The dynamic stabilization of lumbar spine is a non-fusion stabilization system that unloads the disc without the complete loss of motion at the treated motion segment. Clinical outcomes are promising but still not definitive, and the long-term effect on instrumented and adjacent levels is still a matter of discussion. Several experiments have been devised in order to gain a better understanding of the effect of the device on the intervertebral disc. One of the hypotheses was that while instrumented levels are partially relieved from loading, adjacent levels suffer from the increased stress. But this has not been proved yet. The aim of this study was to investigate the long-term effect of dynamic stabilization in vivo, through the quantification of glycosaminoglycans (GAG) concentration within instrumented and adjacent levels by means of the delayed Gadolinium-Enhanced Magnetic Resonance Imaging of Cartilage (dGEMRIC) protocol. Ten patients with low back pain, unresponsive to conservative treatment and scheduled for Dynesys implantation at one to three lumbar spine levels, underwent the dGEMRIC protocol to quantify GAG concentration before and 6 months after surgery. Each patient was also evaluated with visual analog scale (VAS), Oswestry, Prolo, Modic and Pfirrmann scales, both at pre-surgery and at follow-up. Six months after implantation, VAS, Prolo and Oswestry scales had improved in all patients. Pfirrmann scale could not detect any change, while dGEMRIC data already showed a general improvement in the instrumented levels: GAG was increased in 61% of the instrumented levels, while 68% of the non-instrumented levels showed a decrease in GAG, mainly in the posterior disc portion. In particular, seriously GAG-depleted discs seemed to have the greatest benefit from the Dynesys implantation, whereas less degenerated discs underwent a GAG depletion. dGEMRIC was able to visualize changes in both instrumented and non-instrumented levels. Our results suggest that the dynamic stabilization of lumbar spine is able to stop and partially reverse the disc degeneration, especially in seriously degenerated discs, while incrementing the stress on the adjacent levels, where it induces a matrix suffering and an early degeneration.

Our hypothesis was that the enhanced MRI of cartilage (dGEM-RIC) imaging protocol could be used in patients to quantify the sulfated glycosaminoglycan (sGAG) in intervertebral discs (IVD). To test this hypothesis, 23 patients with degenerative disc pathology scheduled for surgery were studied by a specific dGEMRIC protocol: each patient underwent two MRI scans, before and 3.5 hr after Gd(DTPA)2-injection of a nonconventional dose of 40 mL. Then, T 1PRE-ENH and T 1POST-ENH parametric images of the disc were obtained, from which a new index ⌬T 1 of the molecular status of the IVD was computed (T 1PRE-ENH ؊ T 1POST-ENH ). A total of 31 tissue samples (one or two from each patient) obtained at herniectomy were collected and biochemically analyzed for sGAG content and used as the gold standard for comparison.

Background/Aims: Interventional radiologists have played a main role in the technical evolution of gastrostomy, from the first surgical/endoscopical approaches to percutaneous interventional procedures. This study evaluated the results obtained in a 12-year series. Methods: During the period December 1996 to December 2008, 254 new consecutive gastrostomies and 275 replacement procedures were performed in selected patients. All of the cases were treated by a T-fastener gastropexy and tube placement. The procedures were assessed by analyzing indications, patient selection, duration of the procedures, and mortality. Results: All 254 first gastrostomies were successful; replacement procedures were also successfully performed. One (0.2%) patient with severe neurologic disorders died after the procedure without signs of procedure-related complications, and seven (1.3%) major complications occurred (four duodenal lesions with peritoneal leakage, two gastric bleedings, and one gastric lesion). Minor complications were easily managed; three tube ruptures were resolved. Conclusions: This long-term series and follow-up showed that a group of interventional radiologist can effectively provide gastrostomy placement and long-term tube management. Percutaneous gastrostomy is less invasive than other approaches and it satisfies the needs even of high-risk patients. (Gut Liver 2010;4(Suppl. 1):S44-49)

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