On pump coronary artery bypass graft surgery versus off pump coronary artery bypass graft surgery: a review

Impact of coronary artery bypass grafting surgery on the chorioretinal biomicroscopic characteristics

BACKGROUND

Most patients with cardiovascular disorders suffer from coronary artery diseases, which can be treated successfully using coronary artery bypass grafting (CABG). One of the unpleasant events following CABG is postoperative vision loss (POVL). Vulnerability of retinal vessels to hemodynamic changes, an expectable event following CABG, may contribute to the development of POVL, which might be associated with the changes in the choroidal and retinal structures.

AIM

To investigate postoperative changes in chorioretinal and peripapillary nerve fiber layer (NFL) thickness, and progression of diabetic and hypertensive retinopathy after CABG.

METHODS

In this prospective, cross-sectional study, 49 eyes in 25 candidates for CABG underwent both ophthalmic and cardiovascular examinations within 6 mo prior to and 9 mo after surgery.

RESULTS

Among the study participants, 56% were male with a mean age of 62.84 years ± 10.49 years (range 33-80 years). Diabetes mellitus was observed in eight participants (32%). None of the patients suffered from postoperative anterior or posterior ischemic optic neuropathy, central retinal artery occlusion, and cortical blindness. The mean value of the preoperative best corrected visual acuity was 0.11 ± 0.10 logMAR (range, 0-0.4), which worsened to 0.15 ± 0.08 logMAR (range, 0-0.4) after CABG (P = 0.031). No significant difference was observed between the pre- and postsurgical choroidal (P = 0.853) and macular (P = 0.507) thickness, NFL thickness in the subfoveal (P > 0.999) and peripapillary areas (P = 0.659), as well as the severity of diabetic and hypertensive retinopathy.

CONCLUSION

CABG may reduce visual acuity without affecting ocular structures. Postoperative vision reduction might be attributable to molecular or cellular variations, changes in visual pathway function, or central nervous system.

Intensive care unit length of stay and mortality comparison between on-pump and off-pump coronary artery bypass graft: a retrospective study

BACKGROUND

Recently, coronary artery bypass graft (CABG) techniques, both on-pump (ONCABG) and off-pump (OPCABG), were compared to seek the most effective approach to reduce the cost of prolonged intensive care unit length of stay (ICU LOS) and mortality. This study aims to compare ICU LOS and mortality in ONCABG and OPCABG.

RESULTS

Demographic data of 1569 patients show the variance of characteristics. The analysis shows significant and longer ICU LOS in OPCABG than ONCABG (2.151 ± 0.100 vs. 1.573 ± 0.246 days; p = 0.028). Similar results were demonstrated after adjustment of covariates effects (3.146 ± 0.281 vs. 2.548 ± 0.245 days; p = 0,022). Logistic regression shows no significant difference in mortality in OPCABG and ONCABG, both in the unadjusted (OR [CI 95%] 1.133 [0.485-2.800]; p = 0.733) and the adjusted models (OR [CI 95%] 1.133 [0.482-2.817]; p = 0,735).

CONCLUSION

ICU LOS was significantly longer in OPCABG patients than in ONCABG patients in the author's centre. There was no significant difference in mortality between the two groups. This finding highlights a discrepancy between recently published theories and the practices observed in the author's centre.

Endothelial Dysfunction in Patients Undergoing Cardiac Surgery: A Narrative Review and Clinical Implications

Cardiac surgery is one of the highest-risk procedures, usually involving cardiopulmonary bypass and commonly inducing endothelial injury that contributes to the development of perioperative and postoperative organ dysfunction. Substantial scientific efforts are being made to unravel the complex interaction of biomolecules involved in endothelial dysfunction to find new therapeutic targets and biomarkers and to develop therapeutic strategies to protect and restore the endothelium. This review highlights the current state-of-the-art knowledge on the structure and function of the endothelial glycocalyx and mechanisms of endothelial glycocalyx shedding in cardiac surgery. Particular emphasis is placed on potential strategies to protect and restore the endothelial glycocalyx in cardiac surgery. In addition, we have summarized and elaborated the latest evidence on conventional and potential biomarkers of endothelial dysfunction to provide a comprehensive synthesis of crucial mechanisms of endothelial dysfunction in patients undergoing cardiac surgery, and to highlight their clinical implications.

The effect of off-pump coronary bypass graft surgery on subfoveal choroidal thickness, ganglion cell complex, and retinal nerve fiber layer thickness

Background

Cardiac surgery has been associated with adverse ocular events. Off-pump coronary artery bypass graft surgery evades the systemic inflammatory response seen in extracorporeal circulation and is superior to on-pump surgery with regard to end-organ dysfunction and neurological outcomes.

Objectives

To determine the effects of off-pump (without extracorporeal circulation) coronary artery bypass graft surgery on choroidal thickness, ganglion cell complex, and the retinal nerve fiber layer.

Design

Prospective, longitudinal study.

Methods

Patients who underwent off-pump surgery were examined preoperatively and postoperatively at 1 week and 6 weeks after surgery. Choroidal thickness, ganglion cell complex, and the retinal nerve fiber layer measurements were recorded, and the effects of off-pump coronary artery bypass on these parameters were assessed.

Results

A total of 44 eyes of 44 patients were included in the study. There was a statistically significant increase in subfoveal choroidal thickness from 252.84 ± 56.24 µm preoperatively to 273.82 ± 39.76 µm at 1 week and 301.97 ± 44.83 µm at 6 weeks after off-pump coronary artery bypass graft surgery (p = 0.044; p ⩽ 0.001). Ganglion cell complex and retinal nerve fiber measurements showed no significant difference compared to preoperative values.

Conclusion

Off-pump coronary artery bypass graft surgery showed no negative effects on ganglion cell complex and retinal nerve fiber measurements. A significant increase in subfoveal choroidal thickness was seen after off-pump surgery, which might be advantageous in patients who are at high risk or have preexisting ocular diseases that are affected by the choroid.

Single-blind, randomized study comparing clinical equivalence of trulene and prolene polypropylene sutures in elective primary coronary artery bypass graft surgery

BACKGROUND

Coronary artery bypass graft surgery (CABG) is one of the principle therapies for coronary artery disease, as it improves survival rate and quality of life (QoL). Polypropylene suture is commonly used in vascular and cardiac surgeries for anastomosis due to its long-term tensile strength and minimal tissue trauma. This study compared the clinical equivalence of Trulene® (Healthium Medtech Limited) and Prolene® (Ethicon-Johnson & Johnson) polypropylene sutures regarding incidence of myocardial infarction, stroke, renal failure and cardiac death (MACCE) occurring up to 26 weeks' period post-CABG surgery.

METHODS

This multicenter, prospective, two-arm, parallel-group, randomized (1:1), single-blind study (n = 89) was conducted between August 2020 and September 2021. The primary endpoint, post-surgery cumulative incidence of MACCE was evaluated. In addition, anastomotic revision, surgical site infection (SSI), operative time, length of post-operative hospital stay, repeat revascularization, intraoperative suture handling characteristics, time taken to return to work and resume normal day to day activities, subject satisfaction score and QoL, and other adverse events were also recorded.

RESULTS

A total of 80 (89.89%) males and 9 (10.11%) females participated in the study. No incidence of MACCE was recorded in any of the study participants. Non-significant difference was observed in anastomotic revision, SSI, operative time, post-operative hospital stay, revascularization, return to work and normal day-to-day activities, subject satisfaction score and QoL, and intraoperative handling parameters (except ease of passage) between the treatment groups, Trulene® and Prolene®. Compared to screening visit, proportion of subjects with 'no problems' for each QoL dimension and the mean visual analogue scale increased with each subsequent follow-up visit.

CONCLUSION

Trulene® polypropylene suture is clinically equivalent to Prolene® polypropylene suture and is safe and effective for anastomosis construction in CABG surgery during a routine clinical procedure. Trial registration CTRI Registration No.: CTRI/2020/05/025157 (Registered on: 13/05/2020).

Trends in per-operative parameters and postoperative complications associated with coronary artery bypass graft surgery (CABG); A four-year retrospective study

Objective:

To determine the patterns of per-operative parameters and early outcomes of patients that underwent CABG surgery during a four-year period.

Methods:

This is a cross-sectional descriptive study conducted in a tertiary care of hospital from November 2020 to January 2021. All the patients that underwent the isolated coronary artery bypass grafting (CABG) procedure were included in the study from June 2017 till June 2020. Data was collected on a data extraction form and stored in SPSS format which was analyzed for qualitative statistics keeping p<0.05 as significant. All the results were represented in the form of tables.

Results:

A total of 1,613 patients were operated upon for Coronary Artery Bypass Grafting (CABG) procedure during the study period with 1,222 (75.8%) males and 391 (24.2%) females. Dyslipidemia (71.8%) was the most common risk factor. The average perfusion time decreased only slightly (~1 minute) from 96.01 minutes to 95.07 minutes (2017 to 2020). This change however was not significant (p=0.301). The rate of Left Internal Mammary Artery (LIMA) use stayed relatively stable over the 4-year period fluctuating between 88.7% and 92.9% (p=0.360). The average initial ICU stay (in hours), drain at 12 hours and 24 hours stays almost the same. The rate of mortality peaked in 2018 (4.76%) and subsequently fell to 3.57% by 2020.

Conclusion:

More males underwent CABG surgery at this tertiary care hospital and the overall complication rate and per-operative parameters improved over the years. The non-risk stratified mortality in this study was found to be higher than developed nations.

Association between the weekday on which coronary artery bypass graft surgery is performed and the 30-day mortality: A nationwide cohort study in South Korea

BACKGROUND

Postoperative mortality associated with elective coronary artery bypass graft (CABG) surgery may reportedly increase as the weekday of surgery approaches the weekend. We aimed to investigate the potential effect of the weekday of CABG surgery on the 30-day mortality.

METHODS

This population-based cohort study analyzed data obtained from the South Korea national health insurance service database. The cohort included all adult patients diagnosed with ischemic heart disease (International Classification of Diseases-10 codes I20*-I25*) who underwent isolated and elective CABG surgery from January 2012 to December 2017.

RESULTS

Of the 13,556 patients included in the analysis, 595 (4.4%) died within 30 days after CABG surgery. In a multivariable Cox model, the 30-day mortality of patients who underwent CABG surgery later in the week (Wednesday-Friday) was not significantly associated with the weekday of surgery as similar to those who underwent surgery early in the week (Monday-Tuesday) (hazard ratio [HR]: 1.14, 95% confidence interval [CI]: 0.97-1.34; p = .109). Multivariable sensitivity analysis revealed that CABG surgery on Friday was associated with a 1.40-fold higher hazard of 30-day mortality (HR: 1.40; 95% CI: 1.09-1.80; p = .008) than CABG surgery on Monday.

CONCLUSIONS

This South Korean population-based cohort study revealed that relative to surgery early in the week (Monday-Tuesday), CABG surgery later in the week (Wednesday-Friday) was not associated with higher 30-day mortality. However, using surgery on Monday as a reference, CABG surgery on Friday was associated with higher 30-day mortality. Future studies must confirm these findings.

Bilateral sequential lung transplantation in Jehovah's Witnesses

The ethical concerns of refusing lifesaving treatments after receiving an already limited resource such as a solid organ transplantation in a Jehovah's Witness patient have been discussed in the literature. Many of these studies have concluded that with a multidisciplinary approach, solid organ transplantation is possible in the setting of Jehovah's Witness patients. To date, there are no reported cases of bilateral sequential lung transplantation in the literature. We report two successful cases of bilateral sequential lung transplantation in Jehovah's Witness patients with excellent long-term follow-up.

Blocking Extracellular Chaperones to Improve Cardiac Regeneration

Chronic or acute insults to the myocardium are responsible for the onset of cardiomyopathy and heart failure. Due to the poor regenerative ability of the human adult heart, the survival of cardiomyocytes is a prerequisite to support heart function. Chaperone proteins, by regulating sarcomeric protein folding, function, and turnover in the challenging environment of the beating heart, play a fundamental role in myocardial physiology. Nevertheless, a number of evidences indicate that, under stress conditions or during cell damage, myocardial cells release chaperone proteins that, from the extracellular milieu, play a detrimental function, by perpetuating inflammation and inducing cardiomyocyte apoptosis. Blocking the activity of extracellular chaperones has been proven to have beneficial effects on heart function in preclinical models of myocardial infarction and cardiomyopathy. The application of this approach in combination with tissue engineering strategies may represent a future innovation in cardiac regenerative medicine.

Mortality risk factors from converting off-pump coronary artery bypass to on-pump coronary artery bypass

Introduction:

A number of large-scale retrospective studies revealed that off-pump coronary artery bypass (OPCAB) was superior to on-pump coronary artery bypass (ONCAB). The aim of the study was to investigate risk factors for mortality when OPCAB is converted to ONCAB.

Methods:

Patients who underwent OPCAB conversion to ONCAB at the Beijing Anzhen Hospital between January 2003 and January 2013 were assigned to the non-survivor and survivor groups. Background demographics, illness history and preoperative, intraoperative and postoperative variables were compared.

Results:

Of the 247 cases, 15.4% of the patients died. Patients in the non-survivor group were older and more frequently had diabetes mellitus (DM), arrhythmia, myocardial infarction (MI) in the past 30 days (all p<0.05) and MI combined with mitral regurgitation (p<0.0001); they more frequently had bigger left ventricular end-diastolic dimension (p=0.0019), greater fall in blood pressure, ventricular fibrillation for longer periods, longer conversion time and bypass graft occlusion. All patients in the non-survivor group received intra-aortic balloon pump compared to 89.5% in the survivor group and extracorporeal membrane oxygenation was more common. Left main coronary artery disease (OR=4.431, 95%CI: 2.440-8.048, p<0.0001), blood pressure decline ⩽40 mmHg (OR=0.509, 95%CI: 0.447-0.580, p<0.0001) and time for conversion to ONCAB ⩾20 min were independently associated with mortality. Rates of postoperative complications, such as renal failure, cerebral infarction or hemorrhage, MI and redo sternotomy, were higher in the non-survivor group.

Conclusions:

Conversion from OPCAB to ONCAB is associated with high mortality. Risk factors include left main artery disease and duration of blood pressure decline >40 min.

A Secure and High-Fidelity Live Animal Model for Off-Pump Coronary Bypass Surgery Training

OBJECTIVE

Existing simulators for off-pump coronary artery (CA) bypass grafting training are unable to provide cardiac surgery residents all necessary skills they need entering the operation room. In this study, we introduced a secure and high-fidelity live animal model to supplement the in vitro simulators for off-pump CA bypass grafting training.

DESIGN

The left internal thoracic artery (ITA) of 3 Chinese miniature pigs was grafted to the left anterior descending CA using an end-to-side anastomosis. The free segment of the ITA was fixed on the ventricle surface, making it a simulative CA beating in synchrony with the heart. A total of 6 to 8 training anastomoses were made on each ITA.

SETTING

Animal Experiment Center in Fuwai Hospital.

PARTICIPANTS

In total, 19 resident surgeons with at least 3 years of cardiac surgery work experience were trained using the new model. Their performances were recorded and reviewed.

RESULTS

Simulative coronary arteries were successfully constructed in all 3 animals with no adverse event observed. A total of 19 anastomoses were then completed, 1 pig of 7 anastomoses and the other 2 animals of 6 anastomoses. Time consumption for the anastomosis was 782 ± 107 seconds. Anastomotic leakage was observed in 10/19 procedures. The most frequency site (7/10) was at the toe of the anastomosis. Further, the most common cause was uneven spacing or small margin of the stitches or both. Emergencies occurred during the training process included hypotension (7 procedures), tachyarrhythmia (4 procedures), and low blood oxygen saturation (1 procedure).

CONCLUSIONS

This study demonstrated the safety and feasibility of our new live pig model in training resident surgeons. The simulative arteries can be easily accomplished and were long enough to place at least 6 anastomoses. Both on lumen diameter and motion status, they were proven to be a good substitution of the CA.

Plasma cytokine levels in dogs undergoing cardiopulmonary bypass

Currently, there are no reports of inflammatory responses to CPB in dogs. We investigated the time course of pro- and anti-inflammatory cytokine levels during and after CPB.

ANIMALS

The study group included 11 dogs that underwent mitral valve repair with CPB, and the control group included 7 healthy dogs that underwent ovariohysterectomy.

METHODS

Blood samples from the study group dogs were collected before, during and after surgery and analyzed for plasma levels of interleukin-6 (IL-6), tissue necrosis factor-α (TNF-α), interleukin-10 (IL-10), white blood cells (WBC), and C-reactive protein (CRP). Each inflammatory parameter was also compared with that of the control group dogs.

RESULTS

After CPB, plasma levels of IL-6, WBC counts, and CRP levels were significantly higher than preoperative levels, and IL-6 levels in the study group were significantly higher than those in the control group.

CONCLUSIONS

CPB induces a systemic inflammatory response in dogs.