Lateral Route Research Articles

Lateral Route Endoscopic Thyroidectomy with gas Insufflation: Proposed Critical View of Safety

BackgroundThe extra-cervical lateral route endoscopic thyroidectomy (LRET) approaches such as the trans-axillary, breast and axillo-breast approaches are proved to be safe, feasible, esthetic, highly effective. The inherent difficulty and long learning curve of these techniques prevents its widespread application.MethodsBenefiting from the experience of more than 5 years in LRET approaches with CO2 insufflation, the authors developed ten surgical key steps and a critical view of safety (CVS) for performing thyroid lobectomy via LRET approaches. A detailed description and a video of the surgical technique is provided.ResultsApplication of these structured key steps and CVS was feasible and effective in achieving thyroid lobectomy in all selected cases with unilateral goiter up to 8 cm, even in cases with thyroiditis or controlled toxic adenoma, without any adverse events and with shorter operative time than the non-structured surgical technique.ConclusionThe described ten key steps and CVS are conclusive, applicable, easy to learn. Our video could act as a guide for promoting the standardized, safe, and wide application of LRET techniques.

Epidural and subdural interdural approach to the lateral wall of the cavernous sinus for preserving the laterocavernous sinus in trigeminal schwannoma.

Evacuation of middle fossa trigeminal schwannomas (TS) warrants a subtemporal interdural approach through the lateral wall of the cavernous sinus (CS). The dura comprises the dura propria, which follows the trigeminal nerve and develops into the epineurium, and periosteal layer. The interdural approach involves peeling off the dura propria and exposing the epineural sheath. The venous route around the CS is often obstructed due to TS progression. The interdural approach based on venous route preservation remains to be discussed. The laterocavernous sinus (LCS) is formed in these layers, draining to either the medial or lateral route. In the lateral route, the LCS drains to the pterygoid plexus via the middle cranial fossa foramen. Exposure of the interdural space disturbs the lateral route's venous flow. We describe an operative strategy for venous route preservation in TS via the LCS lateral route. The venous route can be preserved by peeling off the dura propria from the posterior end of the foramen ovale short of the venous drainage route to the pterygoid plexus epidurally and then cutting from the middle cranial fossa dura posterior to the venous route subdurally to the exposed interdural space. This technique helps in avoiding postoperative venous complications.

Overcoming Metabolic Constraints in the MEP-Pathway Enrich Salvia sclarea Hairy Roots in Therapeutic Abietane Diterpenes

Abietane diterpenoids (e.g., carnosic acid, aethiopinone, 1-oxoaethiopinone, salvipisone, and ferruginol) synthesized in the roots of several Salvia species have proved to have promising biological activities, but their use on a large scale is limited by the very low content extracted from in vivo roots. In this review, we summarized our efforts and the achieved results aimed at optimizing the synthesis of these diterpenes in Salvia sclarea hairy roots by either elicitation or by modifying the expression of genes encoding enzymes of the MEP-pathway, the biosynthetic route from which they derive. Stable S. sclarea hairy roots (HRs) were treated with methyl jasmonate or coronatine, or genetically engineered, by tuning the expression of genes controlling enzymatic rate-limiting steps (DXS, DXR, GGPPS, CPPS alone or in combination), by silencing of the Ent-CPPS gene, encoding an enzyme acting at gibberellin lateral competitive route or by coordinate up-regulation of biosynthetic genes mediated by transcription factors (WRKY and MYC2). Altogether, these different approaches successfully increased the amount of abietane diterpenes in S. sclarea HRs from to 2 to 30 times over the content found in the control HR line.

Long Range Air Traffic Flow Management with Flight-Specific Flight Performance

The increasing need for dynamic in-flight adjustments of a trajectory allows the airport, air traffic control and the airline a high degree of flexibility in terms of in-flight execution. This concept enables numerous optimisation options to jointly meet the requirements of sustainable air transport to increase economic and ecological efficiency, as well as safety. One promising measure is to control the aircraft arrival rate to prevent over-demand in the approach sector around the airport. In so-called Long-Range Air Traffic Management, the arrival time of long-haul flights, in particular, is already controlled many hours before arrival. However, the control options and their effects on arrival time and fuel burn are heavily dependent on flight performance and the (hardly predictable) influence of the weather. In this study, we optimize the arrival time of 26 long-haul flights in the Asia-Pacific region with arrival at Changi Airport within a peak hour considering the arrival rate of medium-haul and short-haul flights. This control is done by speed adjustments and by choosing alternative routes. For the first time, we model each long-haul flight and its control options individually in real weather conditions. We found that speed adjustments should start three to four hours before arriving at the approach sector to maximize the fuel-saving potential of small deviations from the optimal cruising speed, considering the predictability of the arrival time under real weather conditions. Allowing the aircraft to additionally choose an alternative lateral route, different from the filed flight plan, both maximizes the potential for harmonization of the number of aircraft in the approach sector and minimizes the total fuel burn. Unlike speed adjustments, alternative routes changes are effective even during the last hour of the cruise phase.

Transconjunctival Approach: A Safe and Effective Access to Mass Lesions in the Anterior Orbit

The orbit is an eloquent organ of the body. Safe surgical access to the orbit could be challenging due to the dense network of critical structures confined to it. There are versatile approaches to different parts of the orbit that could be used by neurosurgeons without causing injury to critical neurovascular structures. In this study, we aimed to present our surgical experience with the transconjunctival approach through the bulbar conjunctiva to anterior intraorbital lesions caused by diverse pathologies. We conducted a retrospective review of cases with intraorbital lesions operated via the transconjunctival approach by the same senior surgeon between 2015 and 2017. All patients were evaluated before the surgery by computed tomography, magnetic resonance imaging, and plain anteroposterior and lateral radiographs. Five patients underwent surgery by the transconjunctival approach through the medial or lateral routes for different pathologies: cavernoma, lymphoma, inflammatory reaction, meningocele, and foreign body. No complications were recorded, and all patients were satisfied with their clinical and esthetic results. The transconjunctival approach is a safe, effective, and time-sparing surgical approach to diverse pathologies in the anterior orbit. Navigation systems enhance the ability to maneuver in selected cases. The transconjunctival approach could be performed in collaboration with ophthalmologists since it provides better esthetic outcomes and higher satisfaction rates in operated patients.

Braincase anatomy of extant Crocodylia, with new insights into the development and evolution of the neurocranium in crocodylomorphs.

Present-day crocodylians exhibit a remarkably akinetic skull with a highly modified braincase. We present a comprehensive description of the neurocranial osteology of extant crocodylians, with notes on the development of individual skeletal elements and a discussion of the terminology used for this project. The quadrate is rigidly fixed by multiple contacts with most braincase elements. The parabasisphenoid is sutured to the pterygoids (palate) and the quadrate (suspensorium); as a result, the basipterygoid joint is completely immobilized. The prootic is reduced and externally concealed by the quadrate. It has a verticalized buttress that participates in the canal for the temporal vasculature. The ventrolateral processes of the otoccipitals completely cover the posteroventral region of the braincase, enclose the occipital nerves and blood vessels in narrow bony canals and also provide additional sutural contacts between the braincase elements and further consolidate the posterior portion of the crocodylian skull. The otic capsule of crocodylians has a characteristic cochlear prominence that corresponds to the lateral route of the perilymphatic sac. Complex internal structures of the otoccipital (extracapsular buttress) additionally arrange the neurovascular structures of the periotic space of the cranium. Most of the braincase elements of crocodylians are excavated by the paratympanic pneumatic sinuses. The braincase in various extant crocodylians has an overall similar structure with some consistent variation between taxa. Several newly observed features of the braincase are present in Gavialis gangeticus and extant members of Crocodylidae to the exclusion of alligatorids: the reduced exposure of the prootic buttress on the floor of the temporal canal, the sagittal nuchal crest of the supraoccipital projecting posteriorly beyond the postoccipital processes and the reduced paratympanic pneumaticity. The most distinctive features of the crocodylian braincase (fixed quadrate and basipterygoid joint, consolidated occiput) evolved relatively rapidly at the base of Crocodylomorpha and accompanied the initial diversification of this clade during the Late Triassic and Early Jurassic. We hypothesize that profound rearrangements in the individual development of the braincases of basal crocodylomorphs underlie these rapid evolutionary modifications. These rearrangements are likely reflected in the embryonic development of extant crocodylians and include the involvement of neomorphic dermal anlagen in different portions of the developing chondrocranium, the extensive ossification of the palatoquadrate cartilage as a single expanded quadrate and the anteromedial inclination of the quadrate.

Commentary on: Distribution of the Laterally Supplying Facial Nerve to the Orbicularis Oculi Muscle.

Recently, there has been a growing interest on the terminal branches of the VII nerve that preside to the fine movements of the orbital, pre-septal, and pre-tarsal components of the orbicularis oculi muscle (OOM) and their implications for surgery. The authors of this article are to be commended for identifying the intra-orbicularis nerve fibers that form the lateral route of distribution of the facial nerve.1 Their methodology is sound and is based on the utilization of microscopic surgical dissection on 43 samples, with 3 years of research time to enhance the accuracy and reliability of their anatomical study. Their results, derived mainly by dissecting Asian specimens, were also confirmed in Caucasian specimens, attesting the reproducibility of their findings in at least these 2 racial variations. Although the excellent level of their anatomical demonstration prevents any technical comment, the clinical implications derived and presented in the discussion are flawed by...

Using the Lateral Pontine Safe Entry Zone for Resection of Deep-Seated Cavernous Malformations in the Lateral Pons: 2-Dimensional Operative Video.

The retrosigmoid approach is one of the main approaches used in the surgical management of pontine cavernous malformations. It definitely provides a lateral route to large central lesions but also makes possible resection of some ventral lesions as an alternative to the petrosal approaches. However, when these vascular malformations do not emerge on surface, one of the safe corridors delimited by the origin of the trigeminal nerve and the seventh-eight cranial nerve complex can be used.1-5 Baghai et al2 described the lateral pontine safe entry zone in 1982, as an alternative to approaches through the floor of the fourth ventricle when performing tumor biopsies. They advocated a small neurotomy performed right between the emergence of the trigeminal nerve and the facial-vestibulocochlear cranial nerves complex. Accurate image guidance, intraoperative cranial nerve monitoring, and comprehensive anatomical knowledge are critical for this approach.4,5 Knowing the natural history of a brainstem cavernous malformation after bleeding,6 we sought to demonstrate in this video: (1) the use of the retrosigmoid craniotomy in lateral decubitus for resection of deep-seated pontine cavernous malformations; (2) the wide opening of arachnoid membranes and dissection of the superior petrosal vein complex to improve surgical freedom and prevent use of fixed cerebellar retraction; and (3) the opening of the petrosal fissure and exposure of the lateral pontine zone for gross total resection of a cavernous malformation in a 19-yr-old female with a classical crossed brainstem syndrome. She had full neurological recovery after 3 mo of follow-up. The patient consented in full to the surgical procedure and publication of the video and manuscript.

In-Flight Aircraft Trajectory Optimization within Corridors Defined by Ensemble Weather Forecasts

Today, each flight is filed as a static route not later than one hour before departure. From there on, changes of the lateral route initiated by the pilot are only possible with air traffic control clearance and in the minority. Thus, the initially optimized trajectory of the flight plan is flown, although the optimization may already be based upon outdated weather data at take-off. Global weather data as those modeled by the Global Forecast System do, however, contain hints on forecast uncertainties itself, which is quantified by considering so-called ensemble forecast data. In this study, the variability in these weather parameter uncertainties is analyzed, before the trajectory optimization model TOMATO is applied to single trajectories considering the previously quantified uncertainties. TOMATO generates, based on the set of input data as provided by the ensembles, a 3D corridor encasing all resulting optimized trajectories. Assuming that this corridor is filed in addition to the initial flight plan, the optimum trajectory can be updated even during flight, as soon as updated weather forecasts are available. In return and as a compromise, flights would have to stay within the corridor to provide planning stability for Air Traffic Management compared to full free in-flight optimization. Although the corridor restricts the re-optimized trajectory, fuel savings of up to 1.1%, compared to the initially filed flight, could be shown.

Distribution of the Laterally Supplying Facial Nerve to the Orbicularis Oculi Muscle.

The facial nerve that traverses the lateral border of the orbicularis oculi muscle is considered the primary motor for the muscle. Nevertheless, the lateral motor supply to the orbicularis oculi muscle has not yet been fully described. The aim of this study was to report detailed anatomic information about the lateral motor supply route to the orbicularis oculi. Facial nerve branches that cross the lateral orbicularis oculi border were fully traced from the parotid border to the nerve destinations in 43 fresh hemifaces by microscopic surgical dissection and time-lapse photography. Through the lateral route, the anterior temporal and upper zygomatic branches supply the superior orbital and superior preseptal orbicularis oculi of the upper eyelid, as well as the lateral pretarsal and malar orbicularis oculi, excluding the upper medial pretarsal portion of the upper eyelid and most of the lower eyelid. The nerve supplying the lateral pretarsal orbicularis oculi muscle crosses the anterior area of the zygomatic arch. It then traverses an area 6 mm above and 4 mm below the lateral canthal crease. The anterior area of the zygomatic arch and an area 6 mm above and 4 mm below the lateral canthal crease are the facial nerve danger zones. The present anatomic findings provide surgeons with further insights for performing blepharoplasty, midface lift, facelift, and facial nerve reconstructive surgery.

Impact of indocyanine green‐guided extended pelvic lymph node dissection during robot‐assisted radical prostatectomy

To evaluate the effectiveness of indocyanine green-guided extended pelvic lymph node dissection during robot-assisted radical prostatectomy for intermediate- to high-risk prostate cancer. After institutional review board approval, between July 2017 and December 2018, we carried out 100 indocyanine green-guided extended pelvic lymph node dissections in patients with localized intermediate- and high-risk prostate cancer, using the Firefly (Novadaq Technologies, Mississauga, ON, Canada) and da Vinci Xi surgical system (Intuitive Surgical, Sunnyvale, CA, USA). Indocyanine green was injected transrectally using ultrasound sonography before each surgery. Then, lymphatic drainage patterns and pathological findings were recorded. Lymphatic drainage routes were successfully determined in 91 right-sided and 90 left-sided cases. Five main lymphatic pathways and sites were identified: (i) an internal route (57%); (ii) a lateral route (50%); (iii) a presacral route (20%); (iv) a paravesical artery site (20%); and (v) a pre-prostatic site (5%). Lymph node metastasis was positive in 15 patients, with 44 pathologically confirmed metastatic lymph nodes. Metastatic fluorescent lymph nodes were found in 15 out of 44 lymph nodes (34.1%). For sentinel lymph node identification, the 34% sensitivity and 64.8% specificity rates were detected in regard to identification of lymph node metastasis. Lymphatic drainage patterns from the prostate can be identified and classified using indocyanine green-guided extended pelvic lymph node dissections. Although the direct role of fluorescent lymph nodes in sentinel lymph node identification appears to be limited, the identification of lymphatic pathways could contribute to high-quality extended pelvic lymph node dissection during robot-assisted radical prostatectomy.

The archaeal-bacterial lipid divide, could a distinct lateral proton route hold the answer?

The archaea-bacteria lipid divide is one of the big evolutionary enigmas concerning these two domains of life. In short, bacterial membranes are made of fatty-acid esters whereas archaeal ones contain isoprenoid ethers, though at present we do not have a good understanding on why they evolved differently. The lateral proton transfer mode of energy transduction in membranes posits that protons utilize the solvation layer of the membrane interface as the main route between proton pumps and ATPases, avoiding dissipation of energy to the bulk phase. In this article I present the hypothesis on a proton-transport route through the ester groups of bacterial phospholipids as an explanation for the evolutionary divergence seen between bacteria and archaea.ReviewersThis article was reviewed by Uri Gophna (Editorial Board member) and Víctor Sojo.

Cloud Encounter Impact on Operational and Economical Effectiveness of Hybrid-Laminar-Flow-Control Aircraft

Hybrid laminar flow control (HLFC) on transport aircraft is one of many promising fuel reduction technologies. However, due to high sensitivities of HLFC toward operational boundary conditions, estimations of its overall benefit are usually afflicted with large uncertainties. Among the critical environmental factors is the degradation of laminarity when flying through clouds at high altitudes. This paper provides an assessment on operational and economical effectiveness of HLFC aircraft with a detailed inclusion of the cloud encounter effect in three steps. First the expected time in cloud (TIC) in a real route network with cloud data given by the European Centre for Medium-Range Weather Forecast is analyzed, yielding an average TIC of 10%. Subsequently, HLFC fuel efficiency with and without considering the cloud effect on mid- to long-range aircraft is dealt with. Results show an average drop of fuel benefit from 12.8 to 12.0% due to clouds. The effectiveness of lateral route optimization to reduce the impact of clouds is investigated in the last analysis. Outcomes show that these mitigation strategies are economically beneficial for few cases only. The overall picture confirms that cloud encounter must not be neglected when assessing aircraft with HLFC.

Endoscopic Endonasal Approach to Selected Lesions of the Petrous Apex

Surgery of the petrous apex lesions is considered a surgical challenge. We report our experience and review the literature highlighting current indications and limits in the management of benign and malignant lesions with special focus on the endoscopic approaches. Over the last years, indications and limits of the extended endonasal approaches range from inflammatory disease of the paranasal sinuses to the management of various diseases involving the skull base such as CSF leak, pituitary tumors, ethmoid tumors, petrous apex lesions, and purely intracranial lesions thanks to the development of dedicated surgical instrumentation, the improvement of skull base reconstruction techniques, and a better knowledge of the anatomy. Extended endonasal approach to petrous apex lesions is a safe and effective procedure for appropriately selected patients in the hands of experienced endoscopic skull base surgeons. Nowadays, referral centers equipped by surgical teams with expertise to both endoscopic and lateral skull base routes represent the most safe and effective way of treatment of those diseases.

Endoscopic Endonasal Approach to Foramen Magnum Meningioma—Technical Note and Case Example

AbstractForamen magnum (FM) tumors represent one of the most complex cases for the neurosurgeon, due to their location in a very anatomically complex region surrounded by the brainstem and the lower cranial nerves, by bony elements of the craniocervical junction, and by the vertebrobasilar vessels. Currently, the open approach of choice is a lateral extension of the posterior midline approach including far lateral, and extreme lateral routes. However, the transoraltranspharyngeal approach remains the treatment of choice in cases of diseases affecting the craniocervical junction. For very selective cases, the endoscopic endonasal route to this region is another option. We present a case of a ventral FM meningioma treated exclusively with the endoscopic endonasal approach.

Predicting apparent passive permeability of Caco-2 and MDCK cell-monolayers: A mechanistic model.

Experimentally derived apparent permeabilities, Papp, through cell monolayers such as Caco-2 and MDCK are considered to be an in-vitro gold standard for assessing the uptake efficiency of drugs. Here, we present a mechanistic model that describes ‘passive’ Papp values (i.e., neglecting active transport) by accounting for the different resistances solutes encounter when permeating a cell monolayer. We described three parallel permeation pathways, namely a cytosolic-, paracellular-, and lateral route, each of which consists of a number of serial resistances. These resistances were accounted for via a mechanistic depiction of the underlying processes that are largely based on literature work. For the present Papp dataset, about as much chemicals are dominated by the cytosolic route as were dominated by the paracellular route, while the lateral route was negligible. For the cytosolic route by far the most chemicals found their main resistance in the various water layers and not in the membrane. Although correlations within the subclasses of chemicals dominated by a specific permeation route were rather poor, we could overall satisfyingly predict Papp for 151 chemicals at a pH of 7.4 (R2 = 0.77, RMSE = 0.48). For a specific evaluation of the intrinsic membrane permeability, Pm, a second experimental dataset based on experiments with black lipid membranes, BLM, was evaluated. Pm could be predicted for 37 chemicals with R2 = 0.91 and RMSE = 0.64 log units.

Microsurgical anatomy and approaches around the lateral recess with special reference to entry into the pons.

OBJECTIVE The lateral recess is a unique structure communicating between the ventricle and cistern, which is exposed when treating lesions involving the fourth ventricle and the brainstem with surgical approaches such as the transcerebellomedullary fissure approach. In this study, the authors examined the microsurgical anatomy around the lateral recess, including the fiber tracts, and analyzed their findings with respect to surgical exposure of the lateral recess and entry into the lower pons. METHODS Ten cadaveric heads were examined with microsurgical techniques, and 2 heads were examined with fiber dissection to clarify the anatomy between the lateral recess and adjacent structures. The lateral and medial routes directed to the lateral recess in the transcerebellomedullary fissure approach were demonstrated. A morphometric study was conducted in the 10 cadaveric heads (20 sides). RESULTS The lateral recess was classified into medullary and cisternal segments. The medial and lateral routes in the transcerebellomedullary fissure approach provided access to approximately 140º-150º of the posteroinferior circumference of the lateral recess. The floccular peduncle ran rostral to the lateral recess, and this region was considered to be a potential safe entry zone to the lower pons. By appropriately selecting either route, medial-to-lateral or lateral-to-medial entry axis is possible, and combining both routes provided wide exposure of the lower pons around the lateral recess. CONCLUSIONS The medial and lateral routes of the transcerebellomedullary fissure approach provided wide exposure of the lateral recess, and incision around the floccular peduncle is a potential new safe entry zone to the lower pons.

Midline Suboccipital Endoscopic Transcerebellomedullary Fissure Keyhole Approach.

To study the endoscopic anatomy of the 4th ventricle and lateral brainstem regions via the midline suboccipital endoscopic transcerebellomedullary fissure keyhole approach assisted by a neuronavigation system and discuss the feasibility and indications of this approach. Craniotomy procedures performed via the midline suboccipital endoscopic transcerebellomedullary fissure keyhole approach were simulated on 8 adult cadaveric heads fixed by formalin, and the related anatomic structures in the 4th ventricles or around the brainstem were observed through the 0° endoscope or alternatively 30° one. A neuronavigation system was used to measure the exposed area of the floor of 4th ventricle, the maximum exposure range, the length of the floor of 4th ventricle, the shortest distance from the midpoint of posterior arch of atlas to the opening of the aqueduct in the 4th ventricle and to the jugular foramen on both sides, respectively. All the anatomic structures within the 4th ventricle and partial anatomic landmarks around brainstem were identified by means of the midline suboccipital endoscopic transcerebellomedullary fissure keyhole approach. The exposed area of the floor of 4th ventricle is 459.68 ± 73.71 mm. However, the total exposed area is 1601.70 ± 200.76 mm. The length of the floor of 4th ventricle is 36.08 ± 2.63 mm. The shortest distance from the midpoint of posterior arch of atlas to the opening of the aqueduct in the 4th ventricle is 63.87 ± 2.97 mm, to the jugular foramen on both sides, respectively, is 40.11 ± 2.47 mm/40.30 ± 2.31 mm. Midline suboccipital endoscopic transcerebellomedullary fissure keyhole approach can basically meet the medial and lateral route of the transcerebellomedullary fissure approach. A tumor within the 4th ventricle or near the jugular tubercle extending into the 4th ventricle through the cerebellomedullary fissure can be removed by this approach.

Tissue Microenvironments in the Nasal Epithelium of Rainbow Trout (Oncorhynchus mykiss) Define Two Distinct CD8α+ Cell Populations and Establish Regional Immunity.

Mucosal surfaces require balancing different physiological roles and immune functions. To effectively achieve multifunctionality, mucosal epithelia have evolved unique microenvironments that create unique regional immune responses without impairing other normal physiological functions. Whereas examples of regional immunity are known in other mucosal epithelia, to date, no immune microenvironments have been described in the nasal mucosa, a site where the complex functions of olfaction and immunity need to be orchestrated. In this study we identified the presence of CD8α+ cells in the rainbow trout (Oncorhynchus mykiss) nasal epithelium. Nasal CD8α+ cells display a distinct phenotype suggestive of CD8+ T cells with high integrin β2 expression. Importantly, nasal CD8α+ cells are located in clusters at the mucosal tip of each olfactory lamella but scattered in the neuroepithelial region. The grouping of CD8α+ cells may be explained by the greater expression of CCL19, ICAM-1, and VCAM-1 in the mucosal tip compared with the neuroepithelium. Whereas viral Ag uptake occurred via both tip and lateral routes, tip-resident MHC class II+ cells are located significantly closer to the lumen of the nasal cavity than are their neuroepithelial counterparts, therefore having quicker access to invading pathogens. Our studies reveal compartmentalized mucosal immune responses within the nasal mucosa of a vertebrate species, a strategy that likely optimizes local immune responses while protecting olfactory sensory functions.

Minimally Invasive Surgical Approach for Odontoid Lesions: A Technical Description in a Case of High Cervical Osteomyelitis and Abscess

Cervical approaches to the dens are limited by the presence of several structures, including the spinal cord, vertebral arteries, C1 articular pillars, and C2 nerves. Surgical approaches to access the high anterior cervical spine classically encompass the extended anterior retropharyngeal route, transoral route, and extreme lateral route, each of which has its own pattern of morbidity or complications. Percutaneous procedures to drain infections in this area have a limited yield. Osteomyelitis of the dens is a rare but serious condition that is associated with significant mortality. Patients with cervical osteomyelitis and epidural abscess are likely to have significant coexistent medical comorbidities and are often poor candidates for extensive surgical procedures. A minimally invasive approach that gives access to the entire odontoid process would allow for more aggressive treatments and potentially even a complete odontoidectomy without resection of the C1 anterior arch. We describe a minimally invasive approach to drainage and debridement of an atlantoaxial epidural abscess and osteomyelitis. Using minimally invasive techniques from a posterolateral trajectory in a cadaveric specimen, we were able to safely access the anterior epidural space, odontoid, and retropharynx. We then performed this approach in our patient who was unable to tolerate a large surgical procedure. We developed, tested, and then applied a minimally invasive approach that combined tubular retractors with positioning of the head and neck to optimize the exposure in a patient with a complex abscess that involved the ventral epidural space, odontoid process, and retropharyngeal space. The abscesses were successfully drained along with local tissue debridement without complication. A posterolateral minimally invasive approach is a safe alternative in patients with an atlantoaxial epidural abscess, odontoid osteomyelitis, or retropharyngeal abscess with significant medical comorbidities who are unlikely to tolerate a more extensive surgery. It can also be used for resections of lesions of an oncologic nature and could even be used to resect pannus or os odontoideum, without necessitating an anterior approach or resection even of the C1 arch.