Operative time is an important perioperative parameter because of its impact on cost and complications. Operative time is the primary driver of operative cost and the longer operative time associated with robotic surgery is the main source of cost difference between the open and robotic approaches [5]. A cost analysis by Martin et al. demonstrated that operative time had a greater impact on perioperative costs than any other parameter. On sensitivity analysis, an operative time greater than 361 min was associated with a higher total perioperative cost for robot-assisted cystectomy compared to open cystectomy.

Longer operative time is also associated with perioperative complications, length of stay, and interval to return of bowel function in many procedures, including laparoscopic colorectal surgery [30], though these associations have not been demonstrated conclusively in open or robot-assisted cystectomy [13, 31]. Still, an expeditious operation is desirable, since many cystectomy patients have comorbidities that make them vulnerable to the side effects and complications associated with a prolonged anesthesia and operative time. Longer operative time also limits the productivity of the operative surgeon and other resources.

Operative time may be influenced by surgeon experience, so it may be most appropriate to assess after the “learning curve” flattens. Nonetheless, most case series include the initial cases, so the mean operative time may appear longer than expected, and some of the difference between open and robotic operative times may be exaggerated. Operative time may also be influenced by the extent of lymphadenectomy, diversion type (continent vs. conduit), surgical approach to the diversion (intracorporeal vs. extracorporeal), gender, pelvic anatomy, prior surgery, efficiency of the operative assistant and other operating room staff, and a variety of other factors.

Among the 22 unique case series, 19 reported total operative time [1–8, 10–13, 15–21], and the range of reported means and medians was quite wide: 261–697 min. In series with at least 50 patients [2, 3, 7, 10, 11, 13], the range of means and medians was somewhat narrower: 261–492 min. Five of the six studies reported the mean operative time [2, 3, 7, 10, 11], permitting the calculation of a weighted mean over these 373 cases: 340 min or 5 h 40 min.

Several studies addressed the effect of the learning curve on operative time and, in general, operative time decreases as experience increases. In one example, Richards et al. found that the mean operative time decreased over the course of their first 60 cases, from 524 min for the first 20, to 503 for the second 20, and 449 for the last 20, p = 0.059 [3]. Similarly, Wang et al. found a reduction in mean operative duration of 112 min between the first 16 cases and the second 16 (p = 0.007) [32].

As with the open procedure, continent diversion prolongs operative time. In two of the larger case series, Kauffman and Khan each showed approximately a 2-h difference in mean operative time between conduit and continent diversion [7, 11].

Some robotic surgeons have experimented with intracorporeal diversion (see Chap.​ 11). Intracorporeal urinary diversion was associated with increased operative time of approximately 1 h (mean 318 min vs. 252 min, p < 0.001) in one study which included 10 intracorporeal and 20 extracorporeal diversions [27]. Another study showed no significant difference, but had higher operative times overall (median 372 vs. 384) among 24 intracorporeal and 132 extracorporeal diversions [13].

Most studies comparing open with RARC find that RARC is associated with longer operative time. In the available comparative studies, the difference in mean operative time ranged between 18 and 302 min [5, 20, 21, 23–25], but it seemed to narrow in the more recent series in which the RARC experience is greater. For example in the randomized trial, Nix et al. found a difference of only 41 min between the open (n = 20) and robotic approaches (n = 21) (211 min vs. 252, p < 0.001). In a prospective nonrandomized study, Ng et al. found no significant difference in mean operating room time between the open (n = 104) and robotic (n = 83) approaches (357 min vs. 375, p = 0.29). Another study showed that the difference in operative time between the robotic and open approaches was significant only among patients undergoing continent diversion and not for those in whom a conduit was performed [32].

Clearly, there is quite a bit of variation in operative time between institutions. This may be driven by differences in measurement (e.g., skin-to-skin operative time vs. total time spent in the room), amount of time spent teaching, surgeon experience with robotics in general and RARC in particular, efficiency of the operating assistant and operating room staff, or other factors. The fact that open and robotic times vary in proportion across institutions suggests that “systemic” factors are at play, such as differences in measurement and the overall pace of work in the operating room, and they do not seem to be specific to the procedure itself.

In summary, operative duration is an important parameter because of its clear influence on the economic viability of robot-assisted radical cystectomy and because of its potential impact on postoperative complications. While operative times are longer in RARC compared to the open approach, the difference is decreasing as robotic experience is increasing. As one would anticipate, continent diversion and intracorporeal diversion prolong operative time in RARC, while surgeon and institutional experience tend to decrease it.

Blood loss and transfusion have important implications for the quality of radical cystectomy, since they are strongly associated with postoperative complications [31, 33, 34] although this has not been conclusively demonstrated in RARC [13]. They may also influence convalescence time, time to functional recovery (e.g., ability to perform activities of daily living), and quality of life measures (e.g., sense of well-being). Perioperative blood transfusion is also associated with a higher risk of cancer recurrence and disease-specific mortality in diseases such as colorectal cancer [35] and may be associated with increased overall mortality after cystectomy [36]. Blood loss and transfusion also increase costs associated with surgery [37]. For these reasons, operative blood loss and transfusion are useful clinical indicators for comparing the effectiveness of alternative surgical approaches to radical cystectomy for bladder cancer.

All 22 studies reported a mean, a median and/or a range of estimated blood loss (EBL) [1–22]. The means and medians ranged from 160 to 615 cm³, with most clustered between 200 and 500. Five of the six studies with 50 or more RARC patients reported the mean EBL [2, 3, 7, 10, 11], permitting the calculation of a weighted mean over these 373 cases: 360 cm³.

Each of the studies that compared open with robot-assisted radical cystectomy showed a clinically and statistically significantly lower EBL in the robotic group [5, 20, 21, 23–25]. While there were substantial differences across institutions, within each institution, the mean EBL was approximately twice as much in the open group compared to the robotic. The mean EBL for the robotic group ranged from 255 to 500 cm³, while the mean for the open group ranged from 575 to 1,250. In the randomized trial the open patients had an average EBL of 564 cm³ compared to 273 cm³ for the RARC patients (p < 0.001) [25].

Few publications include data on the use of blood products. In two small comparative studies, Rhee reported use of blood transfusion in four out of seven robotic cases (57 %) compared with 20 out of 23 open cases (87 %) and Galich et al. reported a 54 % transfusion rate in their first 13 robotic cases, compared to 75 % in 24 contemporaneous open cystectomies [20, 21]. More recently, Hayn et al. logged a 16 % transfusion rate among 156 patients undergoing RARC and Khan had only two transfusions in 50 patients (4 %) [7, 13]. Wang et al. demonstrated the difference in transfusion usage between the open and robotic groups by showing the mean number of units per patient: 0.5 units per RARC patient vs. 2 units per open cystectomy patient, p = 0.007 [32].

Much like the total operative time data, there are large discrepancies across institutions, but consistent comparisons between the open and robotic approaches within institutions. One can expect, on average, about twice as much blood loss during an open case than a robotic one. While the transfusion data are sparse, they seem to parallel the EBL data in favoring the robotic approach. These differences could have significant implications for comparisons of cost, complications, recovery metrics, and potentially even cancer recurrence between the open and robotic approaches.

One of the most salient postoperative milestones is the return of bowel function. The timing of its return influences the patient’s sense of well being and quality of life. Some researchers have focused on the role of nutritional status in driving cystectomy outcomes [38]. In this light, the timing of return of bowel function may herald the patient’s emergence from the perioperative catabolic state and may, in turn, affect the pace of functional recovery. In the USA, it also signals the patient’s readiness for discharge. Because the interval to return of bowel function influences length of stay, and length of stay is one of the primary drivers of cost, the return of bowel function has important implications for cost.

Studies from two institutions (UNC Chapel Hill, and University of Saarland, Germany) and one consortium (Korea) included data on time to return of bowel function [2, 10, 12, 24–27]. The single institution studies from the USA and Germany reported a mean of 2.1 days between surgery and flatus, and 2.8–2.9 days to the first bowel movement. The Korean multicenter consortium found an average of 3.4 days to flatus.

One prospective cohort study and one randomized trial (both from the same institution) compared these outcome metrics between open and robotic cohorts. In the cohort study, the average number of days to flatus was 2.1 for the robotic group and 2.9 for the open group (p < 0.001) and time to first bowel movement was 2.8 days compared with 3.8, respectively (p < 0.001) [24]. The results of the randomized trial were similar (median 2.3 vs. 3.2 days, p = 0.0013 for flatus and 3.2 vs. 4.3 days, p = 0.0008 for bowel movement) [25]. This difference was associated with a statistically significantly lower length of stay in the nonrandomized study (mean 4.4 vs. 5.3 days, p = 0.007), but not for the randomized trial (median 5.1 vs. 6.0 days, p = 0.2837).