Early Esophageal Cancer · Journal article

Efficacy of Overtube in Preventing Aspiration Pneumonia During Esophageal Endoscopic Submucosal Dissection.

Den Open · August 11, 2026

Strong Evidence Why this matters to you Expert discussion

Well-designed and adequately powered for the question it asks.

AI Summary

In a retrospective cohort of 393 patients undergoing esophageal ESD without endotracheal intubation, non-use of an overtube was an independent risk factor for aspiration pneumonia. After propensity score matching and adjustment, the incidence of aspiration pneumonia was significantly lower with overtube use (8.1% vs 22.2%, p=0.009), with an adjusted odds ratio of 3.76 (95% CI 1.54–9.21, p=0.004).

What was studied

Retrospective cohort study with propensity score matching and inverse probability of treatment weighting. Consecutive patients undergoing esophageal ESD for early esophageal cancer. Excluded: multiple synchronous lesions on same day, repeat ESD, history of laryngectomy, or prior esophagectomy. Final analysis included 393 patients; 99 matched pairs after propensity score matching.. Intervention: Flexible overtube (MD-48518; Sumitomo Bakelite Co, Tokyo, Japan) inserted through mouth into cervical esophagus during esophageal ESD. Compared with: No overtube use during esophageal ESD. n = 393. Single institution: Department of Gastroenterology, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan.

Key findings

Aspiration pneumonia incidence 22.2% in non-overtube group vs 8.1% in overtube group (p=0.009) Multivariate analysis: non-use of overtube was independent risk factor with OR 4.21 (95% CI 1.66–10.65, p=0.002) After IPTW adjustment: non-use of overtube increased risk with OR 3.76 (95% CI 1.54–9.21, p=0.004)

Safety

Safety was not reported in the material analysed. Check the source before drawing any conclusion about harm.

Who this may help

Clinicians performing esophageal ESD without endotracheal intubation should consider routine overtube use as a preventive measure against aspiration pneumonia, which occurred in approximately 22% of cases without an overtube. The substantial risk reduction (approximately 14 percentage point absolute reduction) supports this intervention as a practical safety measure during the procedure.

Plain-language summary

Rigorous retrospective cohort study with propensity score matching and IPTW adjustment demonstrating a clear, clinically meaningful reduction in aspiration pneumonia incidence with overtube use during esophageal ESD.

Study design

As stated by the source record.

MethodsProspectively collected data from 534 consecutive patients undergoing esophageal ESD between January 2015 and May 2020 were reviewed retrospectively. Propensity score matching (1:1 ratio) and IPTW were applied to reduce selection bias and confounding regarding overtube use. Patients underwent ESD under intravenous anesthesia (pethidine hydrochloride and midazolam or propofol) without endotracheal intubation. Aspiration pneumonia was defined as new pulmonary consolidation on chest radiograph or CT with pulmonary symptoms. Multivariate logistic regression identified independent risk factors.

DesignRetrospective cohort study with propensity score matching and inverse probability of treatment weighting

PopulationConsecutive patients undergoing esophageal ESD for early esophageal cancer. Excluded: multiple synchronous lesions on same day, repeat ESD, history of laryngectomy, or prior esophagectomy. Final analysis included 393 patients; 99 matched pairs after propensity score matching.

Sample size393

InterventionFlexible overtube (MD-48518; Sumitomo Bakelite Co, Tokyo, Japan) inserted through mouth into cervical esophagus during esophageal ESD

ComparatorNo overtube use during esophageal ESD

SettingSingle institution: Department of Gastroenterology, Osaka Metropolitan University Graduate School of Medicine, Osaka, Japan

Reported figures

Quoted from the source exactly as published.

Aspiration pneumonia incidence (non-overtube group)22.2%

Aspiration pneumonia incidence (overtube group)8.1%

Overall aspiration pneumonia incidence15.2%

p-value for incidence comparison0.009

Odds ratio (multivariate analysis, non-use of overtube)4.21

95% CI (multivariate analysis)1.66–10.65

p-value (multivariate analysis)0.002

Odds ratio (IPTW-adjusted, non-use of overtube)3.76

Clinical bottom line

Caveats

Single-institution retrospective study; generalizability to other centers and patient populations uncertain
Discretionary overtube use may introduce residual confounding despite propensity matching
Severity and clinical outcomes of aspiration pneumonia according to overtube use not fully reported in source text
No endotracheal intubation used; findings may not apply to intubated patients

Evidence assessment

Graded across the dimensions that decide whether you should act, each from what the source actually supports. There is no single score, and where a dimension was not assessed it says so.

Study design

strong

Retrospective cohort with propensity score matching and IPTW adjustment to reduce bias

Directness

strong

Directly addresses prevention of aspiration pneumonia, a clinically relevant adverse event

Consistency

moderate

Single institution study; consistency with other centers not evaluated in source

Risk of bias

moderate

Retrospective observational design with discretionary overtube use; propensity matching reduces but does not eliminate confounding

Sample adequacy

strong

198 matched pairs with 15.2% overall aspiration pneumonia incidence provides adequate power

Source abstract

Objectives. Aspiration pneumonia is a potential adverse event of esophageal endoscopic submucosal dissection (ESD). Using an overtube during esophageal ESD may reduce the amount of fluid refluxing into the oral cavity and prevent aspiration pneumonia. This study aimed to clarify the preventive effects of overtubes on aspiration pneumonia during esophageal ESD.Methods. Between January 2015 and May 2020, 534 consecutive patients underwent esophageal ESD under intravenous anesthesia without endotracheal intubation at our hospital. Using propensity score matching and inverse probability of treatment weighting (IPTW), we retrospectively evaluated the risk factors and incidence of aspiration pneumonia during esophageal ESD.Results. A total of 393 patients who underwent esophageal ESD were enrolled. After matching, 99 matched pairs of patients either had an overtube used during esophageal ESD or did not. The overall incidence of aspiration pneumonia was 15.2%. The incidence of aspiration pneumonia was significantly higher in the non-overtube group than in the overtube group (22.2% vs. 8.1%; p = 0.009). Multivariate logistic regression analysis showed that non-use of an overtube was an independent risk factor for aspiration pneumonia (odds ratio [OR], 4.21; 95% confidence interval [CI], 1.66-10.65; p = 0.002). After adjustment with IPTW, non-use of an overtube also increased the risk of aspiration pneumonia (OR, 3.76; 95% CI, 1.54-9.21; p = 0.004).Conclusions. Not using an overtube was a risk factor for aspiration pneumonia during esophageal ESD. Therefore, the use of an overtube is recommended to prevent aspiration pneumonia.Trial registration. N/A.

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Shusei FukunagaEarly Esophageal CancerYasuhiro FujiwaraMitsuhiro KonoMasaki OminamiDaiki KitagawaShunsuke Takahashi