초음파, 약침으로 신경 유착 떼기 hydrodissection

[문형철]

J Pain Res. 2020; 13: 1957–1968.

Published online 2020 Aug 4. doi: 10.2147/JPR.S247208

PMCID: PMC7414936

PMID: 32801851

Ultrasound-Guided Nerve Hydrodissection for Pain Management: Rationale, Methods, Current Literature, and Theoretical Mechanisms

King Hei Stanley Lam,1,2 Chen-Yu Hung,3 Yi-Pin Chiang,4,5 Kentaro Onishi,6 Daniel Chiung Jui Su,7 Thomas B Clark,8 and K Dean Reeves9

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Abstract

Nerve hydrodissection (HD), a technique used when treating nerve entrapments, involves the injection of an anesthetic, saline, or 5% dextrose in water to separate the nerve from the surrounding tissue, fascia, or adjacent structures. Animal models suggest the potential for minimal compression to initiate and perpetuate neuropathic pain. Mechanical benefits of HD may relate to release of nervi nervorum or vasa nervorum compression. Pathologic nerves can be identified by examination or ultrasound visualization. The in-plane technique is the predominant and safest method for nerve HD. Five percent dextrose may be favored as the preferred injectate based on preliminary comparative-injectate literature, but additional research is critical. Literature-based hypotheses for a direct ameliorative effect of dextrose HD on neuropathic pain are presented.

요약

신경 하이드로박리술(HD)은 

신경 포획을 치료할 때 사용되는 기술로 

마취제, 식염수 또는 5% 포도당을 물에 주입하여 

신경을 주변 조직, 근막 또는 인접 구조물로부터 분리하는 것입니다. 

동물 모델에서는 

최소한의 압박이 신경병증성 통증을 유발하고 지속시킬 수 있는 가능성을 시사합니다. 

HD의 기계적 이점은 

nervi nervorum의 방출 또는 혈관 신경 압박과 관련될 수 있습니다. 

nervi nervorum or vasa nervorum compression

병적 신경은 

검사 또는 초음파 시각화를 통해 확인할 수 있습니다. 

인-플레인 기법  in-plane technique 은 

신경 HD에 대한 가장 보편적이고 안전한 방법입니다. 

예비 비교 주사제 문헌에 따르면 

5% 포도당이 선호되는 주사제로 선호될 수 있지만 

추가 연구가 중요합니다. 

덱스트로스 HD의 신경병증성 통증에 대한 직접적인 개선 효과에 대한 

문헌 기반 가설이 제시되어 있습니다.

Keywords: nerve hydrodissection, pain management, ultrasonography, neuropathic pain

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Introduction

The technique of high-resolution ultrasound (US)-guided hydrodissection (HD) of peripheral nerves has recently drawn the attention of the medical profession, especially in the fields of pain and musculoskeletal medicine. Randomized controlled trials published in high impact journals have suggested that this technique can safely and effectively treat carpal tunnel syndrome,1–4 the most extensively studied clinical condition treated by ultrasound-guided HD of peripheral nerves.1–8 Other clinical studies have also used this technique to treat neuropathic pain related to deep nervous structures or the neuraxial spine.9 In this article, we will review the animal model for nerve compression, injuries, or other conditions predisposing to compression-related symptoms, historical characteristics of neuropathic pain, and theoretical benefits of decompression. How to identify pathologic nerves, methods of ultrasound-guided decompression, and available literature related to the choice of an injectate and efficacy of HD will be summarized. Due to empirical and clinical trial evidence of a direct ameliorative effect of dextrose separate from decompression, hypotheses for such a direct effect will be discussed.

소개

말초 신경의 고해상도 초음파(US) 유도 수핵 박리술(HD) 기술은

최근 특히 통증 및 근골격계 의학 분야에서 의료계의 주목을 받고 있습니다.

영향력 있는 저널에 발표된 무작위 대조 시험에 따르면

이 기술은 말초 신경의 초음파 유도 수핵 박리술로

가장 광범위하게 연구된 임상 질환인

손목 터널증후군1-4을 안전하고 효과적으로 치료할 수 있다고 합니다.1-8

다른 임상 연구에서도 이 기술을 사용하여

심부 신경 구조 또는 신경 척추와 관련된 신경병증성 통증을 치료했습니다.9

심부 신경 수핵박리술은 압력을 가한 수액 주사를 사용하여 근막 압박이 의심되는 부위에서 신경을 의도적으로 분리하는데, 이는 난치성 신경병증성 통증/복합부위 통증의 잠재적 지속 요인으로 점점 더 많이 간주되고 있습니다. 저용량 마취제를 사용하거나 사용하지 않고 5% 포도당수(D5W)를 수핵박리술의 기본 주사제로 사용하면 마취 관련 독성을 제한할 수 있습니다. 최근 만성 신경병증성 통증 환자에서 5% 포도당수(D5W)의 경막외 주사 시 진통 효과가 설명되었습니다. 여기에서는 성상 신경절, 상완 신경총, 경추 신경근 및 추간 공간을 포함한 상체의 심부 신경 구조의 수핵 박리를 위한 초음파 유도 방법에 대해 설명합니다. 신경병증성 통증 지속 기간은 16±12.2개월, 평균 수치 통증 평가 척도(NPRS) 0-10 통증 수준은 8.3±1.3으로 연속 26건의 100회 수핵 박리술 치료 결과를 후향적으로 검토했습니다. 마취제 없이 D5W 주사를 사용한 각 치료 세션의 평균 진통 비율은 88.1% ± 9.8%였습니다. 치료 전 8.3 ± 1.3이었던 수치 통증 평가 척도 점수는 마지막 치료 2개월 후 1.9 ± 0.9로 개선되었습니다. 환자들은 첫 치료부터 치료 후 2개월 추적 관찰까지 9.7±7.8개월 동안 3.8±2.6회 치료를 받았습니다. 통증 개선율은 모든 경우에서 50%, 절반에서는 75%를 넘었습니다. 연구 결과는 D5W 주사의 진통 효과를 확인했으며, D5W를 이용한 수핵감압술이 누적적인 통증 감소 효과를 제공한다는 것을 시사합니다.

이 기사에서는

신경 압박, 부상 또는 압박 관련 증상을 유발하는 기타 질환에 대한 동물 모델,

신경병증 통증의 역사적 특성 및 감압의 이론적 이점에 대해 검토해 보려고 합니다.

병적 신경을 식별하는 방법,

초음파 유도 감압 방법,

주사제 선택 및 HD의 효능과 관련된 이용 가능한 문헌을 요약합니다.

감압과는 별개로 덱스트로스의 직접적인 개선 효과에 대한

경험적 및 임상 시험 증거로 인해 이러한 직접적인 효과에 대한 가설이 논의됩니다.

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Nerve Compression Effects: Animal Model, Predisposing Conditions, and Theoretical Benefits of Decompression

Animal Model: Bennett’s Neuropathic Pain Model Demonstrates Peripheral Nerve Vulnerability to Mild Constrictive Effects

Nerve HD is a technique that uses high-resolution US-guided fluid injection to separate nerves from a surrounding or adjacent structure, usually the fascia, which is believed to constrict or irritate the nerve either during movement or at rest.10,11 The vulnerability of mixed sensory/motor nerves to circumferential compression was demonstrated by Bennett et al,12 who developed the most commonly studied animal model of neuropathic pain by placing self-dissolving ligatures about the sciatic nerve of rats. A key aspect of his approach was the use of no more than light constriction to avoid any visible restriction of epineural blood flow or significant indentation of the nerve surface; ensured by placement of ligatures that could be repositioned on the nerve with minimal effort.13 This light constriction led to prominent and rapid morphological changes, and development of allodynia and hyperesthesia, and provided a rationale to suspect that, in humans, peripheral nerves may be more vulnerable to light compression and entrapment effects at multiple locations than previously suspected or reported. Until a precise way to measure the pressure exerted on nerves by various types of compressive forces, including fascial compression, can be identified, Bennett’s consistently reproducible light-constriction animal model is the best available explanation how mild compressive effects in humans can result in neuropathic pain development, and why their release may result in therapeutic benefit.

신경 압박 효과: 동물 모델, 소인 조건 및 감압의 이론적 이점

동물 모델: 베넷의 신경병증성 통증 모델, 경미한 압박 효과에 대한 말초 신경의 취약성 입증

Nerve HD는

고해상도 US 유도 유체 주입을 사용하여

신경을 주변 또는 인접 구조물,

일반적으로 근막에서 분리하는 기술로 운동 중 또는 휴식 중 신경을 수축시키거나 자극하는 것으로 여겨집니다.10,11

혼합 감각/운동 신경이 주변 압박에 취약하다는 것은

쥐의 좌골 신경에 자가 용해 합자를 배치하여

가장 일반적으로 연구되는 신경병성 통증의 동물 모델을 개발한 Bennett등12이 입증한 바 있습니다.

그의 접근법의 핵심은 최소한의 노력으로 신경의 위치를 변경할 수 있는 합자를 배치하여 신경 표면의 눈에 띄는 혈류 제한이나 심각한 함몰을 피하기 위해 가벼운 압박을 사용하지 않는 것이었습니다.13 이러한 가벼운 압박은 눈에 띄고 빠른 형태학적 변화와 이질통 및 감각 과민증의 발생으로 이어졌으며, 인간의 경우 말초 신경이 이전에 의심되거나 보고된 것보다 여러 위치에서 가벼운 압박 및 포획 효과에 더 취약할 수 있다고 의심하는 근거를 제공했습니다. 근막 압박을 포함한 다양한 유형의 압박력이 신경에 가하는 압력을 정확하게 측정할 수 있는 방법이 밝혀질 때까지 베넷의 일관되게 재현 가능한 빛 압박 동물 모델은 인간에게 가벼운 압박 효과가 어떻게 신경병증성 통증을 유발할 수 있는지, 그리고 왜 이러한 압박이 치료 효과를 가져올 수 있는지를 설명하는 가장 좋은 설명이 될 수 있습니다.

Predisposing Conditions Which May Render the Peripheral Sensory Nerves Susceptible to Compressive Effects

Sports Injuries 

- Sudden nerve elongation during sprain or strain injuries, which exceeds the stretch limit of the semi-elastic components of a nerve.

- Forced nerve movement through areas of fascial constrictions.

- Forced nerve movement around bony prominences; e.g., sudden movement of the common fibular nerve about the fibular  head during an inversion sprain injury.

말초 감각 신경이 압박 효과에 취약해질 수 있는 소인 질환

스포츠 부상 
- 염좌 또는 긴장 부상 중 신경의 반탄성 성분의 신장 한계를 초과하는 갑작스러운 신경 신장.
- 근막 수축 부위를 통한 강제 신경 운동.
- 뼈 돌출부 주변의 강제 신경 이동(예: 역염좌 부상 중 비골 두에 대한 비골 신경의 갑작스러운 움직임).

Osteophytosis/Tendinosis/Other Degenerative Changes 

- Osteophytic changes which alter the course of a nerve, serving as a point of friction.

- Reduced flexibility in areas of degenerated soft tissue may alter free movement of nerves coursing through that area.

- Sensitization of nerves within areas of chronic tendinosis or ligamentosis.

Post-Fracture or Post-Surgical Pain 

- Central or peripheral sensitization due to uncontrolled pain.

- Stretch injury to nerves occurring in the process of required nerve retraction during open surgery.

- Direct nerve contusions at the time of injury with secondary nerve swelling resulting in abnormal friction/compression during nerve movement.

- Altered gait post injury resulting in nerve irritation through overuse or misuse of extremities.

- Scar or fibrosis about surgical/fracture sites, altering the normal nerve course.

골다공증/건증/기타 퇴행성 변화 
- 골다공증성 변화는 신경의 경로를 변경하여 마찰 지점으로 작용합니다.
- 퇴화된 연조직 부위의 유연성이 감소하면 해당 부위를 통과하는 신경의 자유로운 움직임이 달라질 수 있습니다.
- 만성 건증 또는 인대증 부위 내 신경의 민감화.

골절 후 또는 수술 후 통증 
- 통제되지 않는 통증으로 인한 중추 또는 말초 감작.
- 개복 수술 중 필요한 신경 후퇴 과정에서 발생하는 신경의 스트레치 손상.
- 부상 당시 직접적인 신경 타박상으로 이차적인 신경 부종으로 인해 신경이 움직이는 동안 비정상적인 마찰/압박이 발생하는 경우.
- 사지의 과도한 사용 또는 오용으로 인한 부상 후 걸음걸이 변화로 인한 신경 자극.
- 수술/골절 부위의 흉터 또는 섬유화로 인해 정상적인 신경 경로가 변경된 경우.

기타 
환자의 병력에서 신경 압박의 원인이나 소인이 드러나지 않을 수 있습니다. 경험적으로 이는 흔한 것으로 보이지만 역학 연구는 부족합니다.

Other 

The patient’s history may not reveal a predisposing cause or predisposition to nerve compression. Empirically this appears to be common but epidemiologic studies are lacking.

Characteristics of Neuropathic Pain and Theoretical Benefits of Decompression

Definition and Characteristics of Neuropathic Pain

Neuropathic pain is defined as pain caused by a lesion or disease of the somatosensory system.14,15 It usually has the following characteristics:

1.  
2.  
3.  
4.  

신경병증성 통증의 특징과 감압술의 이론적 이점

신경병증성 통증의 정의 및 특징

신경병증성 통증은 체성감각계의 병변이나 질환으로 인한 통증으로 정의됩니다.14,15 일반적으로 다음과 같은 특징이 있습니다:

1. 통증의 원인이 잘 드러나지 않는 심부 통증.
2. 통증의 정도는 일반적으로 조직/신경 손상 정도에 비례하지 않습니다.
3. 통증은 통각 과민 및/또는 이질통이 있는 경우 쓰라림, 무감각 또는 전기 충격 감각으로 묘사될 수 있습니다.
4. 감염된 부위에서 냉기나 열감이 느껴질 수 있으며, 감염된 부위의 피부가 푸르스름하게 보일 수 있으며 정맥 정체와 유사하게 보일 수 있습니다.

Potential Benefits of Decompression on Nervi Nervorum, Vasa Nervorum, or Lymphatic Drainage

A potential benefit of the use of fluid (hydro) to separate nerves from the surrounding soft tissue (dissection) to treat neuropathic pain is the release of pressure on the “free nerves supplying the main nerves,” which are called “nervi nervorum,”16–20 which are located outside the epineurium. The nervi nervorum innervate and regulate the function and discharge of sensory, motor, or mixed-modality nerves (Figure 1). “Vasa nervorum,” are small blood vessels, also located outside the epineurium. The arteries supply nutrients to the peripheral nerve and the veins drain away the metabolites from these nerves.21–23 Mild compression of the vasa nervorum would first affect venous outflow, with potential stasis and accumulation of toxins at the affected part of the nerve. Lymphatic drainage, which may be present outside the epineurium (Figure 1), would also be subject to compressive effects. Therefore, the primary objective of HD is to release the entrapment of the peripheral nerves by hydrodissecting the nerves.10

신경 신경, 정맥 신경 또는 림프 배액에 대한 감압술의 잠재적 이점

신경병증성 통증을 치료하기 위해

주변 연부 조직에서 신경을 분리하기 위해 수액(하이드로)을 사용하는 것(박리)의 잠재적 이점은

“신경 신경”16-20이라고 하는 “주요 신경에 공급하는 자유 신경”의 압력을 방출하는 것으로,

이는 신경막 바깥에 위치합니다.

신경절은 감각, 운동 또는 혼합 양식 신경의 기능과 방출을 자극하고 조절합니다(그림 1). “혈관 신경"은 작은 혈관으로, 역시 뇌신경막 외부에 위치합니다. 동맥은 말초 신경에 영양분을 공급하고 정맥은 이러한 신경의 대사 산물을 배출합니다.21-23 혈관 신경이 경미하게 압박되면 먼저 정맥 유출에 영향을 미치고, 신경의 영향을 받은 부위에 독소가 정체 및 축적될 가능성이 있습니다. 또한, 경막외강 외부에 존재할 수 있는 림프 배액(그림 1)도 압박의 영향을 받을 수 있습니다. 따라서 HD의 주요 목표는 신경을 수압 절개하여 말초 신경의 포획을 풀어주는 것입니다.10

Figure 1

Illustration of the “nervi nervorum” and “vasa nervorum” outside the epineurium.

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Identification of Pathologic Nerves and HD Methods

Identification of Pathologic Nerves

1.  
2.  
3.  
4.  
5.  

HD Methods

There are two primary methods of US-guided HD of peripheral nerves.27 Literature review revealed no in-depth comparison of the performance of these techniques with respect to the learning curve, effectiveness, and safety of each.

Method 1 (in-Plane Approach, Needle Perpendicular to the Long Axis of the Nerve) 

Generally, when using method 1 for HD of nerves, the needle and probe are both perpendicular to the long axis of the nerve. The needle is in-plane to the transducer, and the tissues above and below the nerves are hydrodissected. The needle first approaches the inferior surface of the nerve with the needle bevel positioned up, and the pressure of the injectate is used to open the soft tissues around the nerve layer by layer until the injectate surrounds the epineurium. Since flexible hypodermic needles with bevels are typically used, it is safer to approach the inferior surface of the nerve bevel up as the resistance of the soft tissue will generally force the needle to go deep, and avoid damaging the inferior part of the nerve.28 The same process is repeated with the needle approaching from the superior surface of the nerve, with the needle bevel positioned down (Figure 7). The hypodermic needle is bevel down so that the resistance of the soft tissue will force the needle to move more superficial and avoid injuring the superior part of the nerve.28 The hydrodissected nerve appears oval and surrounded by anechoic fluid on US when the release is completed. Video 5 shows the practice of this technique using method 1 (in-plane approach, needle perpendicular to the long axis of the nerve) in clinical situations. A 25-gauge 50 mm, or 22-gauge 70–100 needle is used, depending on the depth of the nerve, and keeping in mind the benefit from an enhanced needle echogenicity that results from reduction of the angle between the probe and the path of needle movement.

말초 신경의 US 유도하 HD에는 두 가지 주요 방법이 있습니다.27 문헌 검토 결과 각 기법의 학습 곡선, 효과 및 안전성과 관련하여 이러한 기법의 성능을 심층적으로 비교한 문헌은 없습니다.

방법 1(평면 내 접근법, 신경의 장축에 수직인 바늘)

일반적으로 신경의 HD에 방법 1을 사용할 때는 바늘과 프로브가 모두 신경의 장축에 수직이 됩니다. 바늘은 트랜스듀서와 평면에 있으며, 신경 위와 아래의 조직은 수압 절개됩니다. 먼저 바늘을 위로 향하게 한 상태에서 바늘이 신경의 하부 표면에 접근하고, 주사제의 압력을 사용하여 주사제가 경막외막을 둘러쌀 때까지 신경 주변의 연조직을 층층이 열어줍니다. 일반적으로 경사가 있는 유연한 피하 주사바늘을 사용하기 때문에 연조직의 저항으로 인해 일반적으로 바늘이 깊숙이 들어가 신경의 하부 손상을 피할 수 있으므로 신경의 하부 표면에 경사가 위로 접근하는 것이 더 안전합니다.28 신경의 상부 표면에서 바늘을 접근하여 바늘 경사를 아래로 배치한 상태에서 동일한 과정을 반복합니다(그림 7). 피하 주사바늘은 연조직의 저항으로 인해 바늘이 더 표면적으로 움직여 신경의 상부를 손상시키지 않도록 아래로 기울어져 있습니다.28 수액 박리가 완료되면 수액 박리된 신경은 타원형으로 보이며 무반향액으로 둘러싸여 있습니다. 비디오 5는 임상 상황에서 방법 1(평면 내 접근, 신경의 장축에 수직인 바늘)을 사용하여 이 기술을 실습하는 모습을 보여줍니다. 신경의 깊이에 따라 25게이지 50mm 또는 22게이지 70-100 바늘을 사용하며, 프로브와 바늘 이동 경로 사이의 각도 감소로 인한 향상된 바늘 에코 발생의 이점을 염두에 두어야 합니다.

Figure 7

Needle position for method 1 of hydrodissection (HD) of nerves. With the “in-plane” technique, first, the inferior surface of the nerve is hydrodissected with the needle bevel positioned up; and thereafter, the superior surface of the nerve is hydrodissected with the needle bevel positioned down.

신경 하이드로박리(HD) 방법 1의 바늘 위치. “평면 내” 기법을 사용하면 먼저 바늘의 경사가 위로 향하게 하여 신경의 하부 표면을 수핵 박리하고, 그 후 바늘의 경사가 아래로 향하게 하여 신경의 상부 표면을 수핵 박리합니다.

Clinical Pearls Related to HD in General and Method 1 Specifically

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Method 2 (Out-of-Plane with Subsequent in-Plane Approach)

During the performance of method 2, the needle is parallel to the long axis of the nerve, and the probe is first perpendicular and then parallel to the long axis of the nerve. An “out-of-plane” technique is used to HD the nerve from the surrounding tissues, confirm‎ing that the nerve is freed from the surrounding soft tissues by the visualization of anechoic fluid surrounding the nerve (both above and below the nerve). Subsequently, the probe is turned “in-plane” toward the nerve, the needle tip is guided back to the top of the nerve, and fluid is injected above it, with the bevel positioned down when approaching the nerve to avoid making accidental contact with the nerve. The injected fluid should be visualized to be tracking above and below the nerve. An illustration of the directions of the needle during method 2 is shown in Figure 10. Video 7 shows an example of one of the practice of method 2 for HD of nerves. Video 8 shows example two of the practice of method 2 for HD of nerves.

방법 2(평면 외 접근 후 평면 내 접근)

방법 2를 수행하는 동안 바늘은 신경의 장축과 평행하고 프로브는 먼저 신경의 장축에 수직이 된 다음 평행합니다. “평면 외” 기법을 사용하여 주변 조직에서 신경을 HD화하여 신경을 둘러싼 무향액(신경 위와 아래 모두)을 시각화하여 신경이 주변 연조직에서 벗어난 것을 확인합니다. 그 후, 프로브를 신경을 향해 “평면”으로 돌리고 바늘 끝을 신경의 상단으로 다시 안내한 다음, 신경에 접근 시 베벨을 아래로 하여 신경에 실수로 접촉하는 것을 방지하면서 그 위에 수액을 주입합니다. 주입된 액체가 신경의 위와 아래를 추적하는 것을 시각화해야 합니다. 방법 2의 바늘 방향에 대한 그림은 그림 10 에 나와 있습니다. 비디오 7은 신경의 HD에 대한 방법 2의 실습 중 한 가지 예를 보여줍니다. 비디오 8은 신경의 HD를 위한 방법 2의 실습 예 2를 보여줍니다.

Figure 10

Relative direction and movement of the needle when using method 2 for hydrodissection (HD) of nerves. This shows the initial out-of-plane portion of method 2 with HD of the nerve on either side until injectate is seen surrounding the nerve, at which point the probe position is changed to in-plane with the nerve to HD the space above the nerve.

방법 2를 사용하여 신경의 수압박리(HD)를 할 때 바늘의 상대적인 방향과 움직임. 이는 방법 2의 초기에는 양쪽 신경의 HD가 신경 주위에 주사제가 보일 때까지 신경과 평면을 벗어난 부분을 보여주며, 이 시점에서 프로브 위치가 신경과 평면으로 변경되어 신경 위 공간을 HD로 만듭니다.

Clinical Pearls Related to Method 2

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Safety of US-Guided HD of Nerves

Whenever a doctor is injecting around the nerve, nerve injury is a potential complication.29 Jeng et al suggest that nerve damage is rare due to the polyfascicular architecture of the peripheral nerve and nerve fiber dispersal within the nerve.29 The importance of avoiding nerve contact cannot be overemphasized, and the advantages of hydrodissection without lidocaine may be considerable, in that it allows the clinician to hydrodissect continually and liberally ahead of the needle, without concern for anesthetic toxicity. Nevertheless, HD of nerves is not a technique for beginners in US-guided pain interventions, requiring relatively advanced skills in US-guided needling techniques. Cadaveric injection experience is crucial, and the authors stress repetitively that the injecting pressure should be the separating agent to release the soft tissues tethered to the nerves, not the needle itself.

신경의 US-Guided HD의 안전성

의사가 신경 주위에 주사할 때마다 신경 손상은 잠재적인 합병증입니다.29 Jeng 등은 말초 신경의 다근막 구조와 신경 내 신경 섬유 분산으로 인해 신경 손상이 드물다고 제안합니다.29 신경 접촉을 피하는 것의 중요성은 아무리 강조해도 지나치지 않으며, 리도카인이 없는 하이드로박리의 장점은 마취 독성에 대한 우려 없이 바늘 앞에서 지속적이고 자유롭게 하이드로박리를 할 수 있다는 점에서 상당할 수 있습니다. 그럼에도 불구하고 신경의 HD는 US 유도 통증 중재술의 초보자를 위한 기술이 아니며, 상대적으로 고도의 US 유도 자침 기술을 필요로 합니다. 사체 주사 경험이 매우 중요하며, 저자는 주사 압력이 바늘 자체가 아니라 신경에 묶인 연조직을 풀어주는 분리제여야 한다고 반복해서 강조합니다.

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Current Literature

HD with Normal Saline (NS) in Carpal Tunnel Syndrome (CTS) Outperformed a NS Control Injection

Traditionally, a large volume of NS and a small volume of steroid and local anesthetic solution are used for HD of nerves.5,6,30 HD alone appears to be beneficial, as shown in a clinical trial by Wu et al in patients with mild-to-moderate carpal tunnel syndrome (CTS). They compared the effect of HD with 5 mL NS to subcutaneous injection of 5 mL NS above the carpal tunnel.3 The Boston Carpal Tunnel Syndrome Questionnaire (BCTSQ) mean subscores for symptom severity and function were followed, with a range from 1 for no symptoms to 5 for the most severe symptoms for each subscale. HD with NS outperformed subcutaneous saline injection at 6 months for improvement in symptom severity (−0.6 ± 0.2 vs. −0.2 ± 0.1; p = 0.024), functional status (−0.6 ± 0.1 vs. −0.2 ± 0.1; p = 0.041), and edema as determined by significantly more reduction in cross-sectional area (CSA) of the median nerve in the intracarpal injection group (−1.3 ± 0.03 vs. 0.3 ± 0.1 mm3; p < 0.001).

HD with Dextrose 5% in Water (D5W) in CTS Outperformed HD with NS or Triamcinolone

Wu et al also compared a single median nerve HD with 5 mL of D5W to HD with 5 mL of NS, and used the total BCTSQ subscore range (11–55 for symptoms and 8 to 40 for function) instead of the mean BCTSQ1 as their outcome measure. Dextrose HD outperformed NS HD at six months for improvement in symptom severity (−14.9 ± 1.2 vs. 6.5 ± 1.5; p < 0.001) and functional status (−10.4 ± 0.8 vs. −2.9 ± 0.09; p < 0.001). The CSA improved (decreased) significantly more in the intracarpal dextrose group (−2.2 ± 0.3 vs. −1.2 ± −0.2 mm3; p < 0.004).

Wu et al next compared a single median nerve HD with 5 mL of D5W to 5 mL HD with 5 mL containing 3 mL of 10mg/mL triamcinolone plus 2 mL NS,2 and dextrose outperformed triamcinolone at six months for mean difference in total BCTSQ symptom (−13.5 vs. 3.9; p <0.005) and function subscores (−9.4 vs. −3.0; p = <0.001) (standard deviations of change scores were not listed.) The cross-sectional area improved in both groups significantly with no between-group difference (−2.1 vs. – 1.6 mm3; p = 0.30).

HD with Hyaluronidase in CTS Outperformed HD with NS

Elawamy et al compared a single median nerve HD with 1500 IU of a proprietary hyaluronidase plus 10 mL NS to HD with 10 mL NS.7 At 6 months the hyaluronidase group outperformed NS alone for mean difference in total BCTSQ symptom (−13.9 vs −0.3; p <0.001) and function subscores (−10.1 vs.+1.4; p <0.001) and the CSA area improved (decreased) only in the hyaluronidase group (−2.7 vs. −0.1 mm3; p < 0.05).

HD with PRP in CTS Outperformed Splint Only Use but Not HD with D5W

Wu et al compared a single median nerve HD with 3 mL of PRP to 8 hours of night splint use daily in randomized open-label fashion. PRP outperformed splint use at six months for mean difference in total BCTSQ symptom (−11.8 ±1.2 vs. 8.7 ± 0.9; p =0.045) and function (−8.7 ± 0.9 vs. −5.2 ± 0.5; p = 0.001) subscores. The cross-sectional area improved in both groups significantly, with no between-group difference (−3.1 ± 0.2 vs. – 2.0 ± 0.3 mm3; p = 0.004).4 Shen et al compared a single median nerve HD with 3 mL of PRP to HD with 3 mL D5W.8 Using the mean subscores for the BCTSQ, both PRP and D5W HD resulted in noteworthy and statistically similar improvements at 6 months in symptom severity (−1.2 ± 0.2 vs. −1.0 ± 0.1; p = 0.447) and functional status (−1.2 ± 0.1 vs. −1.1 ± 0.1; p = 0.267), although edema was significantly more in the PRP injection group (−3.3 ± 0.03 vs. −1.9 ± 0.4 mm3; p =018).8 Raeissadat et al compared single injection PRP with splint versus splint use without injection. However, HD was not utilized during injection, only 1 mL PRP was injected, and follow-up was only 10 weeks.31 Senna et al compared a single median nerve HD with 2 mL PRP to 1 mL of methylprednisolone with ultrasound guidance, with no description of HD and follow-up of only 3 months.32 Catapano et al, in a recent metaanalysis, commented favorably on the potential for benefit of PRP in the treatment of CTS.33

Non-CTS-Research Observations and Summary of Research Status

Other studies have supported the use and efficacy of dextrose solution to treat neuropathic pain. Injection of 10 mL of D5W into the caudal epidural space versus 10 mL of normal saline has been demonstrated by Smigel et al to result in prompt and significantly more pain improvement as measured on a 0–10 numerical rating scale from 15 minutes post-injection (4.4 ± 1.7 vs. 2.4 ± 2.8 points; p = 0.015) through 48 hours post-injection (3.0 ± 2.3 vs.1.0 ± 2.1 points; p = 0.012).34 In a subsequent open-label study, the pattern and degree of pain relief with dextrose was similar after each injection, with a cumulative pain improvement of 3.4 ± 2.3 points (52%) on the 0–10 NRS scale for pain, and functional improvement 18.2 ± 16.4% (42%) on the 0–100 Oswestry Disability Index at 12 months.35

The typical injectate volume for research on HD of the median nerve in the carpal tunnel is 10 mL or less.1–4,7,8 However, according to the authors’ experience, a much larger volume of injectate (typically 20–30 mL) needs to be used to completely release the nerve from the surrounding soft tissues to achieve an oval appearance, as most nerves and plexi are not located in such a confined area as the carpal tunnel. Our clinical experience was summarized in a retrospective usual-care quality-assurance study data collection.9 Twenty-six consecutive patients with severe (8.3 ± 1.3 on a 0–10 NRS scale), chronic (mean 16±12.2 months) neuropathic pain were treated using hydrodissection with D5W of indicated nerve roots and plexi, without lidocaine inclusion. At 2-month follow-up after their last treatment, patients reported an improvement in pain of 6.4 ± 1.7 points (8.3± 1.3 before treatment to 1.9 ± 1.7 points after treatment), for a pain percentage improvement of 77%. The mean number of treatments required for a satisfactory response (3.8 ± 2.6 treatments) and mean treatment duration to 2-month follow-up of 9.7 ± 7.8 months are consistent with our current clinical experience. Two additional observations are of particular interest. One was that, in the absence of lidocaine, multiple procedures were able to be performed simultaneously, if deemed necessary for a more complete approach to nociceptive sources. A second observation was that marked analgesia resulted after each treatment within 15 minutes (88.1% ± 9.8%), consistent with the analgesic effect of dextrose reported by Smigel et al in their randomized caudal epidural study.34 Given the benefit of injection at the nerve root and plexi level, a mechanism of action of 5% dextrose injection at the somatosensory system at the dorsal root level has been proposed.34

Conclusions from the randomized controlled clinical trials in CTS are limited due to small study sizes and a 6-month duration of follow-up. In addition, other clinicians that perform hydrodissection routinely may not be convinced that a single injection of the volume of injection listed in the clinical HD trials will be adequate to expect a consistent clinical and electromyographic benefit in future corroborative studies. Another limitation of all clinical trials of HD to this point is that all of the injectates eval‎uated other than D5W have a volume limitation; e.g. steroid congeners, hyaluronidase or PRP, making them unsuitable for multiple large volume/multiple procedure applications. For that reason, and potentially cost efficacy reasons, D5W may be the primary injectate, followed by addition of second injectate after initial HD has been performed. Further research on current primary injectates is of critical importance.

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Hypotheses for a Direct Ameliorative Effect of Dextrose on Neuropathic Pain

Several hypotheses have been proposed to explain the effect of dextrose solution on treating neuropathic pain such as:

Downregulation of the Transient Receptor Potential Vanilloid Receptor-1 (TRPV1) Ion Channel or Reduction of Its Downstream Mechanism of Action

Upregulation (persistent opening) of the TRPV1 ion channel is strongly associated with the persistence of chronic neuropathic pain.36 The TRPV1 ion channel was previously called the capsaicin receptor because no other ion channels are affected by capsaicin.37 Capsaicin causes a characteristic burning sensation by upregulating the TRPV1 channel. Mannitol, a 6-carbon-atom sugar, has been found to reduce the burning sensation after exposure to capsaicin, suggesting an antagonistic (calming) effect on TRPV1 upregulation, either directly or by downstream effect.38 Dextrose, similar in structure to mannitol, has empirically been observed to have a similar effect, although it has not been formally tested using the capsaicin model developed by Bertrand et al.38

Correction of Perineural/Intraneural Glycopenia

Chronic neuropathic pain may signify glycopenia around the corresponding nerve(s). Injecting dextrose may promptly correct this glycopenia and consequently reduce neuropathic pain. Moreover, 40% of our peripheral somatosensory nervous system is comprised of small capsaicin-sensitive nerves (nerves with the TRPV1 ion channels on their surface), which are predominantly C fibers, and have an apparent homeostatic role in monitoring the level of systemic dextrose.39 Both the brain and peripheral nerves have a high and constant requirement for glucose.11 MacIver reported that when isolated C fibers are exposed in vitro to a hypoglycemic environment by substituting D-glucose with non-metabolizable L-glucose, they demonstrate a dramatic (653±23%) increase in discharge frequency within 5 minutes, maximized after 15 minutes. The C fiber firing rate returned to baseline within 2 minutes of replacement of D-glucose in the culture solution.40 MacIver explains these prompt changes in neural firing rates by reminding us of the central role of D-glucose metabolism in provision of ATP to power the cellular Na+ -K+ pump in animal and human cells. Hypoglycemia results in reduced activity of the ATP dependent Na+-K+ pump, resulting in a progressive nerve depolarization and hyperexcitability.

Potential Improvement of Nerve Mobility Through US Hydrodissection

A cadaveric study done in Mayo clinic showed that HD can decrease the gliding resistance of the median nerve within the carpal tunnel, supporting the concept that HD may result in a beneficial mechanical change in nerve movement.41 However, the gliding resistance was measured immediately after hydrodissection and does not offer proof of a sustainable benefit. At this time that can be implied only indirectly by sustainable symptomatic benefit, and improvement of neural edema and nerve conduction parameters.

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Conclusion

Bennett’s animal model of neuropathic pain is the most well-known and utilized animal model. Neuropathic pain results from such minimal compression that it supports the concept that minimal nerve compression is capable of creating structural changes in nerves as well as neuropathic pain. Many conditions can increase the susceptibility of sensory nerves to compression. A direct mechanical benefit from nerve release may result from the restoration of nervi or vasa nervorum function though the release of pressure effects. Examination and ultrasound visualization are jointly helpful to identify pathologic nerves. In-plane technique (method 1) is recommended as the primary/safer approach with key features of using the injectate jet to dissect the soft tissue in front of the needle, and fully releasing fascia until the nerve appearance is rounded and the nerve is completely surrounded by injectate fluid. The injectate of preference may be D5W for most applications, based on preliminary literature findings eval‎uating comparative injectates, empirical and clinical evidence of a direct analgesic effect of dextrose separate from a hydrodissection mechanism, and the ability of D5W to be used for high volume and multiple-nerve applications. The mechanism of benefit of HD for benefit in neurogenic pain has not been established and will require substantial basic science research.

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Acknowledgments

The authors need to acknowledge Dr. Dick Hui for drawing Figure 1.

Figures 3–6 have been courtesy of 3D4Medical’s Essential Anatomy 5 app for illustrating the transducers positions.

Figure 3

A normal left common fibular nerve (CFN) with a cross-sectional area (CSA) at the upper limits of normal (11 mm2) at fibular head (A and B).24,25 3a is the original ultrasound image, (B) Shows the highlighted CSA of the normal left CFN and the color shadings with labels for sonoanatomy, Image is courtesy of 3D4Medical’s Essential Anatomy 5 app.

Abbreviations: BF, biceps femoris; Gastroc, gastrocnemius; LSCN, lateral sural cutaneous nerve; PA, popliteal artery; SN, sural nerve; TN, tibial nerve.

Dr. Lam has the ownerships for all the figures and videos in this manuscript.

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Funding Statement

This research received no external funding.

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Disclosure

Some of the materials and pictures contained in this manuscript have been used in previous presentations during international academic conferences. The most recent one was the Annual Conference of the Australian Association of Musculoskeletal Medicine on 24–27 October 2019 in Brisbane, Australia. The previous one was the International Symposium of Ultrasound for Regional Anesthesia and Pain Medicine (ISURA 2019) on 9–11 May 2019 in Porto, Portugal. The authors report no conflicts of interest in this work.