Comparison Of Perioperative Outcomes Of Different Left Internal Thoracic Artery Harvesting Techniques,Their Safety And Effect On The Quality Of LITA During The Learning Curve

Background:Coronary artery bypass surgery is the standard procedure for left main coronary artery or multi vessels coronary artery disease.Recently more arterial grafts are used for CABG surgeries because of its patency and long-term survival benefits.Left internal thoracic artery(LITA)is considered to be the gold standard arterial conduit for left anterior descending artery revascularization.With the advancement in cardiac surgery in the recent decades,minimal invasive procedures are performed to harvest internal thoracic arteries and undergo coronary revascularization.Harvesting of ITAs is one of the important steps for coronary revascularization.Herein we observe and compare the quality of LITA harvested with minimal invasive techniques(robotic assisted LITA harvesting,and LITA harvesting through minimal invasive anterolateral thoracotomy)and perioperative outcome of these procedures during the learning curve to the classical sternotomy LITA harvesting technique.The aim of the present study was to observe whether LITA harvesting through the less invasive approaches during the learning curve is feasible,safe,and achieves the same clinical results as that of classical sternotomy LITA harvesting.Materials and Methods:We searched our hospital database,from January 2015 to December 2020 for all cardiac surgeries performed by a single surgical team.Total of 768 surgeries were performed out of which 615 surgeries were off-pump isolated CABG.76 surgeries were minimal invasive left ITA harvesting:32 robotic assisted LITA harvesting(RALH),42 minimal invasive direct LITA harvesting(MIDLH),and two thoracoscopic LITA harvesting.Based on age and gender 64 conventional sternotomy LITA harvesting(CSLH)patients were selected from large conventional sternotomy off pump coronary artery bypass(OPCAB)pool with 1:2 to RALH group.Classical sternotomy was performed and ITAs were harvested under direct vision in CSLH group.In MIDLH group small anterolateral thoracotomy was performed and LITA was harvested under direct vision.In RALH group LITA was harvested with the assistance of da Vinci robot system.So,we had total of 138 patients divided into three different LITA harvesting techniques groups:CSLH(n=64),MIDLH(n=42),and RALH(n=32).The same 138 patients were also divided into sternotomy(n=64),and non-sternotomy(n=74)groups keeping both MIDLH and RALH in the non-sternotomy group for different study design.LITA quality was assessed by LITA damage,perioperative myocardial infarction,computed tomographic angiography(CTA)LITA’s patency on discharge and after one year.Other perioperative parameters such as harvesting time,conversion to sternotomy,need of CPB,reoperation for bleeding,24 hours postoperative chest tube drainage,total ICU stay,and hospital mortality were recorded to observe the safety and feasibility of these minimal invasive LITA harvesting procedures.Results:The mean LITA harvesting time was 36.9±14.3,74.4±24.2,and 164.7±51.9 minutes for CSLH,MIDLH,and RALH groups respectively(p<.001).One patient 1/32(3.1%)in RALH group had LITA damage while other two groups had none.One-month LITA CTA patencywas 56/57(98.2%),34/36(94.4%),and 27/27(100%),(p=.339)while one-year CTA patency was 47/51(92.1%),30/33(90.9%),and 24/25(96%)for CSLH,MIDLH,and RALH groups respectively(p=.754).The 24 hours postoperative chest tube drainage was also significant with 578.8±258.3 ml in CSLH,451.1±399.2 ml in MIDLH,and 285.3±313.0 ml in RALH group(p<.001).ICU stay was with 50.7±36.1 hours in CSLH group,34.9±27.2 hours in MIDLH group,and 37.1±25.8 hours in RALH group(p=.024).Ventilation time was 17.3±19.1 hours in CSLH,9.9±12.6 hours in MIDLH,and 9.2±9.4 hours in RALH group(p=.017).Comparisons of means in case of sternotomy vs non-sternotomy resulted in LITA harvesting time of 36.9±14.3,and 113.6±59.3(p<.001)respectively.One patient 1/74(1.35%)in non-sternotomy group had LITA damage,while none occurred in sternotomy group.CTA patency on discharge was 56/57(98.2%),and 61/63(96.8%),(p=.619),while one-year CTA patency was 47/51(92.1%),and 54/58(93.1%)(p=.850)for sternotomy vs non-sternotomy groups.The 24 hours postoperative chest tube drainage,ventilation time,and ICU stay were also statistically significant in favor of non-sternotomy with 578.8±258.3 ml,and 380.7±372 ml(p<.001),17.3±19.1 hours,and 9.6±11.3 hours(p=.004),and 50.7±36.1 hours,and 35.8±26.5 hours(p=.006)for sternotomy vs non-sternotomy groups respectively.Conclusion:Less invasive left internal mammary artery harvesting during the learning curve has no negative impact on the quality of LITA.Perioperative outcomes are comparable to standard procedure except for prolonged harvesting time.RALH is the least invasive and most time-consuming procedure during the learning curve.Postoperative ICU stay,ventilation time,and 24-hours postoperative chest tube drainage are in the favor of minimal invasive LITA harvesting techniques.These minimal invasive LITA harvesting procedures are feasible and can be performed safely during the learning curve.