Total Endoscopic CABG Using Robotics on Beating Heart

A systematic review on robotic coronary artery bypass graft surgery

BACKGROUND

Robotic-assisted coronary artery bypass graft surgery (CABG) has been performed over the past decade. Despite encouraging results from selected centres, there is a paucity of robust clinical data to establish its clinical safety and efficacy. The present systematic review aimed to identify all relevant clinical data on robotic CABG. The primary endpoint was perioperative mortality, and secondary endpoints included perioperative morbidities, anastomotic complications, and long-term survival.

METHODS

Electronic searches were performed using three online databases from their dates of inception to 2016. Relevant studies fulfilling the predefined search criteria were categorized according to surgical techniques as (I) totally endoscopic coronary artery bypass without cardiopulmonary bypass (TECAB off-pump); (II) TECAB on-pump; and robotic-assisted mammary artery harvesting followed by minimally invasive direct coronary artery bypass (robotic MIDCAB).

RESULTS

The present systematic review identified 44 studies that fulfilled the study selection criteria, including nine studies in the TECAB off-pump group and 16 studies in the robotic MIDCAB group. Statistical analysis reported a pooled mortality of 1.7% for the TECAB off-pump group and 1.0% for the robotic MIDCAB group. Intraoperative details such as the number and location of grafts performed, operative times and conversion rates, as well as postoperative secondary endpoints such as morbidities, anastomotic complications and long-term outcomes were also summarized for both techniques.

CONCLUSIONS

A number of technical, logistic and cost-related issues continue to hinder the popularization of the robotic CABG procedure. Current clinical evidence is limited by a lack of randomized controlled trials, heterogeneous definition of techniques and complications, as well as a lack of robust clinical follow-up with routine angiography. Nonetheless, the present systematic review reported acceptable perioperative mortality rates for selected patients at specialized centres. These results should be considered as a useful benchmark for future studies, until further data is reported in the form of randomized trials.

Learning curves for cardiothoracic and vascular surgical procedures--a systematic review

OBJECTIVES

The aim of this systematic review is to evaluate the learning curve (LC) literature and identify the LC of cardiothoracic and vascular surgical procedures.

SUMMARY AND BACKGROUND

The LC describes an observation that a learner's performance improves over time during acquisition of new motor skills. Measuring the LC of surgical procedures has important implications for surgical innovation, education, and patient safety. Numerous studies have investigated LCs of isolated operations in cardiothoracic and vascular surgeries, but a lack of uniformity in the methods and variables used to measure LCs has led to a lack of systematic reviews.

METHODS

The MEDLINE®, EMBASE™, and PsycINFO® databases were systematically searched until July 2013. Articles describing LCs for cardiothoracic and vascular procedures were included. The type of procedure, statistical analysis, number of participants, procedure setting, level of participants, outcomes, and LCs were reviewed.

RESULTS

A total of 48 studies investigated LCs in cardiothoracic and vascular surgeries. Based on operating time, the LC for coronary artery bypass surgery ranged between 15 and 100 cases; for endoscopic vessel harvesting and other cardiac vessel surgery between 7 and 35 cases; for valvular surgery, which included repair and replacement, between 20 and 135 cases; for video-assisted thoracoscopic surgery, between 15 and 35 cases; for vascular neurosurgical procedures between 100 and 500 cases, based on complications; for endovascular vessel repairs between 5 and 40 cases; and for ablation procedures between 25 and 60 cases. However there was a distinct lack of standardization in the variables/outcome measures used, case selection, prior experience, and supervision of participating surgeons and a range of statistical analyses to compute LCs was noted.

CONCLUSION

LCs in cardiothoracic and vascular procedures are hugely variable depending on the procedure type, outcome measures, level of prior experience, and methods/statistics used. Uniformity in methods, variables, and statistical analysis is needed to derive meaningful comparisons of LCs. Acknowledgment and application of learning processes other than those reliant on volume-outcomes relationship will benefit LC research and training of surgeons.

'The Microhand': a new concept of micro-forceps for ocular robotic surgery

PURPOSE

To test the feasibility of retinal manipulations using a new micromanipulator (Microhand) for ocular robotic microsurgery.

METHODS

Pneumatically actuated four-finger microhands were developed at UCLA with micro electromechanical systems (MEMS) technology to mimic a human hand for small object manipulation. Microhands with four 4 mm finger lengths were used for this study to lift caliper weights and fresh retinal tissue of porcine cadaver eyes to find the maximum force at a given pressure and feasibility of the microhands for retinal manipulation in real surgery.

RESULTS

A full closure of the microhand used for caliper weight lifting was achieved under 65 psi (448 kPa) of air pressure. The four-fingered microhand was able to develop about 20 mN of total lifting force and 5 mN per finger at 80 psi (551 kPa), and was strong enough to displace and lift the retina of pig eyes.

CONCLUSIONS

The microhand is able to apply calibrated forces to ocular tissues and is suitable for ocular microsurgical procedures. This new tool would be useful in the development of robotic microsurgery.

Effects of visual force feedback on robot-assisted surgical task performance

OBJECTIVE

Direct haptic (force or tactile) feedback is negligible in current surgical robotic systems. The relevance of haptic feedback in robot-assisted performances of surgical tasks is controversial. We studied the effects of visual force feedback, a haptic feedback surrogate, on tying surgical knots with fine sutures similar to those used in cardiovascular surgery.

METHODS

By using a modified da Vinci robotic system (Intuitive Surgical, Inc, Sunnyvale, Calif) equipped with force-sensing instrument tips and real-time visual force feedback overlays in the console image, 10 surgeons each tied 10 knots with and 10 knots without visual force feedback. Four surgeons had significant prior da Vinci experience, and the remaining 6 surgeons did not. Performance parameters, including suture breakage and secure knots, peak and standard deviation of applied forces, and completion times using 5-0 silk sutures, were recorded. Chi-square and Student t test analyses determined the differences between groups.

RESULTS

Among surgeon subjects with robotic experience, no differences in measured performance parameters were found between robot-assisted knot ties executed with and without visual force feedback. Among surgeons without robotic experience, however, visual force feedback was associated with lower suture breakage rates, peak applied forces, and standard deviations of applied forces. Visual force feedback did not impart differences in knot completion times or loose knots for either surgeon group.

CONCLUSIONS

Visual force feedback resulted in reduced suture breakage, lower forces, and decreased force inconsistencies among novice robotic surgeons, although elapsed time and knot quality were unaffected. In contrast, visual force feedback did not affect these metrics among surgeons experienced with the da Vinci system. These results suggest that visual force feedback primarily benefits novice robot-assisted surgeons, with diminishing benefits among experienced surgeons.

Catheter-based endoscopic bypass grafting: an experimental feasibility study

PURPOSE

Construction of an endoscopic catheter-guided, bonded anastomosis to facilitate total endoscopic coronary artery bypass.

DESCRIPTION

Total endoscopic coronary artery bypass of the left internal thoracic artery to the left anterior descending coronary artery was performed on the beating heart in six pigs using a telemanipulation system. An angioplasty catheter was advanced through the left internal thoracic artery to stabilize the anastomotic site. The anastomosis was created by applying glue externally to the surrounding tissue of the left internal thoracic artery and the left anterior descending coronary artery while it was kept open by an inflated angioplasty catheter.

EVALUATION

Angiography and catheter placement at the graft site was performed in 12 minutes (10 to 28 minutes). The anastomotic constructions were easily accomplished in 3.5 minutes (2 to 4.5 minutes). The adverse events that were encountered were anastomotic leakage requiring additional glue and left anterior descending artery dissection due to the guidewire. All except one animal with an open graft and anastomosis survived the procedure. Patency was 5 of 6.

CONCLUSIONS

Catheter-based endoscopic bypass grafting is feasible. The combination of robotic technology and this simple technique for anastomotic construction may facilitate beating heart total endoscopic coronary artery bypass.

Teaching robotic surgery: a stepwise approach

BACKGROUND

After an initial institutional experience with 50 robot-assisted laparoscopic Roux-en-Y gastric bypass procedures, a curriculum was developed for fellowship training in robotic surgery.

METHODS

Thirty consecutive robotic gastric bypasses were performed using the Zeus robotic surgical system to fashion a two-layer gastrojejunostomy. For teaching purposes, performance of the anastomosis was divided into three discrete tasks. Robotic suturing tasks were assigned to the trainee in cumulative order in ten-case increments. Our patient population averaged 44 years of age and 47 kg/m(2) in BMI. Patients were predominantly female (87%).

RESULTS

The robotic training experience of the fellow defines the increases in surgical responsibility over the series of cases. Statistical analysis revealed no significant differences in task times or total robotic operative time as participation of the trainee in performing the gastrojejunostomy increased. No adverse robotic events or surgical complications occurred throughout this series. The learning curve of the fellow compared favorably with the initial experience of the institution.

CONCLUSION

Robotic surgery training may be safely implemented in a minimally invasive surgery training program. A gradual introduction of robotic technique appears to maximize the learning experience and minimize the potential for adverse outcomes.