12. Surgery Flashcards
Where does the AV node sit in relation to a membranous VSD?
Posterior-inferior rim
What can cause high-grade AV block after membranous VSD repair?
Damage to AV node
*Possibly a suture in the posterior-inferior rim too close to AV node
True or false: Secundum ASD repair increases risk for AV block
False
Ascending aorta to PA shunt?
Waterston
Descending aorta to LPA shunt?
Potts
Why are Waterston or Potts shunts rarely done?
Hard to regulate size (too big can lead to pulm HTN + PVOD)
High rate branch PS
What do inappropriately large AP shunts have risk for?
- Pulmonary HTN
2. PVOD
What types of AP shunts can result in a more predictable shunt volume?
- Central shunt
- Modified BTT shunt
*Synthetic shunt that is a specific size
What is a classic BTT shunt?
Direct connection to left or right subclavian artery to ipsilateral branch PA
Why are classic BTT shunts no longer preferred?
Frequent shunt obstruction
What effect does severe PS have on risk for PVOD?
Protects the pulmonary vascular bed and decreases risk of pulmonary vascular disease
Most common indication to late reoperation after complete AVSD repair?
Left AVVR
*Uncommon indications: Small residual atrial/ventricular shunts, right AVVR
What % of AVSD patients have a need for late reoperation?
15-20%
In which type of AVSD is LVOTO a frequent indication for reoperation?
Partial
*LVOTO is infrequent indication for reoperation in complete AVSD
Strongest predictor for developing MR after repair of AVSD?
Pre-operative severe MR
*LV size/hemodynamics can influence this, but not as strong of association
True or False: The degree of cleft in the left AV valve is a predictor of post-operative left AVVR
False: Cleft in left AV valve is universal - doesn’t predict post-op regurgitation
Does the need for an annuloplasty ring in repair of left AV valve in AVSD predict post-op regurgitation?
No - It doesn’t independently predict post-op regurgitation
*It may reflect the degree of pre-op regurgitation (which is strongest predictor for MR after AVSD repair)
What index is used to predict operability in PA-VSD?
Nakata
Equation for Nakata index?
LPA area + RPA area + MAPCA area/BSA
*Measure PAs just proximal to 1st lobar branch, include MACPAs that perfuse an entire lung segment and could be unifocalized
Patients with a Nakata over what are considered to be a good candidate for complete repair (including potential unifocalization)?
200
Patients with a Nakata under 200 are at increased risk for what with complete repair?
Pulmonary HTN and right heart failure
*No intervention or limited surgical palliation may be better option
What should you consider for a patient s/p aortic valve replacement with complete heart block post-op?
Compromised coronary artery perfusion
*Can get compression of coronary by valve, transection of coronary or tension/kinking with reimplantation
Post-op heart block
ST segment changes
Ventricular dysfunction
Possible compromised coronary artery perfusion
How do you definitively identify a compromised coronary artery?
Angiography
What supplies the AV node in most people?
Branch of RCA
Fontan with DOE and cyanosis that is worse in standing position… cause?
Pulmonary AVM
What 2 things can cause DOE and orthostatic or exertional cyanosis in Fontan patients?
- R-L shunting at a fenestration
2. R-L shunting from pulmonary AVMs
Most common location for a pulmonary AVM in a Fontan patient?
Basal region
*Why cyanosis is worse with standing v. supine
What EP issue are patients s/p Atrial switch (Mustard) at high risk for?
Sinus node dysfunction
Where is the sinus node located?
Posterior RA along superior-lateral aspect of SVC
Why is sinus node dysfunction seen in atrial switch patients?
In the Mustard/Senning a patch baffle is sutured along the posterior (sinus venosus) wall of the RA to direct systemic venous return across the atrial septum to the left sided subpulmonary ventricle… this is very close proximity to sinus node with risk for damage (surgical disruption of that area)
What are the components of a Stage I hybrid procedure?
- Band PAs
2. Stent PDA (interventionalist does this)
How does a hybrid procedure minimize risk as a stage 1 option?
Doesn’t require CP bypass or circulatory arrest… this minimizes risk and may reduce early-stage mortality in high risk neonates
What would cause progressive left heart distention in a ToF + PA patient after initiation of CP bypass using bicaval and aortic vannulation?
AP collaterals
*Persistent pulmonary blood flow returning to LA not accounted for in bypass circuit
If the aorta isn’t cross-clamped going onto bypass, what could cause LV distention?
Significant AI
During bypass, what would a persistent left SVC cause?
RV distention… the persistent left SVC drains to the CS and blood returns to the RA
Most common cause of reoperation in partial AVSD?
MR
Cause of reoperation for AVSD patients which is more common in partial AVSD versus complete AVSD?
LVOTO
SOB, cardiomegaly and increased pulmonary vascularity in a repaired AVSD should make you consider what 2 things?
- MR
2. LVOTO
In a repaired partial AVSD, what should an ejection-type systolic murmur that diminishes with Valsalva make you consider?
LVOTO
In primary pulmonary HTN, what would you expect to see on CXR?
Diminished pulmonary vascularity
Harsh 4/6 systolic murmur months following bypass surgery with no clear valvular problems, but increased gradient in ascending aorta?
Aortic cannulation injury
*Get narrowing in the aorta where it was cannulated for CP bypass
When does ALCAPA usually present?
2-3 months
Why does ALCAPA present at 2-3 months?
When PVR falls, the anomalous coronary artery loses perfusion pressure
What will echo show in ALCAPA?
Dilated LV with poor function (due to myocardial ischemia from anomalous coronary)
Why would a patient with ALCAPA have MR?
Risk for ischemia/infarction of the mitral valve papillary muscles
What normally perfuses the tricuspid valve papillary muscles?
Branches of RCA
In ALCAPA what pre-op finding is most closely associated with post-op mortality and need for late reoperation?
MR
What is the most common long-term complication in patients with repaired Scimitar?
Pulmonary vein obstruction
What is Scimitar syndrome?
Anomalous right pulmonary veins connecting to IVC
What 2 things is the surgical repair in Scimitar dependent on?
- Proximity of anomalous venous connection to RA
2. Presence of ASD
How is Scimitar repaired?
- Anomalous connection transected
- Right veins reimplanted to RA or LA
- If implanted to RA, right pulmonary venous return is directed across ASD into LA by patch baffle
Interrupted IVC patient s/p Glenn who has become desaturated… what is likely cause?
Intrapulmonary shunting
Why is the development of pulmonary AVMs a risk with Glenn (classic cavopulmonary anastomosis)?
Lack of hepatic effluent in blood flow to lungs
What should be done for a desaturated Glenn with interrupted IVC?
Hepatic vein incorporation (higher risk for development of pulmonary AVMs without hepatic factor)
What is a classic Fontan?
Direct RA-PA anastomosis
What is a modified Fontan?
Extracardiac conduit or lateral tunnel
Patient with a classic Glenn who is desaturated and cath has low sat in RLPV… possible cause?
AVMs in right lung
What is a risk with the classic cavopulmonary anastomosis (Glenn)?
Development of AVMs
What is a classic Glenn?
Direct end-to-end anastomosis of SVC to RPA
What is missing in the pulmonary circulation in Glenn physiology?
Hepatic factor (effluent)
*HF prevents the development of AV fistulae
True or False: Incorporation of hepatic venous return to the pulmonary circulation can resolve pulmonary PVMs and improve saturations?
True
What is a DKS anastomosis
Connection of ascending aorta to MPA (end-to-side)
*Used with single-ventricle/LVOTO and allows for retrograde perfusion of coronaries via a reconstructed “neo-aortic” arch
Why is surgical enlargement of the VSD not used in tricuspid atresia with D-TGA?
Risks damage to conduction system causing rhythm disturbance and ventricular dysfunction
Which type of PV intervention produces better relief of stenosis, but often a greater degree of regurgitation?
Percutaneous (versus surgical)
If there is a good initial outcome after surgical valvotomy for the pulmonary valve, what is the risk of need for future reoperation?
Likely <5% over 10 years
What are features that make someone with PA-IVS not a candidate for 2V repair?
- RV hypoplasia
- TV annulus Z-score <3
- Coronary to RV fistulae
What are some features that make someone with PA-IVS a candidate for 2V repair?
- Reasonable RV size, tripartite
- TV Z-score -2 to -2.5
- Functional TV
- No coronary-cameral fistulas (RV dependent coronary circulation)
What needs done for an infant with PA-IVS and a small RV with coronary-cameral fisulae?
BTT shunt
Why can’t you decompress a RV in someone with PA-IVS and coronary cameral fisulae?
Decreases coronary perfusion pressure resulting in diffuse myocardial ischemia
Successful outcome after complete repair of PA + VSD correlates with what?
Post-operative RVSP
What should be done after coming off bypass for a complete repair of PA+VSD if there is poor systemic BP and near systemic RVSP?
Re-open VSD
- Limited CO due to increase PVR with VSD closed, VSD allows a pop-off
- Patients may need palliation v. complete repair
What is preferred surgical approach for truncus arteriosus?
- Early complete repair within 1st month of life
- Delaying intervention increases risk for irreversible pulmonary vascular obstructive disease
Most common indication for reoperation in a patient with a history of truncus arteriosus?
RV-PA conduit failure
Other Potentials: Neo-aortic valve regurgitation, neo-aortic valve stenosis, RV-PA conduit failure, residual VSD, branch PA stenosis
How long to homograft or synthetic conduits tend to last?
10-15 years
*Almost always become stenotic and/or regurgitant
What is more common in truncus, neo-aortic valve regurgitation or neo-aortic valve stenosis?
-Regurgitation: Can often be managed without surgical intervention until mod-severe
CoA in 1 y/o with LA 117/79 and LL 99/70, bicuspid Ao valve, mild AI, mild AscAo dilation, normal LV function, LV wall thickness upper limits of normal. Strongest reason for surgery?
BP
-Systemic HTN + Mild gradient + CoA = Surgical treatment
What are 2 ways to measure severity of CoA?
- Anatomically (estimated Doppler gradient)
- Non-invasive BP
If the SBP gradient is <20mmHg, what are other factors which may push to surgery for CoA?
- Systemic HTN
- LV dysfunction
- Significant collateral arteries
In HLHS, when is the highest risk of mortality?
Between stage 1 and stage 1
Describe the 3 stages for single ventricle palliation for HLHS
1: Excision of any remaining atrial septal tissue, separation of PAs from MPA trunk, BTT shunt to branch PAs, construction of neo-aortic arch using MPA tissue
- RV is systemic ventricle and pulmonary valve functions as the systemic (neo-aortic) valve
- Usually done in 1st week of life in term neonates without comorbidities
2: Takedown of BT shunt and placement of an SVC to PA anastomosis (bidirectional cavopulmonary anastomosis)
- Typically occurs around 6-9 months (depending on growth and cyanosis)
3: Anastomosis of IVC to PAs via extracardiac conduit or lateral tunnel along the lateral wall of the RA (modified Fontan)
- Can be done as early as 2 years
What could cause progressive cyanosis, mild metabolic acidosis, mild hypotension, tachypnea, increased pulmonary vascular markings in a neonate shortly after hybrid Norwood palliation?
Restrictive ASD
*Pulmonary congestion from pulmonary venous obstruction… only way for pulmonary venous return to reach systemic circulation is via ASD
After a hybrid Norwood palliation, how would retrograde aortic arch obstruction from the PDA stent present?
- Coronary hypoperfusion
- Decreased ventricular function
After a hybrid Norwood palliation, how would obstruction of the branch PAs present?
- Decreased saturations
- Clear lung fields
What is the goal of stage 1 surgical palliation (Norwood) for HLHS?
Relief of ductal-dependent systemic blood flow
- HLHS = No LV output so systemic blood flow is from RV via PDA
- Goal is to establish stable systemic blood flow
What is the most common indication for re-operation after ASO in D-TGA?
Supravalvar PS
What is the repair of choice for D-TGA?
ASO (over atrial switch)
What 2 things are complications of the ASO primarily related to?
- Mobilization and relocation of the great arteries and coronaries
- Coronary issues have a higher mortality risk, but supravalvar PS is more common
Why is the LeCompte used with ASO?
- In D-TGA< the aorta is anterior to the PA
- Relocating the PA anterior introduces a risk of supravalvar stenosis (the artery is stretched behind the ascending aorta)
- In the LeCompte, you transect the MPA and relocate the entire PA trunk and bifurcation anterior
What needs considered in a neonate with regional dysfunction post ASO?
Coronary artery obstruction leading to myocardial ischemia
d-TGA with a nonrestrictive VSD, but severe PS and hypoxia… what should be done?
BTT shunt
-Inadequate pulmonary blood flow
L-TGA with a large VSD (membranous with outlet extension), critical PS s/p BTT and now Glenn. Good biventricular size and function, AVV function well… surgical options?
-Close VSD directing morphologic LV flow across VSD to AoV, RV-PA conduit, Baffle IVC to tricuspid valve
DORV, normally related great arteries, large doubly-committed VSD, severe CoA, mild subaortic stenosis, straddling mitral valve… surgical approach?
- Norwood/Sano, CoA repair (because of straddling MV)
* If no straddling valve, could repair VSD/CoA and resect subaortic stenosis
What is an advantage of Sano over BTT?
Sano has pulsatile flow which may promote better growth of branch PAs
Describe Taussig-Bing physiology
- Form of DORV with VSD being sub-pulmonary
- Physiology similar to transposition: PA getting saturated blood from LV via subpulmonary VSD and aorta is remote from VSD getting desaturated blood from RV
What is the recommended surgical approach for Taussig-Bing?
Arterial switch + Baffle closure of VSD to neo-aorta
DILV with hypoplastic subaortic RV, restrictive bulboventricular foramen (VSD) and severe subaortic stenosis… initial surgery?
DKS + BTT
- Ao from hypoplastic RV with no inflow: Systemic output dependent on VSD size and LVOT patency (severely compromised here with LVOTO and restrictive VSD)
- Need stable pulmonary blood flow: BTT
When do you need to close an ASD surgically v. in the cath lab?
- Deficiency of the posterior-inferior septal rim
- Presence of coexisting abnormalities that would benefit from surgical repair (specifically mod-severe TR- benefit from annuloplasty or valve repair)
What would happen in a Fontan with an anomalous connection of the right lower pulmonary vein to the IVC?
Infarction of the right lower lobe of the lung
- Persistent connection of the anomalous pulmonary vein to the systemic venous circuit = No driving pressure across the the RLPA
- RLPA pressure = Fontan pressure = RLPV pressure
What type of CoA repair has a significant risk for pseudoaneurysm at the site of repair?
Synthetic patch repair
What kind of repair would you suspect in an ECG with sinus rhythm and RBBB?
VSD repair or transannular patch repair (incision of RV wall)
*Pulmonary valvotomy, surgical ASD repair and ASO are done without damage to the RV myocardium
What ECG change might you see after a LV septal myectomy?
LBBB
What is the most frequently recognized post-operative complication after an ASO for d-TGA?
SVC baffle obstruction
How is an atrial switch (Mustard or Senning) done?
Baffle SVC and IVC flow to the left sided AV valve and into the subpulmonary ventricle
How does and SVC or IVC baffle obstruction present after an atrial switch?
- Central venous obstruction
- SVC: JVD, facial edema, increased head size in infants with open fontanelle
- IVC: Hepatomegaly, ascites, LE edema
Which is more common SVC or IVC obstruction after an atrial switch?
SVC
What are 2 approaches to fixing baffle obstruction after atrial switch?
- Surgical revision
2. Stent placement in cath lab
If another indication for cardiac surgery, what should be done for an anomalous RCA from the left sinus of valsalve?
Unroofing intramural segment to enlarge orifice
*Debate if intervention needed if this is only finding in asymptomatic individual
Describe the Warden repair for sinus venosus ASD with anomalous RUPV
-Transection of the SVC above the insertion of the pulmonary veins
Baffling of the anomalous pulmonary vein/SVC stump to the ASD
-Reimplantation of the upper SVC to RA appendage
When is a LeCompte maneuver needed in d-TGA?
When there is an anterior-posterior relationship of the semilunar valves
- When PA is directly posterior to the aorta, switching would cause stenosis of the MPA or RPA
- LeCompte transects the MPA and relocates the entire PA trunk and bifurcation anterior to the aorta
What is the most common indication for reoperation in neonates who have had a Ross?
Pulmonary homograft failure
What is a Ross?
- Autograft replacement of the stenotic aortic valve with native pulmonary valve
- Homograft placed in the pulmonary position
List risks associated with a Ross
- Arrhythmia
- Subaortic stenosis
- Neo-aortic valve failure
- Coronary artery obstruction
What should be done during an Ebstein repair in a patient with a history of SVT?
MAZE
What is a MAZE?
Ablative procedure involving intraoperative cryoablation or RF ablation across several segments in the RA
*Good for supraventricular tachyarrhythmias (A-fib, A-flutter, SVT, etc.)
What surgery is typically done for Ebstein with severe RV hypoplasia and significant TR?
Starnes
*Done in anticipation of Fontan palliation
What is a Starnes procedure?
- Patch occlusion of tricuspid valve at annulus
- Removal of atrial septum
- Placement of systemic to PA shunt
Immediate post-op neonate who is hypotensive despite fluid and increase in epi and vasopressin, CVP 18, lactate elevated, echo with underfilled ventricles with normal function, no effusion, no thrombus… next step?
Open chest
- Poor perfusion, high CVP, normal function, underfilled ventricles with no effusion… external restriction to filling
- Peri-operative swelling can increase intrathoracic pressure and restrict diastolic filling… need to open sternotomy to relieve increased intrathoracic pressure
What is it called when the LPA arises from the RPA and passes posterior to the bronchi?
LPA sling
What should be done for an LPA sling?
Re-implant LPA anterior to bronchi
*Vessel may need angioplasty or stent if it is hypoplastic
Fever + CP in a post-operative patient?
Post-pericardiotomy syndrome
What surgeries is post-pericardiotomy syndrome more common in?
ToF, ASD, VSD
What should be given for post-pericardiotomy syndrome?
- High-dose ASA for 4-6 weeks
- May need steroids if ASA doesn’t help
*No colchicine
What other concern needs to be evaluated in post-pericardiotomy syndrome?
Endocarditis… get blood cultures
