Neuraxial Anesthesia · Inflection Point
The Inflection Point for Neuraxial Guidance Why Real-Time Ultrasound Is Finally Here
The inflection point is not approaching. It is here.
Neuraxial anesthesia (epidurals, spinals, combined spinal-epidurals) is among the most commonly performed procedures in medicine. Globally, against a backdrop of roughly 140 million births each year, tens of millions of women receive neuraxial analgesia or anesthesia for childbirth; in the United States alone, an estimated 3 million patients annually receive obstetric neuraxial analgesia or anesthesia (the large majority of US births), placing neuraxial technique among the single largest procedural domains in the specialty. And for nearly a century, every epidural among them has been guided by the same final confirmation: the feel of loss of resistance.1,2
The loss-of-resistance technique, described by Dogliotti in 19332, remains the standard of care. The clinician palpates landmarks, advances a needle through tissue, and confirms epidural space entry by the subtle change in resistance as the needle tip crosses the ligamentum flavum. It is a skill built on anatomy, experience, and tactile precision; that final tactile confirmation is not something technology replaces.
What has been missing is real-time guidance during needle advancement in the critical distance before loss of resistance is reached.
Three developments have converged in 2025 and 2026 that together represent a genuine inflection point for neuraxial anesthesia: the FDA clearance of the first real-time neuraxial guidance device, a new ICD-10-PCS code recommended by Centers for Medicare & Medicaid Services (CMS) that makes computer-aided neuraxial navigation trackable and accountable for the first time, and a national quality infrastructure through a large anesthesia-led perioperative clinical data registry and quality improvement platform capable of validating outcomes at scale. Understanding why each of these matters, and why their convergence matters more than any one of them alone, is the purpose of this article.
The scale of the problem
Unintended dural puncture
Before discussing the solution, it is worth being clear about the problem.
Unintended dural puncture (commonly called a wet tap) occurs when the epidural needle inadvertently breaches the dura mater and enters the subarachnoid space. The reported incidence during labor epidural analgesia ranges from 0.5% to 1.5% in most published series, with a broader range of 0.04% to 6% reported across the literature depending on institution, trainee mix, and patient population.3,4 Even at the lower end of that range, the absolute numbers are substantial: applied to millions of labor epidurals performed annually worldwide, inadvertent dural puncture represents a meaningful and underreported patient safety event.
Of those who experience dural puncture, more than half go on to develop post-dural puncture headache (PDPH) when a standard Tuohy needle is the causative instrument; worldwide, this represents on the order of 125,000 cases each year.5 Critically, a third of all dural punctures are unrecognized at the time of placement, meaning neither the clinician nor the patient is aware that the complication has occurred until symptoms develop hours later.6
What has changed in recent years is the clinical understanding of what PDPH actually means for patients in the long term. PDPH has historically been described in consent conversations as a nuisance complication, uncomfortable but treatable and self-limiting. The evidence no longer supports that framing.
Niraj et al. (2021) followed obstetric patients prospectively across nine UK units and found that 58% of patients who experienced accidental dural puncture still had persistent headache at 18 months, compared to 17% of controls.7 Chronic low back pain was present in 48% of ADP patients at 18 months versus 17% of controls.
Long-term symptoms after accidental dural puncture
Prevalence at 18 months · ADP patients vs. matched controls (Niraj et al., 2021)
Women who experience PDPH face substantially elevated risks of serious morbidity. Adjusted odds ratios approach 11 for cerebral venous thrombosis and 77 for subdural hematoma, with a roughly 40-fold increased risk of bacterial meningitis.4,9 PDPH is also associated with postpartum depression (aOR 1.9 to 3.1).8,9
Serious neurologic morbidity after PDPH
Adjusted odds ratio vs. women without PDPH (baseline = 1×)
The 2014 MBRRACE-UK report Saving Lives, Improving Mothers’ Care described two maternal deaths following accidental dural puncture during epidural placement, one from cerebral vein thrombosis and one from subdural hematoma, both after weeks of untreated headache without follow-up.
These are not the numbers that appear on most consent forms. The typical consent for labor neuraxial analgesia describes the risk of headache as ‘a slight risk’ that ‘often goes away on its own’ and, if not, can be treated with a blood patch. That language was written around an acute complication model. The data now describe a chronic morbidity model.
The gap between what is disclosed and what the evidence shows is itself an argument for doing better.
There is also a tracking problem. The United States has no mandatory national reporting system for wet tap rates. Institutional audits and administrative billing databases are the primary data sources, and both significantly undercount: unrecognized punctures are by definition absent from audit records, while administrative databases miss outpatient and emergency department presentations of PDPH. The result is a poor grasp of true national incidence, unmeasured institutional variation, and no population-level benchmark for high-performing programs. The incidence of unintended dural puncture has not meaningfully declined in the 90 years since loss-of-resistance became the standard technique.
Where neuraxial ultrasound has been
The scouting phase
Ultrasound use in neuraxial anesthesia is not new. Expert practitioners have used pre-procedural ultrasound scanning for years to identify landmarks, estimate epidural depth, and mark skin entry points before needle insertion, particularly in patients with obesity, scoliosis, or previous spinal surgery where bony landmarks are difficult to palpate.
This pre-procedural scanning approach has demonstrated real clinical value. A 2025 systematic review and meta-analysis by Sharapi et al. of five RCTs comparing the Accuro® ultrasound system to palpation technique found a first-insertion success risk ratio of 1.44 (95% CI 1.01 to 2.05, p=0.05) and a significant reduction in needle passes.10 Ni et al. (2021), in an RCT of 80 obese parturients undergoing cesarean delivery, found first-insertion success of 72.5% with Accuro versus 40.0% with palpation (p=0.003), with paresthesia rates of 7.5% versus 45.0% (p<0.001).11
First-insertion success: Accuro vs. palpation
Meta-analysis of 5 RCTs · risk ratio with 95% CI (Sharapi et al., 2025)
Accuro vs. palpation in obese parturients
RCT of 80 cesarean deliveries (Ni et al., 2021)
But pre-procedural scanning has a fundamental limitation: it is a scouting phase, not a guidance phase. The clinician uses ultrasound to map anatomy, marks the skin, sets the probe down, and then performs the insertion by feel, exactly as they would have without the scan. Skin marks shift when the patient repositions. The insertion itself, the interval between skin entry and loss-of-resistance confirmation, receives no real-time feedback. The probe-down moment is where guidance ends and tactile technique resumes entirely.
This is not a failure of ultrasound as a technology. It is a failure of probe geometry. Conventional single-array ultrasound probes cannot support in-plane midline needle insertion during neuraxial procedures: the physics simply do not permit it. Solving that problem required a fundamentally different probe architecture.
The first real-time neuraxial guidance device
Accuro 3S
Accuro® 3S, developed by RIVANNA® and cleared by the FDA in 2025 (510(k) K243937; clearance letter dated May 23, 2025), is the first and only device purpose-built to provide real-time in-plane needle guidance during neuraxial anesthesia. To be precise about what this means clinically: the system provides continuous needle tip tracking and trajectory guidance from skin entry through needle advancement, up to the point at which the clinician applies loss-of-resistance technique to confirm epidural space entry. Loss-of-resistance skill remains essential; what changes is the quality of guidance available in the critical distance before that confirmation.
The system integrates three distinct technologies that together address the barriers that have prevented real-time neuraxial guidance.
Dual-Array™ convex probe
Rather than a single transducer array, the probe contains two aligned arrays arranged side by side with a narrow central gap. The needle passes through the probe’s center, directly over the midline, enabling real-time in-plane needle tracking during insertion. The arrays transmit angled sound waves that converge along the needle’s trajectory, significantly improving tip detection at the steep insertion angles required for epidural placement: a geometry not achievable with any conventional single-array probe design, and the reason a new patent was required.
Patented probe architectureSpineNav-AI™
The software layer provides automated real-time identification of spinal midline, interlaminar space, and epidural depth, removing operator skill as the primary variable in image interpretation.
Validated across 10,000+ frames · 7 sitesHands-free sterile drape
Neuraxial procedures require the clinician to simultaneously manage the probe, needle, and syringe: the ‘three-hand problem’ that has made continuous ultrasound guidance impractical with conventional setups. The stabilization drape secures the probe against the patient’s back, freeing both hands for needle control and, critically, for the tactile loss-of-resistance confirmation that remains the clinical endpoint of the procedure. A single-operator workflow becomes possible without sacrificing the hands needed for that final step.
Single-operator workflowSafeTrack™
Provides continuous, in-plane needle tip tracking and trajectory feedback during advancement; it is the component that bridges the gap between the scouting phase of pre-procedural scanning and genuine real-time guidance through the needle’s path.
Pending FDA clearanceIn the FDA clearance study (K243937), SpineNav-AI was validated across more than 10,000 image frames collected across seven geographically diverse sites. It performs the landmark identification that previously required substantial POCUS training, which means clinicians without advanced ultrasound expertise can use the device effectively.
Together, these components give the clinician what peripheral nerve block technique already provides: continuous needle tip tracking from skin entry through advancement, with the clinician’s own tactile judgment completing the procedure at the point of loss of resistance.
Making neuraxial guidance visible
ICD-10-PCS code XEZU3HC
A clinical technology is only as useful as the infrastructure that supports its adoption. One of the most consequential developments in neuraxial anesthesia for 2026 is, perhaps unexpectedly, a new procedure code.
In the Spring 2026 ICD-10-PCS Coordination and Maintenance Committee materials (posted for public comment, comment deadline April 17, 2026), CMS recommended the creation of a new ICD-10-PCS code for computer-aided neuraxial navigation: XEZU3HC, formally described as “Computer-aided Guidance for Intraprocedural Navigation using Ultrasound Imaging with Continuous Needle Tracking.” The code is expected to be effective October 1, 2026, pending the Inpatient Prospective Payment System Final Rule.
The code structure places this technology in Section X (New Technology), reflecting CMS’s recognition of Accuro 3S as a genuinely novel category of procedure; not a variation on existing neuraxial technique, but a distinct new approach requiring its own tracking infrastructure.
Why does a procedure code matter clinically? Without a unique identifier, computer-aided neuraxial navigation is invisible in administrative data: there is no way to track utilization, compare outcomes between guided and unguided procedures, build the institutional value case for capital acquisition, or establish the payer recognition prerequisite for future reimbursement pathways. The code enables all four.
Track utilization.
Compare outcomes between guided and unguided procedures.
Build the institutional value case for capital acquisition.
Establish the payer recognition prerequisite for future reimbursement pathways.
The central line parallel is instructive. ICD-10-PCS venous ultrasonography codes (the B54 series) were introduced in October 2015 and are now routinely used in combination with central line insertion codes to document ultrasound-guided CVC placement. That coding infrastructure coincided with the period when ultrasound-guided central line access crossed from “strongly recommended” to broadly treated as standard of care. Coding accountability (the ability to measure and compare who was using real-time guidance and who was not) was part of what closed that gap.
Code XEZU3HC does not trigger a New Technology Add-on Payment for FY2027; RIVANNA did not submit an NTAP application at this stage. That sequencing is deliberate. NTAP requires demonstrated clinical benefit in real-world use; the code creates the tracking infrastructure that will generate precisely that benefit data, prioritizing measurement before reimbursement recognition.
Turning data into evidence
National quality infrastructure
This registry, a large anesthesia-led perioperative clinical data registry and quality improvement platform, spans more than 85 member hospitals across more than 20 states and three countries, with over 28 million anesthetic cases in its registry and more than 70 active quality improvement measures.
The registry extracts data automatically from electronic health records, anesthesia information management systems, administrative billing records (including ICD-10-PCS codes), and physiologic monitoring systems. Once code XEZU3HC is active, cases using Accuro 3S will be automatically identifiable within the registry’s dataset without any additional documentation burden on clinical teams. That linkage enables what individual institutional audits cannot: multi-center, statistically powered analysis of outcomes in procedures where complications like unintended dural puncture occur at approximately 1%, a rate that requires large denominators to study meaningfully.
Within this registry, an obstetric anesthesia quality measure tracks neuraxial catheter replacement in childbirth, serving as a proxy for initial neuraxial failure. A dedicated measure for unintended dural puncture detection and tracking is also under active development; if implemented, it would be the first such measure in a national perioperative registry.12
For the clinician or department administrator evaluating Accuro 3S, this registry connection is significant for a practical reason. The clinical case for the device will be built from real-world multi-center data at scale, not from manufacturer claims or single-institution case series. The infrastructure to generate that evidence already exists.
A precedent worth studying
The central line analog
For OB anesthesiologists evaluating whether real-time neuraxial guidance represents a durable shift or a temporary enthusiasm, the history of ultrasound-guided central venous access offers the clearest available parallel. Ultrasound use for central line placement followed a predictable arc.
approximately 30 years.
In 2002, the UK’s National Institute for Health and Care Excellence issued Technology Appraisal TA49, recommending 2D real-time ultrasound as the preferred method for internal jugular cannulation.14 The recommendation drew on seven randomized controlled trials evaluating 2D ultrasound for internal jugular cannulation in adults, which together showed an 86% reduction in failed catheter placements and a 57% reduction in complications.
The response from the anesthesia community was resistance. The APSF Newsletter published a formal rebuttal in 2002 under the title “Ultrasound Guidance Should Not Be Standard of Care.” The arguments: thousands of central lines are placed safely every day without ultrasound; adding it takes too long; clinicians will lose their landmark skills. These arguments will be familiar to anyone who has participated in conversations about neuraxial ultrasound today.
The ASA issued practice guidelines recommending real-time ultrasound for internal jugular cannulation in 2012.15 The Society of Hospital Medicine recommended real-time guidance regardless of provider experience level in 2019.16 ICD-10-PCS venous ultrasonography codes (the B54 series) were introduced in October 2015 and are now routinely used in combination with central line insertion codes to document ultrasound-guided CVC placement. The argument that ultrasound guidance for central lines is optional is now, as a practical matter, indefensible.
Neuraxial guidance enters at a different starting point. Accuro 3S arrives FDA-cleared, with a purpose-designed probe that solves the geometry problem conventional ultrasound could not, an AI interpretation layer that removes operator skill as the limiting variable, a national quality registry already in place to capture outcomes data, and a dedicated ICD-10 code arriving within the same year as clinical deployment. The conditions that compressed the central line adoption curve — coding accountability, guideline endorsement, quality measurement infrastructure — are arriving simultaneously rather than sequentially over decades.
Where neuraxial guidance sits today
From technology question to adoption question
The question of whether real-time ultrasound guidance will become standard of care for neuraxial anesthesia is no longer primarily a technology question. The technology exists, it is FDA-cleared, and the clinical evidence for ultrasound-assisted neuraxial placement is consistent across multiple RCTs and meta-analyses.
The question is about pace and path of adoption, and about which institutions and clinicians choose to be early in that path versus late. Three barriers that have historically slowed the adoption of imaging guidance in procedural medicine have been addressed simultaneously:
What remains is the clinical will to recognize that post-dural puncture headache, with its 58% rate of persistent symptoms at 18 months and documented associations with cerebral venous thrombosis, subdural hematoma, chronic back pain, and postpartum depression, is a complication the field has accepted as irreducible for too long.
Real-time neuraxial guidance does not require clinicians to abandon the skills that define expert practice. The loss-of-resistance technique remains the endpoint; what changes is the quality of anatomical guidance and needle tracking available in the approach to that endpoint. The patients who will benefit are the same patients who are already in the room: women in labor with obesity, scoliosis, prior spinal surgery, and poorly defined landmarks, for whom the blind interval between skin entry and loss-of-resistance confirmation is longest, most uncertain, and most consequential.
The inflection point is not approaching. It is here.
Sources
References
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- Dogliotti AM. Segmental peridural spinal anesthesia: a new method of block anesthesia. Am J Surg. 1933;20:107–118.
- Van de Velde M, Schepers R, Berends N, Vandermeersch E, De Buck F. Ten years of experience with accidental dural puncture and post-dural puncture headache in a tertiary obstetric anaesthesia department. Int J Obstet Anesth. 2008;17(4):329–335.
- Vallejo MC, Zakowski MI. Post-dural puncture headache: diagnosis and management. Best Pract Res Clin Anaesthesiol. 2022;36(1):179–189.
- Choi PT, Galinski SE, Takeuchi L, Lucas S, Tamayo C, Jadad AR. PDPH is a common complication of neuraxial blockade in parturients: a meta-analysis of obstetrical studies. Can J Anaesth. 2003;50(5):460–469.
- Eley VA, et al. Recognized and unrecognized dural punctures in 12,981 labor epidurals: an audit of management. J Anesth. 2022;36(3):399–404.
- Niraj G, et al. Persistent headache and low back pain after accidental dural puncture in the obstetric population: a prospective, observational, multicentre cohort study. Anaesthesia. 2021;76(8):1068–1076.
- Mims SC, Tan HS, Sun K, Pham T, Rubright S, Kaplan SJ, Habib AS. Long-term morbidities following unintentional dural puncture in obstetric patients: a systematic review and meta-analysis. J Clin Anesth. 2022;79:110787.
- Guglielminotti J, Landau R, Li G. Major neurologic complications associated with postdural puncture headache in obstetrics: a retrospective cohort study. Anesth Analg. 2019;129(5):1328–1336.
- Sharapi M, et al. Ultrasound-based Accuro system versus traditional palpation technique for neuraxial anaesthesia: a systematic review and meta-analysis of randomised controlled trials. J Perioper Pract. 2025;35(3):60–69.
- Ni X, et al. Accuro ultrasound-based system with computer-aided image interpretation compared to traditional palpation technique for neuraxial anesthesia placement in obese parturients undergoing cesarean delivery: a randomized controlled trial. J Anesth. 2021;35(4):475–482.
- Togioka BM, Reale SC, Klumpner T, Aziz MF, Mathis MR. The Multicenter Perioperative Outcomes Group (MPOG) learning health system: a model for promoting evidence-based peripartum care. Int J Obstet Anesth. 2025;64:104765.
- Legler D, Nugent M. Doppler localization of the internal jugular vein facilitates central venous cannulation. Anesthesiology. 1984;60(5):481–482.
- NICE Technology Appraisal TA49. Guidance on the use of ultrasound locating devices for placing central venous catheters. October 2002.
- Rupp SM, et al. Practice guidelines for central venous access. Anesthesiology. 2012;116(3):539–573.
- Franco-Sadud R, et al. Recommendations on the use of ultrasound guidance for central and peripheral vascular access in adults: a position statement of the Society of Hospital Medicine. J Hosp Med. 2019;14(9):E1–E22.