Surgical management of metastatic spinal neoplasms · Surgical management of metastatic spinal neoplasms FRANK D. VRIONIS, M.D., PH.D. AND JOHN SMALL, M.D. H. Lee Moffitt Cancer Center

Approximately 1.2 million cases of cancer are diag-nosed annually in the US. The skeletal system is the thirdmost common site of metastases, with the spine being themost common site of osseous metastasis.1,31 Approximate-ly 1 to 5% of all patients with cancer will present with spi-nal cord compression. Although the incidence of paralysishas decreased somewhat because of new imaging modal-ities and earlier detection, the cost and significance of thisdisability has immense importance for the patient and so-ciety.13

Most patients with cancer who are nonambulatory diewithin 45 days due to a variety of factors.29 They are lesslikely to be treated aggressively with chemotherapy orradiation therapy, and they are also exposed to increasedrisk of sepsis, pneumonia, pulmonary embolism, anddecubitus ulcers. In addition, bladder and bowel inconti-nence creates a psychological and physical burden on pa-tients and their families. For these reasons, aggressivemultimodality treatment has been instituted in most can-cer centers in the US. Surgery plays an important role in

the treatment of patients with spinal cord compression.Other treatments include radiation therapy, chemotherapy,external bracing, pain management, and in certain cases,radiosurgery.

Recent studies have shown that resection accompaniedby spinal stabilization offers patients a greater than 95%improvement in pain, with 90% or more of patients main-taining ambulatory status.30 In addition, preliminary re-sults of a new randomized trial of patients with metastaticspine tumors with cord compression treated either withsurgery followed by radiotherapy or radiotherapy aloneshowed a statistically significantly improved quality oflife in the surgical arm.25 In that study, patients treatedwith both surgery and radiation therapy maintained conti-nence and retained their ability to walk much longer thanpatients treated with radiation therapy (126 comparedwith 35 days). Although there was no statistically signifi-cant difference in immediate survival, there was a trendtoward improved survival with surgery followed by radi-ation therapy.

In this article we review our experience with the sur-gical management of metastatic spine tumors over the last3 years at a comprehensive cancer center, with attentiongiven to surgical techniques, types of reconstruction, andoutcomes.

Neurosurg Focus 15 (5):Article 12, 2003, Click here to return to Table of Contents

Surgical management of metastatic spinal neoplasms

FRANK D. VRIONIS, M.D., PH.D. AND JOHN SMALL, M.D.

H. Lee Moffitt Cancer Center and Research Institute, Neuro-Oncology Program, and Departments ofNeurosurgery and Interdisciplinary Oncology, University of South Florida College of Medicine andFlorida Orthopedic Institute, Tampa, Florida

Object. In this study the authors retrospectively review outcomes in patients treated for metastases to the spine.Surgery for metastatic tumors to the spine remains an important part of the treatment armamentarium. Maximum tumorresection with a minimum number of complications is one of the goals of surgery. Current surgical procedures includetumor resection and spinal stabilization for optimal results.

Methods. The records of 96 patients who underwent surgery for a metastatic spine tumor at the authors’ institutionwere reviewed. Spinal instrumentation was used in the majority of patients. Ambulatory status was maintained in 91%and pain improved in 94% of patients. Complications included infection (5.2%), cerebrospinal fluid leak (2%), anddelayed hardware failure (3.1%). The mortality rate was 4.1%; the main cause was due to tumor progression.

Conclusions. Surgery is indicated in a select group of patients with metastatic tumors to the spine. A multidiscipli-nary approach is recommended for patient selection and complication avoidance. Surgical options, including approach,type of reconstruction and extent of resection (including en bloc spondylectomy) need to be addressed for optimal out-comes.

KEY WORDS • metastasis • spine tumor • spinal instability • spinal stabilization

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Abbreviations used in this paper: CSF = cerebrospinal fluid;MMA = methylmethacrylate; MR = magnetic resonance; VB = ver-tebral body.

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CLINICAL MATERIAL AND METHODS

Patient Population

Between September 1, 2000, and September 1, 2003,96 patients with metastatic spine tumors underwent a totalof 108 operations at H. Lee Moffitt Cancer Center, and arethe focus of this study. There were 56 male and 40 femalepatients with a mean age of 53 years (range 10–76 years).Patients with chordomas, primary bone tumors, and non-metastatic lesions were excluded. The patients’ hospitalrecords were retrospectively reviewed.

Evaluation and Indications for Surgery

Preoperative evaluation included a neurological exami-nation, MR imaging, and plain x-ray films. In selectedcases, computerized tomography scanning was per-formed. All patients except three had an estimated lifeexpectancy of more than 3 months according to theironcologists. Indications for surgery included evidenceof spinal instability (kyphosis, subluxation, or retropulsedbone fragment); evidence of tumor progression (radio-graphically, clinically, or both) despite previous radiother-apy; neurological deterioration during radiotherapy; med-ically intractable pain; rapid development of neurologicalcompromise or myelopathy; lack of tissue diagnosis; orradiation-resistant tumor (melanoma, sarcoma, or renalcarcinoma).

RESULTS

The tumor origin was as follows: lung cancer (28.1%),sarcoma (18.7%), renal carcinoma (12.5%), breast carci-noma (9.3%), hematological malignancy (7.3%), gastroin-testinal malignancy (6.2%), prostate cancer (5.2%), mel-anoma (4.1%), gynecological origin (3.1%), unknownorigin (2%) and miscellaneous (3%). Sixty-six patients(68.7%) had undergone previous external-beam radiother-apy. All patients presented with pain, and 40% exhibit-ed symptoms or signs of myelopathy. Spinal stabilizationwas performed in 71 patients (74%). All but two patientswith myelopathy improved neurologically.

There were no neurological deficits attributable tothe surgery itself. Pain improved in all but five patients(95%). Pain that did not improve was caused by newmetastatic lesions involving other parts of the spine orskeletal system. Although their pain improved, mostpatients continued to use some form of narcotic analgesicmedication. Ambulatory status was maintained for at least3 months postsurgery in 88 (91.6%) of 96 patients. At amean follow-up time of 12 months, 46 (48%) of 96 pa-tients were alive. Complications included five infections(5.2%), four deep and one superficial; only one of theinfections required further surgery. All patients with infec-tions had previously undergone radiation therapy, and twohad undergone previous embolizations. All infections oc-curred after operations performed via a posterior (lam-inectomy) approach. Two patients had a CSF leak. Threepatients (3.1%) had evidence of delayed hardware failure;two of the three required additional revision surgery. Onepatient died of a pulmonary embolism in the immediatepostoperative period. Three more patients died within 4weeks after surgery (total 4.1% mortality rate) because of

tumor progression. Those patients had insisted on surgery,despite the fact that the expected survival time was lessthan 3 months.

ILLUSTRATIVE CASESCases 1 to 6

Simultaneous, Circumferential, Short-Segment TumorResection and Instrumentation in the Thoracic Spine.This technique involves an initial laminectomy with thepatient prone, with definition of the thecal sac and ligationof the exiting nerve root. Subsequently, the operating bedis “airplaned” to a 45° angle position and a retropleuralthoracotomy is performed22 (Fig. 1). An anterior verte-brectomy with resection of the entire tumor is then fol-lowed by an anterior stabilization with a cage and VBscrews. The patient is then moved again to an almostprone position, and a short-segment posterior instrumen-tation is performed through the same J-type incision onelevel above and below the lesion, by using screws, hooks,or both.

A total of six patients underwent this procedure, four ofthem female and two of them male. The tumor origin wasas follows: lung in three of six, esophagus in one of six,sarcoma in one of six, and breast carcinoma in one ofsix. All patients presented with pain, and three of six hadspinal cord compression. Four patients had received priorradiation therapy to the spine. In all cases, the tumorinvolved both the anterior and posterior elements. Allpatients tolerated the surgery well, and there were noimmediate complications. All patients experienced animprovement in pain, and in their neurological condition(if it had been impaired preoperatively). One patient suf-fered junctional kyphosis 4 months postsurgery andrequired revision and additional stabilization. Two of sixpatients were alive at 18-month follow-up review. Allpatients with lung carcinoma died within 6 months ofsurgery.

This approach allows complete tumor resection throughthe same incision, and simultaneous anterior and posteri-or instrumentation. It is recommended for those patientswho have tumor involvement in both the anterior and pos-terior thoracic spine when a complete resection with ashort-segment fixation is the goal. A trapezius flap can beused at the same time to reduce the chance of infection,especially in patients who have previously received radia-tion therapy.4

Case 7

Double Rod Sacroiliac Fixation for a Sacral Tumor.This 56-year-old woman had a 5-year history of locallyinvasive rectal carcinoma to the sacrum. She had under-gone two previous abdominal resections, radioactive seedimplantation, additional radiation therapy, and chemother-apy. She presented to us with bilateral S-1 radiculopathyand incontinence, and she had been unable to bear weightfor 4 weeks. The patient was bedridden, and she weighed230 lbs. She underwent posterior L-5 and S-1 laminec-tomies with bilateral facetectomies and resection of all thedorsal epidural tumor and full decompression of the thecalsac. In addition, a subtotal resection of the sacral tumorwas performed.

F. D. Vrionis and J. Small

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Instrumentation procedures included placement of mul-tiaxial screws in the pedicles of L-2, L-3, and L-4 (Fig. 2).Iliac 8-cm screws were placed bilaterally in the iliac wingsin a typical Galveston rod position.23 In addition, iliacscrews were placed on both sides; they were placed later-al to the sacroiliac joints in the iliac crests from a superi-or-to-inferior direction. All iliac screws were reinforcedwith MMA. Four 6.25 mm titanium rods were connectedwith the iliac screws, creating a dual-rod construct. Thisconstruct combined the iliolumbar fixation of the Gal-veston technique with a second rod that was connectedwith the screws in the iliac crest. The operation lasted 6hours, and the blood loss was 2400 ml. The patient wasable to ambulate 72 hours after the surgery with a walker,and independently after that. She died of tumor progres-sion 9 months after surgery.

This case shows that for patients with metastatic tumorsto the sacrum and limited life expectancy, rigid stabiliza-tion and early mobilization is desired. This requires themaximum possible fixation, especially when there is com-plete instability because of destruction of both sacroiliacjoints. In this technique we used a dual-rod system thatinvolves a combination of the Galveston and iliac crestscrew fixation, which prevents both the “open book” and“windshield wiper” effects associated with previous fixa-

tions.24 The patient does not have to lie in bed for 6 weeksto maximize their chance for fusion; this technique allowsimmediate stability.

DISCUSSIONEn Bloc Resection

The role of en bloc resection in patients with metastaticspine tumors is unclear. Most studies point to a reductionin the recurrence rate but do not show a clear survival ad-vantage in metastatic tumors.6,21 Local malignancies suchas chordomas, selected sarcomas and chondrosarcomas,Pancoast tumors, giant cell tumors, and osteoblastomasare currently the types of tumors for which an en bloc re-section should be considered. En bloc resection is techni-cally more demanding, is associated with a higher risk ofneurological complications, and requires that the tumor beconfined within a limited number of VBs, as well as re-quiring absence of epidural disease and an intact contra-lateral pedicle. In addition, the extent of dissection in-creases, and with it the need for subsequent anterior andposterior spinal reconstruction. In most circumstances(except for certain sacral chordomas), a marginal en blocresection is all that can be achieved. If the pathological ex-amination confirms tumor-free margins, radiation therapy

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Fig. 1. Images obtained in a 57-year-old woman with a history of lung carcinoma metastatic to T-5, who presentedwith a pathological fracture after radiotherapy. She underwent a T-5 vertebrectomy and T-5 laminectomy through aT-shaped incision. She also underwent circumferential tumor resection, with simultaneous anterior and posterior recon-struction performed through the same incision. A: Sagittal T2-weighted MR image demonstrating tumor and spinal cordcompression (arrow). B: Intraoperative photograph showing lateral paraspinal muscles that have been retracted and theproximal left T-5 and T-6 ribs that are exposed and divided. C: Intraoperative photograph obtained after retropleuralthoracotomy and T-5 vertebrectomy, showing the anterior reconstruction with a stackable cage and VB screws connect-ed to a single rod. D: Intraoperative photograph obtained after anterior and posterior reconstruction, demonstrating anipsilateral trapezius muscle graft used to cover the posterior instrumentation. E: Plain anteroposterior (AP) x-ray filmdemonstrating posterior instrumentation from T4–6 with sublaminar hooks.


can be avoided. In some cases, such as sarcomas, en blocresection may require the removal of tumor-adherent dura.In those cases, a watertight duraplasty with autologousfascia is recommended, with appropriate muscle flap cov-erage if there has been previous radiotherapy. This is donebecause CSF fistulas in previously irradiated fields arehard to correct and can be associated with a high risk ofwound infection and meningitis.

Although en bloc resection provides the best chance fordisease-free long-term survival in selected patients, its useis limited by prior surgery or radiation therapy. Certainneoplasms, such as chordomas and sarcomas, may have“skip areas” or “micrometastases” not detected on MRimaging at the time of the surgery, which will eventuallycompromise the clinical result. Because of the magnitudeof the surgery and the risks involved, appropriate preoper-ative psychological counseling is recommended.

Spinal Instability

The definition of spinal instability is not always clear.As defined by Panjabi, et al.,24 spinal stability is the degreeof motion that prevents pain, neurological deficit, and ab-normal angulation. Instability caused by tumors appears tobe different from that associated with traumatic injuries.2Current classification proposals have divided each verte-

bra into two, three, or six columns, but have failed to pre-dict accurately future neuroimaging and/or clinical confir-mation of progression consistent with instability.3,7,20 Thiscould be due to the fact that in normal individuals there isconsiderable variability in bone density, ligamentous in-tegrity, and concomitant degenerative changes, which, to-gether with the subjective nature of pain, confounds theissue of stability and restricts the use of uniform criteria.In addition, ligamentous structures are more frequentlyinvolved in trauma than in tumors, and pathological frac-tures rarely follow the anatomical patterns typical of trau-matic ones. A more practical and pragmatic way of cate-gorizing spinal instability is to classify it as acute orchronic.

Acute Instability. This form of instability includes thepresence of a kyphotic deformity and/or subluxation, withspinal cord compression accompanied by pain and/or my-elopathy. This form of instability is the most obvious andalmost always involves the need for surgical stabilization(Fig. 3).

Chronic Instability. In contrast, chronic instability is amore subtle form that includes compression fractures ofvarious degrees, which are not associated with spinal cordcompression or severe pain (Fig. 4). This form of instabil-ity can be managed conservatively, at least initially, with



Fig. 2. Case 7. A: Sagittal T1-weighted MR image demonstrating metastatic tumor involving L-5 and sacrum. B:Coronal T1-weighted MR image demonstrating tumor involvement in both sacroiliac joints. C: Intraoperative photo-graph showing the thecal sac and exiting L-5 and S-1 nerve roots after L-5 and sacral laminectomy and tumor resection.D: Intraoperative photograph showing double-rod instrumentation connecting screws at L-2, L-3 and L-4, with screwsplaced in the iliac wings. A dual-rod system is used for maximum stability. E: Plain AP x-ray film of lumbosacral spinedemonstrating instrumentation. The patient was able to ambulate with a walker 3 days postsurgery; before that, she hadbeen bedridden for 4 weeks.


observation, bracing, vertebroplasty, or kyphoplasty, aswell as with chemotherapy, radiation, or hormone therapy,depending on the biology of the tumor.12 Chronic instabil-ity has the potential to progress to acute instability, result-ing in the need for surgical fixation; however, given theuncertainty of the progression, we do not recommend pro-phylactic spinal stabilization in these cases (Fig. 5).

Other Factors in Spinal Instability. Other factors thatcontribute to instability and should be taken into accountin the decision-making process include the presence ofcircumferential disease, contiguous multilevel disease,junctional (cervicothoracic or thoracolumbar) tumor lo-cation, and the presence of earlier laminectomy (Fig. 6).Not every resection of metastatic tumor requires spinal

stabilization. Unilateral transpedicular/costotransvers-ectomy/ far-lateral approaches, especially in the thoracicspine, can be used for tumor resection without a need nec-essarily for concomitant spinal instrumentation (Fig. 6).

To Fuse or Not to Fuse

Pseudarthrosis is defined as the failure of an attempt-ed fusion by 1 year postsurgery. In patients with cancer,many do not live long enough to be assessed for fusion orthey undergo spinal reconstruction with MMA. Therefore,pseudarthrosis is more of an issue with primary spine tu-mors or long-term cancer survivors. Although in surgeryfor degenerative spine disease, a solid bone fusion is theultimate goal because it provides lasting spinal stability, inpatients with cancer, fusion may not be achievable. Incases of tumor, fusion is difficult or impossible to accom-plish because of the effects of perioperative radiotherapy,chemotherapy, steroid drugs, malnutrition, anemia, fre-quent use of allograft, and smoking.26 Therefore, in suchcases one may need to rely on rigid spinal instrumentationto provide long-term stability. Rigid systems include pedi-cle screws, and by definition do not rely on adjacent liga-ments or articulations of the spine for load sharing. This isin contrast with semirigid systems such as hooks or sub-laminar wires that rely on those structures for support.

There are few data regarding the presence of pseud-arthrosis in metastatic spine tumors, as the goal of treat-ment shifts to recurrence-free, long-term survival and notnecessarily to fusion. In one retrospective study of 25patients with spine tumors who were treated with anteri-or vertebrectomy, autologous grafting, and perioperativeradiation therapy, a 16% radiographic pseudarthrosis ratewas found at 1 year of follow up.10 There was a trend to-ward pseudarthrosis for lumbar lesions, primary tumors,or patients who received dosages of more than 4000 rads.Clinically, pseudarthrosis is indicated by the presence ofpain, progressive deformity or instrumentation failure af-



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Fig. 3. Neuroimages demonstrating acute spinal instability in a38-year-old man with a history of Hodgkin lymphoma who pre-sented with a T-9 pathological fracture and spinal cord compres-sion at T-9. A: Sagittal T2-weighted MR image demonstratingsubluxation and spinal cord compression (arrow) by retropulsedbone fragment. B: Plain AP x-ray film of the thoracic spine dem-onstrating posterior reconstruction with pedicle screws from T6–12and the anterior Kaneda device from T8–10. C: Lateral plainx-ray film of the stabilized thoracic spine.

Fig. 4. Images depicting chronic spinal instability in a 67-year-old woman with a pathological fracture at L-2 caused by a lung car-cinoma. The patient underwent biopsy sampling, kyphoplasty, andsubsequent palliative radiation therapy, with improvement in herback pain. A: Sagittal T1-weighted MR image demonstratingL-2 tumor. B: Lateral fluoroscopic image obtained after success-ful kyphoplasty.

Fig. 5. Neuroimages obtained in a 77-year-old woman with his-tory of non-Hodgkin lymphoma who underwent a laminectomy fordiagnosis of epidural tumor at T-11; postoperatively she receivedradiation therapy. A: Sagittal T1-weighted MR image demon-strating tumor in T-11 just prior to radiation therapy. B: Plainx-ray film obtained 1 year after radiation therapy, in which thepatient presents with kyphotic deformity of T-11 and spinal cordcompression (lines). Even morphine delivered by an intrathecalpump did not relieve the pain. C: Plain x-ray film showing theconstruct after a T-11 vertebrectomy, anterior instrumentationfrom T9–12 with a Kaneda device, and posterior instrumentationwith a hook and pedicle screw hybrid system from T9–L1.


ter a pain-free interval. Radiographic signs include lucen-cy around cages and/or screws or grafts, resorption ofbone graft, increased motion on dynamic films, disconti-nuity in fusion mass, or a positive bone scan. Pseudarthro-sis implies a persistent motion in a segment that was in-tended to fuse. It may be completely asymptomatic, but itcan also lead to graft collapse or fracture, metal fatiguewith rod or screw breakage, and subsequent spinal defor-mity. In the latter cases, one needs to rule out the possibil-ity of tumor recurrence, radiation necrosis, or infection,which, similar to pseudarthrosis, can lead to delayed struc-tural failure.

In our series, three delayed cases (3.1%) of structuralfailure were seen in two of the three patients who requiredinstrumentation revision. Salvage strategies in those casesincluded the use of more rigid fixation (screws instead ofhooks, larger-diameter screws, longer construct, claws,and MMA reinforcement of the screws). In addition, adifferent approach (ventral if a dorsal approach was per-formed previously and vice versa) is recommended. A

combined anterior–posterior approach is recommendedfor significant kyphotic deformities with spinal cord com-pression.4 The use of bone morphogenetic protein–2, auto-grafts, and electromagnetic stimulation could also be con-sidered in cases requiring revision.

Surgical Approach

Three main approaches have been used in the treatmentof metastatic spine tumors: 1) laminectomy; 2) costotrans-versectomy; and 3) thoracotomy.27,28 The laminectomyapproach is the one most familiar to neurosurgeons and, incombination with a uni- or bilateral transpedicular ap-proach allows access to dorsally and ventrally locatedlesions.21 Its disadvantages include incomplete tumor re-section in ventral lesions and a higher risk of infection.

A costotransversectomy is a 45° approach to the spinealong the angle of the rib head as it attaches to the trans-verse process. It is versatile and can be combined withanterior and/or posterior instrumentation. It is best foreccentrically located neoplasms that involve the lamina,pedicle, and VB on only one side.

For lesions involving the VB exclusively, the thoraco-tomy approach is the most advantageous.16 It is best forcorrecting kyphosis and safest for removal of retropulsedbone fragment after pathological fractures. It is associatedwith a higher risk of pulmonary complications, especiallyin patients of advanced age and those with a history ofchronic obstructive pulmonary disease. The thoracotomycan be performed on the side that allows maximum tu-mor access, or otherwise from the right side for the mid-thoracic region and from the left side for access to thethoracolumbar junction. Usually the thoracotomy is madethrough the rib bed that corresponds to two levels abovethe involved VB. If the thoracotomy is closer to the spine(that is, far-lateral approach) and not centered along themidaxillary line, however, a single level above or the samelevel can be used for optimal exposure. For the upper tho-racic region (Pancoast tumors) the traditional dorsolateralthoracotomy may not provide adequate exposure. In thosecases, one may use a trapdoor or median sternotomyapproach, depending on how anterior the tumor is andwhether major blood vessels are involved. For sacral tu-mors, a dorsal approach can be used below S-3 and a com-bined ventral–dorsal approach above it to avoid vascularcomplications.2,14,15,17

Types of Reconstruction

Anterior Reconstruction. A variety of grafts are avail-able (autologous or allografts) depending on the size ofthe defect (fibula, tibia, femoral ring) and goal of fusion.Vascularized fibula, vascularized rib grafts, or a combina-tion of allograft and autograft can also be used. Tradi-tionally, spondylectomy defects in patients with cancerhave been reconstructed with MMA.23 Its low cost, instantstability, and resistance to tumor invasion and radiothera-py have made it the spacer material of choice in the major-ity of cases, especially in patients with an anticipated lifeexpectancy of less than 6 months. Nevertheless, there isfrequently a need to use K-wires or screws to improveMMA anchorage to the adjacent VBs.19 Because MMAmay “piston” in the setting of weak bone, the pins may



Fig. 6. A–C: Neuroimages obtained in a 50-year-old man witha history of lung carcinoma. He had undergone previous radiationtherapy for a tumor in the cervicothoracic junction, and presentedwith spinal cord compression and instability. A: Sagittal T1-weighted MR image with contrast, demonstrating a tumor involv-ing C-7 and T-1 with epidural invasion and spinal cord compres-sion. B: Lateral x-ray film demonstrating the finished constructafter a C-7 and T-1 vertebrectomy, anterior plating followedby posterior instrumentation, and fusion from C3–T6. C.Postoperative x-ray film, AP view, of the finished construct. Along construct was selected because of the junctional location andmultilevel disease at T-3 and T-4. D: Sagittal MR image obtainedin another patient, demonstrating the “bowstring” effect on thespinal cord and kyphotic deformity caused by multilevel metastat-ic disease secondary to breast carcinoma. E: Axial T1-weightedMR image with contrast obtained in a 64-year-old man with a his-tory of sarcoma involving the left T-7 and T-8 region. The patientunderwent gross-total resection of the tumor via a left lateral cos-totransversectomy approach with no need for reconstruction.


migrate to penetrate vital structures (spinal cord, aorta).The chest tube technique16 and our own modifications(endplate preparation, then distraction, then placement ofMMA against endplates, then compression with ventral ordorsal instrumentation) avoid the use of anchoring pinsand their associated risks (Fig. 7). Nevertheless, MMAnever fuses and its utility in long-term survivors is ques-tionable. Although long-term stability can be seen afterMMA reconstruction, this is usually due to the accompa-nying instrumentation.

For patients with a life expectancy of more than 6months, reconstruction with an allograft or cage is recom-mended.5 We use cages to try to imitate a bone graft. In abone graft the cancellous bone fuses, although it is notload-bearing. The load is supported by the cortical bone,which is imitated by the cage. Cages can be cut to varioussizes and can imitate the normal contour of the spine.Stackable carbon fiber or titanium cages are commonlyused;5 expandable cages that allow distraction are alsoavailable. In our series, we have not observed deformationof the cages, even in recurrent tumors or delayed instru-mentation failure. In contrast to fixation with MMA,cages do not need to be removed in the event of an infec-tion (infection associated with MMA requires either itsremoval or lifelong antibiotic suppression therapy).

Appropriate sizing of the cage to the vertebrectomydefect is of paramount importance to avoid subsidence.Cages can be inserted from a posterior or (preferably) ananterior approach with certain geometric constraints de-pending on surgical exposure, ability to retract the thecalsac, and ability to sacrifice nerve roots (C1–3 and T2–10).Regardless of the graft of choice, the anterior spacer needsto be loaded and maintained in compression by rigid spi-nal instrumentation. A lateral (or anterior) approach al-lows placement of simultaneous anterior instrumentation,except in the lumbosacral and craniocervical junctions.Anterior instrumentation is very useful, especially in thecorrection of kyphotic deformities, and may allow a short-er construct compared with posterior approaches.16

A simultaneous anterior–posterior, short-segment in-strumentation in the thoracic spine was used in six patientsin this study, with good results. Nevertheless, in one pa-

tient delayed junctional kyphosis developed that requiredrevision. In that patient, a large area of chest wall resec-tion and junctional and multilevel involvement led to pro-gressive kyphosis that could have been prevented by theuse of a longer construct. A similar anterior–posterior ap-proach was previously described in 26 patients, with goodresults.11

Posterior Reconstruction. With posterior reconstruc-tion, screws (through the pedicles or lateral masses) arepreferable to hooks. Hooks are useful in patients with os-teoporosis and at the midthoracic region where the pedi-cles are small. Posterior constructs are under high stress atthe proximal and the distal aspects, especially if they areused to address an existing kyphotic deformity. In thosecases a solely posterior approach can be used, with reduc-tion of the deformity by using the cross-rod bending tech-nique. The construct should be well balanced in its proxi-mal and distal ends and should be supported by an anteriorspacer. One should avoid passing wires or hooks throughthe extreme kyphotic or lordotic portion of a deformity.

Posterior constructs can be placed in compression (toreduce kyphosis) or distraction (to produce kyphosis).They should not finish in segments in which there is tu-mor involvement, junctions (T-1 or L-1), spondylolisthe-sis, spinal stenosis, or otherwise significant degenerativechanges. Excessive compression, poor bone quality, or ex-cessive laminotomy may fracture the lamina, transverseprocesses, or pedicles. On the other hand, hooks, if not ad-equately placed in compression, may pull out, especiallywith flexion.

Avoidance of Complication

Surgery in patients with metastatic spine tumors is highrisk and is associated with a significant number of com-plications. The most frequent complication is wound in-fection, which ranges from 0 to 45% and is more preva-lent in patients who have received prior radiotherapy andhave undergone operation via a posterior approach.13 Inthose patients, the operation starts by planning the closure.Prophylactic vascularized flap coverage (trapezius, latis-simus, superior gluteal, or paraspinal muscle flaps) should



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Fig. 7. Neuroimages obtained in a 68-year-old man with a history of hepatocellular carcinoma who presented with anL-1 pathological fracture after radiation therapy. Because of the limited (� 6-month) life expectancy for this patient, weelected to resect the tumor via a posterior approach (transpedicular vertebrectomy), followed by an anterior reconstruc-tion with MMA. After the vertebrectomy, the discs adjacent to the defect were removed. Pedicle screws were placedabove and below the vertebrectomy and distraction was applied. The vertebrectomy defect was then filled with MMAwhich was finally placed in compression by the posterior instrumentation. A and B: Preoperative MR images demon-strating tumor at L-1. C: Plain lateral x-ray film obtained after tumor resection and spine reconstruction.


be considered in radiation-treated wounds, especially if aCSF leak is present.8,9 Tension-free wound closure, cover-age of hardware with vascularized muscle tissue, andadequate postoperative nutrition (with administration oftotal parenteral nutrition if needed) will minimize wound-related complications. Preoperative embolization, especi-ally of renal carcinomas and sarcomas should be con-sidered.18 Intraoperative monitoring of motor evokedpotentials and somatosensory evoked potentials has theadvantage of assessing both ventral and dorsal spinal cordfunction. Monitoring is recommended but not required inpatients with significant spinal cord compression.

Intraoperative euvolemia and normotension is of para-mount importance because blood loss can be challengingin certain cases. Imaging-based guidance can be helpful inplacement of thoracic pedicle screws and for intraopera-tive navigation in sacral lesions.

CONCLUSIONS

Because of the highly individualized nature of spinalneoplasms, a multidisciplinary approach is recommended.A team consisting of a neurosurgeon and/or an orthopedicspine surgeon/radiation and medical oncologist, pain spe-cialist, thoracic, and plastic surgeon is important for pa-tient selection, tumor access, and ultimate avoidance ofcomplications.

References

1. Aaron AD: The management of cancer metastatic to bone.JAMA 272:1206–1209, 1994

2. Allen BL Jr, Ferguson RL: The Galveston technique for L rodinstrumentation of the scoliotic spine. Spine 7:276–284, 1982

3. Bilsky MH, Shannon FJ, Sheppard S, et al: Diagnosis and man-agement of a metastatic tumor in the atlantoaxial spine. Spine27:1062–1069, 2002

4. Bohm H, Harms J, Donk R ,et al: Correction and stabilizationof angular kyphosis. Clin Orthop 258:56–61, 1990

5. Boriani S, Biagini R, Bandiera S, et al: Reconstruction of theanterior column of the thoracic and lumbar spine with a carbonfiber stackable cage system. Orthopedics 25:37–42, 2002

6. Boriani S, Biagini R, De Iure F et al: A: En bloc resections ofbone tumors of the thoracolumbar spine. A preliminary reporton 29 patients. Spine 21:1927–1931, 1996

7. Denis F: The three column spine and its significance in theclassification of acute thoracolumbar spinal injuries. Spine 8:817–831 1983

8. Disa JJ, Smith AW, Bilsky MH: Management of radiated reop-erative wounds of the cervicothoracic spine: the role of trapez-ius turnover flap. Ann Plastic Surg 47:394–397, 2001

9. Dumamian GA, Ondra SL, Liu J, et al: Muscle flap salvage ofspine wounds with soft tissue defects or infection. Spine 28:1203–1211, 2003

10. Emery SE, Hughes SS, Junglas WA, et al: The fate of anteriorvertebral bone grafts in patients irradiated for neoplasm. ClinOrthop 300:207–212, 1994

11. Fourney DR, Abi-Said D, Rhines LD, et al: Simultaneous ante-rior-posterior approach to the thoracic and lumbar spine for theradical resection of tumors followed by reconstruction and sta-bilization. J Neurosurg (Spine 2) 94:232–244, 2001

12. Fourney DR, Schomer DF, Nader R, et al Percutaneous verte-broplasty and kyphoplasty for painful vertebral body fracturesin cancer patients. J Neurosurg (Spine 1) 98:21–30, 2003

13. Ghogawala Z, Mansfield FL, Borges LF: Spinal radiationbefore surgical decompression adversely affects outcomes of

surgery for symptomatic metastatic spinal cord compression.Spine 26:818–824, 2001

14. Gokaslan ZL, Romsdahl MM, Kroll SS, et al: Total sacrectomyand Galveston L-rod reconstruction for malignant neoplasms.Technical note. J Neurosurg 87:781–787, 1997

15. Gokaslan ZL, Romsdahl MM, Kroll SS, et al: Total sacrectomy,in Rengachary SS, Wilkins RH (eds): Neurosurgical Opera-tive Atlas. Rolling Meadows, IL: AANS, 1998, Vol 7, pp11–20

16. Gokaslan ZL, York JE, Walsh GL, et al: Transthoracic verte-brectomy for metastatic spinal tumors. J Neurosurg 89:599–609, 1998

17. Jackson RJ, Gokaslan ZL: Spinal-pelvic fixation in patientswith lumbosacral neoplasms. J Neurosurg (Spine 1) 92:61–70, 2000

18. Jackson RJ, Loh SC, Goklaslan ZL: Metastatic renal cell carci-noma of the spine: surgical treatment and results. J Neurosurg(Spine 1) 94:18–24, 2001

19. Jang JS, Lee SH, Rhee CH, et al: Polymethylmethacrylate-aug-mented screw fixation for stabilization in metastatic spinal tu-mors. Technical note. J Neurosurg (Spine 1) 96:131–134,2002

20. Kostuik JP, Errico TJ, Gleason TF, et al: Spinal stabilization ofvertebral column tumors. Spine 13:250–256, 1988

21. Marmor E, Rhines LD, Weinberg JS, et al: Total en bloc lum-bar spondylectomy. Case report. J Neurosurg (Spine 2) 95:264–269, 2001

22. McCormick PC: Retropleural approach to the thoracic and tho-racolumbar spine. Neurosurgery 37:908–914, 1995

23. Miller DJ, Lang FF, Walsh GL, et al: Coaxial double-lumenmethylmethacrylate reconstruction in the anterior cervical andupper thoracic spine after tumor resection. J Neurosurg (Spine2) 92:181–190, 2000

24. Panjabi MM, Thibodeau LL, Crisco JJ III, et al: What consti-tutes spinal instability? Clin Neurosurg 34:313–339, 1988

25. Patchell R, Tibbs PA, Regine WF, et al: A randomized trial ofdirect decompressive surgical resection in the treatment of spi-nal cord compression caused by metastasis. Proc Am Soc ClinOncol 22:1, 2003 (Abstract)

26. Riseborough EJ: Irradiation induced kyphosis. Clin Orthop128:101–106, 1977

27. Siegal T, Siegal T: Surgical management of malignant epiduraltumors compressing the spinal cord, in Schmidek HH (ed):Schmidek & Sweet Operative Neurosurgical Techniques:Indications, Methods, and Results, ed 4. Philadelphia: WBSaunders, 2000, Vol 1, pp 2171–2197

28. Sundaresan N, Steinberger AA, Moore F, et al: Surgical man-agement of primary metastatic tumors of the spine, in SchmidekHH (ed): Schmidek & Sweet Operative Neurosurgical Tech-niques: Indications, Methods, and Results, ed 4. Phila-delphia: WB Saunders, 2000, Vol 1, pp 2146–2170

29. Vrionis FD, Miguel R: Management of spinal metastases.Semin Pain Med (In press)

30. York JE, Wildrick DM, Gokaslan ZL: Metastatic tumors, inBenzel EC, Stillerman CB (eds): The Thoracic Spine. St.Louis: Quality Medical Publishing, 1999, pp 392–411

31. Zerick W, Fessler RG, Cahill DW: Metastatic spine tumors: anoverview, in Rea GL (ed): Spine Tumors. Rolling Meadows,IL: AANS, 1994, pp 7–22

Manuscript received September 25, 2003.Accepted in final form October 10, 2003.This work was supported in part by an educational grant from

Depuy-Acromed, Inc.(Johnson & Johnson), Raynham, Massa-chusetts.

Address reprint requests to: Frank D. Vrionis, M.D., 12902 Mag-nolia Drive, Suite 3136, Tampa, Florida 33612. email: [email protected].




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Surgical management of metastatic spinal neoplasms · Surgical management of metastatic spinal neoplasms FRANK D. VRIONIS, M.D., PH.D. AND JOHN SMALL, M.D. H. Lee Moffitt Cancer Center