cerebrospinal fluid ( csf ) leakage is a potential complication of cranial and spinal surgery11 ) . duraseal ( covidien , waltham , ma , usa ) is a synthetic product which has been increasingly used to facilitate watertight repair of dural defects after cranial and spinal surgery . the duraseal has been demonstrated to be both safe and effective in clinical studies2,4,7,10 ) and was approved in 2005 by the food and drug administration ( fda ) . the authors report a patient who developed cord compression following the use of duraseal in cervical spine surgery in which the expansion of the duraseal was believed to be the causative factor . a 59-year - old man presented to the outpatient department with a 2-year history of progressive leg numbness . mri ( magnetic resonance image ) had shown intradural mass broad - based on the left side of the dura that compresses the cord severely , displacing it to the right posterior aspect at c7 level ( fig . 1 ) . opening the lamina and dura at c7 level , the mass removal was performed . the mass was totally removed and the histopathologic findings of frozen biopsy were consistent with those of a meningioma . when repairing dura , duraseal was applied to dural surface that was incompletely approximated with sutures . eight hours after surgery , the patient developed left - side weakness to motor grade i. a mri scan was urgently performed , which demonstrated a large extradural mass which was causing severe cord compression at the level of tumor removal ( fig . on reoperating wound , a thick layer of gelatinous material consistent with duraseal was initially encountered . also the minimal amount of surgicel was removed , which was separate and not interfering with the duraseal. after surgery the patient is showing slightly improvement with his power increasing to motor grade ii . leakage of csf can lead to delayed healing of surrounding tissues such as skin , muscle , and bone due to its caustic effect11 ) . the aim therefore once a csf leak is identified , is to stem the leak . hydrogel sealant ( duraseal ) is a synthetic sealant approved by the fda , which has been increasingly used to facilitate watertight repair of dural defects after cranial and spinal surgery , and has been demonstrated to be both safe and effective in clinical studies2,4,7,10 ) . duraseal is a self - polymerizing agent which rapidly forms a firm , watertight hydrogel layer within several seconds of application over the dural surface . in comparison to fibrin glue the firm layer is robust enough to withstand irrigation and gentle suction maneuvers without threat of dislodgement . these properties are advantageous in affecting a watertight barrier to minimize the risk of csf leakage8 ) . reported no evidence of postapplication csf leaks or adverse events in 46 patients who had a spontaneous dural tear treated with duraseal2 ) . cosgrove et al . reported similar findings with no evidence of postapplication csf leaks in 95.5% of patients and no adverse events with the use of duraseal4 ) . after these reports , the use of duraseal was extended as an adjunct to suture closure of an iatrogenic dural tear . duraseal is believed to be an ideal sealant for spine procedures because it is a nontoxic bioabsorbable synthetic hydrogel composed of 90% water with similar properties to tissue2,9 ) . however , one of the drawbacks of using duraseal is its potential to swell up to 50% and slow absorption rate . according to the manufacturers ( covidien , waltham , ma , usa ) , product application to " confined bony structures where nerves are present is contraindicated . " a study in dog models has demonstrated that hydrogel shows in vivo expansion , and mass effect within the first 2 weeks , after insertion characterized by computerized tomography ( ct ) and mri imaging6,11 ) . the first reported complication of duraseal was reported when used as a dural sealant after a posterior fossa decompression for a chiari malformation1 ) . a 13-year - old girl developed a worsening quadriparesis after the mass effect of hydrdogel sealant on the cervicomedullary region following foramen magnum decompression . a case of cervical cord compression has also been reported in a patient who underwent a c5-c6 anterior cervical decompression and fusion who sustained a csf leak when excising the posterior longitudinal ligament with duraseal being used as the primary sealant11 ) . three hours postoperatively , the patient developed progressive upper and lower extremity motor weakness . during emergent exploration and decompression , the surgeons determined the expanded hydrogel was the cause of the compression . also a case has been reported of duraseal causing cauda equina compression after a patient underwent a lumbar laminotomy and discectomy complicated by a dural tear9 ) . this patient 's dural tear was treated with duraseal and the patient developed symptoms of cauda equina compression 9 days postoperatively . the patient was taken emergently to the operating room and during exploration and decompression , a large amount of blue duraseal was visualized . the volume of duraseal removed was measured as 10ml , which is more than three times the amount used primarily , suggesting considerable hydrogel expansion after implantation . duraseal has now been approved for spinal usage by the fda . to date , the time profile and radiographic appearances of this dural sealant has previously only been systematically characterized in a dog craniotomy model6,8 ) . in a dog model , duraseal 's volume expansion was reported to peak between day 3 and 2 weeks after implantation6,9 ) . to avoid such a complication , we would recommend judicious application of the duraseal with thin - layer application to the defective area only . we would also caution against applying duraseal in a manners such that it extends over and beyond the bone edges bordering the dural surface after bony decompression . our case demonstrates the use of duraseal over a site of a dural repair is associated with the risk of developing postoperative cord compression as a result of swelling of the duraseal. duraseal tendency to expand is documented both in the instructions for its use and published case reports , and this is also confirmed by our experience . a very thin layer of duraseal should be delivered over the site of dural repair and the possibility of postoperative expansion of it should be recognized by the surgeon .