Mechanism and clinical implication of gut dysbiosis in degenerative abdominal aortic aneurysm: A systematic review.

The gut microbiome is the entirety of microorganisms and their genomes residing in the gut, characterised by diversity, stability, and resilience. Disrupted gut microbiome has been implicated in multiple disease entities. The aim of this paper is to summarise the rapidly evolving contemporary evidence of gut dysbiosis on the development and progression of abdominal aortic aneurysm (AAA), discuss possible mechanisms, and explore potential microbiota-targeted interventions and prognostic markers for AAA. A systematic literature search was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, using PubMed, ScienceDirect, Web of Science, Ovid, Embase. Search terms of "microbiome" OR "dysbiosis" OR "microorganism"; AND "aneurysm" OR "dilatation" OR "aorta" were used. Study endpoints included effects of microbiota on AAA formation, effects of specific type of bacteria and its metabolite on AAA formation, and pre- or post-treatment by novel small-molecules/inhibitors. From May to August 2023, a total of twelve animal studies and eight human studies were included. Akkermansia muciniphila, Lactobacillus acidophilus and species from the Bacteroidetes phylum were associated with lower AAA incidence in both animal and human studies, while Proteobacteria phylum, Campylobacter, Fusobacterium and Faecalibacterium prausnitzii were found to be in abundance in the AAA group and were associated with larger aneurysms. The diversity of gut microbiota was inversely correlated with AAA diameter. Three important mechanisms were identified: including trimethylamine N-oxide pathway, butyric acid pathway, and aberrant tryptophan metabolism. With our expanding knowledge of the downstream pathogenic mechanisms of gut dysbiosis, novel therapeutics such as short-chain fatty acids and spermidine, as well as prognostic biomarkers such as TMAO have yielded promising preclinical results. In conclusion, there is strong evidence corroborating the role of gut dysbiosis in the pathogenesis of AAA, wherein its therapeutic and prognostic potential deserves further exploration.

Efficacy and Durability of Percutaneous Deep Vein Arterialization: A Systematic Review.

BACKGROUND: Endovascular deep vein arteriaization (DVA) is a novel technique aimed at salvaging peripheral arterial disease unamenable to conventional surgical intervention. This study aims to review contemporary literature on the efficacy, safety, and durability of DVA on patients with no-option critical limb ischemia (NO-CLI). METHODS: The study was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement, using predefined search terms of "percutaneous deep vein arterialization" or "percutaneous deep venous arterialization" in PubMed, Web of Sciences, OvidSP, and Embase. Only studies with 5 or more patients were included, and studies involving open or hybrid DVA were excluded. The primary outcomes included technical success and primary amputation rates. Secondary outcomes included rates of wound healing, complication, reintervention, and all-cause mortality. RESULTS: Ten studies encompassing a total of 233 patients were included. Patients were primarily those deemed to have NO-CLI. The median follow-up period was 12 months (range 1-63 months). The technical success rate was 97% (95% confidence interval [CI] 96.2%-97.9%) and the major amputation rate was 21.8% (95% 21.1%-22.4%). The wound healing rate was 69.5% (95% CI 67.9-71.0%), complication rate was 13.8% (95% CI 11.7%-15.9%), reintervention rate was 37.4% (95% CI 34.9%-39.9%), and all-cause mortality rate was 15.7% (95% CI 14.1%-17.2%). CONCLUSIONS: Our study showed that endovascular DVA is safe for patients with NO-CLI. Nonetheless, studies were small with follow-up period of less than 1 year. There is currently lack of level 1 evidence to recommend routine use in patients with NO-CLI.

Effectiveness and Safety of Endoanchors in Abdominal and Thoracic Endovascular Aneurysm Repair: A Systematic Review and Meta-analysis.

PURPOSE: This systematic review aimed to summarize the effectiveness and safety of endoanchor, a stabilizing device for the proximal endograft designed to prevent endoleak and stent migration in endovascular aneurysm repair (EVAR) and thoracic endovascular aneurysm repair (TEVAR). MATERIALS AND METHODS: A systematic review and meta-analysis was conducted per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline. Literature up to May 31, 2023 was searched and independently screened from 4 databases. Data were pooled for meta-analysis. Primary outcomes included intraoperative and follow-up endoleak, stent migration, and reintervention rates; sac regression; and 30-day all-cause mortality. RESULTS: Sixteen EVAR (n=1145) and 6 TEVAR studies (n=163) using the Heli-Fx EndoAnchor system were included from 2225 retrieved records. For EVAR patients (mean follow-up=11.9 months), the endoleak, graft migration, and reintervention rates were 3.97% (95% confidence interval [CI]=0.36%-1.99%), 0.004% (95% CI=0.00%-0.76%), and 5.43% (95% CI=0.86%-12.54%), respectively. The endoleak rates for primary and revision EVAR were 0.16% (95% CI=0.00%-1.65%) and 3.60% (95% CI=0.14%-9.72%), respectively. Only 4 cases of 30-day mortality (n=4) were reported in the literature. For TEVAR patients, the endoleak, stent migration, and reintervention rates were 7.4% (95% CI=0.03%-0.13%), 0.2% (95% CI=0.00%-0.06%), and 17.1% (95% CI=0.01%-0.45%), respectively. The 30-day mortality was 0.9% (95% CI=0%-0.12%). CONCLUSIONS: Endoanchor fixation in EVAR and TEVAR is effective and safe in preventing and treating endoleak and stent migration. The mortality is minimal in EVAR but higher in TEVAR. CLINICAL IMPACT: Endoleak, graft migration, and reintervention in EVAR and TEVAR with endoanchor use were rare. Mortality in EVAR was low. The adjunctive deployment of endoanchors is an effective and safe means to prevent and treat endoleak and stent migration in EVAR and TEVAR. Yet, long-term efficacy and safety data and randomized controlled trials would be required to definitively recommend endoanchor use in routine clinical practice.

Prevalence and predictors of radiological left common iliac vein compression in asymptomatic patients.

OBJECTIVE: The aim of this study was to investigate the prevalence of radiological left common iliac vein (LCIV) compression among the asymptomatic population and identify possible predictors. METHODS: Contrast-enhanced abdominal and/or pelvic computed tomography scans of eligible asymptomatic patients were examined. The LCIV diameter was measured from different horizontal planes in the venous phase using PACSView. Degree of LCIV compression (Dc) was calculated by a predefined formula and graded as insignificant (Dc < 25%), mild (≥25% Dc < 50%), moderate (≥50% Dc <75%), and severe (Dc ≥ 75%). Venous stenosis was defined as a Dc of ≥50%. Comparison of variables, including gender, age, body mass index (BMI), and comorbidities was performed between the different grades of LCIV compression. RESULTS: Between November 2019 and July 2022, 1698 eligible asymptomatic patients (53.1% females; mean age, 39.3 ± 11.8 years; mean BMI, 22.9 ± 3.6 kg/m2) were reviewed. The mean Dc was 46.2% (range, 0.29%-90.4%). Insignificant, mild, moderate, and severe compression were distributed in 14.5%, 38.0%, 42.2%, and 5.2% of the cohort population, respectively. Prevalence of venous stenosis was higher in females than males (58.1% vs 42.2%; χ2 = 15.52; P < .001). Females aged ≥25 and <35 years accounted for the highest proportion of venous stenosis than other age groups and was a significant predictor (odds ratio [OR], 3.18; 95% confidence interval [CI], 1.74-7.79; P < .001). In the Asian BMI classification group, being underweight is associated with venous stenosis (OR, 4.69; 95% CI, 2.70-8.14; P < .001) and obesity may be a protective factor (OR, 0.38; 95% CI, 0.23-0.64; P < .001). There is an inverse relationship between Dc and age and BMI. CONCLUSIONS: The prevalence of radiological LCIV compression on computed tomography scans was high, but all patients were asymptomatic. Female gender, especially those aged ≥25 and <35 years, and underweight were possible predictors for venous stenosis.

Contemporary Outcomes of Endovascular and Open Surgical Repair for Mycotic Aortic Aneurysms: A Systematic Review.

BACKGROUND: To perform a systematic review on contemporary outcomes of endovascular repair and open surgical repair (OSR) for the treatment of mycotic aortic aneurysm (MAA). METHODS: A comprehensive literature search on the management of MAAs with endovascular repair or OSR was performed between January 1998 and January 2023. Patient demographics, early and late outcomes were analyzed with respect to treatment modality and MAA location. RESULTS: Forty-eight articles were included, encompassing a total of 1,358 patients (75.8% male; mean age 66.9 years; 1,372 aneurysms) treated by open (49.8%) or endovascular (50.2%) repair. Salmonella spp., and Staphylococcus spp. were the most prevalent pathogens in Asian and European countries respectively. An increasing number of descending thoracic MAAs were managed by endovascular repair (27.9% vs. 12.8%). Early mortality rates for supra- and infra-renal MAAs managed by endovascular repair were lower than OSR (suprarenal 5.4% vs. 43.2%; infrarenal 1.8% vs. 16.7%). Overall, endovascular repair demonstrated lower intraoperative (1.0% vs. 1.8%) and early mortality (6.5% vs. 15.9) rates than OSR. However, endovascular repair was associated with higher late sepsis rate (5.7% vs. 0.9%) and reintervention rate (17.6% vs. 7.3%). Pooled survival rates at 1- and 5-year were similar between the 2 groups. CONCLUSIONS: Current literature suggest that endovascular repair is an effective and safe alternative to OSR for descending thoracic, suprarenal, and infrarenal MAAs. However, endovascular repair is associated with higher risk of infection-related complications and reintervention during follow-up.

Safety and Efficacy of Inner Branched Stent-Graft in the Treatment of Aortic Arch Disease: A Systematic Review.

OBJECTIVE: To provide a descriptive overview on the contemporary outcomes of thoracic endovascular arch repair with inner branched endoprosthesis (bTEVAR) for the treatment of aortic arch pathologies. METHODS: A comprehensive literature search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Pre-defined search terms were used to interrogate PubMed and OVID Medline databases from January 1999 to July 2022. Patient characteristics, indication for treatment, procedural data, mortality rates, postoperative complications, and reintervention rate during follow-up were evaluated. RESULTS: Nineteen articles were included, encompassing a total of 618 patients who received bTEVAR, most of which were double-branched (63.9%, n=395). The main indication for treatment was aneurysm secondary to chronic aortic dissection (38.8%, n=240/618) with a mean maximum diameter of 58.3±11.4 mm. Pooled mean technical success rate was 97.4±4.4% (95% confidence interval [CI]=95.1%-99.5%); 2 and 3 patients required conversion to chimney technique and open repair, respectively. Among the pooled rates of early complications, postoperative stroke was the highest (10.5%; 95% CI=6.8%-14.3%). Thirty-day and in-hospital mortality rate was 5.5% (95% CI=2.6%-9.7%). Forty patients (6.5%; 95% CI=2.5%-9.5%) required early reintervention. During a mean follow-up of 20.7±13.5 months, the mortality rate was 18.2% (n=108/593; 95% CI=8.6%-20.6%) where 12 (11.1%) were aortic-related. Pooled late reintervention rate was 9.6% (95% CI=4.8%-14.3%). Comparison of demographics and outcomes found no significant difference between single and double bTEVAR. CONCLUSION: Branched thoracic endovascular aortic repair is a promising approach for aortic arch pathologies with a high technical success rate despite a steep learning curve. However, contemporary outcomes reflect that postoperative stroke remains the predominant concern. Further experience and long-term follow-up are required to sufficiently elucidate the safety and durability of bTEVAR in the management of aortic pathologies for high-risk patients. CLINICAL IMPACT: This systematic review summarized the contemporary outcomes of thoracic endovascular aortic repair with different inner branched stent-grafts for the management of aortic arch pathologies. Pooled results from nineteen studies with 618 patients demonstrated a high technical success rate and an acceptable mortality rate. However, postoperative stroke remains the major concern. Long-term follow-up is needed to evaluate its durability.

Venous Thromboembolism in a Patient with Interrupted Inferior Vena Cava and Compressed Azygos Continuation: A Case Report and Review of Literature.

We report an unusual case of a 40-year-old male patient who experienced painful swelling of the left lower limb that persisted for 1 week. Imaging modalities not only confirmed the diagnosis of acute iliofemoral venous thrombosis and pulmonary embolism (PE), but also an incidental finding of interrupted inferior vena cava (IVC). This congenital anomaly is uncommon but rarely associated with venous thromboembolism (VTE). The azygos continuation was compressed by the descending aorta against the 11th thoracic vertebrae, which was identified as the cause of VTE. He was treated successfully with anticoagulation and compression therapy. The patient was discharged with lifelong oral Rivaroxaban and remained asymptomatic. In the literature, only 9 cases of interrupted IVC-associated PE were identified but none was due to significant venous compression.

Theoretical Feasibility of Using Arch Branched Endograft Devices for Repair of Post Type A Aortic Dissection in Patients With Prior Ascending Aortic Replacement.

PURPOSE: Ascending aortic replacement is a common emergency procedure for treating acute type A aortic dissection. Secondary open or endovascular interventions for residual arch pathologies is difficult because of adhesions, short prosthetic grafts, and distorted anatomies. Aortic arch branched stent grafts have emerged as a potential solution for these patients if they have suitable anatomical conditions. This study aimed to evaluate the theoretical anatomical and technical feasibility of 2 currently used aortic arch branch endografts in patients who had prior replacement of the ascending aorta. MATERIALS AND METHODS: All patients who had a prosthetic ascending aortic or hemiarch replacement for acute type A dissection in a single institution between January 2013 and December 2018 were included. Contrast computed tomography images on the most recent follow-up were analyzed on a 3-dimensional workstation. Morphological parameters were measured individually for the ascending aorta, aortic arch, supra-aortic branches, and access iliac arteries. The computed tomography scan of each patient was individually evaluated for anatomical suitability for the arch branched and double-branch devices according to set selection criteria. RESULTS: Computed tomography images of 56 patients (median age of 57 years, 45 males) were reviewed. Based on our evaluation, 26 patients (46.4%) were good candidates for an endovascular arch branched device. It would be feasible for 13 patients (23.2%), but prudent preoperative planning was required due to complicated anatomy. The other 17 patients (30.4%) were unsuitable because they met at least 1 exclusion criterion. Short prosthetic grafts, extreme graft angulations, and extensive dissections in the supra-aortic branches were the main reasons for exclusion. CONCLUSION: Endovascular repair using arch branched endografts is feasible in patients with prior ascending aortic arch or hemiarch replacement for acute type A aortic dissection. The most common anatomical conditions that may influence the feasibility of the arch branched endograft procedure include insufficient proximal seal length, severe angulation of the graft, and extensive aortic dissection within the supra-aortic vessels.

Trans-Cervical Endovascular Management of Saccular Aneurysm of the Extracranial Internal Carotid Artery Using a Self-Expanding Nitinol Base ePTFE Covered Stent.

Saccular aneurysm of the extracranial internal carotid artery is rare. We present a 56-year-old lady presented with a progressively enlarging pulsatile swelling over the right neck, and the right internal carotid artery aneurysm was successfully treated with trans-carotid endovascular stenting of right common to right carotid artery using a self-expanding nitinol base ePTFE covered stent (COVERA Plus™ stent, Bard, Tempe, USA). The external carotid artery was prophylactically embolised to prevent back bleeding. New generation covered stents have consistently improved flexibility and conformability, and this is to our knowledge the first reported case in the world's literature of using this type of self-expanding nitinol base ePTFE covered stent in endovascular stenting of carotid artery aneurysms, with excellent short-term results.

Risk factor analysis and treatment outcome of patients with spontaneous isolated celiac axis or superior mesenteric artery dissection.

BACKGROUND: Spontaneous isolated mesenteric artery (celiac axis or superior mesenteric artery [SMA]) dissection (IMAD) is a rare clinical entity. The aim of the present study was to examine the patient demographics, comorbidities, clinical and radiologic features, management, and prognosis and to identify the risk factors predictive of symptoms. METHODS: We performed a single-center, retrospective review from November 2005 to November 2021 of prospectively collected data from patients with a diagnosis of IMAD. The clinical data and radiologic images were reviewed, and statistical analysis was performed to compare the symptomatic and asymptomatic groups. RESULTS: A total of 78 patients were identified. Of the 78 patients, 24 (31%) had had celiac dissections, 51 (65%) had had SMA dissections, and 3 (4%) had had both celiac and SMA dissections. The mean age was 57.7 years (range, 36-84 years), with a male predominance (86%). More than one half (55%) of the patients had had hypertension. In addition, 29 patients (37%) were symptomatic, and 24 (31%) had been admitted to the hospital. The symptomatic patients with celiac axis dissections were more likely to have thrombosis (P = .02), significant stenosis (P = .01) or branch extension (P = .02). The symptomatic patients with SMA dissections were more likely to have a smaller artery diameter (P = .07), a longer dissection length (P = .05), thrombosis (P < .001), significant stenosis (P < .001), or branch extension (P = .003). The symptomatic patients were more likely to have been treated with antiplatelet or anticoagulant therapy (P < .001). Only three patients had undergone an intervention. Seven patients (9%) had died of unrelated causes. The Kaplan-Meier survival analysis showed a 5-year survival rate of 96% and 10-year survival rate of 91%. CONCLUSIONS: IMAD is an uncommon disease entity with a risk of visceral ischemia. Nonetheless, most of these patients can be treated conservatively with medication, with only a small minority requiring emergency surgery.

Risk Factor Analysis and Long-Term Outcomes in Patients with Endovascular Revascularization for Intermittent Claudication or Chronic Limb-Threatening Ischemia.

BACKGROUND: The aim of this study is to review long-term outcome and identify risk factors for patients with peripheral arterial disease (PAD) with percutaneous transluminal angioplasty/stent as a primary treatment strategy for intermittent claudication (IC) or chronic limb-threatening ischemia (CLTI). METHODS: A retrospective cohort study with data collected prospectively from Clinical Data Analysis and Reporting System, departmental database, and Clinical Management System. All patients who underwent endovascular procedures for PAD between January 2011 and December 2020 were identified. The primary outcomes are overall survival and amputation-free survival. Predictive factors for OS and AFS were determined using Cox Model. RESULTS: A total number of 640 patients with PAD (IC, n = 243; CLTI, n = 377) underwent endovascular percutaneous transluminal angioplasty/stenting for PAD from January 2011 to December 2020. Patients with CLTI had a significantly higher 30 days readmission rate (18.8% vs. 6.5%, P < 0.001), emergency reoperation within 30 days (3.4% vs. 0%, P = 0.002), and death within same admission (2.7% vs. 0%, P = 0.008) compared to IC patients. The overall survival and amputation-free survival rates were significantly lower in CLTI patients (P < 0.0001 and P < 0.0001, respectively). On Cox multivariate analysis, CLTI was strongly predictive of all-cause mortality and amputation (hazard ratio [HR] 2.33 and HR 14.92, respectively). In patients with CLTI, chronic kidney disease was an independent predictor of mortality and amputation (HR 1.66 and HR 2.36, respectively). Smoking and ischemic heart disease were also independent predictors of mortality in this subgroup (HR 2.06 and HR 2.43, respectively). CONCLUSIONS: Although patients with IC and CLTI both manifest from atherosclerotic occlusive disease of the lower limb arteries, these patients may have different clinical outcomes with significant mortality occurred in both IC and CLTI groups. In patients with IC, the risk of amputation was less than 1% at 5 years following revascularization.

COVID-19 related thrombosis: A mini-review.

INTRODUCTION: COVID-19 associated VTE is a new disease entity with high morbidity and mortality. The aim of this paper is to review contemporary emerging literature on the incidence, pathophysiology, predictive prognostic indicators, and management consensus for Covid-19 related thrombotic complications, in particular DVT and PE. METHODS: A literature review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. All searches were done via PubMed. References of review articles were further screened according to the exclusion criteria. RESULTS: In total, 154 records were identified and 20 duplicates were removed. A final 68 articles were included in the qualitative analysis. COVID-19 related thrombosis can affect multiple organs of the body, presenting in the form of arterial or venous thrombosis such as ischemic stroke, myocardial infarction, mesenteric ischemia, limb ischemia, DVT, or PE. DVT and PE has an overall incidence of 6-26%, and severely ill COVID-19 patients have even higher incidence of thromboembolism. On the other hand, incidence of arterial thromboembolism is much lower with incidence of 0.7%-3.7%. D-dimer is found to be an independent risk factor, and IMPROVE score, Caprini score, and Padua score have all been used as predictors. International guidelines suggest the use of low molecular weight heparin (LMWH) or fondaparinux for prophylaxis of VTE, and therapeutic dosage of weight adjusted LMWH for treatment if confirmed diagnosis. CONCLUSIONS: Contemporary rapidly evolving evidence shows that COVID-19 associated thrombosis was a novel clinical entity, especially in severely ill COVID-19 patients. There are multiple society-driven guidelines only, but without any level 1 evidence for management regimen. The ideal dose for prophylaxis is not established and may vary depending on balance of bleeding and thrombosis risk. The risk of bleeding may be increased in patients in intensive care unit.

Endovascular Thrombus Aspiration and Catheter-Directed Thrombolysis for Acute Thromboembolic Renal Artery Occlusion.

PURPOSE: We report a case of revascularization for an occluded renal artery using endovascular renal thrombus aspiration followed by catheter-directed thrombolysis. CASE REPORT: A 56-year-old man presented with sudden onset severe left-sided abdominal and loin pain for 6 hours. Urgent computed tomography (CT) angiogram showed occlusion of left renal artery. Emergency selective left renal angiogram and thrombus aspiration using a 5-French Cobra catheter was performed. Catheter-directed thrombolysis with urokinase was initiated after aspiration thrombectomy. Angiogram 24 hours after thrombolysis showed the left renal artery and its segmental branches were successfully revascularized. Patient was put on anticoagulation after operation and his renal function recovered well. CONCLUSION: Percutaneous aspiration thrombectomy with conventional catheters combined with intra-arterial local fibrinolysis could be used to salvage the renal function in case of complete renal artery thromboembolic occlusion.

Methods and Outcomes of Endovascular False Lumen Embolization for Thoracic Aortic Dissection.

BACKGROUND: To provide a contemporary review on endovascular false lumen (FL) embolization for thoracic aortic dissection (AD) and evaluate its early outcome. METHODS: A systematic literature review on FL embolization for thoracic AD from January 2003 to December 2020 was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Each article was analyzed using a standardized protocol including predefined demographic characteristics, perioperative mortality, and major complications. RESULTS: A total of 29 papers with 229 patients were included into the analysis. The methods of FL occlusion used were the candy-plug technique, the knickerbocker technique, the "cork in the bottleneck" technique, and direct FL embolization with a combination of stent-grafts, coils, onyx, plugs, and glue. FL embolization procedure was performed in 79 patients (34.5%) with type A AD and 150 (65.5%) with type B AD. FL direct embolization was the most frequently used technique and it was applied in 198 (86.5%) patients. Candy-plug, knickerbocker, and "cork in the bottleneck" techniques were used in 26 (11.4%), 3 (1.3%), and 2 (0.9%) patients, respectively. Technical success was achieved in all patients except one (228/229, 99.6%) in which implantation of a stent to celiac trunk was not possible. There were 4 hospital deaths (1.7%). Neurological complications occurred in 6 patients (2.6%), including 4 (1.7%) spinal cord ischemia and 2 (0.9%) ischemic stroke. There were 1 (0.4%) iatrogenic retrograde dissection and 2 (0.9%) renal failure reported. The mean duration of follow-up was 16.5 months. There were 21 deaths (9.3%) during follow-up and 8 (3.6%) were aorta-related. Thirty three (14.7%) secondary interventions were performed. Five patients (2.2%) required an open completion thoracoabdominal procedure incorporating the stent-graft into the repair. Complete FL thrombosis was observed in 181 (80.4%) patients, 34 (15.1%) had partial thrombosis, and 10 (4.4%) had FL progression. CONCLUSIONS: FL embolization of the distal thoracic aorta is a promising technique in a group of patients to promote FL thrombosis and aortic remodeling in thoracic aorta.

Modification of protocol with one extra drop of endovascular cyanoacrylate improved closure rates in incompetent great saphenous veins.

INTRODUCTION: Great saphenous vein diameter (GSV) of >8 mm was predictor of recanalization following Venaseal cyanoacrylate treatment. The aim of this study was to report our modified protocol with a single extra-drop for treatment for GSV>8 mm, and comparative duplex results in closure rates. METHODS: Patients in our single-centre registry treated with Venaseal were followed up by serial duplex examinations at week 1 and month(s)- 1, 6, 12, 18, 24, and then annually. The primary endpoint was successful obliteration of the GSV, secondary endpoints were closure distance from Saphenofemoral junction (SFJ), presence of endovenous glue-induced thrombosis (EGIT) or deep vein thrombosis. RESULTS: A total of 243 legs in 123 consecutive patients with duplex-proven SFJ/GSV incompetence were included in this study between September 2014 and October 2020. The median duplex follow-up period of this cohort of patients was 24 (range 0.2-58) months. Comparing closure rates in GSV diameter ≥8 mm treated with normal protocol, the 'extra-drop protocol' significantly improved closure rates (p = .034). However, the closure rates of ≥8 mm GSV treated with 'extra-drop protocol' was still not as good as GSV <8 mm (p < .001). There were no statistically significant differences in the stump distance between the three groups and no difference in the occurrence of EGIT. There were no deep vein thrombosis. CONCLUSION: Our experience showed that VenaSeal cyanoacrylate worked best in GSV<8 mm diameter. Even in GSV diameter of ≥8 mm which has a higher recanalization rate on follow-up duplex, our modified extra-drop protocol significantly improved the closure rates, and did not predispose to development of EGIT.

Efficacy and Safety of Intravascular Lithotripsy in Lower Extremity Peripheral Artery Disease: A Systematic Review and Meta-Analysis.

OBJECTIVE: Intravascular lithotripsy (IVL) is a novel technique for plaque modification during endovascular revascularisation for peripheral artery disease (PAD) with severe calcification. The aim of this paper was to perform a systematic review and meta-analysis of contemporary data to elucidate the efficacy and safety of IVL in lower extremity PAD. DATA SOURCES: A systematic literature search with pre-defined search terms was performed using PubMed, Web of Sciences, OvidSP, and EMBASE. REVIEW METHODS: A meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Patient characteristics, lesion calcification, pre-IVL and post-IVL diameter stenosis, complications, and stent rates were evaluated. RESULTS: Nine studies were included, encompassing a total of 681 patients (769 lesions) with IVL performed for PAD, of which 75.53% (95% confidence interval [CI] 66.08% - 83.03%) of the lesions were reported to have severe calcification. Comparison between pre-IVL and post-IVL diameter stenosis demonstrated a diameter stenosis reduction of 59.3% (95% CI 53.30% - 65.31%). Vascular complications were rare, with flow limiting or type D/E/F dissection occurring in only 1.25% (95% CI 0.60% - 2.61%) of cases. The overall pooled event rate for stent placement was 15.89% (95% CI 5.22% - 39.34%). CONCLUSION: This meta-analysis supports IVL as an effective and safe approach for calcified plaque modification in lower extremity PAD, achieving a diameter stenosis reduction of 59.3% (95% CI 53.30% - 65.31%) with minimal vascular complications. Routine use of this device is not recommended; further high quality evidence is required to elucidate the efficacy of IVL with respect to different clinical characteristics such as lesion location and length, and in comparison with other treatment modalities such as atherectomy.

Optical coherence tomography in peripheral arterial disease: A systematic review.

BACKGROUND: Optical coherence tomography (OCT) is a novel adjunct in the field of medicine. The objective of this systematic review was to evaluate the role of OCT in the field of contemporary endovascular surgery in terms of its utility in diagnostics and interventions in peripheral arterial disease (PAD). METHOD: A systematic search of literature published from 1st January 2009 to 1st August 2019 was identified from PubMed, Ovid and Cochrane library database with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The pre-defined selection inclusion criteria were clinical applications of OCT in vascular surgery in relation to diagnostics and interventions. Keywords used included OCT, PAD, endovascular procedures and atherectomy. RESULTS: From an initial search of 310 articles, 27 articles were included in this systematic review: 15 articles were related to diagnostics: peripheral arterial disease was the most studied condition (n = 8), other conditions included in-stent restenosis (n = 4), fibromuscular dysplasia (n = 2) and acute limb ischaemia (n = 1); 12 articles were related to intervention: an OCT-guided crossing catheter was the most used assisting device (n = 10), with an OCT-guided atherectomy device used in four of these studies. CONCLUSION: Although there is currently no level 1 evidence to suggest routine use of OCT in the diagnosis and treatment of PAD, current literature suggests that the use of OCT is safe and effective. The OCT real-time vessel wall structural images clearly distinguish normal anatomy from plaque pathology, and are of great advantage both in the accurate diagnosis and treatment of target lesion, especially in reducing the amount of radiation in the endovascular procedure.

Endovenous cyanoacrylate ablation for chronic venous insufficiency and varicose veins among Asians.

INTRODUCTION: Endovenous cyanoacrylate glue (CAG) ablation for the treatment of chronic venous insufficiency (CVI) and varicose veins has shown non-inferior outcomes with an excellent safety profile, high patient satisfaction rate, and excellent efficacy when compared to the gold standard of endothermal ablation. A review of the current literature for CAG use in CVI showed that most studies and longer-term data are from Caucasian-based populations, which are subject to different anatomical venous variations and socio-economical contexts. This review aimed to gather the current evidence for CAG use in Asian CVI patients. METHODS: Asian studies for the use of CAG in CVI were included in this review. Successful ablation rates, quality of life improvement and novel complications such as glue hypersensitivity reactions are described, along with anatomical descriptions of superficial venous anatomy in study patients. Use of CAG in Singapore and Asia was addressed. RESULTS: CAG has been gaining traction as an option for CVI treatment in Asians. In Singapore, it has been adopted with comparable low complication rates and significant improvement of quality of life after treatment. As we increase our understanding of the variations in venous anatomy in the Asian population, new techniques such as retrograde deployment of the device and use of CAG ablation for venous leg ulcers have been developed. CONCLUSION: Further robust evidence in terms of large randomised control trials along with cost effectiveness studies are needed to determine the true value of CAG ablation in the Asian setting.