Preparation
  • Labs: CBC, BMP and coagulation profile
  • Trans-esophageal echocardiography (TEE): To exclude LAA/LA thrombus and to calculate Wilkins’ Echo score.
 Equipment
  • Sheaths
    • Definitive PMBC – 8Fr sheath for right femoral venous access. 7.5Fr sheath for left femoral venous, 5Fr sheath for left arterial access and a 14Fr Mullins sheath
    • Possible PMBC – 7.5Fr sheath for left femoral venous access and a 5Fr sheath for left arterial access
  • Catheters
    • Swan-Ganz catheter. 5Fr pigtail catheter, and Brockenbrough needle
  • Wires
    • 035” standard J wire, 0.032” straight wire, and 0.025” swan wire
  • Balloon
    • Inoue balloon kit (balloon size is calculated in mm= [Height of patient in cm/10] +10)
    • 025” curled guidewire/Protrack wire
    • 14 Fr dilator
    • Preshaped stylet (LV wire)
  • Contrast
    • 50 cc (1:3 dilution)
  • Manifolds
    • Three manifolds
  • Heparin
    • 5,000 IU
 Vascular access for Definitive PMBC
  • 8Fr right FV, 7.5Fr left femoral vein, and 5Fr left femoral artery
  • Ultrasound/fluoroscopy guided right femoral vein access is obtained using micropuncture needle. Single preclose was performed with one proglide device with or without a figure-of-eight suture or a mattress suture.
 Vascular access for Possible PMBC
  • 5Fr left femoral vein and 5Fr left femoral artery.
 Procedural Steps
  • Assess coronary anatomy for patients > 40 years of age
  • Perform a complete right heart catheterization first through the left femoral vein
  • Leave the Swan-Ganz catheter in PA for hemodynamic monitoring during the procedure.
  • Advance 5Fr pigtail catheter over J wire to LV via left FA access and wedge the Swan-Ganz catheter. Record the left ventricular end diastolic pressure (LVEDP) and pulmonary capillary wedge pressure (PCWP) simultaneously for the transmitral gradient and calculate the mitral valve area (MVA).
  • Medrad LV gram (30 cc volume at 20 cc/sec at 450 PSI in LAO 45 and RAO 30 positions to evaluate for mitral regurgitation (MR).
  • Pull pigtail into ascending aorta and perform an aortogram in LAO 30 to assess for coexisting AI.
  • Place the pigtail in the aorta in noncoronary sinus.
 Trans-Septal Puncture using Fluoroscopy
  • In AP position, advance 0.032” wire to SVC via right FV and change to 8Fr Mullins sheath
  • Remove 0.032” wire and Mullins sheath dilator and de-air the system
  • Advance Brockenbrough needle (with third transducer attached) through Mullins sheath and keep the tip of the needle 2cm below the tip of the Mullins sheath.
  • Use AP view to confirm the correct needle position and pull down the sheath and needle as one unit. Position the Mullins sheath in RA against the interatrial septum (IAS) in AP position.
  • Maintain needle tip direction indicator (at the needle hub) at the 5’o clock position.
  • In the AP position, while keeping the needle inside the sheath, position the needle tip by clockwise rotation to the optimal IAS puncture site (clockwise rotation moves the needle tip toward posterior edge of LA, anticlockwise rotation toward aorta).
  • At the midpoint of “end of mitral annulus” (in AP) and midpoint of anterior and posterior halves of IAS (in LAO), penetrate IAS. Note LA pressure tracing and aspirate bright oxygenated blood to check saturation and/or inject contrast through needle to confirm location.
  • Advance Mullins sheath and dilator together over the needle while holding the needle firmly; Counterclock the entire system so it faces anteriorly during advancement. Withdraw the needle
  • See Figures: landmarks of descent for transseptal puncture.
  • Give 5,000 IU of heparin once IA is crossed (or 100 U/Kg).
  • Measure transmitral gradient using LV pigtail catheter and Mullins sheath.
 Trans-Septal Puncture using TEE
  • Appropriate position of patient for TEE
  • Assess severity of mitral disease/AV disease/TV disease and PA pressure along with LV ejection fraction
  • Rule out LAA/LA thrombus
  • IAS anatomy:
    • Bicaval – Look for thickness/aneurysm/Eustachian valve/PFO
    • Bicaval X plane; Bicaval shows superior and inferior segment of IAS, while simultaneous X plane shows aortic short axis revealing the anterior and posterior segment of IAS (Figure).
  • An Appropriate site of septal puncture for PMBC is in posterior and inferior segment. A LA thrill can be felt with the septal puncture needle. Septal puncture sheath like SL-1/SL-2 or Mullins sheath with Brockenbrough needle or Baylis radiofrequency ablation system can be used for septal puncture. After septal puncture, needle alone is introduced first. Later hemodynamic pressure tracing changes from RA to LA pattern. Aspiration of blood from LA confirms bright red oxygenated blood. Then, the dilator is introduced carefully with counter clock turn to avoid injury to the posterior LA. Position of sheath inside LA is confirmed with TEE. Later needle and dilator are withdrawn. LA sheath is flushed with normal saline.
 Balloon Preparation
  • Open the vent port (short port) and flush the balloon with undiluted contrast.
  • Attach the contrast-filled marked syringe to inflation port (longer port).
  • Inflate the balloon to correct size and measure with measurement gauge. Inject dye through vent port if balloon is to be upsized.
  • Insert the metal balloon stretching tube (Silver color tube) in the center lumen and lock it into place (metal to metal attachment – silver to gold attachment).
Balloon insertion and crossing the mitral valve
  • With the Mullins sheath in LA, now introduce 0.025” curled guidewire into LA and allow it to coil with top of coil against roof of LA.
  • After removing the Mullins sheath, introduce 14Fr black color dilator over the guidewire into LA across IAS puncture site. Also, dilate the groin to allow free passage of the balloon.
  • The stretched balloon is now inserted along the 0.025” curled guidewire to the top of the curve. At this point, the stretching tube is released (loosen metal-to-plastic connection) and withdrawn 2-3 cm and advanced further into LA following the curve of the wire. Thereafter unfasten the metal-to-metal connection and remove the stretching tube completely at this point.
  • Now remove the 0.025” curled guidewire while maintaining balloon position in LA.
  • Insert the stylet through center lumen and guide the balloon into LV in RAO view (counterclockwise rotation of the stylet with gentle withdrawal of the balloon). Wait for the gentle bobbing movement of the balloon, once it is seen, then the stylet is pulled, and balloon is pushed into LV.
  • Once the balloon is across the MV orifice, observe free movement toward the apex.
  • Withdraw the balloon partially and push volume into the balloon to inflate the distal end.
  • Maintain gentle traction while the inflated portion of the balloon is pulled against the mitral valve.
  • Inflate the balloon fully once movement toward the LA stops (figure).
  • Once the waist disappeared and the balloon is fully inflated to its predetermined size, immediately deflate the balloon, and withdraw into LA. 3D TEE can be done in case of echocardiographic guidance to know the post PMBC MV area (Figure).
  • Using the balloon’s central lumen and LV pigtail catheter, measure transmitral gradient.
  • Perform Medrad biplane LV gram and compare with pre-procedure LV gram to assess for the worsening of MR. No need for LV gram when the procedure is TEE or intracardiac echocardiography guided.
  • Document cardiac output (CO), pulmonary artery (PA), and pulmonary capillary wedge (PCW) pressures. If there is no MR and residual mitral gradient >5, repeat the balloon dilation, after increasing the balloon size by 1 mm by injecting contrast via the vent port.
  • Admit patient to coronary intensive care unit (CCU) or telemetry for observation and restart anticoagulation if indicated.
Complications and their management
  • Severe MR, which occurs in 2-4% of patients
  • A large atrial septal defect (ASD) (greater than 1.5:1 left-to-right shunt) occurs in fewer than 12% of patients with the double-balloon technique and fewer than 5% with the Inoue balloon technique. Smaller ASDs may be detected by TEE in larger number of patients.
  • Perforation of the left ventricle (0.5-1.0%).
  • Embolic events (0.5-3.0%).
  • Myocardial infarction (0.3-0.5%).
  • Mortality is 1-2%, but in carefully selected cases at experienced centers, it is <1%.
 Post-procedure care and follow-up
  • As needed by severity of MS and clinical status of the patient. Most patients can be discharged the next day.
  • Coumadin if necessary, for other indications like atrial fibrillation, to be started or restarted the next day (at least 24 h after the procedure to reduce access site bleeding). If patient is not on coumadin, aspirin 81 mg per day to be started daily for next day.