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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).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.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).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.

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.

To provide a contemporary review on endovascular false lumen (FL) embolization for thoracic aortic dissection (AD) and evaluate its early outcome.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.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.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.

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.

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.

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.A systematic literature search with pre-defined search terms was performed using PubMed, Web of Sciences, OvidSP, and EMBASE.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.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%).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.

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.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.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%.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.

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 costeffectiveness studies are needed to determine the true value of CAG ablation in the Asian setting.

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.

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 Conclusion Our experience showed that VenaSeal cyanoacrylate worked best in GSV

Lumivascular optical coherence tomography (OCT) is a novel adjunct in the field of medicine. It offers clear real-time imaging of artery walls before and during endovascular intervention. This study reports our initial experience on the use of lumivascular OCT-guided atherectomy in the management of two patients with recurrent restenosis in their femoropopliteal arteries associated with in-stent restenosis. Endovascular procedures were successful with a Pantheris atherectomy device (Avinger, Redwood City, CA, USA) and drug-eluting balloons. The OCT images clearly distinguished normal anatomy from plaque pathology, were of great advantage in both the accurate diagnosis and treatment of target lesions, and may reduce radiation during the endovascular procedure. However, the price of the device and its need for contrast infusion limit its routine clinical use.

Background The aim of this study was to report midterm outcomes (up to 72 months) of patients who received femoropopliteal helical interwoven nitinol stents (Supera Peripheral Stent System, Abbott Laboratories, Inc, Webster, Tex). Methods Prospectively collected data on patients treated with femoropopliteal non-drug-eluting angioplasty and helical interwoven nitinol stents were retrospectively analyzed. Patients were followed up with 6, 12, 18, 24, 36, 48, 60, and 72 months clinical, duplex, and radiographic assessments. Restenosis is defined as 50% or greater restenosis of the target lesion on duplex ultrasound imaging. Results From October 2011 to September 2018, 315 patients (198 males) with 360 legs and a median age of 78 years (range, 46-100 years) were included. Symptoms of claudication, rest pain, and tissue loss were found in 212 (58.9%), 53 (14.7%), and 150 (41.7%) legs, respectively. In 176 (48.9%) legs, stents were placed in the popliteal segments. The mean stented lesion length was 119.0 mm (range, 40-450 mm). The overall primary patency rates at 6, 12, 24, 36, 48, 60, and 72 months were 90.6%, 80.5%, 73.8%, 68.9%, 65.3%, 63.1%, and 63.1%, respectively. The ankle-brachial pressure index increased from 0.58 ± 0.18 preoperatively to 0.87 ± 0.16 postoperatively. There were no stent fractures on follow-up. Patency rate was not statistically affected by indication of treatment, lesion calcification, or diabetes, but the length of stents and involvement of popliteal arteries were statistically significantly worse (log-rank test, P = .011 and P = .005). Stents with inner diameters of 4-mm had an initial lower patency compared with 5-mm stents, but the patency rates merged and crossed over at 46 months (log-rank test, P = .131). There was no procedural- or device-related morbidity or mortality, and there were nine major amputations after revascularization. Conclusions This study provides long-term clinical data demonstrating that Supera stents are effective and durable.

Background Carotid artery stenosis is a significant cause of ischemic stroke, and studies have shown that transfemoral carotid artery stenting is associated with a higher perioperative stroke risk than open endarterectomy. Transcarotid artery revascularization (TCAR) is a novel technique in carotid stenting via direct transcervical carotid access without the risk of arch manipulation, offers a smaller wound compared with endarterectomy, and employs flow reversal to decrease the risk of antegrade embolic stroke. Contemporary evidence on the safety and efficacy of TCAR is reviewed. Methods A systematic literature review on TCAR from January 2009 to August 2019 was performed in PubMed and EMBASE databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. Clinical studies on TCAR with flow reversal with clinical outcomes of stroke, myocardial infarction (MI), and death were included. Results Initial search of the literature yielded 161 articles, of which 8 studies were included comprising of 5 single-arm studies and 3 comparative studies. Studies demonstrated high technical success rates of TCAR from 90.6% to 100%, with low perioperative stroke, MI, and mortality rates of 0 to 4%, 0 to 0.7% and 0 to 2.7%, respectively. TCAR was significantly associated with a lower in-hospital stroke/transient ischemic attack rate when compared to transfemoral carotid stenting. There was no significant difference in perioperative stroke/MI/death when compared to endarterectomy although TCAR had a significantly lower risk of cranial nerve injury. Conclusions TCAR with flow reversal is a promising treatment option for carotid occlusive disease. Clinical trials are currently underway to provide a better report on outcomes of TCAR and for further comparison between TCAR and carotid endarterectomy.

Objective Despite endovascular advances in fenestrated and branched devices, thoracic endovascular aortic repair (TEVAR) for arch pathologies remains challenging. The aim of this study was to provide a contemporary review on the current evidence for in situ fenestration during TEVAR and to evaluate its short- and mid-term clinical outcome in the management of arch pathology. Methods A systematic literature review on in situ fenestration of thoracic aortic stent-graft from January 2003 to September 2018 was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement. Results Our initial search yielded 169 studies, of which 21 articles were relevant to the topic and were finally included. One hundred and forty-five in situ fenestration procedures in 99 patients were reviewed, involving 25 innominate arteries (17%), 33 left common carotid arteries (23%) and 87 left subclavian arteries (60%). Twelve patients (12/99, 12%) had two-vessel fenestration and three-vessel fenestration was performed in 17 patients (17/99, 17%). Technical success was achieved in 136 arteries (136/145, 93%). Talent/Valiant with monofilament twill woven polyester fabric was the most common (50/99, 51%) stent-graft used for fenestration. Three methods reported for in situ fenestration were needle, laser and radiofrequency. Needle was the most frequently used device for fenestration, which was performed in 60 patients (60/99, 61%). Three patients (3/99, 3%) died with 30 days, none were in situ fenestration TEVAR procedure-related. Perioperative complications including one (1%) retrograde type A aortic dissection, two (2%) type II endoleaks, and three (3%) strokes were reported. The pooled estimate for overall technical success, perioperative mortality and stroke was 88.3% (95% CI, 78.6%–93.9%), 5.9% (95% CI, 2.5%–13.4%) and 9.5% (95% CI, 4.1%–20.6%), respectively. Four patients (4/96, 4%) died during follow-up, none were aortic-related. All the fenestration bridging stents were reportedly patent, with only 1 (1/96, 1%) asymptomatic left subclavian stent stenosis. Two patients (2/96, 2%) with type II endoleak from left subclavian artery required secondary intervention. Conclusion In situ fenestration appeared to be a feasible and effective method to extend proximal landing zone during TEVAR. It had an acceptable short-term result with high technical success and low fenestration related morbidity. Long-term durability data were lacking, and there was no high level evidence to recommend the routine use of in situ fenestration TEVAR for the management of arch pathology.

Background Effectiveness and optimal timing of endovascular treatment for type B aortic dissection (AD) remain controversial. Method An extensive search of literature (January 1999-December 2017) was conducted using PubMed, Cochrane Library and Science-Direct databases for studies on endovascular repair for acute/chronic type B AD; ≥10 patients; not reviews; and reporting predefined baseline data and ≥50% of predefined study outcomes, which were extracted and analysed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses. Primary outcomes were in-hospital all-cause mortality and aorta-related mortality. Result Based on 92 publications (5956 patients), pooled estimate for overall in-hospital mortality was 7.0% [95% CI, 6.2%–7.8%]. Major perioperative complications included stroke (4.2% [3.6%–4.9%]), spinal cord ischemia (3.3% [2.8%–3.9%]), retrograde type A AD (3.2% [2.7%–3.9%]), type I endoleak (4.9% [3.8%–6.2%]), visceral ischemia (3.1% [2.5%–3.8%]) and acute renal failure requiring haemodialysis (5.1% [4.3%–5.9%]). Mid-term mortality incidence was 8.9% [7.2%–10.9%], and secondary intervention rate was 12.5% [10.5%–15.0%] with 6.1% [5.3%–7.2%] conversion to open surgery. Institutions with ≥40 endovascular treatment caseload had significantly lower rates of in-hospital and aorta-related mortality, stroke, type I endoleak, renal failure and retrograde type A AD. Patients treated in the acute phase had significantly higher incidence of in-hospital or aorta-related mortality and renal failure. Patients with chronic dissection required significantly more often secondary intervention during follow-up. Conclusion Endovascular stent-graft for type B AD therefore appeared feasible and safe with a low incidence of mortality and perioperative complications, particularly for delayed intervention and centres with ≥40 caseload. Standardized and long-term follow-up data are warranted.

Purpose: We report a case of revascularization for a totally occluded renal artery using endovascular renal thrombus aspiration followed by catheter-directed thrombolysis.Case Report: A 56 years old man presented with sudden onset of severe left-sided abdominal and loin pain for six hours. Urgent computed tomography angiogram showed total 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 on anticoagulation after operation and his renal function recovered well.Conclusion: Percutaneous aspiration thrombectomy combined with intra-arterial local fibrinolysis are effective in the salvage of renal function.

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.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.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.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.

Background: Intraluminal thrombosis in the aneurysm sac is commonly seen in abdominal aortic aneurysm (AAA). Complete acute thrombosis of an AAA is a rare and catastrophic event. Method: We report a patient with acute AAA thrombosis presenting as bilateral lower limbs critical ischemia. A79-year-old male with a past history of AAA presented with acute onset of bilateral leg pain, coolness, weakness and numbness. His lower extremity pulses including femorals were absent bilaterally on physical examination. Urgent computed tomography angiography showed an infrarenal AAA measuring 45 mm in diameter. The aneurysm sac and bilateral common iliac arteries were completely occluded. Emergency open repair of AAA and bilateral iliac thrombectomy were successfully performed under general anesthesia. Result: Bilateral femoral pulses were present and the neurological deficits were completely resolved after operation. Patient recovered well and was asymptomatic at 3-month follow-up. Conclusion: Acute thrombosis of aortic aneurysm could be an unusual cause of lower limb ischemia, prompt diagnosis followed by surgical revascularization is essential to avoid prolonged ischemia.

Background Embolic stroke is a formidable complication of transcatheter aortic valve implantation (TAVI) and thoracic endovascular aortic repair (TEVAR). Mechanical strategies to reduce the risk of ischemic embolic lesions include embolic protection devices (EPDs) and carbon dioxide flushing (CDF). This study aims to assess the efficacy for EPD and CDF uses in TAVI and TEVAR. Methods A literature review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analysis. All searches were performed via PubMed, OvidSP, MEDLINE, Web of Science Core Collection, and Cochrane Library. Conference abstracts and proceedings were included. Those that were out of scope of interest and review articles were excluded. Results Eighteen studies fulfilled the inclusion criteria of the 456 articles searched. Regarding EPD use in TAVI, systematic review comparing EPD with no-EPD showed smaller total volume of cerebral lesions and smaller volume per lesion in patients with EPD in all studies. They also performed better in postoperative neurocognitive assessments but could not demonstrate clinical prevention of embolic stroke in all studies. While for EPD use in TEVAR, capture of embolic debris and absence of early postoperative neurocognitive deficit were demonstrated in all cases of 2 prospective pilot studies. Concerning CDF in TEVAR, significant reduction in gaseous emboli released during stent-graft deployment was shown by 1 in vitro study. Successful CDF application in all patients, with only 1 case of postoperative nondisabling stroke, was also demonstrated by 1 cohort study. Conclusions This systematic review of medical literature has demonstrated the safety and feasibility of EPD use in TAVI. Although improvements in clinical outcomes have yet been demonstrated, there was level I evidence showing reduced embolic lesions in imaging. The use of EPD and CDF in TEVAR was suggested, but evidence remained inadequate to support routine clinical use.

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.

Aim We present the clinical outcomes of patients who underwent delayed (>30 days) open surgical repair after endovascular aortic aneurysm repair. Methods All patients receiving delayed open repair of infrarenal and juxtarenal aortic aneurysms after endovascular repair from July 2001 to December 2017 were retrospectively reviewed. Patients’ baseline characteristics, indications for delayed open conversion, and time between endovascular repair and open conversion are described. Early outcomes included operative approach, morbidity, and mortality. Midterm outcomes included survival. Results Twenty-two (3.3%) of 667 patients with prior infrarenal endovascular aortic aneurysm repair had delayed open conversion (20 elective and 2 emergency). The time from endovascular repair to open conversion was 60 ± 36 months. The indications were 6 (27%) type Ia endoleaks, 6 (27%) type II endoleaks with enlarging sac size, 2 (9%) endotensions, 7 (32%) unknown types of endoleak, and 1 (5%) graft infection. The 7 minutes unknown endoleaks were confirmed as lumbar leaks in 4 cases and fabric leaks in 3. Operative time was 222 ± 48 min with blood loss of 2211 ± 2057 mL. Hospital stay after conversion was 12 ± 8 days. There was no 30-day mortality. Estimated survival rates were 96%, 91%, 86%, 79% and 57% at 1, 2, 3, 4, and 5 years postoperatively. Conclusion Delayed conversion to open surgery after endovascular aortic aneurysm repair by endograft explantation appears to be safe with good short- and mid-term outcomes. With careful preoperative assessment, open conversion remained a realistic and viable option in patients with failed endovascular treatment.

Introduction We performed a single-center nonrandomized study on patients who underwent endovascular aneurysm repair using polymer-filled or other self-expanding endografts. Methods Consecutive patients with asymptomatic infrarenal abdominal aortic aneurysms who underwent endovascular repair were retrospectively reviewed. They were divided into a polymer-filled ( n = 20) or self-expanding group ( n = 42). Baseline characteristics, operative mortality and morbidity, and follow-up data were compared. Results Aneurysm diameter, neck and iliac morphologies did not differ between the two groups. Technical success was 100%. The 30-day mortality was 0% and 2.4% in the polymer-filled and self-expanding group, respectively. At a mean follow-up of 17 months, the changes in sac size were −2.1 mm and −5.1 mm ( p = 0.144) at one year, and −3.5 mm and −7.7 mm ( p = 0.287) at 2 years in the polymer-filled and self-expanding group, respectively. The polymer-filled group had 7 (35%) type II endoleaks, and the self-expanding group had 1 (2.4%) type Ia and 13 (31%) type II endoleaks. Neck diameter remained stable in the polymer-filled stent-grafts whereas there was progressive neck degeneration in the self-expanding group. The rates of reintervention and overall survival were similar in both groups. The presence of an endoleak was the only predictor of non-regression of the aneurysm (odds ratio = 17.00, 95% confidence interval: 4.46–64.88, p Conclusion Polymer-filled endografts had similar safety, effectiveness, and durability to other self-expanding endografts. The major advantage is the small iliofemoral access. They also have the potential long-term benefit of a more stable neck.

Background The aim of this pilot study was to evaluate the effectiveness and patients satisfaction of using telemedicine virtual communications to provide remote health care to vascular patients during the coronavirus disease 2019 (COVID-19) period in China. Methods Video calls using WeChat software (Tencent, Shenzhen, China) between patients and vascular surgeons were conducted in a period when there were restrictions and limitations for people’ travels in China. At the end of each video call, a short questionnaire was used to evaluate the patient satisfaction level. Results During the COVID-19 period from 19 February to March 16, 2020, a sample of 114 from 165 (69%) patients was reached after one phone call attempt. One hundred forty-two telemedicine remote communications were made between the two vascular surgeons and 114 patients. The mean age of this cohort of patients were 60 ± 15.2 (range 25 to 90) years old, and 74 (65%) were men. Twenty-five patients (22%) were outside of our province when they received the video call. The mean duration of the video call was 11.0 ± 8.9 minutes. All of the patients thought telemedicine was a good substitute for coming to hospital, and 95% (108/114) of them preferred to have remote telemedicine rather than postpone the appointment. All the patients agreed with the advantages of telemedicine including no infection risks, no need to travel, and no need to wait for long time. All the patients were “satisfied” or “highly satisfied” with the video call and they would like to use telemedicine for follow-up in the future. Conclusions Telemedicine virtual communications was effective to provide remote health care with a high patient satisfaction during the COVID-19 period. Telemedicine offers support to vulnerable vascular patients without the need for travel and face-to-face hospital consultation, and so avoided transmission and infection.

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.

Summary: Background: The study aims to report outcomes of open repair (OR) and endovascular aneurysm repair (EVAR) in octogenarians. Methods: Consecutive patients aged between 80 and 89 who underwent OR or EVAR were identified from a prospectively collected departmental database. Short-term outcomes included 30 days mortalities and perioperative complications; long-term outcomes included overall survival and re-intervention using the Kaplan–Meier method. Logistic regression was used to identify predictors for operative mortality and Cox regression analysis was used to identify predictors for long-term survival. Results: From January 1999 to December 2013, 53 underwent open repairs (23 emergency and 30 elective) and 115 underwent endovascular repairs (11 emergency and 104 elective). For elective procedures, 30 days operative mortalities were 6.7% and 0% in OR and EVAR respectively (Chi square test, p = 0.049). For emergency procedures, 30 days mortalities were 39.1% and 27.2% respectively (Chi square test, p = 0.705). Overall 5 years survival rates were 40.4% and 36.7% after OR and EVAR respectively. Rupture of aneurysm (Odd ratio 18.8, 95% CI 3.4–104.5, p = 0.001) was the only predictor for 30 days mortality. Rupture of aneurysm (Hazard ratio 2.0, 95% CI 1.3–3.3, p = 0.003), history of lung disease (Hazard ratio 1.7, 95% CI 1.0–2.9, p = 0.039) and history of renal disease (Hazard ratio 2.1, 95% CI 1.4–3.1, p

Background Aortic stent-graft infection (SGI) is rare but remains one of the most challenging and threatening complications. This systematic review aimed to identify the clinical features, treatment, and outcomes of endograft infection after abdominal endovascular aortic repair (EVAR) and thoracic endovascular aortic repair (TEVAR). Methods A systematic literature review of all published literature from January 1991 to September 2016 on SGI was performed under the instruction of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Aorta, aneurysm, endovascular, stent-graft, endograft and infection were the keywords used in our comprehensive search in PubMed and MEDLINE databases. Data analysis was performed using SPSS, V 22.0. Results A total of 185 potential relevant articles were identified, but only 11 studies with 402 patients met the inclusion criteria. Majority of the patients were male (308/402, 77%), with a mean age ranging from 65 to 73 years. Most of the endografts were implanted for EVAR (351/402, 87%), while the other 51 (13%) endografts were infected following TEVAR. Among the 402 patients, 39 (9.7%) patients presented with aortic rupture. Ninety-two of 380 (24.2%) patients with available data had aortoenteric fistula (AEF). Sixty-nine patients (17%) died in hospital or within 30 days after operation. One hundred fourteen patients (28%) died during follow-up. The most commonly used stent grafts were Zenith (Cook Inc, Bloomington, IN) (22%) and Excluder (W.L. Gore, Flagstaff, AZ) (20%). Of the 402 patients in this series, 108 patients (27%) had negative culture, and multiple microorganisms were identified in 103 patients (26%). The most frequently isolated microorganisms were Staphylcoccus species (30.1%), Streptococcus (14.8%), and fungus (9.2%). Forty-two patients (42/401, 10%) received conservative treatment, whereas 359 (90%) patients underwent surgical treatment, including stent graft removal with in situ reconstruction or extra-anatomical bypass, and secondary endovascular procedure. Patients in the surgical group had a higher survival rate compared with conservative group (58% vs. 33%, P = 0.002). The survival rate was higher in the patients with infected EVAR than TEVAR (58% vs. 27%, P = 0.000). Patient with AEF had a worse prognosis (survival rate 72% vs. 33%, P = 0.002). Conclusions Current evidence suggests that surgical treatment is a better option compared with conservative management in selected patients with aortic endograft infection. The outcome was worse in patients with infected TEVAR and AEF.

Summary Background/Objective Deep vein thrombosis (DVT) was thought to be uncommon in Asians and routine thromboprophylaxis in the form of anticoagulation for surgical patients was considered to be unnecessary. The current study aims to provide a contemporary epidemiology of venous thromboembolism in a population-based scale. Methods Information from January 1, 2010 to December 31, 2011 was retrieved from a centralized computer public healthcare database serving mainly an ethnic Han Chinese population of 7.1 million. The incidence, demographics, and hospital mortality rates of DVT and pulmonary embolism (PE) were obtained, and analyzed for different surgical categories. Results The overall annual incidences of DVT, PE alone, and PE with DVT were 30.0 per 100,000 population, 8.7 per 100,000 population, and 3.0 per 100,000 population, respectively. Overall male to female ratio was 1:1.24. Venous thromboembolic disease was more common with increasing age in both sexes. Thirty days' mortality rates associated with DVT, PE alone, and PE with DVT were 9.0%, 17.4%, and 13.3% respectively. Among the patients who received 103,023 major and intermediate surgical procedures in the study period, the mean incidence of postoperative DVT, PE alone, and PE with DVT were only 0.20% (203.5 patients), 0.08% (85.5 patients), and 0.04% (40.5 patients) respectively. Conclusion Compared with a similar study 10 years ago, there seemed to be a general increase in incidence of DVT and PE. This study showed that postoperative thromboembolic events were not uncommon, with DVT occurring in up to 0.2% of patients and PE in 0.12% of patients in this longitudinal survey.

Summary Background/Objective This study aims to examine the relationship between weather changes and acute aortic events in a subtropical territory. Methods A linear regression analysis was performed in a pan-territory epidemiological survey for a period of 10 years on the impacts of meteorological factors (ambient temperature, atmospheric pressure, relative humidity, amount of cloud, rainfall, number of lightning strikes, presence of typhoon, and thunderstorm warning) on the daily incidences of acute aortic dissections and ruptured aortic aneurysms. Meteorological variables were retrieved on a daily basis from a well-established observatory, and the daily incidences of aortic dissections and rupture of aortic aneurysms were retrieved from the Clinical Data Analysis and Reporting System. Results During the study period (January 2005 to December 2014), 3878 patients were identified as having acute aortic dissections, and 1174 patients had ruptured aortic aneurysms. Corresponding averaged daily incidences were 1.06 and 0.32, respectively. The incidences of aortic dissection and ruptured aortic aneurysm in a day could be predicted by ambient temperature in degrees Celsius using the following linear regression models: (1) incidence of aortic dissection = 1.548 − 0.021 × temperature; (2) incidence of ruptured aortic aneurysm = 0.564 − 0.010 × temperature. In addition, both high atmospheric pressure and absence of thunderstorm warning are positively associated with more aortic dissections. For rupture of aortic aneurysms, high atmospheric pressure and low relative humidity were positive predictors. In multiple regression analysis, however, ambient temperature was the only significant predictor for both acute aortic dissections and ruptured aortic aneurysms. Conclusion This is the first pan-territory study to show an attributable effect of ambient temperature on acute aortic events. This paper confirms that even in a subtropical country, meteorological variables were important factors influencing acute aortic events.

The aim of this study is to investigate the incidence of pulmonary embolism (PE) in a cohort of Chinese patients with acute (14 days) proximal (above-knee) deep vein thrombosis (DVT) in the lower limbs, and to evaluate whether the location of thrombosis is associated with the existence of PE.A retrospective review of patients diagnosed with acute proximal DVT from January 2014 to June 2018 at a single center was performed. Helical computed tomography angiography was performed to screen PE within 48 hr after admission. Multiple factors associated with PE were compared between the PE group and the non-PE group.A total of 100 patients with acute proximal DVT were screened for PE. The mean age was 56.9 ± 18.1 (range 21-88) years, and 55% were male. The most common risk factors of DVT were immobilization (38%), malignancy (27%), and trauma or surgery (21%). Majority of the patients' thrombosis was located at the left leg (66%) and 8 patients had bilateral lower limb DVT. Femoral vein was involved in 52 patients (52%), while iliofemoral thrombosis was identified in 48 patients (48%). PE was identified in 58 patients (58%), including 3 massive and 55 nonmassive PE. There was no statistical difference between the PE group and the non-PE group in terms of age, sex, and risk factors. The D-dimer level was associated with the existence of PE (P = 0.038). Patients with iliofemoral thrombosis had a similar incidence of PE compared with those with femoral thrombosis alone (P = 1.000).PE occurred in more than half of patients with acute proximal DVT, despite the fact that most of them were asymptomatic. In this study, existence of PE did not correlate with pelvic thrombosis. Increasing D-dimer level was statistically associated with the presence of PE.

Objective Endovascular stent-grafts have been used in China to treat type B aortic dissection since 1999, and there is a plethora of cohort studies in the contemporary literature. The aim of this review was to analyse the published results of endovascular treatment for type B aortic dissection in China. Method A systematic literature review of all published literature from January 1999 to October 2014 on endovascular treatment of type B aortic dissection in China was undertaken using PubMed, Medline, and the Chinese National Knowledge Infrastructure databases. Results Seventy papers were retrieved (4 English, 66 Chinese) with a total of 4208 patients; 3396 (80.7%) were male, and the mean age ranged from 43 to 65 years. Procedural success was reported in 99.4% ± 1.7%. Complications were reported in 14.6% ± 11.1%, with major complications in 1.7% ± 2.9%, and the most devastating neurologic complications in 1.1% ± 2.2% (stroke 0.9% ± 2.4%, paraplegia 1.5% ± 0.7%). Postoperative endoleak occurred in 8.1% ± 7.6%. The 30-day postoperative mortality was 2.4% ± 3.3%. During follow-up, false-lumen thrombosis occurred in 92.1% ± 11.7%. Reintervention was performed in 1.3% ± 3.3%. The incidence of proximal and distal stent-graft-induced new entry was 0.5% ± 1.3% and 0.9% ± 2.7%, respectively, with endoleak in 2.7% ± 4.4% and mortality of 2.2% ± 3.2%. Conclusions Current evidence suggests that use of endovascular stent-grafts for type B aortic dissection in China is feasible and safe with low rates of perioperative complications and short-term mortality. However, a standardised reporting system and long-term follow-up data are lacking.

ntroduction This is a single-center clinical study for the evaluation of safety, efficacy, and performance of endovenous cyanoacrylate (Sapheon Venaseal Closure System, now Medtronic Medical) for the treatment of great saphenous vein (GSV) reflux. ethods Primary outcome measures included the GSV obliteration, with clinical recurrence on follow up as detected by serial clinical and duplex examinations of patients at 1 week, 1 month, 6 months, and 1 year. Venous clinical severity score (VCSS), Aberdeen varicose vein questionnaire (AVVQ), Short Form Health Survey 36 Item (SF-36) questionnaires were used at clinical follow up. Diameter of the GSV, treatment length of the GSV, and pretreatment clinical severity of the varicose vein were analyzed to predict recanalization using Cox regression analysis. esults Fifty-seven legs in 29 patients with primary varicose veins were included. One week follow-up duplex showed successful obliteration of the GSV in all except one of the legs. Two legs had minimal extension of thrombus to deep vein. None of the patients had deep venous thrombosis. All the patients were discharged the same day of operation. Median time to return to work was 1 day (range 1–16 days). Our VCSS, AVVQ, and the SF-36 physical and mental scores changed from a mean of 6.91, 23.66, 44.24, 54.26 at baseline to 2.43, 6.10, 43.85, 52.50 at 1 month post operation, respectively. Kaplan–Meier analysis showed that the GSV closure rates were 98.2%, 94.3%, 89.7%, and 78.5% at post-op 1 week, 1 month, 6 months, and 1 year, respectively. With median follow-up period of 9 months (range 1–13 months), no clinical recurrence of varicosity was observed. Mean GSV diameter ≥8 mm was a significant predictor for recanalization (hazard ratio 6.92, 95%CI 1.34–35.67, p = 0.021). onclusion This study showed that the use of endovenous cyanoacrylate in the treatment of the GSV reflux was safe. All patients had symptomatic improvement as shown by the VCSS and AVVQ.

An aortic aneurysm infected by Brucella is rarely seen. In this case report, we describe a Brucella mycotic abdominal aortic aneurysm acquired from ingestion of sheep placenta. Clinical symptoms included fever, fatigue, and abdominal pain. Diagnosis was confirmed by blood culture and computed tomography (CT) angiography. The patient had increased abdominal pain during hospitalization, and repeated CT showed a rapidly enlarging mycotic aneurysm. Emergent endovascular repair was successfully performed using a bifurcated stent graft, and combined intravenous and oral antibiotics were administrated. The patient was asymptomatic after operation, and follow-up CT showed thrombosis in the aneurysmal sac and significant decrease of aneurysmal size.

Bovine aortic arch is known to be associated with an increased rate of aortic arch expansion. The most frequently observed human variant of bovine aortic arch is a common origin of the innominate trunk and left common carotid artery. This is a report of two patients who had successful custom-made arch branch endograft treatment for an arch aneurysm associated with bovine arch anomaly. Modular endovascular repair of aortic arch aneurysms using an inner-branched device adds to the armamentarium of treatment options, and is a minimally invasive management modality without the need for sternotomy or intraoperative extracorporeal bypass.

Background Fluorine-18-fluorodeoxyglucose positron-emission tomography with computed tomography has revolutionized medical diagnosis by adding functional activity to anatomic imaging. We report our experience with this technique in patients with mycotic aortic pathology and aortic vascular graft infection. Methods We conducted a retrospective review of a prospective database of patients who underwent 18F-fluorodeoxyglucose positron-emission tomography with computed tomography for suspected infective aortic disease. From 2012 to 2016, 13 patients underwent 18F-fluorodeoxyglucose positron-emission tomography. Of these, 9 (69%) had a vascular graft infection (5 infrarenal aorta, 1 para-visceral, 2 descending, and 1 arch; 2 had previous open surgery and 7 had endovascular interventions) and 4 (31%) had a mycotic aneurysm (2 aortic arch, 1 infrarenal aorta, and 1 distal aorta and common iliac; 3 had endografts). The indications for imaging, location of pathology, 18F uptake, and clinical outcomes were analyzed. Results Eight (62%) patients had a single scan and 5 (38%) had serial scans performed. Among the 5 patients who had serial imaging, 3 showed decreased 18F uptake and 2 had increased uptake. Only one patient underwent subsequent endograft removal; the others were treated with lifelong antibiotics. There were 5 (38%) deaths on follow-up. Conclusion 18F-fluorodeoxyglucose positron-emission tomography with computed tomography could be a valuable adjunct in the diagnosis and surveillance of patients with aortic infection. Serial scans may be useful for monitoring disease activity and response to antibiotic therapy.

Background Three-dimensional (3D) printing, also known as rapid prototyping or additive manufacturing, is a novel adjunct in the medical field. The aim of this systematic review is to evaluate the role of 3D printing technology in the field of contemporary vascular surgery in terms of its technical aspect, practicability, and clinical outcome. Methods A systematic search of literatures published from January 1, 1980 to July 15, 2017 was identified from the EMBASE, MEDLINE, and Cochrane library database with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The predefined selection inclusion criterion was clinical application of 3D printing technology in vascular surgery of large and small vessel pathology. Results Forty-two articles were included in this systematic review, including 2 retrospective cohorts and 1 prospective case control study. 3D printing was mostly applied to abdominal aortic aneurysm (n = 20) and thoracic aorta pathology (n = 8), other vessels included celiac, splenic, carotid, subclavian, femoral artery, and portal vein (n = 10). The most commonly quoted materials were acrylonitrile-butadiene-styrene (n = 2), polylactic acid (n = 4), polyurethane resin (n = 3) and nylon (n = 3). The cost per replica ranged from USD $4–2,360. Cost for a commercial printer was around USD $2,210–50,000. Conclusion 3D printing was recognized and gradually incorporated as a useful adjunct in the field of vascular and endovascular surgery. The production of an accurate anatomic patient-specific replica was shown to bring significant impact in patient management in terms of anatomic understanding, procedural planning, and intraoperative navigation, education, and academic research as well as patient communication. Further analysis on cost-effectiveness was indicated to guide decisions on applicability of such promising technology on a routine basis.