Comparative study of thulium fiber laser versus holmium:yttrium-aluminum-garnet laser for ureteric stone management with semi-rigid ureteroscopy: A prospective, single-center study

Objective:To compare the efficacy and safety of thulium fiber laser(TFL)and holmium:yttrium-aluminum-garnet(Ho:YAG)laser for ureteric stone management with semi-rigid ureteroscopy.Methods:In a prospective study from January 2020 to December 2021,we compared 40 patients in each group who underwent semi-rigid ureteroscopic lithotripsy with TFL and that with Ho:YAG laser.Stone volume,stone density,stone fragmentation rates,total lasing time,total operative time,endoscopic vision,retropulsion and stone free rates were analyzed in both groups and compared.Results:Mean stone volume was comparable in the TFL group and the Ho:YAG laser group(282.45[standard deviation,SD 139.79]mm3 vs.279.49[SD 312.52]mm3;p=0.964).Mean stone density was also comparable in the TFL group and the Ho:YAG laser group(1135.30[SD 317.04]Hounsfield unit vs.1131.75[SD 283.03]Hounsfield unit;p=0.959).The mean stone fragmentation rates calculated as stone volume divided by lasing time were 25.85(SD 10.61)mm3/min and 21.37(SD 14.13)mm3/min in the TFL group and the Ho:YAG laser group,respectively(p=0.113).The mean total lasing time(10.15[SD]4.69 min vs.11.43[SD 4.56]min;p=0.222),mean operative time(25.13[SD 9.51]min vs.25.54[SD 10.32]min;p=0.866),and mean total hospital stay(2.62[SD 0.77]days vs.2.61[SD 0.84]days;p=0.893)were comparable in the TFL group and in the Ho:YAG group.The vision was better and retropulsion was less in the TFL group.The stone-free rate at 1 month postoperatively was slightly better in the TFL group(100%vs.90%;p=0.095).

Thulium fiber laser lithotripsy:Is it living up to the hype?

Objective:The holmium:yttrium-aluminium-garnet laser(Ho:YAG)has been the gold standard for laser lithotripsy over the last three decades.After demonstrating good in vitro efficacy,the thulium fiber laser(TFL)has been recently released in the market and the initial clinical results are encouraging.This article aims to review the main technology differences between the Ho:YAG laser and the TFL,discuss the initial clinical results with the TFL as well as the optimal settings for TFL lithotripsy.Methods:We reviewed the literature focusing on the technological aspects of the Ho:YAG laser and TFL as well as the results of in vitro and in vivo studies comparing both technologies.Results:In vitro studies show a technical superiority of TFL compared to the Ho:YAG laser and encouraging results have been demonstrated in clinical practice.However,as TFL is a new technology,limited studies are currently available,and the optimal settings for lithotripsy are not yet established.Conclusion:TFL has the potential to be an alternative to the Ho:YAG laser,but more reports are still needed to determine the optimal laser for lithotripsy of urinary tract stones when considering all parameters including effectiveness,safety,and costs.

Flexible ureteroscopic treatment of kidney stones: How do the new laser systems change our concepts?

Objective: Flexible ureteroscopy (fURS) has become a widely accepted and effective technique for treating kidney stones. With the development of new laser systems, the fURS approach has evolved significantly. This literature review aims to examine the current state of knowledge on fURS treatment of kidney stones, with a particular focus on the impact of the latest laser technologies on clinical outcomes and patient safety.Methods: We conducted a search of the PubMed/PMC, Web of Science Core Collection, Scopus, Embase (Ovid), and Cochrane Databases for all randomized controlled trial articles on laser lithotripsy in September 2023 without time restriction.Results: We found a total of 22 relevant pieces of literature. Holmium laser has been used for intracavitary laser lithotripsy for nearly 30 years and has become the golden standard for the treatment of urinary stones. However, the existing holmium laser cannot completely powder the stone, and the retropulsion of the stone after the laser emission and the thermal damage to the tissue have caused many problems for clinicians. The introduction of thulium fiber laser and Moses technology brings highly efficient dusting lithotripsy effect through laser innovation, limiting pulse energy and broadening pulse frequency.Conclusion: While the holmium:yttrium-aluminum-garnet laser remains the primary choice for endoscopic laser lithotripsy, recent technological advancements hint at a potential new gold standard. Parameter range, retropulsion effect, laser fiber adaptability, and overall system performance demand comprehensive attention. The ablation efficacy of high-pulse-frequency devices relies on precise targeting, which may pose practical challenges.

Two-micron （thulium） laser resection of the prostate- tangerine technique： a new method for BPH treatment

Two-micron （thulium） laser resection of the prostate-tangerine technique （TmLRP-TT） is a transurethral procedure that uses a thulium laser fiber to dissect whole prostatic lobes off the surgical capsule, similar to peeling a tangerine. We recently reported the primary results. Here we introduce this procedure in detail. A 70-W, 2-um （thulium） laser was used in continuous-wave mode. We joined the incision by making a transverse cut from the level of the verumontanum to the bladder neck, making the resection sufficiently deep to reach the surgical capsule, and resected the prostate into small pieces, just like peeling a tangerine. As we resected the prostate, the pieces were vaporized, sufficiently small to be evacuated through the reseetoscope sheath, and the use of the mechanical tissue morcellator was not required. The excellent hemostasis of the thulium laser ensured the safety of TmLRP-TT. No patient required blood transfusion. Saline irrigation was used intraoperatively, and no case of transurethral resection syndrome was observed. The bladder outlet obstruction had clearly resolved after catheter removal in all cases. We designed the tangerine technique and proved it to be the most suitable procedure for the use of thulium laser in the treatment of benign prostatic hyperplasia （BPH）. This procedure, which takes less operative time than standard techniques, is safe and combines efficient cutting and rapid organic vaporization, thereby showing the great superiority of the thulium fiber laser in the treatment of BPH. It has been proven to be as safe and efficient as transurethral resection of the prostate （TURP） during the 1-year follow-up.

Thulium laser treatment for bladder cancer

Recent innovations in thulium laser techniques have allowed application in the treatment of bladder cancer.Laser en bloc resection of bladder cancer is a transurethral procedure that may offer an alternative to the conventional transurethral resection procedure.We conducted a review of basic thulium laser physics and laser en bloc resection procedures and summarized the current clinical literature with a focus on complications and outcomes.Literature evidence suggests that thulium laser techniques including smooth incision,tissue vaporization,and en bloc resection represent feasible,safe,and effective procedures in the treatment of bladder cancer.Moreover,these techniques allow improved specimen orientation and accurate determination of invasion depth,facilitating correct diagnosis,restaging,and reevaluation of the need for a second resection.Nonetheless,large-scale multicentre studies with longer follow-up are warranted for a robust assessment.The present review is meant as a quick reference for urologists.

Generation and evolution of multiple operation states in passively mode-locked thulium-doped fiber laser by using a graphene-covered-microfiber

Using graphene-covered-microfiber （GCM） as a saturable absorber, the generation and evolution of multiple operation states are proposed and demonstrated in passively mode-locked thulium-doped fiber laser. The microfiber was fabricated using the flame brushing method to an interaction length of - 1.2 cm with a waist diameter of -10 μm. Graphene layers were grown on copper foils by chemical vapor deposition and transferred onto the polydimethylsiloxane （PDMS） to form a PDMS/graphene film, which allowed light-graphene interaction via evanescent field. With the increase of the pump power from 1.25 W to 2.15 W, five different lasing regimes, including continuous-wave, conventional soliton mode-locking, multi- soliton mode-locking, a period of transition, and noise-like mode-locking, were achieved in a fiber ring cavity. To the best of our knowledge, it is the first report of the generation and evolution of multiple operation states by covering graphene on the microfiber in the 2-μ.m region. The results demonstrate that GCM can be a promising method for fabricating all fiber SA, and the switchable operation states can provide more portability in complex application domain.

A theoretical and experimental investigation of an in-band pumped gain-switched thulium-doped fiber laser

In this paper, the theoretical rate equation model of an in-band pumped gain-switched thulium-doped fiber （TDF） laser is investigated. The analytical formulations of pump energy threshold, peak power extraction efficiency, and pulse extraction efficiency are derived through analyzing the interaction process between the pump pulse and the laser pulse. They are useful for understanding, designing, and optimizing the in-band pumped TDF lasers in a 1.9 μm-2.1 μm wavelength region. The experiment with an all-fiber gain-switched TDF laser pumped by a 1.558-μm pulse amplifier is conducted, and our experimental results show good agreement with theoretical analysis.

Feasibility of en bloc thulium laser enucleation of the prostate in a large case series. Are results enhanced by experience?

Objective:To provide the first large single-operator case series of patients who undergo“en bloc”thulium laser enucleation of the prostate(ThuLEP)and to demonstrate an improvement in enucleation efficacy with experience.Methods:We prospectively evaluated a cohort of patients with symptomatic benign prostatic hyperplasia(BPH)who underwent“en bloc”ThuLEP between May 2015 and November 2017.Association between dependent variables(delivered energy and operating time)and independent variables(adenoma volume and experience)were estimated with regression analysis.The experience was calculated as the time interval between the date of the first operation of the series and the date of the operation being considered.Results:A total of 100 patients were registered for the study.Median operative time was 56.5 min(interquartile range[IQR]:40-85 min).Median enucleation time was 17.4 min(IQR:15-21.5 min).Median enucleation index(enucleation time per adenoma gram)was 0.3 min/g(0.2-0.3 min/g).The overall operative time is not influenced by experience,but we registered a significant trend towards a reduction in the total amount of energy delivered energy normalized per adenoma gram(p=0.0148).Conclusion:We believe that further attention is needed for these new“en bloc”prostatic enucleation techniques,which can facilitate some surgical steps,leading to a widespread use of laser technology for BPH surgical treatment.

Mode-Locked Thulium Ytterbium Co-Doped Fiber Laser with Graphene Oxide Paper Saturable Absorber

A mode-locked thulium ytterbium co-doped fiber laser （TYDFL） is proposed and demonstrated by using a commercial graphene oxide （GO） paper as saturable absorber （SA）. The GO paper is sandwiched between two fiber ferrules and incorporates a ring laser cavity to generate soliton pulse train operating at 1942.0nm at a threshold multimode pump power as low as 1.8 W. The mode-locked TYDFL has a repetition rate of 22.32 MHz and the calculated pulse width of 1.1 ns. Even though the SA has a low damage threshold, the easy fabrication of GO paper should promote its potentiM application in ultrafast photonics.

Analysis of gain distribution in cladding-pumped thulium-doped fiber laser and optical feedback inhibition problem in fiber-bulk laser system

The steady-state gain distribution in cladding pumped thulium-doped fiber laser（TDFL） is analytically and numerically solved based on the rate equations including loss coefficients and cross relaxation effect. With the gain curve, a problem, which is named optical feedback inhibition（OFI） and always occurs in tandem TDFL-Ho：YAG laser system, is analyzed quantitatively. The actual characteristics of output spectra and power basically prove the conclusion of theoretical analysis. Then a simple mirror-deflected L-shaped cavity is employed to restrain the external feedback and simplify the structure of fiber-bulk Ho：YAG laser. Finally, 25 W of 2097-nm laser power and 51.2% of optical-to-optical conversion efficiency are obtained, and the beam quality factor is less than 1.43 obtained by knife-edge method.

“推挑式”铥激光膀胱肿瘤整体剜除术临床疗效研究

目的比较“推挑式”铥激光膀胱肿瘤整体剜除术(TmLRBT)与等离子膀胱肿瘤电切术(TURBT)处理非肌层浸润性膀胱癌(NMIBC)的疗效与安全性。方法分析2018年1月至2020年6月我院99例NMIBC患者的临床资料,其中行“推挑式”TmLRBT 50例,行TURBT 49例,比较两组手术时间、术中出血量、膀胱冲洗时间、保留导尿时间、术后住院时间、术中并发症、尿道狭窄发生及肿瘤复发情况。结果TmLRBT组手术时间(38.56±8.51)min,TURBT组(36.79±9.05)min,差异无统计学意义(P>0.05)。TmLRBT组术中出血量(7.59±3.34)ml,膀胱冲洗时间(1.05±0.82)d,术后留置尿管时间(3.87±2.77)d,术后住院时间(4.96±2.38)d,显著低于TURBT组的(11.84±4.17)ml、(3.23±1.35)d、(5.69±3.01)d、(6.56±2.42)d,差异有统计学意义(P<0.05)。术后TmLRBT组无闭孔神经反射及膀胱穿孔,显著低于TURBT组的14.29%及10.20%(P<0.05);术后发生尿道狭窄两组差异无统计学意义(P>0.05);在12个月肿瘤复发率中,TmLRBT组发生2例(4.00%),TURBT组发生8例(16.33%),差异有统计学意义(P<0.05)。结论TmLRBT与TURBT都是处理NMIBC安全可靠的手术方式,“推挑式”TmLRBT在安全性及疗效上更有优势,值得推广。

优路铥激光结合曲安奈德腔内注射治疗尿道吻合术失败病例的疗效观察

目的:探讨优路铥激光结合曲安奈德腔内注射治疗尿道吻合术失败病例的临床经验。方法:回顾性分析2018年1月至2023年12月收治的盆腔骨折尿道牵张性缺损(PFUDD)男性患者。共纳入尿道吻合术失败患者35例,根据内切开能量平台分别为优路铥激光和等离子组。所有患者均在直视下尿道狭窄内切开术,并予以曲安奈德腔内局部注射,记录年龄、狭窄长度、手术时间、术前最大尿流率、术后最大尿流率、术后并发症以及狭窄复发情况。结果:所有患者均顺利完成所有治疗,两组患者在年龄、狭窄长度、手术时间、并发症率及狭窄复发率上均无统计学差异(P>0.05)。铥激光组和等离子组中位随访时间分别为21.0个月(IQR 16.0~24.0)和21.0个月(IQR 17.0~25.0),术前和术后12个月的最大尿流率均有显著差异(P<0.01)。两组无复发生存期无统计学差异(P=0.398)。结论:优路铥激光尿道内切开结合曲安奈德腔内局部注射在短期内可有效维持尿道狭窄瘢痕的稳定,保持良好的尿道通畅性。与传统等离子内切开相比,该策略术后并发症率较低,具有操作简单、安全、并发症少、疗效可靠等特点,可作为PFUDD患者吻合术失败后的补救治疗方法。

ThuLEP与TUPKP治疗>80 mL良性前列腺增生的临床研究

目的探究铥激光前列腺剜除术(Thulium Laser Enucleation of the Prostate,ThuLEP)与经尿道前列腺等离子双极电切术(Transurethral Bipolar Plasmakinetic Prostatectomy,TUPKP)治疗>80 mL良性前列腺增生的效果。方法回顾性选取2021年2月—2023年11月溧阳市人民医院收治的94例前列腺体积>80 mL的良性前列腺增生患者的临床资料,根据手术方式不同分为ThuLEP组(47例,实施ThuLEP术)和TUPKP组(47例,实施TUPKP术),比较两组的手术指标、尿动力学指标、性功能以及并发症方式情况。结果与TUPKP组比较,Thu-LEP组的手术时间、住院时间、膀胱冲洗时间、尿管留置时间均较短,组织切除/剜除体积更大,差异有统计学意义(P均<0.05)。ThuLEP组的各项尿动力学指标均优于TUPKP组,差异有统计学意义(P均<0.05)。Thu-LEP组的并发症发生率(2.13%)低于TUPKP组(12.76%),差异有统计学意义(χ^(2)=3.859,P<0.05)。结论铥激光前列腺剜除术与TUPKP术治疗>80 mL良性前列腺增生均可获得良好疗效,相较于TUPKP术,铥激光前列腺剜除术手术时间更短,术后恢复更快,且在改善尿动力学状态、恢复性功能的效果更为理想。

2 μm超窄线宽光纤激光实现1 kW近衍射极限输出

2 μm波段光纤激光广泛应用于生物医学、环境监测、非线性频率转换,以及激光雷达和激光通信领域,备受研究人员关注。然而,该波段的激光器功率提升面临着低量子效率、高热负载和部分非线性效应的限制。基于反转概率调谐序列的高阶相位调制技术以抑制SBS效应、多级链路自动反馈的信号激光时域稳定控制技术以提升SRS阈值,以及光纤基横模纯化技术以控制光束质量,采用两级主放大结构,在1 950 nm波长实现了1 kW窄线宽近衍射极限输出,光光转换效率达55.6%,线宽3.8 GHz,光束质量M~2约1.2,在最高功率时无横向模式不稳定效应。

2μm大能量掺铥脉冲光纤激光器研究进展

2μm波段掺铥脉冲光纤激光器目前可实现最高毫焦量级的能量输出,对医疗、材料、通信等领域有重要意义。本文主要介绍近年来大能量掺铥光纤激光器系统研究的主要进展,讨论大能量掺铥光纤激光器的技术类型和影响因素。在此基础上,对大能量掺铥光纤激光器的研究前景进行展望。

铥激光与等离子前列腺剜除术治疗大体积良性前列腺增生的疗效比较

目的比较铥激光前列腺剜除术(ThuLEP)与等离子前列腺剜除术(PKEP)治疗大体积(≥80 mL)良性前列腺增生(BPH)的近期疗效,评估两种手术方法的优劣,为临床选择BPH治疗方法提供参考。方法回顾性分析2021年6月—2023年6月于山东大学附属山东省立第三医院泌尿外科收治的100例大体积BPH患者的临床资料,根据手术方式不同分为两组,其中采用ThuLEP治疗的患者归于ThuLEP组(n=50),采用PKEP治疗的患者归于PKEP组(n=50)。比较两组患者的手术时间、术中出血量、剜除前列腺组织重量、术后膀胱冲洗时间、术后留置导尿管时间、术后住院时间及并发症发生率。比较两组患者术前及术后3个月的国际前列腺症状评分(IPSS)、生活质量评分(QoL)及最大尿流率(Qmax)变化情况。结果ThuLEP组和PKEP组患者的手术时间[(79.04±9.42)min vs.(80.10±8.94)min]、术中出血量[(42.86±7.84)mL vs.(43.32±7.36)mL]及术后膀胱冲洗时间[(19.88±4.13)h vs.(20.10±4.04)h]比较,差异均无统计学意义(P>0.05);ThuLEP组剜除前列腺组织重量大于PKEP组[(69.44±4.90)g vs.(65.06±5.25)g],术后留置导尿管时间及住院时间均短于PKEP组[(27.20±4.07)h vs.(29.02±4.86)h;(3.30±0.66)d vs.(4.05±0.91)d],差异均有统计学意义(P<0.05)。与术前比较,术后3个月ThuLEP组和PKEP组患者的IPSS、QoL及Qmax均有明显改善(P<0.05),但组间比较差异无统计学意义(P>0.05)。ThuLEP组和PKEP组并发症发生率的差异无统计学意义(2%vs.4%,P>0.05)。结论ThuLEP与PKEP治疗大体积BPH均有较好的近期疗效及安全性,但ThuLEP在剜除增生的前列腺组织、缩短术后留置导尿管时间及住院时间方面均优于PKEP。

2μm激光消融技术在生物组织中的应用

激光因其能量集中、稳定性好、易于使用等优点,越来越多地被应用于生物医疗领域。近年来,2μm激光凭借着高水分子吸收系数的优势成为生物组织消融和碎石手术的理想选择,具有极大的应用前景。简要阐述了激光消融生物组织的光分布与光传热机制,介绍了2μm激光在体外组织、体内组织和碎石手术中的应用,总结了激光功率、工作模式、脉冲频率等对不同生物组织目标的影响,得出掺铥光纤激光器具有在激光消融领域替代掺钬钇铝石榴石(Ho:YAG)激光器潜力的结论。最后,讨论了掺铥光纤激光器在生物医疗领域发展的主要问题和趋势。

前列腺铥激光剜除术与等离子电切术治疗良性前列腺增生的对比研究

目的:探讨前列腺铥激光剜除术(ThuLEP)与等离子电切术(PKRP)治疗良性前列腺增生(BPH)的对比研究。方法:回顾性研究本院2021年1月至2023年12月收治的160例BPH患者病历资料,根据手术方式的不同将患者分为观察组(n=80)和对照组(n=80)。对照组实施PKRP治疗,观察组实施ThuLEP治疗。比较两组的手术时间、膀胱冲洗时间、导管留置时间、住院时间,并比较两组术前、术后3个月的最大尿流速(Qmax)、残余尿量(PVR)、前列腺特异性抗原(PSA)、前列腺体积的变化情况和术后并发症。结果:观察组的手术时间、膀胱冲洗时间、导管留置时间、住院时间[(60.10±5.15)min、(43.24±6.65)h、(5.03±1.24)d、(6.55±1.67)d]均短于对照组[(67.25±7.24)min、(46.90±10.77)h、(5.60±1.31)d、(7.31±2.00)d,P<0.05)];观察组术后3个月的Qmax水平[(20.68±1.45)ml/s]高于对照组[(18.50±1.24)ml/s],PVR、PSA、前列腺体积水平[(10.82±3.10)ml、(3.38±0.40)μg/L、(20.12±5.13)ml]均低于对照组[(12.10±3.53)ml、(4.60±0.78)μg/L、(25.35±6.46)ml,P<0.05)];两组术后并发症的总发生率(7.50%vs 5.00%),无统计学意义(P>0.05)。结论:ThuLEP治疗BPH具有显著疗效,能够缩减手术及住院时长,改善尿流动力学和前列腺功能,值得推广。

掺铥光纤激光器设计与仿真

掺铥光纤激光器工作波段在人眼安全波段,凭借其结构紧凑、灵活性高、散热性强、光束质量好、量子效率高等优势得到了越来越多的关注。本研究设计1700~1800 nm波段的光纤激光器,将以泵浦光中心波长786 nm,去激发光纤激光器中心波长1740 nm。其中光纤长度设置为5 m。实验结果表明:泵浦光功率大于5 W时会产生激光,小于5 W时不会产生激光。通过实验可知,泵浦光功率会随光纤长度增长而减小,信号光功率会随光纤长度增大而增大。

铥激光治疗非肌层浸润性膀胱癌的临床研究

目的探讨经尿道膀胱肿瘤铥激光整块切除术与TURBT在治疗NMIBC的差异。方法收集2020年6月1日-2022年7月31日在本院行经尿道膀胱肿瘤铥激光切除术与TURBT的89例NMIBC患者的临床资料,将患者随机分成2组,铥激光组46例(行铥激光术),电切组43例(行电切术),比较分析2组患者的住院时间、术后尿管留置时间、手术出血量、手术耗时,膀胱刺激症、闭孔神经反射等并发症发生率,术后1年复发率。结果铥激光组并发症发生率6.52%低于电切组27.91%,差异有统计学意义(P<0.05)。铥激光组与电切组间,手术耗时无统计学意义(P>0.05)。铥激光组患者术中出血量、尿管留置时间、住院时间,均优于电切组,差异具有统计学意义(P<0.05)。铥激光组与电切组间术后1年复发率差异无统计学意义(P>0.05)。结论经尿道铥激光膀胱肿瘤完整切除术用于对NMIBC患者的治疗优于经尿道膀胱肿瘤电切术。