Management hepatolithiasis with operative choledochoscopic FREDDY laser lithotripsy combined with or without hepatectomy

BACKGROUND: Hepatolithiasis is very common in East Asia. It is benign in nature, but has a high recurrence rate. It is likely to lead to biliary cirrhosis and increase the risk of cholangiocarcinoma. Hence, the treatment of hepatolithiasis is difficult but vital. In this report, we present a novel approach to manage hepatolithiasis using the choledochoscopic Frequency-Doubled Double pulse Nd:YAG (FREDDY) laser lithotripsy combined with or without hepatectomy. METHODS: Between July 2009 and October 2012, 45 patients underwent choledochoscopic FREDDY laser lithotripsy combined with or without hepatectomy (laser lithotripsy group). Fortyeight patients underwent a traditional operation (traditional method group) from January 2009 to June 2009. Comparative analysis was made of demographic and clinical characteristics of the two groups. RESULTS: The final stone clearance rate of the laser lithotripsy group was 93.3%, whereas that of the traditional method group was 85.4% (P=0.22). In the laser lithotripsy group, 2 patients experienced hemobilia and 3 patients had acute cholangitis. In the traditional method group, 3 patients had intraoperative hemorrhage, 1 patient had bile leakage, 6 patients had acute cholangitis, and 1 patient died of liver failure. Moreover, the operative time in the traditional method group was significantly longer than that in the laser lithotripsy group (P=0.01). The mean hospital stay of the patients in the traditional method group was longer than that in the laser lithotripsy group (9.8 vs8.2 days, P=0.17). Recurrent intrahepatic bile duct stones were not found during the follow-up period in the two groups. CONCLUSION: Operative choledochoscopic FREDDY laser lithotripsy combined with or without hepatectomy may be an effective and safe treatment for hepatolithiasis.

Role of Removing Stasis and Reducing Heat Formula in Clearance of Proximal Ureteral Calculi after Ureteroscopic Ho:YAG Laser Lithotripsy: A Prospective Randomized Study

Objective To prospectively evaluate the efficacy of Removing Stasis and Reducing Heat Formula in accelerating calculus clearance and improving lower urinary tract symptoms of patients with proximal ureteral calculi after ureteroscopic Ho:YAG laser lithotripsy. Methods A total of 138 patients with proximal ureteral calculi underwent ureteroscopic Ho:YAG laser lithotripsy by a single endocrinologist. Stone size varied from 10 to 15 mm. After operation, the patients were randomly divided into three groups: the control group(group A), tamsulosin group(group B), and Removing Stasis and Reducing Heat Formula group(group C). The treatment lasted for 4 weeks or until stone clearance. The primary and secondary outcomes of the three groups at follow-up were assessed. Results Of the 131 patients available for follow-up, 44 cases were in the group A, 45 in the group B, and 42 in the group C, respectively. The stone free rate at 2 weeks in the groups B and C were significantly higher than that in the group A(95.56%, 97.62% vs. 79.55%; all P<0.05). The ureteral colic rate and mean time of fragment expulsion were significantly reduced in the groups B(4.44% and 7.86±4.99 days) and C(2.43% and 6.76±4.37 days) compared with the group A(22.73% and 11.54±9.89 days, all P<0.05). On the day of double-J ureteric stent removal, the group C differed significantly from the group A in the total International Prostate Symptom Score, irritative subscore, obstructive subscore, and quality of life score(all P<0.05). Conclusion Removing Stasis and Reducing Heat Formula in the medical expulsive therapy might be an effective modality for patients with calculus in the proximal uretera after ureteroscopic Ho:YAG laser lithotripsy.

Ureteroscopic Holmium:YAG Laser Lithotripsy for Managing Ureteral Calculi (A Report of 168 Cases)

Summary: The effectiveness and safety of ureteroscopic holmium:YAG laser lithotripsy for managing ureteral calculi was evaluated. Ureteroscopic holmium:YAG laser lithotripsy was performed in 168 ureteral calculi (upper 27 cases, middle 33 cases and lower 108 cases). The results showed that the stone-free rate was 92.6 % in the upper ureteral calculi, 93.9 % in the middle ureteral calculi and 94.4 % in the lower ureteral calculi, respectively. The complication rate was 4.8 % (8 cases). It was suggested that ureteroscopic holmium:YAG laser lithotripsy is a highly effective and safe treatment modality for managing ureteral calculi.

Systematic evaluation of a holmium:yttrium-aluminum-garnet laser lithotripsy device with variable pulse peak power and pulse duration

Objective:The Holmium:yttrium-aluminum-garnet(Ho:YAG)laser is the standard lithotrite for ureteroscopy.This paper is to evaluate a Ho:YAG laser with a novel effect function in vitro,which allows a real-time variation of pulse duration and pulse peak power.Methods:Two types of phantom calculi with four degrees of hardness were made for fragmentation and retropulsion experiments.Fragmentation was analysed at 5(0.5 J/10 Hz),10(1 J/10 Hz),and 20(2 J/10 Hz)W in non-floating phantom calculi,retropulsion in an ureteral model at 10(1 J/10 Hz)and 20(2 J/10 Hz)W using floating phantom calculi.The effect function was set to 25%,50%,75%,and 100%of the maximum possible effect function at each power setting.Primary outcomes:fragmentation(mm^3),the distance of retropulsion(cm);
5 measurements for each trial.Results:An increase of the effect feature(25%vs.100%),i.e.,an increase of pulse peak power and decrease of pulse duration,improved Ho:YAG laser fragmentation.This effect was remarkable in soft stone composition,while there was a trend for improved fragmentation with an increase of the effect feature in hard stone composition.Retropulsion increased with increasing effect function,independently of stone composition.The major limitations of the study are the use of artificial stones and the in vitro setup.Conclusion:Changes in pulse duration and pulse peak power may lead to improved stone fragmentation,most prominently in soft stones,but also lead to increased retropulsion.This new effect function may enhance Ho:YAG laser fragmentation when maximum power output is limited or retropulsion is excluded.

Clinical usefulness of transpapillary removal of common bile duct stones by frequency doubled double pulse Nd:YAG laser

AIM: To study the efficacy and the safety of laser lithotripsy without direct visual control by using a balloon catheter in patients with bile duct stones that could not be extracted by standard technique. METHODS: The seventeen patients (7 male and 10 female; mean age 67.8 years) with difficult common bile duct (CBD) stones were not amenable for conventional endoscopic maneuvers such as sphincterotomy and mechanical lithotripsy were included in this study. Laser wavelengths of 532 nm and 1064 nm as a double pulse were applied with pulse energy of 120 mJ. The laser fiber was advanced under fluoroscopic control through the ERCP balloon catheter. Laser lithotripsy was continued until the fragment size seemed to be less than 10 mm. Endoscopic extraction of the stones and fragments was performed with the use of the Dormia basket and balloon catheter. RESULTS: Bile duct clearance was achieved in 15 of 17 patients (88%). The mean number of treatment sessions was 1.7 ± 0.6. Endoscopic stone removal could not be achieved in 2 patients (7%). Adverse effects were noted in three patients (hemobilia, pancreatitis, and cholangitis). CONCLUSION: The Frequency Doubled Double Pulse Nd:YAG (FREDDY) laser may be an effective and safe technique in treatment of difficult bile duct stones.

A Stable Wavelength Operation Ho:YAG Laser with Orthogonally Polarized Pump

A stable wavelength operation Ho:YAG laser dual-pumped by two orthogonally polarized Tm:YLF lasers is reported. Under the cw operation mode, a laser output power of 24 W is measured. The corresponding opticaloptical conversion efficiency is 44.75% and the slope efficiency is 50.12%. Under the Q-switched operation mode,the output maximum average power is 22.8 W at the re-frequency of 6 kHz. The corresponding optical-optical conversion efficiency and slope efficiency are 42.64% and 48.01%, respectively. The output central wavelength is 2090.73 nm, the linewidth is 0.40 nm, and the beam quality is M^2< 1.6. Moreover, the shift of the output central wavelength is less than 0.01 nm, and the linewidth shift is also less than 0.01 nm.

An Actively Mode-Locked Ho:YAG Solid-Laser Pumped by a Tm-Doped Fiber Laser

An actively mode-locked Ho： YAG laser pumped by a diode-pumped Tin-doped fiber laser is reported. For the cw operation, we obtain the maximum output power of 3.43 W with a central wavelength 2022.2nm at the maximum incident pump power of 11.4 W, corresponding to a slope efficiency of 34.5%. The beam quality factor M2 is 1.16, and the output beam is close to fundamental TEMoo. In the case of the CWML operation, a stable pulse train is generated with an average output power up to 3.41 W with a slope efficiency of 34.3% at the incident pump power of 11.4 W and a pulse duration of 294ps at a repetition rate of 81.92MHz. In addition, the maximum single pulse energy is 41.6nJ.

Development of a Single-Longitudinal-Mode Ho:YAG Laser Based on Corner Cube

We present a Tm-doped fiber laser pumped Fabry-Perot etalons Ho：YAG laser based on a corner cube. A maximum single-longitudinal-mode and fundamental transverse mode output power of 478 m W at the wavelength of 2091.06 nm is achieved with a pump power of 16.3 W, corresponding to an optical-to-optical efficiency of 2.9% and a slope efficiency of 7.9%. The single-longitudinal-mode and fundamental transverse mode are less sensitive to the rotating of the corner cube. The results indicate the potential impact of a single-longitudinal-mode Ho： YA G laser with corner cube geometry to improve the anti-maladjustment stability.

A Linearly Polarized Ho:YAG Laser at 2.09 μm with Corner Cube Cavity Pumped by Tm:YLF Laser

A linearly polarized operation Ho： YAG laser at 2090.5 nm with a corner cube cavity is demonstrated. A polarizer with high reflectivity for the s-polarized light at the laser wavelength is employed to achieve a linearly polarized laser. In the same case of resonator length, the corner cube can be used to cut the volume of the Ho：YAG laser and to enhance the stability of the system. The maximum linearly polarized output power of 5.8 W is achieved at the absorbed pump power of 23.3 W, corresponding to a slope efficiency of 29.7%, and the optical-optical conversion efficiency is around 24.9%. The M2 factors of the 2.09μm laser are 2.4 and 1.2 along the horizontal and vertical directions, respectively.

A Mid-IR Optical Parametric Oscillator Pumped by an Actively Q-Switched Ho:YAG Ceramic Laser

We demonstrate a mid-IR ZnGeP2 （ZGP） optical parametric oscillator （OPO） pumped by a dual-end-pumped actively aeoasto-optie Q-switched Ho：YAG ceramic laser. The maximum average output power of 35 W is obtained at a pulse repetition frequency of 20 kHz from the Ho：YAG ceramic laser. Under the maximum incident pump power of Ho：YAG ceramic laser, the maximum output power of 14 W is obtained from the ZGP OPO, corresponding to the slope efficiency of 49.6% with respect to the incident pump power. The wavelength can be tuned from 3.5 μm to 4.2μm （signal）, corresponding to 5.24.1 μm （idler）. The beam quality M2 is less than 2.3 from the ZGP OPO.

High-Power Dual-End-Pumped Actively Q-Switched Ho:YAG Ceramic Laser

We present a high-power Ho：YAG ceramic laser pumped at 1908nm. Using a dual-end-pumped structure, the maximum continuous-wave output power of 48 W is obtained, corresponding to a slope efficiency of 70.4% with respect to the absorbed pump power. At actively Q-switched mode, the maximum average output power of 46 W and the minimum pulse width of 21 ns are achieved at a pulse repetition frequency of 20 kHz, corresponding to a peak power of approximately 109.5kW. In addition, the beam-quality M2 factor is found to be 1.4 at the maximum output power.

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.

Measurements of Laser Induced Bubble Behavior in Elastic Tube and Temperature around Bubble in TUL Treatment

Transurethral ureteral lithotripsy (TUL) is a treatment that breaks stones by irradiating a pulsed laser through an optical fiber. Heat and impulsive force of the laser may affect nearby tissues during treatment. A bubble induced by the pulsed laser plays an important role in laser lithotripsy. It is important to understand effects of the bubble on the surroundings by simulating treatment in a narrow space such as in a ureter. In this study, we observe behaviors of the bubble in the narrow space inside a soft material simulating under in vivo condition. The bubble formed under various laser irradiation conditions exhibits characteristic behavior, and the surrounding elastic wall is compressed and bulged when the bubble grows and collapses. In the case of bubble formed near the elastic wall, the bubble contacts with the elastic wall during growth, and severe large deformation of the elastic wall is observed at bubble collapse. According to the temperature measurement, a temperature rise of 25℃ - 30℃ occurs in the area where the bubbles are in contact. From the above, by presenting the deformation of the elastic wall and temperature increase, we can show useful information to improve the safety for treatment at narrow space.

经尿道电切镜下大功率钬激光治疗膀胱结石

目的探讨膀胱结石治疗的新技巧。方法经电切镜的电极孔置入钬激光纤维光纤将膀胱结石击碎并用艾力克将碎石吸出。结果所有病例均一次性将结石取尽,术中、术后无大出血、膀胱穿孔和水中毒(TURS)等并发症,疗效满意。结论经尿道电切镜下钬激光治疗膀胱结石是一种安全、有效的方法。

钬激光碎石术与体外冲击波碎石术治疗输尿管结石疗效比较

目的比较输尿管镜下钬激光碎石术(URSHL)与体外冲击波碎石术(ESWL)治疗输尿管结石的临床疗效。方法将156例输尿管结石患者根据治疗方式不同分为ESWL组和URSHL组,各78例,分别行ESWL和URSHL治疗。对比两组手术时间、手术并发症发生情况和术后3个月结石排净率。结果 URSHL组结石直径≤1.0cm和>1.0cm患者手术时间分别为(27.6±3.6)min和(35.2±6.4)min,低于ESWL组的(41.8±5.7)min和(50.4±9.1)min,差异有统计学意义(P<0.01)。术后3个月结石排净率比较,URSHL组总有效率为89.74%(70/78),高于ESWL组的76.92%(60/78),差异有统计学意义(P<0.05)。URSHL组结石直径≤1.0cm及>1.0cm患者中下段结石排净率分别为95.45%(21/22)和92.31%(24/26),高于ESWL组的66.67%(14/21)和74.07%(20/27),差异有统计学意义(P<0.05)。两组并发症发生率比较,差异无统计学意义(P>0.05)。结论URSHL与ESWL均能有效治疗输尿管结石,对于位于中下段的结石,URSHL治疗效果优于ESWL。

经输尿管镜钬激光碎石治疗输尿管结石

目的探讨经输尿管镜钬激光碎石治疗输尿管结石的安全性和有效性。方法自2003年11月～2004年9月,应用经输尿管镜钬激光碎石治疗输尿管结石46例共49侧。结果40例共43侧单次碎石成功,单次手术结石粉碎成功率为87.8%(43/49)。术中3例结石移位,其中2例术后行ESWL治愈;1例碎石不全术后二次行钬激光碎石成功;2例伴输尿管小穿孔。术后平均住院时间3.5d。结论经输尿管镜钬激光碎石是一种治疗输尿管结石安全、高效、创伤小、恢复快的方法。

Cr,Tm,Ho∶YAG激光器的理论模拟

为了使CTH∶YAG激光器的设计得到更好的优化,从晶体光谱吸收特性、离子间能量转移过程及准三能级运转方式对CTH∶YAG激光器的工作特性进行了理论分析;依据速率方程理论建立了CTH∶YAG激光器运转的理论模型.模拟能量输出与试验结果较好的吻合,验证了此理论模型描述CTH∶YAG激光器运转规律的合理性.模拟结果表明:CTH∶YAG激光器的激光脉冲输出与泵浦有较长的时间延迟且伴随较强的驰豫振荡,冷却温度对激光输出产生较大的影响.

经软性输尿管镜钬激光治疗输尿管上段结石(附36例报告)

目的探讨经软性输尿管镜钬激光治疗输尿管上段结石的临床应用价值.方法回顾性分析经软性输尿管镜钬激光治疗36例输尿管上段结石的临床资料.对36例输尿管上段结石患者采用软性输尿管镜钬激光碎石术治疗.结果软性输尿管镜直视下一次操作成功33例,成功率91.7%,2～6周内结石全部排净.发生输尿管穿孔1例(2.8%),放置双J管引流后愈合.合并输尿管炎性息肉7例,均于术中用钬激光切除.结论经软性输尿管镜钬激光碎石治疗输尿管上段结石具有创伤小、安全性高、疗效确切、病人恢复快、并发症少的优点,为输尿管结石治疗的有效方法之一,易于临床应用.

脉冲Ho∶YAG激光对犬多种器官的生物效应

目的 为研究平均功率、照射时间、脉冲能量、脉冲频率等激光参数对Ho∶YAG激光生物效应的影响。方法 我们以犬作为实验对象 ,以不同平均功率、不同照射时间及对相同平均功率的又分为高脉冲能量低脉冲频率 (H)组和低脉冲能量高脉冲频率 (L)组照射皮肤、食管、支气管、胃、膀胱粘膜、卵巢、子宫 ,进行配对研究。结果 肉眼、光镜、电镜观察不同激光参数消融、热凝固作用结果的差异 ,各器官Ho∶YAG激光治疗的安全、有效治疗剂量。结论 脉冲式Ho∶YAG激光的组织表面热凝固作用与平均功率、照射时间成正相关 ;照射时间、脉冲频率恒定时 ,脉冲式Ho∶YAG激光的消融作用与脉冲能量成正比 ;在相同平均功率 ,高脉冲能量低脉冲频率 (H)组的消融作用大于低脉冲能量高脉冲频率 (L)组 ,而热凝固损伤作用小于L组。

两种方法治疗嵌顿性输尿管结石并息肉的对比研究

目的:比较输尿管镜下钬激光碎石术联合气压弹道碎石术与单用钬激光碎石术、单用气压弹道碎石术三者治疗嵌顿性输尿管结石并息肉的有效性和安全性。方法:回顾性分析105例采用输尿管镜下钬激光碎石联合气压弹道碎石术32例、单用钬激光碎石术30例、单用气压弹道碎石术43例治疗嵌顿性输尿管结石并息肉患者资料。结果:钬激光碎石联合气压弹道碎石单次碎石率为93.8%(30/32),高于单用钬激光碎石的76.7%(23/30)及单用气压弹道碎石的69.8%(30/43)(P<0.01);钬激光碎石联合气压弹道碎石术组中无输尿管穿孔、撕脱、大出血等并发症;单用钬激光碎石组有1例大出血,3例发生输尿管穿孔;单用气压弹道碎石组有2例发生输尿管穿孔。结论:输尿管镜下钬激光碎石联合气压弹道碎石术的疗效和安全性优于单用钬激光碎石术及单用气压弹道碎石术,是治疗嵌顿性输尿管结石并息肉输尿的一种安全、高效的方法。