Intra-operative localisation of thoracic spine level: a simple "'K'-wire in pedicle" technique

Preoperative coil localization for spinal surgery is accurate, safe and effective: a single-centre initial experience

OBJECTIVE AND STUDY DESIGN

This is a retrospective, descriptive study of consecutive patients undergoing novel preoperative pushable coil localization for spinal surgery, in order to evaluate its feasibility, safety and accuracy.

METHODS

Consecutive patients who underwent pre-operative coil marking for spinal surgery at our institution from May 2018 to July 2021 were included. Data were collected for coil placement, accuracy, complications and fluoroscopy usage. Patient demographic and relevant perioperative and procedural data were also collected.

RESULTS

A total of 34 patients were identified of which 32 (94%) had complete data and imaging at last clinical follow up, with a mean duration of 13.9 months. There were no incorrect level surgeries performed. There were no coil-related complications found in our cohort.

CONCLUSIONS

Preoperative coil placement is an accurate, safe and well-tolerated method for level localization in spinal surgeries.

The utility of internal spinal marking for intraoperative localisation: A systematic review

BACKGROUND

Incorrect level spinal surgery is an avoidable complication, with significant ramifications. Several pre-operative spinal marking techniques have been described to aid intraoperative localisation.

METHODS

A systematic search of Ovid MEDLINE, and EMBASE was performed from inception to July 2022. All publications describing cases of internal spinal marking were included for further analysis. 22 articles describing 503 patients satisfied our eligibility criteria.

RESULTS

A number of localisation techniques, including endovascular coiling (n = 16), fiducials (n = 177), dye (n = 109), needle/fixed wire (n = 199), cement (n = 4), and gadolinium tubes (n = 1) were described. The highest rates of technical success were observed with endovascular coiling, fiducials, cement and dye (100 %), and complication rates were lowest with endovascular coiling, fiducials and cement (0 %).

CONCLUSIONS

Overall, internal spinal marking was effective and safe. When considering practicality and efficacy, fiducial marking appears the optimal technique, as it can be performed in the outpatient setting under local anaesthesia. This review demonstrates the need for more targeted investigation into localisation methods in spinal surgery.

A modified vertebroplasty technique for intraoperative thoracic spine localisation: a technical report

The aim is to illustrate the modified vertebroplasty technique as a fixed marker for intraoperative thoracic spine localisation. Open and minimally invasive surgery in the thoracic spine has been correlated with a disproportionately high rate of wrong-level spinal surgery in pathologies where a focal deformity or fracture is absent. Spinal markers have evolved with time, and vertebroplasty as a spinal marker was initially described in 2008. A significant disadvantage is that the cement in the vertebral body and pedicle may preclude a more extensive osteotomy or subsequent instrumentation at the level of interest. We demonstrate the modified vertebroplasty technique, which introduces percutaneous polymethylmethacrylate cement two levels below the thoracic disc herniation on the contralateral side to the surgical approach using standard vertebroplasty methods. The vertebroplasty was performed as an outpatient procedure, and the radiopaque cement was instantaneously located on intraoperative fluoroscopy, identifying the correct level above. The modified vertebroplasty technique is a quick, safe and accurate method of thoracic spine localisation, facilitating the room required for the bony exposure and instrumentation if needed.

Novel 2D long film imaging utility to avoid wrong level spinal surgery

Wrong-level spinal surgery (WLSS) can lead to increased morbidity, cost, and worse long-term outcomes. Current intraoperative localization methods rely on counting spinal levels from a known reference location using fluoroscopy. Miscounting from a reference is an intraoperative error that leads to WLSS, especially for those with anatomical variations. The problem is exacerbated when fluoroscopy is not able to produce images with the clarity needed to confidently count levels, a prevalent issue for obese patients.

A new feature called the “2D Long Film'' is available for the Medtronic (Minneapolis, MN) O-arm Surgical Imaging System. Using this novel technology and standard fluoroscopy, this study reports the imaging of two obese adult female patients with a body mass index of 36.9 and 42.0 undergoing transforaminal thoracic interbody fusion. Fluoroscopy images of obese patients are difficult to capture for two reasons: increased scatter and restricted field of view. This report demonstrates that 2D Long Film can improve both these issues for obese patients in need of thoracic localization. The 2D Long Film captures existing instrumentation, localization needles, and the vertebral levels in a clear single image.

We display the differences between standard fluoroscopy and the 2D Long Film for thoracic level localization, demonstrating a potential new standard of care and better visualization, leading to a less challenging vertebrae localization process, potentially mitigating WLSS risk. The quality of this new 2D Long Film feature could also reduce time in the operating room and the necessity of other visualization methods.

Transforaminal Thoracic Interbody Fusion for Thoracic Disc Prolapse: Surgicoradiological Analysis of 18 Cases

STUDY DESIGN

Retrospective observational study.

OBJECTIVES

Thoracic disc prolapse (TDP) surgeries have reported complications ranging from paraplegia to approach related complications. This study is to present a series of TDP patients surgically treated with transforaminal thoracic interbody fusion (TTIF). Emphasis on surgical technique and strategies to avoid complications are analyzed.

METHODS

Eighteen patients with TDP were included. Imagings were analyzed for end-plate changes and calcification. Type of disc prolapse (central/para-central) and percentage of canal occupancy were noted. Objective outcome was quantified with Visual Analogue Scale (VAS), modified Nurick's grade, and ASIA (American Spinal Injury Association) score. All complications were noted.

RESULTS

Eighteen patients (average age 43.65 years) having total 22 levels operated, that included double level (n = 2) and missed level (n = 2) are reported. All patients had myelopathy. Calcification of disc (n = 13), central disc prolapses (n = 9), para-central (n = 11) and more than 50% canal occupancy (n = 8) were noted. VAS back pain, modified Nurick's grade and ASIA grade improved significantly in all patients. One patient had postoperative transient deficit. The functional score achieved its maximum at 1 year follow-up and remained static at final follow-up of 65.05 months. Union was achieved in all patients.

CONCLUSIONS

The most important factor for outcome in TDP is the technical aspect of avoiding cord manhandling and avoiding wrong level surgeries. TTIF is not devoid of complications but can give good results to posterior approach trained surgeons.

Surgical treatment of thoracic disc herniation: an overview

BACKGROUND

Surgical treatment of thoracic disc herniation (TDH) is technically demanding due to its proximity to the spinal cord.

METHODS

Literature review.

RESULTS

Symptomatic TDH is a rare condition predominantly localized between T8 and L1. Surgical indications include intractable back or radicular pain, neurological deficits, and myelopathy signs. Giant calcified TDH (> 40% spinal canal occupation) are frequently associated with myelopathy, intradural extension, and post-operative complications. Careful pre-operative planning helps reduce the risk of complications. Pre-operative CT and MRI identify the hernia's location and size, calcifications, and intradural extension. The approach must provide adequate dural sac visualization with minimal manipulation of the cord. Non-anterior approaches are favoured if they provide at least equal exposure than anterior approach owing to higher risk of pulmonary morbidity associated with anterior approach. A transthoracic approach is recommended for central calcified herniated discs. A posterolateral approach is often suitable for non-calcified lateralized TDH. Thoracoscopic approaches are less invasive but have a substantial learning curve. Retropleural mini-thoracotomy is an acceptable alternative. Pre-operative identification of the pathological level is confirmed by intra-operative level check. Intra-operative cord monitoring is preferable but warrant further studies. Magnification and adequate lightening of the surgical field are paramount (microscope, thoracoscopy). Intra-operative CT scan with navigation is becoming increasingly popular since it provides real-time control on the decompression. Indications of fusion consist of pre-operative back pain, Scheuermann's disease, multilevel resection, wide vertebral body resection (> 50%), and herniation at thoracolumbar junction. Neurological deterioration, dural tear, and subarachnoid-pleural fistula are the most severe complications.

CONCLUSION

Further improvements are still warranted in thoracic spine surgery despite the advent of minimally invasive techniques. Intra-operative CT scan will probably enhance the safety of the TDH surgery.

Thoracic disc herniation: Surgical treatment

Thoracic disc herniation is rare and mainly occurs between T8 and L1. The herniation is calcified in 40% of cases and is labeled as giant when it occupies more than 40% of the spinal canal. A surgical procedure is indicated when the patient has severe back pain, stubborn intercostal neuralgia or neurological deficits. Selection of the surgical approach is essential. Mid-line calcified hernias are approached from a transthoracic incision, while lateralized soft hernias can be approached from a posterolateral incision. The complication rate for transthoracic approaches is higher than that of posterolateral approaches; however, the former are performed in more complex herniation cases. The thoracoscopic approach is less invasive but has a lengthy learning curve. Retropleural mini-thoracotomy is a potential compromise solution. Fusion is recommended in cases of multilevel herniation, herniation in the context of Scheuermann's disease, when more than 50% bone is resected from the vertebral body, in patients with preoperative back pain or herniation at the thoracolumbar junction. Along with complications specific to the surgical approach, the surgical risks are neurological worsening, dural breach and subarachnoid-pleural fistulas. Giant calcified herniated discs are the largest contributor to myelopathy, intradural extension and postoperative complications. Some of the technical means that can be used to prevent complications are explored, along with how to address these complications.

Surgical treatment for thoracic disc herniation: an update

STUDY DESIGN

Retrospective review of the literature.

OBJECTIVE

To update recent trends in the surgical treatment for thoracic disc herniation (TDH).

SUMMARY OF BACKGROUND DATA

TDH is rare; however, it is usually accompanied by myelopathy and is indicated for surgical treatment. A variety of surgical approaches have been described to reach these anatomically challenging lesions.

METHODS

Review of the literature.

RESULTS

Recently, minimally invasive techniques for TDH have gained popularity. These include thoracoscopic and mini-open anterolateral retropleural approaches, as well as microscopic and endoscopic surgery. In addition, this article updates important aspects of surgical treatment for TDH such as definition of surgical level, treatment of calcified and/or giant disc, multilevel lesions, and fusion requirements.

CONCLUSION

Definition of surgical level is imperative in the surgical treatment for TDH. Outcomes of minimum invasive surgery are satisfactory. Type of disc herniation and biomechanical stability are the important factors for surgical planning.

Calcified giant thoracic disc herniations: considerations and treatment strategies

INTRODUCTION

Giant herniated thoracic discs (GHTD) remain a surgical challenge. When combined with calcification, these discs require altered surgical strategies and have only been infrequently described. Our objective was to describe our surgical approaches in the management of calcified GHTD.

METHODS

This was a retrospective cohort study of all patients with calcified GHTD operated between 2004 and 2012. Data were collected from review of patients' notes and radiographs and included basic demographic and radiological data, clinical presentation and outcome, operative procedure and complications.

RESULTS

During the study period, there were 13 patients with calcified GHTD, including 6 males and 7 females (mean age 55 years, range 31-83 years). The average canal encroachment was 62% (range 40-90%); mean follow-up 37 months (12-98). All patients were treated with anterior thoracotomy, varying degrees of vertebral resection, removal of calcified disc and with or without reconstruction. The average time for surgery was 344 min (range 212-601 min) and estimated blood loss 1,230 ml (range 350-3,000 ml). Post-operatively, 8 patients improved by 1 Frankel grade (62%), 2 improved by 2 grades (15%) and 3 did not change their grade (23%). The complication rate was 4/13 (31%; 3 patients with durotomies (2 incidental, 1 intentional) and 1 with recurrence).

DISCUSSION

Calcified GHTD remain a surgical challenge. Anterior decompression through a thoracotomy approach, and varying degrees of vertebral resection with or without reconstruction allowed us to safely remove the calcified fragment. All patients remained the same (23%) or improved by at least 1 grade (77%) neurologically, without radiographic failure at final follow-up.

Marking wire placement for improved accuracy in thoracic spinal surgery

OBJECTIVE

To present an innovative approach that does not rely on intraoperative X-ray imaging for identifying thoracic target levels and critically appraise its value in reducing the risk of wrong-level surgery and radiation exposure.

METHODS

96 patients admitted for surgery of the thoracic spine were prospectively enrolled, undergoing a total of 99 marking wire placements. Preoperatively a flexible marking wire derived from breast cancer surgery was inserted with computed tomography (CT) guidance at the site of interest--the wire was then used as an intraoperative guidance tool.

RESULTS

Wire placement was considered successful in 96 cases (97%). Most common pathologies were tumors (62.5%) and degenerative disorders (16.7%). Effective doses from CT imaging were significantly higher for wire placements in the upper third of the thoracic spine compared to the lower two thirds (p = 0.015). Radiation exposure to operating room personnel could be reduced by more than 90% in all non-instrumented cases. No adverse reactions were observed, one patient (1.04%) underwent surgical revision due to an epifascial empyema. No wires had to be removed due to lack of patient compliance or infection.

CONCLUSIONS

This is a safe and practical approach to identify the level of interest in thoracic spinal surgery employing a marking wire. Its application merits consideration in any spinal case where X-ray localization could prove unsafe, particularly in cases lacking bony pathologies such as intradural tumors.