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Chiu Modified parasternal approach for aortic valve surgery

put under right scapula, which tilted the patient left After commencing CPB, the aortopulmonary window
approximately 30 degrees. External defibrillation pads was dissected to facilitate ascending aorta looping
were applied routinely preoperatively. using vascular tape. This step was helpful not only for
securely cross clamping the aorta but also for adding
The skin incision was made longitudinally one sutures for hemostasis at both ends of aortotomy. A
fingerbreadth parallel to right lateral sternal border malleable left ventricular venting catheter was inserted
from the lower margin of 2nd rib to the upper margin of via the right upper pulmonary vein through mitral valve
5th rib. A subcutaneous pocket was created for better into left ventricle. It was helpful to maintain constant
detachment of the underlying muscle. The pectoralis bloodless exposure of aortic valve, to decompress left
major muscle was cut in a reversed C shape from the ventricle and to de-air after crossclamp was removed
sternal border attachment to allow lateral retraction and before CPB was weaned off.
naturally. The intercostal muscle was cut underneath
the 2nd rib and above the 5th rib. The right internal Using the traction sutures on the pericardium and fixing
mammary artery and veins were encountered at both the cross clamp rightward, the aortic exposure was
intercostal spaces and carefully divided after clip usually adequate enough for having an aortotomy and
ligation. The 3rd and 4th ribs were cut at sternochondral delivering cardioplegic solution, even with coronary
junction with a rib cutter. The sharp margin was ostia balloon catheters. Aortic leaflets and annulus
trimmed with a bone file to prevent inadvertent lung could be well-exposed for inspection. Decalcification
injury. The myocostal flap was bent into right pleural and trimming of leaflets were then performed
cavity after manual fracture. The fracture point was meticulously. Repair or replacement of the aortic valve
adjusted based on the width needed for surgical was done by conventional techniques and instruments
exposure, which was approximately at the junction [Figure 2A]. For mitral valve procedures, three
between rib and costal cartilage. Care was taken to approaches could be chosen according to patient’s
maintain the periosteum and soft tissue attachment anatomy and complexity of mitral procedures. By using
to ensure the bony healing and future wound stability. femoral bicaval cannula and snaring of both superior
Then, a small-sized rib or sternal spreader (retractor) and inferior vena cava, trans-septal approach offered
was inserted to keep constant exposure. The two the best mitral exposure. Through Waterston’s groove,
blades of sternal or rib retractor could be asymmetric. the trans-lateral approach was a viable alternative,
The short blade was good for the sternal side and the but the mitral valve would be farther away than trans-
longer blade was suitable for the lateral myocostal septal exposure. For a simplified suture annuloplasty,
flap. Pericardium was opened longitudinally after the left atrial dome approach was an attractive option.
removing the epicardial fat pad. Stay sutures were Meanwhile, tricuspid valve procedures could be
placed to bring the mediastinum right. Placement straightforwardly done. Ablation for atrial fibrillation
of the sternal retractor inside the pericardial cradle (AF) could be performed both endocardially and
provided adequate exposure. If the ascending aortic epicardially by cryoprobe or unipolar radiofrequency
exposure was adequate enough to accommodate probe. Closure of left atrial appendage was feasible.
[8]
aortic cannulation, crossclamp, cardioplegic needle, In brief, most valvular procedures could be achieved
aortotomy and prosthetic manipulation, central through our two-rib parasternal approach, except for
cannulation could be performed. Otherwise, peripheral pulmonary valve procedures. If temporary ventricular
cannulation, mainly femoral and occasionally axillary pacemaker wires were considered, insertion under total
cannulations were used. Femoral vein cannulation decompression of heart chambers over right ventricle
was routinely utilized to ensure better exposure under was highly recommended. Transvenous pacemaker
limited skin incision. Wire-reinforced aortic cannula was wire through right internal jugular or right subclavian
chosen for better positioning without the risk of kinking. vein approach was an alternative.
Single femoral venous cannulation plus vacuum
assisted venous drainage usually provided adequate After our first hundred cases, a single-lumen
drainage. From our experience, left neck central endotracheal intubation was employed to simplify
venous line was preferred. Right neck was preserved anesthetic induction process. Temporary cessation of
for surgeon manipulation. Echo-guided 4-Fr introducer mechanical ventilation would suffice for pleural entry
sheath was inserted via right interal jugular vein before and bending of the myocostal flap. This approach
commencement of cardiopulmonary bypass (CPB). ensured the same prep as a conventional sternal one,
This strategy was helpful when inadequate venous except for left-tilted position and external defibrillation
drainage was encountered in order to insert a superior pads.
vena cana cannula or a tranvenous pacemaker wire
when needed. For the next stage of our experience, we moved to
Mini-invasive Surgery ¦ Volume 1 ¦ June 30, 2017 83