Occipitocervical Fusion Surgery: Review of Operative Techniques and Results.

Objective Varying types of clinicoradiologic presentations at the craniovertebral junction (CVJ) influence the decision process for occipitocervical fusion (OCF) surgery. We discuss the operative techniques and decision-making process in OCF surgery based on our clinical experience and a literature review. Material and Methods A total of 49 consecutive patients who underwent OCF participated in the study. Sagittal computed tomography images were used to illustrate and measure radiologic parameters. We measured Wackenheim clivus baseline (WCB), clivus-canal angle (CCA), atlantodental distance (ADD), and Powers ratio (PR) in all the patients. Results Clinical improvement on Nurick grading was recorded in 36 patients. Patients with better preoperative status (Nurick grades 1-3) had better functional outcomes after the surgery (p = 0.077). Restoration of WCB, CCA, ADD, and PR parameters following the surgery was noted in 39.2%, 34.6%, 77.4%, and 63.3% of the patients, respectively. Complications included deep wound infections (n = 2), pseudoarthrosis (n = 2), and deaths (n = 4). Conclusion Conventional wire-based constructs are superseded by more rigid screw-based designs. Odontoidectomy is associated with a high incidence of perioperative complications. The advent of newer implants and reduction techniques around the CVJ has obviated the need for this procedure in most patients.

Complications of Anterior Cervical Fusion using a Low-dose Recombinant Human Bone Morphogenetic Protein-2.

OBJECTIVE: There are several reports, which documented a high incidence of complications following the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) in anterior cervical fusions (ACFs). The objective of this study is to share our experience with low-dose rhBMP-2 in anterior cervical spine. METHODS: We performed a retrospective analysis of 197 patients who underwent anterior cervical fusion (ACF) with the use of recombinant human bone morphogenetic protein-2 (rhBMP-2) during 2007-2012. A low-dose rhBMP-2 (0.7mg/level) sponge was placed exclusively within the cage. In 102 patients demineralized bone matrix (DBM) was filled around the BMP sponge. Incidence and severity of dysphagia was determined by 5 points SWAL-QOL scale. RESULTS: Two patients had prolonged hospitalization due to BMP unrelated causes. Following the discharge, 13.2%(n=26) patients developed dysphagia and 8.6%(n=17) patients complained of neck swelling. More than half of the patients (52.9%, n=9) with neck swelling also had associated dysphagia; however, only 2 of these patients necessitated readmission. Both of these patients responded well to the intravenous dexamethasone. The use of DBM did not affect the incidence and severity of complications (p>0.05). Clinico-radiological evidence of fusion was not observed in 2 patients. CONCLUSION: A low-dose rhBMP-2 in ACFs is not without risk. However, the incidence and severity of complications seem to be lower with low-dose BMP placed exclusively inside the cage. Packing DBM putty around the BMP sponge does not affect the safety profile of rhBMP-2 in ACFs.

Impact of elective versus emergent admission on perioperative complications and resource utilization in lumbar fusion.

BACKGROUND: The notion of higher complication rate and mortality in emergency surgeries is well established. There is a paucity of literature demonstrating the impact of emergent versus elective admissions for spinal surgery on the perioperative outcomes. We aim to evaluate the influence of the type of admission (elective or emergent) and day of surgery (same day versus other days within the emergent group) on the incidence, pattern of perioperative complications and hospital charges in the patients undergoing lumbar fusion for degenerative spine disease. METHODS: Data was obtained from the Nationwide Inpatient Sample (NIS) database between 2002 and 2011. We performed multivariate analysis to evaluate the impact of admission type and day of surgery on perioperative outcomes. RESULTS: A total of 266439 patients were identified. The majority of the admissions were elective (92.6%). Emergent admission comprised 7.4% of the total admission. Mean Charlson comorbidity index (CCI) was significantly higher in emergent and 'other days' (<0.001) groups. Emergent admission and surgery performed on the 'other days' were the independent risk factors for the higher incidence of the venous thromboembolic events, surgical site infection and wound dehiscence. The patients in the emergent and 'other days' surgery groups had a longer stay in the hospital (P<0.001). The mean total hospital charges were higher in the emergent admission and 'other days' surgery groups (P<0.001). CONCLUSIONS: 'Emergent admission' and surgery performed on the 'other days' in lumbar fusion are independent risk factors for the higher incidence of perioperative complications. Complicated hospital course and longer stay of the patients in the emergent admission and 'other days' group seems to be associated with higher total hospital charges.

Surgical Strategies in the Management of Spinal Nerve Sheath Tumors.

OBJECTIVES: Spinal nerve sheath tumors (SNSTs) are the most common lesions in the extramedullary intradural compartment. Complex and large lesions may pose technical difficulties for the operating surgeons. We discuss the management of SNSTs and technical issues including surgical approaches, spinal fixation, and dural handling with the goal of achieving good clinical outcomes while minimizing the risk of complications. We also propose a new classification for SNSTs to guide surgical treatment of these tumors. METHODS: A retrospective analysis was performed of 61 patients who underwent surgery for SNSTs during the period 1995-2012. The posterior approach was used for removal of most tumors (n = 53). Lesions having a substantial extraforaminal component were accessed from the anterior or lateral approach or a combined approach. Concomitant spinal fixation and fusion was performed in 7 patients. RESULTS: Most of the patients (n = 53) had clinical improvement; clinical status was the same in 4 patients and worse in the remaining 4 patients. One or more complications developed in 18 patients (29.5%). Recurrence was the most common complication (n = 7). Death occurred in 2 patients with malignant peripheral nerve sheath tumors 12 and 8 months, respectively, after surgical resection. CONCLUSIONS: Lesions with large extraforaminal extension pose technical difficulty. Spinal fixation with fusion should be supplemented whenever necessary. Complications related to dura mater may be associated with significant morbidity, and all possible efforts should be made to prevent them.

Impact of body habitus on fluoroscopic radiation emission during minimally invasive spine surgery.

OBJECT: Minimally invasive spine surgeries (MISSs) have gained immense popularity in the last few years. Concern about the radiation exposure has also been raised. The purpose of this study was to demonstrate the impact of body habitus on the radiation emission during various MISS procedures. The authors also aim to evaluate the effect the surgeon's experience has on the amount of radiation exposure during MISS especially with regard to patient size. METHODS: The authors conducted a retrospective analysis of 332 patients who underwent 387 MISS procedures performed at their institution from January 2010 to August 2013 by a single surgeon. The dose of radiation emission available from the fluoroscopic equipment was recorded from the electronic database. The authors analyzed mainly 3 procedure groups: microdiscectomy/decompression (MiDD, n=211) and transforaminal lumbar interbody fusion (TLIF) either with unilateral instrumentation (UnTLIF, n=106) or bilateral instrumentation (BiTLIF, n=70). The patients in each procedure group were divided into 6 categories based on the WHO criteria for obesity: underweight (body mass index [BMI]<18.50), normal (18.50-24.99), overweight (25.00-29.99), Class 1 obese (30.00-34.99), Class 2 obese (35.00- 39.99), and Class 3 obese (>40.00). RESULTS: Patients who underwent BiTLIF had the highest median radiation exposure (113 mGy, SD 9.44), whereas microdiscectomy required minimal exposure (12.62 mGy, SD 2.75 mGy). There was a significant correlation between radiation emission and BMI of the patients during all MISS procedures (p<0.05). The median radiation exposure was substantially greater with larger patients (p≤0.001). In the analyses within the procedure groups, radiation exposure was found to be significantly high in patients who were severely obese (Class 2 and Class 3 obesity). The radiation emission was lower during the surgeries performed in 2013 than during those performed in 2010 especially in obese patients; however, this observation was not statistically significant. CONCLUSIONS: Body habitus of the patients has a substantial impact on radiation emission during MISS. Severe obesity (BMI≥35) is associated with a significantly greater risk of radiation exposure compared with other weight categories. Surgical experience seems to be associated with lower radiation emission especially in cases in which patients have a higher BMI; however, further studies should be performed to examine this effect.

The anabolic effect of plasma-mediated ablation on the intervertebral disc: stimulation of proteoglycan and interleukin-8 production.

BACKGROUND CONTEXT: Plasma-mediated radiofrequency-based ablation (coblation) is an electrosurgical technique currently used for tissue removal in a wide range of surgical applications, including lumbar microdiscectomy. In vitro and in vivo studies have shown the technique to alter the expression of inflammatory cytokines in the disc, increasing the levels of interleukin-8 (IL-8), which may promote maturation and remodeling of the disc matrix. PURPOSE: To better understand the effect of coblation treatment, this study characterizes the temporal and spatial pattern of healing after stab injury to the rabbit intervertebral disc, with and without plasma-mediated radiofrequency treatment. PATIENT SAMPLE: A total of 23 New Zealand white rabbits. STUDY DESIGN: Annular and nuclear stab injuries. OUTCOME MEASURES: Sandwich enzyme-linked immunosorbent assay evaluated the concentrations of cytokines tumor necrosis factor-α, IL-1ß, and IL-8. Histopathologic evaluations were performed on whole discs and end plates. Tissue sections were stained with Safranin-O to evaluate nucleus pulposus and annulus fibrosus proteoglycan content and with Alcian blue for extracellular proteoglycan content. Intradiscal leakage pressure was evaluated by injecting methylene blue dye into the nucleus. METHODS: Animals underwent annular and nuclear stab injuries on three consecutive lumbar discs (L2-L3 to L4-L5). The three levels were randomly assigned into one of the three groups for treatment with a plasma-mediated radiofrequency ablation device (TOPAZ; ArthroCare Corp., Austin, TX, USA): active treatment of the nucleus only (SN); active treatment of both nucleus and annulus (SNA); sham treatment. Unstabbed/untreated discs from L5-L6 (n=5) served as normal controls. Animals were euthanized at 4, 8, and 28 days postsurgery. RESULTS: Tumor necrosis factor-α was detected in sham discs at 4 and 8 days, but not in coblation groups (SN or SNA); IL-1ß was below detection in all three treatment groups. Interleukin-8 levels increased in all treatment groups at 4 and 8 days compared with normal control, peaking at 4th day for sham and SN groups and 8th day (p>.3) for the SNA group (a 2.5-fold increase). Pressure measurements revealed higher leakage in the SN group, but no statistically significant differences. Histopathology showed higher proteoglycan production by 28 days in the SNA and SN groups compared with sham. All three treatment groups showed ruptured annular fibers from the stab injury, but maintained the overall architecture. Remnants of notochordal tissue within the nucleus were evident in all treatment groups at 4 and 8 days, but were only found in sham group by 28 days. At this time, unlike the normal or sham controls, the nucleus of SN and SNA discs had fibrocartilaginous tissue with chondrocyte-like cells. Significant differences in the disc architecture grade were only noted when comparing normal controls with other groups by 28 days (p<.001). CONCLUSIONS: Plasma-mediated radiofrequency ablation appears to have an anabolic effect on disc cells, stimulating proteoglycan and IL-8 production and maintaining annulus architecture. Coblation treatment appears to reduce cellular response to proinflammatory stimuli and restore overall disc architecture that may prove beneficial in a number of degenerative disc paradigms. Further studies are encouraged to investigate the therapeutic effect of the technique.

Gamma Knife stereotactic radiosurgery for intracranial metastases from conventionally radioresistant primary cancers: outcome analysis of survival and control of brain disease.

OBJECTIVE: The aim of this study was to analyze our experience with stereotactic radiosurgery in the management of patients with brain metastases from radioresistant primary cancers. METHODS: We retrospectively reviewed the clinical record of those patients for the outcome measures. All data were coded and entered into multivariate regression analysis for studying the relationship between survival and other variables. RESULTS: Over a 48-month period, 31 patients received radiosurgery for brain metastases from renal cell carcinoma (n = 7), malignant melanoma (n = 14), or colon carcinoma (n = 10) at our institution. The followup ranged from 1-48 months (mean = 17 months). At the time of last followup, 11 patients (35.5%) were alive and 20 had died. Six deaths (30%) resulted from progressive brain disease while 14 patients died from progressive primary and/or extracranial metastatic disease. Mean survival from radiosurgery was 12 months (95% CI, 7-17) and the median survival was 7 months. The 1 and 2 year actuarial survival rates were 32.5 +/- 1% and 12.2 +/- 1% respectively. The overall survival was directly related to tumor control time (P <0.001) and inversely to the number of metastases (P = 0.031). CONCLUSION: Gamma Knife stereotactic radiosurgery for intracranial metastases from conventionally radioresistant primary cancers is a safe and effective method to provide better local control of the brain disease and improve survival time.

Posterior C1-2 fusion for type II odontoid fracture in 2-year-old: case report and review of literature.

The girl, aged 2 years 11 months, had an unstable type II odontoid fracture. Initial non-operative therapy failed to maintain her in proper alignment. She was taken for posterior interlaminar wiring with iliac crest bone graft. Her fracture showed signs of fusion at her six month follow-up.

Amyloidoma presenting as a butterfly glioma on positron emission tomography scan and magnetic resonance-spectroscopy: a case report and review of the literature.

PURPOSE: Isolated amyloidoma rarely involves the nervous system. MATERIALS: We report a patient with progressively worsening triparesis and numbness in his extremities. RESULTS: Magnetic resonance imaging (MRI) of the brain revealed a mass lesion involving both hemispheres, which on positron emission tomography (PET) scan and magnetic resonance-spectroscopy (MR-SPECT) appeared to be a butterfly glioma. However, neuropathological examination revealed a large area with localized vascular amyloidosis. CONCLUSION: This is the first case of a localized central nervous system vascular amyloid to imitate a butterfly glioma on MRI and PET scan studies.

Surgical treatment of myelomeningocele: year 2000 hospitalization, outcome, and cost analysis in the US.

OBJECTIVE: To review cases of surgical repair for myelomeningocele (MMC) using a large inpatient database from the year 2000. MATERIALS AND METHODS: The Nationwide Inpatient Sample (NIS) database with 7.45 million patient admissions for 2000 was retrospectively studied for the first 5 procedure diagnosis of MMC repair (ICD-9 CM procedure code 0352) and ages of less than 1 year. Eighty-eight patient stays were identified. Patient demographic data, length of stay, immediate disposition at the time of discharge, hospital information, and total cost for the hospitalization were determined. CONCLUSION: Myelomeningocele repair is mostly performed in large teaching institutions in small numbers. The majority gets to go home at discharge. It is surprising to note that only 35% also required VP shunt placement during the same hospitalization.

Predictive factors for dural tear and cerebrospinal fluid leakage in patients undergoing lumbar surgery.

OBJECT: A dural tear resulting in a cerebrospinal fluid (CSF) leak is a well-known risk of lumbar spinal procedures. The authors hypothesized that the incidence of CSF leakage is higher in cases involving repeated operations and those in which the surgeon performing the surgery is less experienced; however, they postulated that the overall outcome of the patient would not be adversely affected by a dural tear. METHODS: An institutional review board-approved protocol at Louisiana State University Health Sciences Center, Shreveport, was initiated in August 2003 to allow prospective comparison of data obtained in patients in whom a CSF leak occurred (Group A) and those in whom no CSF leak occurred (Group B) during lumbar surgery. Basic demographic information, descriptive findings regarding the tear, history of other surgeries, hospital length of stay (LOS), and immediate disposition at the time of discharge were compared between the two groups. Seventy-seven patients were eligible for this study. One patient refused to participate. In 12 (15.8%) of 76 patients CSF leakage developed. In three patients the presence of a tear was questioned, and the patients were clinically treated as if a tear were present. The patients in Group A were older than those in Group B (59.8 +/- 16.9 and 49.4 +/- 13.6 years of age, respectively; p = 0.02, Fisher exact test). In terms of those with a history of surgery, there was no significant difference between patients with and patients without a CSF leak (three [25%] of 12 patients [Group A] compared with 28 [43.8%] of 64 patients [Group B]; p = 0.34, two-sample t-test). In the 12 patients with dural tears, nine (75%) were caused by a resident-in-training, and the Kerrison punch was the instrument most often being used at the time (55%). This is significantly greater than 50% at the 5% level (p = 0.044, binomial test). The authors were able to repair the tear primarily with suture in all but one patient, whose tear was along the nerve root sleeve. In all cases fibrin glue and a muscle/fat graft were used to cover the tear, and all patients were assigned to bed rest from 24 to 48 hours after the operation. In Group A one patient required rehabilitation at discharge. The LOS in Group A was greater than that in Group B (median 5 days compared with 3 days), but no additional complication was noted. CONCLUSIONS: The incidence of CSF leakage was 16% in 76 patients, and there were no other complications. Older patient age and higher level of the surgeon's training were factors contributing to the incidence, but the history of surgery was not.

Adopting 540-degree fusion to correct cervical kyphosis.

BACKGROUND: Two cases of severe cervical spine kyphotic deformity resulting from late effects of infection were successfully corrected by combined anterior and posterior instrumentations in a single operative sitting. CASE DESCRIPTION: Case 1 is a 43-year-old man who developed severe cervical kyphosis from C5-6 discitis over a few months despite long-term antibiotic therapy. He was neurologically intact except for severe neck pain and obvious deformity. Case 2 is a 40-year-old woman who had a previous wound infection five years before presentation. There was gradual worsening of swan neck deformity at the C2-3 and C5-6 levels with some spinal cord compression worsening her baseline myelopathy. The patients were placed and maintained in cervical traction on the Stryker frame for the duration of the procedure. Both cases required anterior approach initially to achieve some release of dense scar tissue using a high-speed drill. The wounds were then closed and patients were rotated to the prone position for further release of fused bony elements, including the facets. Lateral mass screws and plates were placed. In Case 2, additional instrument to the occipital was performed to stabilize the C2 using a U-shaped cervical rod. Once adequate reduction had been achieved, the patients were rotated back to supine position for further corpectomy and fibular construct fusion with plates. CONCLUSION: In cases of severe kyphotic deformity complicating infectious vertebral destruction, the spinal alignment can be achieved safely by a multi-step technique combining the anterior as well as posterior surgical approaches.