Less invasive surgery for treating adult spinal deformities: ceiling effects for deformity correction with 3 different techniques.

OBJECT: Minimally invasive surgery (MIS) options for the treatment of adult spinal deformity (ASD) have advanced significantly over the past decade. However, a wide array of options have been described as being MIS or less invasive. In this study the authors investigated a multiinstitutional cohort of patients with ASD who were treated with less invasive methods to determine the extent of deformity correction achieved. METHODS: This study was a retrospective review of multicenter prospectively collected data in 85 consecutive patients with ASD undergoing MIS surgery. Inclusion criteria were as follows: age older than 45 years; minimum 20° coronal lumbar Cobb angle; and 1 year of follow-up. Procedures were classified as follows: 1) stand-alone (n = 7); 2) circumferential MIS (n = 43); or 3) hybrid (n = 35). RESULTS: An average of 4.2 discs (range 3-7) were fused, with a mean follow-up duration of 26.1 months in this study. For the stand-alone group the preoperative Cobb range was 22°-51°, with 57% greater than 30° and 28.6% greater than 50°. The mean Cobb angle improved from 35.7° to 30°. A ceiling effect of 23° for curve correction was observed, regardless of preoperative curve severity. For the circumferential MIS group the preoperative Cobb range was 19°-62°, with 44% greater than 30° and 5% greater than 50°. The mean Cobb angle improved from 32° to 12°. A ceiling effect of 34° for curve correction was observed. For the hybrid group the preoperative Cobb range was 23°-82°, with 74% greater than 30° and 23% greater than 50°. The mean Cobb angle improved from 43° to 15°. A ceiling effect of 55° for curve correction was observed. CONCLUSIONS: Specific procedures for treating ASD have particular limitations for scoliotic curve correction. Less invasive techniques were associated with a reduced ability to straighten the spine, particularly with advanced curves. These data can guide preoperative technique selection when treating patients with ASD.

Comparison of radiographic results after minimally invasive, hybrid, and open surgery for adult spinal deformity: a multicenter study of 184 patients.

OBJECT: Various surgical approaches, including open, minimally invasive, and hybrid techniques, have gained momentum in the management of adult spinal deformity. However, few data exist on the radiographic outcomes of different surgical techniques. The objective of this study was to compare the radiographic and clinical outcomes of the surgical techniques used in the treatment of adult spinal deformity. METHODS: The authors conducted a retrospective review of two adult spinal deformity patient databases, a prospective open surgery database and a retrospective minimally invasive surgery (MIS) and hybrid surgery database. The time frame of enrollment in this study was from 2007 to 2012. Spinal deformity patients were stratified into 3 surgery groups: MIS, hybrid surgery, and open surgery. The following pre- and postoperative radiographic parameters were assessed: lumbar major Cobb angle, lumbar lordosis, pelvic incidence minus lumbar lordosis (PI-LL), sagittal vertical axis, and pelvic tilt. Scores on the Oswestry Disability Index (ODI) and a visual analog scale (VAS) for both back and leg pain were also obtained from each patient. RESULTS: Of the 234 patients with adult spinal deformity, 184 patients had pre- and postoperative radiographs and were thus included in the study (MIS, n = 42; hybrid, n = 33; open, n = 109). Patients were a mean of 61.7 years old and had a mean body mass index of 26.9 kg/m(2). Regarding radiographic outcomes, the MIS group maintained a significantly smaller mean lumbar Cobb angle (13.1°) after surgery compared with the open group (20.4°, p = 0.002), while the hybrid group had a significantly larger lumbar curve correction (26.6°) compared with the MIS group (18.8°, p = 0.045). The mean change in the PI-LL was larger for the hybrid group (20.6°) compared with the open (10.2°, p = 0.023) and MIS groups (5.5°, p = 0.003). The mean sagittal vertical axis correction was greater for the open group (25 mm) compared with the MIS group (≤ 1 mm, p = 0.008). Patients in the open group had a significantly larger postoperative thoracic kyphosis (41.45°) compared with the MIS patients (33.5°, p = 0.005). There were no significant differences between groups in terms of pre- and postoperative mean ODI and VAS scores at the 1-year follow-up. However, patients in the MIS group had much lower estimated blood loss and transfusion rates compared with patients in the hybrid or open groups (p < 0.001). Operating room time was significantly longer with the hybrid group compared with the MIS and open groups (p < 0.001). Major complications occurred in 14% of patients in the MIS group, 14% in the hybrid group, and 45% in the open group (p = 0.032). CONCLUSIONS: This study provides valuable baseline characteristics of radiographic parameters among 3 different surgical techniques used in the treatment of adult spinal deformity. Each technique has advantages, but much like any surgical technique, the positive and negative elements must be considered when tailoring a treatment to a patient. Minimally invasive surgical techniques can result in clinical outcomes at 1 year comparable to those obtained from hybrid and open surgical techniques.

Management of intracranial hemorrhage in a child with a left ventricular assist device.

Pediatric patients bridged to heart transplant with LVADs require chronic anticoagulation and are at increased risk of hemorrhagic complications, including intracranial hemorrhage. In this population, intracranial hemorrhage is often fatal. We report a case of successful management of a five-yr-old-boy with DCM on an LVAD who developed a subdural hematoma. We initially chose medical management, weighing the patient's high risk of thromboembolism from anticoagulation reversal against the risk of his chronic subdural hematoma. When head CT showed expansion of the hemorrhage with increasing midline shift, we chose prompt surgical evacuation of the hematoma with partial reversal of anticoagulation, given the increased risk of acute deterioration. The patient ultimately received an orthotopic heart transplant and was discharged with no permanent neurological complications. This represents a case of a pediatric patient on an LVAD who survived a potentially fatal subdural hematoma and was successfully bridged to cardiac transplantation.

Polymorphisms in complement component 3 (C3F) and complement factor H (Y402H) increase the risk of postoperative neurocognitive dysfunction following carotid endarterectomy.

BACKGROUND: Up to 28% of patients undergoing carotid endarterectomy (CEA) are estimated to experience neurocognitive dysfunction following surgery. The complement cascade plays a central role in ischaemia-reperfusion injury. The authors investigated the effect of common polymorphisms in the complement component 3 (C3F) and complement factor H (CFH Y402H) genes on incidence of neurocognitive dysfunction post-CEA. METHODS: This study examined a nested cohort of prospectively recruited patients receiving elective CEA, who were genotyped for the C3F or Y402H polymorphisms. Each patient underwent a standard battery of eight neuropsychometric tests before, and 1 day and 30 days after, surgery. RESULTS: 57 of 142 (40%) CEA patients had at least one copy of the C3F allele (C3F+), and 17 of 137 (12%) patients had two copies of the CFH Y402H allele (Y402H++). At postoperative day 1, patients were three times (OR 3.05, p=0.045) or six times (OR 6.41, p=0.006) more likely to experience moderate-to-severe neurocognitive dysfunction if they carried the C3F+ or Y402H++ genotype, respectively. Patients with both risk genotypes had an almost eightfold risk of dysfunction (OR 7.67, p=0.046). Right-hand-dominant C3F+ subjects undergoing right-side CEA performed significantly worse on tests of visuospatial function than C3F- subjects. At day 30, C3F+ and Y402H++ genotypes trended towards significance as predictors of dysfunction (p=0.07 and p=0.22, respectively). CONCLUSION: The C3F and Y402H polymorphisms are strong independent predictors of moderate-to-severe neurocognitive dysfunction at 1 day following CEA. Furthermore, patients undergoing right-sided CEA are predisposed to deficits associated with cortex ipsilateral to the operative carotid artery.

Advances in neuroprotective strategies: potential therapies for intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is associated with higher mortality and morbidity than any other form of stroke. However, there currently are no treatments proven to improve outcomes after ICH, and therefore, new effective therapies are urgently needed. Growing insight into ICH pathophysiology has led to the development of neuroprotective strategies that aim to improve the outcome through reduction of secondary pathologic processes. Many neuroprotectants target molecules or pathways involved in hematoma degradation, inflammation or apoptosis, and have demonstrated potential clinical benefits in experimental settings. We extensively reviewed the current understanding of ICH pathophysiology as well as promising experimental neuroprotective agents with particular focus on their mechanisms of action. Continued advances in ICH knowledge, increased understanding of neuroprotective mechanisms, and improvement in the ability to modulate molecular and pathologic events with multitargeting agents will lead to successful clinical trials and bench-to-bedside translation of neuroprotective strategies.

Isoflurane preconditioning affords functional neuroprotection in a murine model of intracerebral hemorrhage.

INTRODUCTION: Exposure to isoflurane gas prior to neurological injury, known as anesthetic preconditioning, has been shown to provide neuroprotective benefits in animal models of ischemic stroke. Given the common mediators of cellular injury in ischemic and hemorrhagic stroke, we hypothesize that isoflurane preconditioning will provide neurological protection in intracerebral hemorrhage (ICH). METHODS: 24 h prior to intracerebral hemorrhage, C57BL/6J mice were preconditioned with a 4-h exposure to 1% isoflurane gas or room air. Intracerebral hemorrhage was performed using a double infusion of 30-µL autologous whole blood. Neurological function was evaluated at 24, 48 and 72 h using the 28-point test. Mice were sacrificed at 72 h, and brain edema was measured. RESULTS: Mice preconditioned with isoflurane performed better than control mice on 28-point testing at 24 h, but not at 48 or 72 h. There was no significant difference in ipsilateral hemispheric edema between mice preconditioned with isoflurane and control mice. CONCLUSION: These results demonstrate the early functional neuroprotective effects of anesthetic preconditioning in ICH and suggest that methods of preconditioning that afford protection in ischemia may also provide protection in ICH.

Spontaneous thrombosis of a giant fusiform aneurysm following extracranial-intracranial bypass surgery.

The authors describe the cases of 2 patients who underwent extracranial-intracranial bypass surgery for a giant fusiform aneurysm but in whom further surgery was then not necessary because the aneurysm spontaneously thrombosed. The authors hypothesize that this thrombosis was caused by alterations in aneurysm's hemodynamics, leading to a decreased rate of blood flow in the aneurysm. In the older of the 2 cases, more than 10 years after surgery the patient has not required further surgical intervention. Spontaneous thrombosis of a giant fusiform aneurysm is a rare occurrence during extracranial-intracranial bypass, and although continual monitoring is recommended, these patients can remain stable long term.

Intraoperative magnesium infusion during carotid endarterectomy: a double-blind placebo-controlled trial.

OBJECT: Recent data from both experimental and clinical studies have supported the use of intravenous magnesium as a potential therapy in the setting of cerebral ischemia. This study assessed whether intraoperative magnesium therapy improves neuropsychometric testing (NPT) following carotid endarterectomy (CEA). METHODS: One hundred eight patients undergoing CEA were randomly assigned to receive placebo infusion or 1 of 3 magnesium-dosing protocols. Neuropsychometric testing was performed 1 day after surgery and compared with baseline performance. Assessment was also performed on a set of 35 patients concurrently undergoing lumbar laminectomy to serve as a control group for NPT. A forward stepwise logistic regression analysis was performed to evaluate the impact of magnesium therapy on NPT. A subgroup analysis was then performed, analyzing the impact of each intraoperative dose on NPT. RESULTS: Patients treated with intravenous magnesium infusion demonstrated less postoperative neurocognitive impairment than those treated with placebo (OR 0.27, 95% CI 0.10-0.74, p = 0.01). When stratified according to dosing bolus and intraoperative magnesium level, those who were treated with low-dose magnesium had less cognitive decline than those treated with placebo (OR 0.09, 95% CI 0.02-0.50, p < 0.01). Those in the high-dose magnesium group demonstrated no difference from the placebo-treated group. CONCLUSIONS: Low-dose intraoperative magnesium therapy protects against neurocognitive decline following CEA.

Mechanical treatment of vasospasm.

OBJECTIVE: Since cerebral vasospasm (CV) was first described nearly half a century ago, significant progress has been made in understanding its underlying pathophysiology and developing treatment modalities. The purpose of this review is to discuss the rationale behind mechanical interventions for CV as well as the efficacy and complications associated with these treatment options. METHODS: The authors summarize the pertinent literature on the mechanical treatment of CV, focusing first on balloon angioplasty, second on therapy combined with intra-arterial drug infusion, and concluding by briefly discussing intra-aortic balloon counterpulsation. The epidemiology, pathophysiology, technique, outcome, timing and complications are discussed for each treatment option. RESULTS: A review of the relevant medical literature reveals that in the last 20 years, endovascular techniques including transluminal balloon angioplasty, intra-arterial drug infusion and newer experimental strategies have provided an important supplement to the established medical therapy. DISCUSSION: Despite these developments, however, CV remains a major contributor to poor outcome following aSAH and continued efforts are necessary to improve and refine endovascular strategies as well as develop new treatment modalities.

Regenerating motor bridge axons refine connections and synapse on lumbar motoneurons to bypass chronic spinal cord injury.

To restore motor control after spinal cord injury requires reconnecting the brain with spinal motor circuits below the lesion. A bridge around the injury is an important alternative to promoting axon regeneration through the injury. Previously, we reported a novel motor bridge in rats. The thirteenth thoracic nerve was detached from the muscle it innervates and the cut end implanted caudally into the lumbar gray matter where motor bridge axons regenerate. In this study, we first determined that regenerating bridge axons project to spinal motor circuits. Stable projections were present in ventral motor laminae of the cord, including putative synapses directly on motoneurons, 2 months after insertion in the intact cord. At this time, earlier-forming dorsal horn projections were mostly eliminated. Regenerating axons were effective in evoking leg motor activity as early as 2 weeks. We next determined that bridge axons could regenerate caudal to a chronic injury. We hemisected the spinal cord at L2 and inserted the bridge nerve 1 month later at L5 and found ventral laminae projections similar to those in intact animals, including onto motoneurons directly. Finally, we determined that the bridge circuit could be activated by neural pathways rostral to its origin. For spinally hemisected animals, we electrically stimulated the rostral spinal cord and recorded evoked potentials from the bridge and, in turn, motor responses in the sciatic nerve. Our findings suggests that bridge motoneurons could be used by descending motor pathways as premotor interneurons to transmit neural signals to bypass a chronic spinal injury.

Expression of Notch-1 and its ligands, Delta-like-1 and Jagged-1, is critical for glioma cell survival and proliferation.

The Notch family of proteins plays an integral role in determining cell fates, such as proliferation, differentiation, and apoptosis. We show that Notch-1 and its ligands, Delta-like-1 and Jagged-1, are overexpressed in many glioma cell lines and primary human gliomas. Immunohistochemistry of a primary human glioma tissue array shows the presence in the nucleus of the Notch-1 intracellular domain, indicating Notch-1 activation in situ. Down-regulation of Notch-1, Delta-like-1, or Jagged-1 by RNA interference induces apoptosis and inhibits proliferation in multiple glioma cell lines. In addition, pretreatment of glioma cells with Notch-1 or Delta-like-1 small interfering RNA significantly prolongs survival in a murine orthotopic brain tumor model. These results show, for the first time, the dependence of cancer cells on a single Notch ligand; they also suggest a potential Notch juxtacrine/autocrine loop in gliomas. Notch-1 and its ligands may present novel therapeutic targets in the treatment of glioma.

Claudin-4, mitogen-activated protein kinase kinase 4, and stratifin are markers of gastric adenocarcinoma precursor lesions.

Approximately 23,000 new gastric cancer cases and 12,000 associated deaths occur annually in the United States. Intestinal metaplasia and gastric epithelial dysplasia are precursor lesions to gastric adenocarcinoma, but are not readily detectable clinically, radiographically, or endoscopically. A noninvasive method of precursor detection would require the ability to distinguish precursor lesions from adjacent normal mucosa. In search of such markers, tissue microarrays were prepared for 133 patients of resected gastric adenocarcinoma. Tissue microarrays contained primary cancer, normal stomach, intestinal metaplasia, and gastric epithelial dysplasia and were probed with antibodies against nine potential markers that were either identified in a database of genes overexpressed in gastric adenocarcinoma or were already of interest to our laboratory: claudin-4, mitogen-activated protein kinase kinase 4 (MKK4), 14-3-3sigma (stratifin), S100A4, mesothelin, fascin, topoisomerase IIalpha, HER-2/neu, and epithelial growth factor receptor. Three markers discriminated gastric adenocarcinoma precursor lesions from normal gastric mucosa. Claudin-4 expression was present in 36 intestinal metaplasia lesions (100%) and 14 gastric epithelial dysplasia lesions (100%), but in only 16 normal stomach samples (15%). MKK4 expression was present in 24 intestinal metaplasia lesions (89%) and 12 gastric epithelial dysplasia lesions (100%), but in only 6 normal stomach samples (8%). Stratifin expression was present in 29 intestinal metaplasia lesions (97%) and 8 gastric epithelial dysplasia lesions (100%), but in only 2 normal stomach samples (3%). Sensitivity and specificity for detection of the precursor lesion intestinal metaplasia were 100% and 85%, respectively, for claudin-4; 89% and 92%, respectively, for MKK4; and 97% and 97%, respectively, for stratifin. In primary cancers, 123 of 125 (98.4%) were positive for claudin-4, 116 of 126 (94%) for MKK4, and 111 of 120 (92%) for stratifin. In conclusion, claudin-4, MKK4, and stratifin immunolabeling detects precursor lesions of gastric adenocarcinoma that are otherwise clinically, radiographically, and endoscopically inapparent. These findings may prove useful in the diagnosis and therapeutic targeting of gastric adenocarcinoma precursor lesions.

MKK4 status predicts survival after resection of gastric adenocarcinoma.

HYPOTHESIS: Lack of expression of the tumor-suppressor gene MKK4 is significantly correlated with poor survival after resection of gastric adenocarcinoma. DESIGN: Retrospective review of medical records after construction and immunolabeling of tissue microarrays for clinical correlation. SETTING: The Johns Hopkins Hospital, Baltimore, Md. PATIENTS: Patients operated on because of gastric adenocarcinoma between 1983 and 1995. Main Outcome Measure Long-term survival and MKK4 status. RESULTS: Primary tumors (N = 124) were scored as 0 (no labeling), 1+ (weak labeling), or 2+ (strong labeling) in 9 (7%), 80 (65%), and 35 (28%) patients, and 5-year survival in these patients was 0%, 21%, and 28%, respectively. Given the small size (7%) of the MKK4-negative group (as expected, given the 5%-10% incidence of genetic loss in carcinomas), a Cox proportional hazards analysis was performed, adjusting for age, sex, and tumor stage. This multivariate analysis revealed a 5-fold increased risk of death (P<.001) in patients whose primary tumors were MKK4-negative. Furthermore, the addition of MKK4 status significantly improved the Cox model, changing log likelihood from -1410 to -369, confirming that MKK4 status was truly the effector of the survival difference and not a bystander. CONCLUSIONS: The lack of expression of the tumor-suppressor gene MKK4 in resected gastric adenocarcinoma is robustly associated with poor survival. This finding may provide a useful prognostic tool in patients with gastric adenocarcinoma.

Spinal nerve root stimulation.

Spinal nerve root stimulation is a recently developed form of neuromodulation used for the treatment of chronic pain conditions. Unlike spinal cord stimulation, in which electrical impulses are directed at the dorsal columns, spinal nerve root stimulation guides electrical current directly to one or more nerve roots. There are a variety of techniques by which this can be accomplished, yet no consistent terminology to describe these variations exists. In this review, the authors group the various techniques according to anatomical approach, define each category, describe and illustrate each of the techniques, review the available reports on their uses, and discuss the advantages and disadvantages of each one.

"Push-Through" Rod Passage Technique for the Improvement of Lumbar Lordosis and Sagittal Balance in Minimally Invasive Adult Degenerative Scoliosis Surgery.

OF BACKGROUND DATA: Traditional open surgical techniques for correction of adult degenerative scoliosis (ADS) are often associated with increased blood loss, postoperative pain, and complications. Minimally invasive (MIS) techniques have been utilized to address these issues; however, concerns regarding improving certain alignment parameters have been raised. OBJECTIVE: A new "push-through" technique for MIS correction of ADS has been developed wherein a rod is bent before its placement into the screw heads and then contoured further to yield improved correction of radiographic parameters. METHODS AND STUDY DESIGN: Preoperative and postoperative radiographic measurements of 3 patients who underwent MIS correction of scoliosis using the "push-through" technique were compared with 22 prior patients who had received traditional MIS correction. All patients received staged correction of scoliosis. The first stage involved insertion of lateral lumbar interbodies. Standing x-rays were then evaluated for overall global balance. The second stage involved appropriate MIS facetectomies, facet fusions, posterior transforaminal interbodies at lower lumbar segments, and finally the placement of rods.TECHNIQUE OVERVIEW:: (1) A long rod composed of titanium is bent with a mild lordosis and passed through the extensions of the screw heads cephalad to caudad. (2) The rod is passed fully through the incision so it extrudes from the caudal end of the construct. At this point, further lordosis is bent into the rods. (3) The rod is then pulled back into the appropriate position. (4) The unnecessary cephalad rod is then cut to appropriate length with a circular saw. (5) Rod reducers are then sequentially lowered and tightened to achieve the desired correction. RESULTS: Mean age for all patients was 66.02 years. Preoperative coronal Cobb, sagittal vertical axis (SVA), and pelvic incidence (PI) were similar in all patients, whereas lumbar lordosis (LL) was smaller (15.27 vs. 29.85 degrees, P=0.00389) and pelvic tilt (PT) was larger (37.00 vs. 27.00 degrees, P=0.00011) in "push-through" patients. Postoperatively, "pushthrough" patients experienced greater correction of LL (21.93 vs. 3.70 degrees, P=0.00001), PI-LL (-18.57 vs. -0.26 degrees, P=0.00471), PT (-7.67 vs. -0.40 degrees, P=0.00341), SVA (-40.67 mm vs. 0.95 mm, P=0.05846), and coronal Cobb (-20.23 vs. -18.76 degrees, P=0.75). CONCLUSIONS: This new method of contouring a rod enables improved LL. This technique is easy to perform and can be a valuable tool in treating ADS using MIS techniques.

Survival after gastric adenocarcinoma resection: eighteen-year experience at a single institution.

Gastric adenocarcinoma is the second leading cause of cancer death worldwide. In Western series, survival rates vary widely and are generally lower than those reported from Eastern series. We performed a retrospective analysis of cases operated on at the Johns Hopkins Hospital over the past 18 years and collected data on demographics, tumor characteristics, pathologic stage, treatment methods, complications, survival time, and other relevant factors. Survival according to stage of disease, Lauren tumor type, tumor location, time period, and administration of adjuvant therapy was analyzed, and results were compared with those of other Western series. During this period, 436 patients with gastric adenocarcinoma underwent resection. We have shown a statistically significant association between survival and margin status, stage of disease, and Lauren tumor type. Overall 5-year survival was 26%, and 5-year survival after R0 resection was 33%. No significant difference was detected between survival and tumor location, time period of treatment, or administration of adjuvant therapy. Analysis of various Western series reveals major differences between the cohorts under study, such as stage of disease, extent of resection, tumor type, and tumor location. Many of the reported differences among Western series may be due to cohort differences, such as stage of disease, extent of resection, tumor type, and tumor location.

Spinal pelvic reconstruction after total sacrectomy for en bloc resection of a giant sacral chordoma. Technical note.

Although radical resection prolongs the disease-free survival period, surgical management of primary sacral tumors is challenging because of their location and often large size. Moreover, in cases of lesions for which a radical resection necessitates total sacrectomy, reconstruction is required. The authors have previously described a modified Galveston technique in which a liaison between the spine and pelvis is achieved using lumbar pedicle screws and Galveston rods embedded into the ilia; additionally, a transiliac bar reestablishes the pelvic ring. Although this reconstruction technique achieves stabilization, several biomechanical limitations exist. In the present report the authors present the case of a patient who underwent spinal pelvic reconstruction after a total sacrectomy was performed to remove a giant sacral chordoma. They describe a novel spinal pelvic reconstruction technique that addresses some of the biomechanical limitations.

Cost minimization in treatment of adult degenerative scoliosis.

OBJECT: Back pain is an increasing concern for the aging population. This study aims to evaluate if minimally invasive surgery presents cost-minimization benefits compared with open surgery in treating adult degenerative scoliosis. METHODS: Seventy-one patients with adult degenerative scoliosis received 2-stage, multilevel surgical correction through either a minimally invasive spine surgery (MIS) approach with posterior instrumentation (n = 38) or an open midline (Open) approach (n = 33). Costs were derived from hospital and rehabilitation charges. Length of stay, blood loss, and radiographic outcomes were obtained from electronic medical records. Functional outcomes were measured with Oswestry Disability Index (ODI) and visual analog scale (VAS) surveys. RESULTS: Patients in both cohorts were similar in age (Age(MIS) = 65.68 yrs, Age(Open) = 63.58 yrs, p = 0.28). The mean follow-up was 18.16 months and 21.82 months for the MIS and Open cohorts, respectively (p = 0.34). MIS and Open cohorts had an average of 4.37 and 7.61 levels of fusion, respectively (p < 0.01). Total inpatient charges were lower for the MIS cohort ($269,807 vs $391,889, p < 0.01), and outpatient rehabilitation charges were similar ($41,072 vs $49,272, p = 0.48). MIS patients experienced reduced length of hospital stay (7.03 days vs 14.88 days, p < 0.01) and estimated blood loss (EBL) (EBL(MIS) = 470.26 ml, EBL(Open)= 2872.73 ml, p < 0.01). Baseline ODI scores were lower in the MIS cohort (40.03 vs 48.04, p = 0.03), and the cohorts experienced similar 1-year improvement (ΔODI(MIS) = -15.98, ΔODI(Open) = -21.96, p = 0.25). Baseline VAS scores were similar (VAS(MIS) = 6.56, VAS(Open)= 7.10, p = 0.32), but MIS patients experienced less reduction after 1 year (ΔVAS(MIS) = -3.36, ΔVAS(Open) = -4.73, p = 0.04). Preoperative sagittal vertical axis (SVA) were comparable (preoperative SVA(MIS) = 63.47 mm, preoperative SVA(Open) = 71.3 mm, p = 0.60), but MIS patients had larger postoperative SVA (postoperative SVA(MIS) = 51.17 mm, postoperative SVA(Open) = 28.17 mm, p = 0.03). CONCLUSIONS: Minimally invasive surgery demonstrated reduced costs, blood loss, and hospital stays, whereas open surgery exhibited greater improvement in VAS scores, deformity correction, and sagittal balance. Additional studies with more patients and longer follow-up will determine if MIS provides cost-minimization opportunities for treatment of adult degenerative scoliosis.

Comparison of two minimally invasive surgery strategies to treat adult spinal deformity.

OBJECT: Minimally invasive surgery (MIS) techniques are becoming a more common means of treating adult spinal deformity (ASD). The aim of this study was to compare the hybrid (HYB) surgical approach, involving minimally invasive lateral interbody fusion with open posterior instrumented fusion, to the circumferential MIS (cMIS) approach to treat ASD. METHODS: The authors performed a retrospective, multicenter study utilizing data collected in 105 patients with ASD who were treated via MIS techniques. Criteria for inclusion were age older than 45 years, coronal Cobb angle greater than 20°, and a minimum of 1 year of follow-up. Patients were stratified into 2 groups: HYB (n = 62) and cMIS (n = 43). RESULTS: The mean age was 60.7 years in the HYB group and 61.0 years in the cMIS group (p = 0.910). A mean of 3.6 interbody fusions were performed in the HYB group compared with a mean of 4.0 interbody fusions in the cMIS group (p = 0.086). Posterior fusion involved a mean of 6.9 levels in the HYB group and a mean of 5.1 levels in the cMIS group (p = 0.003). The mean follow-up was 31.3 months for the HYB group and 38.3 months for the cMIS group. The mean Oswestry Disability Index (ODI) score improved by 30.6 and 25.7, and the mean visual analog scale (VAS) scores for back/leg pain improved by 2.4/2.5 and 3.8/4.2 for the HYB and cMIS groups, respectively. There was no significant difference between groups with regard to ODI or VAS scores. For the HYB group, the lumbar coronal Cobb angle decreased by 13.5°, lumbar lordosis (LL) increased by 8.2°, sagittal vertical axis (SVA) decreased by 2.2 mm, and LL-pelvic incidence (LL-PI) mismatch decreased by 8.6°. For the cMIS group, the lumbar coronal Cobb angle decreased by 10.3°, LL improved by 3.0°, SVA increased by 2.1 mm, and LL-PI decreased by 2.2°. There were no significant differences in these radiographic parameters between groups. The complication rate, however, was higher in the HYB group (55%) than in the cMIS group (33%) (p = 0.024). CONCLUSIONS: Both HYB and cMIS approaches resulted in clinical improvement, as evidenced by decreased ODI and VAS pain scores. While there was no significant difference in degree of radiographic correction between groups, the HYB group had greater absolute improvement in degree of lumbar coronal Cobb angle correction, increased LL, decreased SVA, and decreased LL-PI. The complication rate, however, was higher with the HYB approach than with the cMIS approach.

Complications, outcomes, and need for fusion after minimally invasive posterior cervical foraminotomy and microdiscectomy.

BACKGROUND CONTEXT: Posterior cervical foraminotomy (PCF) with or without microdiscectomy (posterior cervical discectomy [PCD]) is a frequently used surgical technique for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. Currently, these procedures are being performed with increasing frequency using advanced minimally invasive techniques. Although the safety and efficacy of minimally invasive PCF/PCD (MI-PCF/PCD) have been established, reports on long-term outcome and need for secondary surgical intervention at the index or adjacent level are lacking. PURPOSE: To determine the rates of complications, long-term outcomes, and need for secondary surgical intervention at the index or adjacent level after MI-PCF and microdiscectomy. STUDY DESIGN: Retrospective analysis of a prospective cohort. PATIENT SAMPLE: Seventy patients treated with MI-PCF and/or MI-PCD for cervical radiculopathy. OUTCOME MEASURES: Visual Analog Scale for neck/arm (VASN/A) pain and Neck Disability Index (NDI). METHODS: Ninety-seven patients underwent MI-PCF with or without MI-PCD between 2002 and 2011. Adequate prospective follow-up was available for 70 patients (95 cervical levels). The primary outcome assessed was need for secondary surgical intervention at the index or adjacent level. The secondary outcomes assessed included complications and improvements in NDI and VASN/A scores. All complications were reviewed. Mixed-model analyses of variance with random subject effects and autoregressive first-order correlation structures were used to test for differences among NDI, VASA, and VASN measurements made over time while accounting for the correlation among repeated observations within a patient. All statistical hypothesis tests were conducted at the 5% level of significance. RESULTS: Patients were followed for a mean of 32.1 months. Of 70 patients operated, there were 3 (4.3%) complications (1 cerebrospinal fluid leak, 1 postoperative wound hematoma, and 1 radiculitis), none of which required a secondary operative intervention. Five patients required an anterior cervical discectomy and fusion (eight total levels fused) on average 44.4 months after the index surgery. Of those, five (5.3%) were at the index level and three (2.1%) were at adjacent levels. Neck Disability Index scores improved significantly (p<.0001) immediately postoperatively and continued to decrease gradually with time. Visual Analog Scale for neck/arm scores improved significantly (p<.0001) from baseline immediately postoperatively but tended to plateau with time. CONCLUSIONS: Minimally invasive PCF with or without MI-PCD is an excellent alternative for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. There is a low rate (1.1% per index level per year) of future index site fusion and a very low rate (0.9% per adjacent level per year) of adjacent-level disease requiring surgery.