Background: Open surgical closure and small-bore suture-based preclosure devices have limitations when used for transcatheter aortic valve replacement, percutaneous endovascular abdominal aortic aneurysm repair, or percutaneous thoracic endovascular aortic aneurysm repair. The MANTA vascular closure device is a novel collagen-based technology designed to close large bore arteriotomies created by devices with an outer diameter ranging from 12F to 25F. In this study, we determined the safety and effectiveness of the MANTA vascular closure device. Methods and Results: A prospective, single arm, multicenter investigation in patients undergoing transcatheter aortic valve replacement, percutaneous endovascular abdominal aortic aneurysm repair, or thoracic endovascular aortic aneurysm repair at 20 sites in North America. The primary outcome was time to hemostasis. The primary safety outcomes were accessed site-related vascular injury or bleeding complications. A total of 341 patients, 78 roll-in, and 263 in the primary analysis cohort, were entered in the study between November 2016 and September 2017. For the primary analysis cohort, transcatheter aortic valve replacement was performed in 210 (79.8%), and percutaneous endovascular abdominal aortic aneurysm repair or thoracic endovascular aortic aneurysm repair was performed in 53 (20.2%). The 14F MANTA was used in 42 cases (16%), and the 18F was used in 221 cases(84%). The mean effective sheath outer diameter was 22F (7.3 mm). The mean time to hemostasis was 65±157 seconds with a median time to hemostasis of 24 seconds. Technical success was achieved in 257 (97.7%) patients, and a single device was deployed in 262 (99.6%) of cases. Valve Academic Research Consortium-2 major vascular complications occurred in 11 (4.2%) cases: 4 received a covered stent (1.5%), 3 had access site bleeding (1.1%), 2 underwent surgical repair (0.8%), and 2 underwent balloon inflation (0.8%). Conclusions: In a selected population, this study demonstrated that the MANTA percutaneous vascular closure device can safely and effectively close large bore arteriotomies created by current generation transcatheter aortic valve replacement, percutaneous endovascular abdominal aortic aneurysm repair, and thoracic endovascular aortic aneurysm repair devices. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT02908880.

Purpose: To report a prospective, multicenter, observational study (ClinicalTrials.gov identifier NCT01609621) of the safety and effectiveness of tibiopedal access and retrograde crossing in the treatment of infrainguinal chronic total occlusions (CTOs). Methods: Twelve sites around the world prospectively enrolled 197 patients (mean age 71±11 years, range 41-93; 129 men) from May 2012 to July 2013 who met the inclusion criterion of at least one CTO for which a retrograde crossing procedure was planned or became necessary. The population consisted of 64 (32.5%) claudicants (Rutherford categories 2/3) and 133 (67.5%) patients with critical limb ischemia (Rutherford category ≥4). A primary antegrade attempt to cross had been made prior to the tibiopedal attempt in 132 (67.0%) cases. Techniques used for access, retrograde lesion crossing, and treatment were at the operator’s discretion. Follow-up data were obtained 30 days after the procedure. Results: Technical tibiopedal access success was achieved in 184 (93.4%) of 197 patients and technical occlusion crossing success in 157 (85.3%) of the 184 successful tibial accesses. Failed access attempts were more common in women (9 of 13 failures). The rate of successful crossing was roughly equivalent between sexes [84.7% (50/59) women compared to 85.6% (107/125) men]. Technical success did not differ significantly based on a prior failed antegrade attempt: the access success rate was 92.4% (122/132) after a failed antegrade access vs 95.4% (62/65) in those with a primary tibiopedal attempt (p=0.55). Similarly, crossing success was achieved in 82.8% (101/122) after a failed antegrade access vs 90.3% (56/62) for patients with no prior antegrade attempt (p=0.19). Minor complications related to the access site occurred in 11 (5.6%) cases; no patient had access vessel thrombosis, compartment syndrome, or surgical revascularization. Conclusion: Tibiopedal access appears to be safe and can be used effectively for the crossing of infrainguinal lesions in patients with severe lower limb ischemia.

Purpose: To evaluate the performance of peripheral intravascular lithotripsy (IVL) in a real-world setting during endovascular treatment of multilevel calcified peripheral artery disease (PAD). Materials and Methods: The Disrupt PAD III Observational Study ( ClinicalTrials.gov identifier NCT02923193) is a prospective, nonrandomized, multicenter, single-arm observational study assessing the acute safety and effectiveness of the Shockwave Peripheral IVL System for the treatment of calcified, stenotic lower limb arteries. Patients were eligible if they had claudication or chronic limb-threatening ischemia and moderate or severe arterial calcification. Between November 2017 and August 2018, 200 patients (mean age 72.5±8.7 years; 148 men) were enrolled across 18 sites and followed through hospital discharge. Results: In the 220 target lesions, IVL was more commonly used in combination with other balloon-based technologies (53.8%) and less often with concomitant atherectomy or stenting (19.8% and 29.9%, respectively). There was a 3.4-mm average acute gain at the end of procedure; the final mean residual stenosis was 23.6%. Angiographic complications were rare, with only 2 type D dissections and a single perforation following drug-coated balloon inflation (unrelated to the IVL procedure). There was no abrupt closure, distal embolization, no reflow, or thrombotic event. Conclusion: Use of peripheral IVL to treat severely calcified, stenotic PAD in a real-world study demonstrated low residual stenosis, high acute gain, and a low rate of complications despite the complexity of disease.

Cardioprotection from preconditioning reappears 24 h after the initial stimulus. This phenomenon is called the second window of protection (SWOP). We hypothesized that opening of the ATP-sensitive potassium (KATP) channel mediates the protective effect of SWOP. Rabbits were preconditioned (PC) with four cycles of 5-min regional ischemia each followed by 10 min of reperfusion. Twenty-four hours later, the animals were subjected to sustained ischemia for 30 min followed by 180 min of reperfusion (I/R). Glibenclamide (Glib, 0.3 mg/kg ip) or 5-hydroxydecanoate (5-HD, 5 mg/kg iv) was used to block the KATP channel function. Infarct size was reduced from 41.2 ± 2.6% in sham-operated rabbits to 11.6 ± 1.0% in PC rabbits, a 71% reduction ( n = 11, P < 0.01). Treatment with Glib or 5-HD before I/R increased the infarct size to 43.4 ± 2.6 and 37.8 ± 1.9%, respectively ( P < 0.01 vs. PC group, n = 12/group). Sham animals treated with either Glib or 5-HD had an infarct size of 39.0 ± 3.4 and 37.8 ± 1.5%, respectively, which was not different from control (40.0 ± 3.8%) or sham (41.2 ± 2.6%) I/R hearts. Monophasic action potential duration (APD) at 50% repolarization significantly shortened by 28.7, 26.6, and 23.3% in sham animals during 10, 20, and 30 min of ischemia. However, no further augmentation in the shortening of APD was observed in PC hearts. Glib and 5-HD significantly suppressed ischemia-induced epicardial APD shortening, suggesting that 5-HD may not be a selective blocker of the mitochondrial KATP channel in vivo. We conclude that SWOP is mediated by a KATP channel-sensitive mechanism that may have occurred because of the opening of the sarcolemmal KATP channel in vivo.

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The adenosine agonist 2-chloro- N 6-cyclopentyladenosine (CCPA) induces delayed ischemic protection in vivo. We hypothesized that this protection is mediated by opening of ATP-sensitive K+(KATP) channels and increased synthesis of 72-kDa heat shock protein (HSP 72). Six groups ( n = 9–13 animals/group) of animals were studied: group I, control rabbits that received no treatment; group II, animals given glibenclamide (0.3 mg/kg iv) 30 min before ischemia; group III, animals given 5-hydroxydecanoate (5-HD; 5 mg/kg iv) 15 min before ischemia; group IV, rabbits treated with CCPA (0.1 mg/kg iv) 24 h before ischemia; and groups V and VI, CCPA-treated animals that received the KATP-channel blockers glibenclamide or 5-HD, respectively, 30 or 15 min before ischemia. All animals were subjected to ischemia by 30 min of coronary artery occlusion followed by 3 h of reperfusion. Risk area was delineated by injection of 10% Evans blue dye, and infarct size was determined by triphenyltetrazolium staining. Action potential duration (APD) was measured with an epicardial electrode. HSP 72 was measured by Western blotting. CCPA caused a significant reduction in infarct size [12.02 ± 1.0 vs. 40.0 ± 3.8% (%area at risk) in controls, P < 0.01] that was blocked by glibenclamide (36.2 ± 3.1%, P < 0.01) and 5-HD (35.0 ± 2.9%, P < 0.01). Glibenclamide and 5-HD did not change infarct size in control rabbits. These blockers significantly suppressed ischemia-induced APD shortening in control and CCPA-treated animals. CCPA treatment did not induce HSP 72 in hearts. These data suggest that adenosine-initiated delayed protection is mediated via opening of KATP channels but does not involve the synthesis of HSP 72.

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Ischemic preconditioning (PC) induces delayed phase of protection, known as the second window of protection (SWOP). We investigated this phenomenon in rat and correlated it with the expression of 72-kDa heat shock protein (HSP 72). Rats were preconditioned with 1, 2, and 3 cycles of 5-min left anterior descending artery occlusions, each separated by a 10-min reperfusion (PC × 1, PC × 2 and PC × 3, respectively). Another group of rats was preconditioned with heat shock (HS) by raising temperature to 42°C for 15 min. Twenty-four hours later, rats were given sustained ischemia for 30 min and 90 min of reperfusion. Infarct sizes (%risk area) were 40.0 ± 7.5, 37.6 ± 5.6, and 47.6 ± 2.4 (mean ± SE) for PC × 1, PC × 2, and PC × 3 hearts, respectively, which were not different from the sham (49.9 ± 3.9, P > 0.05). In contrast, infarct size was reduced from 47.5 ± 3.8% in sham to 4.7 ± 2.3% ( P < 0.01) 24 h after HS. Additionally, early PC significantly reduced infarct size from 47.5 ± 3.8% in controls to 6.0 ± 1.2 and 5.0 ± 1.1% with PC × 1 and PC × 3. Repeated PC cycles induced over a threefold increase in HSP 70 mRNA after 2 h compared with sham ( P < 0.05). HSP 72, which increased 24 h after PC or HS, was not significantly different between the two PC stimuli. We conclude that PC does not induce SWOP in rat heart despite enhanced expression of HSP 72. In contrast, HS-induced delayed protection was associated with enhanced accumulation of HSP 72. It is possible that SWOP and HS have distinct mechanisms of protection that may not be exclusively related to HSP 72 expression.