First-in-Human Free Flap Tissue Reconstruction Using a Dedicated Microsurgical Robotic Platform

Abstract

Background: 

Microsurgery has become standard of care for increasingly complex techniques in tissue harvest, replantation, reconstruction, allotransplantation, and supermicrosurgery on submillimetric vessels. As techniques become more challenging and are performed at smaller and smaller scale, there is greater potential application for robotic assistance in extreme motion scaling and tremor reduction.

Methods: 

The Symani Surgical System (Medical Microinstruments, S.p.A, Calci, Pisa, Italy), a robotic platform designed for microsurgery, was used in a robot-assisted microsurgical free flap reconstruction using a perforator-to-perforator flap technique. This procedure utilized robot-assisted anastomosis of an artery and vein.

Results: 

The procedure was completed successfully, with vessels fully patent immediately following and 20 minutes after anastomosis. The flap was viable, no re-exploration of the anastomosis was necessary postoperatively, and no flap loss occurred.

Conclusions: 

This novel, dedicated robotic platform with wristed microsurgical instruments was shown to be feasible for carrying out robot-assisted anastomosis of veins and arteries less than 0.8 mm in diameter, in the domain of supermicrosurgery. The system has the potential to open the field of microsurgery to new clinicians and to facilitate new microsurgical applications that were previously rendered inaccessible by the limits of manual precision and physiological tremor.

The evolution of microsurgery from the first cases recorded in the 1960s was made possible by the coevolution of operating microscopes, miniaturized surgical instruments, and microsutures.^1,2 However, some of the newest and most challenging applications in supermicrosurgery require anastomosis of vessels just a few hundreds of microns in diameter,³ challenging the objective boundaries of human physiologic tremor.^4–7 Further advances will depend on technologies that can overcome the limitations of human hands and accomplish for the hands what the microscope has done for the surgeon’s vision. Here, we report our experience evaluating the clinical feasibility of a novel, dedicated robotic platform in its first-in-human use in a perforator-to-perforator flap reconstruction of a posttraumatic lower limb defect.

PATIENTS AND METHODS

Robotic System

The Symani Surgical System is a robotic platform that uses the basic principles of teleoperation to provide surgeons with precision of instrument motion within the range of tens of microns (Fig. 1). [See Video 1 (online), which demonstrates teleoperation.] By scaling down the surgeon’s hand motions between seven- and 20-fold, the system substantially eliminates physiologic tremor and provides motion scaling appropriate for surgeons working at up to 40× visual magnification. The system’s miniaturized and fully articulated microsurgical instruments and robotic arm provides 7 degrees of freedom of motion, imparting manual dexterity and precision that extends beyond that of the human hand (Fig. 2).

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Fig. 1.: Robot and instruments. Schematic drawing of the Symani System.

Fig. 2.: The articulated wrist of the robotic microinstrument compared with fingertip.

During robotic-assisted microsurgical procedures, the surgeon works at the bedside and manipulates the robotic master devices in the same way as manual instruments while viewing the surgical field through the operating microscope. The motions of the surgeon’s hands are transmitted to the robotic microinstruments. These consist of a needle holder and dilator with an outer shaft diameter of 3 mm and closed-jaws tip diameter of 0.3 mm. The Symani Surgical System received European conformity certification in 2019, and it is currently approved to perform microsurgery techniques such as anastomosis, suturing, and ligation on vessels, nerves, and lymphatics in open surgery.

Presurgical Rehearsals and Training

The authors have contributed extensively to bench and preclinical testing of the Symani System since 2015 and are considered fully proficient and able to use the system safely and effectively.

Clinical Case

A 15-year-old girl was referred to our clinic from another hospital with a grade III open fracture of the right foot. We planned the reconstruction of the first metatarsal bone using the two-stage induced-membrane technique and the restoration of the soft tissue using an ultrathin anterolateral thigh flap.⁸ Informed consent based on the guidelines of the CTO Careggi University Hospital in Florence, Italy, was obtained.

The operation was carried out using a two-team approach, one harvesting the flap and the second preparing the recipient vessels and performing the first stage of the induced-membrane technique, as recipient vessels were prepared, the medial tarsal artery and vein—preserving the main vascular axis of the dorsalis pedis.

The area of bone loss was measured and filled with a cement spacer impregnated with 2 g of vancomycin. Then, the flap was transferred to the recipient area and the anastomosis performed using the Symani robotic system (Fig. 3).

Fig. 3.: (Left) Intraoperative image showing the soft-tissue and first metatarsal bone defect. (Right) Schematic drawing of the dorsal foot reconstruction with ultrathin anterolateral thigh flap; the anastomosis is performed between the flap perforator vessels and the medial tarsal artery and vein.

The vessel diameters were 0.6 mm for the artery and 0.8 mm for the vein. The time for the robotic-assisted anastomosis was 22 minutes for the artery and 45 minutes for the vein, using a total of seven stitches for the artery and 11 for the vein. [See Video 2 (online), which demonstrates robotic anastomosis.] The robotically assisted anastomosis was successful, and the flap was well perfused.

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The donor site was closed primarily, and the foot was supported with a cast with 90 degrees of flexion. The postoperative course was uneventful, and the patient was discharged to home on day 4. After 10 months’ follow-up, the patient reports no aesthetic complaints and full foot functional recovery (Fig. 4).

Fig. 4.: Foot reconstruction 10 months after surgery. (Above) Lateral view. (Below) Non–weight-bearing anteroposterior view of the foot.

DISCUSSION

In this report, we have documented the first robotic-assisted free flap reconstructive surgery with a dedicated microsurgical robot. The case was successful and shows the system’s safety and capability in carrying out arterial and venous anastomoses during microsurgery at a submillimeter scale. This new frontier of supermicrosurgery includes the modern surgical approach to lymphedema and the transfer of perforator-to-perforator flaps such as reported here.⁹

The introduction of Intuitive Surgical’s da Vinci Surgical System at the turn of the twenty-first century has had a profound impact on the practice of surgery.¹⁰ It has contributed to the gradual replacement of manual laparoscopic and open procedures for urogynecology and general surgery, and lowered barriers to entry for new robotic platforms.^11–14

However, the size, forces, and scaling factors designed into the da Vinci platform are oriented toward large-scale procedures in the thoracic and abdominal cavities.¹⁵ Accordingly, attempts to apply the da Vinci platform to the challenges of manual microsurgery have proven that both the system architecture and instrumentation are not easily adapted to microsurgical reconstructions.^16–18

The potential of robotic technology to provide clinical benefit through greater precision in open procedures and in the meantime improve surgeon ergonomics and comfort while reducing fatigue and work-related injury¹⁹ has previously been recognized and explored in academic settings.²⁰ More recently, van Mulken and colleagues have published an article describing the use of a robotic micromanipulator to perform lymphovenous anastomosis in a series of eight patients with breast cancer–related lymphedema.²¹

However, the system used by van Mulken et al. holds and manipulates standard, manual instruments. In contrast, the platform used in this study has miniaturized wristed microinstruments providing 7 degrees of freedom of motion controlled by “free air masters.” To our knowledge, this feature is not integrated into other teleoperated surgical robotic devices. Furthermore, the Symani System has the unique feature of reducing the human movement in an inversely proportional manner to the visual magnification, such that as the microscope enables human vision, and robotic motion scaling enables human fine motor skills.

CONCLUSIONS

We have demonstrated that this novel, dedicated robotic platform with wristed microsurgical instruments is suitable for carrying out robotic-assisted anastomosis of veins and arteries during open, free flap reconstructive microsurgery, introducing a new value proposition for robotics across specialties: the potential to improve precision during challenging open operations.

DISCLOSURE

Dr. Innocenti is a clinical advisor to and shareholder of MMI SpA. Drs. Malzone and Menichini have no financial interests to disclose. The Symani System was loaned to the Plastic, Reconstructive, and Microsurgery Unit at CTO Careggi University Hospital by MMI SpA, and the necessary robotic instrumentation was provided free of charge for use in this case.

Acknowledgments

The authors wish to thank Hannah Teichmann, PhD, for invaluable support throughout the hard work to achieve this and, most importantly, for sharing with us her strong faith in robotic technology and her vision for the future of surgery.