Clinical Application Of Percutaneous Endoscopic Interlaminar Discectomy In The Treatment Of L5/S1 Para-central LDH

?Background?The surgical effcacy and safety of Percutaneous Endoscopic Interlaminar Discectomy(PEID)have became a hot topic of spinal surgeon and they often compare it with Percutaneous Transforaminal Endoscopic Discectomy(PTED)in order to clear the applied indications of this two approaches.However,the outcome measures in the existing clinical studies are not comprehensive without a thorough evaluation of life quality.At the same time,the infuence of the differences between subtypes of Lumbar Disc Herniation(LDH)are not been taken into account which tends to reduce the credibility of the results in statistical analysis because of different compositional ratios.?Objective?Observe the improvement of low back and leg pain?neurological functions and postoperative life quality in patients with L5/S1 para-central LDH treated by PEID and analysis the surgical safety of interlaminar approach.Investigate the differences in perioperative parameters and postoperative effcacy between PEID and PTED in the treatment for different subtypes of LDH to provide more evidence for surgical approach selection in clinical practice.?Methods?Patients with L5/S1 para-central LDH undergoing PTED or PTED in our hospital were collected from June 2016 to October 2017 and were divided into two groups according to the surgical approach.The patients of each group were divided into four subtypes: the axilla type?shoulder type?ventral type and mixed type according to the the nucleus pulposus position aganist nerve root.The general features(number,age,gender)?the disease features(LDH subtype,paresthesia,muscle strength,low back and leg pain NRS,JOA,disc Pfrrmann Grading)and anatomical features(intervertebral foramen height,interlaminar space height,apex of iliac crest,iliac crest angle)of two groups were compared.The operation duration?fuoroscopic times and the bed and hospitalization duration of the the two groups were collected in perioperative period.Low back and leg pain NRS?JOA and complications were collected at 1st day and 3rd month after surgery for the patients of both two groups.SF-36 health scale were conducted preoperatively and at 3rd month postoperatively.A pre and post control study was performed on the PEID group with indicators including low back and leg pain NRS?JOA and SF-36 health scale.According to different subtypes,a contrastive study between PEID and PTED group was conducted on the perioperative parameters and postoperative low back and leg pain NRS?JOA?excellent rate as well as complication rate.SPSS was used for data analysis and related testing methods were used to evaluate the signifcance of differences.?Results?(1)Recruitment and follow-up: A total of 68 patients were included.31 patients were in PEID group with 19 males and 12 females;the number of axilla?shoulder?ventral and mixed type was 11?8?8?4 respectively;14 patients underwent the local anesthesia and 17 patients underwent continuous epidural anesthesia;15 operations were completed in axilla way with 9 in the shoulder way and 7 in the axilla-shoulder way.30 follow-ups were complete with 1 patient lost at 3rd month.37 patients were in PTED group with 21 males and 16 females;the number of axilla?shoulder?ventral and mixed type was 9?16?11?1 respectively;37 patients all underwent the local anesthesia and TESSYS.36 follow-ups were complete with 1 patient lost at 3rd month.(2)Baseline comparison: Overall,there was no signifcant difference in age?gender?disease duration?paresthesia?muscle strength?disc Pfrrmann Grading?preoperative low back and leg pain NRS and JOA between PEID and PTED group(P>0.05).When based on differnet subtype,there was no signifcant difference in age?gender?disease duration?preoperative low back and leg NRS and JOA between PEID and PTED group too(P>0.05)except mixed type.(3)Pre and post control study on the PEID group: In PEID group,the preoperative low back pain NRS?leg pain NRS and JOA was 4.94±1.91?4.77±2.04 and 11.52±2.01 respectively and changed into 1.20±0.99?1.67±1.18 and 24.10±2.95 at the last follow-up(P<0.05).The excellent rate was 90.3%.Between the two postperative follow-ups,there was no signifcant difference in low back pain NRS or leg pain NRS(P>0.05),but a signifcant difference in JOA appeared(P<0.05).The eight terms of SF-36 health scale were signifcantly improved at 3rd month postoperatively than preoperative period(P<0.05).Two temporary nerve root paralysises?one transient hypotension?two urinary retentions and one anesthetic overdose occurred without other complications.The overall complication rate was 19.35% of which the surgical complication rate was 6.45%.(4)Comparison of anatomical features between PEID and PTED group: There was no signif-cant difference in intervertebral foramen height and interlaminar space height between two groups(P>0.05).The distribution of apex of iliac crest in PEID group was 5 patients in area A?11 patients in area B and 11 patients in area C,and relatively the number in PTED group was 11?24 and 2.The difference was signifcant(P<0.05).The iliac crest angle of two groups was 32.64±4.39°and 30.52±4.04°with a signifcant difference(P<0.05).(5)Comparison of surgery and effcacy between PEID group and PTED group: The PEID group in four subtypes had signifcantly lower fuoroscopic times than PTED group(P<0.05).The operation duration was lower in PEID group of axilla and shoulder type than in the same subtype of PTED group(P<0.05),but the bed and hospitalization duration of these two subtypes were higher(P<0.05).There was no signifcant difference in operation and hospitalization duration between PEID and PTED group in ventral type(P<0.05),but in this subtype the bed duration of PEID group was higher(P<0.05).There was no signifcant difference in operation?bed and hospitalization duration between two groups in mixed type(P>0.05).Except for the leg pain NRS in PEID group was signifcantly lower than that in PTED group in axilla type at 1st day postoperatively(P<0.05)and the JOA in PEID group was signifcantly higher than that in PTED group in ventral type at 3rd month postoperatively(P<0.05),there was no signif-cant difference in the low back and leg pain NRS?JOA?excellent rate and complication rate between PEID and PTED group in the four subtypes(P>0.05).?Conclusion?PEID can be considered as a routine for L5/S1 para-central LDH,and the kind of LDH and anesthesia has a great infuence on the perioperative period;PEID can improve the patient's clinical symptoms followed by a better life quality and social function;PEID,which has a well long-term effcacy and safety as PTED,represents a better short-term effcacy for axilla type LDH.