Outcomes of minimally invasive valve surgery in patients with chronic obstructive pulmonary disease

Anaesthesia for Minimally Invasive Cardiac Surgery

Minimally invasive cardiac surgery (MICS) has been used since the 1990s and encompasses a wide range of techniques that lack full sternotomy, including valve and coronary artery graft surgery as well as transcatheter procedures. Due to the potential benefits offered to patients by MICS, these procedures are becoming more common. Unique anaesthetic knowledge and skills are required to overcome the specific challenges presented by MICS, including mastery of transoesophageal echocardiography (TOE) and the provision of thoracic regional analgesia. This review evaluates the relevance of MICS to the anaesthetist and discusses pre-operative assessment, the relevant adjustments to intra-operative conduct that are necessary for these techniques, as well as post-operative care and what is known about outcomes.

Comparative Evaluation of the Incidence of Postoperative Pulmonary Complications After Minimally Invasive Valve Surgery vs. Full Sternotomy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials and Propensity Score-Matched Studies

Background: Postoperative pulmonary complications remain a leading cause of increased morbidity, mortality, longer hospital stays, and increased costs after cardiac surgery; therefore, our study aims to analyze whether minimally invasive valve surgery (MIVS) for both aortic and mitral valves can improve pulmonary function and reduce the incidence of postoperative pulmonary complications when compared with the full median sternotomy (FS) approach. Methods: A comprehensive systematic literature research was performed for studies comparing MIVS and FS up to February 2021. Randomized controlled trials (RCTs) and propensity score-matching (PSM) studies comparing early respiratory function and pulmonary complications after MIVS and FS were extracted and analyzed. Secondary outcomes included intra- and postoperative outcomes. Results: A total of 10,194 patients from 30 studies (6 RCTs and 24 PSM studies) were analyzed. Early mortality differed significantly between the groups (MIVS 1.2 vs. FS 1.9%; p = 0.005). Compared with FS, MIVS significantly lowered the incidence of postoperative pulmonary complications (odds ratio 0.79, 95% confidence interval [0.67, 0.93]; p = 0.004) and improved early postoperative respiratory function status (mean difference -24.83 [-29.90, -19.76]; p < 0.00001). Blood transfusion amount was significantly lower after MIVS (p < 0.02), whereas cardiopulmonary bypass time and aortic cross-clamp time were significantly longer after MIVS (p < 0.00001). Conclusions: Our study showed that minimally invasive valve surgery decreases the incidence of postoperative pulmonary complications and improves postoperative respiratory function status.

Minimally invasive or sternotomy approach in mitral valve surgery: a propensity-matched comparison

Objectives

Conventional mitral valve surgery through median sternotomy improves long-term survival with acceptable morbidity and mortality. However, less-invasive approaches to mitral valve surgery are now increasingly employed. Whether minimally invasive mitral valve surgery is superior to conventional surgery is uncertain.

Methods

A retrospective analysis of patients who underwent mitral valve surgery via minithoracotomy or median sternotomy between 2012 and 2018. A propensity score-matched analysis was generated to eliminate differences in relevant preoperative risk factors between the two groups.

Results

Data from 525 patients were evaluated, 189 underwent minithoracotomy and 336 underwent median sternotomy. The 30 day mortality was similar between the minithoracotomy and conventional surgery groups (1 and 3%, respectively; p = 0.25). No differences were seen in the incidence of stroke (p = 1.00), surgical site infections (p = 0.09), or myocardial infarction (p = 0.23), or in total hospital cost (p = 0.48). However, the minimally invasive approach was associated with fewer patients receiving transfusions (59% versus 76% in the conventional group; p = 0.001) or requiring reoperation for bleeding (3% versus 9%, respectively; p = 0.03). There were no significant differences in 5 year survival between the minithoracotomy and conventional surgery groups (93% versus 86%, respectively; p = 0.21) and freedom from mitral valve reoperation (95% versus 94%, respectively; p = 0.79).

Conclusions

In patients undergoing mitral valve surgery, a minimally invasive approach is feasible, safe, and reproducible with excellent short-term outcomes; mid-term outcomes and efficacy were also seen to be comparable to conventional sternotomy.

Is it safe to move away from a full sternotomy for aortic valve replacement?

BACKGROUND

Minimally invasive surgical approaches have gained popularity among patients and surgeons. The aim of this project was to assess the safety of initiating aortic valve replacement via an anterior right thoracotomy program.

METHODS

Between May 2015 and May 2019, data of all isolated primary aortic valve replacements were extracted retrospectively from our prospectively collected database and categorized into conventional median sternotomy, hemisternotomy, and anterior right thoracotomy cases. In total, 661 patients underwent isolated primary aortic valve replacement, of whom 429 (65%) had a median sternotomy, 126 (19%) had a hemisternotomy, and 106 (16%) had an anterior right thoracotomy. Preoperative characteristics were similar in each of the three groups. Statistical testing of the surgical groups was undertaken using the chi-square test for categorical variables and one-way analysis of variance with Tukey post-hoc pairwise tests (where appropriate) for continuous variables, to identify differences between pairs of data.

RESULTS

Cardiopulmonary bypass and crossclamp times were significantly longer in the anterior right thoracotomy group compared to the hemisternotomy and median sternotomy groups (p < 0.001). Blood loss was significantly less and hospital stay significantly shorter in the hemisternotomy group compared to median sternotomy group but not the anterior right thoracotomy group. Mortality, stroke, renal, gastrointestinal and respiratory complications showed no statistical differences.

CONCLUSION

Surgical aortic valve replacement had a very low mortality and morbidity in our experience, and it is safe to start a minimal access program for aortic valve replacement.

[Right thoracotomy approach for minimally invasive mitral valve surgery]

Minimally invasive approach in mitral valve surgery has been applied since the late 1990s. Considerable experience of mini-thoracotomy in cardiac surgery has been gained over this period. Stages of the development of minimally invasive cardiac surgery are reviewed in the article. Features of mitral valve surgery through right-sided mini-thoracotomy are discussed. Surgical outcomes of these procedures are reported considering data of various cardiac surgery centers. Moreover, the authors determined indications and limitations of this technique.

The Opportunities and Limitations of Minimally Invasive Cardiac Surgery

BACKGROUND

Over the past two decades, minimally invasive techniques for classic heart valve surgery and isolated bypass surgery have been developed that enable access to the heart via partial sternotomy for most aortic valve procedures and via sternotomy-free mini-thoracotomy for other procedures.

METHODS

We review the current evidence on minimally invasive cardiac surgery on the basis of pertinent randomized studies and database studies retrieved by a selective search in the MEDLINE and PubMed Central databases, as well as by the Google Scholar search engine.

RESULTS

A PubMed search employing the search term "minimally invasive cardiac surgery" yielded nearly 10 000 hits, among which there were 7 prospective, randomized, controlled trials (RCTs) on aortic valve replacement, with a total of 477 patients, and 3 RCTs on mitral valve surgery, with a total of 340 patients. Only limited reports of specified centers are currently available for multiple valvular procedures and multiple coronary artery bypass procedures. The RCTs reveal that the minimally invasive techniques are associated with fewer wound infections and faster mobilization, without any difference in survival. Minimally invasive procedures are technically demanding and have certain anatomical prerequisites, such as appropriate coronary morphology for multiple bypass operations and the position of the aorta in the chest for sternotomy-free aortic valve procedures. The articles reviewed here were presumably affected by selection bias, in that patients in the published studies were preselected, and there may have been negative studies that were not published at all.

CONCLUSION

Specialized surgeons and centers can now carry out many cardiac valvular and bypass operations via minithoracotomy rather than sternotomy. According to current evidence, these minimally invasive techniques yield results that are at least as good as classic open-heart surgery.

Single-Center Experience with Minimally Invasive Mitral Operations through Right Minithoracotomy

Background: To report single-institution experience with minimally invasive mitral valve operations through the right minithoracotomy over a 5-year period.

Methods: Patients who underwent minimally invasive mitral valve surgery (MIMVS) between January 2012 and December 2016 were included. Clinical follow-up data were collected in a prospective database and analyzed retrospectively.

Results: Data from 151 patients were assessed (mean age, 63.4 ± 9.7 years; 55% were females). Overall 30-day mortality was 0.7% (n = 1). Mean operating time, cardiopulmonary bypass, and aortic cross-clamp times were 254.9 ± 48.7, 140.5 ± 36.1, and 94.8 ± 27.0 minutes, respectively. Associated procedures were tricuspid valve annuloplasty (37.1%, n = 56) and closure of atrial septal defect (6.0%, n = 9). Cryoablation was performed in 43.7% of patients (n = 66). One patient (0.7%) required conversion to median sternotomy and six patients (4.0%) underwent re-explorations due to bleeding. Median postoperative hospital stay was 12 days. Overall survival at 5 years was 94.1% ± 2.0%. Freedom from reoperation was 94.6% ± 2.9% at 5 years.

Conclusions: MIMVS is a feasible, safe, and reproducible approach with low mortality and morbidity. Mitral valve surgery through a small thoracotomy is a good alternative to conventional surgical access.

Outcomes of a hybrid approach of percutaneous coronary intervention followed by minimally invasive aortic valve replacement

BACKGROUND

In patients requiring coronary revascularization and aortic valve replacement, a combined approach of percutaneous coronary intervention followed by minimally invasive aortic valve replacement may be a viable treatment strategy.

METHODS

The outcomes of 123 consecutive patients with significant coronary artery and aortic valve disease, who underwent percutaneous coronary intervention followed by elective minimally invasive aortic valve replacement between February 2009 and April 2014, were retrospectively evaluated.

RESULTS

The cohort consisted of 80 males and 43 females, with a mean age of 75.7±8.1 years. Drug-eluting stents were used in 69.9% of the patients, and 64.2% were on dual anti-platelet therapy at the time of aortic valve replacement. Within a median of 39 days (IQR 21-64), 83.7% of the patients underwent primary and 16.3% underwent re-operative minimally invasive aortic valve replacement. Post-operatively, there was 1 (0.8%) cerebrovascular accident, 1 patient (0.8%) required a re-operation due to bleeding, and 2 (1.6%) developed acute kidney injury. Thirty-day mortality occurred in 2 (1.6%) patients. Follow-up was available for all of the patients, and at a mean follow-up period of 14.3±12.5 months, 4 (3.3%) had an acute coronary syndrome, and 1 (0.8%) required a repeat target vessel revascularization. The actuarial survival rate at 1- and 3-year was 92.7% and 89.4%, respectively.

CONCLUSIONS

In a select group of patients with coronary artery and aortic valve disease, a combined approach of percutaneous coronary intervention followed by minimally invasive aortic valve replacement can be safely performed with excellent short-term and midterm outcomes.

Minimally invasive aortic valve replacement in high risk patient groups

Minimally invasive aortic valve replacement (AVR) aims to preserve the sternal integrity and improve postoperative outcomes. In low risk patients, this technique can be achieved with comparable mortality to the conventional approach and there is evidence of possible reduction in intensive care and hospital length of stay, transfusion requirement, renal dysfunction, improved respiratory function and increased patient satisfaction. In this review, we aim to asses if these benefits can be transferred to the high risk patient groups. We therefore, discuss the available evidence for the following high risk groups: elderly patients, re-operative surgery, poor lung function, pulmonary hypertension, obesity, concomitant procedures and high risk score cohorts.

Minimally invasive valve surgery in high-risk patients

The use of minimally, or less invasive, approaches to cardiac valve surgery has increased over the past decade. Because of its less traumatic nature, early studies in lower risk patients demonstrated the approach to be associated with an enhanced recovery, increased patient satisfaction, and good operative outcomes. With time, despite a steep learning curve, surgeons expanded this approach to perform more complex procedures, and include patients with more co-morbidity. The aim of this publication is to review the current literature involving the use of minimally invasive valve surgery (MIVS) in higher-risk patients.

Outcomes of minimally invasive double valve surgery

BACKGROUND

Double valve surgery is associated with an increased peri-operative morbidity and mortality. A less invasive right thoracotomy approach may be a viable alternative to median sternotomy surgery in these higher-risk patients.

METHODS

We retrospectively analyzed the baseline demographics, operative characteristics, and post-operative outcomes of patients who underwent minimally invasive double valve surgery between January 2009 and December 2011 at our institution.

RESULTS

The cohort consisted of 117 patients, of which 68 (58.1%) were female. The mean age was 73±11 years, and the mean left ventricular ejection fraction was 52±11%. There were 43 (36.8%) patients with a history of congestive heart failure, 45 (38.5%) with chronic obstructive pulmonary disease, and 5 (4.3%) had a history of chronic kidney disease. The patients underwent primary (90.6%) or re-operative (9.4%) double valve surgery, which consisted of 50 (42.7%) aortic valve replacement and mitral valve repair, 31 (26.5%) mitral and tricuspid valve repair, 18 (15.4%) aortic and mitral valve replacement, 17 (14.5%) mitral valve replacement with tricuspid valve repair, and 1 (0.9%) aortic valve replacement with tricuspid valve repair. Post-operatively, there were 40 (34.2%) cases of prolonged ventilation, 9 (7.7%) acute kidney injury, 6 (5.1%) re-operations for bleeding, 1 (0.9%) cerebrovascular accident, and 15 (12.8%) cases of atrial fibrillation. The mean total hospital length of stay was 12±12 days, with an in-hospital mortality of 2 (1.7%).

CONCLUSIONS

A minimally invasive right thoracotomy approach to primary or re-operative double valve surgery is feasible, may be utilized with acceptable peri-operative morbidity and mortality.

Aortic valve replacement in patients with a left ventricular ejection fraction ≤35% performed via a minimally invasive right thoracotomy

BACKGROUND

We evaluated the outcomes of patients with aortic valve pathology in the setting of a left ventricular ejection fraction ≤35% who underwent minimally invasive aortic valve replacement (AVR), with or without concomitant mitral valve (MV) surgery.

METHODS

All minimally invasive AVR in patients with a left ventricular ejection fraction ≤35%, performed via a right thoracotomy for aortic stenosis or regurgitation between January 2009 and March 2013, were retrospectively evaluated. The operative characteristics, perioperative outcomes, and 30-day mortality were analyzed.

RESULTS

There were 75 patients identified: 51 who underwent isolated AVR, and 24 who had combined AVR plus MV surgery for moderate to severe mitral regurgitation. In patients undergoing MV surgery, there were 22 (91.7%) MV repairs [ring annuloplasty =7 (37.5%), transaortic edge-to-edge repair =15 (62.5%)], and 2 (8.3%) replacements. No patient required conversion to sternotomy for inadequate surgical field exposure. The median total mechanical ventilation time and intensive care unit length of stay were 14 (IQR, 8-20) and 42 hours (IQR, 26-93 hours) in the isolated AVR group, and 16.5 hours (IQR, 12-61.5 hours) and 95.5 hours (IQR, 43.5-159 hours) in the AVR plus MV surgery group, respectively. The most common post-operative complication was new-onset atrial fibrillation, which occurred in 15 (29.4%) isolated AVR and 4 (16.7%) AVR plus MV surgery patients. The median hospital length of stay and 30-day mortality was 7 days (IQR, 5-12 days) and 1 (2%) in the isolated AVR group, and 10.5 days (IQR, 5-21 days) and 1 (4.3%) for AVR plus MV surgery.

CONCLUSIONS

In patients with aortic valve pathology in the setting of a left ventricular ejection fraction ≤35%, minimally invasive AVR can be performed, with or without concomitant MV surgery, with a low morbidity and mortality.

Combined Mitral and Tricuspid Valve Surgery Performed via a Right Minithoracotomy Approach

OBJECTIVE

Combined mitral and tricuspid valve surgery is associated with an increased perioperative morbidity and mortality. We evaluated the outcomes of a less invasive right minithoracotomy approach in patients undergoing primary or reoperative double-valve surgery.

METHODS

We retrospectively evaluated 132 consecutive patients with mitral and tricuspid valve disease who underwent double-valve surgery via a right minithoracotomy at our institution between January 2009 and April 2014.

RESULTS

The cohort included 81 female (61%) and 51 male (39%) patients, with a mean ± SD age of 67 ± 13 years. The mean ± SD preoperative left ventricular ejection fraction, mitral regurgitation grade, and creatinine were 53% ± 12%, 3.8 ± 0.6, and 1.26 ± 1.17, respectively. The patients underwent primary (88%) or reoperative (12%) mitral and tricuspid valve surgery, which consisted of 88 mitral repairs (67%), 44 mitral replacements (33%), 131 tricuspid repairs (99%), and 1 tricuspid replacement (1%). Postoperatively, there were 6 cases of acute kidney injury (5%), 6 reoperations for bleeding (5%), 4 cerebrovascular accidents (3%), and 12 cases of atrial fibrillation (9%). The median intensive care unit length of stay and total hospital lengths of stay were 61 hours (interquartile range, 43-112 hours) and 8 days (interquartile range, 6-13 days), respectively. The in-hospital mortality was 4%. Actuarial survival at 1 and 5 years was 93% and 88%, respectively.

CONCLUSIONS

In patients undergoing primary or reoperative mitral and tricuspid valve surgery, a right minithoracotomy approach is associated with a low perioperative morbidity and good midterm survival.

Aortic and/or mitral valve surgery in patients with pulmonary hypertension performed via a minimally invasive approach

Pulmonary hypertension (PH) in the setting of left-sided valvular heart disease is common, and significantly increases the risk of perioperative morbidity and mortality in patients undergoing aortic and/or mitral valve surgery. Minimally invasive valve surgery is associated with a decreased incidence of perioperative complications, and a faster recovery, when compared with conventional sternotomy. In the present study, the outcomes of 569 patients with PH who underwent minimally invasive aortic and/or mitral valve surgery were analysed. The operative mortality was 3.5%, and postoperative strokes occurred in 1.4%. The mean intensive care unit and hospital length of stays were 50 ± 14 h and 7 ± 1 days, respectively. Patients with severe PH (mean pulmonary artery pressure ≥40 mmHg) had a longer duration of postoperative ventilation and intensive care unit length of stay, when compared with mild/moderate PH, and similar clinical outcomes. In conclusion, a minimally invasive approach to aortic and/or mitral valve surgery in patients with PH is safe and feasible, and may be considered as an alternative to conventional median sternotomy.

Minimally invasive aortic valve replacement: the "Miami Method"

For patients undergoing aortic valve replacement (AVR), a minimally invasive approach performed via a right anterior thoracotomy is the preferred method at our institution. This method has evolved over a 10-year span, being applied to over 1,500 patients with the commitment of one surgeon seeking to offer a simplistic and reproducible minimally invasive alternative. We believe that this is truly the least invasive approach to the aortic valve since it avoids sternal invasion. By virtue of being less traumatic, the morbidity is diminished and therefore the recovery is enhanced. We believe that this approach is most beneficial in the high risk patient such as the elderly, the obese, those with chronic obstructive pulmonary, chronic kidney disease and those requiring re-operative surgery. This method has proven to be safe and effective in all patients requiring isolated AVR surgery. The only relative exclusion criteria would be a porcelain aorta with the inability to cannulate the patient.

Minimally invasive concomitant aortic and mitral valve surgery: the "Miami Method"

Valve surgery via a median sternotomy has historically been the standard of care, but in the past decade various minimally invasive approaches have gained increasing acceptance. Most data available on minimally invasive valve surgery has generally involved single valve surgery. Therefore, robust data addressing surgical techniques in patients undergoing double valve surgery is lacking. For patients undergoing combined aortic and mitral valve surgery, a minimally invasive approach, performed via a right lateral thoracotomy (the "Miami Method"), is the preferred method at our institution. This method is safe and effective and leads to an enhanced recovery in our patients given the reduction in surgical trauma. The following perspective details our surgical approach, concepts and results for combined aortic and mitral valve surgery.

Minimally invasive valve surgery with bypass to the right coronary artery

Herein, we report the case of a 60-year-old woman who presented with increasing dyspnea on exertion. Echocardiography revealed significant aortic and mitral regurgitation, which were most likely secondary to previous radiation therapy for breast cancer. On cardiac catheterization a 90% ostial right coronary artery lesion was found and treated with a drug-eluting stent. During minimally invasive valve surgery, via a right anterior thoracotomy, it was noted that the stent had restenosed. Therefore, the right coronary artery was bypassed with a segment of venous graft through the same incision.