Tricuspid Valve Detachment in Perimembranous VSD Closure

Perimembranous VSDs commonly lie beneath the anterior and septal tricuspid leaflets and may be partially or completely covered by leaflet tissue. In this setting, working “through” the valve can provide only a narrow view of the defect, making it difficult to define the posteroinferior rim adjacent to the conduction tissue and predisposing to residual shunt, LVOT obstruction, or valve injury.

Temporary tricuspid valve detachment (TVD)—usually of the septal leaflet, with or without a portion of the anterior leaflet—was introduced to address this problem and has since been validated in multiple series as a safe and effective adjunct for perimembranous VSD closure, without excess tricuspid regurgitation (TR), stenosis, or atrioventricular (AV) block when performed carefully.[1–4]

1. Anatomic Background

1. Location of the defect
• The classic perimembranous VSD is situated just beneath the anterior (ATL) and septal (STL) tricuspid leaflets, often “roofed” by leaflet tissue and chordae arising from the septal leaflet.[4]
• This anatomic relationship explains why standard trans-atrial exposure may not fully reveal the superior and posteroinferior margins of the defect.
2. Relationship to the conduction system
• The AV node and His bundle course along the posteroinferior rim of the VSD, close to the hinge of the septal leaflet.[3]
• Sutures placed too close to this margin or deeply into the septum risk complete heart block, a complication that carries lifelong implications for the child.
3. Tricuspid valve apparatus
• The septal leaflet and its chordae often tether leaflet tissue directly over the defect, limiting exposure.
• Excessive traction or poorly planned detachment may lead to leaflet tear, chordal rupture, or postoperative TR, so the detachment line must preserve leaflet substance and key chordal insertions.

2. Indications for Tricuspid Valve Detachment

TVD is considered when any of the following are present:

• Inadequate visualization of the entire VSD margin through a standard right-atrial approach.
• The septal and/or anterior leaflet obscures the superior or posteroinferior rim, particularly when a chordal fan or pouch-like prolapse of the septal leaflet overlies the defect.[2,5]
• Concern that limited exposure will result in:
• Imprudent suture placement with residual shunting or LVOT obstruction,
• Excess traction on the leaflets with new or worsened TR, or
• Deep stitches threatening the conduction system.
• The TV leaflets appear structurally normal and robust enough to tolerate detachment and reattachment without compromising coaptation.

Pre-operative transthoracic echo can help identify patients in whom chordal attachments or leaflet pouches are likely to obscure the VSD and therefore pre-select candidates for TVD.[5]

3. Stepwise Surgical Technique

3.1 Initial Exposure

1. Perform a right atriotomy and inspect the tricuspid valve and VSD.
2. Identify:
• ATL and STL,
• The portion of the VSD rim that is visible,
• Chordal attachments or leaflet pouches limiting exposure.

In many cases, the perimembranous VSD lies deep beneath the ATL and STL and is largely covered by leaflet tissue; only a small segment of the defect is initially visible.

3.2 Tricuspid Valve Detachment

1. Line of incision
• The leaflet is incised parallel to the tricuspid annulus, usually along the septal leaflet and, if necessary, extending into the anterior leaflet to create a hinged flap.[1,2,4]
• The incision is kept 1–3 mm from the annular hinge, preserving a generous leaflet edge for secure reattachment.
2. Technical points
• Avoid extending the incision too far posteriorly toward the posteroseptal commissure, where the AV node resides.
• Place stay sutures on the detached leaflet edge to maintain orientation and prevent leaflet twisting.
• Detachment creates a wide, unobstructed “window” onto the right-ventricular aspect of the septum and the full circumference of the VSD.

3.3 VSD Patch Closure

1. With the leaflet reflected, the entire VSD margin—including the critical posteroinferior rim—is clearly visualized.[4]
2. A patch (e.g., ePTFE or glutaraldehyde-treated autologous pericardium) is tailored to be slightly larger than the defect, ensuring a tension-free repair.
3. Suturing strategy
• Use interrupted or continuous 5-0 or 6-0 polypropylene sutures, with pledgets where the tissue is fragile.
• Along the posteroinferior rim, place sutures from the left-ventricular side to the right, keeping bites superficial and toward the LV side to maximize the distance from the conduction tissue.[3]
• Seat the patch so it:
• Does not protrude into the LVOT, and
• Lies slightly below the tricuspid annulus so that the leaflets can close freely without catching on the patch.

3.4 Reattachment and Repair of the Tricuspid Valve

1. The detached leaflet edge is reattached to the annulus using fine interrupted or continuous sutures, sometimes with small pledgets when the leaflet tissue is thin.[1,4,7]
2. Key details:
• Reapproximate the leaflet exactly at its original annular position to avoid leaflet restriction, malcoaptation, or annular deformity.
• Restore the commissures and ensure that sutures do not bunch the leaflet edge onto the patch.
3. Assessment:
• Perform a saline test to evaluate TR and leaflet coaptation.
• After weaning from bypass, TEE confirms the absence of significant TR or stenosis and checks for any patch–leaflet interaction.

4. Key Technical Considerations and Pitfalls

• Conduction system protection
• Keep sutures on the posteroinferior VSD margin shallow and toward the LV aspect of the septum.
• Avoid aggressive extension of the detachment incision into the posterior septal annulus.
• Preservation of valve geometry
• Limit the length of detachment to the minimum necessary segment for adequate exposure.
• Preserve critical chordal insertions; if a chord is inadvertently divided, consider chordal transfer or artificial chordal reconstruction.
• Prevention of postoperative TR
• Reattach the leaflet at the native annular level; over-plication or asymmetric reattachment can cause tethering and central regurgitation.
• If significant pre-existing TR or annular dilatation is present, a concomitant tricuspid annuloplasty may be added, with care not to induce stenosis.
• Avoiding patch–leaflet conflict
• Ensure that the superior edge of the patch remains slightly ventricular to the annulus, so that the leaflet closes onto native septal tissue rather than the patch.
• Avoid bulky pledgets on the annular line that might interfere with leaflet motion.

5. Evidence Base and Clinical Outcomes

Early comparative series from the 1990s and early 2000s showed that TVD could be performed without excess TR, stenosis, or heart block compared with conventional trans-atrial closure.[1–4] In Bol-Raap’s series of 149 patients, 39 underwent TVD; at a mean 2-year follow-up, no patient had more than trivial TR and no tricuspid stenosis was observed.[1] Tatebe and colleagues reported similarly favorable outcomes, with most patients showing no or trivial TR and no residual shunts at ≥1-year follow-up.[2]

Gaynor et al. compared children undergoing VSD closure with or without TVD and found no difference in operative mortality, permanent AV block, or significant TR, while TVD markedly improved exposure in anatomically challenging defects.[3] Zhao’s 600-patient series (122 with TVD) further confirmed that leaflet detachment did not increase mortality, AV block, or late TR, and allowed complete closure of difficult perimembranous defects.[4]

Prospective and long-term data have reinforced these findings. Sasson et al. demonstrated that applying predefined echocardiographic criteria to select patients for TVD reduced residual VSD and AV block compared with patients who met the criteria but did not undergo detachment.[5] Lucchese’s prospective cohort of 68 children followed for a median of nearly 6 years showed no deaths, no tricuspid stenosis, and >90% of patients with only trivial or mild TR at last follow-up.[7]

Outcomes are favorable even in vulnerable subgroups. Bang and colleagues studied infants younger than 3 months and found that TVD improved exposure without increasing early mortality, AV block, or significant TR compared with non-TVD repairs.[6] In a large multicenter cohort, Fraser et al. reported that TVD did not compromise long-term valve durability; the prevalence of mild TR and the rarity of moderate TR were similar between TVD and non-TVD groups.[8]

More recent comparative studies and systematic reviews have quantified these observations. Bilen et al. retrospectively analyzed 170 patients (50 with TVD) and showed no adverse effect on mid-term tricuspid valve growth or function, with TVD safely improving exposure in selected patients.[9] Sandoval Boburg et al., using a predominantly TVD strategy (102 of 140 patients), reported 98% of patients with none to mild TR at 1–9 years of follow-up and no cases of moderate/severe TR, AV block, or reoperation, emphasizing that routine septal and anterior leaflet detachment with careful reattachment does not impair valve competence.[10]

A meta-analysis by Yuan et al. synthesizing data from more than 1000 patients confirmed that, compared with non-TVD approaches, TVD does not increase operative mortality, permanent AV block, or early TR, and does not raise the rate of residual VSD.[11] A modestly higher incidence of mild TR during late follow-up was observed, but clinically significant (moderate or greater) TR remained rare and seldom required reoperation.[11] These data support the view that TVD is a safe, effective, and growth-compatible technique when anatomical indications are met and meticulous surgical principles are followed.

6. Practical Summary

• Perimembranous VSDs often lie hidden beneath the anterior and septal tricuspid leaflets, making standard trans-atrial closure hazardous.
• Tricuspid valve detachment provides a controlled way to mobilize the leaflet, create a broad operative field, and permit precise, conduction-sparing patch placement.
• When performed with attention to the detachment line, patch orientation, conduction anatomy, and valve reattachment, TVD:
• Improves exposure of complex defects,
• Maintains excellent short- and long-term tricuspid valve function, and
• Does not increase mortality or the need for reoperation in large contemporary series and meta-analyses.[1–4,7–11]

Thus, TVD is a valuable technique in the congenital surgeon’s armamentarium, converting a deep, poorly visualized perimembranous VSD into a well-exposed and safely repairable lesion while preserving long-term tricuspid valve competence.

References

[1] Bol-Raap G, Bogers AJJC, Boersma H, De Jong PL, Hess J, Bos E. Temporary tricuspid valve detachment in closure of congenital ventricular septal defect. Eur J Cardiothorac Surg. 1994;8(3):145-148.

[2] 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.

[3] 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.

[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] Sasson L, Katz MG, Ezri T, Tamir A, Herman A, Bove EL, Schachner A. Indications for tricuspid valve detachment in closure of ventricular septal defect in children. Ann Thorac Surg. 2006;82(3):958-963.

[6] Bang JH, Park CS, Park JJ, Yun TJ, Baek JS, Yu JJ, et al. Detachment of the tricuspid valve for ventricular septal defect closure in infants younger than 3 months. J Thorac Cardiovasc Surg. 2016;152(2):491-496.

[7] Lucchese G, Rossetti L, Faggian G, Luciani GB. Long-term follow-up study of temporary tricuspid valve detachment as approach to VSD repair without consequent tricuspid dysfunction. Tex Heart Inst J. 2016;43(5):392-396.

[8] Fraser CD III, Zhou X, Palepu S, Lui C, Suarez-Pierre A, Crawford TC, et al. Tricuspid valve detachment in ventricular septal defect closure does not impact valve function. Ann Thorac Surg. 2018;106(1):145-150.

[9] Bilen Ç, Akkaya G, Tuncer ON, Atay Y. Assessment of tricuspid valve detachment efficiency for ventricular septal defect closure: A retrospective comparative study. Acta Cardiol Sin. 2020;36(4):360-366.

[10] Sandoval Boburg R, Schlensak C, Hofbeck M, Magunia H, Berger R, Jost W, Mustafi M. Routine detachment of the anterior and septal tricuspid leaflets simplifies VSD closure and improves the outcomes. Medicina (Kaunas). 2022;58(12):1849.

[11] Yuan D, Chen L, Zhang X, Qian Y. Tricuspid valve detachment for ventricular septal defect closure: A meta-analysis of existing evidence. J Card Surg. 2022;37(12):5395-5403.