3D vs 2D laparoscopic radical prostatectomy: our experience in the robotic era

Francesco Chiancone1, Maurizio Fedelini1, Clemente Meccariello1, Luigi Pucci1, Andrea Oliva1, Domenico Di Lorenzo1, Paolo Fedelini1
  • 1 AORN A. Cardarelli, U.O.S.C. Urologia (Napoli)

Objective

The robotic technology has a shorter learning curve and some technical advantages instead of classical laparoscopy (increased number of degrees of freedom and three-dimensional visualization of the operative field) (1). A difficulty of laparoscopic surgery involves converting two-dimensional (2D) images into three-dimensional 3D images and depth perception rearrangement. 3D imaging may remove the need for depth perception rearrangement and therefore have clinical benefits (2) (3). The aim of this study was to clarify if 3D images are really beneficial in the performance of laparoscopic radical prostatectomy compared with 2D imaging systems and to analyze oncological and functional outcomes at a short-term follow-up.

Materials and Methods

From January 2015 to November 2015, 92 patients underwent a laparoscopic extraperitoneal radical prostatectomy (LERP) at our hospital. Oh these, 50 patients underwent a 3D-LERP (27 patients underwent an iliac/obturator lymph node dissection) and 42 patients underwent a 2D-LERP (24 patients underwent an iliac/obturator lymph node dissection). We divided our department surgeons into two subgroups according to the number of surgeries (less and more than 50 LERP). 41 out of 50 3D-LERP were performed by a surgeon with more than 50 LERP. 29 out of 42 2D-LERP were performed by a surgeon with more than 50 LERP. 2D-HD Storz® system was used to perform 2D procedures and Einstein Vision® 3D system was used to perform 3D procedures. We hypothesized that VUA (vesico-urethral anastomosis) was one of the most difficult and challenging procedures. The primary outcome was the time of VUA. Secondary outcomes were operative time, blood loss, PSMs (post surgical margins) rate, recovery of continence according to the validated questionnaire Incontinence Quality of Life (I-QoL) and the feasibility of basic tasks. The feasibility of basic tasks were measured by eight questionnaires using 7-point Likert scales. Mean values with standard deviations (±SD) were computed and reported for all items. Statistical significance was achieved if p-value was ≤0.05 (two-sides). Categorical data were compared using Pearson's chi-squared test (χ2).

Results

Mean time +/- SD of VUA using the van Velthoven technique (4) was 13.8+/-4.8 min using the 3D imaging system and 14.6+/-4.5 min using the 2D imaging system. No significant difference was observed (p=0.41). Mean time +/- SD of VUA was statistically different in the subgroups of surgeons with less than 50 LERP (14.2+/-3.5 min vs 17.2+/-2.9 min, p=0,04) but no significant difference was observed in the subgroups of surgeons with more than 50 LERP (13.2+/-2.8 vs 13.6+/-3.1 p=0.58).
Mean total operative time +/- SD was 105,6 +/- 27,5 (50-190 min) using 3D imaging system and 106,4 +/- 36,1 (45-235 min) using 2D imaging system. No significant difference was observed (p=0.9043).
The same trend was seen in the subgroup of surgeon with more than 50 LERP (100.25+/-25.5 min vs 101.4+/-39,6 p=0,88) and in the subgroup of surgeon with less than 50 LERP (115.68+/-20.1 vs 113.8+/-29.5, p=0,87).
No significant differences were seen in mean blood loss between the two groups (mean +/- SD 306,2 +/- 230 in the 3D-LERP group and 316.8 +/- 247.9 in the 2D-LERP group, p=0.83).
No conversion from the 3D to the 2D imaging system during LRP was observed.
Feasibility of basic tasks, was significantly better using the 3D imaging system in all questionnaires except for one (Table 1). No differences in PSMs were seen (P=0.93). I-QoL questionnaires showed a significant quality of life improvement at the first month in the 3D-LERP group (91,6+/-7) compared to the 2D-LERP group (81,2+/-5) (p =0). I-QoL questionnaires did not show a significant quality of life improvement at the third month (93,5+/-5 vs 91,9 +/-6) (p =0.17). The overall continence rate did not reach a statistically significant difference at 1 month follow-up (90% vs 88%), (P=0,77) and at 3 month follow-up after pelvic floor rehabilitation (96% vs 94%), (P=0,51).

Discussions

Classical laparoscopic surgery is limited by a two-dimensional vision that does not allow perception of the operative field. The lack of depth perception has repercussions both on the learning curve, and in the possibility for the surgeon to maneuver the instruments with an accuracy comparable to that which would occur in the same “open” operation. In this study, we demonstrate that the 3D imaging system do not decrease the time of VUA compared with the conventional 2D imaging system except for surgeons who are at the beginning of their learning curve. The 3D imaging system do not decreased the mean total operative time compared with the conventional 2D imaging system. No significant differences were seen in mean blood loss between the two groups. Moreover PSMs rate was similar between the two groups. Meticulous handling and tissue dissection obtained with the auxilium of the 3D view have allowed earlier continence recovery according to I-QoL questionnaires. This could be mainly related to less trauma and greater sphincter- structures saving (5). Although the trend is clearly favorable to the 3D-LERP group, the overall continence rate did not reach a statistically significant difference at the first month and at the third month follow-up and I-QoL questionnaires did not show a significant quality of life improvement at the third month follow-up after pelvic floor rehabilitation.
The definition of continence was based on a specific question appropriate to reflect the range of incontinence severity: “How many pads/day did you usually use to control urine leakage during the last 4 weeks?”. We considered “dry” patients without any loss of urine (no pads/day) or those who used a safety pad/day. There is no validated way to measure subjectively the feasibility of different tasks during operation. Therefore, in this study, we measured surgeons’ subjective evaluation of surgical feasibility. In all questionnaires but one, 3D was superior to 2D imaging. These results were the same as those reported for cholecistectomy (6).

Conclusion

In conclusion, performance time of VUA in LERP was not statistically different between 2D and 3D imaging except for surgeon with a low experience in LERP. A positive trend for a better recovery of continence at 1 month follow-up was seen in the 3D group. The 3D laparoscopy may be an intermediate step between the standard 2D laparoscopy and robot assisted laparoscopy, allowing the combination of the low cost of the first with the 3D technology of the second. The experience of surgeon may decrease the advantage of 3D imaging. Further studies are necessary to better comprehend the role of 3D-LERP in radical prostatectomy.

References

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6- Hanna GB, Shimi SM, Cuschieri A (1998) Randomised study of influence of two-dimensional versus threedimensional imaging on
performance of laparoscopic cholecystectomy. Lancet 351:248–251

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