Perforated gastric ulcer causing mediastinal emphysema: A case report

BACKGROUND Mediastinal emphysema is a condition in which air enters the mediastinum between the connective tissue spaces within the pleura for a variety of reasons.It can be spontaneous or secondary to chest trauma,esophageal perforation,medi-cally induced factors,etc.Its common symptoms are chest pain,tightness in the chest,and respiratory distress.Most mediastinal emphysema patients have mild symptoms,but severe mediastinal emphysema can cause respiratory and circulatory failure,resulting in serious consequences.CASE SUMMARY A 75-year-old man,living alone,presented with sudden onset of severe epigastric pain with chest tightness after drinking alcohol.Due to the remoteness of his residence and lack of neighbors,the patient was found by his nephew and brought to the hospital the next morning after the disease onset.Computed tomography(CT)showed free gas in the abdominal cavity,mediastinal emph-ysema,and subcutaneous pneumothorax.Upper gastrointestinal angiography showed that the esophageal mucosa was intact and the gastric antrum was perforated.Therefore,we chose to perform open gastric perforation repair on the patient under thoracic epidural anesthesia combined with intravenous anesthesia.An operative incision of the muscle layer of the patient's abdominal wall was made,and a large amount of subperitoneal gas was revealed.And a continued incision of the peritoneum revealed the presence of a perforation of approx-imately 0.5 cm in the gastric antrum,which we repaired after pathological examination.Postoperatively,the patient received high-flow oxygen and cough exercises.Chest CT was performed on the first and sixth postoperative days,and the mediastinal and subcutaneous gas was gradually reduced.CONCLUSION After gastric perforation,a large amount of free gas in the abdominal cavity can reach the mediastinum through the loose connective tissue at the esophageal hiatus of the diaphragm,and upper gastrointestinal angiography can clarify the site of perforation.In patients with mediastinal emphysema,open surgery avoids the elevation of the diaphragm caused by pneumoperitoneum compared to laparoscopic surgery and avoids increasing the mediastinal pressure.In addition,thoracic epidural anesthesia combined with intravenous anesthesia also avoids pressure on the mediastinum from mechanical ventilation.

The influences of perforating phase and bedding planes on the fracture deflection in laminated shale

The perforating phase leads to complex and diverse hydraulic fracture propagation behaviors in laminated shale formations. In this paper, a 2D high-speed imaging scheme which can capture the interaction between perforating phase and natural shale bedding planes was proposed. The phase field method was used to simulate the same conditions as in the experiment for verification and hydraulic fracture propagation mechanism under the competition of perforating phase and bedding planes was discussed.The results indicate that the bedding planes appear to be no influence on fracture propagation while the perforating phase is perpendicular to the bedding planes, and the fracture propagates along the perforating phase without deflection. When the perforating phase algins with the bedding planes, the fracture initiation pressure reserves the lowest value, and no deflection occurs during fracture propagation. When the perforating phase is the angle 45°, 60°and 75°of bedding planes, the bedding planes begin to play a key role on the fracture deflection. The maximum deflection degree is reached at the perforating phase of75°. Numerical simulation provides evidence that the existence of shale bedding planes is not exactly equivalent to anisotropy for fracture propagation and the difference of mechanical properties between different shale layers is the fundamental reason for fracture deflection. The findings help to understand the intrinsic characteristics of shale and provide a theoretical basis for the optimization design of field perforation parameters.

Numerical Analysis of Perforation during Hydraulic Fracture Initiation Based on Continuous-Discontinuous Element Method

Perforation is a pivotal technique employed to establish main flow channels within the reservoir formation at the outset of hydraulic fracturing operations.Optimizing perforation designs is critical for augmenting the efficacy of hydraulic fracturing and boosting oil or gas production.In this study,we employ a hybrid finite-discrete element method,known as the continuous–discontinuous element method(CDEM),to simulate the initiation of post-perforation hydraulic fractures and to derive enhanced design parameters.The model incorporates the four most prevalent perforation geometries,as delineated in an engineering technical report.Real-world perforations deviate from the ideal cylindrical shape,exhibiting variable cross-sectional profiles that typically manifest as an initial constriction followed by an expansion,a feature consistent across all four perforation types.Our simulations take into account variations in perforation hole geometries,cross-sectional diameters,and perforation lengths.The findings show that perforations generated by the 39g DP3 HMX perforating bullet yield the lowest breakdown pressure,which inversely correlates with increases in sectional diameter and perforation length.Moreover,this study reveals the relationship between breakdown pressure and fracture degree,providing valuable insights for engineers and designers to refine perforation strategies.

Simple procedure for assessing diffuse subarachnoid hemorrhage successfully created using filament perforation method in mice

The murine model of subarachnoid hemorrhage(SAH)is a valuable experimental tool for investigating molecular and cellular mechanisms,and the endovascular filament perforation technique can be used to simulate prominent pathophysiological features observed after human SAH;however,current validation methods for assessing an appropriate SAH model are limited.Here,we introduce a simple procedure for se-lecting a mouse model of diffuse SAH.SAH was induced in 24 mice using a standard filament perforation method.After confirming survival at 24 h,SAH was scored 0-1 based on T2*-weighted images on whole-brain magnetic resonance imaging(MRI)and visual surveillance of the cisterna magna(CM)through the dura mater.The CM-based SAH grading correlated well with a reference parameter defined by extracted brain(r^(2)=0.53,p<0.0001).The receiver operating characteristic curve revealed a sensi-tivity of 85%and a specificity of 91%for detecting diffuse SAH,with a similar area under the curve(0.89±0.06[standard error of the mean])as the MRI-based grading(0.72±0.10,p=0.12).Our data suggest that confirming an SAH clot in the CM is a valuable way to select a clinically relevant diffuse SAH model that can be used in future experimental studies.

Research on the Generation Mechanism and Suppression Method of Aerodynamic Noise in Expansion Cavity Based on Hybrid Method

The expansion chamber serves as the primary silencing structure within the exhaust pipeline.However,it can also act as a sound-emitting structure when subjected to airflow.This article presents a hybrid method for numerically simulating and analyzing the unsteady flow and aerodynamic noise in an expansion chamber under the influence of airflow.A fluid simulation model is established,utilizing the Large Eddy Simulation(LES)method to calculate the unsteady flow within the expansion chamber.The simulation results effectively capture the development and changes of the unsteady flow and vorticity inside the cavity,exhibiting a high level of consistency with experimental observations.To calculate the aerodynamic noise sources within the cavity,the flow field results are integrated using the method of integral interpolation and inserted into the acoustic grid.The acoustic analogy method is then employed to determine the aerodynamic noise sources.An acoustic simulation model is established,and the flow noise source is imported into the sound field grid to calculate the sound pressure at the far-field response point.The calculated sound pressure levels and resonance frequencies show good agreement with the experimental results.To address the issue of airflow regeneration noise within the cavity,perforated tubes are selected as a means of noise suppression.An experimental platformfor airflow regeneration noise is constructed,and experimental samples are processed to analyze and verify the noise suppression effect of perforated tube expansion cavities under different airflow velocities.The research findings indicate that the perforated tube expansion cavity can effectively suppress low-frequency aerodynamic noise within the cavity by impeding the formation of strong shear layers.Moreover,the semi-perforated tube expansion cavity demonstrates the most effective suppression of aerodynamic noise.

Conquer coronary artery perforation with magic hands

Coronary artery perforation(CAP) poses a significant challenge for interventional cardiologists. Management of CAP depends on the location and severity of the perforation. The conventional method for addressing the perforation of large vessels involves the placement of a covered stent, while the perforation of distal and collateral vessels is typically managed using coils, autologous skin, subcutaneous fat, microspheres, gelatin sponge, thrombin or other substances. However, the above techniques have certain limitations and are not applicable in all scenarios. Our team has developed a range of innovative strategies for effectively managing CAP. This article provides an insightful review of the various tips and tricks for the treatment of CAP.

Double-nylon purse-string suture technique: Another addition to the endoscopist's toolbox for full-thickness defect closure

Iatrogenic perforation is the most feared adverse event in endoscopy.With the expansion of interventional endoscopy in favor of traditional surgery,it is now more crucial than ever to develop effective defect closure techniques.This has culminated in the dissemination of multiple novel closure technologies,including through-the-scope clips,over-the-scope clips,through-the-scope suturing and over-the-scope suturing devices.In this editorial,we comment on the recent publication by Wang and colleagues discussing the performance of the double-nylon purse-string suture technique in the closure of large(>3 cm)gastric full-thickness defects.This technique offers a promising,practical and cost-effective approach to closure of large full-thickness defects that can be readily imple-mented across diverse healthcare settings.

Effect of perforation density distribution on production of perforated horizontal wellbore

To address the issue of horizontal well production affected by the distribution of perforation density in the wellbore,a numerical model for simulating two-phase flow in a horizontal well is established under two perforation density distribution conditions(i.e.increasing the perforation density at inlet and outlet sections respectively).The simulation results are compared with experimental results to verify the reliability of the numerical simulation method.The behaviors of the total pressure drop,superficial velocity of air-water two-phase flow,void fraction,liquid film thickness,air production and liquid production that occur with various flow patterns are investigated under two perforation density distribution conditions based on the numerical model.The total pressure drop,superficial velocity of the mixture and void fraction increase with the air flow rate when the water flow rate is constant.The liquid film thickness decreases when the air flow rate increases.The liquid and air productions increase when the perforation density increases at the inlet section compared with increasing the perforation density at the outlet section of the perforated horizontal wellbore.It is noted that the air production increases with the air flow rate.Liquid production increases with the bubble flow and begins to decrease at the transition point of the slug-stratified flow,then increases through the stratified wave flow.The normalized liquid flux is higher when the perforation density increases at the inlet section,and increases with the radial air flow rate.

Scattering of Water Waves by Dual Symmetric Inclined Floating Porous Barriers Using the DBEM

The scattering of normally incident water waves by two surface-piercing inclined perforated barriers in water with a uniform finite depth is investigated within the framework of linear water wave theory.Considering that thin barriers are zero-thickness,a novel numerical method involving the the coupling of the dual boundary element method(DBEM)with damping layers is applied.In order to effectively damp out the reflected waves,two damping layers,instead of pseudoboundaries are implemented near the two side boundaries of the computational domain.Thus,the modified linearized free surface boundary conditions are formulated and used for solving both the ordinary boundary integral equation as well as the hypersingular boundary integral equation for degenerate boundaries.The newly developed numerical method is validated against analytical methods using the matched eigenfunction expansion method for the special case of two vertical barriers or the inclined angle to the vertical being zero.The influence of the length of the two damping layers has been discussed.Moreover,these findings are also validated against previous results for several cases.After validation,the numerical results for the reflection coefficient,transmission coefficient and dissipation coefficient are obtained by varying the inclination angle and porosity-effect parameter.The effects of both the inclination angle and the porosity on the amplitudes of wave forces acting on both the front and rear barriers are also investigated.It is found that the effect of the inclination angle mainly shifts the location of the extremal values of the reflection and the transmission coefficients.Additionally,a moderate value of the porosity-parameter is quite effective at dissipating wave energy and mitigating the wave loads on dual barriers.

Pedicled abdominal flap using deep inferior epigastric artery perforators for forearm reconstruction: A case report

BACKGROUND Pedicled abdominal flaps are a widely used surgical technique for forearm reconstruction in patients with soft tissue defects.However,some drawbacks include restricted flap size,partial flap loss,and donor-site morbidity.To address these concerns,we present a case of a pedicled abdominal flap using the deep inferior epigastric artery perforators(DIEP)for forearm reconstruction in a patient with a large soft tissue defect.CASE SUMMARY A 46-year-old male patient was admitted to our hospital with forearm injury caused by a pressing machine.A 15 cm×10 cm soft tissue defect with complete rupture of the ulnar side structures of the forearm was found.One week after orthopedic management of the neurovascular injury and fractures using the first stage of Masquelet technique,the patient was referred to the plastic and recon-structive surgery department for wound coverage.Surgical debridement and negative-pressure wound therapy revealed a 20 cm×15 cm soft tissue defect.A pedicle abdominal flap with the DIEP was used to cover the defect.Three weeks later,the flap was detached from the abdomen,and the abdominal defect was directly closed.Subsequently,the second stage of Masquelet technique was performed at the fracture site at week 10.Finally,all donor and recipient sites healed without complications,such as flap dehiscence,infection,hematoma,or necrosis.Fracture site osteosynthesis was achieved without complications.CONCLUSION Pedicled abdominal flap using the DIEP provides a reliable option for forearm reconstruction in patients with large soft tissue defects.

Applications of SMILE-extracted lenticules in ophthalmology

AIM:To review recent innovations,challenges,and applications of small incision lenticule extraction(SMILE)extracted lenticule for treating ocular disorders.METHODS:A literature review was performed in the PubMed database,which was last updated on 30 December 2021.There was no limit regarding language.The authors evaluated the reference lists of the collected papers to find any relevant research.RESULTS:Due to the simplicity and accuracy of modern femtosecond lasers and the extensive development of SMILE surgery,many healthy human corneal stromal lenticules were extracted during surgery,motivating some professionals to investigate the SMILE lenticule reusability in different ocular disorders.In addition,new approaches had been developed to preserve,modify,and bioengineer the corneal stroma,leading to the optimal use of discarded byproducts such as lenticules from SMILE surgery.The lenticules can be effectively re-implanted into the autologous or allogenic corneas of human subjects to treat refractive errors,corneal ectasia,and corneal perforation and serve as a patch graft for glaucoma drainage devices with better cosmetic outcomes.CONCLUSION:SMILE-extracted lenticules could be a viable alternative to human donor corneal tissue.

Small intestine angioleiomyoma as a rare cause of perforation:A case report

BACKGROUND Angioleiomyoma is a rare and benign stromal tumor typically found in subcutaneous tissue.It rarely occurs in the gastrointestinal tract.Among the reported cases,the most common complication was gastrointestinal bleeding.Perforation has only been reported as a complication in the last few decades.CASE SUMMARY This case report detailed the discovery of intestinal angioleiomyoma in a 47-yearold male presenting with abdominal pain that had persisted for 3 d.After suspecting hollow organ perforation,surgical intervention involving intestinal resection and anastomosis was performed.CONCLUSION The report underscores the significance of early surgical intervention in effectively treating angioleiomyoma while emphasizing the pivotal role of timely and appropriate measures for favorable outcomes.

Optimizing the Diameter of Plugging Balls in Deep Shale Gas Wells

Deep shale gas reserves that have been fractured typically have many relatively close perforation holes. Due to theproximity of each fracture during the formation of the fracture network, there is significant stress interference,which results in uneven fracture propagation. It is common practice to use “balls” to temporarily plug fractureopenings in order to lessen liquid intake and achieve uniform propagation in each cluster. In this study, a diameteroptimization model is introduced for these plugging balls based on a multi-cluster fracture propagationmodel and a perforation dynamic abrasion model. This approach relies on proper consideration of the multiphasenature of the considered problem and the interaction force between the involved fluid and solid phases. Accordingly,it can take into account the behavior of the gradually changing hole diameter due to proppant continuousperforation erosion. Moreover, it can provide useful information about the fluid-dynamic behavior of the consideredsystem before and after plugging. It is shown that when the diameter of the temporary plugging ball is1.2 times that of the perforation hole, the perforation holes of each cluster can be effectively blocked.

Vomiting-induced pharyngeal perforation during bowel preparation for colonoscopy:A case report

BACKGROUND Effective bowel cleansing is essential for a successful colonoscopy.Laxatives,such as polyethylene glycol,are commonly used for bowel preparation.Vomiting is a frequent complication during bowel preparation,and forceful vomiting can potentially lead to esophageal perforation,as reported in several previous cases.However,pharyngeal perforation during bowel preparation has not been previously documented.Here,we present a case of pharyngeal perforation induced by forceful vomiting during bowel preparation.CASE SUMMARY A 38-year-old man with a history of hypertension,dyslipidemia,diabetes mellitus,and end-stage renal disease on hemodialysis was admitted for evaluation of recurrent abdominal pain.The patient complained of sudden pain in the neck,throat,and anterior chest following forceful vomiting during bowel preparation.Physical examination revealed crepitus under the skin of the neck and anterior chest on palpation,and upper gastrointestinal endoscopy revealed pharyngeal perforation.The perforation site was located above the upper esophageal sphincter,which distinguished it from Boerhaave’s syndrome.Conservative medical management was chosen after consultation with a thoracic surgeon and an otolaryngologist,considering the patient's mild symptoms,stable vital signs,and the small size of the lesion;the perforation resolved without endoscopic or surgical intervention.The patient was discharged from hospital two weeks after the perforation.CONCLUSION Despite its rarity,pharyngeal perforation should be considered a potential complication of bowel preparation for colonoscopy.

Management of a patient with an unusual trajectory of a temporary trans-venous pacing lead

Perforation of the right ventricle during placement of pacing wires is a welldocumented complication and can be potentially fatal.Use of temporary pacemaker,helical screw leads and steroids use prior to implant are recognised as risk factors for development of post-permanent pacemaker effusion.We reported an unusual case of pacing wire perforating interventricular septum into the left ventricle that occurred during the implant procedure performed in another institution.After the preoperative work-up and transfer to our tertiary cardiothoracic centre,the patient underwent successful surgical management.In conclusion,early recognition and timely diagnosis using advanced multimodality imaging can guide surgical intervention and prevent unfavourable consequences of device-related complications.

Fracture propagation law of temporary plugging and diversion fracturing in shale reservoirs under completion experiments of horizontal well with multi-cluster sand jetting perforation

This study conducted temporary plugging and diversion fracturing(TPDF)experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion with multi-cluster sand jetting perforation.The effects of temporary plugging agent(TPA)particle size,TPA concentration,single-cluster perforation number and cluster number on plugging pressure,multi-fracture diversion pattern and distribution of TPAs were investigated.A combination of TPAs with small particle sizes within the fracture and large particle sizes within the segment is conducive to increasing the plugging pressure and promoting the diversion of multi-fractures.The addition of fibers can quickly achieve ultra-high pressure,but it may lead to longitudinal fractures extending along the wellbore.The temporary plugging peak pressure increases with an increase in the concentration of the TPA,reaching a peak at a certain concentration,and further increases do not significantly improve the temporary plugging peak pressure.The breaking pressure and temporary plugging peak pressure show a decreasing trend with an increase in single-cluster perforation number.A lower number of single-cluster perforations is beneficial for increasing the breaking pressure and temporary plugging peak pressure,and it has a more significant control on the propagation of multi-cluster fractures.A lower number of clusters is not conducive to increasing the total number and complexity of artificial fractures,while a higher number of clusters makes it difficult to achieve effective plugging.The TPAs within the fracture is mainly concentrated in the complex fracture areas,especially at the intersections of fractures.Meanwhile,the TPAs within the segment are primarily distributed near the perforation cluster apertures which initiated complex fractures.

Mediastinal emphysema in the context of perforated gastric ulcer

In the context of mediastinal emphysema/pneumomediastinum,the main aetiologies are associated with oesophageal perforation,lung pathology or post head and neck surgery related.The main way to differentiate the pathologies would be through Computed Tomographic Imaging of the Thorax and abdomen with oral and intravenous contrast in the context of triple phase imaging.The causes of pneumomediastinum should be differentiated between traumatic and non-traumatic.Oesophageal perforation(Boerhaave syndrome)is associated with Mackler’s triad in upto 50%of patients(severe retrosternal chest pain,pneumomediastinum,mediastinitis).Whereas in cases of lung pathology this can be associated with pneumothorax and pleural effusion.

Previously undiagnosed Morgagni hernia with bowel perforation detected during repeat screening colonoscopy: A case report

BACKGROUND Morgagni hernia(MH)is a form of congenital diaphragmatic hernia(CDH)characterized by an incomplete formation of diaphragm,resulting in the protru-sion of abdominal organs into the thoracic cavity.The estimated incidence of CDH is between 1 in 2000 and 1 in 5000 live births,although the true incidence is unknown.MH typically presents in childhood and can be diagnosed either pre-natally or postnatally.However,it can also be asymptomatic and carry the risk of developing into a life-threatening condition in adulthood.CASE SUMMARY A 76-year-old female with no history of prior abdominal surgeries presented for an elective colonoscopy for polyp surveillance.During the procedure,when approaching the hepatic flexure,the scope could not be advanced further despite multiple attempts.The patient experienced mild abdominal discomfort,leading to the abortion of the procedure.While in the recovery area,she developed increa-sing abdominal pains and hypotension.Urgent abdominal imaging revealed her-niation of the proximal transverse colon through a MH into the chest with evi-dence of perforation.The patient underwent laparoscopic urgent colonic resection and primary hernia repair and was discharged uneventfully 2 d later.CONCLUSION A MH is a rare condition in adults that can present as a life-threatening compli-cation of colonoscopy,even in patients with a history of uneventful colonoscopies.This case highlights the importance of considering congenital and internal hernias when faced with sudden and unexplained difficulties during colonoscopy.If there is a suspicion of MH,the endoscopist should halt the procedure and immediately obtain abdominal imaging to confirm the diagnosis.

Colon perforation with severe peritonitis caused by erotic toy insertion and treated using vacuum-assisted closure:A case report

BACKGROUND Colorectal foreign bodies are commonly encountered during surgery.They are frequently observed in men 20 to 90 years of age and have bimodal age distribution.Surgical management is necessary for cases of rectal perforation.However,surgical site infections are the most common complications after colorectal surgery.CASE SUMMARY We discuss a case of rectal perforation in a patient who presented to our hospital 2 d after its occurrence.The perforation occurred as a result of the patient inserting a sex toy in his rectum.Severe peritonitis was attributable to delayed presentation.CONCLUSION Vacuum-assisted closure was performed to treat the wound,which healed well after therapy.No complications were noted.

Appendicitis combined with Meckel’s diverticulum obstruction, perforation, and inflammation in children: Three case reports

BACKGROUND Meckel’s diverticulum is a common congenital malformation of the small intestine,with the three most common complications being obstruction,per-foration,and inflammation.To date,only a few cases have been reported world-wide.In children,the clinical symptoms are similar to appendicitis.As most of the imaging features are nonspecific,the preoperative diagnosis is not precise.In addition,the clinical characteristics are highly similar to pediatric acute appendicitis,thus special attention is necessary to distinguish Meckel’s diver-ticulum from pediatric appendicitis.Patients with poor disease control should undergo laparoscopic exploration to avoid serious complications,including intestinal necrosis,intestinal perforation and gastrointestinal bleeding.CASE SUMMARY This report presents three cases of appendicitis in children combined with intestinal obstruction,which was caused by fibrous bands(ligaments)arising from the top part of Meckel's diverticulum,diverticular perforation,and diver-ticular inflammation.All three patients,aged 11-12 years,had acute appendicitis as their initial clinical presentation.All were treated by laparoscopic surgery with a favorable outcome.A complete dataset including clinical presentation,dia-gnostic imaging,surgical information,and histopathologic findings was also provided.CONCLUSION Preoperative diagnosis of Meckel’s diverticulum and its complications is challenging because its clinical signs and complications are similar to those of appendicitis in children.Laparoscopy combined with laparotomy is useful for diagnosis and treatment.