Since their widespread adoption in the late 1990s, self-expandable metal stents (SEMS) have become the cornerstone of palliation for malignant esophageal obstruction. Over the past three decades, refinements in stent design, deployment techniques, and peri-procedural care have further improved outcomes and expanded indications beyond malignant strictures to include tracheoesophageal fistulas and extrinsic malignant compression. Consequently, current guidelines recommend partially or fully covered SEMSs as the preferred modality for palliation of malignant dysphagia [1].

Although historically, most attention has focused on immediate symptom relief and short-term procedural outcomes, improvements in systemic therapy and recent advances have gradually altered the natural history of advanced esophageal cancer. An increasing number of patients are surviving long enough to experience delayed stent-related complications that previously may have failed to manifest. Recurrent dysphagia following SEMS placement, seen in roughly one-third of patients, has traditionally been attributed to tumor ingrowth, tumor overgrowth, stent migration, or food bolus impaction [2,3,4]. Consequently, when patients present with late-onset dysphagia after an initially successful stent placement, progressive malignancy is often assumed to be the most likely explanation. Though this assumption is understandable, given the palliative setting in which these devices are commonly used, it risks overlooking an important subgroup of patients in whom recurrent obstruction is not caused by tumor progression but by benign tissue responses to the stent itself.

The study by Nakamatsu et al. [5] revisits an aspect of esophageal stenting that has received relatively little attention in recent years. In their retrospective cohort of patients undergoing SEMS placement for malignant esophageal stenosis or fistula, epithelial hyperplasia emerged as the most common cause of late stent obstruction. Although benign tissue overgrowth has been reported previously, the study by Nakamatsu et al. refocuses attention on this underrecognized cause of stent dysfunction. Among the twelve patients who developed stent dysfunction, seven had obstruction related to epithelial hyperplasia, exceeding the number attributed to tumor overgrowth. Although the number of events is relatively small, the observation is noteworthy since it challenges conventional assumptions regarding the mechanisms of recurrent dysphagia after SEMS placement. This study also highlights that among patients with re-obstruction, epithelial hyperplasia was the foremost reason.

The concept of benign tissue overgrowth causing stent dysfunction is not new. More than two decades ago, studies demonstrated that benign tissue overgrowth, including granulation tissue and epithelial hyperplasia, accounted for a substantial proportion of stent obstruction events [6, 7]. Despite these early observations, subsequent research largely focused on stent migration, tumor-related obstruction, and technological refinements in stent design. As a result, benign tissue responses remained relatively understudied and rarely became a central focus of investigation. Tissue hyperplasia has been reported in up to one-third of patients, although estimates vary according to follow-up duration and patient survival [8].

The mechanisms underlying epithelial hyperplasia remain incompletely understood. Chronic mechanical irritation at the stent margins, repetitive mucosal injury, local inflammatory responses, and wound-healing pathways likely all contribute. Similar tissue responses were described following stent placement elsewhere in the gastrointestinal tract as well as in vascular interventions. Nevertheless, despite decades of SEMS use, reliable predictors of hyperplastic obstruction remain poorly defined. Notably, neither the current study nor previous reports have consistently demonstrated associations with stent design, covering characteristics, or prior treatment strategy. Although a prior study suggested that fully covered SEMSs may be associated with a lower risk of recurrent dysphagia, tissue hyperplasia and tumor overgrowth were not analyzed separately [3]. Additional prospective studies are needed before definitive conclusions regarding stent-related risk factors can be drawn.

From a practical perspective, the findings have important implications for clinical management. Recurrent dysphagia after SEMS placement should not automatically trigger repeat coaxial stenting or be assumed to represent disease progression. Careful endoscopic evaluation remains essential since management depends on the underlying mechanism of obstruction. Endoscopic evaluation with tissue sampling, when feasible, remains important for distinguishing malignant obstruction from benign tissue overgrowth.

The clinical significance of these findings extends beyond simply identifying another cause of recurrent dysphagia. Accurate differentiation between epithelial hyperplasia and malignant obstruction has direct therapeutic implications. Tumor-related obstruction often prompts repeat stenting, oncologic reassessment, or modification of systemic therapy. Hyperplastic tissue may frequently be managed with endoscopic balloon dilatation, ablation, or resection techniques while preserving the existing stent, although repeat stenting may occasionally be required. Improved recognition of this entity therefore has the potential to reduce unnecessary interventions while facilitating a more individualized approach to managing recurrent dysphagia. In the present study, several patients were successfully managed with endoscopic mucosal resection, cold-snare resection, and snare-tip soft coagulation [5]. These interventions restored luminal patency while preserving the existing stent, thereby avoiding the technical challenges, increased morbidity, and additional costs associated with stent-in-stent placement. Similar success has also been reported with argon plasma coagulation and other ablative techniques. The requirement for repeat intervention in several patients with tissue hyperplasia highlights the importance of careful clinical follow-up after diagnosis. More importantly, the study raises broader questions regarding the biological determinants of long-term stent patency and future directions in stent development.

An important implication of the findings by Nakamatsu et al. is that late stent failure should no longer be viewed solely as a mechanical problem. While considerable effort has been devoted to improving radial force, reducing migration, and preventing tumor ingrowth, comparatively less attention has been directed toward the biological interaction between the stent and the esophageal wall. The predominance of epithelial hyperplasia observed in the current study highlights the importance of this host response. Experimental investigations have demonstrated that modulation of local inflammation and wound-healing pathways may substantially reduce tissue proliferation after stent placement. As the authors have discussed, in animal models, transforming growth factor-β pathway inhibition, silver nanoparticle-coated stents, and nanofunctionalized thermal stent systems have all suppressed granulation tissue formation and hyperplastic tissue growth. Collectively, these observations support a growing view that long-term stent patency may ultimately depend as much on controlling the biological response to an implanted device as on optimizing stent design itself. As patients with advanced esophageal cancer continue to live longer, strategies aimed at minimizing tissue hyperplasia may become increasingly relevant in extending functional stent durability and reducing the need for repeat interventions. Whether such approaches can reduce clinically significant epithelial hyperplasia in human subjects remains uncertain, but they represent an intriguing area for future investigation.

The authors should be commended for drawing attention to an underrecognized cause of late stent dysfunction and for providing detailed endoscopic characterization of obstruction events. Several strengths of the study deserve emphasis. The authors address a clinically relevant but often overlooked cause of late stent dysfunction in a real-world cohort and highlight a potentially treatable mechanism of recurrent dysphagia that may otherwise be mistaken for tumor progression. Importantly, the diagnosis of epithelial hyperplasia was supported by histopathologic confirmation in representative cases, lending credibility to the endoscopic characterization of this entity. By focusing on the histopathologic basis of stent obstruction, the study broadens the current understanding of late SEMS failure beyond traditional mechanical and tumor-related explanations.

Nevertheless, several limitations warrant consideration. The retrospective single-center design, heterogeneous patient population, and relatively small number of obstruction events limit the precision of incidence estimates and preclude robust identification of risk factors. In addition, the cohort spans a prolonged study period that predates many contemporary advances in systemic oncologic therapy, potentially affecting the generalizability of the findings to current practice. Although histopathologic confirmation was obtained in representative cases, subsequent diagnoses were frequently based on characteristic endoscopic appearances, which may have introduced some degree of diagnostic uncertainty. Furthermore, because only patients who survived long enough could develop late obstruction, survivorship bias may have influenced the apparent frequency of epithelial hyperplasia. These limitations, however, do not diminish the central observation that benign tissue hyperplasia may represent an important contributor to recurrent dysphagia after SEMS placement.

The study by Nakamatsu et al. reminds us that recurrent dysphagia is not synonymous with tumor progression and that benign tissue responses may account for a meaningful proportion of late stent dysfunction. These observations provide a foundation for a more systematic diagnostic approach to recurrent stent obstruction and highlight the need for prospective studies aimed at defining optimal management strategies. Recognizing epithelial hyperplasia as a distinct and treatable entity may influence both diagnostic evaluation and therapeutic decision-making, ultimately helping clinicians preserve stent function while avoiding unnecessary reinterventions (Fig. 1). More broadly, this study underscores that successful long-term stent function depends not only on preventing tumor-related obstruction but also on understanding and modulating the host response to implanted devices.

Current and emerging paradigms in the evaluation and management of recurrent dysphagia after esophageal self-expandable metal stent placement