CAPITULO II. ESTADO DEL ARTE O MARCO REFERENCIAL
2.6 INSTRUMENTOS
Franck Bolandard, MD Jean Paul Mission, MD Philippe Duband, MD Clermont-Ferrand (France)
The ilioinginal-iliohypogastric block is usually used for analgesia in children, associated with general or perimedullar anaesthesia. This block is a challenge to general and spinal anaesthesia in adult. Ilioinguinal-iliohypogastric block combined with genitofemoral block and spermatic cord block can provide good anaesthesia and rapid analgesia. In addition, it is used for hernia repair in adults as a sole anaesthesic as a challenge to local field block.
A N A T O M Y
The iliohypogastric nerve is formed by fibres from L1, with some contribution from T12. The nerve runs obliquely across the quadratus lumborum muscle behind the kidney. Close to the iliac crest the nerve pierces the transversus abdominis muscle. Its lateral branch pierces the muscle of the lateral abdominal wall to supply the skin over the lateral gluteal region. The anterior branch runs forwards and down wards between transversus abdominis and internal oblique to supply the skin above the pubis.
The ilioinguinal nerve is formed in common with the iliohypogastric nerve. The nerve lies on the quadratus lumborum muscle and the iliacus until it perforates the body wall near the anterior iliac crest. It lies between the internal and external oblique to pass through the superficial inguinal ring. It distributes sensory fibres to superomedial thigh, root of the penis and upper part of the scrotum in the male, or mons pubis and labium majus in the female.
The genitofemoral nerve is formed from L1-L2 and passes through the psoas to emerge on its anterior surface. It runs down wards on the psoas and divides into genital and femoral branches. The genital branch enters the inguinal canal through the deep inguinal ring to supply the cremaster muscle and a small area of overlying skin. The femoral branch passes behind the inguinal ligament to enter the femoral sheath and supply the skin over the femoral triangle.
M A T E R I A L
A skin marker
A 24–gauge short bevel (45°) needle Plexufix® type
A 30 ml or 50 ml syringe filled up with the chosen local anaesthetic agent
L O C A L A N A E S T H E T I C S O L U T I O N S
For the anaesthetic ilioinguinal-iliohypogastric block, 30 ml for each side are necessary. For the analgesic ilioinguinal-iliohypogastric block, 15 ml for each side are necessary.
Ropivacaine 0,5 % appears to be the local anaesthetic of choice. This concentration can provide up to a 12-hour period of post-operative analgesia [1, 2]. Adding one microg/kg clonidine to 0.5% ropivacaine provide a 18 to 24 hour postoperative analgesia [3].
Bupivacaine 0.5% also for anaesthesia or a mixture of short-acting and long acting drugs. For analgesia a concentration of 0.25 Bupivacaine or Ropivacaine 0.2% might be sufficient.
I N D I C A T I O N S
Anaesthetic indication is the inguinal hernia repair.
Analgesic indications in combination with light general anaesthesia or spinal anaesthesia include inguinal hernia repair and pelvic surgery with Pfannenstiel incision (caesarean section, hysterectomy, myomectomy, Burch), orchidopexia
C O N T R A I N D I C A T I O N S Patient refusal.
Local anaesthetic allergy. Severe coagulation disorders. Local infection.
T E C H N I Q U E
Three punctures point are necessary to perform ilioinguinal-iliohypogastric block:
1/ A line between the anterior superior iliac spine and the umbilicus, injection site is located at intersection between the third lateral and the third medial,
2/ A line between the anterior superior iliac spine and the pubic spine, injection site is located at intersection between the third lateral and the third medial,
3/ Pubic spine.
A 24–gauge short bevel needle is inserted in a 45° angle to the skin, in caudal direction. So, the bevel is parallel to the different plan and allows a good resistance to identify the aponeurosis. After passing through the skin and subcutaneous tissue, the needle meets the firm resistance of the external oblique sheath. The needle is pushed to penetrate this sheath with a definite snap and then pushed deeper to penetrate the internal oblique sheath. Two snap are needed for the two first point and only one for the third. After the usual security tests, 5 ml of local anaesthetic solution are injected after each snap and in subcutaneous at the pubic spine, Thirty ml of local anaesthetic solution are necessary for each side [4]. In men sometimes, it is necessary to complete the block with spermatic cord infiltration.
Analgesic Ilioinguinal-iliohypogastric block is much simpler. The single injection point is located at intersection between the third lateral and the third medial of a line between the anterior superior iliac spine and the umbilicus [5,6]. A 24– gauge short bevel needle is inserted in a 45° angle to the skin, in caudal and medial direction. After passing through the skin and subcutaneous tissue, the needle meets the firm resistance of the external oblique sheath. The needle is then pushed to penetrate this sheath with a definite snap and 15 ml of local anaesthetic solution are injected to each side.
C O M P L I C A T I O N S
Potential complications are intra vascular-injection and penetration of the peritoneum. These complications are rare, as long as good material is used and security test are always performed. Femoral nerve anaesthesia by diffusion is possible and can compromise day case surgery.
The main disadvantage of this block is whole or partial fall. Complement anaesthesia is sometimes needed as hernia orifice and spermatic cord infiltration.
C O N C L U S I O N
This block gives a good rapport benefit/risk and represents an elective anaesthesia and analgesia technique for day case surgery.