Nerve Blocks for Lacrimal Sac Surgeries: A Comprehensive Guide
Hello and welcome to insight ophthalmology! Today, we shall be discussing an important component of the dacryocystorhinostomy surgeries which is the local anesthesia employed in lacrimal sac surgeries.
Let’s start by discussing the nerve blocks crucial for dacryocystorhinostomy. The diagram illustrates the essential nerves requiring anesthesia, including the infra trochlear nerve, infraorbital nerve, anterior ethmoidal nerve, and its branch, the dorsal nasal nerve.
What drugs are used for Lacrimal Sac Anesthesia?
The anesthesia used comprises a combination of 2% Lignocaine and 0.5% bupivacaine with or without adrenaline.For a more in-depth understanding of local anesthesia, refer to our informative video on the same.
Important Nerve block for Lacrimal Sac surgery.
INFRATROCHLEAR NERVE BLOCK
The infratrochlear nerve, a branch of the nasociliary nerve, is located at the superior medial margin of the orbital cavity. It provides sensory innervation to the bridge of the nose. To block this nerve, palpate the supratroclear notch first and, more specifically, find the infratrochlear nerve halfway between the inner canthus and the supratrochlear notch.
INFRAORBITAL NERVE
Originating from the infraorbital foramen, the infraorbital nerve supplies innervation to the lateral nose skin over the cheek and upper lip. Palpate the infraorbital margin and apply the injection just below it, specifically 1 cm below the margin in the mid-pupillary plane.
DORSAL NASAL NERVE BLOCK
The dorsal nasal nerve, a dorsal branch of the anterior ethmoidal nerve, innovates the tip of the nose. To block this nerve, inject the drug at the junction of the nasal cartilage and nasal bone, about 6 to 9 mm away from the midline.
ANTERIOR ETHMOIDAL NERVE
Situated medially in the extraconal space, the anterior ethmoid nerve is a branch of the nasociliary nerve. It arises in the orbit, enters the cranial cavity, and then reaches the nasal cavity. Given its location, a transcaruncular approach is often employed to block the anterior ethmoidal nerve. This involves depositing the anesthetic drug in the medial extraconal space.
While lacrimal sac surgeries like DCR and DCT can be conducted under general anesthesia, understanding the nuances of local anesthesia and nerve blocks enhances the precision and success of these procedures. You can check out the post on exploration of DCR surgery steps and potential complications in this post. Keep reading!
If you are a audiovisual learner and wish to read along with our video on anesthesia you can visit our video on the same.
