Comparison of a new self-gripping mesh with other fixation methods for laparoscopic hernia repair in a rat model

Abdominal Wall Reconstruction with Retrorectus Self-Adhering Mesh: A Single-Center Long-Term Follow-Up

BACKGROUND

Mesh repair has been demonstrated to be superior to suture alone in ventral hernia repair. In a previous short-term pilot study, the authors found lower postoperative narcotic requirements with self-adhering mesh. The aim of this study was to follow-up on that pilot study, using long-term data.

METHODS

This is a retrospective review of a prospectively collected database. All patients who underwent ventral hernia repair with retrorectus mesh and who had at least a 12-month follow-up were reviewed. Comparisons were performed between patients who received self-adhering mesh and those who received transfascially sutured mesh, using matched-pair analysis, examining perioperative outcomes, surgical-site occurrences, and hernia recurrence/bulge.

RESULTS

Forty-two patients were included in the study, with 21 patients undergoing repair with transfascially sutured mesh and 21 patients receiving self-adhering mesh. Average length of follow-up was 1078 days. There were no significant differences between the two groups in baseline characteristics. Patients receiving self-adhering mesh had significantly shorter surgery, and a shorter hospital length of stay. They also had a tendency toward lower narcotic requirements. There were no significant differences in the rate of surgical-site occurrences, hernia recurrences, or bulge between the two groups.

CONCLUSIONS

This long-term study shows that self-adhering mesh in ventral hernia repair results in similar long-term outcomes to transfascially sutured mesh, with shorter surgery, shorter length of stay, and a tendency toward improved pain control. These findings mirror the known advantages of self-adhering mesh in inguinal hernia repair. Further research is needed to study the incidence of chronic pain and the cost-effectiveness of self-adhering mesh.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Immediate Repair With a Self-Gripping Retromuscular Mesh for Abdominal Wall Defect Following Tumor Resection

Background: Prosthetic repair is always employed after large abdominal wall tumor resection, while chronic pain is one of the mesh-related complications after traumatic fixation. The objective of this research was to evaluate the outcomes of retromuscular repair with self-gripping mesh after abdominal wall tumor resection.Methods: The study was a monocentric retrospective analysis following STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) statements of all patients with abdominal wall tumor >5 cm in diameter undergoing tumor excision and retromuscular repair with self-gripping mesh. Demographic, operative, early postoperative, and follow-up data were noted. Visual Analog Scale, ranging from 0 (no pain) to 10 (very severe pain), was used to estimate the wound pain.Results: 24 patients were included in this study, and the defect following tumor resection was 26.9±10.0 cm². There was no tumor recurrence or incisional hernia in median follow-up of 20 months, and the mean VAS score was 0.4. Three had foreign body feeling and no one suffered chronic pain.Conclusions: Immediate repair with a self-gripping retromuscular mesh can be considered as an effective way to treat an abdominal wall defect after resecting an abdominal wall tumor.

On-demand anchoring of wireless soft miniature robots on soft surfaces

Anchoring soft millirobots on surfaces, such as biological tissues, is essential to perform long-duration medical functions robustly on a target position. For robust anchoring, we propose a wireless mechanism that can be precisely controlled by remote heating to achieve on-demand needle release and mechanical interlocking. Such a mechanism can be easily integrated on existing untethered soft robots, allowing them to anchor robustly to soft surfaces while retaining their locomotion capabilities. Furthermore, we demonstrate advanced functionalities of such robots, such as controlled surface detachment and subsurface drug delivery into three-dimensional cancer spheroids. Given these capabilities, the proposed mechanism can serve as a platform for the development of soft robots with a new suite of biomedical capabilities.

Untethered soft miniature robots capable of accessing hard-to-reach regions can enable new, disruptive, and minimally invasive medical procedures. However, once the control input is removed, these robots easily move from their target location because of the dynamic motion of body tissues or fluids, thereby restricting their use in many long-term medical applications. To overcome this, we propose a wireless spring-preloaded barbed needle release mechanism, which can provide up to 1.6 N of force to drive a barbed needle into soft tissues to allow robust on-demand anchoring on three-dimensional (3D) surfaces. The mechanism is wirelessly triggered using radio-frequency remote heating and can be easily integrated into existing untethered soft robotic platforms without sacrificing their mobility. Design guidelines aimed at maximizing anchoring over the range of the most biological tissues (kPa range) and extending the operating depth of the device inside the body (up to 75%) are also presented. Enabled by these advances, we achieve robust anchoring on a variety of ex vivo tissues and demonstrate the usage of such a device when integrated with existing soft robotic platforms and medical imaging. Moreover, by simply changing the needle, we demonstrate additional functionalities such as controlled detachment and subsurface drug delivery into 3D cancer spheroids. Given these capabilities, our proposed mechanism could enable the development of a new class of biomedical-related functionalities, such as local drug delivery, disease monitoring, and hyperthermia for future untethered soft medical robots.

THE USE OF SURGICAL ADHESIVE AND SUTURE FIXING MESHES TO THE ABDOMINAL WALL: AN EXPERIMENTAL STUDY IN RATS

AIM

Proper fixation of the surgical mesh determines the success of a herniorrhaphy. Understanding the inflammatory response and the mechanical properties of the mesh helps to define whether a fixation method is superior. This study aimed to evaluate the healing of defects in the abdominal wall of rats, comparing the repair of macroporous polypropylene meshes fixed with surgical glue and polypropylene thread.

METHODS

In 20 Wistar rats, a defect was produced in the abdominal wall, with the integrity of the parietal peritoneum. For correction, the meshes were fixed with surgical glue (2-octyl cyanoacrylate) (subgroup C1), or polypropylene suture (subgroup C2). The two subgroups of 10 animals were euthanized on the 90th postoperative day, and the fragments of the abdominal wall were submitted to macroscopic, histological, and tensiometric analysis.

RESULTS

Macroscopic analysis did not show any abnormalities. Tensiometry on the 90th postoperative day in subgroup C1 showed mean rupture tension of 28.47N and in subgroup C2 32.06N (p=0.773). The inflammatory process score revealed that both groups are in the subacute phase (p=0.380).

CONCLUSION

The fixation of a polypropylene macroporous mesh to repair an abdominal wall defect can be performed with surgical glue (2-octyl cyanoacrylate) or polypropylene suture, both methods being equally effective.

The comparison of self-gripping mesh and conventional mesh in laparoscopic inguinal hernia repair: the results of meta-analysis

Self-gripping mesh is widely used in laparoscopic inguinal hernia repair and some researches report its advantages compared with conventional mesh. The aim of this study was to assess outcomes of self-gripping mesh and conventional mesh in laparoscopic inguinal hernia repair. A systematic literature review was undertaken to identify studies comparing the results of self-gripping mesh and conventional mesh in laparoscopic inguinal hernia repair. Outcomes, including recurrence, chronic pain, operation time, hematoma, seroma and infection, were measured. Four randomized controlled trials and 1 prospective comparative study were analyzed. The incidence of chronic pain in self-gripping group was significantly lower than that in conventional group (OR 0.43, 95% CI 0.20, 0.93, P = 0.03), and there was no significant difference in hernia recurrence (OR 0.31, 95% CI 0.03, 3.06, P = 0.32), operation time (MD 0.06, 95%CI - 2.32, 2.44, P = 0.96), hematoma (OR 1.01, 95% CI 0.33, 3.07, P = 0.99) and seroma (OR 0.90, 95% CI 0.49, 1.66, P = 0.73). Laparoscopic inguinal hernia repair using self-gripping mesh is associated with a decreased incidence of chronic pain compared with conventional mesh, without increased postoperative complications.

Self-adhesive hydrogel meshes reduce tissue incorporation and mechanical behavior versus microgrips self-fixation: a preclinical study

Purpose

Atraumatic mesh fixation for abdominal hernia repair has been developed to avoid the disadvantages of classical fixation with sutures, which is considered a cause of chronic pain and discomfort. This study was designed to analyze, in the short and medium term, the biological and mechanical behavior of two self-fixing meshes compared to that of a polypropylene (PP) mesh fixed with a cyanoacrylate (CA) tissue adhesive.

Methods

Partial abdominal wall defects (6 × 4 cm) were created in New Zealand rabbits (n = 36) and repaired using a self-adhesive hydrogel mesh (Adhesix™), a self-gripping mesh (ProGrip™) or a PP mesh fixed with CA (Surgipro™ CA). After 14 and 90 days, the host tissue incorporation, macrophage response and biomechanical strength were examined.

Results

At 14 and 90 days, the ProGrip and Surgipro CA meshes showed good host tissue incorporation; however, the Adhesix implants presented poor integration, seroma formation and a higher degree of shrinkage. The Adhesix hydrogel was completely reabsorbed at 14 days, whereas ProGrip microhooks were observed at all study times. The macrophage response was higher in the ProGrip and Surgipro CA groups at 14 and 90 days, respectively, and decreased over time. At 90 days, the ProGrip implants showed the highest tensile strength values and the Adhesix implants showed the highest failure stretch.

Conclusion

Meshes with mechanical microgrip self-fixation (ProGrip) show better biological and mechanical behavior than those with adhesive hydrogel (Adhesix) in a preclinical model of abdominal hernia repair in rabbits.

Strategies for Mesh Fixation in Abdominal Wall Reconstruction: Concepts and Techniques

SUMMARY

Ventral hernias have numerous causes, ranging from sequelae of surgical procedures to congenital deformities. Patients suffering from these hernias experience a reduced quality of life through pain, associated complications, and physical disfigurement. Therefore, it is important to provide these patients with a steadfast repair that restores functionality and native anatomy. To do this, techniques and materials for abdominal wall reconstruction have advanced throughout the decades, leading to durable surgical repairs. At the cornerstone of this lies the use of mesh. When providing abdominal wall reconstruction, a surgeon must make many decisions with regard to mesh use. Along with the type of mesh and plane of placement of mesh, a surgeon must decide on the method of mesh fixation. Fixation of mesh provides an equal distribution of tension and a more robust tissue-mesh interface, which promotes integration. There exist numerous modalities for mesh fixation, each with its own benefits and drawbacks. This Special Topic article aims to compare and contrast methods of mesh fixation in terms of strength of fixation, clinical outcomes, and cost-effectiveness. Methods included in this review are suture, tack, fibrin glue, mesh strip, and self-adhering modes of fixation.

Polymer Hernia Repair Materials: Adapting to Patient Needs and Surgical Techniques

Biomaterials and their applications are perhaps among the most dynamic areas of research within the field of biomedicine. Any advance in this topic translates to an improved quality of life for recipient patients. One application of a biomaterial is the repair of an abdominal wall defect whether congenital or acquired. In the great majority of cases requiring surgery, the defect takes the form of a hernia. Over the past few years, biomaterials designed with this purpose in mind have been gradually evolving in parallel with new developments in the different surgical techniques. In consequence, the classic polymer prosthetic materials have been the starting point for structural modifications or new prototypes that have always strived to accommodate patients’ needs. This evolving process has pursued both improvements in the wound repair process depending on the implant interface in the host and in the material’s mechanical properties at the repair site. This last factor is important considering that this site—the abdominal wall—is a dynamic structure subjected to considerable mechanical demands. This review aims to provide a narrative overview of the different biomaterials that have been gradually introduced over the years, along with their modifications as new surgical techniques have unfolded.

Randomized Trial Comparing Self-Gripping Mesh with Polypropylene Mesh in Female Lichtenstein Hernioplasty

Several randomized trials comparing self-gripping mesh with polypropylene (PL) mesh in Lichtenstein hernioplasty revealed that the self-gripping mesh significantly reduced the operation time. In these studies, some enrolled only male patients, and in others, the proportion of women was extremely low. The aim of this research was to compare outcomes after self-gripping mesh repair with PL mesh secured with sutures in female Lichtenstein hernioplasty. Female patients with primary unilateral inguinal hernia were assigned randomly to undergo Lichtenstein hernioplasty with a self-gripping ProGrip (PG) mesh or a sutured PL mesh, followed-up at one week, one month, three months, one year, and two years. Demographics, hernia characteristics, and operative outcomes data were analyzed. Pain was assessed with a visual analog scale (0–10), and quality of life (QOL) was estimated by a 36-item short-form general survey (0–26). Forty eight patients in the PG group and 51 participants in the PL group completed the follow-up. The operation time of the PG (54.1 ± 12 minutes) group was significantly shorter than that of the PL (60.9 ± 11.3 minutes) group ( P = 0.045). At the one-month follow-up, the incidence of foreign body feeling in the PG group was significantly higher than that in the PL group ( P = 0.031), whereas no significant difference was observed in visual analog scale ≥3 and QOL. In a follow-up of three months, one year, and two years, there was no significant difference in foreign body feeling, chronic pain, QOL, and recurrence between two groups. The surgical outcomes of self-gripping mesh are comparable to those of the ordinary PL mesh with a reduced operation time in female Lichtenstein hernioplasty. Registration number: ChiCTR1800017360 ( http://www.chictr.org.cn ).

Application of the novel enhanced transabdominal preperitoneal (ETAP) technique for laparoscopic suprapubic incisional hernia repair

Suprapubic incisional hernia is a special type of incisional hernia, the optimal choice of surgery for which remains controversial. Inspired by advantages of laparoscopic incisional hernia repair and inguinal hernia repair, we developed a novel laparoscopic surgery procedure for suprapubic incisional hernia repair: the enhanced transabdominal preperitoneal (ETAP) technique. To create a peritoneal flap, the peritoneum was dissected from 2 cm above the abdominal wall defect to 2 cm below the pubic arch, then the hernia defect was closed with a full-thickness transabdominal suture. Following the position of mesh to cover the defect with an 5-cm overlap on all sides, the peritoneal flap was closed with continuous suture. In this study, a total of 57 patients with suprapubic incisional hernia underwent laparoscopic ETAP. The mean hernia size was 61.5 cm², the average mesh size was 173.6 cm², the mean operating time was 90 min, the mean blood loss was 34 cc, and the average hospital stay was 2.6 days. In the follow-up period, which ranged from 12 to 45 months, the overall incidence of complications was 17.86%. Six patients developed seroma without herniation, six patients suffered from obvious postoperative pain, and four patients experienced urinary retention. All complications resolved without treatment. No recurrence was observed. In conclusion, the laparoscopic ETAP technique contributes to reduced rates of suprapubic incisional hernia repair and mesh-induced complications.

Optimal Pain Control in Abdominal Wall Reconstruction

Lack of physician familiarity with alternative pain control strategies is a major reason why opioids remain the most commonly used first-line treatment for pain after surgery. This is perhaps most problematic in abdominal wall reconstruction, where opioids may delay ambulation and return of bowel function, while negatively affecting mental status. In this article, we discuss multimodal strategies for optimal pain control in abdominal wall reconstruction. These strategies are straightforward and are proven to improve pain control while minimizing opioid-associated side effects.

Effects of suture tecnique on mesh shrinkage

OBJECTIVE

Polypropylene meshes are one of the most frequently used patches in inguinal hernia repairs. This material was proved to be not completely inert, and may cause inflammatory responses like foreign body reactions. One of the physical results of these inflammatory reactions against the mesh is mesh shrinkage which is responsible for recurrence and pain. In this study, we aimed to investigate the effects of the suture technique on mesh shrinkage.

METHODS

36 animals were used for the study. Subjects were divided into 3 groups. In the first group the mesh (onlay) was not fixated by any means. In the second group, mesh was placed on the abdomen wall, after which the mesh was fixated with interrupted suturing. In the third group, continuous suturing was applied after the placement of the mesh. Mesh shrinkage was measured macroscopically, and the mesh site reaction was evaluated microscopically. At the end of the second month, 18 subjects were sacrificed again to conduct the same procedure.

RESULTS AND CONCLUSION

When meshes are used for hernia repairs, shrinkage may be observed in meshes placed on fascia. In the first group without mesh fixation, mesh shrinkage was more significant in the second month compared to the first month. The amount of shrinkage of without fixation group was found to significantly differ during the second month from interrupted and continuous suture groups. Even though statistically not significant, fixation of the mesh with interrupted sutures seems to be more advantageous compared to fixation with continuous sutures.

Advances in medical adhesives inspired by aquatic organisms' adhesion

In biomedicine, adhesives for hard and soft tissues are crucial for various clinical purposes. However, compared with that under dry conditions, adhesion performance in the presence of water or moisture is dramatically reduced. In this review, representative types of medical adhesives and the challenging aspects of wet adhesion are introduced. The adhesion mechanisms of marine mussels, sandcastle worms, and endoparasitic worms are described, and stemming from the insights gained, designs based on the chemistry of molecules like catechol and on coacervation and mechanical interlocking platforms are introduced in the viewpoint of translating these natural adhesion mechanisms into synthetic approaches.

Herniorrafia inguinal convencional com tela autofixante versus videolaparoscópica totalmente extraperitoneal com tela de polipropileno: resultados no pós-operatório precoce

RESUMO Objetivo: avaliar o resultado no pós-operatório precoce do tratamento da hérnia inguinal pela técnica convencional com tela autofixante versus videolaparoscópica totalmente extraperitoneal com uso da tela de polipropileno. Foram comparados, sobretudo, dor, tempo cirúrgico e complicações precoces. Métodos: estudo prospectivo, de série de casos, realizado na Clínica Cirúrgica A, do Hospital Universitário Gaffrée e Guinle (HUGG), no qual 80 casos consecutivos foram estudados. Apenas pacientes com hérnia inguinal unilateral, não recidivada e operadas em caráter eletivo foram incluídas no estudo. Os pacientes foram divididos em dois grupos, de 40 pacientes cada; grupo AF (técnica convencional com uso de tela autofixante) e grupo VL (técnica videolaparoscópica com uso de tela de polipropileno). Os pacientes foram acompanhados até o 45º dia de pós-operatório. Resultados: dos 80 pacientes operados no estudo, 98,7% pertenciam ao sexo masculino e a maioria era portadora de hérnia inguinal direita indireta (Nyhus II). Não houve diferença entre os grupos estudados no que diz respeito à dor e tempo operatório. No entanto, ocorreram mais complicações (seroma e hematoma) no grupo da cirurgia aberta. Conclusão: as duas operações realizadas se mostraram factíveis, seguras e estão relacionadas à mínima dor pós operatório e a um baixo tempo cirúrgico.

Abdominal Wall Reconstruction Using Retrorectus Self-adhering Mesh: A Novel Approach

BACKGROUND

In abdominal wall reconstruction, the retrorectus plane offers an ideal location for mesh placement. Mesh fixation in this plane is often achieved using transfascial sutures, which risks entrapping intercostal nerves and causing significant pain, and takes time to place. A novel alternative is the use of sutureless self-adhering mesh. Although the use of this mesh in inguinal hernias has been well described, studies on its use in abdominal wall reconstruction are lacking.

METHODS

Consecutive patients who underwent ventral hernia repair with retrorectus mesh were reviewed. This included patients who received transfascially sutured mesh and those who received sutureless self-adhering mesh. All patients were followed up for at least 12 months. The amount of narcotics required by each patient postoperatively was calculated. Surgical-site occurrences (SSOs) and hernia recurrence and bulge were measured.

RESULTS

Twenty-six patients underwent abdominal wall reconstruction with retrorectus mesh. This included 12 patients with transfascially sutured mesh and 14 patients with self-adhering mesh. Mean follow-up was 600 days. Baseline characteristics were similar between the 2 groups. Patients receiving self-adhering mesh required significantly less narcotics than patients with transfascially sutured mesh. There were no significant differences in the rate of SSOs between the 2 groups. No hernia recurrences, bulges, or chronic pain occurred in either group.

CONCLUSIONS

This is the first study to compare the outcomes of retrorectus self-adhering mesh and transfascially sutured mesh in abdominal wall reconstruction. Our results show low rates of SSO, recurrence, and bulge with both options, with significantly less acute pain with self-adhering mesh.

Design Strategies and Applications of Biomaterials and Devices for Hernia Repair

Hernia repair is one of the most commonly performed surgical procedures worldwide, with a multi-billion dollar global market. Implant design remains a critical challenge for the successful repair and prevention of recurrent hernias, and despite significant progress, there is no ideal mesh for every surgery. This review summarizes the evolution of prostheses design toward successful hernia repair beginning with a description of the anatomy of the disease and the classifications of hernias. Next, the major milestones in implant design are discussed. Commonly encountered complications and strategies to minimize these adverse effects are described, followed by a thorough description of the implant characteristics necessary for successful repair. Finally, available implants are categorized and their advantages and limitations elucidated, including non-absorbable and absorbable (synthetic and biologically derived) prostheses, composite prostheses, and coated prostheses. This review not only summarizes the state of the art in hernia repair, but also suggests future research directions toward improved hernia repair utilizing novel materials and fabrication methods.

Usage of a self-adhesive mesh in TAPP hernia repair: A prospective study based on Herniamed Register

INTRODUCTION

Inguinal hernia repair is one of the most frequently performed surgical procedures worldwide in general surgery. The transabdominal laparoscopic (TAPP) approach in the therapy of inguinal hernia seems to be a suitable alternative to classical open inguinal hernia repair mainly in the hands of an experienced surgeon. TAPP repair offers the possibility of gentle dissection with implantation of the mesh and the possibility of non-invasive fixation of the implanted mesh.

MATERIALS AND METHODS

Data analysis encompassed all patients who underwent inguinal hernia surgery at our Surgical Department within the period from July 1, 2012 to September 30, 2014 and who fulfilled the inclusion criteria. The standard surgical technique was used. Data were entered and subsequently analysed on the Herniamed platform. Herniamed is an Internet-based register in German and English, and includes all data of outpatient and hospitalised patients who underwent surgery for some type of hernia. All relevant patient data are collected via Internet.

RESULTS

There were 241 patients enrolled in the group and there were 396 inguinal hernias repaired in total. Standard long-term follow-up after 12 months was evaluated in 205 patients (85.06%), and in the rest of the patients during the closing of the study, but at least 6 months after operation. The mean follow-up was at 19.69 months. At the 1-year assessment, mild discomfort was reported in the groin in 10 patients (4.88%) [1-3 on the visual analogue scale (VAS)]. Post-operative pain lasting over 12 months in the groin of moderate degree (4-6 VAS) was reported in two cases (0.97%). There was no recurrence and no chronic post-operative pain of severe degree reported.

CONCLUSION

Our study demonstrates that laparoscopic inguinal hernia repair using the TAPP technique with the implantation of a self-fixation mesh is fast, effective, reliable and economically advantageous method in experienced hands and, according to our results, reduces the occurrence of post-herniorrhaphy inguinal pain (CPIP) and has a low recurrence rate.

Reduction of chronic post-herniotomy pain and recurrence rate. Use of the anatomical self-gripping ProGrip laparoscopic mesh in TAPP hernia repair. Preliminary results of a prospective study

Introduction

The role of fixation of the mesh is especially important in the endoscopic technique. The fixation of mesh through penetrating techniques using staples, clips or screws is associated with a significantly increased risk of developing a post-herniotomy pain syndrome.

Aim

To demonstrate the safety and efficacy of the self-fixating anatomical Parietex ProGrip laparoscopic mesh (Sofradim Production, Trévoux France) used with laparoscopic transabdominal preperitoneal hernia repair. The incidence of chronic post-herniotomy pain and recurrence rate in the follow-up after 12 months were evaluated.

Material and methods

Data analysis included all patients who underwent inguinal hernia surgery at our Surgical Department within the period from 1.05.2013 to 31.12.2014, who fulfilled the inclusion criteria. Standard surgical technique was used. Data were prospectively entered and subsequently analyzed on the Herniamed platform. Herniamed is an internet-based register in German and English language and includes all data of patients who underwent surgery for some types of hernia.

Results

There were 95 patients enrolled in the group and there were in total 156 inguinal hernias repaired. The mean follow-up was 15.52 months. At the assessment at 1 year mild discomfort in the groin was reported in 2 patients (3.51%) (1–3 VAS). No recurrence or chronic postoperative pain was reported.

Conclusions

Laparoscopic inguinal hernia repair using the transabdominal preperitoneal technique with implantation of the ProGrip laparoscopic mesh is a fast, effective and reliable method in experienced hands, which according to our results reduces the occurrence of chronic post-operative inguinal pain with simultaneously a low recurrence rate.

The use of self-gripping (Progrip™) mesh during laparoscopic total extraperitoneal (TEP) inguinal hernia repair: a prospective feasibility and long-term outcomes study

BACKGROUND

The use of self-gripping mesh during laparoscopic TEP inguinal hernia repairs may eliminate the need for any additional fixation, and thus reduce post-operative pain without the added concern for mesh migration. Long-term outcomes are not yet prospectively studied in a controlled fashion.

METHODS

Under IRB approval, from January 2011-April 2013, 91 hernias were repaired laparoscopically with self-gripping mesh without additional fixation. Patients were followed for at least 1 year. Demographics and intraoperative data (defect location, size, and mesh deployment time) are recorded. VAS is used in the recovery room (RR) to score pain, and the Carolinas Comfort Scale ™ (CCS), a validated 0-5 pain/quality of life (QoL) score where a mean score of >1.0 means symptomatic pain, is employed at 2 weeks and at 1 year. Morbidities, narcotic usage, days to full activity and return to work, and CCS scores are reported.

RESULTS

Sixty two patients, with 91 hernias repaired with self-gripping mesh, completed follow-up at a mean time period of 14.8 months. Seventeen hernias were direct defects (average size 3.0 cm). Mesh deployment time was 193.7 s. RR pain was 1.1/10 using a VAS. Total average oxycodone/acetaminophen (5 mg/325 mg) usage = 5.0 tablets, days to full activity was 1.6, and return to work was 4.2 days. Thirteen small asymptomatic seromas were palpated without any recurrences or groin tenderness, and all seromas resolved by the 6 month visit. Transient testis discomfort was reported in five patients. Urinary retention was 3.2%. Mean CCS™ scores at the first visit for groin pain laying, bending, sitting, walking, and step-climbing were 0.2, 0.5, 0.4, 0.3, and 0.3, respectively. At the first post op visit, 4.8% had symptomatic pain (CCS > 1). At 14.8 months, no patients reported symptomatic pain with CCS scores for all 62 patients averaging 0.02, (range 0-0.43). There are no recurrences thus far.

CONCLUSIONS

Self-gripping mesh can be safely used during laparoscopic TEP inguinal hernia repairs; our cohort had a rapid recovery, and at the 1-year follow-up visit, there were no recurrences and no patients reported any chronic pain as defined by a CCS™ > 1.

An in vitro study assessing the effect of mesh morphology and suture fixation on bacterial adherence

PURPOSE

Prosthetic infections, although relatively uncommon in hernia surgery, are a source of considerable morbidity and cost. The aims of this experimental study were to assess the influence of the morphological properties of the mesh on bacterial adherence in vitro. The morphological properties assessed were the polymer type, filament type, filament diameter, mesh weight, mean pore size, and the addition of silver chlorhexidine and titanium coatings. In addition, the study assessed the effect on bacterial adherence of adding a commonly used suture to the mesh and compared adherence rates to self-gripping mesh that does not require suture fixation.

METHODS

Eight commercially sourced flat hernia meshes with different material characteristics were included in the study. These were Prolene(®) (Ethicon(®)), DualMesh(®) (Gore(®)), DualMesh(®) Plus (Gore(®)), Parietex™ ProGrip (Covidien™), TiMesh(®) Light (GfE Medical), Bard(®) Soft Mesh (Bard(®)), Vypro(®) (Ethicon(®)), and Omyra(®) (Braun(®)). Individual meshes were inoculated with Staphylococcus epidermidis and Staphylococcus aureus with a bacterial inoculum of 10(2) bacteria. To assess the effect of suture material on bacterial adhesion, a sterile piece of commonly used monofilament suture material (2.0 Prolene(®), ZB370 Ethicon(®)) was sutured to selected meshes (chosen to represent different commonly used polymers and/or the presence of an antibacterial coating). Inoculated meshes were incubated for 18 h in tryptone soy broth and then analysed using scanning electron microscopy. A previously validated method for enumeration of bacteria using automated stage movement electron microscopy was used for direct bacterial counting. The final fraction of the bacteria adherent to the mesh was compared between the meshes and for each morphological variable. One-way analysis of variance (ANOVA) was performed on the bacterial counts. Tukey's test was used to determine the difference between the different biomaterials in the event the ANOVA was significant.

RESULTS

Properties that significantly increased the mean bacterial adherence were the expanded polytetrafluoroethylene polymer (P < 0.001); multifilament meshes (P < 0.001); increased filament diameter (P < 0.001); increased mesh weight (P < 0.001); and smaller mean pore size (P < 0.001). In contrast, mesh coating with antibacterial silver chlorhexidine significantly reduced bacterial adhesion (S. epidermidis mean bacterial count 140.7 ± 19.1 SE with DualMesh(®) vs. 2.3 ± 1.2 SE with DualMesh(®) Plus, P < 0.001; S. aureus mean bacterial count 371.7 ± 22.7 SE with DualMesh(®) vs. 19.3 ± 4.7 SE with DualMesh(®) Plus, P = 0.002). The addition of 2.0 Prolene suture material significantly increased the mean number of adherent bacteria independent of the mesh polymer or mesh coating (P = 0.04 to <0.001).

CONCLUSION

The present study demonstrates the significant influence of the prosthetic load on bacterial adherence. In patients at increased risk of infection, low prosthetic load materials, i.e., lightweight meshes with large pores, may be beneficial. Furthermore self-fixing meshes, which avoid increasing the prosthetic load and antibacterial impregnated meshes, may have an advantage in this setting.

A bio-inspired swellable microneedle adhesive for mechanical interlocking with tissue

Achieving significant adhesion to soft tissues while minimizing tissue damage poses a considerable clinical challenge. Chemical-based adhesives require tissue-specific reactive chemistry, typically inducing a significant inflammatory response. Staples are fraught with limitations including high-localized tissue stress and increased risk of infection, and nerve and blood vessel damage. Here inspired by the endoparasite Pomphorhynchus laevis, which swells its proboscis to attach to its host's intestinal wall, we have developed a biphasic microneedle array that mechanically interlocks with tissue through swellable microneedle tips, achieving ~3.5-fold increase in adhesion strength compared with staples in skin graft fixation, and removal force of ~4.5 N cm(-2) from intestinal mucosal tissue. Comprising a poly(styrene)-block-poly(acrylic acid) swellable tip and non-swellable polystyrene core, conical microneedles penetrate tissue with minimal insertion force and depth, yet high adhesion strength in their swollen state. Uniquely, this design provides universal soft tissue adhesion with minimal damage, less traumatic removal, reduced risk of infection and delivery of bioactive therapeutics.

Randomized controlled multicenter international clinical trial of self-gripping Parietex™ ProGrip™ polyester mesh versus lightweight polypropylene mesh in open inguinal hernia repair: interim results at 3 months

PURPOSE

To compare clinical outcomes following sutureless Parietex™ ProGrip™ mesh repair to traditional Lichtenstein repair with lightweight polypropylene mesh secured with sutures.

METHODS

This is a 3-month interim report of a 1-year multicenter international study. Three hundred and two patients were randomized; 153 were treated with Lichtenstein repair (L group) and 149 with Parietex™ ProGrip™ precut mesh (P group) with or without fixation. The primary outcome measure was postoperative pain using the visual analog scale (VAS, 0-150 mm); other outcomes were assessed prior to surgery and up to 3 months postoperatively.

RESULTS

Compared to baseline, pain score was lower in the P group at discharge (-10%) and at 7 days (-13%), while pain increased in the L group at discharge (+39%) and at 7 days (+21%). The difference between groups was significant at both time points (P = 0.007 and P = 0.039, respectively). In the P group, patients without fixation suffered less pain compared to those with single-suture fixation (1 month: -20.9 vs. -6.15%, P = 0.02; 3 months: -24.3 vs. -7.7%, P = 0.01). The infection rate was significantly lower in the P group during the 3-month follow-up (2.0 vs. 7.2%, P = 0.032). Surgery duration was significantly shorter in the P group (32.4 vs. 39.1 min; P < 0.001). No recurrence was observed at 3 months in both groups.

CONCLUSIONS

Surgery duration, early postoperative, pain and infection rates were significantly reduced with self-gripping polyester mesh compared to Lichtenstein repair with polypropylene mesh. The use of fixation increased postoperative pain in the P group. The absence of early recurrence highlights the gripping efficiency effect.