Study of Ultrasound Guided Hernia Block For Inguinal Hernia Repair in Adults

Abstract Background: Open inguinal hernia repair is one of the most common surgical procedure performed. A hernia is defined as an abnormal protrusion of an organ or tissue through a defect in its surrounding walls1. Inguinal hernia is one of the commonest variety of hernia found in any age group but mainly found in elderly age group(2). Different anaesthetic techniques have been used for this surgery which includes general anaesthesia, spinal anaesthesia, epidural anaesthesia, local anaesthesia (LA), ilioinguinal/iliohypogastric nerve (IIN/IHN) block. Choosing the most efficient as well as cost effective anaesthetic technique for inguinal hernia repair is necessary. Hence, USG guided hernia block is safer and an excellent alternative to general anaesthesia and central neuraxial blockade in compromised patients. As a result of these potential benefits, we decided to do the study on hernia repair using ultrasound guided block. Methods: All the patients underwent a thorough pre anaesthetic checkup which included detailed history, general and physical examinations, laboratory and radiological investigations. Local part was examined and the anaesthetic plan was explained. Ø After taking all aseptic precautions, broad band linear array probe(transducer) was placed obliquely on a line joining anterior superior iliac spine and the umbilicus immediately superior to anterior superior iliac spine, Then probe was tilted as necessary in cephalad or caudal direction until a clear optimized image of 3 lateral abdominal muscles and transverse abdominis plane(TAP) was obtained. Ø Color Doppler image was then utilized to identify the deep circumflex iliac artery After localizing the nerve, a 23 G 1.5 inch block needle was inserted via in plane approach. The needle was advanced till it reaches very close to the nerve under direct vision. Ø When proper needle tip placement was confirmed, 15-20 ml local anaesthetic solution injected after negative aspiration with minimal resistance encountered. While injecting the local anaesthetic, downward bowing of the transverse abdominis muscle was observed as the drug enters the facial plane between the internal oblique and transverse abdominis muscles and spreads it apart. Ø For genitofemoral nerve block, the probe was placed transversely just lateral to the pubic tubercle, parallel and above the inguinal ligament. next to it 8-10 ml local anaesthetic was injected after negative aspiration.. Ø Sensory block on incision site and in whole inguinal region were assessed by pinprick. Results We performed USG guided inguinal hernia block in 30 patients of ASA I to IV undergoing elective inguinal hernia repair. All patients were males above 18 years age and weight ranging from 40 to 90 kilograms. A detailed history was taken and patients were thoroughly examined. The procedure to be performed was explained to the patients and written informed consent was obtained from each patient before surgery. The mean age of patients in the study was 51.7 years with standard deviation of 15.44.The mean time to execute the block was 6.36±1.49 minutes. The mean time for sensory onset was 4.3 ± 0.79 minutes. The mean time taken for complete sensory blockade was 9.8 ± 1.27 minutes. The mean time of perceiving pain by the patient was 269.67 ± 71.50 minutes. Conclusion Ultrasound guided Ilioinguinal nerve, Iliohypogastric nerve and Genital branch of genitofemoral nerve block can be served to be a standalone anaesthesia and analgesia for inguinal hernia surgery providing good quality of block, significantly reducing amount of local anaesthetics as well as avoiding all the peri-operative complications of regional and general anaesthesia with excellent hemodynamic stability and patient satisfaction.