Hemodynamic changes in hepatic cancer before and after cluster electrode radio-frequency ablation

Objective: To evaluate the hemodynamic changes of hepatic artery (HA), portal vein (PV) and tumors in hepatic cancer patients treated by cluster electrode radio-frequency ablation with the aid of color Doppler flow imaging (CDFI). Methods: The hemodynamic changes of HA, PV and 42 tumors in 30 cases of hepatic cancer were investi- gated by CDFI one week before and after cluster e- lectrode radio-frequency ablation. Results: One week after radio-frequency ablation, the velocity of HA decreased (P<0.05), but the dia- meter and velocity of PV unchanged. Before radio- frequency ablation, blood signals were observed in 35 cancer nodes (83.0 % of all 42 nodes). After radio- frequency ablation, blood signals were reduced in 15 nodes and disappeared in 14 nodes. Early investiga- tion implied that the decrease of blood supply was parallel with the reduction of node size. However, the outcome in case of huge nodes with double blood supply was not as promising as those small nodes. Conclusion: CDFI is useful to assess blood supply in ablation of hepatic cancer by using cluster electrode radio-frequency therapy.

High performance micromachining of sapphire by laser induced plasma assisted ablation(LIPAA)using GHz burst mode femtosecond pulses

GHz burst-mode femtosecond(fs)laser,which emits a series of pulse trains with extremely short intervals of several hundred picoseconds,provides distinct characteristics in materials processing as compared with the conventional irradiation scheme of fs laser(single-pulse mode).In this paper,we take advantage of the moderate pulse interval of 205 ps(4.88 GHz)in the burst pulse for high-quality and high-efficiency micromachining of single crystalline sapphire by laser induced plasma assisted ablation(LIPAA).Specifically,the preceding pulses in the burst generate plasma by ablation of copper placed behind the sapphire substrate,which interacts with the subsequent pulses to induce ablation at the rear surface of sapphire substrates.As a result,not only the ablation quality but also the ablation efficiency and the fabrication resolution are greatly improved compared to the other schemes including single-pulse mode fs laser direct ablation,single-pulse mode fs-LIPAA,and nanosecond-LIPAA.

Successful initial ablation therapy contributes to survival in patients with hepatocellular carcinoma

AIM： To evaluate the outcome predictors of percutaneous ablation therapy in patients with unresectable hepatocellular carcinoma （HCC）, especially to identify whether the initial treatment response contributes to the survival of the patients. METHODS： The study cohort included 153 patients with single （102） and two or three （51） HCC nodules 5 cm or less in maximum diameter. As an initial treatment, 110 patients received radiofrequency ablation and 43 patients received percutaneous ethanol injection. RESULTS： The Kaplan-Meier estimates of overall 3- and S-year survival rates were 75% and 59%, respectively. The log-rank test revealed statistically significant differences in the overall survivals according to ChildPugh class （P = 0.0275）, tumor size （P = 0.0130）, serum albumin level （P = 0.0060）, serum protein induced by vitamin K absence or antagonist Ⅱ level （P = 0.0486）, and initial treatment response （P = 0.0130）. The independent predictors of survival were serum albumin level （dsk ratio, 3.216; 950 CI, 1.407-7.353; P = 0.0056） and initial treatment response （risk ratio, 2.474; 95% CI, 1.076-5.692; P = 0.0330） based on the Cox proportional hazards regression models. The patients had a serum albumin level 3.5 g/dL and the 3- and 5-year survival rates of 86% and 82%. CONCLUSION： In HCC patients treated with percutaneous ablation therapy, serum albumin level and initial treatment response are the independent outcome predictors.

Radiofrequency ablation as a treatment for hilar cholangiocarcinoma

AIM: To explore the role of radio-frequency ablation (RFA) as a treatment for hilar cholangiocarcinoma. METHODS: Eleven patients with obstructive cholestasis underwent Computed Tomography (CT) examination, occupying lesions were observed in the hepatic hilar region in each patient. All lesions were confirmed as cholangioadenocarcinoma by biopsy and were classified as type or by percutaneous transhepatic cholangiography. Patients were treated with multiple electrodes RFA combined with other adjuvant therapy. The survival rate, change of CT attenuation coefficient of the tumor and tumor size were studied in these patients after RFA. RESULTS: In a follow-up CT scan one month after RFA, a size reduction of about 30% was observed in six masses, and two masses were reduced by about 20% in size, three of the eleven masses remained unchanged. In a follow-up CT scan 6 mo after RFA, all the masses were reduced in size (overall 35%), in which the most significant size reduction was 60%. The survival follow-up among these eleven cases was 18 mo in average. Ongoing follow-up showed that the longest survival case was 30 mo and the shortest case was 10 mo. CONCLUSION: RFA is a microinvasive and effective treatment for hilar cholangiocarcinoma.

Role of catheter ablation of ventricular tachycardia associated with structural heart disease

In patients with structural heart disease, ventricular tachycardia (VT) worsens the clinical condition and may severely affect the shortand long-term prognosis. Several therapeutic options can be considered for the management of this arrhythmia. Among others, catheter ablation, a closed-chest therapy, can prevent arrhythmia recurrences by abolishing the arrhythmogenic substrate. Over the last two decades, different techniques have been developed for an effective approach to both tolerated and untolerated VTs. The clinical outcome of patients undergoing ablation has been evaluated in multiple studies. This editorial gives an overview of the role, methodology, clinical outcome and innovative approaches in catheter ablation of VT.

局部麻醉下CT/超声双引导经皮双极射频消融术治疗偶发性肾脏小肿瘤的疗效及安全性

目的通过与机器人辅助腹腔镜下肾部分切除术(RAPN)对比,分析局部麻醉下计算机断层扫描(CT)/超声双引导下经皮双极射频消融术(RFA)治疗偶发性肾脏小肿瘤(SRM)的疗效及风险。方法回顾性分析2019年3月—2021年10月南京大学医学院附属鼓楼医院收治的93例T1a期SRM患者,其中51例进行了RAPN(RAPN组),另42例进行了局部麻醉下CT/超声双引导下经皮双极RFA(RFA组)。对两组患者的一般资料、肿瘤特征、围手术期及随访结果进行对比分析。结果两组患者的一般资料和肿瘤特征方面差异无统计学意义(P>0.05)。RFA组较RAPN组的手术操作时间[(96.0±20.0)min vs.(113.5±24.1)min,P<0.001]、住院时间[(3.5±0.8)d vs.(6.9±1.8)d,P<0.001]及住院费用[(2.4±0.7)万元vs.(6.6±0.4)万元,P<0.001]均降低。两组患者的围手术期并发症发生率以及远期无病生存率差异无统计学意义(P>0.05)。而RFA组术后1年估算肾小球滤过率(eGFR)水平与术前eGFR水平之差显著小于RAPN组[-2.3(-4.7~1.3)mL/(min·1.73 m^(2))vs.-5.0(-9.1~-2.8)mL/(min·1.73 m^(2)),P=0.003],RFA组术后1年血肌酐水平与术前血肌酐水平之差略小于RAPN组[4.0(-0.2~5.5)μmol/L vs.4.5(1.8~9.2)μmol/L,P=0.122]。结论RFA与RAPN治疗T1a期肾肿瘤的无病生存率相当。此外,RFA术后并发症发生率更低,能更好地保护肾功能并节省医疗成本。

激光诱导等离子体加工蓝宝石微结构及其润湿性

激光诱导等离子体刻蚀技术在蓝宝石表面微结构制作方面具有独特的优势。通过控制变量法研究了激光能量密度、靶材和蓝宝石之间的距离和扫描速度对激光诱导等离子体加工蓝宝石微槽的微观形貌和几何尺寸的影响规律。通过正交试验研究了激光诱导等离子体工艺参数对蓝宝石表面微结构接触角的影响,发现扫描线间距对接触角的影响最大,靶材和蓝宝石之间的距离和激光能量密度次之,扫描速度的影响最小。当激光能量密度为6.3 J/cm^(2),扫描线间距为200μm,靶材和蓝宝石之间的距离为150μm,扫描速度为10 mm/s时,蓝宝石表面微结构的接触角为136°,表现出良好的疏水性;当激光能量密度为7.4 J/cm^(2),扫描线间距为50μm,靶材和蓝宝石之间的距离为100μm,扫描速度为5 mm/s时,蓝宝石表面微结构的接触角为29°,具有较好的亲水性,并且长时间放置后表面接触角基本保持不变。通过扫描电镜观察发现,蓝宝石表面的微结构上分布着许多纳米颗粒,这些微纳结构共同影响蓝宝石的润湿性。

Comparative study of video-assisted thoracoscopic surgery ablation and radiofrequency catheter ablation on treating paroxysmal atrial fibrillation： a randomized, controlled short-term trial

Background It is unclear whether the effect of video-assisted thoracoscopic surgery ablation is better than catheter ablation on paroxysmal atrial fibrillation （PAF） or not. This study aimed to compare the effects of catheter ablation and video-assisted thoracoscopic surgery ablation on PAF. Methods From March 2008 to March 2012, 138 consecutive patients with PAF were randomly assigned to receive either video-assisted thorecoscopic surgery ablation （thoracoscopy group, n=66） or the traditional catheter ablation （catheter group, n=72）. Results No patient died during the study and all were successfully followed and included in analysis. There were no significant differences in clinical and echocardiographic characteristics between the two groups. All patients were evaluated at 1 week, 1 month, 3 months, 6 months, and 12 months after discharge by physical examination and related laboratory tests. Preoperative left atrium dimensions （LADs） of the recurrent AF were （47±4） mm in the thoracoscopy group and （46±8） mm in the catheter group, whereas the LADs were （40±5） and （39±9） mm, respectively, in non-recurrent PAF. Conclusions The short-term outcome of video-assisted thoracoscopic surgery ablation is safe and effective; and the indications are wider than those for catheter ablation. The larger left atrium diameter is related to the recurrence of atrial fibrillation. Chin Med J 2014;127 （14）： 2567-2570

Ablation enhancement by defocused irradiation assisted femtosecond laser fabrication of stainless alloy

We evaluate the effects of the holes geometry drilled by a femtosecond laser on a stainless alloy with various defocused irradiation time, which ranges from 0 min to 1 h. The laser ablation efficiency is increased by a factor of3 when the irradiation time is elevated from 0 to 30 min. Also, the morphology of the hole is observed by a scanning electron microscope, where the result indicates that the defocused irradiation time has a significant influence on the morphology changes. The reason for such changes is discussed based on the pretreatment effect and the confined plasma plume. As an application example, the microchannel is fabricated by a femtosecond laser combined with the defocused irradiation to demonstrate the advantage of the proposed method in fabricating functional structures.

Laser ablation assisted spark induced breakdown spectroscopy and its application

Recently,laser ablation assisted spark induced breakdown spectroscopy(LA-SIBS)has been growing rapidly and continue to be extended to a broad range of materials analysis.Characterized by employ-ing a speifically designed high voltage and pulse discharge cireuit to generate a spark and used to enhance plasma emission produced by laser ablation,allows direct analysis of materials without prior sample preparation.This paper reviews recent development and application of laser ablation assisted spark induced breakdown spectrosoopy for material analysis.Following a summary of fundamentals and instrumentation of the LA-SIBS analytical techmique,the development and applications of laser ablation assisted spark induced breakdown spectroscopy for the analysis of conducting materials and insulating materials is described.

纳秒激光诱导等离子体辅助烧蚀的玻璃表面金属化图案电路研究

激光诱导等离子体辅助烧蚀(LIPAA)在玻璃表面金属化制备中具有经济、环境友好且高效的优点,本文研究在纳秒激光下以金属铜作为牺牲靶材于玻璃基板上采用LIPAA工艺实现金属化图案电路的可行性。为此,首先对逐行扫描LIPAA制备的玻璃基板上金属化图案电路的导电性能进行详细探讨。针对氧化致其导电率下降的弊端,进一步采用氢气还原对其进行后处理优化,并结合扫描电子显微镜(SEM)和能谱仪(EDS)对电路性能进行分析,揭示了纳秒激光LIPAA方法制备的玻璃金属化图案电路表面的形貌特征及电阻率的变化规律。结果表明,通过激光图案化去除工艺对玻璃表面金属层进行直接烧蚀,可以在玻璃表面制备精细图案化电路。同时,采用化学氢气还原法可克服金属层氧化严重影响电路电阻率这一弊端。化学氢气还原后的平均电阻率仅为8.18×10^(-7)Ω·m,大幅地提升了玻璃表面图案化电路的导电性,具有广阔的应用前景。

基于纳秒激光诱导等离子体辅助烧蚀的玻璃表面金属化实验研究

由于激光诱导等离子体辅助烧蚀(LIPAA)在玻璃表面金属化加工中具有经济、环境友好且高效的特点,该文研究了在纳秒激光下以金属铜作为牺牲靶材,于玻璃基板上采用LIPAA工艺实现直接平面金属化的可行性。为此,对逐行扫描LIPAA制备的玻璃基板上平面金属层的形态和化学成分进行了详细表征;进一步,结合扫描电子显微镜及X射线能谱分析仪对试件在不同激光扫描速度、线间距、激光功率及频率下金属化的表面形貌演变进行了深入分析,揭示了以上加工参数对玻璃表面金属化覆盖率及形貌的影响规律。实验结果表明,当激光功率为20 W,激光频率为20 kHz,激光扫描线间距为2.5μm,扫描速度为300 mm/s时,玻璃表面的金属化可实现全区域覆盖且厚度适中。

超声引导下真空旋切和微波消融兔乳腺肿瘤的实验研究

目的:对比超声引导下真空旋切(vacuum-assisted biopsy,VAB)和微波消融(microwave ablation,MWA)兔乳腺肿瘤的疗效及术后局部恢复情况。方法:将72只新西兰大白兔VX2乳腺肿瘤模型随机分为两组,每组36只,分别行超声引导下VAB与MWA,术后第1、3、7、14、30、60天进行超声检查、大体观察、病理HE染色,并采用免疫组化检测CD31、VEGF、TGF-β进行量化,评价疗效及局部愈合情况。结果:30天后VAB组的治疗成功率为75.0%,MWA组成功率为83.3%。VAB组术后血肿发生率为13.9%,随着时间增长逐渐缩小;MWA组皮肤烫伤发生率为13.9%。两组治疗后第7天肉芽组织达高峰,随后均减少,逐渐上皮化,MWA组稍晚。术后14天、30天、60天愈合量化指标VAB组高于MWA组。术后3天,VAB组的早期愈合标记物CD31表达量更高;术后14天、30天,MWA组VEGF水平更高,TGF-β水平下降速度更慢。结论:VAB和MWA微创治疗兔VX2乳腺肿瘤均有较好疗效。VAB组早期愈合优于MWA组,瘢痕形成更少。

甲状腺微创手术的研究进展

近年来,甲状腺癌的发病率不断攀升。基于人们对美容和高质量生活的追求,加之能量设备和机器人在医学领域不断发展,使外科医师推出疼痛少、美容效果好、精细化和高难度的微创术式。甲状腺手术在原有基础上,衍生出腔镜辅助的甲状腺切除术以及多途径入路的腔镜甲状腺切除术,还有热消融、化学消融以及机器人辅助甲状腺切除术。

输尿管镜在上尿路上皮癌诊治中的利与弊

输尿管镜技术在上尿路上皮癌(UTUC)的诊治中发挥着重要作用。传统输尿管镜检查(URS)不仅可以确定肿瘤的位置、外观和大小,还可以通过活检确定肿瘤分级。电子输尿管软镜及辅助技术的发展为UTUC的诊断带来了显著的进步。输尿管镜激光消融术可以治疗低级别恶性肿瘤、肾功能不全或孤立肾的患者。然而使用URS也有潜在的风险,如延迟根治性治疗、增加手术难度、术中或术后并发症和膀胱内复发等。本文就输尿管镜在UTUC诊治中的利与弊进行综述。

硅片纳秒激光附加电流打孔实验研究

针对硅片具有反射率高、吸收率低等缺点,为了提高纳秒激光(波长为355 nm)在硅片上打孔蚀除材料效率,设计附加电流场装置,建立单脉冲烧蚀阈值模型,经过实验计算得到硅片烧蚀阈值为1.885 J/cm^(2)。采用电流场辅助激光环切式进行硅片打孔,分别在激光加工次数和附加电流不同时做实验研究,当激光加工次数较少而附加电流较大时,激光加工的微孔入口孔和出口孔直径均显著增加,锥度减小,蚀除材料效率增大;当激光加工次数较多时,施加电流后由于多脉冲的累积效应,微孔直径变化不明显,这是由于附加电流场导致硅片内自由电子增多,更多的自由电子与激光光子发生碰撞,增加硅片对激光能量的吸收。实验表明,附加电流增加了硅片对波长为355 nm纳秒激光光子的吸收率,提高了硅片蚀除材料效率,也为高效率的纳秒激光加工硅片提供一种新方法。

心房颤动外科治疗的发展历程及现状

心房颤动(简称房颤)是最常见的快速性心律失常之一,它是美国发病率最高的心律失常类型,在我国的发病率也仅次于室性早搏,而且房颤的发病率会随着年龄的增长而增加,致残率和致死率均较高。近年来,医学技术的进步帮助我们对房颤有了更深入的了解,外科治疗房颤的手段也随之不断创新进步。Cox迷宫Ⅲ型手术是房颤外科治疗的标准术式,但外科医师们又发展出了利用不同能源消融的Cox迷宫Ⅳ型手术、Wolf微创迷宫手术以及杂交消融等多种治疗方法。现对房颤外科治疗的发展历程及现状作一综述如下。

角膜偏心切削LASIK术后白内障一例

准分子激光原位角膜磨镶术(laser-assisted in situ keratomileusis,LASIK)是矫正屈光不正的重要角膜屈光手术方式之一。经过准分子激光切削的角膜,生物测量数据发生改变。对于此类患者,通过常规测量获得的参数数据以及使用常规计算公式确定的IOL屈光度将变得不再准确,由此将会导致术后较大的屈光误差,进而影响患者的视觉质量。本文报道一例46岁的男性白内障患者。该患者既往双眼屈光不正,曾接受过LASIK手术治疗。白内障术前角膜地形图检查发现该患者双眼存在角膜偏心切削,这为IOL屈光度的确定带来困难。手术医生通过角膜地形图判断角膜切削的居中性,在特定区域内选择角膜曲率K值,并采用Barrett True K公式计算出IOL屈光度。白内障术后患眼屈光误差相对较小,视力提高,视觉质量改善。

微波消融术治疗甲状腺良性肿瘤的效果和安全性

目的:探讨微波消融术治疗甲状腺良性肿瘤的效果和安全性。方法:回顾性分析上饶市人民医院2021年10月—2022年6月收治的86例甲状腺良性肿瘤患者资料。根据治疗方案不同,将43例行超声引导下微波消融术治疗患者作为A组,43例行腔镜辅助小切口切除术治疗的患者作为B组,比较两组的手术效果、甲状腺功能和术后并发症发生情况。结果:A组治疗总有效率为95.35%(41/43),高于B组的88.37%(38/43),但组间比较差异无统计学意义(P>0.05)。A组切口长度和住院时间均短于B组,A组术中失血量少于B组,差异均有统计学意义(P<0.05);A组手术时间短于B组,但两组比较差异无统计学意义(P>0.05)。术前,两组FT_(3)、FT_(4)、TSH比较,差异均无统计学意义(P>0.05);术后3 d两组FT_(3)、FT4均较术前升高,差异均有统计学意义(P<0.05),两组TSH均较术前降低,差异均无统计学意义(P>0.05);术后3 d,A组FT_(3)、FT4均高于B组,TSH低于B组,但差异均无统计学意义(P>0.05)。术后7 d内,A组未发生并发症,B组并发症发生率为13.95%(6/43),组间比较差异有统计学意义(P<0.05)。结论:超声引导下微波消融术和腔镜辅助小切口切除术均是目前治疗甲状腺良性肿瘤的先进治疗手段,微波消融术的效果略优于腔镜辅助小切口切除术,同时还具有更明显的安全性优势。

基于影像引导的计算机辅助肝癌微波消融

为了方便临床医生使用医学影像进行手术的规划和引导,提出了一种新颖的计算机辅助肝癌微波消融手术方法.采用基于GPU加速的三维可视化技术实时重构影像的三维模型,显示出患者器官的解剖关系;采用基于生物传热学的三维热场计算技术,规划手术路径及消融设备的作用时间和功率.经过大量的临床应用以及手术影像对比,表明该方法能够有效计算消融手术的作用效果,并在手术的引导过程中发挥了重要的作用,提高了手术的临床精度和效果.