VSD Patch Closure — Surgeon’s View

Ventricular septal defect closure is one of the fundamental operations in congenital heart surgery. However, from the surgeon’s viewpoint, it is not simply the closure of an intracardiac hole. It is a precise reconstructive procedure performed at the intersection of the ventricular septum, tricuspid valve apparatus, semilunar valves, and conduction system. A successful repair requires not only complete elimination of the shunt, but also preservation of valve geometry, conduction integrity, and right ventricular inflow and outflow architecture [1, 2].

The surgical field for a perimembranous or outlet-extended VSD is often limited by the septal leaflet of the tricuspid valve, chordal attachments, papillary muscles, and the spatial relationship to the aortic valve. Therefore, VSD closure should be understood as a three-dimensional operation: the surgeon must identify the true margin of the defect, select an exposure strategy, place sutures safely along different anatomical zones, and seat the patch without distortion.

1. Surgical Concept

The goal of VSD patch closure is to restore ventricular septal continuity while preserving surrounding structures. The patch should not merely “cover” the defect; it should reconstruct the missing septal surface in a way that is smooth, secure, and anatomically respectful.

The essential goals are:

1. Complete closure of the VSD
2. Avoidance of residual shunt
3. Protection of the conduction axis
4. Preservation of tricuspid valve function
5. Avoidance of aortic or pulmonary valve distortion
6. Maintenance of right ventricular geometry and outflow patency

These principles apply to most isolated VSDs, but they become especially important in perimembranous VSDs with outlet extension, defects partially hidden by tricuspid valve tissue, and lesions close to the aortic or pulmonary valve.

2. Exposure Through the Tricuspid Valve

The transatrial approach is the standard route for many perimembranous VSDs. However, the tricuspid valve may obscure the surgical margin, especially when the septal leaflet or chordal structures cross the defect. Inadequate exposure increases the risk of residual VSD, inaccurate suture placement, injury to the conduction system, or distortion of the tricuspid valve.

Several exposure strategies may be used:

• Gentle retraction of the septal leaflet
• Stay sutures on the tricuspid valve tissue
• Working through natural chordal windows
• Detachment of part of the tricuspid valve leaflet when exposure is insufficient

Tricuspid valve detachment should not be considered an aggressive maneuver by default. When used selectively, it can improve visualization and allow safer, more accurate patch placement. Early and subsequent reports have shown that temporary tricuspid valve detachment can provide excellent exposure without increasing the incidence of significant postoperative tricuspid regurgitation or complete heart block [3, 4].

3. Tricuspid Valve Detachment: Indication and Safety

The main indication for tricuspid valve detachment is a hard-to-expose VSD in which the true margin of the defect cannot be clearly visualized through standard transatrial exposure. This is particularly relevant when the surgeon cannot safely identify the inferior rim, the relationship to the aortic valve, or the conduction-sensitive posteroinferior margin.

Tatebe and colleagues reported favorable outcomes after VSD closure with tricuspid valve detachment, supporting the concept that temporary detachment can be performed without significant deterioration of valve function [3]. Zhao and colleagues also demonstrated that tricuspid valve detachment was safe and effective in congenital VSD closure, with excellent exposure and no increase in heart block in the detachment group [4]. Maile and colleagues further described detachment of the anterior leaflet to improve exposure of the subaortic area, emphasizing that this approach can be useful when the superior margin is difficult to visualize [5].

Longer-term data have reinforced this concept. Gaynor and colleagues showed that tricuspid valve detachment improved visualization and was not associated with increased postoperative heart block, operative time, or tricuspid regurgitation [6]. Fraser and colleagues later reported that tricuspid valve detachment did not compromise long-term tricuspid valve function, with similar rates of mild tricuspid regurgitation between detachment and non-detachment groups [7].

Thus, the practical message is clear:

Tricuspid valve detachment is not performed to make the operation easier; it is performed to make the repair more accurate and safer when exposure is inadequate.

4. Patch Placement: A Three-Dimensional Repair

Once the margins are clearly exposed, the patch is tailored to cover the defect without excessive redundancy or tension. The patch should be large enough to avoid tension on the suture line, but not so large that it bulges into the right ventricle or interferes with tricuspid valve motion.

Patch seating should be controlled and gradual. A parachuting technique is often useful: sutures are placed around the defect while the patch remains elevated, then the patch is lowered carefully into position. This allows the surgeon to confirm orientation, avoid twisting, and maintain even tension along the suture line.

Key points include:

• The patch should follow the natural curvature of the septum.
• The suture line should not distort the tricuspid annulus or chordal apparatus.
• The patch should not impinge on the right ventricular outflow tract.
• The superior margin must be placed with awareness of the aortic and pulmonary valves.
• The inferior and posteroinferior margins must be placed with awareness of the conduction axis.

A well-seated patch should look quiet: no folding, no excessive tension, no valve distortion, and no suspicious gap along the margin.

5. Suture Strategy and the Conduction-Sensitive Zone

Suture strategy is central to safe VSD closure. The same suture technique should not be applied mechanically to every part of the defect. Each rim has a different anatomical risk.

Manning emphasized the importance of understanding the transitions around the VSD margin and advocated careful interrupted pledgeted mattress sutures, particularly near regions where the conduction system is at risk [2]. The posteroinferior margin of a perimembranous VSD is the most important area in this regard. The atrioventricular conduction axis courses close to the membranous septum and then toward the crest of the ventricular septum; therefore, deep or poorly oriented sutures in this zone may result in conduction injury.

A practical surgical framework is:

1. Superior and anterosuperior rim

Secure the patch while avoiding injury or distortion of the aortic and pulmonary valves.

2. Anterior rim

Maintain smooth patch orientation and avoid right ventricular outflow obstruction.

3. Inferior and posteroinferior rim

Use conduction-conscious suture placement. Avoid deep bites toward the expected conduction axis.

4. Tricuspid valve side

Avoid chordal entrapment and confirm that the leaflet can coapt normally after patch placement.

In the conduction-sensitive zone, the safest stitch is not necessarily the deepest stitch. The safest stitch is the one that closes the defect while respecting the hidden anatomy beneath the rim.

6. Residual Shunt and Long-Term Follow-Up

Small residual shunts may be detected after VSD closure, especially with sensitive echocardiography. Not all residual shunts require reintervention. Bol-Raap and colleagues reported that trivial residual shunts after surgical VSD closure often decreased or disappeared over time, with many resolving spontaneously during follow-up [8]. Nevertheless, the goal of surgery remains complete closure at the initial operation, especially when the defect margin is well visualized and the patch is securely seated.

Residual shunt is more likely when:

• Exposure is inadequate
• The inferior rim is poorly defined
• The patch is undersized
• Suture spacing is too wide
• Sutures are placed through fragile tissue
• The patch is twisted or seated under uneven tension

Therefore, prevention of residual shunt begins before the first suture is tied. It begins with exposure, anatomical orientation, and patch planning.

7. Special Considerations in Outlet-Extended and Juxtaarterial VSDs

Although much of the tricuspid valve detachment literature focuses on perimembranous VSDs, the same surgical principles are highly relevant to outlet-extended and juxtaarterial defects. In these lesions, the superior rim is close to the semilunar valves, and the surgeon must be particularly cautious about aortic cusp support and pulmonary valve preservation.

In outlet-type defects, the repair is not only a shunt closure. It may also be a valve-preserving operation. Aortic cusp prolapse and progressive aortic regurgitation can develop when the superior rim is deficient or when the right coronary cusp lacks adequate support. Therefore, the patch should restore septal support without deforming the valve hinge or commissural geometry.

The surgeon should repeatedly ask:

• Is the aortic cusp free and undistorted?
• Is the pulmonary valve protected?
• Is the superior patch margin secure?
• Is the outflow tract unobstructed?
• Is the inferior suture line away from the conduction axis?

This is especially important in doubly committed juxtaarterial VSDs, where the relationship between the VSD, pulmonary valve, and aortic valve may determine both the operative approach and the long-term durability of the repair.

8. Final Intraoperative Assessment

After patch closure, the repair should be evaluated systematically. The operation is not complete when the last knot is tied; it is complete when the anatomy, valve function, rhythm, and echocardiographic findings are acceptable.

Final assessment should include:

1. Patch geometry

The patch should be smooth, stable, and well seated.

2. Residual VSD

Intraoperative echocardiography should confirm no significant residual shunt.

3. Tricuspid valve function

Leaflet motion, coaptation, and the repaired detachment line should be assessed.

4. Aortic valve competence

The aortic cusps should remain mobile and competent, especially in outlet-related defects.

5. Pulmonary valve integrity

Important when the defect is close to the pulmonary annulus.

6. Conduction status

Rhythm and atrioventricular conduction should be monitored carefully after repair.

In adults, surgical VSD closure is generally performed with low mortality and morbidity when appropriately indicated, although associated lesions such as aortic regurgitation and long-standing volume loading require careful assessment [9]. In infants and small patients, more recent experience also supports the selective use of tricuspid valve detachment when exposure is otherwise inadequate [10].

9. Practical Summary

VSD patch closure is a disciplined anatomical operation. The surgeon must see the defect clearly, understand the surrounding structures, and adapt the suture strategy to each segment of the rim.

The central lessons are:

• Exposure determines accuracy.
• Patch geometry determines durability.
• Suture placement determines conduction safety.
• Valve preservation determines long-term quality of repair.

Tricuspid valve detachment is a valuable exposure technique when the VSD is difficult to visualize. The accumulated literature supports its safety when performed carefully and repaired precisely. It should be used not as a routine shortcut, but as a deliberate strategy to improve visualization, reduce residual shunt risk, and protect the conduction system and valve apparatus.

The best VSD closure is not defined by the number of stitches or the size of the patch. It is defined by anatomical precision: a quiet patch, competent valves, stable conduction, and no residual shunt.

References

[1] McGrath LB. Methods for repair of simple isolated ventricular septal defect. J Card Surg. 1991;6(1):13-23.

[2] Manning PB. Ventricular septal defect closure: how I teach it. Ann Thorac Surg. 2018;106(2):324-326.

[3] Tatebe S, Miyamura H, Watanabe H, Sugawara M, Eguchi S. Closure of isolated ventricular septal defect with detachment of the tricuspid valve. J Card Surg. 1995;10(5):564-568.

[4] Zhao J, Li J, Wei X, Zhao B, Sun W. Tricuspid valve detachment in closure of congenital ventricular septal defect. Tex Heart Inst J. 2003;30(1):38-41.

[5] Maile S, Kadner A, Turina MI, Prêtre R. Detachment of the anterior leaflet of the tricuspid valve to expose perimembranous ventricular septal defects. Ann Thorac Surg. 2003;75(3):944-946.

[6] Gaynor JW, O’Brien JE Jr, Rychik J, Sanchez GR, DeCampli WM, Spray TL. Outcome following tricuspid valve detachment for ventricular septal defects closure. Eur J Cardiothorac Surg. 2001;19(3):279-282.

[7] Fraser CD 3rd, Zhou X, Palepu S, Lui C, Suarez-Pierre A, Crawford T, Magruder JT, Jacobs ML, Cameron DE, Hibino N, Vricella LA. Tricuspid valve detachment in ventricular septal defect closure does not impact valve function. Ann Thorac Surg. 2018;106(1):145-150.

[8] Bol-Raap G, Weerheim J, Kappetein AP, Witsenburg M, Bogers AJ. Follow-up after surgical closure of congenital ventricular septal defect. Eur J Cardiothorac Surg. 2003;24(4):511-515.

[9] Mongeon FP, Burkhart HM, Ammash NM, Dearani JA, Li Z, Warnes CA, Connolly HM. Indications and outcomes of surgical closure of ventricular septal defect in adults. JACC Cardiovasc Interv. 2010;3(3):290-297.

[10] Lee JH, Cho S, Kwak JG, Lee CH, Kim SH, Shim WS, Lee SY, Baek JS, Choi JY. Tricuspid valve detachment for ventricular septal defect closure in infants <5 kg: should we be hesitant? Eur J Cardiothorac Surg. 2021;60(3):544-551.