By Daniel Dunaieff
Although she hasn’t resolved the debate over the two approaches to one type of heart surgery, Laurie Shroyer, professor and vice chair of research in the department of surgery at the Renaissance School of Medicine at Stony Brook University , provided considerable information over a long period of time.
In a recent study published in JAMA surgeryShroyer, who is the principal investigator and co-PIs Fred Grover and Brack Hattler of Rocky Mountain Regional Affairs Medical Center, revealed that coronary artery bypass surgery had similar postoperative mortality rates for veterans in their study, that the surgeon used a heart-lung machine, called an “on-pump,” or performed the surgery without the machine, called an “off-pump.”
Using long-term outcomes from 2,203 mostly men at 18 VA centers in the Department of Veterans Affairs On/Off Bypass (ROOBY) randomized trial, Shroyer determined that the 10-year mortality rate was 34.2% for pump stop, versus 31.1% for pump.
Patients usually need bypass grafting when they have narrowing of their coronary arteries, which comes from the buildup of fatty material in the walls of the arteries. Doctors take a section of a healthy blood vessel from the leg, wrist, or elsewhere and bypass the blockage, creating a detour for blood and allowing better flow through the heart.
Using the “off-pump” procedure means doctors are operating on a heart that continues to pump blood through the body. The “pump” procedure uses a heart-lung machine to pump blood while the heart remains stationary.
Although the results of this study do not end the debate about the superiority of one procedure over another, doctors welcomed the data as a well-researched and detailed analysis.
“There will always be that last question of whether pump bypass surgery is better,” said Dr. Henry Tannous, chief of cardiothoracic surgery at Stony Brook University’s Renaissance School of Medicine. “There will always be very little nuance with different patients that makes us choose one or the other.”
Dr. Tannous, who has performed the majority of all bypass surgeries at Stony Brook over the past five years, said the hospital offers surgeries with and without the pump. SB has physicians who specialize in each type of bypass should the planned procedure change.
Doctors are usually clear about whether a patient can benefit from pump or non-pump procedures before beginning surgeries. In the vast majority of cases, physicians perform the procedure based on their pre-established expectations for pump use.
Rarely, they switch to the other procedure depending on the interoperative findings that dictate the switch, Dr. Tannous explained.
Dr. Jorge Balauger, Associate Chief of Cardiothoracic Surgery and Director of Advanced Coronary Surgery, has performed 4,000 CABG procedures, including approximately 1,000 without a heart-lung or “off-pump” machine.
Based on his considerable experience, he suggested that an 80-year-old person, who suffers from kidney or liver dysfunction and/or partially clogged arteries in the neck or some other type of comorbidity, such as something in the bone marrow, would not tolerate a heart-lung machine well. A person with cirrhosis would also likely be better served with off-pump surgery.
“Avoiding the heart-lung machine in elderly and sick patients is beneficial,” Dr. Balauger said, adding that he views the CABG procedure as akin to a “tailor-made suit” that must fit the patient specifically. .
In cases where patients need a second bypass procedure, Dr. Balauger also recommends stopping pump efforts because a second operation on the pump is “much more complex” and requires “dissection of all the scar tissue around the heart, which makes it not only time-consuming, but also risky.
Dr. Tannous appreciates the perspective that Shroyer brings to the discussion. “Sometimes it’s an asset to have a researcher and a statistician with a very scientific mind leading the study,” he said, adding that when surgeons meet with patients, they discuss the use of the pump.
Dr Baulager described the trial conducted by Shroyer as having an “excellent design” from a scientific point of view.
He believed, however, that the study did not include surgeons who had sufficient expertise in off-pump procedures. Dr. Baulager believed that more experienced surgeons likely guaranteed better results for non-pump procedures.
One aspect of the study that was “refreshing” for Shroyer was the durability of the surgery, with approximately 70% of patients who underwent the procedure, both with and without the pump, still seeing an improvement in their symptoms. of pre-surgical chest pain after 10 years. years.
“We didn’t expect the high proportion of patients to do so well in the long term in terms of being event and symptom free,” she said. “The fact that the symptoms were not different between pump and pump is good news.”
After this type of study, Shroyer will work with several other trials to determine whether certain high-risk patient subgroups may benefit from a pumpless procedure.
To be sure, Shroyer cautioned that these results could not be extrapolated to the general population, especially women, because nearly everyone in the study was male. “Veterans are a unique population,” she said. “Many have been given cigarettes as part of their rations, and the hypertension is quite high. This is a different population in terms of [health care] complexities and their [underlying] diseases.”
While the 10-year results were similar, Shroyer found a shorter revascularization-free survival period in patients without a pump.
Dr. Tannous said this type of study would generate considerable interest among cardiac surgeons.
“All [Shroyer] wrote about bypass surgery from the ROOBY trials will catch the attention of any cardiac surgeon nationwide,” he said. “This document is no different. It has the added long-term tracking that makes it more relevant.