Comparison of Two Minimally Invasive Techniques with Endoscopy and Microscopy for Extraforaminal Disc Herniations

Minimally Invasive Far Lateral Lumbar Discectomy With Modified Technique: Symptomatic Relief and Intersegmental Stability Study

OBJECTIVE

To evaluate the use of a modified minimally invasive surgery (MIS) technique for far lateral lumbar discectomy (FLDH) that minimizes the degree of bony drilling required for nerve root decompression, increasing postoperative pain reduction rate with reduced risk of iatrogenic spinal instability.

SUMMARY OF BACKGROUND DATA

FLDH accounts for approximately 10% of all lumbar disc herniations and is increasingly recognized in the era of advanced imaging techniques. These disc herniations typically result in extra-foraminal nerve root compression. Minimally invasive spine techniques are increasingly performed with various degrees of foraminal and facet removal to decompress the affected nerve root.

METHODS

The study design involves a single institutional, retrospective cohort technical review. The review was completed of all patients undergoing MIS far lateral lumbar discectomy between 2010 and 2020. Cross-sectional, summary statistics were calculated for all variables. Counts and percentages were recorded for categorical variables and mean and standard deviations were calculated for continuous variables.

RESULTS

A total of 48 patients underwent MIS far lateral lumbar discectomies (FLLD) from 2010 to 2020. The mean age was 63 ± 11.5 years (60.4% males), the mean BMI was 28.5 ± 5.5, and 20.8% smokers. The most common presenting complaint was both low back and radicular pain (79.2%) with 8.3% of patients suffering from motor weakness preoperatively. The mean follow-up time was 4.3 ± 2.7. The mean length of stay was 1.3 ± 1.4 days with 77.1% of patients discharged postoperative day one. Forty-three patients (93.5%) had improvement in their symptoms. Twenty-seven (58.7%) had complete resolution in 2.6 months on average. Six patients (13%) had immediate symptom resolution postoperatively.

CONCLUSIONS

Our modified technique for FLLD allows MIS access to the extra-foraminal site of nerve root compression without the need for bony drilling. This minimizes postoperative pain and reduces the risk of iatrogenic spinal instability without sacrificing symptom resolution.

Full-endoscopic lumbar discectomy via lateral superior articular process approach for treating far lateral lumbar disc herniation: a retrospective study and technical note

PURPOSE

This study aims to evaluate the efficacy and safety of the full-endoscopic lumbar discectomy (FELD) via lateral superior articular process (LSAP) approach and full-endoscopic transforaminal discectomy (FETD) for treating far lateral lumbar disk herniation (FFLDH).

METHODS

From January 2020 to June 2022, patients who were diagnosed as FLLDH underwent the FELD via LSAP approach or FETD. The operation time, estimated blood loss, length of hospital stays, and complications were recorded. The visual analog scale (VAS) for back pain, VAS for leg pain, and the Oswestry Disability Index (ODI) scores was measured during preoperative and postoperative follow-up.

RESULTS

Thirty-two patients were enrolled in this study, of which 12 patients were treated with the FELD via LSAP approach (LSAP-FELD group) and 20 patients underwent FETD (FETD group). The LSAP-FELD group exhibited significantly shorter operation times and hospital stays compared to the FETD group, while no statistically significant differences were observed in intraoperative blood loss and complication rates. There were no significant differences in the VAS for back pain, the VAS for leg pain, and the ODI score between the two groups preoperatively and three days, three months, and the last follow-up postoperatively.

CONCLUSIONS

Both the FELD via LSAP approach and FETD have demonstrated favourable clinical efficacy in the treatment of FLLDH. Notably, the FELD via LSAP approach shows the advantages of shorter operation time and hospital stays.

Surgical Treatment of Far Lateral Lumbar Disc Herniation: Outcomes of the Safe and Simple Midline Approach

Objective

Surgery for far lateral lumbar disc herniation (FLLDH) hernias is different than surgery for median and paramedian disc hernias. Our study offers a minimally invasive surgical technic for far lateral disc herniations.

Methods

The results of the midline surgical approach in 18 patients diagnosed with FLLDH were evaluated retrospectively.

Results

A total of 18 patients (7 females, 11 males), with a mean age of 57.9±9.4 years (range: 35-71 years), were included in the analyses. Three patients (16.7%) had lesions at the left L3-L4 level, six patients (33.3%) on the left L4-L5 level, five patients (27.8%) on the right L3-L4 level, and four patients (22.2%) on the right L4-L5 level. All patients had low back and leg pain. These complaints completely regressed after surgery.

Conclusion

This study presents a review of a consecutive series of patients who underwent minimally invasive surgery for FLLDH using a midline approach.

Magnetic Resonance Neurography for Evaluation of Dorsal Root Ganglion Morphology

BACKGROUND

In this study, the morphologic characteristics and anatomic position of the dorsal root ganglion (DRG) were measured and analyzed in healthy people using magnetic resonance neurography (MRN), which provided an anatomical reference for minimally invasive spinal surgery.

METHODS

From January 2018 to December 2019, 20 healthy adult volunteers (10 male and 10 female volunteers between 20 and 65 years old) were scanned and imaged by 3.0 T magnetic resonance imaging combined with neuroimaging technology. Here, the position of the DRG was located, and the shape and size of the DRG, as well as its distance to the upper pedicle, were measured.

RESULTS

All volunteers provided satisfactory MRN scans of the L1-S1 lumbar DRG. According to the spatial position of the DRG, the morphology of the DRG can be divided into the intervertebral foramen type (81.01%), intraspinal type (16.01%), extraforaminal type (0.8%), and mixed type (2.0%).

CONCLUSIONS

The intervertebral foramen type and Intraspinal type were observed to be the main distribution forms of lumbar DRG. Due to the downward movement of lumbar segments, the position of the DRG was noted to gradually move to the spinal canal while its volume gradually increased. In addition, the distance from the upper pedicle was found to decrease gradually. MRN imaging can clearly show the shape, location, and adjacent relationship of the DRG, providing effective imaging guidance for the minimally invasive lumbar techniques.