Step2_013

使其主動脈內之血流被導引從真腔（True lumen）經過內膜撕裂處（Intimal tear），進入主動脈壁中產生所謂的假腔（False lumen）。從而會有一個剝離內膜瓣（Intimal flap），把主動脈之內膜（Intima）及部份中膜（Medium）從外膜（Adventitia）及部分中膜分離出來。

在此情況除主動脈壁之保護結構受到嚴重之破壞外，另外，由主動脈灌經各個器官之血流都有可能受到影響，並產生各類器官缺血性症狀

主動脈剝離後，除因破裂直接致死外，都有可能因假腔血流壓迫真腔血流造成各個器官缺血情況發生。因此，病人的臨床徵狀之表現千變萬化－除了最常見劇烈胸痛外（約 80% ，有如撕裂感）；也可能因剝離侵犯至冠狀動脈而造成缺血性心臟病之變化，主動脈瓣而造成急性心衰竭，二側頸動脈而造成腦中風，脊髓血管而造成下半身麻痺，腎動脈而造成急性腎衰竭，腸繫膜動脈阻塞造成腸壞死，或是下肢單側、雙側缺血而造成肢體缺血之情形。

只侵襲在升主動脈則稱為第二型（TypeII）；如從升主動脈一直經主動脈弓、降主動脈，甚至到腹部主動脈則稱為第一型（TypeI）；若只有在降主動脈（有無包括腹部主動脈）則稱為第三型（TypeIII）。

I-II-III
全-昇-降

以有無侵犯升主動脈作為分類之依據，升主動脈有包括則為 A 型，其餘皆稱作 B 型

是可以降低一半之死亡率，也被推薦為標準的治療方法。
以長期預後而言，手術仍比藥物治療有較長的存活率（統計學上，以三年為例，90% 對 69% ）。手術的方法最主要的方式是以置換升主動脈（或至主動脈弓）及去除內膜撕裂處為主要目的，以避免病患發生升主動脈破裂及改善各器官缺血情況。

藥物為主要治療方法。據 IRAD 統計，如以藥物治療而言，院內治療死亡率接近 10% ，手術治療大約接近 20%。會有如此差異是因為需要手術治療的病患大都是已經破裂、臨破裂及開始有其他器官衰竭，當然在此情況下手術之失敗率將會大為提高。遠端型的主動脈剝離之手術方式也是以置換破裂或是即將破裂之主動脈，及去除內膜撕裂處為主之治療方法。

A = I, II
B = III

(A) 補體（complement)
(B) 巨噬細胞（macrophage）
(C) 細胞激素（cytokines)

Purified from either porcine intestine or beef lung.
3 to 30 kD; half life: 0.5-2hrs; acts by binding to antithrombin III (AT III)
Dosing for CPB ranges from 300 to 500 units/kg; reversed immediately by protamine

(A) 可減少血小板凝集（platelet aggregation)
(B) 可活化抗血栓素（antithrombin）
(C) 可降低血流黏稠度（blood viscosity)

Systemic temperature less than 20ºC and decrease the demand of oxygen and metabolism
Application during great vessel operation
Merit:
bloodless operation field
avoid unnecessary clamping over aorta
tolerance for as long as 30 to 45 mins

(A)循環完全停止，手術視野較清楚，有利於
血管吻合
(C)主動脈不用夾住，可以減少動脈壁傷害
(D)在低溫下，循環可完全停止30至45分鐘，
而不致引起腦部不可逆的傷害

可以減少因體外循環造成的全身炎性反應

Myocardial revascularization without either CPB or cardioplegia reduces the acute inflammatory response but does not prevent it.

Age > 70 years
Low ejection fraction
Reoperative surgery
Significant comorbidities (CVA, PAOD, liver disease, bleeding disorder, COPD, CRF) 
Atheromatous or calcified aorta
Patients who refuse blood products

Hypothermia: oxygen consumption and metabolic rate ↓
Local cooling: iced slush
Cardioplegia (high K solution)
Venting from aortic root or RSPV: prevent endocardium distention  myocardium blood flow ↓

(A)使用高鉀麻痺保護液灌流
(C)左心室引流（venting of left heart）
(D)心包膜腔使用冰水灌流

Cardioplegic solutions contain high K (8 to 20 mEq/L) and Mg
Infused into the aortic root proximal to the aortic cross clamp or retrograde into the coronary sinus to arrest the heart in diastole.

(C) 由肺動脈灌流

Within 14 days : Acute type
After 14 days : Chronic type ( subacute 15-60 days )

叫自來水公司減少供應

Antihypertensive or anti-impulse therapy for all patients with aortic dissection  Combination therapy β-blocker + Calcium-channel blocker
An arterial line for the monitor of systemic arterial blood pressure Systolic BP < 90 ~ 120 mmHg Mean BP < 80 mmHg
EKG monitor：HR 60 ~ 80 bpm
Pain should first be treated with narcotic analgesics

palliation

AMI stent 也不例外

血管吻合處出血不止

(A) 升主動脈破裂造成心包填塞症

(A)病灶包括上行主動脈（DeBakey types I
及II）
(C)其預後較type B 差
(D)藥物治療的目標應將血壓維持於110-120
mmHg 以下

Accumulation of fluid in the pericardial space, resulting in reduced ventricular filling and subsequent hemodynamic compromise.
Pulsus paradoxus or paradoxical pulse  an exaggeration decrease of SBP (>12 mm Hg or 9%) during the normal inspiration

increased jugular venous pressure
hypotension
diminished heart sounds

手術失敗別讓病人死檯子上

要死死在 SICU

吸氣, venous return 增加, but JVP 上升。常見於 constrictive pericarditis

吸氣時靜脈壓（venous pressure）上升

當病人吸氣末端，其心縮壓下降多於10mmHg

impending rupture
uncontrolled hypertension
intractable pain
aneurysmal formation (>6cm in diameter or > 0.5cm/yr propagation)
organ malperfusion

將有內膜裂口（Intimal tear）的動脈部分切除，
以一小段人工血管銜接，使假性腔（False
lumen）關閉

pathology of aortic wall  three
layers( adventitia, media, intima )

Ectasia ： 1.0 ~ 1.5 time of normal size
Aneurysm ： > 1.5 time of normal size

Hypertension
Atherosclerosis
Genetic：Marfan syndrome...
Cystic medial necrosis （cystic medial degeneration ）
Mycotic Aneurysm ：fungus infection in history, but the same mean as infected aneurysm in now
Infected Aneurysm or Infectious aortitis：bacteria infection induced
Traumatic Aneurysm or pseudoaneurysm
Dissection Aneurysm
Syphilis

Asymptomatic ( almost )
Congestive heart failure ( aortic root, AR )
Chest pain ( impending ruptured )
Back pain ( impending ruptured )
Abdominal pain ( impending ruptured )
Pulsative mass
Shock ( ruptured )
Distal thrombosis ( arterial occlusion )
Aortoentero-fistula ( GI bleeding or shock )

sonography; definite diagnosis  CT

Rapid expansion (>0.5cm/year)
Symptomatic
Diameter > 6 cm
infected

5-6 cm

(A) 可能因下腸繫動脈結紮而引起

心肌缺氧

(D) 腎下之腹部主動脈瘤

Failed PTCA
ongoing ischemia with significant territory at risk
shock

Incidence: 10 to 35%
Most result from CAD and MI (trauma, Chagas’ disease, or Sarcoidosis)

documented expansion/large size
angina
congestive heart failure
arrhythmia
rupture
pseudoaneurysm
congenital aneurysm
embolism

(A)梗塞後持續心絞痛

(C)乳頭肌破裂造成二尖瓣閉鎖不全
(D)心肌壞死造成心室中隔缺損

Acute, severe IMR occurs in 0.1% with symptomatic CAD and 0.4% to 0.9% with AMI
Papillary muscle rupture in 5% of all fatal AMI
2/3 of acute, severe IMR involve the posterior papillary muscle even though anterior myocardial infarctions are more common

Prompt surgery is the best chance for survival for most patients with acute, severe postinfarction MR
High percentage of patients have an IABP inserted before anesthesia

糖尿病病人

(A)靜脈移植五年之通暢率為80～85%
(B)靜脈移植十年通暢率為60%
(C)左內乳房動脈移植十年之通暢率為95%

(A)不同程度之慢性心絞痛

(C)不穩定性心絞痛
(D)急性心肌梗塞之併發症

(B) 糖尿病病患

Patients with UA and diffuse multivessel disease are candidates for transmyocardial laser revascularization (TMLR).
This controversial surgical therapy is employed for the surgical treatment of end-stage ischemic heart disease not amenable to percutaneous or conventional surgical operations.

(A) 6 個月後之追踪，約有60~80%病人症狀有改善
(B)其作用機轉可能和心臟神經被去除作用（Cardiac
denervation）有關
(C)其作用機轉可能是心肌局部血管新生（Local
neovascularization）有關

remain controversial

preserves the patient's native valve without a prosthesis
avoid the risk of chronic anticoagulation related bleeding
avoid prosthetic valve failure late after surgery
less frequent endocarditis

higher technical difficulty with long period of learning curve
potentially longer extracorporeal circulation time
recurrent MR due to failure of the annuloplasty (30%)

1. 增進品質
2. 延續生命

(A)二尖瓣再造術（Mitral valve
reconstruction）

(D) 血栓及栓塞症

(A)左迴旋支冠狀動脈

因為術前中後血壓波動極大，所以很容易 AMI

而且會長到 aneurysm 本來很多都是 HTN 的病人

The percentage reduction of the end-diastolic flow as compared with the systolic flow

(economy class syndrome)

氧氣的供需問題

調整供需天平

stasis, hypercoagulability, vein wall injury

Operation ( hip, knee, NS, GS )
Previous DVT history
Immobilization, CVA patients
CHF
Malignancy
Trauma
Age
Obesity
Oral pill, Pregnancy
Other : protein C def, protein S def, Antithrombin-III def.
Homocysteinemia, Antiphospholibid syndrome
HIT ( heparin induce thrombocytopenia )

calf pain

total occlusion of deep vein