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Background: Chronic total occlusion (CTO) remains the most complex anatomical subset of lesions in percutaneous coronary intervention (PCI), often requiring advanced techniques and technologies, including the use of microcatheters. Methods: The BIOMICS study is a premarket first-in-human prospective, multicenter, open-label, single-arm trial investigating the safety and efficacy of a novel coronary microcatheter (BioMC, Biosensors International) in 100 patients with symptoms of ischemia undergoing elective CTO-PCI. The primary efficacy end point of the study was device success defined according to the CTO-ARC (Chronic Total Occlusion Academic Research Consortium) criteria namely the ability of the microcatheter to successfully facilitate placement of a guide wire beyond the occluded coronary segment. The primary safety end point was the incidence of in-hospital cardiac death or myocardial infarction at hospital discharge. Results: Hundred patients were recruited between March 2022 and January 2023. The primary efficacy end point was achieved in 75% of patients (95% CI, 65.3%-83.1%; P < .0001 for superiority compared to the prespecified performance goal of 54%). The primary safety end point of in-hospital cardiac death or myocardial infarction was observed in 2% of the patients. There were no study device-related coronary perforations or device failures. Conclusions: The use of a novel coronary microcatheter during CTO-PCI was associated with a high device success and an excellent safety profile.
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Dual-lumen microcatheters (DLMC) are utilized in challenging wiring scenarios as well as for contrast and medication injections. Nonetheless, lesion characterization remains extremely challenging in many cases. We describe a DLMC-facilitated technique which can assist in locating the distal anastomosis while navigating an occluded bypass graft during retrograde chronic total occlusion recanalization, as well as in the differential diagnosis of abrupt vessel closure. This "DLMC Pullback Injection" technique is performed by injecting contrast through the over-the-wire port of the DLMC, while the latter is quickly pulled back across the region of interest in a dynamic fashion. We believe this technique has the potential to solve challenging scenarios and to enrich the complex percutaneous coronary intervention operator's armamentarium.
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Background: Transseptal puncture (TSP) performed with the Brockenbrough (BRK) needle is technically demanding and carries potential risks. The back end of the percutaneous transluminal coronary angioplasty (PTCA) guidewire is blunt and flexible, with good support, it can puncture the right ventricle-free wall, which is thicker than the atrial-septum. The guidewire is thin and easy to manipulate. This study evaluated the performance of TSP with a PTCA guidewire and microcatheter without a needle. Methods: The back end of a PTCA guidewire was advanced into the Tiger (TIG) catheter, within the SL1 sheath, to puncture the fossa ovalis (FO) under fluoroscopy. Subsequently, the microcatheter was inserted into the left atrium (LA) above the guidewire, and the front end of the guidewire was exchanged in the LA. After the puncture site was confirmed by contrast, the TIG catheter and a 0.032 inch wire were advanced into the LA. Finally, the sheath, with the dilator, was advanced over the wire into the LA. The safety margin of this method was tested in a pig model. Results: The puncture was successful in all seven pigs tested with a puncture-to-sheath entry time of < 20 minutes and no procedure-related complications. The method was successfully used to perform a difficult TSP in a patient with an extremely tortuous inferior vena cava, in whom puncture with a BRK needle had repeatedly failed. Conclusions: Cardiologists may use the PTCA guidewire and microcatheter as an alternative to the needle while performing TSP in special conditions, such as an extremely tortuous inferior vena cava.
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Rationale and objectives: A new microcatheter was recently developed claiming to reduce beads reflux in drug-eluting bead transarterial chemoembolization (DEB-TACE). The aim of this study was to compare the reflux control microcatheter ability versus a standard microcatheter for TACE treatment in patients with hepatocellular carcinoma. Material and methods: Patients were prospectively included between November 2017 and February 2022. They received a DEB-TACE treatment with charged radiopaque beads using standard microcatheters or the SeQure reflux control microcatheter (Guerbet, France) and were assigned respectively to a control and a test group. Beads distribution mismatch was evaluated between the targeted territory on treatment planning CBCT and beads' spontaneous opacities on the post-intervention CBCT and the 1-month CT scanner. Results: Twenty-three patients (21 men, median age 64 years [12.5 years]) with 37 hepatocellular carcinoma nodules were treated. The control group consisted of 13 patients - 19 nodules, while the test group included ten patients - 18 nodules. Non target embolization (NTE) was found in 20 % (2/10) of patients in the test group and 85 % (11/13) in the control group. NTE involved only an adjacent segment in the test group while it affected the adjacent biliary sector or even the contralateral liver lobe in the control group. No complication linked to NTE was found in the test group, while it led to one case of ischemic cholangitis and another case of biloma in the control group. Conclusion: The reflux control microcatheter may be efficient in reducing NTE and thus eventual adverse events in comparison to standard of care end-hole microcatheters.
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The retrograde approach in chronic total occlusion (CTO) interventions often encounters significant challenges, particularly, when aligning the retrograde microcatheter (MC) with the antegrade system is difficult, complicating or even preventing standard externalization. To address these issues, techniques like the "tip-in" have proven to be effective backup strategies. We introduce the "Manual Microcatheter-tip Modification" (MMM) technique as an alternative when the "tip-in" method faces complications. We present a case of a left anterior descending CTO where MMM was successfully employed for the first time, enabling successful revascularization by manually modifying the MC tip to engage the retrograde guidewire. We explore the technical details within the framework of contemporary CTO PCI. This new technique could enhance the management of CTO interventions, offering innovative solutions when traditional externalization methods are problematic.
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Infections associated with healthcare manipulations, particularly bloodstream infections stemming from catheters and medical devices, significantly heighten the probability of vertebral osteomyelitis. The diagnosis of infective endocarditis (IE) frequently overlaps with vertebral osteomyelitis (VO). In cases where individuals are suspected of having hematogenous vertebral osteomyelitis and have an intravascular catheter or device, it is recommended to undertake blood culture collection. We present a case of a 39-year-old male with a history of interventional AVM embolization and cerebral angiography, experiencing recurrent vertebral osteomyelitis. No definitive source of infection had been found, and transthoracic echocardiography (TTE) yielded negative results for IE. In Trans Esophageal Echocardiography (TEE), a retained micro-catheter extending from the aortic arch to the inguinal artery was discovered. Although we cannot definitively attribute the source of the osteomyelitis to the retained micro-catheter, no episodes of infection have been reported ever since. This case underscores the need to enhance our approaches and guidelines related to operating protocols in the surgical setting. Improving these guidelines can prevent similar occurrences in the future, emphasizing the importance of continuous improvement in healthcare practices.
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INTRODUCTION AND IMPORTANCE: Embolization of an arteriovenous malformation (AVM) via the anterior inferior cerebellar artery (AICA) is difficult. The "pressure cooker" technique in the AICA via a marathon microcatheter can be effective. CASE STUDY: A 43-year-old man with a cerebellar hematoma involving the brainstem. Angiography revealed an AVM supplied by the right AICA. Embolizing the AVM by casting an Onyx-18 liquid embolic system assisted by the "pressure cooker" technique was planned. An Apollo microcatheter was used for Onyx casting, and a Marathon microcatheter was used to establish a coiling plug to prevent Onyx reflux. The AVM was obliterated. Postoperatively, burr hole drainage of the cerebellar hematoma was performed. Postoperative computed tomography showed that the cerebellar hematoma and hydrocephalus had resolved. Magnetic resonance imaging revealed that there was no new serious infarction from damage to the cerebellum or brainstem. The patient recovered well. CLINICAL DISCUSSION: During Onyx casting, the drawback is that reflux can occlude normal vessels. The "pressure cooker" technique was useful for preventing Onyx reflux and for driving the Onyx to penetrate the AVM. However, it was difficult to use this technique in slim AICA; the Marathon microcatheter had a thinner tip than other microcatheters, and it can be used to establish the "pressure cooker" technique. This technique provides more solutions for AVMs in transarterial embolization through small feeding arteries. CONCLUSION: In a selective case, it was feasible to use the "pressure cooker" technique in the AICA via a Marathon microcatheter to embolize the AVM.
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We present a case of prophylactic endovascular embolization in a 51-year-old man with necrotizing pancreatitis (NP) before undergoing endoscopic necrosectomy (EN). Contrast-enhanced CT imaging revealed the presence of a walled-off necrosis (WON) surrounding the pancreas, with the splenic artery coursing through the cavity. The splenic artery was embolized using n-butyl-2-cyanoacrylate (NBCA) and coils to mitigate the risk of massive bleeding in EN. A newly developed polytetrafluoroethylene (PTFE)-coated microcatheter was used to inject NBCA, enabling embolization of a long segment of the splenic artery without adhering to the vessel wall. Coils were placed distal and proximal to the embolized segment to optimize control. Over 5 sessions of EN, no massive bleeding was encountered. This report demonstrates the benefits of utilizing PTFE-coated microcatheters for enhanced safety and maneuverability during embolization with NBCA. Furthermore, it highlights the importance of prophylactic embolization during EN for managing NP.
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INTRODUCTION: Distal medium vessel occlusion (DVO) thrombectomy has been shown to be efficacious with safety profiles comparable to large vessel occlusion (LVO) thrombectomy. A novel, highly-trackable, bevel-tipped Zoom 35 catheter can be used as an aspiration catheter for DVO thrombectomy. METHODS: This is a retrospective, single-arm, multi-institutional observational study evaluating the efficacy and safety of aspiration thrombectomy for DVO using the Zoom 35 catheter. Patient demographics, presenting and discharge NIHSS, primary and rescue thrombectomy, site of occlusion, TICI score, and intracranial hemorrhage were chart abstracted. Descriptive statistics were used to evaluate the efficacy and safety of thrombectomy. RESULTS: Fourteen patients (mean age 66.64 ± 13.75 years) were included. The mean NIHSS at presentation was 10.79 ± 5.48, and the mean ASPECTS was 9.00 ± 0.89. Nine patients (64.3%) received tPA. Primary occlusion location was M3 in nine cases (64.3%), M2/M3 junction in two cases (14.3%), A2 in one case (7.1%), A3 in one case (7.1%), and P1 in one case (7.1%). TICI scores were 3 in seven cases (50.0%), 2C in three cases (21.4%), and 2B in four cases (28.6%). There was one postoperative SAH (7.1%) and one asymptomatic ICH (7.1%). Mean discharge NIHSS was 3.38 ± 4.44, with a mean decrease of 7.31 from presentation (p < 0.0001, t-test). CONCLUSION: Zoom 35 beveled-tip aspiration microcatheters are highly trackable and associated with improved radiographic and clinical outcomes for the treatment of DVO with a good safety profile.
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BACKGROUND: To evaluate the efficacy of a catheter system using a 3-Fr sheath with a steerable microcatheter through right upper limb artery access for superselective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) to treat right maxillary sinus squamous cell carcinoma (MS-SCC). MATERIAL AND METHODS: We retrospectively studied 46 sessions in eight patients treated between November 2020 and February 2023 using the catheter system briefly described below. A 3-Fr sheath was inserted into the distal radial, conventional radial, or brachial arteries. A coaxial catheter system with a 2.9-Fr steerable microcatheter and a 1.9-Fr microcatheter was advanced into the brachiocephalic artery. The right common carotid artery was selected by bending the tip of the steerable microcatheter. Coil embolization and intra-arterial cisplatin infusion after selecting each external carotid artery branch were achieved using this catheter system. RESULTS: Cisplatin infusion and coil embolization were successful in all sessions. Arterial occlusion at the sheath insertion sites was found in 29.4% (5/17) of the distal radial arteries and 33.3% (3/9) of the conventional radial arteries. No other major complications were observed during the procedure. CONCLUSION: Using a 3-Fr catheter system with a steerable microcatheter through right upper limb artery access is a feasible method for RADPLAT in treating right MS-SCC.
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Microcatheters capable of active guidance have been proven to be effective and efficient solutions to interventional surgeries for cardiovascular and cerebrovascular diseases. Herein, a novel microcatheter made of two biocompatible materials, shape memory alloy (SMA) and polyethylene (PE), is proposed. It consists of a reconfigurable distal actuator and a separate polyethylene catheter. The distal actuator is created via embedding U-shape SMA wires into the PE base, and its reconfigurability is mainly dominated by the shape memory effect (SME) of SMA wires, as well as the effect of thermal mismatch between the SMA and PE base. A mathematical model was established to predict the distal actuator's deformation, and the analytical solutions show great agreement with the finite element results. Structural optimization of such microcatheters was carried out using the verified analytical model, followed by fabrication of some typical prototypes. Experimental testing of their mechanical behaviors demonstrates the feasibility of the structural designs, and the reliability and accuracy of the mathematical model. The active microcatheter, together with the prediction model, will lay a solid foundation for rapid development and optimization of active navigation strategies for vascular interventions.
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Objective We noticed that the X-ray absorption value of the tip of each microcatheter used for aneurysm treatment varied from product to product. We hypothesized that the differences were caused by variations in the metal's density braid, which could be related to the ability of the tip to retain its shape. Methods The X-ray absorption value of each microcatheter tip was measured. Next, heat forming was performed using a shaping mandrel at 6 mm and 90 degrees to determine whether there was a correlation between the X-ray absorption value and the forming angle. Next, the optimal mandrel angle for forming each microcatheter at 90 degrees was investigated. We also examined the shape retention after 20 times wire insertions into each microcatheter. Conclusion It was found that the higher the X-ray absorption value, the harder it was for the microcatheter to be formed. The mandrel angle required to form 90 degrees was determined by the X-ray absorption value. The higher the X-ray absorption value, the higher the shape retention of the tip shape. The heat formation and shape-retention conditions of the microcatheter tip were correlated with the X-ray absorption value of the metal braid. Even for unknown microcatheters, the optimum shaping conditions can be inferred from the X-ray absorption value.
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In the present era, the intricacy of procedures undertaken by a pediatric interventional cardiologist has increased, primarily attributed to dealing with smaller, younger patients with more complex anatomies. To adapt to these smaller and more complex patients, we must adapt our interventions and our equipment to perform these procedures. This article outlines various innovative applications of the SwiftNinja steerable microcatheter within the pediatric cardiac catheterization laboratory.
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INTRODUCTION AND IMPORTANCE: The twig-like middle cerebral artery (MCA) is rare and has a plexiform network of small vessels that replaces the MCA trunk, with a prevalence ranging from 0.11 %-1.17 %. It can be associated with an aneurysm. A Marathon microcatheter may be an alternative for coiling procedures. However, this technique has rarely been reported. PRESENTATION OF CASE: A 63-year-old man suffered from headaches. The neurological examination results were unremarkable. Angiography revealed a twig-like MCA with an unruptured aneurysm. Due to stenosis of the aneurysm neck, a Marathon microcatheter was used to successfully reach the aneurysm, and coiling was completed with Chinese Visee coils. Postoperatively, the patient recovered uneventfully. Due to the lack of ischemic changes in the right hemisphere, the patient was kept under follow-up observation. At the 8-month follow-up by telephone, the patient was healthy. CLINICAL DISCUSSION: Aneurysms in the twig-like MCA may have stenosis of the aneurysm neck, and routine microcatheters used to deliver coils are often too thick to catheterize the aneurysm neck. The Marathon microcatheter has a distal inner diameter (ID) of 0.013, and as an alternative for coiling procedures, it may be soft enough to thin enough to go into the aneurysm. However, it can be used in the delivery of certain coils. CONCLUSION: Aneurysms in the twig-like MCA are difficult to catheterize with the routine microcatheters used to deliver coils. A Marathon microcatheter may be used to perform the coiling procedure. However, only certain coils that match the Marathon microcatheter can be chosen.
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OBJECTIVES: To demonstrate in vivo redistribution of the blood flow towards HCC's lesions by utilizing two-dimensional perfusion angiography in b-TACE procedures. MATERIAL AND METHODS: In total, 30 patients with 35 HCC nodules treated in the period between January 2019 and November 2021. For each patient, a post-processing software leading to a two-dimensional perfusion angiography was applied on each angiography performed via balloon microcatheter, before and after inflation. On the colour map obtained, reflecting the evolution of contrast intensity change over time, five regions of interests (ROIs) were assessed: one on the tumour (ROI-t), two in the immediate peritumoural healthy liver parenchyma (ROI-ihl) and two in the peripheral healthy liver parenchyma (ROI-phl). The results have been interpreted with a novel in silico model that simulates the hemodynamics of the hepatic arterial system. RESULTS: Among the ROIs drawn inside the same segment of target lesion, the time-to-peak of the ROI-t and of the ROI-ihl have a significantly higher mean value when the balloon was inflated compared with the ROIs obtained with deflated balloon (10.33 ± 3.66 s vs 8.87 ± 2.60 s (p = 0.015) for ROI-t; 10.50 ± 3.65 s vs 9.23 ± 2.70 s (p = 0.047) for ROI-ihl). The in silico model prediction time-to-peak delays when balloon was inflated, match with those observed in vivo. The numerical flow analysis shows how time-to-peak delays are caused by the obstruction of the balloon-occluded artery and the opening of intra-hepatic collateral. CONCLUSION: The measurements identify predictively the flow redistribution in the hepatic arteries during b-TACE, supporting a proper positioning of the balloon microcatheter.
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Carcinoma Hepatocelular , Quimioembolização Terapêutica , Neoplasias Hepáticas , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/irrigação sanguínea , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/irrigação sanguínea , Masculino , Feminino , Idoso , Pessoa de Meia-Idade , Quimioembolização Terapêutica/métodos , Angiografia/métodos , Estudos RetrospectivosRESUMO
Coil migration can occur when coil embolization is used for treating pseudoaneurysms associated with large arteries. The double microcatheter technique is useful for preventing coil migration; the balloon catheter can reduce blood flow and active bleeding upon balloon inflation, and can also compress the bleeding point and arrest bleeding temporarily. We report a case describing the management of a pseudoaneurysm with coil embolization using double microcatheters and a balloon catheter to control blood flow and prevent coil migration. A 73-year-old male patient presented with a pseudoaneurysm of the celiac artery arising from the splenic artery stump following surgery. Coil embolization of the pseudoaneurysm using a double microcatheter embolization technique with a balloon catheter was considered. A balloon catheter was inserted into the celiac artery and active bleeding was temporarily arrested with the inflated balloon. First, a microcatheter was inserted into the balloon catheter, and another microcatheter was placed in the celiac artery. An electrical detachable coil was inserted into the proximal common hepatic artery just distal to the pseudoaneurysm. The second electrically detachable coil was inserted while the first coil remained attached. After detachment of the second coil, additional electrically detachable coils were inserted for similar embolization. The balloon was gradually deflated. Finally, the first coil was detached and we confirmed absence of the bleeding. Our case report demonstrated that a balloon catheter can control the flow vessels, and the double microcatheter embolization technique with a balloon catheter is useful for coil embolization in high-flow or large vessels.
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BACKGROUND: Aniridia is a rare eye disorder with a high incidence of glaucoma, and surgical intervention is often needed to control the intraocular pressure (IOP). Here, we reported a case of illuminated microcatheter-assisted circumferential trabeculotomy (MAT) performed on an aniridic glaucoma patient following a previous failed angle surgery. The surgical procedures for aniridic glaucoma were also reviewed. CASE PRESENTATION: A 21-year-old man, diagnosed with aniridic glaucoma, came to our hospital consulting for the poor control of left eye's IOP despite receiving goniotomy surgery 3 years ago. The IOP was 26 mmHg with maximum topical antiglaucoma eyedrops. The central cornea was opaque and the majority of iris was absent. The gonioscopy and ultrasound biomicroscopy (UBM) demonstrated that 360° anterior chamber angle was closed. The whole exome sequencing of peripheral blood confirmed a 13.39 Mb copy number loss at chromosome 11p15.1p13, containing PAX6 and WT1 gene. The 360° MAT surgery was performed on his left eye. At 1-year follow-up, the IOP was 19mmHg with 2 kinds of topical antiglaucoma medications, and the postoperative UBM demonstrated the successful incision of the anterior chamber angle. CONCLUSIONS: The case presented here exhibited a case of aniridic glaucoma treated by MAT surgery. The MAT surgery may be an effective option for IOP control in aniridic glaucoma patients following a previous failed angle surgery.
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Aniridia , Glaucoma , Trabeculectomia , Humanos , Masculino , Adulto Jovem , Seguimentos , Glaucoma/diagnóstico , Glaucoma/cirurgia , Gonioscopia , Pressão Intraocular , Fator de Transcrição PAX6 , Estudos Retrospectivos , Trabeculectomia/métodos , Resultado do TratamentoRESUMO
Background: Traditional brain activity monitoring via scalp electroencephalography (EEG) offers limited resolution and is susceptible to artifacts. Endovascular electroencephalography (eEEG) emerged in the 1990s. Despite early successes and potential for detecting epileptiform activity, eEEG has remained clinically unutilized. This study aimed to further test the capabilities of eEEG in detecting lateralized epileptic discharges in animal models. We hypothesized that eEEG would be able to detect lateralization. The purpose of this study was to measure epileptiform discharges with eEEG in animal models with lateralization in epileptogenicity. Materials and methods: We inserted eEEG electrodes into the transverse sinuses of three pigs, and subdural electrodes (SDs) on the surfaces of the left and right hemispheres. We induced epileptogenicity with penicillin in the left brain of pigs F00001 and F00003, and in the right brain of pig F00002. The resulting epileptiform discharges were measured by eEEG electrodes placed in the left and right transverse sinuses, and conducted comparisons with epileptiform discharges from SDs. We also had 12 neurological physicians interpret measurement results from eEEG alone and determine the side (left or right) of epileptogenicity. Results: Three pigs were evaluated for epileptiform discharge detection using eEEG: F00001 (7 months old, 14.0 kg), F00002 (8 months old, 15.6 kg), and F00003 (8 months old, 14.4 kg). The eEEG readings were compared with results from SDs, showing significant alignment across all subjects (p < 0.001). The sensitivity and positive predictive values (PPV) were as follows: F00001 had 0.93 and 0.96, F00002 had 0.99 and 1.00, and F00003 had 0.98 and 0.99. Even though one of the neurological physicians got all sides incorrect, all other assessments were correct. Upon post-experimental dissection, no abnormalities were observed in the brain tissue or in the vascular damage at the site where the eEEG was placed, based on pathological evaluation. Conclusion: With eEEG, lateralization can be determined with high sensitivity (>0.93) and PPV (>0.95) that appear equivalent to those of subdural EEG in the three pigs. This lateralization was also discernible by neurological physicians on visual inspection.
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AIM: To evaluate the efficacy and safety of Usights UC100 illuminated microcatheter in microcatheter-assisted trabeculotomy (MAT). METHODS: Totally 10 eyes of 10 patients with primary open angle glaucoma (POAG) who underwent MAT facilitated by Usights UC100 (5 eyes) or iTrack (5 eyes) were reviewed. The success of this surgery was defined as intraocular pressure (IOP) <22 mm Hg with >30% reduction, without oral glaucoma medications, or additional glaucoma surgery. RESULTS: The mean pre-operative IOP was 25.38±10.22 mm Hg in the Usights UC100 group and 19.98±3.87 mm Hg in the iTrack group. MAT was achieved in all eyes in both groups. The success rates for the Usights UC100 group and iTrack groups were in all and 4 eyes, respectively. Both microcatheters produced a statistically significant reduction in IOP, and eyes using Usights UC100 achieved a lower IOP than the iTrack group at 3mo follow-up (12.58±1.52 and 14.84±1.89 mm Hg, respectively), but no statistical significance was there. No severe side effects were observed in either group. CONCLUSION: MAT using Usights UC100 or iTrack both achieve significant pressure reduction in cases of POAG, and Usights UC100 is as safe as iTrack.
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BACKGROUND: It is not uncommon to encounter retrograde microcatheter-uncrossable lesions in retro-recanalization of Chronic Total Occlusion (CTO) cases, existing solutions were time-consuming or complicated to operate. Therefore, the present study aimed to propose and evaluate the feasibility, safety of a novel technique termed Active Pulling retrograde microcatheter crossing Technique (APT) during retrograde CTO percutaneous coronary intervention (PCI). METHODS: We retrospectively collected retrograde CTO-PCI cases from February 2017 to April 2023, only cases with the retrograde wire successfully crossed the CTO lesion were analyzed. The baseline clinical characteristics, angiographic characteristics, procedural details, and in-hospital major adverse cardiac events (MACEs) were compared. RESULTS: A total of 80 CTO cases were divided into the APT group and the non-APT group according to whether the APT was applied in the procedure. The APT group had a higher rate of device success than the non-APT group (100% vs. 85%, P = 0.013), with shorter duration (5.3 ± 3.8 vs. 18.6 ± 5.9 min, P < 0.001) and a smaller number of retrograde microcatheters were used (P < 0.001). In the APT group, the average air kerma radiation exposure was lower (2.7 ± 1.2 vs. 4.3 ± 1.7 Gy, P < 0.001), the fluoroscopy time (69.0 ± 15.0 vs. 88.1 ± 18.9 min, P < 0.001) and the procedure time (116.2 ± 22.2 vs. 131.6 ± 28.7 min, P = 0.009) was shorter than the non-APT group. The technical success rate of both groups reached 100% while the procedure success rate was higher in the APT group than the non-APT group (100% vs. 85%, P = 0.13). CONCLUSIONS: The APT is an easy and safe technique that can greatly improve procedural efficiency without adding other instruments, and allows the retrograde microcatheter to quickly crossing the CTO body after successful retrograde wire externalization.