A 72-year-old woman (40.3 kg, 139 cm) was referred to our pain clinic for the treatment of low back pain after two back surgeries. She had first undergone back surgery [posterior lumbar interbody fusion (PLIF at L4–5) plus spinal stabilization (L3)] for lumbar spinal canal stenosis 4 years prior to the current presentation. Two weeks after the initial surgery, she underwent reoperation because of screw placement errors, and her symptoms disappeared after surgery. However, her low back pain recurred after a fall 5 months before the current presentation. Paralysis of the lower limbs was not apparent after this episode. A sensory disturbance that had existed before the surgeries remained unchanged. No new lesions such as a lateral recess or foraminal stenosis, herniated nucleus pulposus, or fracture were found on radiographs or magnetic resonance images (Fig. ). The previous medical institution prescribed acetaminophen and tramadol for low back pain and performed a caudal epidural block with 5 ml of 1% lidocaine and dexamethasone 1.65 mg. However, neither treatment provided pain relief, and the patient was referred to our pain clinic. She had several comorbidities, including diabetes mellitus, hypertension, renal dysfunction, hypothyroidism, rheumatic arthritis, and gastroesophageal regurgitation, and was prescribed 27 different drugs by clinicians from five different facilities. Accordingly, we decided not to use additional medication for first-line therapy because of polypharmacy concerns and renal dysfunction and performed bilateral ESP block with the patient in the prone position. A convex type transducer was placed in a longitudinal orientation at the level of the L2 transverse process, 3 cm lateral to the midline. The L4 and L5 transverse processes could not be identified because of the echogenic artifacts due to the surgical instruments. The posterior surface of the L2 transverse process was identified using an aseptic technique. After the puncture point was anesthetized with 2 ml of 1% lidocaine, the needle was inserted in the plane of the ultrasound beam in a cephalad to caudal direction. Following confirmation of the needle tip on the surface of the transverse process of L2, 20 ml of 0.1875% ropivacaine (fourfold dilution of commercial product) was injected into the target plane between the erector spinae muscles and the transverse process (Fig. ). This procedure was repeated on the contralateral side. Twenty-five minutes later, the patient reported a warm feeling in her low back and almost complete relief from pain, which was approximately < 10% of its original severity. There was an area of diminished cold sensation extending from T12 to L5, with no change in the anterior and lateral abdomen. Unfortunately, the pinprick test was not performed. Pain relief lasted for approximately 10 h after the initial block. We repeated this procedure for a total of three times in a month. Finally, the patient reported that her daily baseline level of low back pain had diminished to < 40% of its original severity. She was satisfied with the extent of pain control and did not wish to undergo further treatments such as epiduroscopy or spinal cord stimulation (SCS).
A 19-year-old female (50 kg; 160 cm) was admitted in the palliative care unit of our department with complaints of severe burning and stretching pain in the right flank region. Her pain scores were 10/10 on the Numeric Rating Scale (NRS), where 0 means no pain and 10 means worst possible pain. The patient was a postoperative case of desmoid tumor for which resection was done 2 years back []. Skin on the right side flank region develops pain, thickness, and tenderness from the past 6 months. The patient received medical treatment (morphine, nonsteroidal anti-inflammatory drugs [ibuprofen and paracetamol], and gabapentin), but the pain did not improve. Hence, we decided to perform lumbar ESP block.\nUnder all aseptic precautions, a linear ultrasound probe was placed longitudinally at the level of transverse process of L2. The skin was infiltrated with 2 ml of 1% lignocaine. The 10-cm Stimuplex needle (Stimuplex® A, B. Braun Melsungen AG, Germany) was inserted by the in-plane approach to touch the surface of transverse process of L2 []. A total of 20 ml of 0.375% ropivacaine and 40 mg triamcinolone was injected into the target plane between the erector spinae muscles and the transverse process. The patient had adequate pain relief (3/10 on NRS) 10 min after the block and had extensive sensory blockade from dermatome T10 to L5. NRS was noted for 24 h after the procedure []. The patient was discharged with oral medicines tapered. The patient was still pain-free without consumption of any oral analgesics at follow-up after 8 weeks.