Valve sparing repair of TOF
Repair. In this operation, the PV is left in place and is plastied, usually involving surgical comissurotomies. The VSD is closed either through the TV or through an infundibular incision which is then patched closed. In some cases, there is no infundibulotomy and the RVOT muscle bundles are resected through the PV. (This may decrease the future risk of ventricular arrhythmias by preventing a transmural RV incision.) A fenestrated ASD is often left in place to permit right to left atrial flow.
Postoperative considerations. The postoperative management of TOF/PS is primarily focused upon the degree of restrictive RV physiology. A patient may be desaturated from atrial flow, which is well tolerated. Conversely, a patient without an atrial fenestration and a thickened, muscle-bound RV that receives preload poorly may be fully saturated but exhibit severe low cardiac output (poor color, feeble pulses, RA HTN, narrow pulse pressure). Vasoconstriction to maintain preload and coronary perfusion pressure, and maintenance of mechanical ventilation (if low cardiac output is present) to decrease metabolic demand may provide time for cardiac swelling to abate. RBBB is a common finding.
Transannular patch of TOF
Repair. In this operation, the RVOT incision crosses the PV annulus. The typically rudimentary PV is often left in situ but a patch is placed over the entire RVOT including the PV, such that the valve is usually freely regurgitant. However, in most cases free PR is well tolerated in the early postoperative period. The regurgitant fraction is generally low due to the usually low PA diastolic pressure and the restrictive RV (i.e. low compliance, such that RVEDP increases rapidly with the addition of volume, attenuating regurgitation). At times a monocusp valve is fashioned within the RVOT, which may provide a temporarily competent PV though these have not been shown to be durable.
Postoperative considerations. The postoperative management of TOF/PS with TAP is similar to valve sparing repair. The degree of restrictive RV physiology and the size/patency of atrial fenestration are paramount. A patient may be desaturated from atrial flow, which is well tolerated. Conversely, a patient without an atrial fenestration and a thickened, muscle-bound RV that receives preload poorly may be fully saturated but exhibit severe low cardiac output (poor color, feeble pulses, RA HTN, narrow pulse pressure). Vasoconstriction to maintain preload and coronary perfusion pressure, and maintenance of mechanical ventilation to decrease metabolic demand may provide time for cardiac swelling to abate.
References
1955, Ann Surg – Repair of TOF by direct vision – Lillehei