Internal mammary artery perforator flap in the management of tracheoesophageal fistulae

BACKGROUND

A pathological communication between the trachea and oesophagus - a tracheoesophageal fistula - may be congenital or acquired, benign or malignant, necessitating a multidisciplinary approach. Conservative attempts at closure of this abnormal connection are ineffective; the interposition of healthy vascular tissue offers the least chance of recurrence.

METHODS

Outcomes of an islanded fasciocutaneous internal mammary artery perforator flap applied for tracheoesophageal fistula management were assessed in four radiated patients with laryngeal carcinoma using retrospective records.

RESULTS

Four male patients, with an average age of 60.75 years, underwent tracheoesophageal fistula closure between September 2017 and February 2021. A left-sided second internal mammary artery perforator flap was used in all cases, with an average dimension of 10.5 × 4.5 cm. There were no complications of tracheoesophageal leak, flap issues or donor site morbidity on follow up.

CONCLUSION

Recent advances in angiosomal territory mapping and microvascular dissection techniques, combined with an understanding of tracheoesophageal fistula pathology, have changed management perspectives in these difficult-to-treat patients.

Performance of left internal thoracic artery-left anterior descending artery anastomosis by residents versus attendings and coronary artery bypass grafting outcomes

OBJECTIVES

Performance of a technically sound left internal thoracic artery to left anterior descending artery (LITA-LAD) anastomosis during coronary artery bypass grafting (CABG) is critically important. We used prospectively collected data from the multicentre, randomized REGROUP (Randomized Endograft Vein Perspective) trial to investigate CABG outcomes based on whether a resident or an attending surgeon performed the LITA-LAD anastomosis.

METHODS

This was a post hoc subanalysis of the REGROUP trial, which randomized veterans undergoing isolated on-pump CABG to endoscopic versus open vein harvest from 2014 through 2017. The primary end point was major cardiac adverse events, defined as the composite of all-cause deaths, nonfatal myocardial infarctions or repeat revascularizations.

RESULTS

Among 1,084 patients, 344 (31.8%) LITA-LAD anastomoses were performed by residents and 740 (68.2%), by attending surgeons. Residents (compared to attendings) operated on fewer patients with high tercile SYNTAX scores (22.1% vs 37.4%, P < 0.001), performed fewer multiarterial CABGs (5.2% vs 14.6%, P < 0.001) and performed more anastomoses to distal targets with diameters > 2.0 mm (19.0% vs 10.9%, P < 0.001) and non-calcified landing zones (25.1% vs 21.6%, P < 0.001). During a median observation time of 4.7 years (interquartile range 3.84-5.45), major cardiac adverse events occurred in 77 patients (22.4%) in the group treated by residents and 169 patients (22.8%) in the group treated by attendings (unadjusted HR 1.00; 95% confidence interval, 0.76-1.33; P = 0.99). Outcomes persisted on adjusted analyses.

CONCLUSIONS

Based on this REGROUP trial subanalysis, under careful supervision and with appropriate patient selection, LITA-LAD anastomoses performed by the residents yielded clinical outcomes similar to those of the attendings.

Transient time flow measurement in arterial grafts

Coronary artery bypass grafting (CABG) is one of the foundations of treatment for coronary artery disease. While it has improved substantially since its inception more than 50 years ago, including a rising use of multiple arterial grafting, intraoperative quality assessment is yet to be disseminated as an integral part of the procedure. Herein we review the fundamentals of intraoperative quality assessment in CABG using transient time flow measurement (TTFM) with a focus on its use in arterial grafting.

Radial artery vs right internal mammary artery as a second conduit during coronary artery bypass grafting

OBJECTIVE

To compare the clinical outcomes of radial artery (RA) grafts during CABG to those of right internal mammary artery (RIMA) grafts.

METHODS

This was a retrospective, single-institution cohort study of isolated CABG with multiple grafts between 2010-2022. To balance graft cohorts, propensity score matching (PSM) was performed using a 1:1 match ratio. Long-term postoperative survival was compared among RA and RIMA groups. Similarly, major adverse cardiac and cerebrovascular events (MACCE) were compared among both cohorts, with MACCE comprising death, myocardial infarction (MI), coronary revascularization, and stroke. Kaplan-Meier estimation was performed for mortality, while cumulative incidence estimation was utilized for MACCE.

RESULTS

A total of 8,774 patients underwent CABG. Of those, 1,674 (19.1%) patients who underwent multiarterial CABG were included in this analysis. 326 (19.5%) patients received RA grafts and 1,348 (80.5%) received RIMA grafts. PSM yielded a cohort of 323 RA patients and 323 RIMA patients. After matching, groups were well-balanced across all baseline variables. No significant differences were observed in immediate postoperative complications or long-term survival, with 5-year survival estimates of 89.5% for the RA group vs 90.1% for the RIMA group. There was a nonsignificant trend toward a higher incidence of MACCE at 5 years in the RA group compared to the RIMA group (31.3% in the RA group vs 24.1% in the RIMA group), especially after 1-year follow-up (21.6% in the RA group vs 15.1% in the RIMA group). Specifically, for RA patients, there were higher rates of repeat revascularization in the 5-year postoperative period (14.7% in the RA group vs 5.3% in the RIMA group), particularly in the territory revascularized by the RA during the index operation (45.7% in the RA group vs 10.3% in the RIMA group).

CONCLUSION

Overall, RA and RIMA secondary conduits for CABG were associated with comparable immediate postoperative complications, 5-year MACCE, and 5-year survival after PSM. RA grafting was associated with significantly higher rates of repeat coronary revascularization at 5 years, specifically in the territory revascularized by the RA during the index operation.

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.

Long-term observational angiographic patency and perfect patency of radial artery compared with saphenous vein or internal mammary artery in coronary bypass surgery

OBJECTIVES

It is uncertain if the long-term biological behavior of the radial artery as a conduit for coronary bypass surgery has a similar resistance to the development of atherosclerosis as for the internal mammary artery. We aimed to examine long-term angiographic patency and disease-free patency (perfect patency) for internal mammary artery, radial artery, and saphenous vein grafts.

METHODS

A retrospective, single-center, individual patient cohort study of angiographic observations from patients' latest postoperative angiogram from 1997 to 2020 was performed. Analysis was per anastomosis and assessed for patency and perfect patency. A generalized linear mixed model premised upon logistic regression was used to minimize confounding bias.

RESULTS

A total of 983 patients with 3064 grafts were included, with a median follow-up of 8.6 (interquartile range, 4.4-12.6) years after the operation. Multivariable analysis revealed differences for radial (patency, 86.9%; perfect patency, 86.4%) and internal mammary artery (patency, 93.9%; perfect patency, 93.5%) versus saphenous vein graft (patency, 72.8%; perfect patency, 46.2%). There were no differences between the 2 arterial conduits for patency (odds ratio, 1.40; 95% CI, 0.85-2.33; P = .189) and perfect patency (odds ratio, 1.14; 95% CI, 0.71-1.84; P = .578). If a conduit was patent, then 99.4% of radial artery, 99.6% of internal mammary artery, and 63.5% of saphenous vein graft were reported as perfectly patent.

CONCLUSIONS

Radial artery and internal mammary artery had similar patency and perfect patency while both were superior to saphenous vein graft.

Comparative Analysis of Coronary Artery Bypass Grafting Outcomes in Women Using Different Conduits in the National UK Data Set

BACKGROUND

There is limited report of outcomes in women undergoing isolated coronary artery bypass grafting (CABG) with left internal thoracic artery and different second conduits (saphenous vein graft [SVG], radial artery [RA], and right internal thoracic artery [RITA]).

METHODS

The National Adult Cardiac Surgery Audit database was queried for women undergoing isolated CABG with left internal thoracic artery graft in the United Kingdom from 1996 to 2019. Propensity score-based pairwise comparisons were performed between graft types. The primary outcome was in-hospital mortality.

RESULTS

The study included 58,063 women (SVG, n = 48,881 [84.2%]; RA, n = 6136 [10.6%]; RITA, n = 2445 [4.2%]). SVG use was stable over the years; RA and RITA use decreased. In-hospital mortality was similar between the RA and RITA grafts (2.3% vs 2.8%; odds ratio [OR], 0.80; 95% CI, 0.53-1.22; P = .39) and between the RA and SVG (2.3% vs 2.0%; OR, 1.20; 95% CI, 0.93-1.55; P = .17) but higher in the RITA group compared with the SVG (2.7% vs 1.4%; OR, 2.04; 95% CI, 1.27-3.36; P = .004). Women receiving the RITA graft were more likely to have sternal wound infection (SWI) compared with the RA (0.6% vs 0.06%; P = .004) and the SVG (0.6% vs 0.2%; P = .032). SWI was consistently associated with higher risk of in-hospital mortality.

CONCLUSIONS

Conduit selection may affect operative outcomes in women undergoing CABG. The RA shows similar mortality and risk of deep SWI as the SVG.

Saphenous vein to the right coronary system from the right thoracic artery or the aorta. Long-term propensity-matched results of 2 groups

OBJECTIVES

Since 2000, we anastomosed the saphenous vein graft to the right coronary artery system using the stump of the right internal thoracic artery as inflow. The long-term results of patients where the right coronary artery was grafted with the right internal thoracic artery or the ascending aorta as saphenous vein inflow has not been reported.

METHODS

From 2000 to 2018, 699 consecutive patients had right internal thoracic artery elongated with saphenous vein (I-graft group, n = 358, 51.2%) or saphenous vein from the aorta (Ao-graft group, n = 341, 48.8%) on right coronary artery system. Inclusion criteria were age ≤75 years, bilateral internal thoracic arteries as a Y graft on the left system (three-vessel disease, n = 603, 86.3%) or as a left internal thoracic artery on left anterior descending and right internal thoracic artery elongated with saphenous vein on the right coronary artery system (two-vessel disease, n = 96, 13.7%), only 1 saphenous vein per patient. Propensity-matching identified 272 patients per group. One-hundred and twenty-two patients underwent coronary computed tomographic angiography to asses grafts patency after a median follow-up of 88 (65-93) months.

RESULTS

In the paired samples, there was no difference in the early outcome. Ten-year survival and freedom from death, non-fatal acute myocardial infarction and repeat revascularization were higher in I-graft group: 90.6 [standard error (SE): 2.0] vs 78.2 (SE: 5.3), P = 0.0266, and 85.2 (SE: 2.4) vs 69.9 (SE: 5.3), P = 0.0179. Saphenous vein graft, at a long-time follow-up, showed a higher patency rate (81.6% (SE: 7.0) vs 50.7% (SE: 7.9), P < 0.0001) and a smaller internal lumen diameter (2.7, standard deviation: 0.4 vs 3.4, standard deviation: 0.6 mm, P < 0.0001) when right internal thoracic artery was the inflow.

CONCLUSIONS

Grafting the right coronary artery with saphenous vein may entail higher patency rate and better outcome when the inflow is the right internal thoracic artery than when is the ascending aorta. Prospective randomized data are needed to test this hypothesis.

Effect of right internal mammary artery versus radial artery as a second graft vessel in coronary artery bypass grafting on postoperative wound infection in patients: A meta-analysis

Few studies have shown that radial artery (RA), which is used as a secondary arterial graft, offers superior results compared with right internal thoracic artery (RIMA) in coronary artery bypass grafting (CABG). In a meta-analysis of observational studies starting in 2023, we looked at the effect of re-operation on postoperative infection and haemorrhage in CABG with RA vs. RIMA. The electronic database up to October 2023 was examined in the course of the research. Analysis was carried out on the clinical trials of postoperative wound infections and haemorrhage re-surgery. Among 912 trials associated with CABG, we selected 8 trials to be included in the final data analysis. The main results were secondary wound infection and re-operation after surgery. The odds ratios (OR) and confidence intervals (CIs) were computed on the basis of a randomized or fixed-effect model of wound infection and re-operation. Seven trials showed a significant reduction in the risk of wound infection in RA treated as a secondary artery transplant compared with RIMA (OR, 1.60; 95% CI, 1.03, 2.47 p = 0.04); Four trials showed that RIMA was not significantly different from RA in the rate of re-operation for postoperative bleeding (OR, 1.31; 95% CI, 0.60, 2.88 p = 0.50). In CABG, RA is used as a secondary arterial conduit graft to lower the risk of wound infection in CABG patients.

Single versus bilateral internal thoracic artery grafting in patients with impaired renal function

OBJECTIVE

The optimal strategy for surgical revascularization in patients with impaired renal function is inconclusive. We compared early and late outcomes between bilateral internal thoracic artery (BITA) and single ITA (SITA) grafting in patients with renal dysfunction.

METHODS

This is a retrospective analysis of all the patients with multivessel disease and impaired renal function (estimated glomerular filtration rate <60mL/min/1.73m2) who underwent isolated coronary artery bypass graft (CABG) in our center during 1996-2011, utilizing either BITA or SITA revascularization.

RESULTS

Of the 5301 patients with multivessel disease who underwent surgical revascularization during the study period, 391 were with impaired renal function: 212 (54.2%) underwent BITA, 179 (45.8%) underwent SITA. Patients who underwent BITA were less likely to have comorbidities. Statistically significant differences were not observed between the BITA and SITA groups in 30-day mortality (5.6% vs. 9.0%, p = 0.2) and in rates of early stroke, myocardial infarction, and sternal infection (4.5% vs. 6.1%, p = 0.467; 1.7% vs. 2.8%, p = 0.517; and 2.2% vs. 5.7%, p = 0.088, respectively). Long-term survival of the BITA group was better: median 8.36 vs. 4.14 years, p<0.001. In multivariable analysis, BITA revascularization was associated with decreased late mortality (HR = 0.704, 95% CI: 0.556-0.89, p = 0.003). In analysis of a matched cohort (134 pairs), early outcomes did not differ between the groups; however, in multivariable analysis, BITA revascularization was associated with decreased late mortality ‎‎(HR = 0.35 (95%CI 0.18-0.68), p = 0.002)‎.

CONCLUSIONS

BITA revascularization did not impact early outcome in patients with CRF, but demonstrated a significant protective effect on long-term survival ‎in the unmatched and matched cohorts.

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.

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.

Very Long-term Outcome of Bilateral Internal Thoracic Artery in Diabetic Patients: A Systematic Review and Reconstructed Time-To-Event Meta-analysis

The benefits of single (SITA) and bilateral internal thoracic arteries (BITA) in diabetics undergoing coronary bypass grafting (CABG) are conflicting. We undertook a study-level meta-analysis to compare early and long-term outcomes of both CABG configurations. PubMed, CENTRAL, and EMBASE were searched for studies comparing BITA versus SITA for isolated CABG surgery in diabetics. Randomized trials or observational studies were considered eligible for the analysis. Kaplan-Meier curves of long-term survival were reconstructed and compared with Cox linear regression; incidence rate ratios (IRR) with 95% confidence intervals (CI) for long-term survival were calculated. Landmark analysis and time-varying hazard ratio (HR) were analyzed. Odds ratios (OR) were extracted for early mortality, postoperative stroke, deep sternal wound infection (DSWI), and myocardial infarction (MI). A random effects meta-analysis was performed. Sensitivity analyses included leave-one-out-analyses and meta-regression. Thirteen studies (7332 patients) were included. Overall, at 20-year follow-up, BITA was associated with higher survival (HR = 0.77; 95% CI, 0.71-0.84; P < 0.0001). Time-varying HR and landmark analysis reported BITA was associated with a higher rate of 10-year survival (HR = 0.75, 95% CI 0.68-0.82, P < 0.0001), while from 10 to 20-year follow-up no difference was revealed (HR = 0.99, 95% CI 0.82-1.19, P = 0.93). There was no increase in early mortality, postoperative MI, stroke, or DSWI between the groups. At meta-regression, the higher the age, the higher the long-term overall survival in patients with BITA. In diabetics, the BITA approach is associated with improved 10-year survival with no increase in early mortality, MI, stroke, or DSWI. In the 10-20-year timeframe, BITA and SITA showed comparable survival.

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.

Sternal wound infections following internal mammary artery grafts for a coronary bypass: A meta-analysis

The meta-analysis aims to evaluate and compare the sternal wound infections following internal mammary artery grafts for a coronary bypass. Examinations comparing bilateral internal mammary artery to single internal mammary artery for coronary artery bypass grafting were among the meta-analyses from various languages that met the inclusion criteria. Using dichotomous random- or fixed-effect models, the results of these investigations were examined, and the Odd Ratio (OR) with 95% confidence intervals (CIs) was computed. A total of 31 examinations from 2001 to 2023 were recruited for the current analysis including 181 503 personals with coronary artery bypass grafting. Bilateral internal mammary artery had significantly higher sternal wound infection (OR, 1.51; 95% CI, 1.37-1.68, p < 0.001), superficial sternal wound infection (OR, 1.72; 95% CI, 1.16-2.56, p = 0.007), deep sternal wound infection (OR, 1.62; 95% CI, 1.41-1.86, p < 0.001), sternal wound infection in diabetics (OR, 1.48; 95% CI, 1.16-1.90, p = 0.002), sternal wound infection in elderly (OR, 1.38; 95% CI, 1.22-1.57, p < 0.001), sternal wound infection in pedicled preparation (OR, 1.70; 95% CI, 1.30-2.23, p < 0.001) and sternal wound infection in skeletonized preparation (OR, 1.40; 95% CI, 1.09-1.81, p = 0.009) compared to single internal mammary artery in personals with coronary artery bypass grafting. Bilateral internal mammary artery grafting is linked to a higher risk of impaired wound healing, particularly in diabetic individuals, elderly, pedicled preparation, and skeletonized preparation. Nevertheless, caution should be exercised while interacting with its values since examinations were performed by different surgeons with different skills on different types of personals.

Comparing the patency of the left internal mammary in single, sequential, and Y grafts

BACKGROUND

To maximize arterial grafts, left internal mammary (LIMA) sequential and Y grafts are used. The aim is to compare the angiographic patency of the LIMA in these configurations.

METHODS

Between 2002 and 2020, angiography was performed on 1000 patients who either had a single (570), sequential (100), or LIMA y (129) graft. The LIMA was divided into segments (S); S1: LIMA inflow to the first anastomosis, S2: terminal portion of the LIMA to left anterior descending (LAD), and S3; the y-limb anastomosis to a coronary. S1 and S2 patency analysis was carried out with logistic regression.

RESULTS

Failure of the S1 and S2 was 3.7% single, 9% sequential, and 6.2 Y graft (P = .049). Segment 1 failed in 3.7% in single, 5% in sequential, and 0.8% in Y grafts (P = .049). Segment 3 failure was 10.3%. Regression revealed female sex and sequential grafts were associated with decreased S1 and S2 patency.

CONCLUSIONS

Single grafts have the best patency. Failure in sequential grafts leads to increased occlusion of the LIMA inflow, whereas Y-graft failure tends to occlude the y limb. When arterial conduit is sparse, a Y graft should be considered.

Skeletonized versus Pedicled harvesting of internal mammary artery: A systematic review and Meta-analysis

There are two recognized internal mammary artery (IMA) harvesting techniques during coronary artery bypass grafting (CABG): pedicled and skeletonized. This systematic review and meta-analysis sought to compare the clinical outcomes of the two harvesting techniques. A comprehensive electronic literature search of PubMed, Scopus, and Embase was conducted from inception till June 2023. Thirty-one studies with a total of 13005 patients met our inclusion criteria. The results from the included studies were presented as weighted mean difference (WMD) with its relevant standard deviation (SD) for continuous variables, while Odds Ratio (OR) was used for dichotomous variables. A 95% confidence interval (CI) was used, and the results were pooled using a random effects model. The skeletonized IMA demonstrated a significantly reduced risk of sternal wound infection (SWI) compared to the pedicled IMA (OR = 0.45 [95% CI, 0.32-0.66]; p = 0.0001). The conduit length used was significantly longer in the skeletonized IMA (WMD -2.48, 95% CI, [-3.75, -1.20], P = 0.0001) and a significantly higher postoperative flow rate was observed while using skeletonization compared to the pedicled harvesting (WMD -13.11, 95% CI, [-22.52, -3.70], P = 0.006). However, no significant difference was seen in mortality between the two techniques (OR = 1.19 [95% CI, 1.00-1.41]; p = 0.05). Pedicled harvesting demonstrated significantly reduced incidents of MI (OR = 1.38 [95% CI, 1.13-1.69]; p = 0.002), while significant results in graft patency were observed favoring pedicled harvesting over skeletonization (OR = 0.63 [95% CI, 0.40-0.98]; p = 0.04).

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.

Coronary Artery Bypass Surgery to Treat Anomalous Origin of Coronary Arteries in Adults: A Systematic Review

OBJECTIVE

To review the available literature on the use of coronary artery bypass grafting (CABG) as a treatment option for anomalous origin of coronary artery in adults.

METHODS

A systematic literature search was performed in March 2023 (including Ovid MEDLINE, Ovid Embase, and the Cochrane Library databases) to identify studies reporting the use of CABG in adult patients with anomalous origin of coronary artery.

RESULTS

A total of 31 studies and 62 patients were included, 32 patients (52%) were women, and the mean age was 45.1±16.1 years. The most common coronary anomaly was the right coronary artery arising from the left coronary sinus in 26 patients (42%), followed by an anomalous left coronary artery from the pulmonary artery in 23 patients (37%). A total of 65 conduits were used in 61 patients, and 1 case report did not report conduit type. Reported grafts included saphenous vein (23 of 65 [35.4%]), left internal thoracic artery (15 of 65 [23.1%]), right internal thoracic artery (23 of 65 [35.4%]), and radial artery (2 of 65 [3.1%]); right gastroepiploic artery and basilic vein were used once (1.5%) each. Ligation of the native coronary artery was performed in 42 (67.7%) patients. Patient follow-up was available in 19 studies with a mean of 31.2 months. Only 1 operative mortality was reported.

CONCLUSIONS

Based on the limited available data, CABG can be performed with good early results. Use of arterial conduits and ligation of the native coronary artery may improve long-term graft patency.

Thoracoscopic (non-robotic) harvesting of bilateral internal mammary artery grafts

Minimally invasive coronary surgery offers benefits to the patient. Harvesting the internal mammary artery remains a challenging part of this procedure. We describe our technique for thoracoscopic harvesting of the left and right mammary arteries using routine endoscopic instruments. This is a non-robotic technique that might facilitate a more widespread growth of minimally invasive coronary surgery.

Robotic Totally Endoscopic Coronary Bypass to the Left Anterior Descending Artery: Left Versus Right Internal Thoracic Artery Grafts

INTRODUCTION

The left internal thoracic artery (LITA) is most commonly used to bypass the left anterior descending artery (LAD) given its well-established mortality benefit. In some cases, the grafting strategy necessitates placing the right internal thoracic artery (RITA) on the LAD. We compared outcomes in our robotic beating-heart totally endoscopic coronary bypass surgery (TECAB) population between patients receiving LITA versus RITA-LAD grafts.

METHODS

We retrospectively reviewed patients undergoing robotic TECAB with skeletonized ITA conduits over 9 y. Outcomes were compared between those receiving LITA (Group-1) versus RITA (Group-2) grafts to the LAD (with/without other grafts). End points were early angiographic patency (in patients undergoing hybrid revascularization) and mid-term mortality/major adverse cardiac/cerebrovascular events. A propensity matched subanalysis was performed comparing only patients who received bilateral ITA grafting in each group.

RESULTS

Society of Thoracic Surgeons predicted mortality risk score was higher in Group-2. Group-1 patients had lower incidence of multivessel disease (75% versus 96%, P ≤ 0.001). Early overall graft patency (97% versus 96%, P = 0.718) and LAD graft patency (98% versus 95%, P = 0.372) were equivalent. At mean 42-mo follow-up (longest 8.5 y), Group-1 had lower all-cause mortality but no difference in cardiac mortality or repeat revascularization. In the propensity matched subanalysis, mid-term outcomes were equivalent.

CONCLUSIONS

Grafting the LAD with the LITA or RITA during robotic beating-heart TECAB resulted in similar early outcomes and angiographic patency. RITA-LAD patients were more likely to have multivessel disease and higher Society of Thoracic Surgeons risk and had higher all-cause mortality at mid-term analysis but no difference in major adverse cardiac/cerebrovascular events, including cardiac mortality.

Internal thoracic artery graft failure and recurrence of symptoms following single-vessel coronary artery bypass graft surgery

OBJECTIVES

Coronary events and disease recurrence following coronary artery bypass (CABG) surgery could derive from either failure in the internal thoracic artery (ITA) graft, failure in other conduits or progressive disease in the coronaries. We aim to estimate the contribution of ITA graft failure to the recurrence of symptoms after CABG surgery.

METHODS

Within the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies registry, we identified patients who had coronary artery bypass grafting from 1997 to 2020 with a single-vessel ITA graft bypass. Deaths, postoperative incidence of coronary angiography and the presence of a failed graft at the time of the angiography were recorded.

RESULTS

The study population consisted of 1939 patients with a mean follow-up time (SD) of 17.2 (5.6) years. The cumulative incidence (95% CI) at 20 years for a first clinically-driven postoperative angiography was 38.6% (36.2-41.1). A failed ITA graft was reported in 16.4% of the angiographies.

CONCLUSIONS

A substantial part of recurrent symptoms of coronary artery disease do not seem to be related to ITA failure. Disease progression in the native coronary vessels may instead be the main driver of symptom recurrence.

Blood flow characteristics of the bilateral internal thoracic artery: implications of optimal graft configuration for coronary artery bypass grafting to maximize blood supply

PURPOSE

There is controversy regarding which internal thoracic artery (ITA) should be anastomosed to the left anterior descending artery (LAD). Here, we propose an optimal graft design based on measurement of blood flow in the ITA.

METHODS

Sixty-one patients (53 men, median age 68 [62-75] years) undergoing first elective coronary artery bypass grafting were enrolled. Fifty-seven left ITAs (LITAs) and 28 right ITAs (RITAs) were harvested in either a semi-skeletonized manner using a harmonic scalpel covered with papaverine-soaked gauze (group-A, n = 45) or a fully skeletonized manner using electrocautery with intraluminal papaverine injection (group-B, n = 41). Free flow of 33 ITAs was measured after pharmacological dilatation and in situ ITA-LAD flow was measured in 59 patients by transit-time flowmetry.

RESULTS

RITA and LITA free flow were 147.0 [87.8-213.0] mL/min and 108.0 [90.0-144.0] mL/min, respectively (P = 0.199). The group-B had significantly higher ITA free flow (135.0 [102.0-171.0] mL/min) than group-A (63.0 [36.0-96.0] mL/min, P = 0.009). In 13 patients with bilateral ITA harvesting, free flow of the RITA (138.0 [79.5-204.0] mL/min) was also significantly higher than the LITA (102.0 [81.0-138.0] mL/min, P = 0.046). There was no significant difference between RITA and LITA flow anastomosed to the LAD. The group-B had significantly higher ITA-LAD flow (56.5 [32.3-73.6] mL/min) than group-A (40.9 [20.1-53.7] mL/min, P = 0.023).

CONCLUSION

RITA provides significantly higher free flow than LITA but similar blood flow to the LAD. Full skeletonization with intraluminal papaverine injection maximizes both free flow and ITA-LAD flow.

Twenty-year outcomes of free and I-composite radial artery grafts for coronary artery revascularization

PURPOSE

To compare the 20-year outcomes of coronary artery grafting (CABG) using radial artery (RA) grafts (free and I-composite) and internal thoracic artery (ITA) grafts.

METHODS

Long-term graft patency was evaluated in patients who underwent isolated CABG between August, 1996 and January, 2022. The long-term graft patency of free RA grafts, I-composite ITA-RA grafts, and saphenous vein (SV) grafts were compared.

RESULTS

The RA was used as a coronary bypass conduit in 111 of the 246 patients enrolled in this study. The RA patency after 10 and 20 years was 94.2% and 76.6%, respectively. Landmark analysis showed that although graft patency for up to 10 years did not differ between the RA and ITA grafts (hazard ratio = 0.87; P = 0.8), patency of the ITA grafts was better from 10 to 20 years post-surgery (hazard ratio = 0.19; P = 0.013). The 20-year graft patency of the I-composite RA grafts was better than that of the free RA grafts (80.0% vs. 72.4%; P = 0.029), but not significantly different from that of the ITA grafts (80.0% vs. 90.7%; P = 0.24).

CONCLUSIONS

The 20-year patency of the I-composite ITA-RA graft was better than that of the free RA graft; therefore, the I-composite graft may be an effective conduit for CABG.

Instantaneous wave free ratio value impact on left internal mammary artery graft patency

OBJECTIVES

To assess whether instantaneous wave - free ratio (iFR) value is associated with left internal mammary artery (LIMA) graft failure at 12 months follow-up post coronary artery bypass graft (CABG).

BACKGROUND

Data suggests bypass to a non-significant left anterior descending artery (LAD) lesion due to visual over-estimation may lead to LIMA graft failure. Implementing iFR may result in better arterial graft patency.

METHODS

In iCABG (iFR guided CABG) study patients planned to undergo an isolated CABG procedure was prospectively enrolled and iFR was performed for LAD. Coronary computed tomography angiography was performed at 2 and 12 months follow-up. The primary endpoint of this study was to determine the rate of LIMA graft occlusion or hypoperfusion at 2 and 12-months follow-up. We considered a composite secondary endpoint of Major adverse cardiovascular and cerebrovascular event (MACCE) as a secondary outcome.

RESULTS

In total 69 patients were included with no differences regarding age, sex and risk factors. At 2 months, 50 of LIMAs with pre-CABG iFR median 0.855 (0.785 - 0.892) were patent. Hypoperfusion was found in 8 LIMAs (median iFR 0.88 (0.842 - 0.90)). While, 7 LIMAs (median iFR 0.91 (0.88 - 0.96)) were occluded (p = 0.04). At 12 months, when iFR of LAD was >0.85: just 12 (31.6% out of all patent LIMAS) grafts were patent and 24 (100.0% out of all hypoperfused/occluded) grafts were hypoperfused or occluded (p < 0.001). In terms of MACCE, no difference (p = 1.0) was found between all 3 groups divided according to iFR value.

CONCLUSIONS

Instantaneous wave - free ratio value above 0.85 in LAD is a powerful tool predicting LIMA graft failure at 1-year follow up period.

Bilateral Internal Thoracic Arteries Improve 10-Year Outcomes of Coronary Artery Bypass Grafting

BACKGROUND

This observational cohort study was designed by the PRIORITY (PRedictIng long-term Outcomes afteR Isolated coronary arTery bypass surgery) steering committee to evaluate the 10-year follow-up outcome of bilateral internal thoracic arteries (BITA) versus single internal thoracic artery.

METHODS

The PRIORITY project was designed to evaluate long-term outcome of 2 large prospective multicenter cohort studies of coronary artery bypass grafting. Clinical data on isolated coronary artery bypass grafting were merged with administrative data to collect follow-up information. The primary endpoint was the composite outcome of major adverse cardiac and cerebrovascular events at 10-year follow-up. Secondary endpoints were individual components of major adverse cardiac and cerebrovascular events at 10 years and surgical site complications or infections. A propensity score-based inverse probability treatment weighting (IPTW) was used to overcome the selection bias related to the observational nature of the study.

RESULTS

The study population consisted of 10,988 patients who underwent isolated coronary artery bypass grafting. BITA was used in 23.5%. The use of BITA is related to lower incidence of major adverse cardiac and cerebrovascular events at 10 years (adjusted hazard ratio [HR] 0.88, 95% CI 0.79-0.98, P < .001). BITA correlated with better 10-year survival (IPTW adjusted HR 0.87, 95% CI 0.78-1.00, P = .05), re-revascularization (IPTW adjusted HR 0.83, 95% CI 0.74-0.92, P < .001), and myocardial infarction (IPTW adjusted HR 0.86, 95% CI 0.77-0.95, P = .005) but to increased incidence of surgical site complications or infections (HR 2.12, 95% CI 1.39-3.24, P < .001).

CONCLUSIONS

In propensity-matched patients, use of BITA was associated with improved 10-year survival, freedom from repeat revascularization, and myocardial infarction but also higher incidence of surgical site complications.

Extrapleural harvesting of the internal thoracic artery - impact on early postoperative results and pulmonary function

INTRODUCTION

The internal thoracic artery (ITA) has proven to be the best graft for surgical myocardial revascularization, especially in the configuration left ITA (LITA) to the anterior descending branch of left coronary artery (LAD). Its harvesting is usually accompanied by pleurotomy, followed by drainage tube placement into the pleural cavity, using the so called intrapleural method. Extrapleural technique for LITA harvesting is also practiced in many cardiac surgery centers and with this technique the pleura is left intact.

Differences in long-term survival outcomes after coronary artery bypass grafting using single vs multiple arterial grafts: a meta-analysis with reconstructed time-to-event data and subgroup analyses

OBJECTIVE

We reviewed the available literature on patients with coronary artery disease undergoing isolated coronary artery bypass grafting (CABG) with either single (SAG) or multiple arterial grafting (MAG).

METHODS

Original research studies that evaluated the long-term survival of MAG versus SAG were identified, from 1995 to 2022. The median overall survival (OS) and event-free OS were the primary endpoints. Comparison of median OS between the right internal mammary artery (RIMA) and radial artery (RA) as a second arterial conduit was the secondary endpoint. Subgroup analyses were performed regarding patients older than 70 years, with diabetes mellitus, and females. A sensitivity analysis was performed with the leave-one-out method.

RESULTS

Forty-four studies were included in the qualitative and thirty-nine in the quantitative synthesis. After pooling data from 180 to 459 patients, the MAG group demonstrated a higher OS (HR, 0.589; 95% CI, 0.58-0.60; p < 0.0001) and event-free OS compared with the SAG group (HR, 0.828; 95% CI, 0.80-0.86; p < 0.0001). In addition, RITA was associated with superior OS compared with RA as a second arterial conduit (HR, 0.936; 95% CI, 0.89-0.98; p = 0.009). MAG was also superior to SAG in patients over 70 years, females, and patients with diabetes mellitus. Sensitivity analysis demonstrated a small-size study effect on the female subgroup analysis.

CONCLUSION

The present meta-analysis indicates that MAG is associated with enhanced survival outcomes compared to SAG for patients undergoing isolated CABG.

Left Internal Mammary Artery as an Endocrine Organ: Insights Into Graft Biology and Long-term Impact Following Coronary Artery Bypass Grafting

The left internal mammary artery (LIMA) is considered the criterion standard vessel for use in coronary artery bypass grafting. In recent decades, countless studies have documented its superiority over other arterial and venous coronary artery bypass grafting conduits, although the full mechanisms for this superiority remain unknown. A growing body of literature has unveiled the importance of extracellular vesicles known as exosomes in cardiovascular signaling and various pathologic states. In this review, we briefly compare the clinical longevity of the LIMA relative to other conduits, explore the effects of varying grafting techniques on clinical and angiographic outcomes, and provide physiologic insights into graft function on a cellular and molecular level. Finally, we explore exosome signaling as it pertains to atherosclerosis in support of the LIMA as an "endocrine organ."

Treatment of Complex Two-Vessel Coronary Heart Disease with Single Left Internal Mammary Artery as T-Graft with Itself—A Retrospective Double Center Analysis of Short-Term Outcomes

Background and Objectives: The strategy of revascularization may be constrained in patients with insufficient bypass grafts and with increased risk of wound healing disorders. Among those with complex left-sided double-vessel disease in whom a percutaneous coronary intervention (PCI), as well as the surgical procedure of minimally invasive coronary artery bypass grafting via left minithoracotomy (MICS CABG), is not a treatment option, CABG using the left internal mammary artery as a T-graft with itself may be an effective treatment strategy. Materials and Methods: We reviewed the data from patients treated in Cologne and Tuebingen from 2019 to 2022. We included 40 patients who received left internal mammary artery (LIMA) grafting, and additional T-graft with the LIMA itself. The objective was focused on intraoperative and short-term outcomes. Results: A total of 40 patients were treated with the LIMA-LIMA T-graft procedure with a Fowler score calculated at 20.1 ± 3.0. A total of 37.5% of all patients had lacking venous graft material due to prior vein stripping, and 21 patients presented severe vein varicosis. An overall of 2.6 ± 0.5 distal anastomoses (target vessels were left anterior descending, diagonal, intermediate branch, and/or left marginal ramus) were performed, partly sequentially. Mean flow of LIMA-Left anterior descending (LAD) anastomosis was 59.31 ± 11.04 mL/min with a mean PI of 1.21 ± 0.18. Mean flow of subsequent T-Graft accounted for 51.31 ± 3.81 mL/min with a mean PI of 1.39 ± 0.47. Median hospital stay was 6.2 (5.0; 7.5) days. No incidence of postoperative wound healing disorders was observed, and all patients were discharged. There was one 30-day readmission with a diagnosis of pericardial effusion (2.5%). There was no 30-day mortality within the cohort. Conclusions: Patients requiring surgical myocardial revascularization due to complex two-vessel coronary artery disease (CAD) can be easily managed with LIMA alone, despite an elevated Fowler score and a promising outcome. A prospective study needs to be conducted, as well as longer term surveillance, to substantiate and benchmark the long-term results, as well as the patency rates.

Investigation of the effects of diabetes mellitus on left internal thoracic artery flow patterns in patients scheduled to undergo coronary bypass graft surgery

PURPOSE

Diabetes mellitus (DM) plays a key role in the formation and prognosis of cardiovascular diseases. In this study, we aimed to investigate the effects of DM and glycemic control on left internal thoracic artery (LITA) Doppler flow in patients scheduled to undergo coronary artery bypass graft (CABG) surgery.

METHODS

Patients who were hospitalized with a planned isolated CABG operation to our clinic between October 1, 2019 and March 1, 2020 were consecutively included in this prospective study. The patients were divided into three groups as those without DM (Group 1), those with DM and HbA1c values of below 7.5 (Group 2), and those with DM and HbA1c values of 7.5 and above (Group 3). The differences between the LITA Doppler flow patterns of the patients were analyzed.

RESULTS

The mean ages of Group 1 (n = 103), Group 2 (n = 42), and Group 3 (n = 47) were 59.8 ± 9.6 years, 60.5 ± 9.3 years, and 61.9 ± 8.1 years, respectively. The groups differed in terms of diameter, volume, Vmax, pulsality index (PI), and resistive index (RI) values, both when the groups were compared among themselves (P < .001, for all), and when they were compared between those with (Groups 2 and 3) and without DM (Group 1) (P < .001, for all). Volume (R = -0.627, P < .001) and Vmax (R = -.450, P < .001) were moderately negatively correlated, while PI (R = .523, P < .001) and RI (R = 0.598, P < 0.001) were moderately positively correlated with HbA1c levels.

CONCLUSION

In this study, we showed that increased HbA1c levels may be associated with significant functional and structural changes of LITA.

Cost-effectiveness of bilateral vs. single internal thoracic artery grafts at 10 years

AIMS

Using bilateral internal thoracic arteries (BITAs) for coronary artery bypass grafting (CABG) has been suggested to improve survival compared to CABG using single internal thoracic arteries (SITAs) for patients with advanced coronary artery disease. We used data from the Arterial Revascularization Trial (ART) to assess long-term cost-effectiveness of BITA grafting compared to SITA grafting from an English health system perspective.

METHODS AND RESULTS

Resource use, healthcare costs, and quality-adjusted life years (QALYs) were assessed across 10 years of follow-up from an intention-to-treat perspective. Missing data were addressed using multiple imputation. Incremental cost-effectiveness ratios were calculated with uncertainty characterized using non-parametric bootstrapping. Results were extrapolated beyond 10 years using Gompertz functions for survival and linear models for total cost and utility. Total mean costs at 10 years of follow-up were £17 594 in the BITA arm and £16 462 in the SITA arm [mean difference £1133 95% confidence interval (CI) £239 to £2026, P = 0.015]. Total mean QALYs at 10 years were 6.54 in the BITA arm and 6.57 in the SITA arm (adjusted mean difference -0.01 95% CI -0.2 to 0.1, P = 0.883). At 10 years, BITA grafting had a 33% probability of being cost-effective compared to SITA, assuming a cost-effectiveness threshold of £20 000. Lifetime extrapolation increased the probability of BITA being cost-effective to 51%.

CONCLUSIONS

BITA grafting has significantly higher costs but similar quality-adjusted survival at 10 years compared to SITA grafting. Extrapolation suggests this could change over lifetime.

Use of a Novel Catheter, the MOT-C, for Selective Angiography of the Internal Mammary Artery From Ipsilateral Radial Access

OBJECTIVE

We describe a novel catheter, the MOT-C (Merit Medical Systems), for selective diagnostic angiography of the internal mammary artery from radial access.

METHODS

We analyzed the pattern of radial versus femoral access for bypass angiography at our institution between 2012 and 2020. We also examined the difference in contrast volume and fluoroscopy time between radial and femoral access and between MOT-C and traditional internal mammary artery (IMA) catheter for bypass angiography.

RESULTS

Since the introduction of MOT-C catheter to our laboratory in 2016, there has been a 1.5-fold increase in the use of radial access for bypass angiography. No significant difference in contrast volume or fluoroscopy time was noted between radial and femoral access for bypass angiography. The MOT-C catheter was successfully used in 46% of all cases and 77% of all radial cases between 2016 and 2020 to selectively engage the IMA. When compared with the traditional IMA catheter, no statistically significant difference was noted in contrast volume or fluoroscopy time with the use of MOT-C for bypass angiography, although there was a trend toward lower contrast use. Furthermore, no catheter-related complications occurred.

CONCLUSIONS

The MOT-C facilitates improved engagement of IMA grafts with minimal manipulation and allows for high-quality diagnostic angiograms with a potential decrease in contrast volume compared with the more traditionally used IMA catheter.

OUP accepted manuscript

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was ‘What is the best choice for third conduit when using bilateral internal mammary arteries for coronary artery bypass grafting—radial artery or saphenous vein graft?’. Altogether >525 papers were found using the reported search, of which 7 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Overall, there was no survival benefit demonstrated with the use of a radial artery over the use of a saphenous vein graft as a choice of third conduit following bilateral internal mammary artery grafts for coronary artery bypass grafting. The main limitation of the current evidence available is the restricted follow-up periods and the high attrition rates with small sample sizes affecting the strength of conclusions that can be drawn beyond 10 years of follow-up. We conclude that despite previous evidence supporting improved long-term patency of radial arterial grafts, there is no strong evidence that the use of a radial artery, over a saphenous vein graft, has any survival benefit when used as the third conduit following bilateral internal mammary artery grafts.

Comparison of Long-Term Outcomes Following Coronary Revascularization in Men-vs-Women with Unprotected Left Main Disease

Gender differences have been recognized in several aspects of coronary artery disease (CAD). However, evidence for gender differences in long-term outcomes after left main coronary artery (LMCA) revascularization is limited. We sought to evaluate the impact of gender on outcomes after percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) for unprotected LMCA disease. We evaluated 4,320 patients with LMCA disease who underwent CABG (n = 1,456) or PCI (n = 2,864) from the Interventional Research Incorporation Society-Left MAIN Revascularization registry. The primary outcome was a composite of death, myocardial infarction (MI), or stroke. Among 4,320 patients, 968 (22.4%) were females and 3,352 (77.6%) were males. Compared to males, females were older, had a higher prevalence of hypertension and insulin-requiring diabetes, more frequently presented with acute coronary syndrome, but had less extensive CAD and less frequent left main bifurcation involvement. The adjusted risk for the primary outcome was not different after PCI or CABG in females and males (hazard ratio [HR] 1.09; 95% confidence interval [CI]: 0.73-1.63 and HR 0.97; 95% CI: 0.80-1.19, respectively); there was no significant interaction between gender and the revascularization strategy (P for interaction = 0.775). In multivariable analysis, gender did not appear to be an independent predictor for the primary outcome. In revascularization for LMCA disease, females and males had a comparable primary composite outcome of death, MI, or stroke with either CABG or PCI without a significant interaction of gender with the revascularization strategy.

Resilience of the Internal Mammary Artery to Atherogenesis: Shifting From Risk to Resistance to Address Unmet Needs

Fueled by the global surge in aging, atherosclerotic cardiovascular disease reached pandemic dimensions putting affected individuals at enhanced risk of myocardial infarction, stroke, and premature death. Atherosclerosis is a systemic disease driven by a wide spectrum of factors, including cholesterol, pressure, and disturbed flow. Although all arterial beds encounter a similar atherogenic milieu, the development of atheromatous lesions occurs discontinuously across the vascular system. Indeed, the internal mammary artery possesses unique biological properties that confer protection to intimal growth and atherosclerotic plaque formation, thus making it a conduit of choice for coronary artery bypass grafting. Its endothelium abundantly expresses nitric oxide synthase and shows accentuated nitric oxide release, while its vascular smooth muscle cells exhibit reduced tissue factor expression, high tPA (tissue-type plasminogen activator) production and blunted migration and proliferation, which may collectively mitigate intimal thickening and ultimately the evolution of atheromatous plaques. We aim here to provide insights into the anatomy, physiology, cellular, and molecular aspects of the internal mammary artery thereby elucidating its remarkable resistance to atherogenesis. We propose a change in perspective from risk to resilience to decipher mechanisms of atheroresistance and eventually identification of novel therapeutic targets presently not addressed by currently available remedies.

Is Internal Mammary to the Anterior Descending Always the Best Option?

The left internal mammary artery (LIMA) is the gold standard conduit used to revascularize the left anterior descending artery and has consistently been shown to be associated with better survival, graft patency, and freedom from cardiac events compared with other used conduits. Evaluation of LIMA flow and anatomy is not routinely done by the interventional cardiologist while performing the left heart catheterization. We present a case where the LIMA was found to be the major blood supply to the left leg, which might have led to leg ischemia if the LIMA had been used as graft.

Predictors and In-Hospital Outcomes Among Patients Using a Single Versus Bilateral Mammary Arteries in Coronary Artery Bypass Grafting

The benefit of bilateral mammary artery (BIMA) use during coronary artery bypass grafting (CABG) continues to be debated. This study examined nationwide trends in BIMA use and factors influencing its utilization. Using the National Inpatient Sample, adults undergoing isolated multivessel CABG between 2005 and 2015 were identified and stratified based on the use of a single mammary artery or BIMA. Regression models were fit to identify patient and hospital level predictors of BIMA use and characterize the association of BIMA on outcomes including sternal infection, mortality, and resource utilization. An estimated 4.5% (n = 60,698) of patients underwent CABG with BIMA, with a steady increase from 3.8% to 5.0% over time (p<0.001). Younger age, male gender, and elective admission, were significant predictors of BIMA use. Moreover, private insurance was associated with higher odds of BIMA use (adjusted odds ratio 1.24) compared with Medicare. BIMA use was not a predictor of postoperative sternal infection, in-hospital mortality, or hospitalization costs. Overall, BIMA use remains uncommon in the United States despite no significant differences in acute postoperative outcomes. Several patient, hospital, and socioeconomic factors appear to be associated with BIMA utilization.

Feasibility of bilateral internal thoracic artery harvesting using the da Vinci SP system

PURPOSE

We conducted this study to investigate the feasibility of mobilizing the bilateral internal thoracic arteries (ITAs) using the da Vinci SP through a single intercostal incision and to compare the amount of rib spreading with that required for mini-thoracotomy procedures. We also evaluated the construction of an intrathoracic T-graft anastomosis using existing instrumentation of the SP system.

METHODS

We harvested bilateral ITAs from two male cadavers via a single incision made in the fifth intercostal space using the da Vinci SP. A T-graft end-to-side anastomosis was created in one cadaver.

RESULTS

The bilateral ITAs were harvested in less than 60 min and a T-graft was completed. No additional rib spreading was required. Intraoperative adjustments of the da Vinci SP were necessary to maintain alignment with the surgical targets.

CONCLUSIONS

Bilateral ITA harvest using the da Vinci SP through a single intercostal incision was feasible, with less rib spreading than in mini-thoracotomy procedures. Thus, creating an intrathoracic T-graft with the existing da Vinci SP instruments is possible.

Bilateral Hand Wasting After Coronary Artery Bypass Graft Surgery

Open surgical harvesting of the left internal mammary artery (LIMA) is believed to increase the risk of injury to the brachial plexus. We believe that this approach probably aggravated the neurological damage in our patient. Proper positioning, thoracoscopic harvesting of LIMA, and avoiding prolonged and excessive traction on the rib cage could have reduced the risk of this injury.

[Early and long-term outcomes of bilateral inthernal thoracic artery grafting for coronary artery bypass surgery]

OBJECTIVE

To evaluate safety of coronary artery bypass surgery using bilateral internal mammary artery and effectiveness of this procedure in long-term postoperative period.

MATERIAL AND METHODS

The study involved 129 patients who underwent CABG for the period 2006-2007. There were 2 groups of patients depending on surgical strategy: group 1 (n=61) - double IMA harvesting, group 2 (n=68) - CABG using single IMA. Short-term results were compared using standard statistical methods. Long-term survival was compared using Kaplan-Meyer method.

RESULTS

Revascularization index was 3.014±0.76 in the 1st group and 3.1±0.73 in the 2nd group (p>0.05). In-hospital mortality was 0% and 1.47%, respectively (p> 0.05). A 10-year survival was 95.1% and 91.2%, respectively (p>0.05). Freedom from cardiac events (mortality, myocardial infarction, recurrent angina pectoris) was significantly different (95% vs. 81%, p<0.05).

CONCLUSION

Significantly lower rate of adverse cardiac events in long-term postoperative period in comparison with conventional CABG clearly demonstrates high quality of life after coronary artery bypass surgery using bilateral internal mammary artery for a long time. Therefore, this procedure is preferred in patients with coronary artery disease.

Open Versus Closed Pleura Internal Mammary Artery Harvesting and Early Pulmonary Function After Coronary Artery Bypass Grafting

BACKGROUND

The internal mammary artery is the vessel of choice for myocardial revascularisation during coronary artery bypass grafting (CABG). Although it is possible to harvest the left internal mammary artery (LIMA) without opening the left pleura, pleurotomy is usually performed to provide adequate exposure and allow the placement of the LIMA medial to the upper lobe, preventing any undue tension on the mammary pedicle. However, the intact pleura technique may have a lower risk of postoperative pulmonary complications. We aimed to study the effects of both procedures on pulmonary function and the incidence of complications.

METHOD

One hundred patients with ischaemic heart disease indicated for CABG were included and divided into two groups. The closed pleural technique group included 50 patients with preservation of the pleural integrity during mammary harvesting. The open pleural procedure group included 50 patients without preservation of pleural integrity. Spirometry was done pre- and postoperatively in both groups and postoperative pulmonary complications in both groups were recorded and analysed.

RESULTS

Internal mammary harvesting with preservation of pleural integrity during CABG in patients in the closed pleural procedure group showed significant improvement in forced expiratory volume in the first second (FEV1%), forced vital capacity (FVC%), and FEV1/FVC compared with the corresponding values in patients in the open pleural procedure group, on day 5 postoperatively, at discharge, and at day 30. There were fewer complications in preservation of pleural integrity with regard to lung atelectasis and pleural effusion, which were significantly lower in patients in the open pleural procedure group.

CONCLUSIONS

Preservation of pleural integrity has beneficial effects on pulmonary function and has fewer associated pulmonary complications.

Bilateral versus single internal thoracic artery grafting in hemodialysis patients

BACKGROUND

The use of the bilateral internal thoracic arteries (BITAs) during myocardial revascularization reportedly provides a survival benefit over using a single internal thoracic artery (SITA). However, the advantages in chronic hemodialysis patients, who generally have multiple comorbidities, is unclear.

METHODS

Outcomes of chronic hemodialysis patients who underwent isolated coronary artery bypass grafting (CABG) using a SITA with additional saphenous vein grafts (SVGs) (n = 33) or BITAs (n = 30) for left-side revascularization were retrospectively reviewed.

RESULTS

With the exception of the rate of diabetes mellitus (SITA vs. BITA: 84.8% vs. 50.0%; p = 0.003), the two groups showed similar patient characteristics. Using the off-pump technique, revascularization was completed without manipulation of the ascending aorta in 45.7% of patients in the BITA group, whereas all patients in the SITA group required aortic manipulation (p < 0.001). Of note, the incidence of extensive aortic calcification (>50% of ascending aorta circumference) was not uncommon (14.3%). The in-hospital mortality (3.0% vs. 0%, p = 0.336) and complication rates (including deep wound infection, re-exploration and stroke) were similar in both groups. The 5-year estimated survival rates for freedom from overall death in the SITA and BITA groups were 42.4% and. 57.4%, respectively (p = 0.202).

CONCLUSIONS

BITA grafting was able to achieve revascularization with minimal manipulation of the diseased ascending aorta without increasing the complication rate. The long-term survival benefit of BITA grafting, however, was unclear in dialysis patients, especially because such patients have a relatively short life expectancy.

Five-year costs from a randomised comparison of bilateral and single internal thoracic artery grafts

BACKGROUND

The use of bilateral internal thoracic arteries (BITA) for coronary artery bypass grafting (CABG) may improve survival compared with CABG using single internal thoracic arteries (SITA). We assessed the long-term costs of BITA compared with SITA.

METHODS

Between June 2004 and December 2007, 3102 patients from 28 hospitals in seven countries were randomised to CABG surgery using BITA (n=1548) or SITA (n=1554). Detailed resource use data were collected from the initial hospital episode and annually up to 5 years. The associated costs of this resource use were assessed from a UK perspective with 5 year totals calculated for each trial arm and pre-selected patient subgroups.

RESULTS

Total costs increased by approximately £1000 annually in each arm, with no significant annual difference between trial arms. Cumulative costs per patient at 5-year follow-up remained significantly higher in the BITA group (£18 629) compared with the SITA group (£17 480; mean cost difference £1149, 95% CI £330 to £1968, p=0.006) due to the higher costs of the initial procedure. There were no significant differences between the trial arms in the cost associated with healthcare contacts, medication use or serious adverse events.

CONCLUSIONS

Higher index costs for BITA were still present at 5-year follow-up mainly driven by the higher initial cost with no subsequent difference emerging between 1 year and 5 years of follow-up. The overall cost-effectiveness of the two procedures, to be assessed at the primary endpoint of the 10-year follow-up, will depend on composite differences in costs and quality-adjusted survival.

TRIAL REGISTRATION NUMBER

ISRCTN46552265.

Bilateral versus Single Internal-Thoracic-Artery Grafts at 10 Years

BACKGROUND

Multiple arterial grafts may result in longer survival than single arterial grafts after coronary-artery bypass grafting (CABG) surgery. We evaluated the use of bilateral internal-thoracic-artery grafts for CABG.

METHODS

We randomly assigned patients scheduled for CABG to undergo bilateral or single internal-thoracic-artery grafting. Additional arterial or vein grafts were used as indicated. The primary outcome was death from any cause at 10 years. The composite of death from any cause, myocardial infarction, or stroke was a secondary outcome.

RESULTS

A total of 1548 patients were randomly assigned to undergo bilateral internal-thoracic-artery grafting (the bilateral-graft group) and 1554 to undergo single internal-thoracic-artery grafting (the single-graft group). In the bilateral-graft group, 13.9% of the patients received only a single internal-thoracic-artery graft, and in the single-graft group, 21.8% of the patients also received a radial-artery graft. Vital status was not known for 2.3% of the patients at 10 years. In the intention-to-treat analysis at 10 years, there were 315 deaths (20.3% of the patients) in the bilateral-graft group and 329 deaths (21.2%) in the single-graft group (hazard ratio, 0.96; 95% confidence interval [CI], 0.82 to 1.12; P=0.62). Regarding the composite outcome of death, myocardial infarction, or stroke, there were 385 patients (24.9%) with an event in the bilateral-graft group and 425 patients (27.3%) with an event in the single-graft group (hazard ratio, 0.90; 95% CI, 0.79 to 1.03).

CONCLUSIONS

Among patients who were scheduled for CABG and had been randomly assigned to undergo bilateral or single internal-thoracic-artery grafting, there was no significant between-group difference in the rate of death from any cause at 10 years in the intention-to-treat analysis. Further studies are needed to determine whether multiple arterial grafts provide better outcomes than a single internal-thoracic-artery graft. (Funded by the British Heath Foundation and others; Current Controlled Trials number, ISRCTN46552265 .).

Spiral Pseudodissection of a Tortuous Internal Mammary Artery Graft

Images and videos help describe a high-risk coronary intervention of an elongated and extremely tortuous LIMA graft to the LAD. LIMA had a complete 360° loop at the mid segment, followed by severe tortuosity and a subtotal occlusion at the anastomosis.