Effect of Manufacturing Parameters of Lightweight Hernia Mesh Material on Its Mechanical Properties

The traditional synthetic polypropylene(PP) meshes for hernia surgical repair were controversial due to increasing postoperative complications,including chronic pain,infection and shrinkage.These morbidities may be related to a mismatch of mechanical properties between abdominal wall and the meshes.The aims of this study were to design a large pore,lightweight and anisotropic hernia mesh material and explore the influence of pulling density on mechanical properties of experimental hernia mesh materials.The hernia mesh material included A,B,and C samples knitted by RS4 EL warp knitting machine with 16 E gauge.The results showed that the mechanical properties of hernia mesh materials met the requirement of anisotropy in abdominal wall tissue.With the pulling density increased,bursting strength,uniaxial tensile strength and suture pulling out force tended to increase,while tearing force was no significant difference.Sample C showed superior physical and mechanical properties.

Processing and Mechanical Characterization of Electro-spun Polycaprolactone Membrane Coated Hernia Mesh

Composite hernia meshes designed in this paper consist of polypropylene( PP) knitted meshes and polycaprolactone( PCL)nanofiber membranes,which are produced by electro-spinning the solution composed of PCL as a solute and the mixture of dimethylformamide( DMF) and dichloromethane( DCM) as a solvent. The morphology and diameter of nanofibers in the membrane are well performed when the 15% PCL solution is electrospun under the condition of 18 k V,15 cm,0. 7 m L/h. The poresize of the membranes is less than 10 μm, where such kinds of arrangement are extremely compact to prevent the cells from growing in. The mechanical properties of the membrane with better arrangement state can reach 68. 8 c N/mm^2. The cytotoxicity test of the composite mesh demonstrates the nontoxicity of the materials.However,the bonding fastness between the membrane and the PP mesh is extremely unsubstantial. The better ways to bond PP mesh with PCL membranes should be discussed in the future.

Structure and Mechanical Properties of Polypropylene Hernia Meshes with Various Weight

Polypropylene( PP) is a kind of stable material with excellent mechanical properties. Meshes made of PP have lots of obvious advantages. In this paper,5 PP hernia meshes with different warp-knitting structures which can be sorted into one light-weight hernia mesh,two standard-weight hernia meshes and two heavyweight hernia meshes were chosen to have a serious of mechanical test,including weight density,thickness,pore size,porosity,tensile strength,bursting strength,stitch tear strength,tear strength and bending rigidity. The respective relationship between mechanical performance and weight density were analyzed. The results revealed that heavy-weight hernia meshes had the biggest thickness( 0. 834 mm),the smallest pore size( 462 μm) and the smallest porosity( 58. 40%). The mechanical performance demonstrated that the tensile strength increased more than 800 N,the stitch tear strength increased more than 40 N,the bursting strength increased more than750 N and the tear strength increased more than 40 N by enlarging the weight density by 100-150 g/m^2. However, heavy-weight hernia meshes had problems of high bending rigidity,unevenness and anisotropy. Standard-weight hernia meshes with 70-140 g/m^2 not only met the demand of the mechanical properties,but also had good flexibility and structure parameters,which could be considered as an ideal hernia mesh.

Hernia mesh prevent dislocation after wide excision and reconstruction of giant cell tumor distal radius

Giant cell tumor(GCT) remains as major health problem. GCT which located at the lower end of the radius tends to be more aggressive. Wide excision and reconstruction of the wrist in stage 3 of distal radius GCT lesion is an optimal modality to prevent tumor recurrence. However, dislocation often occurs as its complication. We are reporting patient with GCT of distal radius treated with wide excision and reconstruction using nonvascularized fibular graft and the addition of hernia mesh. Circumferential non-absorbable polypropylene hernia mesh was applied, covered radioulnar joint and volar aspect of radius, and served as additional support to prevent dislocation. During five years and two months of follow-up, we found no dislocation in our patient. Furthermore, good functional outcome was obtained. Our finding suggests that the addition of hernia mesh after wide excision and reconstruction with nonvascularized fibular graft may benefit to prevent dislocation and provides an excellent functional outcome.

Influence of Heat Setting on Mechanical and Structural Properties of Polypropylene Hernia Mesh

Heat setting has important effects on mechanical and structural properties of polypropylene( PP) mesh. However,there is no systematic study on the effects of heat setting. In this paper,the orthogonal array was designed for heat setting,and the influences of heat setting on structural, mechanical properties and flexural rigidity of PP mesh were studied. The experimental results showed that temperature had larger influence than tension and time on thickness,tensile strength,bursting strength, tear strength and bending stiffness of PP meshes, except the fabric weight. The optimum heat setting parameters were as follows: temperature was120 ℃, time was 10 min,and tension was small. These results will provide guideline for the selection of heat setting parameters.

Laparoscopic Surgery of Incisional Hernia: Technique and Short-Term Results in Three Surgical Units in Cameroon

Introduction: Incisional hernia is a common medical situation and its treatment has always been a challenge for general surgeons. If laparoscopic repair has become a gold standard elsewhere, it is increasingly done in our milieu, but no data has been found. The aim of this study was to review this surgery done in our country so far, to describe the operative technique and to evaluate the postoperative outcomes. Patients and Methods: We conducted an observational descriptive study with retrospective collection of data from the 1st of July 2018 to 30th of June 2022, in three hospitals in Cameroon. Data on socio-demographic and clinical characteristics, surgical technique and postoperative outcomes of patients who had a laparoscopic repair of their incisional hernia were collected. Results: We reviewed 20 files. There were 14 women with an average age of 54.6 years. The average BMI was 32.8 kg/m2. Thirteen patients had a moderate size hernia and the hernia was localized at the midline in 18 cases. Only composite biface meshes were used with dimensions chosen to obtain at least 5 cm overlap. Spiral tacks were the only fixation means used. We registered 3 complications. One case of generalized peritonitis secondary to missed digestive perforation, one case of seroma and one case of postoperative ileus. We registered no death. Conclusion: Laparoscopic repair of incisional hernias is feasible in a resource-limited setting like ours. Compliance with the operative technique and recommendations is important to obtain short-term results closed to that put forward by literature.

Regulatory science for hernia mesh: Current status and future perspectives

Regulatory science for medical devices aims to develop new tools,standards and approaches to assess the safety,effectiveness,quality and performance of medical devices.In the field of biomaterials,hernia mesh is a class of implants that have been successfully translated to clinical applications.With a focus on hernia mesh and its regulatory science system,this paper collected and reviewed information on hernia mesh products and biomaterials in both Chinese and American markets.The current development of regulatory science for hernia mesh,including its regulations,standards,guidance documents and classification,and the scientific evaluation of its safety and effectiveness was first reported.Then the research prospect of regulatory science for hernia mesh was discussed.New methods for the preclinical animal study and new tools for the evaluation of the safety and effectiveness of hernia mesh,such as computational modeling,big data platform and evidence-based research,were assessed.By taking the regulatory science of hernia mesh as a case study,this review provided a research basis for developing a regulatory science system of implantable medical devices,furthering the systematic evaluation of the safety and effectiveness of medical devices for better regulatory decision-making.This was the first article reviewing the regulatory science of hernia mesh and biomaterial-based implants.It also proposed and explained the concepts of evidence-based regulatory science and technical review for the first time.

Hernia Mesh and Hernia Repair:A Review

Hernia repair for primary and incisional hernia is the most commonly performed abdominal surgery done with extremely high costs.Treatment for hernia requires surgery to close the defect;however,there are post-operative complications like chronic pain,adhesion,and infection that are common.Hernia repair involves two types of biomaterials:a fixation biomaterial and a mesh biomaterial to close the defect.Synthetic meshes,mostly made from different polymers,provide adequate mechanical support but are associated with postoperative complications like infection.Biological meshes are derived from allografts and xenografts that are prone to less infection;however,their mechanical strength may be too weak depending the characteristics of the hernia defect.Novel meshes being developed try to combat the post-operative complications of current surgical meshes.Composite meshes that have two different surfaces have shown to have less adhesion effects but still produce varying inflammatory responses.Drug-loaded meshes are also a novel mesh that is designed to reduce infection with antibiotics.This review will highlight the different fixation methods as well as the pros and cons of different mesh options.Possible future improvements will be highlighted as well.

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 meshreinforced 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.

Mesh repair of sacrococcygeal hernia via a combined laparoscopic and sacrococcygeal approach: A case report

BACKGROUND Sacrococcygeal hernia is a very rare condition that is usually secondary to sacrococcygectomy, and its ideal treatment regimen is unclear. Herein, we report a case of sacrococcygeal hernia occurring in a patient who had no history of sacrococcygeal operation, present the operative procedures of mesh repair via a combined laparoscopic and sacrococcygeal approach that has not been described,and discuss our experience in diagnosis and treatment with a review of the literature.CASE SUMMARY A 54-year-old woman who chiefly complained of a 10-year history of a reversible bulge in her right sacrococcygeal region was admitted to our hospital. The physical examination revealed a bulge in the right sacrococcygeal region upon standing, which disappeared in the prone position but relapsed when performing the Valsalva manoeuvre. Computed tomography displayed an abnormality in the structure of the tissues between the midline of the sacrococcygeal region and the right gluteus muscle. The patient was diagnosed with sacrococcygeal hernia and received hernia repair with mesh through a combined laparoscopic and sacrococcygeal approach. On laparoscopy, the rectum was dissected posterolaterally, and a defect was identified in the right anterior sacrococcygeal region through which part of the rectum protruded. This was followed by the placement of a self-gripping polyester mesh via a sacrococcygeal approach. There were no postoperative complications. The patient was discharged on postoperative day 7 and was followed for more than 6 mo with no recurrence.CONCLUSION Laparoscopic mesh repair is recommended as a priority of surgical options for sacrococcygeal hernias, while choosing a self-gripping mesh can help avoid the risk of presacral vessel injury by reducing suture fixation.

Mesh migration into the sigmoid colon after inguinal hernia repair presenting as a colonic polyp:A case report and review of literature

Mesh migration and penetration into abdominal visce-ra rarely occur after laparoscopic inguinal hernia repair. We present the first case of mesh migration into the sigmoid colon identified as a colonic polyp at initial co-lonoscopic examination. The patient complained of mild abdominal distention in the lower abdomen over the previous year without changes in bowel habits or stool appearance and without weight loss. By complement-ary endoscopic ultrasonography, a cavity--like structure beneath the suspected polyp was further confirmed. Enhanced abdominal computed tomography merely re-vealed local bowel wall thickening and inflammation of the colosigmoid junction. The migrating mesh, which was lodged in the sigmoid colon and caused intra--abdomi-nal adhesion in the lower abdominal cavity, was finally identified via exploratory surgery. The components of inflammatory granulation tissue around the mesh mate-rial were diagnosed based on histological examination of the surgical specimen after sigmoidectomy. In this patient, nonspecific endoscopic and imaging outcomes during clinical work--up led to the diagnostic dilemma of mesh migration. Therefore, the clinical, radiological and endoscopic challenges specific to this case as well as the underlying reasons for mesh migration are discussed in detail.

Synthetic vs biologic mesh for the repair and prevention of parastomal hernia

AIM To outline current evidence regarding prevention and treatment of parastomal hernia and to compare use of synthetic and biologic mesh.METHODS Relevant databases were searched for studies reporting hernia recurrence,wound and mesh infection,other complications,surgical techniques and mortality. Weighted pooled proportions(95%CI) were calculated using Stats Direct. Heterogeneity concerning outcome measures was determined using Cochran's Q test and was quantified using I^2. Random and fixed effects models were used. Meta-analysis was performed with Review Manager software with the statistical significance set at P ≤ 0.05.RESULTS Forty-four studies were included: 5 reporting biologic mesh repairs; 21,synthetic mesh repairs; and 18,prophylactic mesh repairs. Most of the studies were retrospective cohorts of low to moderate quality. The hernia recurrence rate was higher after undergoing biologic compared to synthetic mesh repair(24.0% vs 15.1%,P = 0.01). No significant difference was found concerning wound and mesh infection(5.6% vs 2.8%; 0% vs 3.1%). Open and laparoscopic techniques were comparable regarding recurrences and infections. Prophylactic mesh placement reduced the occurrence of a parastomal hernia(OR = 0.20,P < 0.0006) without increasing wound infection [7.8% vs 8.2%(OR = 1.04,P = 0.91)] and without differences between the mesh types. CONCLUSION There is no superiority of biologic over synthetic mesh for parastomal hernia repair. Prophylactic mesh placement during the initial surgery significantly reduces parastomal hernia occurrence regardless of the mesh type.

Delayed Mesh Infection: A Rare Complication of Laparoscopic Inguinal Hernia Repair (TEP—Totally Extra-Peritoneal Repair)

Hernias are amongst the oldest afflictions of mankind. The tension-free mesh repairs revolutionized and radically changed the whole concept of anatomical tissue repairs. The introduction of mesh, though beneficial, posed a new set of postoperative problems with the mesh infection being the most morbid one. Laparoscopic surgery has been able to reduce the incidence of mesh infection as opposed to the open hernia repairs. The infection occurs mostly early but rarely does it present several years after the surgery. Herein we report our case of delayed mesh infection developing 6 years postoperatively. This is our first such case in a series of more than 1000 laparoscopic hernia repairs over a period of 6 years (2010-2016). The patient needed an open exploration which revealed a large preperitoneal cavity containing 770 ml of pus with a mesh floating in it. The mesh was removed and the thorough toileting of the wound was done.

Polypropylene versus Polyester Mesh for Laparoscopic Inguinal Hernia Repair: Short-Term Results of a Comparative Study

Background: Polypropylene meshes are commonly used in laparoscopic inguinal hernia repair, although they may cause complications. In this prospective study, a polyester mesh was compared to a polypropylene mesh. Methods: Transabdominal preperitoneal (TAPP) laparoscopic repair was performed in 160 consecutive male patients suffering from unilateral inguinal hernia. The first 80 cases received a polypropylene mesh (Parietene, Covidien, France), and a polyester mesh (Parietex, Covidien, France) was implanted in the second half of patients. Both groups were comparable with respect to clinical and demographic variables. Patients rated their pain using the visual analogue scale (VAS), and ultrasonography was performed on postoperative days 1 and 3 to measure seroma formation. Results: The duration of surgery and the length of stay were similar in both groups. Postoperative pain, measured on day 1 and 3, was significantly less in patients who had received a polyester mesh as compared to the polypropylene group. The size of local seroma was also significantly reduced in the polyester group. Complication rates were 10% in the polypropylene and 9% in the polyester group and included one early recurrence in each group. Conclusions: Polyester meshes may be useful in TAPP, as this mesh material produces less foreign body reaction with less seroma formation and lower pain levels than conventional polypropylene.

Dual-sided composite mesh repair of hiatal hernia: Our experience and a review of the Chinese literature

AIM:To summarize our experience in the application of Crurasoft for antireflux surgery and hiatal hernia(HH)repair and to introduce the work of Chinese doctors on this topic.METHODS:Twenty-one patients underwent HH repair with Crurasoft reinforcement.Gastroesophageal reflux disease(GERD)and HH-related symptoms including heartburn,regurgitation,chest pain,dysphagia,and abdominal pain were evaluated preoperatively and 6mo postoperatively.A patient survey was conducted by phone by one of the authors.Patients were asked about"recurrent reflux or heartburn"and"dysphagia".An internet-based Chinese literature search in this field was also performed.Data extracted from each study included:number of patients treated,hernia size,hiatorrhaphy,antireflux surgery,follow-up period,recurrence rate,and complications(especially dysphagia).RESULTS:There were 8 typeⅠ,10 typeⅡand 3 typeⅢHHs in this group.Mean operative time was 119.29min(range 80-175 min).Intraoperatively,length and width of the hiatal orifice were measured,(4.33±0.84and 2.85±0.85 cm,respectively).Thirteen and eight Nissen and Toupet fundoplications were performed,respectively.The intraoperative complication rate was9.52%.Despite dysphagia,GERD-related symptoms improved significantly compared with those before surgery.The recurrence rate was 0%during the 6-mo follow-up period,and long-term follow-up disclosed a recurrence rate of 4.76%with a mean period of 16.28mo.Eight patients developed new-onset dysphagia.The Chinese literature review identified 12 papers with213 patients.The overall recurrence rate was 1.88%.There was no esophageal erosion and the rate of dysphagia ranged from 0%to 24%.CONCLUSION:The use of Crurasoft mesh for HH repair results in satisfactory symptom control with a low recurrence rate.Postoperative dysphagia continues to be an issue,and requires more research to reduce its incidence.

Cost effective use of mosquito net mesh in inguinal hernia repair

Mesh hernia repair is one of the commonest open techniques of inguinal hernia repair.The main limiting factor in the use of new meshes is the cost.We carried out a prospective randomized double blind study and comprising of a hundred patients with 100 inguinal hernias admitted consecutively for elective surgery,divided into the polypropylene mesh(PPM)group and the mosquito net mesh(MNM)group each containing fifty patients.All cases were completed successfully and results revealed no difference in two groups.The results of the present study,in consistent with the published literature,reveal that the cheap indigenous mosquito mesh,which has similar properties of an imported mesh,can be safely used for tension-free inguinal hernia repair in adults.Further trials with a larger number of patients and longer follow-ups are justified and recommended.

Laparoscopic Extraperitoneal Inguinal Hernia Repair Using a Novel Mesh with Self-Fixating Properties

Laparoscopic totally extraperitoneal (TEP) hernia repair is a well-accepted technique for inguinal hernia repair. Different types of mesh and fixation methods have been described. Recently, a novel, self-fixating mesh has been introduced and used successfully in open inguinal hernia repairs. We report the first initial experience using this mesh for TEP repairs.

Mesh Infection and Migration after Umbilical Hernia Repair

Mesh infection and migration are dangerous and common complications after hernia repair. Many factors cause mesh migration, which may or may not be associated to infection. Before performing hernia repair using a mesh, it is important to choose the right device to avoid this kind of complication, above all in the presence of contaminated wounds or fields. We describe two cases of mesh infection and migration after umbilical hernia repair which were treated, in accordance with recommendations in the literature, by removing the infected mesh and replacing it with a biological mesh. Our experience confirms the feasibility of using biological mesh to perform umbilical hernia repair after infection, with consequent migration, of the previously placed mesh. Our cases are the first to be reported in which mesh migration is associated with infection after umbilical hernia repair, and they demonstrate the advantages of biologic implants in abdominal wall reconstruction.

Open Underlay Mesh Reinforced Large Incisional Hernia Repair—Prospective Observational Hospital Based Study

Introduction: Incisional hernias frequently complicate abdominal surgeries with a varied incidence as reported to be 2% - 20%. The risk factors of development of incisional hernias include immunocompromised state, diabetes mellitus, smoking, obesity, wound infection at the index surgery, emergency surgery. Materials and Methods: The study design was prospective and included 62 patients with incisional hernias. The patients were evaluated preoperatively on OPD basis with history, clinical examination, baseline investigation, ultrasound abdomen and computed tomogram. Results: The mean age was 48.9 years with male:female ratio of 1:1.4. Mean BMI was 30.1 kg/m2. Out of 62 patients in the study 61.2% had concomitant hypertension and were on treatment for the same. 30.6% were clinically hypothyroid, 38.7% were diabetic and 54.8% were smokers. There were multiple factors present in patients in the current study which were observed to be possible to have risked the patients to incisional hernias after an abdominal surgery. 21 patients had defect size ranging from 5 to 10 cm and 41 patients were bearing a hernia of the defect size of 10 cm or more. The mean operative time was 221.7 minutes. Conclusion: Incisional hernias are a part of surgical practice that would probably glue to it to the end of time. A progression from primitive suture repair with recurrence rates of over 65% to modern day mesh reinforced repairs with recurrences aimed at 0% is always welcome. But still then the placement of mesh in different positions or layers of abdominal wall yields different results.

A Long-term Follow-up: Suture versus Mesh Repair for Adult Umbilical Hernia in Saudi Patients. A Single Center Prospective Study

Objective: To report results of mesh repair vs. the modified Mayo’s suture overlap in the surgical treatment of adult umbilical and paraumbilcal hernias in our medical center. Patients & Methods: The study is a Saudi single center single surgeon trial composed of sixty two patients. It was performed in the Surgical Department of King Abdul-Aziz University Hospital at Jeddah. The patients were randomly assigned into 2 groups. Group A patients underwent onlay mesh repair while modified Mayo’s repair was used in group B patients. Median follow-up was 28 months, and data were collected regarding size of hernia, type of the operation, complications, length of follow-up and the recurrence rate. Chi square test was used to compare results at 0.05 levels. Results: Complication was reported in 17% in group A and 8% in group B .There was no difference in scar pain, cosmetic result, and overall patient satisfaction between both groups. The recurrence rate was 10% for mesh repair and 18.8% for suture repair. Conclusions: Despite higher complication rate, mesh repair is superior to suture repair due to lower recurrence rate. Suture repair still has a place under certain circumstances, also it is simple less costly and has insignificant infection rate.