대한척추외과학회지제 14 권제 2 호 Journal of Korean Spine Surg. Vol. 14, No. 2, pp 67~72, 2007 경추신경근병증환자에서최소침습적후방추간공절개술의조기수술결과 권영준 성균관대학교의과대학강북삼성병원신경외과학교실 Early Surgical Results of Minimally Invasive Posterior Foraminotomy using Tubular Retractor for Cervical Radiculopathy Abstract Young-Joon Kwon, M.D. Department of Neurosurgery, Kangbuk Samsung Hospital, Sungkyunkwan University, School of Medicine, Seoul, Korea Study Design: A retrospective review of the clinical and surgical outcomes in 13 patients in which minimally invasive posterior cervical foraminotomy was performed. Objectives: To report early surgical results of cervical posterior foraminotomy using a tubular retractor with minimally invasive deep muscle splitting. Summary of Literature Review: In previous studies of the posterior approach, good outcomes were established. The limitations of the posterior approach used to treat compression that was centrally located in the spinal canal were obvious, so the anterior approach was subsequently performed. Moreover, peri-incisional pain and discomfort related to the subperiosteal detachment of the muscle and ligament were the main limitations of this posterior approach. The use of the microendoscope allows very limited exposure with minimal tissue destruction, and has recently been used by various surgeons. Materials and Methods: Clinical results obtained in 13 patients who underwent posterior foraminotomy from Jan 2005 through Apr 2006 were assessed using a modified Prolo outcome scale. The posterior foraminotomy was performed in a minimally invasive fashion using a tubular retractor with muscle splitting dissection. Results: Eleven of 13 patients showed immediate relief of radiculopathy. Postoperative posterior cervical pain and spasm were negligible, and no surgically related complication was noted. During the follow-up period, 12 of 13 patients demonstrated a good outcome based on the modified Prolo outcome scale. Conclusions: Posterior foraminotomy using a tubular retractor is a minimally invasive surgical option for treating cervical radiculopathy and alleviating post-incisional discomfort on the neck. Key Words: Cervical spine, Posterior foraminotomy, Minimally invasive surgery, Radiculopathy Address reprint requests to Young-Joon Kwon, M.D. Department of Neurosurgery, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine Pyeong-dong 108, Jongno-gu, Seoul, 110-746, Korea Tel: 82-2-2001-2159, Fax: 82-2-2001-2157, E-mail: neuriac@gmail.com - 67 -
대한척추외과학회지 Vol. 14, No. 2, 2007 서 론 박리후원통형견인기를사용한변형된수술술기로좋은결과를얻었기에이를보고하는바이다. 보존적치료에반응하지않는경추부퇴행성추간판질환에의한경추신경근병증에대한수술적인치료법은 Smith 와 Robinson 1) 과 Cloward 2) 에의해시행된전방경유추간판제거술과추체간유합술이표준으로되어왔으며그결과또한상당히만족스러운것으로알려져있다. 하지만장기추적의결과에서유합술과그에따른운동분절의소실에따른주위척추부의증가된추간판압력과그에따른진행성퇴행성추간판질환의발병등 3,4) 이문제점으로대두되고있다. 그에대한대안으로인공경추디스크가개발되어임상에적용되고있으나아직은그적용에있어초기단계이며장기추적관찰이필요한실정이다. 후방경유접근법은예로부터시행되어왔으나후방근육및인대구조물의손상에따른만성적인근경련, 운동저하및경부통등으로그사용이제한되어왔다. 그러나 Foley 와 Smith 5) 가요추추간판절제술에원통형견인기 (tubular retractor) 를사용한근육분리법 (muscle splitting method) 을사용한이후로이접근법이경추부질환으로응용이시도되어왔다 6,7). 이술기는후방경부근육및인대손상의최소화를통한수술후후경부통의최소화와빠른사회복귀를기대할수있으며, 유합술이필요치않으므로운동분절의보존에따른인접분절변성을최소화하는장점이있다. 하지만접근시척추후궁과후관절에과도한압력전달에따른척수손상가능성이있으며외측부근육의끼임으로인해수술시야가방해받기도한다. 이에본저자는최소침습적심부근육 연구대상및방법 2005년 1월부터 2006년 4월까지경추신경근병증으로본원에내원한환자중후방추간공절개술 (posterior foraminotomy) 을시행한 13예를대상으로임상결과를후향적으로분석하였다. 환자들의성별및나이, 증상의이환기간, 수술전후의임상및방사선학적소견을조사하였다. 수술전후의통증의정도는 Visual Analogue Scale (VAS) score를이용하여평가하였으며, 근력은 6 점 (0~5) 척도로평가하였다 8). 수술후추적평가는전화상담과외래방문시행하여졌는데, 기능적인상태와경제적인상태를종합적으로고려한 modified Prolo outcome scale 9) (Table 1) 를사용하였으며 5점이하를 poor outcome, 6~7점을 moderate outcome, 그리고 8점이상을 good outcome으로정의하였다. 진단은증상과이학적검사및 CT, MRI 등의방사선학적검사를토대로이루어졌으며, CT는 3차원재조합을같이시행하여수술전계획수립과수술후감압정도의평가를용이하게하였다. 수술의적응증은경추수핵탈출증이후측방으로돌출되거나경추간공협착증으로경추신경근병증이저명한환자를대상으로시행하였으며 (Fig. 1A, B), 중심성수핵탈출증이동반된경우나과도한 uncinate process의골주 (bony spur) 형성으로인하여배쪽감압 (ventral decompression) 이필요한경우는제외하였다. Table 1. Modified Prolo functional economic outcome scale Score Criteria Economic status 1. Complete invalid 2. No gainful occupation 3. Able to work, but not at previous occupation 4. Working at previous occupation on part-time or limited status 5. Able to work at previous occupation with no restrictions Functional status 1. Total incapacity (worse than before operation) 2. Persistent neck and arm pain, persistent paresthesias, motor weakness same as prior to operation (able to perform tasks of daily living) 3. Moderate neck and arm pain, persistent paresthesias, minimal motor weakness 4. No neck or arm pain, persistent paresthesias in fingers, no motor weakness 5. No neck or arm pain, no paresthesias, no motor weakness, complete recovery, able to perform previous sports activities - 68 -
경추신경근병증환자에서최소침습적후방추간공절개술의조기수술결과 권영준 Fig. 1. Imaging studies obtained in a 52-year-old woman (Case 2) who presented with severe neck and radicular pain on left upper extremity. Preoperative axial (A) and sagittal (B) T2 weighted MR image demonstrating a left C5-C6 disc herniation (arrow). Fig. 2. Fluoroscopic images representing sequence of steps in dilator (A) and retractor placement (B). 수술은복와위로 Mayfield head holder 로고정한후에전신마취하에서시행하였다. C-arm 을보면서후방경부의정중선에서 1 cm 정도떨어져서 2 cm 정도의피부절개후피하조직을박리한다음후방경부근막에절개를한후겸자 (forcep) 로잡아서극돌기부위를바닥 (base) 으로두고들어올리게되는데이렇게함으로써 supraspinous 와 interspinous ligamentous complex 를보존할수가있었다. 그후미세현미경하에서 semispinalis cervicis 와 multifidus 같은심부근육의부착부를손상시키지않으면서 Penfield dissector 로박리한후에확장기 (dilator) 를순차적으로사용하여원통형견인기를위치하고 (Fig. 2A, B), 그것을 retractor arm 을이용하여침대에고정시켰다. 그후미세현미경하에서 Midas Rex drill 을사용하여병변측후궁과후관절을조심스럽게갈아내어황색인대를노출시 켰다. 척추골성협착증 (spondylotic stenosis) 이동반된경우후관절을외측으로더많이제거해야하는데이때관절의절제는 50% 를넘지않게주의하였다 10). 황색인대의외측부를제거하고나서신경근을노출하였는데, 이때황색인대와경막사이의정맥총이손상되는경우다량의출혈이유발되므로주의를기울여야한다. 탈출된추간판은대개신경근의액와부위에서압박을하므로척수와신경근에손상이가지않게미세수술기구를사용하여신경근을상방견인후제거하였다. 결 과 전체환자중남자는 9 명이고여자는 4 명이었으며 34-69 -
대한척추외과학회지 Vol. 14, No. 2, 2007 Fig. 3. Postoperative images obtained in Case 2. (A) Sagittal T2 weighted MR image showing removal of C5-C6 disc fragment (arrow). (B) Axial CT images showing lamino foraminotomy site. (C) 3 dimensional reconstruction CT images depicting foraminotomy site. Table 2. Summary of clinical data and outcome obtained in 13 patients undergoing procedures for cervical radiculopathy Case Age/ Duration No. Sex Side Level Surgery (mo) VAS score Motor score Radicular Neck Pre Post Pre Post Pre Post Outcome F/U (mo) 11 60/M Lt. C7T1 Disc 3 6 0 2 1 5 5 19 (5+4) 24 12 52/F Lt C56 Disc 2.5 7 3 4 2 4 4 18 (5+3) 21 13 55/M Lt. C67 Disc 3 7 0 1 0 4 5 19 (5+4) 21 14 52/M Lt. C56 Disc 4 6 0 2 0 4 5 10 (5+5) 19 15 49/F Lt. C67 Disc 2.5 6 0 3 1 3 5 18 (4+4) 18 16 43/M Lt. C67 Disc 4 8 0 2 1 5 5 19 (5+4) 14 17 43/M Rt. C67 Disc 2 7 0 0 0 5 5 19 (5+4) 13 18 49/M Lt. C67 Disc 2.5 7 2 1 1 5 5 18 (4+4) 14 19 42/M Lt. C56 Fora 3 6 1 1 0 4 5 18 (4+4) 12 10 70/M Rt. C67 Fora 1.5 8 3 4 2 4 4 17 (4+3) 11 11 47/F Rt. C67 Disc 1 8 0 1 0 4 5 19 (5+4) 10 12 44/F Lt. C56 Disc 1 8 1 1 1 4 5 10 (5+5) 10 13 34/M Lt. C67 Fora 20 7 1 1 1 4 5 10 (5+5) 19 disc=discectomy; fora=foraminotomy; VAS=visual analogue scale; Outcome=modified Prolo outcome scale (economic score + functional score) 세에서 70 세까지평균나이는 49.2 세였다. 수술전의이환기간은한달에서 20 개월까지다양하게분포되어있었으며, 주요증상은상지방사통, 후경부통, 어깨통, 저림등으로나타났다. 이학적검사상피부분절 (dermatome) 에지각이상이 10 례에서관찰되었으며, 근력저하는 9 례에서확인되었다. 수술전 MRI 는전예에서시행되었으며발생부위는제 6-7 번경추간이 8 례로가장많았으며, 병소의방향은좌측이 10 례로더호발하였다. CT 는 11 례에서시행되었으며추간공협착증를평가하는데에유용하였다. 추간공협착증으로진단받은 2 례와수술시야에서탈출된추간판을발견하지못한 70 세남자 (Case 10) 를제외하고는추간공절개술과추간판절제술을동시에시행하였 다. 수술직후 11 예에서즉각적인상지방사통의소실을보였으며술후경부통은거의없거나미미하였다. 수술후시행한 dynamic X-ray 상불안정성은관찰되지않았으며 MRI 와 CT 상탈출된추간판의제거및확장된추간공의소견을볼수있었다 (Fig. 3A, B, C). 술기와관련된조기합병증은관찰되지않았다. 술후 9 개월에서 24 개월의추적관찰기간중한명 (Case 10) 을제외하고는모두 good outcome 을보이고있었으며, 증상의재발은관찰되지않았다. 또한수술과관련한후경부의만성통증이나운동장애등은나타나지않았다 (Table 2). - 70 -
경추신경근병증환자에서최소침습적후방추간공절개술의조기수술결과 권영준 고 찰 Frykholm 11) 이경추부수핵탈출증의치료로후방추간공절개술 (posterior foraminotomy) 를처음소개한이후이술기는 Scoville 과 Whitcomb 12) 에의해보편화되기시작하였다. 이술기는유합술을피함으로써인접분절의추간판의변성을최소화할수있고수술시간과술중출혈을줄일수있으며전방수술시발생할수있는합병증의대부분을피할수있다는장점이있으며, 최근에도여러연구자에의해서 90% 이상의환자들이좋은예후를보인다고보고되어왔다 13,14,15,16,17). 하지만고식적인방법에있어서경추부의 dynamic stabilizer 로작용하는 semispinalis cervicis 와 multifidus 의극돌기와후궁으로의부착부위를과도하게손상을주게되어이것이일부환자의경우수술후의지속적인경부통과심한근육연축등의원인이되어왔다. 최근에사용되고있는원통형견인기를이용한미세내시경 (microendoscopic) 추간공절개술은초기보고에서적은합병증과재발률을보이면서기존의고식적인방법과비슷한성공률을보이고있다. 미세내시경 (microendoscope) 의사용으로수술부위의노출을추간공절개술이필요한부위로최소화할수있는데, 이는 nuchal ligament 의손상을피하면서 muscle splitting 만을시행함으로써 multifidus 의일부근섬유만을제거하므로극돌기와후궁에부착되는 trapezius, splenius, 그리고 semispinalis 의손상을막을수있다. 이를통해대부분의환자에서수술후경부통증을줄일수있고따라서수술후진통제나근육이완제의사용이감소하며사회복귀로의시간이단축되는장점을갖는다. Adamson 은편측증상을갖는 100 명의경추신경근병증환자에서미세내시경후궁및추간공절개술을시행하여 97 명의환자에서좋은예후를보였다고보고하였으며, 이수술이전방경유유합술이나기존의후방경유접근법의대안으로사용될수있다고하였다 6). 본연구에서도비록적은환자군에서시행된조기수술성적이기는하나 92% (12/13) 에서좋은결과를나타내었으며수술과관련된경부통증은미미하였다. 원통형견인기를이용한미세내시경수술은 muscle splitting 만을시행함으로써고식적인방법이가지는단점을대부분극복할수있지만, 경추부의경우요추부와는달리후방경부근막이매우두꺼워확장기를이용할때후궁과후관절면에과도한압력전달에따른신경손상의가능성과 c-arm 의측면사진으로만의지하여 K- wire 나확장기를사용하는경우후관절의바깥쪽으로이들이빠지는경우신경근이나척추동맥의손상이있을수도있다 18). 또한시상접근법 (paramedian approach) 이므로후궁의내측부분을완전히보지못하므로과도한외측접근으로인한술중방향감각의상실과후관절의과도한절개에따른척추불안정이나관절손상에의해지속적인경부통이남는등의문제가있을수있다. 하지만저자가응용한이술기는미세현미경하근육박리를통하여미리공간을충분히만들어준후원통형견인기를사용함으로써심부신전근육의극돌기와후궁으로의부착부를손상시키지않으면서, 과도한압력이척추후궁과관절면에가해지는것을피할수있으며또한위치변동을비교적자유롭게할수있게해줌으로써안전하게후관절의과도한절제없이좋은시야에서최소침습적인방법으로수술을시행할수있다. 결 론 경부신경근병증의치료로후방접근법을이용한수술을시행하여좋은결과를나타내었으며, 그수술을시행함에있어최소침습적심부근육박리를행함으로써수술후통증을줄여빠른회복을기대할수있었다. 추후더많은환자군에서장기추적관찰이필요할것으로판단된다. 참고문헌 01) Smith GW, Robinson RA: The treatment of certain cervical-spine disorders by anterior removal of the intervertebral disc and interbody fusion. J Bone Joint Surg Am 1958; 40: 607-624. 02) Cloward RB: The anterior approach for removal of ruptured cervical disks. J Neurosurg 1958; 15: 602-617. 03) DePalma AF, Rothman RH, Lewinnek GE, Canale ST: Anterior interbody fusion for severe cervical disc degeneration. Surg Gynecol Obstet 1972; 134: 755-758. 04) Hilibrand AS, Yoo JU, Carlson GD, Bohlman HH: The success of anterior cervical arthrodesis adjacent to a previous fusion. Spine 1997; 22: 1574-1579. 05) Foley KT, Smith MM: Microendoscopic discectomy. Tech Neurosurg 1997; 3: 301-307. 06) Adamson TE: Microendoscopic posterior cervical laminoforaminotomy for unilateral radiculopathy: results of a new technique in 100 cases. J Neurosurg 2001; 95: 51-57. 07) Fessler RG, Khoo LT: Minimally invasive cervical microendoscopic foraminotomy: an initial clinical experi- - 71 -
대한척추외과학회지 Vol. 14, No. 2, 2007 ence. Neurosurgery 2002; 51: 37-45. 08) Ditunno JF Jr, Young W, Donovan WH, Creasey G: The international standards booklet for neurological and functional classification of spinal cord injury. American Spinal Injury Association. Paraplegia 1994; 32: 70-80. 09) Davis RA: A long-term outcome study of 170 surgically treated patients with compressive cervical radiculopathy. Surg Neurol 1996; 46: 523-530. 10) Raynor RB, Pugh J, Shapiro I: Cervical facetectomy and its effect on spine strength. J Neurosurg 1985; 63: 278-282. 11) Frykholm R: Deformities of dural pouches and strictures of dural sheaths in the cervical region producing nerveroot compression: A contribution to the etiology and operative treatment of brachial neuralgia. J Neurosurg 1947; 4: 403-413. 12) Scoville WB, Whitcomb BB: Lateral rupture of cervical intervertebral disks. Postgrad Med 1966; 39: 174-180. 13) Grieve JP, Kitchen ND, Moore AJ, Marsh HT: Results of posterior cervical foraminotomy for treatment of cervical spondylitic radiculopathy. Br J Neurosurg 2000; 14: 40-43. 14) Kumar GR, Maurice-Williams RS, Bradford R: Cervical foraminotomy: an effective treatment for cervical spondylotic radiculopathy. Br J Neurosurg 1998; 12: 563-568. 15) Witzmann A, Hejazi N, Krasznai L: Posterior cervical foraminotomy. A follow-up study of 67 surgically treated patients with compressive radiculopathy. Neurosurg Rev 2000; 23: 213-217. 16) Woertgen C, Holzschuh M, Rothoerl RD, Haeusler E, Brawanski A: Prognostic factors of posterior cervical disc surgery: a prospective, consecutive study of 54 patients. Neurosurgery 1997; 40: 724-728; discussion 728-729. 17) Kim KK, Choi BK, Choi CH: Surgical Results of Posterior Laminoforaminotomy and Discectomy for Cervical Disc Herniation. J Korean Neurosurg Soc 2004; 36: 138-144. 18) Perez-Cruet MJ, Fessler RG, Perin NI: Review: complications of minimally invasive spinal surgery. Neurosurgery 2002; 51: 26-36. 국문초록 연구계획 : 최소침습적후방후관절절개술을시행한 13명의경추신경근병증환자의임상및수술결과에대해후향적분석을시행하였다. 연구목적 : 최소침습적심부근육박리를통한경추후방후관절절개술의조기수술결과를보고하고자하였다. 대상및방법 : 2005년 1월부터 2006년 4월까지후방후관절절개술을시행한 13명의환자를대상으로하였으며수술후예후는 modified Prolo outcome scale로평가하였다. 수술은미세근육박리후원통형견인기를사용하여이루어졌다. 결과 : 13명중11명에서수술후신경근병증의즉각적인호전이관찰되었다. 수술후후방경부통과연축은미미한정도였으며수술과관련된합병증은관찰되지않았다. 추적관찰의기간동안 13명중12명에서 modified Prolo outcome scale에근거한 good outcome을보이고있었다. 결론 : 경추신경근병증의치료에있어원통형견인기를이용한후방후관절절개술은술후경부통을줄일수있는좋은수술법으로사료된다. 색인단어 : 경추, 후방후관절절개술, 최소침습수술, 신경근병증 통신저자 : 권영준서울특별시종로구평동 108번지성균관대학교의과대학강북삼성병원신경외과학교실 Tel: 82-2-2001-2159 Fax: 82-2-2001-2157 E-mail: neuriac@gmail.com - 72 -