Preoperative Fiducial Marker Placement in the Thoracic Spine: A Technical Report

Minimal Invasive Pre-Op CT-Guided Gold-Fiducials in Local Anesthesia for Easy Level Localization in Thoracic Spine Surgery

Background: The accurate identification of intraoperative levels is of paramount importance in spinal surgery, particularly in cases of obesity or anatomical anomalies affecting the thoracic spine. The aim of this work was to clarify whether the preoperative percutaneous placement of fiducial markers under local anesthesia only, with minimal discomfort to the patient, can be performed safely and efficiently. Methods: Patients treated at our institution between June 2019 and June 2020 for thoracic intraspinal lesions with preoperative percutaneous gold fiducial placement were analyzed. A total of 10 patients underwent CT-guided gold fiducial placement 2-48 h prior to surgery on an outpatient or inpatient basis. Patient characteristics, CT intervention time, and perioperative complications were recorded. Results: In all cases, the gold markers were placed under local anesthesia alone and were easily visualized intraoperatively with fluoroscopy. There was no preoperative dislocation or malposition. The procedure was performed without X-ray exposure to the neuroradiology interventionalist. The average CT intervention time from the planning scout to the final control time was 14.3 min. The percentage of anatomical norm variants in our observation group was high, as 2 of the 10 patients had lumbarization of the first sacral vertebra, resulting in a six-link lumbar spine. Conclusions: Preoperative CT-guided transcutaneous submuscular placement of gold markers under local anesthesia is a practical and safe method for rapid and accurate intraoperative level determination in thoracic spine surgery in a time-saving minimally invasive manner. The virtually painless procedure can be performed either preoperatively on an outpatient basis or as an inpatient procedure.

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.

Oblique radiograph with methylene blue marking: A reliable technique for upper thoracic level localization

Purpose

Traditionally, plain radiographs are used in intraoperative spinal level localization (SLL), whereas counting vertebrae is often hampered by shoulders and scapulae in lateral views, thus increasing the potential for wrong-level surgery. To improve the localization accuracy, this study evaluated the safety and feasibility of oblique radiographs with methylene blue markings for SLL and explored the optimal angle and height of oblique radiographs.

Methods

The clinical data of 33 patients with upper thoracic spine lesions who were operated on in our hospital from January 2021 to April 2022 were retrospectively analyzed. Oblique radiographs with methylene blue markings were used for intraoperative SLL.

Results

A total of 33 patients were included in this study. The average BMI was 24.3 ± 0.7 kg/m². The ipsilateral lamina structures were clearly shown in all cases. The median radiographing times of all the patients was 3, and the median radiographing duration was 2 min and 25 s. The average angle of oblique radiographs was 55.1 ± 3.8°, and the average distance from the skin to the root of the spinous process was 4.9 ± 1.2 cm.

Conclusions

Using oblique radiographs with methylene blue markings, not only the bone structure of an upper thoracic spine can be revealed clearly, but also the positioning deviation of traditional needle localization can be avoided. The lesion segment can be precisely located by this technology during surgery. Our angle of oblique radiographs and height determination method can be used to reduce the radiation exposure and shorten the operation time.

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.

Wrong-Level Spine Surgery: Introduction of a Protocol for Avoidance of This Complication

Wrong-level spine surgery, in which an operation is performed at a vertebral level different from the intended one, is a rare but serious complication with wide-ranging medical and legal effects. Although many protocols have been developed to prevent such a serious unfavorable event, the problem has not yet been eliminated. Research into the effectiveness of strategies to prevent wrong-level spine surgery is lacking. Herein, we describe a case of 44-year-old woman presented with neck pain and bilateral upper extremity weakness and numbness. Magnetic resonance imaging showed C5/6 and C6/7 disc herniations with spinal cord compression. The patient underwent anterior cervical discectomy and fusion; however, at the conclusion of the surgery, intraoperative radiographs showed that it was accomplished at C4/5 and C5/6-one level above the intended level. On the basis of this case and similar ones, a new protocol was developed that included implementation of a Spine Level Safety Checklist to document the reference point, the landmark, and the level of exposure that is marked on the intraoperative radiograph. Since implementation of this protocol, the incidence of wrong-level spine surgery at the senior author's institution has decreased from 4/7000 to 0/11,200. Adoption of this protocol by other centers is thus recommended to reduce the incidence of such complication.

Why X-rays? The importance of radiographs in spine surgery

Despite the advances made in high-resolution spinal imaging, plain films (radiographs or x-rays) remain a cornerstone of evaluating and caring for spine patients in the preoperative, intraoperative, and postoperative settings. Although often undervalued when compared with more advanced imaging such as MRIs or CT scans, plain films provide surgeons invaluable information that other imaging modalities oftentimes cannot. In addition to their use during surgery for localization or evaluation of hardware placement, x-rays provide an overall image of a patient's spine, are useful in evaluating hardware complications, allow detailed assessment of alignment and stability and allow for repeated images in clinic during follow-up. Plain films continue to provide critical information that cannot be obtained with other imaging modalities, and they remain central to providing optimal care for spine patients.

Spinal Tumors: Diagnosis and Treatment

Tumors that present in or around the spine can be challenging to diagnose and treat. A proper workup involves a complete history and physical examination, appropriate staging studies, appropriate imaging of the entire spine, and a tissue biopsy. The biopsy defines the lesion and guides treatment, but in some rare instances, rapid neurological decline may lead to urgent or emergent surgery before it can be analyzed. "Enneking-appropriate" margins should remain the goal for primary tumors while adequate debulking/separation/stabilization are often the goals in metastatic disease. Primary tumors of the spine are rare and often complex tumors to operate on-achieving Enneking-appropriate margins provides the greatest chance of survival while decreasing the chance of local recurrence. Metastatic tumors of the spine are increasingly more common, and timing of surgery must be considered within the greater framework of the patient and the patient's disease, deficits, stability, and other treatments available. The specific tumor type will dictate what other multidisciplinary approaches are available, allowing for chemotherapy and radiation as needed.

Pre- and intraoperative thoracic spine localization techniques: a systematic review

OBJECTIVE

In the era of modern medicine with an armamentarium full of state-of-the art technologies at our disposal, the incidence of wrong-level spinal surgery remains problematic. In particular, the thoracic spine presents a challenge for accurate localization due partly to body habitus, anatomical variations, and radiographic artifact from the ribs and scapula. The present review aims to assess and describe thoracic spine localization techniques.

METHODS

The authors performed a literature search using the PubMed database from 1990 to 2020, compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A total of 27 articles were included in this qualitative review.

RESULTS

A number of pre- and intraoperative strategies have been devised and employed to facilitate correct-level localization. Some of the more well-described approaches include fiducial metallic markers (screw or gold), metallic coils, polymethylmethacrylate, methylene blue, marking wire, use of intraoperative neuronavigation, intraoperative localization techniques (including using a needle, temperature probe, fluoroscopy, MRI, and ultrasonography), and skin marking.

CONCLUSIONS

While a number of techniques exist to accurately localize lesions in the thoracic spine, each has its advantages and disadvantages. Ultimately, the localization technique deployed by the spine surgeon will be patient-specific but often based on surgeon preference.

Prevention of Wrong-level Surgery in the Thoracic Spine: Preoperative Computer Tomography Fluoroscopy-guided Percutaneous Gold Fiducial Marker Placement in 57 Patients

STUDY DESIGN

Retrospective review.

OBJECTIVE

The aim of this study was to evaluate the feasibility, safety,s and complications of computer tomography (CT) fluoroscopy-guided percutaneous transpedicular gold fiducial marker insertion to reduce incidence of wrong-level surgery in the thoracic spine.

SUMMARY OF BACKGROUND DATA

Intraoperative localization of the correct thoracic level can be challenging and time-consuming, especially in obese patients and patients with anatomical variations. In the literature there are very few studies containing low numbers of patients which assessed CT or CT fluoroscopy-guided fiducial marker placement of the thoracic spine. Description of this technique has been similarly scarce.

METHODS

All patients who underwent percutaneous CT fluoroscopy-guided gold fiducial marker placement of the thoracic spine were retrospectively reviewed. Indications for surgery included degenerative disc disease, infection, spinal metastasis, and intra- and extradural tumors. Gold fiducial markers were placed using a percutaneous CT fluoroscopy-guided transpedicular approach with local anesthesia. In addition, sex, age, body mass index (BMI), thoracic level, related pathology, and procedure-related complications were also recorded.

RESULTS

A total of 57 patients (24 females, 33 males) were included. Mean age was 58.6 ± 15.5 years. No complications during CT fluoroscopy-guided gold fiducial marker placement were recorded. Intraoperative localization was successful in all patients. Mean BMI was 32.98 kg/m (range, 18.63-56.03 kg/m), and 63% of patients were obese (>30 kg/m). T7 (n = 11) was the most often marked vertebral body, followed by T10 (n = 10) and T6 (n = 7). The most cranial and most caudal levels marked were T2 and T12, respectively.

CONCLUSION

Preoperative CT fluoroscopy-guided percutaneous gold fiducial marker placement is safe, feasible, and accurate. The resulting facilitated localization of the intended thoracic level of surgery can reduce the length of surgery and prevent wrong-level surgery. Further studies are needed to evaluate in the effect on exposure to radiation and quantify the difference in operating room time.

LEVEL OF EVIDENCE

4.

A safe, reliable, inexpensive and novel technique to localize in the mid thoracic spine in the prone position: Proof of concept and technical illustration

Intraoperative localization within the thoracic spine in the prone position may be particularly difficult on account of absence of common landmarks such as the sacrum or the C2 vertebra, thus increasing the potential for wrong-level surgery that may lead to patient morbidity and potential litigation. Some current localization methods involve implantation of markers that are invasive and serve to add to procedural expense while yet still failing to entirely eliminate errors. We describe a novel, non-invasive, and inexpensive technique for intraoperative localization of the thoracic spine in the prone position using an esophageal temperature probe. Following patient positioning, anteroposterior fluoroscopy is used to localize the radiopaque tip of the esophageal probe relative to the thoracic spine. After determining the probe tip's location, it becomes the counting reference for all subsequent intraoperative fluoroscopic localizations during surgery. As the probe tip is generally visible in the same fluoroscopic image as the surgical level, error from parallax created when moving the fluoroscopy machine from an anatomic landmark either above or below is avoided and a shorter fluoroscopy time is needed. Use of an esophageal temperature probe as a landmark in localizing spinal level may serve as a reliable and It offers a safe, reliable, and inexpensive technique for proper localization of thoracic spine levels.

Bone cylinder plug and coil technique for accurate pedicle localization in thoracic spine surgery: A technical note

Background

Intraoperative identification of the correct level during thoracic spine surgery is essential to avoid wrong-level procedures. Despite technological progress, intraoperative imaging modalities for identifying the correct thoracic spine level remain unreliable and often lead to wrong-level surgery. To counter potential wrong-level operations, here, we have proposed a novel pedicle/bone cylinder marking technique for use in the thoracic spine utilizing biplanar fluoroscopy and confirmed with computed tomography (CT).

Methods

First, under fluoroscopic guidance, a bone cylinder is removed from the correct thoracic pedicle. Next, endovascular coils are packed into the cancellous bone defect followed by reinsertion of the bony plug. The patient then undergoes a CT scan of the entire thoracolumbosacral spine to precisely identify the marked level before surgery.

Results

We utilized this bone cylinder plug/coil technique to identify the T9-T10 level in a 56-year-old female with a soft thoracic disc herniation. The index thoracic pedicle was successfully localized before performing the unilateral minimally invasive laminectomy followed by the transpedicular thoracic disc excision.

Conclusion

The bone cylinder plug/coil technique is a safe and effective method for marking the correct level in thoracic spine surgery, while also reducing the operative time.