Cardiothoracic Surgery Flashcards
Which of the following is not a risk factor in atherosclerosis?
A. Older age
B. Smoking
C. Sleep
D. Alcohol
C. Sleep
Outline the pathophysiological process of atherosclerosis.
Endothelial damage of the tunica intima in combination with elevated lipid levels result in accumulation of LDL in the tunica intima. Macrophages uptake LDL to become lipid-laden foam cells. An inflammatory response is mediated by cytokines which result in Ox-LDL, unable to return to circulation.
Fibrosis and sclerosis may occur which strengthens the atheroma with a fibrous cap.
Increased TNF-a may result in plaque destabilisation and necrosis which leads to plaque rupture.
What is the management for CAD?
Supportive: RF modification; referral to cardiologist
+
Medical: Antiplatelets + Beta blockers + Statins
± Surgery
- PCI with coronary angioplasty
- Coronary artery bypass graft
What is the term for the process of stopping a heartbeat during a CABG?
Cardioplegia using a EC solution with high concentration of electrolytes
What two types of grafts may be used in a CABG?
How do they differ.
Free graft (section entirely separated from original connections before reattaching in new site)
Pedicled graft (graft origin remains in tact and re-routed)
Why may vein grafts have a tendency to become stenosed?
Intimal hyperplasia whereby tunica intima layer becomes thickened due to increased pressure.
What are the complications of a CABG?
Death (2-3%) Stroke (1-5%) Infection AKI Cognitive impairment MI AF
What is the INR range required for those with a mechanical valve?
2.5-3.5
What types of mechanical heart valves exist?
Tilting disc
St Jude (bileaflet valves) - lowest thrombus formation risk
What are the major complications of mechanical heart valves?
Thrombus formation
Infective endocarditis
Haemolysis causing anaemia
What are the types of ASD?
Patent foramen ovale
Ostium secondum
Ostium primum
How is an ASD best heard?
Mid-systolic, crescendo-decrescendo murmur loudest at upper left sternal border with fixed split second heart sound
No change with inspiration and expiration
Why does a fixed split second heart sound occur in ASD?
No change with inspiration and expiration as increased blood flow from L atrium into R atrium across ASD. The increasing volume that the RV most empty before the pulmonary valve ca close thus does not vary with respiration
How may a VSD present?
Pan-systolic murmur more prominent at left lower sternal border in 3/4th ICS
How is a VSD managed?
Surgery: Transvenous catheter closure; Open surgery
How may CoA present?
Systolic murmur infraclavicular; discrepancy of blood pressure in upper cf lower limbs
LV heave
How may a CoA be managed?
Percutaneous balloon angioplasty
Open surgical repair
What are the causes of pericardial effusion?
Infection Autoimmune conditions Injury Uremia Cancer Medications
How may you manage a pericardial effusion?
Tx underlying cause
+
Drainage of effusion: Needle pericardiocentesis; Surgical drainage
A pericardial window may be used to create a fistula allowing fluid to drain the pericardial cavity into pleural or peritoneal cavity
what is the difference between a true and false aneurysm?
True = all 3 layers of aorta
False = 2/3 layers, adventitia contains the blood
How may a thoracic aortic aneurysm present?
Chest or back pain
Trachea or left bronchus compression may cause cough, shortness of breath and stridor
Phrenic nerve compression may cause hiccups
Oesophageal compression may cause dysphagia (difficulty swallowing food)
Recurrent laryngeal nerve compression may cause a hoarse voice
Which type of lung cancer is related to PTHrP secretion?
SCC
Which lung cancer is related to increased ß-hCG secretion?
Large cell carcinoma
Which lung cancer is the most common in non-smokers?
AC
Which lung cancer is typically peripheral and caveatting?
Large cell carcinoma
Which of the following is not an extra pulmonary manifestation of lung cancer?
A. Pemberton’s sign
B. Horner’s Syndrome
C. SIADH
D. Hypocalcaemia
D
Which of the following is not an extra pulmonary manifestation of lung cancer?
A. Pemberton’s sign
B. Horner’s Syndrome
C. Limbic encephalitis
D. Hypernatraemia
D
Which anti-bodies may be present in Limbic encephalitis?
Anti-Hu
What is the management of lung cancer?
MDT meeting \+ Chemo \+ Radio \+ Surgery: Segmentectomy; Lobectomy; Pneumonectomy
What are the three main approaches when doing a lung resection?
Anterolateral thoracotomy with an incision around the front and side
Axillary thoracotomy with an incision in the axilla (armpit)
Posterolateral thoracotomy with an incision around the back and side (the most common approach to the thorax)
A patient presents with SOB suddenly occurring following a fall from height. O/E there is a focal area of hyper resonance and reduced air entry. They are haemodynamically stable.
CXR shows a clear lung edge.
What is your management?
<2cm = watch and wait + 2 week follow up
> 2cm = aspiration by needle
Where do you insert a chest drain?
Emergency is 2nd ICS in MCL
Triangle of safety: AAL + MAL + 5th ICS (lat dorsi edge)
Go above the rib to avoid the NV bundle at the rib edge
Check air is bubbling through fluid into the drain bottle
Should a chest drain fail to correct or there is recurrent pneumothoraces, what management options are available?
Pleurodesis (abrasive or chemical)
Pleurectomy
Talk through the process of a lung/heart transplant.
Indications, approach, incisions, processes and post-op care.
Indications for heart: IHD; CM; CHD
Indications for lung: CF; COPD; PH; PF
Approach: lateral thoracotomy; Midline sternomotomy; Clamshell incision
Time between donor and transplant must be short (<6hrs); cold ischaemic time follows then operation begins whilst organ being transported; cardiopulmonary bypass + LMWH; cardioplegia; transplant; warmed; cardioplegia reversed ± temporary pacing or cardioversion used; transfer to intensive care
Immunosuppression
Following a heart transplant a patient is regularly monitored with CT-Angiography. What complication of heart transplants are being screened?
Cardiac allograft vasculopathy (CAV)
The donor heart is not innervated, meaning the patient will experience symptoms of ischaemia in the heart tissue. This means they will not have any symptoms of angina or myocardial infarction following stenosis of coronary arteries
Destruction of the bronchioles 1 year following lung transplant is termed?
Bronchiolitis Obliterans Syndrome (BOS)
Acute pulmonary oedema and alveolar damage with reduced SpO2 within 2 days of lung transplant surgery is termed?
Primary graft dysfunction
What are the risk factors for a rib fracture?
- Blunt trauma
- Physical abuse
- OP
- Advanced age: > 45 years
- Athletics
- Bone tumours/metastases
How do you manage a rib fracture?
• Supportive: Analgesia/ Physiotherapy/ Tx underlying cause
+
Tx complications
If >2 adjacent ribs…
Surgery: Rib fixation
What clinical feature is key to pleurisy?
Pleuritic chest pain - inspiratory exacerbated chest pain
Give 3 examples of transudative pleural effusion.
Portal hypertension
Cardiac failure
Renal failure
Hypoalbuminaemia
How may a unilateral diaphragm paralysis present?
What may be seen in CXR?
Paradoxical chest wall movements
Elevated hemidiaphragm (due to Phrenic nerve palsy)
