INDIANAPOLIS – Transthoracic esophagectomy for esophageal cancer provides significantly lower in-hospital mortality and major morbidity rates than does transhiatal esophagectomy, according to an analysis of a large multiyear national database.
Further, in-hospital outcomes of esophagectomy didn’t differ significantly between high-volume centers – in this study, defined as those doing 10 or more cases per year – and low-volume centers, Dr. Mehraneh D. Jafari reported at the annual meeting of the American Surgical Association.
That finding was met with skepticism, and discussants were quick to argue that study limitations make it difficult to draw any meaningful conclusions from the data. For one thing, speakers contended that defining a high-volume center based upon an institutional threshold of 10 or more cases per year sets the bar far too low given that a single dedicated esophageal surgery specialist might easily perform 50 or more esophagectomies annually.
Dr. Jafari presented an analysis of 11,473 transthoracic and 3,717 transhiatal esophagectomies performed for esophageal cancer. The data came from the Nationwide Inpatient Sample (NIS) during 2001-2010. The NIS records data on in-hospital outcomes for a nationally representative sample composed of roughly 20% of the country’s hospital discharges each year.
The number of esophagectomies rose steadily by an average of 4% annually during the study years, reflecting the substantial national increase in cases of esophageal cancer. The growing case count, expected to reach an estimated 18,000 cases of esophageal cancer nationwide in 2013, has been attributed to rising rates of gastroesophageal reflux disease, Barrett’s esophagus, and obesity. Transthoracic esophagectomy, used in 76% of cases, remained the preferred operative strategy throughout the study years.
In-hospital outcomes were markedly better in patients who had transthoracic esophagectomy. After adjustment for potential confounding variables in a multivariate analysis, transhiatal esophagectomy recipients had a 67% increased risk of in-hospital mortality and a 39% greater risk of serious complications, including a 37% increased risk of pulmonary complications. However, anastomotic leak rates were similar with both operations, according to Dr. Jafari of the University of California, Irvine.
Of note, the referral rate to high-volume esophagectomy centers climbed steadily over time, rising from 22% of all cases in 2001 to 58% in 2010.
Dr. Michael Zinner
The 35 high-volume centers performed an average of 16 cases per year. In contrast, the 484 low-volume centers averaged 2 cases per year. In-hospital mortality among the 9,386 patients treated in low-volume centers averaged 7.6% compared with 4.3% for patients in high-volume centers. Overall in-hospital serious morbidity rates were greater in the low-volume centers as well: 47% versus 41%. While these raw differences were statistically significant, a risk-adjusted multivariate analysis found no significant outcome differences between low- and high-volume centers.
Discussant Dr. Michael J. Zinner noted that in an earlier study he and his coworkers showed that an institutional threshold of roughly 30 esophagectomies per year is required to discriminate between low- and high-volume centers in terms of in-hospital mortality. So why define high-volume centers as those doing a mere 10 cases per year? asked Dr. Zinner, chairman of the department of surgery at Brigham and Women’s Hospital and professor of surgery at Harvard Medical School, Boston.
"The problem here is if you establish 30 cases per year as the threshold for a high-volume center, I can tell you there are probably less than 20 centers in the whole U.S. capable of doing that volume. That’s a real issue, because then how are patients who live in a remote region going to get care at one of those centers?" replied Dr. Jafari’s senior coauthor Dr. Ninh T. Nguyen, professor and vice-chair of surgery at UC Irvine.
"I think instead we should try to lift all boats: develop a national esophageal center network to identify the qualities reflective of better outcomes in the high-volume centers and introduce those factors at low-volume centers. This way we’re not impeding access to care for our patients," he continued.
Dr. Nguyen said that in-hospital surgical morbidity rates in the NIS need to be taken with a grain of salt, as the accuracy of coding for complications is "rather low." The development of minimally invasive techniques for intrathoracic anastomosis has transformed transthoracic esophagectomy into a procedure with an improved complication profile.
"I switched to transthoracic esophagectomy 5 years ago. One reason was development of the minimally invasive approach. As a result, we’re not scared of a chest anastomosis like we used to be. When patients undergoing transthoracic esophagectomy with thoracotomy had a leak in the chest they had a very high risk for mortality. That’s not the case anymore. We have not observed any mortality associated with a leak in the chest for many, many years now," he said.