Jonas - DORV

DORV Jonas23

DORV Jonas Ch23

-DDX TOF vs DORV- 50% rule is more practical than the presence of a conus because under standard exposure, the surgeon can't tell if there is a subAo conus.

-either way, surgical Tx is the same…

-for malposed GA, use 50% rule for the PA to DDx TGA vs DORV w MGA

Classification by VSD Anatomy (Lev Classification)

-note this classification doesn't focus on the critical anatomical features for the surgeon

-subAo, subPA, doubly committed, remote/noncomitted

-subAo- similar to TOF

-in TOF, there's no conus, so sup end of VSD is the Ao annulus itself

-in DORV, it is the subAo conus

-in TGA end of spectrum, the conus is subAo, and not subPA, so PA closer to the VSD…, thus in TGA the VSD is usually subPA

-Physiologic difference of VSD location:

-subAo- LV Q to Ao, but if it is a subPA VSD, then LV Q to PA… TGA like

-Noncommitted

-often at the inlet (AVCD), thus surgeon has to both separate Ao fr VSD and make the baffle pathway around the TV cords

Anatomic Determinants of Repair Method

-VSD type really doesn't help the surgeon much

-Separation of the PA and the TV

-whether it is like TOF w Ao <50% override, or like DORV w >50% override, there is Ao override of the RV. Must make baffle fr LV to Ao in both, and both via the RV (=intraventricular repair). Even more two the DORV end of spectrum as the subAo conus pushes the Ao cephalad, this remains true, and doesn't per se exclude intraventric repair.

-What does affect repair is that as Ao goes cephalad, the PA moves closer to the TV (thus PA goes more rightward)

-the baffle fr LV to Ao must pass bn the TV and the PA (bc the PA is more anterior than the Ao) --> as PA moves closer to the TV (in the spectrum), then the distance bn TV and PA eventually becomes < diam of Ao annulus, so that >50% of the path bn LV and Ao is made up of baffle --> risk late subAo tunnel stenosis of the baffle, so must avoid this approach…

-if the PA vlv lies within the tract bn the VSD and the Ao, where the baffle will go, c/s a Rastelli- baffle LV to Ao, close MPA, add RV-PA conduit

-Conal Septum Prominence

-Conal septal length d/o mainly the SubAo (vs SubPA) conus.

-if VSD is more L/ant = more subPA than subAo, then the baffle will have to follow a longer course around the inf margin of the conal septum to get to the Ao.

-but if the conal septum is prominent, it might be able to be resected, permitting an intraventric repair, AS LONG AS therearen't important MV cord attchmts (RV cords can be detached and reattached)

-longer conal septum is assoc w a shorter RV-PA distance, so likely exclude intraventric repair.

-long conal septum/long subAo conus- +/- assoc w subAo stenosis, +/-Ao Arch hypoplasia and CoAo…

-SubPA Stenosis

-at TOF end of spectrum, may have subPS, so must repair for intraventric repair- divide the septal and parietal ends of conal septum, and place outflow patch, +/- trans annular patch if hypoplastic PA annulus.

-even if no subPS, the baffle may protrude into RVOT, so may need to infundib patch at the outflow to prevent obstruction of RVOT

-w DORV MGA, SubPA stenosis can be bc of post dev of conal septum, or accessory fibrous tissue that might be assoc w the MV…

-IF there's no subpulm/pulm hypoplasia, and the distanc bn TV and PA is to shoort to allwo for a baffle, then do an art switch regardless of GA relationship (side side vs ant-post) and regardless of cor art anatomy.

-Cor Art Anatomy

-important for TOF and TGA

-TGA- LMCA and LAD usually pass ant to the PA root

-TOF- LAD usually passes post to PA

-if LAD is ant to PA outflow, --> exclude an intraventric repair without a conduit usually (and defet is likely to be mroe like a TGA --> likely should do either an art switch (if no PS) or a Rastelli

-Taussig-Bing Anomaly

-Broad term that covers DORV w a TGA physiology (PA SaO2 >Ao)

-Anatomical term- just applies to: subAo and subPA conuses separate both GAs from the AV vlvs, the GA vlvs are side by side, at same height; large suPA VSD above the septal band and muscular ventric septum

Associated Anomalies

[ ] CoAo

[ ] Ao Arch hypoplasia

[ ] Inter Ao Arch

-usually assoc w at least mildly hypoplastic Ao annulus and subAo conus

-at TOF end of DORV spectrum, very uncommon to have arch hyoplasia

Diagnostics and Presentation

-Sx d/o amt of PS/subPS usually - pulm overcirc vs cyanosis….

-echo is usually enough, maybe cath if older to check PVR, or if MGA if need BAS

-Echo:

[ ] at TOF end of spectrum, must check separation of PV fr TV relative to Ao ann diam,

[ ] VSD type

[ ] degree of conal septum dvp

[ ] degree of subPA and pulm stenosis

[ ] dynamic vs fixed PS/subPS

[ ] cor art anatomy

[ ] relative sizes of GAs

[ ] GA relationship (A/P, S/S…)

[ ] Arch- r/o hyoplasia, interruption, CoAo

[ ] assoc anomalies- multiple VSDs, AVCD…

Rx Mgt

-diuretics if pulm over circ

-BAS if TGA physiology

Surgical Indications & Timing

-Dx alone = indication

-see Ch1 for details on arguments on timing

-neonatal repair preferred regardless of type

-some do systemic-PA shunt first…

Surgical Hx

-first done by Kirklin in 1957, a TOF type of DORV (subAo VSD)

-ref 11, 13,14- early reports

Surgical Technique

-Intraventricular Repair for TOF to Mid-Spectrum DORV

-median sternotomy

-circ arrest or cont bypass

-Cross clamp, cardioplegia

-infundib incision, avoid cor arts, often the conal art is long and reaching twd the apex of the heart, so avoid it

-Define relationship bn the Ao annulus and VSD, and length of conal septum w respect to both GA vlvs

-Assess for TV cord attchmt to conal septum

-Assess for subPS

-may excise conal septum to relieve subPS, and if there's cord attchmts can reattach them to the baffle patch later

-divide septal and parietal extensions of conal septum--> relieve subPS

-+/- place infundib outflow patch…

-should be enough distance bn PV and TV to allow for tunnel bn Ao and VSD until you reach the mid-point of the TOF to TGA spectrum…

-suture around baffle pathway w pledgetted, horizontal mattress sutures, but can use continuous sutures in older pts bc interrupted ones would be impracticle bc too many to place…, But in neonates/infants, tissue is friable so cont sutures may --> resid VSD…

-PTFE is better than Dacron for a long baffle

-at midpt of baffle, ensure you don't make a waist where the pulm vlv starts to approach the TV.

-at site of conal septal excision, ensure the sutures dont tear out the raw muscle surface (bc endocardium was removed…).

-be careful at Ao annulus bc trabeculations can extend into it so if you dont get patch deep in there, you can get residual VSDs (thru the 'valleys').

-Rastelli & REV Repairs for Mid-spectrum to TGA like DORV (DORV-MGA) w subPS and/or Inadequate Pulm vlv to TV Separation

-if PV too close to TV to allow for baffle bn VSD & Ao, then must:

-baffle over both Ao & PA vlvs (similar as Rastelli done for TGA w PS)

-divide MPA

-place RV to PA conduit- pulmonary or Ao allograft conduit

-excise the pulm vlv oversew the MPA

-OR, do a REV (reparation a l'etage ventriculaire)

-mobilize the pulm artery (like for an arterial switch)

-suture MPA direct to RV ventriculotomy (so moved pulm vlv out of way)

-place a generous patch of pericardium anteriorly

-for the Lecompte maneuver, divide ascending Ao (to allow RPA to move antly), and then reattach Ao…; if GA's are in ant-post relationship, then bring both PA branches ant to Ao via Lecompte, so the branch PA doesn't have to traverse an excessively long course around the Ao. …

-if GA's are more side-side (more like a TOF side of spectrum), less need for Lecompte, but ?still useful until Ao lies in a plane post to MPA

-must take care of anterior cor art, likely the RCA, to ensure PA doesn't lie directly on the cor art and compress it...

-Cor Art Anterior to the Infundibulum

-if ant desc cor art crosses infundib at its narrowest pt, then may not be able to do a standard intraventric DORV repair without placing a conduit (bc can't cut across narrowed infundib)

-must place RV incision lower in the RV free wall, then use RV-PA conduit

-usually w Ao allograft (a pulm allograft won't be long enough usually)

-REV usually not feasible in this setting bc the ventriculotomy is too far from the PAs, and the tension on the PA fr the translocation may compress the cor art…

-Nikaidoh Procedure = Ao Translocation

-for DORV or TGA w PS, instead of Rastelli or REV

-Excise Ao root, including the Ao vlv, from the RVOT (like for a Ross), and mobilize and explant the cor arts, like for an art switch.

-Divide the pulm root at level of valve & excise the vlv

-Excise the conal septum, removing the superior margin of the VSD

-Translocate the Ao root post'ly so it lies mainly over the LV

-close the VSD w a patch, anchored to the Ao root at the sup margin

-use pulm homograft to connect RV to PA

-advantages of Nikaidoh- the homograft isplaced more post than for a Rastelli, so less risk of sternal compression. But, there's incr risk of late Ao vlv dysfx and cor art patency

-Arterial Switch Procedure

-very unlikely to need to do an atrial inversion for the DORV-MGA (TGA end of spectrum) as Senning & Mustard are known to have poor results in setting of a VSD repair

-But results for an Arterial Switch are great

-Indication: at TGA end of spectrum if little/no PS

-may need to resect muscular/fibrous tissue, +/- accessory MV tissue, if no important MV cords attaching MV to subpulm area…

-relative contraindicated if the PV is bicupsid, but not absolute bc results are still better than a senning/mustard

-divide GAs

-Inspect PV and LVOT to ensure no LVOTO

-mobilize cor arts, transfer to MPA root

-anastomose Ao to PA…

-can close VSD thru the anterior GA vlv, or thru RA, or thru RV ventriculotomy…

Variations of the Arterial Switch Operation for DORV

-Cor Arts

-unusual cor arts more common w side-side GAs than ant/post

-e.g. RCA & LAD fr single ostium, w circ fr post facing sinus

-…

-e.g. RCA and circ fr post sinus

-Closure of VSD

-may be hard to expose the VSD, bc may be leftward and ant, and may extend into ant trabeculated septum, so it appears that there is no clear left ant margin

-Multiple VSDs

-hard to see, may be amenable to device closure at the OR...

-Repair of Noncommitted VSD

-AVCD is #1 type

-if occur w PS, then as you can't do an art switch, you should patch close teh VSD w creation of a generous ant and sup extension of VSD, then baffle to Ao like Nl. Jonas avoids this bc of risk of VSD of closing and causing subAo stenosis, and instead do Fontan if PVR ok...

-Repair of Assoc SubAS & Arch anomalies

Surgical Results

-ref 28- 2001 Takeuchi report= 7 yr experience in 1990s-

-DORV w subpulm VSD- 12 had a Glenn - none w single ventricle repair died

-4 pts w art switch died early

-in total 87% survival at 5 yrs

-ref 29- 1994 Aoki rev of Boston, bn 1981-91-

-if subPA or remote VSD, more likely to have Arch obst

-TV to PA distance being >Ao ann diam predicted ability to repair w baffle

-81% overall survival at 8yr f/u

-early mortality R/F = multiple VSDs, wt <median of group

-reoperation less likely in subAo VSD, and signif higher if remote VSD