Suture Thread Research Articles

Automation of the wet disinfection process during the production of suture threads from natural collagen, catgut

Surgical sutures are the simplest yet most used medical devices in modern healthcare, they are the preferred type because of its biocompatibility and ability to be resorbed. Bovine intestinal fibers are converted into catgut that serves as the starting material of absorbable surgical suture threads. The mechanical and control subsystems of industrial equipment were designed to automate disinfection of bovine intestinal fibers to increase efficiency during the wet process stage of disinfection without altering its fiber quality. A turbulent regime of the water and disinfectant mix was designed, implemented and validated, this automatic aeration system in the disinfection thank increased the process efficiency by reducing the time used to handle a load of fibers by 50%, and the working time of the personnel involved in the process was reduced from 220 to 20 minutes. Tests on the final product showed that LAL levels comply with what is established by the American Pharmacopoeia: USP <85> Bacterial Endotoxin Test and USP <161> Medical Devices - Bacterial and Pyrogen Endotoxin Test. These results indicate that the disinfected catgut using the proposed automated system complies with all mechanical quality control tests.

Clinical oberservation on rotator cuff suture threader and strapping suture in meniscus tear under arthroscopy

To explore clinical effect of arthroscopic meniscus tear strapping suture by rotator cuff suture threader. Forty patients with meniscus tear injury admitted from July 2015 to May 2019, including 27 males and 13 females, aged from 20 to 55 years old with an average of (36.0±1.4) years old. Menisci laceration was sutured with rotator cuff suture thread under arthroscopy. Postoperative complication was observed, Lysholm knee joint score before and after operation at 12 months were used to evaluate clinical effects, visual analogue scale (VAS) and range of knee flexion and extension were applied to evaluate recovery of pain and function. All patients were followed up from 12 to 15 months with an average of (12.6±0.7) months.No complication such as joint effusion, suture failure occurred. Two patients occurred mild pain after activity without clinical physical abnormality, and 1 patient manifested moderate pain with joint space tenderness, the other rest without abnormal. Lysholm knee joint score was increased from (49.55±1.21) preoperatively to (98.95±0.42) at 12 months after operation, VAS score decreased from (5.18±0.78)preoperatively to (1.03±0.77) at 12 months after operation, and range of knee joint flexion and extension activity increased from (50.63±9.20)°preoperatively to (130.38±4.99)°after operation, and there were statistical differences in Lysholm knee joint score, VAS and range of knee joint flexion and extension activity (P< 0.05). Arthroscopic strapping suture by rotator cuff suture threading device applies to most meniscus injuries, including medial meniscus posterior horn tears, lateral meniscus body tears and lateral meniscus posterior horn tears. This technique meets the need of full-internal meniscus suture without specialmeniscus suture, and has advantages of convenient operation, less complications and good postoperative function.

Sundew-Inspired Adhesive Hydrogel Threads through Reversible Complexation of Polyphenol and Boronic Acid

Adhesive hydrogels have been utilized as tissue sealants, hemostatic agents, and wound dressings, with the aim of replacing conventional sutures. To prevent immune response and serious inflammation from those hydrogels after sealing, natural biocompatible polysaccharides are widely used as a component of the hydrogels. However, the weak mechanical strength, insufficient adhesiveness, and rapid dissociation of the hydrogels necessitates additional suturing at the wound site. In this study, we report on a solid polysaccharide thread reversibly crosslinked with boronic acid-polyphenol complexation and its adhesive gelation for complete tissue sealing without additional suturing. The polysaccharide adhesive suture threads demonstrated long-term stability, which is useful when used for skin wound suturing. Specifically, their robust adhesion property occurred as soon as the threads were soaked, attaining a swollen hydrogel state, dependent on the presence of body fluids after suturing. Moreover, the pH of the body fluids affects the viscoelasticity and adhesiveness of the hydrogels in order to ensure a tight sealing. Therefore, we expect that these pH-responsive adhesive threads would be promising for the development of on-demand functional suture materials.

Vaginal Cuff Closure with Dual-Arm Robot and Near-Infrared Fluorescent Sutures.

This paper presents a dual-arm suturing robot. We extend the Smart Tissue Autonomous Robot (STAR) with a second robot manipulator, whose purpose is to manage loose suture thread, a task that was previously executed by a human assistant. We also introduce novel near-infrared fluorescent (NIRF) sutures that are automatically segmented and delimit the boundaries of the suturing task. During ex-vivo experiments of porcine models, our results demonstrate that this new system is capable of outperforming human surgeons in all but one metric for the task of vaginal cuff closure (porcine model) and is more consistent in every aspect of the task. We also present results to demonstrate that the system can perform a vaginal cuff closure during an in-vivo experiment (porcine model).

Acute Cartilage Injury Induced by Trans-Articular Sutures.

ObjectiveTo determine the extent of acute cartilage injury by using trans-articular sutures.MethodsFive different absorbable sutures, monofilament polydioxanone (PDS) and braided polyglactin (Vicryl), were compared on viable human osteochondral explants. An atraumatic needle with 30 cm of thread was advanced through the cartilage with the final thread left in the tissue. A representative 300 μm transversal slice from the cartilage midportion was stained with Live/Dead probes, scanned under the confocal laser microscope, and analyzed for the diameters of (a) central “Black zone” without any cells, representing in situ thread thickness and (b) “Green zone,” including the closest Live cells, representing the maximum injury to the tissue. The exact diameters of suture needles and threads were separately measured under an optical microscope.ResultsThe diameters of the Black (from 144 to 219 µm) and the Green zones (from 282 to 487 µm) varied between the different sutures (P < 0.001). The Green/Black zone ratio remained relatively constant (from 1.9 to 2.2; P = 0.767). A positive correlation between thread diameters and PDS suturing material, toward the Black and Green zone, was established, but needle diameters did not reveal any influence on the zones.ConclusionsThe width of acute cartilage injury induced by the trans-articular sutures is about twice the thread thickness inside of the tissue. Less compressible monofilament PDS induced wider tissue injury in comparison to a softer braided Vicryl. Needle diameter did not correlate to the extent of acute cartilage injury.

Characterization of Sonic Hedgehog/Gli1 Signal Expression in Human Ureter Either Un-Stented or Fitted with Double-Pigtail Stent or a Thread.

IntroductionThe Sonic Hedgehog/Gli1 signal is involved in smooth muscle activity. An experiment showed that the double-pigtail stent caused ureteral inflammation and decreased Gli1 expression in smooth muscle cells. The innovative pigtail-suture stent (JFil® or MiniJFil®) with a thin 0.3F suture thread significantly decreased stent-related symptoms. Fortuitously, a dilation of the ureter containing the sutures was discovered, and a previous study confirmed that the sutures caused less ureteral inflammation than the double-pigtail stent. However, the mechanisms involved in the ureteral dilation are still unknown. In this study, we assessed ureteral Gli1 expression in the human ureter when it was un-stunted or when fitted with a double-pigtail stent or a suture thread.Material and MethodsAfter consent and inclusion of patients in the protocol, nine segments of ureters were collected during cystectomy procedures for bladder cancers. There was no selection or exclusion, and patients with large tumors were included. Gli1 expression was assessed on the histological section to control the reflection of an active hedgehog signal. The expression of Gli1 in smooth muscle cells of the stented ureter was subjectively compared to un-stented ureter.ResultsA decrease in the intensity of Gli1 expression of smooth muscle cells was observed in all cases of ureter fitted with a double-pigtail stent. For the un-stunted ureters and the ureters fitted with the thin 0.3F suture thread, Gli1 staining of smooth muscle cells was heterogeneous, and the small number of cases did not allow us to conclude.ConclusionApart from the cases of ureters fitted with the double-pigtail stent, Gli1 expression of smooth muscle was heterogeneous. The Shh/Gli1 pathway may not be involved in ureteral dilation by the thread. A broader exploration of molecular mechanisms could make it possible to obtain the mechanisms involved in the dilation of the ureter by the thread.

Fixation of free gingival grafts with cyanoacrylate glues: A histomorphometric and immunohistochemical study

AimThe objective of this study was to evaluate the inflammatory process resulting from the use of two cyanoacrylate-based adhesives to stabilize grafts. MethodologyA total of 45 male Wistar rats were randomly divided into three groups (n = 15/group) treated with ethyl cyanoacrylate glue (TG1), octyl-2-cyanoacrylate glue (TG2) or suture threads (CG). After de-epithelialization in the anterior gingival region of the mandible, the graft was removed from the donor site (hard palate), taken to the recipient site and stabilized according to the protocol of each group. After 7, 14, and 45 days, the animals were euthanized. The graft area was analysed macroscopically, histologically, histochemically (Masson trichrome), and immunohistochemically positive cell count for TGF-β, α-SMA, RANKL, OPG, FGF, and IL-10. The Kruskal-Wallis/Dunn test (SPSS 20.0, p < 0.05) was used for analysis. ResultsThere was no difference in the clinical parameters among the three groups, but TG1 showed the lowest mononuclear inflammatory cell count and the highest amount of total collagen. FGF immunoexpression was significantly higher for the CG group, but the TG2 showed a significant reduction in the RANKL/OPG ratio. ConclusionTG1 had a mild inflammatory response and a higher collagen deposition than other glues, and TG2 had a reduction in the RANKL / OPG ratio.

Suture thread: An unusual etiology of tracheal pseudotumor

A 66-year-old man ingested sodium hydroxide in a suicide attempt in June 2018. In emergency room, he presented burning of the tongue and uvula and supraglottic and vocal cords edema. Because of the risk of airway obstruction, the patient underwent endotracheal intubation and started invasive mechanical ventilation. Five days later, a surgical tracheostomy was performed due to a large laryngeal necrosis including extensive epligottis involvement. After prolonged mechanical ventilation through tracheostomy, the patient presented a favorable clinical course allowing ventilator weaning and decannulation 2 months after initial presentation. In February 2019, cervical Computed Tomography (CT) revealed a polypoid lesion occupying 25% of the tracheal lumen, with contrast uptake and suggestive of malignant etiology (Figure 1A-B). The patient was asymptomatic. Rigid bronchoscopy showed that the pseudotumoral tracheal lesion corresponded to granulation tissue around suture thread from the previous tracheostomy, which were successfully removed during the procedure (Figure 1C-E). Pathological examination showed granulation tissue with extensive inflammatory infiltrate and foreign-body giant cell reaction.

New Strategies for the Development of Multifunctional Suture Threads

AbstractSurgical site infection (SSI) is one of the most frequently reported types of hospital‐acquired infections, associated with severe morbidity and sometimes mortality. It leads to an increase in the clinical and economic burden of surgery, due to the direct costs incurred by prolonged hospitalization, diagnostic tests, outpatient visits, systemic antibiotic treatments, and often reoperations. The SSI is frequently caused by the suture threads material which can become an infection vector. The present mini‐review shows how the research is bringing new skills and knowledge in the design of new suture threads for SSI prevention and the wound healing process improvement.

Micro‐marsupialization technique with suture thread modification for improving the management of oral mucoceles and ranulas: A case series

AbstractAimMicro‐marsupialization is a technique that can be applied in the treatment of mucoceles located on the floor of the mouth (ranula), lower lip or ventral surface of the tongue. The technique is simple, low cost, little invasive and consists of using sutures to promote mucous drainage. Absorbable sutures may have advantages over regular silk sutures. Herein, we report a case series of oral mucoceles and ranulas treated by the micro‐marsupialization technique using synthetic absorbable suture thread.Material and methodsThe convenience sample consisted of five individuals, three males and two females.ResultsThree individuals had a clinical diagnosis of oral mucoceles and two of ranulas. The treatment resulted in the resolution of all cases. Although there was a slight accumulation of plaque, no signs of inflammatory reaction, pain, bleeding, or recurrence were observed after at least 30 months of follow‐up.ConclusionsThis study demonstrated that the use of absorbable suture thread during micro‐marsupialization can be beneficial, mainly because of its similar performance compared to conventional silk suture thread, without the need for removal.

Determination of total and extractable amount of aluminum, copper, zinc, and lead in surgical suture threads by electrothermal atomic absorption spectrometry

Polymer-based materials such as surgical suture threads are the most important raw materials used in the manufacturing of medical devices. Determination of metal contamination in industrial surgical threads such as absorbable polydioxanone (PDO) and polyglycolic acid (PGA), and nonabsorbable polypropylene (PP) is very important for human health. Concentrations of aluminum, copper, zinc, and lead released from these surgical suture samples into various solutions were determined. The effects of parameters such as solvent type, temperature, pH of solvent, and time for release of these metals from the samples were investigated to determine optimum conditions. The extractable and total amount of aluminum, copper, zinc, and lead in PDO, PGA, and PP samples were performed by using electrothermal atomic absorption spectrometry. The aluminum, copper, zinc, and lead in certified standard material solution (IQC-026 mixture) were determined for the accuracy of the method. Limits of detection and quantification values of analytes found were 2.8 and 9.3 µg L−1 for aluminum, 1.5 and 5.0 µg L−1 for copper, 1.5 and 5.0 µg L−1 for zinc, and 2.9 and 9.7 µg L−1 for lead, respectively.

Comparison of Efficacy of Povidone-Iodine, Ethanol, and an Aerosol Formulation of Silver Sulfadiazine in Controlling Microbial Burden on Sutures From Clean Surgeries.

In the surgical suture, the implanted thread can be a source of microbial contamination. Implanted materials are frequently described as being substrates prone for biofilm development provoking surgical site infections. Treatment of postsurgical wounds with different topical antimicrobial agents is a current practice applied to every patient. However, to date, there is little evidence on the efficacy of different antiseptic treatments on suture materials in preventing environmental or skin bacterial adhesion and further infection. Here, the authors compared the ability of an aerosol formulation of silver sulfadiazine, vitamin A, and lidocaine (AF-SSD) and of two of the most frequently used topical treatments, povidone-iodine and ethanol, in eradicating or controlling the microbial contamination of suture threads in patients who have undergone clean surgeries. Postsurgical suture threads treated with AF-SSD showed a significantly reduced proportion of contaminated samples containing viable microbial cells compared with those treated with povidone-iodine or ethanol. Furthermore, those samples that were positive for bacterial growth showed a lesser number of viable cells in AF-SSD-treated sutures than those treated with povidone-iodine or ethanol. Confocal laser scanning microscopy showed that AF-SSD-treated postsurgical sutures presented significantly less attached microbial cells than povidone-iodine and ethanol, with scarce observable microbial cells on the surface of the suture. Taken together, the results suggest that treatment with AF-SSD is more effective than the other two antiseptics, and there is a potential for improvement in reducing the microbial burden of implanted materials such as the suture thread.

Protective Effect of Hydroalcoholic Extract of Stachys pilifera on Oxidant-Antioxidant Status in Renal Ischemia/Reperfusion Injuries in Male Rats.

Background Renal ischemia-reperfusion (I/R) has a pivotal role in the progression of acute renal failure. Reactive oxygen species are considered the major constituents involved in the biochemical and pathophysiological changes that were shown during kidney I/R. The purpose of this study was to examine the renoprotective effects of Stachys pilifera ethanolic extract on oxidant-antioxidant status in renal I/R-injuries in male rats. Material and methods. Twenty-one male Wistar rats were arbitrarily distributed into 3 groups: sham control (SC), I/R, and I/R + Stachys pilifera ethanolic extract (500 mg/kg). The artery and vein of the right kidney were completely blocked, and the right kidney was completely removed in all groups. Then, the left kidney artery was blocked with suture thread for 30 minutes in only I/R and I/R + SP extract groups. Kidney function indices, oxidative stress markers, and hematoxylin and eosin staining were investigated in the plasma and kidney tissues. Results It was shown that the urine Na and K, fractional excretion of Na and K, and protein carbonyl content markedly increased in the merely I/R group as compared to SC rats, while the administration of SP extract markedly reduced these indices (P < 0.05). Also, glomerular filtration rate and total thiol meaningfully reduced in the I/R rats in contrast to the SC group, while the treatment with SP extract markedly augmented these indices (P < 0.05). However, in agreement with renal function tests, SP extract had no significant effects on histopathological examinations. Conclusion It seems that SP extract employs renoprotective effects on renal damage induced by I/R, possibly by improving of oxidant-antioxidant status in favor of the antioxidant system.

Evaluation of Biomechanical Traction of Incisional Gastropexy and Scarification Gastropexy Techniques in Dogs

Background: Gastropexy is used to correct gastric dilation, a disease that usually affects large and giant dogs and leads to death in 23.4 - 43% of patients. This study aimed to evaluate the biomechanical traction of 2 gastropexy techniques, incisional gastropexy and scarified gastropexy, in 10 dog cadavers. Incisional gastropexy comprises a single incision in the abdominal wall and another incision in the stomach wall in the pyloric region followed by simple continuous sutures. The scarification technique creates scarification along the stomach borders of the pexy. Thereby, knowing that both techniques are successful, the biomechanical traction of each technique was compared.Materials, Methods &amp; Results: A total of 10 animals without defined breed weighing from 6.4-43.0 kg were allocated into 2 equal groups (GE [scarified gastropexy] and GI [incisional gastropexy]). Incisional gastropexy was performed with a simple continuous suture pattern in the GI group and scarified gastropexy with an interrupted simple suture pattern was performed in the GE group. Absorbable 2-0 monofilament yarn (polygllecaprone 25) was used for sutures in both groups. Rectangular segments of the gastric antrum were collected from the right abdominal wall and from the bottom of the stomach at the left abdominal wall, which were subjected to a traction test. The scarification technique was easier, faster, and used less surgical sutures than the incisional technique. Both techniques were effective regardless of the site applied, with no significant differences. There was a difference in stretching depending on location.Discussion: The pathogenesis of gastric dilatation volvulus (GDV) is unknown. However, gas accumulation inside the gastric chamber may lead to organ dilation and consequently cause torsion of the cardia region and pyloric antrum, resulting in strangulation of blood vessels and nerves. This torsion could cause stomach ischemia followed by organ necrosis if early emergency care is not provided. In addition, vessel strangulation my lead to a systemic syndrome resulting in shock. The disease presents acute and non-specific clinical signs such as weight loss, vomiting, and abdominal intumescence. Patients with risk factors such as reduced gastric motility, delayed stomach replenishment, lower weight, advanced age, or presence of a foreign body may present with poor prognosis. Once GDV becomes an emergency, surgical correction with the most efficient surgical techniques and procedures is necessary to guarantee patient survival. Based on the results obtained, both the scarified and incisional gastropexy techniques are more efficient than other techniques. In addition, the scarified technique with interrupted simple stitches stood out when compared to the incisional technique with a continuous simple suture pattern as it was faster and used less suture thread. The incisional technique, on the other hand, provides good juxtaposition of the edges of the wounds, avoiding the exposure of muscle tissue, as well as adhesions from other organs. The knowledge of those factors promotes positive effects on the effectiveness of an emergency surgical approach for patients with GDV, since it allows less surgical time, as well as less anesthetic time. Based on the results obtained during the biomechanical traction tests of the study, it was concluded that both scarified gastropexy with interrupted single stitches and incisional gastropexy with a continuous single stitch may be efficient. The scarified technique stood out when compared to the incisional technique as it required less time and used less sutures.

How I Do It: Inferior Turbinectomy: Modified Techniques for Submucosal Resection.

Although inferior turbinectomy with submucosal resection effectively reduces the volume of the inferior turbinate, there is room for improvement in surgical procedures. Techniques have been developed to reduce crusting and bleeding while efficiently achieving volume reduction. State-of-the-art procedures pertaining to the local injection site, incision line, exposure of the periosteum, submucosal outfracture of the turbinate bone, trimming of redundant mucosa, and incision line suturing are described. Pre and postoperative Nasal Obstruction Symptom Evaluation (NOSE) scores and postoperative inferior turbinate bleeding and crusting were evaluated. For the 18 consecutive patients analyzed, the pre and postoperative NOSE scores were 67.8 ± 14.8 and 16.1 ± 13.0, respectively (P = .0002). Postoperatively, bleeding was absent, and only minor suture thread crusting was observed in 13 patients. In conclusion, our novel technique improves the effectiveness of surgery as well as the postoperative quality of the inferior turbinate.

Buyang Huanwu Decoction Enhances Revascularization via Akt/GSK3β/NRF2 Pathway in Diabetic Hindlimb Ischemia.

Background Peripheral arterial disease (PAD) is a typical disease of atherosclerosis, most commonly influencing the lower extremities. In patients with PAD, revascularization remains a preferred treatment strategy. Buyang Huanwu decoction (BHD) is a popular Chinese herbal prescription which has showed effects of cardiovascular protection through conducting antioxidant, antiapoptotic, and anti-inflammatory effects. Here, we intend to study the effect of BHD on promoting revascularization via the Akt/GSK3β/NRF2 pathway in diabetic hindlimb ischemia (HLI) model of mice. Materials and Methods All db/db mice (n = 60) were randomly divided into 6 groups by table of random number. (1) Sham group (N = 10): 7-0 suture thread passed through the underneath of the femoral artery and vein without occlusion. The remaining 5 groups were treated differently on the basis of the HLI (the femoral artery and vein from the inguinal ligament to the knee joint were transected and the vascular stump was ligated with 7-0 silk sutures) model: (2) HLI+NS group (N = 15): 0.2 ml NS was gavaged daily for 3 days before modeling and 14 days after occlusion; (3) HLI+BHD group (N = 15): 0.2 ml BHD (20 g/kg/day) was gavaged daily for 3 days before modeling and 14 days after occlusion; (4) HLI+BHD+sh-NC group (N = 8): local injection of adenovirus vector carrying the nonsense shRNA (Ad-GFP) in the hindlimbs of mice before treatment; (5) HLI+BHD+sh-NRF2 group (N = 8): knockdown of NRF2 in the hindlimbs of mice by local intramuscular injection of adenovirus vector carrying NRF2 shRNA (Ad-NRF2-shRNA) before treatment; and (6) HLI+BHD+LY294002 group (N = 4): intravenous injection of LY294002 (1.5 mg/kg) once a day for 14 days on the basis of the HLI+BHD group. Laser Doppler examination, vascular cast, and immunofluorescence staining were applied to detect the revascularization of lower limbs in mice. Western blot analysis was used to detect the expression of vascular endothelial growth factor (VEGF), interleukin-1beta (IL-1β), interleukin-6 (IL-6), tumor necrosis factor- (TNF-) α, heme oxygenase-1 (HO-1), NAD(P)H dehydrogenase quinone-1 (NQO-1), catalase (CAT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), phosphorylated protein kinase B (p-AKT), and phosphorylated glycogen synthase kinase-3 beta (p-GSK3β). HE staining was used to assess the level of muscle tissue damage and inflammation in the lower extremities. Local multipoint injection of Ad-NRF2-shRNA was used to knock down NRF2, and qPCR was applied to detect the mRNA level of NRF2. The blood glucose, triglyceride, cholesterol, MDA, and SOD levels of mice were tested using corresponding kits. The SPSS 20.0 software and GraphPad Prism 6.05 were used to do all statistics. Values of P < 0.05 were considered as statistically significant. Results and Conclusions. BHD could enhance the revascularization of lower limbs in HLI mice, while BHD has no effect on blood glucose and lipid level in db/db mice (P > 0.05). BHD could elevate the protein expression of VEGF, HO-1, NQO-1, and CAT (P < 0.05) and decrease the expression of IL-1β, IL-6, and TNF-α (P < 0.05) in HLI mice. Meanwhile, BHD could activate NRF2 and promote the phosphorylation of AKT/GSK3β during revascularization (P < 0.05). In contrast, knockdown of NRF2 impaired the protective effects of BHD on HLI (P < 0.05). LY294002 inhibited the upregulation of NRF2 activated by BHD through inhibiting the phosphorylation of the AKT/GSK3β pathway (P < 0.05). The present study demonstrated that BHD could promote revascularization on db/db mice with HLI through targeting antioxidation, anti-inflammation, and angiogenesis via the AKT/GSK3β/NRF2 pathway.

A novel suturing technique, based on physical principles

Introduction: In medicine, sutures have been used for thousands of years to close wounds. However, despite the great advances that have been made in technology, little progress has taken place in suturing techniques and most surgeons continue to use the same two classical techniques (continuous suture or interrupted suture). This paper proposes a suturing technique (“double diabolo”) in which a pattern of eight 45-degree angles is formed, in the view that this achieves a notable reduction in the tension exerted (30% at each angle), thereby increasing the overall strength of the suture. Material and Method: In this study, we compare the physical tensions exerted on the suture thread and its entry/exit points, on the one hand by the two techniques most often used – interrupted suture (Type 1) and continuous suture (Type 2) – and on the other, by the proposed “double-diabolo” suture (Type 3). Results: The Type 3 suturing method produced the lowest levels of tension on the thread, almost 65% less than those of Type 1 and 50% less than those of Type 2. The tension on the wound was also considerably lower, with reductions of 33% and 50% in comparison with Types 1 and 2, respectively. Conclusions: The results obtained in this study corroborate our hypothesis that the proposed double-diameter suture method exerts less tension on the thread and on the entry/exit points than conventional techniques. Theoretically it would be recommended for cases in which the suture must withstand significant tension as laparotomy closure

A predictive micromechanically-based model for damage and permanent deformations in copolymer sutures

An effective description of the mechanical behavior of biodegradable copolymers suture threads requires the analysis of their response under cyclic loading and the prediction of the fundamental damage and residual stretches effects. In this paper we propose a micromechanically-based model adopting a new form of Worm Like Chain free energy for the copolymer chains, which takes care of the insurgence of residual stretches on the basis of a rigorous statistical mechanics result. Under the affinity hypothesis we subsequently derive the macroscopic response of the material. The obtained model has a clear physical interpretation and depends on a small number of parameters, which can be fitted by a simple uniaxial test. The effectiveness of the theoretical results has then been verified by performing cyclic tests on Monocryl® monofilament sutures and showing the ability of the model in predicting with high accuracy the history dependence, the damage and permanent deformations in the obtained response.

Влияние ионизирующего излучения на свойства нетканого спанмелт-материала на основе полипропилена

Currently, polypropylene is one of the most common polymers in the world. Due to its resistance to high temperatures, strength and density, it has found very wide application in the field of medicine. Polypropylene produces medical devices, pharmaceutical packaging, containers, suture threads. But a special place is occupied by non-woven materials based on polypropylene: surgical underwear, surgical gowns. As you know, to sterilize these products using ionizing radiation, which is the most effective of all methods. However, it leads to the destruction of polypropylene, as a result of which its physical and mechanical properties deteriorate. It is also known that the dose of radiation can vary depending on the location of the product in the box. Thus, materials can be degraded to varying degrees depending on the location in the box from the electronic emitter. As the object of study was selected: PP 1562R polypropylene produced by OAO Nizhnekamskneftekhim. It has been established that the location of polypropylene samples upon irradiation has little effect on the degree of their destruction.

Technique of Totally Tubeless Percutaneous Nephrolithotomy with a Safety Suture Thread

Abstract Introduction: Placement of a nephrostomy tube at the conclusion of percutaneous nephrolithotomy (PCNL) has been traditionally considered a standard practice. However, in the past decade, t...