Risk of Encountering Dorsal Scapular and Long Thoracic Nerves during Ultrasound-guided Interscalene Brachial Plexus Block with Nerve Stimulator

Abstract

BackgroundRecently, ultrasound has been commonly used. Ultrasound-guided interscalene brachial plexus block (IBPB) by posterior approach is more commonly used because anterior approach has been reported to have the risk of phrenic nerve injury. However, posterior approach also has the risk of causing nerve injury because there are risks of encountering dorsal scapular nerve (DSN) and long thoracic nerve (LTN). Therefore, the aim of this study was to evaluate the risk of encountering DSN and LTN during ultrasound-guided IBPB by posterior approach.MethodsA total of 70 patients who were scheduled for shoulder surgery were enrolled in this study. After deciding insertion site with ultrasound, awake ultrasound-guided IBPB with nerve stimulator by posterior approach was performed. Incidence of muscle twitches (rhomboids, levator scapulae, and serratus anterior muscles) and current intensity immediately before muscle twitches disappeared were recorded.ResultsOf the total 70 cases, DSN was encountered in 44 cases (62.8%) and LTN was encountered in 15 cases (21.4%). Both nerves were encountered in 10 cases (14.3%). Neither was encountered in 21 cases (30.4%). The average current measured immediately before the disappearance of muscle twitches was 0.44 mA and 0.50 mA at DSN and LTN, respectively.ConclusionsPhysicians should be cautious on the risk of injury related to the anatomical structures of nerves, including DSN and LTN, during ultrasound-guided IBPB by posterior approach. Nerve stimulator could be another option for a safer intervention. Moreover, if there is a motor response, it is recommended to select another way to secure better safety.

Superior Trunk Block Provides Noninferior Analgesia Compared with Interscalene Brachial Plexus Block in Arthroscopic Shoulder Surgery

“…5 Injury to the dorsal scapular nerve and long thoracic nerves is another concern with the posterior in-plane approach to conventional ultrasound-guided interscalene brachial plexus block, because these two nerves run within the middle scalene muscle and thus lie within the needle path. 7,8,28 However, the needle path in superior trunk block does not traverse the middle scalene muscle, instead passing between the deep cervical fascia and middle scalene muscle, thus minimizing the risk of inadvertent needle trauma to these nerves. 9 There are two points we would like to highlight regarding technical performance of the superior trunk block.…”

“…Once the needle tip was in proximity to the brachial plexus, the current was decreased to 0.5 mA, and a contraction of the biceps or deltoid was sought. 7 The final needle tip position was immediately lateral to the brachial plexus sheath and adjacent to C5 and C6 nerve roots, 10 whereupon 15 ml of 0.5% ropivacaine with 5 μg • ml −1 epinephrine was injected. The superior trunk block was performed according to the method described by Burckett-St. Laurent et al 9 The superior trunk was visualized distal to the convergence of the C5 and C6 nerve roots but proximal to the take-off of the suprascapular nerve.…”

“…3,4 Other concerns include the risk of intraneural injection into the relatively unprotected roots 5,6 and injury to the dorsal scapular nerve or long thoracic nerve. 7,8 The superior trunk block was described by Burckett-St. Laurent et al 9 as a refinement of the conventional interscalene block technique that addresses these limitations. The superior trunk is formed by the fusion of C5 and C6 nerve roots, and therefore local anesthetic injection around the superior trunk should produce similar analgesia of the shoulder because all the terminal nerves innervating the shoulder arise distal to the superior trunk.…”

A pictorial review of signature patterns living in musculoskeletal ultrasonography

“…A multifascicular pattern displays a black-and-white speckled (" honeycomb ") image ( Fig. 14 ), whereas an oligofascicular pattern is visualized as a more solid, oval, and black structure [ 15 16 17 18 19 20 ].…”

<p>Dorsal and ventral thoracic 12 vertebra body height is associated with incident lumbar vertebral fracture in postmenopausal osteoporotic women</p>

“…[1][2][3][4][5] The ability to predict risk factors for LVF is crucial because of the negative consequences of LVF that include chronic back pain, related functional disability, kyphosis, and height loss, all of which have major impacts on a patient's quality-of-life; as well as the associated increases in morbidity and mortalitiy. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] Analysis of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DEXA) is the most commonly used index of bone power, and a low BMD is the most important risk factor for LVF prediction. [21][22][23][24] But, almost 50% of LVF occurs in patients with BMD above the World Health Organization (WHO) diagnosis threshold of osteoporosis (T-score#2.5).…”