Jonas - AR

Aortic Valve Repair Jonas17 Part 1

Aortic Regurgitation

-very rare to have true congen AR that is isolated of other disease

Anatomy

-Primary Congenital Aortic Valve Regurgitation

-often bc of a bicuspid Ao vlv (ref 2,3)

-R leaflet freq xx- hypoplastic, partly fused w either non or L leaflet--> poor comissural support, w prolapse; over time--> Ao annulus enlarges bc of vol load on the vlv --> even more regurg.... spiral

-regurg jet also damages free edge of vlv leaflet--> thick and rolled vlv leaflet

-quadricupsid Ao vlv can also --> AR (ref 4)

-Ao Regurg post Balloon Dilation

-after initial balloon dilations, 13% had AR post cath, incr to 38% at f/u (ref 5)

-mainly bc detach R cor leaflet at ant commissure

-factors contributing to AR- anterior commissure avulsion, cusp dehiscence, simple cusp tear, central incompetence, Ca cups... RCC most often affected

-Ao Regurg assoc w VSD

-subpulm VSD- just below the belly of the RCC of Ao vlv--> jet can cause prolapse into the VSD fr Venturi effect; less likely w a PM VSD (however, bc PM VSD is more common than subPA/Ao VSD, we see AR more commonly w PM VSDs...)

-Ao Regurg 2y to SubAS

-membrane or tunnel stenosis--> Ao vlv damage--> AR, w thickened and rolled free edge so poor coaptation (ref 8)

-Ao Regurg assoc w Ao Root Dilation

-Marfan's & Ehlers-Danlos - w root dilation --> AR

-the tops of the commissural posts "are distracted" --> central AR

-may see it p TOF repair...

-Other Ao Regurg causes

-Ao LV tnnel, sinus of Valsalva aneurysm & fistul

-p bacterial endocarditis

-truncal valve...

Path & Sx

-...

Dx

-...

Medical & Interventional Tx

-no cath technique for Tx

-Rx Tx = CHF Tx...

Surgical Indications

-+Sx despite Rx

-decr in preload independent contractile indicies, or LV diln >2SD (ref 11)

-Goal in young child is to avoid Ao vlv replacement

-Longstanding AR - assoc w damage to AO vl free edge, and Ao ann diln--> harder to reconstruct, so if it seems like an easy AR repair, then c/s going sooner to prevent the long term xx of AR that complicate late repair

Surgical Mgt

-CP Bypass with moderate systemic hypothermia

-Cool slower than usual to minimize risk of early VF

-harvest a patch and fix in glutaraldehyde for 30min

-Ao Cross Clamp - apply before the hrt is at risk of distention fr bradycardia and reduced contractility

-helpful to infuse first cardioplegia dose w gentle LV massage- prevent distension, before making the aortotomy or placing the vent

-place LV vent thru R sup pulm vn

-Aortotomy transversely, and extend twd noncor sinus of Vals

-then give rest of the 1st dose of cardioplegia to each cor art ostia

-to do a repair, the Ao must have enough annular diameter to not require LV outflow enlargement, mobile cusps or cusps that can be made mobile w resetion/shaving fibrous tissue, and must have ability to achieve coaptation without -->ing stenosis

-Valvulopasty techniques (ref 5, 12-16) vary

Primary Repair

-excess fibrous tissue (often at raphe of fused commissures) - remove aggressively (shaving)--> more mobile cusp

-open fused commissures with a scalpel

-repair simple tears w simple running sutures

-if the cusps are of ok size, then can repair the RCC and NCC of bicuspid valve by resuspending the commissure w sutures that pass thru the Ao wall. Otherwise, resect the commisssure and then reconstruct the vlv.

-Prolapsed but otherwise good (competent, pliable) cusps- shorten them by ressupending the cusp to the commissure w a pledget supported suture

-If it is central AI w dilated sinus of Valsv, then do a sinus reduction plasty to reduce commiss splaying by resecting a wedge of noncor sinus, then primary close the aortotomy

Treated Aortologous Pericardial Patch Repair

-repair perforated cusps w a patch

-defic cusps, usually fr balloon induced tear w retraction of the free cusp edge- augment w a half moon shaped patch to the free edge; make it so it overlaps with the opposite free cusp edge by a few mm. But, if the opposite cusp is too far or also deficient, then do NOT extend the patch. Instead, use a patch on the other defic cusp, making the free edge slightly longer and redundant, ensure that most patches are further anchored to at least one commissure--> resuspends the leaflet

-if the native usp is very stiff/Calcified, then then partly or completely reset the cusp and replace w path (but this incr risk of calcification later)

Surgical Results

-ref 5- n=21 w Ao vlv surg mainly in 90s- no early or late deaths, mean 31mo f/u

-pericard effusion needing CT in 1 pt

-reop fr dehisced pericardial patch w much AR in 1

-1 pt needed repeat balloon dilation for recur AS 3.5 yrs post vlvplasty

-80% 3yr freedom fr reop (re-repair or replace Ao)

-?nothing found to be assoc w re-op in MVA analysis

-all pts ASx at f/u

-Echo f/u

-most had mild AR at f/u, mean LVEDD was much reduced to Nl range

-ref12-16- ok medium term results w Ao repair

-ref 17- Ross alternative has been "disappointing" at f/u