Sodium hypochlorite accident in dentistry: a narrative review of etiology, diagnosis and management

Introduction

A pivotal step in endodontic treatment is the use of irrigants to eliminate debris, microorganisms, and inorganic tissue within the canal. Sodium hypochlorite (NaOCl) is widely used as an intracanal medicament for canal irrigation, aimed at achieving disinfection and removing pulpal debris and dentin shavings (1). It is the irrigant of choice due to its ability to dissolve living tissue and its bactericidal, lubricating, and bleaching properties (2). While these qualities make NaOCl highly effective, it is important to recognize that it is also highly toxic and can cause serious complications if extruded into surrounding tissues. The prevalence of such injuries has been reported to be around 0.89 percent (3). Although the rate of accidents is relatively low, the potential for severe tissue damage remains significant. Additionally, while well-documented case reports for hypochlorite accidents exists within the literature, their true prevalence is likely underestimated due to factors such as underreporting and inconsistent documentation and follow-ups. Delayed diagnosis also remains to be a challenge due to the nature of the injury and symptoms might be overlooked and confused with normal postoperative sequelae.

Despite the well-established use of NaOCl in endodontics, which has been reported in detail in the literature, there exists a variability in clinician preparedness and familiarity with the prevention and management strategies if a hypochlorite accident were to occur. Another factor affecting clinician preparedness is that much of the available published literature focuses on isolated case reports and individual management reports and the presence of a comprehensive, structured synthesis that aids in triaging and managing such incidents that can be incorporated into everyday practice will be beneficial for safe handling of NaOCl and reducing the incidence of hypochlorite accidents. This review aims to address this gap by integrating the current evidence into a clinical framework that provides clinicians with an overview of the chemical properties of NaOCl, mechanisms of injury, preventive measures, management strategies and the clinician’s medico-legal responsibilities. We present this article in accordance with the Narrative Review reporting checklist (available at https://fomm.amegroups.com/article/view/10.21037/fomm-25-24/rc).

Methods

A search of literature was performed using PubMed, Ovid MEDLINE, Embase, and Google Scholar to identify articles focusing on the history of NaOCl use, its chemical properties, mechanisms of tissue injury, reported clinical cases, prevention strategies, and management guidelines. Prioritizing clinically relevant publications from 2000 onward. Articles were sorted by type, date and the search was supplemented by reviewing the references of the selected articles. Citations were tracked using Mendeley citation manager. The search strategy and selection methodology are summarized in Tables 1,2.

Discussion

Use of hypochlorite in dentistry

Researchers in the field of endodontics recognized early on that the success of endodontic treatment depends on the effective removal of inorganic, organic, and necrotic debris from the root canal system. It soon became evident that endodontic instruments alone are insufficient for complete canal debridement, with approximately 35% of the canal surfaces remaining uninstrumented (4). Beyond the limitations of mechanical instrumentation, complex root canal anatomy and bacterial biofilms, particularly those located in the isthmus, pose additional challenges that necessitate adjunctive measures.

These findings highlighted the critical role of irrigation solutions in reaching both instrumented and uninstrumented areas of the canal system. For an irrigant to be effective, it must exhibit a range of specific properties; however, no single solution has yet been found to possess all the ideal characteristics. The search for the optimal irrigant continues, but a pivotal moment in this pursuit occurred in 1936, when Dr. Alfred Walker proposed the use of NaOCl in root canal therapy due to its unique and beneficial properties (5).

Properties of NaOCl

NaOCl is a colorless to pale yellow chlorine-containing solution that dissociates into sodium (Na⁺) and hypochlorite (OCl⁻) ions. In mildly acidic environments, OCl⁻ becomes protonated, forming hypochlorous acid (HOCl), the active antimicrobial agent (6). HOCl exerts its antibacterial effects by disrupting bacterial membranes, inhibiting mitochondrial metabolism, and interfering with bacterial DNA synthesis (7). Additionally, the chlorine component of HOCl impairs bacterial enzyme function and exhibits proteolytic activity through the degradation and hydrolysis of protein amino acid chains (8). These properties enable NaOCl to dissolve organic matter within the canal, such as pulpal tissue remnants and organic components of dentin, making it one of the most effective irrigants in endodontics (9).

Several factors influence the chemical efficacy of NaOCl, including exposure time, concentration, pH, solution refreshment, and the method of application. Solutions with higher concentrations, lower pH levels, and prolonged contact times, particularly when applied intermittently throughout the instrumentation, demonstrate enhanced antibacterial effectiveness (10). These variables must be carefully optimized to maximize clinical efficacy while minimizing potential cytotoxic effects.

Despite its many favorable properties, NaOCl remains a double-edged sword. The same oxidizing power that underpins its antimicrobial activity can also damage host tissues. Its ability to lyse human cells and degrade connective tissue highlights the importance of careful handling and precise delivery to avoid extrusion beyond the root canal system (2).

Mechanisms of hypochlorite accidents

A hypochlorite accident refers to the unintended contact of NaOCl with tissues outside the confines of the root canal system. This complication most commonly arises during the irrigation phase of endodontic treatment and is often associated with factors such as excessive irrigation pressure, a wedged irrigation needle, or compromised anatomical barriers (11,12). The literature describes three primary types of hypochlorite accidents: (I) spillage onto intraoral or extraoral soft tissues; (II) extrusion into anatomical spaces such as the maxillary sinus or facial spaces; and (III) most commonly, infusion beyond the apical constriction into the periapical tissues (11).

Spillage onto intraoral and extraoral soft tissues

NaOCl can enter the head and neck region through various accidental routes. The most common route is direct contact with the skin or oral tissues, where it can cause corrosive injury leading to severe burns, blistering, and, in some cases, permanent scarring. Exposure to the eyes presents a more serious risk; contact with ocular tissues may result in irreversible damage and potential blindness. Ingesting NaOCl, although rare, can cause significant irritation and inflammation of the alimentary canal and may induce the vomiting reflex (13).

Extrusion into anatomical spaces such as the maxillary sinus and facial spaces

Extrusion of NaOCl into the maxillary sinus has been documented in numerous cases, often resulting from a failure to assess patient-specific risk factors; an aspect that will be further discussed in this paper. Such inadvertent leakage of irrigant into the sinus can lead to a wide range of clinical outcomes, from asymptomatic presentations to severe complications, including burning sensations, profuse bleeding, and pain significant enough to require hospitalization (11,12). A hallmark sign of this type of accident is the perception of a chlorine-like odor in the pharynx, originating from the nasal region. Radiographic evidence may reveal a lack of sinus cortication on cone-beam computed tomography (CBCT), along with the presence of inflammatory cells within the sinus cavity. If not promptly recognized and managed, this condition may progress to infection and tissue necrosis, potentially affecting surrounding soft tissues and neural structures, resulting in swelling and sensory disturbances such as paresthesia or anaesthesia (11).

Infusion beyond the apical constriction and into the periapical tissue

Extrusion of NaOCl beyond the apical foramen is the most frequently reported type of hypochlorite accident. It is commonly associated with improper irrigation techniques, such as inserting the needle too far apically and applying excessive pressure during irrigation (11,12). Notably, the severity of tissue damage is not necessarily proportional to the volume extruded; even as little as 0.5 mL can cause significant inflammation and necrosis of the surrounding tissues (14). In some cases, the resulting soft tissue damage may present externally as ecchymosis, radiating from the site of extrusion.

Figure 1 illustrates the various modalities through which a hypochlorite incident can occur (11).

Figure 1 The principal modalities through which a hypochlorite incident can occur during endodontic irrigation. These include (I) spillage onto intraoral and extraoral tissues; (II) extrusion into anatomical spaces such as maxillary sinus and fascial spaces; and (III) infusion beyond the apical constriction into the periapical tissues (11).

The consequences of NaOCl extrusion beyond the apical foramen can be classified into three categories based on the nature and extent of tissue involvement (15):

• Chemical injury: characterized by chemical burns, intense pain, soft tissue necrosis, and swelling;
• Neurological damage: involves injury to branches of the trigeminal and facial nerves, potentially leading to sensory and motor deficits;
• Airway compromise: although extremely rare, upper airway obstruction is a possible and life-threatening complication that requires immediate emergency intervention.

Hypochlorite accidents occurring via the aforementioned three modalities can lead to local symptoms and sequelae, but in some instances, the effects may extend beyond the immediate site of irrigant application. The clinical manifestations in affected regions can vary widely, ranging from no complications to severe burning, pain, and edema, some of which may necessitate surgical intervention. In more serious instances, long-term or permanent outcomes such as paresthesia, anesthesia, and soft tissue necrosis may occur. Figure 2 showcases a clinical case where the patient was seen 4 days after a hypochlorite accident where the presence of ecchymosis extending from the orbital region towards the neck area can be clearly observed. Fortunately, in most cases, symptoms and clinical manifestations tend to resolve over the course of several weeks (11). Regular follow-up is essential to monitor the patient’s condition and to facilitate timely referral if surgical management becomes necessary. These clinical presentations and associated symptoms will be further explored in subsequent sections of this review.

Figure 2 The facial involvement associated with hypochlorite injury, which includes periorbital ecchymosis that extends to the corner of the mouth, angle of the mandible and reaching the neck region. This picture was taken 4 days after a hypochlorite accident. Clinical photos are courtesy of Dr. Jarom Ray. This image is published with the patient’s consent.

Risk factors

Certain risk factors can increase a patient’s susceptibility to hypochlorite accidents, and it is essential for clinicians to be aware of them in order to perform thorough risk assessments before initiating endodontic treatment. These factors can be broadly categorized into four groups: patient-specific, tooth-specific, irrigant-specific, and operator-specific (1).

Patient-related risk factors include age, gender, medical and dental history, and the degree of alveolar bone calcification. Studies suggest that female patients may be more prone to hypochlorite accidents, potentially due to lower bone density. An alternative explanation may lie in higher dental care-seeking behavior among females, possibly leading to an overrepresentation in reported cases (16).

Age also plays a significant role. Younger patients with open apices are more susceptible to irrigant extrusion, as the immature root anatomy provides an easier path to the periapical tissues (17). Conversely, older patients often present with more complex medical histories and reduced host defenses, which may exacerbate the consequences of an accident. Additionally, maxillary bone density tends to decrease with age, leaving only a thin bony barrier between the root tips and the maxillary sinus, making sinus involvement more likely. Overall, the majority of reported accidents have occurred among individuals in their 40s (18).

A patient’s medical history can further influence the severity of a hypochlorite accident. Individuals who are immunocompromised or undergoing bisphosphonate therapy are more prone to infections and complications such as osteonecrosis. Furthermore, patients with cognitive impairments or speech difficulties may be unable to communicate early symptoms of an accident, potentially delaying diagnosis and treatment. Dental history is also relevant; those with prior orthodontic treatment may have root resorption or bony windows that increase the risk of irrigant leakage into periapical tissues (1).

Tooth-related factors also influence the risk of NaOCl accidents. Primary teeth and immature permanent teeth, which often have shorter roots and open apices, are more vulnerable. In primary teeth, the emphasis on irrigation (due to challenges in mechanical instrumentation) increases the likelihood of an incident (14).

Tooth location also plays a significant role. Hypochlorite accidents are reported more frequently in maxillary teeth than mandibular teeth, and more often in posterior teeth than anterior ones. This is likely due to the thinner, more porous bone in the posterior maxilla, which commonly contains bony fenestrations (18). Small or anatomically complex teeth, such as mandibular incisors or those with cervical constrictions, are more prone to iatrogenic errors such as improper access preparation, increasing the chance of perforations and irrigant spillage. Additionally, the presence of coexisting complexity factors such as endo-perio lesions and sinus tracts may create channels for irrigant to travel beyond the periapical region (1).

The chemical form and concentration of NaOCl are critical in determining the extent of tissue damage. Studies have shown that even low concentrations (as little as 1%) and small volumes (as low as 0.5 mL) can cause significant soft tissue damage, often disproportionate to the amount extruded (1,14). Higher pH levels and the use of NaOCl in liquid form have been associated with increased cytotoxicity. As a result, some researchers have recommended using a gel formulation to reduce leakage. While the gel significantly decreases the risk of extrusion, it also limits the irrigant’s contact with the canal walls. Further research is needed to enhance gel-based formulations and delivery methods, thereby optimizing safety and efficacy (1).

Operator-related variables are perhaps the most critical and most modifiable risk factors. Clinical experience plays a significant role; studies have shown that endodontists and experienced general practitioners are less likely to encounter hypochlorite accidents compared to new graduates, who may be less familiar with the risks associated with improper handling of the irrigant (18).

Timely recognition of the accident and an appropriate referral response are crucial in minimizing tissue damage and, in extreme cases, may be lifesaving. One factor that may be overlooked is the change in patients’ sensory responses while being affected by local anesthesia. Hypochlorite incidents are more likely to go undetected when patients are under local or general anesthesia, as the primary indicator of an accident, which is patient-reported pain, may be absent. This reinforces the importance of cautious irrigation techniques in anesthetized patients (1,19).

Proper access cavity preparation and canal instrumentation are essential, not only for successful treatment outcomes but also for minimizing the risk of irrigant leakage (1,12). Lastly, proper education and understanding of the different delivery modalities can make a big difference. Accidents are most commonly associated with positive pressure irrigation techniques, which involve the use of large-diameter needles placed too deeply and applied with excessive pressure. Newer irrigation technologies, including sonic, ultrasonic, and negative pressure systems, offer more controlled delivery and help mitigate the risks associated with traditional syringe irrigation (1,20).

The purpose behind the identification of the risk factors and providing a comprehensive overview of how such factors increase the probability of hypochlorite accidents is to enable practitioners to conduct more informed patient assessments and adapt treatment protocols accordingly, ultimately enhancing patient safety and minimizing the likelihood of irrigant extrusion.

Clinical examination and identification of the presentation and symptoms of NaOCl extrusion

Extrusion of NaOCl can often occur silently, without immediate awareness by either the patient or the operator. However, there are specific signs and symptoms that clinicians should be familiar with to identify an accidental spillage and respond appropriately. The cardinal signs of an extrusion injury typically include a recent history of root canal treatment (RCT) followed by rapid onset of symptoms such as pain, swelling, and a burning sensation. It is this sudden onset that helps distinguish hypochlorite accidents from other differential diagnoses. In some cases, making this assessment can be complicated if the patient is still under the effects of local anesthesia, as any altered sensation might be attributed to the residual anesthetic effects (21).

In some scenarios, the occurrence of a hypochlorite accident might be missed during the time of the procedure, and the patient might call your office days later with a chief complaint of pain. When the patient presents to the office, a thorough history of the chief complaint should be obtained, and the patient’s pain level should be assessed using a standardized scale (21). During the medical history intake, the clinician should ask whether the patient has experienced an abnormal sense of taste or smell in the back of the throat or a history of nosebleeds. Affirmative responses to either question may suggest extrusion into the maxillary sinus. Additionally, asking the patient about any alterations in sensation in the head and neck region can help assess the possibility of nerve damage (21,22).

A thorough extraoral and intraoral examination should be carried out following the acquisition of the medical history and history of the chief complaint. Analyze the patient for signs of intraoral and extraoral swelling, asymmetries, ecchymosis, hematoma, and neurovascular deficits, which can manifest as motor and sensory deficits. Positive findings of dyspnea and dysphagia should also be noted alongside any changes to airways, breathing, to assess any potential risks to the patient’s airways. Locally surrounding the tooth that has received the RCT, patients might present with ulcerations, necrosis of tissues, and tooth and gingival tissue that might be tender to percussion (21,23). Table 3 is showcasing the steps for diagnosis and assessing the severity of a NaOCl accident. Acquiring a thorough medical history in addition to a proper clinical examination allows the clinician to assess the extent and severity of the injury to triage the patient and evaluate the need for a prompt referral if indicated. The patient is categorized based on their symptoms and clinical manifestations into mild, moderate, and severe injury; each of which has their own recommended guideline for treatment (Figure 3). The description of each category is as follows (21):

• Mild extrusion injuries are characterized by
  • pain and discomfort localized to the RCT tooth and lower is severe;
  • localized ecchymosis and swelling of less than 30 percent relative to the contralateral side of the tooth that received endodontic treatment.
• Moderate extrusion injuries are characterized by
  • pain that is more generalized and higher in severity than the preceding category;
  • ecchymosis that is no longer localized and swelling up to 50 percent relative to the contralateral side of the tooth that received endodontic treatment;
  • presence of intraoral ulceration adjacent to the RCT tooth.
• Severe extrusion injuries are characterized by
  • severe pain and discomfort;
  • ecchymosis and swelling of more than 50 percent compared to the contralateral side of the tooth that received endodontic treatment;
  • intraoral ulceration and necrosis of the tissues that extend beyond the RCT tooth;
  • oedema and compromised airways;
  • neurovascular damage, which can manifest as sensory or motor deficits.

Figure 3 Flowchart guiding clinicians in assessing the severity of a sodium hypochlorite accident and determining appropriate immediate, early, and delayed management steps. This structured approach is based on clinical presentation to support timely and effective treatment. Adapted from Farook et al., published in British Dental Journal (21). The framework has been reorganized to act as a guideline in clinical practice by consolidating symptom recognition, severity stratification, and management timelines into a single streamlined workflow. CBCT, cone-beam computed tomography; MRI, magnetic resonance imaging; NaOCl, sodium hypochlorite; RCT, root canal treatment; WHO, World Health Organization.

Emergency management and treatment protocols

Emergency management of extrusion injuries should be initiated as soon as the clinician is aware of the accident. The procedure should be stopped, and the patient should be informed. Efforts should be made so that the extruded NaOCl is either aspirated, diluted, or bled through the root canal system. Pain and swelling are initially controlled with local anesthetic, analgesics, and ice packs for the first 24 hours. Analgesic regimen most commonly described in the literature include a combination of NSAIDs, either ibuprofen or ketorolac, and acetaminophen (24). Other pharmaceutical agents are also utilized, such as antibiotics to prevent secondary infections and antihistamines and steroids to control the symptoms (11,12,21,25). Augmentin is the most commonly prescribed antibiotic for patients with no allergies; if the patient is allergic, it can be substituted with metronidazole (24,26). Periapical, panoramic, and CBCT images can be acquired to assess the cause and extent of the damage. If the patient’s airway is compromised, the patient should be sent to the emergency department. When the patient arrives at the hospital, based on the extent and severity of damage, incision and drainage, in addition to surgical debridement, may be considered when there is spread to fascial spaces and necrosis of soft and hard tissues, respectively. Despite limited reports of surgical intervention in the literature, its use for deeply embedded inflammatory tissues refractory to medication should be emphasized, as it provides direct irrigation of the injury site and facilitates drainage and healing (27). Following any form of emergency management, patient should be closely monitored, and a routine follow-up is warranted (15,21,25).

While the aforementioned strategies can be applied to all three types of extrusion injuries (mild, moderate, and severe) as immediate treatment which is defined as treatment carried out within the first 24 hours of the accident, each category has its own set of guidelines that are outlined below and is further categorized into early (treatment within the first week) and late treatment (treatment after the first week) (21). These various modalities of treatment can be found in Figure 3.

Prevention and best practices

While guidelines exist for managing and treating an extrusion injury, prevention should always be the primary focus. Preventative measures must be established and emphasized in practitioner training to minimize the risk of such incidents. Both the operator and the patient should wear protective eyewear, and the patient should be draped with a bib that adequately covers the body and clothing. The use of a well-sealed rubber dam should be considered the standard of care in all endodontic procedures, as it provides a critical barrier against potential injury. When delivering irrigants, the operator should utilize side-vented needles positioned short of the apical end, ensuring they are not wedged into the canal and that excessive pressure is avoided during injection. Two techniques frequently cited in the literature can further enhance safety: placing a rubber stopper on the needle at least 2 mm short of the apical foramen and using the index finger, rather than the thumb, to depress the plunger, as this allows for more controlled and safer delivery of the irrigant (12,21,24). Finally, awareness of patient- and tooth-specific risk factors that increase the likelihood of extrusion is essential. Recognizing these variables enables clinicians to approach treatment comprehensively, enhancing patient safety and reducing the risk of hypochlorite accidents and other complications. This is where the role of imaging should be emphasized, as thorough evaluation of preoperative images is invaluable for providing information about patient susceptibility. Limited-field-of-view CBCT images can provide information on the status of the tooth and surrounding tissues, including bony fenestrations and defects that can predispose patients to extrusion injuries. Such variations within the bone pattern are often undetectable and at times underreported in periapical radiographs (28).

Additionally, clinicians should stay current with ongoing research and advancements in technology, as new protocols and instruments can significantly improve the accuracy, control, and safety of irrigant delivery. Various innovative irrigation systems have been developed, including sonic, ultrasonic, and apical negative pressure techniques. Among these, the negative pressure system has demonstrated the most significant reduction in apical extrusion injuries. In this system, both the delivery mechanism (syringe) and the evacuation mechanism (suction) are integrated into a single apparatus. This design enables more effective canal cleaning while minimizing the risk of fluid overflow either apically or beyond the pulp chamber (29).

Remaining informed about technological developments allows clinicians to better understand the products available on the market and their mechanisms of action. With proper evaluation of their effectiveness, these innovations can be thoughtfully integrated into clinical practice to enhance both the safety and efficacy of patient care.

Ethical and legal implications

In addition to the clinical and medical ramifications of hypochlorite accidents, extrusion injuries carry significant legal and ethical considerations for clinicians. Because hypochlorite incidents are well-documented and can occur when the irrigant is mishandled, the risk of tissue damage should be disclosed to the patient during the informed consent process (30,31). Furthermore, treatment must be performed in accordance with the standard of care, most notably, the use of a rubber dam during endodontic procedures. Endodontic literature frequently cautions clinicians about potential negligence or malpractice liability if a rubber dam is not used or if proper personal protective equipment is not provided to the patient (29). Therefore, the dentist must consistently adhere to the standard of care, follow all safety protocols, remain informed about relevant risk factors and management strategies, and thoroughly document any extrusion event and its subsequent management (31).

Regarding the ethical implications of an extrusion injury, the dentist should remain mindful of the significant impact such an incident can have on a patient’s life. Complications may range from mild discomfort to facial deformity, paresthesia, or, in severe cases, airway obstruction; any of which can negatively affect the patient’s self-confidence, social life, finances, and overall well-being. In extreme cases, these outcomes may be life-threatening (24). At a minimum, the clinician must be familiar with emergency management protocols, facilitate timely referrals to specialists, and maintain consistent follow-up with the patient. Delays in care, failure to refer, or, most concerningly, concealment or failure to report a hypochlorite accident constitute negligence and professional misconduct, which can potentially lead to serious legal consequences for the practitioner (21,30,31).

Conclusions

Irrigation of the root canals with NaOCl is a routine step in endodontic treatment, aiding in the disinfection of the entire canal, particularly the areas that remain uninstrumented. Despite the development of new irrigants, NaOCl continues to be the most widely used solution due to its many unique properties, making it an irreplaceable irrigant. However, clinicians must recognize that the same properties that make NaOCl an effective irrigant can also cause significant harm to human tissues if used improperly or in unintended areas. These effects can range from minor to life-threatening, often requiring prompt and decisive action.

Educating dental students on general guidelines, safety precautions and such advancements must remain a core component of every dental school’s endodontic curriculum. Even as practicing professionals, dentists should remain aware that mishandling this material can result in serious consequences for both patient and professional practice. Remaining informed about current research and emerging technologies to ensure that they can deliver this widely sought-after treatment both effectively and safely.

This iatrogenic complication can be prevented via proper rubber dam placement, avoidance of excessive pressure, utilization of side venting needles and new irrigation technologies and a thorough and detailed patient and risk factor assessment. The occurrence of hypochlorite accidents can be attributed to various factors, but most commonly, to operator error. Early recognition of such error is essential to limit damage to the tissues and diagnostic red flags and medical history indicative of recent RCT followed by rapid onset of severe pain and swelling, ecchymosis, burning sensation an altered sense of smell and taste and sensory distribution should prompt close monitoring and immediate assessment and initiation of management in a structured manner. Close monitoring and follow-up are essential to the successful management of these accidents and at times an interdisciplinary approach is required to address the neuromotor, neurosensory and aesthetic deficits. With the advance in technology, safer irrigation modalities continue to be developed with a focus on improving resistance to extrusion and optimizing safer formulations of irrigants. Accordingly, the protocols for identification of extrusion of irrigants and guidelines for their management should remain updated and reflect the most recent techniques and devices. Through this research, clinicians can access the most up-to-date information with regards to prevention, diagnosis and management of NaOCl accidents.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the Narrative Review reporting checklist. Available at https://fomm.amegroups.com/article/view/10.21037/fomm-25-24/rc

Peer Review File: Available at https://fomm.amegroups.com/article/view/10.21037/fomm-25-24/prf

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://fomm.amegroups.com/article/view/10.21037/fomm-25-24/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

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