Hiatoplasty with crura buttressing versus hiatoplasty alone during laparoscopic sleeve gastrectomy

Introduction. In obese patients with hiatal hernia (HH), laparoscopic sleeve gastrectomy (LSG) with cruroplasty is an option but use of prosthetic mesh crura reinforcement is debated. The aim was to compare the results of hiatal closure with or without mesh buttressing during LSG. Methods. Gastroesophageal reflux disease (GERD) was assessed by the Health-Related Quality of Life (GERD-HRQL) questionnaire before and after surgery in two consecutive series of patients with esophageal hiatus ≤ 4 cm2. After LSG, patients in group A (12) underwent simple cruroplasty, whereas in group B patients (17), absorbable mesh crura buttressing was added. Results. At mean follow-up of 33.2 and 18.1 months for groups A and B, respectively (p = 0 006), the mean preoperative GERD-HRQL scores of 16.5 and 17.7 (p = 0 837) postoperatively became 9.5 and 2.4 (p = 0 071). In group A, there was no difference between pre- and postoperative scores (p = 0 279), whereas in group B, a highly significant difference was observed (p = 0 002). The difference (Δ) comparing pre- and postoperative mean scores between the two groups was significantly in favor of mesh placement (p = 0 0058). Conclusions. In obese patients with HH and mild-moderate GERD, reflux symptoms are significantly improved at medium term follow-up after cruroplasty with versus without crura buttressing during LSG.Introduction. In obese patients with hiatal hernia (HH), laparoscopic sleeve gastrectomy (LSG) with cruroplasty is an option but use of prosthetic mesh crura reinforcement is debated. The aim was to compare the results of hiatal closure with or without mesh buttressing during LSG. Methods. Gastroesophageal reflux disease (GERD) was assessed by the Health-Related Quality of Life (GERD-HRQL) questionnaire before and after surgery in two consecutive series of patients with esophageal hiatus ≤ 4 cm2. After LSG, patients in group A (12) underwent simple cruroplasty, whereas in group B patients (17), absorbable mesh crura buttressing was added. Results. At mean follow-up of 33.2 and 18.1 months for groups A and B, respectively (p = 0 006), the mean preoperative GERD-HRQL scores of 16.5 and 17.7 (p = 0 837) postoperatively became 9.5 and 2.4 (p = 0 071). In group A, there was no difference between pre- and postoperative scores (p = 0 279), whereas in group B, a highly significant difference was observed (p = 0 002). The difference (Δ) comparing pre- and postoperative mean scores between the two groups was significantly in favor of mesh placement (p = 0 0058). Conclusions. In obese patients with HH and mild-moderate GERD, reflux symptoms are significantly improved at medium term follow-up after cruroplasty with versus without crura buttressing during LSG

Hydrophobic counter ion effects on the formation of mesh and reversed phases in the perfluorodecanoate/water system

The tetramethylammonium perfluorodecanoate (C10TMA)/water system forms both random, Mh1(0) and correlated mesh, Mh1(R[3 with combining macron]m) phases over a wide range of concentration and temperature. Whilst the random mesh phase is found in the ammonium homologue, the extensive correlated mesh phase seems to be a result of the hydrophobic nature of the tetramethylammonium (TMA) counter ion. In order to explore the reasons for the occurrence of these mesh phases and the effects of hydrophobic counter ions on phase structure the counter ion has been substituted by a series of increasing hydrophobicity namely butyltrimethylammonium (BTMA), dibutyldimethylammonium (DBDMA), and methyltributylphosphonium (MTBP). The phases and their structures were identified by small angle X-ray scattering. Increasing counter ion hydrophobicity causes a change from mesh, to lamellar, and finally to reversed phases. All the hydrophobic counter ions are strongly bound to the water/fluorocarbon interface and, in the case of those with butyl chains, there is penetration of between 50 and 60% of the total number of counter ion methyl groups into the fluorocarbon region of the lamellar phase. These bound counter ions reduce the accessibility of the head group region to solvent water. As the number of butyl chains on the counter ion increases the lamellar phase is progressively lost and is replaced by a reversed micelle phase either as a single phase or as part of an extensive two phase region

Progress in synthetic materials for abdominal wall repair

To improve overall patient outcome after abdominal wall surgery, including patient discomfort, chronic pain and thus quality of life, 3 issues are the pillars of this thesis: 1. Facilitation of surgical technique and the role of the materials used 2. Importance of correct flat positioning of a mesh and the influence of the mesh surface area on subsequent mesh contraction 3. The inflammatory response and fibrotic tissue reaction during tissue integration and possible ways to improve this Using a modified preperitoneal technique using a memory ring containing mesh, surgical repair is facilitating reinforcement of the groin by a minimal invasive open surgical approach. Besides the technical advantages for the surgeon, the memory ring within the mesh has an influence on the inflammatory reaction and fibrosis formation during tissue integration, thereby limiting the mesh contraction and shrinkage. The development of megaporous meshes minimizes the inflammatory response and improves tissue ingrowth. In our analysis we found an equal patient discomfort in both groups 3 years after surgery, but applying a standardized surgical technique with at least 5cm of overlap in all circumstances, we observed also the same outcome regarding recurrences. Secondly, the positive results we obtained by using topical negative pressure therapy (NPT) in cases of mesh infections using these large pore meshes are described. For the small ventral hernias, we compared the conventional retromuscular mesh repair with this intraperitoneal device placement. Although the initial reports were favorable in outcome of the patients, we observed a relatively high recurrence rate after 2 years follow-up of 14%, mainly due to shrinkage and deformation of the patch. The interaction between an anti-adhesive barrier layer of ePTFE and small pore polypropylene causes an extremely intense inflammatory reaction and fibrosis formation leading to shrinkage, inadequate mesh overlap and clinical recurrences. In conclusion, new materials with a reliable intrinsic mesh memory facilitating surgical techniques and consisting of megaporous material with better tissue integration will improve patient discomfort and quality of life

Titanium versus absorbable tacks comparative study (TACS): a multicenter, non-inferiority prospective evaluation during laparoscopic repair of ventral and incisional hernia: study protocol for randomized controlled trial

BACKGROUND: Laparoscopic repair of ventral and incisional hernias has gained popularity since many studies have reported encouraging results in terms of outcomee and recurrence. Choice of mesh and fixation methods are considered crucial issues in preventing recurrences and complications. Lightweight meshes are considered the first choice due to their biomechanical properties and the ability to integrate into the abdominal wall. Titanium helicoidal tacks still represent the "gold standard" for mesh fixation, even if they have been suggested to be involved in the genesis of post-operative pain and complications. Recently, absorbable tacks have been introduced, under the hypothesis that there will be no need to maintain a permanent fixation device after mesh integration. Nevertheless, there is no evidence that absorbable tacks may guarantee the same results as titanium tacks in terms of strength of fixation and recurrence rates. The primary end point of the present trial is to test the hypothesis that absorbable tacks are non-inferior to titanium tacks in laparoscopic incisional and ventral hernia repair (LIVHR) by lightweight polypropylene mesh, in terms of recurrence rates at 3-year follow-up. Surgical complications, post-operative stay, comfort and pain are secondary end points to be assessed. METHODS/DESIGN: Two hundred and twenty patients with ventral hernia will be randomized into 2 groups: Group A (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by titanium tacks; Group B (110) patients will be submitted to LIVHR by lightweight polypropylene mesh fixed by absorbable tacks. DISCUSSION: A few retrospective studies have reported similar results when comparing absorbable versus non-absorbable tacks in terms of intraoperative and early post-operative outcomes. These studies have the pitfalls to be retrospective evaluation of small series of patients, and the reported results still need to be validated by larger series and prospective studies. The aim of the present trial is to investigate and test the non-inferiority of absorbable versus non-absorbable tacks in terms of hernia recurrence rates, in order to assess whether the use of absorbable tacks may achieve the same results as non-absorbable tacks in mid-term and long-term settings

Clustering of discretely observed diffusion processes

In this paper a new dissimilarity measure to identify groups of assets dynamics is proposed. The underlying generating process is assumed to be a diffusion process solution of stochastic differential equations and observed at discrete time. The mesh of observations is not required to shrink to zero. As distance between two observed paths, the quadratic distance of the corresponding estimated Markov operators is considered. Analysis of both synthetic data and real financial data from NYSE/NASDAQ stocks, give evidence that this distance seems capable to catch differences in both the drift and diffusion coefficients contrary to other commonly used metrics

Recent developments in finite element analysis for transonic airfoils

The prediction of aerodynamic forces in the transonic regime generally requires a flow field calculation to solve the governing non-linear mixed elliptic-hyperbolic partial differential equations. Finite difference techniques were developed to the point that design and analysis application are routine, and continual improvements are being made by various research groups. The principal limitation in extending finite difference methods to complex three-dimensional geometries is the construction of a suitable mesh system. Finite element techniques are attractive since their application to other problems have permitted irregular mesh elements to be employed. The purpose of this paper is to review the recent developments in the application of finite element methods to transonic flow problems and to report some recent results

Comparision of Properitoneal Non Tension Sutured Mesh Repair Versus Conventional Mesh Repair for Reducing Postoperative Pain in Direct Inguinal Hernia - A Randomised Control Trial

AbstractBackground: Numerous repairs exist for direct inguinal hernias.  These repairs are limited by the shortcomings of their respective technique. Each study has its own self limitations for the reduction of postoperative pain. With the introduction of  Properitoneal  nontension sutured mesh repair, the postoperative pain has been lessened,proving efficacy in terms of decreased hospital stay, patient comfort and early return to activities. Hence there is need for comparing Properitoneal nontension sutured mesh repair with Conventional mesh repairs for the reduction of postoperative pain.Materials and Methods:A Randomized clinical trial was designed with a sample size of 60 patients, which were divided into 2 groups; Group A (properitoneal non tension sutured mesh repair) & Group B (conventional mesh repair). These two groups were analyzed for postoperative pain (visual analogue score) from 2 weeks to 12 weeks.Results:On analysis, three months follow up pain score is significantly less in the group A patients at 2week and even upto 8weeks, thereafter  no patients experienced any pain. In group B the pain is significantly more than Group A and minimal pain persisted until 11weeks. Conclusion:The results of the new technique demonstrate that it provides less postoperative pain than has been reported in other nontension mesh repairs. There is apparent advantage in the use of properitoneal nontension sutured mesh repair compared to conventional mesh repair. Short term follow up of the study did not allow any conclusion regarding recurrence rates, thus larger cohorts with longer follow up are needed.Keywords: hernia repair, properitoneal  nontension sutured mesh repair, lichenstein mesh repai

Comparison of Results of Surgical Treatments of Primary Inguinal Hernia with Flat Polypropylene Mesh and Three-Dimensional Prolene (Phs) Mesh – One Year Follow Up

The aim of this study was to compare the results of the surgery of inguinal hernias using flat polypropylene mesh and three-dimensional prolene (PHS) mesh. The study included two groups of 40 male patients, aged 18–50 years, with the diagnosis of inguinal hernia. One group was operated with a flat polypropylene mesh, while the second group was operated with three-dimensional prolene (PHS) mesh. The study has shown that the operation with three-dimensional prolene mesh lasted 15 minutes longer and that the patients had stronger inflammatory response. Statistically, there was no significant difference in post-operative pain intensity, post-operative use of analgesics, length of hospitalization, return to daily activities, early and late post-operative complications. No recurrence was registered in any of the groups. The analysis of results indicates that there is no difference in treatment of inguinal hernia with flat polypropylene and three-dimensional prolene (PHS) mesh