Vascular microanastomosis through an endoscopic approach: Feasibility study on two cadaver forearms

The Exoscope versus operating microscope in microvascular surgery: A simulation non-inferiority trial

Background

The Exoscope is a novel high-definition digital camera system. There is limited evidence signifying the use of exoscopic devices in microsurgery. This trial objectively assesses the effects of the use of the Exoscope as an alternative to the standard operating microscope (OM) on the performance of experts in a simulated microvascular anastomosis.

Methods

Modus V Exoscope and OM were used by expert microsurgeons to perform standardized tasks. Hand-motion analyzer measured the total pathlength (TP), total movements (TM), total time (TT), and quality of end-product anastomosis. A clinical margin of TT was performed to prove non-inferiority. An expert performed consecutive microvascular anastomoses to provide the exoscopic learning curve until reached plateau in TT.

Results

Ten micro sutures and 10 anastomoses were performed. Analysis demonstrated statistically significant differences in performing micro sutures for TP, TM, and TT. There was statistical significance in TM and TT, however, marginal non-significant difference in TP regarding microvascular anastomoses performance. The intimal suture line analysis demonstrated no statistically significant differences. Non-inferiority results based on clinical inferiority margin (Δ) of TT=10 minutes demonstrated an absolute difference of 0.07 minutes between OM and Exoscope cohorts. A 51%, 58%, and 46% improvement or reduction was achieved in TT, TM, TP, respectively, during the exoscopic microvascular anastomosis learning curve.

Conclusions

This study demonstrated that experts’ Exoscope anastomoses appear non-inferior to the OM anastomoses. Exoscopic microvascular anastomosis was more time consuming but end-product (patency) in not clinically inferior. Experts’ “warm-up” learning curve is steep but swift and may prove to reach clinical equality.

Robot-assisted microvascular anastomosis in head and neck free flap reconstruction: Preliminary experiences and results

BACKGROUND

The da Vinci Surgical System has facilitated considerable advancements in surgery. The process and results of robot-assisted microvascular anastomosis in real clinical situations have rarely been reported. This study presents our experience of performing robot-assisted microvascular anastomosis in free flap reconstruction in patients with oropharyngeal cancer.

PATIENTS AND METHODS

This was a retrospective study of reconstructive operations using a free radial forearm flap for oropharyngeal defects after tumor extirpation in 15 consecutive adult patients (12 men and 3 women). In total, 17 robot-assisted microvascular vessel anastomoses (2 arteries and 15 veins) were performed; moreover, 13 arteries and 13 veins were anastomosed using the standard operating microscope and hand-sewing technique.

RESULTS

The recipient and donor vessel diameters were 2.5 ± 0.7 and 2.1 ± 0.8 mm, respectively. The donor blood vessel diameter selected for anastomosis using da Vinci Surgical System was significantly smaller (2.1 ± 0.8 vs. 2.5 ± 0.6 mm) than that for a standard operating microscope and hand-sewing technique (p = .021), the operating time spent (38.4 ± 10.4 vs. 28.0 ± 7.7 min) was significantly longer (p < .001). The vascular patency rate was 100%, and all flaps survived without requiring additional operation for revision.

CONCLUSION

Robotic surgical systems can facilitate vascular microanastomosis and provide a blood vessel patency rate comparable to that of a standard operating microscope and hand-sewing technique.

Breathing Life into the Cadaver: Introducing Air Dissection As a New Teaching and Dissecting Method for the Venous System

Air insufflation has been used for various surgical procedures such as during laparoscopy. We hypothesized that the use of pressurized air might enable cadaveric dissection to differentiate smaller veins better than traditional dissection techniques. In three fresh-frozen cadavers, the inferior vena cava (IVC) and right or left femoral veins were exposed just distal to the inguinal ligament and a needle placed into one of them. Pressurized air was then placed into the cannulated femoral vein using an air compressor. In all specimens, the IVC and most of its tributaries, both left and right sides, were clearly insufflated. When the IVC was traced superiorly by resecting the diaphragm through the caval foramen, the right atrium and ventricle were also found to be dilated. Additionally, venous variants that would have not been obvious without dilatation of the IVC were identified. Air dissection of the venous system in fresh-frozen cadavers aids in anatomical dissection. Such a model might also serve as a surgical training model and teaching tool as it better mimics life-like anatomy and physiology. We term this technique "cadaveric air dissection." Clin. Anat. 32:566-572, 2019. © 2019 Wiley Periodicals, Inc.

Current Limitations of Surgical Robotics in Reconstructive Plastic Microsurgery

Surgical robots have the potential to provide surgeons with increased capabilities, such as removing physiologic tremor, scaling motion and increasing manual dexterity. Several surgical specialties have subsequently integrated robotic surgery into common clinical practice. Plastic and reconstructive microsurgical procedures have not yet  benefitted significantly from technical developments observed over the last two decades. Several studies have successfully demonstrated the feasibility of utilising surgical robots in plastic surgery procedures, yet limited work has been done to identify and analyse current barriers that have prevented wide-scale adaptation of surgical robots for microsurgery. Therefore, a systematic review using PubMed, MEDLINE, Embase and Web of Science databases was performed, in order to evaluate current state of surgical robotics within the field of reconstructive microsurgery and their limitations. Despite the theoretical potential of surgical robots, current commercially available robotic systems are suboptimal for plastic or reconstructive microsurgery. Absence of bespoke microsurgical instruments, increases in operating time, and high costs associated with robotic-assisted provide a barrier to using such systems effectively for reconstructive microsurgery. Consequently, surgical robots provide currently little overall advantage over conventional microsurgery. Nevertheless, if current barriers can be addressed and systems are specifically designed for microsurgery, surgical robots may have the potential of meaningful impact on clinical outcomes within  this surgical subspeciality.

A Systematic Review of the Role of Robotics in Plastic and Reconstructive Surgery-From Inception to the Future

Background

The use of robots in surgery has become commonplace in many specialties. In this systematic review, we report on the current uses of robotics in plastic and reconstructive surgery and looks to future roles for robotics in this arena.

Methods

A systematic literature search of Medline, EMBASE, and Scopus was performed using appropriate search terms in order to identify all applications of robot-assistance in plastic and reconstructive surgery. All articles were reviewed by two authors and a qualitative synthesis performed of those articles that met the inclusion criteria. The systematic review and results were conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA) guidelines.

Results

A total of 7,904 articles were identified for title and abstract review. Sixty-eight studies met the inclusion criteria. Robotic assistance in plastic and reconstructive surgery is still in its infancy, with areas such as trans-oral robotic surgery and microvascular procedures the dominant areas of interest currently. A number of benefits have been shown over conventional open surgery, such as improved access and greater dexterity; however, these must be balanced against disadvantages such as the lack of haptic feedback and cost implications.

Conclusion

The feasibility of robotic plastic surgery has been demonstrated in several specific indications. As technology, knowledge, and skills in this area improve, these techniques have the potential to contribute positively to patient and provider experience and outcomes.

Modeling of blood flow through sutured micro-vascular anastomoses

Microanastomosis is a surgical procedure used to reconnect two blood vessels using sutures. The optimal microanastomosis may be predicted by assessing the factors that influence this invasive procedure. Blood flow and hemodynamics following microanastomosis are important factors for the successful longevity of this operation. How is the blood flow affected by the presence of sutures? Computational Fluid Dynamics (CFD) is a powerful tool that permits the estimation of specific quantities, such as fluid stresses, that are hardly measurable in vivo. In this study, we propose a methodology which evaluates the alterations in the hemodynamic status due to microanastomosis. A CFD model of a reconstructed artery has been developed, based on anatomical information provided by intravascular ultrasound and angiography, and was used to simulate blood flow after microanastomosis. The 3D reconstructed arterial segments are modeled as non-compliant 1.24 - 1.47 mm diameter ducts, with approximately 0.1 mm arterial thickness. The blood flow is considered laminar and the no-slip condition is imposed on the boundary wall, which is assumed to be rigid. In analyzing the results, the distribution of the wall shear stress (WSS) is presented in the region of interest, near the sutures. The results indicate that high values of WSS appear in the vicinity of sutures. Such regions may promote thrombus formation and subsequently anastomotic failure, therefore their meticulous study is of high importance.