The Study And Application Of No-Blind-Area Surgical Instrument System In Microendoscopic Discectomy

Partâ… the Study and Application of no-blind-area Surgical Instrument System in Microendoscopic DiscectomyObjective To evaluate the feasibility and efficacy of using self-designed no-blind -area surgical instrument system (NBSIS)for microendoscopic discectomy(MED)of lumbar disc hernia in cadaveric specimens. Methods The no-blind-area surgical instrument system is composed of modified tubular retractor, expander for modified tubular retractor,universe rongeur, miniature trepan and miniature osteotome.All of the components are made of medical stainless steel on the basis of operating conveniently and varied types. In 10 adult male lumbar spine specimens, divided into two sides by spinous process,left and right sides.On the left sides of L1~2 ,L2~3,L3~4,L4~5, in translaminar approach microendoscopic laminotomy,medial facetectomy and ligamentum flavum removal were finished using Kerrison rongeur in tubular retractor held vertically. On the right sides of L1~2 and L2~3,the same surgical plan as the above mentioned were performed using universe rongeur in tubular retractor locked vertically, and on the right sides of L3~4 and L4~5, microendoscopic discectomy were performed using NBSIS in modified tubular retractor locked vertically. On the left sides of L5~S1 microendoscopic discectomy were performed using blind-area surgical instrument system (BSIS)after tubular retractor was pivoted within the same skin incision repeatedly,and on the right the same surgiacal plan were finished using NBSIS in modified tubular retractor locked vertically. The operating area of NBSIS were endoscopic marked by Kirschner wire during operation. After performing the operation the paraspinal muscle and other soft tissue were removed, the size of laminotomy area and operating area of surgical instrument,length of root exposed were measured. Each level of two sides were statistical analysis as a matched group.And furthermore , the bite force of universe ronguer were measured. Results Vertical diameter, transverse diameter of of laminotomy area were significantly greater for the right than for the left sides of L1~2 and L2~3 levels(P<0.05). Vertical diameter, transverse diameter of laminotomy area and operating area of surgical instruments , length of root exposed were all significantly different beteen the two sides of L3~4 and L4~5 levels(P<0.05). In L5~S1 level vertical diameter, transverse diameter of laminotomy area and the length of root exposed were not statistically significantly differencent(P>0.05),and vertical diameter, transverse diameter of operating area of surgical instruments were significantly different(P<0.05). The maximal bite force of universe ronguer was 290N, its mean bite force range from 270N to 290N due to different grasping force exerted by diffeent operator . Conclusion NBSIS proved to be useful in overcoming the flaw of blind area in vitro human cadaveric study,with an original design, and increased convenience in MED.