Bypass Technique Research Articles

Wavelet and time-based cerebral autoregulation analysis using diffuse correlation spectroscopy on adults undergoing extracorporeal membrane oxygenation therapy.

Adult patients who have suffered acute cardiac or pulmonary failure are increasingly being treated using extracorporeal membrane oxygenation (ECMO), a cardiopulmonary bypass technique. While ECMO has improved the long-term outcomes of these patients, neurological injuries can occur from underlying illness or ECMO itself. Cerebral autoregulation (CA) allows the brain to maintain steady perfusion during changes in systemic blood pressure. Dysfunctional CA is a marker of acute brain injury and can worsen neurologic damage. Monitoring CA using invasive modalities can be risky in ECMO patients due to the necessity of anticoagulation therapy. Diffuse correlation spectroscopy (DCS) measures cerebral blood flow continuously, noninvasively, at the bedside, and can monitor CA. In this study, we compare DCS-based markers of CA in veno-arterial ECMO patients with and without acute brain injury. Adults undergoing ECMO were prospectively enrolled at a single tertiary hospital and underwent DCS and arterial blood pressure monitoring during ECMO. Neurologic injuries were identified using brain computerized tomography (CT) scans obtained in all patients. CA was calculated over a twenty-minute window via wavelet coherence analysis (WCA) over 0.05 Hz to 0.1 Hz and a Pearson correlation (DCSx) between cerebral blood flow measured by DCS and mean arterial pressure. Eleven ECMO patients who received CT neuroimaging were recruited. 5 (45%) patients were found to have neurologic injury. CA indices WCOH, the area under the curve of the WCA, were significantly higher for patients with neurological injuries compared to those without neurological injuries (right hemisphere p = 0.041, left hemisphere p = 0.041). %DCSx, percentage of time DCSx was above a threshold 0.4, were not significantly higher (right hemisphere p = 0.268, left hemisphere p = 0.073). DCS can be used to detect differences in CA for ECMO patients with neurological injuries compared to uninjured patients using WCA.

A human cadaveric model for venous air embolism detection tool development.

A human cadaveric model combining standard lung protective mechanical ventilation and modified cardiac bypass techniques was developed to allow investigation into automated modes of detection of venous air emboli (VAE) prior to in vivo human or animal investigations. In this study, in order to create an artificial cardiopulmonary circuit in a cadaver that could mimic VAE physiology, the direction of flow was reversed from conventional cardiac bypass. Normal saline was circulated in isolation through the heart and lungs as opposed to the peripheral organs by placing the venous cannula into the aorta and the arterial cannula into the inferior vena cava with selective ligation of other vessels. Mechanical ventilation and this reversed cardiac bypass scheme allowed preliminary detection of VAE independently but not in concert in our current simulation scheme due to pulmonary edema in the cadaver. A limited dissection approach was used initially followed by a radical exposure of the great vessels, and both proved feasible in terms of air signal detection. We used electrical impendence as a preliminary tool to validate detection in this cadaveric model however we theorize that it would work for echocardiographic, intravenous ultrasound or other novel modalities as well. A cadaveric model allows monitoring technology development with reduced use of animal and conventional human testing.

Cadaveric Feasibility of Robotic-Assisted Radial Artery-Internal Carotid Artery-Middle Cerebral Artery Anastomosis for Neurovascular Surgery.

To the best of our knowledge, this is the first reported cadaveric feasibility study of leader-follower type robotic-assisted middle cerebral artery (MCA)-radial artery-internal carotid artery anastomosis in the neurovascular surgery field using the da Vinci Xi system (da Vinci Surgical System; Intuitive Surgical, Inc.). Vascular suturing is a necessary skill in neurosurgery; however, the learning curve for deep and high-flow bypasses is severely low. Thus, robot-assisted surgery has been introduced. Here, we describe the surgical workflow adaptations of vascular anastomosis using the da Vinci system to assess the feasibility of robot-assisted anastomoses of the radial and middle cerebral arteries. Two fresh cadaver heads were studied using the da Vinci Xi Surgical System with 0° and 30° stereoscopic endoscopes to visualize the neuroanatomy. The da Vinci Xi Surgical System was used throughout the anastomosis of the MCA and intracarotid artery. The optic nerve, optic chiasm, carotid artery, and oculomotor nerve were visualized using standard microdissection techniques. The Sylvian fissure was exposed from the proximal Sylvian membrane to the distal MCA. Using black diamond microforceps and Potts scissors, suturing was achieved on the radial artery-middle cerebral artery using 8-0 Prolene and on the radial artery-internal carotid artery using 7-0 Prolene. A bypass of the MCA-radial artery-internal carotid artery can be achieved using the da Vinci Xi Surgical System in cadaver models. This system provides experts and less experienced neurosurgeons with stable bypass techniques for both superficial and deep-seated arteries. However, further studies are needed to evaluate the safety and benefits of the da Vinci Xi Surgical System for bypass procedures.

Validation of a dynamic 4D microsurgical bypass simulator for training and teaching microvascular anastomosis techniques with blood flow and fluorescence imaging

ObjectiveMicrovascular anastomosis is challenging, and training surgeons to develop and maintain skills is imperative. Current training models either miss the simulation of the surgical workflow, lack 3D key-hole space, need ethical approval, require special preparation, or lack realism. To circumvent these issues, this study describes the use of a mixed reality 3D printed model with integrated blood flow for training cerebral anastomosis and assesses its validity. MethodsDifferent-sized 3D-printed artificial micro artery models in a 3D brain space with a keyhole opening were used. The model was connected to a 4D simulator to induce pulsatile blood flow. Neurosurgical microscopes and exoscopes were used for visualization. Nine participants (n = 6 board-certified cerebrovascular neurosurgeons; n = 3 in-training) participated in the study and practiced anastomosis techniques with the simulator. Two senior, experienced vascular neurosurgeons mentored live teaching activity on the simulator. Participants completed a survey to score the face and content validity of the simulation on a 5-point Likert scale. Simulation time and anastomosis score differences between in-training and board-certified participants were compared for construct validity. ResultsParticipants scored the simulation difficulty similar to actual surgery, proving face validity. All participants agreed that practice on the provided simulator models would improve bypass techniques (μ = 4.67/5 ± 0.47) and instrument handling (μ = 4.56/5 ± 0.68). Board-certified participants had better anastomosis scores than in-training participants (non-significant difference). ConclusionsThe 4D simulator and the high-fidelity artificial 3D printed model effectively simulated actual bypass surgery in a key-hole fashion with blood flow abilities. Limited resources and preparation time are needed for the training setup. The model provides benefits in learning and maintaining anastomosis skills and allows for easy adaptation to different microanatomical scenarios.

Short-term gut microbiota’s shift after laparoscopic Roux-en-Y vs one anastomosis gastric bypass: results of a multicenter randomized control trial

BackgroundRoux-en-Y (RYGB) and one anastomosis gastric bypass (OAGB) represent two of the most used bariatric/metabolic surgery (BMS) procedures. Gut microbiota (GM) shift after bypass surgeries, currently understated, may be a possible key driver for the short- and long-term outcomes.MethodsProspective, multicenter study enrolling patients with severe obesity, randomized between OAGB or RYGB. Fecal and blood samples were collected, pre- (T0) and 24 months postoperatively (T1). GM was determined by V3-V4 16S rRNA regions sequencing and home-made bioinformatic pipeline based on Qiime2 plugin and R packages.ObjectsTo compare OAGB vs RYGB microbiota profile at T1 and its impact on metabolic and nutritional status.Results54 patients completed the study, 27 for each procedure. An overall significant variation was detected in anthropometric and serum nutritional parameters at T1, with a significant, similar decrease in overall microbial alpha and beta diversity observed in both groups. An increase in relative abundances of Actinobacteria and Proteobacteria and a reduction of Bacteroidetes, no significant changes in Firmicutes and Verrucomicrobia, with an increase of the Firmicutes/Bacteroidetes ratio were observed.ConclusionsBMS promotes a dramatic change in GM composition. This is the first multicenter, RCT evaluating the impact of OAGB vs Roux-en-Y bypass on GM profile. The bypass technique per se did not impact differently on GM or other examined metabolic parameters. The emergence of slightly different GM profile postoperatively may be related to clinical conditions or may influence medium or long-term outcomes and as such GM profile may represent a biomarker for bariatric surgery’s outcomes.Graphical abstract

Advanced Techniques of Malware Evasion and Bypass in the Age of Antivirus

Advanced Techniques of Malware Evasion and Bypass in the Age of Antivirus

Microsurgery for Vertebral and Posterior Inferior Cerebellar Artery Aneurysms via Lateral Suboccipital Craniotomy

Among ruptured intracranial aneurysms, aneurysms of the vertebral artery(VA) and posterior inferior cerebellar artery(PICA) are relatively rare, and they exhibit distinct characteristics. These include: 1) a high frequency of diverse aneurysmal morphologies, such as fusiform or dissecting aneurysms; 2) proximity to the lower cranial nerves; 3) the presence of perforators to the medulla oblongata; and, 4) obstruction to the surgical approach by specific bony structures, such as the occipital condyle and jugular tubercle. Consequently, these aneurysms often require interventions that are more complex than simple clipping or coiling, which is typical for anterior circulation aneurysms. Interventions include skull base techniques such as the far-lateral approach and revascularization procedures such as occipital artery(OA)-PICA bypass. Despite these complexities, the rarity of these aneurysms and the recent advancements in endovascular procedures pose challenges for young neurosurgeons in acquiring adequate microsurgical experience. This narrative review addresses the clinical features of VA and PICA aneurysms, the history and variations in the lateral suboccipital approach for these aneurysms, and several bypass techniques for reconstructing the PICA. Lastly, we illustrate our current microsurgical practices through a case presentation accompanied by a surgical video showcasing both the far-lateral approach and the OA-PICA bypass.

Hand Digit Revascularization: Could Be an "Elective-Urgence" Surgery?

Background: A continuous obstacle that has limited access to and implementation of finger replantation surgery is timeliness, as ischemia time is traditionally considered a crucial factor for success. However, claims that the vitality of amputated fingers decreases after 6 h of warm ischemia and 12 h of cold ischemia are mostly based on theoretical considerations. Methods: Here we present a case of multi-digit revascularization after 72 h of warm ischemia using the microsurgical arteriovenous bypass technique. Results: In the reported case, revascularization was performed after a long ischemic period and showed good recovery of motor and sensory function. Conclusions: We identified significant limitations in the literature supporting time limits of ischemia and recent evidence demonstrating the feasibility of delayed finger replantation. The current treatment approach for amputation injuries often requires transfers or nighttime emergency procedures, increasing costs and limiting the national availability of finger replantation. Changes to finger replantation protocols based on evidence could expand access to this service and improve the quality of care.

Intervention principles for complications of arteriovenous graft

Stenosis, thrombosis, and infection are major complications of arteriovenous graft (AVG). Endovascular therapy is usually adopted for stenosis, while bypass, interposition, patch angioplasty and other surgical techniques can also be used for special sites. Interventions of AVG thrombosis include removal of thrombus and treatment of the underlying stenosis. The former includes catheter directed thrombolysis, endovascular intervention, surgical treatment, or hybrid treatment. Etiological detection before the application of empirical antibiotics is the first step of infection management. According to different infection ranges, partial graft excision and interposition, total graft excision and partial graft excision can be performed respectively. Active prevention, timely identification, and appropriate intervention of the complications can improve the long-term outcomes of AVG. Personalized interventional strategy should be employed based on the systemic evaluation.

Incidence of Postoperative Diabetes Mellitus After Roux-en-Y Reconstruction for Gastric Cancer: Retrospective Single-Center Cohort Study.

Sleeve gastrectomy is an effective surgical option for morbid obesity, and it improves glucose homeostasis. In patients with gastric cancer and type 2 diabetes mellitus (DM), gastrectomy, including total gastrectomy, is beneficial for glycemic control. This study aims to clarify the effects of gastrectomy and different reconstructive techniques on the incidence of postoperative DM in patients with gastric cancer. This retrospective, single-center, cohort study included 715 patients without DM who underwent total gastrectomy at the Tokyo Metropolitan Bokutoh Hospital between August 2005 and March 2019. Patients underwent reconstruction by Roux-en-Y (RY) gastric bypass or other surgical techniques (OT), with DM onset determined by hemoglobin A1c levels or medical records. Analyses included 2-sample, 2-tailed t tests; χ2 tests; and the Kaplan-Meier method with log-rank tests to compare the onset curves between the RY and OT groups, along with additional curves stratified by sex. A Swimmer plot for censoring and new-onset DM was implemented. Stratified data analysis compared the RY and OT reconstruction methods. The hazard ratio was 1.52 (95% CI 1.06-2.18; P=.02), which indicated a statistically significant difference in the incidence of new-onset diabetes between the RY and OT groups in patients with gastric cancer. The hazard ratio after propensity score matching was 1.42 (95% CI 1.09-1.86; P=.009). This first-of-its-kind study provides insight into how different methods of gastric reconstruction affect postoperative diabetes. The results suggest significant differences in new-onset DM after surgery based on the reconstruction method. This research highlights the need for careful surgical planning to consider potential postoperative DM, particularly in patients with a family history of DM. Future studies should investigate the role of gut microbiota and other reconstructive techniques, such as laparoscopic jejunal interposition, in developing postoperative DM.

Optimization of Hypothermic Protocols for Neurocognitive Preservation in Aortic Arch Surgery: A Literature Review.

Shifts from deep to moderate hypothermic circulatory arrest (HCA) in aortic arch surgery necessitate an examination of their differential impacts on neurocognitive functions, especially structured verbal memory, given its significance for patient recovery and quality of life. This study evaluates and synthesizes evidence on the effects of deep (≤20.0 °C), low-moderate (20.1-24.0 °C), and high-moderate (24.1-28.0 °C) hypothermic temperatures on structured verbal memory preservation and overall cognitive health in patients undergoing aortic arch surgery. We evaluated the latest literature from major medical databases such as PubMed and Scopus, focusing on research from 2020 to 2024, to gather comprehensive insights into the current landscape of temperature management during HCA. This comparative analysis highlights the viability of moderate hypothermia (20.1-28.0 °C), supported by recent trials and observational studies, as a method to achieve comparable neuroprotection with fewer complications than traditional deep hypothermia. Notably, low-moderate and high-moderate temperatures have been shown to support substantial survival rates, with impacts on structured verbal memory preservation that necessitate careful selection based on individual surgical risks and patient profiles. The findings advocate for a nuanced approach to selecting hypothermic protocols in aortic arch surgeries, emphasizing the importance of tailoring temperature management to optimize neurocognitive outcomes and patient recovery. This study fills a critical gap in the literature by providing evidence-based recommendations for temperature ranges during HCA, calling for ongoing updates to clinical guidelines and further research to refine these recommendations. The implications of temperature on survival rates, complications, and success rates underpin the necessity for evolving cardiopulmonary bypass techniques and cerebral perfusion strategies to enhance patient outcomes in complex cardiovascular procedures.

A Unique and Effective Bypass Technique to Treat Partially Thrombosed Giant Distal Anterior Cerebral Artery Aneurysms in Extremely Narrow Surgical Corridors

Surgical treatment of large or giant thrombosed anterior cerebral artery (ACA) aneurysms often involves revascularization. Herein, we describe a unique and effective bypass technique to treat partially thrombosed giant distal ACA aneurysms in extremely narrow surgical corridors. A 68-year-old man underwent aneurysm trapping and ACA revascularization for a partially thrombosed giant ACA aneurysm in a surgical corridor that was narrow due to anatomic factors. By combining a side-to-side anastomosis and an end-to-side anastomosis at a single anastomotic site, we successfully redirected blood flow from the left pericallosal artery to the right pericallosal and callosomarginal arteries. Postoperatively, cerebral angiography showed that the blood flow in the aneurysm had disappeared, and the bypass remained open. The patient's functional disability gradually improved, and he reported consistently positive outcomes at the 6-month postoperative follow-up examination. This revascularization technique may represent an effective novel treatment option, particularly when multiple revascularization procedures are required within a narrow surgical field.

Anesthesia for Minimal Invasive Cardiac Surgery: The Bonn Heart Center Protocol.

The development and adoption of minimally invasive techniques has revolutionized various surgical disciplines and has also been introduced into cardiac surgery, offering patients less invasive options with reduced trauma and faster recovery time compared to traditional open-heart procedures with sternotomy. This article provides a comprehensive overview of the anesthesiologic management for minimally invasive cardiac surgery (MICS), focusing on preoperative assessment, intraoperative anesthesia techniques, and postoperative care protocols. Anesthesia induction and airway management strategies are tailored to each patient's needs, with meticulous attention to maintaining hemodynamic stability and ensuring adequate ventilation. Intraoperative monitoring, including transesophageal echocardiography (TEE), processed EEG monitoring, and near-infrared spectroscopy (NIRS), facilitates real-time assessment of cardiac and cerebral perfusion, as well as function, optimizing patient safety and improving outcomes. The peripheral cannulation techniques for cardiopulmonary bypass (CPB) initiation are described, highlighting the importance of cannula placement to minimize tissue as well as vessel trauma and optimize perfusion. This article also discusses specific MICS procedures, detailing anesthetic considerations and surgical techniques. The perioperative care of patients undergoing MICS requires a multidisciplinary approach including surgeons, perfusionists, and anesthesiologists adhering to standardized treatment protocols and pathways. By leveraging advanced monitoring techniques and tailored anesthetic protocols, clinicians can optimize patient outcomes and promote early extubation and enhanced recovery.

Robotics in bariatric surgery: Benefits, limitation, and challenges

The greatest long-term alternative for treating obese people is now bariatric and metabolic surgery, a relatively new surgical technique. Mason and Ito used Roux-en-Y gastric bypass techniques to accomplish the first bariatric surgery, RYGB, in 1967. Evidence since then has indicated stable weight loss, correction of obesity-related comorbidities, and low rates of morbidity and death. With perioperative benefits for patients, including shorter hospital stays, less discomfort, and faster recovery times, laparoscopy has emerged as the gold standard for the majority of bariatric surgery operations. However, there are technological limitations to traditional laparoscopy, including space restrictions and a thick abdominal wall. Metabolic syndrome is frequently present in obese people, and can complicate anesthesia and increase the risk of complications following surgery. According to recent studies, laparoscopic bariatric surgery can have complication rates of up to 20% and leakage rates of up to 5.1%. The clinical results of bariatric surgery may be improved by new technology. Robotic devices can help patients heal more quickly, experience less pain, spend less time in the hospital, and manipulate tissue more precisely and deftly in hard-to-reach areas. This study intends to examine the existing data supporting the use of robots in bariatric surgery in comparison to traditional laparoscopy, as well as the accompanying expenses and learning curve. For patients who are obese, robotic surgery is a viable option since it promotes faster recovery, less pain, and shorter hospital stays. Robotic surgery can lead to a quicker recovery, less pain, and more dexterity and accuracy in difficult-to-reach anatomical regions.

Comparison of the Incidence of Dumping Syndrome in Post-Bariatric Surgery Patients with Roux-en-Y Gastric Bypass (RYGB) Techniques and Single Anastomosis Duodeno-Ileal Bypass with Sleeve Gastrectomy (SADI-S)

Introduction: Dumping syndrome (DS) is a common post-bariatric surgery complication. This study aims to compare the incidence of DS between Roux-en-Y gastric bypass (RYGB) and single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) at Sumber Waras Hospital, Jakarta, Indonesia. Methods: This single-center retrospective observational study included 187 patients who underwent RYGB or SADI-S between January 2018 and December 2023. Demographic, clinical, and DS-related data were collected from patients' medical records. Statistical analysis was carried out using SPSS version 25. Results: The overall incidence of DS was 21.4%, with 23.2% in the RYGB group (n=95) and 19.6% in the SADI-S group (n=92). There was no significant difference in the incidence of DS between the two groups (p = 0.56). Young age (OR 2.18; 95% CI 1.05-4.53; p = 0.04) and history of type 2 diabetes mellitus (OR 3.05; 95% CI 1.21-7.70; p = 0.02) is an independent risk factor for DS. Conclusion: There was no significant difference in the incidence of DS between RYGB and SADI-S. Young age and a history of type 2 diabetes mellitus are independent risk factors for DS.

Long-term outcomes of great saphenous vein harvest techniques for infrainguinal arterial bypass in a Medicare-matched registry database

ObjectiveLong-term outcomes for harvesting techniques for great saphenous vein (GSV) and its impact on the outcomes of infrainguinal arterial bypass remains largely unknown. Endoscopic GSV harvesting (EVH) has emerged as a less invasive alternative to conventional open techniques. Using the Vascular Quality initiative Vascular Implant Surveillance & Interventional Outcomes Network (VQI-VISION) database, we compared the long-term outcomes of infrainguinal arterial bypass using open and endoscopic GSV harvest techniques. MethodsPatients who underwent infrainguinal GSV bypass between 2010 and 2019 were identified in the VQI-VISION Medicare linked database. Long-term outcomes of major/minor amputations, and reinterventions up to 5 years of follow-up were compared between continuous incisions, skip incision, and EVH, with continuous incisions being the reference group. Secondary outcomes included 30- and 90-day readmission, in addition to surgical site infections and patency rates at 6 months to 2 years postoperatively. Survival analysis using Kaplan-Meier curves and Cox regression hazard models were utilized to compare outcomes between groups. To adjust for multiple comparisons between the study groups, a P value of 2.5% was considered significant. ResultsAmong the 8915 patients included in the study, continuous and skip vein harvest techniques were used in 44.4% and 43.4% of cases each, whereas 12.3% underwent EVH. The utilization of EVH remained relatively stable at around 12% throughout the study period. Compared with GSV harvest using continuous incisions, EVH was associated with higher rates of reintervention at 1 year (46.5% vs 41.3%; adjusted hazard ratio [aHR], 1.22; 95% confidence interval [CI], 1.06-1.41; P = .01]. However, no significant difference was observed between EVH and continuous incisions, and between skip and continuous incisions in terms of long-term reintervention or major and minor amputations on adjusted analysis. Compared with continuous incision vein harvest, both EVH and skip incisions were associated with lower surgical site infection rates within the first 6 months post-bypass (aHR, 0.53; 95% CI, 0.35-0.82 and aHR, 0.68; 95% CI, 0.53-0.87, respectively). Loss of primary, primary-assisted, and secondary patency was higher after EVH compared with continuous incision vein harvest. Among surgeons performing EVH, comparable long-term outcomes were observed regardless of low (<4 cases/year), medium (4-7 cases/year), or high procedural volumes (>7 cases/year). ConclusionsDespite higher 1-year reintervention rates, EVH for infrainguinal arterial bypass is not associated with a significant difference in long-term reintervention or amputation rates compared with other harvesting techniques. These outcomes are not influenced by procedural volumes for EVH technique.

Surgical Techniques for Lymphovenous Bypass: A Review

Background: Lymphedema is a progressive, debilitating disease that may affect up to 250 million individuals worldwide. Complex decongestive therapy (CDT) remains the first line of treatment for lymphedema, and surgical treatment currently has no formally established role. In recent years, lymphovenous bypass (LVB) has emerged as a potentially efficacious intervention to improve patients' objective and subjective measures of lymphedema. Despite this promise, there are few evidence-based recommendations to inform the adoption of the practice. Methods: A narrative review of the present literature on LVB was performed through a query of records using various combinations of Medical Subject Heading (MeSH) terms and keywords such as “lymphatic vessels,” “lymphedema,” “breast cancer lymphedema,” “surgical anastomosis,” “lymphovenous bypass,” “lymphovenous anastomosis.” The articles were assessed for 1) bibliometric characteristics, 2) preoperative evaluation, 2) operative techniques, 3) postoperative regimens, and 4) outcome measures. Results: The sixty-year evolution of LVB has transformed rapidly in response to technological advances in the last two decades. The geographically distributed investigation of these surgical innovations has prompted a fragmentation of LVB practice. As original research outpaces literature review, there needs to be more consistency in terminology, perioperative practices, and evaluation of outcomes of LVB, which challenge systematic analysis. The systematic reviews to date emphasize the ability of LVB to improve objective measures such as limb circumference. Still, the inconsistent use of subjective measures limits our appreciation of the collective improvement in patient-reported outcomes. Moreover, there are a limited number of accepted methods for patient selection, preoperative evaluation, and surgical planning, with many surgical techniques employed. Conclusion: The unifying principles and scientific evidence must be clarified to guide an overarching consensus before the widespread adoption of LVB. This article aims to synthesize recommendations and current institutional preferences concerning the research and clinical applications of LVB. The collaboration and continued refining of these practices will be necessary to establish the role of LVB in the treatment and prevention of lymphedema.

Advanced Techniques of Malware Evasion and Bypass in the Age of Antivirus

The use of antivirus software as the main line of protection against growing cyber threats highlights the necessity of comprehending and resolving its limits. This study provides light on the ease of use and accessibility of tools used by hackers by carefully examining the complex terrain of malware evasion and bypass tactics. The persistent evolution of malware evasion and bypass techniques presents a significant cybersecurity challenge. The main objective is to educate users about the ever-changing hazards and provide them with the knowledge they need to properly strengthen their digital defenses. The literature analysis highlights the necessity for continued attention by establishing a strong correlation between the effectiveness of evasion strategies and their age and popularity. While modern antivirus software shows strong resistance against a range of tried-and-true techniques when updated on a regular basis, the study reveals a crucial component in its testing. This entails applying simple yet effective tweaks to well-known evasion techniques, demonstrating their capacity to fool even the most recent antivirus software. A thorough examination of malware evasion tactics, including both on-desk and in-memory approaches, is given in the methods section. Packing, obfuscators, protectors, reflective DLL injection, remote process memory injection, process hollowing, and inline hooking are all covered in detail in this paper. Subsequently, the study delves deeper into distinct evasion strategies, such defensive evasion through direct system calls and sophisticated evasion tactics, showcasing malware developers' versatility in evading antivirus and endpoint detection and response (EDR) systems.

Analysis of methods for bypassing modern EDR endpoint protection systems

The purpose of the article is to review and analyze the methods of bypassing complex solutions for endpoint protection (EDR). The article highlights and describes the salient features of each of the EDR bypass methods and provides recommendations for countering them. EDR (Endpoint Detection and Response) is a type of cross-platform software currently most commonly used for event monitoring, security incident generation and formalization, and incident response. For each method and tool, example of it’s useand advantages and disadvantages are described. The article will be useful for cybersecurity analysts who want to deepen their knowledge of EDR and strengthen endpoint security. It will provide readers with an insight into EDR bypass techniques and help them apply recommendations to reduce the risks of EDR bypass during cyber ttacks.

Comparison of a coronary bypass surgery using a combination of both on-pump beating heart and cardioplegic arrest with conventional coronary bypass surgery using cardioplegic arrest on-pump.

Antegrade cardioplegia may cause maldistribution in patients with multivessel coronary artery disease. Surgically bypassing large epicardial vessels before the cross-clamp and then administering cardioplegia from both the aortic root and the anastomosed grafts significantly prevent maldistribution and provide better cardiac protection. This study included 80 patients, all older than 70years with an ejection fraction between 25 and 35%. Patients were equally divided into two groups. Distal anastomoses to some of large epicardial coronary arteries were performed before the cross-clamp was placed. Grafted veins were attached to multi-perfusion set ports. Then, cross-clamping was performed, and the multi-perfusion set was disconnected from the aortic cannula and attached to the cardioplegia route. Antegrade cardioplegia was administered to both the aortic root and saphenous vein grafts. After all distal anastomoses were completed, the cross-clamp was removed, and the multi-perfusion set was connected to the aortic cannula again. Conventional coronary bypass techniques were used in group 2 patients. Inotropic agents were administered in 12 patients in group 1 and 29 patients in group 2 (p < 0.001). The average troponin I value in coronary sinus blood was 1.05 ± 0.8ng/mL in group 1 and 3.12 ± 0.7ng/mL in group 2 (p < 0.001). The average lactate value in coronary sinus blood was 1.15 ± 0.55mmol/L in group 1 and 3.7 ± 2.4mmol/L in group 2 (p < 0.001). Six patients died in the early postoperative period in group 2 (p = 0.028). The current technique considerably reduces cross-clamping time and allows better distribution of the cardioplegic solution, preserving myocardium. Reduced coronary sinus lactate and troponin I levels also indicate better myocardial protection.