1 NISHITH PATEL Waikato Cardiothoracic UnitACUTE AORTIC SYNDROME NISHITH PATEL Waikato Cardiothoracic Unit

2 Nishith Patel 11th August 2017ACUTE AORTIC SYNDROME Nishith Patel 11th August 2017

3 Overview Type A Aortic Dissection Type A Intramural HaematomaType A Penetrating Aortic Ulcer Evidence Who and when to operate? Pre-op management Surgical Strategies

4 History On 25 October 1760 George II, then 76, rose at his normal hour of 6 AM, called as usual for his chocolate, and repaired to the closet-stool. The German valet de chambre heard a noise, memorably described as ‘louder than the royal wind', and then a groan; he ran in and found the King lying on the floor, having cut his face in falling. Mr. Andrews, surgeon of the household, was called and bled his Majesty but in vain, as no sign of life was observed from the time of his fall. At necropsy the next day Dr. Nicholls, physician to his late Majesty, found the pericardium distended with a pint of coagulated blood, probably from an orifice in the right ventricle, and a transverse fissure on the inner side of the ascending aorta 3.75 cm long, through which blood had recently passed in its external coat to form a raised ecchymosis, this appearance being interpreted as an incipient aneurysm of the aorta. Leonard JC. BMJ 1979;2:

5 First Repair of Thoracic Aortic Aneurysm - 1955DeBakey and Cooley, Ann Surg 1955:142:

6 IRAD Registry Multinational, prospective registry of aortic dissections 30 referral centres in 11 countries No UK centres Consecutive patients presenting with AAD enrolled Since 1st January 1996 290 variables: demographics, history, examination, investigations, management, outcomes Coordinating centre at University of Michigan 3800 cases

7 Erbel et al. European Heart Journal 2014;35.Classification of AAS Erbel et al. European Heart Journal 2014;35.

8 Acute Aortic Dissection

9 Howard DPJ et al. Circulation 2013;127:2031-2037Epidemiology Def: Intimal tear causing disruption of the medial layer, resulting in separation of the aortic wall layers and formation of a TL and FL with or without communication Incidence: 6/100,000/yr >70% of patients are male 60% Stanford Type A Mean Age: Most important risk factor: Hypertension Incidence projected to increase Howard DPJ et al. Circulation 2013;127:

10 Natural History 50% of patients with Type A Dissection die before reaching hospital.a For those who survived to hospital admission, the 30-d mortality rate was 50%.a Type A dissection, 30-d mortality b: Surgical: 26% Medical: 58% Type B dissection, 30-d mortality b: Surgical: 31% Medical: 11% aHoward DPJ et al. Circulation 2013;127: bHagan PG et al. JAMA 2000;283:

11 Aetiology/Risk FactorsHypertension (75%) Genetic Marfan syndrome Bicuspid AV Loeys/Dietz syndrome Hereditary TAAD Ehlers-Danlos Syndrome Congenital Coarctation Turner Syndrome TOF Atherosclerosis PAU Trauma/Iatrogenic Cardiac surgery Cardiac cath IABP Cocaine Pregnancy Inflammatory/Connectiv e tissue disorders Giant cell arteritis Takayasu arteritis Aortitis Syphilis

12 Classification of AAD

13 Clinical PresentationSymptom/Sign Prevalence (%) Chest Pain 79% Abrupt onset 85% Severe or worst ever pain 90% Hypertensive 40% Normotensive Hypotensive or Shock 20% Pulse Deficit AR Murmur 44% CXR: Widened mediastinum 63% CXR: Abnormal aortic contour 47% CXR: No abnormalities 11% Hagan PG et al. JAMA 2000;283:

14 AAD Exhibits Circadian and Seasonal VariationMehta RH. Circulation 2002;106: )

15 Imaging Modality Sensitivity (%) TOE 90% CT 93% MRI 100% Aortography87% Moore AG. Am J Card 2002;89:

16 Who to Operate on? Age? 30% of patients with TAAD are >70 yearsMortality for patients treated surgically: < 70 years = 23% > 70 years = 38% Mehta RJ. JACC 2002;40:685-92; Trimarchi S. JTCVS 2010;140:

17 Should we be operating on Octogenarians?Retrospective observational study from Japan 90 octogenarians with AAD between and 2015 FA cannulation and DHCA (200C) Proximal aortic replacement 30-d mortality: 6.5% CVA: 9.1% Haemofiltration: 2.6% Hospital stay>90d: 23% Discharged home: 57% Kondoh H et al. JTCVS 2016;152:439-46

18 Who to Operate on? Neurology?10% of patients with TAAD will present with Major Brain Injury (CVA or coma) Presumed to have poor outcomes if operated upon. Outcome Med Surg Med Coma Surg Mortality 76% 27% 100% 44% Home 21% 62% 0% 59% Di Eusanio et al. JTCVS 2013;145:S

19 Timing of Surgery Emergency surgery in all patientsMortality rate = 1-2% per hour In IRAD database, median time from presentation at ED to diagnosis = 4 hrs Median time from diagnosis to surgery = 4 hrs

20 Tsai TT et al. Circulation 2006;114(Suppl I):I350-I356.Long Term Survival Tsai TT et al. Circulation 2006;114(Suppl I):I350-I356.

21 Aortic Intramural Haematoma

22 Epidemiology Def: Haematoma that develops in the media of the aortic wall in the absence of a FL and intimal tear. 10-25% of AAS Type A: 40%; Type B: 60% Pathophysiology Rupture of vaso vasorum resulting in bleeding into the media Can progress to AAD if intimal layer ruptures Estrera AL. JTCVS 2016;151:374-75

23 Diagnosis Diagnostic features: Circular or crescent shaped thickening>5mm of aortic wall Absence of detectable blood flow TTE Low sensitivity: <40% CT Non-contrast images are equally important High-attenuation crescenteric thickening of the aorta, extending in a longitudinal, non-spiral fashion Sensitivity: 96% MRI Useful for differentiating IMH from atherosclerotic thickening, thrombus or thrombosed dissection Age of haematoma

24 Natural History Mortality rates in medically treated patients in European and North American studies are high compared to Asian studies Progression to dissection and/or rupture Affects older patients Patients more likely to present with pericardial effusions Chou AS et al. JTCVS 2016;151:

25 Harris KM et al. Circulation 2012;126(suppl 1):S91-96.IRAD Data IRAD: 64 cases of Type A IMH Older patients: mean age 69.6 (9.6) Similar presentation to AAD Higher incidence of pericardial effusions (61%) 15.6% medical mx; 84.4% surgical mx. Overall 30-day mortality: 26.6% Medical Mx: 40% Surgically Mx: 24.1% Harris KM et al. Circulation 2012;126(suppl 1):S91-96.

26 Medical Management of Type A IMHKorean observational study 101 patients with Type A IMH Haemodyanamically unstable patients had emergency surgery Remaining patients had medical therapy Hospital mortality: 7.9% 36.5% of patients had an adverse event (AAD, surgery, death) during f/u Initial aorta diameter and haematoma thickness were independent predictors of adverse events Song JK et al. Circulation 2009;120:

27 Medical vs Surgical Mx Yale Aortic Registry55 patients with Type A IMH Initial Medical Mx 57% had progression of IMH on imaging 43% underwent late surgery Better survival for patients with initial surgical management Chou AS et al. JTCVS 2016;151:

28 ESC 2014 Guidelines Emergency surgery: Evidence of rupturePericardial effusion Urgent surgery (<24hrs): Most Type A IMH Elderly pt with comorbidities + Aortic diameter <50mm and IMH thickness <11mm Initial Medical Tx (BP and pain control and imaging)

29 Penetrating Aortic Ulcer

30 Epidemiology Def: ulceration of an aortic atherosclerotic plaque penetrating through the internal elastic lamina into the media. May lead to IMH, pseudoaneurysm, AD, rupture 2-7% of all AAS Elderly, male, smokers with CAD or COPD Affects descending aorta commonly Management as for Type A IMH Chou AS et al. JTCVS 2016;151:

31 Penetrating Aortic Ulcer

32 Operative Strategy

33 Pre-Operative StrategyBP Control: IV Labetalol or GTN Identify any end-organ damage: limbs, CNS, urine output/creatinine, Impending rupture: pericardial or pleural blood Feel femoral pulses Xmatch blood

34 Anaesthetic Considerations2 Arterial Monitoring Lines Cerebral Monitoring: NIRS Temperature monitor TOE: Diagnosis, AV valve, LV/RV function Prep and drape chin to toe.

35 Operative Strategy Safe Sternal Entry CPB - aortic cannulation siteMyocardial protection Managing the Root/Valve, Ascending Aorta, Arch Cerebral Protection

36 Cardiopulmonary Bypass & Myocardial ProtectionAortic Cannulation: Axillary Artery - via dacron graft. Adv: Antegrade flow, cerebral perfusion during DHCA Disadv: Time consuming Femoral Artery Cool down to degrees LV Vent - RSPV/Apical Antegrade (via handheld ostial cannula) and retrograde cardioplegia (coronary sinus) Frequent doses as ischaemic hearts

37 Cerebral Protection HCA – deep vs moderate HCA + RCP HCA + ACPDefinitions of HCA Profound Hypothermia: ≤140C Deep Hypothermia: 14.1 – 200C Moderate Hypothermia: 20.1 – 280C Mild Hypothermia: C

38 Hypothermia

39 Cerebral Protection

40 Tian DH et al. Ann Cardiothoracic Surg 2013;2:148-58.DHCA vs MHCA + ACP Systematic review + Meta-Analysis 9 studies – only 1 RCT Aortic arch surgery Tian DH et al. Ann Cardiothoracic Surg 2013;2:

41 Ascending Aorta Only No AR, 70-85% of casesMorton Bolmon R. Op Tech Thor Card Vasc Surg 2009.

42 Aortic Root Replacement AR or dissected coronary, 15-20% of cases

43 Arch Replacement 5-10% of cases

44 Operative Principles Reinforce dissected tissues with teflonAlways look into the arch for another tear using DHCA Complete the distal anastomosis using DHCA Lots of cardioplegia Protect the brain with ACP

45 Roselli EE et al. JTCVS 2015;149:144-54The Future….. Maybe! Roselli EE et al. JTCVS 2015;149:144-54

46 NIHR HTA Application Round 1 PassedDiReCTion trial Distal aortic Repair versus Conservative surgery in Type A Aortic Dissection NIHR HTA Application Round 1 Passed

47 Background Type A AAD Survivors of surgical repairIncidence in UK: 4.3 per per year Operative mortality: 20-25% Most patients have surgery restricted to ascending aorta (conservative surgery) Survivors of surgical repair Patent false lumen: 60-70% of patients Further surgery: 20-40% of patients 10 year survival: 40-50% Require long term surveillance

48 Problems with False Lumen PatencyShort term: Malperfusion Consumptive coagulopathy Long Term: Late aneurysm formation Distal reoperation Aortic rupture Long-term mortality Fattouch K et al. Ann Thor Surg 2009; 88:

49 Distal Aortic Repair in AADDefinition: Aortic arch replacement Re-implantation of supra-aortic vessels Antegrade deployment of proximal descending aortic stent graft Benefits: Stabilise true lumen Cover distal entry or re-entry tears Several observational studies demonstrate god outcomes.

50 Comparative Observational Studies14 observational studies comparing outcomes in a total of 1435 patients undergoing conservative surgery and 786 patients undergoing distal aortic repair Conservative Surgery Distal Aortic Repair 30-day mortality 3 – 24% 4 – 29% 5-year mortality 15 – 30% 5 – 10% 10-year mortality 40 – 50% (patent FL) 10 – 30% (thrombosed FL) Not available Stroke 5 – 7% 3 – 6% Spinal cord injury 0 – 1% 1 – 3% False lumen patency 60 – 70% 0 – 20% Distal Re-operation 20 – 40% 0 – 10%

51 Research Question In adult patients presenting with Type A AAD, does the addition of arch repair and distal aortic stent-graft placement: Reduce long-term mortality Reduce distal aortic re-intervention Provide equivalent short-term mortality and morbidity Compared to conservative surgery

52 Study Design Multi-centre RCT with 2 parallel groups (Conservative surgery vs Distal aortic repair) Inclusion Criteria Age: years CT proven Type A AAD extending beyond ascending aorta Candidate for emergency surgery and either conservative or distal aortic repair feasible Patient able to give informed consent Exclusion Criteria: Age ≥80 years Onset of symptoms prior to 14 days Patient unable to give informed consent Registry Patients falling outside inclusion criteria will be recorded in a study registry

53 Control and Intervention GroupsControl Group: Conservative Surgery Supra coronary replacement of the ascending aorta with a synthetic graft Intervention Group: Distal aortic Repair Arch Replacement + Placement of Proximal Descending Aortic Stent + Supra coronary replacement of ascending aorta with a synthetic graft For all patients: Aortic root procedures as determined by surgeon Cannulation strategy, anaesthetic monitoring, cerebral and neuro protection according to institutional practice.

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55 Summary Real surgical emergencyHigh mortality associated with condition High mortality if we don't operate Most patients warrant an operation Work out a surgical strategy prior to commencing