Analysis of Distributed Systems Dynamics with Erlang Performance Lab

Modern, highly concurrent and large-scale systems require new methods for design, testing and monitoring. Their dynamics and scale require real-time tools, providing a holistic view of the whole system and the ability of showing a more detailed view when needed. Such tools can help identifying the causes of unwanted states, which is hardly possible with static analysis or metrics-based approach. In this paper a new tool for analysis of distributed systems in Erlang is presented. It provides real-time monitoring of system dynamics on different levels of abstraction. The tool has been used for analyzing a large-scale urban traffic simulation system running on a cluster of 20 computing nodes

Achieving the critical view of safety in the difficult laparoscopic cholecystectomy: a prospective study of predictors of failure

Background: Bile duct injury rates for laparoscopic cholecystectomy (LC) remain higher than during open cholecystectomy. The “culture of safety” concept is based on demonstrating the critical view of safety (CVS) and/or correctly interpreting intraoperative cholangiography (IOC). However, the CVS may not always be achievable due to difficult anatomy or pathology. Safety may be enhanced if surgeons assess difficulties objectively, recognise instances where a CVS is unachievable and be familiar with recovery strategies. Aims and methods: A prospective study was conducted to evaluate the achievability of the CVS during all consecutive LC performed over four years. The primary aim was to study the association between the inability to obtain the CVS and an objective measure of operative difficulty. The secondary aim was to identify preoperative and operative predictors indicating the use of alternate strategies to complete the operation safely. Results: The study included 1060 consecutive LC. The median age was 53 years, male to female ratio was 1:2.1 and 54.9% were emergency admissions. CVS was obtained in 84.2%, the majority being difficulty grade I or II (70.7%). Displaying the CVS failed in 167 LC (15.8%): including 55.6% of all difficulty grade IV LC and 92.3% of difficulty grade V. There were no biliary injuries or conversions. Conclusion: All three components of the critical view of safety could not be demonstrated in one out of 6 consecutive laparoscopic cholecystectomies. Preoperative factors and operative difficulty grading can predict cases where the CVS may not be achievable. Adapting instrument selection and alternate dissection strategies would then need to be considered

Multicenter registry of Impella-assisted high-risk percutaneous coronary interventions and cardiogenic shock in Poland (IMPELLA-PL)

Background: Impella is a percutaneous mechanical circulatory support device for treatment of cardiogenic shock (CS) and high-risk percutaneous coronary interventions (HR-PCIs). IMPELLA-PL is a national retrospective registry of Impella-treated CS and HR-PCI patients in 20 Polish interventional cardiological centers, conducted from January 2014 until December 2021.Aims: We aimed to determine the efficacy and safety of Impella using real-world data from IMPELLA-PL and compare these with other registries.Methods: IMPELLA-PL data were analyzed to determine primary endpoints: in-hospital mortality and rates of mortality and major adverse cardiovascular and cerebrovascular events (MACCE) at 12 months post-discharge.Results: Of 308 patients, 18% had CS and 82% underwent HR-PCI. In-hospital mortality rates were 76.4% and 8.3% in the CS and HR-PCI groups, respectively. The 12-month mortality rates were 80.0% and 18.2%, and post-discharge MACCE rates were 9.1% and 22.5%, respectively. Any access site bleeding occurred in 30.9% of CS patients and 14.6% of HR-PCI patients, limb ischemia in 12.7% and 2.4%, and hemolysis in 10.9% and 1.6%, respectively.Conclusions: Impella is safe and effective during HR-PCIs, in accordance with previous registry analyses. The risk profile and mortality in CS patients were higher than in other registries, and the potential benefits of Impella in CS require investigation

Cystic lymph node identification is more reliable than critical view of safety in difficult cholecystectomies

Background: The cystic lymph node (CLN) represents an anatomic safety marker and a surrogate marker of technique during laparoscopic cholecystectomy (LC). We aim to demonstrate the value of CLN in comparison to the critical view of safety (CVS) and study the effects of increasing difficulty on the 2 approaches. Methods: A prospective study of consecutive LC was conducted. Patient demographics, type of admission, clinical presentation, operative difficulty grade, visualization of CLN, identification of CVS, operative time, and complications were recorded and analyzed. Results: Of 393 LCs, half of the admissions were emergencies. Thirty-four percent had obstructive jaundice or acute cholecystitis. The CLN was visually identified in 81.7% with a small difference between operative difficulty grades 1 to 3 versus 4 to 5. Although CVS was unachievable in 62 patients, 43 (69.4%) still had an identifiable CLN. The median operating time was 68 minutes with 1 mortality but no conversions or intraoperative complications. Conclusions: Identifying the CLN during LC could compliment the CVS in avoiding major ductal injury. Dissecting lateral to the CLN to commence the process of displaying the cystic pedicle structures may be a strategy in safely achieving the CVS. During the more difficult LC where displaying the CVS is impossible, the CLN may be the key anatomic landmark

Doppler tissue perfusion measurement is a sensitive and specific tool for a differentiation between malignant and inflammatory pancreatic tumors.

Differentiation between pancreatic malignant and inflammatory tumors presents an important diagnostic problem. The ability to recognize pancreatic malignant tumors using Doppler evaluation of tissue perfusion has been recently demonstrated. The aim of the study was to assess the diagnostic value of Dynamic Tissue Perfusion Measurement (DTPM) in the differentiation between malignant and inflammatory pancreatic tumors. The study included 60 patients (35M, 25F, age 60.9 ± 2.3 years) with a malignant (Group 1, n = 30) or inflammatory (Group 2, n = 30) pancreatic tumor undergoing endoscopic ultrasound with the evaluation of tissue perfusion by Color Doppler and a simultaneous biopsy of lesions for cytological evaluation. In 20 patients the diagnosis was verified in the postoperative histopathological examination. Flow velocity (FV) and percentiles of the distribution of perfusion intensity (PR) evaluated by DTPM were analyzed with regard to receiver-operator-characteristics. FV as well as PR were significantly higher in Group 2 compared to Group 1. A threshold of 2.0 cm/sec for FV identified patients with malignancies with a sensitivity of 83% and specificity of 86%. In multivariable regression analysis, the best PR parameter for differentiating between malignant and inflammatory tumors was 97.5% percentile, whose value of 0.922 allowed for the recognition of pancreatic malignant tumors with a sensitivity of 62% and specificity of 83% (p < 0.001). In conclusion, Color Doppler ultrasound tissue perfusion parameters are a sensitive and specific tool in the differentiation between malignant and inflammatory pancreatic tumors

The impact of age and sex on the occurrence of pathology in the wall of the upper gastrointestinal tract

Introduction : The growing incidence of gastrointestinal diseases forces to improve both imaging techniques and the identification of the population with a greater risk of a disease. Identification of lesions located inside the wall of intestinal tract or in close proximity often was not possible using endoscopy or computed tomography. Aim : The study was a retrospective evaluation of the occurrence of submucosal lesions (SML) and thickened wall (TW) of the upper gastrointestinal tract (UGIT) depending on age and sex. Material and methods : Out of 20012 gastroscopies during the 4-year follow-up study, we enrolled 199 patients with pathological lesions in the wall of the UGIT. All patients underwent computed tomography and endoscopic ultrasound (EUS). Results : We analysed a total of 122 (78 males, 44 females, age: 64.0 ±12.9 years) out of 187 patients. 23.91% of SML in the oesophagus, 56.52% in the stomach, and 19.57% in the duodenum. A higher number of SMLs was found in men than in women (57.14% vs. 40.45%, p = 0.023), and the difference was greater over 50 years of age (85.71% vs. 40.00%, p = 0.031). We found less malignant SMLs compared to benign (35.87% vs. 64.13%, p = 0.026), especially in women (22.86% vs. 47.46%, p = 0.006). 26.67% of TW were in the oesophagus, 66.67% in the stomach, and 6.67% in the duodenum. There was a tendency towards increased incidence of TW over 50 years of age (8.58% vs. 18.30%, p = 0.074), which concerned men in particular (24.10% vs. 11.43%, p = 0.043). Until 65 years of age, these differences were significant for the oesophagus (27.27% vs. 0.00%, p = 0.044) and the stomach (25.93% vs. 4.00%, p = 0.029). As many as 70% of TW pathologies were malignant. Conclusions : Submucosal lesions and TW of the upper gastrointestinal tract account for 0.61% of performed gastroscopies. They occur in men and usually over 50 years of age