Laser Ablation Research Articles

Boron-Doped Endohedral Metallofullerenes: Synthesis and Computational Analysis of a Family of Heteroatom-Doped Molecular Carbons.

Gas-phase synthesis and detection of boron-doped nitride clusterfullerenes and a large variety of monometallofullerenes have been achieved using a pulsed laser vaporization cluster source. Density functional theory (DFT) calculations show that the electronic structures of boron-doped endohedral metallofullerenes differ from those of the pristine all-carbon cages due to the lack of one electron upon boron substitution. For monometallofullerenes, this is likely the main reason for the somewhat different abundance distribution observed for boron-doped with respect to all-carbon cages. Moreover, the three carbon atoms directly bonded to B show the most negative charges in the cage, and consequently, metal atoms are primarily placed nearby boron.

Electrochemical Aptamer-Based Biosensors for Cocaine Detection in Human Saliva: Exploring Matrix Interference.

Electrochemical aptamer-based biosensors (E-aptasensors) are emerging platforms for point-of-care (POC) detection of complex biofluids. Human saliva particularly offers a noninvasive matrix and unprecedented convenience for detecting illicit drugs, such as cocaine. However, the sensitivity of cocaine E-aptasensors is significantly compromised in saliva. Herein, we investigated the influence of salivary components on the sensing performance of a methylene blue (MB)-labeled classic cocaine aptamer by square-wave voltammetry (SWV), and in parallel, we report the development and optimization of a disposable E-aptasensor for cocaine detection fabricated by laser ablation. Cyclic voltammetry (CV), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were used to study the cleanliness and surface topography of the disposable electrode surface. To enhance the sensing performance of the disposable platform, we developed a co-immobilization strategy by introducing both the target and 6-mercapto-1-hexanol (MCH) into the aptamer immobilization solution, achieving optimal sensing performance at the aptamer-to-MCH ratio of 1:100. In a buffer solution, we revealed that the aptasensor performs best at low ionic strength, the absence of multivalent ions, and neutral pH conditions, while salivary components such as viscosity and mucin have minimal impact. However, upon transition to human saliva, the presence of salivary proteins exerted a profound effect on the sensing performance. To reduce this impact, we discovered that a high NaCl concentration could significantly enhance the sensing response in saliva. This approach circumvents centrifugation and extensive dilution and facilitates cocaine detection in human saliva through a straightforward "mix-and-detect" method. This disposable aptasensor achieved a limit of detection (LOD) of 3.7 μM in 90% saliva, demonstrating immense promise for the application of electrochemical aptasensors in detecting cocaine, especially when administered via smoking.

Evaluating efficacy and outcomes: comparison of laser treatment and crystallized phenol in pilonidal sinus disease.

The aim of this study is to comprehensively evaluate the efficacy of laser ablation and crystallized phenol application in the treatment of pilonidal sinus disease, focusing on treatment success, recurrence rates, complications, and the patients' return to normal life. Data from patients treated for pilonidal sinus disease with laser ablation and crystallized phenol application at our clinic between January 2020 and September 2023 were retrospectively reviewed. Preoperative data including pit counts, disease stage, preoperative pilonidal abscess history, disease duration (week), treatment success, recurrence/persistent disease, postoperative complications, healing time (days), and visual analogue scale (VAS) scores on postoperative days 1 and 7, as well as return to normal life (days), were analyzed. A total of 121 patients were included in the study, with 51 receiving laser ablation and 70 receiving crystallized phenol application. The postoperative outcomes revealed that the wound healing period and postoperative VAS values were statistically significantly better in the laser ablation group. Wound healing was faster and postoperative pain was less in the laser group compared to the phenol group. According to this study, both methods can successfully treat the disease in selected cases.

Transscleral Pars Plana Choroid Ablation Using the Iridex Laser System Yields Improvements for Surgical Insertion of the Port Delivery Implant in a Minipig Model.

To evaluate an alternative surgical approach for Port Delivery System with ranibizumab (PDS) implant and a novel application of Iridex laser system in Gottingen minipig model. A total of seventeen male minipigs (Part 1: 9 animals in non-recovery and Part 2: 8 animals observed for 8-days post-surgery Part 2) received PDS implant insertion into each eye. The effect of Iridex 810 nm infrared diode laser with varying energy (power or duration) on transscleral pars plana ablation, surrounding ocular tissue and postsurgical vitreous hemorrhage (VH) was investigated. The most effective laser parameters for transscleral pars plana ablation in mitigating vitreous hemorrhage with no surrounding tissue damage were continuous wave mode, 1750 mW, 1000 ms, and 16 spots (8 overlapping spots/sweep applied over 2 rows) across a 4 mm segment, posterior to the limbus, delivering a total energy of 28 J. Minimal self-limiting scleral hemorrhage was observed with two of the implants and no VH were observed. µCT imaging was consistent with clinical ophthalmic. On microscopic observations, no tissue damage was observed at these laser settings. This Göttingen minipig model demonstrated a novel application of Iridex laser for transscleral pars plana ablation that streamlines the PDS implantation surgery.

The Distribution of Rare Earth Elements in Coal Fly Ash Determined by LA-ICP-MS and Implications for Its Economic Significance

Coal fly ash represents a potential resource of some critical elements, including rare earth elements (REEs), which are retained and concentrated during coal combustion. Understanding the distribution and modes of occurrence of REEs within fly ash is vital to developing effective recovery methods and enhancing their economic value. Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was applied to investigate the in situ elemental constituents of coal fly ash phases, including aluminosilicates, Ca-(Fe)-enriched aluminosilicates, Fe-oxides, and SiO2/Quartz, in order to explore the distribution of REEs in combustion products. LA-ICP-MS results show that V, Cr, and Nb are mainly enriched in Ca-Ti-enriched aluminosilicates with trace element concentrations referenced to the original fly ash composition. Lithium is primarily enriched in SiO2 glassy grains, followed by Ca, (Fe)-enriched aluminosilicates. Co, Ni, and Cu present a concomitant distribution in the Fe-enriched phases, such as Fe-oxides and Fe-enriched aluminosilicates. The chondrite normalized REE distribution patterns show characteristics of LREE enrichment and Eu-negative anomalies in most phases, while the REE patterns of SiO2 glassy grains have a distinct positive anomaly in Sm, Gd, and Dy, coupled with a deficiency in LREEs. Compared to feed coal, elements such as Li, V, Cr, Co, Ni, and Nb and REEs are enriched 2~10 times in various phases of fly ash, with REEs notably concentrated six times higher in aluminosilicates and Ca-Ti-enriched aluminosilicates than the original coal. This study further discusses the feasibility, calibration principles, and advantages of using LA-ICP-MS to determine REE distribution, as well as the economic implications of REE extraction from coal fly ash.

Protein misfolding by manganese (III) oxide nanoparticles generated by pulsed laser ablation in liquids

The high demand for metal oxide nanoparticles for applications in various fields has led to increased research and investigation. However, one tends to neglect the harmful effects of these synthesized nanoparticles on human health. Mn2O3 nanoparticles are a type of metal oxide nanoparticle that can have harmful effects if ingested or inhaled. In this study, Mn2O3 nanoparticles are synthesized using laser ablation at the manganese-water interface. The structural and optical properties of the nanoparticles are studied using HR-TEM, Micro-Raman, Ultraviolet–visible (UV–vis), and Photoluminescence spectroscopy. The cubic bixbyite α-Mn2O3 nanoparticles produced by laser ablation are used for studying their role in inhibiting or promoting protein fibrillation. Different concentrations of α-Mn2O3 nanoparticles are added to Human serum albumin (HSA) protein, where the fibrillation of the protein is investigated with the help of thioflavin T (ThT) dye using fluorescence spectroscopy. The protein misfolded on adding the nanoparticles that could be seen in the images obtained using fluorescence microscopic imaging, where the HSA forms a dense network of fibrils. In-vitro studies reveal that the increasing concentration of the nanoparticles increases the fibrillation of the HSA protein.

CXL: Challenges and updates

Corneal cross‐linking (CXL) is a critical treatment for keratoconus that combines UVA light and riboflavin (vitamin B2). This procedure received FDA approval in 2016 based on studies by Sykakis et al. (2015) which indicated that CXL could stabilize keratoconus, prevent myopia progression, and improve uncorrected distance visual acuity (UDVA). Despite the promising results, the studies had potential biases and a low number of randomized controlled trials (RCTs).The two primary methods of CXL are epithelium‐off (epi‐off) and epithelium‐on (epi‐on or transepithelial). Epi‐off CXL involves removing the corneal epithelium to allow riboflavin penetration, whereas epi‐on CXL retains the epithelium, reducing patient discomfort but potentially being less effective. NG et al. (2021) found no significant difference in outcomes between these methods, though epi‐on showed fewer side effects such as corneal haze.Accelerated CXL protocols have been developed to increase efficiency. Karam et al. (2023) compared these protocols, revealing that a 10‐minute protocol with 9 mW/cm2 UVA exposure provided better outcomes than a 5‐minute protocol with 18 mW/cm2. Accelerated methods are becoming more common due to their reduced treatment time.In pediatric cases, both conventional and accelerated CXL are effective, although the transepithelial method had a lesser impact, as concluded by Mahdavi Fard et al. (2020). Additionally, combined procedures known as CXL+ integrate CXL with other treatments like laser ablation. The Athens Protocol, developed by Dr. Kanellopoulos, combines topography‐guided laser ablation with CXL to address irregular astigmatism and coma in keratoconus patients.New riboflavin formulations and delivery methods, such as isotonic riboflavin and iontophoresis, have been developed to enhance riboflavin penetration and effectiveness. Glaukos' (Avedro) Mosaic System and the "sub400" protocol for ultrathin corneas are notable advancements, offering customized treatments based on individual corneal characteristics.

Laser surface processing technology for performance enhancement of TENG

<p>The triboelectric nanogenerator (TENG), as a new energy harvesting device, can efficiently harvest mechanical energy from the environment to provide continuous power for electronic devices, which has great potential for powering intelligent distributed network. Laser processing technology, which enables structural, phase, and property control at different scales, can quickly and easily complete the surface patterning of TENG and facilitate efficient energy harvesting. In this work, we outline the working modes and principles of TENG, review the research progress of laser surface processing technology for fabricating TENG in recent years, including laser-induced graphene (LIG), laser ablation, laser carbonization, laser-induced copper, etc., and perspectives on the challenges and future directions for development of laser surface processing for performance enhancement of TENG.</p>

Gold and antimony metallogenic relationship of the Awanda Au (Sb) deposit, South Tianshan, NW China: Constraints from textures, in-situ trace elements and s-pb isotope systematics

The Tianshan is one of the most important gold ± antimony metallogenic province in the world. However, the relationship between Au and Sb mineralization remains poorly understood, largely due to lacking of systematic investigation on typical Au-Sb deposits. Here, we reported in-situ trace elements and S-Pb isotopic dataset on the Awanda Au (Sb) deposit, which is currently the second largest gold deposit in Chinese South Tianshan, and contain highly antimony (Sb) by our new petrographic observations. Sulfide from two minelization stages, i.e., Stage Ⅰ (arsenopyrite, pyrite, pyrrhotite, and minor chalcopyrite) and Stage II (gudmundite, aurostibite and stibnite), were analyzed using laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS) and laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS). Trace element compositions reveal that ore minerals display positive correlations between As and Au-Sb-Cu-Zn-Pb, implying a common source for these elements. In situ δ34S values of sulfides that cluster in the range of − 2.94 to + 0.8 ‰, suggesting that sulfur contained in Au-As-Sb-bearing fluids were most likely derived from Upper Paleozoic sediments (δ34S = − 1.6 to + 0.3 ‰) during regional metamorphism. In-situ 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios (17.882 to 18.002, 15.467to 15.620 and 37.831 to 38.344) from sulfides are also support that the Upper Paleozoic strata may have supplied substantial metals. Combined with published electron microprobe and fluid inclusions data, our textural and chemical data suggest that fluid-rock interaction and decrease in pressure, temperature, and oxygen-sulfur fugacity were the main cause for Au-As and Au-Sb minelization, respectively. In summary, we propose that the Awanda Au (Sb) deposit fits the crust metamorphic model with Au-As and Au-Sb mineralization occur at mesozonal and epizonal depths, respectively.

High-nitrogen-content energetic BNn+ (n = 4-16) clusters.

Nitrogen-rich materials have attracted considerable attention in recent years as potential high-energy-density materials (HEDMs). However, their metastability poses substantial challenges for synthesis under ambient conditions. Here, we employ a novel strategy to explore energetic and structural features of the nitrogen-rich BNn+ (n = 4-16) clusters by doping with the light non-metal boron. A series of boron-doped nitrogen clusters, with nitrogen content ranging from 83% to 96%, were obtained by laser ablation and analyzed via time-of-flight mass spectrometry. The results indicate that the BN6+ cluster is dominant in the mass spectrum, while the BN12+ cluster exhibits the highest abundance after cooling the cluster source with liquid nitrogen. To further confirm the experimental results, extensive structure searches for BNn+ (n = 4-16) clusters are conducted using the CALYPSO method and density functional theory (DFT) calculations. The calculations show that BN6+ (singlet) exhibits a planar [B(NN)3]+ three-branched geometry with D3h symmetry, while BN12+ (singlet) adopts a [(linear-N6)B(N3)2]+ branched geometry with C1 symmetry. Stability analyses reveal the relatively high structural stabilities of BN6+ and BN12+ clusters and agree well with the experimental findings. Notably, the gas-phase enthalpy of formation of the BN12+ cluster is remarkably high, -1385.10 kJ mol-1, suggesting its potential as a high-energy building block for HEDM construction. The present findings enhance the structural diversities of non-metal-doped nitrogen clusters, and offer new perspectives for the rational design and synthesis of nitrogen-rich energetic materials.

Production of Organic Precursors via Meteoritic Impacts and Its Implications for Prebiotic Inventory of Early Planetary Surfaces.

Meteoritic impacts on planetary surfaces deliver a significant amount of energy that can produce prebiotic organic compounds such as cyanides, which may be a key step to the formation of biomolecules. To study the chemical processes of impact-induced organic synthesis, we simulated the physicochemical processes of hypervelocity impacts (HVI) in experiments with both high-speed 13C60+ projectiles and laser ablation. In the first approach, a 13C60+ beam was accelerated to collide with ammonium nitrate (NH4NO3) to reproduce the shock process and plume generation of meteoritic impacts on nitrogen-rich planetary surfaces. In a complementary investigation, a high-power laser was focused on a mixture of calcium carbonate (CaCO3) and either ammonium chloride (NH4Cl) or sodium nitrate (NaNO3) to induce atomization and enable the study of molecular recombination in the postimpact plume. Additionally, isotopically spiked starting material, namely, Ca13CO3, 15NH4Cl, Na15NO3, and 15NH415NO3, was also employed to disambiguate the source of prebiotic molecule production in the resulting recombination plume. Both experiments independently demonstrated the formation of CN- ions as recombination products, with characteristic mass peak shifts corresponding to the isotopic labeling of the starting material. Yield curves generated from the laser experiments using varying ratios of calcite and NH4Cl or NaNO3 indicate that nitrate enables more efficient production of CN- than ammonium. Thermodynamic software modeling of the laser ablation plume confirmed and further elucidated the experimental yield results, producing good agreement of modeled CN- yield with observed yield curves. These models indicate that the reduction of atomic N from incomplete NH4- atomization during the ablation pulse may have contributed to the lower CN- yield from the ammonia source relative to the nitrate source. The results of these experiments demonstrated that CN-, and by proxy, hydrogen cyanide, and other organic precursor molecules could have formed from carbonate deposits, a previously under-appreciated source of organic carbon for impact-induced organic synthesis. These results have implications for the formation of life during meteoritic bombardment on early Earth as well as for other carbonate-bearing planetary bodies such as Mars and Ceres.

Short and Mid-term Outcome of Radiofrequency Ablation without Concomitant Phlebectomy/Sclerotherapy for Tributary Varicose Veins.

Endovenous surgery in the treatment of varicose veins generally consists of laser or radiofrequency ablation (RFA) as endovenous thermal ablation (ETA) with a phlebectomy or foam sclerotherapy of tributary varicose veins to improve symptomatic or cosmetic problems. Nevertheless, the efficacy of their concomitant treatments is still controversial for a decade. In the guidelines of the Japanese Society of Phlebology, concomitant phlebectomy of tributary varicose veins with ETA is described that it is not recommended officially. In our hospital, RFA without concomitant phlebectomy of tributary varicose veins accounts for 74% of the RFA cases and it shows a relatively higher percentage than other institutions in Japan. The data of RFA without concomitant phlebectomy of tributary varicose veins are evenly matched in RFA with concomitant treatments in our data concerning recurrence, remnants, endovenous heat-induced thrombosis (EHIT), and complications. This article provides the conclusion that it would be acceptable to perform isolated RFA compared to RFA with concomitant phlebectomy or foam sclerotherapy of tributary varicose veins in short- and mid-term periods. In addition, concomitant treatments might contribute to rapid improvement of the short-term and better long-term outcomes, not to mention cosmetic problems that are not identified demonstrably. (This is a translation of J Jpn Coll Angiol 2022; 62: 49-54.).

Performance optimization of ammonium dinitramide-based liquid propellant in pulsed laser ablation micro-propulsion using LIBS

Abstract The efficacy of spacecraft propulsion systems significantly depends on the choice of propellant. This study utilized laser-induced breakdown spectroscopy (LIBS) to investigate the impact of different fuel types, fuel ratios, and laser energies on the plasma parameters of ammonium dinitramide (ADN)-based liquid propellants. Our findings suggest that 1-allyl-3-methylimidazolium dicyanamide (AMIMDCA) as a fuel choice led to higher plasma temperatures compared to methanol (CH3OH) and hydroxyethyl hydrazine nitrate (HEHN) under the same experimental conditions. Optimization of the fuel ratio proved critical, and when the AMIMDCA ratio was 21wt.% the propellants could achieve the best propulsion performance. Increasing the incident laser energy not only enhanced the emission spectral intensity but also elevated the plasma temperature and electron density, thereby improving ablation efficiency. Notably, a combination of 100 mJ laser energy and 21wt.% AMIMDCA fuel produced a strong and stable plasma signal. This study contributes to our knowledge of pulsed laser micro-ablation in ADN-based liquid propellants, providing a useful optical diagnostic approach that can help refine the design and enhance the performance of spacecraft propulsion systems.

Genesis of the Wangu Au deposit in the Jiangnan orogenic belt: Constraints from texture, trace element, and in-situ Sr isotope of scheelite

Scheelite occurs widely in quartz vein-type Au deposits and serves as an indicator mineral for ore deposit genesis. The Wangu Au deposit, situated in the central part of the Jiangnan orogen belt, South China, is one of the largest Au deposits, with reserves exceeding 85 tonnes. Scheelite has been well-recognized within the Au-bearing quartz veins with a significant amount. To further elucidate the genesis of the Wangu deposit, this study focuses on scheelite to delineate the nature of ore-forming fluids and ore-forming material, by conducting TESCAN Integrated Mineral Analyzer (TIMA), cathodoluminescence (CL), Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) for texture, trace elements, and in-situ Sr isotope analyses.Scheelite from the Wangu Au deposit exhibits three texture-types: early homogeneous (Sch-I-1), oscillatory zones (Sch-I-2), and late veinlet (Sch-II). These different texture-type scheelites show a relatively flat to slightly MREE-enriched chondrite-normalized fractionation pattern, predominantly governed by the substitution mechanism of Ca2+=2REE3++□Ca (□Ca is a Ca site vacancy). Most positive and few negative europium (Eu) anomalies are observed for these different types of scheelite (0.5 to 46.7, mean 5.0), indicating Eu2+ is predominant over Eu3+. Together with the presence of methane in fluid inclusions within scheelite, indicating reduced nature of ore-forming fluids during its precipitation. All texture-types of scheelite have high Sr (383 to 12558 ppm, mean 3408 ppm) and low Mo (<1.7 ppm, mean 0.1 ppm) contents. In-situ Sr isotope data reveal that the 87Sr/86Sr ratios for Sch-I-1 range from 0.74601 to 0.76920, for Sch-I-2 ranging from 0.76485 to 0.76673, and for Sch-II ranging from 0.75627 to 0.75620. This high radiogenic Sr isotope composition of scheelite implies that fluid-rock interaction process is key to mineralization, and this process will add ore-forming materials from wallrock to the ore-forming system. Combined with the contribution of deep magmatic fluid inferred from the published isotope compositions such as H-O and He-Ar, we propose that W mineralization of Wangu deposit is associated with magmatic fluid, which is different from the classical orogenic Au deposit that formed from metamorphic fluid.

Unveiling ultraviolet photodissociation dynamics of SiO from a laser-ablated supersonic beam with time-sliced ion velocity imaging.

SiO is a widespread molecule found in interstellar space, and its dissociation requires a substantial input of energy due to its high bond energy of 8.34 eV. The present study initially demonstrated across a broad range of ultraviolet (UV) wavelengths (243-288 nm) the one-photon and two-photon dissociation of SiO molecules, which were generated from the laser ablation of a Si rod colliding with an oxygen molecular beam. The images of Si products obtained through time-sliced ion velocity mapping have revealed the existence of distinct dissociation channels, encompassing Si(3P) + O(3P), Si(1D) + O(3P), Si(1D) + O(1D) and Si(1S) + O(1D) from the photodissociation of vibrationally excited SiO(X1Σ+, v) and low-lying electronically excited SiO(C1Σ-, D1Δ, a3Σ+, b3Π, d3Δ and e3Σ-) states. These findings contribute to a more comprehensive understanding of silicon chemistry during the combustion of silica-rich meteorites in the Earth's atmosphere, and have wider implications in the fields of atmospheric chemistry, astrochemistry, and combustion science.

Osteon-mimetic Laser-structured Ti-6Al-4V Supports for Guided Stem Cell Growth

Implant surfaces play an important role in determining cell responses, including attachment, proliferation, migration, and differentiation. With rapid developments in micro-and nano-fabrication methods, precisely controlled patterns can be generated on implant surfaces. Osteon-mimetic structures are of great interest as new surface designs of bone implants for creating conditions of natural bone tissue growth. In this work, we used laser ablation technique to create a biomimetic relief on Ti-6Al-4V supports. The basis of the relief is patterns of micrometer concentric lamellae-like rings of different widths and periodicities. A distinctive feature of these reliefs is the presence of a highly porous nanocoating of titanium alloy component oxides, formed as a result of reverse deposition from the vapor-gas phase during ablation. Our investigation on human mesenchymal stem cells revealed that the osteon-mimetic microreliefs’ topography significantly influenced their adhesion, proliferation, and polarization. However, the presence of the nanocoating further impacted these cells by altering the number and localization of their focal contacts. The outcomes of this work demonstrate an innovative direction towards the design of osteon-mimetic topographies on implantable materials. This work also holds the potential to identify optimal combinations of microrelief and nanocoating parameters to elicit specific cellular responses.

Site-specific femtosecond laser ablation: The pathway to high-throughput atom probe tomography characterization

Site-specific femtosecond laser ablation: The pathway to high-throughput atom probe tomography characterization

Parametric analysis of delivered power during laser ablation for prostate cancer.

Parametric analysis of delivered power during laser ablation for prostate cancer.

Novel calibration approach for particle size analysis of microplastics by Laser Ablation Single Particle-ICP-MS

The need to analyze and characterize microplastics (MPs) is ever-increasing to monitor and understand their environmental impact. In this work, a developed calibration approach that utilizes an in-house-created polystyrene (PS)...

Two-Year Outcomes of Excimer Laser Ablation Combined with Drug-Coated Balloon for Treating De novo Lesions and In-Stent Restenosis in Femoropopliteal Artery of Chronic Limb-Threatening Ischemia Patients.

To evaluate the safety and efficacy of excimer laser ablation (ELA) combined with drug-coated balloon(DCB)in the treatment of Chronic limb-threatening ischemia (CLTI) patients with de novo and in-stent restenosis (ISR) lesions in the femoropopliteal artery. A retrospective, single-center analysis was performed on data collected between January 2017 and December 2021. The study included CLTI patients who underwent treatment with ELA combined with DCB for de novo and ISR lesions in the femoropopliteal artery. The primary endpoint was the 24-month primary patency rate. Secondary endpoints included technical success rate and the incidence of major adverse events (MAEs), defined as death, major limb amputation, or target vessel revascularization. A total of 44 patients were included in the study, comprising 24 cases in the de novo lesion group and 20 cases in the ISR group. The mean patient age was 73.4±7.7years, with approximately one-third presenting with concomitant chronic coronary artery disease or cerebrovascular disease. Around one-third of the patients exhibited foot ulcers or gangrene, with a mean lesion length of 239.09±120.09 mm. In the de novo lesion group, 79.2% of lesions were classified as chronic total occlusions (CTOs), whereas 75% of lesions in the ISR group were categorized as Tosaka III. For such complex lesions, the technical success rates were 100% in both groups. The primary patency rates for the de novo group were 86.9% at 12 months and 64.3% at 24 months, compared to 77.0% and 56.5% in the ISR group. Freedom from target lesion revascularization (TLR) rates in the de novo group were 95.8% and 85.4% at 12 and 24 months, respectively, while the ISR group achieved rates of 88.9% and 76.6%. Despite lower primary patency and freedom from target lesion revascularization rates in the ISR group, the differences were not statistically significant (P=0.74).Major adverse events were observed in 12.5% of patients in the de novo group and 35% in the ISR group, with no statistically significant difference (P=0.27). For CLTI patients with complex lesions, including extensive occlusions and severe calcification, the combination of ELA and DCB demonstrates high technical success and favorable safety profiles for both de novo and ISR lesions. Mid-term outcomes indicate a potential trend toward better efficacy in treating de novo lesions compared to ISR lesions.