Right Mini-Thoracotomy in the Surgical Treatment of Structural Heart Diseases (SHDs): An Institutional Experience

Abstract

Introduction: Surgical treatment of structural heart diseases continues to predominantly involve median sternotomy, despite the ongoing trends favoring minimally invasive approaches that have persisted for many years. In this study, we present data on structural heart disease (SHD) surgeries conducted by our institute using a right mini-thoracotomy approach.

Patients and Methods: This single-center retrospective study included 58 patients who underwent right minithoracotomy procedures between February 2018 and June 1, 2023. Preoperative demographic and medical data were collected from patient files and records. Perioperative and 30-day outcome data were obtained through the national electronic record system.

Results: The average age of the participants was 39.9. Female patients accounted for 31.6% (n= 18) of the participants. The majority of surgeries in this study involved peripheral cannulation and conventional cardioplegia. Mitral valve repair and atrial septal defect closure were the most common procedures performed. Intraoperative outcomes showed favorable results, with no instances of significant bleeding, structural complications, or mortality. Regarding the postoperative 30-day outcomes, the stroke rate was 1.8% (n= 1) among the patients. There were no reported cases of transient ischemic attack (TIA), myocardial infarction (MI), and mortality. The conversion to median sternotomy occurred in 3.4% (n= 2) of the cases. Reoperation and reexploration were required in 1.8% (n= 1) of the cases. The mean length of stay in the ICU was 1.7 days, while the mean length of ward stay was 4.2 days.

Conclusion: This study contributes to the evidence supporting the shift towards minimally invasive approaches in the surgical management of structural heart disease. The low rate of intraoperative conversion, absence of major complications, and favorable postoperative outcomes highlight the safety and feasibility of right mini-thoracotomy. Continued advancements in surgical techniques and clinical expertise are expected to further optimize patient outcomes and improve the quality of care in this field.

Introduction

Open heart surgery initially relied predominantly on sternotomy in the early 20^th century, during its experimental stages, and later during the latter part of the 20^th century and the 21^st century when it became widely adopted and standardized(1). However, thoracotomy has resurfaced as a prominent approach in the past two decades and has gained widespread acceptance(1). Particularly, mini-thoracotomy has gained popularity, initially in the repair of septal defects, and subsequently in interventions involving the mitral and tricuspid valves(2-4). In contrast to median sternotomy, mini-thoracotomy offers advantages such as accelerated recovery and shorter hospitalization periods due to the avoidance of bone tissue incision, which facilitates quicker physical recuperation(2-6). Additionally, mini-thoracotomy minimizes the surgical area, resulting in reduced bleeding and a decreased need for blood transfusions, thereby lowering perioperative morbidity and shortening hospital stays(2-6). However, the diminished surgical field in mini-thoracotomy poses challenges to surgical exposure and visibility, especially in complex heart surgeries involving multiple valve repairs and procedures, casting doubt on the technical success of such operations(7,8).

The present study aims to present the perioperative and postoperative 30-day outcomes of patients with structural heart conditions who underwent right mini-thoracotomy between 2018 and 2023 at our institution, where over 2000 heart surgeries per year were performed using median sternotomy.

Materials and Methods

Study Design

This single-center retrospective study aimed to assess the feasibility and outcomes of right mini-thoracotomy heart surgery in patients with structural heart diseases. A total of 58 patients who underwent this surgical technique between February 2018 and June 1, 2023, were included in the evaluation.

Procedure

CT scan was performed on all patients in order to make preoperative anatomical evaluation and to detect possible adhesions. A 5 to 10 cm long thoracotomy was performed at the right Submammarian area through the 3^rd, 4^th, or 5^th intercostal space according to the procedure (Figure 2). For aortic interventions, it could be also performed at the second intercostal space. A soft tissue retractor or mini-thoracotomy retractor was used to expose the surgical area. (Figure 3). The incisions were extended if adequate exploration was not obtained. Mostly direct right femoral arterial and venous cannulation was performed after ultrasonographic evaluation in addition to jugular venous cannulation with the Seldinger technique under Transesophageal Echocardiography (TEE) guidance. The pericardium was opened from the diaphragm to the aorta by securing the phrenic nerve. Direct aortic arterial and bi-caval venous cannulation were also performed for suitable patients. A cardioplegia cannula was inserted directly into the aorta. Antegrade cold blood cardioplegia was most commonly utilized. Del Nido and Custadiol solutions were also used for complex cases. The aorta was clamped with a Chit-wood clamp through a 1 cm skin incision which then would be used for chest tube insertion.

Figure 1. Central figure.

Figure 2. Right minithoracotomy incision.

Figure 3. Operative view of mini thoracotomy during mitral valve intervention.

Patients and Data

The preoperative demographic and medical information of patients who underwent surgery between 2018 and 2023 were meticulously gathered from patient files and records. This task was performed by a cardiac surgery resident, closely supervised by an academic cardiac surgeon, following the approval of the ethics committee. The collection of perioperative and 30-day outcome data was facilitated through the national electronic record system, with the active involvement of both the cardiac surgery resident and the academic heart surgeon.

Statistical Analysis

In our report, for non-continuous variables, we presented percentages and counts, while for continuous variables, we reported mean values and standard deviations (SDs).

Results

Patient Characteristics

Table 1 presents the preoperative demographics and medical background of 58 individuals who underwent thoracotomy. The average age of the participants was 39.9 years, with a standard deviation of 16.1. Among the participants, 31.6% (n= 18) were female. The mean body mass index (BMI) was 24.1, with a standard deviation of 5.5. Smoking was reported by 29.6% (n= 16) of the participants. In terms of comorbidities, 5.4% (n= 3) had coronary artery disease (CAD), 21.8% (n= 12) had hypertension (HT), 39.3% (n= 22) had pulmonary hypertension (PHT), 3.6% (n= 2) had peripheral artery disease (PAD), 20% (n= 11) had atrial fibrillation (AFib), 10.9% (n= 6) had chronic obstructive pulmonary disease (COPD), 10.9% (n= 6) had type 2 diabetes mellitus (T2DM), and 3.6% (n= 2) had chronic kidney disease (CKD). The left ventricular ejection fraction (LVEF) was measured to be 62.2% with a standard deviation of 7.4. The mean hemoglobin (HGB) level was 12.5 g/dL with a standard deviation of 2.0, and the mean hematocrit (HCT) was 38.6% with a standard deviation of 5.3.

Table 1. Preoperative demographics and medical history

Surgical Techniques and Approaches

Table 2 presents the surgical techniques and surgeries. Regarding cannulation, peripheral cannulation was the chosen method in the majority of cases, accounting for 83.4% (n= 45) of the participants, while central cannulation was used in 16.6% (n= 9) of the cases. In terms of cardioplegia techniques, the Del Nido approach was employed in 12.3% (n= 7) of the surgeries, conventional cardioplegia in 68.3% (n= 39) of the surgeries, and custadiol cardioplegia in 10.5% (n= 6) of the surgeries. Various types of surgeries were performed on the participants. Mitral valve replacement (MVR) accounted for 27.5% (n= 16) of the cases, while aortic valve replacement (AVR) and myxoma resection were performed in only 1.8% (n= 1) each. Mitral valve repair (MVR) was conducted in 22.4% (n= 13) of the cases, followed by tricuspid valve repair in 15.5% (n= 9). Atrial septal defect (ASD) closure was performed in 44.8% (n= 26) of the surgeries. In addition, complex surgeries involving two or more procedures were carried out in 22.4% (n= 13) of the cases.

Table 2. Surgical techniques and surgeries

Intraoperative Findings

Table 3 presents the intraoperative outcomes. The mean cardiopulmonary bypass (CPB) time in this study was 138.0 minutes, with a standard deviation of 65.8. The mean aortic cross-clamp (AXC) time was 85.1 minutes, with a standard deviation of 54.3. Transfusion requirements were observed in 26.3% (n= 15) of the cases, with an average of 1.1 units of packed red blood cells (PRBC) and fresh frozen plasma (FFP) transfused. The conversion to median sternotomy was necessary in 3.4% (n= 2) of the cases. Notably, no instances of massive bleeding, structural complications, or mortality were encountered during the procedures.

Table 3. Intraoperative outcomes

Postoperative Outcomes

The postoperative outcomes at the 30-day mark are demonstrated in Table 4: 40.0% (n= 22) required transfusion, 3.5% (n= 2) experienced infection, 1.8% (n= 1) had new-onset atrial fibrillation, 15.5% (n= 9) developed acute kidney injury, and 1.8% (n= 1) suffered a stroke. There were no reported cases of TIA, myocardial infarction, and mortality. Re-exploration and reoperation occurred in 1.8% (n= 1) of the cases. The average drainage volume was 377 mL, the mean intubation time was 8.6 hours, and the mean length of stay in the ICU was 1.7 days. The length of ward stay was 4.2 days. At postoperative day one, the mean hemoglobin level was 10.6 g/dL and the mean hematocrit level was 29.4%.

Table 4. Postoperative outcomes at 30-day

Discussion

In the realm of surgical interventions for structural heart diseases, the conventional approach has long involved highly invasive procedures utilizing a median sternotomy. However, with the advent of transcatheter therapies and the growing emphasis on quality of life-centered medicine, there has been a notable shift towards a minimally invasive paradigm in the surgical management of structural heart disease(7,9). Recent advancements in valve surgery have highlighted the growing evidence supporting the benefits of mini-thoracotomy(9,10). A comprehensive meta-analysis, encompassing 109 studies and 38.106 patients, published in 2022, revealed that minithoracotomy offers distinct advantages over median sternotomy, including reduced hospitalization durations and decreased blood product utilization(10).

Furthermore, the utilization of right mini-thoracotomy in atrial septal defect (ASD) repair has gained significant traction. This surgical approach, which has a longer history compared to valve surgery, has become relatively more prevalent. In a metaanalysis published in 2021, incorporating data from seven studies and 665 patients, right mini-thoracotomy demonstrated superior recovery parameters compared to median sternotomy(11). Notably, the analysis identified significantly shorter hospitalization times, reduced intensive care unit stays, and decreased intubation durations associated with the right mini-thoracotomy technique.

In our study, a cohort of 58 patients with structural heart disease underwent open heart surgery, with a notable subset requiring complex cardiac procedures. Among these patients, because of strict adhesions, the need for intraoperative conversion from median sternotomy was observed in a mere 3.4% (n= 2) of cases(2-6,10). Encouragingly, these individuals experienced successful postoperative outcomes, with no instances of morbidity or mortality. The observed conversion rate aligns closely with the existing literature, reflecting the effectiveness and feasibility of the surgical approach employed. Furthermore, our findings revealed composite outcomes, such as surgical reoperation and stroke, occurring in one patient each. In addition, one patient had postoperative new atrial fibrillation, which completely resolved on the postoperative sixth day. However, no instances of myocardial infarction (MI), acute kidney injury (AKI), mortality, structural heart defects, significant bleeding necessitating massive transfusion, or the need for renal replacement therapy (RRT) were observed in our patient cohort. These outcomes emphasize the favorable nature of the surgical interventions performed and underscore the successful management of structural heart disease in this context.

At present, our study demonstrates a composite outcomefree survival rate of 96.4% at 30 days, highlighting the overall positive prognosis for patients. Moreover, the overall survival rate of 100% further substantiates the favorable outcomes achieved. Importantly, our study cohort exhibited recovery parameters consistent with previous research, with an average hospital discharge time of less than one week(10,11). Looking ahead, we anticipate that continued advancements in surgical and clinical expertise will further optimize and expedite the recovery process for patients undergoing open heart surgery for structural heart disease. The promising results obtained in this study underscore the potential for future refinement and improvement in patient outcomes, thereby enhancing the overall quality of care in this field.

Conclusion

Our study contributes to the growing body of evidence supporting the shift towards minimally invasive approaches in the surgical management of structural heart disease. By analyzing a cohort of 58 patients who underwent minithoracotomy, with a significant proportion requiring complex cardiac procedures, we observed a remarkably low rate of intraoperative conversion from median sternotomy (3.4%). Importantly, these conversions did not result in any adverse events or mortality, reinforcing the safety and feasibility of the surgical approach employed. Furthermore, our findings highlight the favorable postoperative outcomes achieved in this patient population. We observed low rates of composite outcomes such as surgical reoperation and stroke, and no occurrences of myocardial infarction, acute kidney injury, mortality, structural heart defects, significant bleeding, or the need for renal replacement therapy. These findings emphasize the successful management of structural heart disease through our surgical interventions.

Cite this article as: Özgür MM, Bulut Hİ, Özer T, Aksüt M, Güzeloğlu A, Kırali MK. Right mini-thoracotomy in the surgical treatment of structural heart diseases (SHDs): An institutional experience. Koşuyolu Heart J 2023;26(3):121-127.

This study was approved by the Kartal Koşuyolu High Specialization Training and Research Hospital Ethics Committee (Decision no: 2023/11/702, Date: 04.07.2023).

This is retrospective study, we could not obtain written informed consent from the participants.

Externally peer-reviewed.

Concept/Design - MMÖ; Analysis/Interpretation - HİB; Data Collection - MMÖ, AG; Writing - MMÖ; Critical Revision - TÖ, MA; Final Approval - MKK; Overall Responsibility - MMÖ.

The authors have no conflicts of interest to declare.

The authors declare that this study has received no financial support.

References

1. Bouhout I, Morgant MC, Bouchard D. Minimally invasive heart valve surgery. Can J Cardiol 2017;33(9):1129-37. https://doi.org/10.1016/j. cjca.2017.05.014 DOI: 10.1016/j.cjca.2017.05.014
2. Van Praet KM, Stamm C, Sündermann SH, Meyer A, Unbehaun A, Montagner M, et al. Minimally invasive surgical mitral valve repair: State of the art review. Interv Cardiol 2018;13(1):14-9. https://doi.org/10.15420/ icr.2017:30:1 DOI: 10.15420/icr.2018.13.2.ER1
3. Liava’a M, Kalfa D. Surgical closure of atrial septal defects. J Thorac Dis 2018;10(Suppl 24):S2931-S9. https://doi.org/10.21037/ jtd.2018.07.116 DOI: 10.21037/jtd.2018.07.116
4. Wang Q, Xue X, Yang J, Yang Q, Wang P, Wang L, et al. Right minithoracotomy approach reduces hospital stay and transfusion of mitral or tricuspid valve reoperation with non-inferior efficacy: Evidence from propensity-matched study. J Thorac Dis 2018;10(8):4789-800. https://doi. org/10.21037/jtd.2018.07.53 DOI: 10.21037/jtd.2018.07.53
5. Glauber M, Miceli A, Canarutto D, Lio A, Murzi M, Gilmanov D, et al. Early and long-term outcomes of minimally invasive mitral valve surgery through right minithoracotomy: A 10-year experience in 1604 patients. J Cardiothorac Surg 2015;10:181. https://doi.org/10.1186/s13019-015- 0390-y DOI: 10.1186/s13019-015-0390-y
6. Nakayama T, Nakamura Y, Kanamori K, Hirano T, Kuroda M, Nishijima S, et al. Early and midterm results of minimally invasive aortic and mitral valve surgery via right mini-thoracotomy. J Card Surg 2020;35(1):35-9. https://doi.org/10.1111/jocs.14313 DOI: 10.1111/jocs.14313
7. Gammie JS, Zhao Y, Peterson ED, O’Brien SM, Rankin JS, Griffith BP. J. Maxwell Chamberlain Memorial Paper for adult cardiac surgery. Less-invasive mitral valve operations: Trends and outcomes from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Ann Thorac Surg 2010;90(5):1401-8,10. https://doi.org/10.1016/j.athoracsur.2010.05.055 DOI: 10.1016/j.athoracsur.2010.05.055
8. Semsroth S, Gothe RM, Raith YR, de Brabandere K, Hanspeter E, Kilo J, et al. Comparison of two minimally invasive techniques and median sternotomy in aortic valve replacement. Ann Thorac Surg 2017;104(3):877- 83. https://doi.org/10.1016/j.athoracsur.2017.01.095 DOI: 10.1016/j.athoracsur.2017.01.095
9. Lamelas J, Nguyen TC. Minimally invasive valve surgery: When less is more. Semin Thorac Cardiovasc Surg 2015;27(1):49-56. https://doi. org/10.1053/j.semtcvs.2015.02.011 DOI: 10.1053/j.semtcvs.2015.02.011
10. Eqbal AJ, Gupta S, Basha A, Qiu Y, Wu N, Rega F, et al. Minimally invasive mitral valve surgery versus conventional sternotomy mitral valve surgery: A systematic review and meta-analysis of 119 studies. J Card Surg 2022;37(5):1319-27. https://doi.org/10.1111/jocs.16314 DOI: 10.1111/jocs.16314
11. Lei YQ, Liu JF, Xie WP, Hong ZN, Chen Q, Cao H. Anterolateral minithoracotomy versus median sternotomy for the surgical treatment of atrial septal defects: A meta-analysis and systematic review. J Cardiothorac Surg 2021;16(1):266. https://doi.org/10.1186/s13019-021-01648-y DOI: 10.1186/s13019-021-01648-y

Figure and Tables

Figure 1. Central figure.

Figure 2. Right minithoracotomy incision.

Figure 3. Operative view of mini thoracotomy during mitral valve intervention.

Table 1. Preoperative demographics and medical history

Table 2. Surgical techniques and surgeries

Table 3. Intraoperative outcomes

Table 4. Postoperative outcomes at 30-day