Ilioinguinal, Iliohypogastric, and Genitofemoral Nerve Blocks

Abstract

Ilioinguinal nerve (IIN) and iliohypogastric nerve (IHN) along with genitofemoral nerve (GFN) and subcostal nerve (T12 intercostal nerve) provide sensory and motor supply to the lower abdominal walls (Figs. 36.1 and 36.2). Blocking these nerves can be used for anesthesia and analgesia as a part of acute and chronic pain management. Collectively, the IIN, IHN, and GFN are called the “border nerves,” and the chronic pain originating from these nerves is called “border nerve syndrome.” These nerves show very high rate of anatomical variability from the spinal nerve root origin, divisions, communication between the nerves, fascial plane penetration, and sensory contributions. Blocking these nerves using blind landmark techniques or nerve stimulating techniques has been used for many years with a high rate of failure and complications which is highly understandable due to the anatomical variability and location. Recently various ultrasound-guided techniques are described which showed to have a high success rate with reduced adverse incidents. This chapter aims to give an overview of these nerve blocks with specific attention to the latest ultrasound-guided techniques which are useful for patients with acute, chronic, and palliative pain. For discussion, IIN/IHN and GFN block techniques are discussed under two separate headings.