Global research trends in heterotaxy syndrome with congenital heart defects: a 20-year bibliometric analysis (2006–2025)

Introduction

Heterotaxy syndrome (HS) is a rare congenital disorder characterized by an abnormal arrangement of the thoracic and abdominal organs along the left-right body axis (1,2), with an estimated incidence of approximately 1 per 10,000 live births (3). Early observations of coexisting congenital cardiac malformations and splenic anomalies were reported as early as 1826 (4,5). Subsequently, Ivemark (6) defined this constellation of anomalies as a syndrome characterized by visceral symmetry. Later morphological studies in the 1960s revealed that patients with asplenia and polysplenia exhibited bilateral atrial isomerism, shifting the research focus from splenic status to atrial appendage morphology (7-9). In recent decades, the term “heterotaxy” has been increasingly adopted to emphasize the developmental basis of abnormal left-right axis patterning.

Based on atrial appendage morphology, HS is typically classified into right atrial isomerism (RAI) and left atrial isomerism (LAI). RAI is characterized by bilateral right atrial appendages with broad, triangular morphology and is often accompanied by right-sided thoracoabdominal features, such as bilateral trilobed lungs, bilateral eparterial bronchi, and asplenia (10). LAI is defined by bilateral left atrial appendages with elongated, narrow morphology and is commonly associated with bilateral bilobed lungs, bilateral hyparterial bronchi, and multiple dysplastic spleens (10). HS is frequently associated with complex congenital heart defects marked by substantial anatomical heterogeneity, which complicates clinical diagnosis and management and imposes a significant health burden on affected children (11). The severity of cardiac malformations is the primary determinant of mortality and morbidity in patients with HS (12).

Although advances in diagnostic techniques and surgical management have improved overall survival in children with HS, postoperative complications remain common, and long-term outcomes continue to be suboptimal, posing persistent challenges for clinical management and follow-up. Owing to the rarity of HS, most of the available studies have been limited to case reports or small retrospective cohorts. To date, the overall research landscape and evolving trends in this field have not been systematically characterized. Bibliometric analysis provides a quantitative approach to examining knowledge structures, research priorities, and evolutionary patterns within a given field (13,14). Therefore, we conducted a bibliometric and visualization analysis of research on HS with congenital heart defects over the past two decades to characterize its research landscape, identify emerging themes, and clarify future directions. We present this article in accordance with the BIBLIO reporting checklist (available at https://tp.amegroups.com/article/view/10.21037/tp-2026-0393/rc).

Methods

Data source

Due to its broad multidisciplinary coverage, inclusion of high-impact journals, and availability of comprehensive metadata for citation analysis and collaboration network construction, the Web of Science Core Collection (WoSCC) was selected as the primary data source for this bibliometric study. All data were retrieved on January 5, 2026. The search was conducted in the fields of title, abstract, author keywords, and Keywords Plus. The time span was restricted to publications from January 1, 2006 to December 31, 2025. Records from clearly unrelated research areas (e.g., chemistry, physics, and engineering) were excluded using Web of Science research area filters. Subsequently, two investigators (M.Z. and X.C.) independently screened the titles and abstracts of the remaining records, with full-text review performed when necessary. Document types such as meeting abstracts, editorial materials, letters, conference proceedings, dissertations, and news reports were removed, and duplicate records were excluded. In cases of disagreement, a third investigator (L.W.) participated in the discussion to reach consensus on the final selection of studies. The overall workflow of the bibliometric analysis is illustrated in Figure 1. After removing duplicates, the remaining records were exported in plain text format with full records and cited references.

Figure 1 Flowchart of the literature screening process.

Statistical analysis

In this bibliometric study, CiteSpace (v.6.4.R1) and VOSviewer (v.1.6.20) were employed for network construction and visualization. CiteSpace was used to generate and analyze knowledge networks based on bibliographic data, including keyword co-occurrence, citation and co-citation analysis, bibliographic coupling, and collaboration networks at the country, journal, author, and individual publication levels (15). VOSviewer was used to visualize collaboration and influence patterns among countries and institutions. The R package Bibliometrix was used to calculate publication counts, journal distributions, and local citation metrics. Journal impact factors (IFs) were obtained from the 2024 edition of the Journal Citation Reports (JCR). In CiteSpace, the time span was set from 2006 to 2025, with one year per slice. Unless otherwise specified, selection criteria parameters were set as link retaining factor (LRF) =2.5, links per node (L/N) =10, look-back years (LBY) =5, and e =1.0. The g-index was used as the node selection criterion, with k values adjusted according to the specific objectives of each network analysis. Pruning methods were selected according to the objectives of different network analyses. Detailed parameter settings for each type of CiteSpace network analysis are presented in the corresponding figure legends. Cluster labels were generated using the log-likelihood ratio (LLR) algorithm. Betweenness centrality was used to evaluate the importance of nodes within the network, with higher values indicating a stronger bridging role between different research areas. All other parameters were kept at their default settings.

Results

Annual publications

A total of 8,854 records were retrieved from the WoSCC database. After applying the inclusion and exclusion criteria, 493 articles were included in this bibliometric analysis. As shown in Table 1, these publications were distributed across 184 journals between 2006 and 2025, involving 2,548 authors, with an average of 5.16 authors per article, indicating a predominantly collaborative research pattern. The mean number of citations per article was 14.07. The annual distribution of publications from 2006 to 2025 is shown in Figure 2. The annual output fluctuated during 2006–2015 and remained modest. Publication output increased markedly from 2021, reaching a peak in 2022, followed by a modest decline in subsequent years. Table 2 lists the top 10 most cited articles in HS research ranked by total citations. The article by Kennedy MP, published in Circulation (16), had the highest total citation count (n=302). These studies covered topics such as primary ciliary dyskinesia (PCD), prenatal diagnosis of congenital heart disease, laterality defects, and outcomes following the Fontan procedure.

Figure 2 Annual publication trends in heterotaxy syndrome research.

Country and regional collaboration

Figure 3 and Table 3 illustrate the global distribution of publications on HS research encompassing 53 countries and regions. The United States ranked first in publication output (n=169) and showed a relatively high centrality value (0.19), indicating its prominent position within the field. Japan (n=79) and China (n=51) contributed a large number of publications; however, research in these countries remained relatively independent within the collaboration network, with centrality values of 0. In contrast, the United Kingdom exhibited the highest centrality value (0.55), followed by Italy (0.26), Canada (0.22), and Germany (0.21), with stronger connectivity within the collaboration network.

Figure 3 Global distribution and collaboration network of countries/regions in heterotaxy syndrome research. (A) Global distribution of publications by country/region; (B) centrality map of country/region collaboration.

Institutions collaboration

The included publications involved a total of 666 institutions. As shown in Table 4 and Figure 4A, Harvard Medical School (n=20) and Boston Children’s Hospital (n=20) ranked first in publication output, followed by Newcastle University (n=16) and the Children’s Hospital of Wisconsin (n=14). Figure 4B shows the clustering structure and collaboration patterns among institutions, in which five major clusters were identified. In terms of network centrality, Newcastle University (0.17) and Cincinnati Children’s Hospital Medical Center (0.12) showed relatively high centrality values. The temporal overlay (Figure 4C) showed that Harvard Medical School demonstrated relatively higher publication activity in recent years.

Figure 4 Institutional contribution and collaboration network in heterotaxy syndrome research. (A) Institutional network showing publication volume and time distribution; (B) institutional collaboration map showing structure and strength of cooperation; (C) time-evolution of institutional collaboration.

Author and co-citation analysis

Among all the authors contributing to HS research, Table 5 lists those with the highest publication output. Anderson RH ranked first with 19 publications, followed by Loomba RS (n=8) and Hirose K (n=6). The author collaboration network was visualized using CiteSpace (Figure 5A,5B), which identified 11 collaborative groups forming several distinct clusters. In the co-citation analysis (Table 5 and Figure 5C,5D), Jacobs JP ranked first with 113 citations, followed by Uemura H (75 citations), and Anderson RH (67 citations), indicating their strong academic influence in this field. Notably, Berg C showed the highest centrality value (0.19), followed by Jacobs JP (0.16), suggesting their important role within the co-citation network.

Figure 5 Author collaboration patterns and their temporal evolution. (A) Author collaboration network; (B) author collaboration clusters; (C) temporal evolution of author collaborations; (D) author co-citation clusters.

Reference co-citation and citation burst analysis

Reference co-citation analysis identified nine major clusters representing the intellectual structure of HS research (Figure 6A). The largest clusters were the genetic aspect, multistage palliation, neonatal assessment, and right isomerism. These clusters indicate that the knowledge base of HS research is primarily centered on genetic factors, anatomical and phenotypic characterization, and the management of complex congenital heart disease. Reference burst analysis demonstrated a clear evolution of research priorities in HS (Figure 6B). Early burst references mainly focused on prenatal diagnosis, anatomical characterization, and surgical palliation, represented by the studies of Berg et al. (26), Kim et al. (27), and Anagnostopoulos et al. (28). Subsequent burst references reflected increasing attention to long-term outcomes following Fontan palliation, which has remained a major research focus, as represented by Pundi et al. (29), Baban et al. (30), and Alsoufi et al. (31). More recent burst references indicate growing interest in the genetic basis of HS and arrhythmia management, alongside continued attention to long-term clinical outcomes.

Figure 6 Reference co-citation and citation burst analysis. (A) Reference co-citation clusters; (B) top 25 references with the strongest citation bursts.

Journal analysis

The journals with the highest publication outputs are listed in Table 6. Cardiology in the Young ranked first with 44 publications, followed by Pediatric Cardiology (n=41), Annals of Thoracic Surgery (n=25), Journal of Cardiac Surgery (n=17), and Congenital Heart Disease (n=15). Among these journals, several high-impact journals were also identified, including Journal of Thoracic and Cardiovascular Surgery (IF =4.4, Q1), Annals of Thoracic Surgery (IF =3.9, Q1), and Heart Rhythm (IF =5.8, Q1). Notably, Ultrasound in Obstetrics & Gynecology had the highest IF (IF =6.3, Q1) among the included journals. The thematic distribution of academic publications was visualized using a dual-map overlay (Figure 7). The left and right sides represent citing journals and cited journals, respectively, while the colored trajectories indicate citation relationships across research domains. One major citation pathway was identified, suggesting that publications originating from the “Medicine, Medical, Clinical” domain primarily cited literature within the “Health, Nursing, Medicine” domain. This pattern indicates that HS research is largely rooted in clinical medicine and healthcare-related disciplines.

Figure 7 Dual-map overlay of journal citation pathways in heterotaxy syndrome research.

Keyword and cluster analysis

Table 7 lists the top 20 most frequent keywords in HS research. “Congenital Heart Disease” (n=145) and “Heterotaxy Syndrome” (n=141) ranked highest in frequency. Other highly frequent keywords reflected major research areas including anatomical classification, splenic phenotypes, surgical management, and clinical outcomes. In terms of betweenness centrality, “Asplenia Syndrome” and “Malformations” exhibited the highest centrality values (0.12), followed by “Heterotaxy Syndrome” (0.09) and “Atrial Isomerism” (0.08). The keyword co-occurrence network (Figure 8A) revealed close associations among terms related to anatomical classification, surgical management, and clinical outcomes. Clustering identified eight major thematic areas, including atrial appendage, laterality defects, pulmonary hypertension, surgical results, double outlet right ventricle, potential prognostic markers, perinatal outcomes, and Fontan procedure (Figure 8B). The timeline visualization (Figure 8C) demonstrated the temporal evolution of research topics. Earlier studies mainly focused on anatomical and phenotypic descriptors, such as atrial appendage morphology, atrial isomerism, and asplenia syndrome. Surgical-related topics, particularly those associated with Fontan circulation and operative management, were represented across multiple periods of the study timeline. In more recent years, keywords such as “genetics”, “variants”, “de novo mutations”, “follow up”, and “survival” appeared, indicating increasing attention to genetic factors and long-term outcomes in HS. The thematic map (Figure 8D) further highlights the developmental status and relevance of research themes. The x-axis represents centrality, indicating a theme’s importance within the field, while the y-axis represents density, reflecting the maturity of the theme. Themes such as “heterotaxy”, “left-right asymmetry”, and “prevalence” were located in the motor themes quadrant, suggesting that they represent well-developed and influential research topics. In contrast, themes including “prenatal diagnosis”, “outcome” and “management” were classified as basic themes, indicating important areas that continue to evolve within HS research.

Figure 8 Keyword analysis of heterotaxy syndrome research. (A) Keyword co-occurrence network; (B) keyword cluster map; (C) keyword thematic evolution over time; (D) thematic map.

Keyword burst analysis identified the temporal dynamics of research hotspots in HS (Figure 9). Early burst keywords (2006–2010) included “Modified Fontan Operation”, “Anastomosis”, and “Malformations”, reflecting an initial focus on anatomical characterization and surgical strategies. Subsequently, research attention expanded toward long-term follow-up, cardiac rhythm, and genetic mechanisms, as indicated by burst keywords such as “Cardiac Rhythm”, “Atrial Appendages”, “Follow Up”, and “Genetics”. More recent burst keywords, including “Survival”, “Variants”, “Surgical Management”, “Primary Ciliary Dyskinesia”, and “Congenital Heart Disease”, reflect growing interest in genetic factors and continued attention to long-term prognosis and clinical management.

Figure 9 Top 25 keywords with the strongest citation bursts in heterotaxy syndrome research.

Discussion

HS is a rare and complex congenital disorder characterized by multisystem involvement and is frequently associated with complex congenital heart disease. Its marked phenotypic heterogeneity and intricate anatomy pose substantial challenges for surgical and perioperative management. Despite advances in treatment strategies, long-term outcomes remain suboptimal. In this context, this bibliometric study systematically mapped the HS research landscape over the past two decades to delineate its development trajectory and emerging trends.

General information

Over the past two decades, research activity in HS has steadily increased, with publication output rising markedly after 2021 and peaking in 2022. This trend reflects growing interest in this rare and complex condition. Improvements in prenatal imaging have supported a growing body of research on prenatal diagnosis and perinatal outcomes. At the same time, advances in surgical techniques and perioperative care have enhanced survival among patients with HS, enabling longer-term follow-up and prognostic evaluation. In addition, increasing recognition of the role of ciliary dysfunction and laterality-related developmental mechanisms has promoted research into the genetic and molecular basis of HS. Collectively, these developments have broadened the scope of HS research, leading to a gradual shift from anatomical characterization and phenotypic classification toward perinatal outcomes, prognostic assessment, long-term management, and genetic mechanisms.

From a global perspective, the United States plays a leading role in HS research, reflecting its strengths in resource integration, international collaboration, and knowledge dissemination. This dominance is likely related to the well-established congenital heart disease care system and the sustained research investment. Japan and China also contributed substantially to publication output, but showed relatively limited participation in the global collaboration network. Overall, international collaboration remains concentrated in North America and Europe, with increasing involvement from Asian countries. At the institutional level, research activity is largely concentrated in major pediatric cardiology and congenital heart disease centers. Institutions such as Harvard Medical School and Boston Children’s Hospital occupy prominent positions within the collaboration network, highlighting the advantages of specialized centers in case aggregation and collaborative research. Although this pattern is not unexpected for a rare disease such as HS, it may also reflect an imbalance between research capacity and the global clinical burden of the disease. Research activity is predominantly concentrated in high-resource regions with advanced prenatal diagnosis, surgical techniques, and specialized care systems. These regions contribute a large proportion of publications owing to better case aggregation, comprehensive diagnostic and therapeutic capabilities, and stronger research infrastructure. In contrast, low-resource regions may have a larger number of patients but limited access to systematic diagnostic evaluation, surgical interventions, and research opportunities. Consequently, the current research landscape may not fully represent the global burden and diversity of HS. These findings highlight the importance of stronger international collaboration and multicenter research networks to generate higher-quality evidence, facilitate validation across different populations, and further improve the understanding and management of HS.

At the author level, Anderson RH ranked first in publication output, while Jacobs JP was the most highly co-cited author, reflecting their central role in knowledge production and intellectual influence. The co-citation structure suggests that HS research is shaped by a relatively concentrated group of key contributors, a pattern commonly observed in rare disease research. Despite the dominance of a few highly productive authors, the presence of multiple research groups indicates increasing diversity and considerable potential for further development of the field.

The most highly cited article was published by Kennedy et al. in Circulation (2007), entitled ‘Congenital heart disease and other heterotaxic defects in a large cohort of patients with primary ciliary dyskinesia’ (16). This study systematically evaluated the prevalence of heterotaxy and associated cardiovascular anomalies in a cohort of 337 patients with PCD. It provided large-scale clinical evidence supporting the association between PCD and heterotaxy, thereby contributing to the conceptual linkage between left-right axis developmental abnormalities and ciliary dysfunction. The prominence of this article within the citation network highlights the growing importance of genetic and molecular mechanisms in HS research.

Hotspots and development trends

Keyword analysis revealed a progressive evolution of HS research from anatomical characterization and surgical management toward perinatal evaluation, long-term outcomes, arrhythmias, and genetic mechanisms. These themes reflect the major clinical challenges across the disease spectrum and provide a framework for understanding current research priorities and future directions.

Cardiac anatomy

Cluster analysis indicates that the anatomical characteristics of HS have consistently remained a central research theme. Although RAI and LAI are associated with distinct patterns of cardiac and extracardiac malformations, both subtypes may involve multiple organ systems, including the cardiovascular, bronchopulmonary, and abdominal systems. Patients with RAI frequently present with severe and complex congenital cardiac anomalies, such as single atrium, single ventricle, atrioventricular septal defects, and common atrioventricular valve, and typically exhibit early clinical onset with rapid progression (32). In contrast, the overall severity of cardiac malformations in LAI is generally lower (33). A hallmark anatomical feature of LAI is interruption of the inferior vena cava with azygos continuation to the superior vena cava, reported in approximately 60–90% of cases (33,34). These anatomical differences have important prognostic implications. RAI is generally associated with poorer outcomes and is considered one of the congenital heart disease subtypes with the worst prognosis (35). Previous studies on the natural history of HS reported first-year mortality rates exceeding 85% among patients with RAI and over 50% among those with LAI (24). Complex congenital heart disease remains one of the principal determinants of mortality and morbidity in patients with HS (12). Precise structural delineation is essential for accurate diagnosis, surgical planning, and individualized management in HS patients.

Arrhythmias and electrophysiology

Arrhythmias have emerged as an important research theme in HS because of their substantial impact on morbidity, quality of life, and long-term outcomes. Population-based studies have demonstrated a higher arrhythmia burden in HS compared with non-HS patients, accompanied by increased utilization of invasive electrophysiological procedures (36). The distinct electrophysiological characteristics of RAI and LAI provide the anatomical basis for different arrhythmic phenotypes. RAI is frequently associated with dual sinus or atrioventricular nodes, predisposing patients to supraventricular tachyarrhythmias, whereas LAI is more commonly associated with sinus node dysfunction and atrioventricular conduction abnormalities, including congenital atrioventricular block (36-40). In addition, postoperative arrhythmias remain a major concern, particularly following Fontan palliation, and HS has been identified as an independent risk factor for new-onset arrhythmias after Fontan completion (38,41). Advances in electrophysiological intervention have expanded treatment options for these patients. In a series of adults with atrial isomerism, remote magnetic navigation combined with three-dimensional electroanatomical mapping successfully treated a variety of supraventricular tachyarrhythmias, with 5 of 8 patients remaining arrhythmia-free after a median follow-up of 10 months and only limited self-terminating recurrences observed (42). As survival continues to improve, arrhythmia prevention, early detection, and long-term management are likely to become increasingly important priorities in patients with HS.

Genetic mechanisms and their clinical implications

Genetic mechanisms have become an increasingly prominent research theme in HS, as reflected by the emergence of keywords such as “genetics”, “variants”, and “de novo mutations”. HS is fundamentally a disorder of left-right axis development and exhibits marked genetic heterogeneity. Epidemiological studies suggest that most cases occur sporadically without a clear family history, highlighting the potential contribution of de novo variants (43). Rather than resulting from defects in a single gene, HS involves a complex network of genes and signaling pathways regulating laterality determination, organ asymmetry, and cardiac morphogenesis (44-46). Among these, the Nodal, Hedgehog, and canonical WNT signaling pathways are considered central regulators of left-right patterning and play critical roles in the pathogenesis of HS (44,47,48). Key genes within these pathways, including NODAL, LEFTY, and ZIC3, are essential for establishing embryonic laterality, and pathogenic variants may result in absent, delayed, or aberrant activation of left-right signaling (44). Notably, extensive crosstalk exists among these pathways, and disruption of a single pathway may interfere with the entire left-right patterning program through downstream cascade effects (49). As genomic technologies continue to advance, further elucidation of the molecular basis of HS may facilitate genetic counseling, improve risk stratification, and support the development of more individualized management strategies.

Surgical management and outcomes

Surgical management has remained a central research focus as the primary treatment modality for HS, including staged single-ventricle palliation strategies and outcome assessments. Over the past two decades, outcomes have improved substantially, reflecting advances in surgical techniques, perioperative care, and multidisciplinary management. For example, Ota et al. reported that 5-year survival among patients with RAI increased from 53.8% before 2003 to 81.7% after 2004 (50). Recent Fontan cohorts demonstrated 20-year transplant-free survival exceeding 70% (51). Similarly, recent data on the Kawashima procedure reported favorable outcomes, with no postoperative mortality and successful progression to Fontan completion in the majority of patients (52). Improvements have also been observed in neonatal surgery. Mills et al. reported an operative mortality of 9.8% following neonatal surgical repair or palliation (53). Among HS subtypes, RAI is associated with more severe cardiac malformations—including anomalous pulmonary venous connection, atrioventricular valve abnormalities, and ventricular imbalance—resulting in greater surgical complexity and generally poorer outcomes (3). Notably, several studies have shown that these prognostic differences may be mitigated following successful Fontan completion. Stamm et al. (54) and Kim et al. (27) reported no significant differences in post-Fontan survival between patients with RAI and LAI, indicating that, regardless of subtype, HS patients who successfully undergo Fontan palliation have the potential to achieve favorable long-term survival. Despite these advances, the complex cardiac anatomy, high surgical difficulty, and marked heterogeneity of HS remain major challenges. Non-cardiac manifestations, particularly immune dysfunction, ciliary dyskinesia-related pulmonary complications, and gastrointestinal abnormalities, further contribute substantially to the disease burden of HS (55,56). Postoperative reinterventions remain an area for improvement. A contemporary single-center cohort study reported that approximately half of patients required unplanned surgical or catheter-based interventions during follow-up, likely due to anatomical complexity and progression of residual lesions, particularly in those with prior valve interventions (57). These findings underscore significant progress in surgical techniques and perioperative care, while highlighting the persistent challenges inherent to this complex condition.

Historically, HS has been regarded as a risk factor for adverse surgical outcomes. However, whether HS independently predicts Fontan failure remains controversial. Earlier studies identified HS as a predictor of adverse postoperative outcomes (12), whereas more recent investigations have challenged this view, suggesting that HS itself may not independently increase the risk of Fontan failure (58). A meta-analysis further demonstrated that long-term survival following successful Fontan completion in patients with HS is comparable to that of the broader Fontan population (59). These findings suggest that although HS patients face substantial perioperative challenges, successful establishment of Fontan circulation may mitigate some of the prognostic disadvantages traditionally attributed to heterotaxy.

Despite the continued prominence of Fontan palliation in the literature, emerging strategies have attracted increasing attention in recent years. Heart transplantation has become an important option for patients with Fontan failure or end-stage congenital heart disease. Recent multicenter data demonstrated that heart transplantation in selected children with HS is associated with acceptable mid-term outcomes despite substantial anatomical and surgical complexity, highlighting its potential role in the management of advanced disease (60). While heart transplantation has received relatively limited attention in the literature, it may represent an important direction for future research and clinical practice.

Perinatal outcomes

Recent keyword timeline analyses indicate that perinatal outcomes have gradually emerged as an important research focus, reflecting growing attention to early disease assessment in HS. Both RAI and LAI are closely associated with increased neonatal morbidity and mortality (61). Therefore, early identification of cardiac and extracardiac anomalies in fetuses with HS, together with accurate assessment of their impact on postnatal outcomes, is of substantial clinical importance.

Future directions

Substantial progress has been made in understanding the cardiac anatomy and surgical management of HS. However, evidence regarding long-term outcomes and optimal management strategies remains limited, as current studies are predominantly observational and small in scale. In particular, uncertainties persist in risk stratification, timing of interventions, and long-term follow-up strategies across different HS subtypes. Future research should prioritize large-scale, multicenter prospective studies with extended follow-up. Notably, surgical management in patients with HS remains highly challenging, highlighting the importance of centralized care, early prenatal diagnosis, and more efficient referral and transport systems. Advances in genomic technologies, advanced imaging modalities, electrophysiological techniques, and evolving surgical and interventional strategies may further improve disease characterization, facilitate earlier diagnosis, optimize perioperative planning, and support more individualized management, ultimately improving long-term outcomes for patients with HS.

Limitations

This study provides a comprehensive bibliometric analysis of global research trends in HS over the past two decades. However, several limitations should be acknowledged. First, the literature search was restricted to the WoSCC databases, and only English-language publications were included, which may have introduced selection and language bias. This may have led to the underrepresentation of certain clinically relevant studies, particularly those focusing on surgical and interventional outcomes. Second, bibliometric analyses rely heavily on citation-based indicators, which are inherently time-dependent and may favor older publications because they have had more time to accumulate citations. Although average annual citations were considered, recently published studies may still not fully reflect their academic impact or emerging importance. In addition, because the literature retrieval was conducted on January 5, 2026, database indexing for publications from late 2025 may have been incomplete, which could have led to underestimation of recent publication trends and emerging research hotspots. Third, editorials, conference proceedings, and other non-article documents were excluded, which may have resulted in the omission of potentially relevant contributions. Finally, given the rarity of HS, the overall number of publications in this field remains relatively limited, which may affect the stability and generalizability of the bibliometric findings.

Conclusions

This study provides a comprehensive bibliometric analysis of HS research from 2006 to 2025. Through systematic bibliometric analysis and visualization, the global research landscape and emerging hotspots were clearly delineated. Over the past two decades, HS research has undergone substantial development, with increasing attention extending from anatomical characterization and surgical management to perinatal outcomes, genetic mechanisms, and long-term outcome evaluation. These trends reflect the expanding scope of HS research and a growing emphasis on understanding disease mechanisms and improving clinical outcomes. However, research activity and academic influence remain concentrated in a limited number of countries and specialized centers. Future efforts should aim to strengthen international collaboration and multicenter research networks, integrate multidisciplinary approaches, and generate high-quality evidence to advance the understanding and management of HS.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the BIBLIO reporting checklist. Available at https://tp.amegroups.com/article/view/10.21037/tp-2026-0393/rc

Peer Review File: Available at https://tp.amegroups.com/article/view/10.21037/tp-2026-0393/prf

Funding: This work was supported by the First Hospital of Tsinghua University Leading Talent Fund (No. 2024-YNLJ-03).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tp.amegroups.com/article/view/10.21037/tp-2026-0393/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.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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