Does type of bone graft matter? A retrospective review of the use of biological bone grafts in patients undergoing elective 1-3 level spinal interbody fusion.

OBJECTIVE: There is a lack of strong evidence for use of expensive bone substitutes. This study compares perioperative data and patient reported quality-of-life outcomes across the varied types of bone graft extenders. The study analyzes the existing Quality and Outcomes Database and evaluates patient reported outcomes for 1-3 level lumbar fusion procedures comparing across different types of biologics bone graft. METHODS: We retrospectively analyzed a prospectively collected data registry. Bone graft implant data were collected and grouped into the following categories: (1) Autograft with basic allograft (2) Enhanced, synthetic, or cellular allograft (3) Use of BMP. Preoperative and 1 year patient reported outcomes and perioperative data from the prospective collected registry were analyzed. RESULTS: There were 384 patients included in this study. There were 168 (43.8%) patients in group 1, 133 (34.6%) patients in group 2, and 83 (21.6%) in group 3. There were no group differences in baseline or 1 year back pain, leg pain, ODI, or EQ-5D. The GLM Repeated Measures results indicate a significant difference within each of the three groups between the preoperative and postoperative measures for back pain, leg pain, ODI, and EQ-5D. The change over time was not significantly different between the groups. CONCLUSIONS: Bone graft extenders are a significant contributor to the cost of lumbar fusion. This study demonstrates no difference in preoperative, and 1 year patient reported outcomes between the three groups. There was no significant difference in rate of reoperations across the three groups.

Lumbar arthroplasty for treatment of primary or recurrent lumbar disc herniation.

PURPOSE: Microdiscectomy is the current gold standard surgical treatment for primary lumbar disc herniations that fail non-surgical measures. Herniated nucleus pulposus is the manifestation of underlying discopathy that remains unaddressed with microdiscectomy. Therefore, risk remains of recurrent disc herniation, progression of the degenerative cascade, and on-going discogenic pain. Lumbar arthroplasty allows for complete discectomy, complete direct and indirect decompression of neural elements, restoration of alignment, restoration of foraminal height, and preservation of motion. In addition, arthroplasty avoids disruption of posterior elements and musculoligamentous stabilizers. The purpose of this study is to describe the feasibility of the use of lumbar arthroplasty in the treatment of patients with primary or recurrent disc herniations. In addition, we describe the clinical and peri-operative outcomes associated with this technique. METHODS: All patients that underwent lumbar arthroplasty by a single surgeon at a single institution from 2015 to 2020 were reviewed. All patients with radiculopathy and pre-operative imaging demonstrating disc herniation that received lumbar arthroplasty were included in the study. In general, these patients were those with large disc herniations, advanced degenerative disc disease, and a clinical component of axial back pain. Patient-reported outcomes of VAS back, VAS leg, and ODI pre-operatively, at three months, one year, and at last follow-up were collected. Reoperation rate, patient satisfaction, and return to work were documented at last follow-up. RESULTS: Twenty-four patients underwent lumbar arthroplasty during the study period. Twenty-two (91.6%) patients underwent lumbar total disc replacement (LTDR) for a primary disc herniation. Two patients (8.3%) underwent LTDR for a recurrent disc herniation after prior microdiscectomy. The mean age was 40 years. The mean pre-operative VAS leg and back pain were 9.2 and 8.9, respectively. The mean pre-operative ODI was 22.3. Mean VAS back and leg pain was 1.2 and 0.5 at three months post-operative. The mean VAS back and leg pain was 1.3 and 0.6 at one year post-operative. The mean ODI was 3.0 at one year post-operative. One patient (4.2%) underwent re-operation for migrated arthroplasty device which required repositioning. At last follow-up, 92% of patients were satisfied with their outcome and would undergo the same treatment again. The mean time for return-to-work was 4.8 weeks. After returning to work, 89% of patients required no further leave of absence for recurrent back or leg pain at last follow-up. Forty-four percent of patients were pain free at last follow-up. CONCLUSION: Most patients with lumbar disc herniations can avoid surgical intervention altogether. Of those that require surgical treatment, microdiscectomy may be appropriate for certain patients with preserved disc height and extruded fragments. In a subset of patients with lumbar disc herniation that require surgical treatment, lumbar total disc replacement is an effective option by performing complete discectomy, restoring disc height, restoring alignment, and preserving motion. The restoration of physiologic alignment and motion may result in durable outcomes for these patients. Longer follow-up and comparative and prospective trials are needed to determine how the outcomes of microdiscectomy may differ from lumbar total disc replacement in the treatment of primary or recurrent disc herniation.

Arduino-based, low-cost imaging incubator for extended live cell imaging.

In order to image live cells for prolonged periods of time, an Arduino-based, low-cost imaging incubator was constructed. The imaging incubator keeps cells viable by controlling for temperature and CO 2 in order to maintain physiological conditions for cells during imaging. All devices and parts employed in the build were typical maker-type components in order to minimize the cost of the imaging incubator. The imaging incubator allows for real-time imaging of live cells exposed to any desired perturbation or stimulus. As a proof of the system's functionality, cells are imaged over 24 hours while remaining viable in the imaging incubator.

Preoperative Acetazolamide Challenge in Pediatric Chiari I Malformation.

PURPOSE: In patients who present with headaches and Chiari 1 malformation without cranial nerve or brainstem dysfunction or syrinx formation, the decision to decompress can be difficult to make. We present a case series examining the use of acetazolamide as a diagnostic aid to determine candidacy for decompression. METHODS: A single pediatric neurosurgeon's (M.M.H.) experience from 2003 to 2018 was retrospectively reviewed. All cases evaluated in the clinic for CPT code of Chiari 1 malformation were analyzed. Inclusion criteria were patients with diagnosis of Chiari 1 malformation and headache-predominant symptoms who underwent an acetazolamide challenge test. Exclusion criteria included age over 18, syrinx, or significant clinical evidence of brainstem compression or cranial nerve dysfunction. Data were recorded with respect to response to acetazolamide. Surgical outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS) pain category and the improve/same/worse (IWS) scale. Overall satisfaction from surgery was also recorded. RESULTS: Forty-five patients met inclusion criteria and underwent acetazolamide challenge. Thirty-three (73.3%) patients showed improvement of their symptoms with acetazolamide challenge (responders). Of the 33 responders, 25 (75.8%) underwent Chiari decompression. The remaining 8 (24.2%) responders experienced persistent improvement of their symptoms after the acetazolamide trial and did not require intervention. Twelve (26.7%) patients did not improve with acetazolamide (nonresponders) of which 11 (91.7% of nonreponders) never required intervention. One nonresponder eventually underwent Chiari decompression due to progressively worsening and debilitating headaches. All twenty-five (100%) responders improved after surgery and 24 (96%) were satisfied with the outcome of surgery. The average responder CCOS pain score was 3.52 out of 4. The nonresponder who did not improve with acetazolamide had persistent severe headaches after decompression. The CCOS pain score for this nonresponder was 2 out of 4. CONCLUSION: Pediatric headache-predominant Chiari 1 malformation presents a difficult diagnostic dilemma. The authors describe a trial of acetazolamide as a preoperative diagnostic tool to aid the decision to decompress. Further studies will need to be performed to determine the effectiveness of preoperative acetazolamide in identifying which patients may benefit from surgical decompression.

Accounting for ocean connectivity and hydroclimate in fish recruitment fluctuations within transboundary metapopulations.

Marine resources stewardships are progressively becoming more receptive to an effective incorporation of both ecosystem and environmental complexities into the analytical frameworks of fisheries assessment. Understanding and predicting marine fish production for spatially and demographically complex populations in changing environmental conditions is however still a difficult task. Indeed, fisheries assessment is mostly based on deterministic models that lack realistic parameterizations of the intricate biological and physical processes shaping recruitment, a cornerstone in population dynamics. We use here a large metapopulation of a harvested fish, the European hake (Merluccius merluccius), managed across transnational boundaries in the northwestern Mediterranean, to model fish recruitment dynamics in terms of physics-dependent drivers related to dispersal and survival. The connectivity among nearby subpopulations is evaluated by simulating multi-annual Lagrangian indices of larval retention, imports, and self-recruitment. Along with a proxy of the regional hydroclimate influencing early life stages survival, we then statistically determine the relative contribution of dispersal and hydroclimate for recruitment across contiguous management units. We show that inter-annual variability of recruitment is well reproduced by hydroclimatic influences and synthetic connectivity estimates. Self-recruitment (i.e., the ratio of retained locally produced larvae to the total number of incoming larvae) is the most powerful metric as it integrates the roles of retained local recruits and immigrants from surrounding subpopulations and is able to capture circulation patterns affecting recruitment at the scale of management units. We also reveal that the climatic impact on recruitment is spatially structured at regional scale due to contrasting biophysical processes not related to dispersal. Self-recruitment calculated for each management unit explains between 19% and 32.9% of the variance of recruitment variability, that is much larger than the one explained by spawning stock biomass alone, supporting an increase of consideration of connectivity processes into stocks assessment. By acknowledging the structural and ecological complexity of marine populations, this study provides the scientific basis to link spatial management and temporal assessment within large marine metapopulations. Our results suggest that fisheries management could be improved by combining information of physical oceanography (from observing systems and operational models), opening new opportunities such as the development of short-term projections and dynamic spatial management.

Recent Transport History of Fukushima Radioactivity in the Northeast Pacific Ocean.

The large inventory of radioactivity released during the March, 2011 Fukushima Dai-ichi nuclear reactor accident in Japan spread rapidly across the North Pacific Ocean and was first observed at the westernmost station on Line P, an oceanographic sampling line extending 1500 km westward of British Columbia (BC), Canada in June 2012. Here, time series measurements of 134Cs and 137Cs in seawater on Line P and on the CLIVAR-P16N 152°W line reveal the recent transport history of the Fukushima radioactivity tracer plume through the northeast Pacific Ocean. During 2013 and 2014 the Fukushima plume spread onto the Canadian continental shelf and by 2015 and early 2016 it reached 137Cs values of 6-8 Bq/m3 in surface water along Line P. Ocean circulation model simulations that are consistent with the time series measurements of Fukushima 137Cs indicate that the 2015-2016 results represent maximum tracer levels on Line P and that they will begin to decline in 2017-2018. The current elevated Fukushima 137Cs levels in seawater in the eastern North Pacific are equivalent to fallout background levels of 137Cs that prevailed during the 1970s and do not represent a radiological threat to human health or the environment.

Design and calibration of a digital Fourier holographic microscope for particle sizing via goniometry and optical scatter imaging in transmission.

Goniometry and optical scatter imaging have been used for optical determination of particle size based upon optical scattering. Polystyrene microspheres in suspension serve as a standard for system validation purposes. The design and calibration of a digital Fourier holographic microscope (DFHM) are reported. Of crucial importance is the appropriate scaling of scattering angle space in the conjugate Fourier plane. A detailed description of this calibration process is described. Spatial filtering of the acquired digital hologram to use photons scattered within a restricted angular range produces an image. A pair of images, one using photons narrowly scattered within 8 - 15° (LNA), and one using photons broadly scattered within 8 - 39° (HNA), are produced. An image based on the ratio of these two images, OSIR = HNA/LNA, following Boustany et al. (2002), yields a 2D Optical Scatter Image (OSI) whose contrast is based on the angular dependence of photon scattering and is sensitive to the microsphere size, especially in the 0.5-1.0µm range. Goniometric results are also given for polystyrene microspheres in suspension as additional proof of principle for particle sizing via the DFHM.

Frontalis Sling Surgery With IBCN-Ritleng Probe: A New Technique With a 20-Gauge Catheter.

INTRODUCTION: Frontalis sling surgery is the reference procedure for severe ptosis due to poor Levator function. Autologous or synthetic materials are used for lifting the upper eyelid. OBJECTIVE: To describe a new technique of passage of a silicon wire through a 20-gauge intravenous catheter and to explore literature. METHODS: A 83-year-old male patient with simple, severe ptosis with previous levator resection surgery (7 month before) had frontalis sling with a silicone IBCN wire placed under local anesthesia with a closed technique. It consisted in realization of 3 punctiform incisions upper the eyebrow, through which a 20G intravenous catheter was inserted and droven to the free border of the upper eyelid. The polypropylene part of the IBCN probe silicone tube, IBCN set, was interlocked into the needle tip, enabling to drag the wire through its tunnel without eyelid dissection. The body of the IBCN probe was consequently placed on the free edge of the eyelid, whereas its 2 ends were tied under the middle upper eyebrow incision, enabling to adjust tension of the probe according to the severity of ptosis. The node was kept subcutaneously, allowing correction "on demand" of wire tension in the future by the surgeon. RESULTS: No infections, exposures, or granuloma formations were seen in our patient at 2 months, whereas visual field was improved and the patient fully satisfied. DISCUSSION: Small punctiform incisions and limited skin dissection offer a significant advantage, as well as the materials that are easy to access and cheap, in the frontalis sling surgery. CONCLUSION: The authors added to frontalis sling surgery a simple and cost-effective alternative technique of passage of a subcutaneous probe, with an IBCN wire whose dimensions fit perfectly a 20-gauge intravenous catheter and allowing later correction "on demand" of the ptosis.

Studying an Agulhas ring's long-term pathway and decay with finite-time coherent sets.

Coherent sets in dynamical systems are regions in phase space that optimally "carry mass" with them under the system's evolution, so that these regions experience minimal leakage. The dominant tool for determining coherent sets is the transfer operator, which provides a complete description of Lagrangian mass transport. In this work, we combine existing transfer operator methods with a windowing scheme to study the spatial and temporal evolution of a so-called Agulhas ring: a large anticyclonic mesoscale eddy playing a key role in inter-ocean exchange of climate-relevant properties. Our focus is on ring decay over time and the windowing scheme enables us to study how the most coherent region (our estimate of the ring) varies in position and size over a period of more than two years. We compare the eddy-like structure and its spatio-temporal changes as revealed by our method and by a classical Eulerian approach.

Flow networks: a characterization of geophysical fluid transport.

We represent transport between different regions of a fluid domain by flow networks, constructed from the discrete representation of the Perron-Frobenius or transfer operator associated to the fluid advection dynamics. The procedure is useful to analyze fluid dynamics in geophysical contexts, as illustrated by the construction of a flow network associated to the surface circulation in the Mediterranean sea. We use network-theory tools to analyze the flow network and gain insights into transport processes. In particular, we quantitatively relate dispersion and mixing characteristics, classically quantified by Lyapunov exponents, to the degree of the network nodes. A family of network entropies is defined from the network adjacency matrix and related to the statistics of stretching in the fluid, in particular, to the Lyapunov exponent field. Finally, we use a network community detection algorithm, Infomap, to partition the Mediterranean network into coherent regions, i.e., areas internally well mixed, but with little fluid interchange between them.

Repeated mass strandings of Miocene marine mammals from Atacama Region of Chile point to sudden death at sea.

Marine mammal mass strandings have occurred for millions of years, but their origins defy singular explanations. Beyond human causes, mass strandings have been attributed to herding behaviour, large-scale oceanographic fronts and harmful algal blooms (HABs). Because algal toxins cause organ failure in marine mammals, HABs are the most common mass stranding agent with broad geographical and widespread taxonomic impact. Toxin-mediated mortalities in marine food webs have the potential to occur over geological timescales, but direct evidence for their antiquity has been lacking. Here, we describe an unusually dense accumulation of fossil marine vertebrates from Cerro Ballena, a Late Miocene locality in Atacama Region of Chile, preserving over 40 skeletons of rorqual whales, sperm whales, seals, aquatic sloths, walrus-whales and predatory bony fish. Marine mammal skeletons are distributed in four discrete horizons at the site, representing a recurring accumulation mechanism. Taphonomic analysis points to strong spatial focusing with a rapid death mechanism at sea, before being buried on a barrier-protected supratidal flat. In modern settings, HABs are the only known natural cause for such repeated, multispecies accumulations. This proposed agent suggests that upwelling zones elsewhere in the world should preserve fossil marine vertebrate accumulations in similar modes and densities.

Posterior Transdural Repair of a Spontaneous Ventral Thoracic Cerebrospinal Fluid Leak: 2-Dimensional Operative Video.

Spontaneous intracranial hypotension is a rare but serious condition characterized by orthostatic headaches and a variety of neurological symptoms. 1,2 Spontaneous intracranial hypotension should be considered in all patients with new onset, daily, persistent headaches, and orthostatic symptoms. It is typically caused by spontaneous spinal cerebrospinal fluid (CSF) leaks. 1,2 Traditional first-line treatments include hydration, bedrest, epidural blood patches, and fibrin glue injections. However, refractory cases often require surgical intervention, especially those caused by a small ventral osteophyte, which is classified as a type 1 leak. 3-5 The small osteophyte causes a tear in the dura of the ventral canal, usually near the cervicothoracic junction. Diagnosis of these leaks is challenging because these small osteophytes can also occur asymptomatically, or patients may have several of them at multiple levels. Typically, dynamic myelography is needed for accurate localization due to the inadequacy of standard imaging. 6 This video details a young patient with refractory spontaneous intracranial hypotension from a type 1 spontaneous CSF leak, treated successfully using a posterior transdural surgical approach with spinal cord mobilization. Our video presentation outlines the surgical technique and provides an overview of this underdiagnosed condition. Our described approach offers direct visualization, suturing of the leak site, and a multilayer repair without the need for spinal fusion. It also avoids the morbidity to the neck, chest, and mediastinal structures that is at risk with lateral or anterior approaches. A combined intradural and extradural repair may enhance the durability of repair for ventral CSF leaks. The patient consented to the procedure. This operative video did not require Institutional Review Board approval as all patient information has been anonymized, ensuring no identifiable information is disclosed. The video is a single case that does not involve interventions or pose risks beyond standard care, adhering to ethical guidelines and institutional policies.

Transport patterns and hydrodynamic context of the MERITE-HIPPOCAMPE cruise: Implications for contaminants distribution and origin.

This study aims at characterizing the hydrodynamic context and transport patterns that prevailed during the MERITE-HIPPOCAMPE cruise to assist in the interpretation of in-situ observations. The main physical attributes and structures (mesoscale eddies as well as fine-scale fronts and filaments) are analyzed based on various physical diagnostics. They were computed from satellite data and data-assimilative model outputs to describe ocean dynamics. The Northern and Algerian Currents were prominent features during the cruise while the western basin is divided by the vertically-tilted Balearic front. Temperature and salinity were used to distinguish different water masses at both surface and sub-surface. Sea-level anomalies, relative vorticity, and Okubo-Weiss parameter distributions have shown the presence of marked eddies around stations St10 and St11. Furthermore, Finite-Size Lyaponuv Exponents revealed that the former was rather located on a fine-scale filament near the edge of a cyclonic eddy while the latter was closer to the core of an anticyclone. Nearshore thermal fronts were detected with the Belkin and O'Reilly Algorithm (BOA), especially around stations St17 and St19. The potential coastal sources of contaminants were tested using Lagrangian Origin Maps (LOM), suggesting that stations St1, St2, St4, St11, and St15 were most likely influenced by coastal waters. Additionally, an atmospheric reanalysis combined with a Lagrangian dispersal model allowed for estimating wet deposition events of contaminants while tracking the fate of water masses where rainfall took place. Finally, we provide a set of explanatory quantitative and qualitative variables for future statistical analyses that aim at explaining the distribution of both chemical and biological samples collected during the cruise.

Impact of atmospheric deposition on the dynamics of ultraphytoplanktonic populations in the Gulf of Gabès during an intense dust event (MERITE-HIPPOCAMPE campaign).

The ultraphytoplankton composition and dynamics were assessed during a Saharan dust event occurring off the southern Tunisian coasts during the MERITE-HIPPOCAMPE Trans-Mediterranean oceanographic cruise. The composition of atmospheric dust was characterized in terms of nutriments and trace metals. Data-assimilative hydrodynamic model revealed no differences in the hydrological features along the sampling track and almost no water transport occurred during the period of atmospheric deposition. Dust deposition increased the growth rates and the productivity of the major phytoplanktonic cytometric groups, resulting in the highest surface biomass along the Mediterranean transect. One group, distinguished by low fluorescence and nanoplanktonic size, reacted to dust deposition within hours, exhibiting the highest growth rate and net productivity. The dust composition showed a substantial enrichment with organic phosphorous representing (56 % of Total phosphorus) and trace metals mainly Fe, Mn and V.

A Quantum Mechanical Description of Photosensitization in Photodynamic Therapy using a Two-Electron Molecule Approximation.

A fundamental, Quantum Mechanical description of photoactivation of a generic photosensitizer and the ensuing transfer of energy to endogenous oxygen as part of the Type II pathway to photodamage during photodynamic therapy (PDT) is presented. The PS and molecular oxygen are approximated as two-electron molecules. Conservation of energy and of angular momenta of the two molecule system are abided via selection rules throughout the four-stage process, including initial states, absorption of a photon by the PS, conversion of the PS to an excited spin triplet via intersystem crossing (ISC), and the transition of molecular oxygen to an excited spin singlet state via a Triplet-Triplet Exchange of electrons with the PS. The provided description of photosensitization will provide students and researchers with a fundamental introduction to PDT, while offering the broader population of Quantum Mechanics and Physical Chemistry students an advanced example of quantum systems in an applied, medical context.

An ocean front dataset for the Mediterranean sea and southwest Indian ocean.

Fronts are ubiquitous discrete features of the global ocean often associated with enhanced vertical velocities, in turn boosting primary production. Fronts thus form dynamical and ephemeral ecosystems where numerous species meet across all trophic levels. Fronts are also targeted by fisheries. Capturing ocean fronts and studying their long-term variability in relation with climate change is thus key for marine resource management and spatial planning. The Mediterranean Sea and the Southwest Indian Ocean are natural laboratories to study front-marine life interactions due to their energetic flow at sub-to-mesoscales, high biodiversity (including endemic and endangered species) and numerous conservation initiatives. Based on remotely-sensed Sea Surface Temperature and Height, we compute thermal fronts (2003-2020) and attracting Lagrangian coherent structures (1994-2020), in both regions over several decades. We advocate for the combined use of both thermal fronts and attracting Lagrangian coherent structures to study front-marine life interactions. The resulting front dataset differs from other alternatives by its high spatio-temporal resolution, long time coverage, and relevant thresholds defined for ecological provinces.

Feasibility and Safety of Microendoscopic Posterior Cervical Foraminotomy in an Ambulatory Surgery Center: A Longitudinal Experience with 1000 Cases.

OBJECTIVE: Ambulatory surgery centers (ASCs) have become an increasingly attractive setting for spine surgery in recent decades. Although posterior cervical foraminotomy (PCF) is widely performed in ASCs, there are no studies supporting the safety of this practice. We aimed to demonstrate the feasibility and safety of microendoscopic (MED)-PCF in a large cohort of patients at a freestanding ASC. METHODS: Consecutive patients undergoing MED-PCF for unilateral cervical radiculopathy at a single freestanding ASC from January 2013 to December 2020 were queried. Standard demographic and perioperative data were collected. Outcomes included need for inpatient transfer, perioperative complications, 30-day readmission, 30-day reoperation, and clinical improvement according to the Odom criteria. RESULTS: A total of 1106 patients underwent MED-PCF during the study period. Mean age was 53.3 ± 10.3 years. Most patients underwent decompression at C5-6 (31.4%) or C6-7 (51.9%). Approximately 10% underwent surgery at multiple levels. Mean operative time was 40.0 ± 16.4 minutes. There were no intraoperative or immediate postoperative complications. All patients were discharged home within a few hours of surgery. The rates of 30-day readmission (0.81%) and reoperation (0.36%) were exceedingly low. Nearly 3 quarters of patients (73.7%) achieved a good or excellent clinical outcome (73.7%) according to the Odom criteria. CONCLUSIONS: MED-PCF can be performed in a freestanding ASC with exceedingly low rates of perioperative complications and short-term readmission or reoperation. Our findings support the ongoing migration of PCF from the hospital to the ambulatory setting. Future studies assessing patient-reported outcomes and long-term reoperation rates are necessary.

Minimally Invasive Transforaminal Lumbar Interbody Fusion in the Ambulatory Setting with an Enhanced Recovery After Surgery Protocol.

OBJECTIVE: Enhanced Recovery After Surgery (ERAS) is a multidisciplinary approach to surgical care that aims to improve outcomes and reduce costs. Its application to spine surgery has been increasing in recent years, with a notable focus on lumbar fusion. This study describes the development, implementation, and outcomes of the first ERAS pathway for ambulatory spine surgery and the largest ambulatory minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) series to date. METHODS: A comprehensive protocol for ambulatory lumbar fusion is described, including patient selection criteria, a multimodal analgesia regimen, and discharge assessment. Consecutive patients undergoing 1- or 2-level MIS TLIF using the described protocol at a single ambulatory surgery center (ASC) over a five-year period were queried. RESULTS: A total of 215 patients underwent ambulatory MIS TLIF over the study period. There were no intraoperative or immediate postoperative complications. All but one patient (99.5%) were discharged home from the ASC. Almost three-quarters (71.2%) were discharged on the day of surgery. Thirty- and 90-day readmission rates were 1.4% and 2.8%, respectively. Only one readmission (0.5%) was for intractable back pain. There were no reoperations or mortalities within 90 days of surgery. CONCLUSIONS: MIS TLIF can be performed safely in a freestanding ambulatory surgery center with minimal perioperative and short-term morbidity. The addition of comprehensive ERAS protocols to the ambulatory setting can promote the transition of fusion procedures to this lower cost environment in an effort to provide higher value care.

Microendoscopic Posterior Cervical Laminoforaminotomy for C4 Radiculopathy.

OBJECTIVE: Cervical microendoscopic laminoforaminotomy (MELF) has been proven to be an effective, motion preserving procedure for the surgical treatment of cervical radiculopathy. Cervical 4 (C4) radiculopathies are often unrecognized by the initial evaluating physician and may be misdiagnosed as axial neck pain. In this study, we compare MELF to anterior cervical disk fusion (ACDF) for C4 radiculopathy in the largest series of minimally invasive foraminotomy for C4 radiculopathy to date. METHODS: This is a single-institution retrospective chart review of 42 cases for C4 radiculopathy, 21 MELF and 21 ACDF. Primary outcome measures were length of surgery, length of hospital stay, and time to return to work. Secondary outcome measures were visual analog scale (VAS) neck pain and reoperation rate. RESULTS: All patients were diagnosed with a unilateral C4 radiculopathy using magnetic resonance imaging or steroid injections. The length of surgery and length of hospital stay were significantly decreased in the MELF group compared with ACDF. VAS neck pain significantly decreased for patients in both groups, but the difference between MELF and ACDF was not statistically significant. There were no major complications. No patient underwent revision at the index level or adjacent levels in the MELF group. CONCLUSIONS: We demonstrate that C4 radiculopathy can be identified with appropriate history, physical examination, and targeted nerve root injections. When identified, these radiculopathies that fail conservative therapy can be effectively treated with cervical microendoscopic laminoforaminotomy, with comparable outcomes to ACDF. The length of surgery and length of stay are reduced when compared with ACDF.

Top marine predators track Lagrangian coherent structures.

Meso- and submesoscales (fronts, eddies, filaments) in surface ocean flow have a crucial influence on marine ecosystems. Their dynamics partly control the foraging behavior and the displacement of marine top predators (tuna, birds, turtles, and cetaceans). In this work we focus on the role of submesoscale structures in the Mozambique Channel in the distribution of a marine predator, the Great Frigatebird. Using a newly developed dynamic concept, the finite-size Lyapunov exponent (FSLE), we identified Lagrangian coherent structures (LCSs) present in the surface flow in the channel over a 2-month observation period (August and September 2003). By comparing seabird satellite positions with LCS locations, we demonstrate that frigatebirds track precisely these structures in the Mozambique Channel, providing the first evidence that a top predator is able to track these FSLE ridges to locate food patches. After comparing bird positions during long and short trips and different parts of these trips, we propose several hypotheses to understand how frigatebirds can follow these LCSs. The birds might use visual and/or olfactory cues and/or atmospheric current changes over the structures to move along these biologic corridors. The birds being often associated with tuna schools around foraging areas, a thorough comprehension of their foraging behavior and movement during the breeding season is crucial not only to seabird ecology but also to an appropriate ecosystemic approach to fisheries in the channel.