Table 1:

Best evidence papers

Author, date and country Study type (level of evidence)	Patient group	Outcomes	Key results	Comments
Gao et al. (2011), J Thorac Cardiovasc Surg, China [2] Single-centre, retrospective study (level 2b)	58 patients (mean age 56.97 ± 9.7 years) da Vinci surgical system utilized 16 patients underwent a hybrid procedure Follow-up by computed tomography angiography at 3, 6 and 12 months	Incidence of ITA injury Re-exploration for bleeding Conversions In-hospital mortality Target-vessel reintervention Mean ITA harvest time Mean anastomosis time Mean operation time Predischarge graft patency Post-discharge graft patency	0/58 (0%) 1/58 (1.7%) 2/58 (3%) 0/58 (0%) 0/58 (0%) 31.3 ± 10.5 min (18–55) 11.3 ± 4.7 min (5–21) 264.8 ± 65.6 min (150–420) 100% 100%	TECAB is a safe procedure in selected patients, producing excellent short- and mid-term graft patency results There is a substantial learning curve Careful consideration of patient comorbidities and the location, course and quality of the target vessel are needed
Argenziano et al. (2006), Ann Thorac Surg, USA [3] Multicentre, prospective trial (level 1b)	85 patients (mean age 58.4 years) da Vinci surgical system utilized Follow-up with coronary angiography at 3 months	Incidence of MACE All-cause mortality Perioperative myocardial infarction Target-vessel reintervention Incidence of other adverse events Conversions Reoperation for bleeding Mean ITA harvest time Mean anastomosis time Mean cross-clamp time Mean CPB time Mean operation time 3-month graft patency Overall freedom from reintervention or graft failure	5.9% overall 0/85 (0.0%) 1/85 (1.1%) 4/85 (4.7%) 3/85 (3.5%) 5/85 (6%) 3/85 (3.5%) 60 ± 24 min (26–187) 28 ± 11 min (14–82) 71 ± 26 min (30–140) 117 ± 44 min (41–254) 353 ± 89 min (200–600) Anastomotic occlusion in two cases; ≥50% stenosis in four cases 91%	TECAB can be performed with acceptable safety and efficacy but requires participation in a structured training programme
de Cannière et al. (2007), J Thorac Cardiovasc Surg, Belgium [4] Multicentre, retrospective study (level 2b)	228 patients (mean age 59.2 ± 10.1 years) da Vinci surgical system utilized Patients were categorized to groups: A (on-pump, 90 patients), B (off-pump, 74 patients), or C (conversions, 64 patients) 216 patients were followed up at 6 months	6-month freedom from MACE All-cause mortality Perioperative myocardial infarction (<7 days) Target-vessel reintervention Number of grafts with <50% stenosis in distal anastomosis Negative stress test Combined procedural efficacy	No significant difference between groups Overall: 5/228 (2.1%) A: 1/90 (1.1%) B: 2/74 (2.2%) C: 2/64 (2.31%) Overall: 2/228 (0.9%) A: 1/90 (1.1%) B: 1/74 (1.2%) C: 0/74 (0.0%) Overall: 6/228 (2.6%) A: 2/90 (2.2%) B: 3/74 (4.1%) C: 0/74 (0.0%) A: 61/62 (98.4%) B: 35/38 (92.1%) C: 15/17 (88.2%) A: 23/23 (100%) B: 24/25 (96%) C: 28/28 (100%) A: 97% B: 97% C: 97.7%	Patency rates and 6-month freedom from MACEs were acceptable Both on- and off-pump TECAB are feasible, safe and effective procedures Conversion decreases with time, and does not adversely affect the outcome
Dogan et al. (2002), J Thorac Cardiovasc Surg, Germany [5] Single-centre, retrospective study (level 2b)	45 patients (mean age 63 ± 6 years) da Vinci surgical system utilized 37 patients underwent single-vessel (SV) TECAB; 8 patients underwent double-vessel (DV) TECAB	Operative mortality Bleeding from anastomosis Prolonged cross-clamp time Port-access failure ITA injury Hypovolaemic shock Myocardial infarction Hypoxic brain damage Moderate reperfusion injury Retrograde aortic dissection Conversions Target-vessel reintervention Predischarge graft patency Mean ITA harvest time Mean anastomosis time Mean cross-clamp time Mean CPB time Mean operation time	0/45 (0.0%) 2/45 (4.4%) 4/45 (8.9%) 3/45 (6.7%) 1/45 (2.2%) 1/45 (2.2%) 1/45 (2.2%) 1/45 (2.2%) 1/45 (2.2%) 1/45 (2.2%) 10 of the first 22 patients; 1 in the last 20 patients 0/45 (0%) 100% in the first 22 patients SV: 65 ± 21 min DV: 118 ± 12.3 min SV: 18.4 ± 3.8 min DV: 21.2 ± 6.3 min SV: 61 ± 16 min DV: 99 ± 55 min SV: 136 ± 32 min DV: 197 ± 63 min SV: 4.2 ± 0.9 h DV: 6.3 ± 1.0 h	Majority of complications occurred in the first 20 patients, and are associated with the learning curve Bilateral ITA grafting is possible, but is technically challenging and very time-consuming After learning curve, single-vessel TECAB is a straightforward procedure
Kappert et al. (2008), J Thorac Cardiovasc Surg, Germany [6] Single-centre, retrospective study (level 2b)	41 patients (mean age 60.6 ± 8.9 years) da Vinci surgical system utilized First eight procedures performed on arrested hearts; subsequent procedures were off-pump Mean follow-up period 69 ± 7.4 months	In-hospital survival Conversions Overall survival after 5 years Myocardial infarction Myocardial infarction and cardiac death Repeated revascularization of target vessel Freedom from any major adverse event Freedom from MACE Freedom from LAD intervention	41/41 (100%) 0/41 (0%) 38/41 (92.7%) <6 months: 1/41 (2.4%) >6 months: 1/41 (2.4%) 2/41 (4.8%) <6 months: 3/41 (7.3%) >6 months: 2/41 (4.8%) 75.6% 82.9% 82.7%	Relatively high incidence of target-vessel reintervention following TECAB leaves significant room for improvement Advances in instrumentation and anastomotic technology will produce increasingly reproducible results
Mishra et al. (2008), Asian Cardiovasc Thorac Ann, India [7] Single-centre, retrospective study (level 2b)	13 patients (mean age 56.3 ± 7.2 years) da Vinci surgical system utilized 11 procedures were off-pump; 2 were performed on an arrested heart Follow-up with coronary angiography at 3 months	Perioperative myocardial infarction Reoperation for bleeding New-onset atrial fibrillation Wound infection Postoperative mortality Late mortality Conversions Recurrence of angina Target-vessel reintervention Graft patency at 3 months Mean ITA harvest time Mean anastomosis time Cross-clamp time CPB time Mean operation time	0/13 (0.0%) 1/13 (7.7%) 0/13 (0.0%) 0/13 (0.0%) 0/13 (0.0%) 0/13 (0.0%) 0/13 (0.0%) 0/13 (0.0%) 0/13 (0.0%) 12/13 (92%) 42 min (35–74) 20–36 min 44 min 64 min 236 ± 45 min (196–296)	Authors advocate early conversion to an open procedure where necessary Authors conclude that beating-heart TECAB is a safe procedure that avoids the harmful effects of CPB
Srivastava et al. (2010), Ann Thorac Surg, USA [8] Single-centre, retrospective study (level 2b)	214 patients (mean age 67.9 ± 11.8 years) da Vinci surgical system utilized All procedures performed on a beating heart Single-vessel (SV) TECAB in 139 patients (65%) Double-vessel (DV) TECAB in 68 patients (32%) Triple-vessel (TV) TECAB in 7 patients (3%) 50 patients underwent hybrid procedures Patients followed up for 528 ± 697 days	Mortality ITA injury Reoperation for bleeding Ventilatory support >48 h New-onset atrial fibrillation Conversions Postoperative recurrence of angina Graft patency Overall clinical freedom from graft failure and reintervention Mean single ITA harvest time Mean bilateral ITA harvest time Mean anastomosis time Mean operation time	SV: 0/139 (0%) DV:0/68 (0%) TV: 0/7 (0%) 0/214 (0%) 2/214 (1%) 8/214 (4%) 22/214 (10%) SV: 5/214 (2.1%) DV: 12/214 (5%) TV: 0/214 (0%) 3/214 (1%) 182/182 (100%) 98.6% SV: 34.5 ± 13.2 min (16–110) DV: 33.2 ± 8.5 min (23–51) DV: 63.7 ± 14.5 min (40–110) TV: 65.9 ± 13.1 min (44–82) SV: 12.5 ± 5.5 min (6–38) DV: 13 ± 4.4 min (7–27) TV: 13.1 ± 3.9 min (8–27) SV: 177.3 ± 52.5 min (84–466) DV: 318.5 ± 97 min (161–616) TV: 523.6 ± 112.3 min (337–682)	Beating-heart TECAB is a safe and efficacious procedure for selected patients with single- and multivessel coronary disease and offers excellent early clinical and graft patency results
Bonatti et al. (2006), J Cardiovasc Thorac Surg, Austria [9] Single-centre, retrospective study (level 2b)	40 patients postoperatively categorized to those without (group 1, mean age 59 years) and with (group 2, mean age 59 years) technical difficulties during TECAB da Vinci surgical system and remote access perfusion CPB utilized All procedures carried out on an arrested heart Follow-up coronary angiography at 3 months in 13 patients from group 1, and 11 patients from group 2	Mortality Patients with technical difficulty Conversions On-table revision Postoperative revision procedure Additional sternotomy Additional mini-thoracotomy ITA injury Epicardial lesion Anastomotic problem Remote access perfusion problem Port bleeding Revision for bleeding Atrial fibrillation Target-vessel reintervention Cumulative survival Cumulative 3-year freedom from angina Anastomotic patency at 3 months Distal target-vessel patency at 3 months Proximal target-vessel patency at 3 months ITA harvest time Anastomosis time Cross-clamp time CPB time	Group 1: 0/20 (0%) Group 2: 0/20 (0%) 20/40 (50%) 6/40 (15%) 3/40 (8%) 4/40 (10%) 11/40 (28%) 2/40 (5%) 4/40 (10%) 3/40 (8%) 7/40 (18%) 9/40 (23%) 3/40 (8%) Group 1: 1/20 (5%) Group 2: 6/20 (30%) Group 1: 2/20 (10%) Group 2: 3/20 (15%) 0% in both groups Group 1: 100% Group 2: 100% Group 1: 93% Group 2: 100% Group 1: 13/13 (100%) Group 2: 11/11 (100%) Group 1: 13/13 (100%) Group 2: 11/11 (100%) Group 1: 13/13 (100%) Group 2: 10/11 (91%) Group 1: 48 min (35–85) Group 2: 55 min (37–70) Group 1: 35 min (26–66) Group 2: 35 min (23–60) Group 1: 80 min (44–132) Group 2: 71 min (37–223) Group 1: 113 min (72–230) Group 2: 134 min (79–368)	Overall problem severity level was low and improved with increasing experience Surgical technical challenges translated into significantly increased operative times Technical difficulties may be frequently encountered during TECAB, but patient-related consequences can be minimized with careful observation and intraoperative quality control Freedom from angina and graft patency are not compromised by technical challenges during TECAB

CPB: cardiopulmonary bypass; ITA: internal thoracic artery; LAD: left anterior descending (artery); MACE: major adverse cardiac event; TECAB: totally endoscopic coronary artery bypass.