Accuracy of Using 2D Transesophageal Echocardiography Compared to Balloon Sizing in Determining Valve Size During Transcatheter Aortic Valve Implantation
Accuracy of Using 2D Transesophageal Echocardiography Compared to Balloon Sizing in Determining Valve Size During Transcatheter Aortic Valve Implantation
The method of transcatheter aortic valve implantation (TAVI) introduced in 2002 by Alain
 Cribier et al. has offered new prospects for patients with severe aortic stenosis and
 multiple comorbidities, who are at high operative risk(1).

 The PARTNER series of randomized controlled trials has firmly established the role of TAVI
 with the balloon-expandable Edwards Sapien valve in patients with severe symptomatic aortic
 stenosis (AS) at prohibitive risk of surgery (PARTNER IA), high risk for surgery (PARTNER
 IB), and intermediate risk for surgery (PARTNER 2).(2)

 Also PARTNER 3 and Evolut Low Risk trial strongly suggest that TAVI is not only a suitable
 alternative and may be superior to surgical aortic valve replacement ( SAVR) in low-risk
 patients.(2)

 The accurate determination of the size of the implant is dependent on pre-procedural imaging.
 Annular measurements are important in the TAVI as inaccurate estimation can lead to
 complications e.g paravalvular leakage .(3) Transthoracic echocardiography (TTE),
 transoesophageal echocardiography (TOE), multidetector computed tomography (MDCT) and
 magnetic resonance imaging (MRI) have been extensively studied with respect to pre-procedural
 aortic annular sizing.(3).

 However, even with some of the evidence returning a discrepancy in annular measurements
 between techniques, the literature to date does not clarify whether TOE undersizes
 inappropriately or appropriately with respect to MDCT.(3) In a recent study, 29.5% of
 patients would have been deemed ineligible for TAVI because of overestimation of annular
 measurements by MDCT, a figure reduced to 1.3% with the use of TOE (4)

 In a recent small retrospective study, TOE, MDCT and MRI all performed comparatively well
 with device sizing. (5)

 Balloon aortic valvuloplasty (BAV) dilatation before TAVI is considered a mandatory
 procedural step in the early years of TAVR. BAV is used to confirm annular sizing and to
 enhance trans-catheter heart valve (THV) deliverability.(6) However till now there is no
 comparison of annular measurement by 2D transesophgeal echocardiography with balloon sizing.
Aim of work To compare accuracy of 2D transesophageal echocardiography versus balloon sizing
 in determining size of device during transcatheter aortic valve implantation and inhospital
 outcomes of this approach using 2D TEE and balloon sizing only during TAVI .

 Patients and methods. The study will include (100) patients, prospective observational study

 All patient will undergo :

 1-Written consent. 2-Detailed history including symptoms (NYHA class) ,co morbidities
 3-Clinical examination 4-Electrocardiogram (detection of conduction disturbance , ischemic
 changes). 5-Laboratory investigation (hemoglobin level, creatinine, glomerular filteration
 rate(GFR)) 6-Risk stratification: using STS score 6- Transthoracic Echocardiography: (7)

 1-Assesment of aortic valve by

 1. Mean and maximum pressure gradiant (severe AS if mean pressure >40mmhg and maximum
 pressure >64mmhg) in presence of normal ejection fraction (EF).

 2. Aortic valve area by continuity equation (severe AS if < 1cm2).

 3. Measurement of aortic valve annulus (in parasternal long axis view) .

 4. Assesment of associated aortic regurge (8) :

 -Regurge jet width/LVOT width (mild <25%,moderate 25-65%, severe >65%)

 -  Vena contracta (VC) (mild <0.3cm, moderate 0.3-0.6cm, severe >0.6cm)

 -  Regurge volume (RV) (mild <30ml, moderate 30-60ml, severe >60ml).

 -  Regurge fraction (RF) (mild <30%, moderate 30-50% and severe > 50%).

 -  Effective regurgitant orifice area (EROA) (mild <0.1 cm, moderate 0.1-0.29cm and
 severe ≥0.3cm) 2- Assesment of EF (by M-mode and simpsons method). 3-Assesment of
 other valves .

 7-Transesophegeal Echocardiography.(9):

 1. Morphology of valve (tricuspid, bicuspid , unicuspid).

 2. Measurement of aortic valve area (AVA) by planimetry.

 3. Extent, distribution and location of Calcification. (annular calcification
 symmetrical or asymmetrical, sinuotubular junction , subvalvular
 calcification)

 4. Measurement of aortic annulus dimension, LVOT, sinus of valsalva, sinotubular
 junction and ascending aorta dimensions.

 Determinations of 2D TEE aortic annular and LVOT diameters were performed in the
 3-chamber long-axis view at approximately the 120◦ angle during early systole . The
 aortic annular diameter was measured from the junction of the aortic leaflet with the
 septal endocardium to the junction of the leaflet with the mitral valve posteriorly,
 using the inner edge to inner edge. The LVOT diameter was obtained 5 mm into the LVOT
 from the level of the annulus.(10) Calculation of a cover index: defined as a 100 x
 (prosthesis diameter - transoesophageal echocardiography annulus diameter)/prosthesis
 diameter. (11).

 6- Aortic atheroma: The Katz classification for grading aortic atheromas is as follows:
 Grade 1, normal-appearing intima of the aorta; Grade 2, extensive intimal thickening;
 Grade 3, sessile atheroma protruding <5 mm into the aorta; Grade 4, sessile atheroma
 protruding >5 mm; and Grade 5, mobile atheroma.(12) 7-Associated basal septal
 hypertrophy . 8-Assesment of associated aortic regurge. 8-Pre-TAVI workup in cardiac
 catheterization laboratory:

 1. Access route evaluation: assess peripheral vasculature for size, tortuosity,
 calcification -Iliofemoral angiography: A 5F metric (graded) pigtail is used for
 calibration and accurate determination of vessel calibre and minimal lumen
 diameter. The pigtail is placed at the lumber 4/5 level, which approximates a
 position just proximal to the common iliac bifurcation with injection of 15-20mls
 contrast at 20mls/sec.

 -Iliofemoral diameter: determined by Sheath-to-iliofemoral artery ratio (SIFAR) was
 defined as sheath outer diameter divided by access-side vasculature diameter.

 -Iliofemoral calcification: Calcification can be evaluated on fluoroscopy and
 graded as: none, mild (spotty), moderate (coalescing), severe (bulky, protruding,
 horse-shoe, circumferential ). Iliofemoral tortuosity : determined by tortuosity
 score which is defined as follows: 0 = no tortuosity; 1 = mild tortuosity (30° to
 60°); 2 = moderate tortuosity (60° to 90°); and 3 = marked tortuosity (>90°).(13)

 -Subclavian or axillary angiography if femoral axis is unsuitable.

 2. Diagnostic coronary angiography: for assessment of presence and severity of
 coronary artery disease.

 3. Aortogram: is done to asses for angle between LVOT and ascending aorta , distance
 of coronary vessels from annulus and presence of aortic regurge.

 -  5F graded pigtail is placed into the non-coronary cusp (NCC) and an aortogram
 performed (20mls contrast at 20mls/sec). Fluoroscopic projection of RAO 30◦
 and LAO 30◦.

 4. Aortic valve cross over: to demonstrate feasibility of crossing valve.

 5. Hemodynamic assessment: assess invasive transaortic gradiant with simultaneous
 pressure transduction.

 -  Pigtail will be crossed into the LV cavity, simultaneous measurement of
 pressures from the LV and femoral artery can be obtained. Use of a 5F pigtail
 enables simultaneous pressures to be transduced from the 6F femoral artery
 sheath without the need for a second arterial sheath.

 6. Left ventriculogram: assess EF by eyeballing (mild 40-50%,moderate 30-40% and
 severe <30%) and presence of MR according to seller criteria described later on.

 Left ventriculography is done using 25ml contrast at rate 10ml/second in both RAO
 30◦ and LAO 60◦

 7. Right heart catheterization: assess pulmonary artery (PA) pressure, Pulmonary
 capillary wedge pressure (PCWP).

 TAVI procedure:

 The detailed steps of procedure are reported by Nijhoff F,etal. TAVI is performed
 through transfemoral or transapical approach, based on the feasibility of the
 iliofemoral anatomy and suitable access sites. All procedures are performed in a fully
 equipped hybrid cardiac catheterization laboratory. Surgical cutdown is used to close
 the vascular access site at the femoral arteries.

 Fluoroscopy is used to guide the deployment of the valves and prosthesis positioning.
 Both predilatation of the native valve and prosthetic valve implantation are performed
 during rapid right ventricular pacing (160 to 200 beats/min). Prosthesis position,
 function, and coronary ostia patency are assessed with fluoroscopy and aortography .

 -Balloon sizing: An appropriately sized valvuloplasty balloon is choiced .The initial
 volume of inflation is set to obtain a balloon size of 1 mm less than the TEE
 measurement. The balloon is positioned across the aortic valve through femoral sheath
 and inflated with the same volume during rapid ventricular pacing, using a 30 cc
 inflation syringe.

 At full inflation, an aortography is performed. The following parameters are recorded:
 (I) presence of a waist on the balloon at the level of the annulus, (II) intra-balloon
 pressure, (III) patency of the coronary artery ostia and their relations with the
 displaced aortic valve cusps, (IV) presence and entity of aortic regurgitation on
 aortography at full balloon inflation ("para-balloon leak"). In the absence of a waist
 on the balloon and/or in case of major para-balloon leak, the procedure is repeated with
 a larger diameter balloon (larger balloon or same balloon inflated with a larger volume
 of contrast media).

 Assesment of inhospital outcomes after TAVI procedure:

 1- paravalvular leakage : Assessment of paravalvular leakage

 1-Angiographic evaluation of paravalvular leakage :

 Ten minutes after the deployment of the prosthetic valve, angiography of the aortic root
 is performed to assess the severity of aortic regurgitation according to Sellers
 criteria (14):

 (0) no regurgitation.

 1. only trace of contrast could be seen in the left ventricle, and it is cleared in
 each systole.

 2. contrast filling the entire LV in diastole with less density compared with
 opacification of the ascending aorta.

 3. contrast filling the entire LV in diastole equal in density to the contrast
 opacification of the ascending aorta.

 4. contrast filling of the entire LV in diastole on the first beat with greater
 density compared with the contrast opacification of the ascending aorta.

 Two observers independently score the images. In case of discrepancy the images will be
 re-evaluated and consensus will be reached by a third observer. .

 2-Transthoracic Echocardiographic study:

 All patients will be evaluated after TAVI by pre-discharge transthoracic
 echocardiography. The extent of PVL is assessed according to the main VARC criteria
 (15):

 1. Semiquantitative parameters

 1. Diastolic flow reversal in the descending aorta-pulsed wave : mild (Absent or
 brief) ,moderate ( early diastolic Intermediate), severe (Prominent holodiastolic)

 2. Circumferential extent of prosthetic valve paravalvular regurgitation:

 (0) no regurgitation; (1) mild PVL is defined as<10 % circumferential extent; (2)
 moderate PVL was defined as [>10 % but<30 % of PVL and (3) severe PVL is defined as >30
 % according to the updated VARC guideline , that is the circumferential extent of PVL in
 a parasternal short-axis view (19).

 2. Quantitative parameters:

 1. Regurgitant volume (ml/beat) mild (<30) , moderate (30-59) ,severe (>60).

 2. Regurgitant fraction (%) mild (< 30), moderate (30-49 ) ,severe (>50).

 3. Effective regurgitant orifice area (cm2) mild (<0.10) ,moderate (0.10-0.29) ,
 severe (>0.30).

 2-Other complication results from inaccurate annular sizing : prosthesis embolization,
 annular rupture, aortic dissection, coronary artery occlusion , conduction defects.

 3-Assesment of other complication ,vascular site complication, bleeding, stroke and
 mortality.

 Statistical analysis:

 The collected data will be tabulated and statistically analyzed and will be shown in
 tables and figures.
Inclusion Criteria:

 -  1-Patients must have severe degenerative high flow AS (echocardiographic criteria:
 aortic valve (AV) effective orifice area (EOA) of < 1 cm2, mean AV gradient of > 40
 mmHg, or AV peak systolic velocity of > 4.0 m/s) in presence of normal ejection
 fraction (EF).

 2- Patients must be symptomatic from the AS (dyspnea in NYHA-class II or greater,
 angina pectoris, or syncope), or asymptomatic but with decreased left ventricular
 ejection fraction, positive stress test , Pulmonary hypertension (systolic pulmonary
 artery pressure >60 mmHg).

 4-Symptomatic patients with severe low-flow, low-gradient (<40 mmHg) aortic stenosis
 with reduced ejection fraction and evidence of flow (contractile) reserve.

 3- Patients surviveal time more than one year . 4- Patients have contraindications for
 open chest surgery, such as :

 1. Presence of comorbidities not adequately reflected by risk scores.

 2. Procelain aorta

 3. Squelae of chest radiation.

 4. Severe chest deformation or scoliosis.

 5. Previous cardiac surgery

 Exclusion Criteria:

 1. Evidence of an acute myocardial infarction 30 days before the intended
 treatment.

 2. Aortic valve is a congenital unicuspid or congenital bicuspid valve, or is
 noncalcified.

 3. Mixed aortic stenosis and aortic regurgitation with predominant aortic
 regurgitation > 3+).

 4. Hemodynamic or respiratory instability within 30 days of screening
 evaluation.

 5. Need for emergency surgery for any reason.

 6. Hypertrophic cardiomyopathy with or without obstruction.

 7. Severe left ventricular dysfunction with LVEF <20%.

 8. Severe pulmonary hypertension and RV dysfunction.

 9. Echocardiographic evidence of intracardiac mass, thrombus or vegetation. .
 10-A known contraindication to all anticoagulation regimens, or inability to
 be anticoagulated for the study procedure.

 11-MRI confirmed stroke or transient ischemic attack within 6 months (180 days)
 of the procedure.

 12-Renal insufficiency (creatinine >3mg) and / or end stage renal insufficiency
 requiring chronic dialysis at the time of screening.

 13-Estimated life expectancy<12 month.

 . 14-Severe incapacitating dementia 15-Significant aortic disease, including
 abdominal aortic or thoracic aneurysm defined as maximal luminal diameter 5 cm or
 greater; marked tortuosity (hyperacute bend), aortic arch atheroma [especially if
 thick (>5 mm), protruding or ulcerated] or narrowing of the abdominal or thoracic
 aorta, severe tortuosity of the thoracic aorta.

 Also a minimum iliac or femoral artery diameter of less than 6 mm may be deemed
 unsuitable for femoral approach.

 16-Severe mitral regurgitation. 17-Annulus size out of range of available
 prosthese (<18mm and >29mm). 18-Untreated coronary artery disease requiring
 revascularization. 19- Elevated risk of coronary ostium obstruction (asymmetric
 valve calcification, short distance between annulus and coronary ostium less than
 10mm.