Vsd surgery

Surgical techniques of ventricular septal defect repair

1. VSD Repair Surgical techniques -RAJA LAHIRI

2. VSDs are repaired either through the right atrium, RV, or in special circumstances, LV or pulmonary trunk Currently, RV and LV approaches are rarely used Repair is done on conventional CPB at 20°C to 28°C with direct caval cannulation For infants weighing less than 3kg, a single venous cannula may be used and the repair is performed during hypothermic circulatory arrest Cold cardioplegia is used in all the cases

3. After the usual anesthetic and surgical preparations, a median sternotomy is made. Presence of anomalies of pulmonary or systemic venous return is determined. An open ductus during open cardiotomy, particularly during hypothermic circulatory arrest, allows air to enter the aorta and later migrate to the brain; during CPB an open ductus increases intracardiac return and overdistends the pulmonary circulation. A patent ductus is ligated from the anterior approach, usually during cooling. In neonates and infants undergoing hypothermic circulatory arrest, the ductus is ligated as a routine procedure.

4. Repair of Perimembranous Ventricular Septal Defect After CPB has been established, the aorta is occluded, cold cardioplegic solution injected, and the right atrium opened obliquely. A suction device is placed across the naturally present or surgically created foramen ovale Before repair is started, the defect is carefully examined to establish that all margins can be seen and reached. In rare circumstances in which this is not possible because of chordal arrangement, an incision is made to disconnect a portion of the tricuspid valve from the annulus, and the VSD is exposed through the resulting aperture. Relationship of the bundle of His to the posterior and inferior margins of the defect must be clearly understood to accomplish a safe repair .

5. In older infants and children, the VSD is repaired with a polyester or dacron patch sewn in place with continuous polypropylene sutures. In neonates and small infants, the technique may not be adequate because of the delicate nature and friability of the structures. In these patients, the patch may be sewn into place using a combination of continuous and interrupted pledgeted mattress sutures or, alternatively, employing exclusively interrupted mattress sutures reinforced with small pledgets .

6. A ventricular approach may be used when the VSD cannot be well visualized from the right atrium. An RV approach is performed through a transverse incision. The patch is sewn into place with continuous or interrupted sutures. Suturing begins at the transition point between the septal leaflet of the tricuspid valve and the ventricular septum, 5 to 7 mm below the edge of the septal defect. This critical point is given attention by all experienced surgeons. Usual de-airing procedures are performed, and the remainder of the operation is completed as usual

7. Repair of Doubly Committed Subarterial Ventricular Septal Defect Transverse incision in the RV infundibulum is the classic approach for repair of doubly committed subarterial VSDs. These defects should always be closed with a patch to reduce the possibility of distorting the semilunar valves. A continuous stitch technique is employed. When pledgeted sutures are used, they are placed from just above the pulmonary valve leaflets, and pledgets come to lie in the pulmonary valve sinuses. Care is taken not to damage the left main coronary artery. An approach through the pulmonary trunk is also convenient for repairing doubly committed subarterial VSDs.

8. Repair of Inlet Septal Ventricular Septal Defect Inlet septal (AV septal type) VSD is most easily repaired through the right atrium. Such defects are always repaired with a patch. The defect lies beneath the septal leaflet of the tricuspid valve, and care is taken to avoid damage to the leaflet or its chordae and to tailor the patch such that it is not too bulky beneath the leaflet. One method of avoiding damage to the leaflet and improving exposure is to temporarily detach the base of the septal leaflet and a portion of the anterior leaflet of the tricuspid valve and retract the leaflet anteriorly .

9. Repair of Muscular Ventricular Septal Defect A right-sided approach is used for repair of muscular VSDs. Left ventriculotomy provides excellent exposure and although it has been reported not to be disadvantageous in infants, it can produce ventricular aneurysm and important LV dysfunction early and late postoperatively. Defects in the lower part of the muscular septum may be obscured by trabeculations and thus difficult to visualize, resulting in incomplete closure. Single or multiple muscular defects in the inlet and trabecular septum are approached through the right atrium. When a single defect is slit like or oval, direct suture is satisfactory, but when it is large and circular, a patch is used. A cluster of defects can be closed with a single patch or individually.

10. Division of RV trabeculations can aid exposure of the defects, which may be difficult to close because of multiple sites of jet penetration. A single patch of autologous pericardium supported by pledget -reinforced sutures covering an extensive portion of the trabecular septum is useful when there are multiple defects. Kitagawa and colleagues described resection of trabeculations to expose the defect and attaching an oversized patch to the left side of the ventricular septum by sutures passed through the septum from the left side. They also described placing pledget -supported sutures through the rim of an anterior muscular defect, passing the sutures to the outside and tying down on the epicardial surface

11. When a muscular VSD coexists with a perimembranous VSD, a single patch may be used to avoid damaging the bundle of His. VSDs with a single LV opening but two or more openings into the RV on both sides of the trabecula septomarginalis are also approached through the right atrium. The defect is converted into a single LV orifice by detaching the lower end of the trabecula septomarginalis and moderator band from the septum and retracting them

12. Multiple defects in the anterior portion of the septum may be closed through a high transverse ventriculotomy . At times, VSDs may be considered too numerous to close individually; these VSDs are simply compressed and often totally closed by interrupted mattress sutures between a felt strip on theanterior ventricular wall (away from the left anterior descending coronary artery) and pledgets inside the RV and inferior to the VSDs

13. The rare Swiss cheese septum, with features resembling ventricular noncompaction (spongy ventricular septum) and defects involving all components of the ventricular septum may not be correctable through the right side. Its repair requires an LV approach, and a patch over the entire muscular septum may be necessary Incisions into both ventricles are avoided whenever possible. Great care is used in making and closing the left ventriculotomy incision so as not to damage coronary artery branches.

14. VSD with PDA Dissection of the ductus arteriosus is done after establishing CPB The heart must continue to beat otherwise a large shunt will rapidly overdistend the right side of the heart and lungs as it steals from the systemic and cerebral circulation. If the heart does fibrillate, CPB flow is immediately reduced while the dissection is rapidly completed. One ligature, tied on the ductus while CPB flow is reduced to lower intravascular pressure, is sufficient to close it. A surgical clip may be used instead. The operation then proceeds as usual.

15. RA versus RV Approach for Perimembranous VSD RA Approach Advantages An accurate repair can be obtained through a right atrial approach in nearly all cases. Associated infundibular pulmonary stenosis can be excised. An RV scar is avoided Occurrence of RBBB is lower than with the transventricular approach RV Approach Advantages the nadir of the noncoronary cusp of the aortic valve, which is the area of the right trigone and bundle of His, can be accurately visualized, which may be helpful in choosing the suture technique that will minimize prevalence of heart block

16. RA versus RV Approach for Perimembranous VSD RA Approach Disadvantages Techniques must be accurate to avoid damaging the tricuspid valve leaflets or chordae . RV Approach Disadvantages leaving a scar in the RV being associated with a higher prevalence of complete RBBB than with an atrial approach More incidence of ventricular arrhythmias late postoperatively.

17. Closure of Ventricular Septal Defect Through Less Invasive Approaches Smaller incisions (less invasive approaches) have been used for closure of VSDs. Although it is technically feasible to close a VSD successfully through a variety of these techniques, no advantages have been demonstrated other than the smaller incision.

18. Percutaneous Closure of Ventricular Septal Defects In selected cases, especially in patients with complex cardiac anomalies (e.g., multiple muscular VSDs) and those with overlooked VSDs after surgical repair of a large defect, transcatheter closure of the VSD by a percutaneously placed double umbrella can be considered. This may be particularly advantageous in apical muscular defects. This method in general should be considered only when surgery is contraindicated or has unusually high risks and when suitable skill and equipment are available.

19. Closure of VSD When Pulmonary Resistance Is High Patients with VSD in which pulmonary hypertension is severe, with Ppa at or above systemic blood pressure, have traditionally been thought to be inoperable because of the high risk of operation Zhou et al advocated the use of unidirectional valve patch closure of cardiac septal defects with severe pulmonary hypertension The patch consists of polyester fabric with a 0.5- to 1.0-cm hole covered by a pericardial patch left open at one side to function as a one-way valve, placed on the systemic side of the defect.

20. VSD & Aortic Regurgitation In patients in whom AR is trivial or absent, only the VSD is repaired. When AR is moderate or severe and often when it is mild, the aortic valve is repaired. The aortic valve is usually replaced in adults, and this is done only when AR is moderate or severe.

21. Trusler method of plication This procedure is carried out at the commissure adjacent to the prolapsed cusp (usually the right or noncoronary cusp). A 5-0 or 6-0 polypropylene suture is placed through the fibrous lacunae at the midpoint of each cusp. Cusps can then be assessed for elongation and attenuation. Cusp plication is performed at the elongated free edges of the aortic valve cusps. A 5-0 or 6-0 PTFE suture is woven between the right and noncoronary cusps to adjust the excessive length of the prolapsed cusp to the adjacent aortic wall. Repair may be reinforced by pledgets (pericardial or felt) or a small cap of polyester secured as a pledget over both affected cusps adjacent to the commissure .

22. An entirely different technique has been successfully used by Carpentier , Chauvaud , and colleagues. Its basic feature is triangular excision and reconstruction of the prolapsing cusp. Combined with this is an anuloplasty of the left ventriculoaortic junction. They also recommend that the VSD be repaired through the aortic root, using a glutaraldehyde treated pericardial patch.

23. If the valve requires replacement, it is advisable to do the repair of VSD first, followed by AVR This sequence is advised because occasionally it may be necessary to place sutures from the prosthetic valve ring across the upper margin of the VSD patch where it extends between the base of the right and noncoronary cusps (in the region normally occupied by the membranous septum)

24. VSD and Coarctation of Aorta Management options for this combination of defects include simultaneous repair of both lesions sequential single-stage repair through separate incisions initial repair of the coarctation alone initial coarctation repair and pulmonary trunk banding initial VSD closure alone

25. With a large VSD and severe coarctation , repairing the VSD first has certain theoretic advantages but has been practiced rarely under such circumstances Repair of the coarctation only as the initial operation has the advantage of reducing afterload on the LV and, theoretically at least, reducing shunt through the defect. It also avoids a second operation if the VSD closes spontaneously

26. In the current era, the following practice can be recommended: When the VSD is large, the coarctation is severe, and the infant presents with severe heart failure, a singlestage repair of coarctation and VSD is advisable. When multiple VSDs or Swiss cheese septum is present, the pulmonary trunk is banded, and debanding and repair are delayed if possible until the patient is about age 3 years. When the coarctation is severe and VSD small or moderate-sized, only the coarctation is repaired, and subsequent repair of the VSD is performed according to standard indications. When the coarctation is moderately severe and VSD large, the VSD may be repaired initially and the coarctation repaired either at the same operation or as a second procedure within a few months. Techniques of CPB are standard, with perfusion of the lower body satisfactory in this situation.

27. Pulmonary Trunk Banding There have been only two standard indications for pulmonary trunk banding in infants with primary VSD: severe heart failure from Swiss cheese septum associated severe coarctation of the aorta and severe heart failure during the first few months of life. The second is no longer an indication for banding

28. Banding of the pulmonary trunk may be performed through a small left anterolateral thoracotomy Nowadays banding is often to be followed by a Fontan operation or use of a valved conduit, avoiding distortion of the pulmonary trunk bifurcation by the band is crucial. To ensure this, placement of the pulmonary trunk band via median sternotomy is the best approach because it permits accurate dissection, placement, and anchoring of the band on both the left and right sides of the pulmonary trunk.

29. According to Trusler’s rule, in the case of patients with a two-ventricle circulation, the pulmonary trunk band is marked to a length of 20 mm, plus the number of millimeters corresponding to the child’s weight in kilograms, to indicate the ultimate tightness of the band. If the banding is done for a complex cardiac anomaly with mixed circulation, the length is 24 mm plus the child’s weight. A 3- to 4-mm-wide tape is used. The preferred material for the band is silicone or silicone-impregnated polyester, which minimizes erosion into the pulmonary trunk and allows easy removal.

30. SPECIAL FEATURES OF POSTOPERATIVE CARE Hemodynamic state typically is good early postoperatively after closure of VSD. In the unusual situation of poor hemodynamic performance, the possibility of residual left-to-right shunting must be considered particularly if left atrial pressure is considerably higher than right atrial pressure If a large left-to-right shunt is present, prompt reoperation is probably indicated. It is prudent to place temporary pacing wires on the RV after VSD repair. Complete AV dissociation is often present for a short time intraoperatively . Even if this resolves promptly, AV dissociation may occur temporarily later on

31. RESULTS In the current era in experienced centers , hospital mortality for isolated VSD closure is 1% or less. Risk is higher when VSDs are multiple and when major associated cardiac anomalies coexist

32. Mode of Early death The most common mode of death after repair of a primary VSD is acute cardiac failure This may be related to failure of intraoperative myocardial protection in the face of myocardial dysfunction Pulmonary Hypertensive Crisis may precipitate acute cardiac failure. Persisting severe pulmonary dysfunction, often from viral pneumonitis present before operation, characterizes death of a few infants after repair of VSD

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