Single Stage Combined Approach Sagittal En-Block Spondylectomy for L3 Vertebral Chondrosarcoma: A Technical Note

BACKGROUND

Primary malignant tumors of the spine are rare which most commonly occur in lumbar and thoracic vertebra. Here, we report a rare case of retroperitoneal chondrosarcoma of the L3 vertebra which was managed with sagittal en-block spondylectomy following chemoradiation.

CASE PRESENTATION

A 26-year-old lady was evaluated for abdominal pain with contrast enhanced computer tomogram of abdomen and pelvis which revealed a soft tissue retroperitoneal mass arising from L3 vertebra. She underwent laparotomy and biopsy which revealed chondrosarcoma and she received chemoradiation over a period of 28 weeks, 6 days. After re-imaging she underwent single stage combined approach sagittal en-block spondylectomy of retroperitoneal chondrosarcoma of L3 vertebra with right nephrectomy and spine reconstruction. She was followed for a period of 3 years, there was no evidence of recurrence in follow-up CECT abdomen and pelvis. She has no gait abnormality or spinal deformity.

CONCLUSION

Sagittal en-block spondylectomy is a preferred surgical approach for eccentrically placed spinal tumors which offers better oncological and functional outcomes.

A Novel Technology for 3D-Printing Artificial Vertebral Bodies for Treating Lumbar Spine Adrenal Pheochromocytoma Metastases: A Case Report and Review of the Literature

BACKGROUND

Pheochromocytoma is an adrenal medullary neuroendocrine tumor that rarely metastasizes to the spine. Currently, its specific treatment methods still present challenges.

CASE DESCRIPTION

A 41-year-old male patient who underwent left total adrenalectomy due to pheochromocytoma 3 years ago presented with lower back pain, accompanied by numbness and decreased muscle strength in both legs, as well as decreased sensation. Abnormal transmittance of the L3 vertebral body could be seen on anterior-posterior and lateral lumbar X-rays, irregular bone destruction of the L3 vertebral body was found on CT, and an MRI scan showed that the tumor was located within the L3 vertebral body, protruding into the spinal canal and compressing the epidural sac. No recurrence was found in the abdomen. Preoperatively, perform local embolization of the blood vessels supplying the tumor. First, the L2-3 intervertebral disc, L3-4 intervertebral disc and L3 vertebral body were removed using an anterior approach, the whole tumor was removed, and some of the vertebrae were taken for pathological examination and replaced with a 3D-printed prosthesis. Then, four pedicle screws were placed in the bilateral pedicles of L2 and L4 using the posterior approach, pre-bent connecting rods were installed to replace the bone cortex of the lamina and articular process followed by bone graft fusion of the interlaminar and facet joints. The postoperative results were satisfactory, and there were no perioperative complications.

CONCLUSION

Lumbar pheochromocytoma metastasis is rare, difficult to treat, and should be considered in spinal metastases' differential diagnoses so early diagnosis can be made based on medical history and imaging. Preoperative local vascular imaging and embolization of the blood supply vessels were performed. After total en-bloc spondylectomy of the tumor during surgery, a prosthesis was implanted and combined with pedicle screw fixation to reconstruct spinal biomechanical stability, achieving satisfactory results. Therefore, 3D printed artificial vertebral bodies are a good choice for treating adrenal pheochromocytoma lumbar metastasis. The key to successful treatment is close interdisciplinary collaboration in formulating rigorous comprehensive perioperative plans.

Feasibility of total en-bloc spondylectomy on L5 by a posterior-only approach: An autopsy study

Purpose

To obtain a better understanding of the structures around L5 vertebra and provide some anatomical evidence of the feasibility of total en-bloc spondylectomy (TES) on L5 in a posterior-only approach.

Methods

12 simulated TESs on L5 by a posterior-only approach were conducted on human cadavers. The distance between the traction point of L4 nerve root and the dural sac (Da), the anterior-posterior diameter of the vertebral body,(Va), the distance between the start point of L4 nerve root and the traction point of L5 nerve root (Dh) and the height of the vertebral body (Vh) were measured. Paired t-test and liner regression were performed to determine the difference and correlation between Da and Va, and between Dh and Vh. The risk of nerve roots or blood vessels damages, and the obstruction caused by iliac wings were evaluated.

Results

Liner correlations were found between Da and Va, and between Dh and Vh. The regression equations were Da = 0.6673Va + 11.28 and Dh = 1.009Vh + 1.003. There are statistical significant differences between Dh and Vh, and between Da and Va in those whose Va < 34.96 mm. Nerve roots or blood vessels damages and the obstruction caused by iliac wing were able to be avoided.

Conclusions

If the patient has an anterior-posterior diameter of L5 vertebral body shorter than 34.96 mm, it is possible that the vertebral body can be taken out during TES in a posterior-only approach. Prevention of nerve roots or blood vessels damages, and the obstruction caused by iliac wings are difficulties of this procedure yet not insurmountable. TES on L5 by a posterior-only approach might a possible alternative in treating diseases like L5 vertebral body tumors.