En Bloc Spondylectomy (EBS): Surgical removal of an entire vertebra in one piece (en bloc), including vertebral body, pedicles, and posterior elements, to achieve oncologic margins. Used primarily for primary or isolated metastatic spine tumors.
Posterior Vertebral Column Resection (pVCR): Piecemeal removal of vertebral segments via a posterior-only approach. Main goal is spinal deformity correction (e.g. kyphosis, scoliosis).
Separation Surgery: A palliative procedure for metastatic epidural spinal cord compression. The goal is circumferential decompression of the spinal cord and creation of a safe margin between tumor and dura to allow high-dose stereotactic radiosurgery (SRS). It does not aim to remove the entire tumor.
| Feature | En Bloc Spondylectomy | Posterior Vertebral Column Resection | Separation Surgery |
|---|---|---|---|
| Main Goal | Oncologic resection with margins | Correction of severe deformity | Cord decompression for radiotherapy |
| Type of Resection | One-piece (en bloc) | Fragmented (piecemeal) | Limited debulking with circumferential decompression |
| Tumor Removal | Complete, with wide margins | Not applicable | Partial (only decompression) |
| Indications | Primary or solitary metastatic tumors | Severe kyphosis or scoliosis | Metastatic epidural spinal cord compression |
| Surgical Approach | Anterior, posterior, or combined | Posterior-only | Posterior-only |
| Oncologic Intent | Curative | No | Palliative + adjunct to SRS |
| Radiation Planning | Not typically required | Not applicable | Integral to high-dose SRS planning |
These three procedures, though all involving vertebral resection or manipulation, serve very different purposes:
Understanding the goal behind each is key to choosing the appropriate technique in spinal surgery.
The analyses performed in a study demonstrated key factors affecting intraoperative blood loss and showed that a simple preoperative checklist including these factors can be used to identify patients undergoing surgery for metastatic spine tumors who are at risk for increased intraoperative blood loss 1).
see also Vertebral metastases surgery.
Although the spinal metastases treatment paradigms have changed and separation surgery followed by stereotactic radiosurgery is considered the best strategy, there are still cases in which spinal metastases surgery by 360° decompression with stabilization is indicated.
Techniques of decompression without stabilization have resulted in a worse outcome, and this has misled many in the past to believe that radiotherapy is the preferred option to surgery 2) 3) 4) 5)
If the patient and the presenting pathology are feasible for surgery, 1 of the major criteria is the expected life expectancy of the patient. Generally, if the expected survival is > 3 months, patients are eligible for surgery 6).
Of course, the predicted survival is not the only criterion with which to decide whether the patient is a surgical candidate. The wishes of the patient, comorbidity, and local characteristics are of course of equal importance.
In general, a search for other metastases is performed. The patient is assessed by an oncologist and a survival rate is estimated. This estimation is not very accurate 7) 8).
A randomized, controlled trial proved the effectiveness of surgery in spinal metastatic disease with regard to the improvement of neurologic function. It did not contribute to a longer survival, but to an improvement in the quality of remaining life. One of the most important selection criteria for surgery is life expectancy. Estimation of the life expectancy includes numerous factors such as nature and extension of the primary tumor, clinical performance of the patient, presence of metastases, etc. 9).
At first, surgery was proven to fail in the management of spinal metastases and, compared with radiation therapy, surgery had more complications, whereas neurologic recovery and survival rates did not improve. At that time, surgery was abandoned for the treatment of spinal metastases. It should be stated that surgery was in fact laminectomy 10).
Percutaneous fixation with cement-augmented pedicle screws in patients with pathological spine fractures provides an improvement in mechanical back pain, with a low incidence of failure, and in some patients, spontaneous facet fusion was observed. Further research is necessary with regard to both short-term benefits and long-term outcomes 11).