Skin Tension Research Articles

Impact of Stoma Baseplate Convexity on Tension and Compression Around the Stoma Site: A Finite Element Analysis.

For patients living with intestinal or urinary stomas, skin barriers play an essential role in protecting the peristomal skin and preventing peristomal complications. Convex baseplates press into the peristomal skin and are suitable for retracted stomas that do not protrude, peristomal skin with creases, folds, or dips, and stomas where frequent leaking can occur with flat pouching systems. However, there is a lack of data on the magnitude and location of tension applied to the abdomen by convex baseplates. We evaluated the impact of a range of convex baseplates applied to a simulated stoma site. A comparative finite element analysis investigation was conducted to evaluate the impact of eight different convex stoma system baseplates applied to an idealised flat abdomen, representing skin, subcutaneous tissue, and musculature layers. The baseplates considered had varying convexity with depths of 3.5 mm and 7 mm and internal structural diameters between ~30 mm and ~60 mm. The convex product range provided tension in the skin (maximum principal strain) and compression through the fat layer (minimum principal strain). Large differences in the locations and magnitudes of skin tension and fat layer compression were seen between the baseplates under analysis, with both the depth and diameter of convexity influencing the strain experienced across the abdominal topography. The results generated highlight the importance of having an appropriate range of convexity products available and selecting an appropriate option for use based on the stoma type and condition of the peristomal skin.

Oblique versus Straight skin incision: The impact of incision type on postoperative outcomes in distal radiocephalic arteriovenous fistula creation

Aim: The type of skin incision utilized in arteriovenous (AV) fistula creation may significantly influence the patency, maturation, and overall outcomes of the fistulas. An oblique skin incision may offer distinct advantages in preventing early AV fistula failure by reducing skin tension and minimizing pressure on the newly formed anastomosis. This study aims to compare the postoperative early period outcomes of oblique versus straight skin incision techniques, with a focus on their impact on AV fistula success. Material and Methods: 2020 to 2023, all patients with created AV fistula via distal antebrachial vessels with oblique and straight skin incisions were enrolled. Retrospectively, the patients’ demographics, comorbidities were collated from the hospital data. All patients were operated with local anesthesia for radiocephalic AV fistula creation. The characteristics of the vessels were determined through preoperative Doppler ultrasonography mapping. Evaluations were conducted on primary patency, early maturation, and the incidence of early thrombosis. Results: In Total, 182 patients were operated for AV fistula creation. The mean age was 57±17 years and there was a male predominance with %68. We performed 74 patients AVF creation via straight skin incision and 108 via oblique skin incision. Despite there being no differences in comorbidities and demographic characteristics between the two groups, the group with a straight skin incision exhibited a higher incidence of early thrombosis (p=0.03), a lower maturation rate (p=0.03), and reduced primary patency (p=0.01). Conclusion: Oblique skin incision could be a feasible alternative to conventional straight incision with a higher early AVF patency and lower thrombosis rates. Reducing the pressure on and keeping the incision away from the new anastomosis may be crucial for achieving better outcomes.

The Oxygen Therapy Tube as a Tool for Breast Squeezing during Pedicle De-epithelialization in Reduction Mammaplasty.

During breast reduction, pedicle de-epithelialization, as meticulous as possible, is necessary to ensure satisfying breast sculpting and to avoid any epidermoid cyst. To perform an effective and rapid de-epithelialization, a good tension of the skin is mandatory. Several techniques to improve skin tension of the breast are described in the literature. We report a cheap, effective, and easily reproducible method, based on the use of an oxygen tube with nasal cannula.

An interactive augmented reality software for facial reconstructive surgeries

Background and ObjectiveSurgical trainees need a lot of training and practice before being able to operate independently. The current approach of surgical education mainly involves didactic teaching and psychomotor training through physical models or real tissue. Due to the unavailability of physical resources and lack of objective ways of evaluation, there is a demand for developing alternative training methods for surgeons. In this paper, we present an application that provides additional training opportunities to surgical trainees in the field of facial reconstructive surgeries. MethodsWe built a mobile augmented reality application that helps the user to visualize important concepts and experiment with different surgical plans for facial reconstructive surgeries. The application can overlay relaxed skin tension lines on a live video input or a patient's photo, which serve as bases for aligning a skin flap. A surgical trainee can interactively compare different skin flap design choices with estimated final scars on a photo of a patient. Data collection capability is also added to the application, and we performed a Monte Carlo experiment with simulated users (five classes of 100 users each) as an example of objectively measuring user performance. ResultsThe application can overlay relaxed skin tension lines on a patient's face in real time on a modern mobile device. Accurate overlays were achieved in over 91% as well as 84% and 88% out of 263 generated face images, depending on the method. Visual comparisons of the three overlay methods are presented on sample faces from different population groups. From the Monte Carlo experiment, we see that user actions in each class follow a normal distribution with a distinct set of parameters. ConclusionsThis application can serve as a basis for teaching surgical trainees the fundamentals of different facial reconstructive procedures, especially concepts related to relaxed skin tension lines and skin flaps. It can objectively evaluate the performance of surgical trainees in a course. This setup focuses on illustrating the relationship between the orientation of skin flaps and relaxed skin tension lines, which is a prerequisite of minimizing scarring in patients in addition to good surgical techniques.

Split-thickness Plantar Skin Graft for Foot Syndactyly.

For the treatment of syndactyly, the submalleolar or inguinal area is the common donor site for skin grafts. However, high skin tension of the submalleolar area could potentially delay wound healing or cause scarring. Skin grafts from the inguinal area cause pigmentation. In this study, we have harvested split-thickness skin grafts from the plantar area to treat syndactyly and evaluated the healing course and aesthetic outcome. We analyzed 13 recipient and nine donor sites in eight patients, aged 13-68 months (average 25 months), with syndactyly of the foot. The minimum follow-up was 14 months, and average follow-up period was 22.3 months. Aesthetic outcomes including color and texture match, wound healing of donor site using Vancouver Scar Scale, and complications of both sites were assessed in all patients. At the recipient sites, the graft survived well, and the lack of pigmentation of the graft led to good color match. At the donor sites, hypertrophic scar and high scar scale were seen around postoperative month 3, but were momentary, as all donor sites matured to a flat and soft scar. Morbidity of split-thickness skin graft from the plantar region is limited. It causes minimum scarring of the nonexposed area. Moreover, because it does not cause pigmentation, the split-thickness skin graft technique is a reasonable option for the treatment of syndactyly.

Comparative Efficacy of Chitosan with or Without Honey on Cutaneous Wound Healing in Donkeys

The domesticated donkey, derived from the African wild ass, has played a crucial role in human history for over 5,000 years, serving as a working and pack animal. However, donkeys often suffer from skin wounds and injuries due to various factors, including equipment use, road accidents, and lack of veterinary care. Wound healing is a complex process involving inflammation, proliferation, and maturation phases, with impaired cell proliferation potentially delaying healing. Equines, including donkeys, are particularly susceptible to traumatic skin wounds, with limb wounds healing more slowly due to factors such as tissue loss, contamination, and excessive skin tension. In such cases, wound healing by second intention is common but can lead to complications. Chitosan, a biopolymer derived from the shells of crustaceans, has shown promise in promoting wound healing. It helps with tissue granulation, collagen deposition, and tissue regeneration, while also preventing wound contamination and maintaining a sterile environment. Honey, with its antimicrobial, anti-inflammatory, and antioxidant properties, is another natural remedy that accelerates wound healing and is often used in combination with chitosan for optimal results. This biologically-based approaches hold potential for improving the healing of donkey wounds and preventing infections, offering safer and more effective alternatives to traditional wound care.

Strengthening the Key Features of Volumizing Fillers: Projection Capacity and Long-Term Persistence.

Volumizing fillers aim to create or restore facial volume in fat layers. To provide strong tissue lifting and long-term persistence, gels are generally designed with stiff properties, characterized by a high storage modulus (G'). However, clinical evidence shows a discrepancy between high G' and good lifting capacities, especially after skin tension has been exerted on the gel. To better explore the in vivo behavior of a gel, we first evaluated the elastic moduli of five commercial volumizers (RHA4, JUVVOL, RESVOL, RESLYFT, and BELVOL) in dynamic compression mode, E'. We further developed a Projection Index score based on the rheological assessment of creep in compression to mimic skin tension-induced stress relaxation (flattening). Finally, the ability of a gel to resist enzymatic degradation was analyzed with a multidose approach. Despite similar clinical indications, volumizers exhibited distinct behaviors. RHA4 and BELVOL showed the highest E' values (resistance to strain), RHA4, JUVVOL, and RESVOL exhibited the greatest projection capacities, while JUVVOL and RHA4 offered the largest persistence to enzymatic degradation. In this article, we introduce the use of the Projection Index to efficiently assess the ability of a gel to lift tissues, thus increasing preclinical models' efficiency and reducing the need for animal studies.

A Temperature-Controlled Apparatus for Gas Permeability under Low Gas Pressure

The measurement of soil gas permeability is influenced by the temperature and pressure fluctuation in the low gas pressure region. In order to investigate these influences, a soil temperature-controlled apparatus connected to a low-gas-pressure supply equipment is proposed in this study. The low constant gas pressure is supplied by two Mariotte bottles, by which the airflow rate is measured. Meanwhile, the soil specimen is controlled by a temperature-controlled apparatus. During the test, the negative pore water pressure and volume change of the soil specimen are measured. Through the temperature-controlled apparatus, it is observed that as the temperature increases from 25 °C to 60 °C, there is a corresponding increase in soil sample porosity by 5.4%, while the negative pressure of pore water decreases by 11.1%. This can be attributed to the reduction in the surface tension of contractile skin caused by elevated temperatures. Furthermore, due to variations in gas viscosity with temperature, there was a significant decrease in the gas flow rate by 50.5%. And, the relationship between permeability and volumetric gas content at different temperatures in low-pressure regions well confirms the existing power-law model. In addition, the existence of a temperature-independent critical negative pore water pressure is observed, beyond which the intrinsic permeability remains constant. At 36 kPa of negative pore water pressure, the intrinsic permeability at 60 °C exhibits an 81.8% reduction compared to that at 25 °C. This decline in intrinsic permeability can be attributed to a diminished pore connectivity, resulting from elevated temperatures.

Parallelogram Excision: An Algorithmic Approach for Excision Designs in High-Tension Skin Areas.

The excision of lesions that are not oriented along the skin tension lines may cause the surgeon to design extremely broad elliptical preoperative markings, with the intent to follow the tension lines as recommended for the best postoperative course and the best quality scars. The aim of this study is to describe and clinically apply a new surgical technique called the parallelogram excision technique, in which the traditional ellipse with a major axis parallel to the tension lines is converted into a parallelogram whose lesser sides are coincident with the local skin tension lines. This technique was specifically conceived for lesions whose major axis is non-coincident with skin tension lines, and the primary advantage is that it reduces the amount of healthy tissue excised. Preliminarily to this clinical study, a comparative geometrical analysis was conducted between various excision shapes and angles using Geometry Pad version 2.7.10 (Bytes Arithmetic LLC) and verifying the data obtained through AutoCAD 2D 2016 (Autodesk, San Rafael, CA, USA), with the purpose of optimizing the technique from a geometrical point of view. A comparison was performed between the theoretical traditional elliptical excision and the hypothetical parallelogram excision. A pilot proof of concept clinical study was performed to verify the validity of the excisional design proposed. The patients considered for parallelogram excision suffered from skin lesions with a diameter no greater than 4 cm and oriented 45° to 60° with respect to tension lines. In order to limit variability, patients' ages were between 40 and 80, and the selected areas were limbs, sternum and dorsum. Scar quality was assessed with the validated POSAS method at 6 months post-operation. The geometrical analysis of the parallelogram's design showed that it allows a diminution of the excised healthy skin compared to the traditional ellipse. The clinical series included 16 patients, with a mean age of 63.5. Of these, nine patients were men and seven were women. Diagnoses included basal cell carcinoma in seven cases, dysplastic naevus in five patients, Bowen's disease in three individuals, and one case where a wider excision of a malignant melanoma was performed. Six-month follow up results showed: (1) an uneventful postoperative course; (2) good scar healing with an observer's POSAS median score of 16 and a patient's POSAS median score of 19; and (3) complete excision of lesions. When indicated, the parallelogram excision technique appears to be a good option for the excision and primary closure of skin lesions that are not parallel to skin tension lines, since it allows a reproducible and surgeon-friendly method of preoperative marking and implies a favorable use of the local tension, which determines good quality scars. The amount of healthy tissue removed is smaller compared to traditional elliptic excisions.

Tension as a key factor in skin responses to pollution

Being the more apparent organ exposed to the outdoor stressors, the effect of pollution on the skin has been widely studied in the last few decades. Although UV light is known as the most aggressive stressor to which our cutaneous tissue is daily exposed, other components of the tropospheric pollution have also shown to affect skin health and functionality. Among them, ozone has been proven to be one of the most toxic due to its high reactivity with the epidermal lipids. Studying the cutaneous effect of pollution in a laboratory setting presents challenges, therefore it becomes critical to employ appropriate and tailored models that aim to answer specific questions. Several skin models are available nowadays: in vitro models (2D cell lines and 3D cutaneous tissues), ex vivo skin explants and in vivo approaches (animals and humans). Although in the last 20 years researchers developed skin models that closely resemble human skin (3D cutaneous tissues), ex vivo skin explants still remain one of the best models to study cutaneous responses. Unfortunately, one important cutaneous property that is not present in the traditional ex vivo human skin explants is the physiological tension, which has been shown to be a cardinal player in skin structure, homeostasis, functional properties and responses to external stimuli. For this reason, in this study, to confirm and further comprehend the harmful mechanism of ozone exposure on the integumentary system, we have performed experiments using the state of art in cutaneous models: the innovative TenSkin™ model in which ex vivo human skin explants are cultured under physiologically relevant tension during the whole experimental procedure. Specifically, we were interested in corroborating previous findings showing that ozone exposure modulates the expression of cutaneous antimicrobial peptides (AMPs). The present work demonstrates that cutaneous exposure to ozone induces AMPs gene and protein levels (CAMP/LL-37, hBD2, hBD3) and that the presence of tension can further modulate their expression. In addition, different responses between tension and non-tension cultured skin were also observed during the evaluation of OxInflammatory markers [cyclooxygenase-2 (COX2), aryl hydrocarbon receptor (AhR), matrix-metallo-proteinase 9 (MMP9) and 4-hydroxy-nonenal (4HNE)]. This current study supports our previous findings confirming the ability of pollution to induce the cutaneous expression of AMPs via redox signaling and corroborates the principle that skin explants are a good and reliable model to study skin responses even though it underlines the need to holistically consider the role of skin tension before extrapolating the data to real life.

The deep cervical fascia neck lift

The main and more frequent problem in face lift is recurrence of neck bands. To improve face lift stability, a new aging analysis is proposed. The visible sign of face aging is skin excess. Superficial musculo aponeurotic system (SMAS) retraction is a much less visible sign. Nevertheless, botulinum toxin injections elongate muscles of the SMAS and rejuvenate the face. In the Face Recurve Concept, MRI studies prove the mimic muscles retraction that comes with aging. Face lift techniques include SMAS plication, traction or excision, which increases discrepancy between the envelope, the skin and the core, the SMAS. As skin excision is poorly efficient because performed posteriorly, far from the anterior skin excess located at the medial neck, the association to SMAS retraction exacerbates the gradient difference between envelop and core. This analysis shows that it is paramount to preserve the SMAS. (1) The sub-skin dissection has to be executed moving beyond the marionette fold and the paramedian neck bands; (2) no action is performed on the SMAS, only an horizontal section of the platysma at the hyoid height that will avoid platysma band recurrence. A botulinum toxin injection performed herein just after, blocks muscle regeneration; (3) the skin is pulled backward with a clear posterior transposition to the platysma. The skin at the cervico-mental angle and all along the cervico-mental crease is fixed to the deep cervical fascia, in the gap between the edges of the sectioned platysma, blocking muscle recreation. A resorbable barbed thread is used, with a first bite made at the cervico-mental angle through the deep cervical fascia then in the direction of the mastoid, with long bites through the deep cervical fascia versus short subcutaneous bites. Thanks to this strong shift, the cervico-mental crease is definitely recreated with no need of pre-auricular skin tension. Thirty-two patients have been operated with this technique on a one-year period. The results are a lot more stable and swelling is lowered down to the minimum.

Cellulose-based bioabsorbable and antibiotic coated surgical staple with bioinspired design for efficient wound closure

The quest to design a flawless wound closure system began long ago and is still underway. Introducing surgical staples is one of the most significant breakthroughs in this effort. In this work, we developed a biodegradable surgical staple to meet the optimal wound closure system criteria and other clinical requirements, such as radiography compatibility and secondary infection prevention. To meet these requirements, a naturally derived cellulose acetate (CA) fiber-reinforced poly-(l-lactic acid) (PLLA) composite was synthesized, and its physicochemical properties were determined using several characterizations such as Fourier-transform infrared spectroscopy (FTIR), Differential scanning calorimetry (DSC) and Universal testing machine (UTM), etc. Taking cues from the Mantis's foreleg, a novel staple design was implemented and verified using Finite Element Analysis (FEA). The CA + PLLA staples were fabricated using melt-casted/3D-printing processes. The staples exhibited excellent biodegradation in both wound and physiological microenvironments with sufficient puncturing strength and later closed the wound's edges mechanically. In addition, the CA + PLLA staples also exhibit metal-like ductility properties to withstand horizontal skin tensions during the healing process. Further, the staples are coated with an antibiotic to combat infections effectively to provide better healing.

Nail unit incision lines: A tool to minimize nail unit scarring

Abstract Langer’s lines, lines of cleavage, and biodynamic excisional skin tension (BEST) lines have been defined for cutaneous surgery to ensure excisional wound closure with the least tension on any part of the body and minimize scarring. This article describes nail unit incision lines (NUIL) with a similar perspective. NUIL are followed by nail surgeons to help regrowth of a normal nail; however, they are not widely understood or respected during nail surgery. Within the anatomically small nail unit, the orientation of these lines varies depending on the area being operated upon. Nail bed incisions should be oriented longitudinally, while nail matrix incisions should be oriented horizontally. Being the germinative portion, nail matrix should be dealt with more cautiously, avoiding the lunular margin. Lateral nail fold incisions should be longitudinal, while proximal nail fold incisions should be radial. Distal nail fold (hyponychial) incisions should preferably be oriented parallel to the distal nail ridge. Knowledge and compliance with NUIL can help minimize scarring outcomes in nail surgery.

Characterization of the anisotropy of the natural human cheek skin tension in vivo

Natural skin tension plays an important role during surgical procedures and during the healing process especially for the face. The study of skin tension can be a means of assessing the aging effect, or the application of a medical or cosmetic product.In this work we propose a characterization of the natural human cheek skin tension in vivo and its variability with age using three characterization methods. These methods consist of facial photography to assess the ptosis of the lower face and the nasolabial fold, suction test to estimate mechanical parameters using the cutometer, and topographic analysis of the skin at rest and during folding test to study the skin relief.The study was carried out on 41 volunteers representing two age groups: 18 young volunteers [20–30] years-old and 23 elderly volunteers [50–65] years-old. The results show that the ptosis of the lower face and the nasolabial fold increase with age. The sagging of the skin observed on the facial photos is related to the loss of elasticity and the increase in the skin viscoelasticity with age. The analysis of the cheek skin relief shows that it has a very fine and flexible lines network. This analysis of the skin relief at rest and during the folding test allowed to determine the main directions of skin tension for the different age groups: [20°-40°] for the young group and [20°-60°] for the elderly group. The natural skin tension decreases with age, wrinkles appear and the skin becomes more anisotropic.

A non-invasive computational method to determine the directionality of skin tension lines

The topography of human skin surface has cutaneous lines or skin tension lines whose orientation depends on factors like age, cosmetic use, environmental conditions, etc. Characterizing the orientation of these lines is of immense importance for the cosmetics industry, medical technology and applications like haptics. In this study we propose a simple method based on the ratio of the correlation length to the root mean square roughness along several profiles to characterize the directionality of these lines. This ratio is then normalized across all the profiles leading to a polar plot that varies between 0 and 1, with the major orientation appearing at a value of 1. Our results show that this non-invasive computational approach can be applied to skin roughness data or image intensities. As a practical application of the approach, we demonstrate its ability to capture changes in skin tension line orientation with age, using roughness data from the literature.

Reconstruction of Large Full-Thickness Lower Eyelid Defects With Remnant Eyelid Rotation, Semicircular Skin and Muscle Flap, and Lateral Tarsoconjunctival Flap.

To describe and assess the results of reconstruction of large, full-thickness defects of the central or medial lower eyelid using a semicircular skin flap, rotation of the remnant lateral eyelid, and a lateral tarsoconjunctival flap. The surgical approach is described, and the authors performed a retrospective chart review of consecutive patients between 2017 and 2023 reconstructed with this technique. Outcomes were assessed for size of eyelid defect, vision, subjective symptoms, facial and palpebral aperture symmetry, eyelid position and closure, corneal examination, surgical complications, and need for subsequent surgical intervention. Postoperative appearance was graded on malposition, distortion, asymmetry, contour deformity, and scarring (MDACS). Charts of 45 patients were identified. The average size of the lower eyelid defect was 18 mm (ranging from 12 to 26 mm). Facial and palpebral aperture symmetry were acceptable and all patients had preserved visual acuity and eyelid position and closure. The MDACS cosmetic score was perfect (0) in 15.6% (7/45) of eyelids, good (1-4) in 80.0% (36/45) of eyelids, and mediocre (5-14) in 4.4% (2/45) of eyelids. Second stage reconstruction was not necessary in 32 (71.1%) cases. There were no serious surgical complications, but minor complications included redness of the eyelid margin and pyogenic granulomas. Medial rotation of the remnant lower eyelid with a lateral semicircular skin and muscle flap over a lateral tarsoconjunctival flap was very effective in this series. Benefits include scarring within the facial skin tension lines, maintained vision throughout the recovery period, no eyelid retraction, and often single stage reconstruction.

Gluconolactone in Cosmetic (Review Article)

Introduction: Hidroxy acid is one of the active substances that is widely used in the cosmetic field. Its use is very wide, but there are several classes of hydroxy acid that are irritative. The use of hydroxy acids can cause skin redness, itching, and tension in the skin. Other hydroxy acids are needed that can meet consumer needs without unwanted side effects. Method: This article uses research methods through literature search methods by collecting journals related to research objectives. Articles were found on Google Scholar's seaching engine as many as 27 articles. Objective: To determine the effectiveness of gluconolactone as a skin barrier, antiaging, and as an antiacne. Result and Discussion: The antioxidant effect of gluconolactone can also be used as a sunscreen by capturing free radicals formed when the skin is exposed to the sun. Conclusion: From the search it was found that gluconolacntone can act as a skin barrier protector, anti-acne as well as antianging

Nose tip defect reconstruction with a modified extended Rintala flap: A case report.

Nose tip defect reconstruction with a modified extended Rintala flap: A case report.

Influence of Aging, Sagging and Fat Mass on the Natural Skin Tension of the Human Upper Chest, Belly and Arm In Vivo

Influence of Aging, Sagging and Fat Mass on the Natural Skin Tension of the Human Upper Chest, Belly and Arm In Vivo

Teaching Models for Correct Rhombic Flaps.

The aim of this study was to introduce teaching models for correct rhombic flaps. For the line of maximal extensibility (LME) and flap design, surgical fabric (model 1), scored corrugated cardboard (model 2), and scored polyethylene sheet (model 3) were used. For choosing the correct flaps, a silicone face (model 4) was used. Seven participants in the Plastic Surgery Department were recruited for the workshop. In models 1 to 3, a 2-cm diameter circle and relaxed skin tension line were indicated. Participants were requested to design Limberg flaps. Each flap was elevated, transposed, and fixed with sutures (model 1) or cellophane tape (models 2 and 3). In model 4, a 1-cm diameter circle was indicated on the cheek. Participants were requested to design correct Limberg flaps. Although participants were not provided an article describing how to create correct Limberg flaps, they eventually created correct flaps through trial and error. Participants drew 2 parallel lines tangential to the defect and following the LME, perpendicular to the relaxed skin tension lines, which are the same as the scoring marks. They then drew 2 other sides of 2 possible parallelograms by tilting them medially and laterally with angles of 60 and 120 degrees each. Thus, 4 possible Limberg flaps to close the defect were drawn. Among the 8 possible flaps, 4 flaps that did not follow the LME were eliminated. Scored polyethylene sheet had the best extensibility and least distortion among the 3 models. Through this workshop, participants learned to design rhombic flaps correctly, using 2 parallel LMEs.