Successful Treatment of Abdominal Cutaneous Entrapment Syndrome Using Ultrasound Guided Injection
A 31-year-old man visited our clinic with chronic abdominal pain that persisted for approximately one year. He was 170 centimeters tall, and his body weight was 53 kilograms. He was a car mechanic, and had no specific medical history or trauma history. At first, the pain started after taking a late-night snack. It was described as being severe squeezing in nature, which located on the right side of the periumbilical area that had persisted all day long. He did not have history of any sports activities. The pain intensity in visual analogue scale (VAS) was about 60-70 of 100. He had been on medication for gastrointestinal tract with nonsteroidal anti inflammatory drugs (NSAIDs) at the other hospital for over two months. The medication had no effect at all. For further evaluation, abdominal ultrasonography, abdominal computed tomography (CT), contrast media study of small and large intestine, endoscopy, and colonoscopy were done. Laboratory tests and simple x-rays of chest, abdomen, and lumbar spine were also performed. The examinations showed no specific abnormal findings. The patient was examined in supine position, and the site of maximum tenderness was identified; then he was asked to fold his arms across the upper chest, and to sit half way up. He complained greater tenderness with continuous local palpation, which is called Carnett test positive. It implies that the pain originated from the abdominal wall []. For both diagnostic and therapeutic purpose, we decided to make an injection of local anesthetics at the area of rectus muscle where the entrapment of cutaneous nerve could occur. The patient was placed in supine position. We conducted Carnett test again to find the maximal tender point. The transducer (Linear probe 12-5 Hz, HDI 5000, Philips, USA) was positioned in the midline first, to get a short axis view (anatomic transverse view) so that the medial border of the rectus muscle and the linea alba are visulized. Then the transducer moved laterally to get a view of the lateral end of the rectus muscle and the linea semilunaris (). The abdominal cutaneous nerve generally exists between the rectus abdominis and linea semilunaris, approximately 0.5-1.0 cm medial to linea semilunaris. Using the transverse scan, 25G 38 mm needle (BD Precision Glide™ Needle, Becton Dickinson Medical, Singapore) was advanced with the short axis in plane technique to reach the target area (). We injected 10 ml of 1% of mepivacaine with 10 mg of triamcinolone. The pain intensity in VAS decreased to 30 of 100 with a single injection. With one week of interval, booster injection was done. After the second injection, the pain intensity in VAS decreased to 0-10 of 100. He remained symptom free for 10 months.