Research on Leak Detection of Low-Pressure Gas Pipelines in Buildings Based on Improved Variational Mode Decomposition and Robust Kalman Filtering.

Aiming at the complex characteristics of negative pressure waves in low-pressure pipelines inside of buildings, we proposed an estimation method of pressure fluctuation trends based on the robust Kalman filter and the improved VMD, which can be used for leakage detection. The reconstructed baseline signal can accurately describe the fluctuation trend of the negative pressure wave after the pressure drop, and quantitatively express the characteristic difference between the leakage condition and the gas usage condition. The robust Kalman filter was used to estimate the pressure fluctuations. The parameters of VMD were adaptively calculated based on the WAA and discrete scale space. The trend components contained in the IMFs were separated by a reconstruction based on the Fourier series. Based on the simulation signal, the method can accurately restore the trend component contained in the complex pressure signal. Based on the actual signals, the accuracy of small leakage detection is 96.7% and the accuracy of large leakage detection is 73.3%.

The Right Gastroepiploic Artery as a Potential Organ at Risk in Neoadjuvant Chemoradiation for Esophageal and Gastroesophageal Cancers.

BACKGROUND: Preoperative chemoradiation is a standard of care for esophageal and gastroesophageal cancer. A gastric conduit is usually used for anastomosis with the right gastroepiploic artery (RGEA) being the sole arterial supply to the gastric remnant after such surgeries. Hence, lowering the radiation dose to this vessel may lower the risks of postoperative complications related to poor vasculature. Herein, we report our experience in contouring and replanning cases of distal esophageal/gastroesophageal carcinomas so that the radiation doses to the RGEA could be minimized. MATERIALS AND METHODS: Radiation plans of patients with lower esophageal/gastroesophageal carcinomas were retrieved from our database. Identification and delineation of the RGEA was done and replanning was performed with the aim to keep the maximal and mean doses as well as the V10Gy and V20Gy of the RGEA as low as possible without compromising target volume coverage.  Results: We achieved significant dose reductions in most of the dosimteric parameters in our selected cases without compromising target coverage. CONCLUSION: Lowering the dose to the RGEA, a potential organ-at-risk that may impact the postoperative course after neoadjuvant chemoradiation, is feasible.

Experimental models of high-risk bowel anastomosis in rats: A systematic review.

BACKGROUND: Anastomotic leaks remain one of the most dreaded complications in gastrointestinal surgery causing significant morbidity, that negatively affect the patients' quality of life. Experimental studies play an important role in understanding the pathophysiological background of anastomotic healing and there are still many fields that require further investigation. Knowledge drawn from these studies can lead to interventions or techniques that can reduce the risk of anastomotic leak in patients with high-risk features. Despite the advances in experimental protocols and techniques, designing a high-quality study is still challenging for the investigators as there is a plethora of different models used. AIM: To review current state of the art for experimental protocols in high-risk anastomosis in rats. METHODS: This systematic review was performed according to The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. To identify eligible studies, a comprehensive literature search was performed in the electronic databases PubMed (MEDLINE) and Scopus, covering the period from conception until 18 October 2023. RESULTS: From our search strategy 102 studies were included and were categorized based on the mechanism used to create a high-risk anastomosis. Methods of assessing anastomotic healing were extracted and were individually appraised. CONCLUSION: Anastomotic healing studies have evolved over the last decades, but the findings are yet to be translated into human studies. There is a need for high-quality, well-designed studies that will help to the better understanding of the pathophysiology of anastomotic healing and the effects of various interventions.

Biliary Complications Post Transjugular Intrahepatic Portosystemic Shunt in a Child With Portal Vein Cavernous Transformation.

The transjugular intrahepatic portosystemic shunt is a rising interventional procedure with multiple indications and high technical success but with risks of biliary injuries, an underreported scenario. We present an 11-year-old patient with biliary injury with a leak, biloma formation, and biliary obstruction caused by the percutaneous procedure. Interventional radiology drainages addressed these complications by resolving the leak and biloma. These biliary complications in percutaneous procedures and their management are rarely reported in the medical literature, making their management not standard. We highlight drainage management and the importance of sharing it to add experience to this clinical scenario and encourage sharing cases with similar diagnoses.

Pseudomeningocele Following Posterior Cranial Fossa Surgery Significantly Increases the Risk of Intracranial Infection: A 10-Year Retrospective Analysis.

Background: Posterior fossa craniotomy is commonly performed for various pathologies. However, intra-cranial infection following craniotomy causes morbidity. Pseudomeningocele is one of the main complications following posterior fossa operation. This study aimed to test the hypothesis that the risk of intra-cranial infection is increased in patients who undergo posterior fossa craniotomy with pseudomeningocele compared with those without pseudomeningocele. Methods: We retrospectively analyzed the data of patients undergoing posterior fossa craniotomy for the management of neurological pathologies at our institute from 2011 to 2020. A total of 308 craniotomies were included, and the primary outcome of interest was the occurrence of intra-cranial infection. Standard statistical methods were used to explore associations between several parameters, including pseudomeningocele, intra-cranial infection, and wound leak. Results: Of the 308 craniotomies, 41 (13.3%) developed intra-cranial infection and 59 (19.2%) involved pseudomeningocele. Of cases involving pseudomeningocele, 27 (45.8%) developed an intra-cranial infection compared with only 14 of 249 without pseudomeningocele (5.6%; p < 0.001). In the multi-variable analysis, pseudomeningocele was associated with intra-cranial infection (odds ratio [OR] 8.56; 95% confidence interval [CI] 3.145-23.299; p < 0.001) and wound leak (OR 91.339; 95% CI 10.437-799.364; p < 0.001). Conclusion: The findings indicate that patients undergoing posterior fossa craniotomy are at a greater risk of intra-cranial infection if there is pseudomeningocele after the operation.

Impact of post-hepatectomy biliary leaks on long-term survival in different liver tumors: A single institute experience.

Backgrounds/Aims: A postoperative biliary leak is one of the most morbid complications occurring after a liver resection, the long-term impact of which remains unknown. Methods: Retrospective analysis of consecutive liver resections performed from 1 January 2011 to 31 December 2021. Primary endpoint of disease-free survival (DFS) was compared between patients with and without a bile leak, stratifying for tumor type. Survival curves were plotted using Kaplan-Meier estimates, and differences between them were analyzed using the log-rank test. Results: In toto, 862 patients were analyzed, and included 306 (35.5%) hepatocellular carcinomas, 212 (24.6%) metastatic colorectal cancers, and 111 (12.9%) cholangiocarcinomas (69 intrahepatic cholangiocarcinomas, 42 hilar cholangiocarcinomas). Occurrence of a bile leak was associated with significantly poorer DFS only in patients with cholangiocarcinoma (median DFS 9.9 months vs. 24.9 months, p = 0.013), and further analysis was restricted to this cohort. A Cox regression performed for factors associated with DFS detriment in patients with cholangiocarcinoma showed that apart from node positivity (hazard ratio [HR]: 2.482, p = 0.033) and margin positivity (HR: 2.65, p = 0.021), development of a bile leak was independently associated with worsening DFS on both univariate and multiple regression analyses (HR: 1.896, p = 0.033). Conclusions: Post-hepatectomy biliary leaks are associated with significantly poorer DFS only in patients with cholangiocarcinoma, but not in patients with hepatocellular carcinoma or metastatic colorectal cancer. Methods to mitigate this survival detriment need to be explored.

Overexpression of Plakophilin2 Mitigates Capillary Leak Syndrome in Severe Acute Pancreatitis by Activating the p38/MAPK Signaling Pathway.

Purpose: Capillary leak syndrome (CLS) is an intermediary phase between severe acute pancreatitis (SAP) and multiple organ failure. As a result, CLS is of clinical importance for enhancing the prognosis of SAP. Plakophilin2 (PKP2), an essential constituent of desmosomes, plays a critical role in promoting connections between epithelial cells. However, the function and mechanism of PKP2 in CLS in SAP are not clear at present. Methods: We detected the expression of PKP2 in mice pancreatic tissue by transcriptome sequencing and bioinformatics analysis. PKP2 was overexpressed and knocked down to assess its influence on cell permeability, the cytoskeleton, tight junction molecules, cell adhesion junction molecules, and associated pathways. Results: PKP2 expression was increased in the pancreatic tissues of SAP mice and human umbilical vein endothelial cells (HUVECs) after lipopolysaccharide (LPS) stimulation. PKP2 overexpression not only reduced endothelial cell permeability but also improved cytoskeleton relaxation in response to acute inflammatory stimulation. PKP2 overexpression increased levels of ZO-1, occludin, claudin1, ß-catenin, and connexin43. The overexpression of PKP2 in LPS-induced HUVECs counteracted the inhibitory effect of SB203580 (a p38/MAPK signaling pathway inhibitor) on the p38/MAPK signaling pathway, thereby restoring the levels of ZO-1, ß-catenin, and claudin1. Additionally, PKP2 suppression eliminated the enhanced levels of ZO-1, ß-catenin, occludin, and claudin1 induced by dehydrocorydaline. We predicted that the upstream transcription factor PPARγregulates PKP2 expression, and our findings demonstrate that the PPARγactivator rosiglitazone significantly upregulates PKP2, whereas its antagonist GW9662 down-regulates PKP2. Administration of rosiglitazone significantly reduced the increase in HUVECs permeability stimulated by LPS. Conversely, PKP2 overexpression counteracted the GW9662-induced reduction in ZO-1, phosphorylated p38/p38, and claudin1. Conclusion: The activation of the p38/MAPK signaling pathway by PKP2 mitigates CLS in SAP. PPARγactivator rosiglitazone can up-regulate PKP2. Overall, directing efforts toward PKP2 could prove to be a feasible treatment approach for effectively managing CLS in SAP.

Benign Intravalvular Strut Leak After Placement of the Inspiris Resilia Valve.

OBJECTIVES: To investigate the incidence of intravalvular leak after aortic valve replacement with the Inspiris Resilia valve. DESIGN: This study was a retrospective chart review. SETTING: This study used data from a single tertiary care academic center. PARTICIPANTS: A total of 81 patient charts and echo images were reviewed. INTERVENTIONS: All patients underwent an aortic valve replacement using the Inspiris Resilia valve. Pediatric patients and patients receiving an aortic valve conduit were excluded. MEASUREMENTS AND MAIN RESULTS: Transesophageal echocardiography (TEE) images were reviewed independently by 2 echocardiographers for the incidence and severity of intravalvular leak after Inspiris Resilia valve placement. Outpatient follow-up imaging was then compared to intraoperative findings. Valve size and mean gradients were documented as well. Of the 81 TEEs that were reviewed, 56 (69.1%) were found to have a strut leak at the time of implantation. Among these 56 cases, 30 were classified as trace regurgitation, 21 as mild regurgitation, and 5 as moderate regurgitation. Only 1 case necessitated a return to cardiopulmonary bypass owing to persistent intravalvular leak. Follow-up transthoracic echocardiography reports were available for 50 of the patients with no persistent leaks. CONCLUSIONS: This pattern of intravalvular leak is unique to the Inspiris Resilia valve and is commonly found in the intraoperative period. While many hypotheses exist for the origin of this leak, the exact mechanism is unclear. Given the high frequency of this postprocedure finding, it is essential that intraoperative echocardiographers be able to distinguish this clinically insignificant leak based on its origin, severity, and direction and to provide appropriate recommendations to our surgical colleagues.

Clinical utility of CT myelography renal collecting system density in the evaluation of spinal CSF leak or CSF-venous connection in patients with spontaneous intracranial hypotension.

INTRODUCTION: Identifying spontaneous CSF leaks can be difficult on CT myelography (CTM) in patients with suspected spontaneous intracranial hypotension (SIH). The current study compared renal collecting system (RCS) density during CTM in patients with suspected SIH relative to non-SIH controls and evaluated the overall utility as an indirect sign of spontaneous CSF leak in patients with SIH. METHODS: All CTM performed over an 8-year period (n = 392) were retrospectively reviewed and included cases (n = 295) were divided into groups consisting of SIH patients with (n = 35) or without (n = 77) confirmed CSF leak on CTM and non-SIH controls (n = 183). Average and relative average (relative to systemic contrast density) RCS densities were compared with multivariate analysis adjusting for patient characteristics and CTM technical differences. RESULTS: Average RCS densities were greater for confirmed versus non-confirmed SIH groups and greater for both SIH groups relative to non-SIH controls. Correlations between RCS density and time from injection to CTM were higher within SIH patient groups compared to controls. Measured RCS density had a higher negative predictive value for excluding CSF leak both within the SIH patient groups as well as the overall cohort (84% and 96%, respectively), with optimized thresholds yielding 80% sensitivity and 70% specificity for the presence of leak in the overall cohort. CONCLUSION: Accounting for RCS density may provide reliable additional indirect diagnostic value about the suspicion of a CSF leak in patients undergoing CTM for evaluation of SIH symptoms.

Cerebrospinal Fluid Leak Presenting as Headache: A Case Report.

Headache is a common chief complaint among patients. When presented with this chief complaint, clinicians often form a differential diagnosis of common etiologies, including dehydration, increased stressors, and medication side effects. However, a skillful clinician must always be vigilant of rare etiologies presenting with common chief complaints. Here, we present a rare case of a cerebrospinal fluid leak in a young female presenting with primary symptoms of headache, neck stiffness, and vision changes.

Idiopathic Capillary Leak Syndrome (Clarkson's Disease): First Reported Case in Oman.

Idiopathic capillary leak syndrome, also known as Clarkson's Disease, is a rare cause of hypovolemic shock that physicians should be aware of. It is characterized by a state of hypovolemia with features of widespread fluid third spacing and poses diagnostic and therapeutic challenges. Here, we present a challenging case of a 36-year-old woman who experienced recurrent episodes of widespread edema and hypovolemic shock symptoms suggestive of capillary leak syndrome. The resuscitative and therapeutic measures employed in managing this disease are described in this case report.

At-Home "Tips" for Headache Management: The Use of Self-Trendelenburg to Help Determine the Cause of Worsening Headaches - A Case Series.

Introduction: In-office use of the Trendelenburg position has been shown to be a beneficial clinical tool to help decipher if a CSF pressure/volume component is part of the underlying etiologic process for a patient's persistent headache. Utilizing the Trendelenburg position at home could potentially be an additional diagnostic tool for the treating headache physician. Case Series: Our headache practice has been using at-home self-Trendelenburg for the past 2 years and will present the clinical scenarios in which it seems to be the most helpful utilizing a case series of patients. These include (1) in those who just had a lumbar puncture and call for worsening headaches and do not have an obvious orthostatic component; (2) in those who had a spinal epidural blood patch for a presumed CSF leak and state there was no improvement; (3) in those who are on daily preventive CSF volume-lowering medications and call in with worsening headaches; (4) in those with known CSF pressure-dependent headaches high or low but who are not on daily preventive CSF volume modulatory medications; (5) in those with a history of migraine or other primary headache disorder to see if a new type of headache is possibly from a CSF leak or an abnormal reset of CSF pressure to an elevated state; (6) in those with triggered only headaches like cough or exertional headache. Conclusion: Utilizing at-home self-Trendelenburg can provide valuable information for the treating headache physician on possible underlying headache etiology and can guide specific treatment strategies. Its simplicity and quick declaration of results are very patient pleasing.

Diagnostic Modalities for Early Detection of Anastomotic Leak After Colorectal Surgery.

INTRODUCTION: Anastomotic leak (AL) remains a severe complication following colorectal surgery, leading to increased morbidity and mortality, particularly in cases of delayed diagnosis. Existing diagnostic methods, including computed tomography (CT) scans, contrast enemas, endoscopic examinations, and reoperations can confirm AL but lack strong predictive value. Early detection is crucial for improving patient outcomes, yet a definitive and reliable predictive test, or "gold standard," is still lacking. METHODS: A comprehensive PubMed review was focused on CT imaging, serum levels of C-reactive protein (CRP), and procalcitonin (PCT) to assess their predictive utility in detecting AL after colorectal resection. Three independent reviewers evaluated eligibility, extracted data, and assessed the methodological quality of the studies. RESULTS: Summarized in detailed tables, our analysis revealed the effectiveness of both CRP and PCT in the early detection of AL during the postoperative period. CT imaging, capable of identifying fluid collection, pneumoperitoneum, extraluminal contrast extravasation, abscess formation, and other early signs of leak, also proved valuable. CONCLUSIONS: Considering the variability in findings and statistics across these modalities, our study suggests a personalized, multimodal approach to predicting AL. Integrating CRP and PCT assessments with the diagnostic capabilities of CT imaging provides a nuanced, patient-specific strategy that significantly enhances early detection and management. By tailoring interventions based on individual clinical characteristics, surgeons can optimize patient outcomes, reduce morbidity, and mitigate the consequences associated with AL after colorectal surgery. This approach emphasizes the importance of personalized medicine in surgical care, paving the way for improved patient health outcomes.

Characterisation of pulmonary air leak measurements using a mechanical ventilator in a bench setup.

Prolonged air leakage (AL) following pulmonary resections leads to prolonged hospital stay and post-operative complications. Intra- and postoperative quantification of AL might be useful for improving treatment decisions, but these measurements have not been characterised. AL calculations based on inspiratory and expiratory tidal volumes were investigated in an Intensive Care Unit mechanical ventilator circuit (Servo-I). AL was also measured by a digital chest drainage system. This study shows that AL measurements increase in accuracy when corrected for baseline deviations (R: 0.904 > 0.997, p < 0.001). Bland-Altman analysis revealed a funnel-shape, indicative of a detection threshhold. Corrected measurements were most accurate when averaged over five breaths and AL was >500 mL/min, with an estimated mean systemic bias of 7.4% (95%-limits of agreement [LoA]: 1.1%-13.7%) at 500 mL/min air leak. Breath-by-breath analysis showed most accurate results at AL >20 mL/breath (R: 0.989-0.991, p < 0.001) at tidal volumes between 350-600 mL. The digital drain had a mean systemic bias of -11.1% (95%-LoA: -18.9% to -3.3%) with homogenous scatter in Bland-Altman analysis and a strong correlation to the control measurement over a large range (0-2000mL/min, R: 0.999, p < 0.001). This study indicates that the Servo-I can be used for air leak quantification in clinically relevant ranges (>500 mL/min), but is unsuited for small leak detection due to a detection threshold. Researchers and clinicians should be aware of varying accuracy and interoperability characteristics between AL measurement devices.

Navigating complexities and considerations for suspected anastomotic leakage in the upper gastrointestinal tract: A state of the art review.

This state-of-the-art review explores the intricacies of anastomotic leaks following oesophagectomy and gastrectomy, crucial surgeries for globally increasing esophageal and gastric cancers. Despite advancements, anastomotic leaks occur in up to 30 % and 10 % of oesophagectomy and gastrectomy cases, respectively, leading to prolonged hospital stays, substantial impact upon short- and long-term health-related quality of life and greater mortality. Recognising factors contributing to leaks, including patient characteristics and surgical techniques, are vital for preoperative risk stratification. Diagnosis is challenging, involving clinical signs, biochemical markers, and various imaging modalities. Management strategies range from non-invasive approaches, including antibiotic therapy and nutritional support, to endoscopic interventions such as stent placement and emerging vacuum-assisted closure devices, and surgical interventions, necessitating timely recognition and tailored interventions. A step-up approach, beginning non-invasively and progressing based on treatment success, is more commonly advocated. This comprehensive review highlights the absence of standardised treatment algorithms, emphasizing the importance of individualised patient-specific management.

Applications of endoscopic vacuum therapy in the lower gastrointestinal tract: Tips and tricks and a review of the literature.

Endoscopic vacuum therapy (EVT) is an established technique for the treatment of rectal wall defects and especially anastomotic leaks. A wide range of EVT devices, both handmade and commercially available, allow for their successful placement even in small defects and difficult localizations. Reported success rates range between 85 and 97 %, while periintervenional morbidity is low and major adverse events are very rare. EVT has proven its effectiveness in the lower gastrointestinal tract and is now considered first line treatment for pelvic anastomotic leaks. This narrative review summarizes the current literature on EVT in the lower gastrointestinal tract, focusing on its indications, technical aspects and results, and offers tips and tricks for its clinical applications.

Bronchopleural fistula management in a pediatric patient requiring extracorporeal membrane oxygenation.

Bronchopleural fistula (BPF) is a connection between the bronchus and pleural cavity. It is associated with high morbidity and mortality and management of BPF has not been well described in the pediatric population. We describe a 2-year-old girl who presented with fever and increased work of breathing, found to have atypical hemolytic uremic syndrome and Streptococcus necrotizing pneumonia with development of persistent air leak due to bronchopleural fistulas requiring extracorporeal membrane oxygenation (ECMO). Three endobronchial valves were placed with successful resolution of bronchopleural fistulas. She required tracheostomy for chronic respiratory failure and endobronchial valves were eventually removed. Approximately 3.5 months after discharge to acute care rehabilitation, tracheostomy was successfully decannulated. This case highlights the successful use of endobronchial valves for resolution of BPF while on ECMO as well as the importance of further studies on optimal candidates, timing and duration of intervention in addition to sequelae of endobronchial valve placement.

An algorithm for the surgical approach to spontaneous temporal bone CSF leak.

OBJECTIVE: To suggest a comprehensive algorithm for the surgical approach for correcting of sources of temporal bone CSF leaks. METHODS: A case series for patients operated in a single academic tertiary referral center between 2011 and 4.2022. Included in the study were 46 patients, 5 of whom had a bilateral problem, resulting in 51 pathologic temporal bones. The presentation was an active CSF leak (38 patients) or bacterial otogenic meningitis (8 patients). Follow up ranged from 8 months to 5 years. RESULTS: Of the 42 ears operated via the default middle fossa approach, 37 were successful (88 %) in controlling CSF leak. None had intracranial complications or sensorineural hearing loss. Location, number and size of the defects, hearing status, associated superior semicircular canal dehiscence, additional intra-temporal or intra-cranial pathologies may indicate a transmastoid approach. Of the six ears that had a canal wall up mastoidectomy as a primary procedure, one required revision due to ongoing CSF leak. Five revision cases and three primary cases were effectively sealed with a subtotal petrosectomy and obliteration. One was lost to follow-up. Hearing was reconstructed with bone-anchored hearing implants in 6 out of these 8 ears. CONCLUSIONS: The middle fossa approach could be used as a default approach for sealing TD. There are a number of indications for transmastoid approaches in both primary and revision cases. Obliteration of the ear was used in all revision cases. The suggested algorithm can help in planning surgery for temporal bone CSF leaks or a history of otogenic meningitis.

Natural Chelating Agent-Treated Electron Transfer Layer for Friendly Environmental and Efficient Perovskite Solar Cells.

In perovskite solar cells (PSCs), the electron transfer layer (ETL) characteristics have significant effects on the photoelectric conversion efficiency (PCE) of the devices. Herein, a natural chelating agent polymer polyaspartic acid (PASP) is doped into the SnO2 precursor solution attributed to a strong interaction between PASP molecules and SnO2, which strengthens the interface contact and passivates the vacancy oxygen trap of the obtained SnO2 ETL, thus promoting the transfer of electrons. In addition, PASP can also regulate the growth of perovskite crystals, leading to an improved crystal quality of the perovskite films. Meanwhile, there is an excellent chelate anchoring of PASP to uncoordinated Pb2+, facilitating the reduction of trap defects at the interface, improving the stability of device, and suppressing the leakage of toxic Pb. Finally, the photovoltaic performance of the optimized device was greatly improved, and the PCE was increased from 21.22 to 23.49%, with outstanding environmental stability. This work provides an inexpensive and efficient treatment strategy that improves the performance and stability of friendly environmental PSCs.