Minimally invasive esophagectomy, or MIE, replaces the large incisions of conventional open surgery with thoracoscopic and laparoscopic techniques, aiming to reduce trauma to the chest and abdominal wall while still removing the esophagus and reconstructing the digestive tract. Since the first reported case by Cuschieri and colleagues in 1992, the approach has spread rapidly around the world. In Japan, where esophageal cancer remains one of the more common and lethal malignancies, the proportion of esophagectomies performed minimally invasive rose from just 2 percent in 1996 to 57 percent by 2016, according to national surgical registries. That steep adoption curve reflects advances in instrumentation, the widespread uptake of the prone position for the thoracic phase, and insurance coverage introduced in 2002.

Yet esophagectomy in any form remains one of the most demanding operations in gastrointestinal surgery, and MIE demands even greater technical skill. The operation requires mobilizing the esophagus deep within the mediastinum, performing extensive lymph node dissection near the recurrent laryngeal nerves and airway, and then fashioning a new conduit from the stomach. Given these challenges, the question of whether hospitals that rarely perform the procedure achieve comparable results has been a persistent concern for surgeons and policymakers alike.

The scientific lineage of the volume-outcome question stretches back to 1979, when Luft and colleagues first documented that surgical mortality declines as hospital case volume rises across a range of procedures. Begg and colleagues focused specifically on esophagectomy in 1998, followed by Swisher, van Lanschot, and Birkmeyer, each using different volume thresholds but each reaching the same directional conclusion: the lowest-volume hospitals consistently posted the highest death rates. Japanese investigators, including Kazui and later Nishigori, confirmed similar patterns in national data. What remained unknown was whether these findings, based on open surgery or mixed populations, applied to MIE performed exclusively.

To answer that question, the research team turned to the National Clinical Database, a rigorously audited nationwide registry developed in cooperation with Japan’s surgical board certification system. The database enforces standardized definitions of morbidity and mortality and maintains continuous data verification. The investigators included patients with thoracic esophageal cancer who underwent transthoracic subtotal esophagectomy with reconstruction, defining MIE as either a totally thoracoscopic and laparoscopic approach or a hybrid combining thoracoscopy with open laparotomy. Of the 22,712 eligible cases, 9,739, or 42.9 percent, were performed minimally invasively.

Hospitals were stratified into five categories by their average annual esophagectomy volume, counting both open and minimally invasive operations to capture total institutional experience: very low (1 to 5 cases per year), low (6 to 10), medium (11 to 20), high (21 to 40), and very high (41 or more). The distribution was heavily skewed. Nearly three quarters of all hospitals fell into the very low category, while only 26 institutions performed 41 or more esophagectomies annually. Meanwhile, MIE adoption rose steadily with volume, from 27.9 percent of operations at very low-volume hospitals to roughly 45 to 50 percent at the higher-volume tiers, suggesting that minimally invasive techniques concentrated early in busier centers.

The raw outcomes were unambiguous. Overall operative mortality for MIE across the study period was 2.1 percent, but it ranged from 1.2 percent at very high-volume hospitals to 3.9 percent at very low-volume centers. After adjusting for patient age, comorbidities, American Society of Anesthesiologists class, preoperative therapy, and tumor stage using hierarchical logistic regression, patients at very low-volume hospitals faced 2.70 times the odds of death compared with those at very high-volume hospitals, a difference that was highly statistically significant. Medium-volume hospitals also showed a modest but significant elevation in risk, with an odds ratio of 1.70, while the differences at low and high-volume hospitals did not reach statistical significance.

Intriguingly, the overall complication rate, which averaged 40.9 percent, varied far less across hospital tiers, from 38.7 percent at the busiest centers to 44.2 percent at the least busy, and the adjusted analysis found no significant volume effect on total complications. This dissociation between complications and mortality points toward what surgical health services researchers call failure to rescue: the capacity of an institution to recognize and effectively manage a complication once it arises. Prior work by Abdelsattar and colleagues found that 21.2 percent of patients with major complications died before discharge at low-volume hospitals, compared with 13.4 percent at high-volume hospitals, a gap attributed to differences in evidence-based care processes and structural resources such as dedicated surgical intensive care units and multidisciplinary teams.

The complication-specific analyses sharpened this picture. Anastomotic leakage, one of the most feared complications of esophageal reconstruction, was significantly more likely at very low-volume hospitals, with an adjusted odds ratio of 2.23 relative to very high-volume centers, and remained elevated at both low and high-volume tiers. Atelectasis was also significantly more common at very low-volume hospitals. By contrast, rates of postoperative pneumonia, recurrent laryngeal nerve paralysis, and chylothorax showed no significant volume association, hinting that the core technical execution of MIE has become fairly standardized across Japan. Consistent with that interpretation, operative time and intraoperative blood loss were broadly similar across hospital tiers, while postoperative length of tellingly fell from a median of 30 days at very low-volume hospitals to 21 days at very high-volume centers, a difference the authors attribute partly to more effective perioperative management.

The study period itself was a deliberate choice. Between 2012 and 2015, Japanese esophageal surgery was undergoing its steepest transition toward minimally invasive techniques, with institutional experience varying enormously. The authors argue this transitional window makes the volume effect especially visible. Their analysis also situates the findings within an international debate over volume thresholds. The Leapfrog Group in the United States progressively raised its recommended minimum to 20 esophagectomies per year by 2018, while Japanese researcher Fujita and colleagues identified fewer than 5 cases per year as the risky threshold in an earlier national analysis, a figure closely matching the present study’s definition of very low-volume hospitals.

The implications for policy are nuanced rather than simplistic. Centralizing all MIE to a handful of high-volume centers could save lives, but it would impose geographic burdens on patients in rural regions and may be impractical in a country with a dispersed hospital network. The authors suggest alternative safeguards: paying close attention to surgeon-level volume, which Birkmeyer and colleagues showed explains nearly half of the hospital volume effect on mortality, and ensuring that operations and perioperative care are led by board-certified esophageal surgery specialists. In Japan, senior surgeons at high-volume hospitals frequently supervise less experienced colleagues, and multidisciplinary conferences may spread expertise beyond the operating surgeon, which could explain why earlier Japanese studies found hospital volume mattered while individual surgeon volume did not.

The authors acknowledge important limitations. The registry did not capture institutional factors such as hospital size, intensive care staffing, or the presence of certified esophageal surgeons, any of which could mediate the volume-outcome relationship. Long-term survival, the ultimate measure of cancer care, was not assessed, although prior meta-analytic work by Brusselaers and colleagues suggests high-volume settings confer an 18 to 25 percent survival advantage that persists even after excluding early postoperative deaths. Residual confounding from patient frailty and nutritional status also cannot be excluded despite extensive risk adjustment.

Even with those caveats, the central message lands with force. Patients facing minimally invasive esophagectomy at hospitals that perform the operation only a handful of times a year, roughly once every two to three months, carry a substantially elevated risk of dying from the procedure itself. As minimally invasive esophagectomy continues its global march toward becoming the default approach for esophageal cancer, this study of nearly ten thousand Japanese patients offers a data-driven benchmark: somewhere around five cases a year, institutional experience appears to cross a line separating acceptable outcomes from avoidable deaths.

Subject of Research: The relationship between hospital surgical volume and postoperative outcomes of minimally invasive esophagectomy for esophageal cancer

Article Title: Relationship Between Hospital Volume and Outcomes of Minimally Invasive Esophagectomy for Esophageal Cancer: Analysis of the National Clinical Database in Japan

Article References: Ozawa, S., Kumamaru, H., Kitagawa, Y., Koyanagi, K., Oguma, J., Udagawa, H., Miyata, H., Toh, Y., & Matsubara, H. (2026). Relationship Between Hospital Volume and Outcomes of Minimally Invasive Esophagectomy for Esophageal Cancer: Analysis of the National Clinical Database in Japan. Annals of Gastroenterological Surgery, 10(5), 1518-1526. https://doi.org/10.1002/ags3.70229

Image Credits: AI Generated

DOI: 10.1002/ags3.70229

Keywords: esophageal cancer, minimally invasive esophagectomy, hospital volume, surgical mortality, National Clinical Database, failure to rescue, anastomotic leakage, postoperative complications, thoracic surgery, Japan, volume-outcome relationship, surgical outcomes