Transverse Defects Research Articles

Long-term results of botulinum toxin type A in complex abdominal wall repair and review of the literature.

Administration of botulinum toxin (BTX) is being used in cases of complex ventral hernia for the reconstruction of the linea alba and closure of the abdominal wall. However, there are no published results regarding the long-term effects of BTX and its implication in hernia recurrence. Our purpose is to evaluate the outcomes in hernia recurrence of the administration of BTX in complex ventral hernia repair. 36 patients underwent elective surgery for complex ventral hernia and were evaluated retrospectively. The study included patients with a transverse hernia defect ≥ 100mm and loss of domain hernias, receiving BTX injections 6weeks prior to elective surgery. Global results and long-term recurrence were analysed. There were no complications related to BTX administration. The mean transverse hernia defect was 139.44 ± 50.98mm, the mean abdominal cavity volume (ACV) was 10.19 ± 3.33dm3, the mean hernia sac volume (HSV) was 1.93 ± 1.79dm3, presenting a mean volume ratio (VR) of 20.71 ± 19.76%. Primary closure was achieved in 28 patients (77.8%), 21 of whom (75%) needed an anterior component separation technique. Recurrence rate was 11.4% at 2-years follow-up. BTX administration is a safe and feasible method for abdominal wall expansion prior to complex incisional hernia repair, achieving high rates of primary closure. Long-term follow-up shows good results in terms of recurrence in these patients.

Different surgical techniques that influenced internal hernia prevalence rate after laparoscopic roux-en-Y gastric bypass: a retrospective analysis of 331 cases

BackgroundInternal hernia (IH) is a serious complication following laparoscopic Roux-en-Y gastric bypass (LRYGB), and closure of mesenteric defect has been recommended to reduce this complication. But what kind of material about suture and how to close the mesenteric defects were still controversial. The main aim of this study was to compare the incidence rate of internal hernia after LRYGB between patients with different surgical techniques.MethodThree hundred and thirty-one patients underwent LRYGB between June 2004 and December 2017 in one single institute were retrospective analysed. The IH rate was evaluated according to different surgical methods and surgical materials before and 12 months after LRYGB.ResultsAll the cases were subdivided into three groups based on the suturing method, Roux limb position, and Suture material. The mean follow up time was 36 ± 12 months, and the total incident rate of IH was 1.8% (n = 6). In the six IH cases, the duration of IH occurred time ranged from 1 month to 36 months postoperatively, and for the IH sites, one for intestinal defect, three for transverse mesocolon defect and two Peterson defect respectively. There was a significant difference about IH rate between interrupted suture and running suture groups (p = 0.011), and there were no significant differences between the other two groups.ConclusionCompare with interrupted suture, running suture may prevent IH after LRYGB. Patient’s gender, age, body mass index(BMI), glycometabolism condition, and Roux limb position and suture material had no effects on the IH prevalence after LRYGB.

Congenital transverse colon mesenteric defect in an adult patient leading to acute large bowel obstruction

Congenital transverse colon mesenteric defect in an adult patient leading to acute large bowel obstruction

Congenital limb reduction defects in 1.6 million births in Argentina.

The objectives of this study were to describe the birth prevalence of limb reduction defects (LRD) in Argentina, their clinical features, and to review the literature on this topic. The data source was the National Network of Congenital Anomalies of Argentina, a surveillance system that has been operative since 2009. Data were collected from November 1, 2009 to December 31, 2016. 1,663,610 births and 702 affected patients were registered during this period. The prevalence of LRD was 4.22/10,000 births (CI 95%: 3.93-4.54). In 15,094 stillbirths, prevalence was 30.80/10,000 (CI 95%: 22.31-40.65). Perinatal mortality (stillbirths plus early neonatal deaths) was 24.6%, mostly explained by postnatal deaths. LRD were classified according to different variables, including Gold's anatomic classification. Then, 41.0% of patients had transverse terminal defects and 50.2% had longitudinal defects. We found multiple and syndromic clinical presentation to be associated with both preaxial LRD and lethality. The prevalence of LRD was lower and perinatal mortality was higher in our study compared to that of previously published studies. Because there is heterogeneity in the inclusion and exclusion criteria among publications, a greater effort should be made in order to include similar populations and to use a unified anatomic classification and nomenclature.

The role of bending stress on the initiation of reverse transverse defects

This paper investigated the role of longitudinal reverse bending stress on the initiation of reverse transverse defects. The longitudinal reverse bending stress occurs due to the reverse bending of the rail between two-wheel passage leading to the generation of tensile bending stress at the railhead and the lower head areas. The longitudinal bending stress was investigated as part of a parametric study on the rail cant angle, rail stiffness, lateral-to-vertical load ratio, and rail profile. A finite element model was created by using ABAQUS to analyze the extent of reverse bending in rails with respect to the chosen set of parameters. Under different lateral-to-vertical load ratios of 0, 0.3, 0.5, and 0.7, the maximum stress at the rail lower gauge corner was found to vary between 14.57MPa and 15.47MPa under the reverse bending condition. Similarly, low values of tensile stress under the reverse bending scenario were observed with changes in the rail cant angle and axle spacing with respect to different coal and iron ore wagons. The results revealed that the magnitude of the bending stress under different conditions of reverse bending was not significant enough to initiate a crack at the lower gauge corner.

Ultrasonic guided wave monitoring of an operational rail track

An experimental monitoring system was installed on an operational heavy haul rail track. The system used two piezoelectric transducers mounted under the head of the rail to transmit and receive ultrasonic guided waves in pulse-echo mode and data were captured over a 2-week period. An artificial defect was introduced by glueing a small mass under the head of the rail at a distance of 370 m from the transducers. The size of the signal reflected by the mass varied as the glue joint deteriorated. The measurements were reordered to simulate a monotonically growing defect. The pre-processing of the captured time signals included averaging, filtering, phased array processing, dispersion compensation, signal stretching and amplitude scaling. Singular value decomposition and independent component analysis of the data were performed. Independent component analysis, with dimension reduction achieved by retaining only the larger principal components, produced the best defect detection. The defect signature was separated as an independent component, and the weight of this component increased monotonically. The results indicate that a transverse defect in the rail head could be detected and located at long range by a system comprising only two transducers. The variation of the signals due to changing environmental and operational conditions limits the size of defect that can be detected, but it is expected that even a relatively small defect, which is significantly smaller than the critical size, would be detected.

Challenges in handling congenital anomalies clusters: a recent mediatic example in France

Abstract Issue In 2018 in France, reports of aggregated cases of isolated transverse limb reduction defects, a rare congenital anomaly (1.7 for 10,000 total births) generated a large mediatic interest with environmental factors overtly pointed out. Our aim is to describe the investigations carried out and to share the challenges we met. Description of the response Over a period of 5 years (2010-2015), 3 aggregates were signaled by health professionals in 3 different areas in France. Investigations included case ascertainment, epidemiological analyses, and search for a common exposure. Standardized Incidence Ratios were computed using the 6 French registries’s data as reference. In one area, the local registry performed a concurrent analysis using satscan. Parents filled a questionnaire addressing environmental and occupational exposures. Environmental databases were consulted as well as animal health surveillance data. Results Fourteen cases met the case definition. The excess of cases was ascertained in two aggregates located in a two small towns in the western part of France and comprising respectively 3 children born in 2007-2008 (SIR: 87.8 CI95%:[17-256]) and 4 children born in 2011-2013 (79.8 [2.5-204.2]). The third signal included 7 cases born between 2009 and 2014 residing in 7 towns located above the Alps and did not yield a significant excess when related to expected cases in the administrative subdivision (0.94 [0.38-1.95]). The concurrent analysis found a significant excess, generating a lengthy debate. None of the investigations identified a common cause or notable exposure. Delayed feedback and negative conclusions led to incomprehension among families. Lessons Informing stakeholders timely is crucial but communicating effectively about methods used and negative results can be challenging. Key messages Congenital anomalies clusters are sensitive topics. Cluster investigations involve a scientific and a societal component that must both be taken into account in organizing the public health response.

Expanding the phenotype in Adams-Oliver syndrome correlating with the genotype.

Adams-Oliver syndrome (AOS) is a genetic disorder characterized by the association of aplasia cutis congenita (ACC), terminal transverse limb defect (TTLD), congenital cardiac malformation (CCM), and minor features, such as cutaneous, neurological, and hepatic abnormalities (HAs). The aim of the study is to emphasize phenotype-genotype correlations in AOS. We studied 29 AOS patients. We recorded retrospectively detailed phenotype data, including clinical examination, biological analyses, and imaging. The molecular analysis was performed through whole exome sequencing (WES). Twenty-nine patients (100%) presented with ACC, the principal inclusion criteria in the study. Seventeen of twenty-one (81%) had cutis marmorata telangiectasia congenita, 16/26 (62%) had TTLD, 14/23 (61%) had CCM, 7/20 (35%) had HAs, and 9/27 (33%) had neurological findings. WES was performed in 25 patients. Fourteen of twenty-five (56%) had alterations in the genes already described in AOS. CCM and HAs are particularly associated with the NOTCH1 genotype. TTLD is present in patients with DOCK6 and EOGT alterations. Neurological findings of variable degree were associated sometimes with DOCK6 and NOTCH1 rarely with EOGT. AOS is characterized by a clinical and molecular variability. It appears that degrees of genotype-phenotype correlations exist for patients with identified pathogenic mutations, underlining the need to undertake a systematic but adjusted multidisciplinary assessment.

Verification of the use of Micro-CT scanning to assess the features of entire squat type defects

Squats and studs are defects in railheads that share features, but have different causes. This paper examined four squat and stud samples from three different traffic environments to compare features using μ-CT X-ray scans, surface and subsurface inspection. μ-CT scanning has been used before as a non-destructive method to investigate rail defects, but not the entire defect. The scans were verified and allowed the identification of areas of interest when sectioning the samples further. The scan volumes were also used to create 3D models of the crack networks for the 3 samples that were scanned. All defects contain similar superficial features but the depth and severity of the subsurface damage varies.This work provides a visualisation of the 3D nature of studs in a way not seen before, as a 3D model the crack network from an in-service defect. The models of two of the defects showed the influence of hollow wheels initiating defects, as the crack seemed to initiate on the field side, grow down and towards the gauge side, before resurfacing as the longitudinal crack noted in all four defect samples. One sample is believed to have initiated due to contamination of the weld and the only squat sample, which failed in track, was believed to be ingot cast steel containing many inclusions.Three samples were studs and one was a squat. Each defect developed for different reasons, although the two metro samples were similar. One of the studs shows branching of cracks that, based on its changing angle of growth, could continue to grow into transverse defects, breaking the rail. The three defects that were scanned would all be classed as studs, but their crack morphology varies, possibly because they are all from different traffic environments. They also show slight differences to other studs in literature.

Tunable spin transport and quantum phase transitions in silicene materials and superlattices

In this paper, we study spin transport properties of silicene structures such as ribbons and superlattices with the Kane–Mele model. We investigate the effects of ferromagnetic and antiferromagnetic exchange fields, vertical and transverse electric fields and defects on the band structure, density of states, as well as conductance of the system. Our calculated results indicate that by applying a vertical electric field and/or an antiferromagnetic exchange field, metal–semimetal and also metal–semiconductor quantum phase transitions occur. We show that a zigzag silicene ribbon, when exposed to a transverse electric field in combination with an antiferromagnetic exchange field, behaves as a half-metal that allows one spin state electrons to move. Furthermore, under a vertical electric field and in the simultaneous presence of ferromagnetic and antiferromagnetic exchange fields applied to two half-widths of the ribbon, we observe the half-metallic phase. Our results help to control spin currents and to have new applications in silicene spintronics.

FUZZY MULTI-ATTRIBUTE DECISION MAKING FOR THE SELECTION OF A SUITABLE RAILWAY TRACK MAINTENANCE PLAN: A CASE STUDY IN THAILAND

Degradation of infrastructure has affected service quality; in other words, the rail freight transportation rate has been considerably low at only 2%. As a result, for the purposes of safety and highreliability levels in infrastructure, several organizations have conducted serious research on the interesting topic of railway track degradation. As the focus of the present study was degradation factors, the Fuzzy MultiAttribute Decision Making Method (FMADM) was used to analyze railway track defects and degradation and to select a maintenance plan schedule. Related research and literature were reviewed, and a questionnaire was designed to collect opinions from experts working for the State Railway of Thailand (SRT). The experts prioritized risk levels likely to result in the worst breaks or damage, using UIC defect codes. These consisted of transverse break defects without apparent origin (code 200) with the highest level of impact and relative weight of 0.396, followed by star-cracking of fish bolt holes (code 135) with a relative weight of 0.276 and transverse cracking of profile thermite welding (code 421) with a weight of 0.187. The least severe impact was said to come from horizontal cracking at web-head (code 1321) with a relative weight of 0.142. Analysis results based on FMADM indicated that the railway track structure replacement plan, as considered by the experts, was better than the railway track rehabilitation plan, as shown by their importance weights of 0.575 and 0.425, respectively.

Aplasia cutis congenita

<p>Aplasia cutis congenita (ACC) is a rare condition in which there is congenital focal absence of skin with or without absence of underlying structures such as bone. Consanguinity may play a role. The cause of this condition is unclear and appears to be multifactorial; contributory factors may include teratogens, genes, trauma and compromised blood flow to the skin. Various expressions of Adams Oliver syndrome (AOS) have also been reported which is a rare autosomal dominant congenital disorder characterized by absence of skin and or underlying structure over scalp along with transverse limb defect. It was first described by Adam and Oliver in 1945.</p>

Large Incisional Hernias Increase in Size

BackgroundPatients with an incisional hernia often wait a significant period of time from the first referral to hernia surgery because of waiting lists, watchful waiting, or the need for preoperative optimization. It is unknown if hernia dimensions or patient-reported symptoms increase during this period. The aim of the study was to examine if incisional hernias increase in size during the time from initial assessment to surgical repair. Materials and methodsA prospective controlled trial was performed on patients referred to a regional hernia center for repair of an incisional hernia with a transverse fascial defect of >7 cm. All patients underwent computed tomography scans and answered the Hernia-Related Quality of Life Score questionnaire and International Physical Activity Questionnaire at first assessment and again 30 ± 2 wk later or immediately before hernia repair. Changes in fascial defect sizes and hernia sac volume were assessed along with the patient-reported outcomes. ResultsA total of 35 patients were included. The median fascial defect area increased from 117.3 cm2 (interquartile range 46.5-181.2) to 150.4 cm2 (62.5-199.0), P < 0.001, and the median hernia sac volume increased from 5.11 L (2.28-8.09) to 6.25 L (3.03-10.38), P < 0.001. There were no significant changes in the patient-reported outcomes. ConclusionsIncisional hernias expand during the period from the first assessment to actual hernia repair.

Detection of Transverse Defect in a Railhead Based on Guided Waves Generated by Radiation Laser

The main cause of train derailment is related to transverse defects that arise in the railhead. These consist typically of opened or internal flaws that develop generally in a plane which is orthogonal to the rail direction. Ultrasounds based testing is performed according to the excitation-echo procedure. It is conducted conventionally by using a contactless system using a laser as excitation and air-coupled acoustic sensors for wave reception. The objective of this work is to study theoretically an integrated system for rail diagnosis which is based on guided waves and which does not necessitate any contact with the rail. On the opposite of the existing inspection devices, this paper proposes a laser vibrometry rotational perform the reception of the echoes. Complete modeling of the rail has been performed after that by using the three-dimensional equations of thermoelasticity and the solution in terms of displacements has been calculated by using the finite element method. The study has dealt with a special device configuration for the generation of waves by laser excitation and the detection of echoes by using laser vibrometry.

Predicting rail defect frequency: An integrated approach using fatigue modeling and data analytics

AbstractIn maintenance planning of rail track, it is imperative to assess the potential and frequency of rail defects. Although this problem has been mainly studied in the literature by either data‐driven or mechanic‐based models, in the present study a new method is proposed to account for the strengths of both approaches in a single model. The envisaged model incorporates fatigue crack growth model, through Finite Element Modeling (FEM), into Approximate Bayesian Computation (ABC) framework. The method is applied to the prediction of rail defect frequency for transverse defects obtained from a US Class I Railroad. The results of the proposed model show that inducing the mechanics of rail defects into a data‐driven model outperforms the traditional pure data‐driven models by over 20%. The outcome of this study, along with necessary future developments to broaden the scope of applicability of the method, will benefit railroad existing practice in capital and maintenance planning.

Novel compound heterozygous mutations of the DOCK6 gene in a familial case of Adams-Oliver syndrome 2

IntroductionAdams-Oliver syndrome (AOS) is a rare developmental disorder characterized by the combination of aplasia cutis congenita of the scalp vertex and terminal transverse limb defects. DOCK6 (Dedicator of cytokinesis 6) is one of the six identified AOS genes. MethodsWe performed targeted next-generation sequencing (NGS) of a child with an AOS phenotype. Sanger DNA sequencing further validated her lineal consanguinity. To explore the pathological features of the mutation, a minigene assay was used to investigate the effects of the mutation on splicing. ResultsTwo compound heterozygous DOCK6 mutations (c.4106+2T>C and c.3063 C>G (p.Y1021*)) were identified in this family, and both mutations have not been reported previously. Sanger DNA sequencing indicated that the mutations were inherited maternally and paternally, respectively. The results of the minigene assay showed that the c.4106+2T>C mutation resulted in aberrant splicing and caused a four-nucleotide insertion in the transcript and a premature stop codon. ConclusionsOur findings expanded the number of reported cases of this rare disease and the mutation spectrum of DOCK6 mutations, which can serve as the basis for prenatal diagnosis and genetic counseling.

Internal hernia after gastrectomy for gastric cancer in minimally invasive surgery era

BackgroundThe incidence and clinical presentation of internal hernia after gastrectomy have been changing in the minimally invasive surgery era. This study aimed to analyze the clinical features and risk factors for internal hernia after gastrectomy for gastric cancer.MethodsWe retrospectively analyzed internal hernia after gastrectomy for gastric cancer in 6474 patients between January 2003 and December 2016 at Seoul National University Bundang Hospital. Multivariable logistic regression was performed to evaluate risk factors.ResultsInternal hernias identified by computed tomography or surgical exploration were 111/6474 (1.7%) and the median interval time was 450 days after gastrectomy. Fourteen (0.9%) of the 1510 patients who underwent open gastrectomy and 97 (2.0%) of the 4964 patients who underwent laparoscopic gastrectomy developed internal hernia. Of the 6474 patients, internal hernia developed in 0 (0%), 9 (1.1%), 40 (3.1%), 56 (3.3%), 6 (2.3%), and 0 (0%) patients who underwent Billroth I, Billroth II, Roux-en-Y, uncut Roux-en-Y, double tract, and esophagogastrostomy reconstructions, respectively. Fifty-nine (53.2%) of 111 patients with symptomatic hernia underwent surgery. Of the 59 internal hernias, treated surgically, 32 (53.2%), 27 (45.8%), and 0 (0%) were identified in jejunojejunostomy mesenteric, Petersen’s, and transverse colon mesenteric defects, respectively. In multivariate analysis, non-closure of mesenteric defects (P < 0.01), laparoscopic approach (P < 0.01), and totally laparoscopic approach (P = 0.03) were independent risk factors for internal hernia.ConclusionsThe potential spaces such as Petersen’s, jejunojejunostomy mesenteric, and transverse colon mesenteric defects should be closed to prevent internal hernia after gastrectomy for gastric cancer.

Laparoscopic repair of type III/IV giant para-oesophageal herniae with biological prosthesis: a single centre experience

Repair of giant paraoesophageal herniae (GPEH) is technically challenging and requires significant experience in advanced foregut surgery. Controversy continues on suture versus mesh cruroplasty with the most recent systematic review and meta-analysis putting the onus on the operating surgeon. Study aim was to review whether the biological prosthesis (non-cross-linked bovine pericardium and porcine dermis) and the technique adopted for patients with GPEH had an influence on clinical and radiological recurrences. A retrospective analysis of a prospectively collected data of 60 consecutive patients with confirmed 5cm hiatus hernia and ≥ 30% stomach displacement in the thorax that were operated in the upper gastrointestinal unit of a large district general hospital between September 2010 and August 2017. Pre and post-surgery Gastro-Oesophageal Reflux Disease Questionnaire [(GORD-HRQOL)] and a follow up contrast study were completed. 60 included 2 (3%) and 58 (97%) emergency and elective procedures respectively with a male: female ratio of 1:3, age 71* (Median) (42-89) years, BMI 29* (19-42) and 26 (43%) with ASA III/IV. Investigations confirmed 46* (37-88) mm and 42* (34-77) mm transverse and antero-posterior hiatal defect respectively with 60* (30-100)% displacement of stomach into chest. Operative time and length of stay was 180* (120-510) minutes and 2* (1-30) days respectively. One (2%) converted for bleeding and 2 (3%) peri-operative deaths. Five (8%), 5 (8%) and 4 (7%) have dysphagia, symptomatic and radiological recurrences respectively. GORD-HRQOL recorded preoperatively was 27* (10-39) dropping significantly postoperatively to 0* (0-21) (P < 0.005) with 95% patient satisfaction at a follow up of 60* (36-84) months. Our technique of laparoscopic GPEH repair with biological prosthesis is safe with a reduced symptomatic and radiological recurrence and an acceptable morbidity and mortality.

Numerical Study on the Leakage Magnetic Field of Transverse Defect on T-Joint Fillet Weld

Abstract A 3D finite element method model is established for yoke-magnetization detection of a transverse defect on T-joint fillet weld and solved by the finite element software ANSOFT Maxwell (ANSYS, Canonsburg, PA). The leakage magnetic field around the transverse defect is obtained. The relationship between the width of transverse defect and leakage magnetic field signals is identified. The researchers found that the tangential component of magnetic flux leakage density, BX1, tends to be a parabolic distribution and reaches the maximum value near the center of the defect along the length direction. While BX1 shows a bimodal distribution, featuring two peaks near the edge of the defect and one peak valley at the center along the width direction, the normal component of magnetic flux leakage density, BZ1, is very different than that of BX1 along the width direction, presenting an approximate N-shape as a whole. The leakage magnetic field signals of the transverse defect on the fillet weld of the T joint will decay obviously when the scanning line is perpendicular to the weld surface over 0.5 mm. The results of numerical simulation can provide a theoretical foundation to detect and characterize various defects in the fillet weld.

Online Magnetic Flux Leakage Detection System for Sucker Rod Defects Based on LabVIEW Programming

Aiming at the detection of defects in sucker rod surface, a real-time detection system is designed using the non-destructive testing technology of magnetic flux leakage (MFL). An MFL measurement system contains many components, and this study focuses on the signal acquisition and processing system. First of all, this paper introduces the hardware part of the acquisition system in detail, including the selection and principle of the Hall-effect plural, the design and calculation of the signal conditioning circuit, and the working process of the single chip computer (SCM) control serial port. Based on LabVIEW, a graphical programming software, the software part of the acquisition system is written, including configuration of serial port parameters, identification of detected signals, filtering of original signals, real-time display, storage and playback of data. Finally, an experimental platform for MFL detection is set up, and the MFL measurement is carried out on the transverse and longitudinal defects of the sucker rod surface. The experimental result shows that the designed acquisition and processing system has good detection performance, simple design and high flexibility.