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.

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.

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.

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.

The Evolutionary Profile of Patients Operated for Peptic Ulcer Perforation in Bujumbura

Background: The evolutionary profile of patients operated for peptic ulcer perforation in Bujumbura. Perforated peptic ulcer is a serious complication of peptic ulcer with potential risk of grave complications. Aim: To study the early morbidity and mortality of surgery for peptic ulcer perforation in Bujumbura City Hall hospitals: Kamenge University Hospital Center (CHUK), Kamenge Military Hospital (HMK) and Prince Louis Rwagasore Clinic (CPLR). Patients and methods: This is a retrospective, descriptive and analytical study carried out in the three hospitals of Bujumbura over a period of three years from January 1, 2020 to December 31, 2022. It involved 57 cases (n = 57) of peptic ulcer perforation. Results: The frequency of surgery for peptic ulcer perforation was 2.7% with a mean age of 43.6 years +/- 15.3 years and a male predominance with a sex ratio of 3.7. Eight percent of patients presented with shock, 24.5% were smokers, and 67.9% had taken non steroidal anti-inflammatory drugs. The mean hospital stay was 15.2 days with a standard deviation of 12.1. The morbidity rate was 30.2%, 32% were classified in grade IIIb of the Clavien-Dindo Surgical Complications Scale. There were 9 deaths (17%). Seven patients who underwent surgery and received late consultations died. Conclusion: Surgery for peptic ulcer perforation remains an intervention associated with a high rate of morbidity and mortality in Bujumbura. Surgery for peptic ulcer perforation remains a procedure associated with a high morbidity and mortality rate in Bujumbura. The time before consultation was the only factor associated with early morbidity and mortality of Surgery for peptic ulcer’s perforations.

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.

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.

Clinical Epidemiology and Surgical Treatment of Spontaneous Perforations of the Terminal Ileum: A Multicentre Study in Cameroon

Background: Perforations of the terminal ileum are a frequent clinical situation and a therapeutic challenge. Surgical treatment is controversial. Several surgical modalities have been proposed and postoperative morbidity and mortality remain high. The aim of this study was to review our experience in the surgical management of perforations of the terminal ileum. Patients and methods: This is a descriptive cross-sectional study with retrospective data collection from January 1, 2017 to December 31, 2021, in five hospitals in Cameroon. Patients’ demographic, clinical presentation, surgical findings and 30-days postoperative outcomes data were collected. Results: We collected 34 files. The sex ratio was 1.4 and the average age was 20.28 years. The average consultation time was 9.1 days. Abdominal pain was present in all our patients. Peritoneal irritation was present in 46 cases (88.5%). The mean time to treatment after admission was 17.5 hours. The perforation was unique in 40 cases (76.9%) and located between 6 and 10 cm from the ileocecal valve in 29 cases (55.8%). Typhoid was the most suspected etiology intraoperatively in 38 cases (73.1%). A simple suture was performed in 18 patients (34.6%), resection with anastomosis in 11 patients (21.2%) and an ileostomy in 5 patients (9.6%). The average length of hospitalization was 21.74 days. Postoperative morbidity and mortality were 32.7% and 17.3% respectively. Conclusion: Perforations of the terminal ileum are common and affect young people. Surgical procedures are varied. Reducing consultation and care times and respecting treatment principles could improve postoperative morbidity and mortality, which remain high.

Efficacy of Cyanoacrylate Tissue Adhesive Application in the Management of Corneal Perforations at Preah Ang Duong Hospital in Cambodia

Purpose: The study was to evaluate the efficacy of cyanoacrylate tissue adhesive (CTA) application in corneal perforations. Method: This was a prospective study on 20 patients of corneal perforations who received cyanoacrylate tissue adhesive application as treatment between March 2021 and March 2022 at Preah Ang Duong Hospital. The primary outcome measure was success rate of CTA application, while the secondary outcome was to measure postoperative best-corrected visual acuity (BCVA) and ocular complications. Results: The mean age of patients was 44.15 ± 16.05 years old and 7 (35%) were female. Causes of perforation were microbial infection in 12 patients (60%), trauma in 5 patients (25%), and sterile melting in 3 patients (15%). The perforation of size smaller than 1.5 mm was in 8 patients (40%) while 12 patients (60%) had perforated size between 1.5 mm to 3 mm. The perforation was 60% (12 patients) central, 25% (5 patients) paracentral, and 15% (3 patients) peripherally. Out of 20 patients, 5 patients (25%) received CTA application more than 1 time. The mean glue retention was 57.60 ± 31.84 days. Success rate of glue application (defined as intact globe without surgical intervention regardless of number of CTA applications) was 85%. At the last visit, 7 patients (35%) had BCVA of 6/120 or better. Common complications were uveitis (45%), ocular hypertension (30%), cataract (25%) and neovascularization (20%). No serious complications were found. Conclusion: Cyanoacrylate tissue adhesive is an effective treatment option in sealing corneal perforations with no serious complications. .

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.

Post Blast Tympanic Perforations, Clinical and Paraclinical Study at Six Yaounde Hospitals

Introduction: Post-blast tympanic perforations represent an entity of traumatic perforations;various mechanisms are at the origin of the latter, and the increase in conflicts and acts of violence are increasing the studies on this subject, but few data are available in our context. Objective: This paper aims to study post-blast tympanic perforations in Yaounde, specifically the epidemiological, clinical, and paraclinical aspects. Methodology: We conducted a descriptive cross-sectional study with retrospective and prospective data collection in six Yaounde hospitals over 63 months from January 1, 2018, to March 31, 2023. All patients with at least one post-blast tympanic perforation were included. Socio-demographic, clinical and paraclinical data were collected on a questionnaire and analysed using SPSS 28 software. Results: We included 124 patients. The prevalence of post-blast tympanic perforations was 0.1% of the consultations in the departments. 71 The average age was 28.6 ± 9.1 years, with extremes ranging from 7 to 49 years. The median consultation time was five days. The most frequent injury circumstances were physical aggression (81.45%) and armed conflict (10.5%). The injury mechanisms were slaps (75%), punches (21.74%) and grenades (4.8%). The main symptoms on admission were hearing loss (63.7%), tinnitus (58.1%) and otalgia (57.3%). The tympanic perforations were unilateral in all cases, the anterior-inferior location was more characteristic, and the deafness was conductive in 58.3% of cases, followed by mixed deafness in 23.3% of cases. Conclusion: Post-blast tympanic perforations are rare in consultation. The population is primarily male and from the second decade of life. The main circumstance is aggression.

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.

Bladder Perforation during Transurethral Resection of Bladder Tumor Is Not an Innocent Accident: Literature Review Based on a Clinical Case Experience

Urothelial Carcinoma (UC) is one of the most frequent cancers worldwide. Transurethral Resection of Bladder Tumor (TURBT) is a standard treatment in the disease’s early stages, with bladder perforation being a possible and classical complication. However, extravesical tumor seeding resulting from perforation is a rare phenomenon. We hereby report the case of a 76-year-old man with a history of smoking diagnosed with high-grade T1 urothelial carcinoma. TURBT was performed and bladder perforation occurred during the procedure. Radical cystectomy after neoadjuvant chemotherapy failed to reveal an invasive tumor. However, the patient experienced peritoneal recurrence with liver metastasis 3 years following the operation. This case left physician wondering whether the bladder perforation and the resulting tumor seeding are the cause behind the late peritoneal recurrence of an early-stage urothelial carcinoma.

Gallbladder perforation with fistulous communication

BACKGROUND The management of gallbladder perforation(GBP)with fistulous communication(Neimeier type I)is controversial.AIM To recommend management options for GBP with fistulous communication.METHODS A systematic review of studies describing the management of Neimeier type I GBP was performed according to the PRISMA guidelines.The search strategy was conducted in Scopus,Web of Science,MEDLINE,and EMBASE(May 2022).Data extraction was obtained for patient characteristics,type of intervention,days of hospitalization(DoH),complications,and site of fistulous communication.RESULTS A total of 54 patients(61%female)from case reports,series,and cohorts were included.The most frequent fistulous communication occurred in the abdominal wall.Patients from case reports/series had a similar proportion of complications between open cholecystectomy(OC)and laparoscopic cholecystectomy(LC)(28.6 vs 12.5;P=0.569).Mortality was higher in OC(14.3 vs 0.0;P=0.467)but this proportion was given by only one patient.DoH were higher in OC(mean 26.3 d vs 6.6 d).There was no clear association between higher rates of complications of a given intervention in cohorts,and no mortality was observed.CONCLUSION Surgeons must evaluate the advantages and disadvantages of the therapeutic options.OC and LC are adequate options for the surgical management of GBP,with no significant differences.

Erosion characteristics and simulation charts of sand fracturing casing perforation

Large-scale sand fracturing is a necessary means in the efficient exploitation of shale gas/oil.However,in the process of fracturing operation,the sand carrying fluid and proppant easily causes scouring and wear to production strings,especially the casing perforation system,which damage the wellbore integrity and deformation to affect the subsequent fracturing.For this problem,taking the actual construction conditions and perforation technology of an oilfield in western China as an example,the structural parameters of the downhole string were measured and the wall thickness reduction model of casing perforation suitable for large-displacement sand fracturing in horizontal well section was established.With software ANSYS-FLUENT,the casing perforation erosion under the conditions of different displacements,sand content and perforation sand-passing quantity in the process of sand fracturing was simulated and calculated.The influences of three parameters on perforation erosion and expansion were analyzed and the prediction chart of the influences of three main control factors on perforation erosion and expansion was established.The perforation erosion images after fracturing construction were obtained with the downhole eagle perforation logging technology.The logging chart results were compared with the downhole eagle perforation data.The error between the established numerical simulation calculation charts and the real logging data was about 5%,indicating that the simulation charts were the valuable reference.

Perforation of levonorgestrel-releasing intrauterine system found at one month after insertion:A case report

BACKGROUND The levonorgestrel-releasing intrauterine system(LNG-IUS)is widely used in contraception,menorrhagia,dysmenorrhea and to prevent endometrial hyperplasia during estrogen supplementation.Perforation is more often seen after early postpartum placement.Perforation of the LNG-IUS occurring one month after placement is rare.CASE SUMMARY A 42-year-old female complained of progressive dysmenorrhea and increased menstrual volume.She was diagnosed with adenomyosis and the LNG-IUS was inserted in her uterine cavity.Routine ultrasound examination one month later revealed that the intra-uterine device(IUD)was not found in the uterine cavity,and further X-ray and pelvic magnetic resonance imaging showed an abnormal signal area in the left posterior region of the uterus.Laparoscopic exploratory surgery was performed and the LNG-IUS was found in the left uterosacral ligament.CONCLUSION Perforation of a LNG-IUS occurring one month after placement is rare,and is more common in inexperienced operators and after early postpartum placement.When the operation is difficult,ultrasound monitoring is recommended to reduce the risk of IUD perforation.For patients with inadequate surgery,postoperative imaging is recommended to detect potential risks as soon as possible.

Traumatic Digestive Perforation in the Hospital of Sikasso: Epidemio-Clinical and Therapeutic Aspects

Traumatic digestive perforation is the pathological opening of the wall of a hollow organ of the digestive tract (esophagus, stomach, small intestine, large intestine, rectum, and extrahepatic bile ducts) following trauma. Injuries to the digestive viscera, especially from trauma, have been known since antiquity. Aristotle recognized that a slight blow can cause an intestinal injury. Perforation of a hollow organ of the digestive sphere results in peritonitis, which in this case is the consequence of an infection of the peritoneal cavity by spreading of the digestive contents. The aim of the work was to describe the epidemiological, clinical and therapeutic aspects of traumatic digestive perforation. Patients and method: The study was retrospective and descriptive from January 1, 2016 to December 31, 2020, in the general surgery department of the hospital of Sikasso (Mali). Patients operated for traumatic digestive perforation were included. Results: The clinical records of 42 patients were collected. Traumatic digestive perforations represented 12.3% of patients hospitalized for abdominal trauma. The average age of the patients was 26.6 years, with a sex ratio of 6:1. The most frequent etiology was road traffic accidents with 38% of patients. The average delay of consultation was 5 days. Abdominal pain was present in 38 patients, vomiting in 17 patients. On physical examination, the most frequent signs were abdominal contracture in 61.9% of patients, and disappearance of pre-hepatic dullness in 54.7% of patients. On rectal examination, the douglas was bulging and painful in 21 patients. X-ray of the abdomen without preparation showed pneumoperitoneum in 54.1% of patients. Excision, suture and peritoneal lavage were performed in 31 patients. The postoperative course was marked by parietal suppurations in 5 patients, a digestive fistula in 2 patients and 4 cases of death (9.5%). Conclusion: Traumatic digestive perforation is a frequent pathology in surgery. Road accident was the main cause. The treatment is essentially surgical.

Abdominal pregnancy secondary to iatrogenic uterine perforation: A case report and literature review

Abdominal pregnancy is a rare and life-threatening form of ectopic pregnancy.It is defined as an ectopic pregnancy in a region of the peritoneal cavity that does not include the fallopian tubes,ovaries,or their associated ligamentous structures.Many abdominal pregnancies are caused by secondary implantation in the peritoneal cavity after tubal abortion,rupture,or uterine rupture.Here,we report a case of abdominal pregnancy resulting from iatrogenic uterine perforation during the induced abortion of an early intrauterine pregnancy,which had been misdiagnosed as a ruptured corpus luteum cyst due to the sudden rupture of the abdominal gestational sac,complicating intra-abdominal hemorrhage.The true diagnosis was missed by vaginal ultrasound and confirmed by laparoscopic exploration.We discuss the details of the case management and review the relevant literature.©2023 Zhejiang University.

Bow-and-arrow sign on point-of-care ultrasound for diagnosis of pacemaker lead-induced heart perforation:A case report and literature review

BACKGROUND Pacemaker lead-induced heart perforation is a rare but life-threatening complication of pacemaker implantation,and timely diagnosis remains a challenge for clinicians.Here,we report a case of pacemaker lead-induced cardiac perforation rapidly diagnosed by a“bow-and-arrow”sign on point-of-care ultrasound(POCUS).CASE SUMMARY A 74-year-old Chinese woman who had undergone permanent pacemaker implantation 26 d before suddenly developed severe dyspnea,chest pain,and hypotension.The patient had received emergency laparotomy for an incarcerated groin hernia and was transferred to the intensive care unit 6 d before.Computed tomography was not available due to unstable hemodynamic status,so POCUS was performed at the bedside and revealed severe pericardial effusion and cardiac tamponade.Subsequent pericardiocentesis yielded a large volume of bloody pericardial fluid.Further POCUS by an ultrasonographist revealed a unique“bow-and-arrow”sign indicating right ventricular(RV)apex perforation by the pacemaker lead,which facilitated the rapid diagnosis of lead perforation.Given the persistent drainage of pericardial bleeding,urgent off-pump open chest surgery was performed to repair the perforation.However,the patient died of shock and multiple organ dysfunction syndrome within 24 h post-surgery.In addition,we also performed a literature review on the sonographic features of RV apex perforation by lead.CONCLUSION POCUS enables the early diagnosis of pacemaker lead perforation at the bedside.A step-wise ultrasonographic approach and the“bow-and-arrow”sign on POCUS are helpful for rapid diagnosis of lead perforation.

Unusual case of emphysematous cystitis mimicking intestinal perforation:A case report

BACKGROUND Emphysematous cystitis(EC)is a bladder condition commonly caused by gasgenerating bacterial infections.Factors that increase the risk for developing this condition include female gender,age≥60 years,and diabetes mellitus,glycosuria,and urinary stasis.The symptoms of EC often lack specificity,making diagnostic imaging techniques crucial for accurate identification of the condition.CASE SUMMARY This report presents an unusual case of EC that mimicked intestinal perforation.While it was initially challenging to differentiate between intestinal perforation and EC on admission,the patient managed to avoid unnecessary surgery and made a good recovery solely through antibiotic treatment.CONCLUSION Successful treatment of the patient described herein highlights the importance of accurately diagnosing EC,which can be difficult to differentiate from intestinal perforation.