Covered versus bare-metal stenting of the mesenteric arteries in patients with chronic mesenteric ischaemia (CoBaGI): a multicentre, patient-blinded and investigator-blinded, randomised controlled trial.

BACKGROUND: Mesenteric artery stenting with a bare-metal stent is the current treatment for atherosclerotic chronic mesenteric ischaemia. Long-term patency of bare-metal stents is unsatisfactory due to in-stent intimal hyperplasia. Use of covered stents might improve long-term patency. We aimed to compare the patency of covered stents and bare-metal stents in patients with chronic mesenteric ischaemia. METHODS: We conducted a multicentre, patient-blinded and investigator-blinded, randomised controlled trial including patients with chronic mesenteric ischaemia undergoing mesenteric artery stenting. Six centres in the Netherlands participated in this study, including two national chronic mesenteric ischaemia expert centres. Patients aged 18 years or older were eligible for inclusion when an endovascular mesenteric artery revascularisation was scheduled and a consensus diagnosis of chronic mesenteric ischaemia was made by a multidisciplinary team of gastroenterologists, interventional radiologists, and vascular surgeons. Exclusion criteria were stenosis length of 25 mm or greater, stenosis caused by median arcuate ligament syndrome or vasculitis, contraindication for CT angiography, or previous target vessel revascularisation. Digital 1:1 block randomisation with block sizes of four or six and stratification by inclusion centre was used to allocate patients to undergo stenting with bare-metal stents or covered stents at the start of the procedure. Patients, physicians performing follow-up, investigators, and radiologists were masked to treatment allocation. Interventionalists performing the procedure were not masked. The primary study outcome was the primary patency of covered stents and bare-metal stents at 24 months of follow-up, evaluated in the modified intention-to-treat population, in which stents with missing data for the outcome were excluded. Loss of primary patency was defined as the performance of a re-intervention to preserve patency, or 75% or greater luminal surface area reduction of the target vessel. CT angiography was performed at 6 months, 12 months, and 24 months post intervention to assess patency. The study is registered with ClinicalTrials.gov (NCT02428582) and is complete. FINDINGS: Between April 6, 2015, and March 11, 2019, 158 eligible patients underwent mesenteric artery stenting procedures, of whom 94 patients (with 128 stents) provided consent and were included in the study. 47 patients (62 stents) were assigned to the covered stents group (median age 69·0 years [IQR 63·0-76·5], 28 [60%] female) and 47 patients (66 stents) were assigned to the bare-metal stents group (median age 70·0 years [63·5-76·5], 33 [70%] female). At 24 months, the primary patency of covered stents (42 [81%] of 52 stents) was superior to that of bare-metal stents (26 [49%] of 53; odds ratio [OR] 4·4 [95% CI 1·8-10·5]; p<0·0001). A procedure-related adverse event occurred in 17 (36%) of 47 patients in the covered stents group versus nine (19%) of 47 in the bare-metal stent group (OR 2·4 [95% CI 0·9-6·3]; p=0·065). Most adverse events were related to the access site, including haematoma (five [11%] in the covered stents group vs six [13%] in the bare-metal stents group), pseudoaneurysm (five [11%] vs two [4%]), radial artery thrombosis (one [2%] vs none), and intravascular closure device (none vs one [2%]). Six (13%) patients in the covered stent group versus one (2%) in the bare-metal stent group had procedure-related adverse events not related to the access site, including stent luxation (three [6%] vs none), major bleeding (two (4%) vs none), mesenteric artery perforation (one [2%] vs one [2%]), mesenteric artery dissection (one [2%] vs one [2%]), and death (one [2%] vs none). INTERPRETATION: The findings of this trial support the use of covered stents for mesenteric artery stenting in patients with chronic mesenteric ischaemia. FUNDING: Atrium Maquet Getinge Group.

Endovascular and Surgical Venous Arterialization for No-Option Patients With Chronic Limb-Threatening Ischemia: A Systematic Review and Meta-Analysis.

BACKGROUND: Chronic limb-threatening ischemia (CLTI) is known for its high rates of major amputation and mortality. Conventional revascularization techniques often fail in CLTI patients due to the heavily diseased arteries. Foot vein arterialization (FVA) has been proposed as an alternative technique to provide arterial blood to the foot by using the disease-free venous bed. OBJECTIVES: This systematic review and meta-analysis aimed to determine outcomes of surgical FVA (sFVA) and percutaneous FVA (pFVA) at 6 and 12 months post-procedure. DATA SOURCES: PubMed, Scopus, Web of Science, and the Cochrane Library databases were searched to identify papers reporting clinical outcomes of sFVA and pFVA published between January 1966 and March 2023. METHODS: Databases were searched for eligible studies. A meta-analysis was performed to evaluate the limb salvage rate, overall survival rate, and wound healing rate at 6 and 12 months. RESULTS: A total of 27 studies were included, with 753 patients and 793 limbs. Of the included studies, 16 analyzed the sFVA technique and 11 the pFVA technique. Of the included patients, 86.3% were Rutherford 5/6 in the sFVA group versus 98.4% in the pFVA group. The pooled limb salvage rate at 6 and 12 months was 78.1% and 74.1% in the sFVA group and 81.7% and 78.6% in the pFVA group, respectively. Wound healing rates were not reported in the sFVA group. In the pFVA group, the pooled wound healing rates were 48.1% and 64.5% at 6 and 12 months, respectively. CONCLUSION: This study showed promising results after FVA among a large population of CLTI patients. In high-risk patients, pFVA is a feasible option with favorable limb salvage and wound healing rates.

Twelve-Month Outcomes of Intravascular Lithotripsy for Treatment of Calcified Popliteal and Infrapopliteal Lesions in Patients With Chronic Limb-Threatening Ischemia.

PURPOSE: Vessel calcification is estimated to be present in 30% to 50% of patients with peripheral arterial disease (PAD) and is one of the main challenges in endovascular treatment. The popliteal artery is unique compared with other arteries due to its exposure to significant deformation and biomechanical stress during knee motion. Intravascular lithotripsy (IVL) is a novel technique that uses acoustic pressure waves to cause microfractures within the intimal and medial wall calcification. Intravascular lithotripsy is safe in femoropopliteal and infrapopliteal lesions, but follow-up studies are lacking. Therefore, the purpose of this study was to describe the first follow-up outcomes of IVL in popliteal and infrapopliteal arterial disease. METHODS: This prospective, multicenter cohort study included all patients treated with IVL in the popliteal and infrapopliteal arteries at 4 sites. Standardized follow-up with duplex ultrasonography was scheduled at 6 to 8 weeks and 12 months. The primary safety endpoint was a composite of major adverse events (MAEs) at 30 days. Primary efficacy endpoints were primary patency, limb salvage, and amputation-free survival (AFS) at 12 months. Secondary endpoints were primary-assisted patency and freedom from target lesion revascularization (TLR). Endpoints were distributed for patients with chronic limb-threatening ischemia (CLTI) and intermittent claudication (IC) and estimated using the Kaplan-Meier method. RESULTS: Between April 2021 and March 2023, 29 patients with 30 limbs were treated. Diabetes mellitus (DM) and CLTI were present in 62.1% and 80.0% of patients, respectively. Within the 32 treated lesions, severe calcification was present in 84.4% and bailout stenting was necessary in 12.5% of the lesions. Four MAEs occurred within 30 days: 1 closure device failure, 1 major amputation, and 2 deaths, neither of which was related to the study device. The primary patency, primary-assisted patency, freedom from TLR, limb salvage, and AFS at 12 months were 68.8%, 90.0%, 93.3%, 83.9%, and 57.1% for CLTI patients, respectively. No events occurred in restenosis, re-occlusion, TLR, major amputation, or mortality in patients with IC. CONCLUSIONS: This first-ever analysis on follow-up outcomes of IVL in the popliteal and infrapopliteal arteries demonstrated promising safety and efficacy outcomes with a low rate of bailout stenting. CLINICAL IMPACT: Vessel calcification is a common feature in peripheral arterial disease (PAD) and is one of the main challenges in endovascular treatment. The popliteal artery is subjected to biomechanical stress during knee motion, which makes stenting unappealing and often leads to worse clinical outcomes. This study aimed to describe the first follow-up outcomes of IVL in popliteal and infrapopliteal arterial disease. As in line with previous studies, no relevant procedural complications were found and the rate of bail-out stenting was only 12.5%. Moreover, in a complex patient population, this study demonstrated promising safety and efficacy outcomes. The comparison of IVL with angioplasty alone or other vessel preparation devices for popliteal and infrapopliteal arterial disease is warranted.

The Dutch chronic lower limb-threatening ischemia registry (THRILLER): A study protocol for popliteal and infrapopliteal endovascular interventions.

INTRODUCTION: Chronic limb-threatening ischemia (CLTI) is the end stage of peripheral arterial disease (PAD) and is associated with high amputation rates, mortality and disease-related health care costs. In infrapopliteal arterial disease (IPAD), endovascular revascularization should be considered for the majority of anatomical and clinical subgroups of CLTI. However, a gap of high-quality evidence exists in this field. The aim of the Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER) is to collect real world data on popliteal and infrapopliteal endovascular interventions. METHODS: THRILLER is a clinician-driven, prospective, multicenter, observational registry including all consecutive patients that undergo a popliteal or infrapopliteal endovascular intervention in seven Dutch hospitals. We estimate that THRILLER will include 400-500 interventions annually. Standardized follow-up visits with wound monitoring, toe pressure measurement and duplex ultrasonography will be scheduled at 6-8 weeks and 12 months after the intervention. The independent primary endpoints are primary patency, limb salvage and amputation free survival. Patients must give informed consent before participation and will be included according to predefined reporting standards. A data log of patients who meet the inclusion criteria but are not included in the registry will be maintained. We intend to conduct the first interim analysis two years after the start of inclusion. The results will be published in a scientific journal. DISCUSSION: Despite innovations in medical therapy and revascularization techniques, patients with CLTI undergoing endovascular revascularization still have a moderate prognosis. Previous prospective cohort studies were hampered by small sample sizes or heterogeneous reporting. Randomized controlled trials (RCTs) have high costs, potential conflicts of interest and give a limited reflection of daily practice. THRILLER aims to provide the largest prospective well phenotyped up-to-date dataset on treatment outcomes in CLTI patients to answer multiple underexplored research questions regarding diagnostics, medication, patient selection, treatment strategies and post intervention follow-up.

Biliopancreatic and biliary leak after pancreatoduodenectomy treated by percutaneous transhepatic biliary drainage.

BACKGROUND: Complementary to percutaneous intra-abdominal drainage, percutaneous transhepatic biliary drainage (PTBD) might ameliorate healing of pancreatic fistula and biliary leakage after pancreatoduodenectomy by diversion of bile from the site of leakage. This study evaluated technical and clinical outcomes of PTBD for this indication. METHODS: All patients undergoing PTBD for leakage after pancreatoduodenectomy were retrospectively evaluated in two tertiary pancreatic centers (2014-2019). Technical success was defined as external biliary drainage. Clinical success was defined as discharge with a resolved leak, without additional surgical interventions for anastomotic leakage other than percutaneous intra-abdominal drainage. RESULTS: Following 822 pancreatoduodenectomies, 65 patients (8%) underwent PTBD. Indications were leakage of the pancreaticojejunostomy (n = 25; 38%), hepaticojejunostomy (n = 15; 23%) and of both (n = 25; 38%). PTBD was technically successful in 64 patients (98%) with drain revision in 40 patients (63%). Clinical success occurred in 60 patients (94%). Leakage resolved after median 33 days (IQR 21-60). PTBD related complications occurred in 23 patients (35%), including cholangitis (n = 14; 21%), hemobilia (n = 7; 11%) and PTBD related bleeding requiring re-intervention (n = 4; 6%). In hospital mortality was 3% (n = 2). CONCLUSION: Although drain revisions and complications are common, PTBD is highly feasible and appears to be effective in the treatment of biliopancreatic leakage after pancreatoduodenectomy.

Repeatability, and Intra-Observer and Interobserver Agreement of Two Dimensional Perfusion Angiography in Patients with Chronic Limb Threatening Ischaemia.

OBJECTIVE: Two dimensional (2D) perfusion angiography is a method that provides quantitative foot perfusion information from standard digital subtraction angiography acquisitions. The aim of this study was to test the reliability of this method in patients with chronic limb threatening ischaemia (CLTI) by investigating repeatability, and intra-observer and interobserver agreement. METHODS: Twenty patients with CLTI and a below the knee endovascular revascularisation were included in a prospective clinical study. Prior to treatment two perfusion angiography runs were acquired with a five minute interval without performing an intervention. In these recordings, regions of interest were selected and time density curves and perfusion parameters were determined. To investigate intra-observer agreement one observer performed five measurements on the same acquisition for each patient. To investigate interobserver agreement three observers performed measurements on the same acquisition for each patient. Results were presented in Bland-Altman plots and as the intraclass correlation coefficient per parameter. RESULTS: Two patients were excluded from repeatability analyses because of major motion artefacts. Repeatability analyses of the 18 remaining patients showed excellent correlation for every parameter (> .96). Intra-observer and interobserver agreement for all 20 patients were excellent for all parameters (1.00). CONCLUSION: Repeatability and intra-observer and interobserver agreement of 2D perfusion angiography in patients with CLTI were found to be excellent. It is therefore a reliable tool when used according to the standardised methods described in this study.

Comparison of Contrast Enhanced Magnetic Resonance Angiography to Computed Tomography in Detecting Pulmonary Arteriovenous Malformations.

BACKGROUND: Computed tomography (CT) is considered the imaging modality of choice to diagnose pulmonary arteriovenous malformations PAVMs. The drawback of this technique is that it requires ionizing radiation. Magnetic resonance (MR) imaging does not have the limitation, but little is known about the performance of MR compared to CT for the detection of PAVMs. The aim of this study is to investigate the sensitivity of contrast-enhanced MR angiography (CE-MRA) in the detection of PAVMs with feeding artery diameters (FAD) > 2 mm. METHODS: Patients with a grade 2 or 3 shunt on screening transthoracic contrast echocardiography (TTCE) were asked to participate. Included patients underwent chest CT and CE-MRA. CT was considered the reference standard. CT and CE-MRA scans were anonymized and assessed for the presence of PAVMs with FAD > 2 mm by one and two readers respectively. Data analysis was performed on per patient and per PAVM basis. RESULTS: Fifty-three patients were included. 105 PAVMs were detected on CT, 45 with a FAD ≥ 2 mm. In per patient analysis, sensitivity and specificity of CE-MRA were 92% and 97% respectively for reader 1 and 92% and 62% for reader 2. Negative and positive predictive value (NPV/PPV) were 93% and 96% for R1 and 90% and 67% for R2. In per PAVM analysis, sensitivity, specificity, NPV and PPV were 96%, 99%, 100% and 86% for R1 and 93%, 96%, 100% and 56% for R2, respectively. CONCLUSIONS: CE-MRA has excellent sensitivity and NPV for detection of PAVMs with FAD ≥ 2 mm and can therefore be used to detect these PAVMs. We are hopeful that future advancements in CE-MRA technology will reduce false positive rates and allow for more broad use of CE-MRA in PAVM diagnosis and management.

Novel diagnostic and imaging techniques in endovascular iliac artery procedures.

INTRODUCTION: Endovascular revascularization has become the preferred treatment for most patients with iliac artery obstructions, with a high rate of clinical and technical success. AREAS COVERED: This review will describe novel developments in the diagnosis and treatment of iliac artery obstructions including the augmentation of preprocedural imaging with advanced flow models, image fusion techniques, and state-of-the-art device-tracking capabilities. EXPERT OPINION: The combination of these developments will change the endovascular field within the next 5 years, allowing targeted iliac treatment without the need for radiographic imaging or iodinated contrast media.

A challenging double bubble thoracic aortic and proximal subclavian aneurysm treated via transapical access.

This case report describes a patient with a distal aortic arch and left subclavian artery aneurysm who was considered unsuitable for open surgical repair because of comorbidities and previous bypass surgery. Inadequate peripheral access precluded standard transfemoral thoracic endovascular aortic repair. Nonetheless, successful endovascular repair was possible via transapical access using the new Gore cTAG deployment mechanism, which allowed precise antegrade stent graft deployment in a short proximal neck.

Diagnosis and management of postpancreatectomy hemorrhage: a systematic review and meta-analysis.

BACKGROUND: Postpancreatectomy hemorrhage is a potentially lethal complication after pancreatic resection. The objective of this systematic review is to provide insight in the current status of incidence, detection, management and clinical outcomes of late postpancreatectomy hemorrhage. METHODS: A systematic search was conducted on the literature from February 2007 to July 2018 in PubMed, Embase and the Cochrane library. Included were clinical studies with clinical outcomes on late postpancreatectomy hemorrhage defined according to the International Study Group of Pancreatic Surgery definition (i.e. occurring >24 h after pancreatic resection). RESULTS: A total of 14 studies on 467 patients with late postpancreatectomy hemorrhage were included. The incidence of late postpancreatectomy hemorrhage ranged from 3% to 16% (weighted mean: 5%). Seventy-four patients received conservative treatment; 252 patients underwent primary endovascular intervention; 82 patients underwent primary relaparotomy; 56 patients underwent primary endoscopic intervention; and three patients died before any intervention could be performed. CT-scan and diagnostic angiography were able to identify the source of hemorrhage in 67% (66/98) and 69% (114/166) of patients, respectively. The most frequent origin of the hemorrhage was the gastroduodenal artery stump (79/275; 29%), followed by the common hepatic artery (51/275; 19%) and splenic artery (32/275; 12%). Overall mortality was 21% (98/464 patients; range 0%-38%). Mortality was lower after primary interventional angiography as compared to primary relaparotomy (16% vs 37% respectively). CONCLUSIONS: This systematic review provides a comprehensive overview of the current literature for severe late postpancreatectomy hemorrhages. CT-scan and diagnostic angiography are equally sensitive in detecting the bleeding source. Interventional angiography appears to be associated to lower mortality as compared to relaparotomy and endoscopy as first intervention for postpancreatectomy hemorrhage.

Local Ultrasound-Facilitated Thrombolysis in High-Risk Pulmonary Embolism: First Dutch Experience.

PURPOSE: To provide insight into the current use and results of ultrasound-facilitated catheter-directed thrombolysis (USAT) in patients with high-risk pulmonary embolism (PE). INTRODUCTION: Systemic thrombolysis is an effective treatment for hemodynamically unstable, high-risk PE, but is associated with bleeding complications. USAT is thought to reduce bleeding and is therefore advocated in patients with high-risk PE and contraindications for systemic thrombolysis. METHODS: We conducted a retrospective cohort study of all patients who underwent USAT for high-risk PE in the Netherlands from 2010 to 2017. Characteristics and outcomes were analyzed. Primary outcomes were major (including intracranial and fatal) bleeding and all-cause mortality after 1 month. Secondary outcomes were all-cause mortality and recurrent venous thromboembolism within 3 months. RESULTS: 33 patients underwent USAT for high-risk PE. Major bleeding occurred in 12 patients (36%, 95% CI 22-53), including 1 intracranial and 3 fatal bleeding. All-cause mortality after 1 month was 48% (16/33, 95% CI 31-66). All-cause mortality after 3 months was 50% (16/32, 95% CI 34-66), recurrent venous thromboembolism occurred in 1 patient (1/32, 3%, 95% CI 1-16). CONCLUSIONS: This study was the first to describe characteristics and outcomes after USAT in a study population of patients with high-risk PE only, an understudied population. Although USAT is considered a relatively safe treatment option, our results illustrate that at least caution is needed in critically ill patients with high-risk PE. Further research in patients with high-risk PE is warranted to guide patient selection.

Midterm Single-Center Results of Endovascular Aneurysm Repair With Additional EndoAnchors.

PURPOSE: To review midterm clinical outcomes of EndoAnchor placement during or after endovascular aneurysm repair (EVAR) or chimney EVAR (ch-EVAR). MATERIALS AND METHODS: A retrospective analysis was conducted of 51 consecutive patients [median age 75 years; 38 men] who underwent EVAR/ch-EVAR with EndoAnchor placement between June 2010 and December 2016 to prevent seal failures (31, 61%) or to treat type Ia endoleak and/or migration (20, 39%). Median aortic neck diameter was 27.7 mm and median neck length was 9.0 mm. Thirty-three (65%) had a conical neck; 48 (94%) had at least 1 hostile neck characteristic. Thirty-two (63%) patients had severe comorbidities (ASA score ⩾III). Eight patients had a single ch-EVAR procedure. Baseline patient characteristics, anatomic variables, procedure details, early and late complications, reinterventions, and aneurysm-related and all-cause mortality rates were recorded. Follow-up imaging was performed with computed tomography angiography (CTA) or duplex ultrasonography. RESULTS: Median procedure time was 100 minutes; a median of 6 EndoAnchors were implanted. There were 10 (10%) residual type Ia endoleaks at the end of the procedure; 9 had resolved by the first postoperative CTA. One residual and 2 new type Ia endoleaks were identified at the first postoperative imaging. Median follow-up for the entire cohort was 24.0 months, during which 3 new type Ia endoleaks were identified. Five of the 6 type Ia endoleaks were treated, 1 resolved spontaneously. There was 1 endograft limb occlusion without clinical consequences, 1 chimney graft occlusion without possibilities for a reintervention, 1 rupture after type IV endoleak (a Nellix device was successfully deployed within the main device), and 1 complete graft explantation for infection. There was no new-onset hemodialysis. Kaplan-Meier estimates of freedom from type Ia endoleak, proximal neck-related reinterventions, and aneurysm-related mortality at 2 years were 87.3%, 92.2%, and 94.0%, respectively. CONCLUSION: EndoAnchors are helpful in the endovascular treatment of unfavorable proximal aortic necks, with fair midterm results.

PROMISE international; a clinical post marketing trial investigating the percutaneous deep vein arterialization (LimFlow) in the treatment of no-option chronic limb ischemia patient.

BACKGROUND: Critical limb ischemia (CLI) is the clinical end stage of peripheral artery disease and is associated with high amputation, mortality rates and poor quality of life. For CLI patients with no revascularization options, venous arterialization could be an alternative technique for limb salvage. A systematic review and meta-analysis published in 2017 concluded that venous arterialization may be considered a viable alternative. A recent development, is the Percutaneous Deep Vein Arterialization (pDVA), that is CE-marked and currently under investigation of the FDA. This procedure, called LimFlow, is a novel, minimally invasive, endovascular approach to perform a venous arterialization procedure. The limited evidence for its use necessitates a scientific judgement of the pDVA. Therefore, we initiated a prospective clinical post market trial to investigate the outcome of the pDVA in no-option critical limb ischemia. METHODS/DESIGN: The objective of this prospective study is to collect "real-life" clinical data among a population of patients treated with the pDVA in order to evaluate the clinical effectiveness and safety of the LimFlow System in patients with no-option critical limb ischemia. This study is a single-arm, open-label, prospective, post-market follow-up study to be conducted on up to fifty (50) eligible patients with a twelve-month follow-up period. The Primary endpoint is measured by amputation free survival. Secondary endpoints are complete wound healing, primary and secondary patency, limb salvage, renal function and technical and procedural success. Patients will be assessed at regular intervals during one year after the initial percutaneous deep vein arterialization procedure through clinical evaluation and self-completed questionnaires. DISCUSSION: The last decade several studies have been published with promising results and the number of treated patients has considerably grown. Venous arterialization could be a valuable treatment option in patients with often no other options than amputation of the affected limb. The first results in men are promising although more research and long term follow up is needed to establish the efficacy of this new treatment modality. With this prospective study, we evaluate the clinical effectiveness and safety in patients with no-option CLI treated with the pDVA (LimFlow System). TRIAL REGISTRATION: NCT03321552 .

Fluoroscopy with MRA fusion image guidance in endovascular iliac artery interventions: study protocol for a randomized controlled trial (3DMR-Iliac-roadmapping study).

BACKGROUND: Endovascular iliac artery interventions rely on the use of two-dimensional digital subtraction angiographies with an iodinated contrast agent and ionizing radiation. The amount of iodinated contrast agent should be limited because of its potentially nephrotoxic effects. Three-dimensional (3D) image fusion requires registration of a preprocedural magnetic resonance angiogram (MRA) or computed tomography (CT) angiogram to a perprocedurally acquired cone-beam CT or two fluoroscopic orthogonal projections. After registration, the 3D angiography images can be overlaid on the fluoroscopy screen and will follow table and C-arm movements. This study will assess the added value of the 3D image fusion technique in iliac artery interventions regarding the amount of the iodinated contrast agent administered. METHODS/DESIGN: The study cohort will comprise 106 patients (> 18 years) with symptomatic common and/or external iliac artery stenoses or occlusions and a recent (< 6 months) diagnostic MRA from the pelvis through the lower extremities, for which an endovascular intervention is indicated. Patients will be randomized into the control or study group (i.e. treatment without or with 3D image fusion guidance). The primary endpoint is the amount of administered iodinated contrast agent (mL). Secondary outcomes are technical success of the procedure, defined as < 30% residual stenosis over the treated lesion, fluoroscopy time, and radiation dose as dose area product (mGycm2). Patient participation in the study will be completed after hospital discharge. DISCUSSION: This study is a randomized controlled multicenter trial to provide evidence on the effect of the 3D image fusion technique on the amount of administered iodinated contrast during endovascular common and/or external iliac artery interventions. TRIAL REGISTRATION: Nederlands Trial Register, NTR5008 . Registered on 16 December 2014.

Percutaneous deep venous arterialization in patients with critical limb ischemia.

BACKGROUND: Critical limb ischemia (CLI) is the presentation of end stage peripheral arterial disease and typically presents with rest pain, ulceration and gangrene. The outcome of conservative treatment is poor and often leads to amputations. Arterial revascularization plays an important role in amputation prevention. Unfortunately, a significant percentage of CLI patients cannot be revascularized and subsequently end up with a palliative amputation. This has led to the need and exploration of new treatment options in this no option subgroup of CLI. Deep venous arterialization (DVA) is one of them and has been reported as a save and feasible novel and promising alternative to amputation. The goal of DVA is to provide arterialized blood in significant volumes and pressure to the plantar venous arch and ischemic tissue to enable wound healing. Selecting the right patients is critical for successful DVA and requires that extra attention is paid to the wounds as well as arterial and venous vascular status. METHODS: The procedure was previously described in our initial experience in the first-in-man study performed on 7 patients with NOP-CLI. The angiographic goal of the procedure is to deliver arterialized blood to the plantar venous arch in significant volumes and pressure, circumventing the numerous valves in the process. The clinical goal is to achieve wound healing. RESULTS: Technical success was achieved in all patients. Flow in the plantar arch was achieved in 5 of the 7 patients. One patient with chronic rest pain became pain free within 48 hours after the procedure. Complete wound healing was achieved at 12 months in 5 of the 7 patients. Reinterventions were performed in 5 of 7 patients to maintain patency. Of the 7 study patients, five underwent minor amputation of one or more toes, and two underwent major amputations within 12 months (limb salvage, 71%). CONCLUSIONS: The LimFlow system is currently the only registered device a total percutaneous DVA can be performed with. In addition to the percutaneous creation of an arteriovenous fistula (AVF), it also allows disruption of the veins with a dedicated valvulotome.

The use of 3D image fusion for percutaneous transluminal angioplasty and stenting of iliac artery obstructions: validation of the technique and systematic review of literature.

INTRODUCTION: The effect of the insertion of guidewires and catheters on fusion accuracy of the three-dimensional (3D) image fusion technique during iliac percutaneous transluminal angioplasty (PTA) procedures has not yet been investigated. EVIDENCE ACQUISITION: Technical validation of the 3D fusion technique was evaluated in 11 patients with common and/or external iliac artery lesions. A preprocedural contrast-enhanced magnetic resonance angiogram (CE-MRA) was segmented and manually registered to a cone-beam computed tomography image created at the beginning of the procedure for each patient. The treating physician visually scored the fusion accuracy (i.e., accurate [<2 mm], mismatch [2-5 mm], or inaccurate [>5 mm]) of the entire vasculature of the overlay with respect to the digital subtraction angiography (DSA) directly after the first obtained DSA. Contours of the vasculature of the fusion images and DSAs were drawn after the procedure. The cranial-caudal, lateral-medial, and absolute displacement were calculated between the vessel centerlines. To determine the influence of the catheters, displacement of the catheterized iliac trajectories were compared with the noncatheterized trajectories. Electronic databases were systematically searched for available literature published between January 2010 till August 2017. EVIDENCE SYNTHESIS: The mean registration error for all iliac trajectories (N.=20) was small (4.0±2.5 mm). No significant difference in fusion displacement was observed between catheterized (N.=11) and noncatheterized (N.=9) iliac arteries. The systematic literature search yielded 2 manuscripts with a total of 22 patients. The methodological quality of these studies was poor (≤11 MINORS Score), mainly due to a lack of a control group. CONCLUSIONS: Accurate image fusion based on preprocedural CE-MRA is possible and could potentially be of help in iliac PTA procedures. The flexible guidewires and angiographic catheters, routinely used during endovascular procedures of iliac arteries, did not cause significant displacement that influenced the image fusion. Current literature on 3D image fusion in iliac PTA procedures is of limited methodological quality.

Hemodynamic significance assessment of equivocal iliac artery stenoses by comparing duplex ultrasonography with intra-arterial pressure measurements.

BACKGROUND: This study evaluated the accuracy of duplex ultrasonography (DUS)-based peak systolic velocity ratio (PSVR) and ipsilateral common femoral artery (CFA) velocity waveform analysis to identify a hemodynamically significant equivocal iliac artery stenosis (30-75% lumen diameter reduction). Intra-arterial pressure measurements were used as a reference. METHODS: In a previously performed prospective study (NTR5085), 30 patients with 35 iliac artery stenoses underwent intra-arterial angiography. To determine the hemodynamic significance of the iliac artery stenoses, intra-arterial translesional pressure measurements were performed under hyperemic conditions. Preprocedural DUS was obtained of the iliac and femoral arteries. PSVR over the iliac lesions was determined, and ipsilateral CFA velocity waveforms were retrospectively classified. The intraobserver and interobserver agreement for CFA velocity waveform classification were evaluated. Sensitivity, specificity, and overall accuracy were calculated by comparing PSVR, velocity waveform analysis, and a combination of these parameters to the intra-arterial translesional pressure gradient. A translesional pressure gradient ≥10 mmHg, PSVR ≥2.5, and a monophasic or biphasic CFA velocity waveform were considered to be indicative for a hemodynamically significant iliac artery stenosis. RESULTS: For classification of ipsilateral CFA velocity waveforms, intraobserver and interobserver agreement were 0.94 and 0.82, respectively. A PSVR ≥2.5 could identify a hemodynamically significant stenosis with 83% sensitivity, 67% specificity, and an overall accuracy of 77%. When both a monophasic and a biphasic velocity waveform were considered to indicate a hemodynamically significant iliac artery stenosis, sensitivity was 78%, specificity was 50%, and the overall accuracy was 69%. The combination of a PSVR ≥2.5 with either a monophasic or a biphasic CFA velocity waveform was found in 20 stenoses and resulted in 94% sensitivity, 75% specificity, and 90% accuracy. When the remainder of the stenoses (N.=15) was classified by means of the PSVR, the overall accuracy remained 77%. CONCLUSIONS: DUS is a very useful noninvasive imaging modality to determine the significance of an iliac artery stenosis. A combination of translesional PSVR ≥2.5 with either a monophasic or a biphasic ipsilateral CFA ultrasound waveforms has a good accuracy and helps to select patients that benefit most from follow-up examination by computed tomography angiography or magnetic resonance angiography.

Surgical and endovascular venous arterialization for treatment of critical limb ischaemia.

Patients with critical limb ischaemia have a poor life expectancy. Aggressive revascularization is accepted in order to preserve their independence in the final phase of their lives. Bypass surgery and more recently endovascular interventions with angioplasty and stenting have become the treatment of choice to prevent amputation and to resolve pain. However, as many as 20 % of patients with critical limb ischaemia are unsuitable candidates for a vascular intervention because of extensive occlusions of outflow in the crural and pedal vessels. Such "no-option critical limb ischaemia" may be treated with venous arterialization. In the present review, we discuss the history of the venous arterialization procedure, the mechanisms, the different techniques, and complications of venous arterialization.

In Vivo Validation of Patient-Specific Pressure Gradient Calculations for Iliac Artery Stenosis Severity Assessment.

BACKGROUND: Currently, the decision to treat iliac artery stenoses is mainly based on visual inspection of digital subtraction angiographies. Intra-arterial pressure measurements can provide clinicians with accurate hemodynamic information. However, pressure measurements are rarely performed because of their invasiveness and the time required. Therefore, the aim of the study was to test the feasibility of a computational model that can predict translesional pressure gradients across iliac artery stenoses on the basis of imaging data only. METHODS AND RESULTS: Patients (N=21) with symptomatic peripheral arterial disease and a peak systolic velocity ratio between 2.5 and 5.0 were included in the study. Patients underwent per-procedural 3-dimensional rotational angiography and hyperemic intra-arterial translesional pressure measurements. Vascular anatomical features were reconstructed from the 3-dimensional rotational angiography data into an axisymmetrical 2-dimensional computational mesh, and flow was estimated on the basis of the stenosis geometry. Computational fluid dynamics were performed to predict the pressure gradient and were compared with the measured pressure gradients. A good agreement by overlapping error bars of the predicted and measured pressure gradients was found in 21 of 25 lesions. Stratification of the stenosis on the basis of the predicted pressure gradient into hemodynamic not significant (<10 mm Hg) and hemodynamic significant (≥10 mm Hg) resulted in sensitivity, specificity, and overall predictive values of 95%, 60%, and 88%, respectively. CONCLUSIONS: The feasibility of the patient-specific computational model to predict the hyperemic translesional pressure gradient over iliac artery stenosis was successfully tested. Presented results suggest that, with further optimization and corroboration, the model can become a valuable aid to the diagnosis of equivocal iliac artery stenosis. CLINICAL TRIAL REGISTRATION: URL: http://www.trialregister.nl. Unique identifier: NTR5085.