King George 2 of Great Britain died(october 25,1760)while training on the commode and was the first well documented case of an aortic dissection

King George 2 of Great Britain died(october 25,1760)while training on the commode and was the first well documented case of an aortic dissection.

• King George 2 of Great Britain died(october 25,1760)while training on the commode and was the first well documented case of an aortic dissection.

Recognized since 16 th century.

• Recognized since 16 th century.

• Lannaec(French physician) introduced term Dissection aneurysm in 1819.

First successful outcome of modern treatment of aortic dissection was attributed to Dr. DeBakey in his report, 1955 and later he devised a classification that is widely used today as Debakey classification.

• First successful outcome of modern treatment of aortic dissection was attributed to Dr. DeBakey in his report, 1955 and later he devised a classification that is widely used today as Debakey classification.

Technological and technical improvements follow:

• Technological and technical improvements follow:

• Cardiopulmonary bypass circuit.
• Synthetic placements.
• Hypothermic circulatory arrest in 1960s to 1975( Barnard , Schrire, Borst and Griepp with colleaques)
• Open distal anastomosis technique by Livesay in 1982.
• Bioglue has been approved by US FDA to strengthen the disrupted layer.

De Bakey

• De Bakey

• Type 1 = ascending aorta, aortic arch, descending aorta
• Type 2 = ascending aorta only
• Type 3 = descending aorta distal to left subclavian artery
• Type 3a= limit to descending thoracic aorta
• Type 3b= extend below diaphragm

• Stanford (most common)

• Type A = involves ascending aorta
• Type B = no ascending aorta, distal

The proportion of patients with various types depend on the nature of series reported

• The proportion of patients with various types depend on the nature of series reported

• Type one and two (or type A) comprised 35% of cases (from Debakey series).
• From clinical and autopsy series, acute dissections involved the ascending aorta was found in 62% to 85% of cases.

Most patients who die acutely succumb from false channel rupture with hemopericardium, hemomidiastinum or hemothorax.

• Most patients who die acutely succumb from false channel rupture with hemopericardium, hemomidiastinum or hemothorax.

• Death later can result from delayed rupture or organ dysfunction secondary to arterial occlusions.

False channel usually and gradually become aneurysmal, and then ruptures months or years after the acute episode.

• False channel usually and gradually become aneurysmal, and then ruptures months or years after the acute episode.

• A new dissection or redissection may occur.

40% die immediately

• 40% die immediately

• 30% who present to hospital are first thought to have another diagnosis

• Most common symptom:

• Severe, unrelenting chest pain
• Described as ripping or tearing/ sharp pain

• Patients look agony ( nausea, vomiting, diaphoresis)

• Symptoms of tamponade

• AR murmur

• Abnormal pulse exam

• Abnormal neurologic exam

Can be normal

• Can be normal

• Hypertension ( normal or low does not exclude dissection)

• If subclavian artery involved = asymmetri pulses or BP ( > 20 mmHg difference between arms)

• If proximal dissection

• Shock
• New murmur of AR/ HEART FAILURE

EKG

• EKG

• Normal in 1/3 ( in coronary involement)
• ST-T change

TTE

• TTE

• Useful screening tool in identifying type A dissection
• Limited visualization to distal ascending, transverse and descending
• Paramount in assessing cpx. AR/tamponade/EF

• TEE

• TEE with color flow imaging is considered as the most useful and accurate diagnostic technique

Coronary angiogram

• Coronary angiogram

• selective coronary angiogram to identify involvement of the coronary arties is not indicated.(TEE, direct examination of coronary arteries after the aorta was opened)
• Use of coronary angiogram to detect atherosclerotic disease in patients who are to undergo surgical treatment of acute dissection is arguable.

Helical CT sense-93% spec-100%

• Helical CT sense-93% spec-100%

• Most frequently used

• MRI sens-98% spec 98%

• Presence of artifact in nearly 60% of cases

• Echo TTE sense-59-85%, spec 63-96%

• Echo TEE sense-98%, spec 98%

• IVUS

• Particulary useful for delineating the proximal and distal extent

• Coronary angiography

• Controversial

Acute aortic dissections involving the ascending aorta are considered surgical emergencies.

• Acute aortic dissections involving the ascending aorta are considered surgical emergencies.

In contrast, dissections confined to the descending aorta are treated medically unless there is/are complications.

• In contrast, dissections confined to the descending aorta are treated medically unless there is/are complications.

The primary objective is to normalize pressure and to reduce the force of left ventricular ejection (dP/dt).

• The primary objective is to normalize pressure and to reduce the force of left ventricular ejection (dP/dt).

If beta-blockers alone do not control blood pressure, vasodilators such as NTP ( the first vasodilator of choice)

• If beta-blockers alone do not control blood pressure, vasodilators such as NTP ( the first vasodilator of choice)

• Good pain control as morphine.

• Volume titration.

• Intubation early.

Cardiac tamponade

• Cardiac tamponade

• Severe AR

• True-lumen obstruction

• Acute MI

• Contained rupture of the false lumen into pleural space or mediastinum

• ### every scenarios mandate immediate operative intervention####

Associated with recurrent pericardial bleeding and associated mortality

• Associated with recurrent pericardial bleeding and associated mortality

• Several articles from Asian literature suggest that it may be safe in the setting of acute type A IMH

• Except for cases who cannot survive until surgery, pericardiocentesis can be done by withdrawing just enough fluid to restore perfusion

To treat or prevent the common and lethal complications such as

• To treat or prevent the common and lethal complications such as

• Aortic rupture
• Stroke
• Visceral ischemia
• Cardiac tamponade
• Circulatory failure

Excision of intimal tear

• Excision of intimal tear

• Obliteration of entry into FL

• Reconstitution of aorta with interposition graft +/- coronary reimplantations

• Restoration of aortic valve incompetence

• Valve resuspension
• Aortic valve replacement
• Aortic root replacement

Operative mortality in experienced centers with large surgical series varies widely between 15%-35%, still below the 50% mortality with medical therapy

• Operative mortality in experienced centers with large surgical series varies widely between 15%-35%, still below the 50% mortality with medical therapy

Establishing CPB in traditional way.

• Establishing CPB in traditional way.

• Rt radial a. line/ femoral a. line opposite to cannulation site.
• Routine TEE

• If FEM-FEM bypass is chosen.

• CFA with the most normal pulse
• CFV on the right should be used ( easily positioned to RA )

If circulatory arrest is needed, the core temp should be lower to less than 20 celsius with good LV venting.

• If circulatory arrest is needed, the core temp should be lower to less than 20 celsius with good LV venting.

• If aortic cross clamping is planning, clamp should be placed several centimeters proximal to innominate artery.

Treatment acute type A Dissection

• Treatment acute type A Dissection

• All of aneurysmal aorta and the proximal extent of the dissection should be resected.
• A partially dissected root may be repaired by aortic valve resuspension.

Patients with Type A Dissection

• Patients with Type A Dissection

• Extensive aortic root dissection should be treated with aortic root replacement with a composite graft or with a valve sparing root replacement.
• In DeBekey Type 2 dissection the entire dissected aorta should be replaced

Possible cannulationtion sites

• Possible cannulationtion sites

• Femoral cannulation
• Right axillary artery
• Left common carotid artery
• Direct cannulation of aorta by TEE control
• Direct cannulation( cut open under visual control)
• Transapical cannulation.

Advantages

• Advantages

• For cases that neither right axillary artery nor femoral artery can be used

• Abdominal aortic stenosis/ dissection both axillary arteries

Useful in all patients with acute type A dissection.

• Useful in all patients with acute type A dissection.

• A major advantage is quicker than others conventional methods as no purse-strings or additional dissection is required.

Supracommissural ascending aorta replacement.(ascending aortic replacement)

• Supracommissural ascending aorta replacement.(ascending aortic replacement)

• Composite conduit root replacement.

• Aortic valve-sparing root replacement.

• ± Hemiarch Replacement
• ± Total Arch Replacement
• ±Hybrid-Procedures ( Frozen-elephant trunk)

Straightforward ( standard technique)

• Straightforward ( standard technique)

• Shorter cross-clamp and bypass time compared to valve sparing operations.

Excellent aortic valve function with physiological hemodynamics (Avoidance of PPM)

• Excellent aortic valve function with physiological hemodynamics (Avoidance of PPM)

• Lifelong good functionality ( Avoidance of reoperations)

• Avoidance of prosthetic valve related complications.

Advanced degenerative calcification of the aortic valve.

• Advanced degenerative calcification of the aortic valve.

• Overstretched and thin cusps with stress fenestrations and perforations.

• Acute infective endocarditis.

Patients who are in need of concomitant procedures, who have impaired left ventricular function.

• Patients who are in need of concomitant procedures, who have impaired left ventricular function.

• Patients who are elderly and frail and might not tolerate extended cross-clamp and bypass times.

• Lack of surgical experience.

The false lumen( DeBakey 1) in the arch and descending aorta remains untreated, potentially resulting in

• The false lumen( DeBakey 1) in the arch and descending aorta remains untreated, potentially resulting in

• Aneurysmal(thoraco-abdominal) formation 10%
• Rupture 10%
• Malperfusion 10-30%
• Redo-surgery ?%

Radical approach : resection of all diseased tissue

• Radical approach : resection of all diseased tissue

• High risk
• High mortality
• Increased rate of stroke
• Lower reoperation rate
• Improved event free long term survival

Class 1

• Class 1

• A brain protection strategy……should be a key element of the surgical, anesthetic and perfusion techniques…….(Evidence: B)

• Class 2a

• Deep hypothermic circulatory arrest, and selective antegrade brain perfusion are techniques that alone or in combination are reasonable to minimize brain injury……. Institution experience is an important factor……( Evidence: B)

“bilateral antegrade cerebral perfusion is superior to any other method of brain protection”

• “bilateral antegrade cerebral perfusion is superior to any other method of brain protection”

• Preservation of intracellular pH and energy stores
• Neurological deficit and cognitive dysfunction is lowered compared to other methods.
• Allow extended repair with prolonged perfusion time.
• Monitoring is mandatory (NIRS)

Continuous monitoring of regional cerebral oxygen saturation (rCSO2).

• Continuous monitoring of regional cerebral oxygen saturation (rCSO2).

• Under selective antegrade cerebral perfusion a drop of rCSO2 of 30% of baseline values require immediate control of perfusion modalities.

An aggressive surgical approach, including a full root or hemiarch replacement, is not associated with increased operative risk and should be considered when type A dissections extensively involve the valve, sinuses or arch.

• An aggressive surgical approach, including a full root or hemiarch replacement, is not associated with increased operative risk and should be considered when type A dissections extensively involve the valve, sinuses or arch.

No differences between isolated ascending replacement and ascending + arch replacement in the literature with regard to

• No differences between isolated ascending replacement and ascending + arch replacement in the literature with regard to

• long term survival and freedom from reoperation