Dexterity enhancement with robotic surgery

Robotic approach for cervical cancer: comparison with laparotomy: a case control study

OBJECTIVE

To compare the surgical outcome of robotic radical hysterectomy (RRH) versus abdominal radical hysterectomy (ARH) for the treatment of early stage cervical cancer.

METHODS

A prospective collection of data of all RRH for stages IA2-IIA cervical cancer was done. The procedures were performed at the European Institute of Oncology, Milan, Italy, between November 1, 2006 and February 1, 2009.

RESULTS

A total of 40 RRH were analyzed, and compared with 40 historic ARH cases. The groups did not differ significantly in body mass index, stage, histology, or intraoperative complications, but in age (p=0.035). The mean (SD) operative time was significantly shorter for ARH than RRH, 199.6 (65.6) minutes and 272.27 (42.3) minutes respectively (p=0.0001). The mean (SD) estimated blood loss (EBL) was 78 ml (94.8) in RRH group and 221.8 ml (132.4) in ARH. This difference was statistically significant in favor of RRH group (p<0.0001). Statistically significantly higher number of pelvic lymph nodes was removed by ARH than by RRH, mean (SD) 26.2 (11.7) versus 20.4 (6.9), p<0.05. Mean length of stay was significantly shorter for the RRH group (3.7 versus 5.0 days, p<0.01). There was no significant difference in terms of postoperative complications between groups.

CONCLUSION

This study shows that RRH is safe and feasible. However, a comparison of oncologic outcomes and cost-benefit analysis is still needed and it has to be carefully evaluated in the future.

Robotic assistance improves intracorporeal suturing performance and safety in the operating room while decreasing operator workload

BACKGROUND

Intracorporeal suturing is one of the most difficult laparoscopic tasks. The purpose of this study was to assess the impact of robotic assistance on novice suturing performance, safety, and workload in the operating room.

METHODS

Medical students (n = 34), without prior laparoscopic suturing experience, were enrolled in an Institutional Review Board-approved, randomized protocol. After viewing an instructional video, subjects were tested in intracorporeal suturing on two identical, live, porcine Nissen fundoplication models; they placed three gastro-gastric sutures using conventional laparoscopic instruments in one model and using robotic assistance (da Vinci) in the other, in random order. Each knot was objectively scored based on time, accuracy, and security. Injuries to surrounding structures were recorded. Workload was assessed using the validated National Aeronautics and Space Administration (NASA) task load index (TLX) questionnaire, which measures the subjects' self-reported performance, effort, frustration, and mental, physical, and temporal demands of the task. Analysis was by paired t-test; p < 0.05 was considered significant.

RESULTS

Compared with laparoscopy, robotic assistance enabled subjects to suture faster (595 +/- 22 s versus 459 +/- 137 s, respectively; p < 0.001), achieve higher overall scores (0 +/- 1 versus 95 +/- 128, respectively; p < 0.001), and commit fewer errors per knot (1.15 +/- 1.35 versus 0.05 +/- 0.26, respectively; p < 0.001). Subjects' overall score did not improve between the first and third attempt for laparoscopic suturing (0 +/- 0 versus 0 +/- 0; p = NS) but improved significantly for robotic suturing (49 +/- 100 versus 141 +/- 152; p < 0.001). Moreover, subjects indicated on the NASA-TLX scale that the task was more difficult to perform with laparoscopic instruments compared with robotic assistance (99 +/- 15 versus 57 +/- 23; p < 0.001).

CONCLUSIONS

Compared with standard laparoscopy, robotic assistance significantly improved intracorporeal suturing performance and safety of novices in the operating room while decreasing their workload. Moreover, the robot significantly shortened the learning curve of this difficult task. Further study is needed to assess the value of robotic assistance for experienced surgeons, and validated robotic training curricula need to be developed.

Vision and task assistance using modular wireless in vivo surgical robots

Minimally invasive abdominal surgery (laparoscopy) results in superior patient outcomes compared to conventional open surgery. However, the difficulty of manipulating traditional laparoscopic tools from outside the body of the patient generally limits these benefits to patients undergoing relatively low complexity procedures. The use of tools that fit entirely inside the peritoneal cavity represents a novel approach to laparoscopic surgery. Our previous work demonstrated that miniature mobile and fixed-based in vivo robots using tethers for power and data transmission can successfully operate within the abdominal cavity. This paper describes the development of a modular wireless mobile platform for in vivo sensing and manipulation applications. Design details and results of ex vivo and in vivo tests of robots with biopsy grasper, staple/clamp, video, and physiological sensor payloads are presented. These types of self-contained surgical devices are significantly more transportable and lower in cost than current robotic surgical assistants. They could ultimately be carried and deployed by nonmedical personnel at the site of an injury to allow a remotely located surgeon to provide critical first response medical intervention irrespective of the location of the patient.

Tactile Feedback Induces Reduced Grasping Force in Robot-Assisted Surgery

Robot-assisted minimally invasive surgery has gained widespread use over the past decade, but the technique is currently operated in the absence of haptic feedback during tissue manipulation. We have developed a complete tactile feedback system, consisting of a piezoresistive force sensor, control system, and pneumatic balloon tactile display, and mounted directly onto a da Vinci surgical robotic system. To evaluate the effect of tactile feedback on robotic manipulation, a group of novices (n = 16) and experts ( n = 4) were asked to perform three blocks of peg transfer tasks with the tactile feedback system in place. Force generated at the end-effectors was measured in all three blocks, but tactile feedback was active only during the middle block. All subjects used higher force when the feedback system was inactive. When active, subjects immediately used substantially less force and still maintained appropriate grip during the task. After the system was again turned off, grip force increased significantly to prefeedback levels. These results demonstrate that robotic manipulations without tactile feedback are done with more force than needed to grasp objects. Therefore, the addition of tactile feedback allows the surgeon to grasp with less force, and may improve control of the robotic system and handling of tissues and other objects.

A Multielement Tactile Feedback System for Robot-Assisted Minimally Invasive Surgery

A multi-element tactile feedback (MTF) system has been developed to translate the force distribution, in magnitude and position, from 3times2 sensor arrays on surgical robotic end-effectors to the fingers via 3times2 balloon tactile displays. High detection accuracies from perceptual tests (> 96%) suggest that MTF may be an effective means to improve robotic control.

Validated robotic laparoscopic surgical training in a virtual-reality environment

BACKGROUND

A robotic virtual-reality (VR) simulator has been developed to improve robot-assisted training for laparoscopic surgery and to enhance surgical performance in laparoscopic skills. The simulated VR training environment provides an effective approach to evaluate and improve surgical performance. This study presents our findings of the VR training environment for robotic laparoscopy.

METHODS

Eight volunteers performed two inanimate tasks in both the VR and the actual training environment. The tasks were bimanual carrying (BC) and needle passing (NP). For the BC task, the volunteers simultaneously transferred two plastic pieces in opposite directions five times consecutively. The same volunteers passed a surgical needle through six pairs of holes in the NP task. Both tasks require significant bimanual coordination that mimics actual laparoscopic skills. Data analysis included time to task completion, speed and distance traveled of the instrument tip, as well as range of motion of the subject's wrist and elbow of the right arm. Electromyography of the right wrist flexor and extensor were also analyzed. Paired t-tests and Pearson's r were used to explore the differences and correlations between the two environments.

RESULTS

There were no significant differences between the actual and the simulated VR environment with respect to the BC task, while there were significant differences in almost all dependent parameters for the NP task. Moderate to high correlations for most dependent parameters were revealed for both tasks.

CONCLUSIONS

Our data shows that the VR environment adequately simulated the BC task. The significant differences found for the NP task may be attributed to an oversimplification in the VR environment. However, they do point to the need for improvements in the complexity of our VR simulation. Further research work is needed to develop effective and reliable VR environments for robotic laparoscopic training.

Computer-based laparoscopic and robotic surgical simulators: performance characteristics and perceptions of new users

BACKGROUND

This study aimed to define perceptions of the need and the value of new simulation devices for laparoscopic and robot-assisted surgery. The initial experience of surgeons using both robotic and nonrobotic laparoscopic simulators to perform an advanced laparoscopic skill was evaluated.

METHODS

At the 2006 Society of American Gastroesophageal Surgeons (SAGES) meeting, 63 Learning Center attendees used a new virtual reality robotic surgery simulator (SEP Robot) and either a computer-enhanced laparoscopic simulator (ProMIS) or a virtual reality simulator (SurgicalSIM). Demographic and training data were collected by an intake survey. Subjects then were assessed during one iteration of laparoscopic suturing and knot-tying on the SEP Robot and either the ProMIS or the SurgicalSIM. A posttask survey determined users' impressions of task realism, interface quality, and educational value. Performance data were collected and comparisons made between user-defined groups, different simulation platforms, and posttask survey responses.

RESULTS

The task completion rate was significantly greater for experts than for nonexperts on the virtual reality platforms (SurgicalSIM: 100% vs 36%; SEP Robot: 93% vs 63%; p < 0.05). Prior robot use was predictive of task completion on the SEP Robot, and nonexperts were more likely to complete the virtual reality task on the SEP Robot than on the SurgicalSIM. Experts performed better than nonexperts for all performance measures on the ProMIS. All the survey scores pertaining to realism except image quality were higher for the ProMIS than for either virtual reality trainer.

CONCLUSION

The task completion rate was the best discriminant of expert performance on both virtual reality platforms, whereas simulator metrics best discriminated expertise for the videoscopic platform. Similar comparisons for the virtual reality platforms were not feasible because of the low task completion rate for nonexperts. The added degrees of freedom associated with the robotic surgical simulator instruments facilitated completion of the task by nonexperts. All platforms were perceived as effective training tools.

Robotically assisted laparoscopic transhiatal esophagectomy

BACKGROUND

Esophagectomy is a technically demanding operation with high procedure-related morbidity and mortality rates. Minimally invasive techniques were introduced in the late 1980s in an effort to decrease the invasiveness of the procedure. Data concerning the use of robotic systems for esophageal cancer are scarce in the literature. The goal of this report is to describe the authors' early experience using robotically assisted technology to perform transhiatal esophagectomy (RATE).

METHODS

Between September 2001 and May 2004, 18 patients underwent RATE at the authors' institution. A retrospective review of prospectively collected data was performed. Gender, age, postoperative diagnosis, operative time, conversion rate, blood loss, hospital stay, length of the follow-up period, and complications were assessed.

RESULTS

At the authors' institution, 18 patients underwent RATE, including 16 men (89%), with a mean age of 54 years (range, 41-73 years). The RATE procedure was completed for all 18 patients (100%). The mean operative time was 267 +/- 71 min, and estimated blood loss was 54 ml (range, 10-150 ml). The mean intensive care unit stay was 1.8 days (range, 1-5 days), and the mean hospital stay was 10 days (range, 4-38 days). A total of 12 perioperative complications occurred for 9 patients, including 6 anastomotic leaks, 1 thoracic duct injury, 1 vocal cord paralysis, 1 pleural effusion, and 2 atrial fibrillations. Anastomotic stricture was observed in six patients. There were no perioperative deaths. Pathologic examination of the surgical specimen yielded an average of 14 lymph nodes per patient (range, 7-27). During the mean follow-up period of 22 +/- 8 months, 2 patients died, 2 were lost to follow-up evaluation, 3 had recurrence, and 11 were disease free.

CONCLUSION

The current study shows that RATE, with its decreased blood loss, minimal cardiopulmonary complications, and no hospital mortality, represents a safe and effective alternative for the treatment of esophageal adenocarcinoma.

Objective evaluation of expert performance during human robotic surgical procedures

Robotic laparoscopic surgery has revolutionized minimally invasive surgery and has increased in popularity due to its important benefits. However, evaluation of surgical performance during human robotic laparoscopic procedures in the operating room is very limited. We previously developed quantitative measures to assess robotic surgical proficiency. In the current study, we want to determine if training task performance is equivalent to performance during human surgical procedures performed with robotic surgery. An expert with more than 5 years of robotic laparoscopic surgical experience performed two training tasks (needle passing and suture tying) and one human laparoscopic procedure (Nissan fundoplication) using the da Vinci™ Surgical System (dVSS). Segments of the human procedure that required needle passing and suture tying were extracted. Time to task completion, distance traveled, speed, curvature, and grip force were measured at the surgical instrument tips. Single-subject analysis was used to compare training task performance and human surgical performance. Nearly all objective measures (8 out of 13) were significantly different between training task performance and human surgical performance for both the needle passing and the suture tying tasks. The surgeon moved slower, made more curved movements, and used more grip force during human surgery. Even though it appears that the surgeon performed better in the training tasks, it is likely that during human surgical procedures, the surgeon is more cautious and meticulous in the movements performed in order to prevent tissue damage or other complications. The needle passing and the suture tying training tasks may be suitable to establish a foundation of surgical skill; however, further training may be necessary to improve transfer of learning to the operating room. We recommend that more realistic training tasks be developed to better predict performance during robotic surgical procedures and testing the transferability of basic skill acquisition to surgical performance.

Precision in stitches: Radius Surgical System

BACKGROUND

The Radius Surgical System is a manual manipulator with two additional degrees of freedom compared with conventional laparoscopic instruments (CLIs). This study aimed to compare the performance of laparoscopic suturing tasks with the use of the Radius Surgical System and CLIs, respectively.

METHODS

Five experienced laparoscopic surgeons performed laparoscopic surgical tasks in a training box. The tasks consisted of knot-tying, suturing, and needle control tasks. The needle control task was performed to evaluate the precision of the needle drive by analysis of the needle exit point on a suture pad. In the knot-tying and suturing tasks, required time and accuracy value were measured. Needle control tasks were performed on three different angulations of plane. The angles between the instrument plane and the target plane (AIT) were 30 degrees, 60 degrees, and 90 degrees. The distance of the exit point to the center of the target field, the number of actions needed to fulfill a single task, and the required time were recorded and analyzed.

RESULTS

In the knot-tying and frontal suturing tasks, there were no significant differences between the two groups. In the sagittal suturing task, the required time in the Radius group was significantly shorter than in the CLI group. In the needle control tasks on 30 degree and 60 degree AIT, the distance was significantly shorter in the Radius group than in the CLI group. There were no significant differences in the number of actions or the required time. In the frontal and sagittal needle control task on 90 degree AIT, the distance was significantly shorter in the Radius group than in the CLI group. The number of actions and the required time were significantly less in the Radius group than in the CLI group.

CONCLUSIONS

The two additional degrees of freedom contributed to accurate and controlled needle guidance, especially in difficult spatial situations.

The current state of miniature in vivo laparoscopic robotics

Minimally invasive surgery (MIS) reduces patient trauma and shortens recovery time, but also limits the dexterity of the surgeon because degrees of freedom are lost due to the fulcrum effect of the entry incisions. Visual feedback is also limited by the laparoscope, which typically provides two-dimensional feedback and is constrained by the entry incision. Developments within surgical robotics aim to mitigate these constraints. However, these developments have primarily included large external machines that augment vision and improve dexterity, but are still fundamentally constrained by the use of long tools through small incisions. An alternative concept is the use of miniature in vivo surgical robots that can be placed entirely into the peritoneal cavity through either an abdominal incision, or, after insertion into the stomach through the esophagus, can enter through a gastrotomy. This paper reviews the development of fixed-base camera robots for providing auxiliary views of the surgical field and of mobile robots with a movable platform for vision and task assistance in laparoscopic procedures. Moreover, the progress towards the application of similar robots for natural orifice transluminal endoscopic surgery (NOTES) and forward environments is discussed.

Effect of Visual Feedback on Surgical Performance Using the da Vinci® Surgical System

BACKGROUND

Robotic surgical systems quantify human movements in terms of position, velocity, and time span. This information can be used to objectively assess surgical skill. The aim of this study was to test the effects of three-dimensional vs. two-dimensional visualization on performance using the da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA).

MATERIALS AND METHODS

The movements of novice and expert surgeons were recorded using the da Vinci Surgical System for a two-handed task in two visual environments (two-dimensional and three-dimensional). Data were analyzed to investigate the effect of visual feedback on performance.

RESULTS

Velocities and task completion times were significantly different for novices and experts (P < 0.05) for all velocity parameters in both visual conditions. Additionally, there was a significant difference between two-dimensional and three-dimensional times for novices (P < 0.05). Novices were idle significantly longer in two-dimensional than in three-dimensional visual input (P = 0.037), and overall, novices were idle longer than experts for both visual conditions (P = 0.001).

CONCLUSION

Three-dimensional visual input allows novice surgeons to perform tasks with higher velocities, less idle time, and greater economy of motion. However, three-dimensional visual input provides no significant enhancement of performance for expert surgeons.

Learning curve using robotic surgery

The da Vinci (Intuitive Surgical, Inc., Sunnyvale, CA) surgical system is being used by an increasing number of surgeons across several surgical specialties. The robotic interface is different not only to open surgery, but also to laparoscopy because it involves remote surgical control, stereoscopic vision, and lack of haptic feedback. As the transition is made from traditional open to robotic surgery, factors such as learning of robotic skills, assessment of proficiency in robotics, and structured training for urologists in practice and residents assumes importance. Understanding how the robotic surgical technique is learned and how such learning can be best assessed will enable us to define protocols for training and set standards for proficiency. Learning curve and surgical dexterity are two parameters that are used to compare surgical learning and training. This article presents the current gold standard for assessing skill training and compares surgical skill acquisition and proficiency using conventional laparoscopy and robotic interfaces.

Advantages of advanced laparoscopic systems

BACKGROUND

Conventional laparoscopy offers great benefits to our patients, but suffers from major technical drawbacks. Advanced laparoscopic systems are being developed addressing some of these drawbacks.

METHODS

We performed a training-box based study, performing laparoscopic tasks using conventional laparoscopy and advanced laparoscopic systems in order to assess the influence of these technical drawbacks in order to predict where the biggest advantages of newly developed surgical systems can be expected.

RESULTS

The most significant technical drawbacks were two-dimensional vision, disturbed eye-hand target axis and (possibly to a lesser extent) the rigid instruments with a limited five degrees of freedom.

CONCLUSION

Major advances in advanced laparoscopy might only be expected using console-based robot-arm manipulated systems like the daVinci surgical system, or a combination of a high-quality 3-dimensional vision system, restoration of the eye-hand-target axis and the use of an advanced handheld instrument offering seven degrees of freedom such as the Radius surgical system.

In vivo laparoscopic robotics

Robotic laparoscopic surgery is evolving to include in vivo robotic assistants. The impetus for the development of this technology is to provide surgeons with additional viewpoints and unconstrained manipulators that improve safety and reduce patient trauma. A family of these robots have been developed to provide vision and task assistance. Fixed-base and mobile robots have been designed and tested in animal models with much success. A cholecystectomy, prostatectomy, and nephrectomy have all been performed with the assistance of these robots. These early successful tests show how in vivo laparoscopic robotics may be part of the next advancement in surgical technology.

Totally endoscopic robotic-assisted repair of patent ductus arteriosus and vascular ring in children

BACKGROUND

This study reports on our initial experience with robotically assisted patent ductus arteriosus (PDA) closure and vascular ring division in children.

METHODS

From April 2002 to May 2004, 15 patients underwent PDA closure (n = 9) and vascular ring repair (n = 6) by a totally endoscopic approach, utilizing the Da Vinci robotic system. The mean age of the patients was 8.3 +/- 4.7 years (range, 3 to 18) and the mean weight, 35.5 +/- 19.0 kg (range, 14.1 to 77.0 kg). Three thoracoscopic trocars were used to accommodate the endoscopic camera and two surgical instruments with an additional small incision for lung retraction. After dissection by the surgeon seated at the master console, PDA ligation with clips or division of the atretic arch and ductal ligament was performed.

RESULTS

Total operative times were 170 +/- 46 minutes (PDA) and 167 +/- 48 minutes (vascular ring). One patient with vascular ring was converted to thoracotomy because of dense adhesions due to previous surgery. Precise and easy surgical maneuver was possible with the articulated surgical instruments and three-dimensional visualization in 14 patients. Intraoperative transesophageal echocardiography confirmed no persistent shunt in all PDA patients. No laryngeal nerve injury and hemorrhage were noted. All patients were extubated in the operating room. Median length of postoperative hospital stay was 1.5 days.

CONCLUSIONS

Robotically assisted PDA closure and vascular ring division is a feasible and safe procedure. Future technologic improvement, including smaller instrument size and incorporation of tactile feedback, may permit application of this technique to even younger infants and intracardiac repairs.

Robotic surgery training and performance: identifying objective variables for quantifying the extent of proficiency

BACKGROUND

To understand the process of skill acquisition in robotic surgery and to allow useful real-time feedback to surgeons and trainees in future generations of robotic surgical systems, robotic surgical skills should be determined with objective variables. The aim of this study was to assess skill acquisition through a training protocol, and to identify variables for the quantification of proficiency.

METHODS

Seven novice users of the da Vinci Surgical System engaged in 4 weeks of training that involved practicing three bimanual tasks with the system. Seven variables were determined for assessing speed of performance, bimanual coordination, and muscular activation. These values were compared before and after training.

RESULTS

Significant improvements were observed through training in five variables. Bimanual coordination showed differences between the surgical tasks used, whereas muscular activation patterns showed better muscle use through training. The subjects also performed the surgical tasks considerably faster within the first two to three training sessions.

CONCLUSIONS

The study objectively demonstrated that the novice users could learn to perform surgical tasks faster and with more consistency, better bimanual dexterity, and better muscular activity utilization. The variables examined showed great promise as objective indicators of proficiency and skill acquisition in robotic surgery.

Robotic pediatric cardiac surgery: Present and future perspectives

Advances in robotic technology and imaging systems have enabled the broad application of minimally invasive techniques in cardiac surgery, including coronary artery bypass grafting and mitral valve repair in adults. In pediatric cardiac surgery, however, current robotic systems have been used primarily to facilitate thoracoscopic pediatric procedures on extracardiac lesions, such as ligation of patent ductus and division of vascular rings. The use of smaller instruments with sophisticated robotic wrists may make it possible to perform more complex extracardiac procedures even in young infants. Additionally, future technological improvements, including incorporation of tactile feedback, instrument tracking, and intracardiac imaging (such as real-time 3-dimensional echocardiography), may enable intracardiac robotic surgery to be performed in children. This article reviews the current and potential future applications of pediatric robotic surgery and the developmental work required to enable performance of these procedures, along with an overview of the problems associated with the use of current robotic surgical systems in children.