|Christopher Weyant in The New Yorker, June 8-15, 2015|
I've found little in the recent literature about this topic, although--based on my small sample of anaesthesiologists--it is a significant concern among their profession. The concern most often expressed has to do with the extended length of procedures conducted robotically compared to traditional laparoscopic procedures or open procedures. While anaesthesiologists are very good at handling long cases--and even unexpectedly long cases--they will generally tell you that, everything else being equal, the less time spent under anaesthesia the better.
The articles I have found about anaesthesia risk interestingly do not cover the extended time in the operating room. This study from Henry Ford back in 2007, for example, focused on difficult airways and the like.
The length of robotic procedures results from two factors--the time it takes to accomplish pre-surgical "docking" of the machine and the time actually spent to conduct the procedure. In the living donor liver resection case I discussed in a previous blog post, I noted:
Of particular note, the authors acknowledge that "the length of surgery was longer than that normally required for open right donor hepatectomy," but then state that "it must be considered that the complicated venous anatomy prolonged the total operating time." I can't evaluate the latter clause, but my understanding from experts in the field is that the 8-hour duration of this case was considerably longer than a standard open donor hepatectomy, which is usually 5 to 6 hours.
A colleague noted in a recent recent case that five hours had been budgeted in the operating room for a robotically assisted hysterectomy and uterine fibroid removal, well longer than would have been required for a manual approach. Fully two hours of that time was budgeted for docking of the robot to align it and its instruments with the patient's body.
In another case, an esophogeal cancer resection in the early days of robotic surgery, the patient was under anaesthesia for 12 hours because of complications due to the use of robotic technique.
There seems to be a reluctance in the surgical profession to even acknowledge these more lengthy procedures. Note the liver case above, where the surgeon's article--without support--ascribed the length to "complicated venous anatomy." In the esophogeal cancer case, when the case was brought to departmental M&M's for review, no one in the room dared speak up about the wisdom of proceeding with robotic assistance because the surgeon in question was a favorite of the chief of the department and because the institution in question had invested heavily in being a national leader in robotic surgery.
Beyond the time concerns, there are other anaesthesia risks. One example comes from an early case involving a thyroid removal. As part of the consent process, a highly experienced anaesthesia attending informed the patient that in traditional thyroidectomies, he would normally be sitting at the head of the table during such a procedure. He noted that the instruments being used in a robotic thyroid removal had the increased potential to cause a unilateral or bilateral pneumothorax. Use of the robot would require him to be six feet away, making it challenging to detect such a complication as quickly, and he might thus respond more slowly to it.
This article mentions this kind of risk as well as others:
The endotracheal tube should be taped securely, appreciating that patient positioning may alter tube placement over time (unintended extubation or mainstem intubation), robotic instrumentation may dislodge a tube, and an obstructed view may delay recognition of a tube that has become dislodged. Replacing an endotracheal tube would be challenging for robotic surgery patients based on positioning and the time delay associated with undocking.
Others appear to be less concerned. A similar type of risk was noted in this 2009 article. but then it was quickly dismissed:
Finally, the bulk of the robot is positioned over the abdomen and chest. Although the incidence of airway or serious cardiovascular events are no greater in robot-assisted surgery, if they do occur, the position of the robot will interfere with effective cardiopulmonary resuscitation and airway interventions. The theatre team should practise and be familiar with an emergency drill for the removal of the robotic cart. With practise, at our institution, this drill has enabled us to be able to consistently remove the robot within 30 s. It is possible to deliver a DC shock with the robot docked in position if required.
In the thyroid surgery case, the patient inquired about the matter to the surgeon, who was very upset that the anaesthesiologist would convey these additional risks to "his patient." The anaesthesiologist was never asked to attend on another robotic procedure with that surgeon.
My concern today is not risk per se, as all surgery involves a balancing of benefits and risks. The question I ask is whether hospitals have properly incorporated the full spectrum of risks into their informed consent and shared decision-making processes. I also have a concern that anaesthesiologists, because of professional risk and institutional commercial priorities, will not feel empowered to point out such risks to patients under their care.