Influence of body mass index on outcomes after minimal-access aortic valve replacement through a J-shaped partial upper sternotomy

Impact of Body Mass Index on the Initial Phase of a Minimally Invasive Aortic Valve Program

BACKGROUND

 In obese patients, minimally invasive surgical aortic valve replacement (MIS-AVR) presents challenges, and the risk of patient-prosthesis mismatch (PPM) is elevated. This retrospective single-center study evaluates the impact of body mass index (BMI) on the outcome of an initial MIS-AVR program.

MATERIAL AND METHODS

 A total of 307 patients underwent MIS-AVR between January 2013 and December 2015, the initial phase of our MIS-AVR program. They were divided into normal/overweight (BMI <30 kg/m2) versus obese patients (BMI ≥30 kg/m2). Primary endpoints included 30-day and 2-year mortality and stroke. Secondary endpoints comprised type 3 bleeding, PPM, paravalvular leakage, wound healing disorders (WHDs), and pacemaker rates.

RESULTS

 In all 191 patients exhibited a BMI <30 kg/m2, while 116 patients had a BMI ≥30 kg/m2. The BMI groups did not differ in baseline characteristics, excepting a higher peripheral arterial disease incidence among obese patients (15.7% vs. 26.7%; p = 0.01). Aortic clamp time (75 ± 29 min vs. 87 ± 37 min; p = 0.001), cardiopulmonary bypass (104 ± 36 min vs. 124 ± 56 min; p = 0.0002), and ventilation times (26 ± 6 h vs. 44 ± 8 h; p = 0.03) were longer in obese patients. They demonstrated a higher risk for bleeding (2.6% vs. 9.5%; p = 0.008) but lower pacemaker rates (9% vs. 3%; p = 0.02). PPM, paravalvular leakage, and WHD exhibited no group differences. No BMI-related differences revealed in 30-day mortality (4.7% vs. 3.4%) and stroke rates (2% vs. 2.6%), as well as 2-year mortality (12.6% vs. 11.2%) and stroke rates (2.1% vs. 2.6%).

CONCLUSION

 In the initial phase of an MIS-AVR program, the 30-day mortality may be elevated. Despite longer operative times and an increased risk for bleeding in obese patients, no influence of BMI on postoperative morbidity, mortality, or stroke rates was observed.

Minimally Invasive Aortic Valve Replacement for High-Risk Populations: Transaxillary Access Enhances Survival in Patients with Obesity

Background/Objectives: Minimally invasive cardiac surgery is often avoided in patients with obesity due to exposure and surgical access concerns. Nonetheless, these patients have elevated periprocedural risks. Minimally invasive transaxillary aortic valve surgery offers a sternum-sparing "nearly no visible scar" alternative to the traditional full sternotomy. This study evaluated the clinical outcomes of patients with obesity compared to a propensity score-matched full sternotomy cohort. Methods: This retrospective cohort study included 1086 patients with obesity (body mass index [BMI] of >30 kg/m2) undergoing isolated aortic valve replacement from 2014 to 2023. Two hundred consecutive patients who received transaxillary minimally invasive cardiac lateral surgery (MICLAT-S) served as a treatment group, while a control group was generated via 1:1 propensity score matching from 886 patients who underwent full sternotomy. The final sample comprised 400 patients in both groups. Outcomes included major adverse cardio-cerebral events, mortality, and postoperative complications. Results: After matching, the clinical baselines were comparable. The mean BMI was 34.4 ± 4.0 kg/m2 (median: 33.9, range: 31.0-64.0). Despite the significantly longer skin-to-skin time (135.0 ± 37.7 vs. 119.0 ± 33.8 min; p ≤ 0.001), cardiopulmonary bypass time (69.1 ± 19.1 vs. 56.1 ± 21.4 min; p ≤ 0.001), and aortic cross-clamp time (44.0 ± 13.4 vs. 41.9 ± 13.3 min; p = 0.044), the MICLAT-S group showed a shorter hospital stay (9.71 ± 6.19 vs. 12.4 ± 7.13 days; p ≤ 0.001), lower transfusion requirements (0.54 ± 1.67 vs. 5.17 ± 9.38 units; p ≤ 0.001), reduced postoperative wound healing issues (5.0% vs. 12.0%; p = 0.012), and a lower 30-day mortality rate (1.5% vs. 6.0%; p = 0.031). Conclusions: MICLAT-S is safe and effective. Compared to traditional sternotomy in patients with obesity, MICLAT-S improves survival, reduces postoperative morbidity, and shortens hospital stays.

Comparative effects of minimally invasive approaches vs. conventional for obese patients undergoing aortic valve replacement: a systematic review and network meta-analysis

BACKGROUND

Minimally invasive approaches like mini-thoracotomy and mini-sternotomy for Aortic Valve Replacement (AVR) showed impressive outcomes. However, their advantages for obese patients are questionable. We aimed in this network meta-analysis to compare three surgical approaches: Full sternotomy (FS), Mini-sternotomy (MS), and Mini-thoracotomy (MT) for obese patients undergoing AVR.

METHODS

We followed the PRISMA extension for this network meta-analysis. PubMed/Medline, Scopus, Web of Science, and Cochrane searched through March 2023 for relevant articles. The analysis was performed using R version 4.2.3.

RESULTS

Out of 344, 8 articles met the criteria with 1392 patients. The main outcomes assessed were perioperative mortality, re-exploration, atrial fibrillation, renal failure, ICU stay, hospital stay, cross-clamp time, and bypass time. In favor of MS, the length of ICU stay and hospital stay was significantly lower than for FS [MD -0.84, 95%CI (-1.26; -0.43)], and [MD -2.56, 95%CI (-3.90; -1.22)], respectively. Regarding peri-operative mortality, FS showed a significantly higher risk compared to MS [RR 2.28, 95%CI (1.01;5.16)]. Also, patients who underwent minimally invasive approaches; MT and MS, required less need of re-exploration compared to FS [RR 0.10, 95%CI (0.02;0.45)], and [RR 0.33, 95%CI (0.14;0.79)], respectively. However, Intraoperative timings; including aortic cross-clamp, and cardiopulmonary bypass time, were significantly lower with FS than for MS [MD -9.16, 95%CI (-1.88; -16.45)], [MD -9.61, 95%CI (-18.64; -0.59)], respectively.

CONCLUSION

Our network meta-analysis shows that minimally invasive approaches offer some advantages for obese patients undergoing AVR over full sternotomy. Suggesting that these approaches might be considered more beneficial alternatives for obese patients undergoing AVR.

Prehabilitation of Cardiac Surgical Patients, Part 1: Anemia, Diabetes Mellitus, Obesity, Sleep Apnea, and Cardiac Rehabilitation

The concept of "prehabilitation" consists of screening for and identification of pre-existing disorders followed by medical optimization. This is performed for many types of surgery, but may have profound impacts on outcomes particularly in cardiac surgery given the multiple comorbidities typically carried by these patients. Components of prehabilitation include direct medical intervention by preoperative specialists as well as significant care coordination and shared decision making. In this two-part review, the authors describe existing evidence to support the optimization of various preoperative problems and present a few institutional protocols utilized by our center for cardiac presurgical care. This first installment will focus on the management of anemia, obesity, sleep apnea, diabetes, and cardiac rehabilitation prior to surgery. The second will focus on frailty, malnutrition, respiratory disease, alcohol and smoking cessation, and depression.

Minimally invasive aortic valve surgery in obese patients: Can the bigger afford the smaller?

BACKGROUND

Ministernotomy and right minithoracotomy are well-known minimally invasive approaches for aortic valve replacement (AVR); however, controversial opinions exist for their utilization in obese patients. The aim of this study is to check a potential positive role of minimally invasive surgery in this population.

METHODS

From January 2010 to November 2019, 613 obese patients (defined by a body mass index ≥30) underwent isolated AVR at our institution. Surgical approach included standard median sternotomy (176 patients), partial upper sternotomy (271 patients), or right anterior minithoracotomy (166 patients). Intra- and postoperative data were retrospectively collected.

RESULTS

Patients treated with minimally invasive approaches had shorter cardiopulmonary bypass time (p = .012) and aortic cross-clamp time (p = .022), mainly due to the higher utilization of sutureless valve implantation. They also presented advantages in terms of reduced postoperative ventilation time (p = .010), incidence of wound infection (p = .009), need of inotropic support (p = .004), and blood transfusion (p = .001). The univariable logistic regression showed the traditional full sternotomy approach as compared with ministernotomy (p = .026), active smoking (p = .009), peripheral vascular disease (p = .003), ejection fraction (p = .026), as well Logistic European system for cardiac operative risk evaluation (EuroSCORE; p = .015) as factors associated with hospital mortality. The multivariable logistic regression adjusted for the logistic EuroSCORE revealed that surgical approaches do not influence hospital mortality.

CONCLUSIONS

Obese patients with severe aortic valve pathology can be treated with minimally invasive approaches offering a less biological insult and reduced postoperative complications, but without impact on hospital mortality.

A requiem for BMI in the clinical setting

PURPOSE OF REVIEW

Quetelet reported in the nineteenth century that body weight varies across adults with the square of height. Quetelet's index, now known as BMI, is accepted by most health organizations as a first-level measure of body fat and as a screening tool for diagnosing excess adiposity. Modern imaging methods now, however, indicate that BMI has limited predictive value for estimating body fat and lean mass at the individual level. The use of BMI as a measure of body composition in the clinical setting should therefore be challenged.

RECENT FINDINGS

Recent studies enrolling cancer and surgical patients reported discrepant outcomes when BMI was used as a body composition surrogate. Sarcopenia, loss of muscle mass and function, which affects the elderly and those with chronic and acute diseases, is not accurately diagnosed with BMI. The distribution of adipose tissue is not characterized by BMI, specific measures of which have greater predictive value for metabolic impairments and clinical outcomes.

SUMMARY

BMI, as the traditional tool for assessing malnutrition and obesity, is not appropriate to accurately differentiate between important body weight components and therefore should not be used for making clinically important decisions at the individual patient level.

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.