Ultrasound-Guided Obturator Nerve Block
作者Sam Van Boxstael, Catherine Vandepitte, Philippe E. Gautier, and Hassanin Jalil
FACTS 事实
Indications: Relief of painful adductor muscle contractions, to prevent adduction of the thigh during transurethral bladder surgery, additional analgesia after major knee surgery, and may provide postoperative analgesia after hamstring tendon harvest for anterior cruciate ligament (ACL) reconstruction (Figure 1).
Transducer position: medial aspect of the proximal thigh.
适应症：缓解内收肌收缩时的疼痛，防止大腿在经尿道膀胱手术期间的内收，在膝关节大手术后附加镇痛，亦可在取腘绳肌腱供前十字韧带（ACL）重建后提供术后镇痛（图1）。探头位置：近侧大腿的内侧段。
Goal: Local anesthetic spread in the interfascial plane in which the nerves lie or around the anterior and posterior branches of the obturator nerve.
目标：局部麻醉药在闭孔神经位于的筋膜间平面或围绕闭孔神经前后分支的平面上扩散。
Local anesthetic: 5 mL into each interfascial space or around the branches of the obturator nerve.
局部麻醉药：每个筋膜间隙或者闭孔神经的分支周围给予5ml。
FIGURE 1. Expected distribution of obturator nerve sensory and motor blockade.
图1.闭孔神经感觉与运动阻滞后期望的分布。
GENERAL CONSIDERATIONS
一般考虑
Ultrasound (US)-guided obturator nerve block is simpler to perform and more reliable than surface landmark–based techniques. There are two approaches to performing a US-guided obturator nerve block. The interfascial injection technique relies on injecting local anesthetic solution into the fascial planes that contain the branches of the obturator nerve. With this technique, it is not important to identify the branches of the obturator nerve on the sonogram, but rather to identify the adductor muscles and the fascial boundaries within which the nerves lie. This is similar in concept to other fascial plane blocks (eg, the transversus abdominis plane [TAP] block in which local anesthetic solution is injected between the internal oblique and transverse abdominis muscles without the need to identify the nerves). Alternatively, the branches of the obturator nerve can be visualized with US imaging and blocked after eliciting a motor response.
超声引导的闭孔神经阻滞比基于体表标志的技术更可靠与便于实施。执行超声引导的闭孔神经阻滞有两种途径。筋膜间注射技术依赖于将局部麻醉液注射到包含闭孔神经分支的筋膜平面中。使用这种技术，在超声图像上识别闭孔神经的分支并不重要，而是要识别神经所在部位的内收肌和筋膜之边界。这在概念上类似于其他筋膜平面阻滞（例如，腹横肌平面阻滞 [TAP] ，局部麻醉药注射在腹内斜肌和腹横肌之间，而无需识别神经）。或者，闭孔神经的分支可以通过超声成像而可视化，并在诱发运动反应后阻滞之。
ULTRASOUND ANATOMY 超声解剖
The obturator nerve forms in the lumbar plexus from the anterior primary rami of the L2–L4 roots and descends to the pelvis on the medial side of the psoas muscle. In most individuals, the nerve divides into an anterior branch and posterior branch before exiting the pelvis through the obturator foramen. In the thigh, at the level of the femoral crease, the anterior branch is located between the fascia of the pectineus and adductor brevis muscles. The anterior branch lies further caudad between the adductor longus and adductor brevis muscles. The anterior branch provides motor fibers to the adductor longus, brevis and gracilis muscles; and cutaneous branches to the medial aspect of the thigh. The anterior branch has great variability in the extent of sensory innervation of the medial thigh.
闭孔神经形成于腰丛中，由L2-L4神经根的前腹侧支的前股组成，并下降到骨盆至腰大肌内侧。在大多数个体中，在通过闭孔穿出骨盆之前，神经分成前支和后支。在大腿上，在腹股沟皱褶的水平，前支位于耻骨肌与短收肌筋膜之间。前支向尾端继续走形位于长收肌与短收肌之间。前支提供运动纤维至长收肌，短收肌，股薄肌；发出皮支到大腿的内侧。前支在大腿内侧的感觉支配有很大的变异性。
The posterior branch lies between the fascial planes of the adductor brevis and adductor magnus muscles (Figures 2 and 3). The posterior branch is primarily a motor nerve for the adductors of the thigh; however, it also may provide articular branches to the medial aspect of the knee joint. The articular branches to the hip joint usually arise from the obturator nerve, proximal to its division and only occasionally from the individual branches (Figure 4). In 8–30% of patients, an accessory obturator nerve arises from L3 and L4, travels with the femoral nerve, and gives branches to the hip joint
A helpful mnemonic to remember the order of the adductor muscles, from anterior to posterior, is as follows: Alabama: Adductor Longus, Adductor Brevis, Adductor MAgnus.
后支位于短收肌和大收肌的筋膜平面之间（图2和3）。后支通常主要是大腿内收肌的运动神经：然而，它也可以提供关节分支到膝关节的内侧区域。髋关节关节分支通常由闭孔神经发出，接近其分开的位置，只是偶尔从单个分支发出（图4）。在8-30%的患者中，副闭孔神经产生于L3和L4，与股神经一起走形，并发出分支到髋关节。一个有用助记来记住内收肌的顺序，从前到后，如下所示：。Alabama: Adductor Longus, Adductor Brevis, Adductor MAgnus.（长’短’大收肌）
FIGURE 2. Cross-sectional anatomy of relevance to the obturator nerve block. Shown are the femoral vessels (the femoral vein [FV] and femoral artery [FA]), pectineus muscle, adductor longus muscle (ALM), adductor brevis muscle (ABM), and adductor magnus muscle (AMM). The anterior branch of the obturator nerve is seen between the ALM and ABM, whereas the posterior branch is seen between the ABM and AMM. (Reproduced with permission from Hadzic A: Hadzic’s Peripheral Nerve Blocks and Anatomy for Ultrasound-Guided Regional Anesthesia, 2nd ed. New York: McGraw-Hill, 2011.)
闭孔神经周围相关组织的断层解剖。如图所示股血管（FV,FA），耻骨肌，长收肌（ALM），短收肌（ABM）和大收肌（AMM）。在长收肌与短收肌之间可见闭孔神经的前支，短收肌与大收肌之间可见后支。
FIGURE 3. The anterior branch (ant. br.) of the obturator nerve (ObN) is seen between the adductor longus muscle (ALM) and the adductor brevis muscle (ABM), whereas the posterior branch (post. br.) is seen between the ABM and the adductor magnus muscle (AMM). (Reproduced with permission from Hadzic A: Hadzic’s Peripheral Nerve Blocks and Anatomy for Ultrasound-Guided Regional Anesthesia, 2nd ed. New York: McGraw-Hill, Inc.; 2011.)
在长收肌(ALM)与短收肌（ABM）之间可间闭孔神经的前支(ant. br.)。在短收肌（ABM）与大收肌（AMM）之间可见闭孔神经的后支(post. br.)。
FIGURE 4. The course and divisions of the obturator nerve and its relationship to the adductor muscles.
图4 闭孔神经的走形与分支及其与内收肌的关系。
NYSORA Tips 纽约局部麻醉学院小贴士
A psoas compartment (lumbar plexus) block is required to reliably block the articular branches of the obturator nerve to the hip joint because they usually depart proximal to the level at which the obturator nerve block is performed in the proximal thigh.
For a more comprehensive review of the lumbar plexus, see Functional Regional Anesthesia Anatomy
可靠的髋关节的闭孔神经关节分支阻滞需要行腰大肌间隙（腰丛）阻滞，因其在接近大腿近端实施闭孔神经阻滞时的水平，关节支常已经离开。
DISTRIBUTION OF ANESTHESIA麻醉药的分布
Because there is great variability in the cutaneous innervation to the medial thigh, demonstrated weakness of adductor muscle strength is the only reliable method of documenting a successful obturator nerve block (Figure 1).
由于大腿内侧的皮神经支配存在极大的变异，内收肌肌力的显示减弱只是表明闭孔神经阻滞成功的一个可靠的方法（图1）。
However, the adductor muscles of the thigh may have co-innervation from the femoral nerve (pectineus) and the sciatic nerve (adductor magnus).
然而，大腿的内收肌群存在共同支配，如股神经支配（耻骨肌），坐骨神经支配（大收肌）。
Adductor motor strength is decreased by about 25% following femoral nerve blockade and 11% following sciatic nerve blockade. For this reason, complete loss of adductor muscle strength is uncommon despite a successful obturator nerve block.
内收肌的运动力量在股神经阻滞后降低25%，坐骨神经阻滞后降低11%。由于这个原因，尽管一个成功的闭孔神经阻滞，内收肌完全的肌力缺失并不常见。
NYSORA Tips纽约局部麻醉学院小贴士
A simple method of assessing adductor muscle strength (motor block) is to instruct the patient to adduct the blocked leg from an abducted position against resistance. Weakness or inability to adduct the leg indicates a successful obturator nerve block.
一个简单的方法来评估内收肌群的力量（运动阻滞）可以让患者以内收的姿势，让阻滞的腿部做对抗运动。减弱或没有能力内收腿部提示成功的闭孔神经阻滞。
EQUIPMENT设备
The equipment recommended for an obturator nerve block includes the following:闭孔神经阻滞推荐的设备包括以下：
Ultrasound machine with linear (or curved) transducer (5–13 MHz), sterile sleeve, and gel
Standard block tray
A 10-mL syringe containing local anesthetic solution
A 10-cm, 21- to 22-gauge, short-bevel, insulated needle
Peripheral nerve stimulator (optional)
Sterile gloves
Learn more about Equipment for Peripheral Nerve Blocks
有线阵探头的超声机器(5–13MHz),
无菌套管和耦合剂
标准的神经阻滞托盘
一个含有局部麻醉剂的10mL注射器
一根10cm, 21-22G规格短斜面的绝缘针头
周围神经刺激器（可选）
无菌手套
学习更多关于外周神经阻滞的设备
LANDMARKS AND PATIENT POSITIONING
体表标志和病人体位
With the patient supine, the thigh is slightly abducted and laterally rotated. The block can be performed either at the level of femoral (inguinal) crease medial to the femoral vein or 1–3 cm inferior to the inguinal crease on the medial aspect (adductor compartment) of the thigh (Figure 5).
患者处于仰卧位，大腿轻微外展外旋。阻滞可以在腹股沟线水平股静脉内侧或腹股沟线下方1–3 cm
大腿内侧区域（内收肌间隔）。FIGURE 5. Transducer position to image the obturator nerve. The transducer is positioned medial to the femoral artery, slightly below the femoral crease. (Reproduced with permission from Hadzic A: Hadzic’s Peripheral Nerve Blocks and Anatomy for Ultrasound-Guided Regional Anesthesia, 2nd ed. New York: McGraw-Hill, Inc.; 2011.)
图5，显示闭孔神经图像超声探头的位置。探头位于股动脉的内侧，腹股沟线稍微偏下。
GOAL目标
The goal of the interfascial injection technique for blocking the obturator nerve is to inject local anesthetic solution into the interfascial space between the pectineus and adductor brevis muscles to block the anterior branch and the adductor brevis and adductor magnus muscles to block the posterior branch.
When using US guidance with nerve stimulation, the anterior and posterior branches of the obturator nerve are identified and stimulated to elicit a motor response prior to injecting local anesthetic solution around each branch.
闭孔神经阻滞的筋膜间注射技术的目标是将局部麻醉药溶液注射到耻骨肌和短收肌之间的筋膜空间中，以阻断前支；短收肌和大收肌之间，从而阻断后支。当使用超声引导神经刺激，先是闭孔神经的前后支被识别和刺激，诱发运动反应，然后注射局部麻醉剂溶液周围的每个分支。
TECHNIQUE技术
The interfascial approach is performed at the level of the femoral crease. With this technique, it is important to identify the adductor muscles and the fascial planes in which the individual nerves are enveloped. Color Doppler can be used to visualize the obturator arteries located near the nerve branches in order to avoid puncturing them, although they are not always visible.
筋膜间途径在腹股沟线水平实施。运用此技术，识别包含单个神经的内收肌与筋膜平面是非常重要的。运用彩色多普勒识别位于神经分支附近的闭孔动脉，从而避免穿破它们，尽管它们并不总是可见。
The US transducer is placed to visualize the femoral vessels. The transducer is advanced medially along the crease to identify the adductor muscles and their fasciae. The anterior branch is sandwiched between the pectineus and adductor brevis muscles, whereas the posterior branch is located in the fascial plane between the adductor brevis and adductor magnus muscles. The block needle is advanced to initially position the needle tip between the pectineus and adductor brevis (Figure 6a).
超声探头被放置用以识别股血管。探头沿腹股沟线向内移动识别内收肌群和它们的筋膜。前支一如三明治一样位于耻骨肌与短收肌，后支在短收肌与大收肌筋膜之间。阻滞穿刺针针尖的初始位置在耻骨肌与短收肌之间推进（图6a）.
At this point, 5–10 mL of local anesthetic solution is injected.
The needle is advanced farther to position the needle tip between the adductor brevis and adductor magnus muscles, and another 5–10 mL of local anesthetic solution is injected (Figure 6b). It is important for the local anesthetic solution to spread into the interfascial space and not be injected into the muscles. Correct injection of local anesthetic solution into the interfascial space results in an accumulation of the injectate between the target muscles. The needle may have to be repositioned to allow for precise interfascial injection.
在这个点，注射局部麻醉药液5–10 mL。穿刺针继续前进，使针尖位于短收肌与大收肌之间，另外的5–10 mL局部麻醉药液被注射（图6b）.局部麻醉药在筋膜间而不是注射到肌肉内非常关键。正确注射局部麻醉药液到筋膜间隙导致注射液在目标肌肉之间累积。穿刺针可能需要再调整来保证准确的筋膜间注射。
FIGURE 6. (A) Needle paths (1, 2) required to reach the anterior branch (ant. br.) and posterior branch (post. br.) of the obturator nerve (ObN). (B) Simulated dispersion of local anesthetic (blue-shaded areas) to block the anterior and posterior branches of the obturator nerve. In both examples, an in-plane needle insertion has been used. (Reproduced with permission from Hadzic A: Hadzic’s Peripheral Nerve Blocks and Anatomy for Ultrasound-Guided Regional Anesthesia, 2nd ed. New York: McGraw-Hill, Inc.; 2011.)
图 6. (A)抵达闭孔神经前后支需要的针的路径(1, 2) (B)闭孔神经前后支阻滞局部麻醉药模拟的扩散（蓝染区域）。在两例中，都运用了平面内技术。
Alternatively, the cross-sectional image of obturator nerve branches can be obtained by scanning 1–3 cm distal to the inguinal crease on the medial aspect of thigh. The nerves appear as hyperechoic, flat, thin, fusiform-shaped structures invested in the fascia of the adductor muscles. The anterior branch is located between the adductor longus and adductor brevis muscles, whereas the posterior branch is located between the adductor brevis and adductor magnus muscles. An insulated block needle attached to the nerve stimulator is advanced toward the nerve with either an out-of-plane or in-plane trajectory. After eliciting contraction of the adductor muscles, 5–7 mL of local anesthetic is injected around each branch of the obturator nerve (see Figure 6b).
或者，在大腿内侧区域腹股沟线远端1–3 cm扫查可看到闭孔神经分支的横截面图像。神经在内收肌群的筋膜内显示为高回声，平坦瘦长，纺锤形的结构。前支位于长收肌与短收肌之间，后支位于短收肌与大收肌之间。可用平面内或者平面外方法，连接神经刺激仪的绝缘穿刺针向神经推进。当诱发内收肌群的收缩后，闭孔神经每个分支的周围注射5–7 mL的局部麻醉药(见图6b).
Continue reading: Obturator Nerve Block – Landmarks and nerve stimulator technique
继续阅读：闭孔神经阻滞-体表标志和神经刺激技术
翻译：路过蜻蜓
2021- 4-15于徽州
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