Percutaneous Transforaminal And Interlaminar Endoscopic Discectomy(PELD)in Treating Lumbar Disc Herniation: Clinical Outcomes Of Surgically Treated Patients

BackgroundPercutaneous endoscopic lumbar discectomy（PELD）is a minimally invasive technique started during the late 20^th century.This process is done through microscopic view under local anesthesia.There is a growing but still insufficient evidence that lumbar EDS shows slightly better results in terms of minor tissue damage,shorter hospital stay,faster return to ordinary daily activities,and patient satisfaction.Recurrence rate still remains a matter of debate,and is related with the surgical skills of the surgeon.The complication rate seems to be similar in both of the techniques i.e.,open and endoscopic.More randomized controlled trials,systematic reviews and meta-analysis are needed to clarify whether lumbar EDS can be considered comparable if not superior to standard open discectomy.In spite of lacking defined clinical evidence,lumbar EDS is without doubt a rapidly expanding PELD and its future developments are incredibly promising.Due to less complication rate this technique can be considered as a gold standard compared to the open discectomy.The surgeons still require more cadaveric practices because of high level learning curve.ObjectiveThe aim of this study is to assess the clinical outcomes of patients in different age groups,with lumbar disc disease undergoing PELD surgery at a single institution,thus evaluating the effectiveness and efficacy of percutaneous endoscopic lumbar discectomy（PELD）.The recurrence rate was analyzed and the evaluation of risk factors for disc reherniation were evaluated.Materials and MethodsA total of 344 patients with final diagnosis of lumbar disc herniation were retrospectively analyzed who had been admitted to orthopedic spine department of Zhongda Hospital affiliated to Southeast University from June 2015 to December 2016.These cases were divided into three groups according to their age,which included a)young age group（18-40 years,127 cases）,b)middle age group（41-60 years,177 cases）and c)old age group（61-80 years,40 cases）.The visual analog scale（VAS）was used to quantify the pain relief.The degree of pain and disability were measured on the basis of the Oswestry Disability Index（ODI）and the modified MacNab criteria.Complications,duration of hospital stay,and operation time were recorded and compared between the three groups.All patients were followed for 3 months and one year after the surgery.Statistical analysis:Data were input in a Microsoft Excel database,and analysis was performed by SPSS for Mac-osx version 22.0.Comparison between subgroups was made repeated ANOVA,one way–ANOVA test to find the signified value and p<0.05 was considered statistically significant.Kruskal-Wallis test.ResultsThe mean pre-operative and postoperative VAS and ODI scores significantly improved in all the three age groups,with no significant differences among them.In young age group after 3months of surgery 54 patients（42.52%）had excellent results,67 patients（52.75%）good results and 4 patients（3.16%）fair results and 2 patients（1.57%）have poor results,in middle age group after 3 months 44 patients（24.86%）had excellent results,117 patients（66.10%）good results,13 patient（7.35%）fair results and 3 patients（1.69%）have poor results and in the old age group12 patients（30%）had excellent results,25 patients（62.5%）good results,3 patients（7.5%）with fair results whereas compared to 3 months the 12 month follow up after surgery showed 100%excellent results in young age and old age groups and 70.63%excellent and 28.8%good results with a significant difference（p=0.00）.The average lengths of hospital stay for the young,middle and the old age groups were 5.3,5.6 and 5.9 days,respectively.The mean operative time for the young age group was 68.39 minutes,middle age was 66.1 and that for old age group was 67.4 minutes.During the follow-up period 315（91.5%）patients had no complaints,5（1.45%）（2 from middle and 3 from old age group）patients had post-op pain,and 24（7%）patients had no improvement.During postoperative follow-up,11（3.2%）patients required repeat surgery for recurrence or residual fragments.Postoperatively,6（1.75%）patients experienced dysesthesia,which completely resolved in time.Neurologic deterioration occurred in 9（2.6%）patients,8（2.3%）of whom recovered completely without any intervention.Dural tears occurred in 9（2.6%）patients.In our study we have 11 reherniation patients compared with the herniated patients showed no significant change in the disc degeneration and facet joint degeneration.The adjacent disc degeneration showed a significant change in between the reheniation and non reherniation groups.ConclusionPercutaneous endoscopic interlaminar or transforaminal surgeries are safe and effective treatment modalities for lumbar disc herniations.Despite the difficulties of acquiring this new technique,good results can be achieved with sufficient experience.The efficacy of PELD is relatively good for the selected age group patients in this study.Therefore,age is not a predictor of PELD surgery-related outcomes.The adjacent disc degeneration could be a major risk factor in the lumbar disc reherniation and further studies should be done to evaluate this risk factor.