Upon assessment of the data collected, a common trend was the presence of much variability in visual acuity from surgery to surgery, supported by the standard deviations of average cleaning and occlusion times. A variety of factors may contribute to this variability including the nature of the occlusion, experience of the surgeon and robot technician, differences in patient characteristics, or operating room (OR) equipment and team structure. Anecdotal data collected during OR observations suggests that surgeon and surgical technician’s comfort with RAS techniques play a major role in clear visualization. Despite not collecting quantifiable data on this metric, raw feedback suggested that some surgical technicians were able to interface with the robotic system more effectively than others; this variability may be partially reflected in the high standard deviation observed in cleaning times (28.7 ± 21.0 seconds). Variability in occlusion and cleaning times may also be explained by the nature and severity of the occlusion, given there are numerous types of debris variables that can lead to lens occlusion such as blood smearing, miscellaneous fluids contacting the lens, lens location for obstruction, or even manufacturing and equipment performance variations. In addition, relative standard deviations (RSDs) for time spent with occluded vision were larger for surgeries lasting under one hour (RSD = 115%) than for those over one hour (RSD ~ 50%). This may be due to shorter case times lending themselves more readily to high variation, though such a large decrease may also indicate that overall surgery length affects the variability of time spent with suboptimal vision.
When assessing the potential impact of surgical specialty on laparoscopic outcomes, the data showed a significant increase in occlusion count and time spent with occluded vision for urology cases versus general surgery or OB/GYN cases. There did not appear to be a significant difference between OB/GYN and general surgery cases, though the raw data showed that OB/GYN had a longer average occlusion time. In addition, the rate of occlusions per minute was not significantly different between specialties. Given that the average length of urology cases was longer than the other surgical specialties and the occlusion rate was similar between specialties, the significantly higher occlusion counts and time spent with occluded vision in urology is likely attributed to longer case length, not a higher frequency of occlusions occurring. Despite this, an interesting dichotomy can be seen between OB/GYN and general surgery cases where OB/GYN had a longer average surgery length but a lower average occlusion time than that of general surgery. In addition to this, OB/GYN cases had a significantly lower occlusion count than urology cases. While this could be for a number of clinically related reasons, it is interesting to note that the data shows debris events occurring less in OB/GYN compared to the other specialties observed. This difference may also be attributable to the type of case, step in the procedure, and location/anatomy of the operative area (i.e., deep within the pelvis behind pubic bone versus anteriorly). More case counts would help further explore and validate the significance of this potential trend. In contrast to occlusion counts and time, there was no observed difference in cleaning count and cleaning time between different surgical specialties. This suggests that surgeons across specialties may only be willing to clean at certain points in surgery and/or only every so often despite significant differences in occlusion counts.
In the comparative analyses performed, there was a significantly greater presence of active electrocautery devices in the surgical field during lens occlusion events than any other instrument category. The statistical significance in this dataset shows an interesting relationship between cautery activity and distorted surgical vision. Despite this putative connection, this study has raised the question of whether cautery use can be directly correlated with visualization that is poor enough to warrant subsequent cleaning. Subset analysis was performed on the data that exclusively comprised the final occlusion event before a lens cleaning. When comparing active instrumentation in all occlusion events to the subset of occlusion events, camera movement increased in proportion while cautery decreased. Further data collection surrounding the metric of occlusions preceding cleanings could validate the significance of that trend. Although active cautery occlusions made up a significantly larger proportion of total occlusion events, camera movement occlusions preceded a cleaning slightly more often. In addition, of all camera movement occlusions, 53.3% preceded a cleaning while only 34.4% of all cautery occlusions preceded a cleaning. The higher proportion of occlusions preceding a cleaning for camera movement may be attributed to the surgeon’s preference to clean the lens at a time in which they may be searching for a new visual angle by moving the camera, which could, in turn, be further connected to the position of the visual distortion related to pursuit of a better viewing angle. Other notable categories where a high proportion of a specific occlusion type preceded a cleaning were ‘Insert/Remove Instrument’ (67.7%) and Irrigation (61.1%). Data here, given the type of active instrumentation preceding the occlusion event, may indicate that such instruments could create debris events severe enough to warrant an immediate cleaning. Conversely, this may also suggest these instruments are used at points in the surgery where the surgeon deems it more acceptable to stop the surgery and clear the lens based on their assessment of the risk threshold.
Perhaps the most intriguing finding within this study involves a comparison between average time spent cleaning the scope and time spent under suboptimal vision. Although cleaning the lens comprised 1.16% of the operative time, 41.4 ± 28.1% of all surgical observation time was spent with distorted visualization. Given that surgeons operated under suboptimal conditions for nearly 35 times as long as it would take to clear the lens, this may indicate a tendency to avoid interrupting surgical progress to clean the lens. As hinted at above, this is further supported by data from this study showing that active instrument categories such as cautery and scissors/cutting less commonly preceded a cleaning event when compared to transitional events such as camera movement and inserting/removing equipment. In other words, when using instruments for a critical part in a procedure, such as manipulation or destruction/repairing of tissue, the surgeon may be less likely to stop the procedure and clear the lens. Conversely, during less involved portions of surgery, such as when instruments needed to be swapped, a cleaning event was executed more often since the risk level to the patient was deemed lower and the need for enhanced operative focus may be deemed less critical at such a time. This is particularly important as one would surmise that surgeons prefer clear visualization in more critical moments; however, the data suggests that operating under suboptimal vision may still be preferred to the interruption and total loss of visualization that is required by a lens cleaning. This is an interesting “surgical catch-22” to consider, given the data. Anecdotal evidence via surgeon and surgical technician feedback also supports this hypothesis.
Lens occlusions were commonly discussed by surgeons and other OR personnel as a frequent inconvenience or source of frustration. One surgeon commented on his personal dislike for removing the lens to be cleaned, as it left him blind while surgical instruments were still inside the body cavity. Several surgeons and surgical residents expressed their irritation with occlusions and cleanings interrupting workflow and stated that they clean the lens as infrequently as possible to avoid that interruption. Of note, there was a high degree of variability observed for operative time spent with suboptimal vision. Based upon our observations, we postulate that this is due to the personal preference of the surgeon operating, with some tending to clean immediately and often, and others operating with an occluded lens for longer. Again, this appears to be due to frustration surrounding the prospect of interrupting surgical progress. Future research should investigate potential trends seen in different surgeons and surgical specialties.
The importance of clear visualization in RAS cannot be understated and is important for surgical success. However, this study has shown that it is impacted by a number of factors surrounding lens occlusions, including surgeon reluctance to remove and clean the scope to prevent disruption of the surgery, based on raw interview feedback. This has potential implications for surgical efficacy and at the very least reveals a need for future research that may examine the impact of occluded visualization and lens cleaning on other aspects of surgery.
Despite this study showing how profound visual disruptions are in the operating room for RAS, there are several limitations that need to be addressed. First, data collection for this study was conducted at a teaching institution where surgeons of multiple subspecialties performed RAS. All surgeons had received specialized training for RAS, but some variability in experience exists due to the participation of surgical residents during the cases. This variability is also true of the surgical technicians who handled scope cleaning. Second, a variety of procedures and surgeons were observed in order to gain a broad understanding of lens occlusions and cleanings across different uses of RAS. Following this study, we acknowledge that a larger scale inquiry would be able to further explore the explanations for some of the results seen. For example, variation in time spent operating with suboptimal vision between individual surgeons and variation in lens cleaning time between types of occlusions would be valuable. Third, a more formalized method of collecting surgeon interview data about visual acuity and lens cleaning could yield concrete conclusions on the impact of occlusions on their actions during a case.