Early-term Outcomes And Experience Of No-touch Endoscopic Saphenous Vein Graft Harvesting

Rihito Tamaki1, Kohei Abe1, Kunihiko Yoshino2, Yuichi Nakamura1, Ryota Nakamura1, HidefumiNishida1, Hiroyasu Misumi1
1 St. Luke's International Hospital, Chuo-ku, Tokyo, Japan
2 Tokyo Bay Urayasu Ichikawa Medical Center, Urayasu, Chiba, Japan

Background

　Saphenous vein graft (SVG) is one of the most versatile and frequently used graft in coronary artery bypass surgery and an endoscopic vein harvesting (EVH) was developed to reduce its invasiveness. Recently, no-touch saphenous vein graft (NT-SVG) has been reported to increase graft patency, however, NT-SVG is often associated with wound complication. To address this issue, we developed a no-touch endoscopic vein harvesting (NT-EVH) technique¹⁾. 

Methods

　NT-EVH is performed by initially dissecting the anterior and posterior surfaces of the connective tissue surrounding SVG, and then the lateral side of the SVG is dissected with a 0.5-1 cm gap. NT-EVH was initiated in 2018 and we retrospectively evaluated its early patency rate and perioperative characteristics.

Statistical Analysis

　Descriptive statistics are presented as count (%) for categorical variables and mean ± standard deviation (SD), as appropriate. Fisher’s exact test for categorical variables and  the student t test or Wilcoxon rank sum test for continuous variables were used, as appropriate. Spearman's rank correlation coefficient was used to analyze the learning curve. The criterion of significance was an α value of 0.05 or less. 

Results

Baseline Characteristics (Table1)
 
　59 patients underwent coronary artery bypass grafting (CABG) with 63 endoscopically harvested NT-SVGs. The average age was 67.3±9.9, and 50 patients (84.7%) were male. The mean ejection fraction was 51.2±13.5% and the mean Euro2 score was 3.05±4.12. 
Perioperative Characteristics (Table2)

　41 patients (69.5%) underwent off-pump CABG, and 11 patients (18.6%) underwent urgent or emergent surgeries. No patient experienced lower extremity surgical-site infections requiring antimicrobial therapy.

Details of the harvested SVGs (Table3)

　 The early graft patency rate was 91.4% (53/58 grafts). The right coronary artery was the most common anastomotic site (91.5%). Intraoperative graft flow tended to be lower in the early occlusion group of SVG compared to the patency group (25.0±8.0 vs 61.7±44.1 ml/min, p=0.071).

Learning Curve of NT-EVH (Figure1)

　There was a learning curve for NT-EVH (64.3±19.9min) and a correlation between case number and harvesting time (r=-0.425, p=0.001).

Discussion

　The NT-SVG technique has a high early patency rate of 97.2%, but wound infections can occur in about 10.3% of cases.²⁾Conventional EVH has an 85% patency rate at 6 months.³⁾ NT-EVH combines the advantages of both techniques and has good early patency and no wound infections.

The NT-EVH technique takes longer to harvest and requires more learning compared to EVH. However, the difference in harvest time is not significant, with NT-EVH taking 60 minutes on average⁴⁾ and EVH taking 57 minutes. Furthermore, the harvesting device is not designed for pedicle harvesting and needs improvements

Conclusion

 　NT-EVH has shown good initial results with few wound complications. It is an innovative technique that requires further study to determine its long-term patency.

References

　1. Yoshino K, et al. Innovations 2020;15:475-7
　2. Tian M, et al. Circulation 2021;144:1120-9.
　3. Williams J B, et al. JAMA 2012;308:475-84.
　4. Zenati M A, et al. N Engl J Med 2019;380:132-41