A Review on Retinal Blood Vessel Enhancement and Segmentation Techniques for Color Fundus Photography.

The retinal image is a trusted modality in biomedical image-based diagnosis of many ophthalmologic and cardiovascular diseases. Periodic examination of the retina can help in spotting these abnormalities in the early stage. However, to deal with today's large population, computerized retinal image analysis is preferred over manual inspection. The precise extraction of the retinal vessel is the first and decisive step for clinical applications. Every year, many more articles are added to the literature that describe new algorithms for the problem at hand. The majority of the review article is restricted to a fairly small number of approaches, assessment indices, and databases. In this context, a comprehensive review of different vessel extraction methods is inevitable. It includes the development of a first-hand classification of these methods. A bibliometric analysis of these articles is also presented. The benefits and drawbacks of the most commonly used techniques are summarized. The primary challenges, as well as the scope of possible changes, are discussed. In order to make a fair comparison, numerous assessment indices are considered. The findings of this survey could provide a new path for researchers for further work in this domain.

Using Fuzzy Mathematical Model in the Differential Diagnosis of Pancreatic Lesions Using Ultrasonography and Echographic Texture Analysis.

Malignant tumors of the pancreas are the fourth leading cause of cancer-related deaths. This is mainly because they are often diagnosed at a late stage. One of the challenges in diagnosing focal lesions in the pancreas is the difficulty in distinguishing them from other conditions due to the unique location and anatomy of the organ, as well as the similarity in their ultrasound characteristics. One of the most sensitive imaging modalities of the pancreas is endoscopic ultrasonography. However, clinicians recognize that EUS is a difficult and highly operator-dependent method, while its results are highly dependent on the experience of the investigator. Hybrid technologies based on artificial intelligence methods can improve the accuracy and objectify the results of endosonographic diagnostics. Endoscopic ultrasonography was performed on 272 patients with focal lesions of the pancreatobiliary zone, who had been treated in the surgical section of the Kursk Regional Clinical Hospital in 2014-2023. The study utilized an Olympus EVIS EXERA II video information endoscopic system, along with an EU-ME1 ultrasound unit equipped with GF UM160 and GF UC140P-AL5 echo endoscopes. Out of the focal formations in the pancreatobiliary zone, pancreatic cancer was detected in 109 patients, accounting for 40.1% of the cases. Additionally, 40 patients (14.7%) were diagnosed with local forms of chronic pancreatitis. The reference sonograms displayed distinguishable focal pancreatic pathologies, leading to the development of hybrid fuzzy mathematical decision-making rules at the South-West State University in Kursk, Russian Federation. This research resulted in the creation of a fuzzy hybrid model for the differential diagnosis of chronic focal pancreatitis and pancreatic cancer. Endoscopic ultrasonography, combined with hybrid fuzzy logic methodology, has made it possible to create a model for differentiating between chronic focal pancreatitis and pancreatic ductal adenocarcinoma. Statistical testing on control samples has shown that the diagnostic model, based on reference endosonograms of the echographic texture of pancreatic focal pathology, has a confidence level of 0.6 for the desired diagnosis. By incorporating additional information about the contours of focal formations obtained through endosonography, the reliability of the diagnosis can be increased to 0.9. This level of reliability is considered acceptable in clinical practice and allows for the use of the developed model, even with data that is not well-structured.

Circular External Fixation of Ankle and Pilon Fractures Using Novel Polyaxial Locking Struts.

Ankle fractures and pilon fractures are common injuries and can range in severity from low-energy rotational injuries to high-energy fractures of the articular surface. External fixation can be used in a staged treatment strategy to allow for a closed reduction and soft tissue rest before definitive internal fixation or as a definitive treatment method. We describe a technique that involves the use of novel polyaxial locking struts in conjunction with circular external fixation that can be used as a temporary form of external fixation or as definitive treatment of high-energy ankle and pilon fractures.

Analysis of the Imaging Features and Prognosis of Pulmonary Tuberculosis Complicated with Pulmonary Embolism

OBJECTIVE: This study aimed to explore the imaging characteristics of patients with pulmonary tuberculosis complicated with pulmonary embolism and analyze the prognosis of the condition, thereby reducing the mortality and misdiagnosis rate of complications in this type of pulmonary tuberculosis. METHODS: In this retrospective study, a total of 70 patients diagnosed with pulmonary embolism by computed tomography pulmonary angiography (CTPA) from January 2016 to May 2021 in Anhui Chest Hospital were included. Among them, 35 patients with pulmonary embolism combined with pulmonary tuberculosis were set as the study group, and the other 35 patients with pulmonary embolism only were set as the control group. The imaging findings of chest CT examination, the incidence of pulmonary hypertension, the level of N-terminal proto-B-type brain natriuretic peptide (NT-proBNP), and the prognosis of patients were compared between the two groups. The incidence of deep venous embolism was evaluated by ultrasonography of the lower extremity. RESULTS: In the study group, the median age of patients was 71 years, and the ratio of males to females was 2.5 to 1. In the control group, the median age was 66 years old, and the male-to-female ratio was 2.2 to 1. There were 16 cases (16/35, 45.71%) in the study group and 10 cases (10/35, 28.57%) in the control group with an increased level of NT-proBNP. Pulmonary hypertension occurred in 10 patients (10/35, 28.57%) in the study group and 7 patients (7/35, 20.00%) in the control group. Patients who lost follow-up included 5 in the study group (5/35, 14.29%) and 3 in the control group (3/35, 8.57%). There were 17 cases (17/35, 48.57%) in the study group and 3 cases (3/35, 8.57%) in the control group with pulmonary artery widening, and the difference was significant (P < 0.001). There were 13 deaths in the study group (13/35, 37.14%) and 1 death in the control group (1/35, 2.86%), and the difference was significant (P <0.001). CONCLUSION: Special signs of pulmonary artery widening, pulmonary hypertension of varying degrees, and increased levels of NT-proBNP of varying degrees can be found in patients with pulmonary tuberculosis complicated with pulmonary embolism, and the three signs are positively correlated. The mortality of patients with pulmonary tuberculosis complicated with pulmonary embolism is significantly higher than that of patients with pulmonary embolism alone. Pulmonary tuberculosis and pulmonary embolism both occur in the ipsilateral lung, causing clinical symptoms to cover each other, thereby making diagnosis difficult.

18 F-FDG PET/MRI of Primary Hepatic Malignancies: Differential Diagnosis and Histologic Grading

BACKGROUND: Distinguishing between IHCC and HCC is important because of their differences in treatment and prognosis. The hybrid Positron Emission Tomography/magnetic Resonance Imaging (PET/MRI) system has become more widely accessible, with oncological imaging becoming one of its most promising applications. OBJECTIVE: The objective of this study was to see how well 18F-fluorodeoxyglucose (18F-FDG) PET/MRI could be used for differential diagnosis and histologic grading of primary hepatic malignancies. METHODS: We retrospectively evaluated 64 patients (53 patients with HCC, 11 patients with IHCC) with histologically proven primary hepatic malignancies using 18F-FDG/MRI. The Apparent Diffusion Coefficient (ADC), Coefficient of Variance (CV) of the ADC, and standardized uptake value (SUV) were calculated. RESULTS: The mean SUVmax value was higher for IHCC (7.7 ± 3.4) than for HCC (5.2 ± 3.1) (p = 0.019). The area under the curve (AUC) was 0.737, an optimal 6.98 cut-off value providing 72% sensitivity and 79% specificity. The ADCcv value in IHCC was statistically significantly higher than in HCC (p=0.014). ADC mean values in HCCs were significantly higher in low-grade tumors than in high-grade tumors. The AUC value was 0.73, and the optimal cut-off point was 1.20x10-6 mm2/s, giving 62% sensitivity and 72% specificity. The SUVmax value was also found to be statistically significantly higher in the high-grade group. The ADCcv value in the HCC low-grade group was found to be lower than in the highgrade group (p=0.036). CONCLUSION: 18F FDG PET/MRI is a novel imaging technique that can aid in the differentiation of primary hepatic neoplasms as well as tumor-grade estimation.

A Novel Combined Model to Predict the Prognosis of COVID-19: Radiologicalmetabolic Scoring

AIM: To investigate the performance of a novel radiological-metabolic scoring (RM-S) system to predict mortality and intensive care unit (ICU) requirements among COVID-19 patients and to compare performance with the chest computed-tomography severity-scoring (C-CT-SS). The RMS was created from scoring systems such as visual coronary-artery-calcification scoring (V-CAC-S), hepatic-steatosis scoring (HS-S) and pancreatic-steatosis scoring (PS-S). METHODS: Between May 2021 and January 2022, 397 patients with COVID-19 were included in this retrospective cohort study. All demographic, clinical and laboratory data and chest CT images of patients were retrospectively reviewed. RM-S, V-CAC-S, HS-S, PS-S and C-CT-SS scores were calculated, and their performance in predicting mortality and ICU requirement were evaluated by univariate and multivariable analyses. RESULTS: A total of 32 (8.1%) patients died, and 77 (19.4%) patients required ICU admission. Mortality and ICU admission were both associated with older age (p < 0.001). Sex distribution was similar in the deceased vs. survivor and ICU vs. non-ICU comparisons (p = 0.974 and p = 0.626, respectively). Multiple logistic regression revealed that mortality was independently associated with having a C-CT-SS score of ≥ 14 (p < 0.001) and severe RM-S category (p = 0.010), while ICU requirement was independently associated with having a C-CT-SS score of ≥ 14 (p < 0.001) and severe V-CAC-S category (p = 0.010). CONCLUSION: RM-S, C-CT-SS, and V-CAC-S are useful tools that can be used to predict patients with poor prognoses for COVID-19. Long-term prospective follow-up of patients with high RM-S scores can be useful for predicting long COVID.

Does Morphology of the Shoulder Joint Play a Role in the Etiology of Rotator Cuff Tear?

BACKGROUND: The etiology of rotator cuff tears (RCTs) have been investigated for years and many underlying causes have been identified. Shoulder joint morphology is one of the extrinsic causes of RCTs. AIM: Morphometric measurements on MRI sections determined which parameters are an important indicator of RCT in patients with shoulder pain. The aim of this study was to determine the risk factors in the etiology of RCTs by evaluating the shoulder joint morphology with the help of previously defined radiological parameters. METHOD: Between January 2019-December 2020, 408 patients (40-70 years old) who underwent shoulder MRI and met the criteria were included in the study. There were 202 patients in the RCT group and 206 patients in the control group. Acromion type, acromial index (AI), critical shoulder angle (CSA), acromiohumeral distance (AHD), lateral acromial angle (LAA), acromial angulation (AA), acromion-greater tuberosity impingement index (ATI), and glenoid version angle (GVA) were measured from the MRI images of the patients. RESULTS: AI (0.64 vs. 0.60, p = 0.003) CSA (35.3° vs. 32.4°, p = 0.004), ATI (0.91 vs. 0.83, P < 0.001), and AA (13.6° vs. 11.9°, p = 0.011) values were higher in the RCT group than in the control group and the difference was significant. AHD (8.1 mm vs. 9.9 mm, P < 0.001), LAA (77.2° vs. 80.9°, p = 0.004) and GVA (-3.9° vs. -2.5°, P < 0.001) values were lower in the RCT group than in the control group, and again the difference was significant. According to the receiver operating characteristic curve analysis, the cutoff values were 0.623 for AI and 0.860 for ATI. CONCLUSION: Acromion type, AI, CSA, AHD, LAA, AA, ATI, and GVA are suitable radiological parameters to evaluate shoulder joint morphology. High AI, CSA, AA, ATI, GVA and low AHD and LAA are risk factors for RCT.

Sclerosing Angiomatoid Nodular Transformation of the Spleen: Radiological Findings and Radiological-pathological Correlation

Introduction: The objective of this study was to describe the CT and MRI features of sclerosing angiomatoid nodular transformation (SANT) of the spleen with pathologic correlation. Materials and Methods: Ten patients with surgically resected and pathologically confirmed SANTs were included. Clinical history was reviewed, and gross pathologic, histologic, and immunohistochemical findings were recorded. CT and MRI examinations were evaluated by two radiologists. Results: Patients included seven men and three women, with a mean age of 42.9±16.7 years. Pathologic features of SANTs involved multiple angiomatous nodules in a radiating pattern with a central stellate fibrous scar and evidence of hemosiderin deposition. 9 cases showed a lobulated demarcated margin, 8 cases a slight hypoattenuating, 1 isoattenuating, and 1 case with two lesions demonstrated a slight hyperattenuating margin, respectively. Multiple scattered punctate calcifications were involved in 2 cases. 5 cases manifested hypointensity on in-phase imaging, 1 iso-intensity, and 4 iso-hypointensity on out-of-phase imaging. Progressive and centripetal enhancement were exhibited in 10 cases, spoke-wheel pattern in 3 cases, and nodular enhancement in 4 cases, respectively. The central fibrous scar was identified in 8 cases during delayed enhancement. Conclusion: Characteristics of SANTs on CT/MRI reflected the underlying pathology. Hypointensity on DWI and T2WI, and change of signal on T1 chemicalshift imaging were found to be due to hemosiderin deposition and fibrous tissue. Typical feature was a solitary, round, lobulated mass with a fibrous scar. Progressive and centripetal enhancement, spoke-wheel pattern, nodular enhancement, and delayed enhancement of central fibrous scar were observed.

Endometrial Adenofibroma in a Patient Receiving Toremifene: A Case Report

INTRODUCTION: Adenofibroma is a rare benign Müllerian mixed tumor composed of epithelial and mesenchymal cells. This tumor may occasionally be associated with toremifene therapy which is used as an adjuvant drug for breast cancer. CASE PRESENTATION: We describe a case of a 55-year-old woman with adenofibroma of the endometrium. This patient was receiving toremifene after surgery and neoadjuvant chemotherapy for breast cancer. She underwent a total abdominal hysterectomy and bilateral salpingectomy. There was no evidence of tumor residual or recurrence at 32 months of MRI follow-up. CONCLUSION: In conclusion, we report a rare case of endometrial adenofibroma in a patient receiving toremifene. It must be borne in mind that long-term toremifene therapy may increase the frequency of endometrial neoplasms.

A Comprehensive Review on MRI-based Knee Joint Segmentation and Analysis Techniques

Using magnetic resonance imaging (MRI) in osteoarthritis pathogenesis research has proven extremely beneficial. However, it is always challenging for both clinicians and researchers to detect morphological changes in knee joints from magnetic resonance (MR) imaging since the surrounding tissues produce identical signals in MR studies, making it difficult to distinguish between them. Segmenting the knee bone, articular cartilage and menisci from the MR images allows one to examine the complete volume of the bone, articular cartilage, and menisci. It can also be used to assess certain characteristics quantitatively. However, segmentation is a laborious and time-consuming operation that requires sufficient training to complete correctly. With the advancement of MRI technology and computational methods, researchers have developed several algorithms to automate the task of individual knee bone, articular cartilage and meniscus segmentation during the last two decades. This systematic review aims to present available fully and semi-automatic segmentation methods for knee bone, cartilage, and meniscus published in different scientific articles. This review provides a vivid description of the scientific advancements to clinicians and researchers in this field of image analysis and segmentation, which helps the development of novel automated methods for clinical applications. The review also contains the recently developed fully automated deep learning-based methods for segmentation, which not only provides better results compared to the conventional techniques but also open a new field of research in Medical Imaging.

Acute Pancreatitis Complicated by Thrombosis in the Right Brachiocephalic Veins and Superior Vena Cava: A Case Report

BACKGROUND: Acute pancreatitis (AP) is one of the most common digestive emergencies, and vascular complication is one of the primary reasons for death, with splanchnic venous thrombosis being the most common. Although extra-splanchnic venous thrombosis is rare, it carries the risk of life-threatening secondary pulmonary embolism. CASE PRESENTATION: We have, herein, reported a case of AP complicated by rare brachiocephalic vein thrombosis and superior vena cava thrombosis. A 40 years old woman was diagnosed with severe AP for abdominal pain 21 days ago. The patient received symptomatic treatment, including acid suppression, enzyme suppression, lipid-lowering, fluid infusion, anti-infection, and continuous renal replacement therapy. The patient was discharged after symptomatic relief. Recently, the patient was admitted again for middle-upper abdominal pain and discomfort. On admission, her blood platelet, DDimer, fibrin degradation products (FDP), and triglyceride levels have been found to be increased; abdominal enhanced CT showed pancreatic necrosis and an accumulation of peripancreatic necrosis and fluid, while chest enhanced CT suggested thrombosis in the right brachiocephalic vein and superior vena cava. The patient, however, improved and was discharged after anticoagulation combined with insulin and trypsin inhibitors. CONCLUSION: In diagnosing and treating AP, dynamic monitoring of D-dimer levels is necessary for the timely detection of the development of thrombotic complications.

Evaluation of Main Lacrimal Gland through Shear-wave Ultrasound Elastography in Patients with Low Schirmer Value

OBJECTIVE: To compare main lacrimal gland values through shear-wave elastography (SWE) in patients with low Schirmer value and unspecified Sjögren's syndrome (SS) with healthy controls. MATERIAL AND METHOD: Admitted to the ophthalmology department with Schirmer value <10 mm, randomly selected 46 eyes of 46 patients evaluated for Sjögren's syndrome (SS) in the rheumatology department between December 2022 and April 2023 were classified as low Schirmer group (LSG). Randomly selected 48 eyes of 48 patients at a similar age with Schirmer value >10 mm were included as controls. Main lacrimal gland SWE measurements in LSG and control groups were recorded and compared as meter/second (m/sec). RESULTS: Mean SWE values of the main lacrimal gland were measured as 2.78 ± 0.66 m/sec and 2.26 ± 0.29 m/sec in LSG and controls. SWE measurements were significantly higher in LSG patients than in controls (p<0.001). No significant correlation was found in the analysis between the Schirmer and the main lacrimal gland SWE values in LSG patients (p=0.702, r=0.058). No significant correlation was also detected between the Schirmer and main lacrimal gland SWE values in controls (p=0.097, r=0.242). No significant relationship was also found between age, gender, body mass index (BMI), and SWE values (p=0.351, p=0.493, p=0.328, respectively). CONCLUSION: Mean SWE value of the main lacrimal gland was determined as significantly higher in patients with aqueous lacrimal insufficiency without SS than in controls. We consider that SWE measurements may be an imaging method to support the diagnosis of aqueous lacrimal insufficiency and used in follow-ups of those with dry eye syndrome (DES) in the future.

Effects of Deep Venous Thrombosis Treatments on Early and Long-term Quality of Life: Medical Therapy vs. Systemic Thrombolysis vs. Pharmacomechanical Thrombolysis.

OBJECTIVES: The present study aimed to compare the effects of medical therapy (MT), systemic thrombolysis (ST), and pharmacomechanical thrombolysis (PMT) methods used in our clinic for the treatment of deep venous thrombosis (DVT) on symptom reduction, the incidence of post-thrombotic syndrome (PTS) development, and quality of life. METHODS: Data from160 patients diagnosed with acute DVT between January 2012 and May 2021 and treated and followed up in our clinic were retrospectively analyzed. The patients were divided into three groups according to treatment method. The patients who received MT treatment were defined as Group 1, anticoagulant treatment after ST as Group 2, and anticoagulant treatment after PMT as Group 3. The patients were called to the outpatient clinic, informed consent was obtained, EuroQol-5D-3 L (EQ-5D-3 L) scoring and Villalta scoring were performed, and anamnesis was taken. RESULTS: A total of 160 patients were included, with 71 (44.4%) patients in Group 1, 45 (28.1%) in Group 2, and 44 (27.5%) in Group 3. The mean age was 48.9 ± 14.9 years for Group 1, 42.2 ± 10.8 for Group 2, and 29.0 ± 7.2 for Group 3. When the time to return to normal life and the EQ-5D-3 L score index were compared, the differences between Groups 1 and 2 and between Groups 1 and 3 were statistically significant (P = .000 and P = .000, respectively). However, the differences between Groups 2 and 3 were statistically insignificant (P = .213 andp = .074, respectively). When Villalta scores and EQ Visual Analogue Scale (EQ-VAS) scores were compared between groups, the difference between all groups was statistically significant (P = .000). CONCLUSIONS: The medical treatment alone was observed to be insufficient in terms of symptomatic improvement, development of PTS, quality of life, and long-term complications. When the ST and PMT groups were compared, it was determined that PMT treatment was more advantageous in terms of EQ-VAS score and PTS development, although there was no statistical difference regarding complications, such as return to normal life and long-term quality of life, the incidence of recurrent DVT development, and pulmonary thromboembolism incidence.

Paradoxical Embolism Is an Unusual Etiology of Acute Limb Ischemia in Patients Suffering from COVID-19 Infection.

Acute limb ischemia (ALI) is a large contributor to morbidity and mortality annually and can be managed either operatively or medically. ALI is most often caused by arterial embolism or in situ thrombosis and treatment is often dependent upon the severity. Anticoagulation is considered standard of care and first line therapy. However, more severe cases of ALI require surgical intervention.Paradoxical emboli are a rare and potentially under-appreciated cause of ALI. They arise when venous emboli, from a variety of sources, traverse a patent foramen ovale (PFO) to enter the arterial system, compromising blood flow to the affected end organ. In most cases, they can only be proven if the thrombus is identified as it crosses the cardiac defect, at which point it is an indication for surgery requiring PFO closure, management for the ischemia itself, and possible intervention for the embolism.In this report, we identify and discuss management of a series of cases where ALI was precipitated by PFOs that were discovered in the context of a pulmonary emboli that developed into paradoxical emboli. All patients had a confirmed diagnosis of COVID-19 which has been associated with a state of hypercoagulability and subsequent thrombus formation.

Treatment of Uncomplicated Type B Aortic Dissection: Optimal Medical Therapy vs TEVAR + Optimal Medical Therapy.

Optimal Medical Therapy (OMT) has been the accepted mode of treatment for uncomplicated Type B Aortic Dissection (uTBAD). There is growing evidence that despite the short-term benefits of OMT, patients suffer deleterious consequences in the long-term with OMT alone. Thoracic Endovascular Aortic Repair (TEVAR) along with OMT has emerged as an alternative option for patients with uTBAD. This study evaluates the available literature for TEVAR + OMT as an alternative to OMT for treatment of uTBAD. In addition, issues related to TEVAR as a treatment for uTBAD are discussed.

Long-Term Outcome of Carotid-Subclavian Bypass in the Management of Coronary-Subclavian Steal Syndrome.

OBJECTIVE: The presence of a significant left subclavian artery stenosis may occasionally lead to blood flow reversal through a LIMA-to-coronary artery bypass graft during left arm exertion; with "stealing" of myocardial blood supply. The aim of this study was to review our experience with carotid-subclavian bypass in patients with post-CABG coronary-subclavian steal syndrome. METHODS: This is a retrospective review of all patients who underwent carotid-subclavian bypass grafting for post-CABG coronary-subclavian steal syndrome at Mainz University Hospital between 2006 and 2015. Cases were identified in our institutional database, and data were retrieved from surgical records, imaging studies, and follow-up records. RESULTS: Nine patients (all males, mean age of 69.1 years) underwent surgical treatment for post-CABG coronary-subclavian steal syndrome. Medium interval between original CABG and carotid-subclavian bypass grafting was 86.1 months. There were no perioperative deaths, strokes or myocardial infarctions. At a mean follow-up period of 79.9 months, all patients remained asymptomatic and all carotid-subclavian bypass grafts remained patent. One patient required stenting of a common carotid artery stenosis proximal to the graft anastomosis site, and coronary artery stenting was required in four patients in regions other than those supplied by the patent LIMA graft. CONCLUSION: Carotid-subclavian bypass surgery is a safe treatment option even in patients with multivessel disease and severe comorbidities and should be taken into consideration in patients who are deemed fit for surgery and those who would benefit from the excellent long-term patency rates.

Angiolymphoid Hyperplasia With Temporal Artery Eosinophilia: A Case Report.

Angiolymphoid Hyperplasia with Eosinophilia (ALHE) is a benign vascular proliferative disorder with uncertain etiology and pathogenesis. The aim of this paper is to report a case of ALHE in the temporal artery and discuss the general aspects of this pathology. A 29-year-old female black patient sought the Vascular Surgery Outpatient Service, complaining of bulging in the right temporal region, associated with pain and local discomfort. Physical examination revealed pulsatile bulging in the right temporal region measuring approximately 2.5 × 1.5 cm. Nuclear Magnetic Resonance showed an expansive fusiform lesion in the superficial soft parts of the right temporal region, measuring 2.9 cm in the longest longitudinal axis. Surgical excision proved to be the best therapeutic option for the patient in this case. Histopathological sections showed the proliferation of vessels of different sizes, covered by swollen endothelium, prominent inflammatory infiltrate composed of lymphocytes, plasma cells, eosinophils, and scarce histiocytes. Immunohistochemical analysis of the lesion showed positivity for CD31, corroborating the diagnosis of ALHE.

Stentgraft Limb Occlusion After Endovascular Aneurysm Repair: Incidence and Risk Factors.

INTRODUCTION: Stentgraft limb occlusion (SLO) is a potential complication of endovascular aneurysm repair (EVAR). The purposes of this single centre study are to report the incidence of SLO after EVAR and to detect possible risk factors. METHODS: All patients who underwent EVAR between June 2001 and February 2020 were included in this retrospective study. Demographic data, cardiovascular risk factors, aneurysm characteristics, arterial anatomy, repair strategy, systemic and stentgraft-related complications, and in-hospital and late mortality were collected. Routine follow-up included duplex examination and/or CT angiography at 3 months, 12 months and annually thereafter. Logistic regression analysis was performed to detect predictors for SLO. RESULTS: A total of 221 patients (425 stentgraft limbs) were included; of whom 11 patients (5.0%) occluded. Median time to occlusion was 3.3 months and most of the patients presented ischemic signs. Two risk factors for SLO could be identified: symptomatic aneurysm (P .015, odds ratio 4.62, 95% confidence interval 1.35-15.86) and length of the infrarenal abdominal aortic aneurysm (AAA) (P .021, odds ratio 1.31, 95% confidence interval 1.04 - 1.64). CONCLUSION: The incidence of SLO after EVAR is low, and most occlusions occur within the first year. Predictors for SLO are the symptomatic aneurysm and the length of the infrarenal AAA. Further research is necessary to pool all predictors and to assess the clinical impact of different follow-up strategies for high-vs low-risk patients.

Transcaval Coil Embolization of Type 2 Endoleak After Endovascular Aortic Repair: An Institutional Review.

OBJECTIVES: Endovascular aortic repair may be complicated by type 2 endoleaks. Intervention is generally recommended when the native sac continues to grow more than 5 mm. Transcaval coil embolization (TCE) of the native aneurysm sac is an emerging technique for repair of type 2 endoleaks. The objective of this study is to report an institutional review of our experience with this technique. METHODS: 11 patients underwent TCE during the study period. Data were gathered on demographics, size increase of native aneurysm sac, operative details, and outcomes. Technical success was defined as resolution of the endoleak during completion sac angiogram at end of the procedure. Clinical success was defined as no growth in the aneurysm sac at interval follow-up. RESULTS: Coils were the embolant of choice in all cases. Technical success was achieved in all cases except 1 resulting in a 91% technical success rate. Median follow-up was 25 months (range, 3-33). Of the ten patients that had technically successful embolization, 8 patients had repeat computed tomography (CT) scans which showed no further expansion of the native sac resulting in a 80% clinical success rate. No complications were noted immediately post-op or at interval follow-up. CONCLUSIONS: This institutional retrospective review demonstrates that TCE is an effective and safe option for type 2 endoleaks after endovascular aortic repair (EVAR) in selected patients with favorable anatomy. Longer term follow-up, more patients, and comparison studies are needed to further define durability and efficacy.

Applying Artificial Intelligence to Predict Complications After Endovascular Aneurysm Repair.

Objective: Complications after Endovascular Aneurysm Repair (EVAR) can be fatal. Patient follow-up for surveillance imaging is becoming more challenging as fewer patients are seen, particularly after the first year. The aim of this study was to develop an artificial intelligence model to predict the complication probability of individual patients to better identify those needing more intensive post-operative surveillance. Methods: Pre-operative CTA 3D reconstruction images of AAA from 273 patients who underwent EVAR from 2011-2020 were collected. Of these, 48 patients had post-operative complications including endoleak, AAA rupture, graft limb occlusion, renal artery occlusion, and neck dilation. A deep convolutional neural network model (VascAI©) was developed which utilized pre-operative 3D CT images to predict risk of complications after EVAR. The model was built with TensorFlow software and run on the Google Colab Platform. An initial training subset of 40 randomly selected patients with complications and 189 without were used to train the AI model while the remaining 8 positive and 36 negative cases tested its performance and prediction accuracy. Data down-sampling was used to alleviate data imbalance and data augmentation methodology to further boost model performance. Results: Successful training was completed on the 229 cases in the training set and then applied to predict the complication probability of each individual in the held-out performance testing cases. The model provided a complication sensitivity of 100% and identified all the patients who later developed complications after EVAR. Of 36 patients without complications, 16 (44%) were falsely predicted to develop complications. The results therefore demonstrated excellent sensitivity for identifying patients who would benefit from more stringent surveillance and decrease the frequency of surveillance in 56% of patients unlike to develop complications. Conclusion: AI models can be developed to predict the risk of post-operative complications with high accuracy. Compared to existing methods, the model developed in this study did not require any expert-annotated data but only the AAA CTA images as inputs. This model can play an assistive role in identifying patients at high risk for post-EVAR complications and the need for greater compliance in surveillance.