This study explores a high-risk cardiac surgical case involving a 75-year-old male undergoing redo mitral valve replacement (MVR). The patient presented with a history of multiple prior cardiac interventions, including coronary artery bypass grafting and valve replacement, as well as severe mitral regurgitation, mild aortic regurgitation, and significant calcifications in the abdominal and iliac arteries. These factors, combined with a low ejection fraction and chronic kidney disease, created a challenging surgical environment.
Traditionally, effective cardiac arrest during such procedures is achieved using cardioplegia with aortic cross-clamping (ACC). However, in this case, adhesions and low aortic root pressure rendered both antegrade and retrograde cardioplegia delivery unfeasible. To circumvent these challenges, the surgical team opted for systemic hyperkalemia cardiopulmonary bypass (CPB) without ACC, combined with circulatory arrest.
The surgical process began with the administration of CPB through minimally invasive cannulation techniques. Continuous monitoring and hypothermic conditions helped maintain patient stability. Initial cardioplegia successfully induced cardiac arrest, but subsequent attempts were thwarted by inadequate root pressure and inaccessible retrograde pathways due to adhesions. This led to a pivot in strategy toward systemic hyperkalemia-induced arrest.
A mixed solution of potassium, magnesium, and lidocaine was infused, targeting a potassium level of 9.0 mEq/L to sustain cardiac arrest. Challenges posed by aortic regurgitation were addressed by integrating intermittent circulatory arrest, ensuring a clear surgical field for valve replacement. Periodic circulatory arrest was implemented during critical steps like annulus suturing, with temperature-controlled CPB ensuring tissue preservation.
Post-surgery, potassium levels were gradually normalized using gravity drainage hemodiafiltration and saline infusion. The CPB process concluded without significant complications, and the patient was successfully weaned off mechanical support. Postoperative monitoring revealed no major organ dysfunction, and the patient experienced an uneventful recovery, marked by minimal creatine kinase and creatinine elevation.
This case highlights the innovative application of systemic hyperkalemia CPB in conjunction with circulatory arrest to overcome the limitations of standard cardioplegia delivery. It also underscores the importance of flexibility in surgical planning, particularly for redo surgeries where anatomical alterations complicate traditional approaches.
Minimally invasive cardiac surgery (MICS) offers significant benefits, including reduced mortality, renal failure risk, and recovery time. However, redo cases often involve extensive adhesions, complicating traditional strategies like ACC. Systemic hyperkalemia avoids the risks of myocardial hypoperfusion associated with alternative techniques like ventricular fibrillation, delivering consistent cardiac protection even in anatomically complex cases.
Despite the absence of large-scale studies, this approach demonstrates promise for high-risk cardiac surgeries. By avoiding open conversion and leveraging systemic hyperkalemia, the surgical team achieved effective myocardial protection while minimizing patient trauma.
Future investigations should explore the broader applicability of this method, including its integration into standard protocols for redo surgeries involving challenging cardioplegia delivery. This case emphasizes the evolving role of MICS and systemic hyperkalemia in advancing cardiac surgery outcomes.
