Evaluation of robotic coronary surgery with intraoperative graft angiography and postoperative multislice computed tomography

Graft Patency after Robotically Assisted Coronary Artery Bypass Surgery

Objective

With advances in robotic instrumentation and technology, both robotically assisted minimally invasive direct coronary artery bypass (RMIDCAB) and totally endoscopic coronary artery bypass (TECAB) have been widely used over the past 20 years. Graft patency is the most important outcome in coronary bypass surgery and is associated with long-term prognosis. In this article we reviewed all experts’ studies in the field of robotic assisted coronary artery bypass and investigated graft patency in patients who underwent RMIDCAB or TECAB.

Methods

We performed a literature search in PubMed from 1999 to 2018 using the terms “Robotic” and “Coronary bypass” and/or “Minimally invasive” and/or “Totally endoscopic.” Of the articles found, studies investigating graft patency were specifically selected.

Results

In 33 articles, a total of 4,000 patients underwent robotic assisted coronary artery bypass surgery either by a RMIDCAB (2,396) or by a TECAB (1,604) approach. The graft patency was assessed by invasive angiography or computed tomographic angiography in all studies. The mean graft patency at early (<1 month), midterm (<5 years), and long-term (>5 years) follow-up was 97.7%, 96.1%, and 93.2% in RMIDCAB and 98.8%, 95.8%, and 93.6% in TECAB, respectively.

Conclusions

The graft patency of robotic assisted coronary artery bypass was equivalent to reported outcomes of the conventional approach. These results should encourage the adoption of robotic approaches in coronary bypass surgery.

The state of robotic cardiac surgery in Europe

BACKGROUND

In the past two decades, the introduction of robotic technology has facilitated minimally invasive cardiac surgery, allowing surgeons to operate endoscopically rather than through a median sternotomy. This approach has facilitated procedures for several structural heart conditions, including mitral valve repair, atrial septal defect closure and multivessel minimally invasive coronary artery bypass grafting. In this rapidly evolving field, we review the status of robotic cardiac surgery in Europe with a focus on mitral valve surgery and coronary revascularization.

METHODS

Structured searches of MEDLINE, Embase, and Cochrane databases were performed from their dates of inception to June 2016. All original studies, except case-reports, were included in this qualitative review. Studies performed in Europe were presented quantitatively. Data provided from Intuitive Surgical Inc. are also presented.

RESULTS

Fourteen papers on coronary surgery were included in the analysis and reported a mortality rate ranging between 0-1%, revision for bleeding between 2-7%, conversion to a larger incision between 2-15%, and patency rate between 92-98%. The number of procedures ranged between 23 and 170 per year. There were only a small number of published reports for robotic mitral valve surgery from European centers.

CONCLUSIONS

Coronary robotic surgery in Europe has been performed safely and effectively with very few perioperative complications in the last 15 years. On the other hand, mitral surgery has been developed later with increasing applications of this technology only in the last 5-6 years.

Anatomy-based eligibility measure for robotic-assisted bypass surgery

OBJECTIVE

Robotic-assisted endoscopic single-vessel small thoracotomy allows clinicians to perform coronary artery bypass grafting surgery in a minimally invasive manner using the da Vinci Surgical System. Not all patients are suitable for this technique, and the lack of an appropriate method for patient eligibility avoids completion of the procedure robotically. The objective of this study was to develop a patient eligibility method based on the anatomy of the chest of the patient.

METHODS

Preoperative computed tomography thorax scans of 110 patients were analyzed. Two-dimensional measurements taken on the axial images were used with the goal of finding a relation between the anatomy of the patient and the completion of the procedure robotically.

RESULTS

Patients with a distance from the left anterior descending coronary artery to the anterior chest wall of smaller than 15 mm have a 20% probability of requiring conversion of the procedure to open surgery. This probability increases if the chest of the patient is very elliptical, having an anterior-posterior dimension of less than 45% of the transverse dimension.

CONCLUSIONS

The smaller the distance is from the left anterior descending artery to the anterior chest wall, the lower the chances are of completing the procedure robotically.

Systematic review of robotic-assisted, totally endoscopic coronary artery bypass grafting

BACKGROUND

Advancements in surgical robotic technology over the last two decades have enabled coronary artery bypass grafting to be performed totally endoscopically, and have the potential to significantly change clinical practice in the future.

METHODS

A systematic review of studies reporting clinical outcomes of total endoscopic coronary artery bypass grafting (TECABG) was performed.

RESULTS

14 appraised studies included 880 beating heart TECABGs, 360 arrested heart TECABGs, 633 one-vessel operations and 357 two-vessel operations. Patients were generally low-risk. There was a significant learning curve. The weighted means for short-term beating heart and arrested heart TECABG results respectively were: intraoperative exclusion rate of 5.7% and 1.9%, intraoperative conversion rate of 5.6% and 15.0%, all-cause mortality of 1.2% and 0.4%, stroke of 0.7% and 0.8%, myocardial infarction of 0.8% and 1.8%, new onset atrial fibrillation of 10.7% and 5.1% and post-operative reintervention rate of 2.6% and 2.3%. The overall rate of short term postoperative graft patency for beating heart and arrested heart TECABG was 98.3% and 96.4% respectively.

CONCLUSIONS

Appropriate patient selection was important in minimizing the risk of intraoperative and postoperative complications. Short-term outcomes of both beating and arrested heart TECABG were acceptable, but results so far have been heterogeneous. There were fewer studies reporting intermediate to long-term outcomes, but results were encouraging, and further investigation and development of the procedure is warranted.

Predictors, causes, and consequences of conversions in robotically enhanced totally endoscopic coronary artery bypass graft surgery

BACKGROUND

Totally endoscopic coronary artery bypass graft surgery (TECAB), using the da Vinci telemanipulator, has become a reproducible operation at dedicated centers. As in every endoscopic operation, conversion is an important and probably inevitable issue.

METHODS

We performed robotic TECAB in 326 patients (age, 60 years; range, 31 to 90 years); 242 were single-vessel and 84 were multivessel TECAB.

RESULTS

Forty-six of 326 patients (14%) were converted to a larger incision (minithoracotomy, n = 5; sternotomy, n = 41). Left internal mammary artery injury (n = 7), epicardial injury (n = 4), balloon endoocclusion problems (n = 7), and anastomotic problems (n = 18) were common reasons for conversions. Conversion rate was significantly less for single-vessel versus multivessel TECABs (10% versus 25%; p = 0.001). Non-learning-curve case (7% versus 21%; p < 0.001) and transthoracic assistance (11% versus 22%; p = 0.018) were associated with lower conversion rates. In multivariate analysis, learning-curve case was the only independent predictor of conversion (p = 0.005). Conversion translated into increased packed red blood cell transfusion in the operating room (3 versus 0 units; p < 0.001), longer ventilation time (14 versus 8 hours; p < 0.001), and intensive care unit stay (45 versus 20 hours; p = 0.001). Hospital mortality was 0.6% in this series, with 1 patient in the conversion group (2.2%) and 1 patient in the nonconverted group (0.4%; not significant). Five-year survival was 98% in nonconverted patients and 88% in converted patients (p = 0.018). There was no difference in freedom from angina or freedom from major adverse cardiac and cerebral events.

CONCLUSIONS

Conversion in TECAB is primarily learning curve-dependent and associated with increased morbidity, but does not significantly affect hospital mortality. Both nonconverted and converted patients show good long-term survival, which is comparable to patients undergoing open sternotomy coronary artery bypass grafting. Long-term freedom from angina or freedom from major adverse cardiac and cerebral events is not influenced by conversion.

Low dose high-pitch spiral acquisition 128-slice dual-source computed tomography for the evaluation of coronary artery bypass graft patency

OBJECTIVES

To prospectively assess electrocardiography (ECG)-synchronized dual-source computed tomography (CT) in high-pitch spiral acquisition mode for the evaluation of coronary artery bypass graft (CABG) patency regarding image quality and radiation dose.

MATERIALS AND METHODS

Fifty consecutive patients (47 men, age 69.6 +/- 9.6 years, body mass index 26.6 +/- 3.5 kg/m) underwent clinically indicated 128-slice dual-source CT angiography of the entire thorax for the evaluation of graft patency after CABG surgery using a prospectively ECG-synchronized high-pitch spiral acquisition mode (pitch 3.2; 100 kV tube voltage, 0.28 seconds gantry rotation time). Heart rates (HR) were noted. Image quality of the proximal anastomosis, graft body, distal anastomosis, and postanastomotic coronary artery were graded by 2 independent readers on a 3-point scale (1 = excellent, 2 = moderate, and 3 = poor/nondiagnostic). Quantitative image quality parameters (noise, contrast-to-noise ratio) were measured. Effective radiation doses were calculated.

RESULTS

Mean HR was 76 +/- 19 bpm (range, 45-135 bpm). Median scan time was 0.9 seconds (range, 0.76-1.17 seconds), mean scan length was 349 +/- 38 mm (range, 294-452 mm). A total of 125 CABG (54% arterial grafts) and 465 vessel sections were analyzed. Twelve grafts were proximally occluded. Diagnostic image quality was obtained in 462 (99.4%) sections. Of those, image quality was excellent in 397 (85.4%) and moderate in 65 (14.0%). All 3 (0.6%) nondiagnostic sections affected the distal anastomosis due to motion artifacts caused by high HR. Separating the study population by the median HR of 71 bpm, image quality of the distal anastomosis regarding motion artifacts was significantly lower at high HR (P < 0.05). Interobserver agreement in grading image quality of graft segments was good (kappa = 0.77). Image noise in the aorta was 36.9 +/- 8.1, contrast-to-noise ratio was 13.1 +/- 4.2. Effective radiation dose was 2.3 +/- 0.3 mSv.

CONCLUSIONS

The patency of coronary artery bypass grafts can be assessed with decreasing image quality at high HR in high-pitch prospectively ECG-synchronized thoracic 128-slice dual-source CT angiography at a low radiation dose.

Preoperative Evaluation of Patient Anatomy to Increase Success of Robotics-Assisted Bypass Surgery

Objective

Robotics-assisted endoscopic atraumatic coronary artery bypass has been shown to be effective in reducing surgical morbidity and length of hospital stay. Unfortunately, the criteria for selecting eligible patients for this procedure are still primitive. This has motivated the use of preoperative computed tomography scans to establish patient eligibility. The objective of this study is to establish which image measurements can be correlated to procedure success.

Methods

A retrospective study was performed in 144 patients who underwent robotics-assisted coronary bypass surgery. After an initial set of 55 patients, preoperative computed tomography scans of the other patients were used to obtain patient specific measurements: the lateral distance between the midline of the sternum to the left anterior descending coronary artery and its depth from the skin surface, anteroposterior diameter of the thoracic cavity, and the transverse diameter of the thoracic cavity. The procedures were rated as successful if completed in a minimally invasive manner. Different combinations of the variables were evaluated and correlated with success.

Results

A strong correlation was found between success rate and the ratio of the lateral distance to the transverse diameter in the female patients only (0.532, P = 0.006). A ratio of less than 0.20 significantly increased the occurrence of conversion during this procedure in female cases.

Conclusions

The lateral distance of the left anterior descending coronary artery from the midline divided by the transverse thoracic width of a female patient shows a significant correlation with procedure success. No significant correlations were found for male patients.

Robotic Technology—Probably a Safe Tool for Development of Completely Endoscopic Coronary Revascularization Procedures

Background

Totally endoscopic coronary artery bypass grafting (TECAB) requires telemanipulation technologies because attempts using conventional thoracoscopic instrumentation have completely failed. These complex operations require individual and team learning curves and necessitate a stepwise approach. The aim of this study is to assess risk adjusted outcome in robotically assisted coronary artery bypass grafting (CABG) after the first 6 years of application.

Methods

From 2001 to 2007, 177 CABG procedures were performed using the da Vinci system. A low risk patient population [age 59 (31–76) years, EuroSCORE 1 (0–7)] was treated. The following procedures were carried out: endoscopic internal mammary artery takedown in minimally invasive direct coronary artery bypass, Off-pump coronary artery bypass, and CABG (n = 26); robotic suturing of left internal mammary artery to left anterior descending artery anastomoses through sternotomy (n = 32); TECAB on the arrested heart (n = 108); TECAB on the beating heart (n = 11).

Results

There was no hospital mortality, and cumulative risk adjusted mortality plots showed that 2.76 predicted events did not occur. Given 177 event free procedures Clopper Pearson estimations revealed a 95% confidence interval between 0.0% and 2.3% for perioperative mortality.

Conclusions

Introduction of robotic TECAB grafting appears to meet current CABG safety standards. Initial application in low risk patients and a stepwise approach towards completely endoscopic versions of the operation are worthwhile. Despite a high grade of innovation and despite learning curves, perioperative mortality may be lower than predicted.

Diagnostic Performance of 64-Slice Computed Tomography in Evaluation of Coronary Artery Bypass Grafts

OBJECTIVE

The purpose of this study was to compare the diagnostic accuracy of 64-slice CT with that of invasive angiography in the detection of greater than 50% graft stenosis within 2 weeks of coronary artery bypass grafting and to investigate the clinical value of 64-slice CT.

SUBJECTS AND METHODS

Forty-one patients (70 grafts, 46 arterial and 24 venous) underwent 64-slice CT a mean of 2.6 years after minimally invasive or conventional coronary artery bypass surgery.

RESULTS

All 70 grafts were assessable, and none of the grafts was excluded from analysis. For the detection of 50-90% graft stenosis, the sensitivity of CT was 75%, the specificity was 95%, the positive predictive value was 67%, and the negative predictive value was 97% (true disease prevalence, 8/70 grafts; 11%). Greater than 50% graft stenosis and occlusion pooled together (prevalence, 14/70; 20%) were detected with a sensitivity of 85%, specificity of 95%, positive predictive value of 80%, and negative predictive value of 96%. Vein graft disease was found in eight (42%) of 19 patent vein grafts (graft age, 15.6 +/- 2.3 years). The disease was nonobstructive in three (16%) of the 19 grafts. The course of the left internal mammary artery was median retrosternal (< 1 cm deep) in 33.3% of conventionally sutured grafts.

CONCLUSION

Sixty-four-slice CT angiography can be used for accurate exclusion of greater than 50% graft stenosis, but detection of distal anastomotic stenosis is limited, and the degree of stenosis can be overestimated. The advantages of CT, however, are that it is noninvasive, vein graft disease can be diagnosed at an early stage, and complementary evaluation of extracardiac anatomic features provides useful information before coronary artery bypass grafting is redone.

[Clinical development of cardiac CT diagnostics: clinical and scientific applications from the cardiologist's point of view]

The development of cardiac CT imaging has been extraordinary in the last few years. Due to excellent cooperation with our radiology departments we have been able to gain a very close insight into the newest clinical and technical improvements made in this field. The following article aims to highlight the relevant, practically orientated indications and applications of cardiac CT. Furthermore you will find a summary of clinically driven multicenter and interdisciplinary scientific work using this fascinating imaging modality.

Hybrid Coronary Artery Revascularization—Review and Update 2007

Hybrid coronary revascularization is a combination of minimally invasive coronary artery bypass grafting and percutaneous coronary intervention in patients with multivessel coronary artery disease. The concept is now 10 years old. Implementation was slow, but major developments have taken place. The surgical part of the procedure can be performed in a totally endoscopic fashion instead of by a mini-incision approach and catheter-based intervention includes the use of drug-eluting stents. Whereas during early development staged approaches were taken, simultaneous interventions have become feasible. Hybrid procedures are an attractive option for high-risk patients or for patients who seek a less traumatic revascularization option.

Multislice Computed Tomography for Preoperative and Postoperative Assessment in Totally Endoscopic Coronary Artery Bypass Grafting

This article reviews the clinical value of noninvasive multi-slice computed tomography (MSCT) angiography before and after totally endoscopic coronary artery bypass surgery. The use of coronary and aorto-iliaco-femoral MSCT angiography in the preoperative assessment is addressed and the use of bypass MSCT angiography for postoperative control of bypass graft patency is discussed.