Effects of release and decompression techniques on nerve roots through percutaneous transforaminal endoscopic discectomy on patients with central lumbar disc herniation

Assessing the Effect of Intrathecal Dexmedetomidine on Cerebrospinal Fluid Levels of Apoptotic Factors: A Clinical Trial Study in Lumbar Disc Surgery

Background: Dexmedetomidine protective effects on apoptosis in the brain and peripheral organs have been reported in vivo and in vitro. Apoptotic factors of cerebrospinal fluid (CSF) may influence the prognosis of patients undergoing open discectomy surgery. Objectives: This study evaluated the effect of intrathecal dexmedetomidine administration on the CSF levels of apoptotic factors and clinical outcomes in patients undergoing lumbar discectomy. Methods: This clinical trial was conducted on patients undergoing open lumbar discectomy. Forty patients were randomly divided into control and dexmedetomidine groups. In the dexmedetomidine group, 0.1 μg/kg of dexmedetomidine was intrathecally injected after anesthesia induction. Patients’ hemodynamic status during surgery was recorded; additionally, their pain scores were recorded by the Numeric Rating Scale (NRS) in the recovery room. The levels of apoptotic factors including Bax/Bcl-2 and caspase-3 in the CSF were measured at the beginning and end of discectomy, and the results were compared between the two groups. Results: Of the 40 evaluated patients, the mean levels of caspase-3 in the intervention and control groups were 2.28 ± 0.35 and 2.34 ± 0.32 ng/mL before surgery and 2.56 ± 0.42 and 2.72 ± 0.39 ng/mL after surgery, respectively. The levels of Bax/Bcl-2 in the intervention and control groups were 1.01 ± 0.11 and 0.89 ± 0.07 before surgery and 1.28 ± 0.14 and 1.16 ± 0.19 after surgery, respectively. The levels of these two factors were not significantly different. However, the NRS scores were significantly lower in the dexmedetomidine group than in the control group. Conclusions: Intrathecal dexmedetomidine could significantly and safely reduce the NRS score in the intervention group but did not have any significant effect on the CSF levels of apoptotic factors before and after lumbar discectomy surgery.

The protection of superior articular process in percutaneous transforaminal endoscopic discectomy should decreases the risk of adjacent segment diseases biomechanically

PURPOSE

Facetectomy is a useful procedure in percutaneous transforaminal endoscopic discectomy (PTED) for the enlargement of surgical field and operative space and for the decompression of existing nerve roots for patients who suffer foraminal stenosis. Biomechanical deterioration can initially trigger the adjacent segment disease (ASD), and our previous literature proved that a large grade of facetectomy can increase the risk of biomechanical deterioration and resulting low back pain. However, no study has discussed whether different grades of facetectomy influence the risk of ASD.

METHODS

A validated osteoligamentous lumbosacral finite element model and corresponding PTED models with quarter and half facetectomy were constructed in our previous study. Biomechanical indicators were computed and recorded to evaluate the risk of ASD.

RESULTS

Obvious differences between the intact model and the quarter facetectomy model had no basis. Nevertheless, in most body positions, most of the above indicators deteriorated in the half facetectomy model.

CONCLUSION

On the basis of achieving the surgical purpose in PTED, the superior articular process should be protected to decrease the risk of ASD biomechanically.

Treatment of L5 - S1 intervertebral disc herniation with posterior percutaneous full-endoscopic discectomy by grafting tubes at various positions via an interlaminar approach

Background

Depending on the location of the herniated disc at the shoulder, axilla, or ventral side of the compression nerve root, various puncture sites and channel entrances were selected so that the goal of targeted removal of the herniated disc could be achieved by a full-endoscopic technique. Achieving good clinical therapeutic efficacy through the natural gap of bones can maximally avoid related access complications, and the necessary techniques and relevant anatomical factors were analyzed.

Methods

Between August 2012 and August 2014, 98 patients with L5 - S1 intervertebral disc herniation were treated with posterior percutaneous full-endoscopic discectomy (PPFED) by grafting tubes at various positions via the interlaminar approach. The visual analog scale (VAS) and the Oswestry disability index (ODI) were used to assess the patients’ back and leg pain and the improvements in daily function, and the modified Macnab standard was used to evaluate the treatment efficacy.

Results

All 98 patients successfully completed the surgery, 84 patients got out of bed and walked on the first postoperative day, and 14 patients got out of bed and walked on the second postoperative day. The preoperative ODI (56.032 ± 3.625) was significantly higher than the ODI score (8.147 ± 1.398) (F = 5343.054, P ≤ 0.001) 48 months after surgery. The preoperative VAS score (7.193 ± 0.875) was significantly higher than the postoperative VAS score (0.914 ± 0.500 points) (F = 1656.173, P ≤ 0.001). The differences in ODI and VAS scores before and after surgery were statistically significant (P < 0.05). Follow-up was conducted 1, 6, 12 and 48 months postoperatively, and the modified Macnab standard was used during the last follow-up to evaluate the efficacy: 67 cases were excellent, 20 cases were good, 7 cases were fair, and 0 cases were poor; the proportion of excellent and good cases was 92.6%.

Conclusions

The treatment of L5 - S1 intervertebral disc herniation with PPFED by grafting tubes at various positions via an interlaminar approach is a safe, effective, and minimally invasive surgical method. Reaching the location of a disc herniation directly through the natural gap in the bones can maximally avoid collateral injury from spine surgery.

Trial registration

The registration number of this clinical study is ChiCTR1800014588; it has been retrospectively registered with a registration date of 05/01/2018.

Reducing the extent of facetectomy may decrease morbidity in failed back surgery syndrome

Background

Percutaneous transforaminal endoscopic discectomy (PTED) is widely used for the treatment of lumbar disc herniation. Facetectomy in PTED is necessary for accessing the intraspinal region and for decompressing the exiting nerve roots in patients who suffer from hypertrophy of the facet joints. However, this may increase morbidity in failed back surgery syndrome (FBSS) and has not been clearly elucidated.

Methods

A three-dimensional lumbosacral model was reconstructed and validated. And corresponding models after PTED with one-quarter and one-half excisions of the superior articular process were reconstructed. The maximum shear stress on the annulus in L5, von Mises stress of the facet cartilage, maximum principle capsular strain and deformation of the lumbosacral model were calculated using finite element methods.

Results

Calculated results show no significant differences in the complete model and the model with one-quarter excision of the superior articular process, but all biomechanical indexes have been deteriorated under most of the loading conditions tested in the model with one-half excision of the superior articular process.

Conclusions

Less facetectomy is better because it may reduce the risk of biomechanical deterioration and consequently, that of FBSS.

Outcomes of percutaneous endoscopic trans-articular discectomy for huge central or paracentral lumbar disc herniation

PURPOSE

This study reports a new technique known as percutaneous endoscopic trans-articular discectomy (PETAD) for huge central/paracentral lumbar disc herniation (LDH).

METHODS

Sixteen patients with huge central/paracentral LDH who underwent PETAD in our department from July 2015 to July 2016 were retrospectively analyzed. Clinical outcomes were evaluated according to pre-operative and post-operative visual analog scale (VAS) and Oswestry disability index (ODI) scores and the MacNab criteria. Immediate post-operative MRI and CT were conducted to confirm complete removal of LDH along with follow-up flexion-extension X-ray to observe lumbar stability.

RESULTS

The huge central/paracentral LDH was completely removed by PETAD in 16 patients, as confirmed by post-operative MRI and CT. Leg pain was eased after removal of the disc herniations. The satisfactory (excellent/good) results were 93.7%. The mean follow-up duration was 15.6 (range, 3-24) months. The mean pre-operative VAS and ODI scores were 5.72 ± 1.18 (range, 4-9) and 60.1 (range, 51-87), respectively, which decreased to 1.26 ± 0.81 (range, 0-3) and 18.1 (range, 10-31), respectively at the third month post-operatively and to 0.78 ± 0.62 (range, 0-1) and 7.2 (range, 0-15), respectively by the last follow-up visit. No recurrence and segmental instability was observed in any of the 16 patients during the follow-up period.

CONCLUSION

PETAD could be a good alternative for treatment of huge central/paracentral LDH.

Significance and pitfalls of percutaneous endoscopic lumbar discectomy for large central lumbar disc herniation

Background

Percutaneous endoscopic lumbar discectomy (PELD) is a relatively less invasive treatment for lumbar disc herniation (LDH). The present study focused on the transforaminal approach (TFA) and investigated the significance of PELD via this approach for large central LDH.

Methods

LDH that did not show cerebrospinal fluid (CSF) on axial T2-weighted magnetic resonance images was defined as large central LDH. PELD via the TFA was performed in 11 patients with large central LDH. Pre- and post-operative statuses were evaluated using the modified Japanese Orthopedic Association (mJOA) and Numerical Rating Scale (NRS) scores.

Results

The patients' mean age was 44.1 years; there was single-level involvement, mostly at L4/5 (seven cases). The mean recovery rate of the mJOA score was 48.7%, and mean pre- and post-operative NRS scores were 7.1 and 1.5, respectively. The mean operative time was 38.1 min. Although there were no major complications, the dura was accidentally punctured at the initial operative step for discography in one case. LDH recurred in one case at 5 months after the operation, and the patient was treated by PELD via the TFA on the contralateral side.

Conclusions

The TFA for PELD is a safe, minimally invasive, effective treatment for large central LDH. However, the operator should pay attention to malpositioning of the flat and laterally expanded dural sac.