Two-criteria optimisation problem for ventral hernia repair

Two-criteria optimisation problem related to laparoscopic ventral hernia repair is formulated in this paper. An optimal implant from a given set and its orientation is sought. The implant is subjected to kinematic extortions due to a patient’s body movement and intra-abdominal pressure. The first criterion of the optimisation problem deals with the reaction force in the implant fastener, while the deflection of the implant constitutes the second criterion. A two-stage optimization procedure is proposed and the optimal solution is determined with the aid of minimization of an additional objective function. Numerical examples for typical locations of hernia are provided.     

腹腔镜腹壁切口疝修补术的临床疗效分析

目的探讨腹腔镜腹壁切口疝修补术的临床疗效。方法选取2015年6月~2016年5月我院收治的腹壁切口疝患者89例,根据治疗方式的不同将患者分为开放组44例和腹腔镜组45例。开放组44例患者采用开放式腹壁切口疝修补术,腹腔镜组45例患者行腹腔镜腹壁切口疝修补术,并对两组患者的手术时间、术中出血量、术后疼痛评分、并发症及复发情况、住院时间进行比较。结果腹腔镜组患者的手术时间长于开放组(P0.05),而术中出血量、术后疼痛评分和住院时间均低于开放组(P0.05),并发症发生率和复发率低于开放组(P0.05)。结论腹腔镜腹壁切口疝修补术是一种安全、有效、可行的治疗手段,值得临床推广应用。     

Herniography in symptomatic patients following inguinal hernia repair.

Patients with symptoms at the site of a previous inguinal hernia repair may constitute a diagnostic dilemma. The usefulness of herniography in the assessment of these patients was evaluated at 54 symptomatic sites in 46 subjects. Ten persistent or recurrent hernias were shown by herniography, only 2 of which were definitely detected on physical examination. The herniogram was normal at 44 sites, of which, on physical examination, 5 were equivocal and 1 was diagnosed as a definite hernia. On the unoperated-on or asymptomatic side, a total of 14 hernias were shown herniographically. Of these hernias, 8 were not detected on physical examination. Herniography was found to be more sensitive than physical examination in detecting hernias at the symptomatic, previously operated-on sites, as well as at the unoperated-on or asymptomatic sites. When a herniogram provides corroborative evidence that hernia has not recurred, the need for reexploration may be eliminated.     

Mechanical properties of mosquito nets in the context of hernia repair

The paper deals with issue of applying mosquito nets as implants in hernia repair, which have already been used in resource-poor developing countries. Uniaxial tensile tests have been conducted on polyester mosquito meshes in two orthogonal directions. Non-linear elastic constitutive laws parameters have been identified to be applied in dense net material models. Mechanical performance of tested mosquito nets has been compared with properties of commercial implants used in treatment of hernia and with properties of human tissue. This study contributes to mechanical knowledge of hernia repair issue by investigation of cheaper alternative to commercial implants.     

Skeletal muscle tissue engineering approaches to abdominal wall hernia repair

Abdominal wall hernias resulting from prior incisions are a common surgical complication affecting hundreds of thousands of Americans each year. The negative consequences associated with abdominal hernias may be considerable, including pain, bowel incarceration, vascular disruption, organ loss, and death. Current clinical approaches for the treatment of abdominal wall hernias focus on the implantation of permanent biomaterial meshes or acellular xenografts. However, these approaches are not infrequently associated with postoperative infections, chronic sinuses, or small bowel obstruction. Furthermore, the most critical complication, hernia recurrence, has been well described and may occur in a large percentage of patients. Despite many advances in repair techniques, wound healing and skeletal muscle regeneration is limited in many cases, resulting in a decrease in abdominal wall tissue function and contributing to the high hernia recurrence rate. This review will give an overview of skeletal muscle anatomy, skeletal muscle regeneration, and herniation mechanisms, as well as discuss the current and future clinical solutions for abdominal wall hernia repair. Birth Defects Research (Part C) 84:315–321, 2008. © 2008 Wiley‐Liss, Inc.     

Computational framework to model and design surgical meshes for hernia repair

Surgical procedures for hernia surgery are usually performed using prosthetic meshes. In spite of all the improvements in these biomaterials, the perfect match between the prosthesis and the implant site has not been achieved. Thus, new designs of surgical meshes are still being developed. Previous to implantation in humans, the validity of the meshes has to be addressed, and to date experimental studies have been the gold standard in testing and validating new implants. Nevertheless, these procedures involve long periods of time and are expensive. Thus, a computational framework for the simulation of prosthesis and surgical procedures may overcome some disadvantages of the experimental methods. The computational framework includes two computational models for designing and validating the behaviour of new meshes, respectively. Firstly, the beam model, which reproduces the exact geometry of the mesh, is set to design the weave and determine the stiffness of the surgical prosthesis. However, this implies a high computational cost whereas the membrane model, defined within the framework of the large deformation hyperelasticity, is a relatively inexpensive computational tool, which also enables a prosthesis to be included in more complex geometries such as human or animal bodies.     

Lipid peroxidation and inguinal hernia repair. Tension-free vs. Andrews technique

AIM OF THE STUDY: To evaluate the early effect of inguinal hernia repair by the tension-free method compared to the conventional Andrew's technique on lipid peroxidation. PATIENTS-METHODS: Thirty-four patients subjected to elective hernia repair were enrolled in the study divided in two groups. Group A (n=18) underwent hernia repair by the tension-free method using a polypropylene mesh. Group B (n=16) underwent hernia repair by the Andrew's technique (i.e. a modification of the Bassini's technique). Venous blood samples were drawn preoperatively and at 12, 24 and 48 h postoperatively. Malondialdehyde (MDA) was estimated by the thiobarbiturate assay. RESULTS: Neutrophil counts were significantly higher in patients of group B compared to group A at 12 and 48 h postoperatively. Concentrations of fibrinogen were similar between the two groups. MDA was significantly higher in patients of group B hours compared to group A at 12, 24 and 48 h postoperatively. Positive correlation was found between neutrophil counts and MDA at 12 h (r: +0.43, P: 0.015) and 48 h (r: +0.496, P: 0.005) but not at 24 h. No correlation was found between serum fibrinogen and MDA. CONCLUSION: Hernia repair by the Andrews's technique elicits a sustained triggering of lipid peroxidation, compared to the tension-free method.     

Incidence and estimated need of caesarean section,inguinal hernia repair,and operation for strangulated hernia in rural Africa.

Numbers of caesarean sections, inguinal hernia repairs, and operations for strangulated hernia performed in 1979-81 at 10 rural hospitals in eastern Africa were matched against estimated populations in the respective catchment areas. Annual rates of each operation varied considerably between hospitals, the averages being: for caesarean sections 25 per 100 000 per year; for inguinal hernia repairs 25 per 100 000 per year; and for operations for strangulated hernia four per 100 000 per year. The estimated minimum needs for these operations, based on available data for morbidity were 225, 175, and 30 per 100 000 per year, respectively. Numerous deaths and cases of permanent disability occur in remote rural villages because common conditions requiring urgent surgery are neither prevented nor properly cared for. A balanced improvement of both primary and secondary care in rural Africa is needed.     

Mathematical modelling of implant in an operated hernia for estimation of the repair persistence

This paper presents mathematical modelling of an implanted surgical mesh used in the repair process of the abdominal hernia. The synthetic implant is simulated by a membrane structure. The author provides a material modelling of the implant based on the dense net model appropriate for technical fabrics. The accuracy of the proposed solution is evaluated by comparing the simulations of the dynamic behaviour of the system with the experiments carried out on physical models of implanted mesh. The model can be used to estimate the repair persistence for different mesh materials, fixing systems and different numbers of tacks to be provided during the surgery in order to resist the cough pressure and required action to avoid hernia recurrence. The persistence of the repaired hernia is assessed on the basis of the values of the forces in the tissue–implant joints because the usual form of the repair failure is due to as the joint disconnection or tissue failure.