Nearly 50 percent of older cancer patients with bone metastases had the spine affected. Bone metastases are frequently encountered in these individuals with other malignancy ^[1]. Lung metastases are the most frequent in renal cell carcinoma (RCC), with 20–35% of cases involving bone involvement, followed by lymph nodes, liver, adrenal glands, and brain ^[2]. The quality of life for cancer patients has increased due to advancements in radiation therapy, surgery, and medicine. Patients with bone metastases now have better survival rates and functional status ^[3]. Contrary to the belief of hematogenous dissemination, a recent study has supported a locoregional spread mechanism of early spinal dissemination of RCC ^[4]. As a spine surgeon, we are more concerned of two main entities for spinal metastasis: stability of the spine and prognosis of the patient. Various scoring systems have been described for pre-operative assessment of the patient with metastasis to the spine. Two widely used scoring systems for identifying the best course of treatment are the New England Spinal Metastasis Score and the Revised Tokuhashi score (RTS) ^[5]. The primary tumor site classification and the effects of hormone therapy and chemotherapy are included in the new Katagiri score for the prognosis of skeletal metastasis ^[6]. A more thorough operation plan can be created by using the Kostuik classification and the spine instability neoplastic score (SINS), which are frequently used to assess spine stability ^[7]. Total en bloc spondylectomy (TES) and separation surgery with post-operative stereotactic radiosurgery (SSRS) are the two major types of surgical techniques for isolated metastatic patients ^[8]. Here, we report a case of clear cell type RCC with thoracic spine (T8) metastasis managed with a TES at the Hospital for Advanced Medicine and Surgery, Kathmandu, Nepal.

Patient information

A 61-year-old male patient, previously diagnosed with RCC in 2019, presented with a history of back pain and difficulty walking in 2024. He underwent nephrectomy 5 years ago, and his RCC had metastasized to the lungs in 2020. He was treated with Sunitinib, and a Positron Emission Tomography scan in 2022 showed no evidence of active disease. In May 2024, the patient developed back pain, and Magnetic Resonance Imaging (MRI) revealed metastasis to the T8 vertebra with minimal cord compression. He had paraparesis at that time and received 10 cycles of radiotherapy, which resulted in some neurological improvement. However, in November 2024, the patient continued to report back pain and had difficulty walking.

Clinical examination

Upon examination, the patient had the following neurological findings:

• Motor: Bilateral lower extremity strength was 4/5 (American Spinal Injury Association scale)
• Sensory: Sensory function was partially preserved (50%) in the bilateral lower limb
• Bowel/Bladder: Normal function.

Imaging

• MRI (May 2024): demonstrated metastasis at the T8 with cord compression (Fig. 1a and b), while MRI (November 2024): revealed continued deterioration at the T8 level (Fig. 1c and d).

Pre-operative planning

• Given the prognosis of more than 6 months survival (RTS = 10 points) and features of instability (SINS score = 14), the patient was deemed a candidate for TES. The surgery planned involved the TES of T8 vertebrae, including excision of Costo-vertebral joints of T8 and T9 to gain access and to relieve spinal cord compression.

• A detailed computed tomography angiography was performed to assess the vascular supply to the affected vertebrae.
• Embolization: Pre-operative embolization of the T8 vertebra was performed to minimize bleeding and enhance the resection process (Fig. 2).

Surgical procedure

Posterior decompression of T8 Vertebra

The surgery began with a posterior approach for the exposure of the thoracic spine. The excision of posterior elements of T8 vertebrae, including both rib heads of T8 and T9, was performed (Fig. 3a).

Anterior decompression

A Gigli saw was passed through the neural disc space to facilitate the excision of the affected vertebrae (Fig. 3b).

Spinal cord protection

During excision, the dura was carefully protected using a spatula to avoid any damage to the spinal cord (Fig. 3c).

Stabilization

Pedicle screws were placed at the T5, T6, T7, T9, T10, and T11 levels. An expandable cage was inserted at the T8 level along with contoured rods and an interrod connector to provide spinal stability (Fig. 4).

The gross specimen was sent to pathology for histopathological examination and it turned out to be the metastatic lesion from clear cell type RCC (Fig. 5).

Post-operative course

The patient was closely monitored in the intensive care unit following the surgery. His intraoperative blood loss was 645 mL. There was no neurological deterioration, and he began rehabilitation therapy after a few days. Pain management was optimized, and his walking ability improved over the subsequent days.

Spinal metastases from RCC, especially in the thoracic spine, pose a significant challenge to both diagnosis and treatment. Although RCC metastasize mainly to the vertebra, isolated intramedullary spinal cord metastasis from RCC has also been reported ^[9]. The presence of epidural cord compression can lead to permanent neurological deficits if not treated promptly. TES, while technically demanding, offers the advantage of complete tumor excision and, in select cases, improves both pain control and neurological outcomes. TES, initially defined by Tomita et al., is a surgical procedure used in oncological spine surgery to remove the complete vertebral body and posterior parts as single pieces to achieve negative margins ^[10,11]. Other than isolated metastasis to the spine, TES has been utilized for aggressive hemangiomas of vertebrae ^[12], oligometastatic liposarcoma ^[13], spinal giant cell tumors combined with secondary aneurysmal bone cyst ^[14], chondrosarcoma, chordoma, Ewing’s sarcoma, osteosarcoma, and osteoblastoma ^[15]. Paholpak et al. demonstrated posterior-only TES for L3-involved vertebrae, which yielded excellent results in the local control of metastatic disease ^[16]. There has been a great evolution in the literature regarding the management of metastatic lesions to the spine. TES has been performed in metastatic RCC to the spine. The previous reports have been illustrated in Table 1. TES is a commonly used technique; however, it is not devoid of its drawbacks, particularly when combined with primary malignant and metastatic disorders ^[17]. Implant failure was found to be prevalent in patient undergoing surgery for metastasis to the spine ^[18]. TES is also linked to substantial blood loss since it requires extensive tissue dissection, bone work, and a lengthy operative period ^[19]. Demura et al. reported the following potential TES complications: bleeding over 2,000 mL, hardware failure, neurological complications, surgical site infection, wound dehiscence, cerebrospinal fluid leakage, and respiratory and cardiovascular complications ^[20]. Tsukamoto et al. reported that, to select the optimal treatment for spinal metastasis, neurological status by epidural spinal cord compression grade (axial T2-weighted magnetic resonance image), mechanical instability by SINS scoring system, and systemic disease should be evaluated by a multidisciplinary team ^[21]. Cao et al. compared two major surgical procedures TES and SSRS. They were reported as efficient methods for treating solitary spinal metastasis patients with metastatic spinal cord compression. Better local tumor control and mental health were found in the TES group, and most patients felt as if they were free of spinal tumors. Compared with TES, the SSRS caused less operation-related trauma ^[8]. According to Terzi et al., the primary prognostic markers influencing overall survival for spinal metastases in clear cell type RCC were high Tokuhashi score, the existence of visceral metastases, additional bone metastases, and the kind of surgery ^[22]. In this case, we describe the step-by-step approach of management, each surgical step of the TES procedure for metastatic lesion of clear cell RCC to T8 vertebra with no perioperative complications being encountered. The patient was able to mobilize post-surgery though it might be palliative care for him. The decision to proceed with surgery should be made carefully, considering the patient’s overall prognosis, the extent of metastasis, and the potential for neurological recovery and symptoms of instability, such as severe pain. The use of pre-operative embolization to control bleeding and the step-by-step procedure of the surgery could lead to good outcomes.

This case highlights the feasibility and step-by-step approach of TES in the treatment of thoracic spinal metastasis from RCC along with the review of the literature. Early diagnosis and intervention are critical to improving the quality of life and preventing irreversible neurological damage. Validated scoring systems, such as modified Tokuhashi score and SINS score could help surgeons in decision-making of surgery.

In patients with mechanical instability and favorable prognostic scores, TES is a viable and effective surgical approach for addressing solitary thoracic spinal metastasis from RCC. It is crucial for determining surgery with the help of validated scoring systems, such as the Modified Tokuhashi Score and SINS. This case illustrates the significance of employing a multidisciplinary approach, the value of pre-operative embolization to reduce intraoperative bleeding, and careful surgical technique to enhance neurological and functional outcomes – even in palliative situations.