Combining Minimally Invasive Mitral Valve Replacement with Kidney Transplantation: A Pioneering Case

Introduction

Cardiovascular disease remains the leading cause of morbidity and mortality in patients with end-stage renal disease (ESRD), affecting more than 50% of those receiving dialysis [1,2]. Hypertension and diabetes mellitus are shared risk factors contributing to the high prevalences of coronary artery disease and valvular heart disease in this population [3]. Among patients with ESRD, approximately 9% undergo cardiac valve surgery, and more than 35% receive coronary artery bypass grafting before renal transplantation [4,5]. However, perioperative mortality among dialysis-dependent patients undergoing cardiac surgery remains disproportionately high, ranging from 15% to 25%, substantially exceeding that of the general population [6].

Mitral valve pathology, particularly severe mitral regurgitation (MR), complicates the treatment of patients awaiting kidney transplantation. Uncorrected valve disease increases the risks of hemodynamic instability, volume overload, and post-transplant cardiac complications. Therefore, timely surgical correction is often necessary before transplantation [7]. Simultaneous correction of cardiac and renal disease in a single operation has been described using conventional sternotomy for cardiac surgery [8,9], but this approach remains uncommon due to its complexity and potential for hemodynamic compromise.

Minimally invasive mitral valve replacement (MIMVR) via right mini-thoracotomy has emerged as a viable option for selected high-risk patients. It offers advantages such as reduced surgical trauma, less postoperative bleeding, lower risk of sternal wound infection, and shorter recovery time [10]. In renal transplant candidates, efforts to minimize blood loss and transfusion are particularly important because of the immunologic and infectious risks associated with allogeneic blood products [11].

Previous reports, such as those by Tekin et al [8] and Zengin et al [9], have described combined cardiac and kidney surgeries; however, both utilized conventional median sternotomy for cardiac procedures. To our knowledge, no prior reports have described simultaneous mitral valve replacement using a minimally invasive approach combined with living-donor kidney transplantation.

This case report presents a rare and complex surgical approach involving simultaneous MIMVR and renal transplantation in a 42-year-old man with ESRD and severe symptomatic MR. It highlights the surgical coordination, clinical decision-making, and postoperative outcomes associated with this integrated management strategy.

Case Report

PREOPERATIVE STATUS AND MEDICATIONS:

Laboratory findings included serum creatinine 8.3 mg/dL, blood urea nitrogen 148 mg/dL, hemoglobin 7.8 g/dL (managed preoperatively with subcutaneous epoetin alfa 4000 IU, twice weekly for 2 weeks), sodium 135 mmol/L, and potassium 5.2 mmol/L. The patient received mycophenolate mofetil (1 g) and prophylactic cefuroxime (1 g) before surgery.

SURGICAL TECHNIQUE:

MIMVR was performed through a 6-cm right mini-thoracotomy at the fourth intercostal space, avoiding median sternotomy. Cardiopulmonary bypass (CPB) was established via femoral arterial and venous cannulation. After left atriotomy, the mitral valve was excised and replaced with a 31-mm mechanical prosthesis (St. Jude Medical) using a total chordae-sparing technique. Intraoperative transesophageal echocardiography confirmed a well-seated valve with a mean gradient of 3 mmHg and no paravalvular leak. Total CPB and aortic cross-clamp times were 156 and 127 min, respectively (Figure 1).

Although Carpentier type II MR is often amenable to repair, valve replacement was preferred in the present case. The decision was based on intraoperative findings of complex posterior leaflet prolapse, rheumatic leaflet changes, and annular dilation, which rendered repair technically unfeasible. Additionally, the surgical team’s experience favored valve replacement as a safer and more durable option under the local circumstances. The minimally invasive approach was deliberately selected for its specific advantages in this combined cardiac and transplant procedure: reduced intraoperative bleeding, elimination of sternal wound infection risk, and avoidance of postoperative blood transfusion – an essential consideration for patients receiving immunosuppression after organ transplantation.

The CPB strategy emphasized adequate perfusion pressures and minimized hemodilution to limit ischemia-reperfusion injury.

KIDNEY TRANSPLANTATION:

After CPB discontinuation and hemodynamic stabilization, kidney transplantation was performed in the standard right iliac fossa location. The renal vein was anastomosed to the external iliac vein, and the donor kidney – containing 3 renal arteries – was managed via sequential end-to-side anastomoses to the external iliac artery. Ureteric reimplantation was completed without complications. Cold ischemia time was 12 min, and warm ischemia time was 8 min. Immediate urine output was observed intraoperatively, indicating prompt graft function (Figure 2). Intraoperative immunosuppression was initiated, consisting of calcineurin inhibitors, mycophenolate mofetil, and corticosteroids.

POSTOPERATIVE COURSE:

The patient was extubated within 2 h after surgery and transferred to the ward on postoperative day 1. Hemodynamic stability was maintained throughout, and no inotropic support was required. Renal function rapidly improved, with a serum creatinine level of 1.1 mg/dL at discharge on postoperative day 11. Hemoglobin levels remained stable, and no blood transfusions were required during the perioperative period. Furthermore, no infections, rejection episodes, arrhythmias, or other complications occurred during that period. At the 1-month follow-up, the patient demonstrated excellent mechanical mitral valve function, stable renal graft performance, and no evidence of infection or wound complications. This favorable outcome underscores the importance of integrated, multidisciplinary care within a tertiary center equipped for both cardiac surgery and renal transplantation. Our center performs more than 100 cardiac surgeries and 60 kidney transplants annually, with close collaboration across specialties to facilitate advanced combined procedures. It also highlights the value of meticulous perioperative planning and the role of minimally invasive cardiac surgery in optimizing recovery and reducing complications among carefully selected high-risk renal transplant recipients.

Discussion

Combined cardiac and renal surgery remains a rare and technically demanding approach due to substantial hemodynamic risks and perioperative challenges. Although simultaneous coronary artery bypass grafting or valve surgery with kidney transplantation has been reported [5,8,9], these procedures typically involve conventional median sternotomy. Cardiovascular disease is the leading cause of death among dialysis patients, responsible for approximately 35% to 50% of all mortalities [11]. Cardiac surgery in this population carries increased perioperative morbidity and mortality, attributed to multiple factors including reduced physiological reserve and susceptibility to fluid and electrolyte imbalances during CPB [8].

Patients on dialysis have limited ability to compensate for major fluid shifts. Excessive fluid retention during surgery can lead to interstitial edema, adversely affecting organ function and delaying wound healing [12]. Moreover, hemodynamic alterations and microembolization during CPB may compromise renal perfusion and worsen renal dysfunction [13]. The use of high-potassium cardioplegic solutions further increases renal burden. Collectively, these factors enhance the risk of hemodynamic instability and raise postoperative inotropic support requirements [12,13].

Given these risks, a simultaneous approach combining cardiac surgery and kidney transplantation in a single operative session may provide hemodynamic advantages. The correction of MR before transplantation restores forward cardiac output, improving renal graft perfusion immediately after surgery. Early diuresis in the combined procedure mitigates fluid overload, hyperkalemia, and metabolic acidosis. These factors contribute to reduced inotropic support requirements and earlier hemodynamic stabilization [14]. In the present case, euvolemia was achieved through preoperative dialysis and meticulous intraoperative fluid management. The correction of MR likely improved forward cardiac output, enhancing graft perfusion and function. No postoperative inotropic support was required, possibly due to immediate graft function with effective diuresis, a reduced systemic inflammatory response from the minimally invasive approach, and the absence of right ventricular dysfunction.

MIMVR was a critical factor in optimizing outcomes for our high-risk patient. Compared with conventional sternotomy, the minimally invasive approach reduces surgical trauma, blood loss, and the risk of sternal wound infection or mediastinitis, promoting faster recovery and decreasing perioperative complications [15,16]. These advantages are particularly important in transplant recipients who require lifelong immunosuppression, given that infections remain a major cause of morbidity and mortality in this population [12,13]. In the present case, the minimally invasive approach also eliminated the need for blood transfusion, which can adversely affect graft survival and immunologic status.

Our experience supports the feasibility and safety of simultaneous MIMVR and kidney transplantation in carefully selected patients, particularly those with poor dialysis tolerance for whom delayed transplantation could risk graft loss. This combined strategy requires a highly coordinated multidisciplinary team and access to advanced surgical expertise but may reduce cumulative surgical burden, anesthetic exposure, and overall hospitalization time.

Conclusions

Simultaneous MIMVR and kidney transplantation represents a feasible and effective treatment option for carefully selected patients with coexisting severe mitral valve disease and ESRD. This single-session approach can substantially reduce the cumulative surgical burden, minimize perioperative complications, and promote faster postoperative recovery compared with staged procedures. The present case demonstrates that, with multidisciplinary coordination and advanced surgical techniques, combined minimally invasive cardiac and renal transplantation surgeries can achieve excellent short-term outcomes.