Department of Thoracic Surgery, Assistance Publique - Hôpitaux de Paris, Tenon Hospital, Paris, France.
Eur J Cardiothorac Surg. 2012 Aug;42(2):333-9. doi: 10.1093/ejcts/ezr324. Epub 2012 Mar 7.
Phrenic nerve stimulation for diaphragm pacing allows patients with central respiratory paralysis to be weaned from mechanical ventilation. Two procedures are available, either intrathoracic (bilateral thoracotomy) or intradiaphragmatic (four ports laparoscopy). The present experimental work assesses the feasibility, safety and efficacy of a trans-mediastinal implantation of intradiaphragmatic phenic nerve stimulation electrodes using a flexible gastroscope through a cervical incision.
We operated on nine ewes. After selective bronchial intubation, we dissected the latero-tracheal space and opened both mediastinal pleura. We then introduced a flexible gastroscope into the pleural cavities, in a sequential manner. The phrenic nerves were located and followed up to the diaphragm dome. Electrodes loaded within a long, pliable needle were introduced through the adjacent intercostal space and implanted in each hemidiaphragm, at a 'tendinous' location (as close as possible to the entry of the nerve in the central tendon), and at a more lateral 'muscular' location. Postoperatively, the animals were ventilated using bilateral phrenic nerve stimulation. After euthanasia, abdominal verification of the electrodes position was performed through a laparotomy.
The mediastinal and pleural parts of the procedure were uneventful. The insertion of electrodes was associated with transdiaphragmatic puncture and small abdominal haematomas in the first two animals studied. After a slight modification of the insertion technique, this was not observed anymore. Phrenic nerve stimulation produced efficient ventilation, with tidal volumes significantly higher when delivered at the tendinous site than at the muscular site.
The trans-mediastinal implantation of intradiaphragmatic phrenic nerve stimulation electrodes is feasible, appears reasonably safe, and allows efficient ventilation.
膈神经刺激用于膈肌起搏可使中枢性呼吸麻痹患者脱离机械通气。有两种方法，一种是胸内（双侧开胸），另一种是膈内（四孔腹腔镜）。本实验工作评估了通过颈部切口使用柔性胃镜经纵隔植入膈神经刺激电极的可行性、安全性和有效性。
我们对 9 只绵羊进行了手术。选择性支气管插管后，我们解剖侧气管空间并打开双侧纵隔胸膜。然后，我们将柔性胃镜依次引入胸腔。定位膈神经并将其追踪到膈肌穹顶。将装有电极的长而柔韧的针通过相邻的肋间空间引入，并将其植入每个半膈肌，一个在“腱性”位置（尽可能靠近神经在中央腱中的进入处），另一个在更外侧的“肌肉”位置。术后，动物使用双侧膈神经刺激进行通气。安乐死后，通过剖腹术对电极位置进行腹部验证。
纵隔和胸膜部分的手术过程顺利。在前两只研究的动物中，插入电极与膈穿刺和小腹部血肿有关。在稍微修改了插入技术后，这种情况不再发生。膈神经刺激产生了有效的通气，在腱性部位输送时潮气量明显高于在肌肉部位输送时。
膈神经刺激的经纵隔植入膈内电极是可行的，似乎是安全的，并允许有效的通气。
