Optimal port placement and enhanced guidance in robotically assisted cardiac surgery

Preoperative planning of three axis intersection surgical laparoscopic arm system based on characteristic parameters

PURPOSE

The application of robotics in the field of minimally invasive surgery solves some shortcomings of traditional minimally invasive surgery. Preoperative planning is an important prerequisite for the successful completion of robot-assisted surgery. The optimization of surgical incision position and the initial location of surgical robot are two important parts of preoperative planning. In this paper, a novel structure and preoperative planning method of a three-axis intersection surgical manipulator are proposed.

METHODS

Firstly, a mathematical model of human abdominal wall was established. Three characteristic parameters between the lesion and the incision are defined and used to optimize the surgical incisions. Then, the spatial position relationship between the laparoscopic arm and the incision was analyzed to obtain the effective solution groups of each passive joint of the laparoscopic arm. Lastly, the optimal initial location of the laparoscopic arm was determined by taking the total joint variables of the telecentric mechanism as the optimization index.

RESULTS

According to a given set of lesion parameters and the position of laparoscopic arm base, the optimal incision position was obtained using the surgical incision characteristic parameters and the optimal triangle criterion, and the positioning angles of the laparoscopic arm were optimized by using the Total Joint Variable (TJV) as the evaluation index.

CONCLUSIONS

The proposed preoperative planning method is verified by simulation. The proposed method can realize the preoperative planning process of the three axis intersection laparoscopic arm. The proposed method of preoperative planning will provide important reference to improve the intelligence of robot-assisted surgery.

Robotically assisted mitral valve surgery-experience during the restart of a robotic program in Germany

BACKGROUND

Following the first robotic-assisted mitral valve operations in Paris and Leipzig, the era of this innovative technique expired after a few years in Germany. At that time, the main arguments against robotic surgery within the German cardiac surgical community were low cost effectiveness and operative time utilization. Encouraged by favorable results, we re-started our robotic-assisted cardiac program as the first and only center in Germany in 2019.

METHODS

Between July 2019 and December 2021, 329 patients underwent robotic-assisted operations using the daVinci Xi system, including mitral and coronary operations, myxoma resection, atrial septal closure and stand-alone atrial ablation. Of these, 182 patients underwent mitral valve repair (MVR). Isolated MVR was performed in 96 patients (isolated mitral group, IMG) and 86 underwent concomitant operations, such as tricuspid valve repair, Cox-Maze IV, pulmonary vein isolation (PVI) and left atrial appendage (LAA) closure (complex mitral group, CMG). For cost analysis, the InEK calculation for 2020 was used.

RESULTS

MVR was successful (MR ≤I°) in all patients. Patients in the IMG had a hospital mortality of 1.0% (O/E ratio 0.69) and stroke rate of 2.0%. Four patients (4.0%) required conversion to sternotomy and 6 patients (6.0%) needed re-exploration for bleeding. Mortality was 3.5% (O/E ratio 0.74) in the CMG and stroke rate 2.3%. The conversion and bleeding rates were 4.6% each, respectively. The steep learning curve resulted in significant reduction of operating times greater than 25% in the IMG. Comparing the results of robotic-assisted procedures to minimally-invasive mitral surgeries (MIMS) in 2020, a reduction in length of hospital stay of almost 25% resulted in significantly lower costs for the medical service and medical infrastructure. However, within the German health service, overall cost for robotic-assisted procedures were more expensive compared to MIMS by 5% due to higher material costs.

CONCLUSIONS

The re-establishment of robotic mitral valve surgery in Germany was successful with comparable results to MIMS in terms of mortality and morbidity. Robotic-assisted cardiac operations resulted in accelerated postoperative recovery with significant shortening of the hospital length of stay. The avoidance of liver injury is one focus for the future.

Preoperative Computer-Assisted Laparoscopy Planning for the Minimally Invasive Surgical Repair of Hiatal Hernia

Minimal invasive surgical procedures such as laparoscopy are preferred over open surgery due to faster postoperative recovery, less trauma and inflammatory response, and less scarring. Laparoscopic repairs of hiatal hernias require pre-procedure planning to ensure appropriate exposure and positioning of the surgical ports for triangulation, ergonomics, instrument length and operational angles to avoid the fulcrum effect of the long and rigid instruments. We developed a novel surgical planning and navigation software, iMTECH to determine the optimal location of the skin incision and surgical instrument placement depth and angles during laparoscopic surgery. We tested the software on five cases of human hiatal hernia to assess the feasibility of the stereotactic reconstruction of anatomy and surgical planning. A whole-body CT investigation was performed for each patient, and abdominal 3D virtual models were reconstructed from the CT scans. The optical trocar access point was placed on the xipho-umbilical line. The distance on the skin between the insertion point of the optical trocar and the xiphoid process was 159.6, 155.7, 143.1, 158.3, and 149.1 mm, respectively, at a 40° elevation angle. Following the pre-procedure planning, all patients underwent successful surgical laparoscopic procedures. The user feedback was that planning software significantly improved the ergonomics, was easy to use, and particularly useful in obese patients with large hiatal defects where the insertion points could not be placed in the traditional positions. Future studies will assess the benefits of the planning system over the conventional, empirical trocar positioning method in more patients with other surgical challenges.

Multiportal Combined Transorbital and Transnasal Endoscopic Resection of Fibrous Dysplasia

Introduction Historically, access to the anterior skull base was achieved with open procedures. The paradigms to this approach were challenged with the advent of minimally disruptive endoscopic surgical techniques and supporting technology. The next step in the evolution of minimally disruptive surgery was the combination of multiportal endoscopic surgery. Results The patient was an 18-year-old man who presented with right-sided proptosis. Further diagnostic tests revealed a fibrous dysplasia (FD) occupying the skull base and orbit. The lesion was successfully resected. Conclusions The location of the tumor in this case was challenging, in which surgeons at some centers would have opted to have performed as an open procedure instead of endoscopically. The combined transnasal/transorbital approach is an uncommonly used technique that we have used to remove this tumor successfully. The patient also had a unique disease (FD) in a unique location that was treated without complications. This case report highlights how surgeons may use an expanded armamentarium in dealing with complex pathologies.

Ultrasound guidance for beating heart mitral valve repair augmented by synthetic dynamic CT

Minimally invasive valvular intervention commonly requires intra-procedural navigation to provide spatial and temporal information of relevant cardiac structures and device components. Recently intra-procedural trans-esophageal echocardiography (TEE) has been exploited for this purpose due to its accessibility, low cost, ease of use, and real-time imaging capacity. However, the position and orientation of tissue targets relative to surgical tools can be challenging to perceive, particularly using 2D imaging planes. In this paper, we propose the use of CT images to provide a high-quality 3D context to enhance ultrasound images through image registration, providing an augmented guidance system with minimal impact on standard clinical workflow. We also describe an approach to generate synthetic 4D CT images through non-rigid registration of available ultrasound. This can be employed to avoid a requirement for higher radiation. Synthetic CT images were validated through direct comparison of synthetic and real multi-phase CT images. Validation of CT and ultrasound image registration was performed for both dynamic and synthetic CT image datasets. Our results demonstrated that the synthetically generated dynamic CT images provide similar anatomical representation for relevant cardiac anatomy relative to real dynamic CT images, and similar high registration accuracy that can be achieved for intra-procedural TEE to this versus real dynamic CT images.

Computer modeled multiportal approaches to the skull base

Skull base surgical approaches have evolved significantly to minimize collateral tissue damage and improve access to complex anatomic regions. Many endoscopic surgical portals have been described, and these can be combined in multiportal approaches that permit improved angles for visualization and instrumentation. To assist in the choice of entry portal and surgical pathway analysis, a three-dimensional computer model with virtual endoscopy was created. The model was evaluated on transnasal and transorbital approaches to access 11 specified sellar and parasellar target locations on 14 computed tomography (CT) scans. Data were collected on length of approach, angle between instruments, and approach angle with respect to anatomical planes. Optimal multiportal approach combinations were derived. The data demonstrated that the shortest, most direct pathway to many sellar and parasellar targets was through transorbital portals. Distances were reduced by 35% for certain target locations; combining transorbital and transnasal portals increased the angle between instruments 4-fold for many targets. The predicted values from the model were validated on four cadaver specimens. Computer modeling holds the potential to play an integral role in the design, analysis, and testing of new surgical approaches, as well as in the selection of optimal approach strategies for the unique pathology of individual patients.

Image overlay navigation by markerless surface registration in gastrointestinal, hepatobiliary and pancreatic surgery

BACKGROUND

We applied a new concept of "image overlay surgery" consisting of the integration of virtual reality (VR) and augmented reality (AR) technology, in which dynamic 3D images were superimposed on the patient's actual body surface and evaluated as a reference for surgical navigation in gastrointestinal, hepatobiliary and pancreatic surgery.

METHODS

We carried out seven surgeries, including three cholecystectomies, two gastrectomies and two colectomies. A Macintosh and a DICOM workstation OsiriX were used in the operating room for image analysis. Raw data of the preoperative patient information obtained via MDCT were reconstructed to volume rendering and projected onto the patient's body surface during the surgeries. For accurate registration, OsiriX was first set to reproduce the patient body surface, and the positional coordinates of the umbilicus, left and right nipples, and the inguinal region were fixed as physiological markers on the body surface to reduce the positional error.

RESULTS

The registration process was non-invasive and markerlesss, and was completed within 5 min. Image overlay navigation was helpful for 3D anatomical understanding of the surgical target in the gastrointestinal, hepatobiliary and pancreatic anatomies. The surgeon was able to minimize movement of the gaze and could utilize the image assistance without interfering with the forceps operation, reducing the gap from the VR. Unexpected organ injury could be avoided in all procedures. In biliary surgery, the projected virtual cholangiogram on the abdominal wall could advance safely with identification of the bile duct. For early gastric and colorectal cancer, the small tumors and blood vessels, which usually could not be found on the gastric serosa by laparoscopic view, were simultaneously detected on the body surface by carbon dioxide-enhanced MDCT. This provided accurate reconstructions of the tumor and involved lymph node, directly linked with optimization of the surgical procedures.

CONCLUSIONS

Our non-invasive markerless registration using physiological markers on the body surface reduced logistical efforts. The image overlay technique is a useful tool when highlighting hidden structures, giving more information.