Navigated Transtubular Extraforaminal Decompression of the L5 Nerve Root at the Lumbosacral Junction: Clinical Data, Radiographic Features, and Outcome Analysis

Lumbar Decompression Using the Far-Lateral Approach: Patient-Reported Outcome is Associated With the Involved Vertebral Level and Coronal Segmental Angle

STUDY DESIGN

A single-centre retrospective study of prospectively collected data.

OBJECTIVE

Analyse factors associated with the patient-reported outcome after far lateral decompression surgery (FLDS) for lumbar nerve root compression using the far-lateral approach.

SUMMARY OF BACKGROUND DATA

To date, no studies have investigated the influence of vertebral level, coronal segmental Cobb angle, and the nature of the compressive tissue (hard or soft) on the patient-reported outcome following FLDS.

PATIENTS AND METHODS

Patients who had undergone FLDS between 2005 and 2020 were included. Coronal segmental angle (CSCA) was measured on preoperative, posteroanterior radiographs. The primary outcome measure was the core outcome measures index (COMI) score at two years' follow-up (2Y-FU). Patients who had undergone microsurgical decompression using a midline approach served as a comparator group.

RESULTS

There were 148 FLDS and 463 midline approach patients. In both groups, there was a significant improvement in the COMI score from preoperative to 2Y-FU ( P <0.0001), with greater improvement in patients treated at higher vertebral levels than in those treated at L5/S1 ( P =0.014). Baseline COMI, American Society of Anesthesiologists grade, body mass index, and low back pain as the "chief complaint" all had a significant association with the two-year COMI score. The nature of compressive tissue showed no association with the COMI score at 2Y-FU. In the FLDS group, there was a statistically significant correlation between the preoperative CSCA and the change in COMI score preoperatively to 2Y-FU ( P <0.001). The association was retained in the multiple regression analysis, controlling for confounders. A one-degree increase in CSCA was associated with a 0.35-point worse COMI score at 2Y-FU ( P =0.003).

CONCLUSION

Treatment of far lateral nerve root compression showed an overall good patient-reported outcome, but with less improvement with advanced CSCA. Modified approaches and techniques might be preferable for levels L5/S1.

Long-term follow-up results of surgically treated patients with foraminal and far lateral disc herniations

PURPOSE

Foraminal and far lateral disc herniations are rarer cause of nerve root compression. There are reports regarding the outcome, however long-term follow-up results of surgically treated patients are few. The purpose of this retrospective study is to analyze the clinical characteristics and long-term surgical outcomes of the foraminal and far lateral disc herniations.

MATERIALS AND METHODS

The 114 patients who underwent an operation for foraminal and far lateral disc herniaitions were reviewed. Visual analogue scale of back and leg pain, the ocurrence of motor deficit and sensory dysesthesia before and after operations were used to compare the results of early and long-term outcome.

RESULTS

A total of 114 telephone interviews were conducted. The mean follow up was 134 months. Complete relief of symptoms were reported by 77 patients (67.1%). The average VAS of radicular leg pain was 7.5 Post-operatively the average VAS of radicular pain decreased to 2.2. Preoperatively, 9 patients (7.6%) had motor deficit and 17 (14.4%) patients had sensory dysesthesia. Post-operatively 9 (100%) of the patients showed motor, and 12 (70.6%) of the patients showed sensory improvement. In 17 patients with hypoesthesia the complaints continued during 2 weeks to 6 months. They were given gabapentin as medical treatment, however 5 of these patients still have sensory dysesthesia. The outcome was: 67.1% excellent (77 patients), 26.3% good (30 patients), 6.1% fair (7 patients).

CONCLUSION

The far lateral approach is a minimally invasive and safe procedure with low complication rates.

Minimally Invasive Far-Lateral Microdiscectomy: A New Retractor for Far-Lateral Lumbar Disc Surgery

Background

To date, a number of approaches have been described for far-lateral disc surgery, including midline, paramedian, and intertransverse approaches. These approaches pose challenges for surgeons due to the difficulty in retraction caused by the anatomy of the foramen. We designed a retractor suitable for the three-dimensional anatomical structure of the foramen. In this study, we aimed to evaluate the surgical outcomes of the patients who were operated on using this retractor in our clinic.

Methods 

The retrospective study included patients who were operated on due to far-lateral disc herniation using the retractor designed in our clinic between February 2013 and December 2018.

Results 

The study included 11 (64.7%) women and 6 (35.3%) men, with a mean age of 56 years (range: 42-70 years). The mean operative time was 49 minutes (range: 40-70 minutes), the mean estimated blood loss was 42 mL (range: 25-60 mL), and the mean follow-up period was 22.6 months (range: 13-48 months). No complication occurred in any patient. A minimally invasive discectomy was performed via the paramedian approach in each patient. The patients were evaluated using the visual analog scale (VAS) for radicular pain, Oswestry Disability Index (ODI), 36-Item Short Form Survey (SF-36), and the modified MacNab criteria.

Conclusion 

The retractor developed in our study provided numerous benefits during the surgical procedure as it led to minimal blood loss and reduced operative times by avoiding bone resection in extraforaminal discs and requiring minimal bone resection in foraminal discs.

Narrative review of intraoperative imaging guidance for decompression-only surgery

Decompression of the spine is defined as removal of bony and soft tissue structures in order to provide space for the spinal cord and/or nerve roots. This definition, however, underscores the dangers and complexity of safely providing anatomical space for these neurologic structures. Complications such as neurologic injury, vascular injury, and durotomy can make these procedures hazardous for the patient and surgeon. Furthermore, inability to fully decompress the neural elements will result in continued symptoms for patients. Intraoperative image guidance can provide important anatomical landmarks to perform these decompressive surgeries safely and efficiently. In particular, performing decompression surgery utilizing minimally invasive techniques with image guidance can allow for the least amount of muscle/soft tissue trauma possible. Within our article we outline research on the forefront of use of intra-operative imaging guidance for spine surgery and implications for decompression surgery. We also outline a case from the senior author to illustrate an example of image-guided spine decompression for cervical radiculopathy. Future technology, such as augmented reality and robotics, is also discussed in the context of image guided decompression. The authors hope this article shows surgeons that use of image guidance in specific clinical situations can allow for better/safer spinal decompression procedures.

A Modified Percutaneous Endoscopic Technique to Remove Extraforaminal Disk Herniation at the L5-S1 Segment

OBJECTIVE

To introduce a modified percutaneous endoscopic lumbar diskectomy (PELD) technique to remove extraforaminal disk herniation at the L5-S1 segment, including the technical essentials and preliminary results.

METHODS

The geometric parameters of the transverse process, facet joint, and sacrum (TFS) space based on imaging examination were measured in 100 common patients. The technical essentials, including working cannula placement and disk removal involved in the technique, were described. Ten cases (7 men and 3 women) with extraforaminal disk herniation at L5-S1 were surgically treated with the PELD technique through the TFS space from June 2015 to March 2017.

RESULTS

The maximum diameter of the TFS space varied from 2.73 to 11.81 mm (6.84 ± 2.01 mm) on the left and 3.00 to 10.47 mm (7.02 ± 2.05 mm) on the right. The distance of possible skin entry points from midline varied from 33.28 to 84.18 mm, and the distance of external iliac vessels to skin varied from 70.05 to 119.14 mm. All 10 patients who underwent the modified PELD technique were back to previous activities in 1 month. Visual analog scale (VAS) or Oswestry Disability Index (ODI) scores reduced to 2.5 ± 2.0 or 25.4 ± 10.8 from 7.5 ± 1.3 or 75.2 ± 13.3, respectively, 1 day after operation. At 30 days after the operation, the VAS score was 1.0 ± 0.6 and ODI score was 10.2 ± 3.2. No neurologic deficit or surgical site infection occurred.

CONCLUSIONS

We introduced a modified PELD technique to remove extraforaminal disk herniation at the L5-S1 segment. This technique was less invasive, effective, and safe. We also summarized a detailed protocol to identify and remove the herniated disk for nerve protection.