Minimally invasive valve surgery in high-risk patients

A review and meta-analysis of conventional sternotomy versus minimally invasive mitral valve surgery for degenerative mitral valve disease focused on the last decade of evidence

OBJECTIVES

Early meta-analyses comparing minimally invasive mitral valve surgery (MIMVS) with conventional sternotomy (CS) have determined the safety of MIMVS. We performed this review and meta-analysis based on studies from 2014 onwards to examine the differences in outcomes between MIMVS and CS. Specifically, some outcomes of interest included renal failure, new onset atrial fibrillation, mortality, stroke, reoperation for bleeding, blood transfusion and pulmonary infection.

METHODS

A systematic search was performed in six databases for studies comparing MIMVS with CS. Although the initial search identified 821 papers in total, nine studies were suitable for the final analysis. All studies included compared CS with MIMVS. The Mantel - Haenszel statistical method was chosen due the use of inverse variance and random effects. A meta-analysis was performed on the data.

RESULTS

MIMVS had significantly lower odds of renal failure (OR: 0.52; 95% CI 0.37 to 0.73, p < 0.001), new onset atrial fibrillation (OR: 0.78; 95% CI 0.67 to 0.90, p < 0.001), reduced prolonged intubation (OR: 0.50; 95% CI 0.29 to 0.87, p = 0.01) and reduced mortality (OR: 0.58; 95% CI 0.38 to 0.87, p < 0.01). MIMVS had shorter ICU stay (WMD: -0.42; 95% CI -0.59 to -0.24, p < 0.001) and shorter time to discharge (WMD: -2.79; 95% CI -3.86 to -1.71, p < 0.001).

CONCLUSION

In the modern era, MIMVS for degenerative disease is associated with improved short-term outcomes when compared to the CS.

Minimally invasive versus sternotomy mitral valve surgery when initiating a minimally invasive programme

OBJECTIVES

An increasing number of mitral valve operations are performed using minimally invasive procedures. The initiation of a minimally invasive mitral valve surgery programme constitutes a unique opportunity to study outcome differences in patients with similar characteristics operated on through a sternotomy versus a minimally invasive procedure. The goal of this study was to compare short-term outcomes of patients undergoing mitral valve surgery before versus those having surgery after the introduction of a minimally invasive programme.

METHODS

The single-centre study included mitral valve procedures performed through a sternotomy or with a minimally invasive approach between January 2012 and May 2019. Propensity score matching was performed to reduce selection bias.

RESULTS

A total of 605 patients (294 sternotomy, 311 minimally invasive) who underwent mitral valve surgery were included in the analysis. Propensity score matching resulted in 251 matched pairs. In the propensity score-matched analysis, minimally invasive procedures had longer extracorporeal circulation duration (149 ± 52 vs 133 ± 57 min; P = 0.001) but shorter aortic occlusion duration (97 ± 36 vs 105 ± 40 min, P = 0.03). Minimally invasive procedures were associated with a lower incidence of reoperation for bleeding (2.4% vs 7.2%; P = 0.012), lower need for transfusion (19.1% vs 30.7%; P = 0.003) and shorter in-hospital stay (5.0 ± 2.7 vs 7.2 ± 4.6 days; P < 0.001). The 30-day mortality was low in both groups (0.4% vs 0.8%; P = 0.56).

CONCLUSIONS

Minimally invasive mitral valve surgery was associated with short-term outcomes comparable to those with procedures performed through a sternotomy. Initiating a minimally invasive mitral valve programme with a limited number of surgeons and a well-executed institutional selection strategy did not confer an increased risk for adverse events.

Variability in clinicians' understanding and reported methods of identifying high-risk surgical patients: a qualitative study

Background

High-risk patients presenting for surgery require complex decision-making and perioperative management. However, given there is no gold standard for identifying high-risk patients, doing so may be challenging for clinicians in practice. Before a gold standard can be established, the state of current practice must be determined. This study aimed to understand how working clinicians define and identify high-risk surgical patients.

Methods

Clinicians involved in the care of high-risk surgical patients at a public hospital in regional Australia were interviewed as part of an ongoing study evaluating a new shared decision-making process for high-risk patients. The new process, Patient-Centred Advanced Care Planning (PC-ACP) engages patients, families, and clinicians from all relevant specialties in shared decision-making in line with the patient’s goals and values. The semi-structured interviews were conducted before the implementation of the new process and were coded using a modified form of the ‘constant comparative method’ to reveal key themes. Themes concerning patient risk, clinician’s understanding of high risk, and methods for identifying high-risk surgical patients were extricated for close examination.

Results

Thirteen staff involved in high-risk surgery at the hospital at which PC-ACP was to be implemented were interviewed. Analysis revealed six sub-themes within the major theme of factors related to patient risk: (1) increase in high-risk patients, (2) recognising frailty, (3) risk-benefit balance, (4) suitability and readiness for surgery, (5) avoiding negative outcomes, and (6) methods in use for identifying high-risk patients. There was considerable variability in clinicians’ methods of identifying high-risk patients and regarding their definition of high risk. This variability occurred even among clinicians within the same disciplines and specialties.

Conclusions

Although clinicians were confident in their own ability to identify high-risk patients, they acknowledged limitations in recognising frail, high-risk patients and predicting and articulating possible outcomes when consenting these patients. Importantly, little consistency in clinicians’ reported methods for identifying high-risk patients was found. Consensus regarding the definition of high-risk surgical patients is necessary to ensure rigorous decision-making.

Long-Term Outcomes of Right Minithoracotomy Versus Hemisternotomy for Mitral Valve Repair

OBJECTIVE

Minimally invasive mitral valve repair has been increasingly adopted. Right minithoracotomy (RT) and lower hemisternotomy (HS) have each been associated with improved short-term outcomes; however, these approaches have not been directly compared to each other. The aim of this study was to compare long-term survival and durability of 2 minimally invasive approaches to mitral repair.

METHODS

We retrospectively identified all isolated mitral repairs performed via RT or HS between October 1997 and June 2018; 100 RT cases and 719 HS cases were included. Outcomes of interest were postoperative complications, long-term survival, and freedom from mitral reoperation. A Cox proportional hazard model was used to compare RT and HS to a reference cohort of full-sternotomy cases. Total observation time was 9,901 patient-years and mean follow-up time was 12.2 years.

RESULTS

Mean age was 58±12 years in the RT group and 56±13 years in the HS group (P = 0.2). The RT group had longer bypass (143 minutes vs. 112 minutes; P < 0.001) and cross-clamp times (99 minutes vs. 78 minutes; P < 0.001) compared with the HS group. There were no differences in operative mortality or 30-day outcomes. Survival at 5, 10, and 15 years was 99% (96-100), 92% (85-100), and 69% (30-100) in the RT group and 98% (97-99), 92% (90-94), and 89% (86-92) for HS (P < 0.9). There were no differences in risk-adjusted survival between RT, HS and full sternotomy. No long-term mitral reoperations occurred in the RT group and 8 (1%) occurred in the HS group (P < 0.50).

CONCLUSIONS

Minimally invasive mitral valve repair can be performed safely through RT or HS with excellent survival and durability at 15 years.

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.