Effect of minimally invasive cardiac surgery compared with conventional surgery on post-operative physical activity and rehabilitation in patients with valvular heart disease
Egyptian Rheumatology and Rehabilitation volume 50, Article number: 5 (2023)
Minimally invasive cardiac surgery (MICS) has steadily become more and more popular. MICS is less invasive and has a faster return to normality after surgery. Patients who had MICS continue to exercise more frequently than those who had the conventional median sternotomy surgery. It is generally established that physical activity lowers mortality and the risk of cardiac disease. The purpose of the study: is to evaluate and compare physical activity levels in MICS and conventional surgery.
The level of preoperative physical activity did not significantly differ between the two groups. However, the MICS group significantly exceeded the conventional group in terms of postoperative progress, amount of physical activity, and 6-minute walking test. Also, Visual Analog Scale (VAS) score was significantly less.
Minimally invasive cardiac surgery has a higher margin of benefit, and speedy recovery to normality, which is accompanied by a lower VAS score and increased physical activity in comparison to conventional surgery.
Minimally invasive cardiac surgery (MICS) refers to procedures that require only a small chest incision. Additionally, MICS minimizes the need for blood products, shortens the duration of mechanical ventilation, decreases hospital stays, and reduces postoperative discomfort . Over the past 20 years, MICS procedures have become more common. Such procedures are carried out through tiny incisions, which restrict visibility and the surgeon's range of motion in comparison to conventional techniques. As a result, two-dimensional or three-dimensional thoracoscopic cameras are frequently used to improve visibility. The MICS needs a well-trained skilled surgeon .
The prognosis after cardiac surgery is correlated with the level of postoperative physical activity and the level of activity during hospitalization. There has been an increase in interest in measuring physical activity, and numerous subjective and objective methods have been developed .
In this study, we aimed to assess and compare the amount of physical activity in patients who had MICS versus those who had conventional surgery.
Subjects and methods
The trial was prospectively authorized by the FMASU (faculty of medicine Ain Shams University) Research Ethics Committee (R 65/2022), and when it was retroactively submitted to the Pan African Clinical Trial Registry (PACTR), the registration number was PACTR202209591144366.
Our study abided by the Declaration of Helsinki; patients gave informed written consent and were aware of the procedure. This prospective comparative study included 60 patients who had elective mitral valve repair and were recruited from the authors' institution's cardiothoracic department between May 2020 and May 2022. Ten patients did not complete the study (two patients died after surgery and eight patients refused to use the triaxial accelerometer after the surgery). Patients who had not been dependent on their daily activities (ADL) before the operation or who recorded 1,000 steps or fewer before the operation were excluded.
According to the surgical procedure, the patients were divided into two groups: MICS and conventional surgery (median sternotomy). The MICS group received mitral valve replacement through a right small thoracotomy incision (less than 10 cm) using femoral arterial and venous cannulation, however, the conventional surgery group underwent a median sternotomy and central cannulation to replace the mitral valve.
All patients received the same basic rehabilitation program that followed the Japanese Circulation Society Guidelines .To improve postoperative mobility, all patients received preoperative physical exercise and breathing exercises. Walking independently within the ward was completed by the eighth day postoperatively, according to the guidelines. The patients had daily aerobic training on a bicycle and treadmill, as well as unassisted walking throughout the hospital until they were discharged.
All the participants were subjected to (i) measurement of the pre and post-operative physical activity (ii) Postoperative Assessment: using a Visual Analogue Scale (VAS), the day of standing at the bedside, and the day on which the subject had the ability to walk independently for 100 m (iii) 6-Minute Walk Test before and after surgery.
Measurement of the pre and post-operative physical activity
It was measured by a triaxial accelerometer (Active Style Pro, Omron, Japan). The daily average steps were recorded and served as an indicator of physical activity measurements. The accelerometer was left in place around the waist and measurements were taken every day from the hospitalization time to discharge, with the exception of bathing and diagnostic testing. The preoperative activity was calculated using the daily average number of steps from the day of hospitalization to the day of surgery. The postoperative activity was calculated using the average number of steps taken from the day the patient could perform a 100-meter unassisted walk until the day of the discharge .
Visual analog scale (VAS)
For postoperative pain was done seven days after reaching a 100 m independent walk; zero represents (lack of pain) and ten denotes (pain) (maximum feeling the pain). VAS is a reliable and acceptable tool for assessing pain .
6-minute walk test (6-MWT)
Was conducted on a 30-meter corridor in accordance with recommendations from the American Thoracic Society. It was done one day prior to surgery and seven days following the completion of a 100-meter independent walk. The patients were instructed to walk in a quiet manner for six minutes. Ordinary verbal instructions were softly delivered each minute, and every 15 seconds inside the last minute, the remaining time was revealed . When signs or symptoms such as severe dyspnea, confusion, exhaustion, chest pain, or significant musculoskeletal pain appeared, patients were instructed to stop and then resume testing until the sex minute was reached. Furthermore, the test was terminated once the Borg scale reached 15 or more out of 20 .The distance was measured in meters and the heartbeat and rhythm were checked using an ECG . The Borg scale is a reliable indicator for monitoring and guiding exercise intensity. The scale allows individuals to descriptively rate their level of exertion throughout the activity or exercise testing, with 6 indicating "no exertion at all" and 20 indicating "maximal exertion" .
The Statistical Package for Social Science (IBM SPSS) version 23 was used to collect, edit, code, and enter the data for statistical analysis. When the quantitative data were parametric, they were displayed as means, standard deviations, and ranges; when they were non-parametric, they were displayed as medians and interquartile ranges (IQR). Numbers and percentages were also displayed for the qualitative factors. Based on qualitative data, groups were compared using the Chi-square test. Two independent groups with parametric distribution and quantitative data were compared using an independent t-test. The Mann-Whitney test for nonparametric distribution was used. the P-value was considered significant at the level of ≤ 0.05.
A Prospective comparative study. Prospectively recruited 50 patients who had elective mitral valve surgery and were divided into MICS group and Conventional surgery group.
Demographic data and the preoperative data
There were no significant differences in age, height, weight, or preoperative cardiac functioning across groups. (Table 1).
Result of VAS, pre and post-operative physical activity Assessment
The group of MICS recovered quicker than the group of conventional surgery (postoperative standing day at the bedside was 1.84 ± 0.37 vs. 2.28 ± 0.68, t =2.840, P= 0.007) and postoperative 100-m independent walking was 3.24 ± 0.72 vs 5.08 ± 0.70 days, t =9.12, P<0.001). In addition, MICS group showed significantly less post-operative VAS compared to the group of Conventional surgery group (t= -5.352 , P<0.001) (Table 2).
Before and after surgery, the two groups' physical activity levels were measured (Figure 1&2). There was no significant difference between the two groups as regards the preoperative daily step number. However, in MICS group, the number of daily steps increased significantly (preoperative 2,740 ± 1,330 vs. postoperative 3,536 ± 1,885) with a significantly faster improvement rate than the other group (793.2± 543.2 vs. 181.9 ± 205, t= -4.569, P<0.001)
The result of the 6-Minute Walk Test
The preoperative test revealed no significant difference between them. The MICS group scored significantly higher improvement (preoperative 346.72 ± 55.76 vs. postoperative 506.56 ± 86.9, P< 0.001) (Table 4).
In our research, the MICS group showed significantly less post-operative VAS compared to the conventional surgery group and performed significantly better in terms of standing at the bedside, 100 m independent walking, Triaxaile accelerometer findings, and 6MWT (P< 0.05). Previous studies have found that MICS patients had less postoperative pain and returned to normal activity sooner (10, 11). In individuals who had a minimally invasive method, recovery wasshown to be quicker and less painful following conventional surgery. Minimal bleeding decreased ventilation periods, wound infections, and shorter hospital stays.
Our results were in line with those of Nakajima and his colleagues, who compared the physical activity in the MICS group with that in the conventional median sternotomy group and noted that the group of MICS was statistically earlier at 100 m independent walking . Our findings were also aligned with those of the Iribarne et al. study, which compared the clinical outcomes of elderly patients after MICS to those after conventional surgery . Their theory was that avoiding sternotomy was the key contributor to the MICS group's earlier commencement of independent walking. This finding may point to the possibility of a rapid rise in physical activity following MICS.
Physical activity assessment has piqued the curiosity of many people, and several subjective and objective approaches have been established. Triaxial accelerometers are sensitive to both gravity and dynamic momentum, allowing them to detect motion intensity and physical activity [13, 14]. The triaxial accelerometers were used to evaluate the physical activity levels in elderly patients while they were hospitalized, as well as their functional capacity and physical activity in various positions .
Postoperatively, both groups showed improvement as regards the quantity of physical activity but the MICS group showed significantly higher improvement, Participants in the group of MICS were physically active during the day compared to those in the conventional surgery group, which could be attributed to the absences of the invasiveness of a sternotomy and its impact on postoperative physical activity recovery. Furthermore, Individuals who had MICS recovered more quickly from surgery and felt less postoperative pain.
These outcomes are Similar to Marin et al., who observed that MICS, when compared to conventional median sternotomy, offers comparable effectiveness and safety, as well as reduced postoperative morbidity and mortality. In addition, better aesthetic outcomes, shorter recovery times, and less physical activity restriction all contribute to higher patient acceptance . On the other hand, Nakajima et al. discovered that the level of physical activity reduced postoperatively in the conventional group . This could be due to the small number of patients in their study (the conventional group had only six), their age being significantly older than the MICS group, and the presence of significant comorbidity in this group While in our study, the numbers in each group, as well as age and comorbidity, were matched.
Compared to the bicycle or treadmill, the 6MWT is a more "natural" type of fitness test, and it may accurately reflect daily activity. The 6MWT has several benefits over traditional stress tests, including its flexibility and low price. It is generally well tolerated by participants, is simple to give, and has satisfactory repeatability .
In order to establish the comparison between MICS and the conventional methods using a reliable test. We utilized the 6 MWT because it is simple to administer, well-tolerated, and more representative of daily activity . This test is ideal for use in older individuals with cardiac problems since it allows for the estimation of the cardiovascular system's capability as well as the evaluation of the symptoms connected with it [19, 20].
There was a significant improvement in the MICS group in terms of functional capacity, which was determined by the walked distance in meters during the 6MWT. This resulted from subjects in the group of MICS recovered more quickly from the surgery group and experienced less postoperative pain.
Our results concur with those of Chen et al. Their major goal was to determine if the 6MWT might be used to assess physical performance and thus use it for the assessment postoperatively. They reported that there was a moderate to strong correlation between the 6MWT distances at baseline and at the 3-month follow-up and physical functioning and activities . In cardiac rehabilitation, 6MWT is a valid test that could be used in conjunction to evaluate a patient's compliance with recommended levels of physical activity during a post-rehabilitation checkup .
The limitation of the study
This research has certain drawbacks. For starters, the 6MWT results were not compared to those of a reference test, such as the maximum exercise test with oxygen uptake measurement. Second, the sample size was small. Finally, a brief time of review following surgery. Future research should assess physical activity over longer time periods in broader patient populations.
Minimally invasive cardiac surgery has a higher margin of benefit, and speedy recovery to normality, which is accompanied by less VAS score and an increase in the amount of physical activity during hospitalization in comparison to the conventional surgery.
Availability of data and materials
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Activity of Daily Life
Faculty of Medicine, Ain Shams University
Minimally invasive cardiac surgery
Pan African Clinical Trial Registry
Visual Analogue Scale
Sex minute walking test
Rosengart TK, Feldman T, Borger MA, Vassiliades TA Jr, Gillinov AM, Hoercher KJ, Vahanian A, Bonow RO, O'Neill W (2008). Percutaneous and minimally invasive valve procedures: a scientific statement from the American Heart Association Council on Cardiovascular Surgery and Anesthesia, Council on Clinical Cardiology, Functional Genomics and Translational Biology Interdisciplinary Working Group, and Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation. Apr 1;117(13):1750-67. https://doi.org/10.1161/CIRCULATIONAHA.107.188525. Epub 2008 Mar 10. PMID: 18332270
Cuartas MM, Davierwala PM (2020). Minimally invasive mitral valve repair. Indian J Thorac Cardiovasc Surg. Jan;36(Suppl 1):44-52. doi: https://doi.org/10.1007/s12055-019-00843-w. Epub 2019 Jul 27. PMID: 33061184; PMCID: PMC7525482
Zisberg A, Shadmi E, Sinoff G, Gur-Yaish N, Srulovici E, Admi H (2011) Low mobility during hospitalization and functional decline in older adults. J Am Geriatr Soc. 59(2):266–73. https://doi.org/10.1111/j.1532-5415.2010.03276.x. (PMID: 21314647)
Guidelines for Rehabilitation in Patients with Cardiovascular Disease: JCS 2013. http://www.j-circ.or.jp/guideline/pdf/JCS2007_nohara_d.pdf (Accessed Jul. 22, 2017)
Nakajima M, Totsugawa T, Sakaguchi T, Yuguchi S, Matsuo T, Ujikawa T, Morisawa T, Takahashi T (2017). Changes in the amount of physical activity in minimally invasive cardiac surgery. J Phys Ther Sci. 2017 Nov;29(11):2035-2038. doi: https://doi.org/10.1589/jpts.29.2035. Epub Nov 24. PMID: 29200652; PMCID: PMC5702842
Jensen MP, Turner JA, Romano JM (1994) What is the maximum number of levels needed in pain intensity measurement? Pain 58:3
American Thoracic SocietyATS statement (2002) guidelines for the six-minute walk test. Am J Respir Crit Care Med 166:111–7
Chen YC, Chen KC, Lu LH, Wu YL, Lai TJ, Wang CH (2018). Validating the 6-minute walk test as an indicator of recovery in patients undergoing cardiac surgery: A prospective cohort study. Medicine (Baltimore). Oct;97(42):e12925. doi: https://doi.org/10.1097/MD.0000000000012925. PMID: 30335028; PMCID: PMC6211883
Löllgen H, Ulmer HV (2004) Das" Gespräch" während der Ergometrie: Die Borg-Skala. Dtsch Arztebl 101(15):A1014–A1015
Yamada T, Ochiai R, Takeda J, Shin H, Yozu R (2003) Comparison of early postoperative quality of life in minimally invasive versus conventional valve surgery. J Anesth. 17(3):171–6
Santana O, Reyna J, Grana R, Buendia M, Lamas GA, Lamelas J (2011) Outcomes of minimally invasive valve surgery versus standard sternotomy in obese patients undergoing isolated valve surgery. Ann Thorac Surg 91:406–10
Iribarne A, Easterwood R, Russo MJ, Chan EY, Smith CR, Argenziano M. (2012). Comparative effectiveness of minimally invasive versus traditional sternotomy mitral valve surgery in elderly patients. J Thorac Cardiovasc Surg. Apr;143(4 Suppl): S86-90. doi: https://doi.org/10.1016/j.jtcvs.2011.10.090. PMID: 22423605
Skotte, Jørgen & Korshøj, Mette & Kristiansen, Jesper & Hanisch, Christiana & Holtermann, Andreas. (2012). Detection of Physical Activity Types Using Triaxial Accelerometers. Journal of physical activity & health. 11. https://doi.org/10.1123/jpah.2011-0347
Mathie MJ, Celler BG, Lovell NH, Coster AC (2004) (2004): Classification of basic daily movements using a triaxial accelerometer. Med Biol Eng Comput. 42(5):679–87. https://doi.org/10.1007/BF02347551. (PMID: 15503970)
Peter Hartley, Victoria L. Keevil, Kate Westgate, Tom White, Søren Brage, Roman Romero-Ortuno, Christi Deaton (2018). "Using Accelerometers to Measure Physical Activity in Older Patients Admitted to Hospital", Current Gerontology and Geriatrics Research, vol. 2018, Article ID 3280240, 9 pages, . https://doi.org/10.1155/2018/3280240
Marin Cuartas M, Javadikasgari H, Pfannmueller B, Seeburger J, Gillinov AM, Suri RM, Borger MA (2017). Mitral valve repair: Robotic and other minimally invasive approaches. Prog Cardiovasc Dis. 2017 Nov-Dec;60(3):394-404. doi: https://doi.org/10.1016/j.pcad.11.002. Epub 2017 Nov 9. PMID: 29128572
Fiorina C, Vizzardi E, Lorusso R et al (2007) The 6-min walking test early after cardiac surgery. Reference values and the effects of rehabilitation programme. Eur J Cardiothorac Surg. 32:724–9
Solway S, Brooks D, Lacasse Y, Thomas S (2001) A qualitative systematic overview of the measurement properties of functional walk tests used in the cardiorespiratory domain. Chest 119:256–270
Chodór P, Wilczek K, Zielińska T, Przybylski R, Głowacki J, Włoch Ł, Zembala M, Kalarus Z.(2017). Assessment of cardiovascular function following transcatheter aortic valve implantation based on six-minute walk test. Cardiol J ;24(2):167-175. doi: https://doi.org/10.5603/CJ.a2016.0086. Epub 2016 Oct 7. PMID: 27714724
Kleczyński P, Bagieński M, Sorysz D, et al.(2014). Short- and intermediate-term improvement of patient quality ter aortic valve implantation: a single-centre study. Kardiol Pol.; 72(7): 612–616, doi: https://doi.org/10.5603/KP.a2014.0065, indexed in Pubmed: 24671914
Racodon M, Porrovecchio A, Pezé T (2019). Utility of the 6-minute walk test in assessing maintenance of physical activity after cardiac rehabilitation. Rech Soins Infirm. Jun;137(2):18-25. English, French. doi: https://doi.org/10.3917/rsi.137.0018. PMID: 31453668
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This study was approved by Ain Shams University, Faculty of Medicine Research Ethics Committee (REC) FWA 000017585. FMASU (R 65/2022) A written informed consent was obtained from patients sharing in the study.
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Labib, H.s.A., Fawaz, S.I., Ghanam, M.E. et al. Effect of minimally invasive cardiac surgery compared with conventional surgery on post-operative physical activity and rehabilitation in patients with valvular heart disease. Egypt Rheumatol Rehabil 50, 5 (2023). https://doi.org/10.1186/s43166-023-00171-3