Robotics and surgery: A sustainable relationship?

Table 1 Drawbacks associated with robotic surgery

Drawback	Discussion
Cost	The da Vinci system costs approximately $1.5 million with maintenance fees of about $150000 per year[43,44]. Likewise, robotic endovascular catheter systems are expensive, have high maintenance costs, with the additional cost of disposable catheters. However, there is no conclusive data regarding the cost-effectiveness of these robotic systems. Moreover, an economic model, with quality of life adjustment, has not been performed for any of the robotic systems[44]
Evidence	Currently, the evidence for robotic surgery’s efficacy and safety is largely from retrospective studies often with small sample sizes or from an institution’s initial cases/experiences, where the surgeon may be at the start of his/her learning curve[44]. Hence, conclusions about safety and efficacy must be interpreted with caution
Preparation, floor space and emergencies	The Theatre team must also be trained with the device set-up including troubleshooting problems that may arise during operations. Hence, the robotic surgery venture is likely a time, cost and resource-intensive process[45]. Moreover, considerable floor space is needed, with bulky instruments; this may be problematic and considerable cost may be incurred for renovations before robotic surgery can be employed. Furthermore, in an emergency, there may be a delay in converting to an open procedure since the bulky instruments cannot be as easily removed as in conventional laparoscopy[44]
Unproven efficacy	Current evidence base for efficacy of robotic surgery is mainly from small, retrospective studies. Prospective, multicentre randomized clinical trials to evaluate safety, efficacy, long term outcomes and cost analysis are required to prove that robotic assistance is indeed superior to conventional techniques before its widespread use

Table 2 Definitions of validity and reliability

Type	Definition
Face Validity	Extent to which the simulator resembles real life scenarios
Content Validity	Extent to which the domain that is being measured is being measured by the simulator/assessment tool
Construct Validity	Extent to which a simulator measures the trait it purports to measure
Concurrent Validity	Extent to which the results of the assessment tool correlate with the gold standard for that domain
Predictive Validity	Ability of the simulator to predict future performance
Test-Retest Reliability	Measure of a test to generate similar results when applied at two different points
Inter-Rater Reliability	Measure of agreement between two or more observers when rating an individual’s performance