Robotic total endoscopic sutureless aortic valve replacement: proof of concept for a future surgical setting

The Perceval Sutureless Bioprosthetic Aortic Valve: Evolution of Surgical Valve Technology

OBJECTIVE

The surgical treatment of aortic stenosis continues to evolve, and sutureless aortic valve replacement (SUAVR) is an emerging technology. With the Perceval S (Corcym, London, UK) as the only true sutureless valve on the market, the objective of this review is to analyze the current literature on Perceval S. Focusing on valve design and deployment as well as applications of the technology for challenging pathology, clinical outcomes are assessed, including a comparison with transcatheter AVR (TAVR).

METHODS

PubMed and MEDLINE were searched by 3 authors for studies analyzing SUAVR from inception to May 19, 2023.

RESULTS

SUAVR facilitates minimally invasive surgery and offers an alternative strategy for patients with small aortic annuli. It also has a time-saving advantage for patients who require complex operations. SUAVR results in excellent long-term morbidity, mortality, durability, and hemodynamic function. In comparison with conventional surgical AVR (SAVR), SUAVR does have a greater risk of postoperative pacemaker implantation; however, increasing user experience and refinements in implantation technique have contributed to reductions in this outcome. SUAVR results in morbidity and mortality that is similar to rapid-deployment AVR. Midterm outcomes are superior to TAVR; however, further robust investigation into all of these comparisons is ultimately necessary.

CONCLUSIONS

SUAVR bridges the gap in technology between SAVR and TAVR. The application of this exciting technology will undoubtedly grow in the coming years, during which additional investigation is paramount to optimize preoperative planning, valve deployment, and reintervention strategies.

Semiautonomous Robotic Manipulator for Minimally Invasive Aortic Valve Replacement

Aortic valve surgery is the preferred procedure for replacing a damaged valve with an artificial one. The ValveTech robotic platform comprises a flexible articulated manipulator and surgical interface supporting the effective delivery of an artificial valve by teleoperation and endoscopic vision. This article presents our recent work on force-perceptive, safe, semiautonomous navigation of the ValveTech platform prior to valve implantation. First, we present a force observer that transfers forces from the manipulator body and tip to a haptic interface. Second, we demonstrate how hybrid forward/inverse mechanics, together with endoscopic visual servoing, lead to autonomous valve positioning. Benchtop experiments and an artificial phantom quantify the performance of the developed robot controller and navigator. Valves can be autonomously delivered with a 2.0±0.5 mm position error and a minimal misalignment of 3.4±0.9°. The hybrid force/shape observer (FSO) algorithm was able to predict distributed external forces on the articulated manipulator body with an average error of 0.09 N. FSO can also estimate loads on the tip with an average accuracy of 3.3%. The presented system can lead to better patient care, delivery outcome, and surgeon comfort during aortic valve surgery, without requiring sensorization of the robot tip, and therefore obviating miniaturization constraints.

Robotic Surgery for Triple Valve Insufficiency: A Case Report

A 63-year-old woman was referred to our institution for surgical treatment of triple valve (aortic, mitral, and tricuspid) insufficiency and underwent a robot-assisted endoscopic procedure. Three intercostal ports were placed in the right lateral chest for robotic instruments and a retrograde cardioplegic cannula, and a 5 cm thoracotomy was made for the procedure, which was a mitral valve repair with neochords and ring annuloplasty, an aortic valve replacement with bioprosthetic valve, and a ring tricuspid annuloplasty. Surgery was successfully achieved without blood transfusion or any complications.

Alimentary tract obstruction attributed to use of barbed suture for double tract reconstruction after robot-assisted proximal gastrectomy: a case report

Background

Anastomotic stenosis following esophagojejunostomy reconstruction by the overlap method with absorbable barbed sutures occurs only rarely in patients who have undergone laparoscopic surgery. We report anastomotic stenosis by the overlap method that we attributed to the lack of tactile sensation during robot-assisted surgery.

Case presentation

An 83-year-old man underwent robot-assisted laparoscopic proximal gastrectomy and lymph node dissection at our hospital for treatment of gastric cancer. Double tract reconstruction followed with side-to-side esophagojejunostomy (overlap method) performed with an endoscopic linear stapler. On completion of the anastomosis, the enterotomy was closed under robotic assistance with absorbable barbed suture. Once solid foods were introduced, the patient had difficulty swallowing and felt as though his digestive tract was stopped up. When upper gastrointestinal endoscopy was performed, we found the anastomotic lumen to be coated with food residue. After rinsing off the residue with water, we could see barbed suture protruding into the anastomotic lumen that had become entangled upon itself, which explained how the food residue had accumulated. We cut the entangled suture under endoscopic visualization using a loop cutter.

Conclusion

This case highlights a stricture caused by insufficiently tensioning barbed suture, which subsequently protruded into the anastomotic lumen and became entangled upon itself. We believe this occurrence was associated with the lack of tactile sensation in robot-assisted surgery.

ValveTech: A Novel Robotic Approach for Minimally Invasive Aortic Valve Replacement

OBJECTIVE

Aortic valve disease is the most common heart disease in the elderly calling for replacement with an artificial valve. The presented surgical robot aims to provide a highly controllable instrument for efficient delivery of an artificial valve by the help of integrated endoscopic vision.

METHODS

A robot (called ValveTech), intended for minimally invasive surgery (MIS) and consisting of a flexible cable driven manipulator, a passive arm, and a control unit has been designed and prototyped. The flexible manipulator has several features (e.g., stabilizing flaps, tiny cameras, dexterous introducer and custom cartridge) to help the proper valve placement. It provides 5 degrees of freedom for reaching the operative site via mini-thoracotomy; it adjusts the valve and expands it at the optimal position. The robot was evaluated by ten cardiac surgeons following a real surgical scenario in artificial chest simulator with an aortic mockup. Moreover, after each delivery, the expanded valve was evaluated objectively in comparison with the ideal position.

RESULTS

The robot performances were evaluated positively by surgeons. The trials resulted in faster delivery and an average misalignment distance of 3.8 mm along the aorta axis; 16.3 degrees rotational angle around aorta axis and 8.8 degrees misalignment of the valve commissure plane to the ideal plane were measured.

CONCLUSION

The trials successfully proved the proposed system for valve delivery under endoscopic vision.

SIGNIFICANCE

The ValveTech robot can be an alternative solution for minimally invasive aortic valve surgery and improve the quality of the operation both for surgeons and patients.

Positioning and stiffening of an articulated/continuum manipulator for implant delivery in minimally invasive surgery

BACKGROUND

Hollow, bendable manipulators can advance implant delivery in minimally invasive surgery, by circumventing the drawbacks of straight-line delivery and fostering single-port approaches. Variable stiffness manipulators are sought to be safe and effective.

METHODS

We designed and experimentally assessed a cable-driven articulated/continuum manipulator, devised for cardiac valve delivery. Positioning and stiffening were teleoperated, based on cable shortening. Stiffening was parameterized by using the leading tension (LT, ie, tension of the cables driving bending). We assessed positioning (repeatability/reversibility along eight/two bending directions) and stiffening (eight bent configurations).

RESULTS

We achieved good repeatability and reversibility (mean errors <1% and 1.5%, respectively, of the workspace characteristic length). Stiffening was effective (up to 9-fold increase, depending on pose). Stiffening was linearly correlated (R² = 0.92) with LT for all the considered configurations.

CONCLUSION

We accurately positioned and effectively stiffened the manipulator in several bent configurations. The proposed stiffness modulation strategy can be extended to other manipulators.