"En-bloc" vertebrectomy in the mobile lumbar spine

The Clinical Characteristics and Prediction Nomograms for Primary Spine Malignancies

Background

Primary spine malignancies (PSMs) are relatively rare in bone tumors. Due to their rarity, the clinical characteristics and prognostic factors are still ambiguous. In this study, we aim to identify the clinical features and proposed prediction nomograms for patients with PSMs.

Methods

Patients diagnosed with PSMs including chordoma, osteosarcoma, chondrosarcoma, Ewing sarcoma, and malignant giant cell tumor of bone (GCTB) between 1975 and 2016 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. The patient and tumor characteristics were described based on clinical information. The significant prognostic factors of overall survival (OS) and cancer-specific survival (CSS) were identified by the univariate and multivariate Cox analysis. Then, the nomograms for OS and CSS were established based on the selected predictors and their accuracy was explored by the Cox–Snell residual plot, area under the curve (AUC) of receiver operator characteristic (ROC) and calibration curve.

Results

The clinical information of 1,096 patients with PSMs was selected from the SEER database between 1975 and 2016. A total of 395 patients were identified with full survival and treatment data between 2004 and 2016. Chordoma is the commonest tumor with 400 cases, along 172 cases with osteosarcoma, 240 cases with chondrosarcoma, 262 cases with Ewing sarcoma and 22 cases with malignant GCTB. The univariate and multivariate analyses revealed that older age (Age > 60), distant metastasis, chemotherapy, and Surgery were independent predictors for OS and/or CSS. Based on these results, the nomograms were established with a better applicability (AUC for CSS: 0.784; AUC for OS: 0.780).

Conclusions

This study provides the statistics evidence for the clinical characteristics and predictors for patients with PSMs based on a large size population. Additionally, precise prediction nomograms were also established with a well-applicability.

Results following surgical resection of recurrent chordoma of the spine: experience in a single institution

Background

Chordoma of the spine is a low-grade malignant tumor with vague and indolent symptoms; thus, large tumor mass is encountered at the time of diagnosis in almost cases and makes it difficult for en-bloc free-margin resection. Salvage therapy for recurrent chordoma is very challenging due to its relentless nature and refractory to adjuvant therapies. The aim of this present study was to report the oncologic outcome following surgical resection of chordoma of the spine.

Materials and methods

Retrospective review of 10 consecutive cases of recurrent chordoma patients who underwent surgical treatment between 2003 and 2018 at one tertiary-care center was conducted.

Results

There were 10 patients; 4 females and 6 males were included in this study. Eight patients had local recurrence. The recurrence was encountered at the muscle, surrounding soft tissue, and remaining bony structure. Distant metastases were found in 2 patients. The median time to recurrence or metastasis was 30 months after first surgery.

Conclusion

En-bloc free-margin resection is mandatory to prevent recurrence. The clinical vigilance and investigation to identify tumor recurrent should be performed every 3 to 6 months, especially in the first 30 months and annually thereafter. Detection of recurrent in early stage with a small mass may be the best chance to perform an en-bloc margin-free resection to prevent further recurrence.

Total En Bloc Spondylectomy for the Fifth Lumbar Solitary Metastasis by a Posterior-Only Approach

BACKGROUND

Relatively few cases of total en bloc spondylectomy (TES) for the L5 tumors have been reported. TES in the lower lumbar region is usually performed through a combined anterior and posterior approach. TES for L5 tumors by a posterior-only approach is technically challenging.

CASE DESCRIPTION

A 62-year-old woman with persistent pain in her lumbosacral area and lower extremities and numbness of her lateral left lower extremity for 2 months came to our department. She had undergone radical mastectomy 4 years earlier. X-ray and magnetic resonance imaging (MRI) showed that the tumor had destroyed the vertebral body of L5. No other lesions were revealed by emission computed tomography (ECT) or positron emission tomography/computed tomography (PET/CT). With a diagnosis of breast cancer and a solitary metastasis to L5, the patient was treated with posterior-only TES of the L5 tumor and reconstruction. The whole procedure took 10 hours, and her intraoperative blood loss was 9000 mL. The lumbar and leg pain of the patient disappeared postoperatively without serious complications. She started walking 4 weeks after surgery and resumed her daily life. New multiple metastases developed 6 months after surgery, with no sign of local recurrence. Despite active treatment, she died 18 months after surgery.

CONCLUSION

TES of the L5 tumor can be achieved by a posterior-only approach, with good results and limited complications.

A Novel Technique for Total En bloc Spondylectomy of the Fifth Lumbar Tumor Through Posterior-Only Approach

STUDY DESIGN

A retrospective study.

OBJECTIVE

To describe a new surgical technique for total en bloc spondylectomy (TES) of the fifth lumbar (L5) tumor and evaluate the efficacy and safety of this new technique.

SUMMARY OF BACKGROUND DATA

TES has been considered an optimal treatment for tumor, including certain spinal tumors, but it requires a combined posterior-anterior approach, which is often complicated by a long operation time, considerable blood loss and severe trauma.

METHODS

Seven patients with primary or solitary metastatic tumors of L5 were treated with this new technique in our center between March 2014 and November 2017. The critical points were fabrication of the iliac graft, dissection, resection, and reconstruction. Other parameters including surgical time, blood loss, complications, pre- and postoperative neurological function, tumor control, and overall survival (OS) were presented and analyzed.

RESULTS

All the included patients received one stage TES. The mean surgical time was 365.7 minutes with an average blood loss of 2514.3 mL. No serious perioperative complication was observed or reported during the mean follow-up period of 27.4 months. Wound disruption occurred in one patient and numbness of the left lower limb in another, but both recovered rapidly after appropriate management. Adventitial avulsion of the abdominal aorta occurred during dissection in one patient. Two patients died during the follow-up period due to advanced malignancy. One patient was alive but developed a newly diagnosed thoracolumbar tumor in 40 months. The other four patients recovered well without evidence of disease. All patients were able to walk independently 3 to 4 weeks after operation, with satisfied fusion of the iliac grafts in a mean period of 6.7 months after operation. No evidence of internal fixation failure occurred.

CONCLUSION

This new technique offers satisfactory surgical exposure, total en bloc spondylectomy, reliable reconstruction, and good tumor control for certain L5 tumors through the posterior-only approach.

LEVEL OF EVIDENCE

4.

Total En Bloc Spondylectomy for Solitary Metastatic Tumors of the Fourth Lumbar Spine in a Posterior-Only Approach

BACKGROUND

Total en bloc spondylectomy (TES) significantly decreases the rate of local recurrence and provides long-term survival in patients with malignant tumor of the spine. This procedure can be performed through a posterior-only approach. However, TES for lower lumbar spine through a posterior-only approach is technically challenging.

METHODS

We retrospectively reviewed 9 patients with solitary metastatic tumors of the fourth lumbar spine who underwent TES in a posterior-only approach from June 2012 to December 2015. This series included 5 female and 4 male patients, with a mean age of 54.1 years. Endpoints included length of surgery, estimated blood loss, visual analogue scale for pain, instrumentation failure, perioperative complications, local control rate, and overall survival.

RESULTS

All patients underwent TES and circumferential reconstruction of the involved level. Average operative time and estimated blood loss were 282 minutes and 2421 mL, respectively. The mean follow-up time was 41.2 months. We encountered nerve roots stretches in all patients during the surgeries. Three patients experienced acute lower-extremity neurologic dysfunction, but the symptoms were significantly alleviated in 4 weeks postoperatively and fully resolved within 6 months. Five patients showed no evidence of disease at the latest follow-up. Three patients died of metastasis and systemic failure. One patient developed new metastases and was alive with disease. Titanium mesh cage subsidence was observed in 3 patients, but no implant failures or related clinical symptoms were found.

CONCLUSIONS

TES for the fourth lumbar spine in a posterior-only approach is feasible. Although the surgery is challenging, long-term oncologic and neurologic outcomes are satisfying.

Spinal stereotactic body radiotherapy following intralesional curettage with separation surgery for initial or salvage chordoma treatment

OBJECTIVE Chordoma is a rare malignant tumor for which en bloc resection with wide margins is advocated as primary treatment. Unfortunately, due to anatomical constraints, en bloc resection to achieve wide or marginal margins is not feasible for many patients as the resulting morbidity would be prohibitive. The objective of this study was to evaluate the efficacy of intralesional curettage and separation surgery followed by spinal stereotactic body radiation therapy (SBRT) in patients with chordomas in the mobile spine. METHODS The authors performed a retrospective chart review of all patients with chordoma in the mobile spine treated from 2004 to 2016. Patients were identified from a prospectively collected database. Initially 22 patients were identified with mobile spine chordomas. With inclusion criteria of cytoreductive separation surgery followed closely by SBRT and a minimum of 6 months of follow-up imaging, 12 patients were included. Clinical and pathological characteristics of each patient were collected and data were analyzed. Patients were divided into two cohorts-those undergoing intralesional resection followed by SBRT as initial chordoma treatment at Memorial Sloan Kettering Cancer Center (MSKCC) (Cohort 1) and those undergoing salvage treatment following recurrence (Cohort 2). Treatment toxicities were classified according to the Common Terminology Criteria for Adverse Events version 4.03. Overall survival was analyzed using Kaplan-Meier analysis. RESULTS The 12 patients had a median post-SBRT follow-up time of 26 months. Cohort 1 had 5 patients with median post-SBRT follow-up time of 65.9 months and local control rate of 80% at last follow-up. Only one patient had disease progression, at 48.2 months following surgery and SBRT. Cohort 2 had 7 patients who had been treated at other institutions prior to undergoing both surgery and SBRT (salvage therapy) at MSKCC. The local control rate was 57.1% and the median follow-up duration was 10.7 months. One patient required repeat irradiation. Major surgery- and radiation-related complications occurred in 18% and 27% of patients, respectively. Epidural spinal cord compression scores were collected for each patient pre- and postoperatively. CONCLUSIONS The combination of surgery and SBRT provides excellent local control following intralesional curettage and separation surgery for chordomas in the mobile spine. Patients who underwent intralesional curettage and spinal SBRT as initial treatment had better disease control than those undergoing salvage therapy. High-dose radiotherapy may offer several biological benefits for tumor control.

L4 and L5 spondylectomy for en bloc resection of giant cell tumor and review of the literature

Study Design Case report and review of the literature.

Objective We present the case of a two-level lumbar spondylectomy at L4 and L5 for en bloc resection of a giant cell tumor (GCT) and lumbopelvic reconstruction.

Methods A 58-year-old woman presented with a 7-month history of progressive intractable back and leg pain secondary to a biopsy-proven Enneking stage III GCT of the L4 and L5 vertebrae. The patient underwent a successful L4–L5 spondylectomy and lumbopelvic reconstruction using a combined posterior and anterior approach over two operative stages.

Results Postoperative complications included a deep wound infection and a cerebrospinal fluid leak; however, following surgical debridement and long-term antibiotic treatment, the patient was neurologically intact with minimal pain and there was no evidence of tumor recurrence or instrumentation failure at more than 2 years of follow-up.

Conclusion Spondylectomy that achieves en bloc resection is a viable and effective treatment option that can be curative for Enneking stage III GCTs involving the lower lumbar spine. The lumbosacral junction represents a challenging anatomic location for spinal reconstruction after spondylectomy with unique technical considerations.

Outcomes following attempted en bloc resection of cervical chordomas in the C-1 and C-2 region versus the subaxial region: a multiinstitutional experience

Object

Chordomas involving the mobile spine are ideally managed via en bloc resection with reconstruction to optimize local control and possibly offer cure. In the cervical spine, local anatomy poses unique challenges, limiting the feasibility of aggressive resection. The authors present a multi-institutional series of 16 cases of cervical chordomas removed en bloc. Particular attention was paid to clinical outcome, complications, and recurrence. In addition, outcomes were assessed according to position of tumor at the C1–2 level versus the subaxial (SA) spine (C3–7).

Methods

The authors reviewed cases involving patients who underwent en bloc resection of cervical chordoma at 4 large spine centers. Patients were included if the lesion epicenter involved the C-1 to C-7 vertebral bodies. Demographic data and details of surgery, follow-up course, exposure to adjuvant therapy, and complications were obtained. Outcome was correlated with presence of tumor in C1–2 versus subaxial spine via a Student t-test.

Results

Sixteen patients were identified (mean age at presentation 55 ± 14 years). Seven cases (44%) cases involved C1–2, and 16 involved the subaxial spine. Median survival did not differ significantly different between the C1–2 (72 months) and SA (60 months) groups (p = 0.65). A combined (staged anteroposterior) approach was used in 81% of the cases. Use of the combined approach was significantly more common in treatment of subaxial than C1–2 tumors (100% vs 57%, p = 0.04). En bloc resection was attempted via an anterior approach in 6% of cases (C1–2: 14.3%; SA: 0%; p = 0.17) and a posterior approach in 13% of cases (C1–2: 29%; SA: 0%; p = 0.09). The most commonly reported margin classification was marginal (56% of cases), followed by violated (25%) and wide (19%). En bloc excision of subaxial tumors was significantly more likely to result in marginal margins than excision of C1–2 tumors (C1–2: 29%; SA: 78%; p = 0.03). C1–2 tumors were associated with significantly higher rates of postoperative complications (C1–2: 71%; SA: 22%; p = 0.03). Both local and distant tumor recurrence was greatest for C1–2 tumors (local C1–2: 29%; local SA: 11%; distant C1–2: 14%; distant SA: 0%). Statistical analysis of tumor recurrence based on tumor location was not possible due to the small number of cases. There was no between-groups difference in exposure to postoperative adjuvant radiotherapy. There was no difference in median survival between groups receiving proton beam radiotherapy or intensity-modulated radiotherapy versus no radiation therapy (p = 0.8).

Conclusions

Compared with en bloc resection of chordomas involving the subaxial cervical spine, en bloc resection of chordomas involving the upper cervical spine (C1–2) is associated with poorer outcomes, such as less favorable margins, higher rates of complications, and increased tumor recurrence. Data from this cohort do not support a statistically significant difference in survival for patients with C1–2 versus subaxial disease, but larger studies are needed to further study survival differences.

[Solitary spinal metastases. Is aggressive surgical management justified?]

Advances in oncological and surgical therapies have led to a significant increase in life expectancy of cancer patients and also prolonged survival of patients with isolated or multiple metastases. Among the skeletal manifestations the spine is the most often affected site. Using novel imaging techniques with higher resolution and use of metabolic signatures, the screening of cancer patients has improved considerably. Consequently, the diagnosis of metastases is becoming increasingly more sensitive. Therefore, but also due to more effective polychemotherapy protocols, singular or solitary metastases are more frequently observed either in the early stages or as a result of a controlled malignant tumor entity (stable disease). The questions whether a solitary metastasis really exists (illusion or reality?) and its radical oncological and surgical treatment as a circumscribed singular tumor manifestation, is really relevant for the overall prognosis, remains controversial. However, it seems evident that a biologically favorable underlying tumor biology, radical treatment of the primary tumor and a long metastasis-free interval are valid predictors of a good oncological outcome. In the presence of a solitary metastasis under these circumstances (typical example: solitary metastasis of renal cell carcinoma many years after radical tumor nephrectomy) a radical surgical procedure (en bloc spondylectomy) can significantly improve the long-term prognosis of this patient group in combination with adjuvant chemotherapy and/or radiotherapy. However, a thorough evaluation of the overall survival prognosis, a detailed and complete staging followed by a treatment consensus in the interdisciplinary tumor board has to precede any therapeutical decisions.

Acute cauda equina syndrome secondary to lumbar chordoma: case report and literature review

BACKGROUND CONTEXT

Chordomas are rare tumors in the craniospinal axis arising from persistent notochordal rests commonly seen in the skull base, including the clivus and the sacrum. Chordomas in the mobile spine occur less commonly. To the best of our knowledge, the clinical presentation of acute cauda equina syndrome (CES) due to chordoma of the lumbar vertebra is not published in the English literature.

PURPOSE

To describe an unusual cause of acute CES resulting from chordoma of the lumbar vertebra and discuss management dilemmas in this clinical context.

STUDY DESIGN

Case report with review and discussion.

METHODS

We report the case of a 75-year-old man who presented with acute CES that was clinically considered a metastasis from his previously documented carcinoma of the urinary bladder treated a year ago. Clinical, radiological, and histopathological features of the case and a review of chordomas in the lumbar vertebrae in adults in the published English literature are presented.

RESULTS

He underwent urgent surgical decompression with laminectomy of L3/L4 and L4/L5 with debulking and open biopsy of the tissue mass. Histopathological examination of the tissue mass confirmed the unsuspected diagnosis of chordoma. The salient features of chordomas in the lumbar vertebrae published in the English literature over the last 22 years are summarized. The origin, classification, clinical presentation, and management protocols for lumbar chordomas are also reviewed.

CONCLUSIONS

The clinical presentation of acute CES as the first symptom of chordoma in the lumbar vertebrae is extremely rare. Preoperative tissue diagnosis of this uncommon pathology is usually unavailable. In the face of acute CES, surgical decompression remains the primary goal of management with a planned definitive second-stage curative surgical resection for chordoma.

En bloc resection of a multilevel high-cervical chordoma involving C-2: new operative modalities

En bloc resection of cervical chordomas has led to longer survival rates but has resulted in significant morbidities from the procedure, especially when the tumor is multilevel and located in the high-cervical (C1–3) region. To date, there have been only 5 reported cases of multilevel en bloc resection of chordomas in the high-cervical spine. In this technical report the authors describe a sixth case. A complete spondylectomy was performed at C-2 and C-3 with spinal reconstruction and stabilization, using several new modalities that were not used in the previous cases. The use of 1) preoperative endovascular sacrificing of the vertebral artery, 2) CT image-guidance, 3) an ultrasonic aspirator for skeletonizing the vertebral artery, and 4) the custom design of an anterior cage all contributed to absence of intraoperative or long-term (20 months) hardware failure and pseudarthrosis.

Expert's comment concerning Grand Rounds case entitled "a novel 'pelvic ring augmentation construct' for lumbo-pelvic reconstruction in tumor surgery" (by Sathya Thambiraj, Daren Forward, James Thomas and Bronek Boszczyk)

INTRODUCTION

Historically, metastatic spine tumor surgery has been palliative for pain control, to maintain neurologic and ambulatory function. The thought of curing cancer with limited metastatic disease by resecting the primary and the metastatic lesions is becoming more common. Multilevel spondylectomy for resection of metastatic disease has been reported in the literature, mostly at the thoracic or lumbar level with some success. Reconstruction of the lumbosacral junction after tumor resection is a difficult endeavor and several techniques have been utilized. Subcutaneous anterior pelvic fixation has been described for the treatment of unstable pelvic fractures.

MATERIALS AND METHODS

Review of the Grand Rounds case "A novel Pelvic Ring Augmentation Construct for Lumbo-Pelvic Reconstruction in Tumour Surgery" by Sathya Thambiraj, Daren Forward, James Thomas, Bronek Boszczyk and review of the pertinent literature.

CONCLUSION

The authors describe a novel percutaneous rod technique and construct for buttressing a posterior spinal construct to a subcutaneous anterior pelvic fixator after tumor resection of the lumbo-pelvic junction. They manage to salvage a difficult situation for which they should be commended. This technique may be useful in situations where instrumentation has to be preformed to the pelvis: i.e., in tumor reconstruction, fusions such as neuromuscular scoliotic disease to the pelvis, to augment a lumbo-pelvic construct when a nonunion occurs or in osteoporotic patients as a salvage procedure.

Anterior construct location following vertebral body metastasis reconstruction through a posterolateral transpedicular approach: does it matter?

Object

The posterolateral transpedicular approach (PTA) is a widely used method for the surgical treatment of vertebral body metastases. It is crucial to understand the optimal location of the anterior graft in terms of sound and durable reconstruction following PTA. The purpose of this study was to investigate whether postoperative construct stability is related to the location of anterior grafts.

Methods

The authors conducted a retrospective review of 45 cases of metastatic spine disease with epidural tumor extension in which patients underwent circumferential decompression and fusion by means of PTA. Mechanical (anterior construct stability), pain (visual analog scale score), and neurological (American Spinal Injury Association scale) outcomes were evaluated and correlated with the anterior graft location (lateral or central) and surgical approach (unilateral or bilateral), number of decompressed levels, types of anterior graft, screw density of posterior fixation (number of screws used divided by the number of pedicles spanned), and kyphotic angle change from the immediate postoperative period to the most recent follow-up.

Results

Seven of 45 constructs were judged unstable—5 with a lateral location of the anterior graft and 2 with a central location.

The anterior graft was located laterally in 31 cases (69%), centrally in 11 (24%), and bilaterally in 3 (7%). A unilateral approach was used in 33 cases and a bilateral approach in 12. Neither the location of the anterior graft nor the approach had a significant effect on the stability of the reconstructed spine (p > 0.05). There was a significant difference in construct stability between the single-level decompression group (33 patients) and the multiple-level decompression group (12 patients) (p = 0.0001). The types of anterior graft, screw density, and kyphotic angle change were not correlated to the mechanical outcome.

Conclusions

The anterior graft location showed no significant relationship to the final mechanical, pain, and neurological outcomes.

Surgical management of primary bone tumors of the spine: validation of an approach to enhance cure and reduce local recurrence

STUDY DESIGN

Multicenter ambispective cohort analysis.

OBJECTIVE

The purpose of this study is to determine whether applying Enneking's principles to surgical management of primary bone tumors of the spine significant decreases local recurrence and/or mortality.

SUMMARY OF BACKGROUND DATA

Oncologic management of primary tumors of spine has historically been inconsistent, controversial, and open to individual interpretation.

METHODS

A multicenter ambispective cohort analysis from 4 tertiary care spine referral centers was done. Patients were analyzed in 2 cohorts, "Enneking Appropriate" (EA), surgical margin as recommended by Enneking, and "Enneking Inappropriate" (EI), surgical margin not recommended by Enneking. Benign tumors were not included in mortality analysis.

RESULTS

Two cohorts represented an analytic dataset with 147 patients, 86 male, average age 46 years (range: 10-83). Median follow-up was 4 (2-7) years in the EA and 6 (5.5-15.5) years in the EI. Seventy-one patients suffered at least 1 local recurrence during the study, 57 of 77 in the EI group and 14 of 70 in the EA group. EI surgical approach caused higher risk of first local recurrence (P < 0.0001). There were 48 deaths in total; 29 in the EI group and 19 in the EA. There was a strong correlation between the first local recurrence and mortality with an odds ratio of 4.69, (P < 0.0001). EI surgical approach resulted in a higher risk of mortality with a hazard ratio of 3.10, (P = 0.0485) compared to EA approach.

CONCLUSION

Surgery results in a significant reduction in local recurrence when primary bone tumors of the spine are resected with EA margins. Local recurrence has a high concordance with mortality in resection of these tumors. A significant decrease in mortality occurs when EA surgery is used.

Total en bloc spondylectomy of the lower lumbar spine: a surgical techniques of combined posterior-anterior approach

STUDY DESIGN

Ten patients with a spinal tumor of the lower lumbar spine underwent total en bloc spondylectomy (TES) by combined posterior-anterior approach. The oncological and neurologic results are analyzed.

OBJECTIVE

To describe the surgical technique and evaluate the clinical outcome of this surgery.

SUMMARY OF THE BACKGROUND DATA

TES at lower lumbar spine is technically challenging because of its anatomy such as the presence of major vessels and lumbosacral plexus nerves.

METHODS

Six aggressive benign tumors and 4 solitary spinal metastases involving L4 or L5 were treated. The approache of operative procedure are discussed as follows: Posterior approach: Dissection of the lumbar nerve roots to the conjunction of the adjacent nerves were performed after en bloc laminectomy by T-saw pediculotomy. The psoas muscle was dissected away, from the vertebral body. The posterior halves of the anterior column at the craniocaudal adjacent levels of the lumbar tumor were cut. Anterior approach: Major vessels were dissected from the vertebral body. Anterior halves of the anterior column were cut at the corresponding levels. The tumor vertebral body was removed en bloc, followed by anterior spinal reconstruction.

RESULTS

Seven of 10 cases had no evidence of disease at 57 months on average, 1 case was alive with disease at 66 months, 1 case had death of disease at 42 months, and 1 case had death of another disease at 14 months after surgery. All patients improved or preserved neurologic in the last follow up. The resected specimen of vertebral bodies and laminae showed marginal or wide margin in all cases, although pedicles showed intralesional margin in 8 cases. No local recurrence was observed during lifetime with mean 52 months.

CONCLUSION

TES for spinal tumor of L4 or L5 preserving lumbar nerves was achieved by combined posterior- anterior approach.

En Bloc Resection for Primary and Metastatic Tumors of the Spine

BACKGROUND

The efficacy of en bloc resection for spinal tumors is unknown because most of the current evidence is provided by small, single-institution clinical series or case reports.

OBJECTIVE

To combine all previously published reports of en bloc resection for primary and metastatic spinal tumors, to describe the overall pattern of disease-free survival, and to investigate potentially prognostic factors for recurrence.

METHODS

A complete MEDLINE search for all articles reporting survival data for en bloc resection of spinal tumors was undertaken; 44 articles met inclusion criteria from which 306 eligible patients were identified.

RESULTS

There were 229 cases of primary tumors with a mean follow-up of 65.0 months and 77 cases of solitary metastatic tumors with a mean follow-up of 26.5 months. Median time to recurrence was 113 months for the primary group and 24 months for the metastatic group. Disease-free survival rates at 1, 5, and 10 years were 92.6%, 63.2%, and 43.9%, respectively, for the primary group and 61.8%, 37.5%, and 0%, respectively, for the metastatic group; 5-year disease-free survival rates were 58.4% for chordoma and 62.9% for chondrosarcoma. After adjusting for covariates, age, male sex, metastatic tumors, and osteosarcomas were significantly associated with a tumor recurrence.

CONCLUSION

This study provides the largest published series of patients undergoing en bloc resection for spinal tumors. Median time to recurrence reached almost 10 years in patients with primary tumors; however, it was only 2 years in those with isolated metastatic tumors.

Chordoma of the sacrum and vertebral bodies

Chordomas are relatively rare tumors of bone. These primary malignant lesions occur throughout the spinal column and often show advanced growth at the time of diagnosis. Because such tumors are minimally responsive to radiation and chemotherapy, surgical resection is the mainstay of treatment. Patient survival and local control are associated with the ability to achieve wide surgical margins during excision. However, surgical morbidity may be substantial given the propensity for chordomas to abut or surround neural, vascular, and visceral structures. Thus, early recognition is essential, and treatment by a multidisciplinary team is ideal.

Solitary vertebral metastasis

As survival time increases for many cancers, it is likely that the incidence and prevalence of spinal metastases will increase also. Given that most patients first present with solitary lesions in the spine, proper initial diagnosis and management are of paramount importance in minimizing pain, improving neurologic function, and potentially lengthening survival. Although pain control and standard radiation are still used, spinal stereotactic radiosurgery, vertebroplasty and kyphoplasty, and spinal cord decompression and fusion are now consistently used in aggressive management and offer exciting preliminary results.

Chordoma: the nonsarcoma primary bone tumor

Chordomas are rare, slowly growing, locally aggressive neoplasms of bone that arise from embryonic remnants of the notochord. These tumors typically occur in the axial skeleton and have a proclivity for the spheno-occipital region of the skull base and sacral regions. In adults, 50% of chordomas involve the sacrococcygeal region, 35% occur at the base of the skull near the spheno-occipital area, and 15% are found in the vertebral column. Craniocervical chordomas most often involve the dorsum sella, clivus, and nasopharynx. Chordomas are divided into conventional, chondroid, and dedifferentiated types. Conventional chordomas are the most common. They are characterized by the absence of cartilaginous or additional mesenchymal components. Chondroid chordomas contain both chordomatous and chondromatous features, and have a predilection for the spheno-occipital region of the skull base. This variant accounts for 5%-15% of all chordomas and up to 33% of cranial chordomas. Dedifferentiation or sarcomatous transformation occurs in 2%-8% of chordomas. This can develop at the onset of the disease or later. Aggressive initial therapy improves overall outcome. Patients who relapse locally have a poor prognosis but both radiation and surgery can be used as salvage therapy. Subtotal resection can result in a stable or improved status in as many as 50% of patients who relapse after primary therapy. Radiation therapy may also salvage some patients with local recurrence. One series reported a 2-year actuarial local control rate of 33% for patients treated with proton beam irradiation.

En bloc resection of a C4 chordoma: surgical technique

The prognosis of aggressive benign and low-grade malignant tumors in the spine as in the limbs, seems to be mostly related to the feasibility of en bloc resection, while in the treatment of high-grade malignant tumors the protocols of treatment include the combination of chemotherapy, radiation and surgery. Indications, criteria of feasibility and surgical technique are extensively reported for the thoracic and lumbar spine. In the cervical spine few cases are reported of resection, due not only to anatomical constraint, but also to the rarity of finding a tumor accomplishing the criteria of feasibility. A case of double-approach vertebrectomy finalized to remove en bloc the body of C4 for a stage IA chordoma is reported. The first stage was posterior, aiming to remove the posterior healthy elements by piecemeal technique. The anterior approach consisted of contemporary right and left prevascular presternocleidomastoid approaches The specimen was submitted for the histological study of the margins, which resulted tumor-free. This technical note is finalized to confirm that en bloc resection of the vertebral body through total vertebrectomy is feasible in the midcervical spine by double approaches, provided the tumor involves only layers B and C, maximum extension sectors 5-8.

Total L-5 spondylectomy and reconstruction of the lumbosacral junction

✓The authors describe a technique for total L-5 spondylectomy and reconstruction of the lumbosacral junction. The technique, which involves separately staged posterior and anterior procedures, is reported in two patients harboring neoplasms that involved the L-5 level. The first stage consisted of a posterior approach with removal of all posterior bone elements of L-5 and radical L4–5 and L5–S1 discectomies. Lumbosacral and lumbopelvic instrumentation included pedicle screws as well as iliac screws or a transiliac rod. The second stage consisted of an anterior approach with mobilization of vascular structures, completion of L4–5 and L5–S1 discectomies, and removal of the L-5 vertebral body. Anterior lumbosacral reconstruction included placement of a distractable cage and tension band between L-4 and S-1. Allograft bone was used for fusion in both stages. No significant complications were encountered. At more than 1 year of follow-up, both patients were independently ambulatory, without evidence of recurrent or metastatic disease, and adequate lumbosacral alignment was maintained. The authors conclude that this technique can be safely performed in appropriately selected patients with neoplasms involving L-5.

Morphometric effects of acute shortening of the spine: the kinking and the sliding of the cord, response of the spinal nerves

Spinal shortening is performed for a wide spectrum of diseases. This study was designed to investigate the morphologic effects of shortening on the spinal cord, to enlighten the amount and direction of the sliding of the cord, the alteration of the angles of the roots, and to identify the appropriate laminectomy length. Total vertebrectomy of T12 was applied to ten sheep models after spinal instrumentation. Gradual shortening was applied to five sheep; then, the degree and direction of the sliding of the spinal cord and the angles of the adjacent roots were measured. On five other sheep, additional sagittal sectioning was performed via excision of the pedicles. Measurements were taken at different laminectomy lengths to record kinking of the spinal cord with gradual shortening. The mean sliding of the spinal cord was 9 mm cranially and 7.8 mm caudally. T11 spinal nerves became more vertical caudally, and T12 spinal nerves achieved an ascending position with gradual shortening. Both T11 and T12 spinal nerves were sharply bent in the foramen and on the pedicle of T13, respectively. In full-length shortening, the mean kink of the spine in the sagittal plane was 92.4 degrees for two levels of hemi-laminectomies, 24.6 degrees for complete laminectomy of T11 with hemilaminectomy of T13, and 20.2 degrees for two levels of complete laminectomies. The slippage of the cord is dominant in the earlier stages and kinking is dominant in later stages of shortening. Increasing the laminectomy length by only a half or one level prevents excessive kinking and compressions at the upper and lower margins of the laminectomy. In the later stages of shortening, the spinal nerves near the vertebrectomy site are at risk because of the sharp bending of the nerves. This study describes the mechanism of the sliding and kinking of the cord due to gradual shortening of the spine, which might be useful in spinal surgery procedures. It also states that it is possible to avoid excessive kinking by planning the appropriate technique of laminectomy style in full-length shortening.

En bloc marginal excision of a multilevel cervical chordoma

✓ The purpose of this case report is to demonstrate that an en bloc resection with negative surgical margins can be successfully achieved in a case of a seemingly unresectable C-2 chordoma if appropriate preoperative staging and planning are performed. The management of chordomas is controversial and challenging because of their location and often large size at presentation. Because chordomas are malignant and will aggressively recur locally if intralesional resection is conducted, wide or true en bloc resection is generally recommended. The literature indicates, however, that surgeons are reluctant to perform wide or even marginal resections because of the lesion’s complex surrounding anatomy and the risk of significant neurological compromise when a tumor abuts the dura mater or neural tissues. In this report the authors outline the successful en bloc resection of a large C1–3 chordoma and discuss the importance of preoperative staging and planning.

Chordoma of the mobile spine: fifty years of experience

STUDY DESIGN

A consecutive series of 52 chordomas of the mobile spine observed over a 50-year period includes a retrospective review of 15 cases treated prior to 1991 and a prospective group of 37 cases treated from 1991 to 2002.

OBJECTIVES

This series reviews epidemiologic issues as well as clinical patterns of spinal chordomas. We attempt to correlate tumor extent, treatment, and outcomes over time.

SUMMARY OF BACKGROUND DATA

Chordoma is the most frequent primary tumor of the mobile spine. Due to slow growth, both initial symptoms and recurrences after treatment arise later, making it difficult to evaluate the effectiveness of treatment protocols.

METHODS

A prospective series of 37 cases is compared with a retrospective group of 15 patients observed between 1954 and 1991. In the prospective study, all patients had imaging studies, and oncologic and surgical staging. When en bloc resection was not feasible, intralesional extracapsular excision was combined with radiation therapy. The prospective patients were clinically evaluated and imaged. Patients in the retrospective group were evaluated by chart and available images; of these, only one en bloc resection (intralesional margin) was performed. Survivors were all evaluated clinically and had radiographic studies.

RESULTS

Forty-eight patients were available for long-term follow-up. Four died due to post-operative complications, and six due to disease less than 2 years after treatment. Forty-two patients were followed over 2 years; 26 patients had over 5 years follow-up. All patients having radiation alone, intralesional excision, or a combination had recurrences in less than 2 years, and died in some cases after a long survival with symptomatic disease. Intralesional extracapsular excision with radiation had a high rate of recurrence (12 of 16 at average 30 months), but 3 patients are continuously disease-free (CDF) at mean 52 months and 5 are alive with disease at average 69 months (ranging 24 to 146). Twelve of 18 patients having en bloc resection are CDF at average 8 years (48 to 155 months). The remaining 6 recurred and of these 1 died. All of these (6) had been previously treated and/or had en bloc resections with contaminated margins.

CONCLUSIONS

The only treatment protocol associated with CDF at follow-up longer than 5 years is margin-free en bloc resection.

The surgical management of primary tumorsof the spine: initial results of an ongoing prospective cohort study

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

To prospectively validate the application of appendicular surgical oncology principles to the treatment of primary bone tumors of the spine at a quaternary care spine center using local recurrence, survival, and health-related quality of life as outcome measures.

SUMMARY OF BACKGROUND DATA

There is clear evidence that violating the margins of a sarcoma or other malignancy during surgical resection will risk local recurrence and diminish overall survival. Previous publications have retrospectively demonstrated this oncologically sound approach to spine tumor management to be internally valid. The external validity or limited generalizability has not been assessed.

METHODS

Included were all patients who underwent en bloc surgical resection of a primary tumor of the spine between January 1994 and November 2003, at the authors' institution. Patients were uniformly staged before surgery and baseline demographic and surgical variables were recorded, as well as a cross-sectional evaluation of generic health-related quality of life.

RESULTS

Twenty-six patients (12 males and 14 females) were eligible for the study. Average age was 42 (range 16 to 70). There were 19 malignant tumors and 7 benign. There are 20 surviving patients with an average follow-up of 41.5 months (range 6 to 111 months), 15 of whom had malignant tumors. None of these patients have evidence of local recurrence, and one has evidence of systemic disease. The health-related quality of life, using the SF-36, shows acceptable morbidity of these procedures (physical component summary = 37.73 +/- 11.52, MCS = 51.69 +/- 9.54).

CONCLUSIONS

Principles of wide surgical resection, commonly applied in appendicular oncology, can and should be used for the treatment of primary bone tumors of the spine with anticipated acceptable morbidity and satisfactory survival.

Principles and techniques of en bloc vertebrectomy for bone tumors of the thoracolumbar spine: an overview

Oncological principles for en bloc resection of bone tumors were initially developed for tumors of the long bone by orthopedic surgical oncologists. Recently, spine surgeons have adopted these principles for the treatment of vertebral column tumors. The goal of en bloc resection is to establish a surgical margin that can be designated marginal or wide. In this article, the principles of surgical oncology for bone tumors of the spine are briefly reviewed and the different surgical approaches used to remove these tumors in an en bloc fashion are described in detail.

Surgery for solitary metastases of the spine: rationale and results of treatment

STUDY DESIGN

A spine tumor database of patients with solitary sites of spine involvement from solid tumors was retrospectively reviewed.

OBJECTIVES

To analyze the long-term survival, neurologic outcome, and results of surgery in a well-defined subset of patients who had spinal metastases with epidural extension to define future treatment strategies.

SUMMARY OF BACKGROUND DATA

Currently accepted indications for surgical treatment of spinal metastases include histologic diagnosis, neurologic palliation in those who have failed prior irradiation, and spinal stabilization. In all others, external irradiation is considered the mainstay of therapy. Several studies have shown that prior irradiation increases the frequency of complications from surgery and affects functional outcome.

METHODS

A retrospective review of 80 consecutive patients with solitary sites of spine involvement from solid tumors with varying degrees of epidural extension was performed. Complete clinical and radiologic follow-up assessment was available for all the patients. Clinical parameters, neurologic grade, preoperative pain, radiologic evaluation, and outcome measures were analyzed. Survival analysis was performed using the Kaplan-Meier product limit method, and differences between subgroups were analyzed using chi2. Prognostic factors for long-term survival also were evaluated.

RESULTS

The overall median survival after surgery was 30 months, with 18% surviving 5 years or more. Survival varied by tumor type, with the best prognosis noted in patients with breast or kidney cancer. The surgical morbidity was significantly higher in those receiving prior irritation (P < 0.03), and the local recurrence rate also increased in patients who had received prior irradiation.

CONCLUSIONS

Patients with solitary sites of spine involvement from solid tumors represent a biologically favorable subgroup with potential for long-term survival. In this group, complete surgical excision before irradiation should be considered to increase the prospects of long-term palliation and possible cure.

Relationship between surgical margins and local recurrence in sarcomas of the spine

The combination of improved resection, stabilization, and fusion techniques allows for more aggressive removal of malignant spinal tumors with acceptable mortality and morbidity. Thirty consecutive patients with primary sarcomas of the mobile spine, who were operated on at the authors' institution from January 1970 to December 2000, were included in the current study. Demographic information, tumor location, type of resection, resection margins, local recurrence, and overall survival data were retrieved and analyzed. Treatment consisted of en bloc resection in 12 patients (40%) and piecemeal resections in 18 patients (60%). The resection was classified as wide in seven patients (23.3%), marginal in three patients (10%), and intralesional in 20 patients (66.7%). Pathology reports showed tumor-free resection margins in 12 patients (40%). In the remaining 18 patients (60%), resection margins were positive and resulted in a fivefold increase in the risk of a local recurrence. Ninety-two percent of the patients with local recurrence died of sequelae associated with the local recurrence. Primary sarcomas of the mobile spine in certain cases, can be removed completely with tumor-free resection margins. En bloc resection with tumor-free margins provides substantial improvement in overall survival.

En bloc removal of the lower lumbar vertebral body for chordoma. Report of two cases

En bloc removal of the lower lumbar vertebral bodies (VBs) is a major surgical challenge. The authors describe the surgical technique used in two patients who presented with chordoma confined to the L-5 and L-4 VB, respectively. These tumors were diagnosed using magnetic resonance (MR) imaging during investigation for back pain. Both patients underwent a combined (two-stage) anterior-posterior approach. In the first case the posterior stage of the procedure was followed by an anterior retroperitoneal approach, and in the second case a lateral retroperitoneal approach was used. Complete en bloc excision of the tumor was achieved in each case, even though in the second case the VB fractured when it was mobilized. The correlation between the MR imaging findings and surgical specimens was remarkable. The authors conclude that en bloc resection is feasible in these cases. Because mobilization of the VB is more difficult in the lateral approach, the authors favor the anterior retroperitoneal approach. The authors anticipate the need for such procedures to increase with the widespread use of MR imaging, which demonstrates the extent of these tumors with remarkable accuracy.

Single-stage posterolateral transpedicle approach for spondylectomy, epidural decompression, and circumferential fusion of spinal metastases

STUDY DESIGN

Retrospective review of prospectively maintained institutional spine database.

OBJECTIVES

To assess the pain, neurologic, and functional outcome of patients with metastatic spinal cord compression using a posterolateral transpedicular approach with circumferential fusion.

SUMMARY OF BACKGROUND DATA

Patients with spinal metastases often have patterns of disease requiring both an anterior and posterior surgical decompression and spinal fusion. For patients whose concurrent illness or previous surgery makes an anterior approach difficult, a posterior transpedicular approach was used to resect the involved vertebral bodies, posterior elements, and epidural tumor. This approach provides exposure sufficient to decompress and instrument the anterior and posterior columns.

METHODS

During the past 15 months, 25 patients were operated on using a posterolateral transpedicular approach. The primary indications for surgery were back pain (15 patients) and neurologic progression (10 patients). All patients had vertebral body disease, and 21 patients had high-grade spinal cord compression from epidural disease as assessed by magnetic resonance imaging. Seven patients underwent preoperative embolization for vascular tumors. In each patient, the anterior column was reconstructed with polymethyl methacrylate and Steinmann pins and the posterior column with long segmental fixation.

RESULTS

All patients achieved immediate stability. Pain relief was significant in all 23 patients who had had moderate or severe pain. Neurologic symptoms were stable or improved in 23 patients. One patient with an acutely evolving myelopathy was immediately worse after surgery, and one patient had a delayed neurologic worsening, progressing to paraplegia.

CONCLUSIONS

The posterolateral transpedicular approach provides a wide surgical exposure to decompress and instrument the anterior and posterior spine. This technique avoids the morbidity associated with anterior approaches and provides immediate stability. Vascular tumors may be removed safely after embolization. Patients can be mobilized early after surgery.