Severe twin-twin transfusion syndrome: outcome after fetoscopic laser ablation of the placental vascular equator

Objective  To assess the safety and efficacy of a modified fetoscopic laser ablation technique for the management of severe twin–twin transfusion syndrome (TTTS) in a large series of pregnancies.
Design  Prospective cohort study.
Setting  Tertiary referral fetal medicine unit.
Population  Women with pregnancies complicated by severe TTTS (Quintero stage III or IV), before 26 weeks of gestation.
Methods  Fetoscopic laser ablation of placental anastomoses was performed. The sonoendoscopic approach was used to identify the placental vascular equator and to photocoagulate crossing vessels.
Main outcome measures  Overall survival, fetal and perinatal mortalities, gestational age at delivery, birthweight, operating time and recurrence of TTTS.
Results  A total of 77 women underwent the procedure. The mean gestational age at treatment was 20 (range 16–26) weeks. On average, four vessels were ablated during each procedure, with a mean operative time of 15 (range 5–25) minutes. None of the women required a repeat fetoscopic laser treatment for recurrence of the TTTS. There was at least one survivor in 74% (57/77) of pregnancies, and the overall survival rate was 57% (88/154).
Conclusions  Fetoscopic laser ablation is a safe and effective form of treatment in the management of severe TTTS. The technique of identifying the common villous district of the placenta by ultrasound and photocoagulating any vessels crossing the vascular equator appears to be an acceptable alternative to both the nonselective and highly selective methods described so far. This approach is associated with a short operating time, low likelihood of TTTS recurrence or fetal anaemia and with survival results that are equivalent to previously reported techniques.     

Percutaneous recanalization of chronic subclavian artery occlusion using optical coherence reflectometry-guided radiofrequency ablation guidewire.

Subclavian artery lesion that is associated with low complication rate could be treated by percutaneous intervention effectively. However, the success of endovascular therapy for occlusive lesion may be limited by failure to cross with a guidewire. We describe the use of a system using optical coherence reflectometry for navigation and radiofrequency ablation to enable wire passage through subclavian artery occlusion that could not be crossed by conventional guidewires.     

射频消融治疗室上性心动过速10例报告

作者报告了１０例室上性心动过速，共１１条径路的射频消融的成功经验。介绍了左侧显性旁路、隐匿性旁路及房室结双径路射频导管改良的基本方法以及定位标准。     

超声引导经皮肝穿刺射频治疗肝癌

目的　探讨经皮肝穿刺射频治疗肝癌的有效性、安全性和肿瘤局部的控制情况。　方法　采用RF2 0 0 0射频治疗仪在超声引导下将射频电极放置于肝肿瘤内进行治疗。　结果　 (1) 30例肝癌患者 (肿瘤病灶直径 <5 cm及 >5 cm各 2 3个 )经过治疗 ,肿瘤完全缓解和部分缓解率占 5 4 .3% (2 5 /46 )。半年生存率为 93.3% ,1年生存率为 75 %。 (2 ) 2例出现肿瘤细胞针道种植转移 ,其他未见严重并发症。　结论　射频治疗肝癌是一种安全、有效的方法。对于肿瘤直径 <5 cm的肝癌治疗效果较佳 ;对于肿瘤直径 >5 cm者 ,应配合其他局部介入的综合治疗     

QT间期校正和QT离散度检测方法的探讨

目的　探讨QT间期校正方法和心率、QRS时间、描记纸速对QT离散度 (QTd)的影响。方法　(1)对比分析 5 0例纸速 2 5mm·s-1和 5 0mm·s-1描记时QT间期和QTd;(2 )对比分析 5 0例室上性心动过速(SVT)发作时和发作前QT间期 ,并比较QTC、QTLC、QTFC三种方法校正结果 ;(3)对比分析 5 0例SVT发作时与发作前QTd;(4)对比分析 2 0例显性预激综合征消融旁路前后QTd。结果　 (1)在SVT时QTC 出现假性延长 ,QTLC、QTFC有助克服上述假象 ;(2 ) 2 5mm·s-1与 5 0mm·s-1纸速QTd、SVT发作时与发作前QTd、显性预激射频消融前后QTd,均无显著性差异。结论　QT间期受心率影响 ,但QTd 不受心率影响 ;对QT间期校正建议应修改QTC,试用QTLC或QTFC。     

导管射频消融治疗飞行员快速心律失常临床分析

目的探讨导管射频消融（RFCA）在治疗飞行员多种快速性心律失常中的安全性及临床应用价值，探讨飞行员快速性心律失常的航空医学鉴定标准。方法对13例快速性心律失常的飞行员进行了电生理（EP）检查，特发性室性心动过速（VT）1例，频发室性期前收缩（VE）2例，阵发性心房纤颤（AF）1例，房室折返性心动过速（AVRT）5例，房室结折返性心动过速（AVNRT）3例，房性心动过速（AT）1例。对其中12例采用RFCA治疗。结果RFCA即刻成功率为100％，全组无并发症发生。1例房性心动过速未行导管射频消融治疗。所有飞行员术后地面观察6个月后，返院进行随访复查，同时进行飞行鉴定。12例导管射频消融治疗，术后6个月24h动态心电图、12导联心电图检查和食道电生理检查均未检测到术前的同型快速性心律失常发作，延迟成功率为100％，医学鉴定合格。1例AT仍有发作，飞行不合格。结论对于飞行员快速性心律失常进行导管射频消融治疗是一种安全、有效的治疗方法。心脏电生理检查应作为飞行员快速性心律失常医学鉴定的主要指标之一。     

射频消融治疗老年肝脏肿瘤(附126例临床分析)

目的探讨射频消融(radiofrequency ablation,RFA)治疗老年肝肿瘤患者的安全性。方法对126例老年肝肿瘤患者进行了161次RFA治疗,临床观察治疗后其对机体的反应、并发症发生及防治情况。结果并发症发生率7.1%(9/126),其中皮肤烧伤3例,胸腔积液2例,肝功能不全2例,结肠穿孔1例,皮下出血1例,无临床死亡病例。结论射频消融治疗老年肝肿瘤是一种较安全的方法,对机体影响轻微。     

Prostatectomy by transurethral balloon Laserthermia™ (PROSTALASE™) in the canine

Prostatectomy by transurethral balloon Laserthermia (PROSTA-LASE?) was performed in a canine model. This balloon device monitored by transrectal ultrasound can cylindrically irradiate with a laser beam. The treatment was performed in 8 canines using 15 watts for 20 minutes at 60°C at a 5 mm depth of the prostate from the urethral surface. Immediately following the laser therapy, an area of coagulation necrosis was observed around the urethra to a depth of 4–5 mm from the surface. After 1 week, cavitation formation was seen in 3 or 4 canines by ultrasound, and the urethral reepithelialization was shown in 1 of 2 canines. After 2 weeks, cavitation formation was observed in both canines, and the urethra was completely reepithelialized in one canine. There was no tissue damage in the bladder neck of urethral sphincter and no urinary incontinence in any animal. This system is thought to be simple and, satisfactorily performed, is an effective transurethral prostatectomy. © 1994 Wiley-Liss, Inc.     

Counter Intuitive Relations Between in vivo RF Lesion Size, Power, and Tip Temperature

Background: Radiofrequency (RF) lesion size in vitro is positively correlated with applied power and catheter tip temperature. However, the relation between RF lesion size, power, and tip temperature in vivo remains unclear. We hypothesized that due to flow, anatomy and tip contact effects in vivo, increased tip temperature would be inversely related to applied power and RF lesion size. Methods: RF lesions were created on the endocardium of 16 pigs using 5, 6, and 7 Fr catheters. The ablation generator was set to achieve a temperature of 70°C. RF lesions were created in different regions of the heart so as to encompass a wide range of blood flow and catheter movement conditions. RF lesions were measured acutely (DIMEN, mm) and correlated with average power applied (POWER, W), and average tip temperature (TEMP, °C). The POWER and TEMP relation was also examined. Results: For TEMPs below 55°C, the power output from the generator was typically maximized at 50 W. At TEMPs above 55°C, POWER decreased exponentially with increasing TEMP {POWER = 50 – exp(-((41-TEMP)/7)), r = 0.98, p < 0.05}. Further, DIMEN tended to be inversely related to TEMP (Slope: –0.07 ± 0.04, r = –0.15, p = 0.07); but, was positively related to POWER (Slope: 0.04 ± 0.02, r = 0.23, p < 0.05). These relations varied by tip size and estimated local blood flow characteristics. Conclusion: In vivo, variable tissue contact and flow yield DIMEN-POWER-TEMP relations opposite to those found in vitro. These counterintuitive results suggest that maximum in vivo RF lesion size is achieved when power is maximized at tip temperatures between 50 and 60°C.     

Ostial PV Isolation:

Pulmonary vein (PV) isolation by elimination of spike potentials has been reported to cure drug refractory atrial fibrillation. Because of the heterogenous morphology of the PVs, sequential electroanatomic reconstruction of the PVs was performed in 39 patients (group A), who underwent subsequent PV isolation by interruption of all conductive myocardial fibers by distinct RF current applications using a "lasso" approach. In group B (157 patients), only biplane two-dimensional fluoroscopy was performed to guide the diagnostic and the ablation catheters. After reprocedures (in 7% of patients in group A and 22% of group B), which depicted a recurrence of a spike potential inside or at the ostium of  >1 previously isolated PV in all restudied patients, stable sinus rhythm was documented in 69% of patients in group A and 60% of patients in group B. Reasons for the relapse of the previously eliminated spike potentials include a temporary ablation effect and a too distal interruption of the conducting myocardial fiber. Detailed knowledge of the individual three-dimensional morphology enhanced the clinical success rate of PV isolation but is time-consuming using CARTO   (8.0 ± 1.7 vs 5.0 ± 1.6, P < 0.001)   . Further technical improvement to fuse the individual three-dimensional anatomy and the electrophysiological markers to a composed "electroanatomic" map may overcome this limitation in the future. (PACE 2003; 26[Pt. II]:1624–1630)