Improved Thoracoscopic-Assisted Surgery for the Treatment of Metastatic Thoracic Vertebral Tumors

Summary

Here, we present a protocol to demonstrate an improved thoracoscopic-assisted surgery for the treatment of metastatic thoracic vertebral tumors.

Abstract

The significant progress made in the diagnosis and treatment of malignant tumors has led to improved patient survival rates. However, the metastatic spread of these tumors to the thoracic vertebrae remains a significant challenge, often resulting in bone-related adverse events, such as pathological fractures and severe complications. To address this issue, a refined multidisciplinary approach has been explored, which utilizes thoracoscopic techniques for tumor resection and spinal interventions. Thoracoscopic techniques offer a minimally invasive alternative to traditional open surgical methods, aiming to reduce the overall trauma experienced by patients. By leveraging the advantages of thoracoscopy, clinicians can effectively resect metastatic tumors within the thoracic vertebrae while minimizing the impact on surrounding tissues and structures. This approach, combined with targeted spinal interventions, has the potential to improve patient outcomes and quality of life by mitigating the debilitating effects of pathological fractures and other complications associated with metastatic bone disease. The implementation of this multidisciplinary strategy, incorporating thoracoscopic tumor resection and spinal interventions, represents a promising avenue for the management of metastatic tumors within the thoracic vertebrae. Further research and clinical evaluation are necessary to fully elucidate the long-term benefits and establish the optimal treatment protocols for this patient population, ultimately enhancing the care and outcomes for individuals afflicted by this challenging condition.

Introduction

As advances in the diagnosis and treatment of malignant tumors continue, the survival rates of patients with malignancies have significantly increased¹. However, a concomitant rise in the incidence of bone-related adverse events caused by malignant tumors, particularly metastases to the thoracic vertebrae, has been observed². Many patients with widespread bone metastases, especially those with thoracic vertebral involvement, experience pathological fractures leading to severe pain and even paralysis³.

Open procedures require large skin incisions and extensive muscle dissection, leading to significant surgical trauma and prolonged patient recovery times. These open operations are also associated with greater blood loss, as they involve damage to major blood vessels, which increases the overall surgical risks⁴. Additionally, the extensive trauma incurred during open surgeries elevates the rates of postoperative complications, such as pulmonary issues and deep vein thrombosis. The protracted recovery period following open procedures also results in extended hospital stays, imposing a substantial burden on both patients and their caregivers. Furthermore, the limited visual field provided by open surgeries makes it challenging to precisely localize and resect the diseased areas, thereby increasing the technical difficulty of the operation⁵.

In 1993, German physician Mack first reported thoracoscopic spine surgery, followed by Rosenthal from the United States in 1994, who reported endoscopic thoracic vertebral disc excision⁶. This approach utilizes well-established thoracoscopic techniques to create a channel, enabling tumor resection, spinal cord decompression, artificial vertebral body implantation, and fixation with thoracic vertebral screws. This technique is characterized by minimal trauma, reduced bleeding, and less postoperative pain. Thoracoscopic-assisted spine surgery encompasses various procedures, including spine lateral convex release, intervertebral disc excision, vertebral body biopsy, intervertebral disc space abscess drainage, and anterior fusion surgery⁷. Some researchers have reported the use of microsurgical endoscopes for anterior chest and thoracolumbar vertebral reconstruction and anterior release and fusion in the treatment of metastatic tumors, fractures, and deformities⁸.

The rationale behind the development and use of this technique stems from the increasing incidence of bone-related adverse events, particularly pathological fractures, caused by the metastatic spread of malignant tumors to the thoracic vertebrae⁸. These complications can lead to severe pain, paralysis, and a significant reduction in the quality of life for affected patients. Compared to traditional open surgical methods, the thoracoscopic approach offers several advantages, including minimal trauma, reduced bleeding, and less postoperative pain⁹. This technique, which involves the creation of a channel for tumor resection, spinal cord decompression, artificial vertebral body implantation, and fixation with thoracic vertebral screws, has been reported to be effective in the treatment of various spinal conditions, such as metastatic tumors, fractures, and deformities¹⁰.

The use of thoracoscopic techniques for the management of metastatic tumors in the thoracic vertebrae is situated within the broader context of advancements in the diagnosis and treatment of malignant tumors, which have led to improved patient survival rates¹. However, the ongoing challenge of metastatic bone disease, particularly in the thoracic spine, has necessitated the exploration of innovative, minimally invasive approaches to address this clinical problem. This article presents a case series of 40 patients who underwent thoracoscopic surgery for metastatic tumors in the thoracic vertebrae, providing clinicians with valuable insights into the efficacy and potential applicability of this technique. The overall goal of this study is to explore the use of a refined multidisciplinary approach, incorporating thoracoscopic techniques for tumor resection and spinal interventions, in the management of metastatic tumors within the thoracic vertebrae.

Protocol

Written informed consent was obtained from the patients for publication. This surgical protocol adheres to the ethical standards established bythe Ethics Committee of The First Affiliated Hospital, Zhejiang University School of Medicine (Grant number: IIT20240869A).

1. Preoperative assessment

1. Use the following inclusion criteria: Participants aged 18 years and older; confirmed diagnosis of metastatic thoracic vertebral tumors using imaging (MRI, CT scans) and biopsy; the tumor must be located within the thoracic vertebrae, T1-T12; participants must have a performance status that indicates they are fit for surgery; participants must provide informed consent to undergo surgery as part of the study.
2. Use the following exclusion criteria: Participants with wide-spread metastasis beyond the regional area of the thoracic vertebrae; severe concurrent medical conditions such as uncontrolled diabetes, cardiovascular disorders, and kidney or liver failure, which may increase the risk of surgery; due to potential risks to the fetus, pregnant women will be excluded; prior spinal surgery participants who have previously undergone surgery at the same site of the current thoracic vertebral tumor; active systemic infections or local infections at the surgery site, as they may complicate surgical outcomes; patients with a life expectancy of less than 3 months, based on physician assessment, may be excluded; participants that have undergone previous treatments such as radiation therapy or chemotherapy; allergies or adverse reactions to materials or medications used during the hospitalization; patients with prior chest surgeries, traumas, or infectious that may have caused pleural adhesions.
3. Perform standard spine imaging along with anteroposterior and lateral chest radiographs to evaluate for any potential pleural issue.
   1. Spine anteroposterior (AP) view: Ask the patient to stand facing the X-ray machine, with the arms naturally at the sides. Raise the chin slightly to extend the cervical spine. Align the center line with the midpoint of the sternum. Ask the patient to hold their breath at the end of inspiration.
   2. Lateral chest view: Ask the patient to lie down with the left side facing the X-ray machine and arms raised above the head. Ensure the body remains upright and the shoulders relaxed. Align the center line at the level of the 4th thoracic vertebra. Ask the patient to hold their breath at the end of the inspiration
4. Commence steroid therapy for patients with symptomatic spinal cord compression: A typical starting dose is 10-16 mg. After the initial dose, provide a maintenance dose of 4-6 mg every 4-6 h. Gradually taper the dose over several days to weeks, depending on the patient's response.
5. Evaluate patients with high Tokuhashi scores and low Tomita scores but without involvement of the vertebral arch roots and appendages.
   NOTE: The Tokuhashi Score is a prognostic scoring system designed to predict survival in patients with metastatic spine tumors. The revised Tokuhashi score categorizes patients into three prognostic groups: those with scores of 0-8 (less than 6 months survival), 9-11 (6-12 months survival), and 12-15 (more than 12 months survival)¹¹. The Tomita Score is a prognostic tool used to evaluate patients with spinal metastases, aiding in the selection of appropriate surgical strategies. It assigns scores based on factors such as the growth rate of the primary tumor, the presence and resectability of visceral metastases, and the number of bone metastases. The total score helps clinicians categorize patients into different prognostic groups, guiding decisions on whether to pursue radical surgery, palliative surgery, or conservative treatment¹².
6. Consider preoperative embolization for patients with tumors that are highly vascular. Identify patients with prior chest surgeries, traumas, or infectious that may have caused pleural adhesions.
7. Rule out thoracoscopic surgery in patients with severe pulmonary conditions, such as COPD or asthma, that may complicate single-lung ventilation.

2. Anesthetization and positioning of the patient

1. Begin the anesthesia induction by establishing intravenous access and administering high-concentration oxygen through a face mask to increase oxygen reserves. Next, intravenously inject anesthetic induction agents (such as propofol 20 mg/mL), analgesics (such as fentanyl 50 µg/mL), and muscle relaxants (such as rocuronium 10 mg/mL).
2. Once the patient loses consciousness, choose the appropriate size and side (left or right) of a double-lumen endotracheal tube (DLT) based on the procedure. Perform direct laryngoscopy or video laryngoscopy to visualize the vocal cords. Insert the DLT through the vocal cords with the bronchial lumen facing anteriorly. Advance the tube until slight resistance is felt, usually at 28-30 cm at the teeth. Inflate the tracheal cuff.
3. Position the patient laterally and secure them with fixing straps to the operating table, ensuring the patient's airway is secure. Gently support the patient's head and neck. Slowly turn the patient's body to the side, starting with the shoulders and then the hips. Keep a lateral decubitus position with the thorax exposed, legs flexed, and upper limbs extended anteriorly (Figure 1).
4. Keep the spine aligned and avoid any twisting motions. Place a pillow between the knees and the arms for support. Check the patient's vitals and comfort level to avoid undue pressure or misalignment. Attach securing straps around the patient's shoulders and hips to prevent movement.
5. Use C-arm fluoroscopy to confirm spinal alignment: Position the C-arm fluoroscopy to obtain AP and lateral views of the spine. Confirm the alignment of the spine by checking that spinous processes are centered between the pedicles in the AP view.

3. Surgical access and visibility

1. Prepare the ultrasonic bone knife and other surgical instruments for later use.
2. Define strategic port locations around the affected site to ensure optimal instrument manipulation and retraction. The incision for surgical instruments is performed at the 3^rd, 5^th, and 7^th intercostal spaces along the anterior axillary line, as well as at the 7^th intercostal space along the mid-axillary line (Figure 2).
3. Prepare the chest wall for a potential switch to open thoracotomy. After confirming the need to convert to an open approach, carefully transition the patient into the lateral decubitus position if access to the lateral or anterior thoracic spine is required. If posterior access is needed, maintain the prone position but ensure that the patient is properly aligned. If necessary, proceed carefully when creating the portals to prevent injury.

4. Surgical procedure

1. Create access ports: Make a small incision with a scalpel (1-2 cm) for the camera port in the 7^th intercostal space and the mid-axillary line. Insert the thoracoscope through this port and ensure a clear view of the thoracic cavity. Create additional working ports, usually two or three, in the 3^rd and 5^th intercostal spaces. Adjust the exact positions based on tumor location and anatomy.
2. Deflate the lung: Collapse the lung on the operative side using single-lung ventilation to provide a clear operative field. Confirm adequate lung deflation with visual inspection through the thoracoscope.
3. Expose the tumor: Carefully dissect the parietal pleura overlying the vertebral bodies and tumor using endoscopic scissors and graspers. Identify and protect important anatomic structures such as the aorta, esophagus, sympathetic chain, and segmental vessels.
4. Resect the tumor: Dissect the tumor from the surrounding tissues using a combination of blunt and sharp dissection techniques. If the tumor is adherent to the dura mater or spinal cord, use fine, delicate instruments to release it carefully. Be cautious not to damage the spinal cord or surrounding neural structures.
5. Remove the tumor: Grasp and remove the tumor in segments (Figure 3). Continuously inspect the resection margins to ensure complete removal of the tumor. Obtain samples for intraoperative pathology.
6. Prepare the disc space: Use curettes, rongeurs, and suction to clean and debride the intervertebral space, removing any residual tumor tissue, necrotic material, or disc remnants. Prepare the vertebrae's endplates for the placement of an artificial vertebral body. Ensure that the surface of endplates is smooth and free of irregularities. The goal is to create a uniform, flat surface to promote optimal contact with the artificial vertebral body. Be careful not to damage the subchondral bone.
7. Place the artificial vertebral body: Choose an appropriately sized artificial vertebral body that matches the resected vertebral body's dimensions. Insert the artificial vertebral body into the prepared disc space. Ensure it fits securely and restores the height and alignment of the spinal column.
8. Secure the implant: Confirm the correct position and alignment of the artificial vertebral body using fluoroscopic imaging.
9. Place and secure spinal fusion devices: Insert pedicle screws and rods above and below the resection and implant site. Secure these devices to stabilize the spine, manually checking for any mobility or instability in the construct. Confirm proper alignment and fixation using fluoroscopic imaging, ensuring that the pedicle screws and rods are securely in place and the spine is stabilized.
10. Achieve hemostasis: Control any bleeding from the tumor bed, intervertebral space, or surrounding tissues using bipolar cautery, hemostatic agents, or sutures. Ensure the surgical field is free of excessive bleeding before proceeding with closure.
11. Reinflate the lung and close: Reinflate the lung slowly while checking for air leaks through the thoracoscope. Place a chest tube through one of the port sites to allow for postoperative drainage and re-expansion of the lung. Remove the thoracoscope and other instruments and close the port sites with 4-0 size sutures or staples.

5. Postoperative management

1. Monitoring: Transfer the patient to the recovery room or intensive care unit (ICU) for close monitoring of vital signs, respiratory function, and neurological status. Monitor for complications such as bleeding, infection, or respiratory distress.
2. Pain Management: Initiate a pain management protocol, which includes intravenous opioids, non-opioid analgesics, and patient-controlled analgesia (PCA).
3. Chest Tube Management: Monitor chest tube output, transition to water seal upon stable lung inflation, and prepare for removal when output decreases to less than 100 mL/day, typically by the 2^nd postoperative day. Get AP and Lateral chest view before and after chest tube removal to check lung re-expansion and exclude pneumothorax.
4. Mobility and Rehabilitation: Encourage early mobilization when the patient is hemodynamically stable, with vital signs within normal limits. This can help prevent complications such as deep vein thrombosis (DVT) and pulmonary embolism (PE). Work with physical therapists to design a tailored rehabilitation plan that includes gentle exercises to improve mobility and strength.
5. Nutrition: Promote a balanced diet rich in proteins, vitamins, and minerals to support healing and bone fusion. Encourage hydration and a high-fiber diet to prevent constipation, especially if the patient is on opioid pain medications.
6. Activity and Lifestyle: Advise the patient to avoid heavy lifting, bending, or twisting movements that could strain the spine. Encourage regular, gentle exercise such as walking, swimming, or low-impact aerobics to maintain overall health and support spinal recovery.

Results

The patient data includes preoperative Tokuhashi Score, preoperative Tomita score, preoperative Visual Analog scale (VAS) score, and postoperative VAS score. The statistical analysis is shown in Table 1. The postoperative VAS and preoperative VAS scores were analyzed using paired t-tests. The results of the data indicate that individuals who undergo the improved thoracoscopic-assisted procedure demonstrate a significant reduction in their VAS score (Figure 4). The status of ...

Discussion

The disadvantages of open surgery include larger incisions and longer scars, leading to more extensive tissue disruption and greater postoperative pain¹³. This approach often results in higher blood loss during the procedure and increases the risk of infection and complications due to broader exposure. Patients experience longer recovery times, extended hospital stays, and delayed return to normal activities. Additionally, open surgery has a greater impact on lung function, increasing the risk of ...

Materials

Name	Company	Catalog Number	Comments
Absorbable sutures	ETHICON	VCP739D	Johnson & Johnson 2-0 Absorbable Suture for suturing incisions
anesthesia drug	Anlibang Pharmaceuticals	propofol injectable emulsion	Sedation used in anesthesia procedures
anterior fixation system	Medtronic	VANTAGE	Medtronic's Vertebral Lateral Fixation System can be used to fixate the adjacent vertebral bodies to the implanted artificial vertebral body from the lateral side of the vertebrae, creating a stable overall structure.
Artificial vertebral body	Stryker	VLIFT	Stryker Artificial Vertebral Body is used for implanting an artificial vertebral body prosthesis after the removal of a diseased vertebra to support the spine.
C-arm	GE	OEC One CFD	Used for intraoperative fluoroscopic confirmation of the proper positioning of metal implants.
Thoracoscope System	stryker	Precision Ideal Eyes HD	Used for imaging of visceral organs within the thoracic cavity to facilitate the surgical manipulation of pathological structures.
Ultrasonic bone knife	SMTP	XD860A	Used for intraoperative cutting of bone tissue.