Harvesting techniques of the saphenous vein graft for coronary artery bypass: Insights from a network meta-analysis

Does the experience of the endoscopic vein harvester matter to the quality of the vein conduit: A critical thematic literature review

Coronary artery bypass graft surgery remains the golden standard surgical option for multiple vessel disease. Harvesting the long saphenous vein using endoscopic vein harvesting requires advanced surgical skills dexterity, but the lack of a national standardised training programme allows for variance in the learning curve and the quality of the vein during the learning cycle is unknown. A search of bibliographic databases: CINHAL Plus, Embase, Pubmed and the Cochrane register for randomised controlled trials identified 11 articles eligible for review. The themes emerging were learning curve-associated injuries to the long saphenous vein, intimal wall remodelling of the long saphenous vein and incidence of graft patency rates. Harvesting practitioners with less than 100 cases of experience inflict more conduit injuries leading to endothelial remodelling and narrowed vein grafts at the six-month point resulting in lumen loss. Practitioners with more than 100 cases demonstrated reduced learning curve-related injuries on the conduit. Adopting a formalised structured training programme such as the Manchester Endoscopic Learning Tool has shown to reduce endothelial injury to the long saphenous vein minimising early vein graft failure during the learning cycle.

A Comprehensive Clinical Outcome Analysis of Endoscopic Vessel Harvesting for Coronary Artery Bypass Surgery

Background: The long saphenous vein is routinely used for coronary bypass graft (CABG) surgery, and two primary techniques are commonly utilized: endoscopic vessel harvesting (EVH) and open vessel harvesting (OVH). The aim of this study was to compare the clinical outcomes of the EVH and OVH techniques used for CABG within the confines of a tertiary hospital. Methods: The clinical data of all patients subjected to either EVH or OVH for CABG surgery between 2014 and 2018 were retrospectively analyzed. Statistical analysis was performed to discern variations in the rates of postoperative complications between EVH and OVH. Results: A cohort of 1884 individuals were included in this study, 75.3% of whom underwent EVH. Notably, the incidence of postoperative leg wound complications was significantly different between the patients who underwent OVH and the patients who underwent EVH, with incidence rates of 18.6% and 32%, respectively (p < 0.001). Leg wound complications (p < 0.001; OR 1.946; 95% CI 1.528-2.477) and leg wound infections (p = 0.050, OR 1.517, 95% CI 0.999-2.303) were significantly associated with OVH. Moreover, leg wound hematoma (p = 0.039, OR = 0.402, 95% CI = 0.169-0.957) and EVH were strongly associated. Conclusions: The large sample of patients and the inclusion of a range of Asian ethnic groups provided notable insights into postoperative complications related to different modalities. EVH was associated with a lower incidence of postoperative leg wound complications, which suggests that EVH is a better modality for those undergoing CABG surgery.

Influence of Three Different Surgical Techniques on Microscopic Damage of Saphenous Vein Grafts-A Randomized Study

Background and Objectives: The saphenous vein is one of the most common used grafts (SVG) for surgical revascularization. The mechanism of the SVGs occlusion is still unknown. Surgical preparation techniques have an important role in the early and late graft occlusion. Our study analyzed the influence of the three different surgical techniques on the histological and immunohistochemical characteristics of the vein grafts. Methods: Between June 2019 and December 2020, 83 patients who underwent surgical revascularization were prospectively randomly assigned to one of the three groups, according to saphenous vein graft harvesting (conventional (CVH), no-touch (NT) and endoscopic (EVH)) technique. The vein graft samples were sent on the histological (hematoxylin-eosin staining) and immunohistochemical (CD31, Factor VIII, Caveolin and eNOS) examinations. Results: The CVH, NT, and EVH groups included 27 patients (mean age 67.66 ± 5.6), 31 patients (mean age 66.5 ± 7.4) and 25 patients (mean age 66 ± 5.5), respectively. Hematoxylin-eosin staining revealed a lower grade of microstructural vein damage in the NT group (2, IQR 1-2) in comparison with CVH and EVH (3, IQR 2-4), (4, IQR 2-4) respectively (p < 0.001). Immunohistochemical examination revealed a high grade of staining in the NT group compared to the CVH and EVH group (CD 31 antibody p = 0.02, FVIII, p < 0.001, Caveolin, p = 0.001, and eNOS, p = 0.003). Conclusion: The best preservation of the structural vein integrity was in the NT group, while the lowest rate of leg wound complication was in the EVH group. These facts increase the interest in developing and implementing the endoscopic no-touch technique.

Total arterial coronary artery bypass grafting in patients with preoperative anemia

OBJECTIVES

Blood transfusions after coronary artery bypass grafting (CABG) has been associated to adverse outcomes, especially in anemic patients. However, little is known about the influence of the modality of revascularization. Total arterial revascularization (TAR) was shown to reduce postoperative transfusion when compared to saphenous vein-based (SV)-CABG (LIMA plus one/more SV grafts). We, therefore, aimed to investigate the impact of TAR-CABG versus SV-CABG on blood products use and perioperative outcomes in patients with preoperative anemia, normally at higher risk for postoperative transfusions.

METHODS

From a cohort of 936 patients with mild preoperative anemia undergoing primary elective on-pump CABG, 166 matched pairs of patients undergoing either TAR- or SV-CABG were obtained. Anemia was defined as hemoglobin level <13 g/dl for men and <12 g/dl for women. The primary endpoint was the evaluation of red packed cells (RPC) use over the entire hospital stay.

RESULTS

TAR patients showed significantly reduced RPC usage compared with SV (mean difference 0.45 units). TAR patients had a reduced intubation time (mean difference 7.6 h) and were discharged 1.24 days earlier than SV patients. Pneumonia and acute kidney injury were doubled among SV patients. Adjusted regression showed that TAR technique is a predictor of reduced RPC unit use regardless of age and EuroSCORE II (odds ratio: 0.63, p < .01).

CONCLUSION

Patients with preoperative anemia might benefit from TAR regardless of age or calculated operative risk. TAR-CABG was associated to reduced postoperative use of blood products and postoperative length of stay in comparison with SV-CABG in this subset of patients.