Management of Complex Left Ventricular Outflow Tract Obstruction: A Comparison of Konno and Modified Konno Techniques
Mahwish Haider, Laura Carlson, Hua Liu, Christopher Baird, John E. Mayer, Meena Nathan
Pediatr Cardiol. 2021 Feb 8 : 1–14. doi: 10.1007/s00246-020-02522-9 [Epub ahead of print]
Take Home Messages
- In patients who undergo Modified Konno operation for LVOT obstruction, there is a significantly higher rate of LVOT reintervention compared to Konno operation.
- Transplant free survival is statistically similar for Konno and modified Konno operations.
- The use of the Konno operation is associated with patients who have multiple left sided lesions.
Commentary from Dr. Luis Quinonez (Boston MA USA), section editor of Congenital Heart Surgery Journal Watch:
Purpose: To compare outcomes of the Konno procedure to the Modified Konno procedure
Population: 122 patients, single institution, 1990 to 2014
Intervention: Konno (n=51) and modified Konno operations (n=71)
Design: Retrospective review
Primary outcome: LVOT re-intervention
Secondary outcomes: Overall re-interventions; transplant-free survival; composite of re-interventions and transplant-free survival; hospital mortality and major adverse events; hospital length of stay
- Median age, Konno vs. modified Konno: 8.2 years vs 3.9 years (p=0.03)
- Median Follow-up: 8 years
- Patients with multiple left sided lesions more likely to have Konno (p=0.017)
- Hospital outcomes (Konno vs. modified Konno):
- No statistical difference: mortality (7.8% vs. 4.2%), major adverse events, permanent pacemaker (11.8% vs. 9.9%)
- Multivariate analysis:
- Konno had longer LOS
- Patients with multiple left sided lesions: more complications (48%), more surgical reinterventions (22.9%); longer ICU and hospital LOS
- Post-Discharge outcomes, Konno vs. modified Konno:
- LVOT reintervention at 10 years: 11% vs. 47% (p=0.002)
- Multivariate analysis: Modified Konno risk factor for LVOT intervention
- Overall reintervention at 10 years: 44% vs. 60% (p=0.114)
- Transplant free survival at 10 years: 92% vs. 85% (p=0.188)
- Multivariate analysis: Konno or modified Konno are not risk factors for survival.
This paper is a large, single institution experiences comparing outcomes of Konno against modified Konno procedures with long-term follow-up. The results are mostly intuitive, in that Konno patients were operated at an older age; they had less LVOT interventions; and patients with multiple left sided lesions fare worse. Despite modified Konno patients having more LVOT interventions, the overall rate on interventions was similar in both groups over time. Both groups would have reinterventions on the RVPA conduit, but patients who had Konno procedures would have more MV interventions, as they were more likely to have multiple left sided lesions. Being retrospective, underlying surgical selection biases are reflected: modified Konno in younger patients to try to preserve the aortic valve; and Konno in patients with multiple left sided lesions.
The study also demonstrates a significant operative mortality for the groups, as well as need for permanent pacemaker for both procedures. Although the overall reintervention rate and transplant free survival was not statistically different between the two procedures, the absolute numbers favour the use of the Konno, which is worth noting.
Patients with LVOT obstruction continue to remain a surgical challenge so these data are worth reviewing. The literature review provided is helpful.