Surgery 1 – vascular and cardiac surgery

Last updated on July 14, 2020 at 16:22

1. Indications and complications of carotid endarterectomy

  • Carotid endarterectomy
    • A surgical procedure where the inner lining of a carotid artery is removed, along with any atherosclerosis
    • The procedure effectively reduces the risk of later strokes, but carries some risk for perioperative stroke and other complications
    • Indications
      • Symptomatic patients with > 60% stenosis
        • I.e., the carotid artery stenosis has caused stroke/TIA
      • Asymptomatic patients with > 70% stenosis
    • Contraindications
      • Asymptomatic 100% occlusion
      • Large risk of perioperative stroke
      • Previous neck surgery/irradiation
    • Complications
      • Perioperative hypertension is the largest risk factor for complications
      • Myocardial infarction
      • Stroke
        • Ischaemic, due to postoperative thrombosis or embolism
        • Haemorrhagic
      • Cerebral hyperperfusion syndrome
        • If a previously hypoperfused area suddenly receives perfusion again
        • Previously hypoperfused areas have impaired autoregulation, causing hyperperfusion of the area when perfusion returns
        • Can cause oedema and seizures
      • Cervical haematoma
      • Nerve injuries
        • Especially hypoglossal, facial, recurrent laryngeal
      • Carotid restenosis
  • Percutaneous transluminal angioplasty (balloon dilation)
    • Can be used as an alternative after restenosis or in case of previous neck surgery/radiation

2. Open and endovascular surgery in the treatment of abdominal aortic aneurysm

  • Abdominal aortic aneurysm (AAA)
    • = focal dilation of abdominal aorta by > 1,5x the normal diameter or > 3 cm
    • Epidemiology
      • > 60 years
      • White men
    • Etiology
      • Smoking
      • Hypertension
      • Hypercholesterolaemia
      • Atherosclerosis
    • Classification according to location
      • Suprarenal
      • Infrarenal (below renal arteries)
        • Most common
    • Clinical features
      • Most are asymptomatic
        • Symptoms indicate a leaking AAA or imminent rupture
      • Lower back pain
      • Pulsatile abdominal mass
      • Bruit (swishing) on auscultation
      • Grey Turner sign (ecchymosis of flank)
      • Cullen sign (periumbilical ecchymosis)
    • Diagnosis
      • US
      • US has near 100% sensitivity and specificity
    • Complications
      • Rupture
        • Hypovolaemic shock
        • Sudden severe tearing pain in back or abdomen
        • Painful pulsatile abdominal mass
      • Thrombosis
        • Due to turbulence, thrombi can form inside the aneurysm
        • Can cause embolism of distal vessels
    • Treatment
      • Conservative
        • If asymptomatic and < 5,5 cm
        • Normalize BP
        • Smoking cessation
        • Regular (1-3x a year) ultrasound
      • Surgery
        • Elective surgery indicated if any of the following:
          • Diameter > 5,5
          • Aneurysm expands > 1 cm per year
        • Immediate surgery indicated if any of the following:
          • Symptoms are present
          • Rupture
        • Endovascular aneurysm repair (EVAR)
          • Preferred over open surgery
          • Done under local anaesthesia
          • Entry through femoral or iliac arteries
          • An expandable stent graft is placed inside the lumen of the AAA
        • Open surgery
          • Laparotomy -> the aneurysm is replaced with a tube graft

3. Endovascular and hybrid procedures in the arteries of the lower extremity

  • Indicated if medical treatment fails to improve symptoms
    • See topic 12
  • Endovascular procedures
    • Access to the artery through the skin (percutaneous)
    • Often common femoral artery
  • Hybrid procedures
    • Refers to performing both endovascular and surgical procedures in the same operative setting
    • Used in more severe cases
    • See topic 15 for more information on surgical procedures
    • Common hybrid procedures
      • Iliac stenting + femoro-popliteal bypass
      • Iliac stenting + common femoral endarterectomy
  • Vascular imaging
    • Must be done before the procedures
    • CT angiography
  • Treatment options
    • Balloon angioplasty
      • A balloon is led into the stenosed area, which will then inflate to dilate the vessel
      • The balloon will remain inflated for a few minutes
    • Stent placement
      • A stent is led into the stenosed area
      • The stent will either expand by itself or by the help of a balloon, depending on the type of stent
      • The stent will remain in the vessel, keeping it open
    • Atherectomy
      • Specialized tools “shaves” atherosclerotic plaques from the inside of the vessel
  • Treatment choice according to anatomical site of disease
    • Aortoiliac region
      • Balloon angioplasty or stents
    • Femoropopliteal region
      • Balloon angioplasty or stents
    • Infrapopliteal region
      • Balloon angioplasty
      • Stents are not used due to narrow arteries
  • Postinterventional management
    • Antiplatelet treatment
      • Lifelong aspirin
    • Statins
    • Regular monitoring

4. Epidemiology and pathophysiology of peripheral occlusive arterial disease

  • Peripheral artery disease
    • = narrowing or occlusion of peripheral arteries due to atherosclerosis
    • Generally coexists with CAD
    • Etiology (risk factors for atherosclerosis)
      • Smoking
      • Hypertension
      • Hypercholesterolaemia
      • General risk factors for AS
    • Epidemiology
      • Rare < 40 years
      • Peak 60 – 80 years
      • Equal gender distribution
      • Blacks are at higher risk than whites
    • Fontaine classification
      • Stage I – asymptomatic
      • Stage II – pain on exertion
        • IIa – claudication at walking distance > 200 m
        • IIb – claudication at walking distance < 200 m
      • Stage III – pain at rest
      • Stage IV – necrosis/gangrene/ulcers
    • Clinical symptoms of peripheral artery disease
      • Claudication
        • Pain which is consistently reproduced with exercise, and relieved by rest
        • The location of the occlusion determines the location of the pain
        • Buttock and hip pain – aortoiliac disease
          • Aortoiliac disease refers to occlusion of abdominal aorta or common iliac artery
          • Erectile dysfunction can also occur
        • Thigh pain – aortoiliac or common femoral artery
        • Upper 2/3 of calf pain – superficial femoral artery
        • Lower 1/3 of calf pain – popliteal artery
        • Foot pain – Tibial or peroneal artery
      • Skin changes
        • Cold skin
        • Decreased hair growth
        • Decreased nail growth
        • Muscle atrophy
      • Pain at rest
        • In severe stenosis (Fontaine stage III)
      • Ulcer, gangrene
        • In limb-threatening stenosis (Fontaine stage IV)
  • Peripheral embolism
    • See topic 12

5. Imaging of Vascular Disease

  • Doppler ultrasound
    • A small device which uses Doppler ultrasound to amplify the sound of arterial blood flow
    • Used because the sound of arterial blood flow in the arteries of the ankles are too small to be heard with a stethoscope
    • Indications
      • Used to measure the ankle-brachial index (ABI)
  • Duplex ultrasound
    • Duplex ultrasound combines B-mode ultrasound and Doppler ultrasound to produce images with both anatomical information and information of blood flow
      • This is sometimes also called “Doppler ultrasound”, which makes the distinction from the previous device confusing
    • Is the first-line investigation for most arterial and venous diseases
    • Indications
      • Identify the site of arterial occlusion in peripheral artery disease
      • Identify aneurysms
      • Identify DVTs
      • Identify incompetent valves in chronic venous insufficiency
  • Angiography
    • Indications
      • If revascularization treatment is indicated, to plan the procedure
    • Each modality has advantages and disadvantages, but frequently CTA or MRA is performed before DSA
    • CT angiography
      • Cannot be used in heavily calcified vessels
    • MRi angiography
      • Tend to overestimate the severity of vascular disease
    • Digital subtraction angiography
      • Invasive
      • Therapeutic intervention can be done in the same procedure

6. The pathophysiology and symptoms of chronic venous insufficiency

  • Chronic venous disorders (CVD)
    • An umbrella term for chronic disorders of the veins of the legs
    • More common in women
    • Includes disorders like varicose veins, chronic venous insufficiency, etc.
    • The chronic venous disorders are classified according to the CEAP classification
    • CEAP stands for Clinical, Etiological, Anatomical and Pathophysiological
      • However, classifying the patient according to E, A and P are not as important as C
    • Clinical classification
      • C0 – No signs of venous disease
      • C1 – Telangiectasias
      • C2 – Varicose veins
      • C3 – Oedema
      • C4a – Pigmentation or eczema
      • C4b – Lipodermatosclerosis or atrophie blanche (white atrophy)
      • C5 – Healed venous ulcer
      • C6 – Active venous ulcer
      • When classifying the patient clinically, subscripts A and S are used to indicate whether the patient is asymptomatic or asymptomatic, respectively
    • Etiological classification
      • Ec – Congenital
      • Ep – Primary
        • Family history
        • Sedentary lifestyle
        • Obesity
        • Smoking
      • Es – Secondary
        • Prior thrombosis (in which case it’s called post-thrombotic syndrome)
        • Prior trauma
      • En – No cause identified
    • Anatomical classification
      • As – Superficial veins
      • Ap – Perforating veins
      • Ad – Deep veins
      • An – No location identified
    • Pathophysiological classification
      • Pr – Reflux
      • Po – Obstruction
      • Pr,o – Reflux and obstruction
      • Pn – No pathophysiology identified
  • Chronic venous insufficiency (CVI)
    • Refers to severe chronic venous disease, where there is significant oedema, skin changes or ulceration (clinical stage C3 or higher)
    • CVI affects 2 – 5 % of adults in US
    • Pathophysiology
      • Venous hypertension, whether due to obstruction or reflux, impedes flow in the veins
        • Reflux occurs if the valves of the deep veins become incompetent, so that blood refluxes backwards instead of flowing back to the heart, increasing the pressure in the veins
          • When walking, calf muscles pump blood from the deep veins toward the heart, reducing the pressure inside the veins
          • When the valves are incompetent, blood is pumped backwards into the superficial veins during walking instead of towards the heart, thereby increasing pressure in these veins rather than reducing it
        • Obstruction, e.g. due to a thrombus, also causes hypertension proximal to the obstruction
      • Poor flow traps WBCs in the veins, which release proteolytic enzymes which damage the capillary basement membranes
      • This causes plasma to leak into the interstitium, causing oedema
      • Oedema decreases oxygen delivery to tissues, causing inflammation and hypoxia
      • Extravasation of RBCs causes haemosiderosis, causing pigmentation
    • Clinical features
      • Oedema
      • Heaviness of the leg
      • Pain
        • Pain is worsened when standing and relieved by walking
        • This is opposite of how it is in PAD
      • Skin changes
        • Itching
        • Stasis dermatitis
        • Pigmentation
        • Varicose veins
        • Lipodermatosclerosis
          • Localized inflammation and fibrosis of skin
          • Causes induration and pain
        • White atrophy (atrophie blanche)
          • White atrophic plaques of skin
          • Due to absence of capillaries in the fibrotic tissue
  • Varicose veins
    • Varicose veins are superficial veins which have become dilated and tortuous to the point where they’re visible and palpable on the legs
    • Varicose veins affect 25% of all adults in the US
    • Pathophysiology
      • Incompetence of the valves of the deep veins causes reflux into the superficial veins, increasing the pressure in these veins
      • As the pressure increases the lumen dilates
      • Eventually the lumen is so dilated that the flaps of the valves can’t make contact in the lumen of the superficial veins, making them incompetent too

7. Surgical treatment of chronic venous insufficiency

  • Diagnosis of chronic venous insufficiency
    • Duplex ultrasound
      • Shows retrograde flow lasting > 0,5 seconds
  • Treatment
    • Conservative
      • Indications
        • All patients
      • Compression
        • Stockings which apply 20 – 30 mmHg
      • Frequent elevation of legs
      • Physical therapy
      • Manual lymphatic drainage by massage
      • Avoid long periods of standing
    • Surgical
      • Indications
        • Symptoms despite conservative therapy
        • Recurrent superficial thrombophlebitis
        • Variceal bleeding
        • Venous stasis ulceration
      • Endovenous thermal ablation
        • First-line
        • Radio waves or laser are used to heat the vein, damaging the endothelium and causing obliteration
      • Sclerotherapy
        • Second-line
        • Direct injection of a sclerosing agent into the vein, which obliterates the vein
      • Open surgical removal of vein
        • Only for veins not accessible by the above techniques

8. Diagnosis and treatment of acute deep vein thrombosis and superficial thrombophlebitis

  • Deep vein thrombosis (DVT)
    • Diagnosis
      • The Wells score for DVT is used to identify the probability of the patient having DVT
        • Active cancer -> +1 point
        • Previous DVT -> +1
        • Recent immobilization of lower extremity -> +1
        • Recently bedridden or major surgery -> +1
        • Tenderness along deep veins -> +1
        • Swelling of entire leg -> +1
        • Calf swollen > 3 cm compared to other calf -> +1
        • Unilateral pitting oedema -> +1
        • Presence of collateral (non-varicose) superficial veins -> +1
        • Alternative diagnosis at least as likely as DVT -> -2 points
      • If the score is < 2 then DVT is unlikely
        • Perform D-dimer.
          • Negative result: DVT excluded
          • Positive result: Perform compression ultrasound
            • Negative: Repeat ultrasound after 5 days
            • Positive: DVT most likely, start therapy
      • If the score is 2 or more then DVT is likely
        • Perform compression ultrasound
          • Negative result: Perform D-dimer
            • Negative: DVT excluded
            • Positive: Repeat ultrasound after 5 days
          • Positive: DVT most likely, start therapy
      • D-dimer
        • High sensitivity, low specificity
        • Normal value rules out DVT (high negative predictive value)
        • High value can occur in many conditions
          • DVT
          • Cancer
          • Infection
          • Inflammation
          • etc.
      • Compression ultrasound with Doppler
        • Examiner applies gentle pressure to the veins
          • Healthy veins are compressed
          • Obstructed veins aren’t compressed (by gentle pressure)
        • Findings indicative of DVT
          • Non-compressible vein
          • Hyperechoic thrombus
          • Absent or abnormal flow on Doppler imaging
    • Treatment
      • Acute (initial) anticoagulation
        • Heparin, LMWH or fondaparinux
        • Is stopped after the secondary prophylaxis has reached stable level
      • Secondary prophylaxis (long-term maintenance therapy)
        • Warfarin (INR 2,0 – 3,0) or DOACs
        • Should be initiated same day as the acute anticoagulation
        • Treatment should remain for at least 3 months
          • Unless there is thrombophilia or recurrent thrombosis, in which case the treatment will last indefinitely
      • Thrombolysis or thrombectomy
        • Indicated in phlegmasia cerulea dolens and massive DVT
        • Thrombolysis can be systemic or catheter-directed
        • Thrombectomy is used if thrombolysis is contraindicated
  • Superficial thrombophlebitis
    • = inflammation and thrombosis of a superficial vein, rather than a deep vein
    • May co-exist with DVT
    • Risk factors same as for DVT, plus
      • Varicose veins
      • Venous cannulation
    • Clinical features
      • Pain
      • Induration
      • Erythema
      • All of these over a superficial vein
      • The thrombosed vein may be visible as a palpable cord
    • Diagnosis
      • Based on clinical findings
      • Duplex ultrasound may show thickened non-compressible vessel with or without thrombus
    • Treatment
      • If uncomplicated (< 5 cm vein affected, remote from deep veins, no risk factors for DVT)
        • NSAID
        • Compression
        • Elevation
      • If complicated (infection, > 5 cm vein affected, close to deep veins)
        • Anticoagulation
        • Surgery

9. Mesenteric and renal artery disease. Symptomatology and management

  • Mesenteric artery disease
    • Acute mesenteric ischaemia
      • Relatively rare
      • High mortality rate (> 70%)
      • Etiology
        • Mesenteric artery occlusion (2/3 of cases)
          • Embolic origin (1/3 of cases)
          • Thrombotic origin (1/3 of cases)
        • Non-occlusive mesenteric disease (1/3 of cases)
        • Mesenteric venous thrombosis (very rare)
      • Clinical features
        • Severe, diffuse abdominal pain
        • Vomiting
        • Diarrhoea
      • Treatment
        • Thrombectomy/embolectomy
        • Determine viability of bowel
        • Resect any non-viable bowel
        • Determine viability of bowel again after 24 hours
    • Chronic mesenteric ischaemia
      • Etiology
        • Atherosclerosis of mesenteric artery
      • Pathophysiology
        • Causes chronic mesenteric ischaemia if at least two of the three major splanchnic arteries (coeliac trunk, SMA, IMA) have severe stenosis
        • These arteries have good collaterals, so ischaemia occurs only if two or three of them are stenotic
        • The SMA is one of the stenotic arteries in almost 100% of cases
      • Clinical features (of chronic mesenteric ischaemia)
        • Abdominal angina
          • Dull postprandial pain in epigastrium
          • Patient avoids eating to avoid pain -> weight loss
        • Patient often has other symptoms of atherosclerosis as well
          • PAD, CAD, etc.
      • Diagnosis
        • Rule out cancer
          • Can cause similar symptoms
        • DSA
        • Duplex ultrasound
        • MR angiography
      • Treatment
        • Percutaneous transluminal angioplasty of affected arteries
          • With stenting
        • Surgical bypass of stenosed arteries
          • Only if anatomy doesn’t allow for stenting
  • Renal artery disease
    • Refers to renal artery stenosis
    • Etiology
      • Atherosclerosis (90% of cases)
      • Fibromuscular dysplasia (10% of cases)
        • Mostly affects young women
    • Clinical features
      • Renovascular hypertension
        • Reduced blood flow to the kidney is interpreted by the juxtaglomerular apparatus as low BP -> RAAS activation
        • Renovascular hypertension is usually encountered in clinical practice as hypertension which is resistant to treatment
      • Hypokalaemia
        • Due to RAAS overactivation
      • Renal dysfunction
        • Due to chronic renal ischaemia
    • Diagnosis
      • Decrease in renal function (increased creatinine) when using ACEIs or ARBs indicates renal artery stenosis
        • These patients are usually put on RAAS-blocking drugs for their hypertension, which will worsen renal function
      • Imaging
        • Duplex ultrasonography
        • CT angiography or MR angiography
        • Renal arteriography
          • Invasive, so only performed if non-invasive imaging is inconclusive
    • Treatment
      • Indicated in
        • Treatment-resistant hypertension
        • Decreased renal function
      • Procedures
        • Percutaneous transluminal renal angioplasty
          • = dilating a balloon in the stenosed segment of the renal artery
          • First-line
          • If atherosclerosis is present: Stenting is performed
          • If fibrodysplasia is present: Stenting is not performed
        • Surgical bypass of stenosed segment
          • Only if anatomy doesn’t allow for stenting

10. Physical and instrumental examination of vascular anomalies

  • Vascular anomaly = any type of anomaly of the vascular system
  • Two main groups:
    • Vascular tumours – abnormal proliferation of endothelium
      • Infantile haemangioma
        • Not present at birth, arises during infancy
      • Congenital haemangioma
        • Present at birth
      • Angiosarcoma
      • Others
    • Vascular malformations – abnormal development of vessels
      • Low-flow vascular malformations
        • Venous, capillary and/or lymphatic malformations
      • High-flow vascular malformations
        • Arterial malformations
        • Arteriovenous fistula – single, direct connection
        • Arteriovenous malformation – “tangle” of abnormal vessels
  • History
    • Was the lesion present at birth?
    • How is the rate of growth of the lesion?
      • Proportionate to the child’s growth
      • Disproportionate to the child’s growth
  • Physical examination
    • High-flow vascular malformations
      • Have palpable pulse or thrill
      • Are warm
    • Low-flow vascular malformations
      • Soft, compressible
      • Venous malformations
        • Blue mass
      • Capillary malformations
        • Flat pink or red macules
      • Lymphatic malformations
        • Large, non-tender, spongy mass
  • Instrumental examination
    • Duplex ultrasound
      • First examination to be performed
        • Often provides enough information so that other examinations are not necessary
      • Vascular tumours
        • Solid masses
        • High flow inside
      • Arteriovenous malformations and fistulae
        • No mass
        • High flow inside
      • Venous malformations
        • No mass
        • Low flow inside
      • Lymphatic malformations
        • No mass
        • Low or no flow inside
        • Cystic structure
      • Try to compress the lesion
        • High-flow anomalies can’t be compressed
        • Low-flow anomalies can be compressed
      • Identify important nearby structures
        • Important for surgical planning
    • MRI
      • Can also examine flow
      • Can examine deeper structures
    • Invasive imaging
      • For deep vascular malformations

11. The conservative treatment options for peripheral arterial disease

  • Aims of therapy
    • Reduce risk factors for atherosclerosis
    • Stimulate collateral angiogenesis
  • Conservative treatment
    • Smoking cessation
    • Supervised graded exercise therapy
      • Patient should walk to the point of claudication for 30 – 45 minutes at least three times per week
      • Claudication pain is not dangerous
    • Weight loss
    • Improve diet
  • Medical treatment
    • Long-term antithrombotic therapy
      • Aspirin or clopidogrel
    • Medical treatment of hypertension
    • Medical treatment of diabetes
    • Medical treatment of dyslipidaemia
      • Statin
    • Cilostazol or nafridrofuryl
      • Indicated if symptoms don’t improve after 3 months of conservative and medical therapy

12. Acute clinical symptoms and treatment of peripheral arterial disease

  • Acute limb ischaemia
    • Acute limb ischaemia is a vascular emergency
    • It can be caused by thrombosis or embolism
    • The clinical features and treatment are different, depending on the cause
  • Acute limb ischaemia due to embolism
    • Pathophysiology
      • An embolus, often from a heart with A-fib or an aortic aneurysm, occludes an artery in the leg
      • These patients often don’t have PAD and therefore don’t have good collaterals
      • This occlusion is therefore limb-threatening
    • Clinical features
      • 6 P’s distal to the site of occlusion
        • (strong) Pain
        • Pallor
        • Pulselessness
        • Paralysis/paresis
        • Paraesthesia
        • Poikilothermia
          • The affected area takes the temperature of the surrounding (usually cold)
    • Treatment
      • IV heparin
      • Emergency embolectomy, thrombolysis or transcatheter thrombectomy
      • Amputation
        • If the limb is unsalvageable
  • Subacute limb ischaemia due to thrombosis
    • Pathophysiology
      • Rupture of an atherosclerotic plaque causes thrombosis to form on the ruptured surface
      • This almost always occurs in patients who already have PAD
      • These patients have developed a good collateral circulation, which makes this occlusion less severe
      • This causes subacute ischaemia rather than acute
    • Clinical features
      • The patient will experience a subacute worsening of PAD symptoms
        • Over hours/days
      • 4 P’s distal to the site of occlusion
        • (Strong) Pain
        • Pallor
        • Pulselessness
        • Poikilothermia
      • Paralysis/paresis and paraesthesia don’t occur, thanks to the collateral circulation
    • Treatment
      • Angiography to localize occlusion
      • Open or catheter-directed thrombectomy, or thrombolysis
      • Amputation
        • If the limb is unsalvageable
  • Revascularization syndrome
    • A potential complication of restoring blood flow to severely ischaemic limb
    • May develop if acute ischaemic limb is not managed within 8 hours
    • Clinical features
      • Oedema
      • Myoglobinuria
      • Renal injury
      • Hyperkalaemia
      • ARDS
    • Treatment
      • Forced diuresis
      • Haemodialysis
      • Fasciotomy
        • To prevent compartment syndrome due to muscle swelling

13. Symptoms and Treatment of Thoracic Outlet Syndrome

  • Thoracic outlet syndrome
    • Symptoms occurring due to compression of structures like
      • Brachial plexus (95% of cases)
      • Subclavian vein (4% of cases)
      • Subclavian artery (1% of cases)
    • Caused by narrowing of the anatomical opening called “thoracic inlet”, “thoracic outlet” or “superior thoracic aperture”, which is a hole surrounded by
      • Clavicula
      • The first rib
      • Scalenus anterior
      • Scalenus medius
    • Etiology
      • Trauma
        • Collarbone fracture
      • Hypertrophy of scalenus muscles
      • Pancoast tumor
      • Congenital cervical (extra) rib
    • Clinical features
      • Neurogenic thoracic outlet syndrome
        • Due to compression of brachial plexus
        • Pain, anaesthesia, paraesthesia in neck and arm
        • Often in areas innervated by ulnar nerve
      • Venous thoracic outlet syndrome
        • Due to compression of subclavian vein
        • Swelling
        • Venous distension
        • Venous thrombosis
      • Arterial thoracic outlet syndrome
        • Due to compression of subclavian artery
        • 4 Ps
          • Pulselessness
          • Pain
          • Pallor
          • Paraesthesia
    • Treatment
      • Physical therapy
        • In mild cases, can be enough
      • Thoracic outlet decompression surgery
        • Transaxillary resection of extra rib or first rib
        • Angioplasty, if vessels are affected

14. Clinical manifestations and treatment of upper extremity arterial disease

  • Etiology
    • Atherosclerosis
    • Vasculitis
    • Arterial dissection
  • Clinical features
    • Most are asymptomatic, having only a difference in systolic BP between the arms
    • Arm pain with exertion (claudication)
    • In severe cases
      • Arm pain in rest
      • Ulceration of the digits
  • Subclavian steal syndrome
    • Occurs if the subclavian artery is occluded proximal to the origin of the vertebral artery, causing symptoms
      • If the patient has this occlusion but is asymptomatic, they don’t have subclavian steal syndrome (yet)
    • Pathophysiology
      • As the subclavian artery is occluded it cannot supply the ipsilateral arm with blood
      • However, the blood can flow from the contralateral vertebral artery into the ipsilateral vertebral artery (at the level of the basilar artery), and flow retrograde through the vertebral artery to supply the arm
      • The vertebral artery functions as a “bypass” for the subclavian stenosis
      • During exertion of the arm either of these symptoms can occur
        • Arm ischaemia – as the vertebral bypass is insufficient for the arm
        • Cerebral ischaemia – as blood is “stolen” from the brain
          • This doesn’t occur unless cerebrovascular occlusions exist simultaneously, as the carotids can supply the brain
    • Clinical features
      • Arm ischaemia
        • Pain
        • Cool skin
      • Cerebral ischaemia
        • Dizziness
        • Syncope
  • Diagnosis
    • Arm blood pressure difference of > 15 mmHg
    • Duplex ultrasound
  • Treatment
    • Similar to that of PAD of the lower extremities

15. Surgical treatment options of the chronic lower extremity arterial disease

  • Invasive treatment of PAD
    • Indicated if
      • Symptoms don’t improve after 3 – 6 months of conservative and medical therapy (including cilostazol)
      • Patient has rest pain
      • Patient has arterial ulcer or gangrene
    • Endovascular treatment
      • = Percutaneous transluminal angioplasty
      • First choice
      • Often with stent
    • Surgical treatment
      • Thrombendarteriectomy may be performed, but bypass is most common
      • Surgical bypass
        • A graft connects an artery proximal to the stenosis to an artery distal to the stenosis, allowing blood to bypass the stenosis
      • Used if endovascular treatment was insufficient or anatomy does not allow for endovascular approach
      • The great saphenous vein is preferred as a graft
        • Other veins and even artificial prostheses may also be used
        • The veins must be turned so that the valves point the right way
      • “Anatomical” (normal) bypass
        • Aorto-iliac bypass
          • The graft connects the aorta to the common iliac artery
        • Aorto-bifemoral bypass (Y-graft)
          • The graft connects the aorta to both common femoral arteries
        • Femoro-popliteal bypass
          • The graft connects the common femoral artery to the popliteal artery
        • Femoro-distal bypass
          • The graft connects the common femoral artery to an artery distal to the popliteal artery, like the posterior tibial artery
      • Extra-anatomical bypass
        • The surgical creation of new pathways for the blood which don’t follow normal anatomical arteries
          • The graft will connect two arteries which normally aren’t connected
        • Axillo-femoral bypass
          • A graft connects the right axillary artery with the femoral artery
        • Axillo-bifemoral bypass
          • A graft connects the right axillary with both femoral arteries
        • Femoro-femoral bypass (crossover bypass)
          • A graft connects one femoral artery to the contralateral one

16. A brief history of heart surgery. Overview of the cardiac surgery interventions.

  • Brief history of heart surgery
    • 1896 – First successful myocardial suture
    • 1928 – First cardiac catheterization
      • Dr Forssmann catheterized his own heart with a urinary catheter through the cephalic vein, walked to the radiology department and took an x-ray, which showed the catheter inside his right atrium
    • 1950s – Extracorporeal circulation was invented
    • 1950s – ASD and VSD operations
    • 1960 – First CABG
    • 1964 – First internal thoracic artery – LAD bypass
  • Overview of cardiac surgery interventions
    • Coronary artery bypass grafting (CABG)
    • Valve replacement
      • Aortic valve replacement (AVR)
      • Mitral valve replacement (MVR)
      • Tricuspid valve replacement (TVR)
    • Valvuloplasty – valve repair
      • Tricuspid valvuloplasty (TVP)
      • Mitral valvuloplasty (MVP)
    • Treatment of congenital condition
      • Ventricular septal defects (VSD)
      • Atrial septal defects (ASD)
      • Ductus Botalli persistens (DBP) = Patent ductus arteriosus (PDA)
    • Operations on thoracic aorta
      • On ascending aorta
      • On the aortic arch
    • Aneurysmectomy
    • Aneurysm plication
    • Heart transplantation
    • Pacemaker implantation

17. Extracorporeal circulation, hypothermia, cardioprotection.

  • Extracorporeal circulation (ECC)
    • Refers to a procedure where part of the patient’s circulation is moved outside the body
    • There are multiple types of extracorporeal circulation
      • Cardiopulmonary bypass
      • Extracorporeal membrane oxygenation (ECMO)
      • Not important for us right now:
        • Haemodialysis
        • Haemofiltration
        • Plasmapheresis
    • Cardiopulmonary bypass (CPB)
      • Also called heart-lung machine or simply “the pump”
      • Used together with cardioplegia in heart surgery
        • Cardioplegia = temporary cessation of cardiac activity
        • Used to keep the heart still during heart surgery
        • Is most commonly accomplished by administering a potassium-rich solution, which stops the heart in diastole
        • Can also be accomplished by cooling the heart
      • Can also be used to induce hypothermia, by cooling the blood
      • Procedure
        • Patient is heparinised (300 – 400 units/kg)
        • First cannula is inserted to a vein
          • Right atrium, vena cava, etc.
        • Second cannula is inserted to an artery
          • Ascending aorta, femoral artery, etc.
        • Aorta is clamped to isolate the heart from the systemic circulation
        • The machine pumps blood out from the first cannula, filters and oxygenates it, then pumps it back into the second cannula
      • Complications
        • Haemolysis
        • Haemodilution
        • Acidosis
        • Inflammatory response
        • Abnormal coagulation, possibly DIC
        • Embolization
    • Extracorporeal membrane oxygenation (ECMO)
      • A “simplified” CPB used to support the circulatory system in severe respiratory or cardiac failure
      • Indications
        • Respiratory distress syndrome
        • Severe pulmonary oedema
        • Acute decompensated heart failure
      • Used as a
        • bridge to recovery – buying patient time to recover
        • bridge to decision – buying physicians time to decide next step
        • bridge to transplant – supporting patient while waiting for transplant
      • Differences from CPB
        • Can be used long-term, unlike CPB
        • Cannot cool the blood
        • Cannulas are inserted into peripheral vessels, not central ones
        • Less heparin is required
      • 2 cannulas are either inserted into a vein and an artery (VA ECMO) or into two veins (VV ECMO)
      • VV ECMO
        • Used to support patients with respiratory failure
        • Does not provide cardiac support
      • VA ECMO
        • Used to support patients with cardiac failure with or without respiratory failure
        • Provides both respiratory and cardiac support
  • Hypothermia
    • Induced hypothermia is used, together with a CPB, to allow total circulatory arrest in the surgical treatment of some vessels
      • Aneurysms involving aortic arch
      • Valve surgery
    • Hypothermia can be used instead of cardioplegic solution to induce cardioplegia
      • In patients who has contraindication to cardioplegic solution
    • Hypothermia is used to decrease oxygen consumption of patient on CPB, decreasing the required CO and protecting the brain
  • Cardioprotection
    • = measures to protect the myocardium from perioperative damage, especially myocardial infarct
    • Certain high-risk patients experience high rate of perioperative myocardial infarct
    • Several measures have been proposed to protect the hearts of these high-risk patients against this
    • Possible contributing factors of perioperative myocardial infarct
      • Graft occlusion
      • Graft kinking or overstretching
      • Graft spasm
      • Ischaemic reperfusion injury
      • Systemic inflammatory injury due to CPB
      • Surgical manipulation of the heart
    • Ischaemic reperfusion injury
      • When the clamp on the aorta is removed, the heart is reperfused, causing reperfusion injury
    • The only cardioprotection measure currently in wide use is cardioplegia

18. Cardiac surgery anaesthesia, perioperative intensive therapy.

  • Preoperative
    • Assessment of patient’s state
    • Evaluate risk and benefit of procedure
      • The EUROSCORE scoring system scores the patient based on risk factors, and provides an estimate of perioperative mortality
    • Premedication
      • Benzodiazepines
  • Cardiac surgery anaesthesia
    • The most important goal during anaesthesia is to maintain haemodynamic stability
      • Tachycardia can increase myocardial oxygen demand, causing ischaemia
    • Monitoring
      • ECG
        • Continuous monitoring for myocardial ischaemia
      • Invasive blood pressure
      • Central venous pressure
        • Via central venous catheter
      • Right heart catheter (Swan-Ganz catheter)
        • Catheter in the pulmonary artery via the right heart
        • Can measure pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, systemic vascular resistance (SVR)/total peripheral resistance (TPR)
      • PiCCO – pulse-induced continuous cardiac output
        • More modern system
        • Can measure CO, SVR
        • Needs only a central venous catheter and a special PiCCO catheter, no catheterization of the heart needed
      • SpO2
      • Urine output
      • Temperature
      • Transoesophageal echocardiography
    • Induction
      • Fentanyl + propofol + pipecuronium
      • Heparin before the CPB
      • Start tranexamic acid infusion
        • An antifibrinolytic which reduces bleeding complications
      • Antibiotic prophylaxis
    • Maintenance
      • Propofol infusion (total intravenous anaesthesia (TIVA)) and/or sevoflurane
    • Weaning from CPB
      • Normalize patient’s circulation
      • Gradually let the heart take over the CPB’s function
      • Reinfusion of blood inside the CPB
    • Post-bypass period
      • Venous and arterial decannulation
      • Protamine to reverse heparin
        • May cause the so-called “protamine reaction”
      • The SVR is low after the CPB and protamine
        • Vasoconstrictors are often necessary
      • In case of acute heart failure
        • Inotropes
        • Mechanical support
          • Intra-aortic balloon pump (IABP)
            • See topic 24
          • VA ECMO
      • Patient remains on ventilator and in anaesthesia
  • Postoperative intensive care
    • Ensure haemodynamic stability
      • Monitoring
      • Administering fluid
      • Reduction of vasoconstrictor dose
      • Control bleeding
    • Monitor for complications
      • Pericardial tamponade
      • Acute kidney injury
      • Arrhythmias
        • 40% of patients having cardiac surgery develop A-fib
    • Control pain
      • Pain causes tachycardia, tachypnoea and sympathetic activation, all of which increase oxygen demand, increasing the risk for hypoxic damage to the heart and other organs
      • Opioid + NSAID or paracetamol
    • Eventually wean patient from ventilator and anaesthesia

19. The surgery of pericardial diseases. Heart tumors.

  • Pericardial diseases
    • Acute cardiac tamponade
      • Treatment
        • Pericardiocentesis
          • Percutaneous drainage of pericardial fluid
          • Echo guidance is often used
          • Faster than surgical drainage
          • Difficult to drain small amounts of fluid
        • Surgical drainage of pericardial fluid
          • Preferred over pericardiocentesis in:
          • Purulent pericarditis
          • Haemopericardium after trauma or aortic dissection
          • Post-infarction rupture of ventricular wall
          • Re-accumulation of fluid after pericardiocentesis
          • Small amounts of fluid
    • Chronic constrictive pericarditis
      • Treatment
        • Pericardiectomy
          • Surgical removal of pericardium
    • Chronic effusive pericarditis
      • Etiology
        • Cancer
        • Autoimmune disease
      • Treatment
        • Medical
          • Diuretics
          • NSAIDs
        • Surgical
          • If medical treatment fails or effusion causes tamponade
          • Pericardiocentesis
          • Percutaneous balloon pericardial window
            • An incision in the pericardium which allows continuous drainage from pericardial space into pleural cavity
            • A balloon catheter is lead into the incision
            • The balloon is inflated to create a window
          • Pericardiotomy
  • Heart tumours
    • 70% of heart tumours are benign
    • The most common benign tumour is the myxoma
    • Cardiac myxoma
      • Most arise in the left atrium
      • Clinical features
        • May produce emboli, causing stroke
          • Embolization occurs in 30% of cases
        • May obstruct blood flow, causing syncope or sudden death
        • May deform valves, causing symptoms of valve regurgitation or stenosis
      • Treatment
        • Open the left atrium or both atria
        • Remove the myxoma and the part of the atrial septum it was attached to
          • This is done to reduce the recurrence rate
        • The defect in the atrial septum is closed by a suture or a patch

20. Surgical treatment of ischemic heart disease.

  • Coronary artery bypass grafting (CABG)
    • Indications
        • See cardio topic 17
    • Autologous grafts
      • Internal thoracic/mammary artery
        • Best graft
          • Lowest mortality
          • Longest durability
          • Best results
        • This artery originates from the subclavian artery, so it can simply be cut on the distal end and attached to the coronary vessel to bypass
      • Great saphenous vein
      • Radial artery
    • Technique (for traditional (on-pump) CABG)
      • Midline sternotomy
      • Cardiopulmonary bypass
        • Heart empties of blood and becomes motionless
      • Induce cardioplegia
      • Two approaches are possible at this point
        • Left internal thoracic artery is diverted and attached distally to the stenosis
        • The great saphenous vein is attached to the aorta and distally to the stenosis
    • Variations
      • Traditional (on-pump) CABG
      • Minimally invasive CABG
        • Off-pump CABG
          • Used to avoid complications of cardiopulmonary bypass (CPB), which can be serious in patients with comorbidities
          • No CPB is used, so heart is beating
          • Stabilizers are used to stabilize the surface of the heart, so that surgery can be performed on the arteries
        • Minimally invasive direct CABG
          • No CPB is used
          • Minimally invasive techniques, like anterolateral thoracotomy or minithoracotomy are used
        • Totally endoscopic CABG
          • Robot-assisted
    • Complications
      • Perioperative infarction
      • Postpericardiotomy syndrome
      • Cardiac tamponade
      • Occlusion of bypass graft
      • Arrhythmias
    • Follow-up
      • Life-long antiplatelets
        • ASA with or without clopidogrel
      • Secondary prevention of AMI
        • Statins
        • Beta blocker
        • Lifestyle changes
      • Regular controls (1 – 2x a year)
  • Treatment of acute mechanical complications of AMI
    • Life-threatening conditions with close to 100% mortality
    • Etiology
      • Wall rupture
      • Ventricular septal rupture
      • Papillary muscle rupture
      • Chorda rupture
    • Treatment
      • Circulatory support
      • Correct mechanical complication
      • CABG

21. Surgical management of valvular heart disease.

  • General
    • The aortic and mitral valves are those valves which are most commonly in need of surgical treatment
    • For most diseases of heart valves, the definitive surgical treatment is valve replacement
      • Heart valves can be replaced by biological or mechanical valves
      • Mechanical valve
        • Patients must be on life-long anticoagulation
      • Biological valve
        • A portion of the valve comes from cow or pig
        • Patients must only be on anticoagulation for 3 months
        • Doesn’t last as long as a mechanical valve
    • In some cases, valve repair (valvuloplasty) may be an option
    • Cardiopulmonary bypass and hypothermic cardioplegia are standard for open heart procedures on the valves
    • Diagnosis of heart valve disease is mainly by Doppler echocardiography
      • Can detect calcification, scarring, abnormal motion of leaflets, decreased area, direction and speed of flow, etc.
    • Follow-up after valve operation
      • Anticoagulation with coumarins
        • Life-long with mechanical valves
        • 3 – 6 months with biological valves
        • INR 2 – 3 for aortic valves and 2,5 – 3,5 for mitral valves
        • If the patient should undergo any operation, they should change to LMWH 1 week before the operation
      • Endocarditis prophylaxis
        • Amoxicillin + clavulanic acid or erythromycin
        • Before dental procedure or other invasive interventions
  • Surgical valve replacement (SVR)
    • Open surgery
    • Procedure
      • Diseased valve is removed
      • The size of the patient’s annulus is measured
      • A replacement valve of appropriate size is chosen and sutured to the annulus
  • Transcatheter valve implantation (TVI)
    • Minimally invasive surgery
    • Preferred in most patients where possible and feasible
      • Especially patients who have high surgical risk
    • Procedure
      • A valve replacement is folded and inserted into a catheter
      • The catheter is led retrograde from the femoral artery and into the heart
      • The diseased valve is not removed, but the valve replacement is expanded over it, pushing the diseased valve to the side and replacing its function
  • Aortic stenosis
    • Clinical features
      • Dyspnoea on exertion
      • Angina
      • Syncope
    • Area of aortic valve
      • Normal area – 4,0 – 3,0 cm2
      • Mild stenosis – 3,0 – 1,5 cm2
      • Significant stenosis – < 1,5 cm2
    • Valve replacement indicated in
      • Symptomatic patients
      • Asymptomatic patients with significant stenosis
      • Signs of heart failure or progressive LV dilation
  • Aortic regurgitation
    • Acute aortic regurgitation causes pulmonary oedema and dyspnoea, possibly acute heart failure
    • Chronic aortic regurgitation causes progressive heart failure
    • Valve replacement indicated in
      • Symptomatic patients
      • Asymptomatic patients with significant regurgitation
      • Signs of heart failure or progressive LV dilation
  • Mitral regurgitation
    • Many cases of mitral regurgitation can be treated by surgical valve repair rather than replacement
      • Valve repair is preferred over replacement, where possible
    • Valve repair or replacement indicated in
      • Symptomatic patients
      • Asymptomatic patients with significant regurgitation
      • Signs of heart failure or progressive LV dilation
  • Complications of valve replacement
    • Paravalvular leak
      • Blood may pass next to the valve instead of only through it
      • This may cause progressive heart failure or haemolytic anaemia
    • Thromboembolism of the valve
    • Endocarditis of the implanted valve
      • Prosthetic valves are at higher risk for endocarditis
  • Acute valve diseases
    • Examples
      • Tearing of mitral valve chord
      • Valve perforation (due to endocarditis)
      • Rupture of aortic valve cusp
      • Thrombosis on artificial valve
      • Rupture of papillary muscle
    • Require emergency surgical repair and/or replacement

22. Aortic atherosclerosis, aneurysm, dissection.

  • Acute aortic syndrome (AAS)
    • An umbrella term for three diseases of the aorta:
    • Aortic dissection
    • Intramural thrombus
    • Penetrating aortic ulcer
  • Aortic dissection
    • Epidemiology
      • Males > females
      • 60 – 80 years
    • Etiology
      • Hypertension
      • Trauma
      • Syphilis
      • Drug abuse
      • Atherosclerosis
      • Connective tissue disease
    • Stanford classification
      • Stanford type A (proximal)
        • Affects the ascending aorta, may extend to the descending aorta too
      • Stanford type B (distal)
        • Any dissection which does not involve the ascending aorta
    • Clinical features
      • Sudden, severe, ripping pain
        • Location depends on the dissected aortic segment
    • Diagnosis
      • X-ray
        • Widened mediastinum
      • Transoesophageal echo
        • If patient is haemodynamically unstable or there is suspicion for ascending aortic involvement
      • CT angiography
        • If patient is haemodynamically stable and there is no suspicion for ascending aortic involvement
      • ECG
        • To exclude ACS, or to detect myocardial ischaemia as a consequence of the dissection
    • Treatment
      • Stanford type A
        • Emergency surgery
      • Stanford type B
        • If complications -> emergency surgery
        • If no complications -> medical treatment only
          • Medical treatment appears to have a lower mortality rate than surgery in this population
      • Medical treatment
        • Medical treatment is always indicated
          • It lowers BP and decreases LV contraction velocity, thereby decreasing stress on the aortic wall
          • The medical treatment for aortic dissection is called “anti-impulse therapy”
        • Beta blockers (Esmolol or labetalol)
        • Nitrates
        • Opioids
      • Emergency surgery
        • Bentall procedure
          • Replacement of the aortic valve and the aortic root by a graft
          • If the aortic valve is damaged, it has to be replaced too
        • Aortic arch repair – replaces the aortic arch with a prosthesis
          • Total arch prosthesis – if the brachiocephalic trunk is affected
          • Hemi-arch prosthesis – if the brachiocephalic trunk is unaffected
        • Frozen elephant trunk
          • A hybrid (open + endovascular) procedure for Stanford type A
          • Ascending aorta is replaced with open surgery (arch prosthesis)
          • Descending aorta is repaired by endovascular surgery (stent graft)
    • Complications
      • Organ ischaemia
        • Arteries which originate from the aorta may be occluded or connected to the false lumen after a dissection
        • Myocardial infarction
        • Stroke
        • Acute renal failure
        • Acute mesenteric ischaemia
      • Rupture
        • -> Haemorrhagic shock
      • Aortic regurgitation
        • If the dissection extends into the aortic valve
  • Thoracic aortic aneurysm (TAA)
    • For abdominal aortic aneurysm, see topic 2
    • TAA = focal dilation of thoracic aorta > 150% of normal diameter
    • Location
      • Ascending aorta
        • Most common location
      • Descending aorta
        • May extend into the abdomen
      • Aortic arch
    • Clinical features
      • Often asymptomatic, or causing nonspecific symptoms
      • Feeling of pressure in chest
      • Thoracic chest pain
    • Diagnosis
      • X-ray
        • Not sensitive or specific
      • CT or MR angiography
        • Gold standard
    • Treatment
      • Medical treatment
        • To limit further dilation
        • Beta blockers to maintain normal BP
      • Surgical treatment
        • Endovascular surgery (Stent grafting)
        • Open surgery
      • Indications for surgical repair:
        • For asymptomatic patients:
          • Ascending aneurysm > 5,5 cm
          • Descending aneurysm > 5,5 cm
          • Aneurysm expands > 1 cm/year
        • All symptomatic patients
      • If surgery is not indicated
        • Medical treatment and regular follow-up
    • Complication
      • Rupture

23. Injuries of the heart and the great arteries.

  • Injuries of the heart and great arteries
    • Etiology
      • Gunshot
      • Stab wound
      • Compression
      • Deceleration
        • Car accident
        • Falls
      • Iatrogenic injury
    • Complications
      • Haemorrhagic shock
      • Tamponade
      • Pneumothorax or haemothorax
    • Diagnosis
      • eFAST
      • Chest x-ray
      • CT
    • Treatment
      • Emergency thoracotomy
        • In tamponade, haemodynamic instability or cardiac arrest
        • To stabilize the patient

24. The surgical treatment of heart failure.

  • Surgical options in heart failure
    • Heart transplantation
    • Mechanical circulatory support
    • Cardiac resynchronization therapy
  • Heart transplantation (HTX)
    • The gold standard treatment for end-stage heart failure
    • Unfortunately, there is a relative lack of donors
      • Annually there are about 3000 HTX, but there is a need for several ten thousand
    • Indication
      • NYHA class IV +
      • EF < 20% +
      • No other viable treatment options
    • Contraindications
      • > 60 – 65 years
      • Active infection
      • Diabetes
      • Severe PAD
      • Lung disease
      • Cancer
      • Pulmonary hypertension
      • Alcohol or drug abuse
    • Roughly 40% of patients receiving HTX have been bridged with mechanical circulatory support
      • Bridging to HTX reduces mortality and costs
    • Patients must take immunosuppressants life-long
      • Mycophenolate mofetil + tacrolimus + steroids
  • Mechanical circulatory support
    • Indications
      • Severe heart failure despite optimal medical therapy
    • Aims
      • Bridge to heart transplantation
        • They are used as a temporary measure to keep patient alive and stable until transplantation
      • Destination therapy
        • They are used as a permanent measure, if the patient is not eligible for transplant
    • Types
      • Temporary vs permanent
      • Total artificial heart vs ventricular assist devices
      • Pulsatile vs continuous flow
      • Extracorporeal vs intracorporeal
  • Ventricular assist devices (VAD)
    • = A mechanical device implanted into the heart which supports the function of one or both ventricles
    • Types
      • Left ventricular assist device (LVAD)
      • Right ventricular assist device (RVAD)
      • Biventricular assist device (BiVAD)
    • Products
      • Berlin Heart INCOR VAD
        • Intracorporeal, continuous flow, permanent VAD
      • Berlin Heart EXCOR VAD
        • Extracorporeal, continuous flow, permanent VAD
      • HeartMate
        • Intracorporeal, pulsatile flow, permanent VAD
  • Total artificial heart (TAH)
    • = A mechanical device which replaces the heart and its function
    • Used instead of VAD as a bridge to transplant when there is considerable biventricular dysfunction or structural abnormalities which prevent VAD implantation
      • Using it as destination therapy is under investigation
    • Much less frequently used than VADs
    • Products
      • SynCardia TAH
  • Intra-aortic balloon pump
    • A device which lies in the aorta
    • It pumps itself up once every diastole, providing an extra “heartbeat” which pumps blood to coronaries and brain
    • Temporary, pulsatile mechanical circulatory support
    • Indications
      • Failure of inotropic treatment
      • Cardiogenic shock
  • Cardiac resynchronization therapy (CRT)
    • A biventricular pacemaker which coordinates the timing of the ventricles
      • It has three leads, one in right atrium, one in right ventricle and one in left ventricle
    • This solves cardiac desynchrony in patients with intraventricular conduction delay, like LBBB
      • This improves CO and slows the progression and improves symptoms
    • Indication
      • Symptomatic HF despite optimal medical treatment +
      • LVEF < 35% +
      • Wide QRS
    • Types
      • Cardiac resynchronization therapy pacemakers (CRT-P)
        • Does not have defibrillator function
      • Cardiac resynchronization therapy defibrillators (CRT-D)
        • Has defibrillator function (it’s basically a combined CRT and ICD)
        • Used if there is a concomitant indication for ICD (see cardio topic 12 and surgery 1 topic 25)

25. Surgical treatment of arrythmias, and pacemaker therapy.

  • Cardiovascular implantable electronic devices (CIED)
    • Includes temporary and permanent pacemakers, ICDs, CRTs
  • Pacemakers
    • Parts
      • Pulse generator
        • Contains battery and generator
          • Battery lasts 8 – 15 years
        • Generates the impulses which are conducted to the leads
        • Also senses impulses coming from the heart
      • Leads
        • Wires which transmit impulses to and from the heart
        • The wires elute steroids to decrease the inflammation it causes
    • Pacing modes
      • Pacemakers can be programmed into many different modes, depending on how they should work
        • Which chambers the pacemaker paces, which chambers the pacemaker senses the spontaneous rhythm of, the response of the pacemaker to the sensing, etc.
        • Three letters are used to describe the mode
          • The first letter describe the chamber which the pacemaker can pace, and is either O (none), A (atrium), V (ventricle) or D (dual/both)
          • The second letter describes the chamber which the pacemaker can sense the spontaneous rhythm of, and is either O, A, V, or D
          • The third letter describes the pacemaker’s response to the sensed signal, and is either I (inhibition), T (trigger), or D (both)
      • On demand modes
        • Includes AAI, VVI, DDD
        • The pacemaker senses the spontaneous rhythm of the chamber and only paces the chamber if the spontaneous rhythm of the patient goes below a certain programmed threshold, like 60 bpm
        • Most commonly used
        • AAI – for sinus node dysfunction with intact AV node
          • In this mode the pacemaker only paces the atria if the SA node rate goes below the programmed threshold
        • VVI – for intact SA node with AV block
          • In this mode the pacemaker only paces the ventricle if the AV node rate goes below the programmed threshold
        • DDD – for both SA and AV dysfunction, intact SA node + AV block, or SA dysfunction + intact AV node
          • DDD has the advantage over AAI and VVI in that the pacing will be physiological, i.e. the pacemaker will ensure that the ventricles contract some time after the atria, like physiologically
      • Asynchronous modes
        • Includes AOO, VOO, DOO
        • The pacemaker doesn’t sense the spontaneous rhythm of the patient at all and instead paces the heart at a fixed rhythm
        • Small risk of R-on-T
        • Only used during surgical procedures
          • As the pacemaker could sense the tools used during the surgery
      • Synchronous modes
        • Includes AAT, VVT
        • The pacemaker will pace the same chamber as it senses the spontaneous rhythm too, which there is no use in
        • Virtually never used
  • Temporary pacemakers
    • Usually used to treat symptomatic bradyarrhythmias until they resolve, or permanent treatment can be initiated
      • If it’s evident that a permanent pacemaker will be needed later, it’s usually better to skip the temporary pacemaker and just implant a permanent one
        • If a permanent pacemaker cannot be implanted at the current time, for example if the patient needs urgent pacing, a temporary pacemaker can be used as a bridge to permanent pacemaker implantation
      • As such, temporary pacemakers are most commonly used as bridge to recovery, i.e. to wait for the resolution of a transient or reversible cause
    • Indications
      • AV block
        • As a bridge to permanent pacemaker, unless the AV block is reversible
      • Acute myocardial infarction-induced rhythm disorders
        • These are often temporary
      • Electrolyte disturbances
      • Drug toxicity
        • Beta blockers
        • CCBs
    • Technique
      • Temporary pacing is most commonly achieved with a transvenous approach
      • This means that the catheter will be inserted into a vein and led back to the heart
      • Commonly used veins are the jugular, subclavian and femoral veins
      • Transcutaneous approach is also possible, but is only used when urgent temporary pacing is needed
  • Permanent pacemakers
    • Indications
      • Sick sinus syndrome
        • Only if symptomatic
      • Type II second degree AV block
      • Third degree AV block
      • Bundle branch block
        • Only if symptomatic
    • Procedure
      • A small incision is made inferior to the clavicle
      • The leads are led through the subclavian into the desired heart chamber
        • Fluoroscopy is often used to guide the lead
      • The generator will be placed in a subcutaneous pocket
  • Implantable cardioverter-defibrillator (ICD)
    • An implantable device similar to a pacemaker
    • Can detect a fibrillating heart and defibrillate it
    • Used to prevent sudden cardiac death and all-cause mortality
    • Primary prevention
      • Patients with symptomatic HF and LVEF < 35%, AND have either ischaemic heart disease OR dilative cardiomyopathy
      • These patients should receive an ICD
    • Secondary prevention
      • Patients who have experienced ventricular arrhythmia causing haemodynamic instability and recovered
        • Like V-fib, sudden cardiac arrest, ventricular flutter
      • These patients should receive an ICD

26. Atrial septal defect (ASD), Partial pulmonary vein transposition. Atrioventricular septal defect (AVSD).

  • General about congenital heart surgery
    • Indications for operation
      • Symptoms of circulatory failure
      • Frequent airway infections
      • Growth retardation
      • Prevention of Eisenmenger syndrome
    • Earlier, congenital heart diseases were treated with several stages of operations
      • Initially, palliative surgeries would reduce symptoms, while the final, reconstructive surgery was delayed
    • Nowadays total anatomical reconstruction is performed in one surgery, even in newborns
    • Diagnosis
      • Mainly echocardiography
    • Some congenital heart diseases, like transposition of the great vessels and tetralogy of Fallot, require the ductus arteriosus to remain open in order to ensure adequate circulation
      • They are so-called “ductus-dependent” lesions
      • Prostaglandin E1 (alprostadil) is administered in these patients to maintain the ductus arteriosus
    • The degree to which the congenital heart condition causes left-to-right shunting is important for the prognosis, and can be measured
      • Physiologically, the pulmonary blood flow (Qp) and systemic blood flow (Qs) are the same
      • In most cases, the left-to-right shunting is significant if the pulmonary blood flow is more than twice that of the systemic (Qp/Qs > 2)
  • Palliative surgeries
    • Pulmonary artery banding
      • A band is tied around the pulmonary artery, thereby reducing blood flow into the lungs, decreasing pulmonary hypertension
      • It is used in congenital heart defects with high pulmonary blood flow
    • Aorto-pulmonary shunts
      • These extra-anatomical shunts connect the aorta or subclavian artery with the pulmonary artery, increasing the blood flow into the lungs
      • It is used in congenital heart defects with low pulmonary blood flow
  • Atrial septal defect (ASD)
    • A left-to-right shunt
    • Most commonly a patent foramen ovale
    • Surgical treatment
      • Indications
        • Qp/Qs > 2
        • Paradoxical embolism has occured
      • Should be performed before school age
      • The defect can be closed by a patch or by direct closure (suturing)
  • Partial anomalous pulmonary venous return (PAPVR)
    • (= partial pulmonary vein transposition)
    • Some of the pulmonary veins don’t drain into the left atrium
    • Often occurs with ASD
    • A left-to-right shunt
    • Surgical treatment
      • In symptomatic patients and large defects
      • Surgical correction of the anomaly
  • Atrioventricular septal defect (AVSD)
    • A left-to-right shunt
    • Classified according to the Rastelli classification
      • Rastelli type A, B and C
    • Surgical treatment
      • Closed with patches
      • AV valves must also be repaired

27. Ventricular septal defect (VSD). Persistent ductus arteriosus (PDA).

  • Ventricular septal defect (VSD)
    • A left-to-right shunt
    • Surgical treatment
      • Indications
        • Qp/Qs > 2
      • The defect is closed by a patch
  • Patent ductus arteriosus (PDA)
    • A left-to-right shunt
    • Ductus arteriosus usually closes after a few days
    • The DA can be closed in premature infants by administering NSAIDs
      • This does not work in older infants
    • Surgical treatment
      • All PDAs should be closed
      • The ductus arteriosus is closed by a clip, by stitching or by a patch
      • A more recent approach is to occlude the PDA during cardiac catheterization

28. Congenital aortic stenosis, pulmonary stenosis.

  • Congenital aortic stenosis
    • 75% are valvular
    • 20% are subvalvular
    • 5% are supravalvular
    • Surgical treatment
      • In those with severe obstruction
      • Balloon aortic valvuloplasty or surgical valvotomy
  • Pulmonary stenosis
    • Surgical treatment
      • In everyone with significant stenosis
      • Balloon pulmonary valvuloplasty or surgical valvotomy

29. Complete Pulmonary vein transposition. Transposition of the great arteries.

  • Total anomalous pulmonary venous return (TAPVR)
    • None of the pulmonary veins connect to the left atrium
    • Patient is usually haemodynamically unstable at birth
    • Surgical treatment
      • All cases must be treated
      • As soon as diagnosis is made and patient is stable
      • A direct pathway between pulmonary veins and left atrium is established surgically
  • Transposition of great vessels
    • Incompatible with life unless a bidirectional shunt exists in the heart
      • If no such shunt exists, an artificial ASD can be made by balloon dilatation
    • Surgical treatment
      • All cases must be treated
      • An “arterial switch procedure” is performed, where the two great vessels are resected, switched and sutured back

30. Tetralogy of Fallot. Tricuspid atresia, Ebstein’s anomaly

  • Tetralogy of Fallot
    • Involves
      • Pulmonary infundibular stenosis (= right ventricular outflow tract obstruction)
      • VSD
      • Overriding aorta
      • Right ventricular hypertrophy
    • Surgical treatment
      • In all patients
      • Patch closure of the septal defect
      • Reconstruction of the outflow
  • Tricuspid atresia
    • Surgical treatment
      • In all patients
      • Consists of three separate surgeries performed at three separate times
        • First stage – in neonatal period
        • Second stage – after a few months
        • Third stage – after a few years
  • Ebstein’s anomaly
    • Involves malformed and displaced tricuspid valve leaflets, causing tricuspid regurgitation, causing right ventricle enlargement
    • Surgical treatment
      • In severely symptomatic patients
      • Repair of tricuspid valve (valvuloplasty)
      • Reconstruction of right ventricle

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4 thoughts on “Surgery 1 – vascular and cardiac surgery”

  1. Hello dear sir,

    I would like to draw your attention to topic 3, in which under hybrid techniques the example of iliac stenting + femoral-popliteal bypass combination is a classical example and mentioned in class as the example we should know (back in the days when we still had seminars)

  2. Dear sir,

    I would like to draw your attention to topic 2; the laparotomy surgery is not the aorta replaced by it a tube graft, but rather you have to exclude it from circulation, thorough an aorto-aortic anastamosis with tubing (after removing potential wall thrombus and stuff)

    1. I’m not sure that’s correct, I find multiple sources writing that the aneurysm is “replaced” by the tube graft. It also seems like that on pictures.

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