Mavroudis Pulmonary Veins

Mav Chapter 34 - TAPVR - Totally Anomalous Pulmonary Venous Return

-1-5% of CHD

-TAPVC = abNl connection of PVns to systemic circulation --> oxygenated bld to R heart

-need ASD/PFO to survive

-TAPV Connection = anatomic arrangement; TAPV Return or TAPV Drainage refers to the HD/physiologic state. One might have Nl PVn connection but abNl drainage (e.g. sinus venosus ASD)

-PAPVC = Partial - some PVns abNl...

Embryo

-resp system is an outpouch fr primative pharyngeal floor at day 26-27 gestation

-forgut bud is engulfed by splanchnic plexus, which --> vn drainage into the cardinal & umbilicoviteline venous systems

-common pulm vn dvps fr evagination fr the LA at day 27-29GA, then connects to splanchnic plexus by day 28-30.

-bn week 5-8, common pulm vn is absorved by LA wall--> 4 PVn orifices into lA

-at same time, the PVn connections to cardinal and umbilicovitelline vns degenerate--> lung Q just to LA

-get TAPVC fr xx at any pt. - TAPVC, PAPVC, cor triatriatum...

Classification

-Type I = Supracardiac - SVC, LSVC, azygous vn (40-50% pts)

-Type II = Cardiac - RA, coronary sinus (20-30% pts)

-Type III = Infracardiac - portal vn or a portal branch (10-30%)

-Type IV = mixed (5-10%)

....

Sx

-may have mild tachpnea/cyanosis vs rapid HD collapse, d/o degree of obstruction at PVns & ASD

-all will have at least some systemic desaturations, d/o Qp:Qs

-Qp:Qs d/o ASD size and downstream PVR:SVR. Most have unrestrictive ASD--> Qp:Qs decides

-if no PVn obstruction, then --> "R heart dilation and phtn eventually"

-can have CHF or irreversible pulm vasc obstructive dz

--> neonate w tachypnea, cyanosis, R sided heart failure (pulm overcirc Sx)

-if +PVn obstruction--> high Pulm P early w large R to L shunt

-decr Qp and pulm edema bc of Pulm outflow obstruction --> rapidly progressive hypoxemia--> HD collapse if no Tx

-CXR shows parenchymal opacification bc pulm edema

-ABG shows marked hypoxemia & acidosis

-most common w infracardiac TAPVC bc signif obstruction

Dx

-if no PVn obst & mild early HF--> Sx of a large ASD

-incr Qp--> parasternal lift, wide S2 split, pulm flow murmur, diastolic rumble fr Q thru TV, mild tachpnea, some cyanosis

-if + PVn obst--> high PAPs and severe hypoxemia as a newborn, persistent fetal circulation, resp distress syndrome

-shock and hypoxia

-CXR- PA's are engorged --> Snowman/figure of eight cardiac shadow w supracardiac TAPVC

-fr vertical vn into L innom, w thymus involution, rounded shadow seen at superior mediastinum, just above the cardiac silhouette--> snowman look, but might not appear till later in infancy as the PVns enlarge & thymus shrinks

-echo- RV dilation, absent PVN connections to LA, anom vns..., R to L shunting at ASD

Pre-op Mgt

-If no obst, may need diuresis

-If obstruction, then intubate, 100% FiO2 to decr PVR, "PGE for PDA--> protective conduit for R side to shunt to L side"

-Balloon atrial septostomy as needed

-ECMO as needed

NHx

-80% mortality by 1yo --> Dx = indication to Tx

Surgery

-Surgical goals:

-Connect all PVns to LA, eliminate anomalous connections, correct cardiac anomalies (ASD)

-Some use deep hypothermic circ arrest, others try to avoid this

-CPB is initiated w Ao and RA cannulation

-Ligate the PDA

-Cool pt

-Start DH circ arrest or low flow bypass

Supracardiac TAPVC

-4 PVn to a conf or common PVn directly posterior to LA --> drain to a vertical vn--> to innom vn

-Ligate vertical vn, but ensure you don't damage phrenic n, often right next to it

-Mobilize the heart & retract superiorly & to the right (or mobilize RA and retract it to the L)

-Incise the vn conf & LA

-Close the ASD

-make a generous anastomosis bn LA and conf, as big as possible

-avoid making purse string w sutures, to avoid residual obst

-Can repair ASD thru the LA or thru a separate RA incision

-Alternate approach for pts w PVn conf drainage directly to SVC

-RA incision, then baffle placed to direct PVn drainage across the ASD and into the LA

-but avoid obst to PVns or SVC

-may need a Warden if the PVn connection is high- transect the SVC above the conf, baffle the SVC Q to LA, then connect the prox SVC to the RA stump

Cardiac TAPVC

-PVns to cor sinus or RA

-RA incision

-may need short pds of DHCA to visualize in small infants

-unroof cor sinus if it is involved

-connect coronary sinus ostium to the ASD

--> large opening bn cor sinus and LA

-Close the ASD w a patch that includes the cor sinus ostium -->directs pulm and cardiac vn Q to LA

-if PVns go direct to RA, then baffle them across teh ASD to LA, or displace teh ASD to include the PVns on the L side of the septum- mobilize the posterior atrial septum and reattach it bn the PVn ostia and the SVC/IVC...

Infracardiac TAPVC

-usually, PVns drain to a confluence behind LA, then to desc vertical vn, then to diaphragmatic hiatus, then to portal system

-Must ligate verticle vn at level of diaphragm

-PVn conf then anast to LA as above

-ASD is closed

-Alt approach: ligate the inferior vertical vn at level of diaph, and incision in the cephalic direction twd the PVns--> allow larger anastomosis after you mobilize the PVns. Goal is as wide an anastomosis as possible

Mixed TAPVC

-Most common is Conf of 3 PVns w separate drainage of a 4th PVn

-If there is a single PVn, can try to reanastomose it, but it is hard bc likely to get stenotic...

-If the single PVn is unobst, it can be left alone for reimplantation later once pt is grown, or no reimplantation at all

-pts in one study w highest Qp:Qs after leaving it alone were w single PVn fr the RU or RM lung

-If 2 pair of PVns to diff locations, then must individualize Tx....

-in one case, PVns to SVC, RA, Cor Sius mgt w unroof of cor sinus to LA, large baffle for Warden

Outcome

-Operative mortality 10-30% in 1970-80s, 5-9% more recently

-Predictors of Poor outcome (table 34-1)

-severe preop or residual postop PVn obst

-assoc cardiac anomalies present

-Morbidity -varied

-Yee ref 11- 12 of 68 hospital survivors needed a reoperation mainly for residual PVn gradient & intracardiac shunts

-SVT and nodal arrhythmia noted

-postop phtn- iNO responsive

-Postop PVn stenosis incidence 6-11%

-more common w infra and mixed type

-?improved w absorbable sutures- ref 36

Cor Triatriatum Sinister

-rare- 0.1% of CHD

-only 33-50% found in isolation

-obstruction fr fibromuscular membrane subdividing the LA to a prox chamber w Q fr PVns, and distal chamber w MV & LAA

-Variations

-no comm'n bn prox and distal chambers

-comm'n thru a small perforation in the obstructing membrane

-incomplete membranous subdivision in LA

-Classification

-Type A (64%) = classic - defect in the membrane bn prox and distal chambers

-may have an ASD w prox chamber (subtype A1), or distal chamber (subtype A2)

-Type B (18%) = w enlarged coronary sinus receiving PVns (a TAPVC)

-Type C (9%) = no connection bn PVns and prox chamber

-Sx like severe MS w CHF, obst d/o amt of ASDs...

-if the connection bn prox and distal chambers is <3mm, most present at <1yo (ref 10)

-larger commn may be ASx for life

-but NHx- 75% fatal w/o Tx if small commn (<3mm)

-if larger comm'n, may not present till teens. Sx similar to MS

-Main Tx is surgical, though cath has been reported (ref 18)

-Need CPB and hypothermia, cardioplegia, via median sternotomy usually, and RA atriatomy

-may do an LA atriotomy if no TAPVC

-Excise the membrane

-Results:

-Good, 17-10% periop mortality, but most in kids w assoc xx

-long term great Px p 32yrs postop (ref 6)

-relatively simple to repair... early Dx reduces M&M

Common PVn Atresia

-~Rarest CHD

-Pts are cyanotic and in sev HF at birth

-Cath- no communicating Vn found --> thus NOT TAPVC

-Postnatal survival only bc of collateral vns to atria/systemic circ

-must Dx immediately and Tx w surgery immediately for survival

-Tx- anastomosis bn post LA and the confluence

-<25 cases reported, <10pts underwent repair, and only 2 survived

PVn Stenosis

-~Rarest CHD (0.4-0.6% of CHD)

-Usually fatal

-bn AbNl union bn the LA and common PVn

-Variations:

-tubular hypoplasia extending fr the venoatrial jct proximally

-weblike intimal stenosis at the venoatrial jct

-multiple short, hypoplastic PVn

-bc of fibrous intimal thickening/irregularity of media

-1/2 of pts have unilateral stenosis, 30% have all 4 vns, 10% just 1 vn stenotic (ref 23)

-Survival better if unilateral dz (ref 24)

-presentation d/o amt of obstruction.. if all 4 then CHF rapid w FTT/pulm edema etc

-Cath is the Dx modality of choice

-see phtn w or w/o elevation of pulm cap wedge pressure or LVOTO

-see gradient on pullback fr PVn and LA

-angio shows stenosis/hypoplasia

-Tx

-c/s in all pts at Dx bc it is rapidly fatal

-enlarge stenotic PVns when possible

-Sutureless pericardial patch technique or lung transplant are options

-PerQ balloon dilation has much restenosis (but ??better than surg...)

-Najm sutureless PVn augmentation w a pericardial patch:

-CPB

-incise PVn until normal intima encountered

-enlarge the communication bn PVns and LA w pericardial patch

--> minimize postop neointimal response that causes restenosis (ref 27)

-18% get postop PVn stenosis in TAPVC pts, w high mortality (37-100%) (ref 28)

Cor Triatriatum Dexter

-=subdivided RA bc of persistence of the R valve of sinus venosus

-R horn of the sinus venosus is incorporated into the RA, giving rise to IVC and SVC ostia

-as the heart grows, this should move more caudally--> leaves crista terminalis and the vlvs of the IVC (eustachian) and cor sinsu (Thebesian vlv) as its remnants

-minor RA septation is common in 86% of specimens, but if it is a large membranous obstrucction, then it can obstruct the TV, RVOT, or IVC

-Most are ASx, and incidental finding at echo/OR

-Some have SVT

-Some have R heart failure Sx- incr CVP, HSM

-if +ASD, may get cyanosis, looks like Ebstein's by presentation

-Surgery only indicated if +Sx

-perQ cath disruption has been tried, uncomplicated --> Tx of choice

-Operation only if other xx needing surgery