MANAGEMENT OF
ACUTE TYPE B AORTIC DISSECTION
นพ.อรรถภูมิ สู่ศุภอรรถ
รพ.ราชวิถี
COMPLICATIONS IN ACUTE TYPE
B AORTIC DISSECTION
• No uniform criteria to define “complicated”
• 15-20% of cases
• Impending rupture
• Malperfusion syndrome (10%)
• Hemodynamic instability (15%)
• Refractory hypertension
MALPERFUSION SYNDROMES
• About 10% of patients with type B aortic dissection
1. Dynamic malperfusion caused by branch
vessel occlusion of the true lumen by the
pressurized false lumens
2.
Static malperfusion caused by propagation of
the dissection into branch vessel ostia with
distal vessel occlusion
MALPERFUSION SYNDROMES
• Mesenteric ischemia
• abdominal pain, nausea, and diarrhea
• associated with an increase in laboratory markers (bilirubin,
amylases, hepatic, and intestinal enzymes).
• Highly devastating and has a major impact on early mortality
• Lower limb ischemia
• Relatively benign and surgical intervention should be performed in
symptomatic patient.
• Spinal cord ischemia
• paraparesis or paraplegia
STRATEGY
Therapeutic Aim
• To restore the perfusion of the organs
• To stop/limit the dissecting process to
protect the organs
• Central Aortic Repair
• Aortic Replacement
• Fenestration
• Endograft
• Re-entry fenestration
• Peripheral repair
• Graft Bypass
• Stenting
• A 59-year-old male with history of hypertension and COPD
presented with abdominal pain, painful, pulseless right lower
extremity
TL
TL
Celiac a.
TL
TL
Rt CIA
Rt RA
Lt RA
FL
STENT-GRAFT PLACEMENT
IVUS/ TEE
superior to angiography for identifying
• Primary and distal reentry tears
• Documenting guidewire position in the true
lumen
• Assessing seal zones
• Detecting endoleaks
• assessment of the ascending aorta to be
mandatory at the conclusion of each TEVAR
case to assess for retrograde ascending aortic
dissection
Circulation. 2005;112:I260-4.
STENT PLACEMENT
• Uncovered stents improve flow
1. inadequate relief of dynamic
obstruction after surgery
2. static obstruction of abdominal aortic
branch vessels, which is typically
unaffected by proximal aortic stentgraft treatment and fenestration.
IMPENDING RUPTURE/RUPTURE
• Persistent pain despite good blood pressure control
• Aortic dissection with persistent uncontrolled
hypertension
• Evidence of dissection progression despite optimal
medical management.
• An increase in perioaortic hematoma and hemorrhagic
pleural effusion in 2 subsequent CT examinations
• Requires sealing off the primary tear as well as the site of the
leak
• Frequently necessitates paving the entire thoracic aorta
when the site of the leak is unclear.
J Am Coll Cardiol Intv 2008;1:395– 402.
Circulation 2010;122:1283–9.
REFRACTORY HYPERTENSION
• International Registry of Acute Aortic Dissection
(IRAD) trial data showed that in-hospital mortality
after medical management was significantly
increased in average-risk patients with type B
aortic dissection under medical therapy with
refractory hypertension/pain compared with those
without these features (35.6% vs. 1.5%; p 0.0003)
Circulation 2010;122:1283–9.
OPEN SURGERY
UNCOMPLICATED ACUTE TYPE B
AORTIC DISSECTION
• Medical management
• Anti-impulse therapy
• uncomplicated dissection
• lack of appropriate facilities
• presence of comorbidities or morphology that made open
surgery or TEVAR not feasible
• IRAD: 3-yr survival = 78%
• Late aortic-related complications= 25-50%
PROPHYLACTIC TEVAR?
• Thrombosed false lumen predicts lower event rates after type B
dissection
• Randomized comparison of strategies for type B aortic dissection:
the INvestigation of STEnt Grafts in Aortic Dissection (INSTEAD)
trial
• Found no difference in the primary end point of all-cause mortality at
2 years
• Thoracic false lumen thrombosis, TEVAR> Medical Mx :91.3%VS
19.4% (P < .001)
• high rate of aorta-related deaths in the TEVAR group resulting from
periprocedural technical complications
Circulation. 1993;87:1604-15.
Circulation. 2009;120:2519-28.
HIGH-RISK FEATURES OF
UNCOMPLICATED TYPE B DISSECTION
• Initial aortic diameter ≥ 4.0 cm with patent false lumen *,€,ɸ
• Initial false lumen diameter ≥ 22 mm in proximal DTA ∞
• IMH with PAU in proximal DTA *,ɸ
* Eur J Vasc Endovasc Surg.2006;32:349-55.
€ J Thorac Cardiovasc Surg. 2007;134:1163-70.
ɸ Circulation. 2010;122: S74-80.
∞J Am Coll Cardiol. 2007;50:799-804.
LONG-TERM MANAGEMENT
• Specific predictors of follow-up mortality include
• Female gender
• Prior aortic aneurysm
• Atherosclerosis
• Pleural effusion
• In-hospital acute renal failure
• Hypotension or shock
• β-blockade & blood pressure control
• IRAD: calcium channel blockers at discharge was associated with
improved long-term survival selectively in medically treated type B
dissection patients
• >1/3 of patients will require surgery for aortic-related complications
within 5 years of the initial dissection
• Serial imaging at 1, 3, 6, and 12 months after discharge, and annually
OUTCOME DATA FROM MEDICAL
THERAPY
• Early mortality rate = 6.4% (95% CI: 5.1% to 7.9%)
• Stroke = 4.2% (95% CI:2.3% to 7.4%)
• spinal cord ischemia = 5.3% (95% CI: 3.4% to 8.4%)
• 5-year survival rates ranged from 70.2% to 89%
• Aortic adverse event freedom (including aortic death, rupture,
new dissection, enlargement, reintervention) ranged from 75%
to 88.5% at 5 years, but there were variable event definitions
among studies
OUTCOME DATA FROM TEVAR
• in most of the papers, indication for TEVAR was complicated acute
type B dissection
• criteria for defining complicated were variable
• Early mortality rate =10.2% (95%CI: 9.0% to 11.6%)
• Stroke = 4.9% (95% CI: 4.0% to6.0%)
• Spinal cord ischemia = 4.2.% (95% CI: 3.3% to 5.2%)
• 5-year survival rates ranged from 56.3% to 87%
• Freedom from aortic events ranged from 45% to 77% at 5 years.
OUTCOME DATA FROM OPEN
SURGERY
• Early mortality rate = 17.5% (95% CI: 15.6% to 19.6%)
• Stroke = 5.9% (95% CI: 4.8% to 7.3%)
• Spinal cord ischemia = 3.3%(95% CI: 2.4% to 4.5%)
• 5-year survival rates ranged from 44% to 64.8%
• Freedom from aortic events ranged from 58.7% to 68% at 5
years.
MEDICAL THERAPY VS TEVAR
AND
OPEN SURGERY VERSUS TEVAR
• invalidated by unbalanced populations (unmatched illness
conditions and rates of complicated vs. uncomplicated cases of
patients assigned to each treatment).
• Complicated cases Open Sx, TEVAR
• uncomplicated cases Medical treatment
COMPARISON OF EARLY (30 DAYS/IN-HOSPITAL) OUTCOMES WITH MEDICAL
THERAPY AND TEVAR IN ACUTE TYPE B AORTIC DISSECTIONS
SUBACUTE TYPE B AORTIC
DISSECTION
• Very limited outcome data
• INSTEAD (Investigation of Stent Grafts in Aortic Dissection)
trial
• Primary success rate = 95.7%
• Early mortality = 2.8%
• Stroke rate =1.4%
• Spinal ischemia= 2.9%
• Required secondary procedures = 18%
VIRTUE (VALIANT THORACIC STENT GRAFT EVALUATION FOR
THE TREATMENT OF DESCENDING THORACIC AORTIC
DISSECTIONS- POST MARKETING SURVEILLANCE REGISTRY)
REGISTRY
• 24 patients with complicated subacute type B aortic dissections treated with
TEVAR
• Primary procedural success rate= 100%
• Early mortality rate =1.8%
• Late deaths = 0%
• Strokes or cases of spinal cord ischemia = 0%
• Negative prognosis in the subacute phase
• Change in aortic morphology (expanding diameter 4 mm, new onset of periaortic
hematoma, and/or pleural hemorrhagic effusion)
• Refractory hypertension
• Recurrent thoracic pain
• Malperfusion
SUBACUTE TYPE B AORTIC
DISSECTION