Case presentation and short perspective on management of foraminal/far lateral discs and stenosis

Transtubular Endoscopic Neuronavigation-Assisted Approach for Extraforaminal Lumbar Disk Herniations: A New Trend for a Common Neurosurgical Disease

BACKGROUND

Extraforaminal lumbar disk herniations (ELDHs) are relatively rare and are, till today, diagnostic and therapeutic challenges. The transmuscular paramedian approach to the extraforaminal space is today the standard surgical approach. Nevertheless, controlling the correct trajectory to the extruded disk fragment continues to represent a challenge. The application of spinal navigation and spinal endoscopy seems to offer great advantages to ELDH treatment.

OBJECTIVE

The purpose of this study is to demonstrate the advantages of spinal navigation for ELDHs by taking a purely endoscopic transtubular approach, focusing on technical aspects and clinical outcomes.

METHODS

Nine consecutive patients who underwent a navigation-assisted, muscle-splitting, transtubular, purely endoscopic approach for ELDHs were retrospectively analyzed. Their clinical records were reviewed. Pain evaluations and neurological assessments were conducted.

RESULTS

We recorded a notable visual analog scale (VAS) score improvement in postoperative examinations. The mean operation time was 47.05 min. All patients were discharged on postoperative day 1.

CONCLUSION

The use of spinal navigation offers a great advantage to ELDH treatment. The aid of navigation allows for a patient-tailored approach and adequate surgical exploration even in face of complex lesion anatomies. The endoscopic transtubular navigated approach seems to offer a significant reduction in operative time, at least in the selected cases.

The effect of smoking on achieving meaningful clinical outcomes one year after lumbar tubular microdecompression: a matched-pair cohort analysis

BACKGROUND CONTEXT

There has been a shift in the spine literature in reporting meaningful outcomes, including meaningful clinically important difference (MCID), after surgery. The evidence on the effect of tobacco smoking at the time of lumbar tubular microdecompression (LTMD) on meaningful outcomes is limited.

PURPOSE

To compare differences in 1-year functional outcomes and rates of achieving MCID between current smokers and non-smokers who underwent LTMD for lumbar spinal stenosis (LSS).

STUDY DESIGN

A nested case control study to compare the difference in patient reported outcomes (PROs) between smokers and non-smokers 1-year after undergoing LTMD.

PATIENT SAMPLE

This study included patients that underwent single level LTMD by a single surgeon between January 2014 through August 2019.

OUTCOME MEASURES

Preoperative and postoperative PROs were recorded using the questionnaires EQ-5D, Oswestry Disability Index (ODI), and the visual analog scale (VAS) for back pain and leg pain. The MCID was also used.

METHODS

Current tobacco smokers at the time of surgery were matched 1:2 to non-smokers by age (+/- 1year). Preoperative and postoperative functional scores were compared between the two groups using independent t-tests. Additionally, thresholds for achieving MCID were calculated for each individual functional score, and were compared using Fisher's exact test.

RESULTS

Of the 183 patients with 1-year follow-up who met inclusion criteria, 35 patients were identified as smokers and were matched to 70 non-smokers. No statistical differences were identified between age, BMI, or gender. Comparison of preoperative PROs showed no statistically significant differences between smokers and non-smokers (p>0.05 for all), while smokers had statistically lower EQ-5D (p<0.001) and higher ODI (p=0.05), VAS back (p=0.033), and VAS leg (p=0.03) score averages at a minimum of one year follow-up. Evaluation of meaningful outcomes demonstrated non-smokers had higher rates of achieving MCID on at least 1 threshold score as compared to smokers (98.5% vs. 91.1%; p=0.043).

CONCLUSIONS

Current smokers at the time of surgery have inferior postoperative EQ-5D scores, increased pain and disability, and lower odds of achieving the MCID at 1-year after undergoing LTMD when compared to patients without any smoking history.

Navigation-assisted extraforaminal lumbar disc microdiscectomy: Technical note

Background:

Extraforaminal lumbar disc herniation (ELDH) amounts of 7%–12% of all lumbar disc herniations. Although they have already been widely described, an optimal treatment is still under discussion in the literature.

Objective:

We describe a novel application of navigation using 2D/3D imaging system to plan an adequate surgical trajectory and performing a neuronavigated microdiscectomy in ELDH that has not been previously described.

Methods:

This is a retrospective study in a single institution. Between February 2017 and July 2020, a total of 12 patients (7 males and 5 females), with a mean age of 56 years (range 49–71 years), have been treated because of ELDH through a far lateral microdiscectomy using 2D/3D imaging system-assisted neuronavigation (O-arm).

Results:

No intraoperative and/or postoperative complications were recorded. Patients presented a mean preoperative Visual Analog Scale (VAS) score of 7.83 ± 0.83 (range 7–9). At the day of discharge, leg pain VAS score effectively improved, decreasing to a mean value of 1.83 ± 0.83 (range 1–3). Further, low back and radicular pain improvement was recorded at 1-, 6-, and 12-month follow-up, respectively.

Conclusion:

We described a novel use of 2D/3D imaging system navigation in the microsurgical treatment of ELDH that has not previously reported. This technique is safe and effective and provides more intraoperative details compared to fluoroscopy, which can be crucial for the success of the procedure and to reduce complications and particularly indicated in complex cases with altered anatomy.

Diagnosis and Safe Excision of Lumbar Synovial Cysts and Accompanying Pathology: A Perspective

Background:

Lumbar synovial cysts are often not sufficiently diagnosed prior to spine surgery. Utilizing both MR and CT studies is critical for recognizing the full extent/severity of these lesions.

Methods:

In patients with chronic, acute, or subacute lumbar disease, obtaining both MR and CT studies is critical to correctly diagnose; disc disease, hypertrophy/ossification of the yellow ligament (OYL), stenosis, with/without degenerative spondylolisthesis, and/or synovial cysts (SC).

Results:

MR T2 weighted images directly demonstrate hyperintensity within a SC. They initially cause lateral recess/caudad nerve root and/foraminal compromise, with larger extrusions causing significant lateral thecal sac, and far lateral/superior cephalad root compromise. CT 2 mm cuts often better demonstrate mid-vertebral level compression of cephalad nerve roots with/without SC calcification, along with the extent of mid-vertebral stenosis, hypertrophy/OYL, and DS. When CT studies directly document SC calcification, it alerts the surgeon to the increased potential risk of creating a cerebrospinal fluid fistula with full SC excision, and should prompt the adoption of alternative measures such as decompression/partial removal. Most critically, surgery for synovial cysts often warrants a 2-level laminectomy for fuller visualization of the cephalad and caudad nerve roots, and clearer differentiation of neural tissues from the large fibrotic SC capsule, to effect safer removal.

Conclusions:

Preoperatively, establishing the full cephalad and cauda extent of lumbar synovial cysts with both MR and CT studies is critical. Anticipation and better visualization of the foraminal/far lateral and superior extent of these lesions often warrants more extensive multilevel laminectomies for thecal sac and both cephalad and caudad root decompression.

Lumbar microdecompression in elderly versus general adult patients: Comparable outcomes and costs despite group differences

This study investigated differences between patients <65 and ≥65 years of age following lumbar microdecompression. Differences between age groups were investigated with univariate analyses. A linear mixed effects model was fit to the study outcomes. 144 patients were studied. There was no difference in two-year outcomes between the age groups. Outcome measures showed improvement compared to baseline at one- and two-years (p < 0.001). Age group had a significant effect on back pain (p = 0.016). Patients ≥65 years of age may experience greater relief in back pain following microdecompression. Nonetheless, significant improvement is observed in both age groups at two-years.

Far Lateral Tubular Decompression: A Case Series Studying One and Two Year Outcomes with Predictors of Failure

Introduction The optimal surgical treatment of isolated lumbar foraminal stenosis has not been defined. Minimally invasive decompression of the foramen from a far lateral tubular decompression (FLTD) approach has been shown to not only have minimal morbidity but also highly variable success rates at short-term follow-up. It is important to quantify improvement and define the demographic and radiographic parameters that predict failure in this promising, minimally invasive surgical technique. This study investigates pain and disability score improvement following FLTD at 12 and 24 months and investigates associations with failure. Methods All patients who underwent lumbar FLTD by a single surgeon at a single institution from September 2015 to January 2018 were included in this prospective case series. Visual analog scale (VAS) for back pain and leg pain and Oswestry Disability Index (ODI) were collected preoperatively and at the 12- and 24- month follow-ups. Outcomes between visits were fitted to a linear mixed-effects model. The univariate analysis investigated demographic, radiographic, and operative associations with subsequent open revision. Results A total of 42 patients were included in this study. Back pain (VAS 5.84 to 3.32, p<0.001), leg pain (VAS 7.33 to 2.71, p<0.001), and ODI (48.97 to 28.50, p<0.001) demonstrated significant improvements at the 12-month follow-up. Back pain (VAS 3.71, p=0.004), leg pain (VAS 3.04, p<0.001), and ODI (30.63, p<0.001) improvements were maintained at 24-month follow-up. Four patients (9.5%) required subsequent open revision. Subsequent open revision was associated with prior spine surgery (RR=2.85 (2.07-3.63), p=0.045) and scoliosis ≥10° (RR=6.33 (4.87-7.80), p=0.013). Conclusion Back pain, leg pain, and ODI showed significant improvement postoperatively. Improvement is maintained at two years. Prior spine surgery and scoliosis ≥ 10° may be relative contraindications to FLTD.