- Email: [email protected]
Ilioinguinal Nerve Block
510
SECTION 5 ADVANCED INTERVENTIONAL PAIN MANAGEMENT
CHAPTER
288
Ilioinguinal Nerve Block The ilioinguinal nerve is a branch of the L1 nerve root with a contribution from T12 in some patients. The nerve follows a curvilinear course that takes it from its origin of the L1 and occasionally T12 somatic nerves to inside the concavity of the ilium. The ilioinguinal nerve continues anteriorly to perforate the transverse abdominal muscle at the level of the anterior superior iliac spine. The nerve may interconnect with the iliohypogastric nerve as it continues to pass along its course medially and inferiorly, where it accompanies the spermatic cord through the inguinal ring and into the inguinal canal. The distribution of the sensory innervation of the ilioinguinal nerves varies from patient to patient because there may be considerable overlap with the iliohypogastric nerve. In general, the ilioinguinal nerve provides sensory innervation to the upper portion of the skin of the inner thigh and the root of the penis and upper scrotum in men or the mons pubis and lateral labia in women. To perform ilioinguinal nerve block, the patient is placed in the supine position with a pillow under the knees if extending the legs increases the patient’s pain because of traction on the nerve. The anterior superior iliac spine is identified by palpation. A point 2 inches medial and 2 inches inferior to the anterior superior iliac spine is then identified and prepared with antiseptic solution. A 11=2-inch, 25-gauge needle is then advanced at an oblique angle toward the pubic symphysis (Fig. 288-1). From 5 to 7 mL of 1.0% preservative-free lidocaine is
injected in a fanlike manner as the needle pierces the fascia of the external oblique muscle. Care must be taken not to place the needle too deep and enter the peritoneal cavity and perforate the abdominal viscera. If the pain has an inflammatory component, the local anesthetic is combined with 80 mg of methylprednisolone and is injected in incremental doses. Subsequent daily nerve blocks are performed similarly, substituting 40 mg of methylprednisolone for the initial 80-mg dose. Because of overlapping innervation of the ilioinguinal and iliohypogastric nerves, it is not unusual to block branches of each nerve when performing ilioinguinal nerve block. After the solution is injected, pressure is applied to the injection site to decrease the incidence of postblock ecchymosis and hematoma formation, which can be dramatic, especially when the patient is receiving anticoagulants. The main side effect of ilioinguinal nerve block is postblock ecchymosis and hematoma formation. If needle placement is too deep and enters the peritoneal cavity, perforation of the colon may result in intra-abdominal abscess and fistula formation. Early detection of infection is crucial to avoid potentially life-threatening sequelae.
SUGGESTED READING Waldman SD: Ilioinguinal nerve block. In: Atlas of Interventional Pain Management, ed 2. Philadelphia, Saunders, 2004.
CHAPTER 289 ILIOHYPOGASTRIC NERVE BLOCK 511
Ant. sup. iliac spine
2"
2"
Ilioinguinal n.
FIGURE 288–1 Ilioinguinal nerve block. (From Waldman SD: Atlas of Interventional Pain Management, ed 2. Philadelphia, Saunders, 2004, p 297.)
CHAPTER
289
Iliohypogastric Nerve Block The iliohypogastric nerve is a branch of the L1 nerve root with a contribution from T12 in some patients. The nerve follows a curvilinear course that takes it from its origin of the L1 and occasionally T12 somatic nerves to inside the concavity of the ilium. The iliohypogastric nerve continues anteriorly to perforate the transverse abdominal muscle to lie between it and the external oblique muscle. At this point, the iliohypogastric nerve divides into an anterior and a lateral branch. The lateral branch provides cutaneous sensory innervation to the posterolateral gluteal region. The anterior branch pierces the external oblique muscle just beyond the anterior superior iliac spine to provide cutaneous sensory innervation to the abdominal skin above the pubis. The nerve may interconnect with the ilioinguinal nerve along its course, resulting in variation of the distribution of the sensory innervation of the iliohypogastric and ilioinguinal nerves.
To perform iliohypogastric nerve block, the patient is placed in the supine position with a pillow under the knees if extending the legs increases the patient’s pain because of traction on the nerve. The anterior superior iliac spine is identified by palpation. A point 1 inch medial and 1 inch inferior to the anterior superior iliac spine is then identified and prepared with antiseptic solution. A 25-gauge, 11=2-inch needle is then advanced at an oblique angle toward the pubic symphysis (Fig. 289-1). From 5 to 7 mL of 1.0% preservative-free lidocaine is injected in a fanlike manner as the needle pierces the fascia of the external oblique muscle. Care must be taken not to place the needle too deep and enter the peritoneal cavity and perforate the abdominal viscera. If the pain has an inflammatory component, the local anesthetic is combined with 80 mg of methylprednisolone and is injected in incremental doses. Subsequent
SECTION 5 ADVANCED INTERVENTIONAL PAIN MANAGEMENT
CHAPTER
288
Ilioinguinal Nerve Block The ilioinguinal nerve is a branch of the L1 nerve root with a contribution from T12 in some patients. The nerve follows a curvilinear course that takes it from its origin of the L1 and occasionally T12 somatic nerves to inside the concavity of the ilium. The ilioinguinal nerve continues anteriorly to perforate the transverse abdominal muscle at the level of the anterior superior iliac spine. The nerve may interconnect with the iliohypogastric nerve as it continues to pass along its course medially and inferiorly, where it accompanies the spermatic cord through the inguinal ring and into the inguinal canal. The distribution of the sensory innervation of the ilioinguinal nerves varies from patient to patient because there may be considerable overlap with the iliohypogastric nerve. In general, the ilioinguinal nerve provides sensory innervation to the upper portion of the skin of the inner thigh and the root of the penis and upper scrotum in men or the mons pubis and lateral labia in women. To perform ilioinguinal nerve block, the patient is placed in the supine position with a pillow under the knees if extending the legs increases the patient’s pain because of traction on the nerve. The anterior superior iliac spine is identified by palpation. A point 2 inches medial and 2 inches inferior to the anterior superior iliac spine is then identified and prepared with antiseptic solution. A 11=2-inch, 25-gauge needle is then advanced at an oblique angle toward the pubic symphysis (Fig. 288-1). From 5 to 7 mL of 1.0% preservative-free lidocaine is
injected in a fanlike manner as the needle pierces the fascia of the external oblique muscle. Care must be taken not to place the needle too deep and enter the peritoneal cavity and perforate the abdominal viscera. If the pain has an inflammatory component, the local anesthetic is combined with 80 mg of methylprednisolone and is injected in incremental doses. Subsequent daily nerve blocks are performed similarly, substituting 40 mg of methylprednisolone for the initial 80-mg dose. Because of overlapping innervation of the ilioinguinal and iliohypogastric nerves, it is not unusual to block branches of each nerve when performing ilioinguinal nerve block. After the solution is injected, pressure is applied to the injection site to decrease the incidence of postblock ecchymosis and hematoma formation, which can be dramatic, especially when the patient is receiving anticoagulants. The main side effect of ilioinguinal nerve block is postblock ecchymosis and hematoma formation. If needle placement is too deep and enters the peritoneal cavity, perforation of the colon may result in intra-abdominal abscess and fistula formation. Early detection of infection is crucial to avoid potentially life-threatening sequelae.
SUGGESTED READING Waldman SD: Ilioinguinal nerve block. In: Atlas of Interventional Pain Management, ed 2. Philadelphia, Saunders, 2004.
CHAPTER 289 ILIOHYPOGASTRIC NERVE BLOCK 511
Ant. sup. iliac spine
2"
2"
Ilioinguinal n.
FIGURE 288–1 Ilioinguinal nerve block. (From Waldman SD: Atlas of Interventional Pain Management, ed 2. Philadelphia, Saunders, 2004, p 297.)
CHAPTER
289
Iliohypogastric Nerve Block The iliohypogastric nerve is a branch of the L1 nerve root with a contribution from T12 in some patients. The nerve follows a curvilinear course that takes it from its origin of the L1 and occasionally T12 somatic nerves to inside the concavity of the ilium. The iliohypogastric nerve continues anteriorly to perforate the transverse abdominal muscle to lie between it and the external oblique muscle. At this point, the iliohypogastric nerve divides into an anterior and a lateral branch. The lateral branch provides cutaneous sensory innervation to the posterolateral gluteal region. The anterior branch pierces the external oblique muscle just beyond the anterior superior iliac spine to provide cutaneous sensory innervation to the abdominal skin above the pubis. The nerve may interconnect with the ilioinguinal nerve along its course, resulting in variation of the distribution of the sensory innervation of the iliohypogastric and ilioinguinal nerves.
To perform iliohypogastric nerve block, the patient is placed in the supine position with a pillow under the knees if extending the legs increases the patient’s pain because of traction on the nerve. The anterior superior iliac spine is identified by palpation. A point 1 inch medial and 1 inch inferior to the anterior superior iliac spine is then identified and prepared with antiseptic solution. A 25-gauge, 11=2-inch needle is then advanced at an oblique angle toward the pubic symphysis (Fig. 289-1). From 5 to 7 mL of 1.0% preservative-free lidocaine is injected in a fanlike manner as the needle pierces the fascia of the external oblique muscle. Care must be taken not to place the needle too deep and enter the peritoneal cavity and perforate the abdominal viscera. If the pain has an inflammatory component, the local anesthetic is combined with 80 mg of methylprednisolone and is injected in incremental doses. Subsequent