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2018 년도대한통증학회춘계연수교육 Epiduroscopy 아주대학교병원마취통증의학과신경통증클리닉 최종범 Epiduroscopy is the examination of the epidural space by a minimally invasive technique that allows the diagnosis and treatment of chronic back pain and radiculopathy, Myeloscopy-the direct examination of the spinal intrathecal canal and its contents-was first described by Michael Burman in 1931. Myeloscopy was initially used in cadavers, but by 1937 it was being used in vivo by Dr J Lawrence Pool of New York to diagnose lesions affecting the cauda equina and lower end of spinal cord. Myeloscopy however could not allow visualisation of the nerve roots or soft tissues in the epidural canal. There was little work carried out in this field until 1969, when Ooi et al became the first to take clear color endoscopic pictures of the spinal canal via a newly designed fiberoptic system. By 1985, Blomberg was using epiduroscopy to study the lumbar epidural space at autopsy. In 1989. he carried out the first percutaneous epiduroscopy in living subjects via a lumbar approach using a rigid arthroscope. Fiberoptics remained poor, however, and the procedure was further complicated by difficulties visualizing a potential space often obliterated by bleeding. In the early 1990s, Heavner. Shimoji and Schutze each described the use of small diameter flexible fiberoptic endoscopes for visualization of the epidural space. The Myelotec flexible fiberoptic endoscope combines both the image fiber bundle and illumination fiber bundle in a 0.9mm flexible fiberoptic endoscope. Despite these advances, the acute angle of entry of the endoscope into the lumbar epidural space meant that maneuvering the endoscope in this space remained difficult. A straight angle of entry via sacral hiatus was found to facilitate steering of endoscope in all planes within the epidural space. By 1996 the advent of a video-guided catheter system (Myelotec ) allowed an easily steerable system through which the epidural endoscopy system could be fed. Thus, improved maneuverability, coupled with saline distension of the epidural canal, gave better visualization allowing real-time color images of the epidural canal. The therapeutic potential of epiduroscopy and adhesiolysis, a minimally invasive but potentially useful treatment modality in the management of refractory radiculopathy, emerged during the 1990s. Epiduroscopy- including indications, clinical technique, complications and clinical effectiveness-is based on current evidence. Also epiduroscopy as a diagnostic tool for the treatment of lower back and leg pain has been well described by Jo. Since medical treatment is based on accurate diagnosis, the importance of the diagnostic role of epiduroscopy cannot be over-emphasized; however, the use of epiduroscopy has been limited due to technical difficulty and cost containment. Currently, the clinical significance of diagnostic epiduroscopy is not widely understood, and epiduroscopy is mainly used for therapeutic purposes. Diagnostic information from epiduroscopy is beneficial in determining the underlying epidural condition, which is also useful for educational purposes. Epidural steroid injection is a common procedure performed routinely with an unsupported assumption of nerve root inflammation since there is no opportunity to see the virtual inflammatory condition of the epidural contents, and epidural injections applied in such a blind fashion may fail to resolve the inflammation and pain. Epiduroscopy can help physicians see the actual status of epidural inflammation and establish a proper treatment plan leading to successful pain relief. Conclusively the use of epiduroscopy for diagnose and treat spinal disease is very expected hereafter. 83

2018 년도대한통증학회춘계연수교육 TELA (Trasforaminal Epiduroscopic Laser Annuloplasty) 서울대학교의과대학, 분당서울대학교병원다학제통증센터 이평복 서론벌써 TELA 를국내에소개한지 5년이되어가고있다. 그사이국내의척추통증의학의방향도많은변화를가져왔다고생각된다. 2006년말 Gabor G Racz 선생님이국내에오셔서 racz catheter를소개하고, 학회차원에서이를이용한 decompressive neuroplasty 라는신기술을비급여로등재하기위해서많은노력을기울여왔었다. 당시보험이사로서 neuroplasty 의명명이나비급여등록과정에전념하면서가지고있었던다짐과기대는통증의학과의사들이이와같은새로운접근법을가지고환자치료에획기적전기를마련하고도약할수있는계기가될것이라생각했었다. 물론신경외과, 정형외과선생들을중심으로한척추전문병원설립의발판을제공했다는지적이나국민들및의료진에게고가의치료법을유도하게하여교과서적진료가아닌과잉진료의표상으로비난받은점은안타까운측면이다. 그러나더더욱아쉬운것은이러한시도가실제통증의학과의사들의학문적및경제적발전에끼친영향이기대에미치지못한것이아닌가하는점이다. 이제또다시문재인케어로대표되는새로운도전에직면해있다는것은주지의사실이다. 좀더침습적이지만충분히통증의학과의사들이할수있는치료법으로서내시경적디스크치료술이다시한번수면위로부상하고있다. 그중심에서간단한입문정도로할수있는시술법이 TELA라고생각된다. 바로시도해보자는것이서론의골자이다. 본론우선적으로해부학적인접근법에대한이해를하는것이필요하다. 대부분의척추디스크환자들이 L4-5, L5-S1 의팽윤등으로인한지속적인통증을가지게된다. 물론일차적으로 Transforaminal epidural block 등으 로충분히통증조절이되는경우가많고이러한치료가우선되어야함은당연하다. 그러나 2-3차례의신경치료에도반응하지않거나일시적호전이있을경우, 저린듯한양상의신경자극증상이계속반복되는경우, 수술적처치를원하지않는경우등에서돌출된추간판부분을조금만제거하거나레이저소작을통해메꾸어주는방식을고려해봄직도하다. 이를위해서는통상적인경추간공접근방법이있을수있고, 장골능이높게위치하는경우후궁접근법으로바꾸어시도할수도있다. 1) 경추간공접근법전통적으로미세침습적외과적내시경술 (PELD) 에서는추간공이나후추간판부위로의접근을통해돌출된디스크외연을물리적으로 decompression 하는방법을사용한다. 평소에 transforaminal epidural block에익숙한통증전문의들에게있어서는접근법자체는매우간편하다. 따라서조금두꺼운바늘을 retrodiscal approach로접근하여 C-ARM 을이용하여디스크후면에위치시킨다. 추간공을싸고있는인대들은쉽게젖혀지고주변의지방조직들이보이기도하지만예상외로쉽게디스크후면또는측면을아래쪽으로발견할수있게된다 ( 그림4). Cannular가 SAP 등에걸리게되면단단한뼈모양이보이기도하고이는 C-ARM 영상에서바늘의접근이경막외후면에위치하게되거나 SAP 에걸려있는양상을보이게된다. 필요한경우디스크내에 indigo-carmin과같은조영제를미리주입하게되면파란색구조물을내시경을통해확인할수있게된다. 물론경추간공접근시에도혈관이주행하는경막을구분하거나약간두껍고균일하게외측으로뻗어가는하얀신경근조직을구분하여레이저나겸자사용을조심해야하는것이필요하다. 구분이잘안되는경우에는가볍게건드려보는방법을이용하여최악의합병증을예방할필요가있다. 따라서교과서적으로는환자마취를최소화해서하도록권장하고있다. 84

이평복 : TELA (Trasforaminal Epiduroscopic Laser Annuloplasty) 3) TELA 기구의몇가지특징들 Rigid epiduroscope 이지만구부러지게할수있다는장점이있고이를통해접근각도를좀더중앙과가깝게할수있다는장점이있다 ( 그림 1). 그림 4. 추간공접근법으로보여진경막외내시경영상 2) 후궁간접근법 ( 그림 5) 요추5번-천추1번사이의디스크돌출의경우미골접근법이나경추간공접근법으로해결하기어려운경우가많다. 특히장골능이높게위치하거나미골사이경막외공간이좁은경우등은내시경이접근하기불가능하다고할수있다. 이런경우후궁간접근법으로전방경막외공간으로접근해가는것을고려할수있다. 경막외블록을할때바늘이황색인대를만나면저항이느껴지고이를뚫고조심스럽게접근해서경막외공간을확인하게되는데이공간에서경막을확인하고이를살짝옆으로젖히고들어가면전방의경막외공간으로진입할수있게된다. 황색인대-경막- 전방경막외공간- 디스크후연을확인해가는것을 C-ARM 영상과함께차례차례확인할수있다. 디스크의돌출양상이소위 Shoulder type이냐 axillary type이냐에따라접근하는높이를외측영상에서조정하고경막과신경근의분지부위를확인하여조심스럽게앞쪽으로진행하게되면미리파랗게조영시켜놓은디스크를발견할수있게된다. 이를확인하여레이저나겸자를이용한디스크치료를시행할수있을것이다. 그림 5. 후궁간접근법의 C-ARM 영상및모식도 그림 1. Side beam laser 는 1414nm 파장의 Nd-YAG 레이저로펄스폭이짧아깊이가얕게침투하고 ( 조직투과력 : 0.4 mm), 주변조직에대한불필요한열손상을최소화한다는장점이있다. 따라서피부화상가능성이가장적고안전하다는평가이다. 더욱이레이저가나오는방향이아래쪽으로나오게설계되어있어서원하는 lesion 부위에조사하는것을실제육안으로확인할수있다는것이큰장점이아닐수없다 ( 그림2). 겸자등을통해디스크조직의 annulus fibrosis 뿐아니라 nucleus pulposus 도일정부분제거할수있다는장점을가진다 ( 그림 3). 결론아직정확한적응증을잡아나가고어떤환자에서예후가좋을것인가하는것에대해서는결론이나있지않다. 다만앞서언급한바와같이일차적으로는추간판탈출증환자이고 extrusion이나 protrusion이 subarticular area, 또는 extraforaminal 부위에있는경우에접근이가능하였고, 발생한지오래되지않은경우가오래된경우보다효과가좋았다는경험을가지고있다. 물론아무것도하지않으면아무일도발생하지않는다. 그러나이러한새로운도전을위해공부하고경험하고발생할수있는합병증을줄이기위해노력하는것이좀더다양한환자들에대한치료로나아갈수있는기반이될것이라생각된다. 일단시작해야한다. 85

2018 년도대한통증학회춘계연수교육 그림 2. 그림 3. 86

2018 년도대한통증학회춘계연수교육 PELD (Percutaneous Endoscopic Lumbar Discectomy) 세연마취통증의학과 최봉춘 PELD 시술법은절제술시에손상을줄수있는주위구조물을잘보존할수있으며, 시술후에일상생활로의복귀가빠르고, 척추디스크의높이를비교적잘보존할수있는등의장점으로최소침습수술로최근에각광을받고있는시술이다. 하지만내시경의한계로그동안치료의어려운점을최근들어여러가지기술과기구의발전으로추간판탈출증뿐만아니라척추관협착증까지도그치료영역이넓어지게되었다. 이러한기술의발전중에가장중요한것이내시경하드릴의사용이다. 리멀를이용해서 foraminoplsty를했지만, 이제는드릴을이용해서리머사용시접근이어려운부위에쉽게도달할수가있어, 탈출된디스크를제거할수있게되었다. 또한추궁판을일부넓혀서쉽게황색인대를제거하여척추관협착증의치료에도중요한역할을하게되었다. 그래서 contained disc 뿐만아니라 Down-migrated, Up-migrated, Foraminal or extraforaminal, Central disc herniation or up-migrated disc with high iliac crest (transiliac), Upper lumbar: L1-2, 2-3, 3-4 같은예전에는금기였던것들이가능해져적응증이확대되었다. 또한척추관협착증으로 central stensis, foraminal stenosis,facet hypertrophy, facet cyst, lat recess stenosis 등의치료가가능해졌다. Transforaminal approach, Interlaminar approach, Laminotomy and decompression에대해서알아보자. 1. Transforaminal PELD 시술하는부위에국소마취제를이용하여경막외마취를시행하고, 환자와의사소통이가능할정도의 MAC마취를시행한다. 환자를복와위로엑스레이투시가가능한 Table에무릎이밑으로내려가는수술대에눕힌다. 20G-needle로 discogram을시행한다. midline에서약 12 14cm 외측을자입점으로한다. 국소마취제로피부마취를시행한후 18G spinal needle로 medial pedicular line, superior articular process 안쪽, 척추후방선을따라서 C-arm guide 하에진입한다. spinal needle에 guide wire를 삽입하고 wire를따라 serial dilator로확장후 working cannula를삽입해서 sup. articular proc. 위에위치하여놓고 endoscope을 cannula 통해삽입한다. 내시경하에상관절돌기부위을드릴로아래부분을제거하여 foramen을확장한후경막외강으로진입한다. 흘러나온디스크조각을내시경을보면서 Forceps과 ellman을이용해제거한다. 신경이자유롭게움직이는 Pulsation을확인한후내시경과 cannula 제거후피부부위봉합한후마친다. 상부요추부에 Up-migrated, Foraminal or extraforaminal disc herniation 인경우에는 midline에서 8cm 떨어진부위에서상관절돌기를향해진입해서접근을하게된다. 이때 exit root와가까운경우에는 drill을이용해서신경공을넓히고진입해서목표에접근할수있다. 요추5 번천추1번사이에 foraminal stenosis 인경우에는척추중심선에서약 8cm 외측을자입점으로해서상관절돌기에접근하여상관절돌기를드릴을이용해서넓혀서 exit root 가나오는신경공을확장시킨다음, 신경을약간밀치고밑에쪽에있는디스크를제거하면된다. 2. Interlaminar PELD Transforaminal PELD와마찬가지로환자를복와위자세취한후경막외마취를하고 discogram을시행한다. 자입점은정면상 (AP view) 에서위쪽추궁간 (lamina) 의아래쪽가장자리와측면상 (Lateral view) 에서디스크레벨이다. shoulder type의디스크일때는자입점은좀더추궁판간 (interlaminar) 공간의바깥쪽경계선에가깝고, axillary type의디스크일때는병변부위를중심으로바깥쪽중간부분이다. 피부와근막을작게절개한후 dilator 를 L5 추궁간 (lamina) 의아래쪽경계부위에삽입하고도킹한다. working channel을 dilator를따라끼우면서최종위치를영상의 AP, Lateral view를보면서확인한다. 이후 endoscope를넣는다. paraspinal muscle을포함한주변조직을일부제거하여황색인대를노출시킨다. 이후황색인대에구멍을만든다. 이구멍을통해 working 87

2018 년도대한통증학회춘계연수교육 cannula를경막외강으로넣은후경막경계와신경뿌리 (root) 를노출시킨다. 이후신경뿌리를부드럽게당긴 (retraction) 후 epidural dissection을한다. 튀어나오거나 (protruded) 격리된 (sequestrated) 신경조각들을확인후디스크 forceps으로제거한다. 디스크조각들을제거한후신경뿌리가잘움직이는지확인한다. 이후내시경을제거하고피부봉합한후끝낸다. 3. Percuaneous Endoscopic Stenosis Lumbar Decompression 척추관협착증의경우에는기존내시경으로접근은가능하지만작은시야와기구의한계로인해서황색인대를제거하기힘들다. 이러한단점을보완해서최근에나온내시경은내시경이 10mm 이며, 작업공이 6mm로인대제거를할수있는케리슨펀치와같은다양한기구가들어가서황색인대제거를가능하게하였다. 그래서 central spinal stenosis, foraminal stenosis, extraforaminal stenosis 등의치료가가능하다. 시술과정을보면우선환자의마취는경막외마취와 정맥으로진정마취를시행한다. 시술부위를리도카인으로국소마취를시행후절개를하여 10mm working sheath를삽입한다. 척추궁을확인후드릴을이용해서상부및하부척추궁, 관절부위를일부제거한다. 황색인대를확인후켈리슨펀치를이용해서인대를제거한다. 한쪽인대를모두제거한후경막외강에진입하여경막과신경이감압된것을확인후반대쪽부위를비스듬히내시경을눕혀서황색인대를제거한다. 황색인대가양쪽으로모두잘제거되고충분히감압이된것을확인한후지혈하고내시경을제거한후상처부위를봉합한다. 대개시술시간은한시간반정도걸린다. 시술후에는출혈이있는지잘관찰하고다음날퇴원한다. 시술후에합병증으로는출혈로인해혈종이생기는경우, 유착된부위에경막에파열되어뇌척수액의누출로인한두통, 관절에불안정성으로인해서관절낭종이생겨신경을압박하여증상이재발될수있다. 기존에수술보단내시경으로시술을하기때문에시술후에빠른회복과적은합병증이장점이며, 결과도수술한결과와크게차이가없다. 88

2018 년도대한통증학회춘계연수교육 Relevance of pain interventions in treating and diagnosing low back pain--is the quality decisive? 경희의료원신경외과 이준호 Diagnostic nerve blocks The popularity of neural blockade as a diagnostic tool in painful conditions, especially in the spine, is due to features like the unspecific character of spinal pain, the irrelevance of radiological findings and the purely subjective character of pain. It is said that apart from specific causes of pain and clear radicular involvement with obvious neurological deficits and corresponding findings of a prolapsed disc in MRI or CT pictures, a diagnosis of the anatomical cause of the pain can only be established if invasive tests (e.g. zygapophyseal joint blocks, sacroiliacal joint blocks, disc stimulation, and nerve root blocks) are used. 1 The diagnostic use of neural blockade rests on three premises; First, pathology causing pain is located in an exact peripheral location, and impulses from this site travel via a unique and consistent neural root. Second, injection of local aneasthetic totally abolishes sensory function of intended nerves and does not affect other nerves. Third, relief of pain after local anesthetic block is attributable solely to block of the target afferent neural pathway. The validity of these assumptions is limited by complexities of anatomy, physiology, and psychology of pain perception and the effect of local anesthetics on impulse conduction. 2 Two primary syndromes concerning the ventral compartment have been described: annular fissures of the disc and instability of the motion segment. Intradiscal injections of local anaesthetics may succeed in relieving the patient's pain, but such injections are liable to yield false negative results if the injected agent fails to adequately infiltrate the nerve endings in the outer annulus fibrosus that mediate the patient's pain. In the majority of cases MRI provide adequate information, but discography may be superior in early stages of annular tear and in clarifying the relation between imaging data and pain. 3 Selective spinal nerve injection: In patients with complicated radiculopathy, the contribution of root inflammation to pain may not be certain, or the level of pathology may be unclear. Diagnostic root blocks are indicated in the following situations: atypical topography of radicular pain, disc prolapses or central spinal stenosis at more than one level and monoradicular pain, lateral spinal stenosis, post-laminectomy syndrome. Injection of individual spinal nerves by paravertebral approach has to be used to elucidate the mechanism and source of pain in this unclear situations. The premise is that needle contact will identify the nerve that produces the patient's characteristic pain and that local anaesthetic delivered to the pathogenic nerve will be uniquely analgesic. Often, this method is used for surgical planning, such as determining the site of foraminotomy. Pain relief with blockade of a spinal nerve cannot distinguish between pathology of the proximal nerve in the intervertebral foramen or pain transmitted from distal sites by that nerve. Besides, the tissue injury in the nerve's distribution and neuropathic pain (e.g. root injury) likewise would be relieved by a proximal block of the nerve. The positive predictive value of indicated radiculopathy confirmed by surgery ranged between 87-100%. 4,5 The negative predictive value is poorly studied, because few patients in the negative test 89

2018 년도대한통증학회춘계연수교육 group had surgery. Negative predictive values were 27% and 38% of the small number of patients operated on despite a negative test. Only one prospective study was published, which showed a positive predictive value of 95% and an untested negative predictive value. 6 Some studies repeatedly demonstrated that pain relief by nerve root block does not predict success by neuroablative procedures, neither by dorsal rhizotomy nor by dorsal gangliectomy. 7 Therapeutic nerve blocks 1. Discogenic pain: Intradiscal radiofrequency lesions, intradiscal injections of steroids and phenol have been advocated, but there are no well controlled studies. Just recently, intradiscal lesion and denervation of the annulus has been described with promising results, but a randomized controlled study is lacking up to now. 8,9 2. Epidural Steroids: Steroids relieve pain by reducing inflammation and by blocking transmission of nociceptive C-fiber input. Koes et al. 10 reviewed the randomized trials of epidural steroids: To date, 15 trials have been performed to evaluate the efficacy, 11 of which showed method scores of 50 points (from 100) or more. The trials showed inconsistent results of epidural injections. Of the 15 trials, 8 reported positive results and 7 others reported negative results. Consequently the efficacy of epidural steroid injections has not yet been established. The benefits of epidural steroid injections seem to be of short duration only. Future efficacy studies, which are clearly needed, should take into account the apparent methodological shortcomings. Furthermore, it is unclear which patients benefit from these injections. In the case of epidural adhesions in postoperative radicular pain 11, the study of Heavner 12 showed that the additional effect of hyaluronidase and hypertonic saline to steroids was minimal. In our hands there was no effect in chronic radicular pain 3 months after the injection. Reference 1. Bogduk N (1999) Back pain and neck pain: an evidence-based update. In: Max M (ed) Pain 1999 - an updated review. IASP Press, Seattle, pp 371-377 2. Hogan QH, Abram SE (1997) Neural blockade for diagnosis and prognosis. Anaesthesiology 86: 216-241 3. Vahanranta H, Sachs, BL, Spivey MA et al.(1987) The relationship of pain provocation to lumbar disc detoriation as seen by CT/discography. Spine 12:295-298 4. Dooley JF,McBroom JR,Taguchi T, MacNan I (1988) Nerve root infiltration in the diagnosis of radicular pain. Spine 13:79-83 5. Haueisen DC, Smith BS,Myers SR,Pryce ML (1985) The diagnostic accuracy of spinal nerve injection studies. Clin Orthop 198:179-183 6. Stanley D,McLaren MI, Euinton HA, Getty CJM (1990) A prospective study of nerve root infiltration in the diagnosis of sciatica. Spine 15:540-543 7. North RB, Han M, Zahurak M, Kitt DH (1994) Radiofrequency lumbar facet denervation: analysis of prognostic factors. Pain 57:77-83 8. Karasek M,Bogduk N (2000) Twelve months follow up of a controlled trial of intradiskal thermal anuloplasty for back pain due to internal disc disruption. Spine 20:2601-2607 9. Saal JA,Saal JS (2000) Intradiskal electrothermal treatment for chronic discogenic low back pain. Spine 25:2622-2627 10. Koes BW, Scholten RJPM, Mens JMA,Bouter LM (1999) Epidural steroid injection for low back pain and sciatica: an updated systematic review of randomized clinical trials. Pain Digest 9:241-247 11. Racz GB, Sabongy M, Gintautas J, Kline WM (1982) Intractable pain therapy using a new epidural catheter. JAMA 248:32-39 12. Heavner JE,Racz GB,Raj P (1999) Percutaneous epidural neuroplasty: prospective evaluation of 0.9% NaCl versus 10% NaCl with or without hyaluronidase. Reg Anaesth Pain Med 24:202-207 90