Mirror, Mirror on the Wall; He Had a "Bypass" After All!

How to cite this article: Magoon R, Jose J, Kumar M. Mirror, Mirror on the Wall; He Had a "Bypass" After All! Indian J Crit Care Med 2024;28(7):706-707.

Meta-analysis of BITA versus SITA grafting in diabetic patients: evidence from propensity score-matched studies.

BACKGROUND: It has been demonstrated that the use of bilateral internal thoracic artery (BITA) grafting in coronary artery bypass grafting (CABG) improves long-term survival in comparison to the use of a single internal thoracic artery (SITA) graft. However, the optimal transplantation technique for diabetic patients remains undetermined. The purpose of this meta-analysis was to compare the effectiveness and safety of BITA and SITA CABG in diabetic patients. METHODS: A comprehensive search of Google Scholar, Science Direct, and PubMed was conducted for studies with propensity score-matched comparing between BITA and SITA grafting in diabetic patients. The main goal was to know mid- to long-term mortality, and the supplementary results included incidence of deep sternal wound infection, 30-day mortality, and incidence of reoperation due to hemorrhage. RESULTS: The meta-analysis included 11 studies involving 3762 diabetic patients with matched propensity scores. Compared to SITA grafting, BITA grafting was associated with a significant reduction in long-term mortality (HR 0.78; 95% CI 0.67-0.91), P = 0.03, I2 = 54%. There were no significant differences between the two groups in terms of 30-day mortality, reoperation for bleeding, cerebrovascular accident, or renal failure. CONCLUSIONS: BITA grafting appears to provide better overall survival than SITA grafting in patients with diabetes. However, using BITA grafting is associated with a greater risk of deep sternal wound infection. These findings may help guide the choice of grafting technique in diabetic patients undergoing CABG.

Superior Outcomes of Dual-Arterial Coronary Artery Bypass Grafting Are Maintained in the Veterans Health Administration.

INTRODUCTION: Controversy surrounds the long-term clinical benefit of coronary artery bypass grafting (CABG) using dual arterial grafts (DAGs) compared to single arterial grafts (SAGs). We investigated outcomes of DAG, using single internal thoracic artery and radial artery (DAG-RA) or bilateral internal thoracic artery grafts (DAG-BITA), compared to SAG, using the left internal thoracic artery and saphenous vein grafts, in the U.S. Veterans Health Administration (VA). METHODS: We conducted a cross-sectional study of U.S. Veterans undergoing isolated on-pump CABG between 2005 and 2015 at 44 VA medical centers. The primary composite outcome was first occurrence of a major adverse cardiac and cerebrovascular event (MACCE), comprised of death from any cause, myocardial infarction, stroke, or repeat revascularization. RESULTS: Among 25,969 Veterans undergoing isolated CABG, 1261 (4.9%) underwent DAG (66.8% DAG-RA and 33.2% DAG-BITA). Over a 5-y follow-up, DAG was associated with lower rates of all-cause death (adjusted hazard ratio [AHR] 0.70, 95% confidence interval [CI] 0.58-0.85), MACCE (AHR 0.80, 95% CI 0.71-0.91), and stroke (AHR 0.74, 95% CI 0.57-0.96) versus SAG. DAG-BITA was associated with lower rates of all-cause death (AHR 0.52, 95% CI 0.35-0.77) and MACCE (AHR 0.66, 95% CI 0.51-0.84) than SAG, while DAG-RA was associated with lower rates of all-cause death (AHR 0.79, 95% CI 0.64-0.99). CONCLUSIONS: In the VA, DAG was associated with improved long-term MACCE outcomes compared to SAG. These results suggest that the practice of DAG in the VA benefits Veterans and should be promoted further.

Author Response: Mirror, Mirror on the Wall; He Had a "Bypass" After All!

How to cite this article: Shukla MP. Author Response: Mirror, Mirror on the Wall; He Had a "Bypass" After All! Indian J Crit Care Med 2024;28(7):708.

Skeletonized Versus Pedicled Harvesting of the Internal Thoracic Artery and Long-Term Clinical Outcomes in Coronary Artery Bypass Surgery.

BACKGROUND: The internal thoracic artery (ITA) is the most important conduit for coronary artery bypass grafting. Recent evidence suggests that skeletonized ITA harvesting yields long-term outcomes inferior to those of pedicled harvesting. The aim was to investigate the impact of the ITA harvesting method on 10-year mortality and major adverse cardiovascular events. METHODS AND RESULTS: In this observational cohort study, we identified all patients from the SWEDEHEART (Swedish Web-System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) register who underwent isolated coronary artery bypass grafting using at least 1 ITA at Karolinska University Hospital from 2012 to 2021. The main outcome was all-cause mortality, and the secondary outcomes were a combination of myocardial infarction, repeat revascularization, heart failure, and stroke. Outcomes were ascertained using national health data registers and compared between the skeletonized and pedicled groups using weighted flexible parametric survival models. Among 3267 patients, 1657 (51%) underwent pedicled ITA harvesting and 1610 (49%) underwent skeletonized ITA harvesting. The patients' mean age was 66 years, and 15% were women. The weighted all-cause mortality incidence rate in the pedicled versus skeletonized ITA group was 2.6% (95CI, 2.2%-3.0%) versus 2.6% (95% CI, 2.2%-3.1%), respectively (hazard ratio (HR), 1.01 [95% CI, 0.81-1.27]). The weighted major adverse cardiovascular events incidence rate was 7.8% (95% CI, 7.1%-8.6%) versus 7.5% (95% CI, 6.7%-8.4%), respectively (HR, 0.94 [95% CI, 0.82-1.08]). CONCLUSIONS: We found no significant differences in all-cause mortality or major adverse cardiovascular events rates between the 2 ITA harvesting methods.

Endovascular Embolization for Idiopathic Serial Right Internal Mammary Artery Aneurysms.

CLINICAL IMAPCT: This article showed images of a patient with idiopathic serial right internal mammary artery true aneurysms treated by endovascular embolization, which is a rare diagnosis and should be considered in differential diagnosis of paratracheal mass.

Internal Mammary Artery-saphenous Vein Y Anastomosis in Coronary Artery Bypass Grafting - Is there a Possibility of Coronary Steal?

Recent advances in coronary revascularization include total arterial grafting, however, in a few cases, harvesting the right internal thoracic artery (RITA) is not possible due to various reasons. In such cases, where the aorta is also calcified, few surgeons perform Y anastomosis configuration with the left internal thoracic artery(LITA) and saphenous vein which can have disastrous complications. Our patient is a 65-year-old man who was diagnosed with multivessel coronary disease and presented with a coronary steal during coronary artery bypass grafting surgery. The RITA was not harvested due to osteoporosis sternum. LITA-saphenous vein Y anastomosis configuration was done as the aorta was calcified. The anastomosis was done between the LITA to the left anterior descending (LAD) artery and the Y arm saphenous vein was anastomosed to an obtuse marginal (OM)branch. He developed coronary steal following anastomosis of the Y graft to the OM branch. The patient had ischemic changes inside the operation theatre in LAD territory, hence grafts were revised following which the patient became stable. There is a high possibility of a coronary steal when the caliber of the Y arm does not match with the LITA. LITA-saphenous vein Y anastomosis can cause more complications as the saphenous vein is much bigger in caliber compared to the LITA.

Management of massive hemothorax due to internal mammary pseudoaneurysm treated with angioembolization post-cesarean section involving traumatic fetal extraction: A case report.

Introduction: Pseudoaneurysm, or false aneurysm, is a clinical entity caused by rupture of the arterial wall, leading to blood leakage that is confined by sorroundig tissue. Massive hemothorax constitutes a life-threatening condition demanding timely and accurate medical response. Case report: A puerperal presented with a massive hemothorax precipitated by a traumatic cesarean section due to hemorrhage from a pseudoaneurysm of the left internal thoracic artery. Initial treatment involved a sternotomy, followed by a conclusive therapy via angioembolization. Conclusion: Precise assessment, including the measurement and localization of the ITA pseudoaneurysm is crucial to formulate an appropriate therapeutic strategy. Current medial practice favors endovascular embolization as a reliable and minimally invasive alternative to open surgery, establishing ir as the treatment of choice.

Long-Term Outcomes of Coronary Artery Bypass Grafting Using an Internal Thoracic Artery versus a Radial Artery as a Second Arterial Graft.

PURPOSE: To compare the outcomes of left circumflex artery (LCx) revascularization using an internal thoracic artery (ITA) or radial artery (RA) as the second arterial graft. METHODS: Patients who underwent primary isolated coronary artery bypass grafting with left anterior descending artery revascularization using an ITA and LCx revascularization using another bilateral ITA (BITA group) or an RA (ITA-RA group) were included. All-cause mortality (primary endpoint), cardiac death, major adverse cardiac events, in-hospital death, and deep sternal wound infection (secondary endpoints) were evaluated. RESULTS: Among 790 patients (BITA, n = 548 (69%); ITA-RA, n = 242 (31%)), no significant difference in all-cause mortality between the groups was observed (hazard ratio (HR): 0.87; 95% confidence interval (CI): 0.67-1.12; p = 0.27) during follow-up (mean, 10 years). Multivariate analysis revealed that the BITA group exhibited significantly lower rates of long-term all-cause mortality (HR: 0.63; 95% CI: 0.48-0.84; p = 0.01). In the propensity-matched cohort (n = 480, 240 pairs), significantly fewer all-cause deaths occurred in the BITA group (HR: 0.66; 95% CI 0.47-0.93; p = 0.02). There were no significant differences in secondary outcomes. CONCLUSIONS: When used as second grafts for LCx revascularization, ITA grafts may surpass RA grafts in reducing all-cause mortality 10 years postoperatively.

Subcostal bilateral internal thoracic artery harvesting with the da Vinci Single Port system: an experimental feasibility study.

We evaluated the feasibility of harvesting bilateral internal thoracic arteries with the da Vinci Single Port system (SP) through a single left-sided subcostal incision. Complete bilateral mobilization with sufficiently long conduits for multivessel grafting was possible in 2 human cadavers and 2 live porcine. Creating the subcostal access and docking the SP system took between 14 and 21 min and the total harvest time ranged from 65 to 125 min in all models. No major bleeding was observed in the live porcine and hemostasis was managed with the available instrumentation. One porcine deceased during surgery due to ventricular fibrillation followed by cardiac arrest. The robotic harvesting was technically easily reproduced by the surgeons and required no additional rib-spreading. Further studies will be required to assess if this subcostal approach with the da Vinci SP system yields true clinical benefits in patients.

Internal thoracic artery as a growing conduit for pulmonary shunt.

Studies suggest the internal thoracic artery as a shunt option due to its growth potential. However, long-term data are lacking. Here, a patient with a failing single ventricle shunt had an enlarged internal thoracic artery. We followed the patient for 12 years after converting this artery into a Blalock-Taussig shunt, analysing its growth to assess its effectiveness.

Left Internal Thoracic Artery versus Saphenous Vein Grafts to Left Anterior Descending Artery after Isolated Coronary Artery Bypass Surgery.

BACKGROUND: This study compared perioperative outcomes and long-term survival of saphenous vein grafts (SVGs) versus left internal thoracic artery (LITA) to left anterior descending artery (LAD) in isolated coronary artery bypass graft surgery (CABG). METHODS: In this retrospective, single-centre study, we included patients with primary isolated CABG from January 2001 to July 2022. Baseline demographics were compared between SVG-LAD and LITA-LAD. Univariable and multivariable regressions were performed for predictors of in-hospital death. Propensity score matching was performed for LITA-LAD vs. SVG-LAD. Kaplan-Meier survival curves were generated for comparison of survival. Cox proportional hazards model was used for predictors of survival. RESULTS: A total of 8237 patients (1602 SVG-LAD/6725 LITA-LAD) were included. Median age was 67.9 years (LITA-LAD; 67.1 years vs. SVG-LAD; 71.7 years, p < 0.01). A total of 1270 pairs of SVG-LAD were propensity-matched to LITA-LAD. In matched cohorts, in-hospital mortality (0.8% vs. 1.6%, LITA-LAD and SVG-LAD respectively; p = 0.07), deep sternal wound infection, new cerebrovascular events, renal replacement therapy and hospital stay >30 days were similar. SVG-LAD did not adversely affect in-hospital mortality (OR; 2.03, CI; 0.91, 4.54, p = 0.08). Median long-term survival was similar between the groups (13.7 years vs. 13.1 years for LITA-LAD and SVG-LAD respectively, log rank p < 0.31). SVG-LAD was not a predictor of adverse long-term survival. (HR; 1.06, 95% CI; 0.92, 1.22, p < 0.40). Long-term survival was better with LITA-LAD for LVEF <30% (log rank p < 0.03). CONCLUSIONS: There was no difference in the propensity-matched cohorts for use of SVG vs. LITA to the LAD. Further contemporary long-term studies are needed for substantiation.

Randomized comparison of HARVesting the Left Internal Thoracic Artery in a skeletonized versus pedicled technique: the HARVITA trial-study protocol.

Latest research has indicated a potential adverse effect on graft patency rates and clinical outcomes with skeletonizing the left internal thoracic artery. We aim to provide a prospective, randomized, multicentre trial to compare skeletonized versus pedicled harvesting technique of left internal thoracic artery concerning graft patency rates and patient survival. A total of 1350 patients will be randomized to either skeletonized or pedicled harvesting technique and undergo surgical revascularization. Follow-up will be performed at 30 days, 1 year, 2 years and 5 years after surgery. The primary outcome will be death or left internal thoracic artery graft occlusion in coronary computed tomography angiography or invasive angiography within 2 years (+/- 3 months) after surgery. The secondary outcome will be major adverse cardiac events (composite outcome of all-cause death, myocardial infarction and repeated revascularization) within 1 year, 2 years and 5 years after surgery. The primary end point will be compared in the modified intention-to-treat population between the two treatment groups using Kaplan-Meier graphs, together with log-rank testing. Hereby, we present the study protocol of the first adequately powered prospective, randomized, multicentre trial which compares skeletonized and pedicled harvesting technique of left internal thoracic artery regarding graft patency rates and patient survival.

Chest Compression-Associated Internal Thoracic Artery Injury During Cardiopulmonary Resuscitation: Incidence, Injury Patterns and Efficacy of Transcatheter Arterial Embolization.

PURPOSE: To investigate the incidence and patterns of chest compression-associated internal thoracic artery injury (CAI) during cardiopulmonary resuscitation and identify the embolization techniques used to treat hemorrhage. MATERIALS AND METHODS: A retrospective study was conducted in the patients who underwent transcatheter arterial embolization (TAE) for life-threatening hemorrhage caused by CAI at two tertiary care centers between May 2013 and December 2019. Data on background characteristics, imaging findings, embolization and outcomes were collected from the medical records. RESULTS: Among 385 patients in whom circulation returned after resuscitation, there were 9 patients (2.3%) who required TAE for CAI. Eight of 9 patients had acute myocardial infarction, and all had been started on extracorporeal membrane oxygenation before TAE. Seven patients had unilateral, and two had bilateral internal thoracic artery injuries. Main trunk injury of internal thoracic artery was seen in 27%, while branch injury in 73%. Six patients (67%) had multiple injuries in the internal thoracic artery territory, and five (56%) had injuries to other vessels. In all cases, we embolized the main trunk of the internal thoracic artery using n-butyl 2-cyanoacrylate and coils (n = 8), a gelatin sponge only (n = 2), or coils and a gelatin sponge (n = 1). TAE was technically successful in all, without any complication. The 30-day mortality rate was 44%. CONCLUSIONS: CAI needing hemostatic intervention occurred in 2.3% of patients after successful cardiopulmonary resuscitation. Branch injury was more common than main trunk injury, and multiple vessel injuries were common. TAE appears to be safe and effective for controlling life-threatening hemorrhage.

Off-pump bilateral internal thoracic artery grafting in patients with left main coronary artery disease.

BACKGROUND: To compare postoperative outcomes in patients with left main coronary artery disease who underwent off-pump isolated coronary artery bypass grafting for multivessel disease using either skeletonized bilateral or single internal thoracic artery (ITA). METHODS: Among 1583 patients who underwent isolated coronary artery bypass grafting (CABG) in our hospital between 2002 and 2022, 604 patients with left main coronary artery disease underwent single (n = 169) or bilateral (n = 435) ITA grafting. We compared postoperative outcomes between the two groups after adjusting preoperative characteristics using inverse probability of treatment weighting. RESULTS: After adjustment using inverse probability of treatment weighting method, the sum of weights was 599.74 in BITA group and 621.64 in SITA group. There was no significant difference in postoperative deep sternal wound infection (p = 0.227) and 30-day mortality (p = 0.612). Follow-up was completed in 98.7% (596/604) of the patients, and the mean follow-up duration was 6.7 years. At 10 years, the overall survival following bilateral versus single ITA grafting was 71.2% and 60.6%, respectively (log-rank test, p = 0.040), and freedom from major adverse cardiac and cerebrovascular events (MACCE) was 63.3% and 46.3%, respectively (log-rank test, p = 0.008). In multivariate Cox proportional hazard models, bilateral ITA grafting was significantly associated with a lower risk of all-cause death (hazard ratio [HR]: 0.706, 95% confidence interval [CI]: 0.504-0.987; p = 0.042) and MACCE (HR: 0.671, 95% CI: 0.499-0.902; p = 0.008). CONCLUSIONS: Bilateral skeletonized ITA grafting is associated with lower rates of all-cause death and MACCE than single ITA grafting in patients with left main coronary artery disease undergoing off-pump CABG.

Strategies to Minimize Sternal and Leg Wound Complications after Coronary Artery Bypass Grafting Using No-Touch Saphenous Vein Grafts.

PURPOSE: The aims of the present study were to examine sternal and saphenous vein (SV) harvest site wound complication rates, and to assess the strategies to minimize the sternal and leg wound complications after coronary artery bypass grafting using a no-touch (NT) SV. METHODS: Patients who underwent coronary artery bypass grafting (CABG) using internal thoracic artery (ITA) and/or NT SV grafts from March 2021 to June 2023 (N = 166) at a newly opened cardiac surgical program were included. We obeyed the current guidelines for the prevention of sternal wound infection. In addition, unilateral ITA was used in most of the patients and the sternal wound was meticulously closed using multiple sternal wires (≥7) and ZipFix. For the NT SV harvesting, the LigaSure device was used to minimize thermal injury, and the wound was meticulously closed. RESULTS: Sternal wound infections developed in 3/166 (1.8%) patients; all three patients showed superficial sternal wound infections. Leg wound complications were present in 2/153 (1.3%) patients, who recovered after secondary intention healing. CONCLUSION: Sternal wound complications after CABG could be minimized by the unilateral ITA usage, meticulous closure of the sternal wound in addition to compliance with the current guidelines. Wound complications after NT SV harvest may also be minimized by preoperative evaluation, careful harvesting, and meticulous wound closure.

Impact of coronary-subclavian steal after surgical myocardial revascularization with internal thoracic artery in chronic hemodialysis patients: A meta-analysis.

Patients in hemodialysis with an arm arteriovenous fistula undergoing coronary artery bypass grafting (CABG) with an internal thoracic artery have been reported to suffer from coronary-subclavian steal (CSS) during dialysis session. However, its occurrence is still debated. A systematic literature review was performed to identify all studies investigating the occurrence of a CSS event in this subset of patients. The primary endpoint was the analysis of CSS and the following early and late survival outcomes. Independent determinants of CSS and the impact of the distance between the arteriovenous fistula (upper arm vs forearm) and the ipsilateral internal thoracic artery graft on CSS events and mortality were studied. Early and late survival outcomes were analyzed by comparing ipsilateral versus contralateral arteriovenous fistula. Of the 1,383 retrieved articles, 10 were included (n = 643 patients). The pooled event rate of CSS was 6.46% [95%CI=2.10-18.15], while of symptomatic CSS incidence was 3.99% [95%CI=0.95-15.25]. No survival differences were noted when comparing ipsilateral to contralateral arteriovenous fistula-internal thoracic artery combinations. On meta-regression, the upper arm was associated with more CSS events, while the forearm to lower late mortality rates. Independently from arteriovenous fistula-internal thoracic artery combination, CSS was not associated to higher mortality rates. Particular attention is warranted when selecting the type of conduits for CABG in patients with an arteriovenous fistula or if highly expected to need one in the near future after surgery. A contralateral arteriovenous fistula-internal thoracic artery combination is preferable. If this is not possible, a forearm arteriovenous fistula position should be preferred.

A systematic review and meta-analysis of internal thoracic artery harvesting techniques: Skeletonized vs pedicled.

OBJECTIVES: The aim of this meta-analysis was to compare clinical and angiographic outcomes of skeletonized versus pedicled internal thoracic artery for coronary artery bypass grafting. METHODS: A comprehensive search on Ovid MEDLINE, Ovid EMBASE and Scopus was performed from inception to December 2022. The primary outcome was follow-up mortality and graft failure. Secondary outcomes were repeat revascularization, cardiovascular death and operative mortality, myocardial infarction, stroke, and sternal wound complications (SWCs). Pooled estimate for follow-up outcomes was summarized as incidence rate ratio (IRR) and 95% confidence interval (CI) while short-term outcomes were pooled as odds ratio (OR) and 95% CI. For all outcomes, inverse variance weighting was used for pooling. RESULTS: Twenty-eight studies, including 7 randomized trials and 21 observational studies, for a total of 5664 patients in the skeletonized group and 7434 in the pedicled group, were included in the analysis. At a mean weighted follow-up of 4.8 years, there was no difference in mortality between the two groups (IRR 1.14; 95% CI 0.59-2.20). However, the skeletonized group had a higher incidence of graft failure compared to the pedicled group (IRR 1.87, 95% CI 1.33-2.63) but a lower risk of SWCs (OR 0.42; 95% CI 0.30-0.60). There was no difference in short-term outcomes. CONCLUSIONS: Compared to the pedicled harvesting technique, skeletonization of the internal thoracic artery is associated with higher rate of graft failure and lower risk of SWCs without mortality difference.

Negative pressure wound therapy in patients with diabetes undergoing left internal thoracic artery harvest: A randomized control trial.

BACKGROUND: Patients with diabetes undergoing CABG are at risk of wound infection. Incisional negative pressure wound therapy has been shown to be effective in decreasing incidence of infection in high-risk wounds. Near infrared spectroscopy (NIRS) can be used to assess wound oxygenation and low values can predict infection. OBJECTIVES: To evaluate utility of NIRS to assess wound oxygenation, to assess effect of sternotomy, left internal thoracic artery harvest, and wound dressing type on wound edge oxygenation. METHODS: In this blinded randomized control trial, patients with diabetes undergoing isolated coronary artery bypass grafting with a left internal thoracic artery were randomized to receive either incisional negative pressure wound therapy dressing or a standard dressing. NIRS measurements were made on the left upper arm (control), and left and right parasternal regions on day -1 (preoperative), day 5, and week 6 after surgery. Results were analyzed using repeated measures parametric methods. RESULTS: Eighty patients with diabetes were recruited, 40 to the incisional negative pressure wound therapy group and 40 to the standard dressing group. Adjusted NIRS readings dropped significantly in all patients by day 5 and partially recovered by week 6. In both groups, there was no difference between readings on the left and right. At all time points and on both sides, there was no difference in readings between patients in the 2 groups. CONCLUSIONS: NIRS can be used to assess oxygenation adjacent to a sternotomy wound. Adjusted tissue oxygen levels change with time after sternotomy and left internal thoracic artery harvest in patients with diabetes. Wound dressing type does not influence day 5 wound edge oxygenation.