one radiologist retrospectively reviewed the medical records of the patients who received tfesi using the conventional approach at our department during a 1-year period , from june 2003 to may 2004 . this involved performing tfesi at the location of the exiting nerve root , regardless of the level of the nerve root compression . for example , tfesi for l5 radiculopathy was performed at the neural foramen of l5-s1 even when the l5 nerve root compression was in the paracentral or subarticular region at the level of the l4 - 5 disc . after a consensus meeting between three radiologists who were unaware of the clinical results after tfesi , we selected those cases treated by conventional tfesi with supra - adjacent nerve root impingement . the inclusion criteria were ( a ) the presence of lumbar radiculopathy , ( b ) nerve root compression in the paracentral or subarticular region at the level of the supra - adjacent intervertebral disc ( for example , at the l4 - 5 disc level for the l5 nerve root ) , ( c ) one level tfesi from l1 to s1 , ( d ) no prior therapeutic tfesi , ( e ) no prior surgery , and ( f ) clear identification of the nerve root compression by using a cross - sectional imaging study ( either computed tomography or magnetic resonance imaging ) . thirteen patients who met all the criteria were included and they were referred to as the conventional tfesi group . however , since june 2004 , we have used tfesi with the preganglionic approach at the supra - adjacent intervertebral disc ( for example , at the neural foramen of l4 - 5 for a l5 nerve root ) if the nerve root compression was at the level of the supra - adjacent intervertebral disc . using the same inclusion criteria as mentioned above , a total of 20 patients were consecutively enrolled and they were referred to as the preganglionic tfesi group . ttransforaminal epidural steroid injection using the conventional approach was conducted under biplane fluoroscopic guidance by two radiologists who were very experienced in spinal interventions . all the treatments were performed as outpatient procedures , and written informed consents were obtained from all the patients . with a patient lying in the prone position , the tube was rotated obliquely to ensure injection at the neural foramen . the goal of positioning was to allow a perpendicular needle tract toward the classic injection site underneath the pedicle , in the so - called " safe triangle " ( 5 , 7 ) . the safe triangle was defined by the pedicle superiorly , the lateral border of the vertebral body laterally , and the outer margin of the spinal nerve medially . after disinfecting the skin , local anesthetic was administered by using a 25-gauge needle . under fluoroscopic guidance , a 12-cm 22-gauge spinal needle was then advanced into the safe triangle . at the same time , a lateral view was obtained to verify that the anterior - posterior position of the needle tip was appropriate . the needle position was checked by biplane fluoroscopy , and this was followed by the injection of about 1 ml of contrast material ( omnipaque 300 [ iohexol , 300 mg of iodine per milliliter ] ; amersham health , princeton , nj ) . the posteroanterior and lateral spot radiographs were obtained to document the distribution of the contrast material . bupivacaine hydrochloride ( 0.5 ml , marcaine spinal 0.5% heavy ; astrazeneca , westborough , ma ) and 40 mg ( 1 ml ) of triamcinolon acetonide suspension ( tamcelon ; hanall , seoul , korea ) were slowly injected . in terms of tfesi with using the preganglionic approach , the goal of positioning the needle tip was medial and inferior to that used in the conventional approach . in our department , we target injections just lateral to the pars interarticularis on the oblique view during the preganglionic approach ( fig . a fortnight after tfesi , the patients were followed - up at our outpatient department . this length of follow - up has been proposed in the literature and relates to the duration of the therapeutic effect of corticosteroid ( 7 ) . to check the effect of tfesi , all the patients were recommended not take any drugs or to participate in any physical therapy for their sciatica before this 2-week follow - up . the level and cause of nerve root compression on the ct or mr imaging and the level of radiculopathy were documented in the medical charts before performing tfesi . after retrospectively reviewing medical records , we classified the cause of radiculopathy as being due to a herniated intervertebral disc ( hivd ) or it was due to spinal stenosis . the patients ' demographic variables were also detailed at the initial clinical evaluation . for statistical analysis , we classified the patients ' ages into six age groups ; < 29-years - old , 30 - 39 , 40 - 49 , 50 - 59 , 60 - 69 and > 70 . the duration of radiculopathy was also treated as a potential predictive variable , and it was classified as acute or subacute , i.e. , < 6 months or chronic ( > 6 months ) ( 8) . the treatment outcome was assessed using a 5-point patient satisfaction scale , i.e. , 0 ( poor ) , 1 ( fair ) , 2 ( good ) , 3 ( very good ) , and 4 ( excellent ) , and by using a vas ( visual assessment scale ) that ranged from 0 to 100 . a successful outcome required a patient satisfaction score of 3 ( very good ) or 4 ( excellent ) , and a reduction on the vas of > 50% two weeks after the tfesi . the patients with a successful outcome were referred to as having received effective treatment and those patients without a successful outcome were referred to as having received ineffective treatment . logistic regression analysis was performed and the factors included were conventional or preganglionic tfesi , the cause of radiculopathy , the patients ' age and gender and the duration of radiculopathy . the mann - whitney u test was also used to evaluate for age differences between the two groups ( the conventional and preganglionic groups ) . spss , version 10.0 ( spss , chicago , il ) was used throughout the analysis . one radiologist retrospectively reviewed the medical records of the patients who received tfesi using the conventional approach at our department during a 1-year period , from june 2003 to may 2004 . this involved performing tfesi at the location of the exiting nerve root , regardless of the level of the nerve root compression . for example , tfesi for l5 radiculopathy was performed at the neural foramen of l5-s1 even when the l5 nerve root compression was in the paracentral or subarticular region at the level of the l4 - 5 disc . after a consensus meeting between three radiologists who were unaware of the clinical results after tfesi , we selected those cases treated by conventional tfesi with supra - adjacent nerve root impingement . the inclusion criteria were ( a ) the presence of lumbar radiculopathy , ( b ) nerve root compression in the paracentral or subarticular region at the level of the supra - adjacent intervertebral disc ( for example , at the l4 - 5 disc level for the l5 nerve root ) , ( c ) one level tfesi from l1 to s1 , ( d ) no prior therapeutic tfesi , ( e ) no prior surgery , and ( f ) clear identification of the nerve root compression by using a cross - sectional imaging study ( either computed tomography or magnetic resonance imaging ) . thirteen patients who met all the criteria were included and they were referred to as the conventional tfesi group . however , since june 2004 , we have used tfesi with the preganglionic approach at the supra - adjacent intervertebral disc ( for example , at the neural foramen of l4 - 5 for a l5 nerve root ) if the nerve root compression was at the level of the supra - adjacent intervertebral disc . using the same inclusion criteria as mentioned above , a total of 20 patients were consecutively enrolled and they were referred to as the preganglionic tfesi group . ttransforaminal epidural steroid injection using the conventional approach was conducted under biplane fluoroscopic guidance by two radiologists who were very experienced in spinal interventions . all the treatments were performed as outpatient procedures , and written informed consents were obtained from all the patients . with a patient lying in the prone position , the tube was rotated obliquely to ensure injection at the neural foramen . the goal of positioning was to allow a perpendicular needle tract toward the classic injection site underneath the pedicle , in the so - called " safe triangle " ( 5 , 7 ) . the safe triangle was defined by the pedicle superiorly , the lateral border of the vertebral body laterally , and the outer margin of the spinal nerve medially . after disinfecting the skin , local anesthetic was administered by using a 25-gauge needle . under fluoroscopic guidance , a 12-cm 22-gauge spinal needle was then advanced into the safe triangle . at the same time , a lateral view was obtained to verify that the anterior - posterior position of the needle tip was appropriate . the needle position was checked by biplane fluoroscopy , and this was followed by the injection of about 1 ml of contrast material ( omnipaque 300 [ iohexol , 300 mg of iodine per milliliter ] ; amersham health , princeton , nj ) . the posteroanterior and lateral spot radiographs were obtained to document the distribution of the contrast material . bupivacaine hydrochloride ( 0.5 ml , marcaine spinal 0.5% heavy ; astrazeneca , westborough , ma ) and 40 mg ( 1 ml ) of triamcinolon acetonide suspension ( tamcelon ; hanall , seoul , korea ) were slowly injected . in terms of tfesi with using the preganglionic approach , the goal of positioning the needle tip was medial and inferior to that used in the conventional approach . in our department , we target injections just lateral to the pars interarticularis on the oblique view during the preganglionic approach ( fig . a fortnight after tfesi , the patients were followed - up at our outpatient department . this length of follow - up has been proposed in the literature and relates to the duration of the therapeutic effect of corticosteroid ( 7 ) . to check the effect of tfesi , all the patients were recommended not take any drugs or to participate in any physical therapy for their sciatica before this 2-week follow - up . the level and cause of nerve root compression on the ct or mr imaging and the level of radiculopathy were documented in the medical charts before performing tfesi . after retrospectively reviewing medical records , we classified the cause of radiculopathy as being due to a herniated intervertebral disc ( hivd ) or it was due to spinal stenosis . the patients ' demographic variables were also detailed at the initial clinical evaluation . for statistical analysis , we classified the patients ' ages into six age groups ; < 29-years - old , 30 - 39 , 40 - 49 , 50 - 59 , 60 - 69 and > 70 . the duration of radiculopathy was also treated as a potential predictive variable , and it was classified as acute or subacute , i.e. , < 6 months or chronic ( > 6 months ) ( 8) . the effectiveness of tfesi was evaluated two weeks after the procedures . the treatment outcome was assessed using a 5-point patient satisfaction scale , i.e. , 0 ( poor ) , 1 ( fair ) , 2 ( good ) , 3 ( very good ) , and 4 ( excellent ) , and by using a vas ( visual assessment scale ) that ranged from 0 to 100 . a successful outcome required a patient satisfaction score of 3 ( very good ) or 4 ( excellent ) , and a reduction on the vas of > 50% two weeks after the tfesi . the patients with a successful outcome were referred to as having received effective treatment and those patients without a successful outcome were referred to as having received ineffective treatment . logistic regression analysis was performed and the factors included were conventional or preganglionic tfesi , the cause of radiculopathy , the patients ' age and gender and the duration of radiculopathy . the mann - whitney u test was also used to evaluate for age differences between the two groups ( the conventional and preganglionic groups ) . spss , version 10.0 ( spss , chicago , il ) was used throughout the analysis . the study subjects were 22 women and 11 men with a mean age of 55.1 years ( age range : 17 - 76 , standard deviation [ sd ] : 14.1 ) . the mean age was 53.9 years ( sd : 13.4 ) in the conventional tfesi group and it was was 55.8 years ( sd : 14.8 ) in the preganglionic tfesi group . of the 13 patients in the conventional tfesi group , nine showed effective treatment two weeks after tfesi ( 69.2% ) , and 18 of the 20 patients ( 90% ) in the preganglionic tfesi group showed effective treatment , and the difference in the two rates of effective treatment was of borderline significance ( p = 0.056 ; odds ratio 10.483 ) . the cause of radiculopathy , the age of the groups , gender and the duration of symptoms were not found to be statistically related to the effectivness of tfesi ( p > 0.05 ) . these results are summarized in tables 1 , 2 . in the conventional tfesi group , seven patients ( 53.8% ) had spinal stenosis and six patients ( 46.2% ) had hivd , and in the preganglionic tfesi group , 13 patients ( 65% ) had spinal stenosis and seven patients ( 35% ) had hivd . in the conventional tfesi group , the radiculopathy was acute or subacute in eight patients ( 61.5% ) and chronic in five patients ( 38.5% ) ; in the preganglionic tfesi group , radiculopathy was acute or subacute in six patients ( 30% ) and it was chronic in 14 patients ( 70% ) . in the conventional tfesi group , tfesi at l5-s1 was performed in 10 patients and tfesi at l4 - 5 was performed in three patients ; in the preganglionic tfesi group , tfesi was performed at l5-s1 in five patients , at l4 - 5 in 14 patients and at l3 - 4 in one patient . lumbosacral radiculopathy is a common and costly medical disease , and its lifetime prevalence has been estimated to be 40 - 60% ( 9 ) . based on the recent concepts of pain generation in the sciatic condition , it 's believed that concomitant chemical irritation of the nerve root that 's caused by disk material is the decisive factor for the development of severe sciatica , rather than the pain being due to mechanical compression alone ( 10 - 16 ) . according to this concept , the local application of corticosteroids in the area of the compressed thus , percutaneous injection based therapies , including tfesi , are being used with increasing frequency to treat the radiculopathy resulting from a herniated disc or degenerative lumbar spinal stenosis ( 17 - 19 ) . in contrast to an interlaminar or a caudal epidural steroid injection , tfesi provides a low volume of concentrated medication to a selected nerve root . medical journals and texts often incorrectly refer to transforaminal epidural injections as " selective epidural injections " , " selective nerve root blocks " , or " nerve root sleeve injections " . however , the international spinal intervention society ( isis ) , has promoted the used of a nomenclature based on precise anatomic descriptors , and it recommends the term " transforaminal " ( 5 ) . gajraj ( 4 ) mentioned that to be selective , a nerve root block should be performed extraforaminally and distal to the division of the ventral and dorsal rami ; otherwise , the dorsal ramus and its innervated structures would also be anesthetized . therefore , they suggested that the therapeutic procedure be referred to as a ' transforaminal epidural steroid injection ' and that the diagnostic procedure should be referred to as a ' selective spinal nerve block ' or a ' selective ventral ramus block . ' in the case of tfesi with using the conventional approach , the spinal needle is positioned within the " safe triangle " ( bordering the pedicle , the exiting nerve root and the lateral border of the vertebral body ) , with the bevel placed below the inferior aspect of the pedicle ( 5 , 7 ) . using this conventional approach , the injectate typically bathes the epidural space around the dorsal root ganglion and then it descends along the distal aspect of the nerve root . ideally , if there is no stenosis and the needle tip is appropriately positioned , the injectate may spread rostrally to the epidural portion of the preganglionic nerve root as well . however , for most cases of lumbosacral radiculopathy that are secondary to stenosis or a herniated disc , the site of impingement usually lies at the level of the supra - adjacent intervertebral disc , which is rostral to the conventional lumbar tfesi bevel position . in addition , one can not always guarantee a rostral spread of injectate to the epidural / preganglionic portion of the nerve root . thus , performing preganglionic tfesi at the supra - adjacent level may be a more effective method to deliver injectate to a target site . for the preganglionic approach , it is important that the injectate distributes itself predominantly in the epidural space at the disc level ( more inferior than that for the conventional approach ) , and that it does not excessively spread along the spinal nerve at the supra - adjacent level , which is not inflamed or compressed . lew et al . ( 6 ) inserted the needle into the inferior and anterior neural foramen for performing preganglionic tfesi , and we use a modification of this method . the landmark we use for needle insertion is just lateral to the pars interarticularis on the oblique view ; this is medial and inferior to that used for the conventional approach ( fig . first , it is not a controlled , randomized prospective study ; thus , it has the limitations of a retrospective study and so a randomized , prospective study is warranted . third , other factors that probably influenced the therapeutic effect were not included . in conclusion , preganglionic tfesi was found to have a better therapeutic effect on the radiculopathy caused by compression at the supra - adjacent level than did conventional tfesi , and this result had borderline statistical significance .
objectivethe present study was undertaken to evaluate the effectiveness of transforaminal epidural steroid injection ( tfesi ) with using a preganglionic approach for treating lumbar radiculopathy when the nerve root compression was located at the level of the supra - adjacent intervertebral disc.materials and methodsthe medical records of the patients who received conventional tfesi at our department from june 2003 to may 2004 were retrospectively reviewed . 
 tfesi was performed in a total of 13 cases at the level of the exiting nerve root , in which the nerve root compression was at the level of the supra - adjacent intervertebral disc ( the conventional tfesi group ) . since june 2004 
 , we have performed tfesi with using a preganglionic approach at the level of the supra - adjacent intervertebral disc ( for example , at the neural foramen of l4 - 5 for the l5 nerve root ) if the nerve root compression was at the level of the supra - adjacent intervertebral disc . using the inclusion criteria described above , 20 of these patients 
 were also consecutively enrolled in our study ( the preganglionic tfesi group ) . 
 the treatment outcome was assessed using a 5-point patient satisfaction scale and by using a vas ( visual assessment scale ) . 
 a successful outcome required a patient satisfaction scale score of 3 ( very good ) or 4 ( excellent ) , and a reduction on the vas score of > 50% two weeks after performing tfesi . 
 logistic regression analysis was also performed.resultsof the 13 patients in the conventional tfesi group , nine showed satisfactory improvement two weeks after tfesi ( 69.2% ) . 
 however , in the preganglionic tfesi group , 18 of the 20 patients ( 90% ) showed satisfactory improvement . 
 the difference between the two approaches in terms of tfesi effectiveness was of borderline significance ( p = 0.056 ; odds ratio : 10.483).conclusionwe conclude that preganglionic tfesi has the better therapeutic effect on radiculopathy caused by nerve root compression at the level of the supra - adjacent disc than does conventional tfesi , and the diffence between the two treatments had borderline statistical significance .