The utility of routine post-hospitalization CT imaging in patients with non-operative mild to moderate traumatic brain injury.

Primary Objective: The purpose of this study was to determine the utility of CT imaging in patients with non-operative mild-moderate TBI with respect to changes in management.Methods: We conducted a retrospective analysis for 191 patients over a 5-year interval to examine whether follow-up CT initiated a change in management. We created a logistic regression model to incorporate different variables contributing to change in management.Results: Of 191 patients, 31 (16.2%) underwent a change in management. Change in management was associated with older age (65 yo vs. 55 yo, p = .011), diagnosis of subdural hematoma (p = .041), antiplatelet/anticoagulant therapy (p = .009), imaging performed (p = .16), and increased blood products on CT (p = <0.0001). For patients on antiplatelet/anticoagulant therapy, only those with worsening findings on CT required a change in management (p = .0002, 0.039). Surgical intervention was indicated in two patients.Conclusions: Limited clinical value exists in repeat CT scans for patients with mild TBI. Most patients with traumatic SAH, contusions, or asymptomatic patients should not have repeat imaging, as our study revealed only 2% of patients with positive CT finding and 0.6% requiring surgical intervention.

Multistage Hybrid Approach to Management of Significant Sagittal Malalignment: 2-Dimensional Operative Video.

Minimally invasive surgery (MIS) approaches for the correction of adult spinal deformity have gained popularity in the past decade. MIS approaches can result in decreased hospitalization times and decreased morbidity. However, compared to open techniques, MIS approaches are challenging in the setting of fixed sagittal deformity and strategic surgical staging. Combined MIS and miniopen techniques are described as "hybrid" techniques. We report on the surgical approach for a fixed sagittal deformity using both MIS and miniopen techniques, specifically a miniopen pedicle subtraction osteotomy (PSO) and an anterior column release (ACR). The patient gave written informed consent for surgical treatment; institutional review board approval was not required. The patient first underwent the placement of percutaneous modular pedicle screws from T12 to the pelvis as well as a mini-PSO across the previously fused L5 vertebral body, with the placement of a temporary rod. The following day, the patient underwent lateral transpsoas interbody fusion and ACR at L2/3; a percutaneous rod was then passed from T12 to the pelvis for segmental fixation. The patient recovered well and was discharged home without complication 6 d after the initial day of surgery. The combined use of surgical staging and traditional open techniques in a selective, minimalistic fashion and adherence to minimally invasive principles provide for a powerful set of surgical techniques that capitalize on less invasive approaches to deformity management. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.

Timing of Lateral Lumbar Interbody Subsidence: Review of Exclusive Intraoperative Subsidence.

BACKGROUND: All interbody fusions are associated with a risk of subsidence. In the case of lateral lumbar interbody fusion (LLIF), an interbody device that spans the apophyseal rings reduces subsidence. Small interbody device size, aggressive end plate preparation, and poor bone quality are contributors to subsidence. The goal of this study was to analyze the perioperative morbidity, particularly the timing of subsidence (intraoperative vs. postoperative), associated with transpsoas LLIF. METHODS: A retrospective review of consecutive LLIF cases was performed. Perioperative complications were reviewed. Intraoperative fluoroscopy and postoperative radiography, computed tomography, and magnetic resonance imaging were reviewed. RESULTS: Seventy-seven consecutive patients (39 men; mean [range] age, 66.2 [46-86] years) were identified. Subsidence occurred in 3 patients (4%) and was found to occur exclusively in the intraoperative setting. Anterior thigh paresthesias lasting longer than 24 hours occurred in 2 patients (3%). No femoral nerve injuries manifesting as weakness were observed. No visceral, vascular, or ureter injuries were identified. CONCLUSIONS: As LLIF becomes more common, it is important to better understand common complications, such as subsidence, and the specific rates at which they occur. A unique finding of exclusive intraoperative subsidence was observed. The use of cage size to obtain segmental lordotic correction and indirect decompression must be weighed against the potential risk of subsidence.

Single position spinal surgery for the treatment of grade II spondylolisthesis: A technical note.

BACKGROUND AND IMPORTANCE: Minimally invasive transpsoas approach to treat lumbar spondylolisthesis is associated with increased clinical benefits. CLINICAL PRESENTATION: Robotic and navigation aided deformity correction for grade II spondylolisthesis was performed using transpsoas approach with pedicle screw placement in lateral decubitus position. CONCLUSION: Keeping the patient in the lateral decubitus position, we supplemented interbody cage placement with screws. Single position lateral transpsoas approach provides grade II spondylolisthesis improvement.

A Quantitative Assessment of the Accuracy and Reliability of Robotically Guided Percutaneous Pedicle Screw Placement: Technique and Application Accuracy.

BACKGROUND: Minimally invasive surgery (MIS) and anterior (ALIF), transforaminal (TLIF), or lateral lumbar interbody fusion (LLIF) often require percutaneous pedicle screw fixation (PSF) to achieve circumferential fusion. Robotic guidance technology may augment workflow to improve screw placement and decrease operative time. OBJECTIVE: To report surgical experience with robotically assisted percutaneous screw placement following LLIF. METHODS: Data from fusions with robotically assisted PSF in prone or lateral decubitus positions was reviewed. A CT-guided robotic guidance arm was used for screw placement (Excelsius GPS™, Globus Medical Inc, Audubon, Pennsylvania). Postoperative CT imaging facilitated screw localization. 3-dimensional and 2-dimensional coordinates of the screw tip and tail were calculated and compared with a target trajectory to calculate targeting errors. Breach was defined as a violation of the lateral or medial pedicle wall. RESULTS: Robotic-guided screw placement was successful in 28/31 patients. In those patients, 116/116 screws were successfully implanted. The breach rate was 3.4% (4/116). Across 17 patients (70 screws), mean 3-D accuracy was 5.0 ± 2.4 mm, mean 2-D accuracy was 2.6 ± 1.1 mm, and mean angular offset was 5.6 ± 4.3° with corresponding intraclass correlation coefficients (ICC) of 0.775 and 0.693. 3-dimensional accuracy correlated with age (R = 0.306, P = .011) and BMI (R = 0.252, P = .038). Accuracy did not significantly differ among vertebral body levels (P > .22). Mean operative time for MIS-TLIF and percutaneous screws was 277 ± 52 and 183 ± 54 min, respectively. Operative time did not significantly decrease across either group (P > .187). CONCLUSION: The Excelsius GPS™ robotic guidance system allows accurate PSF in most cases with 2 mm 2-D accuracy. Future studies are needed to demonstrate the utility of this novel guidance system and workflow improvement.

Complications for minimally invasive lateral interbody arthrodesis: a systematic review and meta-analysis comparing prepsoas and transpsoas approaches.

OBJECTIVEMinimally invasive anterolateral retroperitoneal approaches for lumbar interbody arthrodesis have distinct advantages attractive to spine surgeons. Prepsoas or transpsoas trajectories can be employed with differing complication profiles because of the inherent anatomical differences encountered in each approach. The evidence comparing them remains limited because of poor quality data. Here, the authors sought to systematically review the available literature and perform a meta-analysis comparing the two techniques.METHODSA systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A database search was used to identify eligible studies. Prepsoas and transpsoas studies were compiled, and each study was assessed for inclusion criteria. Complication rates were recorded and compared between approach groups. Studies incorporating an analysis of postoperative subsidence and pseudarthrosis rates were also assessed and compared.RESULTSFor the prepsoas studies, 20 studies for the complications analysis and 8 studies for the pseudarthrosis outcomes analysis were included. For the transpsoas studies, 39 studies for the complications analysis and 19 studies for the pseudarthrosis outcomes analysis were included. For the complications analysis, 1874 patients treated via the prepsoas approach and 4607 treated with the transpsoas approach were included. In the transpsoas group, there was a higher rate of transient sensory symptoms (21.7% vs 8.7%, p = 0.002), transient hip flexor weakness (19.7% vs 5.7%, p < 0.001), and permanent neurological weakness (2.8% vs 1.0%, p = 0.005). A higher rate of sympathetic nerve injury was seen in the prepsoas group (5.4% vs 0.0%, p = 0.03). Of the nonneurological complications, major vascular injury was significantly higher in the prepsoas approach (1.8% vs 0.4%, p = 0.01). There was no difference in urological or peritoneal/bowel injury, postoperative ileus, or hematomas (all p > 0.05). A higher infection rate was noted for the transpsoas group (3.1% vs 1.1%, p = 0.01). With regard to postoperative fusion outcomes, similar rates of subsidence (12.2% prepsoas vs 13.8% transpsoas, p = 0.78) and pseudarthrosis (9.9% vs 7.5%, respectively, p = 0.57) were seen between the groups at the last follow-up.CONCLUSIONSComplication rates vary for the prepsoas and transpsoas approaches owing to the variable retroperitoneal anatomy encountered during surgical dissection. While the risks of a lasting motor deficit and transient sensory disturbances are higher for the transpsoas approach, there is a reciprocal reduction in the risks of major vascular injury and sympathetic nerve injury. These results can facilitate informed decision-making and tailored surgical planning regarding the choice of minimally invasive anterolateral access to the spine.

Analysis of Cost and 30-Day Outcomes in Single-Level Transforaminal Lumbar Interbody Fusion and Less Invasive, Stand-Alone Lateral Transpsoas Interbody Fusion.

BACKGROUND: A comparative evaluation of operative costs between single-level transforaminal interbody fusion (TLIF) and stand-alone lateral transpsoas interbody fusion (LIF) has not yet been done. We analyzed the costs, operative parameters, and early outcomes of single-level stand-alone LIF versus single-level TLIF. METHODS: Ten patients who underwent single-level TLIF and 10 patients who underwent single-level stand-alone LIF were included in the analysis. Total, variable, and fixed costs from perioperative data were available from a single institution. In addition, patient demographics, length of hospital stay, and 30-day outcomes and readmission rates were reviewed. RESULTS: Total cost, variable cost, and fixed costs were significantly lower in the LIF group, and there was no difference in outcomes. CONCLUSIONS: Single-level stand-alone LIF may prove to be more cost-effective and provide cost savings with analogous 30-day outcomes compared with single-level TLIF procedures.

The Patient Size Setting: A Novel Dose Reduction Strategy in Cerebral Endovascular Neurosurgery Using Biplane Fluoroscopy.

BACKGROUND: In some fluoroscopy machines, the dose-rate output of the fluoroscope is tied to a selectable patient size. Although patient size may play a significant role in visceral or cardiac procedures, head morphology is less variable, and high dose outputs may not be necessary even in very obese patients. We hypothesized that very small patient size setting can be used to reduce dose for cerebral angiography without compromising image quality. METHODS: Patients who underwent endovascular neurosurgical procedures during the 2015-2016 academic year were identified, and estimated procedural air kerma (AK) was tabulated retrospectively. Technologists were instructed to begin using the very small patient size setting for all procedures performed using our Philips Allura Xper FD20 biplane fluoroscopy system beginning in March 2016. No changes were made in a second procedure room using a Toshiba Infinix system. Student t tests and logistic regression models were used to compare radiation exposure before and after March 1, 2016, for both machines. RESULTS: For diagnostic cerebral angiograms performed on the Philips system (n = 302), AK was reduced by approximately 17% (1277 vs. 1061 mGy; P = 0.0006.) Changes in table height, total fluoroscopy time, patient weight, and body mass index did not contribute to this difference. No significant change was seen in total AK using the Toshiba system (n = 237). Blinded review by a neuroradiologist did not demonstrate any change in image quality. CONCLUSIONS: Using the very small patient size reduces fluoroscopy dose by 17% for cerebral angiography without impacting image quality.

Neurologic Decline After Spinal Angiography for Dural Arteriovenous Fistula and Improvement with Emergent Surgical Ligation.

BACKGROUND: Although angiography does not generally lead to increased clinically significant neurologic deficits, it has been reported that angiography for spinal dural arteriovenous fistulas (SDAVFs) can lead to acute neurologic decline. This has been rarely reported, and outcome after decline and the subsequent intervention performed have not been clarified. We describe a patient with SDAVF who experienced acute neurologic decline shortly after spinal angiography. Acute surgical treatment resulted in improvement of symptoms. CASE DESCRIPTION: A 70-year-old woman presented following 5 months of progressive numbness and weakness in her lower extremities. Spinal magnetic resonance imaging revealed thoracic spinal cord edema. Spinal angiography revealed a type 1 SDAVF. Several hours after spinal angiography, the patient's lower extremity motor strength declined significantly. This neurologic change led to emergent surgical intervention and ligation of the SDAVF. The patient's neurologic decline subsequently improved and ultimately resolved completely. CONCLUSIONS: Although acute worsening of neurologic deficits is a rare complication following angiography of SDAVFs, the reversibility of these deficits by emergent intervention argues for careful surveillance after angiography with protocols in place to rapidly intervene if needed. Warming and diluting the contrast agent should be considered to reduce contrast viscosity, a potential aggravating factor to the venous congestion of spinal fistulas.

Monoallelic silencing and haploinsufficiency in early murine intestinal neoplasms.

Studies of tumors from human familial adenomatous polyposis, sporadic colon cancer, and mouse and rat models of intestinal cancer indicate that the majority of early adenomas develop through loss of normal function of the Adenomatous polyposis coli (APC) gene. In murine models of familial adenomatous polyposis, specifically the multiple intestinal neoplasia mouse (Min) and the polyposis in the rat colon (Pirc) rat, most adenomas have lost their WT copy of the Apc gene through loss of heterozygosity by homologous somatic recombination. We report that large colonic adenomas in the Pirc rat have no detectable copy number losses or gains in genomic material and that most tumors lose heterozygosity only on the short arm of chromosome 18. Examination of early mouse and rat tumors indicates that a substantial subset of tumors shows maintenance of heterozygosity of Apc in genomic DNA, apparently violating Knudson's two-hit hypothesis. Sequencing of the Apc gene in a sampling of rat tumors failed to find secondary mutations in the majority of tumors that maintained heterozygosity of Apc in genomic DNA. Using quantitative allele-specific assays of Apc cDNA, we discovered two neoplastic pathways. One class of tumors maintains heterozygosity of Apc(Min/+) or Apc(Pirc/+) RNA expression and may involve haploinsufficiency for Apc function. Another class of tumors exhibits highly biased monoallelic expression of the mutant Apc allele, providing evidence for a stochastic or random process of monoallelic epigenetic silencing of the tumor suppressor gene Apc.