VSD Closure with Inlet Extension — Evidence-Integrated Update

Perimembranous VSDs with inlet extension sit at the intersection of the tricuspid valve apparatus and the atrioventricular conduction axis, so exposure and suture strategy must be designed to protect both. Contemporary data support selective tricuspid valve (TV) detachment or chordal detachment to obtain safe exposure, and careful, shallow, well-spaced bites near the posteroinferior rim to minimize conduction injury [1–5].

Operative Strategy (refined)

1. Cannulation & Myocardial Protection. Standard CPB and cross-clamp. Favor a transatrial approach to maintain an intact RV free wall.
2. Right atriotomy & exposure. Inspect the septal leaflet and chordae; in inlet extension, the VSD margin is often obscured. If visualization is inadequate, employ targeted tricuspid maneuvers:
• Septal leaflet detachment (limited annular detachment with precise re-attachment) — improves exposure with low rates of TR or AV block in multiple series [1,2].
• Anterior leaflet detachment when the subaortic margin is the issue — provides excellent exposure with continuous PTFE patch closure and favorable early outcomes [3].
• Chordal detachment (no annular incision) — can reduce early RBBB without increasing TR versus no detachment in matched cohorts [5].
3. Anatomic “no-fly zone.” The AV node/His bundle courses along the posteroinferior VSD rim at the hinge of the septal TV leaflet; the right bundle emerges just beyond. Prioritize small, shallow bites on the RV (right-sided) surface of the septum, slightly off the rim in the high-risk posteroinferior sector, advancing more confidently where myocardium thickens [2,4].
4. Patch selection & suture line. Autologous pericardium or PTFE are both acceptable; either interrupted or continuous techniques are used in expert hands. Series employing continuous closure with small bites near the conduction tissue report excellent closure and no complete heart block (CHB), with residual shunts uncommon and usually trivial [3,4].
5. Leaflet re-attachment. Re-approximate the detached leaflet precisely at the annulus (or re-suspend divided chordae), avoiding leaflet foreshortening or commissural distortion; this prevents functional stenosis or regurgitation [1–3].
6. Completion. De-air, remove cross-clamp, and assess by TEE for: residual shunt, TR grade, and any leaflet tethering.

Pearls & Pitfalls

• Detachment is a tool, not a liability. Across early and contemporary series, TV detachment (septal or anterior) does not increase TR, need for reoperation, or CHB when re-attachment is meticulous [1–3,6,7].
• Chordal detachment can be a low-footprint alternative to leaflet detachment when a few obstructing chords are the culprit; it has shown lower postoperative RBBB in matched analyses [5].
• Conduction safety lives in the details. The best-performing techniques share themes: shallow, close-to-rim bites near the posteroinferior margin; economical needle angles; and avoidance of full-thickness bites where the His/right bundle are vulnerable [2,4].
• Outcome benchmarks to counsel teams: In large single-center experiences of transatrial closure with and without detachment, CHB is rare (≈0–1%), significant TR is uncommon, and reoperation for TR or residual VSD is infrequent when these principles are followed [2,3,6–8].

Postoperative Management Focus

• Conduction monitoring. Continuous telemetry with a low threshold for temporary pacing; late AV block is rare but recognized, so ensure discharge ECG and early follow-up in high-risk anatomy [8].
• Valve function surveillance. Early and interval echocardiograms to document TR grade and leaflet motion; durable none–mild TR is the norm after careful re-attachment [1–3,6,7].

Practical Summary

For perimembranous VSD with inlet extension, exposure is protection: use tailored tricuspid maneuvers (septal/anterior leaflet detachment or chordal detachment) to see the true rim, then execute a conduction-conscious patch closure with small, shallow, evenly spaced bites at the posteroinferior margin. The literature consistently shows low CHB, stable tricuspid competency, and low reintervention when these steps are applied deliberately [1–7], with population-level CHB risk after modern VSD repair generally <1% [8].

References

[1] 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.

[2] 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.

[3] 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.

[4] Mullen JC, Lemermeyer G, Schipper SA, Bentley MJ. Perimembranous ventricular septal defect repair: keeping it simple. Can J Cardiol. 1996;12(9):817–821.

[5] Ashry A, Khan S, Johns M, Moran D, Mohammed HM, Lotto R, et al. Ventricular septal defect exposure by tricuspid valve chordal detachment—A retrospective matched study. World J Pediatr Congenit Heart Surg. 2023;14(3):350–356.

[6] Giordano R, Cantinotti M, Di Tommaso L, Comentale G, Tozzi A, Pilato E, et al. The fate of the tricuspid valve after the transatrial closure of the ventricular septal defect. Ann Thorac Surg. 2018;106(4):1229–1233.

[7] 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.

[8] Andersen HØ, de Leval MR, Tsang VT, Elliott MJ, Anderson RH, Cook AC. Is complete heart block after surgical closure of ventricular septum defects still an issue? Ann Thorac Surg. 2006;82(3):948–956.