Offergeld C, Tschöpe C, Brambs H J
Dept. of Otorhinolaryngology, Head and Neck Surgery, University of Dresden, Germany.
Endoscopy. 1996 Nov;28(9):740-5. doi: 10.1055/s-2007-1005597.
Although there have been many reports concerning the therapeutic use and potential of laser and monopolar electrocoagulation therapy, little has been published on the effects of bipolar electrocoagulation on biliary tissue. Although it has been reported that endoscopic recanalization of malignant stent obstruction using bipolar electrocoagulation is an advantageous form of treatment, the optimal parameters for this type of treatment have not yet been determined. The purpose of this prospective study was therefore to evaluate, under in-vitro conditions, the maximum applicable energy required; the influence of probe angle and duration time on the extent of the coagulation achieved; and whether multiple intermittent short pulses show any significant differences in the extent of coagulation achieved, in comparison with the use of a single continuous pulse.
In this in-vitro study, experiments were carried out in 84 common bile ducts from freshly slaughtered swine. The extension of tissue injury after electrocoagulation treatment was measured at 60 combinations of varying levels of power output, probe angles, duration times, and pulse patterns. All of the results were correlated with the diameter of the untreated and normal bile duct walls under in-vitro conditions.
When energy was applied at levels up to a maximum of 16 J, the extension of tissue coagulation was about 58% of the untreated bile duct wall diameter. Energy settings exceeding 16 J involved the whole wall diameter in most cases, often including the periductal fatty tissue. Additional energy applications higher than 16 J, 32 J, and 100 J, showed undesirable tissue changes, such as an increasing diameter in the treated bile duct walls of up to 56.8% of the wall diameter of control specimens.
The study evaluated the standard settings in an in-vitro model. The results indicate that protective and effective use of bipolar electrocoagulation on normal porcine bile duct tissue requires: the use of a low power setting (less than 16 J); the use of continuous short pulse patterns; placement of the probe tip at an obtuse angle (0 degree); and the use of short application times.
虽然已有许多关于激光和单极电凝疗法的治疗用途及潜力的报道，但关于双极电凝对胆管组织影响的文献却很少。虽然有报道称使用双极电凝进行恶性支架梗阻的内镜再通是一种有利的治疗方式，但此类治疗的最佳参数尚未确定。因此，这项前瞻性研究的目的是在体外条件下评估所需的最大适用能量；探头角度和持续时间对凝血范围的影响；以及与使用单个连续脉冲相比，多个间歇性短脉冲在凝血范围上是否存在显著差异。
在这项体外研究中，对刚屠宰猪的84条胆总管进行了实验。在60种不同功率输出水平、探头角度、持续时间和脉冲模式的组合下，测量了电凝治疗后组织损伤的范围。所有结果均与体外条件下未处理的正常胆管壁直径相关。
当能量施加至最高16焦耳时，组织凝血范围约为未处理胆管壁直径的58%。在大多数情况下，能量设置超过16焦耳会涉及整个管壁直径，通常还包括胆管周围脂肪组织。高于16焦耳、32焦耳和100焦耳的额外能量应用显示出不良的组织变化，例如处理后的胆管壁直径增加，最多可达对照标本管壁直径的56.8%。
该研究在体外模型中评估了标准设置。结果表明，在正常猪胆管组织上安全有效地使用双极电凝需要：使用低功率设置（小于16焦耳）；使用连续短脉冲模式；将探头尖端以钝角（0度）放置；以及使用短应用时间。
