<p>Ultrasound-Guided Thoracic Paravertebral Block as a Sympathetic Blockade for Upper Extremity Neuropathic Pain: A Prospective Pilot Study</p>

Abstract

Purpose Ultrasound-guided thoracic paravertebral block (US-TPVB) is considered a treatment option for the management of acute pain in various pain-related conditions. We conducted a prospective pilot study to evaluate the possibility of US-TPVB as a sympathetic blockade in patients with neuropathic pain disorders in the upper extremities. Patients and Methods A total of 12 patients underwent US-TPVB between the T2 and T3 paravertebral space with 10 mL of 1% mepivacaine. The temperature change (°C) before and after the procedure was compared between the ipsilateral and contralateral hands. We counted the proportion of patients showing a temperature increase ≥1.5°C and compared a change in the pain intensity before and after the procedure. Results The median increase in the temperature change between the ipsilateral and contralateral hands was 1.54°C (interquartile range, 1.28–2.20). There were seven patients (58.3%) who showed a temperature difference ≥1.5°C between both hands after the US-TPVB. Eleven patients (91.7%) reported a reduction in pain according to the score on the 11-point numerical rating scale. No serious complications relevant to the procedure were reported. Conclusion US-TPVB could be a useful technique for sympathetic blockade in patients with upper extremity pain.

Use of thoracoscopy for thoracic sympathetic nerve block in primary hyperhidrosis

“…Like the landmark-based approach with the aid of X ray direct vision, TSNB can be conducted under imaging guidance, such as US-guidance, CT-guidance, and under uoroscopy (12,22,23). TSNB under uoroscopy and the CT-guided approach results in inevitable radiation exposure and uncomfortable posture of the operator and patient during the procedures (12). In addition, TSNB with the CT-guided approach is not practical in clinical practice.…”

“…Over the past decades, there have been several approaches to blocking thoracic sympathetic nerve: the landmark-based approach, US-guided approach, CT-guided approach, uoroscopically, and thoracoscopically (10)(11)(12)(13)(21)(22)(23). A classic technique that does not use image guidance is a landmarkbased approach that elicits a loss of resistance (21).…”

“…Research examining a landmark-based approach TSNB found that the failure rate varies from 6.8 to 10% (28-30). Like the landmark-based approach with the aid of X ray direct vision, TSNB can be conducted under imaging guidance, such as US-guidance, CT-guidance, and under uoroscopy (12,22,23). TSNB under uoroscopy and the CT-guided approach results in inevitable radiation exposure and uncomfortable posture of the operator and patient during the procedures (12).…”

“…On the other hand, the US-guided approach is preferable over the previously mentioned approaches for checking the surrounding structures, including vascular and soft tissue structures, in detail to reduce complications (32,33). A recent study by Kim and his colleagues reported that TSNB under the US-guided approach achieved a temperature increase (≥ 1.5°C) between the ipsilateral and contralateral hands in 7 of 12 patients (58.3%), and minimized complications including pneumothorax (12). It is true that the US-guided and CTguided approaches are less invasive and that US-guided approach can be done at one's bedside, while TSNB is done under thoracoscopy in the operating room.…”

“…Thoracic sympathetic nerve block (TSNB) can be done either in an ultrasound (US)-guided manner (12), in a computed tomography (CT)-guided manner (13), or thoracoscopically (10). The US-guided and CTguided approaches are less invasive than the thoracoscopic approach.…”