Onders Raymond P, Aiyar Harish, Mortimer J Thomas
Department of Surgery, University Hospitals of Cleveland and Case Western Reserve University, Ohio, USA.
Am Surg. 2004 Mar;70(3):241-7; discussion 247.
Diaphragm pacing from laparoscopically placed electrodes is an alternative to conventional phrenic pacers that use electrodes placed in direct contact with the nerve in the neck or chest. The challenge with the laparoscopic approach is determining where to implant the electrodes, as the phrenic nerves are not visible from the abdomen. The objective of this study was to locate the phrenic nerve "motor points" in the human diaphragm muscle from an abdominal perspective. Twenty-five cadavers were examined by excising the diaphragm muscle and assessing for the thickness of the muscle, the motor point area, and the accessibility of the motor point from the abdominal approach. The data indicate the average thickness of the muscle in the motor point region was 3.0 mm for the left and 2.9 mm for the right hemidiaphragm. The average motor point area was 73 mm2 for the left and 58.7 mm2 for the right hemidiaphragm. The motor points were accessible from an abdominal approach, but the motor point on the right hemidiaphragm was located on the central tendon in many cases (12 of 25). Thus, although the nerves branch prior to entry into the muscle on the right side, several well-placed electrodes could still activate the entire nerve. In this study, we have characterized the human diaphragm muscle in the motor point region and found that it is feasible to place laparoscopically intramuscular electrodes in the motor point region. This is the foundation for the laparoscopically placed diaphragm pacing device that has been utilized in a small series of patients.
通过腹腔镜放置电极进行膈肌起搏是传统膈神经起搏器的一种替代方法，传统起搏器使用的电极直接与颈部或胸部的神经接触。腹腔镜方法面临的挑战是确定电极的植入位置，因为从腹部无法看到膈神经。本研究的目的是从腹部视角定位人膈肌中的膈神经“运动点”。通过切除膈肌并评估肌肉厚度、运动点区域以及从腹部入路到达运动点的难易程度，对25具尸体进行了检查。数据表明，运动点区域的左侧膈肌平均厚度为3.0毫米，右侧膈肌为2.9毫米。左侧膈肌的平均运动点面积为73平方毫米，右侧膈肌为58.7平方毫米。运动点可通过腹部入路到达，但右侧膈肌的运动点在许多情况下（25例中有12例）位于中心腱上。因此，尽管右侧神经在进入肌肉之前就已分支，但几个放置得当的电极仍可激活整条神经。在本研究中，我们对运动点区域的人膈肌进行了特征描述，并发现将腹腔镜下肌内电极放置在运动点区域是可行的。这是已在一小部分患者中使用的腹腔镜放置膈肌起搏装置的基础。
