In This Issue:
 Costotransversectomy and Corpectomy for Solitary Spinal Metastases
Simple Device to Prevent the Inadvertent Removal of Jackson-Pratt Drain
Spondylolysis without Spondylolisthesis: A Missed Diagnosis by MRI
Costotransversectomy and Corpectomy for Solitary Spinal Metastases
Provided by Neil R. Malhotra, MD
Department of Neurological Surgery, University of Pennsylvania
Combining costotransversectomy for corpectomy with implant-based surgical decompression and stabilization in conjunction with chemotherapy and radiation to treat patients with metastatic tumors of the spine is an emerging alternative to thoracotomy for this disease process. The goals of spinal tumor surgery are to achieve decompression of neural tissue and stabilize the spinal column to preserve neurologic function, relieve pain and restore mobility and bowel control.
Forty percent of cancer patients will develop metastases to the spine, primarily in the thoracic region. In the majority of cases, the posterior half of the vertebral body is the initial focus for spinal metastases. Of the common approaches to spinal surgery, costotransversectomy provides superior access to the posterior spine. The procedure also minimizes or avoids the complications associated with thoracotomy, an anterior approach associated with pneumothorax, and thus with pulmonary complications. In combination with corpectomy, costotransversectomy is preferred at the University of Pennsylvania for solitary tumors involving multiple thoracic vertebrae in patients at risk for neurologic deficits or with significant comorbidities. The level, position and extraosseous spread of the tumor are considered preoperative determinants for the choice of costotransversectomy.
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The decision to pursue surgery is complex. To ensure optimal treatment for patients with spine metastases, their management involves collaboration among neurosurgical oncologists, neurologists, radiation oncologists, radiologists and pain management specialists. Following confirmatory diagnosis via MRI, CT, or radioscans, the cardiopulmonary status of the patient and his or her comorbidities are evaluated. Patients who are able to tolerate surgery are candidates for costotransversectomy and corpectomy. During the procedure, the tumor is excised at the site of compression, the spinal column is reconstructed and internal fixation devices are placed to achieve stabilization. The majority of patients retain or regain ambulation postoperatively, and have substantial improvement in pain parameters.
Case Study
The targeted treatment of tumors of the spine at Penn Medicine involves a treatment plan developed by a specialized team, including neurosurgeons, and, as appropriate, neurologists, rheumatologists, oncologists, rehabilitation specialists, physical therapists, radiologists, and pain management specialists. This extensive and collaborative team approach to spine care ensures a thorough consideration of both surgical and nonsurgical treatment of pain and neurological symptoms to both maximize function and quality of life for patients with spinal tumors.
Case Presentation
The targeted treatment of tumors of the spine at Penn Medicine involves a treatment plan developed by a specialized team, including neurosurgeons, and, as appropriate, neurologists, rheumatologists, oncologists, rehabilitation specialists, physical therapists, radiologists, and pain management specialists. This extensive and collaborative team approach to spine care ensures a thorough consideration of both surgical and nonsurgical treatment of pain and neurological symptoms to both maximize function and quality of life for patients with spinal tumors.
Case Presentation
A 57-year-old woman presented with severe axial back pain associated with reduced mobility over six months. On physical exam of the lower extremities increased tone and loss of position sense is noted. Past medical history revealed that she had undergone mastectomy and radiation for breast cancer four years previously. She made full recovery without any medical problems and maintained healthy living until she developed axial back pain with ambulation.
Preoperative magnetic resonance imaging revealed a circumferential vertebral tumor infiltrating T10 vertebral body and posterior elements impinging upon the spinal cord (Fig. 1). Considering severe pain, neurological deficit and life expectancy, surgical resection was planned. Because tumor resection necessitated disruption of components of each of the three columnar component of the thoracic spine instability was expected. To address instability from circumferential tumor resection, circumferential reconstruction was planned to include anterior column support with titanium mesh cage with autograft bone and posterior and middle column support with pedicle screw-rod instrumentation.
Operative Techniques
Following induction of general anesthesia, the patient was positioned prone on the operating table with generous padding at all pressure points. Posterior midline incision was extended from T7 to T12 to expose the whole extent of the posterior spine. 3D Stealth neuronavigation and intraoperative neuromonitring permitted safe rapid placement of posterior pedicle instrumentation from T7-T12 excluding T10. Laminectomy of T10 and inferior T9 was performed.
Tumor mass was found to be compressing the dural sac. The consistency of tumor was soft. The tumor mass was removed at its point of posterior compression. The T10 rib head on the left was elevated and removed creating pathway of approach to the vertebral body. Superior and inferior endplates were elevated and infiltrated vertebral body and tumor was resected disc space to disc space and side to side. The pleura laterally and spinal cord medially were not was manipulated. Autograft was harvested from the PSIS via separate incision and packed into a precisely measured titanium mesh cage. Mesh cage was carefully placed under compression against the exposed T9 and T11 endplates without manipulation of the spinal cord. Pedicle instrumentation was compressed about the cage and finally tightened.
Intra-operative 3D imaging confirmed site of decompression and instrumentation to be in ideal position. A combination of autograft and allograft bone was placed over decorticated bone to promote arthrodesis. Meticulous hemostasis was achieved, and closed suction drainage catheter was placed. Skin was closed layer by layer. The patient recovered without any complications. Post operative CXR showed no signs of pneumothorax.
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Follow-up
Her axial back pain immediately disappeared and incisional back pain diminished quickly enough to permit discharge on post operative day number 3 ambulating without pain or difficulty. Bowel and bladder function was unaffected. Pathological examination revealed breast cancer consistent with prior findings from the breast. Radiation therapy was executed for three weeks. The stability and alignment was fully maintained after radiation therapy (Fig. 4). Patient has been followed for one year.
Simple Device to Prevent the Inadvertent Removal of Jackson-Pratt Drain
By Bennett Blumenkopf, MD, FACS; Paul B. Blumenkopf; and Raj Nangunoori, BA, Department of Neurosurgery, Allegheny General Hospital, Pittsburgh PA
The Jackson-Pratt Drain ("JP") is a closed suction device system that is made up of: 1) the bulb (“grenade”), a soft plastic container with two openings at the top in order to facilitate the creation of a vacuum after the drain tubing has been inserted; and 2) the drainage tube, a soft flexible Teflon tubing with a long flat surface with multiple small holes which can be trimmed to fit the desired drainage area, and connected to a longer flexible round tubing, which is then secured or attached to the grenade. A variety of sizes and designs are available.
The JP drain is used in situations where there is risk of fluid accumulation post operatively, as may be the case with bowel anastomosis, neck surgery, spinal surgery and cranial surgery/subdural hematoma evacuation. These drains prevent fluid build up in the tissues, which could result in poor wound healing and a greater propensity for infection. Also, in the case of neurosurgical procedures, these drains allow for continued drainage of fluids in the subdural space and/or prevention of compressive hematomata or other fluid collections in the epidural space.
The JP drain is generally withdrawn through the skin via a separate “stab” wound a few centimeters from the primary wound incision. This allows not only for the removal of the drain without disrupting the primary suture line, but also for the exit site of the drain tubing via the opening in the skin to be a “tight fit” necessary for the desired suction effect. Since the base of the JP flexible tubing is larger in width/diameter than the drain’s round exiting tubing, upon the withdrawal/removal of the drain it is the skin’s elastic flexibility that allows for the wider base to be pass through this “tight” stab wound.
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To avoid the inadvertent removal of the JP drain, the drain’s round tubing portion is often ecured to the skin at the exit site. A suture is tied to the skin, and then wrapped a number of times around the tubing and tied tightly. However, it is not uncommon for the drain to be removed prematurely by inappropriate pulling upon the tubing by accident, by a non-compliant patient, or by getting caught upon some other stationary device tethering it while the patient moves about, etc.
A simple device similar in concept to a collet has been developed that prevents the inadvertent removal of a Jackson-Pratt Drain by countering the elastic flexibility of the skin and taking advantage of the size differential between the base of the flexible tubing and the exteriorized round drain tubing. A collet is a holding device - specifically, a subtype of chuck – that forms a collar around the object to be held. A 1-2 cm length non-flexible collet is utilized to “secure” the JP drain to the skin. The diameter of the collet is approximately 1 mm greater than that of the respective JP drain chosen for use (e.g., the 10 mm flexible JP drain exteriorized tubing is ~ 6.5 mm in diameter: the collet utilized is ~ 6 mm in diameter; 7 mm ~ 5mm diameter with collet utilized ~ 5 mm.) [see schematic, below].
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Two small holes drilled along the equator of the collet approximately 3 mm from its base are used for suturing it to the skin. The suture is drawn through both holes, and the JP drain tubing is drawn through the collet past the suture. The suture is then tied to the skin at the exit/stab wound site. The non-flexible character of the collet prevents the withdrawal of the base of the flexible portion of the JP drain since its width/diameter exceeds that of the collet itself. Furthermore, the collet and the drain engage one another at the skin exitus, where the stuture is tied to the skin. This engagement at the skin surface prevents a tether up effect upon the suture and therefore the suture cannot be broken or disrupted.
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At the appropriate time, the suture is cut releasing the collet from the skin. This then allows for the usual withdrawal of the flexible portion of the JP drain through the elastic stab wound opening in the skin.
For drains of uniform diameter, a new design to the drain tubing itself will work equally well with the collet [see schematic, below].
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In this design small ball-like excrescences similar to the snap button design for height adjustments on a walker-assist device (see photo, below) will “engage” the collet upon attempted withdrawal of the drain. Upon release of the suture, the flexibility of the skin will again “allow” for the usual withdrawal of the drain despite the additional diameter.
An experiment was performed to demonstrate the efficacy of the device in restraining the drain. A non-fixed human torso, stored at room temperature, was used for testing of the skin elasticity and pull-out strength using the surgical device as described, herein. Six stab wounds were placed on the skin of the non-fixed human torso in one line. Each stab wound was approximately 5 mm in length and approximately 5 cm in depth. The surgical drain device was secured to the skin of the human torso using the device described, herein. The drain tubing was withdrawn through the stab wound and then the drain itself was pulled out with the pull out strength requirement which was measured with a spring scale.
In order to measure the added strength of the surgical drain deivce, this procedure was repeated with a JP drain device that was only suture-secured to the skin with a 2 -O vicryl suture. A 10 mm JP drain was used: Cardinal Health product # SU130-1309.
This experiment demonstrated that the drain tubing itself has a fracture point of 12 to 15 pounds of pull strength with the spring scale. The JP drain can be withdrawn through a standard stab wound with a pull strength of 4 pounds. The device will “withhold” the drain to a pull strength of 8 pounds. Thus, approximately an additional 4 pounds of resistance/strength is added via the retain device.
Spondylolysis without Spondylolisthesis: A Missed Diagnosis by MRI
By Bennett Blumenkopf, MD, FAANS, FACS
Department of Neurological Surgery
Allegheny General Hospital
Pittsburgh PA
Introduction
Lumbar MRI has become the imaging study of choice for the evaluation of low back pain, especially in the primary care setting. Spondylolysis – defect of the pars interarticularis – is among the etiologies of low back pain, particularly in adolescents and athletes. While MRI provides superb soft tissue detail, its capability in detecting fine osseous changes, such as spondylolysis, is less clear; failure to do so may result in delays in referrals by the primary care physicians to the spine specialist.
Methods
The formal MRI reports authored by board-certified radiologists of 15 consecutive patients with surgically verified spondylolysis were reviewed, retrospectively, for any mention or discussion of spondylolysis. The images themselves were also reviewed by the operating surgeon at the time of initial clinical presentation. Reports were also reviewed for mention of spondylolisthesis – abnormal vertebral alignment, generally anteriorly oriented – and compared to formal radiology CT scan reports, as well.
Results
The series included six women and nine men, ages 34 to 68 years. All patients presented with complaints of lower (lumbar) back pain, as well as 12 experiencing coincidental lumbar radiculopathy. Seven of the 15 authored reports by the radiologists made no mention whatsoever of spondylolysis. Some of the highlighted features included in their reports were “disk degeneration,” “facet arthropathy,” and “stenosis.” Six of these 7 patients did not have spondylolisthesis noted in their report.
Eight reports characterized the finding of spondylolysis both in the discussions and impressions sections of the reports; seven of these eight reports also made note of spondylolisthesis. The two-tailed Fisher’s exact test p value = 0.0101: spondylolysis without spondylolisthesis will be missed by MRI (see Table 1)
The neurosurgeon recognized/inferred the pars interarticularis defect in all cases during the first examination. Secondary lumbar CT scans obtained pursuant to that inference confirmed that impression in the seven “false negative by MRI” instances. Intraoperatively, the pars interarticularis defects were unequivocal; a Gill procedure – i.e., laminectomy with removal of the abnormal facets – was performed in all 15 cases. The postoperative outcomes were uniformly excellent in these 15 patients with relief of the lumbar back pain.
Conclusion
Spondylolysis without spondylolisthesis proved to be a neuroimaging diagnostic challenge for board-certified radiologists utilizing MRI. MRI may not be the imaging study-of-choice for some patients with chronic back pain, especially in the adolescent primary care and sports medicine settings. As such, an alternative/supplemental evaluation with either CT or SPECT may be appropriate. The diagnosis of spondylolysis represents an indication for surgical management in patients with lumbar back pain.
References
1. Spondylolysis:Imaging. Weinberg, EP http://emedicine.medscape.com/article/395916-imaging
2. Juvenile spondylolysis:a comparative analysis of CT, SPECT, and MRI. Campbell, RSD, et.al. Skeletal Radiol (2005)34:63-73
3. The Prevalence of Spondylolysis and Spondylolisthesis in Symptomatic Elite Athletes: Radiographic Findings. Rossi, F Radiography 7, 2001.
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Society members are encouraged to submit scientific articles of interest to Pennsylvania neurosurgeons. Members are also invited to solicit similar articles from colleagues who are not members. Final decisions on publication are made by the Editor, in consultation with members of the Council of the Pennsylvania Neurosurgical Society.
Send submissions to pns@pamedsoc.org.
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