Algos Techniques
Sphenopalatine Ganglion Block
| INDICATION: chronic intractable headaches and facial pain POSITIONING: Supine with head straight AP. 1-1.5 inch diameter soft mouth bite inserted between incisors ANATOMY: The sphenopalatine gangion (SPG) lies in the pterygopalatine fossa. The pterygopalatine fossa is bound by the medial pterygoid plate laterally, the palatine bone perpendicular plate medially, the maxillary sinus anteriorly, superiorly by the sphenoid sinus. Laterally, it is open to the infratemporal fossa via the pterygomaxillary fissure. APPROACH: Infrazygomatic through the mandibular notch to the lateral pterygoid plate. The needle is then redirected anteriorly and cephalad to enter the pteryomaxillary fissue which leads to the pterygopalatine fossa. The needle is advanced anterior-superior off the lateral pteyrogoid plate (usually contacted at about 2.5cm) and advanced in AP views until the palatine bone is contacted adjacent to the middle conchae. There is often a small indentation in the bone where the SPG lives. Care should be taken not to place any significant pressure on the needle (curved tip) during advancement due to the potential of penetration of the maxillary or sphenoid sinus, or penetration of the palatine bone into the nasal mucosa. Contrast, then local anesthetic (usually <2ml is used) as a diagnostic block. Potential complications include sinus rupture, deep facial infection, maxillary artery penetration, etc. (Click pics to enlarge) . |
