# Laser Reconstruction of Spinal Discs Experiments and Clinic
## 4 Clinical Aspects of LRD of IVD in DDD of the Spine
### LRD Puncture
In addition, the data of histological and electron microscopic examination of biopsy samples of IVD tissues were obtained from three patients in two or three years after LRD (Figure 9). In the irradiated part of the discs, pronounced regenerative processes were found in the form of proliferation of chondrocytes and neoplasms of cartilage tissue of the fibrous-hyaline type. In the non-irradiated part of the discs, the replacement of the disc tissue with degeneratively altered nonspecific fibrous cicatricial connective tissue continued [33]. LRD after Surgical Interventions on the Spine as a Means of Preventing the Development of Recurrent Disc Hentiation, Instability of the Affected Segment and Further Development of the DDD  
Once started, DDD progresses over time. When observing the natural course of the degenerative process after 2 years, the deterioration of the disc condition by 1-2 points according to Pfirrmann was observed in 47.6% of patients, and in the next 5 years, it reached 95.2% [77]. At the same time, the actual intervention on the IVD to remove symptomatic hernial protrusion can accelerate the degenerative process. During long-term follow-up from 5 to 25 years for patients after open classical dissectomy, based on radiological changes,  
Figure 8: MRI results for a patient 53-year-old in 24 months after LRD: (**A**) before and (**B**) after punction transforaminal LRD of L4L5 disc. T1W1—**left column**, T2 WI—**center column**, STIR—**right column**. Change of the disc degeneration from Pfirrmann 5 to Pfirrmann 4 (T2 WI), formation of the new cartilage tissue in the center of the disc (T2 WI, STIR), change of the signal from the adjacent to the disc vertebral bone as the mark of disc metabolism shift (T1 WI). Figure 9: Morphological structure of the IVD of a patient in 2.5 years after LRD: (**A**) numerous isogenic groups of chondrocytes with high levels of PGs. Toluidine Blue, \(\times\)400; (**B**) biosynthetically active chondrocytes in isogenic groups, thin CFs and PGs around the cells in the ECM. SEM, \(\times\)6000; (**C**) on the left is the transition area of fibrous cartilage into hyaline ones. H&E, \(\times\)400; (**D**) in the center-bright metachromatic areas. Groups of chondrocytes of the type of hyaline cartilage cells are visible. Toluidine Blue, \(\times\)400; (**E**) on the left is a fibro-hyaline cartilage: chondrocytes in lacunae and homogeneous, in places fine-fibrous, basophilic ECM. H&E, X400; (**F**) CFs and PGs are randomly located in the ECM of hyaline-like cartilage. SEM \(\times\)40,000.  
acceleration of disc degeneration was noted in 48.7% of cases, microsurgical technique reduces this risk, but not completely, provoking such negative changes in 9.1% [15]. This leads to the progression of pain syndrome, and in 7-15% of patients it leads to recurrence of herniated discs. Removal of an intervertebral hernia by any method, including puncture, endoscopic or microsurgical, leads to the inevitable progression of DDD due to iatrogenic mechanical action on IVD structures. The minimal puncture of a healthy IVD in a rabbit causes delamination of its AF and, after 12 weeks, visible degenerative changes in the disc on radiographs [78]. Puncture of an IVD with a needle serves as a standard model of its degenerative lesion in experimental studies [79]. LRD induces a regenerative response of the cartilaginous tissue, accompanied by the formation of new hyaline and fibrohyaline cartilage in the disc cavity. The possibility of combining laser irradiation of the disc with the procedure for removing a disc hernia makes the laser technique a valuable addition to the surgical intervention and transforms it from ablative to regenerative, when the disc tissue is not only removed, but also internal trophic processes in the IVD are stimulated, leading to disc regeneration [34]. In this case, the LRD is performed through the operating wound after the completion of microsurgical removal of the hernial protrusion and decompression of the nerve structures.