Clinical Outcomes Following Endoscopic Carpal Tunnel Release With the Arthrex NanoScopic Release System—A Single Surgeon Experience

Abstract

Purpose

Endoscopic carpal tunnel release (ECTR) is a minimally invasive alternative to open release, offering faster recovery and reduced postoperative discomfort. The Arthrex NanoScopic ECTR system, a novel single-use device using chip-on-tip digital imaging and designed for use under local anesthesia without arthroscopic equipment, may further streamline care and expand surgical access.

Methods

A retrospective review was conducted of the first 50 consecutive ECTR procedures performed using the Arthrex NanoScopic system by a single hand fellowship-trained hand surgeon. All procedures were completed under wide-awake local anesthesia no tourniquet technique in an outpatient surgical center. Outcomes included operative times, adverse events, infections, need for reoperation, and anesthesia conversion rates. Patients were followed for a minimum of 3 months after surgery.

Results

A total of 50 procedures were performed on 37 patients (13 bilateral), with a median age of 58 years. All cases were completed under local anesthesia without conversion to sedation or general anesthesia. The average operative time was 8 minutes, with the total room time averaging 22 minutes. No reoperations occurred. Four patients (8%) developed postoperative median neuritis, with three cases resolving spontaneously and one attributed to underlying polyneuropathy. One patient presented to the emergency department for pain unrelated to the surgical site, and one patient developed a superficial wound infection resolved with oral antibiotics.

Conclusions

The Arthrex NanoScopic ECTR system appears to be a safe, efficient, and minimally invasive option for carpal tunnel syndrome decompression under wide-awake local anesthesia no tourniquet. Its single-use, portable design may reduce the procedural burden and expand access to endoscopic release in office-based or ambulatory settings. Early outcomes demonstrate low complication rates and high procedural success, supporting further evaluation of this technique in broader clinical practice, particularly in an office setting.

Type of study/level of evidence

Prognostic II.

Carpal tunnel syndrome (CTS) is a compressive neuropathy of the median nerve at the wrist, typically causing pain, numbness, and tingling in the thumb, index, middle, and radial half of the ring finger. It is the most common entrapment neuropathy of the upper extremity, affecting approximately 3% to 4% of adults, with women affected far more than men.^1,2 Surgical release of the transverse carpal ligament reliably relieves nerve compression and is indicated when conservative measures fail.

The modern diagnosis and surgical treatment of CTS was first introduced by Phalen beginning in the 1950s.^3,4 Traditionally, open carpal tunnel release (OCTR) was performed through an extensile open palmar incision, thereby exposing the transverse carpal ligament and sharply releasing it to decompress the median nerve. In time, the surgical footprint for the open approach has decreased in size. Although effective, the OCTR approach often requires several weeks of recovery and may result in pillar pain or scar sensitivity. Endoscopic carpal tunnel release (ECTR) was introduced as a minimally invasive alternative to avoid an incision in the sensitive palmar base of the hand. In ECTR, one or two small incisions (usually <1 cm) are made at the wrist level, and an arthroscopic camera and cutting blade are used to visualize and transect the ligament from beneath. High-quality studies and meta-analyses have shown that ECTR provides equivalent long-term symptom relief compared with open release, but with faster functional recovery.^5,6 For example, patients undergoing ECTR typically return to work approximately 1 week sooner than those treated with open release. Endoscopic carpal tunnel release is also associated with less early postoperative pain, less scar tenderness, and higher patient satisfaction.⁷

Various ECTR systems have been developed since the original Agee and Chow techniques of the 1990s.⁸ Many modern devices seek to improve visualization and ergonomics while reducing instrument complexity. One recent example is the Arthrex NanoScopic Release system (Arthrex, Inc; Fig. 1).⁹ The Arthrex system, unlike traditional ECTR systems that use arthroscopic camera systems, uses a 1.5-mm digital camera on the end of a 180 mm stick (aka, “chip-on-tip” imaging technology) that provides high-definition digital visualization connecting to a portable console or tablet, without heat generation, fogging, or need for any arthroscopic equipment (Fig. 2). The NanoScope is inserted into a Centerline device, which represents the handle with cannula and the undersurface retractable sharp cutting knife. The entire system is single-use, consisting of the NanoScope, Centerline handle, synovial elevator/ dilator, and High-Definition Multimedia Interface (HDMI) wiring that connects to the console of the surgical field. The rational and purported advantages include an even less invasive surgical approach with smaller instrumentation, greater portability, and the ability to perform an ECTR outside of an operating room without the need for arthroscopic equipment, single-use instrumentation that eliminates sterilization costs and arthroscopic system wear, and greater simplicity for setup by the surgical team.

Figure 1.

An assembled Arthrex NanoScopic Release within the Centerline handpiece.

Figure 2.

Surgical setup with the console off the surgical field.

To better understand outcomes for this new ECTR system leveraging new digital technology with a smaller footprint and greater portability, a single surgeon retrospective study of consecutive patients undergoing ECTR under only local anesthesia in a wide-awake fashion was conducted.

Materials and Methods

This retrospective study was approved by our institutional review board. The medical records of the first 50 consecutive patients who underwent ECTR using the Arthrex NanoScopic ECTR system since January 2024 were reviewed. All cases were performed by a single hand surgery fellowship-trained hand surgeon, at a single surgical center, using the wide-awake local anesthesia no tourniquet (WALANT) technique.

Study cohort

The 50 consecutive cases studied, consisting of 37 patients, were limited to patients over 18 years old, with electrodiagnostically confirmed CTS, undergoing ECTR with the Arthrex NanoScopic system, without any associated or additional procedures. All ECTR surgeries were performed using the WALANT technique, as per the practice of the surgeon. Data were extracted from surgical reports, office notes, and telephone encounters. The minimum re-evaluation period was 3 months after surgery, based on surgeon practice. The primary outcomes of interest were adverse events, infection, reoperations, and conversion from local anesthesia to regional or general anesthesia.

Surgical technique

The surgical technique consisted of an injection of 9cc of 1% lidocaine with epinephrine and 1cc of 8.4% bicarbonate with a 27-gauge needle placed subcutaneously in the volar wrist extending into the palm in the preoperative holding area. Patients were not fasting, an intravenous therapy was not placed, and antibiotics were not given. Patients were then brought into a procedure room in a single outpatient surgical center by a circulating nurse. The surgical site was prepared in a standard sterile fashion by a surgical technician. No tourniquet was applied. After a timeout but before incision, the surgical field was injected with an additional 10cc of 1% lidocaine with epinephrine. A 1-cm transverse incision was then placed just proximal to the wrist crease. The palmaris longus tendon was identified and retracted radially with a Ragnell retractor. The antebrachial fascia was then transversely opened using a blunt technique. The median nerve was identified in the floor, and the antebrachial fascia distally was elevated with a double skin hook. A freer elevator was first introduced to confirm the position. The single-use Arthrex NanoScopic ECTR system was opened. The dilator-scraper tool was inserted first to dilate and second to scrape the undersurface of the transverse carpal ligament to clear any associated synovium. The NanoScopic needle was then inserted into the Centerline handpiece and connected to the freestanding console off the field. The handpiece was then inserted within the carpal tunnel. Once satisfied that there are no crossing tendons or median nerve, the ligament is released sharply retrograde, distal to proximal, along the undersurface of the transverse carpal ligament. Once satisfied with the release of the transverse carpal ligament, 2–3 cm of proximal antebrachial fascia is released with dissecting scissors while visualizing and protecting the median nerve. The wound was washed and closed with buried sutures and skin glue. A soft dressing was applied that can be removed in 2 days. After surgery, the patients were prescribed Tylenol 500 mg po q4 for 5 days and Naprosyn 500 mg po q12 for 14 days, unless there were allergies or comorbidities contraindicating either medication. Patients were also offered three tablets of oxycodone 5 mg to be used as needed for severe pain.

Statistical analysis

Descriptive statistics were calculated to summarize patient characteristics and the frequency of postoperative complications. All analyses were performed using basic statistical software.

Results

A total of 37 patients underwent ECTR using the Arthrex NanoScopic system during the study period. Of these, 13 patients (35%) underwent bilateral releases on different surgical dates, resulting in a total of 50 ECTR cases (Table). The cohort included 21 men (57%) and 16 women (43%), with a median age of 58 years (range: 40–82 years). The average follow-up time was a minimum of 3 months after surgery, with an average of 3.3 months (range: 3–12 months).

Table 1.

Patient Demographics

Patient Demographics	Number (Percent)
N	37
Bilateral	13 (35%)
Gender
Male	21 (57%)
Female	16 (43%)
Age	62 (55–69)

In terms of the surgical course, all cases were performed under only local anesthesia using the WALANT technique, with no cases requiring an open release or conversion from local to sedation or any other form of anesthesia change. The surgical time was, on average, 8 minutes (range: 5–14 minutes), representing from time out to closure. The operating room time was, on average, 22 minutes (range: 17–33 minutes), consisting of wheels in to wheels out of the procedure room.

In terms of the postoperative course, there were no cases of reoperation. There were four cases of median neuritis after surgery, with three cases resolving spontaneously on average between 6 weeks and 6 months after surgery, but with one case of persistent numbness even 1 year after surgery. In this one patient, at 3 months after surgery, an ultrasound was performed, which confirmed a complete carpal tunnel release and no median nerve injury. At 6 months after surgery, a repeat electrodiagnostic study confirmed improved median nerve latency of 7.0 ms before surgery to 4.7 ms after surgery (normal < 4.2 ms). Moreover, the repeat electrodiagnostic study also identified polyneuropathy, also clinically correlated by increasing numbness in the patient’s feet as well. It was concluded that the carpal tunnel was adequately decompressed and persistent numbness may be a manifestation of his polyneuropathy.

In terms of readmission, there was one case of severe postoperative pain where the patient decided to go to the emergency room. The patient, who had a history of chronic kidney failure and was on three times per week dialysis, complained of severe pain in the hand and forearm that began 2 days after surgery following dialysis through his forearm fistula in the ipsilateral side as the ECTR. The symptoms of pain resolved spontaneously with emergency department treatment but without the need for reoperation or other interventions related to the surgical site.

In terms of infection, there was one case of a postoperative superficial wound infection treated with oral antibiotics for 1 week that resolved the infection without further treatment, including no treatment with intravenous antibiotics and no hospital admission. Of note, no patients were prescribed antibiotics before or after surgery per the surgeon’s protocol.

Discussion

Endoscopic carpal tunnel release has been increasingly adopted because of its association with reduced postoperative pain, earlier return to function, and smaller incisions compared with the OCTR approach. The Arthrex NanoScopic ECTR system represents a novel iteration leveraging new digital technology with a smaller footprint and greater portability. The present study provides data on this new system’s safety, efficacy, and feasibility under WALANT in a consecutive patient cohort. All procedures were completed successfully under local anesthesia alone without the need for intraoperative conversion to sedation or general anesthesia. Importantly, no cases required reoperation or secondary intervention, and postoperative complications were infrequent. These findings underscore the potential of this technique to deliver efficient, resource-sparing care without compromising surgical outcomes.

Wide-awake local anesthesia no tourniquet has been extensively validated in the setting of OCTR, with multiple studies demonstrating its benefits in terms of cost, efficiency, and patient recovery.10, 11, 12 Its application in ECTR, however, remains less well studied. The current findings expand the utility of WALANT to endoscopic decompression, further broadening its clinical scope. The use of WALANT may also mitigate the logistical and economic barriers associated with ECTR by obviating the need for anesthesia support and postoperative recovery facilities, thereby facilitating office or ambulatory surgical workflows.

When compared with existing literature on traditional ECTR techniques, including both two-portal and single-portal systems, the Arthrex NanoScopic ECTR system demonstrates comparable early safety outcomes. Recent studies on ECTR have examined various outcome measures such as functional recovery, complication rates, and patient satisfaction. Evidence suggests that ECTR offers comparable or superior results with OCTR in terms of postoperative discomfort, quicker return to function, improved grip strength, and earlier return to work. For example, a recent meta-analysis published in 2024 demonstrated that ECTR patients experienced lower scar sensitivity and fewer wound-related complications, although with a slightly higher rate of reversible nerve injuries.¹³ Patient satisfaction remains high across multiple studies, with most individuals reporting marked symptom improvement and willingness to undergo the same procedure again if needed.¹⁴

Recent single surgeon studies on ECTR provide valuable insights into the procedure's efficacy, safety, and learning curve. A retrospective review of 129 patients who underwent ECTR over 13 years reported that 96% experienced improvement in nerve symptoms. The study emphasized the importance of surgeon experience in achieving favorable outcomes.¹⁴ In a larger series, a single surgeon performed 1,278 consecutive ECTR procedures over 7 years, reporting minimal early major complications. All surgeries were conducted under local anesthesia on an outpatient basis using the Agee single-portal technique.¹⁵ A retrospective study of 390 consecutive ECTR cases using the two-portal Chow technique reported favorable outcomes in 98% of patients, with a 90% satisfaction rate. The average return to work was 20 days, and the complication rate was low.¹⁶ In another single surgeon series, the average return to work was just 3 weeks, and the cost was reportedly 9% lower than traditional open release, further underscoring the efficiency of ECTR when performed by an experienced hand surgeon.¹⁷

Despite the benefits, the literature emphasizes that ECTR demands a steep learning curve.¹³ Surgeon experience plays a critical role in minimizing intraoperative complications and achieving consistent results. Interestingly, some studies have shown that postoperative therapy, whether supervised or home-based, may not considerably influence outcomes, suggesting that recovery is primarily driven by surgical precision and patient compliance.¹⁸

The device’s integrated cannula and blade design simplifies the procedure and eliminates the need for reusable instrumentation or complex endoscopic towers, making it particularly amenable to settings with constrained operative infrastructure. Moreover, the reproducibility and low complication profile observed in this study suggest a minimal learning curve when adopted by experienced hand surgeons.

Nevertheless, this study is limited by its retrospective design, the lack of a control group, and the absence of long-term follow-ups or validated patient-reported outcome measures. The relatively small sample size also precludes robust statistical comparisons to other techniques. Future prospective studies should include standardized outcome metrics, cost-effectiveness analyses, and stratification by surgeon experience to further delineate the comparative efficacy of Centerline ECTR under WALANT.

In conclusion, this study adds to the growing body of evidence supporting the use of disposable single-port ECTR systems and introduces early clinical data on their implementation under WALANT. The combination of the Centerline system with local anesthesia represents a viable, efficient approach to carpal tunnel decompression with favorable short-term outcomes. Its adoption may enhance the accessibility and scalability of ECTR in both high- and low-resource settings.

Conflicts of Interest

Dr Ilyas has consultancy/advisory board involvement with Arthrex. No benefits in any form have been received or will be received by the other author related directly to this article.