Arch replacement with FET not worse when acute

TORONTO – Operative mortality with total aortic arch replacement using a four-branched graft and frozen elephant trunk implantation (Sun’s procedure) was 6.5%, including those whose type A aortic dissection was defined as acute.

Operative mortality was higher in acute versus chronic type A aortic dissection (TAAD) patients undergoing the procedure (8.1% vs. 4.3%; P = .031), as was the incidence of stroke (2.2% vs. 0.6%; P = .046), and respiratory complications (20.8% vs. 8.6%; P less than .001).

However, although the risk of operative mortality in acute patients was 1.95 times higher than for chronic patients, in multivariate analysis, acuteness was not identified as a significant risk factor for operative mortality (odds ratio, 1.67; P = .152).

The factors identified as increasing risk of operative mortality were coexisting cerebrovascular disease; malperfusion of the brain, kidneys, spinal cord, and viscera; concomitant extra-anatomic bypass; and cardiopulmonary bypass time exceeding 180 minutes.

"This study proves the safety of frozen elephant trunk with total arch replacement," said Dr. Wei-Guo Ma of Yale University, New Haven, Conn.

"Operative mortality was not affected by either the acute or chronic phase. Instead it was affected by seven other factors, such as prior CVD [cerebrovascular disease], malperfusion, and longer CPB [cardiopulmonary bypass] time.

"If a patient comes without those risk factors, surgeons can go ahead and perform this emergent frozen elephant trunk for him without fear of imposing greater risk of mortality," he said.

Standard TAAD remains a highly lethal condition, with the greatest surgical risk seen during the acute phase. Although some progress has been made, surgeons continue to debate the optimal surgical approach to TAAD, in particular the extent of distal aortic repair. Some advocate a more limited approach of hemiarch repair only, while others propose that total arch repair offers better outcomes.

Sun’s procedure is performed with right axillary artery cannulation for cardiopulmonary bypass and selective antegrade cerebral perfusion, under moderate hypothermic circulatory arrest at 25° C.

The frozen elephant trunk (Cronus, MicroPort Medical, Shanghai, China) is implanted into the descending aorta, followed by total arch replacement using a four-branched vascular graft, with a special sequence for aortic reconstruction (i.e., proximal descending aorta to left carotid artery to ascending aorta to left subclavian artery to innominate artery). Associated operations, including coronary artery bypass grafting, are performed during the cooling phase, if needed.

In this case series, presented by Dr. Ma at the annual meeting of the American Association for Thoracic Surgery, acuteness was defined as an interval between onset of symptoms and surgery of 14 days or less.

TAAD was diagnosed preoperatively by transthoracic echocardiography or computed tomographic angiography, with the location of the intimal tear confirmed during surgery.

The surgeons retrospectively compared early outcomes between acute and chronic TAAD patients after Sun’s procedure, seeking to identify risk factors for operative mortality in both groups and seeking to determine whether acuteness significantly affects operative mortality after this extensive surgical approach.

Between April 2003 and September 2012, Sun’s procedure was performed on 803 patients with acute or chronic TAAD. Mean age was 46 years and 80% of the cohort was male. A total of 456 were classified as acute TAAD patients, with a mean of 5.5 days lapsing between onset of symptoms to surgery (median, 4.1 days), and 347 were chronic, with 197 days lapsing between onset of symptoms and surgery (median, 38 days).

Clinically apparent malperfusion was common, seen in 12.6% of cases, 12.3% of the acute arm and 9.2% of the chronic arm. Patients with malperfusion had an overall mortality of 19.3% (25% in the acute arm and 9.4% in the chronic arm; P less than .001).

"Visceral malperfusion tended to be the most lethal, with five of seven patients dying," reported Dr. Ma. He also noted the young age of their cohort as compared to other regions of the world: 88.8% of patients were under 60 years of age.

Acute, minus natural selection

The invited discussant on the abstract, Dr. Malakh L. Shrestha took issue with the study’s conclusion that acuteness did not affect operative mortality. Dr. Shrestha is the division manager of valvular and coronary artery surgery at the Hannover (Germany) Medical School.

"As a high volume center, what we’ve learned is that acute and chronic aortic dissection patients are two totally different subsets of patients in terms of clinical presentation and mortality. The greatest danger in the acute patient is in the first few hours after the dissection, with the majority of patients dying without surgical intervention."

At Dr. Shrestha’s center in Germany, a high-volume aortic center, they often see patients within the first few hours of their dissection and they’ve found a significantly higher mortality in these patients, compared with chronic TAAD whether an ascending aortic replacement or a frozen elephant trunk procedure is done.

With a median of 4.1 days lapsing between onset of symptoms and surgery in the Ma et al. study, Dr. Shrestha argued that "although on the basis of classification, you can still say they’re acute, there has been some sort of natural selection. So, I think that means, at least for your conclusions, that you need to clarify the statement that there is no difference between acute and chronic, because these are obviously not the same subset of patients that we see in the Western world."

Dr. Ma agreed that natural selection was indeed at play in their series, in that about 80% of their patients were referrals that were transferred in some cases from hundreds of miles away, with many dying en route or before surgery. He also concurred that had their mean and median number of days in their acute cohort been less, indeed, mortality might have been higher.

Dr. Ma reported having no conflicts of interest. Dr. Shrestha is a consultant for Edwards Lifesciences.

TORONTO – Operative mortality with total aortic arch replacement using a four-branched graft and frozen elephant trunk implantation (Sun’s procedure) was 6.5%, including those whose type A aortic dissection was defined as acute.

Operative mortality was higher in acute versus chronic type A aortic dissection (TAAD) patients undergoing the procedure (8.1% vs. 4.3%; P = .031), as was the incidence of stroke (2.2% vs. 0.6%; P = .046), and respiratory complications (20.8% vs. 8.6%; P less than .001).

However, although the risk of operative mortality in acute patients was 1.95 times higher than for chronic patients, in multivariate analysis, acuteness was not identified as a significant risk factor for operative mortality (odds ratio, 1.67; P = .152).

The factors identified as increasing risk of operative mortality were coexisting cerebrovascular disease; malperfusion of the brain, kidneys, spinal cord, and viscera; concomitant extra-anatomic bypass; and cardiopulmonary bypass time exceeding 180 minutes.

"This study proves the safety of frozen elephant trunk with total arch replacement," said Dr. Wei-Guo Ma of Yale University, New Haven, Conn.

"Operative mortality was not affected by either the acute or chronic phase. Instead it was affected by seven other factors, such as prior CVD [cerebrovascular disease], malperfusion, and longer CPB [cardiopulmonary bypass] time.

"If a patient comes without those risk factors, surgeons can go ahead and perform this emergent frozen elephant trunk for him without fear of imposing greater risk of mortality," he said.

Standard TAAD remains a highly lethal condition, with the greatest surgical risk seen during the acute phase. Although some progress has been made, surgeons continue to debate the optimal surgical approach to TAAD, in particular the extent of distal aortic repair. Some advocate a more limited approach of hemiarch repair only, while others propose that total arch repair offers better outcomes.

Sun’s procedure is performed with right axillary artery cannulation for cardiopulmonary bypass and selective antegrade cerebral perfusion, under moderate hypothermic circulatory arrest at 25° C.

The frozen elephant trunk (Cronus, MicroPort Medical, Shanghai, China) is implanted into the descending aorta, followed by total arch replacement using a four-branched vascular graft, with a special sequence for aortic reconstruction (i.e., proximal descending aorta to left carotid artery to ascending aorta to left subclavian artery to innominate artery). Associated operations, including coronary artery bypass grafting, are performed during the cooling phase, if needed.

In this case series, presented by Dr. Ma at the annual meeting of the American Association for Thoracic Surgery, acuteness was defined as an interval between onset of symptoms and surgery of 14 days or less.

TAAD was diagnosed preoperatively by transthoracic echocardiography or computed tomographic angiography, with the location of the intimal tear confirmed during surgery.

The surgeons retrospectively compared early outcomes between acute and chronic TAAD patients after Sun’s procedure, seeking to identify risk factors for operative mortality in both groups and seeking to determine whether acuteness significantly affects operative mortality after this extensive surgical approach.

Between April 2003 and September 2012, Sun’s procedure was performed on 803 patients with acute or chronic TAAD. Mean age was 46 years and 80% of the cohort was male. A total of 456 were classified as acute TAAD patients, with a mean of 5.5 days lapsing between onset of symptoms to surgery (median, 4.1 days), and 347 were chronic, with 197 days lapsing between onset of symptoms and surgery (median, 38 days).

Clinically apparent malperfusion was common, seen in 12.6% of cases, 12.3% of the acute arm and 9.2% of the chronic arm. Patients with malperfusion had an overall mortality of 19.3% (25% in the acute arm and 9.4% in the chronic arm; P less than .001).

"Visceral malperfusion tended to be the most lethal, with five of seven patients dying," reported Dr. Ma. He also noted the young age of their cohort as compared to other regions of the world: 88.8% of patients were under 60 years of age.

Acute, minus natural selection

The invited discussant on the abstract, Dr. Malakh L. Shrestha took issue with the study’s conclusion that acuteness did not affect operative mortality. Dr. Shrestha is the division manager of valvular and coronary artery surgery at the Hannover (Germany) Medical School.

"As a high volume center, what we’ve learned is that acute and chronic aortic dissection patients are two totally different subsets of patients in terms of clinical presentation and mortality. The greatest danger in the acute patient is in the first few hours after the dissection, with the majority of patients dying without surgical intervention."

At Dr. Shrestha’s center in Germany, a high-volume aortic center, they often see patients within the first few hours of their dissection and they’ve found a significantly higher mortality in these patients, compared with chronic TAAD whether an ascending aortic replacement or a frozen elephant trunk procedure is done.

With a median of 4.1 days lapsing between onset of symptoms and surgery in the Ma et al. study, Dr. Shrestha argued that "although on the basis of classification, you can still say they’re acute, there has been some sort of natural selection. So, I think that means, at least for your conclusions, that you need to clarify the statement that there is no difference between acute and chronic, because these are obviously not the same subset of patients that we see in the Western world."

Dr. Ma agreed that natural selection was indeed at play in their series, in that about 80% of their patients were referrals that were transferred in some cases from hundreds of miles away, with many dying en route or before surgery. He also concurred that had their mean and median number of days in their acute cohort been less, indeed, mortality might have been higher.

Dr. Ma reported having no conflicts of interest. Dr. Shrestha is a consultant for Edwards Lifesciences.

TORONTO – Operative mortality with total aortic arch replacement using a four-branched graft and frozen elephant trunk implantation (Sun’s procedure) was 6.5%, including those whose type A aortic dissection was defined as acute.

Operative mortality was higher in acute versus chronic type A aortic dissection (TAAD) patients undergoing the procedure (8.1% vs. 4.3%; P = .031), as was the incidence of stroke (2.2% vs. 0.6%; P = .046), and respiratory complications (20.8% vs. 8.6%; P less than .001).

However, although the risk of operative mortality in acute patients was 1.95 times higher than for chronic patients, in multivariate analysis, acuteness was not identified as a significant risk factor for operative mortality (odds ratio, 1.67; P = .152).

The factors identified as increasing risk of operative mortality were coexisting cerebrovascular disease; malperfusion of the brain, kidneys, spinal cord, and viscera; concomitant extra-anatomic bypass; and cardiopulmonary bypass time exceeding 180 minutes.

"This study proves the safety of frozen elephant trunk with total arch replacement," said Dr. Wei-Guo Ma of Yale University, New Haven, Conn.

"Operative mortality was not affected by either the acute or chronic phase. Instead it was affected by seven other factors, such as prior CVD [cerebrovascular disease], malperfusion, and longer CPB [cardiopulmonary bypass] time.

"If a patient comes without those risk factors, surgeons can go ahead and perform this emergent frozen elephant trunk for him without fear of imposing greater risk of mortality," he said.

Standard TAAD remains a highly lethal condition, with the greatest surgical risk seen during the acute phase. Although some progress has been made, surgeons continue to debate the optimal surgical approach to TAAD, in particular the extent of distal aortic repair. Some advocate a more limited approach of hemiarch repair only, while others propose that total arch repair offers better outcomes.

Sun’s procedure is performed with right axillary artery cannulation for cardiopulmonary bypass and selective antegrade cerebral perfusion, under moderate hypothermic circulatory arrest at 25° C.

The frozen elephant trunk (Cronus, MicroPort Medical, Shanghai, China) is implanted into the descending aorta, followed by total arch replacement using a four-branched vascular graft, with a special sequence for aortic reconstruction (i.e., proximal descending aorta to left carotid artery to ascending aorta to left subclavian artery to innominate artery). Associated operations, including coronary artery bypass grafting, are performed during the cooling phase, if needed.

In this case series, presented by Dr. Ma at the annual meeting of the American Association for Thoracic Surgery, acuteness was defined as an interval between onset of symptoms and surgery of 14 days or less.

TAAD was diagnosed preoperatively by transthoracic echocardiography or computed tomographic angiography, with the location of the intimal tear confirmed during surgery.

The surgeons retrospectively compared early outcomes between acute and chronic TAAD patients after Sun’s procedure, seeking to identify risk factors for operative mortality in both groups and seeking to determine whether acuteness significantly affects operative mortality after this extensive surgical approach.

Between April 2003 and September 2012, Sun’s procedure was performed on 803 patients with acute or chronic TAAD. Mean age was 46 years and 80% of the cohort was male. A total of 456 were classified as acute TAAD patients, with a mean of 5.5 days lapsing between onset of symptoms to surgery (median, 4.1 days), and 347 were chronic, with 197 days lapsing between onset of symptoms and surgery (median, 38 days).

Clinically apparent malperfusion was common, seen in 12.6% of cases, 12.3% of the acute arm and 9.2% of the chronic arm. Patients with malperfusion had an overall mortality of 19.3% (25% in the acute arm and 9.4% in the chronic arm; P less than .001).

"Visceral malperfusion tended to be the most lethal, with five of seven patients dying," reported Dr. Ma. He also noted the young age of their cohort as compared to other regions of the world: 88.8% of patients were under 60 years of age.

Acute, minus natural selection

The invited discussant on the abstract, Dr. Malakh L. Shrestha took issue with the study’s conclusion that acuteness did not affect operative mortality. Dr. Shrestha is the division manager of valvular and coronary artery surgery at the Hannover (Germany) Medical School.

"As a high volume center, what we’ve learned is that acute and chronic aortic dissection patients are two totally different subsets of patients in terms of clinical presentation and mortality. The greatest danger in the acute patient is in the first few hours after the dissection, with the majority of patients dying without surgical intervention."

At Dr. Shrestha’s center in Germany, a high-volume aortic center, they often see patients within the first few hours of their dissection and they’ve found a significantly higher mortality in these patients, compared with chronic TAAD whether an ascending aortic replacement or a frozen elephant trunk procedure is done.

With a median of 4.1 days lapsing between onset of symptoms and surgery in the Ma et al. study, Dr. Shrestha argued that "although on the basis of classification, you can still say they’re acute, there has been some sort of natural selection. So, I think that means, at least for your conclusions, that you need to clarify the statement that there is no difference between acute and chronic, because these are obviously not the same subset of patients that we see in the Western world."

Dr. Ma agreed that natural selection was indeed at play in their series, in that about 80% of their patients were referrals that were transferred in some cases from hundreds of miles away, with many dying en route or before surgery. He also concurred that had their mean and median number of days in their acute cohort been less, indeed, mortality might have been higher.

Dr. Ma reported having no conflicts of interest. Dr. Shrestha is a consultant for Edwards Lifesciences.