Vascular

To date, the ultimate decision to treat iliac artery stenoses in patients suffering from symptomatic peripheral arterial disease is based on the patient’s symptoms and on visual inspection of angiographical images. The primary aim of this study was to investigate the accuracy of geometry-based methods (i.e. visual inspection and quantitative vascular analysis (Viewforum version R7.2v1 Advanced vessel analysis, Philips Healthcare, Best, The Netherlands) of 3D rotational angiography) to identify the severity of equivocal iliac artery stenosis in peripheral arterial disease patients with intra-arterial hyperemic pressure measurements (gold standard) as a reference.

Twenty patients with symptomatic iliac artery stenoses were subjected to 3D rotational angiography. Intra-arterial pressure measurements under hyperemic conditions were performed across 24 visually identified iliac artery stenoses. Three experienced interventional-radiologists retrospectively estimated the lumen diameter reduction by visual inspection. Furthermore, quantitative vascular analysis was performed on the 3D rotational angiography data. Geometry-based estimates were classified into two groups: lumen diameter reduction of <50% (non-significant) and diameter reduction ≥ 50% (significant), and compared to the intra-arterial hyperemic pressure gradients. A stenosis causing a pressure gradient (Δp) ≥10 mmHg was considered hemodynamically significant.

Visual inspection and quantitative vascular analysis correctly identified hemodynamically significant stenoses in, respectively, 83% and 67% of the 24 iliac artery stenoses. Quantitative vascular analysis-based identification of hemodynamic significant stenoses (Δp ≥ 10 mmHg) could be optimized by lowering the threshold to a 42% lumen diameter reduction which improved the accuracy from 67% to 83%.

Visual inspection of 3D rotational angiography by experienced interventional-radiologists has an 83% accuracy to identify hemodynamic significant iliac artery stenoses (Δp ≥10 mmHg). The use of quantitative vascular analysis software did not improve accuracy.

Arteriovenous graft for hemodialysis shows poorer outcomes than arteriovenous fistula, due to frequent stenosis and thrombosis. We investigated arteriovenous graft patency outcomes and prognostic factors for these outcomes.

We included a single-center cohort of patients receiving arteriovenous graft for hemodialysis access from 2010 to 2014. Demographics, laboratory data, comorbidities, and medications were collected from medical records. Surgical factors related to graft operation including the type and diameter of connected vessels, graft location, and type of operation (elective or emergency) were also recorded. Outcomes included primary and secondary patency. Survival analysis was conducted using the Kaplan-Meier method; univariate and multivariate analyses were used to evaluate the prognostic factors.

Data from 225 grafts were analyzed. During the follow-up period (mean: 583 days, range: 1–1717 days), 138 (61%) grafts required intervention and 46 (20%) permanently failed. Primary patency at one, two, and three years was 42%, 20%, and 16%, respectively. Secondary patency at one, two, and three years was 85%, 72%, and 64%, respectively. Multivariate analysis showed that primary patency was negatively associated with increasing age and location of vessel anastomosis (reference-brachiobrachial anastomosis; brachiobasilic – HR, 0.569; 95% CI, 0.376–0.860; p = 0.007; brachioaxillary anastomosis – HR 0.407; 95% CI, 0.263–0.631; p < 0.0001); secondary patency was positively associated with diastolic blood pressure, serum albumin level, and hemoglobin over 10 g/dL. Adverse events other than stenosis or thrombosis, such as infection/inflammation or pseudoaneurysm were observed in approximately 20% of grafts.

Factors associated with diminished primary arteriovenous graft patency included increased patient age and location of vessel anastomosis (brachiobrachial type compared to brachiobasilic or brachioaxillary type); diminished secondary patency was associated with low diastolic blood pressure, low serum albumin, and hemoglobin level under 10 g/dL. Among these factors, diastolic blood pressure, serum albumin, and hemoglobin level may be modifiable and could improve arteriovenous graft patency outcomes.

To evaluate access success according to plaque cap morphology in subjects with lower limb chronic total occlusion.

A retrospective study was performed for a three-year period. Subjects with lower extremity chronic total occlusion (Rutherford category 3–6, ischaemia) were included in the study. Cap morphology was classified according to The chronic total occlusion crossing approach based on plaque cap morphology (CTOP) classification system. When describing the classification by a traditional antegrade approach, Types I, II, III and IV were defined as follows: Type I: concave proximal and distal caps; Type II: concave proximal and convex distal caps; Type III: convex proximal and concave distal caps; Type IV: convex proximal and distal caps. For the study, the data on demographics, access type, and direction crossed, access conversion, crossing success, crossing location, extravascular ultrasound guidance, catheter used, subjects, and localization of were recorded. The effect of cap morphology on crossing strategy and success was evaluated.

A total of 110 subjects were enrolled in this study. The type of chronic total occlusion was determined by angiography in 100% of the subjects. The number of the subjects according to CTOP morphology for Types I, II, III and IV were 22 (20%), 39 (35.5%), 23 (20.9%) and 26 (23.6%), respectively. Superficial femoral artery, popliteal, anterior tibial, posterior tibial localizations did not differ among the CTOP types (p = 0.649, p = 0.831, p = 0.923 and p = 0.903, respectively). Among the pre-operation parameters, lesion length was the only one that is significantly shorter in Type I (14.23 ± 1.93 cm) subjects when compared with Types II (21.77 ± 3.78 cm), III (21.17 ± 2.31 cm) and IV (19.85 ± 3.29 cm) subjects (p < 0.001, for all comparisons). Antegrade access was significantly higher in group I than in group III. Planned dual access was also significantly lower in CTOP Type I than in CTOP Types II, III and IV. Antegrade crossed direction was significantly higher in CTOP Type I than in CTOP Types II, III and IV (p = 0.001, for all comparisons). True lumen crossing was significantly higher in CTOP Type I than in CTOP Type II (p = 0.002). In univariate analysis, chronic total occlusion Type IV was the only significant factor for antegrade crossing (p = 0.001). Multivariate analysis demonstrated that chronic total occlusion Type IV (OR = 0.09, p = 0.001) was an independent risk factor for antegrade crossing. The odds of antegrade crossing for chronic total occlusion Type IV was 0.190 times that of chronic total occlusion Types I–II–III combined (OR (95% CI): 0.190 (0.070, 0.519), p = 0.001).

CTOP Type I accesses with an antegrade access, and Type IV accesses with a retrograde strategy. Type II and Type III CTOP will need planned dual access in order to prevent device bending and subintimal access.

There is paucity in the literature reporting radiation usage analysis in vascular surgery. In the era of endovascular surgeries, analyzing the surgeons’ use of radiation in vascular procedures can help establish quality improvement initiatives.

A retrospective review was undertaken of intraoperative fluoroscopic-guided vascular surgery procedures at a single institution from 2010 to 2017. Mobile C-arms were utilized to gather the six radiation usage metrics and cases were categorized into 6 anatomic surgical fields and 10 surgical procedure types.

Three hundred and eighteen vascular surgery cases were analyzed and notable trends in all radiation usage metrics were identified both across the surgical field location and type of surgical procedure. The highest cumulative dose was identified in embolization cases with a mean of 932.5 mGy. The highest fluoroscopic time was seen in atherectomies with a mean of 2629.6 s. In terms of surgical field, the highest cumulative does and fluoroscopic time was identified in abdomen/pelvis procedures with a mean of 352.1 mGy and 1186.8 s, respectively. Analysis of dose reduction techniques also demonstrated notable trends.

There were notable trends in the analyzed radiation usage variables both across the surgical field location and type of surgical procedure. Specifically, cases that involve the abdomen/pelvis, embolization and atherectomy have the highest radiation use. These types of cases can be targeted for future improved dose reduction techniques or staged procedures. This data can serve as baseline information for future quality improvement initiatives for patient and personnel radiation exposure safety.

Endovascular intervention involving the aortic arch, particularly in thoracic aortic dissection, remains challenging and controversial at current time when there is no commercially suitable grafts on most of the international markets. This study compared two endovascular treatments that maintain left subclavian artery perfusion using two modified techniques for type-B aortic dissection patients.

Consecutive cases utilizing chimney or in situ fenestration techniques to preserve left subclavian artery in type B AD from 2006 to 2015 in our single institution were retrospectively reviewed. Statistical analyses were performed with Student t-test, Wilcoxon rank sum, and Fisher exact tests when appropriate. Significant statistical differences were determined with p < 0.05.

A total of 85 cases, including 67 (79.8%) with chimney and 18 (21.2%) with in situ fenestration techniques were identified in this retrospective study. In chimney group, there were 18 (26.9%) acute, 29 (43.3%) sub-acute, and 20 (29.9%) chronic aortic dissections. We implanted 24 Zenith and 43 Talent aortic endografts along with 55 balloon-expandable bare stents and 12 self-expanding covered stents in chimney group. Whereas in in situ fenestration group, there were four (22.2%) acute, six (33.3%) subacute, and eight (44.5%) chronic aortic dissections, all of which received Zenith endografts with 11 balloon-expandable covered and seven self-expanding covered stents, respectively. Demographic variables were similarly distributed with 100% intraoperative technical overall success in both groups. Comparing to in situ fenestration group, chimney group has shorter procedural and fluoroscopy time, less blood loss, and contrast volume used. All patients were followed-up to 52 months (median 38, range 24–52). Overall group mortality is 3.6% (3/84). All deaths were from chimney group. There was no procedure-related stroke observed within the study series. Primary patency was maintained while aortic remodeling with complete false lumen was achieved in all patients except that there were three (4.55%) Type-I endoleak cases in early post-operative period and one (1.5%) stent compression at 3-months follow-up in chimney group. There were no stent-related complications observed in in situ fenestration group.

Although there were previous studies describing the similar techniques, this study appears to be the first study to compare in situ fenestration and chimney techniques for aortic dissection involving the left subclavian artery according to the MEDLINE search. Although we are unable to establish the superiority between two approaches due to small sample size and relative short period of follow-up, in situ fenestration may represent a more favorable option, especially among aortic dissections with short proximal landing zones in the study.

The current advancement and increasing use of diagnostic imaging has led to increased detection of abdominal aortic aneurysms (AAA). Many of these patients are unfit for elective AAA surgery.

To investigate the outcome of conservative management of unfit patients with large AAA (>5.5 cm) who are turned down for elective surgical intervention.

Between January 2006 and April 2017, 457 patients presented with AAA >5.5 cm. Seventy-six patients (M: F 54:22) were deemed unfit for elective repair. Mean age was 79.8 years (range 64–96). Mean AAA size was 60.22 mm (55–83).

Forty-nine of the 76 patients (64%) had died by April 2017. Fifteen (19.7%) patients died directly because of their aneurysm rupture. A further 34 (44.7%) patients died from non-aneurysm-related causes.

Patients with large AAA deemed unfit for elective surgery have an overall poor prognosis and die mainly from other causes than AAA. Surgical intervention when rupture occurs results in poor survival.

Proximal type 1A endoleaks on completion intra-operative angiography are not infrequently seen following endovascular abdominal aneurysm repair (EVAR). The natural course of these leaks is not well established. We sought to determine the rate of spontaneous resolution and a conservative treatment approach to these endoleaks.

All cases involving endovascular repairs of infra-renal abdominal aortic aneurysms resulting in proximal type 1A endoleak on final intra-operative completion angiography were retrospectively reviewed from 1 April 2010 and 30 March 2015. Demographic, pre and post-procedural imaging, and clinical outcomes were reviewed. Summarizing descriptive statistics are reported.

Of the 337 patients who underwent an EVAR, 24 patients (7.1%) had a proximal type 1A endoleak on final intra-operative angiography. Twenty-two of 24 patients (92%) with proximal type 1A endoleaks had spontaneous resolution on follow-up imaging without any intervention, while two (8%) patients had a persistent endoleak. One of these patients required intervention. The median follow-up for patients with resolved endoleaks was 2.5 years vs. 4 and 6 years, respectively, for patients that did not resolve spontaneously.

A conservative approach may be used in the management of patients with proximal type 1A endoleaks on completion angiography once maximum proximal seal was achieved intra-operatively as the vast majority of these leaks spontaneously seal.

Chimney endovascular aortic aneurysm repair is gaining ever greater acceptance. However, persistent gutters leading to type IA endoleaks represent an unsolved issue. The aim of the current study was to analyze the impact of abdominal endograft oversizing to the occurrence of this phenomenon.

The PERformance of the snorkel/chImney endovascular teChnique in the treatment of compLex aortic PathologiesES registry includes the largest experience with chimney endovascular aortic aneurysm repair from 13 vascular centers in Europe and the U.S. Prospectively collected data from centers with standard use of the Endurant stent-graft and balloon-expandable covered stents as chimney grafts only were included in the present analysis. The parameter which varied was the degree of oversizing of the aortic stent-graft classifying the cohort in two groups, group A (20% and less oversizing) and group B (>20% of oversizing). The primary endpoint was the incidence of persistent type IA endoleak needed reintervention. Secondary endpoints were all-cause mortality and freedom from reintervention.

Group A included 21 patients while group B 144. The mean preoperative pathology’s neck length and diameter was 5.8 mm (±4.4) versus 4.9 mm (±3.8) and 27.6 mm (±4.7) versus 24.9 mm (±3.7) for group A and group B, respectively. The mean length of the new sealing zone after chimney graft placement was similar for both groups (group A versus group B; 17.9 mm versus 18.3 mm, respectively, P = .21). The percentage of oversizing of the aortic stent-graft ranged between 13.8 and 20% versus 22.2 and 30%, for group A and group B, respectively. Patients of group A had more type 1A endoleaks, (14.3%) versus patients of group B (2.1%) based on the first follow-up imaging, P = .02. The incidence of persistent type IA endoleaks needing a reintervention was 14.3 and 1.4% for the group A and group B, respectively, P = .01. The mean volume of contrast medium used was greater in group A versus group B with 239 ml versus150 ml, P = .05. Additionally, 14.3% of patients of group A experienced acute renal failure compared to those in group B which was 1.0%, P = .01.

Oversizing of ideally 30% of the Endurant stent-graft is associated with significant lower incidence of type IA endoleaks requiring reintervention for patients treated by chimney endovascular aortic aneurysm repair.

Thoracic endovascular aortic repair has become a preferred treatment strategy for thoracic aortic aneurysms and dissections. Yet, it is not well understood if the performance of endografts is affected by physiologic strain due to cyclic aortic motion during cardiac pulsation and respiration. We aim to quantify cardiac- and respiratory-induced changes of the postthoracic endovascular aortic repair thoracic aorta and endograft geometries.

Fifteen thoracic endovascular aortic repair patients (66 ± 10 years) underwent cardiac-resolved computed tomography angiographies during inspiratory/expiratory breath holds. The computed tomography angiography images were utilized to build models of the aorta, and lumen centerlines and cross-sections were extracted. Arclength and curvature were computed from the lumen centerline. Effective diameter was computed from cross-sections of the thoracic aorta. Deformation was computed from the mid-diastole to end-systole (cardiac deformation) and expiration to inspiration (respiratory deformation).

Cardiac pulsation induced significant changes in arclength, mean curvature, maximum curvature change, and effective diameter of the ascending aorta, as well as effective diameter of the stented aortic segment. Respiration, however, induced significant change in mean curvature and effective diameter of the ascending aorta only. Cardiac-induced arclength change of the ascending aorta was significantly greater than respiratory-induced arclength change.

Deformations are present across the thoracic aorta due to cardiopulmonary influences after thoracic endovascular aortic repair. The geometric deformations are greatest in the ascending aorta and decline at the stented thoracic aorta. Additional investigation is warranted to correlate aortic deformation to endograft performance.

Data about renal artery stenosis association with left ventricular remodeling in patients coexisting with coronary artery disease are scanty.

Patients with suspected both coronary artery disease and renal artery stenosis undergoing coronary and renal arteriography between October 2013 and December 2015 were prospectively enrolled. Left ventricular remodeling patterns were compared among different severity of renal artery stenosis group. Logistic regression was done to investigate the determinants of the left ventricular morphology.

The overall prevalence of left ventricular hypertrophy was 40.5%, the highest in bilateral renal artery stenosis group compared to unilateral or normal ones (65.4% versus 41.8% versus 34.8%, p = 0.012). Significantly lower estimated glomerular filtration rate and higher cystatin C level were found in bilateral renal artery stenosis group than that in other two groups. Multivariate regression analysis showed that bilateral renal artery stenosis was associated with increased left ventricular hypertrophy and concentric hypertrophy with statistical significance (adjusted odds ratio = 2.909 (95%CI: 1.063–7.961), and 3.021 (95%CI: 1.136–8.033)). In addition, estimated glomerular filtration rate level was also related to left ventricular hypertrophy, while there was no significant interaction between renal artery stenosis and coronary artery disease on left ventricular hypertrophy/concentric hypertrophy occurrence.

Bilateral renal artery stenosis is significantly associated with increased left ventricular hypertrophy/concentric hypertrophy in patients with suspected concomitant coronary and renal artery disease, while no synergic effect could be found in coronary artery disease.

The aim of this retrospective single-center study was to analyze the immediate results, failures and complications of percutaneous mechanical thrombectomy using the Rotarex catheter in the treatment of peripheral artery occlusion.

In this study, we identified a total of 42 patients who underwent mechanical thrombectomy using Rotarex catheter at our institution. Procedural outcomes and complications were evaluated.

The cohort consisted of 42 patients (31 men and 11 women), aged 32–93 years (median 68 years). The number of external iliac artery occlusion was 5, with common femoral artery 5, superficial femoral artery 28, femoral profound artery 2, popliteal artery 12, and brachial artery 2. The causes of occlusion were thrombosis (29 cases, 69%), embolism (6 cases, 14%), and reocclusion after percutaneous intervention (7 cases, 17%). We achieved primary success in 100% of the patients with mechanical thrombectomy, associated with balloon angioplasty (40/42, 95.2%) and stent deployment (16/42, 38.1%). The median time of the interventional procedure was 145 min. We encountered lower percentage of distal embolization (2.4%) and artery dissection (2.4%) during usage of Rotarex catheter in our cohort.

Rotarex thrombectomy was a useful tool to recanalize occluded vessels with additional treatment such as balloon angioplasty or stent deployment, with a low rate of failures and complications. And prospective studies in this issue are recommended.

Whilst the management of blunt traumatic thoracic aortic injury has seen a paradigm shift to an ‘endovascular first’ approach, the limitations of thoracic endovascular aortic repair remain. An inadequate proximal landing zone limits the use of thoracic aortic stent grafts and in an emergent polytrauma setting, aortic arch debranching via open surgery may not be practical or feasible. A wholly endovascular approach to debranching utilising ‘off-the-shelf’ stents and parallel graft techniques may represent a possible solution. Hence, we sought to perform a systematic review investigating the use of chimney graft techniques alongside thoracic aortic stenting in blunt traumatic thoracic aortic injury.

We performed the systematic review in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Searches were performed on Medline (PubMed), Web of Science and Scopus to identify articles describing the use of chimney grafts in traumatic aortic transection (PROSPERO: CRD42017082549).

The systematic search revealed 172 papers, of which 88 duplicates were removed resulting in 84 papers to screen. Based on title, abstract and full text review, six articles were included for final analysis. There were nine patients in total with an average age of 41 (three females, five males, one unspecified), all with significant polytrauma, secondary to the mechanism of injury. A variety of stents were used between centres, with techniques showing a predominance to stenting of the left subclavian artery (77%, n = 7). The technical success rate was 82%, with two (18%) cases of type 1 endoleaks, of which one resolved spontaneously.

Despite the encouraging results, this by no means provides for a firm conclusion given the small sample size. Patients should still be judiciously selected on a case-by-case basis when employing the chimney graft technique. Larger cohort studies are needed to establish these findings.

Blunt traumatic thoracic aortic injury, the second leading cause of death from trauma, poses unique challenges in its management. However, there has not yet been a corresponding consolidated series of outcomes reported in Asia, which this systematic review aims to address.

This review was performed as per the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Searches were performed on MEDLINE, EMBASE, Google Scholar, and Cochrane Database for studies performed in Asia reporting the endovascular management of blunt traumatic thoracic aortic injury. Risk of bias was assessed using the Newcastle-Ottawa scale. Meta-analyses of pooled proportions were performed using the metaprop command in STATA. This review has been prospectively registered in PROSPERO (CRD42018083773).

Sixteen retrospective cohort studies were included, reporting a total of 238 patients. The pooled Injury Severity Score was 32.5 (95%CI 27.8–37.1). The pooled mean time to operation from diagnosis was 39.2 hours (95%CI 24.6–53.8 hours), and operation time was 100 min (95%CI 63.5–136.5 min). The pooled rate of procedural conversion from endovascular repair to open surgery was 0.17% (95%CI 0–3.7%), and the proportion of left subclavian artery coverage was 55% (95%CI 37–72%). The pooled prevalence of intra-operative all-cause and aortic-related mortality was 0.72% (95%CI 0–4.9%) and 0.27% (95%CI 0–3.8%), respectively. The pooled prevalence of 30-day all-cause and aortic-related mortality was 2.2% (95%CI 0.16–5.6%) and 2.1% (95%CI 0–3.7%), respectively. In terms of 30-day complication, the pooled prevalence rates of type 1 endoleak, endograft complications, vascular access injury, strokes, and aortic re-rupture were 1.2%, 0.34%, 0.14%, 0.02%, and 0.01%, respectively. There were no cases of types II and III endoleak, and renal failure.

Short- to mid-term results for thoracic endovascular aortic repair for blunt traumatic thoracic aortic injury in Asia are encouraging. However, there is a distinct disparity in reporting across Asia. We propose a prospective database for outcome reporting post thoracic endovascular aortic repair in this patient population, and ongoing follow up to assess long-term efficacy of this treatment strategy.

Whilst autologous vein conduits have been heralded as the first-line approach for patients undergoing lower limb bypass grafting procedures, patients with peripheral arterial occlusive disease may have exhausted venous options given prior use for cardiac surgery, varicose vein surgery, or lower limb revascularization. Hence, the use of a radial artery graft may serve as a viable alternative.

The systematic review was performed in accordance to the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. An electronic search was performed on the following databases: Medline (via PubMed); EMBASE; Cochrane library to search for relevant publications. A narrative analysis was conducted.

Four publications were included in this review including two retrospective cohort studies, one case series, and one case report, with a total of 43 patients. The most common indication for lower limb bypass grafting was critical limb ischemia, and the radial artery was chosen as graft conduit, most commonly due to the absence of suitable arm or leg vein. There was one case of 30-day mortality and 11 reinterventions.

Despite the encouraging results, the paucity of high-quality studies prevents the establishment of any firm conclusion. This warrants the need for appropriately conducted randomized controlled trials to compare the radial artery graft to autologous vein grafts and prosthetic grafts for lower limb bypass grafting.