Assessment of the Impact of Commonly used Beverages on Durability of Suture Materials: An In Vitro Study

Aim

The current study was conducted to evaluate the influence of frequently ingested beverages on the stability of suture materials.

Materials and Methods

This research comprised of two kinds of chromic catgut, polyglactin 910 (4-0) absorbable suture materials. Every specimen was subjected to tying using a square surgeon's knot. Subsequent to pretensioning, 80 suture samples (40 of every material) were employed in this research. Every specimen was subjected to immersion in artificial saliva to replicate the oral atmosphere. Specimens were sunken in the acidic drink (Coca Cola) and tea for 10 min every day. Tensile strengths of the suture specimens were subjected to test at particular time periods: before immersion and 1, 7, and 14 days after immersion. Tensile strength evaluation of the suture specimens was performed employing the microtensile tester at a cross-head speed of 2.0 mm/60 s.

Results

When subjected to exposure to acidic beverages, the tensile strength of chromic catgut suture before immersing was 25.14 ± 0.16, 25.02 ± 0.08 on the first day, 16.34 ± 0.23 on the seventh day, and 9.18 ± 0.28 on the fourteenth day. When the suture substance made contact with tea, the tensile strength before immersing was 24.48 ± 0.02, 24.14 ± 0.16 on the first day, 18.26 ± 0.11 on the seventh day, and 12.39 ± 0.14 on the fourteenth day. When subjected to exposure to acidic beverages, the tensile strength of polyglactin 910 sutures before immersing was 25.21 ± 0.02, 25.08 ± 0.01 on the first day, 18.12 ± 0.06 on the seventh day, and 10.06 ± 0.32 on the fourteenth day. When the suture substance made contact with tea, the tensile strength before immersing was 25.02 ± 0.14, 24.96 ± 0.04 on the first day, 20.48 ± 0.18 on the seventh day, and 14.10 ± 0.08 on the fourteenth day. The differences between the groups were statistically significant.

Conclusion

In conclusion, polyglactin 910 exhibited a maintained strength superior than chromic catgut sutures subsequent to 14 days.

Intracranial pressure monitoring in neurosurgery: the present situation and prospects

Intracranial pressure (ICP) is one of the most important indexes in neurosurgery. It is essential for doctors to determine the numeric value and changes of ICP, whether before or after an operation. Although external ventricular drainage (EVD) is the gold standard for monitoring ICP, more and more novel monitoring methods are being applied clinically.Invasive wired ICP monitoring is still the most commonly used in practice. Meanwhile, with the rise and development of various novel technologies, non-invasive types and invasive wireless types are gradually being used clinically or in the testing phase, as a complimentary approach of ICP management. By choosing appropriate monitoring methods, clinical neurosurgeons are able to obtain ICP values safely and effectively under particular conditions.This article introduces diverse monitoring methods and compares the advantages and disadvantages of different monitoring methods. Moreover, this review may enable clinical neurosurgeons to have a broader view of ICP monitoring.

Rates of complications in Achilles tendon rupture repair using absorbable and nonabsorbable suture material; A systematic review

BACKGROUND

The impact of suture type on tensile strength, re-rupture rates and infection risk in Achilles tendon rupture repair is not been well established. The aim of this review is to evaluate existing literature on the associated risk of postoperative infection with absorbable and non-absorbable suture materials in Achilles tendon rupture repair.

METHODS

A systematic review of search databases PubMed; Google Scholar; and OVID Medline was made to identify studies related to complications associated with Achilles tendon rupture repair. PRISMA guidelines were utilised for this review. Meta-analysis was used to compare rupture rates and infections following rupture repair.

RESULTS

12 studies with a total of 460 patients, 230 in both nonabsorbable and absorbable suture groups were included for analysis. Risk of wound complications was significantly higher in patients with non-absorbable sutures (p < 0.001).

CONCLUSION

Nonabsorbable braided sutures is associated with the highest risk of postoperative wound complications following Achilles tendon rupture repair.

Evaluation of self-prepared absorbable hemostatic cellulose fibrils

To evaluate the effectiveness and safety of self-prepared absorbable hemostatic fibrils.A kind of absorbable hemostatic fibrils were prepared by self-developed patent technique. The physical form and molecular structure of the fibrils and a marketed product Surgicel were characterized by general observation and infrared spectroscopy; the carboxyl content, pH value and relative molecular mass of fibrils were determined by potentiometric titration method, pH meter and copper ethylenediamine method, respectively. The behavior of the fibrils and Surgicel in contact with blood was observed by inverted microscope, the cytotoxicity was evaluated by agarose diffusion cell assay . The external iliac artery hemorrhage model and the back muscle infiltration model in rats were established. The hemostatic effectiveness of the fibrils was investigated by hemostasis time and blood weight, and the degradation and biosafety of fibrils were investigated by observation photography, immune organ weighing, hematology and coagulation index measuring, and histopathological examination. The fibrils and Surgicel had similar molecular structures. Compared with the raw material regenerated cellulose, the typical carboxyl stretching vibration absorption peak of -COOH appeared near in both fibrils and Surgicel. The carboxyl content of the two materials was about 20%, and the pH value was about 3. The relative molecular mass of the fibers after oxidation was 4466±79, which was close to that of Surgicel(>0.05). After contacting with blood, the volume of fibrils and Surgicel expanded, and absorbed blood of dozens of times as their own weight. The results of agar diffusion test showed that the fibrils had no cytotoxicity. The results of animal experiments showed that the hemostasis completed within and there was no significant difference in blood weight and speed of hemostasis between two products (both >0.05). The fibrils could be degraded 1 week after being implanted to the bleeding sites of the muscle. There were no pathological effects on the appearance, body weight, food intake, immunological tissue thymus, spleen, lymph nodes, hematology and coagulation indexes of the rats, and no obvious abnormality found in the histopathological examination. The prepared absorbable hemostatic fibrils have excellent biological safety and effectiveness.

Comparison of Absorbable Packing versus No Packing in Wound Healing after Endoscopic Sinus Surgery: A Systematic Review and Pooled Analysis

INTRODUCTION

Nasal packing after endoscopic sinus surgery (ESS) is controversial. The aim of this systematic review was to compare absorbable packing versus no packing in wound healing after ESS for the treatment of chronic rhinosinusitis.

DATA SOURCE

English electronic databases, including Cochrane Library, EMBASE, MEDLINE, and PubMed, were searched, and only randomized controlled trials were included.

METHODS

The outcome measures were the presence of synechiae/adhesion formation, mucosal edema, crusting, granulation formation, and infection. The McNemar's test was used for pooled analysis.

RESULTS

Four studies with 148 participants were included. The pooled analysis showed that absorbable packing may offer benefit in reducing adhesion at 6-8 weeks (odds ratio [OR]: 0.3864; 95% confidence interval [CI]: 0.2136-0.7235) and 12 weeks (OR: 0.2396, 95% CI: 0.08267-0.7709) postoperatively compared with no packing. There was no significant difference between the packed and the unpacked side at 2, 6-8, and 12 weeks after ESS in terms of presence of crusting, edema, and granulation formation.

CONCLUSION

There is insufficient evidence to suggest that absorbable packing after ESS does not increase mucosal edema, granulation formation, and infection. However, the absorbable packing may be more effective than no packing for the prevention of mucosal adhesion after ESS. The use of absorbable nasal packing after ESS is recommended when used to reduce postoperative mucosal adhesion. More research in this area is clearly needed.

Evaluation of the histological and biomechanical properties of poly-4-hydroxybutyrate scaffold for pelvic organ prolapse, compared with polypropylene mesh in a rabbit model

INTRODUCTION AND HYPOTHESIS

Poly-4-hydroxybutyrate (P4HB) is a biopolymer produced by Escherichia coli K12 bacteria. P4HB is fully resorbed in vivo by 18-24 months post-implantation. The aim of this study is to evaluate P4HB in the rabbit abdomen and vagina to determine that the biomechanical and histological properties are similar to the standard polypropylene mesh. Our hypothesis is that the histological and biomechanical properties of a fully absorbable graft will be similar to a lightweight polypropylene (PP) mesh when implanted in rabbit vagina and abdomen.

METHODS

Sixteen (n = 16) female New Zealand White (retired breeder) rabbits were equally divided between two time points (3 and 9 months). A total of 17 rabbits were used owing to one death secondary to suspected cardiomyopathy. P4HB scaffold and PP mesh were subcutaneously and peri-vaginally implanted into the rabbit abdomen and vagina respectively. All rabbits had both posterior and anterior vaginal implants, and half of the rabbits had four abdominal implants in addition to the vaginal implants. The abdominal implants were 4.5 cm long × 1.5 cm wide whereas the vaginal implants were 1.5 cm long × 0.5 cm wide. At 3 and 9 months, gross necropsy was performed and samples were obtained, sectioned, stained and evaluated via histological analysis. Specimens were assessed for host inflammatory response, neovascularization, elastin content, and collagen deposition/maturation. Specimens were also biomechanically evaluated via uniaxial tensile test to determine the stiffness, ultimate tensile strength and load at ultimate tensile strength of the device/tissue composite.

RESULTS

No abdominal mesh exposures were noted. A comparable number of asymptomatic partial vaginal exposures were observed at 3 months (P4HB: n = 3; PP: n = 2) and 9 months (P4HB: n = 3; PP: n = 2) respectively. Histological analysis of specimens showed comparable results in the P4HB and PP groups at 3 and 9 months post-implantation. Although no acute inflammation was seen, chronic inflammation was demonstrated in all specimens. Elastic fibers were present in the 3-month vaginal PP and P4HB specimens, but were not seen again. There was an increase in type I/III collagen noted over time. Biomechanical evaluation of the vaginal mesh tissue complex showed ultimate tensile strength was not significantly different between P4HB and PP groups at 3 (P = 0.625) and 9 months (P = 0.250) respectively.

CONCLUSIONS

P4HB scaffold may represent a fully absorbable alternative to permanent mesh for pelvic organ prolapse (POP) repair.

A review of preclinical absorbable inferior vena cava filters

OBJECTIVE

Absorbable inferior vena cava filters (IVCFs) could be more effective and safer than standard IVCFs in theory, as they will self-resorb over time, thus rendering the need for filter retrieval and the risks associated with it unnecessary. This scoping review aims to evaluate the design of current absorbable IVCFs, review the development phase of the absorbable IVCFs, assess the efficacy of the absorbable IVCFs and their complications, and discuss the limitations and areas for future research.

METHODS

MEDLINE, PubMed, and Embase databases were electronically searched and citations of relevant studies manually searched. Study selection and data extraction were performed by two independent reviewers using predetermined criteria and stored on premade proforma, respectively. The risk of bias (RoB) for both in vitro and in vivo studies were performed using established RoB tools.

RESULTS

Eight studies were suitable for inclusion in this scoping review; five were in vivo and three were in vitro studies. No clinical trials were found. The RoB varied from moderate to high for in vivo studies and from low to moderate for in vitro studies. Overall, there was evidence from both in vivo and in vitro studies that absorbable IVCFs were effective in clot capturing and self-resorption and could decrease complications associated with standard IVCFs. However, there was a broad lack of statistical analyses and control groups to determine the significance of these findings.

CONCLUSIONS

Absorbable IVCFs have shown promising features and results in preclinical models. However, significant research needs to be further performed to achieve the ideal characteristics of an absorbable IVCF before the first human trial can be conducted safely.

The use of bioabsorbable compression screws & polyethylene tension band for fixation of displaced olecranon fractures

INTRODUCTION

Transverse fractures of the olecranon are commonly fixed using tension-band wiring techniques. However the superficial nature of this area leads to high complication rates requiring removal of metalwork. The purpose of this retrospective study is to report and evaluate functional outcomes of polyethylene tension-band and bioabsorbable Magnesium alloy screw fixation of olecranon fractures.

METHODS

A retrospective case-control study was undertaken. Demographics, injury type and post-operative details were collected. All patients were treated in the same institution by a single surgeon. Primary outcomes included radiographic healing and post-operative range of motion. Secondary outcome was post-operative complications.

RESULTS

A total of five cases were identified. Mean age was 52.4. The control group was made up of six patients treated with a traditional tension band wire fixation. One patient in study group was lost to follow up. 80% of fractures in study group demonstrated anatomic post-operative radiographic union, compared with 83% of control group. All patients had range of motion above 100°, with full protonation and supination. One patient did have an extension lag of 15°.

CONCLUSION

Surgical repair of olecranon fractures is often complicated by the need for re-operation. This method provides both intramedullary fixation and conversion of distraction forces to compression forces with bioabsorbable materials, and aims to reduce the high re-operation rates commonly seen by avoiding the use of permanent indwelling metal hardware.

Mechanical and Histological Characteristics of Phasix™ ST Mesh in a Porcine Model of Hernia Repair

PURPOSE

The objective of this study was to determine mechanical and histological properties of Phasix™ ST Mesh in various defect sizes and characterize the tissue replacing Phasix™ ST Mesh in a porcine model of ventral hernia repair.

METHODS

Simulated hernia defects were surgically created in the midline of twenty-four (n = 24) Yucatan pigs. Treatment groups included 8 cm defect sutured closed (buttress) and unclosed 4 cm and 8 cm defect groups. Phasix™ ST Mesh (15 cm diameter circle) was implanted laparoscopically and fixated circumferentially with SorbaFix™ Absorbable Fixation System fasteners. The repair sites underwent mechanical, molecular weight, and histological evaluation at 48 and 72 weeks postimplantation.

RESULTS

Mechanical testing of Phasix™ ST Mesh-repaired sites revealed similar strengths at both time points for all three repair types, p > 0.05 in all cases (48 weeks: 142.4 ± 6.0 N, 142.3 ± 16.5 N, and 168.8 ± 38.5 N; 72 weeks: 110.0 ± 18.3 N, 138.6 ± 42.2 N, and 160.6 ± 42.0 N for 4 cm defect, 8 cm defect, and 8 cm buttress, respectively. mean ± SEM) No significant differences were observed over time except at 72 weeks postimplantation when the 4 cm defect group exhibited significantly lower strength than the T₀ strength of Phasix™ ST Mesh (204.6 ± 5.0 N, p < 0.05). The molecular weight of Phasix™ ST Mesh decreased over time, regardless of repair type. Histological analysis showed comparable mature collagen/fibrovascular tissue around and within the Phasix™ ST Mesh interstices, including the segment of mesh overlying the defect.

CONCLUSION

Phasix™ ST Mesh-repaired sites exhibited similar mechanical strengths and histological properties across all defect sizes in this porcine model.

Use of absorbable meshes in laparoscopic paraesophageal hernia repair

Paraesophageal hernia (PEH) repair is one of the most challenging upper gastrointestinal operations. Its high rate of recurrence is due mostly to the low quality of the crura and size of the hiatal defect. In an attempt to diminish the recurrence rates, some clinical investigators have begun performing mesh-reinforced cruroplasty with nonabsorbable meshes like polypropylene or polytetrafluoroethylene. The main problem with these materials is the occurrence, in some patients, of serious mesh-related morbidities, such as erosions into the stomach and the esophagus, some of which necessitate subsequent esophagectomy or gastrectomy. Absorbable meshes can be synthetic or biological and were introduced in recent years for PEH repair with the intent of diminishing the recurrence rates observed after primary repair alone but, theoretically, without the risks of morbidities presented by the nonabsorbable meshes. The current role of absorbable meshes in PEH repair is still under debate, since there are few data regarding their long-term efficacy, particularly in terms of recurrence rates, morbidity, need for revision, and quality of life. In this opinion review, we analyze all the presently available evidence of reinforced cruroplasty for PEH repair using nonabsorbable meshes (synthetic or biological), focusing particularly on recurrence rates, mesh-related morbidity, and long-term quality of life.

Effect of physical cues of altered extract media from biodegradable magnesium implants on human gingival fibroblasts

Volume stable barrier membranes made of magnesium are very promising in Guided Bone Regeneration (GBR) to treat periodontal bone defects in dentistry due to their excellent biocompatibility and biodegradability. During the degradation process the cells are exposed to the alteration of various parameters, so called physical cues, involving surface alterations due to the formed corrosion layer and medium alterations arising from the dissolved corrosion products. Cell migration of human gingival fibroblasts (HGF), as a crucial parameter for optimal healing process in GBR, has been investigated on magnesium membranes and revealed that medium alterations by dissolved corrosion products have a higher impact on cell migration than surface alterations. However, the effect of each altered medium parameter on cell migration has not been adequately studied, but their roles are crucial to explain the slower migration rate on magnesium surfaces compared to titanium and tissue culture plastic surfaces. Our study investigates the single effect of Mg²⁺, Ca²⁺, H₂ and increased osmolality as well as the effect of magnesium extracts, which contain a dynamic mixture of previous parameters on cell migration, proliferation and viability of HGF. We showed that at 75 mM Mg²⁺ concentration and at 0 mM Ca²⁺, respectively, the cell migration rate is greatly reduced. In complex magnesium extract media, we found that a temporarily increased ratio of Mg²⁺ to Ca²⁺ conditioned a slow HGF migration rate. Based on these findings and the characterization of supernatants from HGF migration assays on Mg membranes, we propose, that the slower migration rate of HGF can be explained by the altered ratio of Mg²⁺ to Ca²⁺, caused by increasing concentrations of Mg²⁺ and decreasing concentrations of Ca²⁺ in the vicinity of the corroding Mg implant, combined with a constantly increased molecular hydrogen concentration in the supernatant. These results are cell type specific and should be checked carefully, if necessary, for Mg implant performance. STATEMENT OF SIGNIFICANCE: The study is providing a systematic approach to explain the main effects of extract medium parameters (physical cues) such as magnesium or calcium ion concentration, osmolality and dissolved molecular hydrogen and CO₂ in cell culture media modified by co-incubating with corroding magnesium implants on the migration rate of human gingival fibroblasts (HGF). This study uncovers for the first time the combinatory effect of slightly increased molecular hydrogen and the change in Mg²⁺/Ca²⁺ ratio on HGF cell migration.

Current status and perspectives of zinc-based absorbable alloys for biomedical applications

Absorbable metals have the potential to serve as the next generation of temporary medical implant devices by safely dissolving in the human body upon vascular tissue healing and bone regeneration. Their implementation in the market could greatly reduce the need of costly and risky additional surgeries for either implant replacement or removal, often required in current permanent implants. Despite the extensive research done over the last two decades on magnesium (Mg) and iron (Fe) based alloys, they have not generally shown a satisfactory combination of mechanical properties, biocompatibility and controlled degradation rate in the physiological environment. Consequently, zinc (Zn) based alloys were introduced in the last few years as alternative materials to overcome the limitations of Fe and Mg-based alloys. The blend of different alloying elements and processing conditions have led to a wide variety of Zn-based alloys having tunable mechanical properties and corrosion rates. This review provides the most recent progress in the development of absorbable Zn-based alloys for biomedical implant applications, primarily for cardiovascular and orthopedic devices. Their biocompatibility, processability and metallurgical aspects, as well as their mechanical behavior and corrosion properties are presented and discussed, including their opportunities, limitations and future research directions. STATEMENT OF SIGNIFICANCE: Temporary orthopedic bioimplants have become increasingly popular as they offer an alternative to prevent complications, like infections or secondary surgeries, often related to the implantation of permanent devices. Iron and magnesium alloys were extensively studied as candidates for absorbable medical applications, but they generally failed to provide a desirable mechanical performance and corrosion characteristics in the physiological environment. Zinc was introduced in the last decade as a potential implant material after showing outstanding biocompatibility and biodegradability. This review summarizes the research advances to date and provides a thorough discussion of the future challenges of absorbable zinc alloys to satisfy the demanding clinical benchmarks for absorbable medical applications. Their biocompatibility, mechanical, and corrosion aspects, both in vitro and in vivo, are comprehensively reviewed and assessed accordingly.

Augmented debridement for implant related chronic osteomyelitis with an absorbable, gentamycin loaded calcium sulfate/hydroxyapatite biocomposite

We report outcomes from 52 patients with chronic osteomyelitis from implant infection treated with a single stage protocol including debridement augmented with application of CERAMENT™/G biocomposite after resection of Cierny-Mader (C-M) stage III and IV chronic osteomyelitis. Mean age was 53 years with a mean follow up of 17 months. Infection was eradicated in 48 (92.3%) patients. There were four (7.7%) recurrences. Eighteen patients (35%) had a flap. Staphylococci (51%) and Enterococci (15%) were the commonest microorganisms. Local antibiotic augmentation (CERAMENT™/G biocomposite) with dead space management is effective in the treatment of implant related chronic osteomyelitis.

Level of evidence

Prognostic Level IV.

Biomechanical evaluation of osteoporotic fracture: Metal fixation versus absorbable fixation in Sawbones models

OBJECTIVE

The failure of osteoporotic fracture after internal fixation is mainly caused by the underlying bone loss and strength compromise. The aim of this study is to investigate whether absorbable internal fixation can provide adequate mechanical stability and a reduction in the incidence of failure of fixation caused by bone loss and stress shielding.

METHODS

A low density cancellous bone model was selected to compare the insertion of screw (screw-in), removal of screw (screw -out) and pull - out strength of absorbable screw and metal screw. The long bone model of thin cortical bone was used to create the transverse fracture model. The model was fixed with absorbable plate-screw system and metal plate-screw system respectively. The fatigue test and static bending test were compared. Moreover, the size of screw hole area was assessed.

RESULTS

The maximal screw - in and screw - out torque of the absorbable screw was significantly greater than that of the metal screw (P < 0.05), but there was no significant difference in pull-out test (P > 0.05). No visible failure occurred in fatigue test. There was no significant difference between the maximum load of static bending test (P > 0.05). The screw hole area of absorbable samples was significantly smaller than that of metal samples (P < 0.05).

CONCLUSIONS

In this experimental set-up it was found that the stability of absorbable screws in osteoporotic bone was better than metal screws. The absorbable system tested can achieve good stability, and the destruction of osteoporotic bone is small, which can reduce the occurrence of bone failure. Considering that absorbable material avoids the need of second surgery (implant removal) and reduces the stress shielding effect, we believe that absorbable internal fixation can be considered for fixation treatment of osteoporotic fractures.

Investigation of zinc‑copper alloys as potential materials for craniomaxillofacial osteosynthesis implants

In this study, zinc‑copper (ZnCu) alloys were investigated regarding their feasibility as absorbable metals for osteosynthesis implants, especially in the craniomaxillofacial area. Mechanical properties and in vitro corrosion behavior of as-rolled Zn-xCu (x = 1, 2 and 4 wt%) alloys were systematically evaluated and screened. The as-rolled Zn4Cu alloy had mechanical properties that were superior to the most absorbable craniomaxillofacial osteosynthesis materials recently reported. The addition of Cu to Zn showed to have no apparent effect on the corrosion rates of the samples. The rolling process on Zn and Zn1Cu resulted in more uniform corrosion than on as-cast counterparts after 28 days immersion. Furthermore, the Zn4Cu alloys exhibited no apparent cytotoxic effect towards L929, TAg or Saos-2 cells. Proliferation rates of TAg and Saos-2 cells were shown to be activated by specific Zn ion concentrations in the as-rolled Zn4Cu alloy extracts. Analysis of in vitro antibacterial properties revealed that the as-rolled Zn4Cu alloy possessed the potential to inhibit biofilm formation of mixed oral bacteria. We conclude that the as-rolled Zn4Cu alloy might be a promising material for fabrication of craniomaxillofacial osteosynthesis implants.

A Retrospective Review of Vaginal Cuff Dehiscence: Comparing Absorbable and Nonabsorbable Sutures

STUDY OBJECTIVE

To compare the rate of spontaneous and complete vaginal cuff dehiscence (VCD) using absorbable versus nonabsorbable sutures for vaginal cuff closure.

DESIGN

Retrospective comparative cohort design.

SETTING

Freestanding ambulatory surgery center in suburban Maryland.

PATIENTS

Women age >18 years old who underwent hysterectomy for benign conditions between October 2013 and April 2018.

INTERVENTION

Laparoscopic retroperitoneal hysterectomy was performed by 2 gynecologic surgical specialists. Transvaginal cuff closure was performed using either absorbable Vicryl (polyglactin 910) sutures (n = 881) or nonabsorbable Ethibond (polyester) sutures (n = 574). The nonabsorbable sutures were surgically removed after 90 days.

MEASUREMENTS AND MAIN RESULTS

No statistically significant differences in age, race, weight, body mass index, parity, uterine weight, or number of comorbidities were noted between the nonabsorbable and absorbable suture groups. Spontaneous vaginal cuff dehiscence (VCD) occurred in 3 patients (0.52%) in the nonabsorbable group and in 12 patients (1.4%) in the absorbable group (p = .183). Eleven of the 12 cases of VCD in the absorbable group were precipitated by intercourse and occurred within 90 days of surgery.

CONCLUSION

Our data suggest that use of a nonabsorbable suture may be an effective approach to prevent spontaneous VCD, but the benefits should be weighed against the inherent risk associated with a second procedure to remove sutures.

Design of a migration assay for human gingival fibroblasts on biodegradable magnesium surfaces

A novel regenerative approach to Guided Bone Regeneration (GBR) in dental surgery is based on the development of biodegradable and volume stable barrier membranes made of metallic magnesium. Currently used volume stable barrier membranes are made of titanium-reinforced PTFE or titanium-reinforced collagen membranes, both, however, are accompanied by a high incidence of wound dehiscence resulting in membrane exposure, which leads to an increased infection risk. An exposed membrane could also occur directly after insertion due to insufficient soft tissue coverage of the membrane. In both cases, fast wound margin regeneration is required. As a first step of soft-tissue regeneration, gingival fibroblasts need to migrate over the barrier membrane and close the dehiscent wound. Based on this aim, this study investigated the migration behaviour of human gingival fibroblasts on a magnesium surface. Major experimental challenges such as formation of hydrogen bubbles due to initial magnesium corrosion and non-transparent material surfaces have been addressed to allow cell adhesion and to follow cell migration. The designed scratch-based cell migration assay involved vital fluorescent cell staining on a pre-corroded magnesium membrane to simulate invivo wound dehiscence. The assay has been used to compare cell migration on pre-corroded magnesium to titanium surfaces and tissue culture plastic as control substrates. First results of this assay showed that human gingival fibroblasts migrate slower on pre-corroded magnesium compared to plastic and titanium. However, the scratch was finally closed on all materials. Compared to titanium surfaces and tissue culture plastic, the surface roughness and the surface free energy (SFE) could not explain slower cell migration on magnesium surfaces. Immunohistological investigations of cellular structure revealed, that magnesium ions increased focal adhesion at concentration of additionally 75 mM MgCl₂ in cell culture medium. The use of our designed cell migration assay has shown that ionic medium alterations due to magnesium corrosion has a higher impact on the cell migration rate than surface alterations.

STATEMENT OF SIGNIFICANCE

The design of a migration assay on non-transparent magnesium surfaces will add the option to study cell response to surface modifications, coatings and the corrosion process itself under life view conditions.

A comparative study of immediate wound healing complications following cleft lip repair using either absorbable or non-absorbable skin sutures

Objectives

The aim of the study was to compare wound healing complications following the use of either absorbable or non-absorbable sutures for skin closure in cleft lip repair.

Materials and Methods

This was a randomized controlled trial conducted at the Department of Oral and Maxillofacial Surgery, Lagos University Teaching Hospital, Idi Araba, Lagos State, Nigeria. Sixty subjects who required either primary or secondary cleft lip repair and satisfied all the inclusion criteria were recruited and randomized into two groups (Vicryl group or Nylon group). The surgical wounds in all subjects were examined on 3rd, 7th, and 14th postoperative days (POD) for presence or absence of tissue reactivity, wound dehiscence, and local wound infection.

Results

Hemorrhage, tissue reactivity, wound dehiscence, and local wound infection were identified as wound healing complications following cleft lip repair. The incidence of postoperative wound healing complications on POD3 was 33.3%. Tissue reactivity was more common throughout the evaluation period with the use of an absorbable (Vicryl) suture compared to a non-absorbable (Nylon) suture, although the difference was statistically significant only on POD7 (P=0.002). There were no significant differences in the incidences of wound dehiscence and infection between the two groups throughout the observation period.

Conclusion

There were no statistically significant differences in the incidences of wound dehiscence and surgical site wound infection following the use of either Vicryl or Nylon for skin closure during cleft lip repair. However, more cases of tissue reactivity were recorded in the Vicryl group than in the Nylon group on POD7. Particular attention must be paid to detect the occurrence of wound healing complications, most especially tissue reactivity, whenever a Vicryl suture is used for skin closure in cleft lip repair.

Comparative analysis of non-absorbable 10-0 nylon sutures with absorbable 10-0 Vicryl sutures in pediatric cataract surgery

Purpose:

The purpose of the study is to compare the efficiency as well as the rate and type of suture-related complications between 10-0 monofilament nylon (Aurolab Nylon Sutures, double arm, Aurolab) and 10-0 polyglactin 910 sutures (Vicryl, single arm, Aurolab) for pediatric cataract surgery.

Methods:

It is a prospective, comparative study performed in children who underwent surgery for congenital or developmental cataract from March 2013 to February 2016. Patients underwent suturing with either nylon or Vicryl in unilateral cases, but in most bilateral surgeries, one eye received Vicryl sutures while the other eye received nylon. The sutures were compared for their complications and the need for suture removal.

Results:

Forty-one children (72 eyes) were included in the study, of which 31 children (62 eyes) underwent bilateral surgery while 10 (10 eyes) underwent unilateral surgery. Sixty-four nylon sutures were placed in 32 children (34 eyes), of which 22 (34.4%) were removed due to suture-related complications, whereas 14 (19.7%) (P = 0.03) of the 71 Vicryl sutures placed in 32 children (38 eyes) needed suture removal at an average of 2.9 weeks with the earliest at 6 days postoperatively. The odds of Vicryl suture being removed was 0.42 times with respect to nylon. The most common reason encountered for suture removal in both the materials was sutures becoming loose (16.3%), followed by vascularization (14.1%), infiltration (1.5%), and opacification (4.4%).

Conclusion:

Absorbable suture such as 10-0 Vicryl is preferred over nonabsorbable suture 10-0 nylon for suturing incisions in pediatric cataract surgery, to avoid subjecting the child to repeated anesthesia.

Updates on the research and development of absorbable metals for biomedical applications

Absorbable metals, metals that corrode in physiological environment, constitute a new class of biomaterials intended for temporary medical implant applications. The introduction of these metals has shifted the established paradigm of metal implants from preventing corrosion to its direct application. Interest toward absorbable metals has been growing in the past decade. This is proved by the rapid increase in scientific publication, progressive development of standards, and launching the first commercial products. Iron, magnesium, zinc, and their alloys are the current three absorbable metals families. Magnesium-based metals are the most progressing family with a large data set obtained from both basic and translational research. Iron-based metals are still facing a major challenge of low in vivo corrosion rate despite the significant efforts that have been put to overcome its weakness. Zinc-based metals are the new alternative absorbable metals with moderate corrosion rates that fall between those of iron and magnesium. This manuscript provides a brief review on the latest progress in the research and development of absorbable metals, the most important findings, the remaining challenges, and the perspective on the future direction.

Absorbable versus non-absorbable tacks for mesh fixation in laparoscopic ventral hernia repair: A systematic review and meta-analysis

OBJECTIVES

To investigate the outcomes of absorbable versus non-absorbable tacks in patients undergoing laparoscopic ventral hernia repair.

METHODS

We performed a systematic review in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement standards. We conducted a search of electronic information sources, including MEDLINE; EMBASE; CINAHL; the Cochrane Central Register of Controlled Trials (CENTRAL); the World Health Organization International Clinical Trials Registry; ClinicalTrials.gov; and ISRCTN Register, and bibliographic reference lists to identify all randomised controlled trials (RCTs) and observational studies investigating outcomes of absorbable versus non-absorbable tacks for mesh fixation in patients undergoing laparoscopic ventral hernia repair. We used the Cochrane risk of bias tool and the Newcastle-Ottawa scale to assess the risk of bias of RCTs and observational studies, respectively. Fixed-effect or random-effects models were applied to calculate pooled outcome data.

RESULTS

We identified three RCTs and two observational studies enrolling a total of 1149 patients. The included patients were comparable in terms of age [Mean difference (MD) 0.28, 95% confidence intervals (CI) -1.45-2, P = 0.75], male gender (MD 0.81, 95% CI 0.63-1.04, P = 0.10), body mass index (MD -041, 95% CI -1.28-0.46, P = 0.36) and hernia defect size (MD 0.12, 95% CI -0.26-0.49, P = 0.54). The mean and median follow-up period was 30 months and 13 months, respectively There was no difference between the two mesh fixation techniques in terms of recurrence [Risk difference (RD) 0.03, 95% CI -0.04, 0.09, P = 0.47], chronic pain [Odds ratio (OR) 0.91, 95% CI 0.62-1.33, P = 0.64], seroma (OR 0.98, 95% CI 0.37-2.60, P = 0.96), haematoma (RD -0.00, 95% CI -0.04- 0.04, P = 0.99), prolonged ileus (OR 0.99, 95% CI 0.24-4.03, P = 0.99), length of hospital stay (MD 0.10, 95% CI -0.36-0.56, P = 0.68) and port-site hernia (OR 0.98, 95% CI 0.13-7.16, P = 0.98). The operative time was longer in absorbable tack group (MD 7.53, 95% CI 1.49-13.58, P = 0.01). The results remain consistent when randomised trials were analysed separately.

CONCLUSIONS

We found no difference in clinical outcomes between absorbable and non-absorbable tacks for mesh fixation in patients undergoing laparoscopic ventral hernia repair. The quality of the available evidence is moderate with a possibility of type 2 error. High quality RCTs with adequate statistical power are required to provide more robust basis for definite conclusions. Considering the similarity of both techniques in terms of clinical outcomes, the cost-effectiveness of each technique would be an important outcome determining which technique should be used; this needs to be considered as an outcome of interest in future studies.

The Bidirectional, Absorbable, No-Drain Abdominoplasty

This article outlines the author's technique, and the concepts of Bidirectional, Absorbable, No-Drain Abdominoplasty (BAND-Abdominoplasty). The attendant advantages and disadvantages are reviewed in the context of a retrospective, 5-year, single surgeon series. 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 .

Advancements in Bone Fixation Utilizing Novel Biointegrative Fixation Technology

Advancement in orthopedics have been increasing rapidly. The most important advances have been in fixation. With time, metallic hardware will begin to be replaced by materials that become one with the body. This progress will not only aid in the repair process it will allow permanent and improved reinforcement of the fixated region. Biointegrative technology is a promising new generation of materials capable of achieving this goal. Over time, it is expected that plates, screws, pins, interference screws, and even possibly joint replacements will incorporate into patients' bodies, negating the need for hardware removal and adding structure and stability to an iatrogenically weakened area.

Effectiveness of hemostatic gelatin sponge as a packing material after septoplasty: A prospective, randomized, multicenter study

OBJECTIVE

Although hemostatic gelatin sponge is a gelatin-based packing material with a powerful hemostatic effect, there were no studies in regard to its efficacy for packing material after septoplasty. The purpose of this study was to investigate the efficacy of hemostatic gelatin sponge nasal packing on patient's subjective symptoms, hemostasis, and wound healing following septoplasty.

SUBJECTS AND METHODS

Seventy six adult patients with nasal septum deviation requiring septoplasty were included. Following surgery, one nasal cavity was packed with hemostatic gelatin sponge and the other one with polyvinyl acetate. Patients' subjective symptoms while the packing was in situ, hemostatic properties, patients' pain on removal, degree of bleeding on removal of the packing, time for hemostasis after removal, postoperative wound healing, and the cost of the pack were evaluated.

RESULTS

Both packs were equally effective in the control of postoperative bleeding following septoplasty. However, hemostatic gelatin sponge packing was significantly more comfortable while in situ and less painful on removal of the pack. The polyvinyl acetate packing was associated with significantly more bleeding on removal, therefore much time was needed to control hemorrhage. There was no significant difference in the cost of the pack used and outcome of wound healing.

CONCLUSION

The use of hemostatic gelatin sponge after septoplasty results in significantly less discomfort and greater patient satisfaction with no adverse reactions when compared with polyvinyl acetate packing. Therefore, hemostatic gelatin sponge may be a useful packing material after septoplasty.

Advances in Absorbable Biomaterials and Nasal Packing

Nasal biomaterials have been developed to improve postoperative outcomes after functional endoscopic sinus surgery (FESS). These products have been designed to overcome certain common complications in FESS, and to maximize patient comfort. This article evaluates the performance of nonabsorbable and absorbable packing with respect to these outcomes. The collected trials suggest superior performance of bioabsorbable packs compared with absorbable packs with respect to patient comfort. For hemostasis and wound healing, variation in performance metrics makes interstudy comparison difficult. Before further trials are conducted, consensus must be reached among rhinologists as to the proper method of evaluating these products.

Evaluation of a fully absorbable poly-4-hydroxybutyrate/absorbable barrier composite mesh in a porcine model of ventral hernia repair

Background

The objective of this study was to evaluate the mechanical and histological properties of a fully absorbable poly-4-hydroxybutyrate/absorbable barrier composite mesh (Phasix™ ST) compared to partially absorbable (Ventralight™ ST), fully absorbable (Phasix™), and biologically derived (Strattice™) meshes in a porcine model of ventral hernia repair.

Methods

Bilateral abdominal surgical defects were created in twenty-four Yucatan pigs, repaired with intraperitoneal (Phasix™ ST, Ventralight™ ST) or retromuscular (Phasix™, Strattice™) mesh, and evaluated at 12 and 24 weeks (n = 6 mesh/group/time point).

Results

Prior to implantation, Strattice™ demonstrated significantly higher (p < 0.001) strength (636.6 ± 192.1 N) compared to Ventralight™ ST (324.3 ± 37.1 N), Phasix™ ST (206.9 ± 11.3 N), and Phasix™ (200.6 ± 25.2 N). At 12 and 24 weeks, mesh/repair strength was significantly greater than NAW (p < 0.01 in all cases), and no significant changes in strength were observed for any meshes between 12 and 24 weeks (p > 0.05). Phasix™ mesh/repair strength was significantly greater than Strattice™ (p < 0.001) at 12 and 24 weeks, and Ventralight™ ST mesh/repair strength was significantly greater than Phasix™ ST mesh (p < 0.05) at 24 weeks. At 12 and 24 weeks, Phasix™ ST and Ventralight™ ST were associated with mild inflammation and minimal–mild fibrosis/neovascularization, with no significant differences between groups. At both time points, Phasix™ was associated with minimal–mild inflammation/fibrosis and mild neovascularization. Strattice™ was associated with minimal inflammation/fibrosis, with minimal neovascularization at 12 weeks, which increased to mild by 24 weeks. Strattice™ exhibited significantly less neovascularization than Phasix™ at 12 weeks and significantly greater inflammation at 24 weeks due to remodeling.

Conclusions

Phasix™ ST demonstrated mechanical and histological properties comparable to partially absorbable (Ventralight™ ST) and fully resorbable (Phasix™) meshes at 12 and 24 weeks in this model. Data also suggest that fully absorbable meshes with longer-term resorption profiles may provide improved mechanical and histological properties compared to biologically derived scaffolds.

Absorbable and non-absorbable suture fixation results in similar outcomes for tibial eminence fractures in children and adolescents

PURPOSE

To evaluate efficacy and safety of extraphyseal tibial eminence avulsion fracture repair with absorbable sutures and a distal bone bridge fixation in comparison to previously described technique with non-absorbable sutures and distal screw fixation.

METHODS

In a physeal-sparing technique, tibial eminence fractures (n = 25; McKeever type II/III n = 11/14) were either treated in group A (n = 15, follow-up 28.1 months) using an absorbable suture fixed over a bone bridge or in group B (n = 10, follow-up 47.4 months) with a non-absorbable suture wrapped around an extraarticular tibial screw. IKDC and Lysholm scores were assessed, and the difference between the surgical and contralateral knee in anteroposterior (AP) translation, measured with a Rolimeter.

RESULTS

There was no significant difference between group A and group B in IKDC and Lysholm scores with 90.1 points ± 10.2 and 94.1 points ± 8.1, respectively (n.s.). AP translation did not differ between groups (n.s.). Eight of ten screws in group B had to be removed in a second intervention. A total of four arthrofibroses were counted (three in group A).

CONCLUSION

Extraphyseal tibial eminence repair with absorbable sutures and a distal bone bridge fixation results in similar rates of radiographic and clinical healing at 3 months after surgery as non-absorbable sutures tied around a screw, while avoiding the need for hardware removal. The minimal invasive technique to fix an eminence fracture without any permanent sutures or hardware is advantageous for children. To our knowledge, this is the first study that compares non-absorbable with absorbable sutures for a physeal-sparing technique.

LEVEL OF EVIDENCE

III.

6-0 nylon versus 6-0 vicryl rapide in chieloplasty

Context:

Facial cosmetic result is one of the most concerning issues for the parents who get their children operated for cleft lip. Moreover, the discomfort associated with the suture removal encourages one to use any new technology that may replace the need for suture placement. The type of suture material used in surgery has been a long-standing debate among surgeons. In this study, we compared rapidly absorbable suture material (Vicryl Rapide™) with nonabsorbable suture material (nylon).

Aims:

The aim of this study is to compare the appearance and course of scar, wound infection, and patient's parent perception using Vicryl Rapide and nylon in nonsyndromic congenital cleft lip repair.

Settings and Design:

This was a randomized prospective controlled clinical trial.

Materials and Methods:

Twenty patients, in the age group of 3–18 months treated for unilateral congenital cleft lip deformity, were included and randomly allocated to two groups with ten patients each. Skin suturing was done with 6-0 polyamide and 6-0 irradiated polyglactin in Groups A and B, respectively. Patients were evaluated at 1 week, 1, 3, 6 months, and 1 year postoperatively in person by the observer as well as by the patient's parent.

Statistical Analysis Used:

Descriptive statistical analysis was done using SPSS 20, and Student's t-test was applied.

Results:

It was found that Vicryl Rapide showed more hypopigmented scars and raised scars than nylon at the end of 1 year though overall appearance was comparable between the groups.

Conclusions:

Vicryl Rapide showed poorer cosmetic outcomes in terms of height and pigmentation of car as compared to nylon suture of same thickness. However, since scars tend to improve with time, a bigger sample size and a longer follow-up are required to generalize this statement.

How effective is postoperative packing in FESS patients? A critical analysis of published interventional studies

The present study aimed to assess the clinical effectiveness of absorbable packing alone, non-absorbable packing alone, and absorbable versus non-absorbable packing in the postoperative care of FESS patients, regarding bleeding control, adhesion formation, wound healing, and overall patient comfort. Systematic literature review in Medline and other database sources until July 2013, and critical analysis of pooled data were conducted. Blinded prospective randomized control trials, prospective, and retrospective comparative studies were included in study selection. The total number of analyzed studies was 19. Placing packs in the middle meatus after endoscopic procedures does not seem to be harmful for postoperative patient care. Regarding the postoperative bleeding rate, absorbable packing is not superior to no postoperative packing (strength of recommendation A). Comparing absorbable to non-absorbable packing, the former one seems slightly more effective than the latter in the aforementioned domain (strength of recommendation C). Absorbable packing was also found more effective than non-absorbable packing as a means of reducing the postoperative adhesion rate (strength of recommendation B), and more effective in comparison with not placing any packing material at all (strength of recommendation C). Non-absorbable packing also proves more effective than no postoperative packing in preventing the appearance of such adhesions (strength of recommendation A). Absorbable packing is also more comfortable compared to non-absorbable materials (strength of recommendation A), or no postoperative packing in FESS patients (strength of recommendation B). The comparative analysis between the different packing modalities performed in the present study may help surgeons design a more individualized postoperative patient care.

Mesh wrapping for severe hepatic injury: a beneficial option in the trauma surgeon's armamentarium

BACKGROUND

The purpose of this study was to assess the efficacy of absorbable mesh wrapping (MW) versus perihepatic packing (HP) for severe hepatic injury.

METHODS

From January 2001 to December 2012, data were collected for MW patients with hepatic injury. Patients who underwent HP were matched with MW patients by injury mechanism, liver injury grade, Injury Severity Score, and age.

RESULTS

Twenty-six MW and twenty-six HP patients were matched. Eighteen blunt and 8 penetrating injuries were present in each group. There were 9 (35%) mortalities in the MW group and 16 (62%) in the HP groups (P = .03). Average transfusions were 12.0 and 24.5 (P = .03) packed red blood cells in the MW and HP groups, respectively. Average laparotomies per survivors were 1.3 for the MW and 3.1 for the HP groups (P = .01). Average length of stay for survivors was 19 and 47 (P = .04) days in the MW and HP groups, respectively.

CONCLUSION

MW for hepatic injuries can significantly decrease mortality, transfusions, laparotomies, and length of stay.

Absorbable biologically based internal fixation

Absorbable devices for use in internal fixation have advanced over the years to become reliable and cost-effective alternatives to metallic hardware. In the past, biodegradable fixation involved a laborious implantation process, and induced osteolysis and inflammatory reactions. Modern iterations exhibit increased strength, smoother resorption, and lower rates of reactivity. A newer generation manufactured from silk has emerged that may address existing limitations and provide a greater range of fixation applications.

Evaluation of arterial impairment after experimental gelatin sponge embolization in a rabbit renal model

OBJECTIVE

Arterial stenosis is a major obstacle for subsequent interventional procedures. We hypothesized that the stenosis is caused by gelatin sponge embolization and performed an experimental study in a rabbit renal model.

MATERIALS AND METHODS

A total of 24 rabbits were embolized with porcine gelatin sponge particles injected into the renal arteries. Four rabbits were sacrificed on 1 day, 4 days, 1 week, 2 weeks, 3 weeks, and 4 weeks after embolization. Microscopic evaluations were performed on hematoxylin-eosin and smooth muscle actin immunohistochemical stained sections.

RESULTS

Gelatin sponge particles were mainly observed in the segmental and interlobar arteries. Transmural inflammation of the embolized arterial wall and mild thickening of the media were observed 1 week after embolization. Resorption of the gelatin sponge and organization of thrombus accompanied by foreign body reactions, were observed from 2 to 4 weeks after embolization. Microscopic images of the 3 weeks group showed vessel lumens filled mostly with organized thrombi, resulting in severe stenosis. Additionally, vessels showed a thickened intima that contained migrating smooth muscle cells and accompanying interruption of the internal elastic lamina. The migrating smooth muscle cells were distributed around the recanalized arterial lumen.

CONCLUSION

Gelatin sponge embolization may induce arterial stenosis by causing organized thrombus and intimal hyperplasia, which consists of migrating smooth muscle cells and intimal collagen deposits.

Cytotoxicity studies of AZ31D alloy and the effects of carbon dioxide on its biodegradation behavior in vitro

Magnesium alloys have been advocated as potential artificial bone materials due to their biocompatibility and biodegradability. The understanding of their corrosive mechanism in physiological environments is therefore essential for making application-orientated designs. Thus, this in vitro study was designed to assess the effects of CO2 on corrosive behavior of AZ31D to mimic in vivo special ingredient. Electrochemical technologies accompanied with Scanning electron microscope, Fourier transform infrared, X-ray diffraction, Energy dispersive spectroscopy and hydrogen evolution measurement were employed to analyze corrosive rates and mechanisms of AZ31D. Moreover, the biocompatibility of AZ31D was assessed with a direct cell attachment assay and an indirect cytotoxicity test in different diluted extracts. The ion concentrations in extracts were measured using inductively coupled plasma mass spectrometry to offer explanations on the differences of cell viability in the indirect test. The results of the direct cytotoxicity assay showed that the corrosive rate of AZ31D was too rapid to allow for cell adhesion. Extracts diluted less than 20 times would cause adverse effects on cell proliferation, likely due to excessive ions and gas release. Moreover, the presence of CO2 did not cause significant differences on corrosive behavior of AZ31D according to the results of electrochemical testing and hydrogen evolution measurement. This might be caused by the simultaneous process of precipitation and dissolution of MgCO3 due to the penetration role of CO2. This analysis of corrosive atmospheres on the degradation behavior of magnesium alloys would contribute to the design of more scientific in vitro testing systems in the future.