Reiza Rayman

Simultaneous integrated coronary artery revascularization with long-term angiographic follow-up

OBJECTIVE Traditionally integrated coronary artery revascularization has been described as a 2-stage procedure. We evaluated the safety and feasibility of 1-stage, simultaneous, hybrid, robotically assisted coronary artery bypass grafting surgery and percutaneous coronary intervention. METHODS Fifty-eight patients underwent simultaneous, integrated coronary artery revascularization in an operating theater equipped with angiographic equipment. Forty-five patients were men. The mean age was 59 years. All internal thoracic arteries were harvested with robotic assistance. All anastomoses were manually constructed through a small anterior non-rib-spreading incision without cardiopulmonary bypass on the beating heart. Immediately after and within the same operative suite, both angiographic confirmation of graft patency and percutaneous coronary intervention were performed. In 52 patients therapeutic anticoagulation was achieved with the direct thrombin inhibitor bivalirudin. RESULTS There were no deaths or wound infections. There was 1 perioperative myocardial infarction. One patient had a stroke, and 3 patients required re-exploration for bleeding. The median lengths of intensive care and hospital stay were 1 and 4 days, respectively. All patients were alive and symptom free at follow-up (mean, 20.2 months; range, 1.1-40.8 months). Long-term angiographic follow-up in 54 patients showed 49 (91%) patent grafts (mean, 9.0 months; range, 4.3-40.8 months). There were 7 in-stent restenoses and 2 occluded stents. CONCLUSION For multivessel coronary artery disease, simultaneous integrated coronary artery revascularization with bivalirudin is safe and feasible. This approach enables complete multivessel revascularization with decreased surgical trauma and postoperative morbidity. Further studies are necessary to better determine patient selection and long-term outcomes.

Cumulative sum failure analysis of a policy change from on-pump to off-pump coronary artery bypass grafting

BACKGROUND Use of the sequential probability cumulative sum (CUSUM) technique may be more sensitive than standard statistical analyses in detecting a cluster of surgical failures. We applied CUSUM methods to evaluate the learning curve after a policy change by a single surgeon from routine on-pump (cardiopulmonary bypass [CPB]) to off-pump coronary artery bypass grafting (OPCAB). METHODS Fifty-five consecutive first-time coronary artery bypass patients (CPB group) were compared with the next 55 patients undergoing an attempt at routine OPCAB using the same coronary stabilizer. The goal in OPCAB patients was to obtain complete revascularization, albeit with a low threshold for conversion to CPB to maximize patient safety during the learning curve. Preoperative patient risk was calculated using previously validated models of the Cardiac Care Network of Ontario. The occurrence of operative mortality and nine predefined major complications (myocardial infarction, bleeding, stroke, renal failure, balloon pump use, mediastinitis, respiratory failure, life-threatening arrhythmia, and sepsis) was compared between the CPB and OPCAB groups using Wilcoxon, Fisher exact, and two-tailed t tests, as well as CUSUM methodology. An intention to treat analysis was performed. RESULTS The CPB and OPCAB groups had similar predicted mortality and length of stays (2.2% +/- 2.5%, 8.1 +/- 2.5 days versus 2.4% +/- 3.5%, 8.1 +/- 2.4 days, respectively). The mean number of grafts per patient was 3.1 +/- 0.7 in the CPB group versus 3.0 +/- 0.7 in the OPCAB group (p = 0.45). Two of 55 (3.6%) CPB patients died, as opposed to 1 of 55 (1.8%) OPCAB patients (p = 0.99). Eight of 55 CPB patients (14.5%) incurred major complications, as opposed to 4 of 55 (7.3%) OPCAB patients (p = 0.36). Median hospital length of stay was 6.0 days in the CPB group versus 5.0 days in the OPCAB group (p = 0.28). On CUSUM analysis, the failure curve in CPB patients approached the upper 80% alert line after eight cases, whereas the curve in OPCAB patients reached below the lower 80% (reassurance) boundary 28 cases after the policy change, indicating superior results in the OPCAB group despite the learning curve. CONCLUSIONS A policy change from coronary artery bypass on CPB to routinely attempting OPCAB can be accomplished safely despite the learning curve. CUSUM analysis was more sensitive than standard statistical methods in detecting a cluster of surgical failures and successes.

A comparison of robot-assisted versus manually constructed endoscopic coronary anastomosis.

BACKGROUND New technology has enabled surgeons to attempt totally endoscopic coronary artery bypass grafting. Our purpose was to compare three different techniques of totally endoscopic anastomosis using a porcine animal model. METHODS Porcine hearts were excised and the right coronary artery was dissected free for use as an arterial graft. The hearts were placed in a human thoracic model and an endoscopic arterial anastomosis between the free right coronary artery and the left anterior descending coronary artery was performed using one of the following: (1) two-dimensional visualization with straight endoscopic instruments (n = 8); (2) three-dimensional head-mounted visualization with curved endoscopic instruments (n = 7); or (3) three-dimensional visualization with robotic telemanipulation (n = 8). Pathologic analysis of suture placement, vessel trauma, and patency was performed. Anastomoses were graded according to quality, ease, and patency using a seven-point Likert scale (1 = excellent, 7 = very poor). RESULTS Endoscopic anastomotic ease and quality were significantly improved when three-dimensional visualization and curved endoscopic instruments were employed. Telemanipulation enhanced the process and provided the best operative results with regard to time required to construct the anastomosis, as well as ease and quality. CONCLUSIONS Totally endoscopic anastomosis is feasible using currently available technology. Three-dimensional visualization and robotic telemanipulation significantly facilitate anastomosis construction and will likely benefit clinical operative outcome.

Effects of latency on telesurgery: an experimental study

The paper is concerned with determining the feasibility of performing telesurgery over long communication links. It describes an experimental testbed for telesurgery that is currently available in our laboratory. The tesbed is capable of supporting both wired and satellite connections as well as simulated network environments. The feasibility of performing telesurgery over a satellite link with approximately 600 ms delay is shown through a number of dry and wet lab experiments. Quantative results of these experiments are also discussed.

Robotic pyeloplasty using internet protocol and satellite network-based telesurgery.

In North America, the urological community has embraced surgical robotic technology in the performance of complex laparoscopic surgery. The performance of complex long‐distance telesurgery requires further investigation prior to clinical application.

Effect of off-pump coronary artery bypass grafting on risk-adjusted and cumulative sum failure outcomes after coronary artery surgery.

Abstract Background and Aim: We have shown that cumulative sum (CUSUM) failure analysis may be more sensitive than standard statistical methods in detecting a cluster of adverse patient outcomes after cardiac surgical procedures. We therefore applied CUSUM, as well as standard statistical techniques, to analyze a surgeons experience with off‐pump coronary artery bypass grafting (OPCAB) and on‐pump procedures to determine whether the two techniques have similar or different outcomes. Methods: In 320 patients undergoing nonemergent, first time coronary artery bypass grafting, preoperative patient characteristics, rates of mortality and major complications, and ICU and hospital lengths of stay were compared between the on‐pump and OPCAB cohorts using Fishers exact tests and Wilcoxon two sample tests. Predicted mortality and length of stay were determined using previously validated models of the Cardiac Care Network of Ontario. Observed versus expected ratios of both variables were calculated for the two types of procedures. Furthermore, CUSUM curves were constructed for the on‐pump and OPCAB cohorts. A multivariable analysis of the predictors of hospital length of stay was also performed to determine whether the type of coronary artery bypass procedure had an independent impact on this variable. Results: The predicted mortality risk and predicted hospital length of stay were almost identical in the 208 on‐pump patients ( 2.2 ± 3.9% ; 8.2 ± 2.5 days) and the 112 OPCAB patients ( 2.0 ± 2.2% ; 7.8 ± 2.1 days). The incidence of hospital mortality and postoperative stroke were 2.9% and 2.4% in on‐pump patients versus zero in OPCAB patients (p= 0.09 and 0.17, respectively). Mechanical ventilation for greater than 48 hours was significantly less common in OPCAB (1.8%) than in on‐pump patients (7.7%, p= 0.04). The rate of 10 major complications was 14.9% in on‐pump versus 8.0% in OPCAB patients (p= 0.08). OPCAB patients experienced a hospital length of stay that was a median of 1.0 day shorter than on‐pump patients (p= 0.01). The observed versus expected ratio for length of stay was 0.78 in OPCAB patients versus 0.95 in on‐pump patients. On CUSUM analysis, the failure curve in OPCAB patients was negative and was flatter than that of on‐pump patients throughout the duration of the study. Furthermore, OPCAB was an independent predictor of a reduced hospital length of stay on multivariable analysis. Conclusions: OPCAB was associated with better outcomes than on‐pump coronary artery bypass despite a similar predicted risk. This robust finding was documented on sensitive CUSUM analysis, using standard statistical techniques and on a multivariable analysis of the independent predictors of hospital length of stay.(J Card Surg 2002;17:520‐528)

Steady flow visualization in a rigid canine aortic cast

Steady flow studies were conducted in a transparent canine aortic cast. The cast segment stretched from the aortic valve to beyond the renal arteries and included all major branches. Flow was visualized by analysis of dye streaklines. Flow rates for basal and exercising cardiovascular states were simulated. The Reynolds numbers in the ascending aorta for basal and exercising conditions were 900 and 1587 respectively. Aortic core flow was laminar in basal simulations. Disturbed flow commenced in the upper descending aorta with exercising flow rates. Separation zones existed along the inner curvature of the aortic arch and the proximal walls of the brachiocephalic, left subclavian, and coeliac arteries. Such zones may exist over a portion of the cardiac cycle. If either renal artery was occluded, then a vortex formed. This vortex is associated with high shear regions which correlate well with sites where sudanophilic lesions have been reported in cholesterol-fed nephrectomized rabbits.

Early experience with robotically assisted internal thoracic artery harvest

We sought to determine the efficacy of using robotic assistance to facilitate endoscopic harvesting of internal thoracic arteries (ITAs). A total of 104 patients had ITAs harvested endoscopically with use of both the AESOP 3000 system (Computer Motion, Goleta, CA, U.S.A.) and Zeus robotic telesurgical system (Computer Motion). All ITAs were harvested with a harmonic scalpel (Ethicon Endosurgery, Cincinnati, OH, U.S.A.). With the left lung collapsed, ITAs were harvested with CO2 insufflation through three 5-mm ports in the left chest. All patients tolerated insufflation without hemodynamic compromise. Average ITA harvest time was 61.3 ± 20.9 minutes. Intraoperative graft flows averaged 36.3 ± 22.4 mL/min. There were three distal ITA injuries; all other vessels were patent after harvesting and demonstrated no angiographic evidence of injury. This article demonstrates a technique by which ITA can be safely harvested totally endoscopically with use of computer-enhanced robotic systems and a harmonic scalpel, allowing complete pedicle dissection through 5-mm ports with minimal ITA manipulation.

Bivalirudin as an anticoagulant for simultaneous integrated coronary artery revascularization – a novel approach to an inherent concern

BACKGROUND Simultaneous integrated coronary artery revascularization combines coronary artery bypass surgery and percutaneous coronary intervention into a single procedure. This approach provides immediate, complete and optimal myocardial revascularization in a less invasive manner. Because simultaneous integrated coronary revascularization necessitates two distinct anticoagulation protocols for the surgical and percutaneous aspects of the procedure, combining these anticoagulation protocols carries a bleeding risk. Using a single anticoagulant to facilitate the necessities of both aspects of the integrated approach may alleviate this risk. CASE PRESENTATION A 45-year-old man with an occluded left anterior descending artery and a moderately stenotic circumflex artery underwent simultaneous integrated coronary revascularization. Bivalirudin was used to achieve anticoagulation for the duration of the procedure. The patient was asymptomatic with excellent patency of both the bypass graft and the stented circumflex artery via angiography at 10 months. CONCLUSION Bivalirudin can be used to effectively achieve a unified anticoagulation protocol for simultaneous integrated revascularization.

Robotic-assisted left atrial ligation for stroke reduction in chronic atrial fibrillation: a case report.

Patients with atrial fibrillation are at significant risk for sustaining a thromboembolic stroke. More than 90% of thromboemboli form in the left atrial appendage. Ligation of the left atrial appendage to reduce the risk of stroke is often performed in connection with other cardiac surgical procedures. As a stand-alone procedure, however, left atrial ligation has generally been deemed too invasive and has gained little support as an alternative therapeutic option. We report a case of port-access robotic-assisted left atrial ligation as a stand-alone procedure in a patient with chronic atrial fibrillation in whom anticoagulation was a contraindication. To our knowledge, this is the first reported case of stand-alone robotic-assisted left atrial ligation in the literature.