Epidural Fat-Derived Mesenchymal Stem Cell: First Report of Epidural Fat-Derived Mesenchymal Stem Cell

STUDY DESIGN: Experimental study. PURPOSE: To determine whether epidural fat (EF) tissue contains mesenchymal stem cells (MSC). OVERVIEW OF LITERATURE: Spine surgeons are unaware of the contents of EF tissue and the reason for its presence between the ligamentum flavum and the dura mater; therefore, EF tissues are routinely eliminated during surgical procedures. However, EF removal causes certain postoperative problems, such as post-laminectomy syndrome. We hypothesized that the EF tissue may play a significant supportive role for the neural structures and other nearby conditions. METHODS: EF tissues were obtained from consenting patients (n=3) during posterior decompression surgery of the lumbar spine. The primary cells were isolated and cultured as per previously described methods with some modifications, and the cell morphology and cumulation were examined. Thereafter, reverse transcription–polymerase chain reaction (RT-PCR), a fluorescence-activated cell sorting (FACS) analysis, and differentiation potency for differentiation into osteoblasts, chondroblasts, and adipocytes were investigated to identify whether the cells derived from EF are MSC. RESULTS: The cells from the EF tissue had a fibroblast or neuron-like morphology that persisted until the senescence at p18. MSC-specific genes, such as OCT4, SOX2, KLF4, MYC, and GAPDH were expressed in the RT-PCR study, while MSC-specific surface markers such as CD105, CD90, and CD73 were exhibited in the FACS analysis. The differentiation properties of EF-MSC for differentiation into the three types of cells (osteoblast, chondroblast, and adipocyte) were also confirmed. CONCLUSIONS: Based on the cell culture, FACS analysis, RT-PCR analysis, and differentiation potent outcomes, all the features of the cells corresponded to MSC. This is the first study to identify EF-MSC derived from the EF tissue.

Surgical Results of Herniated Lumbar Disc

The surgical outcome for lumbar discectomy has improved with development of surgical techniques and strict selection of patients. The authors could follow up and analyse 818 cases who underwent surgery due to herniated lumbar disc from Jan. 1980 to Dec. 1991 at Chonbuk National University Hospital. The early operative complications were delayed wound healing(36 cases), extradural hermatoma(2 cases), discitis(2 cases), but there was no injury to nerve root and abdominal vessels. The specially designed paravertebral muscle retractor and nerve root retractor were useful in reducing the operative complications. Sixteen patients were reoperated due to acute recurrent symptoms(within one month). More than one-third of these(7/16) were due to missed disc material, and all of them had good results after reoperation. Twenty five patients were reoperated due to late recurrent symptoms(more than 6 months later). In almost two-third of them(14/25), rerupture of remained disc material was found. Reoperation of these cases had a good result as well. Epidural fibrosis and severe adhesion of nerve root were showed for reoperation in 9 of the 25 cases. These complications had a poor result except 1 case even after reoperation. The surgical outcome of 818 cases were classified ; Excellent 618 cases(82%), Good 110 cases(13.5%), Fair 29 cases(3.5%) and Poor 8 cases(1%). Surgical technique and proper selection of patients were considered as important facter obtaining the better result.