A opaleshoni ya msana ndi anesthesia wa m'munsi thupi. Zimapangidwa ndi kubaya mankhwala oletsa ululu mwachindunji mu cerebrospinal fluid (CSF), madzimadzi omwe amazungulira msana wa msana, pamlingo wa msana wam'munsi pakati pa ma vertebrae awiri a lumbar. Ndi mtundu wa anesthesia womwe umagwiritsidwa ntchito kwambiri pa opaleshoni.

Anesthesia ya msana ndi yofanana ndiepidural anesthesia, koma jekeseni wa mankhwala oletsa ululu samachitika mu "chipinda" chomwecho.

Zowonadi, pali 3 nembanemba kuzungulira chapakati mantha dongosolo (awa ndi meninges):

• la wokhazikika
• ndiarachnoid
• la nayenso

Izi zikugawa mipata iwiri: epidural space ndi subbarachnoid space (pakati pa arachnoid ndi piamater, yomwe ili ndi CSF),

Anesthesia ya msana imaphatikizapo kubaya mankhwala ochititsa dzanzi mu malo a subbarachnoid, pamene mankhwala oletsa ululu, panthawi ya epidural, sadutsa dura (chitetezo cha cerebrospinal fluid).