Current Status of Single-Site Robotic Cholecystectomy, its feasibility, economic and overall impact

Abstract

This paper reviews recent, though limited, articles on the topic of robotic single-site cholecystectomy (RSSC), a relatively new approach that is rapidly advancing in both research and clinical application. Laparoscopy has typically been the standard method of performing a cholecystectomy, but recent medical advances have led to usage of the da Vinci^® Surgical System robot technology to assist in performing the procedure. Several studies have compared outcomes of the RSSC to single-port laparoscopic cholecystectomies and to the traditional multiport laparoscopic cholecystectomies. Single port advocates think it as a tool with better cosmetic results and questionable less post-operative pain; however, single port also limits the maneuverability of the instrument arms, making some tasks more difficult, bigger single incision, more chances of post operative hernia. Overall, the RSSC is considered as safe with no worse outcomes regarding pain, hospital stay length, operative time, and patient satisfaction when compared to other cholecystectomy methods. Future direction includes expanding use of the miniature instruments and further advanced tools to overcome manipulation and visualization limitations. Thus far, though, there may be enough evidence with these smaller studies to support lack of harm with more use of resources.

Introduction

There have been countless advances in the surgical treatment of cholelithiasis; beginning in 1684 with the first abdominal incision for cholecystitis with calculi, and then in 1882 with the development of the technique of cholecystectomy²¹. Laparoscopy was first introduced to medicine in 1987, and robotics became integrated in 1991¹¹. The latest advancements in biliary surgery include single-incision laparoscopy in 1997, multiple-port robotic-assisted laparoscopic cholecystectomy, and most recently the single-port robotic-assisted laparoscopic cholecystectomy in 2010^17,10. This paper reviews recent, though limited, articles on the topic of robotic single-site cholecystectomy (RSSC), a relatively new approach that is rapidly advancing in both research and clinical application.

RSSC (Robotic single-site cholecystectomy)

Laparoscopy has typically been the standard method of performing a cholecystectomy, but recent medical advances have led to usage of the da Vinci^® Surgical System robot technology to assist in performing the procedure. The first robotic-assisted laparoscopic surgeries occurred in the early nineties, and the first trial of single-site robotic cholecystectomy was performed on pigs. These cases were completed satisfactorily, without external collision of the robotic arms and without technical complications⁸. The efficient arrangement of the robotic arms significantly improved operative time and decreased the number of errors⁸.

A pilot study found that, in general, the same procedure with robotic assistance took an average of ¹⁵ fewer more minutes to set-up than its non-robotic counterpart, and it had no additional morbidities¹. One study performed the RSSC in pigs using the GelPort^® system: a platform used to dock multiple da Vinci^® laparoscopic ports into one small single incision¹⁸. This study determined the procedure to be successful, safe, and have minimal blood loss; without having to convert to an open operation¹⁸. The procedure took an average of 70 minutes¹⁸. The GelPort^® design with one incision provides reliable maintenance of pneumoperitoneum by using a gel seal cap¹⁸.

The first RSSC performed on a human was in April 2010, and the first 13 cases study that followed reported them all successful and without intraoperative complications^6,10. The robotic assistance is becoming popular for reasons that include fewer incisions and scars, shorter recovery time, easier visualization, more precision and decreased risk of injuring nearby structures. There are some recent articles and medical authorities who are concerned of collateral damage from the Robotic Surgery, as a whole. Although laparoscopy may also be performed with one port, the single-site port (22.5cm vertical incision at the umbilicus) is better accommodated for a robotic approach simply due to the physical limitations of one port having enough space for laparoscopic instruments, a camera, and room to allow for instrument manipulation without collision^10,14. The da Vinci^® Robotic System was specifically designed to address these issues; it employs more ergonomic instruments that have better range of motion, enabling restoration of triangulation by separating the instruments beyond the port entry, at the working end¹⁰. Hence, once intraperitoneal, the surgery is more similar to the standard laparoscopic cholecystectomy than the single-port laparoscopic method¹⁰. The da Vinci^® system also provides clearer visualization via 3-dimensional view, magnification, and suppressing tremor^10,2. These features allow for a more consistently safe cholecystectomy¹⁰. However, this robotic approach is more costly, time-consuming, has a learning curve, and some say it may not provide any further benefit to the patient¹⁴.

Another early report studied forty-five patients who underwent the RSSC using da Vinci^® with the Single-Site^® platform. This platform employs flexible endoscopic robotic arms that helped prevent instruments from clashing during each case. There were no reported technical problems, major intraoperative complications, multiport or open conversions; there was one postoperative hemorrhage⁹. The average operative time was 84.5 minutes. Most patients went home within 24 hours, and were content with the procedure and results by two months. There were a few minor postoperative complications, but overall, perioperative pain was reportedly minimal and patients resumed normal activity in an average of 4.5 days. This equipment was successful in patients with high BMIs⁹.

RSSC vs. SILS (Single-Incision Laparoscopic Surgery)

One study compared 25 patients who underwent RSSC to 25 patients who had SILS. They found the operative time difference to be significant, with an average of 62.7 minutes for RSSC and 83.2 minutes for SILS¹⁷. Neither group had major complications nor readmissions. The average hospital stays were not significantly different¹⁷. The study also reported the RSSC easier to complete than SILS due to its similarity to the standard 4-port cholecystectomy with better precision and clarity of vision. There was good patient satisfaction with the RSSC¹⁷.

Another study of 100 patients who had RSSCs reported that two were converted to open surgery, twelve had minor intraoperative complications, and there were no deaths or major intraoperative injuries¹⁴. The study concluded that these findings were comparable to those of single-port laparoscopy. The RSSC took an average of 71 minutes, similar to the average of 75 minutes for the single-post laparoscopic approach¹⁴. A separate study agreed that the procedure times for RSSC and SILS are comparable¹⁸. These operative times are expected to continue to decrease as the number of cases increases; when RSSCs were first done, the average operative time was 107 minutes¹⁰. Despite the reported similarities, a survey of five surgeons revealed agreement that the RSSC is easier than the single-incision laparoscopy¹⁴.

RSSC vs. 4-port Laparoscopy

One report mentioned that RSSC and 4-port laparoscopy are similarly superior to SILS because of the 3-D image, clearer vision, and better instrument dexterity¹⁷. The study has its limitations.

Another study found that some surgeons did not perceive any significant difference in the ergonomy of the single-site setup from the standard multiport robotic surgery, but they agreed the RSSC was more technologically complex than the standard 4-port laparoscopy. They also perceived the RSSC to be as safe as the 4-port laparoscopy¹⁴.

In a study that compared ten RSSC patients with ten 4-port laparoscopies, there was no significant difference between operating times, with the average of 105.3 minutes for RSSC, 106.1 minutes for the standard 4-port method²⁰. Both groups had two male patients with post-operative urine retention. One patient in the 4-port laparoscopic group had postoperative atrial fibrillation. The RSSC group had no intraoperative, post-operative or late complications (average 201 days), although in two cases part of the access port broke off but the problem was resolved without further complications or recurrence. All of the RSSC patients at 30 days reported being very satisfied and would recommend it to a loved one²⁰. Many studies have agreed that the RSSC is safe and has good patient satisfaction.

Limitations and Economic Implications

The Pietrabissa study included a total of 100 patients and 5 surgeons, limiting its power, especially when evaluating the survey responses from the 5 surgeons on their opinions. Patients with BMIs over 30 were excluded, limiting interpretation and applicability of this study because much of the general population has a BMI over 30. Patients were also excluded if they had a prior right-upper or periumbilical abdominal surgery, also eliminating potential outcomes and complications that may be often encountered.

Kroh’s study used previous laparotomy as exclusion criteria, therefore eliminating patients with potential complications including adhesions. However, unlike many similar studies, patient BMI was not a criteria for exclusion in Kroh’s report.

The Wren study looked at only ten patients. This study excluded significant comorbid medical conditions, prior upper abdominal surgery, inpatient status, current diagnosis of acute cholecystitis or pancreatitis, or known common bile duct stone²⁰. Many patients have at least one of these conditions, making Wren’s results minimally applicable. Also, the patients were not followed past thirty days.

Spinoglio’s exclusion criteria were a BMI over 33, acute cholecystitis, or previous upper abdominal surgery. Patients were followed for two months.

The study by Konstantinidis had patients choose whether they would rather have the single-port or multi-port robotic surgery. Exclusion criteria included prior upper abdominal surgery, pregnancy, or suspicion of common bile duct stones. The patients’ BMIs ranged from 18.4 to 46.7. All operations were performed by the same surgeon and OR team.

A general limitation of all studies is that the surgeries were generally performed at one site with a limited number of surgeons, thereby decreasing external validity. Lot of studies did mention the use of resources is much more with robotic in general and single port in particular. There has been discussion of more incisional hernia with longer incision for single site port and that will be a long term outcome study that will be coming out shortly.

There were also many differences on RSSC operative time alone between studies, limiting the studies’ generalizability due to inconsistent data between similar studies.

Future Direction

Given the above limitations, further studies both long term and with larger patient number are needed to support external validity and generalizability, in order to fully endorse the success of the RSSC and its preference over its predecessors. Thus far, though, there may be enough evidence with these smaller studies to support lack of harm with more use of resources.

As a whole, robotic-assisted laparoscopy is considered safe and effective and has good patient satisfaction, especially because it is aesthetically pleasing without scars. Sugimoto’s study concluded that RSSC is safe and “enormously advantageous to the patient.” And, four out of five surgeons who performed many RSSCs were interested in using the robotic technology for more types of operations¹⁴. It was considered that this robotic technology “will eventually add significant value in the performance of complex hepatobiliary surgery”¹⁵.

However, multiple instruments used through one port certainly make manipulation and triangulation more difficult, increasing instrument clashing. These characteristics likely lead to “surgeon fatigue and frustration”¹⁰. One study felt that a “more flexible robot arm would be required to perform single-incision surgery more comfortably”¹⁸. As robotic single-port procedures are being done in urology and gynecology, it is important to gather whether or not these fields are experiencing the same limitations, and if there are any ideas or proposals to overcome the limitations¹⁰.

Perhaps the latest advancement in this field is the use of miniature in vivo robots⁴. These small, multidexterous robots are meant to allow for better manipulation and efficiency, and with a lower morbidity rate and cost⁴. This was performed in 3 pigs. The in vivo robot users reported better visualization with good robotic arm flexibility and triangulation without collision. These robots may be controlled remotely or by telepresence. Efforts are being made to still decrease the robot size, in hopes to potentially use more than one robot during a case to complete various tasks⁴.

Conclusion

Robotic-assisted cholecystectomy is not inferior for outcome to the laparoscopic cholecystectomy. Various studies have shown relatively consistent data supporting the non-inferior use of RSSC, especially when it comes to, post-operative pain, recovery time, and cosmetic appeal. There is need for long term outcome studies and financial benefit studies before making a decision in favor/against of RSSC. Definitely next generation robots that are economically and physically more manageable will lead to more general and rapid acceptability.