Biomechanical properties of raw meshes used in pelvic floor reconstruction

Female urinary incontinence and pelvic organ prolapse are common conditions. The aim of this study was to assess the biomechanical properties of raw meshes commonly used in pelvic floor surgery, particularly the effects of cyclical loading on these meshes. The material properties of nine different types of surgical meshes were examined using uniaxial tensile tests. The strength and extensibility of the mesh designs differed considerably. Most mesh types exhibited curvilinear loading curves. Cyclical loading of mesh samples produced significant permanent deformation in all mesh designs. This non-recoverable extension ranged from about 8.5% to 19% strain. Hysteresis also varied considerably between materials from 30% to 85%. All mesh groups tested for their biomechanical properties displayed differences in results for failure load, stiffness, non-recoverable extension and hysteresis.     

四种聚丙烯网用于矫正乳房下垂的生物相容性研究

目的探讨外科网片的皱缩和粘连影响其作为内置式乳罩纠正轻、中度乳房下垂的术后效果，通过比较4种不同的聚丙烯网在生物相容性上的差异，找出异物反应与术后效果的关系，以便为内置式乳罩选用聚丙烯网片提供依据。方法以实验用小型诸作为动物模型，将4种不同的聚丙烯网置入腹部皮下，90d后采集标本，比较并发症、肄物反应、胶原纤维与弹力纤维的形成，并在透射电子最微镜下观察超微结构。结果4种聚丙烯网在生物相容性上存存差异。异物反应的程度决定生物相容性的差异，同时对术后乳房形态有显著的影响。结论Premilene Mesh LP作为新型的轻质量网片，生物相容性优于其他网片。     

Viability of impacted bone allografts under metal mesh at the calcar in revision surgery of the hip

Metal meshes are used in revision surgery of the hip to contain impacted bone grafts in cases with cortical or calcar defects in order to provide rotational stability to the stem. However, the viability of bone allografts under these metal meshes has been uncertain. We describe the histological appearances of biopsies obtained from impacted bone allografts to the calcar contained by a metal mesh in two femoral reconstructions which needed further surgery at 24 and 33 months after the revision procedure. A line of osteoid and viable new bone was observed on the surface of necrotic trabeculae. Active bone marrow between these trabeculae showed necrotic areas in some medullary spaces with reparative fibrous tissue and isolated reactive lymphocytes. This is interpreted as reparative changes after revascularisation of the cancellous allografts. These pathological findings are similar to those reported in allografts contained by cortical host bone and support the hypothesis that incorporation of morcellised bone under metal meshes is not affected by these devices.     

Inguinal hernia: mesh or no mesh in open repair?

The operative repair of inguinal hernias is the most common surgical procedure in general surgery. This review gives a survey of the current data on the "mesh or no mesh" question in open inguinal hernia surgery. The Cochrane Database Systematic Review of 2002 has the highest level of evidence. Five randomised controlled trials were published after the Cochrane analysis and in a retrospective study, 1,513,008 patients were summarised accordingly. According to these data, the incidence of postoperative complications (haematoma, seroma, wound infection and serious complications like bowel/vessel injury and bleeding) does not depend on the operative technique used. The implantation of meshes significantly decreases the overall recurrence rate, the occurrence of chronic pain and the time of return to normal activity, as compared to non-mesh techniques. The published data shows significant advantages for mesh techniques.     

Incisional hernia: challenge of re-operations after mesh repair

Background and aims The widespread use of meshes for the repair of incisional hernia is currently followed by an increasing number of re-operations. The incidence of incisional hernia recurrence after mesh repair varies between 3 and 32%. The problem of mesh failure and options for another surgical intervention seem rather unattended. Methods We present our experience of 77 re-operations after previous mesh repair that were performed between 1995 and 2004 out of a total of 1,070 operations for incisional hernia. The retrospective analysis focused on recurrence in relation to location, material of the previous mesh repair and the surgical procedure to resolve the problem. Results The locations of the preceding meshes were epifascial as onlays (n=23), retromuscular as sublays (n=46), within the defect as inlays (n=6) or intraperitoneally (n=2). The direction of the incision was vertical medial (n=41) or horizontal crossing the linea semilunaris (n=36). Recurrences after median incisional hernia mesh repair mainly occurred at the cranial border of the mesh subxiphoidal. Except for two patients, all recurrences manifested at the margin of the enclosed mesh. Conclusions Re-operation after previous mesh repair is a surgical challenge. The type of revision procedure has to consider the position and material of the previous mesh. In our clinic recurrences, heavyweight polypropylene meshes were mostly treated with mesh exchange and lightweight polypropylene meshes could be treated by extension with a second mesh. In contrast to suture techniques, deficient mesh repairs are more evidently related to technical problems.     

Prosthetic closure of the esophageal hiatus in large hiatal hernia repair and laparoscopic antireflux surgery

BACKGROUND: Laparoscopy has become the standard surgical approach to both surgery for gastroesophageal reflux disease and large/paraesophageal hiatal hernia repair with excellent long-term results and high patient satisfaction. However, several studies have shown that laparoscopic hiatal hernia repair is associated with high recurrence rates. Therefore, some authors recommend the use of prosthetic meshes for either laparoscopic large hiatal hernia repair or laparoscopic antireflux surgery. The aim of this article was to review available studies regarding the evolution, different techniques, results, and future perspectives concerning the use of prosthetic materials for closure of the esophageal hiatus. METHODS: A search of electronic databases, including Medline and Embase, was performed to identify available articles regarding prosthetic hiatal closure for large hiatal or paraesophageal hernia repair and/or laparoscopic antireflux surgery. Techniques and results as well as recurrence rates and complications related to the use of prosthetics for hiatal closure were reviewed and compared. Additionally, recent experiences and recommendations of experienced experts in this field were collected. RESULTS: The results of 42 studies were analyzed in this review. Some techniques of mesh hiatal closure were evaluated; however, most authors prefer posterior mesh cruroplasty. The type and shape of hiatal meshes vary from small angular meshes to A-shaped, V-shaped, or complete circular meshes. The most frequently utilized materials are polypropylene, polytetrafluoroethylene, or dual meshes. All studies show a low rate of postoperative hernia recurrence, with no mortality and low morbidity. In particular, comparative studies including two prospective randomized trials comparing simple sutured hiatal closure to prosthetic hiatal closure show a significantly lower rate of postoperative hiatal hernia recurrence and/or intrathoracic wrap migration in patients who underwent prosthetic hiatal closure. CONCLUSIONS: Laparoscopic large hiatal/paraesophageal hernia repair with prosthetic meshes as well as laparoscopic antireflux surgery with prosthetic hiatal closure are safe and effective procedures to prevent hiatal hernia recurrence and/or postoperative intrathoracic wrap migration, with low complication rates. The type of mesh, particularly the size and shape, is still controversial and is a matter for future research in this field.     

Biological tissue adhesive for mesh-application in pigs: An experimental study

Background Tissue damage during herniotomy may attribute to postoperative complications including chronic pain, bleeding and infection. Thus the aim of this study was to evaluate a due and simple operative procedure with intraperitoneal application of mesh with glue in an experimental model prior to use in humans.Method Laparoscopic insertion of a mesh was performed in three pigs. The meshes were fixed with a collagen glue. The pigs were sacrificed after 8 weeks and macroscopic and microscopic evaluation of the meshes, were performed.Results The intraperitoneal placed meshes did not migrate through the study period, and there was no sign of inflammation in surrounding tissue or adhesions around the meshes.Conclusions If these findings can be applied to human inguinal herniotomy, this may lead to significant fewer complications including development of acute and chronic pain, formation of seroma and infection. Furthermore the operation technique is very simple.     

Revision of thumb trapeziometacarpal arthroplasty

PURPOSE: To determine the incidence of revision surgery after thumb trapeziometacarpal joint arthroplasty and to present the expected results of future surgical treatment. METHODS: We reviewed the patient database at our medical center and found 654 procedures performed between 1988 and 2000 for the treatment of thumb basal joint arthritis. From the database we found that revision arthroplasties were performed on 15 patients with 17 arthroplasties in the treatment of mechanical pain related to instability or bone impingement. Referred patients with primary surgery performed elsewhere and patients with neurogenic pain were reviewed but not included as a primary focus of this study. The revision surgical procedures included soft-tissue interposition alone or soft-tissue interposition with ligament reconstruction for mechanical symptoms and neurolysis of peripheral nerves for associated neurogenic pain. The assessment included preoperative and postoperative patient chart review, measurement of pinch and grip strengths, radiographic assessment, and patient contact to provide complete medical information including any further medical or surgical treatment. RESULTS: Based on a grading system previously used to evaluate thumb revision surgery, objective good (or satisfactory) results were found in 13 of 17 revision procedures. The method of soft-tissue revision (resection with soft-tissue interposition or resection with ligament reconstruction) did not influence the outcome of good versus fair or poor results. Persistent failures (2 fair, 2 poor) resulted from both soft-tissue interposition alone and revision with ligament support arthroplasties. Revision arthroplasty with soft-tissue procedures for mechanical pain provided predictably good results unless a nerve injury occurred at the time of the revision surgery. CONCLUSIONS: Failure of primary thumb trapeziometacarpal arthroplasty can be salvaged by a second surgery with ligament reconstruction procedures combined with soft-tissue interposition and provides satisfactory patient outcomes in more than 75% of cases studied. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.     

Collagen-coated vs noncoated low-weight polypropylene meshes in a sheep model for vaginal surgery. A pilot study

The aims of this study were dual. First, to evaluate the feasibility of a sheep model as an animal model for vaginal surgery with meshes. Second, to compare host response to two low-weight polypropylene (PP) meshes, a noncoated (Soft Prolene™, Gynecare, Ethicon) and a coated mesh with an absorbable hydrophilic film (Ugytex™, Sofradim). Thirty-six 20×20 mm polypropylene meshes (18 coated and 18 noncoated) were surgically implanted by the vaginal route in 12 adult ewes. Meshes were implanted in the anterior (n=12) and the posterior vaginal compartments (n=24). Animals were killed 1 (n=6) and 12 (n=6) weeks after surgery. Postimplantation evaluation included macroscopical examination, histological and immunohistochemical analysis and histomorphometrical measures of the distance between the meshes and the vaginal epithelium. The experimental procedure was feasible in all cases. Vaginal erosions were observed twice as frequently with the noncoated-PP meshes (6/18, 33.3%) as with the coated-PP meshes (3/18, 16.7%), even if that difference was not significant (p=0.4). However, no differences were observed between the two meshes in terms of shrinkage, tissue ingrowth, inflammatory response, and position of the mesh in the vaginal wall. The mechanism involved in the reduction of vaginal erosion could be due to the lesser adhesion of the coated mesh on the vaginal wound during the early postoperative period.     

Biomechanische Forschung – von der Testung zur klinischen Anwendung

Necessity of testing

In order to increase the success of a surgical procedure on the spine, new and improved implant systems and surgical techniques are constantly being developed. Analyses should be performed using in vitro human specimens and in silico models to assess and quantify postoperative and long-term functional ability. To ensure the mechanical reliability of these techniques, standardized test methods are prescribed on the implant itself.

Testing of implants

In all tests, it is important that the implants are exposed to both possible physiological and extreme loading situations. The goal is to identify weak points of the implant prior to its clinical use in order to avoid later implant-related revision surgery. Therefore, an individual experimental design is required for each implant.     

The effects of different hernia repair methods on postoperative pain medication and CRP levels

Although tension-free techniques of hernia repair using synthetic meshes have yielded encouraging results, the best method of inguinal hernia repair is still unclear. The aim of this study was to compare the responses of inflammatory mediators and postoperative pain relief following laparoscopic total extraperitoneal (TEP) hernioplasty, open tension-free mesh hernioplasty (Lichtenstein), posterior preperitoneal mesh hernioplasty (Nyhus procedure), and Bassini procedure. Patients with primary inguinal hernia were randomized in the operating room to undergo one of these repair techniques. Group I comprised 24 patients treated by Lichtenstein procedure; Group II comprised 21 patients treated by Nyhus procedure; Group III comprised 19 patients treated by Bassini procedure; and Group IV comprised 20 patients treated by laparoscopic TEP mesh hernioplasty. Postoperative pain levels following hernia repair were compared by measuring the use of patient-controlled analgesia (PCA) during the 24 hours after surgery. Serum samples withdrawn before surgery and 48 hours after surgery were assayed for C-reactive protein (CRP) content. Patient characteristics, operating time, and operative and early complications were noted. Serum CRP levels rose markedly following Nyhus (184.5 +/- 41.6 mg/L), Lichtenstein (138.4 +/- 72.5 mg/L), and Bassini repair (137.2 +/- 55.9 mg/L) compared with that of patients who underwent TEP mesh hernioplasty (55.5 +/- 41.2 mg/L). There were also significant differences in the postoperative need for analgesics via PCA among patients undergoing Nyhus (382.9 +/- 189.1 mg), Bassini (303.2 +/- 173.7 mg), and Lichtenstein (253.9 +/- 129.3) procedures compared with 196.6 +/- 148.8 mg for the TEP mesh hernioplasty group. Patients in the Lichtenstein group also had significantly less need of analgesics than those in the Nyhus and Bassini groups. In conclusion, TEP mesh hernioplasty is less traumatic and yields less postoperative pain than the Nyhus, Lichtenstein, and Bassini procedures.     

Comparison between two laparoscopic retropubic urethropexy

BACKGROUND: To compare two different transperitoneal laparoscopic urethropexy procedures. METHODS: In this prospective randomized open trial, 60 women affected by genuine stress incontinence were enrolled and randomized in two groups of surgical technique. Group A was treated with transperitoneal laparoscopic retropubic urethropexy using non absorbable sutures, and group B with prolene meshes fixed with tackers or staplers. The failure rate was defined subjectively and objectively. The subjective evaluation was performed asking the patients if they had urine loss and expressing the symptomatology using a visual analog scale before surgery and after each follow-up visit. The objective evaluation was performed with clinical evaluation and/or with the use of multichannel urodynamic studies. RESULTS: No significant differences in intra- operative and postoperative complications between the two groups were observed. The subjective failure rate was not significantly different between the two groups at 3, 6, and 12 months from surgery. At 3 and 6 months follow-up, the objective failure rate was not significantly different between the two groups. Moreover, at 12 months from surgical procedure the objective failure rate was significantly lower in group A than in group B. CONCLUSIONS: Transperitoneal laparoscopic retropubic urethropexy performed using sutures is more effective than the mesh technique.     

Prospective randomized controlled study using polyethylene mesh for inguinal hernia meshplasty as a safe and cost-effective alternative to polypropylene mesh

Most patients who come to a general hospital in a developing country are poor. The most important prohibiting factor for use of polypropylene mesh in hernia repair is its exorbitant cost. Hence, research workers have been on the lookout for an equally effective but economically affordable mesh. Worldwide, surgical repair of inguinal hernia is the most common general surgery procedure performed at the present. Lifetime risk of groin hernia is 15% in males and 5% in females. Most of the patients who visit a general hospital are from either lower middle class or poor socioeconomic strata. The most important prohibiting factor for use of polypropylene mesh in hernia repair for the common man is its exorbitant cost. The aim of this study is to document the feasibility, safety and cost-effectiveness of the use of polyethylene mesh. A single blind, prospective, randomized controlled study, comparing 35 patients of two groups was conducted in a tertiary teaching hospital over a period of 5?years. The patients in both groups underwent inguinal hernioplasty, and were administered similar antibiotics and analgesics. The postoperative course with regard to pain, seroma formation, infection, hospital stay, recurrence and scar quality was evaluated and compared. Statistical analysis was performed with Chi square test. The properties of both meshes were the same with respect to ease of handling, pain score, seroma formation, infection rate, resumption of daily activities, scar quality and mesh rejection. Recurrence rate was zero for both groups. Polyethylene mesh was 2,808 times cheaper than the commercially available polypropylene mesh. This study proved the safety, simplicity, efficacy and cost-effectiveness of polyethylene mesh for inguinal hernia meshplasty, insuring economical, accessible health care for the financially weak section of the population.     

Effects of different kinds of meshes on postoperative adhesion formation in the New Zealand White rabbit

The aim of this study was to compare the effect of different kinds of surgical meshes on postoperative adhesion formation. Forty-two New Zealand White rabbits were studied. The rabbits were grouped into six groups, according to the type of surgical meshes (Prolene, Mersilene, Vypro, polytetraflouroethylene (PTFE), Proceed and control group) implanted into the peritoneum cavity. Thirty days after the operation, the relaparotomies were carried out, and any adhesions observed between the implanted mesh and tissues were evaluated and graded. The mean adhesion degree was 9.2 in the Mersilene mesh group, 9.5 in the Prolene mesh group, 9.7 and in the Vypro mesh group (P > 0.05). The mean adhesion degree was 1 in the control group, 2.75 in the Proceed mesh group and 2.25 in the PTFE mesh group. There was a significant difference in adhesion degree between the control, Proceed and PTFE groups and the Prolene, Mersilene and Vypro mesh groups. The adhesion degree was significantly lower in the Proceed and PTFE mesh groups when comparing them with the Prolene, Mersilene and Vypro meshes.     

Surgical technic in femur shaft fenestration within the scope of revision operations following hip joint total endoprostheses

In revision arthroplasty the loss of stability secondary to fenestration of the proximal femur reduces the loading capacity of the limb and increases the risk of postoperative fractures. Trying to improve the fenestration technique we tested the usual fenestration procedure experimentally. Besides pure axial load we investigated the torsional forces of the proximal femur in the bended hip position. We recorded the deformation under increasing load and analysed the fracture pattern. The results shows an unwarantable loss of stability in lateral or complete ventral fenestration procedures. Ventral fenestration procedures with smooth edges and intact proximal bony ring having additional prosthesis stem support presented the best mechanical results. According to the tolerated load it is possible to give guide-lines for the postoperative treatment in the cemented and cementless arthroplasty of the hip joint.     

Bi-layer hernioplasty in day surgery

Nowadays the modern surgical techniques of hernia repair highly consider not only the decrease of the recurrence rate, but also a fast recovery, minimal postoperative pain and low costs of this type of surgery. This paper presents the preliminary results of a study performed on 41 patients diagnosed with inguinal hernia and operated under local anesthesia, as day surgery cases, during 2004-2006. The selection of the patients was performed under the "Guidelines and Standards for Day Surgery in Australia". We used local "step by step" anesthesia with a solution of 20 ml of lydocaine 1%, 20 ml of marcaine 0.5% and and 20 ml of NaCl 0.9%. The surgical procedure based on the sutureless technique "Gilbert", implied the placement of two polypropylene meshes: one of them introduced through the deep inguinal ring, and the other one in the inguinal channel, minimally fixed. We studied: intraoperative comfort and postoperative pain of the patients, problems related to the surgical technique, the operative time, complications and the recurrence rate. The follow-up period was 14 months. 85.36% of the patients had a very good intraoperative comfort, and only 14.64 % of them needed supplementary intravenous analgesia; none of the patients needed conversion to general anesthesia. The mean operative time was 65 minutes. The complications were: seroma (3 patients) and hematoma (1 patient), all of them treated conservatively. No recurrence was noticed. From this preliminary study it seems that the surgical treatment of the inguinal hernia with double polypropylene mesh, under local anesthesia and as day surgery is feasible and secure. The minimal postoperative complications and the patients' satisfaction show that the new concept of day surgery must be promoted in our surgery clinics. However, we must emphasize that, in order to obtain good results on a larger scale, certain measures are mandatory, such as: organizing a special area and circuits for day surgery, nursing at home, precise inform of the patients (video samples), the use of modern communication (internet) with patients.     

Reconstruction of femoral defects in revision hip surgery: risk of fracture and stem migration after impaction bone grafting

The use of impaction bone grafting during revision arthroplasty of the hip in the presence of cortical defects has a high risk of post-operative fracture. Our laboratory study addressed the effect of extramedullary augmentation and length of femoral stem on the initial stability of the prosthesis and the risk of fracture. Cortical defects in plastic femora were repaired using either surgical mesh without extramedullary augmentation, mesh with a strut graft or mesh with a plate. After bone impaction, standard or long-stem Exeter prostheses were inserted, which were tested by cyclical loading while measuring defect strain and migration of the stem. Compared with standard stems without extramedullary augmentation, defect strains were 31% lower with longer stems, 43% lower with a plate and 50% lower with a strut graft. Combining extramedullary augmentation with a long stem showed little additional benefit (p = 0.67). The type of repair did not affect the initial stability. Our results support the use of impaction bone grafting and extramedullary augmentation of diaphyseal defects after mesh containment.     

不同材质补片固定大鼠膈肌后的炎症反应、粘连及补片皱缩情况对比研究

背景与目的：食管裂孔疝是外科常见病症，临床上多采用补片以无张力修补的方式进行治疗。食管裂孔疝的补片修补中补片的选择及其应用效果方面的实验数据仍相对缺乏。因此，本研究通过在大鼠食道裂孔处膈肌组织上分别固定聚丙烯补片和复合补片，比较两种材质补片对周围组织的影响，以及自身皱缩情况，为临床食管裂孔疝补片的选择提供参考。方法：雄性SD大鼠在分离胃部与肝脏相连接组织显露胃食道裂孔后，分别用单丝缝线将轻量聚丙烯补片（聚丙烯补片组）或复合补片（复合补片组）固定于食道裂孔处膈肌组织，或不进行补片固定（假手术组）。分别在术后7、15、30 d时记录每组每只大鼠的体质量和饮食量。观察30 d后处死大鼠，分析补片皱缩程度、粘连强度以及膈肌组织的病理学变化。结果：各组大鼠手术前后的体质量及每天进食量均无明显的变化（均P>0.05）。复合补片组膈肌组织与补片的粘连范围及粘连程度分值均明显低于聚丙烯补片组（均P<0.05）；两组补片均出现皱缩，但复合补片组术后补片面积明显大于聚丙烯补片组，皱缩率明显低于聚丙烯补片组（均P<0.05）；与假手术组比较，聚丙烯补片组和复合补片组膈肌组织出现局部肌纤维萎...     

What do we know about titanized polypropylene meshes? An evidence-based review of the literature

Purpose

Despite the vast selection of brands available, nearly all synthetic meshes for hernia surgery continue to use one or other of three basic materials: polypropylene, polyester and ePTFE. These are used in combination with each other or with a range of additional materials such as titanium, omega 3, monocryl, PVDF and hyaluronate. This systematic review of all experimental and clinical studies is aimed at investigating whether titanized meshes confer advantages over other synthetic meshes in hernia surgery.

Materials and methods

A search of the medical literature from 2002 to 2012, as indexed by Medline, was performed, using the PubMed search engine (http://www.pubmed.gov). The search terms were: hernia mesh, titanium coating, lightweight mesh, TiMesh, mesh complications. All papers were graded according to the Oxford hierarchy of evidence.

Results

Patients operated on with the Lichtenstein technique performed using the lightweight titanium-coated mesh have a shorter convalescence than those with the heavy-weight mesh Prolene. For inguinal hernias operated on with the TAPP technique and using a lightweight titanium-coated mesh in comparison to a heavy-weight Prolene mesh, the early postoperative convalescence seems to improve. Titanized meshes do exhibit a negative effect on sperm motility 1 year after a TEP operation, but not after 3 years. The laparoscopic IPOM technique with a titanium-coated polypropylene mesh was associated with less postoperative pain in the short term, lower analgesic consumption and a quicker return to everyday activities compared with the Parietex composite mesh.

Conclusion

In clinical studies, the titanium-coated polypropylene mesh shows in inguinal hernia repair certain benefits compared with the use of older heavy-weight meshes.     

Multicentric observational study of pain after the use of a self-gripping lightweight mesh

Introduction  

Investigation in the field of inguinal hernia surgery is now focused on postoperative pain. The extended use of lightweight meshes and alternative methods of fixation may play a relevant role in the reduction of pain. In this study, a new self-gripping lightweight polypropylene mesh is tested.