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.
Robert J. Bohinski and Laurence D. Rhines
Technical note and description of operative technique
Robert J. Bohinski, Ehud Mendel and Laurence D. Rhines
✓ The authors describe and demonstrate an innovative modification of the osteotomy procedure required to achieve a supraforaminal high sacral amputation in a patient harboring a large sacral chordoma. Via a combined anterior—posterior approach, three carefully placed threadwire saws were used to create releasing osteotomies through specific portions of the dorsal iliac crests and through the axial midportion of the S-1 vertebral body. The threadwire saws are pulled away from neurovascular and visceral structures, ensuring greater protection. Other advantages include markedly reduced blood loss while performing the osteotomies, a high degree of cutting accuracy, negligible bone loss, and ease and speed of bone cutting.
Ganesh Rao, Robert Bohinski, Iman Feiz-Erfan and Laurence D. Rhines
✓The retroperitoneal surgical approach has gained acceptance as a way to access the ventral aspect of the lumbar spine. Visualization is often limited, however, by the psoas muscle, which lies along the posterolateral aspect of the spine. Improved visualization is often attempted by retracting the muscle from the wound, which generally pulls the muscle laterally from the spine but not posteriorly, which is desirable for a better exposure of the spine, particularly the neural elements. In this paper, the authors describe a simple, atraumatic technique for retraction of the psoas muscle that allows excellent visualization of the spine.
Claudio E. Tatsui, Ganesh Rao and Laurence D. Rhines
Allen W. Burton, Laurence D. Rhines and Ehud Mendel
Vertebroplasty and kyphoplasty are relatively new techniques used to treat painful vertebral compression fractures (VCFs). Vertebroplasty is the injection of bone cement, generally polymethyl methacrylate (PMMA), into a vertebral body (VB). Kyphoplasty is the placement of balloons (called “tamps”) into the VB, followed by an inflation/deflation sequence to create a cavity prior to the cement injection. These procedures are most often performed in a percutaneous fashion on an outpatient (or short stay) basis. The mechanism of action is unknown, but it is postulated that stabilization of the fracture leads to analgesia. The procedures are indicated for painful VCFs due to osteoporosis or malignancy, and for painful hemangiomas. These procedures may be efficacious in treating painful vertebral metastasis and traumatic VCFs. Much evidence favors the use of these procedures for pain associated with the aforementioned disorders. The risks associated with the procedures are low but serious complications can occur. These risks include spinal cord compression, nerve root compression, venous embolism, and pulmonary embolism including cardiovascular collapse. The risk/benefit ratio appears to be favorable in carefully selected patients. The technical aspects of the procedures are presented in detail along with guidelines for patient selection. A comprehensive review of the evidence for the procedures and the reported complications is presented.
Stephen J. Hentschel, Ehud Mendel, Sanjay Singh and Laurence D. Rhines
✓ Despite the relatively high incidence of prostate carcinoma involving the spinal column, those that are associated with spinal intradural extramedullary metastases are rare. The role of surgery for metastases to this spinal compartment is limited and palliative because presentation tends to be late in the course of the disease, particularly for prostate carcinoma. It is also considered to be part of the spectrum of leptomeningeal carcinomatosis and is associated with a high incidence of brain metastases. The authors review a rare case of prostate carcinoma metastatic to the spinal intradural extramedullary space and discuss its clinical presentation, imaging features, and surgical management.
Michele R. Aizenberg, Benjamin D. Fox, Dima Suki, Ian E. McCutcheon, Ganesh Rao and Laurence D. Rhines
Patients presenting with spinal metastases from unknown primary tumors (UPTs) are rare. The authors reviewed their surgical experience to evaluate outcomes and identify predictors of survival in these patients.
This study is a retrospective analysis of patients undergoing surgery for metastatic spine disease from UPTs between June 1993 and February 2007 at The University of Texas M. D. Anderson Cancer Center.
Fifty-one patients undergoing 52 surgical procedures were identified. The median age at spine surgery was 60 years. The median survival from time of diagnosis was 15.8 months (95% CI 8.1–23.6) and it was 8.1 months (95% CI 1.6–14.7) from time of spine surgery. Postoperative neurological function (Frankel score) was the same or improved in 94% of patients. At presentation, 77% had extraspinal disease, which was associated with poorer survival (6.4 vs 18.1 months; p = 0.041). Multiple sites (vs a single site) of spine disease did not impact survival (12.7 vs 8.7 months; p = 0.50). Patients with noncervical spinal disease survived longer than those with cervical disease (11.8 vs 6.4 months, respectively; p = 0.029). Complete versus incomplete resection at index surgery had no impact on survival duration (p > 0.5) or local recurrence (p = 1.0). Identification of a primary cancer was achieved in 31% of patients.
This is the first reported surgical series of patients with an unknown source of spinal metastases. The authors found that multiple sites of spinal disease did not influence survival; however, the presence of extraspinal disease had a negative impact. The extent of resection had no effect on survival duration or local recurrence. With an overall median survival of 8.1 months following surgery, aggressive evaluation and treatment of patients with metastatic disease of the spine from an unknown primary source is warranted.
Case report and review of the literature
Robert J. Bohinski, Ehud Mendel, Kenneth D. Aldape and Laurence D. Rhines
✓ Solitary fibrous tumor is a spindle cell tumor deriving from mesenchymal cells that arises most commonly in the pleura. Only very recently has this tumor been reported in the spine. A solitary fibrous tumor strongly resembles other spindle cell neoplasms of the spine and may be an unrecognized entity if not routinely considered in the differential diagnosis of spinal neoplasms. The authors report an unusual intra- and extramedullary location for a solitary fibrous tumor of the cervical spine. Findings in this case and a comprehensive review of the literature indicate that solitary fibrous tumors can originate from various spinal anatomical substrates and mimic both intra- and extramedullary tumor types.
Case report and description of operative technique
Laurence D. Rhines, Daryl R. Fourney, Abdolreza Siadati, Ian Suk and Ziya L. Gokaslan
✓ Chordomas are locally aggressive neoplasms with an extremely high propensity to recur locally following resection, despite adjuvant therapy. This biological behavior has led most authors to conclude that en bloc resection provides the best chance for the patient's prolonged disease-free survival and possible cure.
The authors present a case of an extensive upper cervical chordoma treated by en bloc resection, reconstruction, and long-segment stabilization. Total spondylectomy of C2–4 with sacrifice of the right C2–4 nerve roots and a segment of the right vertebral artery was performed. The inherent anatomical complexities of en bloc resection in the upper cervical spine are discussed. To the authors' knowledge, this represents the first report of an en bloc resection for multilevel cervical chordoma.
Stephen J. Hentschel, Allen W. Burton, Daryl R. Fourney, Laurence D. Rhines and Ehud Mendel
Object. The purpose of this study was to examine a group of patients with cancer who underwent a vertebroplasty or a kyphoplasty for a vertebral body (VB) fracture, even though the procedure may have been considered contraindicated based on previous reports in the literature.
Methods. The electronic database maintained by the Departments of Neurosurgery and Anesthesiology—Pain Management at the University of Texas M. D. Anderson Cancer Center was searched for patients who underwent vertebroplasty or kyphoplasty between January 2001 and July 2003. The criteria defining a contraindicated procedure were based on a review of the literature. Group I consisted of patients who did not undergo a contraindicated vertebroplasty or kyphoplasty, whereas Group II consisted of patients who underwent one of these procedures even though it may have been considered contraindicated.
There were 53 patients with fractures at 132 levels who met the criteria for the study. Of these, 17 patients with fractures at 18 levels (14% of total) were considered to have undergone a contraindicated vertebroplasty or kyphoplasty (Group II). There were 12 complications (11%) in the 114 levels in Group I and seven complications (39%) in the 18 levels in Group II (p = 0.03). The most common complication was cement extrusion from the anterior VB that did not involve the venous system. No patient required an open surgical procedure to remove extruded cement.
Conclusions. Vertebroplasty and kyphoplasty appear to be safe and effective in the setting of severe back pain caused by VB fracture that is unresponsive to other therapies, even in the presence of relative contraindications to the procedures.