Prospective randomized comparison of three‐dimensional (3D) versus conventional laparoscopy in total colectomy for ulcerative colitis

3D laparoscopy has been proposed with the aim of improving the depth perception and overall operative performance. To aim of this study is to compare 3D laparoscopy with conventional 2D laparoscopy in terms of operative time and visual parameters.


Introduction
Three-dimensional (3D) visualization technology for laparoscopy has been proposed since the early 1990s as a method to facilitate laparoscopic performance.However, early 3D laparoscopic technology was limited in terms of image quality, and its widespread use had not been implemented. 1As the field of laparoscopy continues to evolve and new advances in technology are frequently introduced, the latest technical developments try to allow high definition 3D visualization with the same or even better quality than conventional, two-dimensional (2D) systems provide.While many components vary, one of the main thrusts of 3D visualization was to enhance the depth perception of the image.
Unlike 2D imaging, 3D systems capture separate images using dual-channel laparoscopes consisting of either two separate rod lenses or two separate chips at the end of the scope to provide two vertically separated images.The result is a different fixed distance perspectives of the operative field and simulates binocular imaging as if the viewer were positioned at the tip of the laparoscope. 2hen using a 3D system, users wear lightweight glasses that polarize the alternate horizontal rows of pixels corresponding to the right-and left-eye images. 3ultiple studies have been published on the use of 3D laparoscopy in different specialties as far back as two decades ago.However, 3D laparoscopy is still not routinely used in most specialties. 4,5he use of 3D laparoscopy in colorectal surgery has been reported in a few studies, with most studies centering around right colectomies and rectosigmoid resections. 6There is paucity of literature on the use of 3D laparoscopy in comparison to traditional 2D laparoscopy for advanced multi-quadrant operations such as total abdominal colectomy (TAC).Although some studies reported shorter operative time with the use of 3D laparoscopy with comparable perioperative outcomes, most of the studies comparing 3D with 2D laparoscopy are not standardized, 6,7 hence the effects of 3D laparoscopy on the operative performance remains to be controversial. 8herefore, the aim of this prospective randomized clinical trial was to compare 3D laparoscopy with 2D laparoscopy in terms of operative time and visual parameters in patients with the diagnosis of ulcerative colitis (UC) who underwent TAC with end ileostomy.We hypothesized that 3D laparoscopic visualization would provide surgeons visual advantages over 2D laparoscopy and reduce the overall operative time with comparable perioperative outcomes.

Methods
This is an Institutional Review Board approved, prospective, randomized single center trial designed to determine a 10% reduction in the mean operative time in patients who underwent laparoscopic TAC with end ileostomy for medically refractory UC at the Cleveland Clinic Main Campus between January 2015 and December 2020.
Eligible patients for this trial were recruited by investigators from those scheduled to undergo TAC with end ileostomy.All subjects were randomized into two groups: 3D or 2D laparoscopy (Fig. 1).Randomization was done by using REDCap (a secure web program for building and managing online databases and surveys) prior to study.Allocation of patients to groups is summarized in Supplementary Table 1.All patients gave full consent.
The Olympus HD 3D Laparoscopic Surgical Video System that utilizes ENDOEYE FLEX 3D Videoscope (Olympus Inc., Center Valley, PA) was used for operations that were randomized to 3D group.This setup required 3D glasses or clip on 3D spectacles to be worn by the operating surgeon and all operating room staff.Three staff surgeons who are highly experienced in the field of laparoscopic surgery performed the procedures with 2D and 3D laparoscopy.One of three surgeons performed all operations using a single-port laparoscopy approach.Colorectal surgery fellows or chief residents were responsible for driving the camera were trained on how to drive the camera prior to scrubbing.
Collected data included patient demographics (e.g., age, gender and BMI), clinical characteristics (e.g., American Society of Anesthesiologists scores, comorbidities, preoperative steroid/biologic usage and doses and time from UC diagnosis to surgery) and peri-operative data (e.g., procedure types, duration of surgery and surgical steps and estimated blood loss).Total operating time was defined as the period from the first skin incision to last closure of the skin.The time spent for adhesiolysis was subtracted from the total time.The time to complete each step of the procedure (ileocolic pedicle take-down, mobilization of transverse colon, sigmoid mobilization, and mobilization of left colon, rectum/rectosigmoid transection and mesenteric division) was documented separately.Additional data collected included serious intra-and post-operative complications and the number of incidences the scope had to be cleaned/exchanged/fogged.
Surgeons' subjective evaluation of the visualization system was measured with a standardized survey after completion of each surgery.This survey evaluated the following parameters: eye fatigue/strain, dizziness, headache, disorientation, physical discomfort, illumination, colour reproduction, sharpness/resolution, ghosting (double image) and overall quality of image.Visual parameters were scored using the scoring system 1-5, 1 being poor and 5 being excellent.The primary outcomes were operative time and visual parameters.The secondary outcomes were the time spent for each step of the surgery, estimated blood loss and postoperative complications.

Statistical analysis
Sample size was determined to be 27 for each group utilizing a power analysis based on 80% with an alpha of 5% significance.All relevant patient characteristics, operative and postoperative data were presented as mean (standard deviation), median [interquartile range] or frequency (percent).T-tests or non-parametric Wilcoxon rank sum tests was used for continuous factors, chi-square test or Fisher exact test was used for categorical variables and Wilcoxon rank sum tests was used to compare ordinal factors between 3D and conventional laparoscopy (2D) groups.The associations between the two laparoscopic approaches and the total operating time was assessed using mixed effect model, with a random intercept for surgeon to account for the correlation of surgeries done by the same surgeon.All comparisons were made at a significance level of 0.05, and all analyses were performed with R version 3.6.1.

Results
Overall, 54 subjects with the diagnosis of UC above 18 years of age who underwent elective TAC with end ileostomy between January 2015 and December 2020 were enrolled in the study.One subject in the 2D group underwent conversion to open surgery and therefore excluded from the final analysis (Fig. 1).A total of 53 subjects (26 in 2D group, 27 in 3D group) were included in the final analysis, of which 56% were male with a mean age of 40 (16.3) years and body mass index of 23.5 (4.7) kg/m 2 .Twenty-five subjects underwent single port laparoscopic surgery.Among these subjects, 12 of them were in the 2D laparoscopy group and 13 of them were in the 3D laparoscopy group.There were no significant differences between the groups in terms of demographics and perioperative variables (Table 1).Mean and median operative times were 75.3 (30.8) and 79 (48;97.5)min for 3D laparoscopy group, respectively.For 2D laparoscopy group, the mean and median operative times were 82.7 (38.6) and 77 (46.5;108) min, respectively.Mean operative time was 8.9% lower in the 3D group, however the large variance in time led to no statistically significant difference (P = 0.45).Comparison of median operative times did not lead to a statistically significant result as well (P = 0.57).Operative times for each step of the procedure were comparable between the groups.Mean estimated blood loss for 3D and 2D laparoscopy were 36.2 (20.9) mL and 53.5 (55.3) mL, respectively (P = 0.15).Median number of times the scope required maintenance were comparable between the groups (Table 1).
Overall, 69% of the visual evaluation survey results favoured 3D laparoscopy over 2D (P = 0.014).In terms of illumination, colour reproduction, sharpness/resolution and overall quality of image, 3D laparoscopy was found to be superior to 2D (Table 2).

Discussion
3D visualization was developed to enhance the visual experience of the surgeon and assist in easier identification of the resection planes.It provides more detailed visualization and potential decrease in the duration of surgery.Although 3D visualization has been integrated in robotic platforms, it is not being widely used in laparoscopic colorectal surgery.Current study aimed to compare 3D laparoscopy with conventional 2D laparoscopy, and assess the effect of 3D system on operative time and visual parameters.
We analysed 53 patients with medically refractory UC who underwent laparoscopic TAC and end ileostomy procedure.There were no statistically significant differences in terms of procedural time between the two groups, nor was there a significant difference in the time needed to complete each individual step of the procedure.In terms of visual parameters, 3D system was superior to 2D laparoscopy.
Changes in the operative time with 3D laparoscopy was investigated before, mostly with standardized tasks in experimental settings.Previously, it was studied in 50 patients who were undergoing laparoscopic right hemicolectomy and complete procedure time and times of the single tasks were comparable between the groups, except for the anastomosis time, which was shorter in the 3D group. 9In another study of 120 patients who underwent laparoscopic colon resections, the 3D group had a significantly shorter operative time by 19 minutes. 8Similar differences in operative time have also been observed in laparoscopic cholecystectomy and bariatric surgery in previous studies. 10,11In our study, there was a 7.4 min reduction in the operative time in 3D laparoscopy group, but due to the large variability in times, the result was not statistically significant.Inclusion of single-port procedures might have led to this large variance in times which resulted in the operative time difference being non-significant.Also, one should acknowledge that in expert hands, the difference in operative time can be subtle.Surgeons performing these operations were all highly experienced in the field of laparoscopic surgery.One of the major proposed benefits of 3D laparoscopy is superior images.In a recent systematic review of 13 trials comparing 3D versus 2D in abdominal surgery, all but one of the trials reported advantage of the 3D system in terms of image quality, depth perception and mental workload. 7Similarly, our results report 3D to be superior to 2D in the subjective evaluations, in terms of illumination, colour reproduction, sharpness/resolution and overall quality of image.It is important that the visual advantages of the 3D laparoscopy system are complemented by the superior comfort levels and suitable ergonomics.Wearing polarized glasses during 3D laparoscopy is necessary in most instances and can affect the surgeons' experience.It has been suggested that 3D laparoscopy may not be favoured by the surgeons, causing visual strain and physical discomfort. 7In our study, 73% experienced no eye fatigue/eye strain, 81% never experienced dizziness and none of the surgeons experienced headaches while using the 3D laparoscopy system with polarized glasses.These results show that optical adjustment to this system is attainable without compromising the comfort of the surgeon.
Previous studies showed that the 3D system is superior in terms of visual parameters regardless of the experience level of the surgeon.Although our study was not designed to evaluate this, we believe that this system can potentially be incorporated in resident education and can improve laparoscopic surgery practice for residents and future studies are needed. 7egardless of the benefits, a system should be safe for it to be used frequently.It should be highlighted that this system was safe and feasible as emphasized by the comparable complication rates in the current study.In addition, there were no complications solely due to use of the 3D laparoscopy system.Previous studies has also shown similar results proving 3D laparoscopy to be safe with comparable complication rates to 2D laparoscopy. 7e acknowledge the limitations of this study.First of all, operations were performed by different surgeons and the numbers of 2D and 3D cases performed by each surgeon were not equal, which might have led to the variability of the procedure times.Additionally, inclusion of single-port procedures, although all of them were performed by the same surgeon and distributed equally between the groups, can be a contributing factor to the large variance of operative times.As a result, we observed a reduction in operative time in 3D laparoscopy group, but the result was not statistically significant.With such a large variance, 53 patients were only able to provide 23% power to detect 7.4 min time reduction.When groups were compared by median operative times, there was not any statistically significant difference as well.Also, one should acknowledge that in expert hands, the difference in operative times might be subtle.
Secondly, because of the nature of the operation, we could not analyse the time needed to perform an anastomosis which could be highly affected by the use of 3D laparoscopic technique.Exclusion of morbidly obese patients may also be considered as a limitation as these patients obtain high benefit from laparoscopic surgery.However, obese patients pose many challenges to surgery, leading to longer operative times when compared with non-obese patients. 12Since the primary outcome in this study was the operative time, inclusion of morbidly obese patients might have introduced biases.Therefore, they are excluded from the study.
And finally, 3D laparoscopy system was found to be associated with overall improved visualization scores.However, surgeons were not blinded as this would not inherently be possible, thus the evaluation of visual parameters were very subjective.The 3D system was provided at no cost to our institution, therefore the cost of the system was not analysed in this study.
Nevertheless, the complexity of the cases were relatively similar and standardized in our study.This helped us to focus on the effects of 3D system on surgeons' experience.Choosing TAC as the procedure of interest helped us to evaluate different tasks (time for ileocolic pedicle take-down, mobilization of right colon, transverse colon and sigmoid colon and rectosigmoid resections).Considering the fact that previous studies were mostly centered on right colectomies and rectosigmoid resections, this can be mentioned as one of the strengths of this study.
To our best knowledge, this study is one of the few randomized clinical trials that investigate the effects of 3D laparoscopy in colorectal surgery compared to 2D laparoscopy.Our results show that three-dimensional laparoscopy for TAC in UC patients is a safe and feasible option, providing better visualization scores.Future studies are needed to further evaluate surgeons' experience with 3D laparoscopy in colorectal surgery and investigate integration of this system in daily surgical practice.

Fig. 1 .
Fig. 1.A CONSORT flow diagram of included patients

Table 1
Demographics and perioperative variables Note: Variables are presented as mean (standard deviation), median [interquartile range] or frequency (%).† ASA, American Society of Anesthesiologists.

Table 2
Subjective evaluation of 3D laparoscopy system