Surgical Neurology International

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1 Surgicl Neurology Interntionl SNI: Peditric Neurosurgery, supplement to Surgicl Neurology Interntionl OPEN ACCESS For entire Editoril Bord visit : How I Do It: Mngement of spin ifid in hospitl in The People's Repulic of Chin Nn Bo, 1 Jorge Lzreff Editor: Sndi Lm, M.D. Bylor College of Medicine; Houston, TX, USA Deprtment of Neurosurgery, Shnghi Children s Medicl Center Affilited to Shnghi Jiotong University School of Medicine, Shnghi, People's Repulic of Chin, 1 Deprtment Neurosurgery, UCLA Center for World Helth t Dvid Geffen School of Medicine, Tiverton Drive, Los Angeles, CA 90024, USA E-mil: *Nn Bo - nscmc@shsmu.edu.cn; Jorge Lzreff - jlzreff@mednet.ucl.edu *Corresponding uthor Received: 25 Novemer 14 Accepted: 02 Decemer 14 Pulished: 23 July 15 This rticle my e cited s: Bo N, Lzreff J. How I Do It: Mngement of spin ifid in hospitl in The People's Repulic of Chin. Surg Neurol Int 2015;6:S Copyright: 2015 Bo N. This is n open ccess rticle distriuted under the terms of the Cretive Commons Attriution License, which permits unrestricted use, distriution, nd reproduction in ny medium, provided the originl uthor nd source re credited. Astrct We present our personl experience on ptients with Spin Bifid. It is the result of hving treted 1600 children for 12 yers t Shnghi Children s Medicl Center. We clssify the cses on Spin Bifid Mnifest (myelomeningocele, myelocele, lypomyelomeningocele) or Spin Bifid Ocult (lipom, derml sinus nd thickened filum terminle). For the former, we recommend surgery within h fter irth. For the ltter we recommend preventive surgery months fter irth. We cknowledge tht the dimeter of the spinl cnl is prolem for lrge remnnt lesions. In cses of myelomeningocele, we prefer to plce the shunt nd close the defect in the sme procedure, it reduces the risks inherent to exposure to nesthesi, reduces hospitl sty, nd relted costs. If there is suspicious of infection, we do not plce the shunt on the sme procedure. The personl description of the preferred techniques for closure of the different defects is descried. Access this rticle online Wesite: DOI: / Quick Response Code: Key Words: Myelomeningocele, spin ifid, surgicl technique, spinl lipom, tethered cord CLASSIFICATION There re severl types of neurl tue defects nd ech type cn e divided into vrious sutypes. According to our experience in the tretment of nerly 1600 ptients with different types of neurl tue defects t the Neurosurgery Deprtment of Shnghi Children s Medicl Center over the pst 12 yers, we divided common neurl tue defects into the following types: Spin ifid mnifest This type cn e further divided into the following sutypes ccording to the pthologicl morphology: Myelomeningocele Ptients with this sutype of neurl tue defect hve mss on their ck. The surfce of the mss is thin cyst wll nd in some cses there is no skin [Figure 1]. In other cses, the mss is covered y skin ut the color is lue; there is no sucutneous ft tissue, nd the dermis shows scr like degenertion nd dheres directly to the cyst wll [Figure 2]. The cyst wll is composed of the dur mter, rchnoid mter, pi mter, nd deformed spinl cord, which protrudes outside the skin vi the spinl defect. According to differences in the disesed segments nd morphologies of spinl cord hernition, this sutype cn e further divided into two sutypes. Type I is hernition of the end of the spinl cord, in which the hernited spinl cord termintes t the roof of the ulging dur mter. It is commonly seen in the lumoscrl nd scrl segments [Figures 1 nd 2]. Type II is n omeg shped (Ω shped) hernition of the spinl cord, in which the middle prt of the hernited spinl cord mkes up the roof of the ulging dur mter, ut the end of the spinl cord is locted in the distl S337

2 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl spinl cnl. This type is commonly seen in the lumr nd thorcolumr segments [Figure 3]. Neurologicl dmge is very serious in ptients with myelomeningocele. Most ptients with type I myelomeningocele hve ldder sphincter dysfunction nd most ptients with type II myelomeningocele hve lower extremity dysfunction, foot deformities, nd even ldder sphincter dysfunction nd spinl deformities, etc., The incidence of Chiri mlformtion nd hydrocephlus is s high s 99%, nd these conditions re followed in incidence y syringomyeli, distemtomyeli, rchnoid cyst, etc. Myelocele Ptients with this sutype of neurl tue defect hve mss on their ck. There is purple grnultion t the center of the mss, which is surrounded y thin cyst wll. The purple grnultion is ctully the Ω shped hernited spinl cord, which is directly exposed outside of the skin [Figure 4]. This sutype is commonly seen in the lumoscrl, lumr, nd thorcolumr segments is ccompnied y the most serious neurologicl dmge, nd is ssocited with lower extremity dysfunction, foot deformities, ldder sphincter dysfunction, spinl deformities, Chiri mlformtion, hydrocephlus, etc. Lipomyelomeningocele In this sutype the enlrged spinl cord protrudes dorslly vi the defect in the spinl cnl to form mss tht protrudes over the skin surfce. The skin on the surfce of the mss is intct. The mss contins sucutneous ft tissue, cererospinl fluid (CSF), nd spinl cord. The sucutneous ft grows together with the hernited spinl cord nd dur mter to form the cyst roof. Similr to myelomeningocele, this sutype cn e divided into two sutypes ccording to the different morphologies of the hernited spinl cord. Type I is hernition of the end of the spinl cord nd is commonly seen in the lumoscrl nd scrl segments [Figure 5]. Type II is n Ω shped hernition of the spinl cord nd is commonly seen in the lumr nd thorcolumr segments [Figure 6]. Lipomyelomeningocele is mss covered with norml skin, nd there my e norml pigmenttion or skin depression on the mss surfce. Ptients with lipomyelomeningocele my hve vrying degrees of lower extremity prlysis, foot deformities, git normlity, nd ldder sphincter dysfunction. Severe cses re often ssocited with Chiri mlformtion, hydrocephlus, cererl dysplsi, hydromyeli, distemtomyeli, etc. Lte symptoms include scoliosis, hydronephrosis, etc. Simple meningocele This sutype is chrcterized y ulging of the dur mter from the one defect, nd the cyst contins only CSF without spinl cord or cud equin. If the cyst protrudes dorslly from the spinl cnl, it is clled posterior simple meningocele [Figure 7]. If the cyst protrudes ventrlly from the spinl cnl, it is clled n nterior scrl meningocele [Figure 8]. It ws previously elieved tht simple meningocele usully hs no neurologicl symptoms. However, more nd more investigtors hve found tht simple meningocele is ssocited with very high rte of tethered spinl cord, which results in grdul neurologicl symptoms with incresing ge. During the Figure 2: () Myelomeningocele. The tumor surfce is covered y skin, there is no sucutneous ft tissue, the dermis shows scrlike degenertion, nd () the end of the spinl cord protrudes into Figure 1: ( nd ) Myelomeningocele. The tumor surfce is thin cyst wll, nd the end of the spinl cord protrudes into the ulging the ulging durl sc vi the spinl defect durl sc vi the spinl defect Figure 3: ( nd ) Myelomeningocele. There is Ω-shped protrusion of the spinl cord into the ulging durl sc Figure 4: () Myelocele. There is purple grnultion surfce, nd Ω-shped protrusion of the spinl cord is directly exposed outside the skin. () Sgittl MRI of the lesion S338

3 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl Figure 5: () Lipomyelomeningocele. The skin on the surfce of ulging durl sc is completely covered with sucutneous ft tissue. () The end of the spinl cord protrudes into the ulging durl sc nd grows together with the sucutneous tissue to form the cyst roof Figure 6: ( nd ) Lipomyelomeningocele. There is cpillry hemngiom on the tumor surfce nd skin depression in the scrococcygel region, n Ω-shped protrusion of the spinl cord cn e seen within the ulging durl sc, nd sucutneous ft grows into the spinl cord Figure 7: Posterior simple meningocele. There is no neurl tissue in the ulging durl sc, the conus medullris is locted low t the level of L5, nd there is ssocited ft degenertion lst 4 yers of continuous oservtion, we found tht in 37 of 38 cses (97%) simple meningocele ws ssocited with other spinl cord diseses, such s tight filum terminle, rchnoid cyst, epidermoid cyst, tethered spinl cord due to firous nds, dhesion etween the dur mter nd the spinl cord or cud equin, etc. Occult spinl ifid Skin in the ffected re often hs chrcteristic fetures including pigmenttion, cpillry hemngiom, skin depression, locl hirsutism, smll skin tgs, etc. No significnt symptoms cn e oserved in infnts, nd tethered spinl cord syndrome ppers during the grdul development of the child fter norml trction of the spinl cord occurs. It ws reported tht mny ptients hve symptoms only fter they grow up. Neurl injury is mostly cused y the compression, trction, or incresed tension of the spinl cord. If there is no surgicl tretment, neurl injury will ecome further ggrvted nd irreversile. Therefore, erly dignosis is very importnt for performing surgicl intervention s soon s possile. Occult spinl ifid is further divided into the following sutypes: Figure 8: Anterior scrl meningocele. The cyst protrudes towrd the ventrl side of the scrum nd coccyx, the end of the spinl cord, which is locted t the se of the ulging durl sc, sends out nd growing into the ulging durl sc, which results in spinl cord tethering Spinl cord lipom A lrge mount of sucutneous ft moves into the spinl cnl vi the spinl defect, nd the dorsl dur mter is completely invded y the sucutneous lipom nd loses its norml structure. The lipom enters the sudurl spce nd grows with the lower locted spinl cord. If the lipom grows into the superficil prt of the dorsl spinl cord, it is clled dorsl spinl cord lipom [Figure 9]. If the lipom grows deep into the spinl cord unilterlly or ilterlly nd even reches the ventrl side, it is clled ventrl spinl cord lipom [Figure 10]. Hence, the spinl cord is compressed nd pulled, which results in tethered spinl cord. A spinl cord lipom is seen s sucutneous lipom in the ck with cpillry nevus or skin depression. Sometimes, it is only evident s smll skin tg. Affected ptients my hve vrying degrees of ldder sphincter dysfunction, lower extremity prlysis, foot deformities, nd git normlity. Spinl cord lipoms re commonly seen in the lumoscrl nd scrococcygel segments, nd re clled lumoscrl spinl cord lipom [Figure 11] nd scrococcygel spinl cord lipom, respectively [Figure 12]. These two types S339

4 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl Figure 9: Dorsl spinl cord lipom. The lipom grows into the superficil lyer of the spinl cord Figure 10: Ventrl spinl cord lipom. The lipom grows deep into the spinl cord nd even grows to the ventrl side Figure 11: Lumoscrl spinl cord lipoms. () sucutneous lipom in the lumoscrl region. () MRI evidences tht it grows into the spinl cns vi the defects in the lumoscrl fsci, spinous process, dur mter nd pi mter, nd grows together with the lower locted spinl cord hve slightly different pthologicl chnges nd the corresponding surgicl procedures re lso different. A spinl defect of lumoscrl spinl cord lipom is locted in the lumoscrl segment, nd the conus medullris is locted t the lumoscrl region or even lower. A sucutneous lipom invdes the dur mter vi the spinl defect nd grows together with the spinl cord. Due to the lck of dorsl dur mter, ilterl residul dur tissues grow into the spinl cord inferior to the lipom nd lie superior to the ilterl nerve roots nd the end of the conus medullris. Therefore, the spinl cord is pulled downwrd nd is tethered to the dur mter. Menwhile, the lipom grows cephliclly nd cudlly within the spinl cnl. In generl, cephliclly growing lipom enters the norml sudurl spce nd grows into the dorsl prt nd/or one side of the spinl cord, while cudlly growing lipom is mostly locted outside the dur mter. Unlike lumoscrl spinl cord lipom, scrococcygel spinl cord lipom is locted in the scrl cnl. The sucutneous lipom in the scrococcygel region invdes the dur mter vi the scrl cnl defect nd grows together with the lower locted spinl cord. Insted of terminting in the middle of the lumoscrl durl sc, the conus medullris termintes in the distl end of the durl sc. Figure 12: Scrococcygel spinl cord lipoms. () sucutneous lipom in the scrococcygel region. () MRI evidences tht it grows into the dur mter vi the scrl defect nd grows together with the lower locted spinl cord Therefore, the cud equin does not extend longitudinlly from the end of the conus medullris in ccordnce with norml ntomy, ut extends oliquely downwrd from the ventrl side of the conus medullris. The lipom is locted in the superficil lyer of the conus medullris nd grows into the conus medullris. Differences in surgicl procedures will e descried in detil in the prt on tretment. Bck derml sinus This sutype develops on the dorsl side of the cererospinl xis, t ny site etween the occiput nd the scrococcygel region, most commonly in the lumoscrl region. The sinus my terminte outside or inside the dur mter. At the termintion of the sinus is often derml cyst, which is locted t the end of the spinl cnl or grows into the spinl cord nd cuses tethered spinl cord [Figure 13]. It is seen s pinprick like holes on the skin with peripherl norml hirs, pigmenttion, or cpillry hemngiom like chnges. Surgery should e performed s erly s possile to prevent serious results such s secondry cyst infection, cererospinl meningitis, etc. Distemtomyeli This sutype cn e further divided into two sutypes ccording to the presence or sence of clinicl symptoms: S340

5 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl Type I (presence of symptoms): There re two durl scs nd two spinl cords, tht is, the spinl cord is divided into two prts. Ech hs its own dur mter nd rchnoid mter nd there is firous tissue, crtilge, or one crest etween the two prts, which cuses tethered spinl cord [Figure 14]. Type II (sence of symptoms): The spinl cord is divided into two prts t the distemt, ut these two prts shre common dur mter nd rchnoid mter nd there re no foreign odies cusing tethering, so most cses do not hve clinicl symptoms. It is commonly seen in the thorcic nd lumr segments, nd is seen s n norml hir clump in the center of the ck. Ninety percent of ptients with distemtomyeli hve ssocited scoliosis. Thickened filum terminle syndrome When the terminl filment is invded y ft nd firous tissues, it degenertes nd ecomes thickened, consequently pulling down the spinl cord nd cusing neurl symptoms. The neurl symptoms cused y the tethered terminl filment re often reltively mild, nd ptients only hve pin, enuresis, urinry urgency, fecl lekge, pes cvus, slight foot vrus or vlgus, etc. Loction of the conus medullris my e norml or lower [Figure 15]. Intrdurl lipom There is loclized ft ccumultion in the sudurl spce without connection to the sucutneous ft tissue in the ck. The lipom is often dhered to the dur mter on one side nd locted on the surfce of the spinl cord on the other side. It lso cn grow into the spinl cord nd cuse tethered spinl cord [Figure 16]. Smller lipoms do not develop symptoms for life if they do not enlrge significntly s children grow. Tretment Aims: The gol of tretment is to improve neurologicl function nd prevent further neurl degenertion. Idel ge nd indiction for surgery: Myelocele nd myelomeningocele without skin covering my result in continuous CSF lekge due to the thin cyst wll. c Figure 13: Bck derml sinus. () there is pinprick-like hole in the skin. (, c) MRI shows tht sucutneous sinus enters the spinl cnl vi the dur mter, nd the terminl is derml cyst, which grows form the outside into the spinl cord c Figure 14: Distemtomyeli. () there is n norml hir undle n the ck. () Three dimensionl CT shows tht the one crest grows into the spinl cnl. (c) MRI show two spinl cords divided y centrl one crest Figure 15: () MRI shows tht the conus medullris is locted t the L2 level, nd there is ft signl inside the distl end of the filum terminle. () intropertive endoscopy shows ft degenertion in the filum terminle Figure 16: A dorsl spinl cord lipom compresses the spinl cord S341

6 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl To reduce the risks of CSF lekge nd infection, nd susequent continuous degenertion of neurologicl function, we often perform surgery to close the defect within h fter irth. For skin covered neurl tue defects, such s lipomyelomeningocele, elective surgery should e performed fter considering the ptient s ge, ody weight, generl condition, nd tolernce of the delicte spinl cord to outside intervention. Becuse the tethering nd compression cused y the disese during the growth of the spinl cord my led to further dysfunction, we perform surgery for ptients with lipomyelomeningocele nd spinl cord lipoms within 2 3 months fter irth. However, the spinl cnl is thinner in 2 to 3 month old infnts while the protruded spinl cord is normlly thick, which mkes complete reduction of the spinl cord difficult, produces extensive spinl cord dhesion, nd increses the risk of susequent tethered spinl cord. Therefore, the most suitle ge for surgery in these children should e further investigted. In ptients with occult spinl ifid the disese is often detected few yers fter irth sed on mnifesttions including thickened filum terminl syndrome, distemtomyeli, nd ck derml sinus. Surgery is often performed lte in these ptients. Myelocele nd myelomeningocele re ssocited with high incidence of hydrocephlus. With regrd to hydrocephlus requiring shunt surgery, there re differing opinions out whether shunt surgery should e performed together with surgeries for the originl diseses or whether surgery should e crried out in two stges. We gree with those who dvocte one stge surgery ecuse it llows the ptients to undergo surgery nd nesthesi only once, shortens the length of hospitl sty, nd reduces the medicl cost. Becuse surgery for hydrocephlus is reltively less ssocited with prolems, nd CSF loss occurs during myelomeningocele repir, which my decrese the volume of the cererl ventricle nd mke ventriculr puncture ecome difficult, we perform shunt surgery fter plcing the ptient in the supine position nd then crry out myelomeningocele repir fter turning the ptient over to the prone position. To reduce the rte of complictions including shunt occlusion nd infection, we crry out strict decontmintion of the surgicl site, use very strict septic technique during surgery, minimize intropertive loss of CSF, prevent cephlic spred of loody CSF, reduce the time of wound exposure, etc., Of course, for ptients with definite or potentil infection of the centrl nervous system, myelomeningocele repir is done first nd second stge hydrocephlus shunt surgery is performed fter the infection of the centrl nervous system is controlled. Surgicl principle: The spinl cord should e seprted from the dhered lesion nd the lesion removed to relieve spinl cord compression nd tethering. Surgicl technique: Becuse the tumor surfce is not covered y skin in ptients with myelocele nd myelomeningocele, the site of defect should e wrpped with sline moistened guze immeditely fter the ptient is rought into the NICU to void drying nd direct injury of the neurl sustrtes due to exposure. The ptient should e plced in supine or lterl recument position nd dministered ntiiotics intrvenously. Vrious mesures should e used to prevent possile intropertive hypothermi. For exmple, we increse the temperture of the operting room nd put heting pd underneth the child, void wrpping the domen nd chest using wet towels during opertion, nd perform surgery s soon s possile ccording to the pln. The whole procedure should e crried out under microscope. The ptient is plced in prone position nd soft pd is plced underneth the lower domen to elevte the lower domen nd uttock to the level of the hed to mximlly reduce CSF lekge during the procedure. At the eginning of the surgery, n incision is mde long the mrgin of exposed neurl plcode nd the plcode is seprted from the peripherl tissue to get it ck into the spinl cnl. All the contents re trimmed including skin nd grnultion tissue on the plcode. A neurl tue resemling the spinl cord is then reconstructed, nd the pi mter nd rchnoid mter re drwn close to the midline from the ilterl mrgins of the plcode nd sutured. All the neurl tissues re crefully protected nd specil ttention is pid to electrocogultion in order to void therml urn injury to the plcode, which my hve residul function. The dur mter is then dissected. One side of the dur mter is djcent to the mrgin of the skin defect nd is completely isolted from the skin. The dur mter is closed using 5 0 sorle suture line without compressing the spinl cord. Finlly, the skin is sutured. If ptient hs lrge myelomeningocele, the lrge re skin defect cnnot e repired y simple closure. Therefore, Z shped skin flps re used or lrge scle sucutneous dissection is performed s fr s oth sides of the ck to ensure tension free skin closure. Blunt finger dissection is crried out to void dmging lrge lood vessels. This kind of dissection cn e performed quickly, which not only reduces leeding ut lso ensures lood supply to the skin flp. Use of Z shped skin flps or performing lrge scle sucutneous dissection gurntees direct skin suture for ll ptients. S342

7 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl In ptients with lipomyelomeningocele, fter the cyst is seprted, most of the time, hlf of the lmine of the vertere superior nd inferior to the spin ifid is removed to sufficiently expose the se of the cyst. The norml dur mter is cut open to identify the reltionship etween the hernited spinl cord nd myelomeningocele to void dmging the spinl cord when seprting the cyst wll. An incision is mde t the side of the pex of the cyst contining protruded spinl cord, the nerve within the cyst is crefully protected, nd nnulr resection of the remining prts is done under direct vision. Complete dissection is performed to relese the spinl cord nd neurl fiers dhered to the cyst wll. Becuse sucutneous lipom invdes the spinl cord in cses with lipomyelomeningocele, the ft outside the spinl cord should e removed using scissor nd the ft inside the spinl cord should e removed using micro scissor or n ultrsonic spirtor s much s possile to expose the lyer of neurl plcode. Finlly, interrupted suturing is performed for the split spinl cord, which is plced into the spinl cnl. The redundnt ulging dur mter is trimmed, nd expnded suturing to the durl sc is done to prevent neurl tissue compression nd dhesion. Surgicl procedures for the two sutypes of myelomeningocele or lipomyelomeningocele re similr. For type I, the only requirement is to dissect nd cut off the hernited distl end of the spinl cord from the ulging dur mter [Figure 17]. For the Ω shped spinl cord hernition in type II, the hernited spinl cord cnnot e cut off s is done in type I ecuse it my rek the spinl cord into two prts nd result in irreversile neurologicl dmge. The spinl cord should e seprted from the ulging durl sc long the course of the spinl cord nd plced ck into the spinl cnl [Figure 18]. For simple meningocele, fusiform incision should e mde round the mss nd dissection should e performed from the outside of the cyst wll to the neck of the cyst. The cyst wll should e cut open t the pex to explore the presence of neurl tissue. According to the preopertive MRI findings, the ottom of the cyst cvity should e slightly expnded to explore the spinl cnl, nd find out whether there is ft degenertion of filum terminle, firous nd tethering of the spinl cord, nd dhesion etween the dur mter nd the spinl cord or the cud equin. Corresponding tethering should e relesed. The redundnt cyst wll should e trimmed nd the dur mter sutured t the se. The pr spinl muscle nd fsci should e dissected round the lminr defect nd the spinl defect covered using the reinforced suture technique. Becuse there is no definite oundry etween n intrmurl lipom nd norml spinl cord, complete resection of the lipom is impossile. The im of surgery is to dissect dhesion etween the lipom nd the dur mter, reduce the volume of the lipom, nd relese spinl cord tethering nd compression to llow the reconstructed spinl cord to e suspended in the surchnoid spce stisfctorily. The surgicl technique for spinl cord lipom involves cutting open the dur mter from the cephlic norml site until the lipom is completely exposed. The tumor memrne should e cut open nd the lipom should e grdully removed outside the spinl cord with micro scissor. After most lipom lesions outside the spinl cord re removed nd the spinl cord is decompressed, the spinl cord should e slowly lifted from the ventrl side of the spinl cnl. At this point, the oundry of spinl cord is not yet isolted nd the lipom close to the spinl cord surfce should not e removed in hurry to void dmging the spinl cord elow it. The spinl cord should e gently retrcted to one side to expose c d Figure 17: () MRI, () skin lesion, (c) cord tethered to the ottom of the cnl nd to the extrdurl ft, (d) cord untetehered c d Figure 18: () MRI evidencing cord hernited in omeg shpe, () the ulging dur sc hs een opened, (c) the spinl cord is seprted from the sc, (d) the freed cord is out to e plced in the spinl cnl S343

8 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl the dur mter on the lterl side. The spinl cord should e dissected nd cut off from oth sides of the dur mter using micro scissor in cephlic to cudl direction to relese the tethering nd expose the spinl cord oundry. Then the ft nd firous tissue should e further removed from the spinl cord surfce sfely, effectively, nd mximlly using the ultrsonic spirtor or CO 2 lser knife until the lyer of the neurl plte is exposed. The smll mount of ft tissue within the spinl cord should not e forcefully removed in order to protect spinl cord function. Surgery for scrococcygel spinl cord lipom is more difficult thn surgery for lumoscrl spinl cord lipom. In ptients with lumoscrl spinl cord lipom, the conus medullris is locted in the middle segment of the lumoscrl dur mter nd the oundry is esily oserved. As long s the norml dur mter is dissected t the cudl end of the lipom nd cut open cephliclly, the conus medullris cn e identified nd isolted from the dur mter. However, in ptients with scrococcygel spinl cord lipom, the conus medullris is locted in the distl end of the durl sc. The lipom on the surfce of the conus medullris not only grows together with the conus medullris, ut lso grows outside the scrl cnl nd connects with the norml ft tissue in the scrococcygel re without oundries. Becuse the lipom completely covers the conus medullris nd distl end of the dur mter, it is extremely difficult to identify the oundry etween the conus medullris nd distl end of the dur mter during surgery nd seprte them. Our method is to diminish the ft from the cephlic end, lift the spinl cord from the ventrl side fter the ft ecomes thinned, nd then cut off the spinl cord from the dur mter. When the spinl cord oundry is exposed, the ft inside the spinl cord should e further removed in cephlic to cudl direction, nd the lipom of the conus medullris nd tethering should then e treted. The key point is to ccurtely identify the oundry etween the distl end of the durl sc nd the conus medullris in order to move towrd the midline from oth sides, dissect the conus medullris, nd relese it from the end of the durl sc. If dissection towrd the midline is performed too erly, it will cut off nd dmge the conus medullris, nd if the dissection is crried out too lte, it my cuse disorienttion nd result in the mnipultion eing moved outside the cudl thecl sc or even the scrl cnl, which not only cnnot relese the conus medullris tethering, ut lso my dmge the scrococcygel epidurl spinl nerve. The ft on the surfce of the conus medullris should e diminished. When the firous ft lyer is exposed, the durl sc end on the surfce of the conus medullris should e initilly identified. The conus medullris should e gently pulled side t this point to further identify the distl end of the durl sc inside the scrl cnl ecuse the course of the durl sc end slnts upwrd within the scrl cnl. After the scrl sc end is reched, dissection should e crried out from oth sides to the midline to completely isolte the conus medullris from the end of the durl sc nd entirely relese the tethered spinl cord. After the oundry of the conus medullris is totlly exposed, the firous ft tissue on the surfce of the conus medullris should e removed sfely nd effectively nd the neurl plte reched. Finlly, the opened spinl cord should e repired with interrupted suture to reduce the risk of postopertive dhesion etween the dorsl side of the spinl cord nd the suture site in the dur mter, nd minimize the possiility of secondry tethering. The key point of surgery for distemtomyeli is to remove the septum, regrdless of one, ft, or crtilge, ecuse it is the cuse of tethering. The ony septum outside the dur mter should e removed s much s possile using rnger or smll wl. In most cses, there re mny lood vessels round the septum, which my cuse mssive leeding if injured. The dur of the two spinl cords should e cut open. Often there re firous dhesions etween the spinl cord nd the dur mter t the site of the septum, nd ny such dhesions should e completely seprted. Surgery for thickened filum terminle syndrome should e performed vi n incision etween L4 nd L5 or L5 nd S1 spinouts processes. The dur mter nd rchnoid mter should e cut open nd the filum terminle identified ccording to midline loction, yellow or silver chnge of filum color, disppernce of nodes of Rngier, nd ft infiltrtion. The filum terminle should e seprted from the peripherl nerve nd slightly rotted to identify the presence of nerve dhesion on the ventrl side. After electrocogultion, 5 mm of filum terminle should e cut off s specimen for pthologicl evlution. Surgery for ck derml sinus requires complete removl of the derml cyst nd sinus inside nd outside the spinl cord. It is necessry to identify the terminl of the sinus. Though sometimes ck derml sinus tht termintes on the surfce of the dur mter is shown in imging exmintions, cutting open the dur mter is still needed for explortion ecuse some tiny derml cysts within the dur mter re often not shown on MRI. Postopertive follow up Becuse some chnges such s swelling cused y surgery disppers t lest 1 month fter surgery on MRI imges, we often perform MRI 2 3 months fter surgery to lern the postopertive sttus of the spinl S344

9 SNI: Peditric Neurosurgery 2015, Vol 6: Suppl 11 - A Supplement to Surgicl Neurology Interntionl cord. Close oservtion is crried out for ptients with myelocele or myelomeningocele to identify the presence or sence of progressive ggrvtion of hydrocephlus. If the neurologicl function is stle, we regulrly follow up our ptients 1, 3, nd 5 yers fter surgery. We hve complete ptient dtse nd every ptient is followed up y n experienced doctor. This my help doctors otin first hnd informtion, lern the postopertive sttus of neurologicl function, find prolems, nd in time, djust or improve surgicl procedures. ACKNOWLEDGEMENT This work hs een supported y the UCLA Center for World Helth. S345