Optical coherence tomography imaging as a quality assurance tool for evaluating endoscopic harvest of the radial artery

Cost Analysis of Endoscopic Conduit Harvesting Technique Using a Non-Sealed System for Coronary Artery Bypass Surgery

Objective: Endoscopic vessel harvest (EVH) is evolving as the standard of care for coronary artery bypass grafting. However, the increase in upfront equipment-related costs has resulted in reluctance of uptake globally. We investigated the costs involving a non-sealed technique for EVH versus open vessel harvesting techniques (OVH) for both the greater saphenous vein and radial artery with a 6-month follow-up. Methods: From September 2016 to December 2018, 226 patients underwent OVH while 251 patients underwent EVH using a reusable non-sealed system and a single-use radiofrequency sealing system. Cumulative costs for OVH versus EVH were calculated as a summation of total operative and in-hospital stay costs. Costs related to harvest site complication management were also analyzed for up to 6 months. Results: Total operative costs were greater in the EVH group (Can$2,283.70 [Can$1,377.60 to $4,183.50] vs Can$1,742.40 [Can$998.50 to $3,628.10], P < 0.001). Total length of stay was significantly shorter for the EVH group (5.9 [4 to 43] days vs 6.8 [4 to 55] days, P = 0.018). Cumulative costs were comparable at the end of the hospitalization period (EVH, Can$6,534.70 [Can$2,076.50 to $33,087.70] vs OVH, Can$6,112.50 [Can$3,322.30 to $45,503.50], P = 0.06). After discharge, harvest site-related complications occurred more frequently in the OVH group (27% vs 4.4%, P < 0.001), resulting in increased use of antibiotics (2.2% vs 0.8%, P = 0.02) as well as more frequent requirement for home nursing assistance in the OVH group (5.7% vs 0.8%, P = 0.002) at 6 months of follow-up. Conclusions: Cumulative costs did not show a statistical difference between OVH and EVH, with higher intraoperative costs for EVH being offset by higher harvest site management costs in the OVH group.

Radial artery harvesting in coronary artery bypass grafting surgery-Endoscopic or open method? A meta-analysis

We analyzed the clinical outcomes of open radial artery harvesting (OAH) and endoscopic radial artery harvesting (EAH) undergoing coronary artery bypass grafting (CABG). We designed this meta-analysis conducted using Pubmed, Medline, the Cochrane Library, and EMBASE. Articles with comparisons of OAH and EAH undergoing CABG were included. Primary outcomes included the wound infection rate, the wound complication rate, neurological complications of the forearm, in-hospital mortality, long-term survival, and the patency rate. The results of our study included six randomized controlled trials (RCTs), two non-randomized controlled trials (NRCTs) with matching, and 10 NRCTs. In total, 2919 patients were included in 18 studies, while 1187 (40.7%) and 1732 (59.3%) patients received EAH and OAH, respectively. EAH was associated with a lower incidence of wound infection (RR = 0.29, 95% confidence interval (CI) = 0.14 to 0.60, p = 0.03), and neurological complications over the harvesting site (RR = 0.41, 95% CI = 0.27 to 0.62, p < 0.0001). There was no significant difference in 30-day mortality, long-term survival (over one year), and the graft patency rate. According to our analysis, endoscopic radial artery harvesting can improve the outcome of the harvesting site, without affecting the mortality, long-term survival, and graft patency.

Randomized Trial of 2 Endoscopic Radial Artery Harvesting Devices-Immunofluorescence Assessment

BACKGROUND

Various devices are available for endoscopic radial artery harvesting during coronary artery bypass grafting. Thermal spread and graft damage, however, are common concerns. The aim of this study was to compare the MiFusion TLS2 system (Endotrust, Nettetal Germany) with direct heat technique and the LigaSure Maryland system (Medtronic, Dublin, Ireland) using advanced bipolar technique in a prospective randomized study.

METHODS

One hundred consecutive patients undergoing coronary artery bypass grafting with endoscopic radial artery harvesting were prospectively included and randomized 1:1. The proximal (brachial) ends of the grafts were analyzed using fluorescence microscopy with focus on graft integrity. In addition, harvesting time, graft sealing, residual bleeding, and incidence of neurological disorders were compared.

RESULTS

Patient age was 67 ± 8 years. Mean harvesting time was 26.5 ± 9 minutes for the TLS2 and 23.2 ± 8 minutes for the LigaSure (P = .049). Overall graft integrity was good in both groups. A significantly better graft integrity was observed in the LigaSure group (scale 0 to 3; 3 = best) with 2.5 ± 0.6 for TLS2 and 2.8 ± 0.4 for LigaSure (P = .031). LigaSure provided significantly better graft sealing (scale 0 to 2; 0 = best) with 0.6 ± 0.7 vs 1.0 ± 0.6 (TLS2) (P = .006) and less residual bleeding (scale 1 to 5; 1 = best) with 1.4 ± 0.6 vs 2.0 ± 0.9 (TLS2) (P < .001). Transient sensibility disorders were less frequently observed with LigaSure (2% vs 16%, P = .015).

CONCLUSIONS

Endoscopic radial artery harvesting can be performed with excellent results and good graft integrity using both devices. Compared with the MiFusion TLS2, the LigaSure device led to faster procedural times and resulted in better graft integrity. Along with providing a better seal, LigaSure was associated with less sensibility disorders.

Radial artery neointimal hyperplasia after transradial PCI-Serial optical coherence tomography volumetric study

Aims

Transradial catheterization (TRC) is a dominant access site for coronary catheterization and percutaneous coronary interventions (PCI) in many centers. Previous studies reported higher intimal thickness of the radial artery (RA) wall in patients with a previous history of TRC. In this investigation the aim was to assess the intimal changes of RA using the optical coherence tomography (OCT) intravascular imaging in a serial manner.

Methods and results

100 patients with the diagnosis of non-ST-elevation myocardial infarction (nSTEMI) treated by PCI were enrolled (6 patients were excluded from this analysis because of occluded RA at follow-up [2 patients] and insufficient quality of OCT images [4 patients]). An 54mm long OCT run of the RA was performed immediately after the index PCI and repeated 9 months later. Volumetric analyses of the intimal layer and lumen changes were conducted. Median intimal volume at baseline versus 9 months was 33.9mm³ (19.0; 69.4) versus 39.0mm³ (21.7; 72.6) (p<0.001); and median arterial lumen volume was 356.3mm³ (227.8; 645.3) versus 304.7mm³ (186.1; 582.7) (p<0.001). There was no significant difference in the effect of any clinical factor on the RA volume changes.

Conclusions

OCT volumetric analyses at baseline and 9 months showed a significant increase in the radial artery intimal layer volume and a decrease in lumen volume after transradial PCI. No significant factors affecting this process were identified.

Comparison of endothelial function of coronary artery bypass grafts in diabetic and nondiabetic patients: Which graft offers the best?

OBJECTIVE

Diabetes associated endothelial dysfunction, which determines both long and short term graft patency, is not uniform in all coronary artery bypass surgery (CABG) grafts. Herein this study, we aimed to investigate the degree of endothelial dysfunction in diabetic radial artery (RA), internal mammarian artery (IMA) and saphenous vein (SV) grafts in vitro tissue bath system.

METHODS

This is a prospective experimental study. Fifteen diabetic and 15 non-diabetic patients were included to the study. A total number of 96 graft samples were collected; 16 graft samples for each graft type from both diabetic and non-diabetic patients. Arterial grafts were harvested with pedicles and SV grafts were harvested by 'no touch' technique. Vasodilatation response of vascular rings to carbachol, which induces nitric oxide (NO) mediated vasodilatation, was designated as the measure of endothelial function.

RESULTS

The IMA grafts had the most prominent NO mediated vasodilatation in both diabetic and non-diabetic patients, concluding a better preserved endothelial function than SV and RA. The 'no- touch' SV and RA grafts had similar vasodilatation responses in non-diabetic patients. In diabetic patients, on the other hand, RA grafts exhibited the least vasodilatation response (ie. worst endothelial function), even less vasodilatation than 'no touch' SV grafts (p<0.0001).

CONCLUSION

Deteriorated function of RA grafts in diabetic patients, even worse than SV grafts made evident by this study, encourages the use of 'no touch' technique as the method of SV harvesting and more meticulous imaging of RA before its use as a graft in diabetic patients.

Short sheath benefit in radial artery injury after PCI - optical coherence tomography serial study

BACKGROUND AND AIMS

Transradial catheterization is the predominant access site for coronary catheterization and percutaneous coronary interventions (PCI). Previous studies have reported a high incidence of radial artery (RA) injury. The aim of this investigation was to evaluate the incidence of RA injury using last generation optical coherence tomography (OCT) intravascular imaging in a serial manner.

METHODS

100 patients with a diagnosis of non-ST-elevation myocardial infarction (nSTEMI) treated by PCI were enrolled. OCT of RA was performed immediately after the index PCI. OCT was repeated 9 months later.

RESULTS

There were 11 patients with RA injuries (11.0%) at baseline, including 3 patients with RA medial dissection and 8 patients with intimal tears. In the follow-up OCT data, the number of RA injuries was 10 (10.0%), including 7 patients with RA medial dissection and 3 patients with intimal tear. All injuries were clinically asymptomatic and there was no finding of vessel perforation. There was no significant difference between the baseline and follow-up procedure in terms of number of injuries.

CONCLUSION

The study showed no significant difference between baseline and follow-up RA injury incidence. There was a higher risk of radial injury for repeated catheterization in women. The conclusion is that radial catheterization is a very safe procedure in terms of radial artery damage. This is evidenced by considerably fewer injuries compared to published studies. The use of the short radial sheath (7 cm in this study) is protective and reduces the incidence of radial injury.

Five-Year Clinical Outcome of Endoscopic Versus Open Radial Artery Harvesting: A Propensity Score Analysis

BACKGROUND

Despite the popularity of less invasive approaches for conduits procurement in coronary artery bypass graft surgery, concerns have been raised about the potential detrimental effects of the endoscopic technique when compared with the conventional "open" technique.

METHODS

Among 470 patients undergoing coronary surgery with the use of a radial artery conduit, a propensity score analysis was performed among those patients assigned either to an open technique (n = 82) or to an endoscopic approach (n = 82). Endoscopic harvesting was performed with a nonsealed system. The primary endpoint was cardiac-related mortality, and secondary endpoint was survival free from major cardiac and cerebrovascular adverse events. Moreover, hand and forearm sensory discomfort and forearm wound healing were also assessed.

RESULTS

No conversion to the open technique occurred in patients undergoing endoscopic harvesting. No patients in either group showed hand ischemia; wound infection occurred only in the open group (open 7.3% versus endoscopic 0%, p = 0.007). Wound healing (Hollander scale) was considerably better in the endoscopic group (open 3.3, endoscopic 4.7; p < 0.001) as well as paresthesia at the latest follow-up (open 19.5% versus endoscopic 3.6%, p < 0.001). Pain (visual analog scale score) was significantly reduced with the endoscopic technique (open 3.2, endoscopic 1.2; p = 0.003). At 5 years of follow-up, freedom from cardiac-related mortality (open 96.3% ± 2.1% versus endoscopic 98.1% ± 1.8%; p = 0.448) as well as survival free from major cardiac and cerebrovascular adverse events (open 93.9% ± 2.6% versus endoscopic 93% ± 3.4%; p = 0.996) were similar among the groups.

CONCLUSIONS

Endoscopic radial artery harvesting allows for incremental benefits in the short term in terms of improved cosmesis and reduced wound and neurologic complications, without yielding detrimental effects in terms of graft-related events at 5 years of follow-up.

Long-term patency of endoscopically harvested radial arteries: from a randomized controlled trial

OBJECTIVE

From 2005 to 2007, 119 patients were enrolled in a prospective randomized controlled trial comparing open and endoscopically harvested radial arteries for coronary artery bypass grafting. The objective of the current study was to compare graft patency between intervention groups at more than 5 years from the initial trial. We hypothesized that endoscopically harvested radial arteries would show equivalent patency to those conventionally harvested.

METHODS

At 5 years or greater from their operation, all consenting patients underwent a single-day anatomic and functional cardiac assessment with coronary computed tomography angiography and sestamibi myocardial perfusion scanning. Medical Outcomes Study 36-Item Short-Form Health Surveys and Seattle Angina Questionnaires were completed to assess the overall quality of life. All patients had received calcium channel blocker therapy for at least 6 months postoperatively.

RESULTS

The mean (SD) duration of follow-up was 79.2 (8.6) months for all patients. One death occurred within 30 days of coronary artery bypass grafting in each treatment group, and eight additional noncardiac deaths occurred during the study time frame. Of 119 patients, 66 consented to follow-up. Thirty-two had open radial artery harvest, and 34 had endoscopic radial artery harvest. At more than 5 years, there were 28 patent conventionally harvested radial arteries (87.5%) and 31 patent endoscopically harvested radial arteries (91.2%) (P = 0.705). Measured quality of life was comparable between groups.

CONCLUSIONS

Endoscopic radial artery harvest is safe and effective when compared with open radial artery harvest, with excellent graft patency demonstrated at more than 5 years. Patency results are noninferior in endoscopic radial artery harvest.

Endoscopic saphenous vein and radial harvest: state-of-the-art

PURPOSE OF REVIEW

Over the past decade, there has been an increased adoption of minimally invasive techniques for saphenous vein and radial artery procurement during coronary artery bypass surgery, albeit concerns have been raised about the potential detrimental effects of the endoscopic approach when compared with the conventional 'open' technique. The aim of the present review is to analyse the current available techniques and evidence about the impact of an endoscopic approach on conduit quality and clinical outcomes.

RECENT FINDINGS

At present, the available techniques for endoscopic vessel harvesting can be based on a sealed or non-sealed concept, for both saphenous vein and radial artery procurement. Despite the proven advantages of a minimally invasive approach in terms of reduced incidence of wound complications, pain reduction and improved cosmetic results, some studies questioned the impact of this technique in terms of potential graft damage, thus impairing the longevity of the graft itself.

SUMMARY

Endoscopic conduit harvesting can be performed safely and effectively with the currently available techniques, albeit a careful knowledge of the pitfalls of each technique is mandatory. Since there is ample evidence in literature that a minimally invasive approach for saphenous vein and radial artery procurement is not associated with an increased risk of graft damage and related failure in the mid-long term, the endoscopic technique should be adopted as the approach of choice for saphenous vein and radial artery harvesting in coronary artery bypass graft surgery.

Impact of the learning curve for endoscopic vein harvest on conduit quality and early graft patency

BACKGROUND

Recent studies have suggested that endoscopic vein harvest (EVH) compromises graft patency. To test whether the learning curve for EVH alters conduit integrity owing to increased trauma compared with an open harvest, we analyzed the quality and early patency of conduits procured by technicians with varying EVH experience.

METHODS

During coronary artery bypass grafting, veins were harvested open (n=10) or by EVH (n=85) performed by experienced (>900 cases, >30/month) versus novice<100 cases, <3/month) technicians. Harvested conduits were imaged intraoperatively using optical coherence tomography and on day 5 to assess graft patency using computed tomographic angiography.

RESULTS

Conduits from experienced (n=55) versus novice (n=30) harvesters had similar lengths (33 versus 34 cm) and harvest times (32.4 versus 31.8 minutes). Conduit injury was noted in both EVH groups with similar distribution among disruption of the adventitia (62%), intimal tears at branch points (23%), and intimal or medial dissections (15%), but the incidence of these injuries was less with experienced harvesters and rare in veins procured with an open technique. Overall, the rate of graft attrition was similar between the two EVH groups (6.45% versus 4.34% of grafts; p=0.552). However, vein grafts with at least 4 intimal or medial dissections showed significantly worse patency (67% versus 96% patency; p=0.05).

CONCLUSIONS

High-resolution imaging confirmed that technicians inexperienced with EVH are more likely to cause intimal and deep vessel injury to the saphenous vein graft, which increases graft failure risk. Endoscopic vein harvest remains the most common technique for conduit harvest, making efforts to better monitor the learning curve an important public health issue.

Consensus statement: minimal criteria for reporting the systemic inflammatory response to cardiopulmonary bypass

The lack of established cause and effect between putative mediators of inflammation and adverse clinical outcomes has been responsible for many failed anti-inflammatory interventions in cardiopulmonary bypass (CPB). Candidate interventions that impress in preclinical trials by suppressing a given inflammation marker might fail at the clinical trial stage because the marker of interest is not linked causally to an adverse outcome. Alternatively, there exist examples in which pharmaceutical agents or other interventions improve clinical outcomes but for which we are uncertain of any antiinflammatory mechanism. The Outcomes consensus panel made 3 recommendations in 2009 for the conduct of clinical trials focused on the systemic inflammatory response. This panel was tasked with updating, as well as simplifying, a previous consensus statement. The present recommendations for investigators are the following: (1) Measure at least 1 inflammation marker, defined in broad terms; (2) measure at least 1clinical end point, drawn from a list of practical yet clinically meaningful end points suggested by the consensus panel; and(3) report a core set of CPB and perfusion criteria that maybe linked to outcomes. Our collective belief is that adhering to these simple consensus recommendations will help define the influence of CPB practice on the systemic inflammatory response, advance our understanding of causal inflammatory mechanisms, and standardize the reporting of research findings in the peer-reviewed literature.

Redefining the Systemic Inflammatory Response

From the first description of the “systemic inflammatory response” in the early 1990s, it has been recognized that this is a multifaceted response of the body to the combined insult of cardiothoracic surgery with bypass, involving causation by “activation of complement, coagulation, fibrinolytic, and kallikrein cascades, activation of neutrophils with degranulation and protease enzyme release, oxygen radical production, and the synthesis of various cytokines from mononuclear cells.” Yet the intervening 15 years have seen a narrowing of research into individual systems and interventions naively targeted at single pathways without achieving clinically meaningful benefits. The time has come to redefine the systemic inflammatory response so that research can be more productively focused on objectively measuring and interdicting this multisystem disorder. A key concept of this new understanding is that translation into a hard adverse event occurs when the systemic imbalance is combined with a localized trigger. Triggers might be inadvertently provided by transient episodes of ischemia/malperfusion to vulnerable organs or handling trauma to major vessels. Future research should be directed at suppressing systemic activation with combinations of drugs and improved circuit coating, whereas changes in clinical practice and continuous monitoring of perfusion parameters can help eliminate localized triggering events.

Harmonic scalpel versus electrocautery for harvest of radial artery conduits: reduced risk of spasm and intimal injury on optical coherence tomography

OBJECTIVE

Vasospasm is the primary obstacle to widespread adoption of the radial artery as a conduit in coronary artery bypass grafting. We used optical coherence tomography, a catheter-based intravascular imaging modality, to measure the degree of radial artery spasm induced by means of harvest with electrocautery or a harmonic scalpel in patients undergoing coronary artery bypass grafting.

METHODS

Radial arteries were harvested from 44 consecutive patients with a harmonic scalpel (n = 15) or electrocautery (n = 29). Vessels were imaged before harvesting and after removal from the arm, with saphenous vein tracts serving as internal controls. Optical coherence tomographic findings for the degree of harvesting-induced injury were validated against histologic measures.

RESULTS

Optical coherence tomographic measures of endovascular dimensions and injury correlated strongly with histologic findings. Mean luminal volume, a measure of vasospasm, decreased significantly less after harvesting with a harmonic scalpel (9% +/- 7%) than with electrocautery (35% +/- 6%, P = .015). Completely intact intima was present in 11 (73%) of 15 radial arteries harvested with a harmonic scalpel (73%) compared with 9 of 29 arteries harvested by means of electrocautery (31%, P = .011). Intraoperative flow measurements and patency rates at 5 days postoperatively were not significantly different among groups.

CONCLUSIONS

Optical coherence tomography provides a level of speed and accuracy for quantifying endothelial injury and vasospasm that has not been described for any other modality, suggesting potential as an intraoperative quality assurance tool. Our optical coherence tomographic findings suggest that the harmonic scalpel induces less spasm and intimal injury compared with electrocautery.