【晨读】脑桥前池吗啡泵植入术缓解头面部癌痛（二）

 英语晨读 ·

山东省立医院疼痛科英语晨读已经坚持10余年的时间了，每天交班前15分钟都会精选一篇英文文献进行阅读和翻译。一是可以保持工作后的英语阅读习惯，二是可以学习前沿的疼痛相关知识。我们会将晨读内容与大家分享，助力疼痛学习。

本次文献选自Zou D, Zhang W, Wang Y. Prepontine cistern intrathecal targeted drug delivery for cancer-related craniofacial pain [published online ahead of print, 2021 Feb 23]. Pain Med. 2021;pnab059. 本次学习由林小雯副主任医师主讲。

Discussion

This patient had severe cancer pain in the forehead which greatly impacted her quality of life. Despite receiving large doses of oral analgesics, she experienced limited pain relief, and subsequently she elected to undergo implant of an intrathecal catheter with the catheter tip placed at the prepontine cistern. After placement of the intrathecal catheter with an external pump, her pain was significantly improved, suggesting prepontine cistern intrathecal targeted drug delivery can be an effective treatment for intractable craniofacial cancer pain.

讨论

该患者的前额剧烈癌痛严重影响了她的生活质量。尽管口服大剂量的镇痛药，但疼痛缓解有限，随后选择鞘内植入吗啡泵，导管尖端放置在脑桥前池。导管放置后外接泵头，疼痛明显缓解，脑桥前池吗啡泵植入术是治疗难治性头面部癌痛的有效方法。

This case suggests that the catheter tip location plays a crucial role in pain relief when considering an intrathecal catheter for cancer related pain. A previous study found that the drug distribution during chronic intrathecal infusion was very limited and most of the drug recovered in the cerebrospinal fluid was within 1 cm of the site of administration(1). The nerves that innervate the face are cranial nerves including V, VII, IX, and X. The second order neuron to these nerves is located in the brainstem to convey the pain signal centrally. The traditional approach has been to place the intrathecal catheter tip usually below the level of cranial nerve root entry zones, which may lead to an insufficient analgesic effect. The prepontine cistern intrathecal targeted drug delivery method for pain control utilizes the dense concentration of opioid receptors surrounding the brainstem, particularly in the cranial nerve entry zones, so it is reasonable to anticipate the analgesic effect can be more obvious compared with the traditional approach.

本病例提示，当考虑使用鞘内导管治疗癌症相关疼痛时，导管尖端位置在疼痛缓解中起着至关重要的作用。有研究发现，慢性鞘内输注时药物分布非常有限，大部分药物在脑脊液中的分布面积在1cm以内。支配面部的神经为颅神经V, VII, IX和X。这些神经的二级神经元位于脑干，介导中枢疼痛信号传递。传统的方法是将鞘内导管尖端通常放置在颅神经根入颅水平以下，这可能导致镇痛效果不足。脑桥前池鞘内给药的作用靶点是脑干周围密集的阿片类受体，特别是在颅神经入颅区，由此推测其镇痛效果比传统方法更为合理。

To improve the success rate of catheterization and decrease potential damage to the tissues, the catheter used was very flexible and has a soft tip. The placement of the catheter was performed carefully under continuous X-ray guidance. Due to the delicacy of the surrounding structures, the catheter tip was moved very slowly and slightly at the level of C1, and was not advanced against resistance. If the catheter encountered resistance, it was withdrawn and attempted again. The prepontine cistern is part of the subarachnoid space, and the catheter was easily advanced to this level in our case. The case we described here did not show any serious side effects or severe complications, such as subarachnoid hemorrhage, suggesting the prepontine cistern catheter placement can be safe and feasible.

In conclusion, the prepontine cistern intrathecal targeted drug delivery can be an effective method of treating severe, cancer-associated craniofacial pain.

为了提高置管的成功率和减少对组织的潜在损害，所使用的导管具有较高的灵活性且导管尖端质地柔软。导管放置是在连续x线引导下完成。由于周围结构的特殊性，导管头端在C1水平上移动时操作应缓慢而轻柔，置管过程无明显阻力。如果导管前端遇到阻力，应后退导管并再次尝试。脑桥前池是蛛网膜下腔的一部分，我们在临床中发现鞘内置管至该位置较为容易。本病例未出现任何严重的副作用或并发症，如蛛网膜下腔出血，提示脑桥前池置管是安全可行的。

综上所述，脑桥前池吗啡泵植入术是治疗顽固性头面部癌痛的有效方法。