Wall Perforation Research Articles

A prospective study evaluating patient reported outcome measures in patients who have undergone chest wall perforator flaps

To evaluate Patient Reported Outcome Measures (PROMs) and surgical outcomes in patients undergoing Chest Wall Perforator Flaps (CWPFs). This was an observational single cohort study using an audit approach and a survey instrument. 84 patients who had undergone CWPFs in the last 5 years at the Department of Breast Surgery, City Hospital Birmingham, were identified from a pre-existing database. Surgical outcomes were recorded. Patients were contacted telephonically or in person at the time of follow-up and were asked to fill up a PROMs questionnaire. Out of 84 patients, 58 patients chose to respond. The average age of the patients was 51.3 years (±8.2 years). The average follow-up was 15.4 months (±9.9 months). The most common histological subtype was Infiltrating ductal carcinoma (IDC)-Not otherwise specified 34/58 (58.6%). Majority of the patients had T2 cancers-28/58 (48.3%). 26/58 (44.8%) were node negative. Eight patients (13.7%) had post-operative complications. No patient had total/partial flap loss. Nine patients (15.5%) had margin re-excision. One patient developed distant metastasis while 1 patient developed a second primary. Fifty-one patients (88%) were either satisfied or very satisfied with the post-operative appearance of the breasts. Thirty-six patients (62%) had no/little persistent pain or tenderness post-surgery. Eighty-six per cent (38/44) of the patients undergoing Lateral Intercostal Artery Perforator (LICAP) Flap and 16/18 (89%) of patients undergoing Anterior Intercostal Artery Perforator (AICAP) flap had no/little difficulty in carrying out normal activities at follow up. CWPFs are associated with a low complication rate and a high patient satisfaction rate.

Chest wall perforator flaps in breast cancer surgery are safe and can decrease mastectomy rates. A multicentre study.

Chest wall perforator flaps in breast cancer surgery are safe and can decrease mastectomy rates. A multicentre study.

Comparison of Monopolar Versus Bipolar Repeat Transurethral Resection of Bladder Tumours.

To compare the effects of monopolar and bipolar energy sources on efficacy of both techniques and possible complications in bladder cancer patients undergoing repeat Transurethral resection of bladder tumour (re-TURBT). Descriptive study. Place and Duration of the Study: University of Health Science, Izmir Bozyaka Research and Training Hospital, Turkiye, from 2019 to 2021. Patients undergoing re-TURBT were inducted. Patients with residual tumour at initial TURBT, recurrent bladder cancer and patients with a non-urothelial pathology report in initial TURBT were excluded. The primary outcome was the complication ratio of the TURBT which were obturator reflex, bladder wall perforation, coagulum retention, fever, and TUR syndrome. The secondary outcome was the efficacy of the TURBT procedure, such as complete tumour resection, adequate sampling of deep muscle tissue, and sampling of qualified tissues without any thermal damage. One hundred and twenty-three patients were enrolled; 75 patients in re-M-TURBT group and 48 patients in re-B-TURBT group were analysed. Demographic and tumour characteristics, and complication rates according to the Clavien classification, were similar between the two groups (p = 0.302). The catheterisation time was shorter significantly in the bipolar re-TURBT group (median 4 vs. 3 days, respectively, p = 0.025). Monopolar and Bipolar energy sources are techniques that can be used safely in re-TURBT in terms of both appropriate pathology sampling (adequate muscle tissue sampling, cautery artifact) and complication (obturator reflex, hyponatraemia, haemoglobin decrease, bleeding) rates. Bladder Cancer, Monopolar, Bipolar, TURBT, Obtrator reflex, Complications.

In vivo high-speed microscopy of microbubbles in the chorioallantoic membrane model.

Rationale: The acoustic stimulation of microbubbles within microvessels can elicit a spectrum of therapeutically relevant bioeffects from permeabilization to perfusion shutdown. These bioeffects ultimately arise from complex interactions between microbubbles and microvascular walls, though such interactions are poorly understood particularly at high pressure, due to a paucity of direct in vivo observations. The continued development of focused ultrasound methods hinges in large part on establishing links between microbubble-microvessel interactions, cavitation signals, and bioeffects. Methods: Here, a system was developed to enable simultaneous high-speed intravital imaging and cavitation monitoring of microbubbles in vivo in a chorioallantoic membrane model. Exposures were conducted using the clinical agent DefinityTM under conditions previously associated with microvascular damage (1 MHz, 0.5-3.5 MPa, 5 ms pulse length). Results: Ultrasound-activated microbubbles could be observed and were found to induce localized wall deformations that were more pronounced in smaller microvessels and increased with pressure. A central finding was that microbubbles could extravasate from microvessels (from 34% of vessels at 1 MPa to 79% at 3 MPa) during insonation (94% within 0.5 ms) and that this occurred more frequently and in progressively larger microvessels (up to 180 µm) as pressure was increased. Following microbubble extravasation, transient or sustained red blood cell leakage ensued at the extravasation site in 96% of cases for pressures ≥1 MPa. Conclusions: The results here represent the first high-speed in vivo investigation of high-pressure focused ultrasound-induced microbubble-microvessel interactions. This data provides direct evidence that the process of activated microbubble extravasation can occur in vivo and that it is linked to producing microvessel wall perforations of sufficient size to permit red blood cell leakage. The association of red blood cell leakage with microbubble extravasation provides mechanistic insight into the process of microvessel rupture, which has been widely observed in histology.

Immediate implant placement in the premolar maxillary area: a cone-beam computed tomography study.

This research aimed to investigate potential factors associated with the risk of perforation of the labial bone plate, nasal floor, or maxillary sinus floor during immediate implant placement (IIP) in the maxillary premolar area, utilizing a cone-beam computed tomography (CBCT) virtual study. CBCT exams from 179 eligible participants, encompassing 716 teeth, were included. Implants were virtually positioned in 2 orientations: along the long axis of the tooth (the prosthetically-driven position) and in an optimal position relative to adjacent anatomical structures (the bone-driven position). Binary logistic regression analysis was employed to assess potential associations between perforation or invasion and various covariates, including sex, age, tooth region, the distance from the tooth apex to the nasal floor or maxillary sinus floor, the angle between the prosthetically- and bone-driven positions (implant-line A angle [ILAA]), and the labial concavity angle (LCA). The mean ILAA was 18.3°±8.0°, and the angle was significantly larger for the second premolar compared to the first premolar. The mean minimum implant length was 13.0±2.1 mm, with a bone anchorage of 4 mm. The incidence of perforation was 84.1% for the prosthetically-driven position and 40.5% for the bone-driven position. Factors associated with a higher risk of cortical bone wall perforation or invasion of the 2-mm safety margin from surrounding anatomical structures (in the bone-driven position) included female sex, older age, shorter distance from the tooth apex to the nasal cavity/maxillary sinus, and smaller LCA. A high prevalence of cortical bone wall perforation or invasion of the 2-mm safety margin is anticipated when performing IIP in the maxillary premolar region.

A before and after evaluation of patient reported outcomes assessed by Breast Q following LICAP turnover flap in breast conservative therapy.

Chest-wall perforator-based techniques to replace volume for breast conservative therapy allow excision of large breast areas with minimal sequalae, such as the nipple-areolar complex displacement, parenchymal indentation or contour deformity. Furthermore, chest wall perforator flaps facilitate the maintenance of breast symmetry, hence decreasing the need for contralateral surgery. Lateral intercostal flap was described in numerous variants among which the most famous are the propeller flap and the turnover version. The turnover version is the easiest and fastest version that allows the replacement of large amount of volume. In this paper, we evaluate patients reported outcomes, before and after surgery, collected through the Breast Q. This study was conducted on 21 patients who were admitted to the plastic surgery department. A prospectively maintained database was used to identify the patients and their records were assessed retrospectively. The pre/post operative patients data were collected. The Breast-Q questionnaire was administered before the surgery and at least 1year after. No major surgical complications were reported. Mean Breast-Q scores were evaluated at least 1year after surgery and radiotherapy and compared with pre-surgical scores. Among all the modules, no significant differences between the pre-surgical and post-surgical Breast-Q scores were observed. Until now, the lateral intercostal artery perforator flap has not been widely used, due to a difficult dissection and a challenging preoperative planning. According to the reported surgical technique, the execution is easy. This technique provides the same breast-related quality of life compared to preoperative values, reduces the mastectomy rate and increases the overall survival.

A counter-swirl design concept for dry powder inhalers

A swirling airflow is incorporated in several dry powder inhalers (DPIs) for effective powder de-agglomeration. This commonly requires the use of a flow-straightening grid in the DPI to reduce drug deposition loss caused by large lateral spreading of the emerging aerosol. Here, we propose a novel grid-free DPI design concept that improves the aerosol flow characteristics and reduces the aforementioned drug loss. The basis of this design is the implementation of a secondary airflow that swirls in the opposite direction (counter-swirl) to that of a primary swirling airflow. In-vitro deposition, computational fluid dynamics simulations and particle image velocimetry measurements are used to evaluate the counter-swirl DPI aerosol performance and flow characteristics.In comparison with a baseline-DPI that has only a primary swirling airflow, the counter-swirl DPI has 20% less deposition of the emitted drug dose in the induction port and pre-separator of a next generation impactor (NGI). This occurs as a result of the lower flow-swirl generated from the counter-swirl DPI which eliminates the axial reverse flow outside of the mouthpiece and substantially reduces lateral spreading in the exiting aerosol.Modifications to the counter-swirl DPI design were made to prevent drug loss from the secondary airflow tangential inlets, which involved the addition of wall perforations in the tangential inlets and the separation of the primary and secondary swirling airflows by an annular channel. These modified DPI devices were successful in that aspect but had higher flow-swirl than that in the counter-swirl DPI and thus had higher drug mass retained in the device and deposited in the induction port and pre-separator of the NGI. The fine particle fraction in the aerosols generated from all the counter-swirl-based DPIs and the baseline-DPI are found to be statistically similar to each other.

Patient reported outcomes and aesthetic assessment following chest wall perforator flap partial volume replacement for primary breast cancer

Patient reported outcomes and aesthetic assessment following chest wall perforator flap partial volume replacement for primary breast cancer

IBC-Oxford University2023_BJSPoster_10Surgical management of intra-gastric balloon complications

Abstract In Saudi Arabia, the intra-gastric balloon (IGB) is the most used endoscopic modality. Surgical management for IGB complications has been reported for gastrointestinal perforation and/or obstruction. However, the literature seems to underestimate these complications. We aim to report our experience as a tertiary university hospital in the Eastern Province of Saudi Arabia in dealing with different complications of IGBs that necessitated any type of surgical interventions. A retrospective descriptive study was conducted in a tertiary hospital in Saudi Arabia for 5 years to include all patients with complicated IGB who necessitated any surgical procedure. Exclusion criteria were patients with complicated IGBs that were only managed conservatively, and any complications related to other bariatric procedures. Six patients were referred due to IGB complications that necessitated operative intervention. All patients were young females. Three patients had gastric wall perforation and were managed by endoscopic removal of the IGBs followed by exploratory laparotomy. One patient had an intestinal obstruction on top of a migrated IGB that was surgically removed. One patient had failed endoscopic retrieval of IGB and required a laparoscopic gastrostomy. Another patient had esophageal rupture that required left thoracotomy, pleural flap and insertion of an esophageal stent. All cases were discharged and followed up with no related complications.

Chest wall perforator flaps for partial breast reconstruction after conservative surgery: Prospective analysis of safety and reliability

IntroductionBreast-conserving surgery associated with adjuvant radiotherapy is the state of the art in the surgical treatment of breast cancer. Oncoplastic surgery through dermo-adipose flaps based in perforating arteries (muscle sparing flaps) for partial reconstruction is increasingly used as a good option for avoiding musculocutaneous flaps. In this study we evaluate the outcomes of the use of chest wall perforator flaps in the replacement of partial breast volume. MethodsA prospective cohort study of female patients that underwent a conservative oncoplastic surgery procedure with partial breast reconstruction using a dermo-adipose flap of perforating arteries of the chest wall was conducted between November 2020 and March 2022 at our centre. Primary outcomes were surgical morbidity, positive margins and reoperation rates. Characteristics associated with the occurrence of complications were further identified. ResultsForty-five patients underwent the procedure of interest during the study period. The mean age was 55 years. The median larger dimension of the tumor was 23 mm. Lateral intercostal artery perforator (LICAP), lateral thoracic artery perforator (LTAP), a combined flap and Anterior Intercostal Artery Perforator/Medial Intercostal Artery Perforator (AICAP)/(MICAP) were performed in 22, 16, 2 and 5 patients, respectively. The mean operative time was 126 min. A total of 9 (20.0%) patients required a reoperation after definitive diagnosis, 4 due to positive margins and 5 due to immediate/early surgical morbidity. ConclusionsLocal perforator flaps in oncoplastic breast-conserving surgery are a good option for immediate reconstruction after conservative surgery, showing low morbidity and favourable outcomes.

Analysis of nonlinear landscape structure components accurate construction information delivery based on Rhino+Grasshopper parametric modeling

The development of digital construction technology has made the practical construction of nonlinear forms possible. In landscape architecture projects, Nonlinear Landscape Structures (NLS) have become the mainstream in design and aesthetics. However, the complex forms of NLS components make it challenging to deliver accurate construction information using traditional design methods. The application of Rhino+Grasshopper Parametric Modeling (RGPM) technology allows the construction of nonlinear geometric forms based on mathematical logic, facilitating precise engineering construction information delivery for NLS components. Nevertheless, there are existing gaps in current research on accurate construction information delivery for NLS components based on RGPM. Firstly, current research primarily focuses on large public buildings, lacking attention to the spatial scale of landscape structures. Secondly, there is a lack of systematic integration based on technical research contents. Thirdly, there is a lack of specific technical application analysis combining actual design, leading to weaker practical guidance for industry practitioners. Therefore, this study selects the precise engineering construction information delivery of perforated panel walls in the space under the Sanya Bridge and the landscape platform of the Beijing Jinding Mountain as research cases. Through the analysis of construction information delivery content and technical challenges in these cases, the necessity of RGPM application is clarified. By analyzing the application of RGPM technology and its outcomes in these cases, concrete examples are provided for the precise construction information delivery of NLS components to fill the research gaps and provide theoretical foundations and application examples for future research.

Analysis of nonlinear landscape structure components accurate construction information delivery based on Rhino+Grasshopper parametric modeling

The development of digital construction technology has made the practical construction of nonlinear forms possible. In landscape architecture projects, Nonlinear Landscape Structures (NLS) have become the mainstream in design and aesthetics. However, the complex forms of NLS components make it challenging to deliver accurate construction information using traditional design methods. The application of Rhino+Grasshopper Parametric Modeling (RGPM) technology allows the construction of nonlinear geometric forms based on mathematical logic, facilitating precise engineering construction information delivery for NLS components. Nevertheless, there are existing gaps in current research on accurate construction information delivery for NLS components based on RGPM. Firstly, current research primarily focuses on large public buildings, lacking attention to the spatial scale of landscape structures. Secondly, there is a lack of systematic integration based on technical research contents. Thirdly, there is a lack of specific technical application analysis combining actual design, leading to weaker practical guidance for industry practitioners. Therefore, this study selects the precise engineering construction information delivery of perforated panel walls in the space under the Sanya Bridge and the landscape platform of the Beijing Jinding Mountain as research cases. Through the analysis of construction information delivery content and technical challenges in these cases, the necessity of RGPM application is clarified. By analyzing the application of RGPM technology and its outcomes in these cases, concrete examples are provided for the precise construction information delivery of NLS components to fill the research gaps and provide theoretical foundations and application examples for future research.

EGS P15 Perforated Stomach within an Inguinal Hernia: A Rare Case Report and Surgical Management

Abstract Background Inguinal hernias are a common surgical condition requiring urgent medical attention. While complications of inguinal hernias are frequently encountered, the presence of a stomach herniation within this anatomical site is an exceptionally rare occurrence. This rare phenomenon presents diagnostic challenges and necessitates prompt surgical intervention. This case report aims to provide a detailed account of a patient with a perforated stomach within an inguinal hernia, emphasizing the unique clinical presentation, diagnostic dilemmas, and the subsequent surgical management required for such a complex condition. Methods We report the case of an 83-year-old male who presented with severe abdominal pain and a tender mass in the left groin. Clinical examination revealed an irreducible inguinal hernia with signs of peritonitis. CT scan confirmed a giant incarcerated inguinal hernia containing part of the stomach with associated gas and fluid collection. An emergency open hernia repair was attempted but swiftly converted to an exploratory laparotomy. The hernia content was reduced intraabdominally, surprisingly revealing a posterior stomach wall perforation. Damage-control suture repair, washout, and laparostomy were performed. Tragically, he succumbed to multiorgan failure soon after in ITU. Results The occurrence of a perforated stomach within an inguinal hernia is an exceptionally rare and diagnostically challenging entity. Timely diagnosis and intervention are vital to prevent life-threatening complications. Imaging, particularly CT scan, aids in diagnosis and surgical planning. Prompt surgical management, involving hernia reduction and gastric repair, is crucial for optimal outcomes. play a critical role in identifying the gastric perforation and guiding the surgical approach. Conclusions This case underscores the importance of recognizing rare complications, such as stomach herniation in inguinal hernias. Heightened awareness and appropriate use of imaging facilitate accurate diagnosis and guide surgical interventions. Timely surgical intervention is essential in reducing morbidity and mortality associated with this rare presentation.

Morphological structure of the right ventricular outflow tract (RVOT) muscle including anatomical variations - clinical implications for electrocardiological procedures using autopsy material

Abstract Background/Introduction The therapeutic effect of the electrocardiological procedure results not only from the correct supply of rhythm or conduction disturbances, but also from the avoidance of complications. The optimisation of the procedure is furthermore related to the efficient reaching of the target site and avoiding blockage of the used equipment by myocardial bridges or trabeculations. Purpose The purpose of our study was to evaluate in detail the right ventricular outflow tract (RVOT) muscle and to determine the types and extent of variation in this area. Methods We analysed 220 hearts (82 female, 37.2%) obtained during forensic medicine section from adult donors without structural heart disease. Collected hearts were fixed in 10% formaldehyde solution. The RVOT was opened by dissecting the muscle along its right periphery. The researchers assessed the presence and position of myocardial bridges, myocardial recesses and trabeculations. In addition, wall thickness and the presence of epicardial fat were assessed at 3 levels along the long axis of the RVOT at 4 points at each level. Linear dimensions were recorded using a precision electronic calliper by 2 different investigators. Statistical analyses were performed using STATISTICA 13.1. Results The presence of myocardial trabeculations covering the entire RVOT free wall was found in 72 hearts (35.5%), with 12 (5.90%) having a completely smooth wall. In the remaining 119 (58.6%), myocardial trabeculations covering the free wall partially were found. In the transition of the free wall to the posterior wall, trabeculations were found on the right and left periphery in 44 (21.6%) and 72 (35.6%) cases, respectively. At the same time, trabeculations were found in the middle part of the posterior wall in only 2 cases (1%). The RVOT recesses were found in 190 cases (92.2%), their number ranging from 1 and 6, with 3 being the most frequently found (26.7%). They were most frequently described on the left and right periphery (in 62.4%, 59.9% of hearts, respectively). Muscle bridges, running through the RVOT lumen, were localised within the left periphery in 109 cases (40.1%). RVOT muscle thickness ranged from 10.5 mm [5.24 mm] (median [IQR]) on the posterior wall, in the middle level, to 4.00 mm [1.36 mm] (mean [SD]), proximally, on the left periphery of the RVOT. The occurrence of epicardial adipose tissue ranged from 196 (96.1%) on the right periphery, in the middle part of the RVOT, to 102 [54.5%] proximally, on the anterior periphery. Conclusions The presence of myocardial bridges and RVOT recesses, while varying in their location and size, are factors that make full access difficult. The small thickness of the RVOT free wall in different regions suggests to consider wall perforation as a probable complication of the procedure, and the concomitant epicardial adipose tissue may be a factor explaining the subacute course of complications, including cardiac tamponade.

Analytical investigation on a wave energy converter-dual-arc breakwater integration system

A wave energy converter (WEC)-breakwater integration system consisting of a heaving WEC and a bottom-mounted dual-arc breakwater is proposed. The energy extraction performance and wave attenuation performance of the integration system were investigated using a theoretical model based on linear potential flow theory. The permeability of the dual-arc breakwater is considered in the theoretical model. The singularity at the edges of the perforated arc-shaped wall was solved using the multiterm Galerkin method. The unknowns in the expressions of velocity potential were solved using the eigenfunction expansion matching method. After successful validation, a comparative study between the models with dual-arc breakwater of different permeability was carried out first. Then, a parametric study on the configuration with a solid inner and a perforated outer arc-shaped wall is carried out. The performance of the proposed integration system is further investigated in multi-directional irregular waves, and it was found that the fluctuations of the average power capture width ratio are much lower compared with that under unidirectional regular wave conditions. The overall performance of the integration system is better with a larger directional spreading parameter.

Masonry Shear Triplets Coated with Fiber Reinforced Mortars

Unreinforced brick masonry walls (URM) have been widely used in construction for centuries and represent a large part of building heritage. However, these walls are prone to cracking and failure under certain loading conditions. Addressing this issue requires a comprehensive understanding of URM structures and the implementation of effective retrofitting techniques to enhance their structural integrity. wherefore, researchers have proposed the use of thin Fiber reinforced mortar coating as a reinforcement technique. This experimental study aims to investigate the effectiveness of this approach in improving the behavior of perforated brick masonry walls. To carry out this investigation, a shear triplets test under uniaxial loading has been conducted to evaluate the performance of the reinforcement technique. A series of shear triplets were built with perforated masonry of dimensions (220 x110 × 55) using bastard mortar (1: 1: 5). These specimens were coated with a thin layer of polypropylene fiber reinforced mortar. The test results of the reinforced and unreinforced specimens were compared to analyze the effectiveness of this technique of reinforcement. The test results showed that the application of fiber reinforced coating significantly increased the deformation ability and improved the stiffness and the bond strength of the masonry walls.

Effects of aeration and season on the composting of hatchery waste

AbstractHatchery waste is characterized as biomass with a high concentration of pollutants, therefore, such waste should be composted in static windrows in the initial phase of the process. The current research was carried out aiming to investigate the need for forced aeration in static piles built in cells with perforated walls during the composting of hatchery waste, in association with a bulking agent, during winter and summer. Aeration resulted in greater breakdown of volatile solids (VS), carbon (C), and lignin in the summer up to 50 days of composting. However, at 70 and 90 days, the results between aerated and non‐aerated windrows were similar. The highest N breakdown took place during winter with no aeration. The concentrations of humic acids were influenced only by the season and were higher in the compost generated during summer. Micronutrient concentrations in the compost were impacted by season and were higher in the summer. It is concluded that, in winter, forced aeration is only recommended after 50 days of composting, whereas in summer, forced aeration was beneficial throughout the composting process.

'PartBreCon' study. A UK multicentre retrospective cohort study to assess outcomes following PARTial BREast reCONstruction with chest wall perforator flaps.

Partial breast reconstruction with a pedicled chest wall perforator flap (CWPF) enables breast conservation in a higher tumour: breast volume ratio scenario. Since there is limited evidence, this retrospective cohort study aimed to ascertain immediate (30-days) and medium-term (follow-up duration) surgical outcomes. STROBE-compliant protocol ascertained CWPF outcomes between March 2011-March 2021. UK centres known to perform CWPF were invited to participate if they performed at least 10 cases. Data were retrospectively collected, including patient demographics, tumour and treatment characteristics, and surgical and oncological outcomes. Statistical analysis (R™) included multivariable logistic regression and sensitivity analysis. Across 15 centres, 507 patients with median age (54 years, IQR; 48-62), body mass index (25.4kg/m2, IQR; 22.5-29), tumour size (26mm, IQR; 18-35), and specimen weight (62g, IQR; 40-92) had following flap types: LiCAP (54.1%, n=273), MiCAP/AiCAP (19.6%, n=99), LiCAP+LTAP (19.8%, n=100) and TDAP (2.2%, n=11). 30-days complication rates were in 12%: haematoma (4.3%, n=22), wound infection (4.3%, n=22), delayed wound healing (2.8%, n=14) and flap loss (0.6%, n=3; 1 full) leading to readmissions (2.6%, n=13) and re-operations (2.6%, n=13). Positive margins (n=88, 17.7%) led to 15.9% (n=79) re-excisions, including 7.5% (n=37) at the planned 2nd of 2-stage surgery and 1.8% (n=9) mastectomy. At median 23 months (IQR; 11-39) follow-up, there were 1.2% (n=6) symmetrisations; recurrences: local (1%), regional/nodal (0.6%) and distant (3.2%). This large multicentre cohort study demonstrates acceptable complication and margin re-excision rates. CWPF extends the range of breast conservation techniques. Further studies are required for long-term oncological outcomes.

Risk of cardiac rupture among elderly patients with diabetes presenting with first acute myocardial infarction.

We aimed to analyze the risk of cardiac rupture (CR) in aged diabetic patients with acute ST-segment elevated myocardial infarction (STEMI) who were followed up for one month, and analyze its independent risk factors. A total of 3063 aged patients with first onset STEMI admitted to Beijing Anzhen Hospital from January 2001 to December 2020 were retrospectively included. There were 2020 patients without diabetes mellitus (DM) and 1043 patients with DM. We used propensity scores matching (PSM) method to balance baseline exposure factors between patients with or without DM, and all were divided the DM group (1043 cases) and the non-DM group (1043 cases) after the PSM. The primary outcome was CR (the composite rate of papillary muscle rupture, ventricular septum perforation, free wall rupture), which was diagnosed based on clinical manifestations and/or echocardiographic findings. Kaplan-meier survival analyses and log-rank test was used to evaluate the risk of CR between the two groups, and Cox regression analysis was used to evaluate the independent risk factors for CR. After PSM, the baseline clinical data were similar between the DM and non-DM group (all P>0.05). However, level of glycated hemoglobin was significantly higher in the DM group (P<0.05). During 1 month of follow-up, there were 55 (2.64%) cases of CR, most occurred within 48h after admission (40 cases). Among the 55 cases, 11(0.53%) had papillary muscle rupture, 18(0.86%) had ventricular septum perforation, and 26(1.25%) had free wall rupture. Kaplan-meier survival analyses detected that the DM group was associated with significantly increased risk of CR (3.36% vs. 1.92%, HR=1.532, 95% CI: 1.054-2.346, P=0.030), ventricular septum perforation (1.05% vs. 0.67%, HR=1.464, 95% CI: 1.021-2.099, P=0.038) and free wall rupture (1.63% vs. 0.86%, HR=1.861, 95% CI: 1.074-3.225, P=0.027) than those in the non-DM group. Among the 2031 aged STEMI patients without CR, 144 cases (6.90%, 144/2086) died; and among the 55 patients with CR, 37 cases (1.77%, 37/2086) died due to CR. Therefore, twenty percent (20.44%, 37/181) of death was due to CR. Multivariate Cox regression analysis indicated that DM (HR=1.532, 95%CI: 1.054-2.346), age (HR=1.390, 95%CI: 1.079-1.791), female (HR=1.183, 95%CI: 1.049-1.334), troponin I (HR=1.364, 95%CI: 1.108-1.679), brain natriuretic peptide (HR=1.512, 95%CI: 1.069-2.139), revascularization (HR=0.827, 95%CI: 0.731-0.936) and β-receptor blocker (HR=0.849, 95%CI: 0.760-0.948) were independent risk factors of CR (all P<0.05). DM as well as a few other factors, are independent determinants of CR. CR is not a rare event among the aged STEMI patients and twenty percent of deaths are due to CR. However, large sample-sized studies are warranted to confirm these findings.

Influential mechanism of perforation parameters in geothermal fixed-plane perforation recovery

The fixed-plane perforation technology, which is derived from oil and gas production, offers remarkable advantages in inducing fracturing and increasing fracture volume, but its theoretical foundation incompatible with the practical application of hot dry rock (HDR). In this study, a coupled thermal–hydraulic–mechanical model is developed to reveal the influence of perforation parameters on fracturing results in an environment of HDR. The stress, temperature distribution and damage volume of the rock at different numerical levels of the perforation parameters are compared to characterize the mechanism of the effect of perforation parameters on the fracturing results. Under the experimental conditions, the results of the control experiments show that the EGS system achieves a high techno-economic performance when the injection angle is about 45°, the injection density is about 5 clusters/m, and the injection depth is about 2.0 m. The analysis of orthogonal results not only reveals the time-varying sensitivity of rock cracking to perforating parameters, but also reveals that the in-plane perforation spacing is crucial to the effect of perforating parameters on fracturing. The analysis of variance also indicates that the degree of influence of perforation parameters on fracture varies over time. The area of the perforation wall defines the fracturing efficiency in the early stage of fracturing; the volume of fluid-rock interaction space, determined by in-plane perforation spacing, controls the fracturing efficiency in the later stage of fracturing. The results of the orthogonal analysis considering the interactions demonstrate that the interactions between the perforation parameters have a negligible effect on the fracturing results compared to the perforation parameters. This research can be utilized to optimize perforation parameters for fixed-plane fracturing.