Percutaneous endoscopic thoracic discectomy via posterolateral approach: A case report of migrated thoracic disc herniation

Transforaminal endoscopic thoracic discectomy: surgical technique

The major challenge inherent to the surgical treatment of thoracic disc herniations is that the disc herniation is often ventral to the spinal cord. Posterior approaches are difficult and dangerous due to the morbidity associated with retraction of the thoracic spinal cord. A ventral approach is not feasible due to the thoracic viscera. A lateral transcavitary approach is the standard for treating ventral thoracic disc pathology but is also quite morbid. Transforaminal endoscopic spine surgery has emerged as a minimally invasive technique for treating thoracic disc pathology and it can be performed in the outpatient setting even with the patient awake. Advances in endoscopic camera technologies as well as the availability of specialty instruments that can be used down a working channel endoscope has now made a myriad of spine pathologies accessible to the minimally invasive spine surgeon. The transforaminal approach and the angled endoscopic camera are an ideal combination for creating a technical advantage to accessing thoracic disc pathology in a minimally invasive fashion. The principal challenges to the approach are needle targeting and understanding the endoscopic visual anatomy. Many surgeons interested in pursuing this technique are often deterred by the burden of the cost and time it takes to become adept and performing the technique. Detailed here are the authors' step-by-step technique and illustrative video that demonstrate transforaminal endoscopic thoracic discectomy (TETD).

A modified percutaneous transforaminal endoscopic surgery for central calcified thoracic disc herniation at the T11/T12 level using foraminoplasty and decompression: A case report

Background

Thoracic disc herniation (TDH) is uncommon. Central calcified TDH (CCTDH) is even rare. Traditional open surgery was considered a gold standard to treat CCTDH, but it was accompanied by a high risk of complications. Recently, a technique called percutaneous transforaminal endoscopic decompression (PTED) was adopted to treat TDH. Gu et al. designed a simplified PTED technique and named it percutaneous transforaminal endoscopic surgery (PTES) to treat various types of lumbar disc herniation; it offered the advantages of simple orientation, easy puncture, reduced steps, and little x-ray exposure. However, PTES to treat CCTDH has not been reported in the literature.

Methods

Here, we describe the case of a patient with CCTDH treated with a modified PTES through the unilateral posterolateral approach under local anesthesia and conscious sedation by using a flexible power diamond drill. First, we report that the patient was treated with PTES with later-stage endoscopic foraminoplasty, with an inside-out technique employed at the initial endoscopic decompression stage.

Results

A 50-year-old male with progressive gait disturbance and bilateral leg rigidity with paresis and numbness was diagnosed with CCTDH at the T11/T12 level on MRI and CT examinations. A modified PTES was performed on November 22, 2019. The total mJOA (modified Japanese Orthopedic Association) score preoperatively was 12. The method of the determination of incision and the soft tissue trajectory establishment process were the same as those in the original PTES technique. The foraminoplasty process was divided into initial fluoroscopic and final endoscopic stages. At the fluoroscopic stage, the hand trephine's saw teeth were just rotated into the lateral portion of the ventral bone from the superior articular process (SAP) to seize the SAP firmly, while at the endoscopic stage, in order to remove the ventral bone from the SAP safely under direct endoscopic visualization, adequate foramen enlargement was achieved without causing any risk of damage to the neural structures in the spinal canal. During the endoscopic decompression process, the soft disc fragments ventral to the calcified shell were undermined to form a cavity using an inside-out technique. Then, a flexible endoscopic diamond burr was introduced to degrade the calcified shell, and a curved dissector or a flexible radiofrequency probe was used to dissect the thin bony shell from the dural sac. Eventually, the shell was fractured within the cavity piece by piece to remove the whole CCTDH and achieve adequate dural sac decompression, resulting in minimal blood loss and no complications. The symptoms were gradually alleviated and the patient almost completely recovered at the 3-month follow-up, with no symptom recurrence found at the 2-year follow-up. The mJOA score improved to 17 at the 3-month follow-up and to 18 at the 2-year follow-up compared with 12 points preoperatively.

Conclusions

A modified PTES may be an alternative minimally invasive technique for the treatment of CCTDH and provide similar or better outcomes over traditional open surgery. However, this procedure requires good endoscopic experience on the part of the surgeon and is beset with technical challenges and therefore should be performed with utmost care.

Costotransversectomy in the Surgical Treatment of Mediolateral Thoracic Disk Herniations: Long-Term Results and Recent Minimally Invasive Technical Adjuncts

Thoracic herniated disks are relatively rare. They account for approximately 2% of all intervertebral herniated disks in large series. Traditional surgery via laminectomy has frequently yielded disappointing results, although the recent literature reports that anterior calcified thoracic herniation was successfully treated with this approach. This issue has encouraged a search for alternatives, such as anterolateral, lateral, and posterolateral approaches to the thoracic spine. From January 2009 to December 2019, we selected 66 patients harboring a symptomatic median-paramedian herniated disk at the level of the thoracic spine, treated at the authors' institutions. The present experience would give further support to the use of costotrasversectomy, along with its "mini-invasive" modifications, as a suitable and safe approach for thoracic disk disease. Although we must admit that endoscopy is likely to become the gold standard of surgical method in the future and that the anterior approach with mini-toracotomy without rib removal will become popular, the future scenario could certainly reserve an important place for the approach we have used in the surgical management of this challenging spinal pathology, mainly because of the approach's versatility and short learning curve.

Comparative Analysis of Transforaminal Endoscopic Thoracic Discectomy and Microscopic Discectomy for Symptomatic Thoracic Disc Herniation

OBJECTIVE

To evaluate the clinical outcomes of transforaminal endoscopic thoracic discectomy (TETD) and microscopic discectomy (MD) for the treatment of symptomatic thoracic disc herniation (TDH).

METHODS

Seventy-seven patients (mean, 55.9 years; follow-up, 11.2 months) with symptomatic TDH were retrospectively reviewed (39 TETD and 38 MD). Radiological factors and perioperative outcomes were reviewed. Visual analogue scale (VAS), Oswestry Disability Index (ODI), and American Spinal Injury Association impairment scale were used to evaluate clinical and functional outcomes. Patient satisfaction was evaluated using modified MacNab criteria.

RESULTS

The levels of surgery and the location of hernia were evenly distributed in the both groups. The operative time (70.6 minutes vs. 175.7 minutes), estimated blood loss (3.8 mL vs. 357.4 mL), and length of hospital stay (7.0 days vs. 13.0 days) were significantly different between the TETD and MD groups (p < 0.05). VAS scores for dorsal back pain and ODI scores were significantly improved in both groups (p < 0.05). Patients who underwent TETD tended to be more satisfied with the outcome in terms of the modified MacNab criteria (89.7% vs. 73.0%, p = 0.059). Two patients in the MD group underwent revision surgery, whereas one patient in the TETD group underwent MD because of incomplete decompression.

CONCLUSION

TETD for the symptomatic TDH is a feasible and safe procedure that could be used for a wider range of surgical levels with a shorter operative time and hospital stay and less blood loss. While achieving similar outcomes, TETD achieved better patient satisfaction because of the use of local anesthesia and its minimal invasiveness.

Phase I 270° single-incision percutaneous spinal endoscopy for decompression treatment of thoracic spinal stenosis

This study aimed to explore the feasibility of Phase I percutaneous spinal endoscopy with a 270° single incision in the ventral and dorsal dura mater for decompression treatment of thoracic spinal stenosis (TSS). Phase I percutaneous spinal endoscopy with a two-path (posterior and posterolateral approaches) single incision with a 270° decompression was performed in four cases of TSS with compression in the ventral and dorsal dura mater. The affected intervertebral space was located during the surgery, and the ossified ligamentum flavum in the ventral and dorsal dura mater was removed via laminectomy, which formed a decompression space in the thoracic cord. Next, posterolateral transforaminal expansion and plasty were performed to remove the ventral intervertebral disk. The visual analogue scale (VAS) score, thoracic spinal cord function score of the Japanese Orthopaedic Association (JOA) (11-point method), and Oswestry Disability Index (ODI) scores were used to evaluate the clinical efficacy. No dura mater or thoracic nerve injury occurred during the surgery. The symptoms of weakness in the lower extremities improved after the surgery. The postoperative magnetic resonance imaging and computed tomography examinations showed compression removal and dura mater bulging. The postoperative VAS, JOA, and ODI scores improved compared with the preoperative scores. Two surgical trajectories, posterior and posterolateral approaches, were established by a single incision using thoracic spinal canal decompression with Phase I 270° single-incision percutaneous spinal endoscopy. The posterior approach was performed mainly by translaminar unilateral fenestration and bilateral decompression in the ventral and dorsal dura mater, whereas the posterolateral approach was performed by decompression in the ventral dura mater to the midline of the vertebrae. This surgical method could be applied as a safe and feasible minimally invasive treatment for TSS with compression on both the ventral and dorsal dura mater.

A Review of Endoscopic Spine Surgery: Decompression for Radiculopathy

PURPOSE OF REVIEW

With this manuscript the authors sought to write a succinct review of the origins, as well as the latest advancements in endoscopic spine surgery to serve as a reference frame for physicians looking to learn this approach.

RECENT FINDINGS

At its infancy, the indications for posterolateral and transforaminal endoscopic decompression remained narrow, which prevented the procedure from gaining rapid traction during those days. However, more recently the tides have turned and an increasing number of surgeons are starting to adopt this technique given all its advantages. With the advent of higher quality camera systems and instruments, indications to use a minimally invasive option have gotten significantly broader. The most basic indication for the use of this technology is a soft disc herniation causing compromise of a neural structure that has failed to be managed successfully with non-surgical therapies. The use of endoscopic techniques provides significant advantages to patient outcomes and patient recovery. Endoscopic procedures should not be used as a blanket approach to nerve root decompression, as they certainly have limitations. Most contraindications to this procedure are relative and serve mostly as points to consider when selecting the methods to address neural compression. As these techniques become more widely accepted, we expect its reach and indications to continue to broaden and diversify. The full integration of navigation technologies will likely leapfrog this procedure into the mainstream use.

Full-Endoscopic Transforaminal Ventral Decompression for Symptomatic Thoracic Disc Herniation with or without Calcification: Technical Notes and Case Series

Background

Symptomatic thoracic disc herniation is a challenge in spinal surgery, especially for cases with calcification. Traditional open operation has a high complication rate. The authors introduced a modified full-endoscopic transforaminal ventral decompression technique in this study and evaluated its imaging and clinical outcomes.

Materials and Methods

Eleven patients with symptomatic thoracic disc herniation who underwent full-endoscopic transforaminal ventral decompression in a single medical center were enrolled. The surgical technique was performed as described in detail. Dilator sliding punching, endoscope-monitored foraminoplasty, and base cutting through the “safe triangle zone” are the key points of the technique. Clinical outcomes were assessed by the modified Japanese Orthopedic Association (mJOA) score for neurological improvement and the visual analogy score (VAS) for thoracic and leg pain. The operation time, hospital stay, and complications were also analyzed.

Results

Postoperative magnetic resonance imaging (MRI) revealed good decompression of the spinal cord. The mJOA improved from 7.4 (range: 5–10) to 10.2 (range: 9–11). Axial thoracic pain improved in 8 of 9 patients. Leg pain and thoracic radicular pain improved in all patients. No complications were observed. The average operation time was 136 minutes (range: 70–180 minutes). The average length of hospital stay was 5.3 days (range: 2–8 days).

Conclusion

Minimally invasive full-endoscopic transforaminal ventral decompression for the treatment of symptomatic thoracic disc herniation with or without calcification is feasible and may be another option for this challenging spine disease.

Full endoscopic surgery for thoracic pathology: an assessment of supportive evidence

In the last five years, surgeons have applied endoscopic transforaminal surgical techniques mastered in the lumbar spine to the treatment of thoracic pathology.

The aim of this systematic review was to collate the available literature to determine the place and efficacy of full endoscopic approaches used in the treatment of thoracic disc prolapse and stenosis.

An electronic literature search of PubMed, Embase, the Cochrane database and Google Scholar was performed as suggested by the Preferred Reporting Items for Systematic Review and Meta-analysis statements. Included were any full-text articles referring to full endoscopic thoracic surgical procedures in any language.

We identified 17 patient series, one cohort study and 13 case reports with single or of up to three patients.

Although the majority included disc pathology, 11 papers related cord compression in a proportion of cases to ossification of the ligamentum flavum or posterior longitudinal ligament. Two studies described the treatment of discitis and one reported the use of endoscopy for tumour resection.

Where reported, excellent or good outcomes were achieved for full endoscopic procedures in a mean of 81% of patients (range 46–100%) with a complication rate of 8% (range 0–15%), comparing favourably with rates reported after open discectomy (anterior, posterolateral and thoracoscopic) or by endoscopic tubular assisted approaches. Twenty-one of the 31 author groups reported use of local anaesthesia plus sedation rather than general anaesthesia, providing ‘self-neuromonitoring’ by allowing patients to respond to cord and/or nerve stimuli.

Cite this article: EFORT Open Rev 2021;6:50-60. DOI: 10.1302/2058-5241.6.200080

A Historical Review of Endoscopic Spinal Discectomy

As an essential component of minimally invasive spine surgery, endoscopic spine surgery (ESS) has continuously evolved and has been accepted as a practical procedure by the worldwide spine community. Especially for lumbar disc herniation (LDH), the percutaneous endoscopic or full-endoscopic discectomy technique has been scientifically proven through randomized controlled trials and meta-analyses to be a good alternative to open discectomy. The initial concept of endoscopic spine discectomy was concerned with indirect disc decompression using various instruments such as blind forceps, a nucleotome, laser, radiofrequency coblation, and some chemical agents. The main surgical field has been shifted from the intradiscal space to the epidural space. Precise and selective discectomy for extruded LDH in the epidural space under high-quality endoscopic visualization is now feasible. Furthermore, the medical applications of ESS is broadening to include spinal stenosis, segmental instability, infection, and even intradural lesions. In this review article, I describe the history of endoscopic spine discectomy and decompression techniques, as well as evolution of the paradigm. This history may help indicate the future of practical ESS.