Evaluation of the PAS-Port Proximal Anastomosis System in coronary artery bypass surgery (the EPIC trial)

Sutureless vascular anastomotic approaches and their potential impacts

Sutureless anastomotic devices present several advantages over traditional suture anastomosis, including expanded global access to microvascular surgery, shorter operation and ischemic times, and reduced costs. However, their adaptation for arterial use remains a challenge. This review aims to provide a comprehensive overview of sutureless anastomotic approaches that are either FDA-approved or under investigation. These approaches include extraluminal couplers, intraluminal devices, and methods assisted by lasers or vacuums, with a particular emphasis on tissue adhesives. We analyze these devices for artery compatibility, material composition, potential for intimal damage, risks of thrombosis and restenosis, and complications arising from their deployment and maintenance. Additionally, we discuss the challenges faced in the development and clinical application of sutureless anastomotic techniques. Ideally, a sutureless anastomotic device or technique should eliminate the need for vessel eversion, mitigate thrombosis through either biodegradation or the release of antithrombotic drugs, and be easily deployable for broad use. The transformative potential of sutureless anastomotic approaches in microvascular surgery highlights the necessity for ongoing innovation to expand their applications and maximize their benefits.

Off-pump coronary artery bypass grafting with clampless aortic anastomosis devices: Aortic sealing devices versus automated anastomosis punching

Objectives

Clampless aortic anastomosis devices aim to lower stroke risk in off-pump coronary artery bypass grafting. Two main strategies for clampless anastomosis devices emerged with automated anastomosis punching and aortic sealing devices, prompting the question of perioperative outcome differences.

Methods

All consecutive patients undergoing elective off-pump coronary artery bypass grafting with a clampless aortic anastomosis device between September 2014 and December 2021 in 2 centers were retrospectively included. Cohorts were divided by the use of an automated anastomosis punching device or an aortic sealing device to achieve proximal anastomosis on the ascending aorta. To reach group comparability propensity score matching was performed. The primary end point was defined as a composite of all-cause mortality, stroke and rethoracotomy. Secondary end points were perioperative outcome parameters.

Results

A total of 3703 patients were enrolled of whom 575 and 3128 were included in the automated anastomosis punching and the aortic sealing device group, respectively. By propensity score matching a total of 1150 patients were included with 575 in each group. The primary composite endpoint showed no significant difference with 6.3% versus 5.9% events (odds ratio, 0.9; 95% confidence interval, 0.58-1.53, P = .81). All-cause mortality (P = .36), stroke (P = .81), and rethoracotomy (P = .89) also exhibit no disparity. Operation time was significantly longer in the aortic sealing device cohort with 220.0 ± 50.8 minutes and 204.6 ± 53.8 minutes (P < .01).

Conclusions

Clampless aortic anastomosis strategies aortic sealing device and automated anastomosis punching did not differ in perioperative outcome parameters, whereas the implementation of aortic sealing devices were associated with a prolonged operation time without inducing any inferior clinical outcome.

Effects of the harvesting technique and external stenting on progression of vein graft disease 2 years after coronary artery bypass

OBJECTIVES

In a post hoc analysis of the VEST III trial, we investigated the effect of the harvesting technique on saphenous vein graft (SVG) patency and disease progression after coronary artery bypass grafting.

METHODS

Angiographic outcomes were assessed in 183 patients undergoing open (126 patients, 252 SVG) or endoscopic harvesting (57 patients, 114 SVG). Overall SVG patency was assessed by computed tomography angiography at 6 months and by coronary angiography at 2 years. Fitzgibbon patency (FP I, II and III) and intimal hyperplasia (IH) in a patient subset were assessed by coronary angiography and intravascular ultrasound, respectively, at 2 years.

RESULTS

Baseline characteristics were similar between patients who underwent open and those who underwent endoscopic harvesting. Open compared with endoscopic harvesting was associated with higher overall SVG patency rates at 6 months (92.9% vs 80.4%, P = 0.04) and 2 years (90.8% vs 73.9%, P = 0.01), improved FP I, II and III rates (65.2% vs 49.2%; 25.3% vs 45.9%, and 9.5% vs 4.9%, respectively; odds ratio 2.81, P = 0.09) and reduced IH area (-31.8%; P = 0.04) and thickness (-28.9%; P = 0.04). External stenting was associated with improved FP I, II and III rates (odds ratio 2.84, P = 0.01), reduced IH area (-19.5%; P < 0.001) and thickness (-25.0%; P < 0.001) in the open-harvest group and reduced IH area (-12.7%; P = 0.01) and thickness (-9.5%; P = 0.21) in the endoscopic-harvest group.

CONCLUSIONS

A post-hoc analysis of the VEST III trial showed that open harvesting is associated with improved overall SVG patency and reduced IH. External stenting reduces SVG disease progression, particularly with open harvesting.

Direct angiography demonstrates equal 8-12 years patency rates of radial artery and saphenous vein grafts

Objectives: The benefits of coronary artery bypass surgery depend on lasting graft patency. To aid rational graft selection, the relative long-term merits of radial artery and saphenous vein grafts need to be determined by a gold standard method and with minimal clinically driven selection bias. Methods: The patency rates of various conduits were determined by direct angiography in 76 patients from a cohort of 119 undergoing coronary artery bypass grafting 7.6-12.1 (mean 8.9) years before. Results: 14 out of 76 radial artery and 10 out of 61 saphenous vein grafts were occluded (rates 0.18 and 0.16, respectively). Conclusion: The high long-term patency rate of saphenous vein grafts does not support a preferential use of the radial artery as a coronary artery bypass conduit. Clinical registration number: ISRCTN23118170.

Clinical outcomes of automated anastomotic devices: A metanalysis

Background and Aims

We investigated neurological events, graft patency, major adverse cardiovascular events (MACEs), and mortality at 1 year following coronary artery bypass grafting (CABG) surgery using automated proximal anastomotic devices (APADs) and compared the overall rates with the current literature.

Methods

A systematic review of all available reports of APADs use in the literature was conducted. Cumulative incidence and 95% confidence interval (CI) were the main statistical indexes. Nine observational studies encompassing a total of 718 patients were included at the end of the selection process.

Results

The cumulative event rate of neurological complications was 4.8% (lower‐upper limits: 2.8‐8.0, P < .001; I² = 72.907%, P = .002; Egger's test: intercept = –2.47, P = 0.16; Begg and Mazumdar test: τ = −0.20, p = 0.57). Graft patency was 90.5% (80.4 to 95.7, P < .001; I² = 76.823%, P = .005; Egger's test: intercept = –3.04, P = .10; Begg and Mazumdar test: τ = −0.67, P = .17). Furthermore, the overall incidence of MACEs was 3.7% (1.3‐10.4, P < .001; I² = 51.556%, P = .103; Egger's test: intercept = –1.98, P =  < .11; Begg and Mazumdar test: τ = −0.67, P = .17). Finally, mortality within 1 year was 5% (3.5‐7, P < .001; I² = 29.675%, P = .202; Egger's test: intercept = –0.91, P = .62; Begg and Mazumdar test: τ = −0.04, P = .88).

Conclusions

APADs do not seem to be correlated with a reduction of either neurological events or mortality. By contrast, these tools showed satisfactory one‐year graft patency and a low incidence of MACEs. Further research on this topic is warranted.

“No-Touch” versus “Endo” Vein Harvest: Early Patency on Symptom-Directed Catheterization and Harvest Site Complications

Objective

“No-touch” (NT) saphenous vein harvesting preserves the adventitial vasa vasorum, prevents medial ischemia, and is associated with an improved short-term and long-term vein graft patency. It may also be associated with a higher rate of harvest site complications. Endovascular vein harvesting (endo-vein) has a low rate of harvest site complications but also a tendency toward a lower patency rate.

Methods

During a 2-year period (2011–2012), we compared the vein graft patency at symptom-directed cardiac catheterization as well as wound complication rates in 210 patients who received either NT (87 patients) or endo-vein (123 patients).

Results

The recatheterization rate for the two groups was similar: 9 (10.3%) of 87 of the NT patients versus 11 (9.0%) of 123 of the endo-vein patients. There was a significant difference in vein graft patency between the groups: 15 (94%) of 16 NT vein grafts were patent versus 6 (27%) of 22 of endo-veins ( P < 0.02). The endo-vein graft patency during this 2-year period was similar to the total endo-vein patency (37%) during a 4-year period. A comparison between a more experienced and a less experienced harvester revealed no difference in patency rate. Harvest site complications were significantly higher with the NT harvest: 18% of the NT patients requiring vacuum-assisted wound closure or intravenous antibiotics versus 2% of the endo-vein patients ( P < 0.0001). The application of platelet-rich plasma did not significantly lower wound complication rates ( P = 0.27).

Conclusions

These results suggest that NT vein harvesting may be associated with improved graft patency, but methods should be developed to lower wound complication rates.

Multicenter Assessment of Grafts in Coronaries: Midterm Evaluation of the C-Port Device (the MAGIC Study)

OBJECTIVE

The commercially available C-Port distal anastomotic device (Food and Drug Administration cleared in 2007) is an automated miniature vascular stapler that performs the coronary anastomosis. This prospective multicenter registry sought to evaluate midterm patency using this device compared with hand-sewn grafts.

METHODS

Patients receiving at least one C-Port anastomosis during coronary artery bypass grafting surgery were enrolled at eight sites. Of the 117 patients enrolled, 78 patients (67%) with 104 C-Port vein grafts completed the study to patency assessment via computed tomography angiography. Clinical follow-up and index graft patency (Gated 64-slice computed tomography scan) were performed at least 12 months postoperatively. The primary efficacy endpoint was patency compared with the peer-reviewed results from the PRoject of Ex-vivo Vein graft ENgineering via Transfection IV (PREVENT IV) trial.

RESULTS

The patient population was consistent with the PREVENT IV placebo cohort. The mortality at 12 months was 0.85% (1/117). The major cardiac morbidity rate was 3.4% (4/117). The C-Port vein graft occlusion rate was 16.3% (17/104) compared with 26.6% (597/2242) in the PREVENT IV trial (P = 0.011). Within this study, C-Port graft occlusion rates were not significantly different from the hand-sewn grafts (P = 0.821).

CONCLUSIONS

The C-Port device is safe and effective in creating the distal anastomosis with equivalent patency rates to hand-sewn grafts at 12 months. When compared with hand-sewn anastomoses from a recent large prospective trial, the C-Port device demonstrated a statistically significant reduction in midterm graft occlusion. Further studies are required to evaluate its effect in less invasive coronary surgery.

Graft patency after open versus endoscopic saphenous vein harvest in coronary artery bypass grafting surgery: a systematic review and meta-analysis

Background

Saphenous vein grafts (SVG) are a commonly used conduit for coronary artery bypass graft (CABG) surgery and can be harvested by either an open or endoscopic technique. Our goal was to evaluate long-term angiographic and clinical outcomes of open compared to endoscopic SVG harvest for CABG.

Methods

Electronic search was performed to identify all studies in the English literature that compared open and endoscopic SVG harvesting for CABG with at least one year of follow-up. The primary outcome was graft patency. Secondary outcomes included perioperative morbidity and mortality.

Results

Of 3,255 articles identified, a total of 11 studies were included for analysis. Of 18,131 patients, 10,873 (60%) patients underwent open SVG harvest and 7,258 (40%) patients underwent endoscopic SVG harvest. The mean age of patients was 65 years and 87% were male. The overall mean follow-up period was 2.6 years. During follow-up, patients who underwent open SVG harvest had superior graft patency per graft [open 82.3% vs. endoscopic 75.1%; OR: 0.61 (95% CI, 0.43-0.87); P=0.01], but higher rates of overall wound complications in the immediate post-operative period [open 3.3% vs. endoscopic 1.1%; OR: 0.02 (95% CI, 0.01-0.06); P<0.001]. Patients who underwent open SVG harvest had higher postoperative 30-day mortality [open 3.4% vs. endoscopic 2.1%; OR: 0.59 (95% CI, 0.37-0.94); P=0.03], but no significant difference in overall mortality [open 4.9% vs. endoscopic 4.9%; OR: 0.34 (95% CI, 0.50-1.27); P=0.34].

Conclusions

Patients who underwent an open SVG harvest technique had improved graft patency and comparable overall mortality to endoscopic SVG harvest at average follow-up time of 2.6 years. Patients with open SVG harvest had higher rates of early wound complications and postoperative 30-day mortality, however, there was no difference in overall mortality.

Surgical repair of a celiac artery aneurysm using a sutureless proximal anastomosis device

Some celiac artery aneurysms are not suitable for endovascular therapy. We describe the case of a 63-year-old man with a celiac trunk aneurysm extending to the hepatosplenic bifurcation. The aneurysm was resected and oversewn at the origin from the abdominal aorta. A saphenous vein bypass from the supraceliac aorta to the celiac artery bifurcation was performed using a sutureless anastomotic device (PAS-Port system; Cardica, Redwood City, Calif) to create the proximal anastomosis, eliminating the need for aortic clamping. This system is thought to make direct proximal aortic anastomosis safe and easy in patients requiring surgical reconstruction of celiac artery aneurysms.

Clampless versus clamped coronary bypass grafting: does it make a difference?

PURPOSE OF REVIEW

The techniques of coronary artery bypass grafting (CABG) have evolved remarkably over the last two decades since the introduction of off-pump coronary artery bypass (OPCAB). This article focuses on the clinical outcomes of 'clampless' CABG strategies, that include OPCAB with a partial clamp, OPCAB with a proximal suture device, and aorta no-touch OPCAB.

RECENT FINDINGS

Observational studies have shown the superiority of OPCAB for preventing strokes and pulmonary complications. Conversely, recent large-scale randomized controlled trials (RCTs) have been unable to demonstrate the benefits of OPCAB. Because of these differing results across numerous studies, the debate about the overall superiority of OPCAB versus on-pump CABG remains controversial. However, the literature regarding the OPCAB technique with minimized manipulation of the aorta suggests this has likely benefits, especially for high-risk patients.

SUMMARY

Previous large RCTs did not focus on specific approaches of OPCAB or the importance of the experience of surgeons and institutions, and so further studies are needed. Observational studies and meta-analyses have indicated that improved outcomes can be achieved by applying specific OPCAB approaches according to each patient's characteristics.

Coronary Artery Bypass Grafting With and Without Manipulation of the Ascending Aorta: A Network Meta-Analysis

BACKGROUND

Coronary artery bypass grafting (CABG) remains the standard of treatment for 3-vessel and left main coronary disease, but is associated with an increased risk of post-operative stroke compared to percutaneous coronary intervention. It has been suggested that CABG techniques that eliminate cardiopulmonary bypass and reduce aortic manipulation may reduce the incidence of post-operative stroke.

OBJECTIVES

A network meta-analysis was performed to compare post-operative outcomes between all CABG techniques, including anaortic off-pump CABG (anOPCABG), off-pump with the clampless Heartstring device (OPCABG-HS), off-pump with a partial clamp (OPCABG-PC), and traditional on-pump CABG with aortic cross-clamping.

METHODS

A systematic search of 6 electronic databases was performed to identify all publications reporting the outcomes of the included operations. Studies reporting the primary endpoint, 30-day post-operative stroke rate, were included in a Bayesian network meta-analysis.

RESULTS

There were 13 included studies with 37,720 patients. At baseline, anOPCABG patients had higher previous stroke than did the OPCABG-PC (7.4% vs. 6.5%; p = 0.02) and CABG (7.4% vs. 3.2%; p = 0.001) patients. AnOPCABG was the most effective treatment for decreasing the risk of post-operative stroke (-78% vs. CABG, 95% confidence interval [CI]: 0.14 to 0.33; -66% vs. OPCABG-PC, 95% CI: 0.22 to 0.52; -52% vs. OPCABG-HS, 95% CI: 0.27 to 0.86), mortality (-50% vs. CABG, 95% CI: 0.35 to 0.70; -40% vs. OPCABG-HS, 95% CI: 0.38 to 0.94), renal failure (-53% vs. CABG, 95% CI: 0.31 to 0.68), bleeding complications (-48% vs. OPCABG-HS, 95% CI: 0.31 to 0.87; -36% vs. CABG, 95% CI: 0.42 to 0.95), atrial fibrillation (-34% vs. OPCABG-HS, 95% CI: 0.49 to 0.89; -29% vs. CABG, 95% CI: 0.55 to 0.87; -20% vs. OPCABG-PC, 95% CI: 0.68 to 0.97), and shortening the length of intensive care unit stay (-13.3 h; 95% CI: -19.32 to -7.26; p < 0.0001).

CONCLUSIONS

Avoidance of aortic manipulation in anOPCABG may decrease the risk of post-operative stroke, especially in patients with higher stroke risk. In addition, the elimination of cardiopulmonary bypass may reduce the risk of short-term mortality, renal failure, atrial fibrillation, bleeding, and length of intensive care unit stay.

Patency of Saphenous Vein Grafts Using the PAS-Port System During Coronary Artery Bypass Surgery

BACKGROUND

Several proximal anastomosis devices have been developed to shorten the time required for a proximal anastomosis and to avoid aortic cross-/side-clamping during coronary artery bypass grafting. This study retrospectively examined the patency of saphenous vein grafts (SVGs) using the PAS-Port System (Cardia Inc, Redwood City, CA).

METHODS

From 2004 to 2014, 451 patients underwent coronary artery bypass graft operations requiring at least 1 proximal anastomosis using a PAS-Port device. A total of 802 PAS-Port devices were used, and 95.0% (762 of 802) were implanted successfully. Among the successfully implanted anastomoses, 76.8% (585 of 762) were evaluated using coronary angiography or multidimensional computed tomography, or both. The evaluations were performed between postoperative days 4 and 3,182 (mean, 319 ± 624 days). The early (1 to 365 days) and the midterm to long-term (more than 366 days) occlusion rates were examined. A complete postoperative clinical course was recorded for 70.7% of the patients.

RESULTS

Overall, 93.8% (549 of 585) of the device-dependent SVGs were patent. The patency rates of device-dependent SVGs that were 1, 2, 3, 4, 5, 6, 7, and 8 years old were 90.1% ± 1.8%, 87.1% ± 2.3%, 86.1% ± 2.5%, 82.9% ± 3.3%, 80.6% ± 3.9%, 77.2% ± 5.0%, 77.2% ± 5.0%, and 70.2% ± 8.1%, respectively. The longest follow-up period was 3,182 days (8.7 years). The occlusion rate for device-dependent SVGs tended to decrease as the number of patients accumulated.

CONCLUSIONS

The PAS-Port system provided acceptable SVG patency and clinical outcome for the early and midterm to long-term. There may be a learning curve for the use of PAS-Port device that affects the device-dependent SVG patency.

Partially anaortic clampless off-pump coronary artery bypass prevents neurologic injury compared to on-pump coronary surgery: a propensity score-matched study on 286 patients

Anaortic coronary artery bypass proved to prevent early neurologic injury compared to on-pump CABG. The Cardica PAS-Port(®) is a fully automated device that might be able to perform proximal aorto-venous anastomoses without an increased embolic risk. We evaluated early post-operative neurologic outcome in a matched population following clampless OPCAB (CCAB: either "all-arterial" or with automatically anastomosed venous grafts) or on-pump CABG. 366 consecutive patients were submitted to isolated coronary bypass by a single surgeon experienced in both off and on-pump procedures between January 2009 and December 2013. Of these patients, 223 underwent a clampless off-pump revascularization. After propensity score matching, 143 pairs were selected, who received either off-pump or on-pump surgery. In the off-pump group, CCAB was performed with an all-arterial approach (n = 33) or with automated proximal anastomosis of the venous graft(s) by means of the Cardica PAS-Port(®) connector (n = 110). Neurologic injury was defined as non-reversible (NRNI: lethal coma or stroke) or reversible (RNI: TIA or delirium). Operative mortality was 2.4 % (CCAB 1.4 %; CABG 3.5 %; p = 0.14). The global rate of early neurologic injury was 5.6 % (CCAB 2.1 vs. CABG 9.1 %; p = 0.006). Incidence was 1.4 % for NRNI (CCAB 0 vs. CABG 2.8 %; p = 0.04) and 4.2 % for RNI (CCAB 2.1 vs. CABG 6.3 %; p = 0.06). No differences were found among other major perioperative outcomes. CCAB prevents both early post-operative RNI and NRNI. This result can be achieved with a totally anaortic strategy and also with the aid of a fully automated device for proximal aorto-venous anastomoses.

Early Outcomes of Endoscopic Vein Harvesting during the Initial Learning Period

Background

The endoscopic vein harvesting (EVH) method has been used in coronary artery bypass surgery in many countries. We started using the EVH method recently, and investigated the results during the early learning period.

Methods

Between March 2012 and June 2014, 75 patients (31 patients in the EVH method group, and 44 patients in the open method group) who underwent isolated first-time coronary artery bypass grafting using vein grafts were retrospectively analyzed with respect to the early outcomes including graft patency and risk factors for leg wound complications. For assessing the patency of vein graft, we performed coronary computed tomography angiography during the immediate postoperative period and 6 months later.

Results

Mean harvesting time of endoscopic method was about 15 minutes. Patency rate during the immediate operative period and the 6-month patency rate were similar between the two groups (postoperative period: EVH 100% vs. open method 94.4%, p=0.493; at 6 months: EVH 93.3% vs. open method 90.9%, p=0.791). Leg wound complications occurred more frequently in the open method group (EVH 3.2% vs. open method 13.6%, p=0.127). According to the analysis, age was an independent risk factor for leg wound complications.

Conclusion

EVH is a feasible method even for beginners and can be performed satisfactorily during their learning period.

Morphological Evaluation of Proximal Anastomosis by PAS-Port(®) System in Patients with Long-Term Patent Grafts

PURPOSE

We examined grafts employing for morphological analysis of early and long-term results on proximal anastomosis with the PAS-Port(®).

METHODS

One hundred and four patients treated by OPCAB with PAS-Port(®) were performed postoperative MDCT. Morphological evaluation of the proximal anastomotic region was classified into three groups (A; graft was anastomosed almost perpendicularly to the aortic wall, B; graft was same type A, but subsequently curved to form an acute angle with the aortic wall, C; graft take off acute angle with the aortic wall) evaluated on planar and sagittal sections.

RESULTS

One hundred twenty-six PAS-Port(®) were used. Patency rate was 99.0% at discharge, 94.7% at 1 year, and no blockages were detected thereafter in patients examined. The morphology rate was A 50.6%, B 15.3% and C 34.1% on planar sections, and A 58.8%, B 10.6% and C 30.6% on sagittal sections.

CONCLUSION

The morphological evaluation of grafts revealed the degree of freedom in graft design to be relatively high and long-term patency posed no particular problem even if the layout of the proximal anastomotic region involved a relatively acute angle. The PAS-Port(®) was considered to be a highly reliable device which performed appropriate proximal anastomosis and improved the patency of vein grafting to the aortic wall.

Five-year clinical outcome and patency rate of device-dependent venous grafts after clampless OPCAB with PAS-port automated proximal anastomosis: the PAPA Study

OBJECTIVE

To evaluate long-term clinical performance and angiographic patency of automated proximal venous anastomoses following clampless coronary artery bypass (C-CAB).

METHODS

Observational study in patients submitted for isolated C-CAB and at least one proximal aortosaphenous anastomosis performed with an automated connector (Cardica PAS-Port) including 152 consecutive patients (165 devices and 199 device-dependent distal anastomoses), with LVEF > 30% and saphenous vein diameter of 4-6 mm. Clinical follow-up was 96% complete (4101/4269 pt-months). Graft patency rate was assessed with 64-slice CT-scan or coronary angiography. Freedom from major adverse cardiac and cerebrovascular events (MACCE) was reported as actuarial probability with 95% confidence limits and venous graft patency as actual rate at every year interval.

RESULTS

Early operative mortality was 1.9%; incidence of neurologic injury was zero. Freedom from MACCE was 92.7 ± 2.1 at one year and 85.2 ± 4.8 at five years. The actual patency rate of device-dependent venous grafts was 90%, 85%, 84%, 84%, and 93% for one-, two-, three-, four-, and five-year-old grafts, respectively.

CONCLUSIONS

The device is a well-performing system for proximal anastomoses. The incidence of neurologic complications seems to be reduced with this clampless approach. The high patency rate is stable over time.

Endoscopic versus open radial artery harvest and mammario-radial versus aorto-radial grafting in patients undergoing coronary artery bypass surgery: protocol for the 2 × 2 factorial designed randomised NEO trial

Background

Coronary artery bypass grafting using the radial artery has, since the 1990s, gone through a revival. Observational studies have indicated better long-term patency when using radial arteries. Therefore, radial artery might be preferred especially in younger patients where long time patency is important. During the last 10 years different endoscopic techniques to harvest the radial artery have evolved. Endoscopic radial artery harvest only requires a small incision near the wrist in contrast to open harvest, which requires an incision from the elbow to the wrist. However, it is unknown whether the endoscopic technique results in fewer complications or a graft patency comparable to open harvest. When the radial artery has been harvested, there are two ways to use the radial artery as a graft. One way is sewing it onto the aorta and another is sewing it onto the mammary artery. It is unknown which technique is the superior revascularisation technique.

Methods/Design

The NEO Trial is a randomised clinical trial with a 2 × 2 factorial design. We plan to randomise 300 participants into four intervention groups: (1) mammario-radial endoscopic group; (2) aorto-radial endoscopic group; (3) mammario-radial open surgery group; and (4) aorto-radial open surgery group.

The hand function will be assessed by a questionnaire, a clinical examination, the change in cutaneous sensibility, and the measurement of both sensory and motor nerve conduction velocity at 3 months postoperatively. All the postoperative complications will be registered, and we will evaluate muscular function, scar appearance, vascular supply to the hand, and the graft patency including the patency of the central radial artery anastomosis. A patency evaluation by multi-slice computer tomography will be done at one year postoperatively.

We expect the nerve conduction studies and the standardised neurological examinations to be able to discriminate differences in hand function comparing endoscopic to open harvest of the radial artery. The trial also aims to show if there is any patency difference between mammario-radial compared to aorto-radial revascularisation techniques but this objective is exploratory.

Trial registration

ClinicalTrials.gov identifier: NCT01848886.

Danish Ethics committee number: H-3-2012-116.

Danish Data Protection Agency: 2007-58-0015/jr.n:30–0838.

Anastomotic devices in coronary artery surgery: it is about the anastomosis?

Excellent long-term graft patency remains the primary goal of any surgical coronary revascularization procedure, irrespective of how the operation itself is performed. Inter- and intra-surgeon variability in the surgical technique and in the subsequent quality of the anastomosis have the potential to significantly impact not only on graft patency but also, as a result, on patient outcomes. Anastomotic devices, proximal and distal, can facilitate the creation of rapid, reproducible, compliant anastomoses, on- or off-pump, in potentially difficult-to-access areas, often through minimal-access incisions, potentially with neuro-protective benefits, and can thus mitigate some of the hazards inherent in manually constructing anastomoses in technically challenging or suboptimal conditions. We review the three most commonly employed anastomotic devices in adult cardiac surgical practice today.

Trends in aortic clamp use during coronary artery bypass surgery: effect of aortic clamping strategies on neurologic outcomes

OBJECTIVE

The purpose of the present study was to determine the effect of different clamping strategies during coronary artery bypass grafting on the incidence of postoperative stroke.

METHODS

In the present case-control study, all patients at Emory hospitals from 2002 to 2009 with postoperative stroke after isolated coronary artery bypass grafting (n = 141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (n = 565). The patients were matched according to the Society of Thoracic Surgeons' predicted risk of postoperative stroke score, which is based on 26 variables. The patients who received on-pump and off-pump coronary artery bypass grafting were matched separately. Multiple logistic regression analysis with adjusted odds ratios was performed to identify the operative variables associated with postoperative stroke.

RESULTS

Among the on-pump cohort, the single crossclamp technique was associated with a decreased risk of stroke compared with the double clamp (crossclamp plus partial clamp) technique (odds ratio, 0.385; P = .044). Within the on-pump cohort, no significant difference was seen in the incidence of stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002 to 2009, clamp use decreased from 97.7% of cases to 72.7%.

CONCLUSIONS

During on-pump coronary artery bypass grafting, the use of a single crossclamp compared with the double clamp technique decreased the risk of postoperative stroke. The use of any aortic clamp decreased and epiaortic ultrasound use increased from 2002 to 2009, indicating a change in the operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta.

Major innovations and trends in the medical device sector

Activities related to medical innovation are accelerating and becoming increasingly important due to the demand for better and less invasive therapies, a rapidly aging population in the developed world and a globally larger population able to afford advanced medical care. Medical Innovation is occurring in the fields of pharmacy, diagnostics and therapeutic imaging, surgical products, interventional procedures and devices. Increasing understanding of basic disease processes further opens the opportunities for innovators. Increased knowledge often cause major paradigm shifts in therapeutic methods.

Is endoscopic harvesting bad for saphenous vein graft patency in coronary surgery?

PURPOSE OF REVIEW

Endoscopic vein harvest (EVH) has quickly been adopted as the standard-of-care for coronary artery bypass grafting (CABG). Despite clear advantages in terms of wound morbidity, healing, pain, and patient satisfaction, data from recent large clinical trials have called the safety of this technique into question.

RECENT FINDINGS

Post-hoc analyses of a variety of prospective trials have suggested EVH is associated with decreased graft patency, higher rates of cardiovascular complications (e.g. myocardial infarction, need for repeat revascularization) and mortality. Imaging studies of veins procured by EVH have revealed retained clot and vascular injury, particularly during the 'learning curve' of the technician. These findings may alter the quality of the conduit and, therefore, the outcome of the bypass graft. Elucidating the mechanisms that underlie any differences in results produced by the open and endoscopic procedures would help better inform clinical practice and the development of targeted strategies to improve EVH.

SUMMARY

Clear clinical advantages over traditional open vein harvest have allowed EVH to rapidly become the standard-of-care for harvesting of one or more vein grafts during CABG. The quality of these conduits, suggested to be equivalent by early studies, has come into question as groups with varying levels of experience have adopted the endoscopic technique. Elucidating the principles of 'best practice' for vein harvest will likely help shorten the learning curve and improve the safety of EVH.

Endoscopic Saphenous harvesting with an Open CO2 System (ESOS) trial for coronary artery bypass grafting surgery: study protocol for a randomized controlled trial

Background

In coronary artery bypass grafting surgery, arterial conduits are preferred because of more favourable long-term patency and outcome. Anyway the greater saphenous vein continues to be the most commonly used bypass conduit. Minimally invasive endoscopic saphenous vein harvesting is increasingly being investigated in order to reduce the morbidity associated with conventional open vein harvesting, includes postoperative leg wound complications, pain and patient satisfaction. However, to date the short and the long-term benefits of the endoscopic technique remain controversial. This study provides an interesting opportunity to address this gap in the literature.

Methods/Design

Endoscopic Saphenous harvesting with an Open CO₂ System trial includes two parallel vein harvesting arms in coronary artery bypass grafting surgery. It is an interventional, single centre, prospective, randomized, safety/efficacy, cost/effectiveness study, in adult patients with elective planned and first isolated coronary artery disease. A simple size of 100 patients for each arm will be required to achieve 80% statistical power, with a significant level of 0.05, for detecting most of the formulated hypotheses. A six-weeks leg wound complications rate was assumed to be 20% in the conventional arm and less of 4% in the endoscopic arm. Previously quoted studies suggest a first-year vein-graft failure rate of about 20% with an annual occlusion rate of 1% to 2% in the first six years, with practically no difference between the endoscopic and conventional approaches. Similarly, the results on event-free survival rates for the two arms have barely a 2-3% gap. Assuming a 10% drop-out rate and a 5% cross-over rate, the goal is to enrol 230 patients from a single Italian cardiac surgery centre.

Discussion

The goal of this prospective randomized trial is to compare and to test improvement in wound healing, quality of life, safety/efficacy, cost-effectiveness, short and long-term outcomes and vein-graft patency after endoscopic open CO₂ harvesting system versus conventional vein harvesting.

The expected results are of high clinical relevance and will show the safety/efficacy or non-inferiority of one treatment approach in terms of vein harvesting for coronary artery bypass grafting surgery.

Trial registration

www.clinicalTrials.gov NCT01121341.

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.

Long-term follow-up of patients operated with the symmetry proximal connector device

OBJECTIVE

: The Symmetry proximal connector device was introduced as a facilitator for construction of proximal anastomosis in coronary bypass surgery. Use of the connector made it unnecessary to clamp the ascending aorta. Early results were promising, but a controlled study performed in our center demonstrated poor angiographic patency of saphenous veins attached with the connector. The objective of this study was to investigate long-term clinical results in patients operated with connector or traditional suture technique.

METHODS

: At a minimum of 5 years after surgery, medical records of 46 patients who had undergone off-pump coronary bypass with Symmetry (n = 23) or traditional suture (n = 23) were examined, and the patients were interviewed personally by phone. Patients were asked about the presence of angina pectoris, hospital admission for cardiac conditions, or the need for new interventions. The Norwegian population registry was used to document survival status.

RESULTS

: Two control patients and five Symmetry patients died during the observation period (P = 0.414). Seven Symmetry and one control patient required reintervention (P = 0.015). Of the patients who were interviewed, 8 of 19 Symmetry patients suffered from angina and none of 20 control patients (P = 0.003).

CONCLUSIONS

: Patients who were operated with the Symmetry connector device have a high chance of having cardiac ischemia in the intermediate to long term after surgery, despite of relatively frequent reintervention. Patients operated with this connector requires close clinical follow-up.

Impact of endoscopic versus open saphenous vein harvest technique on late coronary artery bypass grafting patient outcomes in the ROOBY (Randomized On/Off Bypass) Trial

OBJECTIVE

In the Randomized On/Off Bypass (ROOBY) Trial, the efficacy of on-pump versus off-pump coronary artery bypass grafting was evaluated. This ROOBY Trial planned subanalysis compared the effects on postbypass patient clinical outcomes and graft patency of endoscopic vein harvesting and open vein harvesting.

METHODS

From April 2003 to April 2007, the technique used for saphenous vein graft harvesting was recorded in 1471 cases. Of these, 894 patients (341 endoscopic harvest and 553 open harvest) also underwent coronary angiography 1 year after coronary artery bypass grafting. Univariate and multivariable analyses were used to compare patient outcomes in the endoscopic and open groups.

RESULTS

Preoperative patient characteristics were statistically similar between the endoscopic and open groups. Endoscopic vein harvest was used in 38% of the cases. There were no significant differences in both short-term and 1-year composite outcomes between the endoscopic and open groups. For patients with 1-year catheterization follow-up (n=894), the saphenous vein graft patency rate for the endoscopic group was lower than that in the open harvest group (74.5% vs 85.2%, P<.0001), and the repeat revascularization rate was significantly higher (6.7% vs 3.4%, P<.05). Multivariable regression documented no interaction effect between endoscopic approach and off-pump treatment.

CONCLUSIONS

In the ROOBY Trial, endoscopic vein harvest was associated with lower 1-year saphenous vein graft patency and higher 1-year revascularization rates, independent of the use of off-pump or on-pump cardiac surgical approach.

Sutureless proximal anastomosis using the PAS-Port system: six-month patency and five-year follow-up in "all-comers"

BACKGROUND

The PAS-Port system (Cardica, Inc, Redwood City, CA) was used routinely for patients undergoing coronary surgery with at least one venous graft. Graft patency and clinical results were evaluated, respectively, at 6 months and 5 years after surgery.

METHODS

A total of 100 patients (82 males, 18 females; mean age 68.9 ± 12 years) underwent coronary bypass surgery with at least one PAS-Port anastomosis (total number of PAS-Port implants: n = 117). At 6 months after surgery all patients were followed up clinically and 86 patients with 101 PAS-Port implants underwent either a multidetector computed tomographic scan or coronary angiography. Actuarial freedom from MACCE (major adverse cardiac and cerebrovascular events) was assessed at 5 years after surgery.

RESULTS

Six-month PAS-Port patency was 88%. The inner diameter of the graft at the implant site (measured in 26 patients) did not reveal any pathologic narrowing (mean inner diameter 3.1 ± 0.6 mm). At 5 years, freedom from overall MACCE was 79% ± 5% and freedom from PAS-Port target vessel revascularization was 94% ± 6%.

CONCLUSIONS

The routine use of PAS-Port was associated with good vein graft patency at 6 months and a low incidence of MACCE at 5 years after surgery. No evidence of implant-related graft stenosis was detected.