Ludwig Maximilian University of Munich, between 2013 and 2018. RESULTS: A highly significant correlation (rp = 0,658; p < 0,001) between number of trials and patent anastomoses was observed. There was no significant correlation between years of surgical experience and age and total number of patent anastomoses achieved during the course. No statistically significant difference of total number of patent anastomoses between residents and board-certified surgeons was detected. CONCLUSION: Looking at the steep learning curves of our participants and the high rate of patent anastomoses, we recommend the setting of microsurgical courses using in-vivo models to overcome potential failures in the beginning of vascular microsurgery careers.

Quantitative Analysis of the Lifting Effect of Facial Soft-Tissue Filler Injections.

BACKGROUND: Although injectable soft-tissue fillers are frequently used for facial rejuvenation, there is a dearth of objective data evaluating the tissue-lifting effects. Current practices for efficacy evaluation include some subjectivity. This study seeks to evaluate the lifting effects of facial soft-tissue fillers in a quantifiable, objective setting. METHODS: Twenty fresh hemifaces obtained from 10 Caucasian body donors (seven women and three men) with a mean age of 83.5 ± 6.8 years and a mean body mass index of 25.3 ± 4.3 kg/m2 were injected with soft-tissue fillers following a predefined treatment algorithm. Three-dimensional surface scanning procedures were performed to assess postinjection effects. RESULTS: Injections in the medial face [i.e., forehead, medial midface, and perioral (chin and labiomandibular sulcus)] increased the local surface volume by 0.67, 0.56, and 0.87 cc and created local (but not regional) lifting effects of 1.11, 0.11, and 0.74 mm. Injections in the lateral face (temple, lateral midface, and jawline) changed the local surface volume by 0.45, 0.02, and -0.38 cc, and created local lifting effects of 0.57, 0.81, and 0.29 mm, respectively. Lateral face injections, however, created additional regional lifting effects by co-influencing neighboring lateral facial regions, which was not observed for medial face injections. CONCLUSIONS: This cadaveric study provides evidence that soft-tissue fillers, although typically classified as volumizers, can induce lifting effects of the face. Whereas temporal deep supraperiosteal injections have limited lifting effects, the combined effects of subdermal injections of the temple, lateral midface, and mandibular angle can induce lifting effects of the total lateral face. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Use of photosynthetic transgenic cyanobacteria to promote lymphangiogenesis in scaffolds for dermal regeneration.

Impaired wound healing represents an unsolved medical need with a high impact on patients´ quality of life and global health care. Even though its causes are diverse, ischemic-hypoxic conditions and exacerbated inflammation are shared pathological features responsible for obstructing tissue restoration. In line with this, it has been suggested that promoting a normoxic pro-regenerative environment and accelerating inflammation resolution, by reinstating the lymphatic fluid transport, could allow the wound healing process to be resumed. Our group was first to demonstrate the functional use of scaffolds seeded with photosynthetic microorganisms to supply tissues with oxygen. Moreover, we previously proposed a photosynthetic gene therapy strategy to create scaffolds that deliver other therapeutic molecules, such as recombinant human growth factors into the wound area. In the present work, we introduce the use of transgenic Synechococcus sp. PCC 7002 cyanobacteria (SynHA), which can produce oxygen and lymphangiogenic hyaluronic acid, in photosynthetic biomaterials. We show that the co-culture of lymphatic endothelial cells with SynHA promotes their survival and proliferation under hypoxic conditions. Also, hyaluronic acid secreted by the cyanobacteria enhanced their lymphangiogenic potential as shown by changes to their gene expression profile, the presence of lymphangiogenic protein markers and their capacity to build lymph vessel tubes. Finally, by seeding SynHA into collagen-based dermal regeneration materials, we developed a viable photosynthetic scaffold that promotes lymphangiogenesis in vitro under hypoxic conditions. The results obtained in this study lay the groundwork for future tissue engineering applications using transgenic cyanobacteria that could become a therapeutic alternative for chronic wound treatment. STATEMENT OF SIGNIFICANCE: In this study, we introduce the use of transgenic Synechococcus sp. PCC 7002 (SynHA) cyanobacteria, which were genetically engineered to produce hyaluronic acid, to create lymphangiogenic photosynthetic scaffolds for dermal regeneration. Our results confirmed that SynHA cyanobacteria maintain their photosynthetic capacity under standard human cell culture conditions and efficiently proliferate when seeded inside fibrin-collagen scaffolds. Moreover, we show that SynHA supported the viability of co-cultured lymphatic endothelial cells (LECs) under hypoxic conditions by providing them with photosynthetic-derived oxygen, while cyanobacteria-derived hyaluronic acid stimulated the lymphangiogenic capacity of LECs. Since tissue hypoxia and impaired lymphatic drainage are two key factors that directly affect wound healing, our results suggest that lymphangiogenic photosynthetic biomaterials could become a treatment option for chronic wound management.

Performing Distance Measurements in Curved Facial Regions: A Comparison between Three-Dimensional Surface Scanning and Ultrasound Imaging.

Facial flap surgery depends strongly on thorough preoperative planning and precise surgical performance. To increase the dimensional accuracy of transferred facial flaps, the methods of ultrasound and three-dimensional (3D) surface scanning offer great possibilities. This study aimed to compare different methods of measuring distances in the facial region and where they can be used reliably. The study population consisted of 20 volunteers (10 males and 10 females) with a mean age of 26.7 ± 7.2 years and a mean body mass index of 22.6 ± 2.2 kg/m2. Adhesives with a standardized length of 20 mm were measured in various facial regions through ultrasound and 3D surface scans, and the results were compared. Regardless of the facial region, the mean length measured through ultrasound was 18.83 mm, whereas it was 19.89 mm for 3D surface scans, with both p < 0.0001. Thus, the mean difference was 1.17 mm for ultrasound measurements and 0.11 mm for 3D surface scans. Curved facial regions show a great complexity when it comes to measuring distances due to the concavity and convexity of the face. Distance measurements through 3D surface scanning showed more accurate distances than the ultrasound measurement. Especially in "complex" facial regions (e.g., glabella region and labiomental sulcus), the 3D surface scanning showed clear advantages.