Paul M. Arnold
Ali K. Ozturk, Patricia Zadnik Sullivan and Vincent Arlet
The importance of sagittal spinal balance and lumbopelvic parameters is now well understood. The popularization of various osteotomies, including Smith-Peterson, Ponte, and pedicle subtraction osteotomies (PSOs), as well as vertebral column resections, have greatly enhanced the spine surgeon’s ability to recognize and effectively treat sagittal imbalance. Yet rare circumstances remain, most notably in distal kyphotic deformities and patients with extremely elevated pelvic incidences, where these techniques remain inadequate. In this article, the authors describe a patient with severe sagittal imbalance despite multiple prior anterior and posterior reconstructive surgeries in which a sacral PSO was performed with good results. A description of this technique as well as a brief review of the literature is provided.
Mari L. Groves, Patricia L. Zadnik, Pablo F. Recinos, Violette Renard and George I. Jallo
The authors present a case of a 27-year-old patient who presented with spastic gait and worsening difficulty walking over a 6 month period. Spinal MR imaging revealed a heterogeneously enhancing intramedullary spinal cord tumor (IMSCT) with associated syrinx in the cervical spine. The lesion was resected through posterior en bloc laminotomy, durotomy, and microscopic resection of the intramedullary component followed by laminoplasty reconstruction. Surgical resections with a goal of gross total resection can significantly improve overall survival and progression free survival in patients with low-grade IMSCT. The procedure is presented in an edited, high-definition format with accompanying narrative.
The video can be found here: http://youtu.be/Ui9bn82PtP8.
Paul E. Kaloostian, Patricia L. Zadnik, Ahmed J. Awad, Edward McCarthy, Jean-Paul Wolinsky and Daniel M. Sciubba
Resection of metastatic pheochromocytomas may be complicated by transient postoperative neurological deficits due to hypotension. The authors report the first case of en bloc excision of a spinal pheochromocytoma with associated long-term hypertensive management off all medication. Interestingly, this is the first case of transient hypotension following en bloc resection of pheochromocytoma associated with temporary hypotension-associated neurological decline that resolved completely after correction of hypotension postoperatively. A 23-year-old man with a prior adrenalectomy for pheochromocytoma presented with focal thoracic pain. He had a known T-10 vertebral body lesion for which he received chemotherapy and radiation therapy. Imaging demonstrated increased destruction of the T-10 vertebral body, which was concerning for tumor growth. The patient underwent angiographic embolization followed by single-stage posterior en bloc vertebrectomy with placement of a cage and posterior instrumentation and fusion without event. However, approximately 24 hours after surgery, the patient's systolic blood pressure was consistently no higher than 70 mm Hg. During this time, he began suffering from severe bilateral lower-extremity weakness. His systolic blood pressure increased with dopamine, and his strength immediately improved. The patient's oral regimen of adrenergic blockade was stopped, and he recovered without event. Since that time, the patient has been symptom free and requires no antihypertensive medication. The role of en bloc resection for metastatic lesions of the spine is controversial but may be warranted in cases of metastatic pheochromocytoma. En bloc resection avoids intralesional tumor resection and thus may help prevent complications of hypertensive crisis associated with hormonal secretion and extensive blood loss, which are not uncommon with pheochromocytoma resection surgeries. Additionally, the role of en bloc spondylectomy in this setting may allow for metabolic treatment as patients with actively secreting tumors may no longer require antiadrenergic medications.
Michelle J. Clarke, Patricia L. Zadnik, Mari L. Groves, Daniel M. Sciubba, Timothy F. Witham, Ali Bydon, Ziya L. Gokaslan and Jean-Paul Wolinsky
Recently, aggressive surgical techniques and a push toward en bloc resections of certain tumors have resulted in a need for creative spinal column reconstruction. Iatrogenic instability following these resections requires a thoughtful approach to adequately transfer load-bearing forces from the skull and upper cervical spine to the subaxial spine.
The authors present a series of 7 cases in which lateral mass reconstruction with a cage or fibular strut graft was used to provide load-bearing support, including 1 case of bilateral cage placement.
The authors discuss the surgical nuances of en bloc resection of high cervical tumors and explain their technique for lateral mass cage placement. Additionally, they provide their rationale for the use of these constructs throughout the craniocervical junction and subaxial spine.
Lateral mass reconstruction provides a potential alternative or adjuvant method of restoring the load-bearing capabilities of the cervical spine.
Sean Dangelmajer, Patricia L. Zadnik, Samuel T. Rodriguez, Ziya L. Gokaslan and Daniel M. Sciubba
Historically, adult degenerative lumbar scoliosis (DLS) has been treated with multilevel decompression and instrumented fusion to reduce neural compression and stabilize the spinal column. However, due to the profound morbidity associated with complex multilevel surgery, particularly in elderly patients and those with multiple medical comorbidities, minimally invasive surgical approaches have been proposed. The goal of this meta-analysis was to review the differences in patient selection for minimally invasive surgical versus open surgical procedures for adult DLS, and to compare the postoperative outcomes following minimally invasive surgery (MIS) and open surgery.
In this meta-analysis the authors analyzed the complication rates and the clinical outcomes for patients with adult DLS undergoing complex decompressive procedures with fusion versus minimally invasive surgical approaches. Minimally invasive surgical approaches included decompressive laminectomy, microscopic decompression, lateral and extreme lateral interbody fusion (XLIF), and percutaneous pedicle screw placement for fusion. Mean patient age, complication rates, reoperation rates, Cobb angle, and measures of sagittal balance were investigated and compared between groups.
Twelve studies were identified for comparison in the MIS group, with 8 studies describing the lateral interbody fusion or XLIF and 4 studies describing decompression without fusion. In the decompression MIS group, the mean preoperative Cobb angle was 16.7° and mean postoperative Cobb angle was 18°. In the XLIF group, mean pre- and postoperative Cobb angles were 22.3° and 9.2°, respectively. The difference in postoperative Cobb angle was statistically significant between groups on 1-way ANOVA (p = 0.014). Mean preoperative Cobb angle, mean patient age, and complication rate did not differ between the XLIF and decompression groups. Thirty-five studies were identified for inclusion in the open surgery group, with 18 studies describing patients with open fusion without osteotomy and 17 papers detailing outcomes after open fusion with osteotomy. Mean preoperative curve in the open fusion without osteotomy and with osteotomy groups was 41.3° and 32°, respectively. Mean reoperation rate was significantly higher in the osteotomy group (p = 0.008). On 1-way ANOVA comparing all groups, there was a statistically significant difference in mean age (p = 0.004) and mean preoperative curve (p = 0.002). There was no statistically significant difference in complication rates between groups (p = 0.28).
The results of this study suggest that surgeons are offering patients open surgery or MIS depending on their age and the severity of their deformity. Greater sagittal and coronal correction was noted in the XLIF versus decompression only MIS groups. Larger Cobb angles, greater sagittal imbalance, and higher reoperation rates were found in studies reporting the use of open fusion with osteotomy. Although complication rates did not significantly differ between groups, these data are difficult to interpret given the heterogeneity in reporting complications between studies.
Jennifer E. Kim, John Pang, Joani M. Christensen, Devin Coon, Patricia L. Zadnik, Jean-Paul Wolinsky, Ziya L. Gokaslan, Ali Bydon, Daniel M. Sciubba, Timothy Witham, Richard J. Redett and Justin M. Sacks
Total en bloc sacrectomy is a dramatic procedure that results in extensive sacral defects. The authors present a series of patients who underwent flap reconstruction after total sacrectomy, report clinical outcomes, and provide a treatment algorithm to guide surgical care of this unique patient population.
After institutional review board approval, data were collected for all patients who underwent total sacrectomy between 2002 and 2012 at The Johns Hopkins Hospital. Variables included demographic data, medical history, tumor characteristics, surgical details, postoperative complications, and clinical outcomes. All subtotal sacrectomies were excluded.
Between 2002 and 2012, 9 patients underwent total sacrectomy with flap reconstruction. Diagnoses included chordoma (n = 5), osteoblastoma (n = 1), sarcoma (n = 2), and metastatic colon cancer (n = 1). Six patients received gluteus maximus (GM) flaps with a prosthetic rectal sling following a single-stage, posterior sacrectomy. Four required additional paraspinous muscle (PSM) or pedicled latissimus dorsi (LD) fasciocutaneous flaps. Three patients underwent multistage sacrectomy with an anterior-posterior approach, 2 of whom received pedicled vertical rectus abdominis myocutaneous (VRAM) flaps, and 1 of whom received local GM, LD, and PSM flaps. Flap complications included dehiscence (n = 4) and infection (n = 1). During the 1st year of follow-up, 2 of 9 patients (22%) were able to ambulate with an assistive device by the 1st postoperative month, and 6 of 9 (67%) were ambulatory with a walker by the 3rd postoperative month. By postoperative Month 12, 5 of 9 patients (56%)—or 5 of 5 patients not lost to follow-up (100%)—were able to able to ambulate independently.
The authors' experience suggests that the GM and pedicled VRAM flaps are reliable options for softtissue reconstruction of total sacrectomy defects. For posterior-only operations, GM flaps with or without a prosthetic rectal sling are generally used. For multistage operations including a laparotomy, the authors consider the pedicled VRAM flap to be the gold standard for simultaneous reconstruction of the pelvic diaphragm and obliteration of dead space.
A novel animal model of human breast cancer metastasis to the spine: a pilot study using intracardiac injection and luciferase-expressing cells
Presented at the 2012 Spine Section Meeting
Patricia Zadnik, Rachel Sarabia-Estrada, Mari L. Groves, Camilo Molina, Christopher Jackson, Edward McCarthy, Ziya L. Gokaslan, Ali Bydon, Jean-Paul Wolinsky, Timothy F. Witham and Daniel M. Sciubba
Metastatic spine disease is prevalent in cancer victims; 10%–30% of the 1.2 million new patients diagnosed with cancer in the US exhibit spinal metastases. Unfortunately, treatments are limited for these patients, as disseminated disease is often refractory to chemotherapy and is difficult to treat with surgical intervention alone. New animal models that accurately recapitulate the human disease process are needed to study the behavior of metastases in real time.
In this study the authors report on a cell line that reliably generates bony metastases following intracardiac injection and can be tracked in real time using optical bioluminescence imaging. This line, RBC3, was derived from a metastatic breast adenocarcinoma lesion arising in the osseous spine of a rat following intracardiac injection of MDA-231 human breast cancer cells.
Upon culture and reinjection of RBC3, a statistically significantly increased systemic burden of metastatic tumor was noted. The resultant spine lesions were osteolytic, as demonstrated by small animal CT scanning.
This cell line generates spinal metastases that can be tracked in real time and may serve as a useful tool in the study of metastatic disease in the spine.
Paul E. Kaloostian, Patricia L. Zadnik, Jennifer E. Kim, Mari L. Groves, Jean-Paul Wolinsky, Ziya L. Gokaslan, Timothy F. Witham, Ali Bydon and Daniel M. Sciubba
Pheochromocytomas of the spine are uncommon and require careful preoperative planning. The authors retrospectively reviewed the charts of 5 patients with metastatic spinal pheochromocytoma who had undergone surgical treatment over the past 10 years at their medical center. They reviewed patient age, history of pheochromocytoma resection, extent and location of metastases, history of alpha blockage, surgical level, surgical procedure, postoperative complications, tumor recurrence, and survival. Metastases involved the cervical (1 patient), thoracic (3 patients), and lumbar (2 patients) levels. Preoperative treatment included primary pheochromocytoma resection, chemotherapy, alpha blockade, embolization, and radiation. Three patients had tumor recurrence, and 2 underwent 2-stage reoperations for tumor extension. Hemodynamic complications were common: 2 patients developed pulseless electrical activity arrest within 4 months after surgery, 1 patient had profound postoperative tachycardia with fever and an elevated creatine kinase level, and 1 patient experienced transient postoperative hypotension and paraplegia. One patient died of complications related to disseminated cerebral and spinal disease.
With careful preoperative and surgical management, patients with symptomatic metastatic spinal pheochromocytoma can benefit from aggressive surgical treatment. Postoperative cardiovascular complications are common even months after surgery, and patients should be closely monitored long term.
Camilo A. Molina, Christopher P. Ames, Dean Chou, Laurence D. Rhines, Patrick C. Hsieh, Patricia L. Zadnik, Jean-Paul Wolinsky, Ziya L. Gokaslan and Daniel M. Sciubba
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).
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.
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).
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.