percutaneous laser disc decompression ( pldd ) is a minimally invasive treatment option for vertebral disc herniation refractory to conservative treatment .
food and drug administration in 1991 1 . based on the reduced risk associated with less invasive procedures ,
pldd has increased in popularity , with reportedly over 30,000 pldd procedures performed in 2001 2 .
pldd is performed under local anesthesia via a laser fiber percutaneously inserted into the nucleus pulposus .
laser energy is applied through the fiber , resulting in vaporization of nucleus pulposus contents 3 .
improvement in discogenic pain with pldd is based upon laser - induced evaporation of water within the disc ; this results in a very slight decrease in disc size due to water loss .
because the intervertebral disc is essentially a closed hydraulic system , a small decrease in volume leads to a significantly larger decrease of intradiscal pressure ; in vitro experiments confirm this 4,5 .
the short term decrease in pressure is due to evaporation of water content within the nucleus pulposus ; long term effects are thought to be due to protein denaturation , which limits the ability of the nucleus to resorb additional water and reduces stiffness of the disc 3,6,7 .
this hypothetically results in a more even distribution of weight across the intervertebral disc 8 .
consistent with a lumbar location for the majority of intervertebral disc herniations , most published studies have focused on the use of pldd for the treatment of lumbar disc disease .
thoracic discogenic pain or herniation causing neural impingement is less common than that in the cervical or lumbar regions .
certain impact injuries , such as parachute landings , can result in thoracic disc damage .
invasive treatment of such injuries often involves a thoracotomy procedure with either a discectomy or fusion implantation .
although many studies have been done on lumbar and cervical pldd procedures , few have been done on the thoracic region . in order to assess the efficacy and safety of pldd for the treatment of thoracic disc disease
, we performed a study of ten patients with thoracic discogenic pain who were unresponsive to conservative intervention .
we performed a prospective study of ten patients ( 8 male and 2 female ) with an age range of 35 - 73 years .
all patients presented with mid - thoracic axial ( n=7 ) or radicular ( n=1 ) pain that failed to improve with conservative management , which included typical modalities such as physical therapy , pain medication , and epidural steroid injections . physical examination revealed localized thoracic pain without recreation of symptoms with palpation .
all the patients had negative facet injections , to evaluate for the possibility of facet joint pain as the underlying cause .
the patients had positive discograms that correlated to their pain ; in the case of the individual with radicular symptoms , she had total relief of her pain with a thoracic nerve root block , confirming this as the source of her pain .
all patients were diagnosed with thoracic discogenic pain based on mri and provocative discogram results . magnetic resonance imaging ( mri )
findings that were considered abnormal included changes described as irregular nuclear shape , reduced disc height , hypo - intense disc signal , annular tears , high intensity zones , endplate changes , and modic changes 9,10,11 .
all patients underwent diagnostic injections to confirm the source of their pain ; these injections included either thoracic nerve root blocks for radicular symptoms and/or provocative discograms 12 .
the provocative discograms involved low - pressure injections of at least three disc levels and one of the levels was utilized as a control .
thoracic discography has been utilized as a controversial confirmatory test for discogenic pain for some time with debatable results 13,14 .
the authors identified only two studies by the same authors for inclusion , each over 10 years old .
due to the lack of established accuracy of discography , we required the combination of an abnormal mri and a positive provocative discogram to diagnose intervertebral discs as the source of pain and to identify potential study participants .
it was felt that gross herniations producing significant cord compression would be better treated with a laminotomy approach , and that not enough disc material would be removed to resolve the stenosis in such situations .
thus only patients with contained disc protrusions were considered for pldd and patients with gross herniation were removed from the study and sent for laminotomy or conventional discectomy .
patients ' chosen for the procedure reported their thoracic pain using the visual analog scale ( vas ) pain scores at baseline .
posttreatment , patients were evaluated every six months via telephone call or direct patient contact for at least 18 months .
the patient was specifically asked to address the pain level of the thoracic spine region and not the body as a whole .
a double - blinded study would have been preferable with a sham group but was not possible at our facility .
cefofloxin was utilized unless there was an allergy , in which case ciprofloxin was used .
mild sedation was used during the procedure and the patient was able to converse with the surgeon in order to express any unusual pain .
fluoroscopy was utilized during the procedure for proper count of the thoracic vertebrae and to determine the entry site .
the entry site was similar in position to a typical thoracic discogram and was approximately 3 inches lateral to the midline of the spine .
caution was necessary due to the lung fields being close to the needle entry site , increasing the risk of pneumothorax .
once the entry site was determined , the skin and deeper tissues were anesthetized with a mixture of 0.25% bupivacaine and 1% lidocaine with epinephrine via a 27-gauge needle .
a 15 blade was used to create a stab incision of approximately  inch . through the incision , an 18-gauge , 3.5-inch spinal needle was inserted and the needle was guided into the middle of the disc using fluoroscopy .
once properly placed , a direct firing holmium laser ( diameter 0.5 mm ) at 20 watts and 10 repetitions per second ( 6030 - 10405 joules , mean 7633 ) was utilized in short bursts to vaporize the inside of the disc .
in most cases these burst were of ten second intervals ; the patient usually complained of burning mid back pain which limited the time per lasing period .
after the lasing periods , the disc was  cooled  with normal saline ( at least 100 ml ) mixed with cefazolin ( unless there was an allergy ) .
saline irrigation was performed after , not simultaneously with , laser application due to the size of the diameter of the working environment and because a running irrigant would reduce the laser 's effectiveness and thus increase operating times .
total lasing time was approximately 3 minutes , but varied from 80 seconds to 300 seconds .
in most cases , the end point was when the pressure in the disc was reduced and injection of the normal saline occurred without any resistance .
at this point the needle was removed and either the next disc was commenced or the procedure was finished .
expected possible complications included those seen with thoracic discogram and laser usage such as infection or discitis , pneumothorax , nerve injury , and burn injuries 14 . each patient had a post procedural chest x - ray to rule out pneumothorax ; no pneumothorax was seen .
length of follow - up ranged from 18 to 31 months ( mean : 24.2 months ) .
patients were asked to assess their thoracic pain via a vas score preoperatively and at final follow - up visit .
median vas score pretreatment was 8.5 ( range : 5 - 10 ) and median vas at final follow - up was 3.8 ( range : 0 - 9 ) .
six of ten patients ' scores improved by at least 6 points ; one patient improved by 1 point and three patients ' scores did not improve .
. however , certain types of impact , such as parachute landing , carry an increased risk of thoracic disc injury .
optimal treatment of thoracic discogenic pain is identical to that of disease of other spinal regions , i.e. aggressive medical management with anti - inflammatory medication , hot compresses , and physical therapy .
although epidural steroid injections are questionably proven to help with such cases , they are commonly utilized and are thus considered as a conservative therapy .
patients who fail to improve with conservative treatments have several invasive options , including conventional thoracotomy procedures for discectomy and fusion , posterior fusion , laminotomy , and disc decompression .
high energy laser carriers the risk of tissue burns , but low energy lasers may be insufficient to adequately induce vaporization 1 .
lasers near the infrared region currently used in pldd include neodymium : ytrium - aluminum garnet laser [ nd : yag ] , holmium : ytrium- aluminum - garnet laser [ ho : yag ] , and diode laser .
lasers with visible green radiation include double - frequency nd : yag laser and potassium - titanyl - phosphate [ ktp ] laser .
most lasers use a 3 mm outer cannula combined with a fiberoptic viewing cable 17 .
there is no clear consensus regarding the most effective and safe laser or the ideal wavelength that should be used 1 .
pldd is a minimally invasive technique that reduces intradiscal pressure by vaporization of a small volume of water within the nucleus pulposus .
this results in decreased overall pressure and a more even distribution of weight across the disc , with subsequent relief of discogenic pain .
pldd is performed most commonly for lumbar disc disease , and published reports on the efficacy of pldd in thoracic discogenic pain are lacking .
the majority of pldd studies are of small size and observational in nature ; thus the true efficacy of this technique is uncertain 18 .
multiple case series have reported success with pldd for the treatment of lumbar discogenic pain 15,19 - 30 ; however , no randomized controlled trials have been performed . a systematic review by singh et al .
reported that conclusive evidence of efficacy is lacking , and large scale , comparative trials are warranted given the potential benefit of pldd 18 .
the majority of authors report fair to good improvement in approximately 75% of patients , most commonly based upon the mcnab scale .
rates of complication are low , the most common being septic or aseptic discitis , disc rupture , epidural hematoma , and nerve root damage 24,30 - 32 . a recent study on thoracic pldd procedures by hellinger et al .
reported improvement in 41 of 42 patients six weeks after percutaneous laser decompression and nucleotomy ( pldn ) 35 .
the authors reported three adverse events : one occurrence each of pneumothorax , pleurisy , and spondylodiscitis .
long - term outcome was not reported and thus it is unknown if their results extended beyond the study period of 6 weeks . in our study , six of ten patients reported significant pain relief based on visual analog scale pain scores concerning their thoracic pain issue . utilizing a paired student 's t - test , the differences between the pre- and post - treatment groups showed greater than a 99% confidence interval confirming that the improvement was indeed significant .
the 60% improvement level noted is slightly lower , although still in agreement , with published reports of pldd in patients with lumbar disc disease 15,19,34 . of interest
, patients appeared to fall into two main groups : those gaining significant improvement and those receiving little or no improvement at all . in reviewing the patients who failed treatment
, we could not distinguish any specific features , such as mri findings or other clinical data , which could be utilized to screen these potential failed patients in the future .
intervention for the treatment of thoracic disc disease carries a risk of pneumothorax , and particular concern was given to this possibility during the intervention .
no patient developed pneumothorax , and no evidence of discitis , infection , or nerve injury was noted .
this is one of the first reports of the successful application of pldd for the treatment of thoracic discogenic pain .
although the study group is small with only ten patients , six out of the ten patients reported significant improvement at long - term ( greater than 18 month ) follow - up , and no adverse events were reported .
pldd could be considered a viable option with a low risk of complication for the treatment of thoracic discogenic pain that does not resolve with conservative treatment .
nonetheless , due to the small study size , we recommend a larger double - blinded study to confirm our results .
 background : discogenic pain or herniation causing neural impingement of the thoracic vertebrae is less common than that in the cervical or lumbar regions . 
 treatment of thoracic discogenic pain usually involves conservative measures . 
 if this fails , conventional fusion or discectomy can be considered , but these procedures carry significant risk.objectives : to assess the efficacy and safety of percutaneous laser disc decompression ( pldd ) for the treatment of thoracic disc disease.methods : ten patients with thoracic discogenic pain who were unresponsive to conservative intervention underwent the pldd procedure . 
 thoracic pain was assessed using the visual analog scale ( vas ) scores preoperatively and at 6-month intervals with a minimum of 18-months follow - up . 
 patients were diagnosed and chosen for enrollment based on abnormal mri findings and positive provocative discograms . 
 patients with gross herniations were not included.results : length of follow - up ranged from 18 to 31 months ( mean : 24.2 mo ) . 
 median pretreatment thoracic vas score was 8.5 ( range : 5 - 10 ) and median vas score at final follow - up was 3.8 ( range : 0 - 9 ) . 
 postoperative improvement was significant with a 99% confidence interval . of interest 
 , patients generally fell into two groups , those with significant pain reduction and those with little to no improvement . although complications such as pneumothorax , discitis , or nerve damage were possible , no adverse events occurred during the procedures.limitations : the study is limited by its small size and lack of a sham group . 
 larger controlled studies are warranted.conclusions : with further clinical evidence , pldd could be considered a viable option with a low risk of complication for the treatment of thoracic discogenic pain that does not resolve with conservative treatment . 
Background and objectives
Methods
Results
Discussion
Conclusion