Question of the Week 570
Authors: Joseph Vitale, MD - Cincinnati Children’s Hospital AND Fernando Cuadrado, MD - Cincinnati Children’s Hospital
A 4‑month‑old female with a history of Trisomy 21 and a Rastelli type A atrioventricular septal defect (AVSD) presents for surgical repair using a two‑patch technique. Pre‑operative TTE demonstrated trivial common AV valve regurgitation, a large inlet VSD with bidirectional shunting, and a moderate primum ASD with left‑to‑right shunting. Intraoperatively, the case is complicated by low cardiac output and hemodynamic instability on weaning from bypass. Which of the following TEE findings is MOST likely to require a return to bypass for surgical revision?
EXPLANATION
Atrioventricular septal defects (AVSDs) constitute approximately 4–5% of congenital heart disease and are often repaired between 3–6 months of age. Accompanying mortality rates are as low as 1–3%, but up to 20% of patients will require reoperation on the LAVV.¹,² Risk factors for reoperation have been identified and include preoperative LAVV regurgitation, the presence of a single papillary muscle, and widely spaced papillary muscles.³ Intraoperative TEE is used during surgical repair to identify the size, location, and severity of any residual lesions post‑repair. Difficulty separating from bypass following AVSD repair may be caused by incomplete VSD closure, persistent LAVV regurgitation, or diastolic dysfunction coupled with reduced ventricular chamber size and stroke volume (with the latter more common in unbalanced canal defects).
A retrospective study by Buratto et al. included 134 patients undergoing AVSD repair between 2010–2020 and investigated predictors of LAVV reoperation detectable on intraoperative echocardiogram.³ Of the patients who underwent repair, 20.1% had moderate or greater LAVV regurgitation (LAVVR). A second bypass run was performed in 8.2% of patients, after which the LAVVR significantly improved.³ Freedom from LAVV reoperation at 10 years was 89.6% in those without LAVVR, 86.1% in patients with mild LAVVR, and 61.2% in those with moderate LAVVR. Patients with moderate or greater LAVVR with eccentric jets are more likely to require future reoperation and thus may benefit from a second bypass run to correct the regurgitation.
Intraoperative TEE is also used to detect residual VSD. A study by Rychik et al. evaluated the frequency and size of residual VSDs and the rate of reoperation in 294 patients undergoing repair.⁴ Return to bypass with immediate reoperation was performed in 9 patients, all of whom had both a Qp:Qs >1.5:1 on oximetry and a VSD color jet diameter >3 mm. All patients with a residual VSD of 4 mm or greater underwent immediate reoperation, while 7 patients with a 3 mm residual VSD did not demonstrate a significant shunt and therefore did not return to bypass. Thus, a residual defect of 4 mm or greater predicts the need for immediate reoperation, and a 3 mm defect with significant shunting and hemodynamic stability should also be considered for reoperation. A small atrial fenestration is not likely to result in hemodynamic instability requiring reoperation.
REFERENCES
1. Pasquali SK, Jacobs ML. Contemporary outcomes of complete atrioventricular septal defect repair: analysis of the Society of Thoracic Surgeons Congenital Heart Surgery Database. J Thorac Cardiovasc Surg. 2014 Dec;148(6):2526-31. doi: 10.1016/j.jtcvs.2014.05.095. Epub 2014 Jul 21. PMID: 25125206; PMCID: PMC4527871.
2. Ramgren JJ, Nozohoor S, Zindovic I, Gustafsson R, Hakacova N, Sjögren J. Long-term outcome after early repair of complete atrioventricular septal defect in young infants. J Thorac Cardiovasc Surg. 2021 Jun;161(6):2145-2153. doi: 10.1016/j.jtcvs.2020.08.015. Epub 2020 Aug 10. PMID: 32919770.
3. Buratto E, Cheung MMH, Ratnaraj V, Perrier S, Konstantinov IE, Brizard CP. Intraoperative predictors of left atrioventricular valve reoperation after repair of complete atrioventricular septal defect. J Thorac Cardiovasc Surg. 2026 Jan;171(1):277-285. doi: 10.1016/j.jtcvs.2025.08.033. Epub 2025 Sep 2. PMID: 40907694.
4. Yang SG, Novello R, Nicolson S, Steven J, Gaynor JW, Spray TL, Rychik J. Evaluation of ventricular septal defect repair using intraoperative transesophageal echocardiography: frequency and significance of residual defects in infants and children. Echocardiography. 2000 Oct;17(7):681-4. doi: 10.1046/j.1540-8175.2000.00681.x. PMID: 11107205.