3-year clinical outcomes of A Singapore VenaSeal™ real world post-market evaluation Study (ASVS) for varicose vein ablation.

INTRODUCTION: Medium-term clinical outcome data are lacking for cyanoacrylate glue (CAG) ablation for symptomatic varicose veins, especially from the Asian population. OBJECTIVES: Aim was to determine the 3-year symptomatic relief gained from using the VenaSeal™ device to close refluxing truncal veins from the Singaporean ASVS prospective registry. METHODS: The revised Venous Clinical Severity Score (rVCSS) and three quality of life (QoL) questionnaires were completed to assess clinical improvement in venous disease symptoms along with a dedicated patient satisfaction survey. 70 patients (107 limbs; 40 females; mean age of 60.9 ± 13.6 years) were included at 3 years. RESULTS: At 3 years, rVCSS showed sustained improvement from baseline (5.00 to 0.00; p < 0.001) and 51/70 (72.9%) had improvement by at least 2 or more CEAP categories. Freedom from reintervention was 90% and 85.7% patients were extremely satisfied with the treatment outcome. No further reports of further hypersensitivity reactions after one year. CONCLUSION: The 3-year follow-up results of the ASVS registry demonstrated continued and sustained clinical efficacy with few reinterventions following CAG embolization in Asian patients with chronic venous insufficiency. TRIAL REGISTRATION: ClinicalTrials.gov Registration: NCT03893201.

Understanding the use of evidence-based medical therapy in patients with peripheral artery disease: A qualitative study using the Tailored Implementation for Chronic Diseases Framework.

Introduction: The global burden of peripheral artery disease (PAD) has been increasing. Guidelines for PAD recommend evidence-based medical therapy (EBMT) to reduce the risks of cardiovascular events and death but the implementation of this is highly variable. This study aimed to understand the current practices regarding EBMT prescription in PAD patients and the key barriers and facilitators for implementing PAD guidelines. Method: A qualitative study was conducted in the largest tertiary hospital in Singapore from December 2021 to March 2023. The participants included healthcare professionals and in-patient pharmacists involved in the care of PAD patients, as well as patients with PAD who had undergone a lower limb angioplasty revascularisation procedure. Data were collected through in-depth, individual semi-structured interviews conducted face-to-face or remotely by a trained research assistant. Interviews were audio-recorded, transcribed and systematically coded using data management software NVivo 12.0. The Tailored Implementation for Chronic Diseases (TICD) framework was used to guide the interviews and analysis. Results: Twelve healthcare professionals (4 junior consultants, 7 senior consultants, and 1 senior in-patient pharmacist) and 4 patients were recruited. Nine themes in 7 domains emerged. Only a small proportion of doctors were aware of the relevant guidelines, and the generalisability of guidelines to patients with complicated conditions was the doctors' main concern. Other barriers included cost, frequent referrals, lack of interprofessional collaboration, not being the patients' long-term care providers, short consultation time and patients' limited medication knowledge. Conclusion: Findings from this study may inform strategies for improving healthcare professionals' adherence to guidelines and patients' medication adherence.

A case study of pyelolymphatic backflow demonstrated on CT.

Pyelolymphatic backflow is a rare type of pyelolymphatic fistula that occurs in cases of urinary obstruction. This phenomenon may help to decompress an acutely obstructed kidney, and therefore, alleviate renal function from deteriorating. Pyelolymphatic backflow has specific imaging characteristics best shown on CT urography. Our case study aims to improve the understanding and diagnosis of pyelolymphatic backflow by presenting a case of pyelolymphatic backflow seen on CT urography, including discussions on the pathophysiology, clinical relevance and management of this phenomenon. Our case study demonstrates the opacification of landmark lymphatic structures including the retroperitoneal para-aortic lymphatic chain, cisterna chyli and thoracic duct, which have not been demonstrated previously.

Pilot single-arm study to investigate the efficacy and safety of endovenous Microwave ablations for treatment of varicose veins in Singapore - one year results of the MAESTRO registry.

OBJECTIVES: Aim was to report a prospective two-centre Singaporean experience using Endovenous Microwave Ablation (EMA) to treat symptomatic primary great saphenous vein reflux. We evaluated 1-year safety, efficacy and patient satisfaction. METHODS: 50 patients (63 limbs; 29 females; mean age 58.0 ± 12.1 years) were included. Patients were reviewed at 2-weeks, 3-, 6- and 12-months and underwent Duplex ultrasound assessment. Three quality of life (QoL) questionnaires were completed. RESULTS: The truncal closure rates at 2-weeks, 3-, 6- and 12-months were 63/63 (100%), 59/59 (100%), 58/58 (100%) and 59/60 (98.3%), respectively. There was 100% technical success and no serious adverse events. There were sustained improvement of QoL questionnaire scores from 2 weeks to 12 months. CONCLUSION: EMA is a safe and efficacious venous ablative technology at 12 months and is associated with a high rate of target vein occlusion and sustained QoL improvement.

Improved Productivity Using Deep Learning-assisted Reporting for Lumbar Spine MRI.

Background Lumbar spine MRI studies are widely used for back pain assessment. Interpretation involves grading lumbar spinal stenosis, which is repetitive and time consuming. Deep learning (DL) could provide faster and more consistent interpretation. Purpose To assess the speed and interobserver agreement of radiologists for reporting lumbar spinal stenosis with and without DL assistance. Materials and Methods In this retrospective study, a DL model designed to assist radiologists in the interpretation of spinal canal, lateral recess, and neural foraminal stenoses on lumbar spine MRI scans was used. Randomly selected lumbar spine MRI studies obtained in patients with back pain who were 18 years and older over a 3-year period, from September 2015 to September 2018, were included in an internal test data set. Studies with instrumentation and scoliosis were excluded. Eight radiologists, each with 2-13 years of experience in spine MRI interpretation, reviewed studies with and without DL model assistance with a 1-month washout period. Time to diagnosis (in seconds) and interobserver agreement (using Gwet κ) were assessed for stenosis grading for each radiologist with and without the DL model and compared with test data set labels provided by an external musculoskeletal radiologist (with 32 years of experience) as the reference standard. Results Overall, 444 images in 25 patients (mean age, 51 years ± 20 [SD]; 14 women) were evaluated in a test data set. DL-assisted radiologists had a reduced interpretation time per spine MRI study, from a mean of 124-274 seconds (SD, 25-88 seconds) to 47-71 seconds (SD, 24-29 seconds) (P < .001). DL-assisted radiologists had either superior or equivalent interobserver agreement for all stenosis gradings compared with unassisted radiologists. DL-assisted general and in-training radiologists improved their interobserver agreement for four-class neural foraminal stenosis, with κ values of 0.71 and 0.70 (with DL) versus 0.39 and 0.39 (without DL), respectively (both P < .001). Conclusion Radiologists who were assisted by deep learning for interpretation of lumbar spinal stenosis on MRI scans showed a marked reduction in reporting time and superior or equivalent interobserver agreement for all stenosis gradings compared with radiologists who were unassisted by deep learning. © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Hayashi in this issue.

Use of Blue Light in the Management of Chronic Venous Ulcer in Asian Patients: A Case Series.

Chronic venous ulcers, often complicated by late diagnosis and persistent infections, present major clinical and financial challenges. Recently, photobiomodulation therapy (PBMT) has been shown to be effective in overcoming physiological impairments such as hemostasis and inflammation, accelerating the wound healing process. This case series summarises our experience in the treatment of two Asian patients with lower-extremity chronic venous ulcers using PBMT with blue light. Case 1 was a 71-year-old male with a history of hypertension, chronic venous insufficiency and previous deep vein thrombosis. Prior to blue light therapy, the average duration of treatment until wound closure with compression dressings used to be 10-12 weeks. Complete wound closure with the blue light therapy was eight weeks, with a total reduction of 67% of wound size by week 4. Case 2 was a 77-year-old male with a background of hypertension and ischaemic heart disease. Prior to blue light therapy, the patient had also underwent iliac venoplasty and stenting for his recurring bilateral malleolus venous ulcers. By week 4, the right malleolus wound had healed, while the left malleolus wound had a size reduction of 38%. Complete closure of both the wounds was noted at week 6. Blue light was administered to the wounds of both patients for 120 seconds per session, as an adjunct to compression therapy. Both patients reported no additional wound pain during the administration of blue light therapy, with an overall reduction of wound pain at three weeks. The cases demonstrated that PBMT with blue light was well-tolerated, safe, and efficacious in improving wound healing with an adjunct to standard treatment of chronic venous ulcers.

Cardioprotection mediated by exosomes is impaired in the setting of type II diabetes but can be rescued by the use of non-diabetic exosomes in vitro.

Many patients with ischaemic heart disease also have diabetes. As myocardial infarction is a major cause of mortality and morbidity in these patients, treatments that increase cell survival in response to ischaemia and reperfusion are needed. Exosomes-nano-sized, lipid vesicles released from cells-can protect the hearts of non-diabetic rats. We previously showed that exosomal HSP70 activates a cardioprotective signalling pathway in cardiomyocytes culminating in ERK1/2 and HSP27 phosphorylation. Here, we investigated whether the exosomal cardioprotective pathway remains intact in the setting of type II diabetes. Exosomes were isolated by differential centrifugation from non-diabetic and type II diabetic patients, from non-diabetic and Goto Kakizaki type II diabetic rats, and from normoglycaemic and hyperglycaemic endothelial cells. Exosome size and number were not significantly altered by diabetes. CD81 and HSP70 exosome markers were increased in diabetic rat exosomes. However, exosomes from diabetic rats no longer activated the ERK1/2 and HSP27 cardioprotective pathway and were no longer protective in a primary rat cardiomyocytes model of hypoxia and reoxygenation injury. Hyperglycaemic culture conditions were sufficient to impair protection by endothelial exosomes. Importantly, however, exosomes from non-diabetic rats retained the ability to protect cardiomyocytes from diabetic rats. Exosomes from diabetic plasma have lost the ability to protect cardiomyocytes, but protection can be restored with exosomes from non-diabetic plasma. These results support the concept that exosomes may be used to protect cardiomyocytes against ischaemia and reperfusion injury, even in the setting of type II diabetes.

Functional Kidney Bioengineering with Pluripotent Stem-Cell-Derived Renal Progenitor Cells and Decellularized Kidney Scaffolds.

Recent advances in developmental biology and stem cell technology have led to the engineering of functional organs in a dish. However, the limited size of these organoids and absence of a large circulatory system poses limits to its clinical translation. To overcome these issues, decellularized whole kidney scaffolds with native microstructure and extracellular matrix (ECM) are employed for kidney bioengineering, using human-induced pluripotent-stem-cell-derived renal progenitor cells and endothelial cells. To demonstrate ECM-guided cellular assembly, the present work is focused on generating the functional unit of the kidney, the glomerulus. In the repopulated organ, the presence of endothelial cells broadly upregulates the expression level of genes related to renal development. When the cellularized native scaffolds are implanted in SCID mice, glomeruli assembly can be achieved by co-culture of the renal progenitors and endothelial cells. These individual glomerular units are shown to be functional in the context of the whole organ using a simulated bio-reactor set-up with urea and creatinine excretion and albumin reabsorption. Our results indicate that the repopulation of decellularized native kidney using clinically relevant, expandable patient-specific renal progenitors and endothelial cells may be a viable approach for the generation of a functional whole kidney.

Incidence and predictors of side-branch compromise in primary percutaneous coronary intervention for acute myocardial infarction.

OBJECTIVE: We aimed to determine the incidence and predictors of side-branch compromise (SBC) in patients who underwent primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). BACKGROUND: Little data exist on SBC in AMI patients, especially in the drug-eluting stent era. METHODS: We recruited 174 patients who underwent primary PCI over a 12-month period. After reviewing their coronary angiograms, we included for analysis 102 patients with a side branch >2 mm arising from the culprit lesion and that was spanned by a coronary stent. SBC was defined as post-stent implantation TIMI flow of <3 in the side branch. RESULTS: Among the 102 patients analyzed, drug-eluting stents (n = 77), bare-metal stents (n = 17), and bioresorbable vascular scaffolds (n = 8) were used to treat the culprit lesions. Final TIMI flow of the main vessel was 2 or 3 in 101 patients (99%). SBC occurred in 23 patients (final side branch TIMI flow 0, n = 6; TIMI 1, n = 4; TIMI 2, n = 13), giving an incidence of 22.5%. Multivariate analysis showed non-left anterior descending (LAD) culprit vessel (odds ratio [OR], 3.66; 95% confidence interval [CI], 1.22-10.95; P=.02), higher peak creatine kinase level (OR, 1.03 for every 100-unit increase; 95% CI, 1.01-1.05; P=.01), and Rentrop score of 2/3 (OR, 3.57; 95% CI, 0.98-13.04; P=.055) to be independent predictors of SBC. CONCLUSIONS: The incidence of SBC was 22.5%. The independent predictors of SBC were non-LAD culprit vessel, larger infarct size, and good collateral vessel formation.

Determination of the severity of underlying lesions in acute myocardial infarction on the basis of collateral vessel development.

BACKGROUND: We aimed to address the conflict over whether the underlying lesion that leads to acute myocardial infarction (AMI) is representative of low-grade or high-grade stenosis. Because the development of collateral vessels is an indication of ischemia, their presence was used as a surrogate marker for the existence of a high-grade lesion. METHODS: Coronary angiography was used to assess 159 patients, divided into two groups, with (Rentrop 1-3) and without (Rentrop 0) collateral vessels, who had AMI with ST-segment elevation for which they underwent a percutaneous coronary intervention with the implantation of a coronary stent and had baseline thrombolysis in myocardial infarction 0/1 flow. RESULTS: Of the 159 patients recruited, the presence of collateral vessels was detected in 95 (collateral group; 60%), indicating that the causal lesion was representative of a high-grade stenosis. Among these 95 patients, the Rentrop scores were 1, 2, and 3 in 57 (60%), 33 (34.7%), and six (5.3%) patients, respectively. Logistic regression analysis showed that a baseline thrombolysis in myocardial infarction 0 flow (hazard ratio, 4.6; 95% confidence interval, 1.4-14.6; P=0.01) and a culprit right coronary artery (hazard ratio, 3.0; 95% confidence interval, 1.4-6.2; P=0.007) were independent predictors of the development of collateral vessels. CONCLUSION: The majority of AMI cases can be attributed to a severe stenosis, as demonstrated by the presence of collateral vessels in 60% of the patients in this study.