Percutaneous Femoropopliteal Bypass: 2-Year Results of the DETOUR System.

PURPOSE: This study investigated the 2-year safety and effectiveness of the PQ Bypass DETOUR system as a percutaneous femoropopliteal bypass. MATERIALS AND METHODS: Seventy-eight patients with 82 long-segment femoropopliteal lesions were enrolled in this prospective, single-arm, multicenter study. The DETOUR system deployed Torus stent grafts directed through a transvenous route. Eligible patients included those with lesions of >10 cm and average of 371±55 mm. Key safety endpoints included major adverse events (MAEs) and symptomatic deep venous thrombosis in the target limb. Effectiveness endpoints included primary patency defined as freedom from ≥50% stenosis, occlusion, or clinically-driven target vessel revascularization (CD-TVR), primary assisted, and secondary patency. RESULTS: Chronic total occlusions and severe calcium occurred in 96% and 67% of lesions, respectively. Core laboratory-assessed total lesion length averaged 371±51 mm with a mean occlusion length of 159±88 mm. The rates of technical and procedural success were 96%, with satisfactory delivery and deployment of the device without in-hospital MAEs in 79/82 limbs. The MAE rate was 22.0%, with 3 unrelated deaths (4%), 12 CD-TVRs (16%), and 1 major amputation (1%). Deep venous thrombosis developed in 2.8% of target limbs, and there were no reported pulmonary emboli. Primary, assisted primary, and secondary patency rates by the Kaplan-Meier analysis were 79±5%, 79±5%, and 86±4%, respectively. CONCLUSIONS: The PQ Bypass DETOUR system is a safe and effective percutaneous alternative to femoropopliteal open bypass with favorable results through 2 years. The DETOUR system provides a durable alternative to conventional endovascular modalities and open surgery for patients with long, severely calcified, or occluded femoropopliteal lesions.

Venous outcomes at 1 year after using the femoral vein as a conduit for passage of percutaneous femoropopliteal bypass.

OBJECTIVE: The DETOUR 1 study was performed to assess the safety of the femoral vein as a "pass through" conduit for covered stent placement during fully percutaneous femoropopliteal bypass, also known as the DETOUR procedure. METHODS: At eight participating centers in this prospective, single-arm, international trial, 78 patients (82 femoropopliteal lesions) were enrolled. All patients had patent femoral veins measuring ≥10 mm in diameter at baseline. The DETOUR procedure involved delivery of a series of TORUS stent grafts, deployed from contralateral common femoral artery access, to the ipsilateral proximal superficial femoral artery, with entry into the femoral vein and re-entry into the arterial vasculature at the above-the-knee popliteal artery. The TORUS stent grafts are deployed in an overlapping configuration as an arterial-arterial conduit. Due to this novel transvenous approach, we assessed specific considerations related to the venous system to analyze the risk of risk of venous thromboembolic complications. Symptomatic deep vein thrombosis, nonocclusive material associated with the graft such as benign endovenous graft-associated material, pulmonary embolism, Venous Clinical Severity Score (VCSS) and Villalta scores, and luminal occupancy by the stent graft were assessed as the ratio of cross-sectional areas of the stent graft to the native vein at baseline and 1 year after the procedure. RESULTS: A duplicate femoral vein was present in 20.7% of cases. The majority of patients (86.8%) had a femoral vein luminal area preservation of ≥55%. Thirty-two patients experienced an increase in the vein diameter over time after the procedure, but this pattern of venous remodeling was not uniform. The patients who had a compensatory increase in the vein diameter had a smaller average baseline vein diameter compared with the patients who did not have a compensatory increase in vein diameter (P = .0414). Only two patients (2.4%) developed ipsilateral symptomatic deep vein thrombosis) through 1 year of follow-up. There were no pulmonary embolism in any patient in the series. The overall VCSS and Villata scores did not change during follow-up. Mean VCSS and Villata were 0.8 ± 1.4 and 0.5 ± 1.1 at 1 year, compared with 0.6 ± 1.0 and 0.4 ± 0.9 at baseline, respectively. CONCLUSIONS: As a percutaneous alternative to open surgical bypass for complex femoropopliteal peripheral arterial disease, the transvenous bypass has a low rate of deep venous thrombotic and obstructive complications. Cross-sectional vein area is preserved, and in some patients, the compensatory vein diameter increases with time, supporting the feasibility and safety of using the lower extremity deep venous system as a pass-through conduit for the DETOUR percutaneous femoropopliteal bypass. TRIAL REGISTRATION: NCT02471638.

One-year results from the DETOUR I trial of the PQ Bypass DETOUR System for percutaneous femoropopliteal bypass.

OBJECTIVE: The objective of this study was to evaluate the 1-year safety and effectiveness outcomes associated with the PQ Bypass DETOUR System (PQ Bypass, Milpitas, Calif) for the percutaneous bypass of long-segment femoropopliteal occlusive disease. METHODS: This prospective, single-arm, multicenter trial enrolled patients with long-segment femoropopliteal arterial disease. The DETOUR System percutaneously deploys modular stent grafts to bypass femoropopliteal lesions through a transvenous route. Eligible patients included those with TransAtlantic Inter-Society Consensus C and D lesions >100 mm in length. The primary safety end point was the major adverse event (MAE) rate through 1 month, defined as the composite of death, clinically driven target vessel revascularization (CD-TVR), or major amputation. The primary effectiveness end point was stent graft patency through 6 months, defined as freedom from stenosis ≥50%, occlusion, or CD-TVR. RESULTS: During a 24-month period, 78 patients (82 limbs) were enrolled. The average core laboratory-measured lesion length was 371 ± 55 mm; 79 of 82 lesions (96%) were chronic total occlusions, and 55 of 82 lesions (67%) had severe calcification. The rates of technical and procedural success measured during the index procedure were both 96%, with satisfactory delivery and deployment of the device without MAEs in 79 of 82 limbs. Through 1 month, there were no deaths or amputations; CD-TVRs occurred in 2 of 81 limbs (3%), and freedom from MAEs was 98% (79/81). The 1-year Kaplan-Meier primary, assisted primary, and secondary patency rates were 81% ± 4%, 82% ± 4%, and 90% ± 3%, respectively. The ankle-brachial index increased an average of 0.25 ± 0.27 between baseline and 1 year (P < .001). Through 1 year, the Kaplan-Meier estimates of freedom from stent graft thrombosis, CD-TVR, and MAE were 84% ± 4%, 85% ± 4%, and 84% ± 4%, respectively. At 1 year, the Rutherford class improved in 77 of 80 limbs (96%), and 65 of 80 (81%) were asymptomatic. Deep venous thrombosis developed in 2 of 79 target limbs (3%) through 1 year, both at the femoropopliteal vein level. There were no instances of pulmonary embolism. CONCLUSIONS: The 1-year results from the DETOUR I trial show that the PQ Bypass DETOUR System is a safe and effective percutaneous treatment option for patients with longer, severely calcified, above-knee femoropopliteal lesions.

Relative Cerebral Blood Transit Time Decline and Neurological Improvement in Patients After Internal Carotid Artery Stenting.

In this study we hypothesized that the alleviation of neurological symptoms long after internal carotid artery (ICA) stenting may be related to sustained improvement of cerebral perfusion. Thirty-four subjects (F/M; 15/19) with >70% stenosis of a single internal carotid artery and neurological symptoms, who underwent a carotid artery stenting procedure, were studied. Brain computed tomography perfusion (CTP) imaging was performed before and 3 years after ICA stenting. The following relative variables were compared: cerebral blood flow (rCBF), cerebral blood volume (rCBV), mean transit time (rMTT), time to peak (rTTP), and permeability surface area product (rPS). A survey also was conducted to compare the patients' clinical symptoms. Overall, we found that a trend toward rMTT decline was the only persisting change after ICA stenting. We then stratified the patients into the subgroups of <2%, 2-5%, and > 5% rMTT decline and found that those with a rMTT decline >2% reported a prominent reduction in subjective clinical symptoms such as headache, dizziness, tinnitus, blurred vision, transient blindness, a sense of gravity of the head, and pain in the eyeballs. We conclude that a shortened mean rMTT, likely reflecting improved cerebral microcirculation, underlies the improvement of neurological symptoms in patients with ICA stenosis.

Computed tomography indicators of cerebral microperfusion improve long term after carotid stenting in symptomatic patients.

OBJECTIVES: We tested the hypothesis that computed tomography (CT) perfusion markers of cerebral microcirculation would improve 36 months after internal carotid artery stenting for symptomatic carotid stenosis while results obtained 6-8 weeks after the stenting procedure would yield a predictive value. METHODS: We recruited consecutive eligible patients with >70% symptomatic carotid stenosis with a complete circle of Willis and normal vertebral arteries to the observational cohort study. We detected changes in the cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP) and permeability surface area-product (PS) before and after carotid stenting. We have also compared the absolute differences in the ipsilateral and contralateral CT perfusion markers before and after stenting. The search for regression models of "36 months after stenting" results was based on a stepwise analysis with bidirectional elimination method. RESULTS: A total of 34 patients completed the 36 months follow-up (15 females, mean age of 69.68±S.D. 7.61 years). At 36 months after stenting, the absolute values for CT perfusion markers had improved: CBF (ipsilateral: +7.76%, contralateral: +0.95%); CBV (ipsilateral: +5.13%, contralateral: +3.00%); MTT (ipsilateral: -12.90%; contralateral: -5.63%); TTP (ipsilateral: -2.10%, contralateral: -4.73%) and PS (ipsilateral: -35.21%, contralateral: -35.45%). MTT assessed 6-8 weeks after stenting predicted the MTT value 36 months after stenting (ipsilateral: R2=0.867, contralateral R2=0.688). CONCLUSIONS: We have demonstrated improvements in CT perfusion markers of cerebral microcirculation health that persist for at least 3 years after carotid artery stenting in symptomatic patients. MTT assessed 6-8 weeks after stenting yields a predictive value.

Regional resting state perfusion variability and delayed cerebrovascular uniform reactivity in subjects with chronic carotid artery stenosis.

The aim of this study was to assess regional perfusion at baseline and regional cerebrovascular resistance (CVR) to delayed acetazolamide challenge in subjects with chronic carotid artery stenosis. Sixteen patients (ten males) aged 70.94±7.71 with carotid artery stenosis ≥ 90% on the ipsilateral side and ≤ 50% on the contralateral side were enrolled into the study. In all patients, two computed tomography perfusion examinations were carried out; the first was performed before acetazolamide administration and the second 60 minutes after injection. The differences between mean values were examined by paired two-sample t-test and alternative nonparametric Wilcoxon's test. Normality assumption was examined using W Shapiro-Wilk test. The lowest resting-state cerebral blood flow (CBF) was observed in white matter (ipsilateral side: 18.4±6.2; contralateral side: 19.3±6.6) and brainstem (ipsilateral side: 27.8±8.5; contralateral side: 29.1±10.8). Grey matter (cerebral cortex) resting state CBF was below the normal value for subjects of this age: frontal lobe - ipsilateral side: 30.4±7.0, contralateral side: 33.7±7.1; parietal lobe - ipsilateral side: 36.4±11.3, contralateral side: 42.7±9.9; temporal lobe - ipsilateral side: 32.5±8.6, contralateral side: 39.4±10.8; occipital lobe - ipsilateral side: 24.0±6.0, contralateral side: 26.4±6.6). The highest resting state CBF was observed in the insula (ipsilateral side: 49.2±17.4; contralateral side: 55.3±18.4). A relatively high resting state CBF was also recorded in the thalamus (ipsilateral side: 39.7±16.9; contralateral side: 41.7±14.1) and cerebellum (ipsilateral side: 41.4±12.2; contralateral side: 38.1±11.3). The highest CVR was observed in temporal lobe cortex (ipsilateral side: +27.1%; contralateral side: +26.1%) and cerebellum (ipsilateral side: +27.0%; contralateral side: +34.6%). The lowest CVR was recorded in brain stem (ipsilateral side: +20.2%; contralateral side: +22.2%) and white matter (ipsilateral side: +18.1%; contralateral side: +18.3%). All CBF values were provided in milliliters of blood per minute per 100 g of brain tissue (ml/100g/min). Resting state circulation in subjects with carotid artery stenosis is low in all analysed structures with the exception of insula and cerebellum. Acetazolamide challenge yields relatively uniform response in both hemispheres in the investigated population. Grey matter is more reactive to acetazolamide challenge than white matter or brainstem.

Social, demographic and clinical characteristics of patients suffering from peripheral vascular disease treated surgically compared to patients treated with endovascular angioplasty.

INTRODUCTION: Atherosclerosis is the most common cause of chronic lower limb ischaemia. Many factors that have a crucial influence on the development of the disease, its course and prognosis have been identified. The risk factors seem to be subject to interventions due to their susceptibility to changes. It is important to increase the engagement of doctors and nurses performing the screening oriented on risk factors, medical consultation regarding giving up smoking, changing the diet and undertaking physical activity. Therefore, knowledge of the patients' health situation allows introduction of optimal treatment in this group of patients. MATERIAL AND METHODS: The study group consisted of 119 patients with peripheral artery atherosclerosis, who underwent surgical and endovascular repair. The diagnostic survey method was used in this study. The socio-demographic and clinical data were collected using an originally developed questionnaire. The statistical analysis was performed using the data analysis software system Statistica, version 10.0, by StatSoft Inc. (2011) and an Excel spreadsheet. The statistical significance was set at p < 0.05 for all calculations. RESULTS: There were statistically significant differences between the analysed groups with regard to severity of ischaemia (p = 0.0001), intermittent claudication (p = 0.0001), rest pain (p = 0.0001), ulceration (p = 0.0031), smoking (p = 0.0075) and comorbidities (percutaneous coronary interventions p = 0.0299; ischaemic stroke p = 0.0235). CONCLUSIONS: There are significantly more patients with more advanced disease and ex-smokers in the surgically treated group. There are significantly more patients with a history of ischaemic stroke, surgical coronary interventions and current smokers in the endovascular group.

Carotid Artery Stenting and Blood-Brain Barrier Permeability in Subjects with Chronic Carotid Artery Stenosis.

Failure of the blood-brain barrier (BBB) is a critical event in the development and progression of diseases such as acute ischemic stroke, chronic ischemia or small vessels disease that affect the central nervous system. It is not known whether BBB breakdown in subjects with chronic carotid artery stenosis can be restrained with postoperative recovery of cerebral perfusion. The aim of the study was to assess the short-term effect of internal carotid artery stenting on basic perfusion parameters and permeability surface area-product (PS) in such a population. Forty subjects (23 males) with stenosis of >70% within a single internal carotid artery and neurological symptoms who underwent a carotid artery stenting procedure were investigated. Differences in the following computed tomography perfusion (CTP) parameters were compared before and after surgery: global cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP) and PS. PS acquired by CTP is used to measure the permeability of the BBB to contrast material. In all baseline cases, the CBF and CBV values were low, while MTT and TTP were high on both the ipsi- and contralateral sides compared to reference values. PS was approximately twice the normal value. CBF was higher (+6.14%), while MTT was lower (-9.34%) on the contralateral than on the ipsilateral side. All perfusion parameters improved after stenting on both the ipsilateral (CBF +22.66%; CBV +18.98%; MTT -16.09%, TTP -7.62%) and contralateral (CBF +22.27%, CBV +19.72%, MTT -14.65%, TTP -7.46%) sides. PS decreased by almost half: ipsilateral -48.11%, contralateral -45.19%. The decline in BBB permeability was symmetrical on the ipsi- and contralateral sides to the stenosis. Augmented BBB permeability can be controlled by surgical intervention in humans.

Perfusion computed tomography: 4 cm versus 8 cm coverage size in subjects with chronic carotid artery stenosis.

OBJECTIVE: The impact of coverage size on global cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak (TTP) parameters has not been investigated in patients with chronic carotid artery stenosis. METHODS: 63 patients with stenosis of >70% within a single internal carotid artery and neurological symptoms were randomly assigned to two well-matched groups. Differences in CT perfusion scan over a 4 cm or 8 cm range of the brain were compared between the two groups. RESULTS: The CBF and CBV values were higher in the 4 cm coverage size than in the 8 cm coverage size (by 14.7 and 10.7% on the ipsilateral side and 17.2 and 7.8% on the contralateral side, respectively; all p < 0.001). The MTT value was higher in the 4 cm coverage size than in the 8 cm coverage size on the ipsilateral side (9.6%; p < 0.001). There was no difference between MTT values in the contralateral size. There were no differences between TTP values on the ipsilateral and contralateral sides. The relative indices rMTT and rTTP were higher in the 4 cm coverage size than in the 8 cm coverage size (8.2%, p < 0.001, and 1.1%, p < 0.005, respectively). CONCLUSION: Absolute CBF and CBV values and relative rMTT and rTTP indices in patients with low CBF and low CBV are highly dependent on coverage size. We recommend using a 4 cm coverage size to assess global cerebral perfusion parameters owing to better accuracy and quicker post-processing. ADVANCES IN KNOWLEDGE: To the best of our knowledge, this is the first article to compare the influence of 4 cm vs 8 cm coverage size on cerebral perfusion parameters such as CBF, CBV, MTT and TTP in subjects with chronic carotid artery stenosis.

Retroperitoneal fibrosis as a rare cause of lower limb claudication.

The study presented a case of a 58-year-old male patient treated for retroperitoneal fibrosis, right hydronephrosis, and right common iliac artery stenosis and saccular aneurysm of the above-mentioned vessel. The patient was qualified for endovascular treatment. Stentgraft implantation was performed with good long-term patency during more than 3 years of follow-up. Complete relief of intermittent claudication was observed. However, the endovascular exclusion of the aneurysm did not influence the course of retroperitoneal fibrosis.

[Autologous in situ reconstruction of aortic bifurcation in a patient with ruptured, mycotic abdominal aneurysm--case report]. / Rekonstrukcja podzialu aorty z uzyciem zyly wlasnej chorego jako metoda leczenia peknietego, zakazonego tetniaka aorty brzusznej--opis przypadku.

Primarily infected aortic aneurysms represent a small percentage (0.7-1.31%) of abdominal aortic aneurysms. In this paper, we present a case of a 57-year-old man who was admitted to hospital because of abdominal pain and accompanying fever. Initial diagnosis revealed rupture of aortic bifurcation and the patient was qualified for surgical treatment. Intraopeatively, we encountered ruptured aneurysm of aortic bifurcation, additionally we discovered features of infection (cultures revealed Staphylococcus aureus spp.), which precluded the use of a dacron prostheis. Due to the stable hemodynamic status of the patient, we decided to perform "in situ" aorto-iliac reconstruction using deep vein harvested from the single lower limb. Such procedures are rarely performed on an emergency basis, however, potential benefits may outweigh the risk of a more technically challenging procedure. In the postoperative course antimicrobial treatment against Staphylococcus aureus was continued for 12 weeks after surgery. There has been a good long-term patency during more than 5 years of follow-up with no signs of reinfection or degeneration of the graft.

Near-infrared transillumination back scattering sounding--new method to assess brain microcirculation in patients with chronic carotid artery stenosis.

PURPOSE: The purpose of the study was to assess the responses of pial artery pulsation (cc-TQ) and subarachnoid width (sas-TQ) to acetazolamide challenge in patients with chronic carotid artery stenosis and relate these responses to changes in peak systolic velocity (PSV), cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT) and time to peak response (TTP). METHODS: Fifteen patients with carotid artery stenosis ≥ 90% on the ipsilateral side and <50% on the contralateral side were enrolled into the study. PSV was assessed using colour-coded duplex sonography, CBF, CBV, MTT and TTP with perfusion computed tomography, cc-TQ and sas-TQ with near-infrared transillumination/backscattering sounding (NIR-T/BSS). RESULTS: Based on the ipsilateral/contralateral cc-TQ ratio after acetazolamide challenge two groups of patients were distinguished: the first group with a ratio ≥ 1 and the second with a ratio <1. In the second group increases in CBF and CBV after the acetazolamide test were significantly higher in both hemispheres (ipsilateral: +33.0% ± 8.1% vs. +15.3% ± 4.4% and +26.3% ± 6.6% vs. +14.3% ± 5.1%; contralateral: +26.8% ± 7.0% vs. +17.6% ± 5.6% and +20.0% ± 7.3% vs. +10.0% ± 3.7%, respectively), cc-TQ was significantly higher only on the ipsilateral side (+37.3% ± 9.3% vs. +26.6% ± 8.6%) and the decrease in sas-TQ was less pronounced on the ipsilateral side (-0.7% ± 1.5% vs. -10.2% ± 1.5%), in comparison with the first group. The changes in sas-TQ following the acetazolamide test were consistent with the changes in TTP. CONCLUSIONS: The ipsilateral/contralateral cc-TQ ratio following acetazolamide challenge may be used to distinguish patient groups characterized by different haemodynamic parameters. Further research on a larger group of patients is warranted.

Evaluation of changes in the parameters of brain tissue perfusion in multi-slice computed tomography in patients after carotid artery stenting.

BACKGROUND: CT perfusion of the brain allows functional evaluation of cerebral blood flow. Patients with chronic internal carotid artery (ICA) stenosis may suffer from malperfusion. Improvement of cerebral blood flow and remission of neurological symptoms indicate the effectiveness of treatment of internal carotid artery stenosis. MATERIAL/METHODS: The aim of the study was to analyze alterations within cerebral perfusion parameters in CT brain perfusion examination in patients who were scheduled for endovascular therapy due to ICA stenosis. Forty patients with ICA stenosis of over 79% who were included in this prospective study underwent perfusion CT examination twice - 24 hours prior to stenting and after 6-8 weeks following the procedure. CBF, CBV, MTT and TTP were evaluated. RESULTS: Prior to endovascular therapy, an increase in MTT and TTP, and a decrease in CBV and CBF were observed within arterial supply of the hemisphere ipsilateral to stenosis. After the procedure, a decrease in MTT and TTP was seen in all cases, while no statistically significant changes of CBF or CBV were observed. MTT proved to be the most sensitive indicator of ICA stenosis, as its values allowed differentiation between critical and non-critical stenosis. No correlation between the degree of ICA stenosis and TTP values was found. Mild cerebral hyperperfusion syndrome (CHS) was observed in only one patient and the difference between pre-treatment MTT values calculated for both hemispheres was shown to be a prognostic factor for CHS incidence. CONCLUSIONS: Endovascular stent placing in patients with hemodynamically significant internal carotid artery stenosis results in alteration of perfusion parameters, especially concerning TTP and MTT.