Sphenopalatine Ganglion Block in Endoscopic Transphenoidal Pituitary Gland Surgery

Patients will be placed in 15-degree reverse Trendelenburg position, between the middle and inferior turbinates. This passage will be sterilized by an cotton-tipped applicator soaked with iodine solution. A 20-gauge/5-inch spinal needle will be used after bending 2-3 mm of its tip along the port side with a sterile needle holder to form a 45 angle. The needle will be lubricated with 5% lidocaine jelly, inserted into the nasal meatus and advanced with the bevel pointer facing laterally. Under endoscopic control (0\_ optics, 4 mm diameter), the needle will be inserted between middle and inferior turbinate. A total of 4 ml 0.25% bupivacaine will be injected after negative aspiration just behind and over middle turbinate tail, where the pterygopalatine fossa is deeply located.

US- guided percutaneous PPFB: Patients will be placed in the lateral head position; the patient's mouth is slightly opened. Following standard sterile preparations, US linear probe covered with sterile sheath is positioned horizontally on the side of the face just below the zygomatic bone superior to the mandibular notch and anterior to the mandibular condyle to visualize the coronoid process, the lateral pterygoid muscle, the lateral pterygoid plate, and the maxillary bone, and the maxillary artery. Needle will be inserted in-plane parallel to the transducer probe and advanced from medial to lateral toward the pterygopalatine fossa. Following negative aspiration, the injectate is deposited deep to the lateral pterygoid muscle and plate. A total of 4 ml 0.25% bupivacaine will be injected.