Surg Endosc DOI 10.1007/s00464-015-4203-0
and Other Interventional Techniques
Robotic single-site versus laparoscopic cholecystectomy: Which is cheaper? A cost report and analysis Kareem Bedeir1 • Andrew Mann2 • Yassar Youssef1
Received: 8 October 2014 / Accepted: 28 March 2015 Ó Springer Science+Business Media New York 2015
Abstract Objective There is a need for a comparison of costs of robotic single-site cholecystectomy (RSSC) and laparoscopic cholecystectomy (LC) in the US healthcare model. Summary and background data Cholecystectomy is one of the most common procedures in general surgery. Singleincision laparoscopic surgery is beneficial but cumbersome. Robotic surgery is ergonomic but expensive. Costs of RSSC and LC have not been compared within the US healthcare model. Methods Cost categories were compared between RSSC and LC in consecutive outpatient-elective cases during the same period. Cost efficiency of outpatient-elective cases before and after the first 50 institutional RSSC cases (including outpatients, inpatients, emergent, and elective) were compared to investigate for a learning curve that would subsequently affect cost. Results A total of 458 cases included 177 RSSCs and 281 LCs. Non-emergent non-admitted cases included in cost analysis were 46 RSSCs and 175 LCs. Costs were less with RSSC: median total ($1319 vs. $1710, p \ 0.001), driven mainly by cost category ‘‘Supplies’’ ($913 vs. $1244, p \ 0.001), and to a lesser extent ‘‘Operating room’’ ($196 vs. $232, p \ 0.001), and ‘‘Anesthesiology’’ ($127 vs. $168, p \ 0.001). Supplies were responsible for 87 % of & Yassar Youssef [email protected] Kareem Bedeir [email protected] 1
Department of Surgery, Sinai Hospital of Baltimore, Baltimore, MD, USA
2
Financial Department, Sinai Hospital of Baltimore, Baltimore, MD, USA
median total cost reduction. Other cost categories were not significantly different. There were 11 and 9 % drops (p \ 0.006) in RSSC OR times and costs, respectively, after our 50th institutional case. Conclusion In a hospital that has already acquired infrastructure for robotic surgery, we observed procedural costs for RSSC that were lower than LC. This decreased cost was mainly driven by cutting down on supplies (87 % of median total cost reduced), and to a lesser extent OR time. A steep learning curve exists after which RSSC OR times can be significantly shortened. A randomized study is needed. Keyword Robotic single-site cholecystectomy Robotic cholecystectomy Robotic surgery Yassar Youssef Robotic cost
Single-incision laparoscopic surgery (SILS) has been proposed as a less invasive alternative to multi-port laparoscopic surgery, providing better cosmesis and less pain [1– 4]. Complexity and loss of triangulation, however, hindered the widespread use of SILS and resulted in the technique being regarded as too cumbersome. Later with the advent of robotic surgery, single-site surgery was possible with restored triangulation, adding 3D visualization, enhanced surgeon’s control and better ergonomics [5– 7]. Robotic single-site cholecystectomy (RSSC) has been described, and despite its increasing popularity, many questions remain unanswered, including cost and revenue for the hospitals. Laparoscopic cholecystectomy (LC) is currently the standard of care for acute cholecystitis, symptomatic cholelithiasis and biliary dyskinesia [8]. In a recent cost and revenue analysis of outpatient LC, the hospital break-even
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point at Medicaid reimbursement rates was at 454 cases per year, demonstrating a limited ability of lower-volume hospitals to continue to provide LC and warning from the resulting impact on the Medicaid population’s access to care [9]. To date, the evidence is lacking as to whether RSSC compares favorably to LC from a financial standpoint within the US healthcare system. Our institutional RSSC experience is one of the largest in the USA. The aim of this study is to compare the cost of both techniques.
Patients and methods Cost data were collected from our institutional financial department for elective outpatient RSSC and LC between November 2012 and April 2014. Robotic single-site cholecystectomy was started in our institution in November 2012, hence the study start date. Only ‘‘elective’’ cases were included in the cost comparisons to rule out any selection bias of emergent versus non-emergent cases to either technique. Only ‘‘outpatient’’ procedures were included to rule out cost confounders related to preoperative length of stay and complicated surgeries with resultant increased postoperative length of stay and/or procedural costs. We thus only compared procedures that were uncomplicated. There were no exclusion criteria. All LCs were performed by minimally invasive surgeons with at least 10 years of experience (five surgeons). All RSSC were done by a single surgeon, whose out-oftraining robotic surgery experience started with the start date of our study, November 2012. For the robotic surgeon, no LCs were done during the period of the study, and the robotic cases were a consecutive group of all-comers with no exclusion criteria based on patients’ characteristics. A second comparison was made between RSSC before and after our initial robotic experience to assess our learning curve. The time cutoff for ‘‘early’’ versus ‘‘later’’ experiences was defined as the date of our 50th RSSC, all RSSCs included. These 50 cases included outpatient-elective cases, elective cases that were admitted and inpatient-emergent cases. Cost comparisons were only for outpatient-elective cases of RSSCs and LCs to ensure comparing uncomplicated procedural costs only, as mentioned earlier (Fig. 1). Cost data were obtained and categorized with the aid of our institutional financial department. We report actual hospital cost in US dollars, not billed amount or hospital revenue. Our cost categories are first divided into fixed and variable costs. Only variable costs are included in our report. Fixed costs include fixed salaries and hospital infrastructure, i.e., buildings, machines, robots, nondisposable instruments and other non-disposable hospital property. Fixed costs do not differ from one procedure to
123
another. Variable costs reported are divided into the following categories: (1) Operating room (OR), (2) Supplies, (3) Anesthesiology, (4) Drugs, (5) Radiology, (6) Laboratory and (7) Respiratory. Category definitions are shown in Table 1. Categorical variables were compared using the Chisquare test and described in percentages. For continuous variables, central tendency was described in means/standard deviations for normally distributed variables and medians/inter-quartile ranges for abnormally distributed ones. In comparisons, the student t test was used for the former and the Mann–Whitney U test for the latter. Normality of distribution was defined using the Shapiro–Wilk test. Significance was based on a 95 % confidence interval (CI). Analysis was performed using the Statistical Package for the Social Sciences (SPSS) v.17 (SPSS Inc, Chicago, IL).
Results Over the 18-month period of the study, a total of 458 cholecystectomies were done (177 RSSCs and 281 LCs). There were significantly more emergent RSSC than LC (70 vs. 22 %, CI 95 % p \ 0.001). Among the elective cases, there was no difference in the rate of admission (13 vs. 11 %, CI 95 % p = 0.075). A total of 46 RSSC and 195 LC-elective outpatient cases were included in the cost analysis (Table 2). Costs with RSSC were significantly less under the categories of the ‘‘Operating room’’ ($196 vs. $239, CI 95 % p \ 0.001), ‘‘Supplies’’ ($913 vs. $1277, CI 95 % p \ 0.001) and ‘‘Anesthesiology’’ ($127 vs. $169, CI 95 % p \ 0.001). Other cost categories were not significantly different between the two groups. Total cost was less with RSSC ($1319 vs. $1737, CI 95 % p \ 0.001) (Table 4). Before the 50th RSSC case in our institution, 12 cases were outpatient elective. The remaining 34 cases were after the 50th RSSC (Table 3). The later 34 cases had shorter OR time (98 vs. 87 min, CI 95 % p \ 0.006) and less ‘‘Operating room’’ and ‘‘Anesthesiology’’ cost categories compared with the earlier RSSC cases ($210 vs. $191, CI 95 % p \ 0.006 and $147 vs. $127, CI 95 % p \ 0.026, respectively) (Tables 4, 5).
Discussion Nearly three quarters of a million LCs are performed in the USA every year [10]. With the current US healthcare model, little or no room for profit exists from LC in centers with small-to-medium volumes [9]. This triggered a search for cheaper alternatives. On the other hand, the utility of
Surg Endosc
Fig. 1 Case volume and setting, as well as approach to dividing early and late cases compared
Table 1 Definitions of cost categories Cost Category
Definition
‘‘Operating room’’
Including costs of OR time, OR circulating nurse and scrub technician, as well as PACU stay
‘‘Supplies’’
Including all non-anesthesia and non-respiratory disposable or semi-disposable material as dispensed and billed by our OR central distribution. These include but are not limited to disposable instruments, endoscopic retrieval bags, clip appliers, ports, cautery, sequential compression devices, bair huggers and other similar supplies. Multi-use disposable instruments used in robotic cases are calculated per case as instrument price divided by the number of uses allowed by the manufacturer prior to being discarded
‘‘Anesthesiology’’
Include but are not limited to medications used by the anesthesiologist, disposable supplies for ventilators and airways as well as fluids and vascular access
‘‘Drugs’’
Includes all medications administered to the patient in the preoperative holding area and in the PACU
‘‘Radiology’’
Includes intraoperative cholangiograms as well as any X-rays obtained in PACU
‘‘Laboratory’’
Includes any laboratory tests ran while the patient stayed in the PACU
‘‘Respiratory’’
Includes any respiratory support the patient required while in PACU
OR operating room, PACU postoperative care unit
robotic techniques in general surgery have been criticized for trading surgeon’s convenience with a higher cost, while little outcome benefit is added over laparoscopic techniques [11–13]. This has been a major impediment to the widespread use of robotic surgery. Robotic-assisted multiport cholecystectomy has been studied, and cost analysis concluded that despite its feasibility, the technique is more expensive than standard LC with no added benefit and therefore was deemed unnecessary [14]. Single-site surgery generally provides patient benefits in terms of cosmesis, pain and faster recovery [1–4]. This technique has been made more feasible with robotic
assistance and thus added patient benefit to surgeon convenience with single-site robotic surgery. The feasibility of RSSC has been described in the literature [15–18]. Cost comparison of this technique to standard LC is the knowledge gap our study addresses. Over the period of the study, we had 177 RSSCs done in our institution, and almost 75 more cases till the time of submission of this manuscript. This experience is considered one of the larger ones in the USA. There was no difference in the rates of admission of elective case after either technique, which agrees with the feasibility and safety reports of RSSC published [15–18]. It is of note that
123
Surg Endosc Table 2 Volume of non-open cholecystectomies during the study period RSSC
LC
n = 177
n = 281
Emergent [n (%)]
124 (70)
61 (22)
Elective [n (%)]
53 (40)
220 (78)
Total cases
Elective cases
p
\0.001
n = 53
n = 220
Admitted [n (%)]
7 (13)
25 (11)
Outpatient [n (%)]
46 (87)
195 (89)
RSSC robotic single-site cholecystectomy
cholecystectomy,
0.749
LC
laparoscopic
Table 3 Robotic single-site cholecystectomy cases before and after the first 50 cases
Emergent
First 50 cases
Subsequent cases (n = 127)
35
89
Elective, admitted
3
4
Elective, outpatient
12
34
during the period of the study, zero RSSC cases required conversion to LC or open cholecystectomy, and we had no common or hepatic duct injuries or bile leak. We had more acute cases that were done robotically, which is probably related to two reasons: (1) that the robotic surgeon also functions as an acute care surgeon, and (2) the fact that all his cholecystectomies done during the period of the study
were done exclusively robotic. Neither the acute cases nor the elective cases that were admitted were included in the cost analysis to compare only uncomplicated procedures on similar elective patients with minimal inflammation and adhesions. With small early experiences with multi-port roboticassisted cholecystectomy (RAC), increased operative time has been reported and shared to the increased costs [19, 20]. With increasing experience, 50 cases of multi-port RAC were reported by Breitenstein and colleagues [14] and showed no increase in operative time. This suggests a learning curve, and similarly, early experience of 20 RSSC cases reported by Buzad and colleagues [21] showed equivalent operative times with LC, and with our larger report, we show an operative time using RSSC that is shorter than with standard LC. We believe that results from operative time and cost reports with earlier experiences are misleading. We thus showed a 10 % decrease in RSSC OR time and cost after our 50th institutional case. The learning curve represented in OR times is illustrated in Fig. 2. There was a decrease of 45 % of OR time between the first and last case in our series. We had an overall decreased cost with RSSC compared with standard LC. This was mainly driven by OR costs and supplies. The decrease in costs of supplies alone equaled 21 % of the median total cost of LC. This was also equivalent to 87 % of the median total cost difference between RSSC and LC. The decrease in supply costs was secondary, making in our institution
Table 4 Cost comparison between RSSC and LC
RSSC (n = 46)
LC (n = 195)
p
Operating room [median (IQR)]
196 (181–215)
239 (211–289)
\0.001*
Supplies [median (IQR)]
913 (886–1014)
1277 (114–1578)
\0.001*
Anesthesiology [median (IQR)]
127 (126–148)
169 (146–209)
\0.001*
Drugs [median (IQR)]
28 (20–39)
29 (17–49)
0.624
Radiology [median (IQR)]
0 (0)
0 (0)
0.024*
Total range
0
0–106
Laboratory [median (IQR)]
30 (27–30)
30 (27–37)
0.391
Respiratory [median (IQR)]
0 (0)
0 (0)
0.750
Other [median (IQR)]
0 (0)
0 (0)
Total [median (IQR)]
1319 (1236–1462)
1737 (1568–2098)
0.109 \0.001*
RSSC robotic single-site cholecystectomy, LC laparoscopic cholecystectomy, IQR inter-quartile range * Values listed are actual hospital costs per case described in US dollars Table 5 Comparison of operating time and operating-time-related costs between elective outpatient RSSC within the first 50 all institutional RSSC cases and subsequent cases Early cases (n = 12) Operating room time [median (IQR)] (min) Operating room [median (IQR)] (USD) Anesthesiology [median (IQR)] (USD)
123
Late cases (n = 34)
p
98 (92–114)
87 (75–95)
0.006*
210 (200–236) 147 (146–167)
191 (172–204) 127 (123–148)
0.006* 0.026*
Surg Endosc
Fig. 2 Learning curve over time for elective outpatient robotic single-site cholecystectomies
limit costs by significantly limiting non-essential instruments in the standard set, and creating peel packs should a specific instrument be needed. Hook cautery, crocodile grasper, scissor, and clip appliers remained standard within the trays. We included a bariatric length grasper and minimal open instruments within the single-site tray and removed the single-site Maryland dissector. The avoidance of opening a full laparoscopic cholecystectomy tray or minor instrument tray during the procedure decreased overall costs. Not utilizing a retrieval bag for specimen removal also decreased disposable costs without evidence of increased wound infection rates. While the same attempts at cost reduction took place with the laparoscopic group, these cases were done by five different surgeons. Due to variability in techniques and preferences, we assume that those attempts were less uniform when compared to the RSSC group performed by a single surgeon. To a lesser extent, reduced operative time shared 10 % of total cost difference between the two groups. This might be secondary to enhanced ergonomics and visualizations. This has in turn but to a lesser extent, impacted costs related to anesthesiology. Resident participation, although difficult to quantify, was more or less equal between the
two groups. Our institution developed a resident robotic curriculum with advancing resident role with advancing PGY level. Residents operate at the console as early as their PGY-2 level. Even if slight differences existed in the extent of resident role between the two groups, the total cost difference that is secondary to OR time was minimal compared with costs of supplies. Robotic single-site cholecystectomy can be made cheaper than standard laparoscopic cholecystectomy in a hospital setting that already owns the infrastructure for robotic surgery. This is mainly driven by consciousness toward robotic supplies with minimalist standard sets and selective additions as needed per case. There is a further decrease of almost 10 % in operating-room-related costs after the institutional 50 first cases of RSSC. Results from our study should be interpreted in the context of a retrospective observational study. While we attempted to rule out confounders by strict inclusion and exclusion criteria, the potential for unmeasured confounders cannot be excluded. Further limitations to our study include being a single institution analysis, and attempts at cost reduction in the RSSC group performed by a single surgeon may have been more uniform than the LC group performed by different surgeons. Our results should
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trigger a multicenter randomized controlled study to confirm or refute our observation. Disclosures Yassar Youssef has lectured for intuitive surgical LLC and proctored other surgeons on robotic surgery. Kareem Bedeir and Andrew Mann have nothing to disclose.
References 1. Makino T, Milsom JW, Lee SW (2012) Feasibility and safety of single-incision laparoscopic colectomy: a systematic review. Ann Surg 255:667–676 2. Lai EC, Yang GP, Tang CN, Yih PC, Chan OC, Li MK (2011) Prospective randomized comparative study of single incision laparoscopic cholecystectomy versus conventional four-port laparoscopic cholecystectomy. Am J Surg 202:254–258 3. Wang L, Liu B, Wu Z, Yang Q, Chen W, Sheng H, Xu Z, Xiao L, Wang C, Sun Y (2012) Comparison of single-surgeon series of transperitoneal laparoendoscopic single-site surgery and standard laparoscopic adrenalectomy. Urology 79:577–583 4. Wong JS, Cheung YS, Fong KW, Chong CC, Lee KF, Wong J, Lai PB (2012) Comparison of postoperative pain between singleincision laparoscopic cholecystectomy and conventional laparoscopic cholecystectomy: prospective case–control study. Surg Laparosc Endosc Percutan Tech 22:25–28 5. Vidovszky TJ, Smith W, Ghosh J, Ali MR (2006) Robotic cholecystectomy: learning curve, advantages, and limitations. J Surg Res 136:172–178 6. Maeso S, Reza M, Mayol JA, Blasco JA, Guerra M, Andradas E, Plana MN (2010) Efficacy of the da vinci surgical system in abdominal surgery compared with that of laparoscopy: a systematic review and meta-analysis. Ann Surg 252:254–262 7. Moorthy K, Munz Y, Dosis A, Hernandez J, Martin S, Bello F, Rockall T, Darzi A (2004) Dexterity enhancement with robotic surgery. Surg Endosc 18:790–795 8. Nih consensus conference (1993) Gallstones and laparoscopic cholecystectomy. JAMA 269:1018–1024 9. Frazee RC, Elliott VG, Larsen W, Lerner S, Minnis KW, Huber C, Nolan J, Papaconstantinou H, Smythe WR (2014) Can laparoscopic cholecystectomy be performed with a positive margin at medicaid reimbursement rates? J Am Coll Surg 218:546–551 10. Vollmer CM Jr, Callery MP (2007) Biliary injury following laparoscopic cholecystectomy: Why still a problem? Gastroenterology 133:1039–1041
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11. Morino M, Pellegrino L, Giaccone C, Garrone C, Rebecchi F (2006) Randomized clinical trial of robot-assisted versus laparoscopic nissen fundoplication. Br J Surg 93:553–558 12. Delaney CP, Lynch AC, Senagore AJ, Fazio VW (2003) Comparison of robotically performed and traditional laparoscopic colorectal surgery. Dis Colon Rectum 46:1633–1639 13. Muhlmann G, Klaus A, Kirchmayr W, Wykypiel H, Unger A, Holler E, Nehoda H, Aigner F, Weiss HG (2003) Davinci roboticassisted laparoscopic bariatric surgery: Is it justified in a routine setting? Obes Surg 13:848–854 14. Breitenstein S, Nocito A, Puhan M, Held U, Weber M, Clavien PA (2008) Robotic-assisted versus laparoscopic cholecystectomy: outcome and cost analyses of a case-matched control study. Ann Surg 247:987–993 15. Pietrabissa A, Sbrana F, Morelli L, Badessi F, Pugliese L, Vinci A, Klersy C, Spinoglio G (2012) Overcoming the challenges of single-incision cholecystectomy with robotic single-site technology. Arch Surg 147:709–714 16. Konstantinidis KM, Hirides P, Hirides S, Chrysocheris P, Georgiou M (2012) Cholecystectomy using a novel single-site((r)) robotic platform: early experience from 45 consecutive cases. Surg Endosc 26:2687–2694 17. Spinoglio G, Lenti LM, Maglione V, Lucido FS, Priora F, Bianchi PP, Grosso F, Quarati R (2012) Single-site robotic cholecystectomy (ssrc) versus single-incision laparoscopic cholecystectomy (silc): comparison of learning curves. First European experience. Surg Endosc 26:1648–1655 18. Morel P, Hagen ME, Bucher P, Buchs NC, Pugin F (2011) Robotic single-port cholecystectomy using a new platform: initial clinical experience. J Gastrointest Surg 15:2182–2186 19. Kornprat P, Werkgartner G, Cerwenka H, Bacher H, El-Shabrawi A, Rehak P, Mischinger HJ (2006) Prospective study comparing standard and robotically assisted laparoscopic cholecystectomy. Langenbecks Arch Surg 391:216–221 20. Nio D, Bemelman WA, Busch OR, Vrouenraets BC, Gouma DJ (2004) Robot-assisted laparoscopic cholecystectomy versus conventional laparoscopic cholecystectomy: a comparative study. Surg Endosc 18:379–382 21. Buzad FA, Corne LM, Brown TC, Fagin RS, Hebert AE, Kaczmarek CA, Pack AN, Payne TN (2013) Single-site robotic cholecystectomy: efficiency and cost analysis. Int J Med Robot 9:365–370
and Other Interventional Techniques
Robotic single-site versus laparoscopic cholecystectomy: Which is cheaper? A cost report and analysis Kareem Bedeir1 • Andrew Mann2 • Yassar Youssef1
Received: 8 October 2014 / Accepted: 28 March 2015 Ó Springer Science+Business Media New York 2015
Abstract Objective There is a need for a comparison of costs of robotic single-site cholecystectomy (RSSC) and laparoscopic cholecystectomy (LC) in the US healthcare model. Summary and background data Cholecystectomy is one of the most common procedures in general surgery. Singleincision laparoscopic surgery is beneficial but cumbersome. Robotic surgery is ergonomic but expensive. Costs of RSSC and LC have not been compared within the US healthcare model. Methods Cost categories were compared between RSSC and LC in consecutive outpatient-elective cases during the same period. Cost efficiency of outpatient-elective cases before and after the first 50 institutional RSSC cases (including outpatients, inpatients, emergent, and elective) were compared to investigate for a learning curve that would subsequently affect cost. Results A total of 458 cases included 177 RSSCs and 281 LCs. Non-emergent non-admitted cases included in cost analysis were 46 RSSCs and 175 LCs. Costs were less with RSSC: median total ($1319 vs. $1710, p \ 0.001), driven mainly by cost category ‘‘Supplies’’ ($913 vs. $1244, p \ 0.001), and to a lesser extent ‘‘Operating room’’ ($196 vs. $232, p \ 0.001), and ‘‘Anesthesiology’’ ($127 vs. $168, p \ 0.001). Supplies were responsible for 87 % of & Yassar Youssef [email protected] Kareem Bedeir [email protected] 1
Department of Surgery, Sinai Hospital of Baltimore, Baltimore, MD, USA
2
Financial Department, Sinai Hospital of Baltimore, Baltimore, MD, USA
median total cost reduction. Other cost categories were not significantly different. There were 11 and 9 % drops (p \ 0.006) in RSSC OR times and costs, respectively, after our 50th institutional case. Conclusion In a hospital that has already acquired infrastructure for robotic surgery, we observed procedural costs for RSSC that were lower than LC. This decreased cost was mainly driven by cutting down on supplies (87 % of median total cost reduced), and to a lesser extent OR time. A steep learning curve exists after which RSSC OR times can be significantly shortened. A randomized study is needed. Keyword Robotic single-site cholecystectomy Robotic cholecystectomy Robotic surgery Yassar Youssef Robotic cost
Single-incision laparoscopic surgery (SILS) has been proposed as a less invasive alternative to multi-port laparoscopic surgery, providing better cosmesis and less pain [1– 4]. Complexity and loss of triangulation, however, hindered the widespread use of SILS and resulted in the technique being regarded as too cumbersome. Later with the advent of robotic surgery, single-site surgery was possible with restored triangulation, adding 3D visualization, enhanced surgeon’s control and better ergonomics [5– 7]. Robotic single-site cholecystectomy (RSSC) has been described, and despite its increasing popularity, many questions remain unanswered, including cost and revenue for the hospitals. Laparoscopic cholecystectomy (LC) is currently the standard of care for acute cholecystitis, symptomatic cholelithiasis and biliary dyskinesia [8]. In a recent cost and revenue analysis of outpatient LC, the hospital break-even
123
Surg Endosc
point at Medicaid reimbursement rates was at 454 cases per year, demonstrating a limited ability of lower-volume hospitals to continue to provide LC and warning from the resulting impact on the Medicaid population’s access to care [9]. To date, the evidence is lacking as to whether RSSC compares favorably to LC from a financial standpoint within the US healthcare system. Our institutional RSSC experience is one of the largest in the USA. The aim of this study is to compare the cost of both techniques.
Patients and methods Cost data were collected from our institutional financial department for elective outpatient RSSC and LC between November 2012 and April 2014. Robotic single-site cholecystectomy was started in our institution in November 2012, hence the study start date. Only ‘‘elective’’ cases were included in the cost comparisons to rule out any selection bias of emergent versus non-emergent cases to either technique. Only ‘‘outpatient’’ procedures were included to rule out cost confounders related to preoperative length of stay and complicated surgeries with resultant increased postoperative length of stay and/or procedural costs. We thus only compared procedures that were uncomplicated. There were no exclusion criteria. All LCs were performed by minimally invasive surgeons with at least 10 years of experience (five surgeons). All RSSC were done by a single surgeon, whose out-oftraining robotic surgery experience started with the start date of our study, November 2012. For the robotic surgeon, no LCs were done during the period of the study, and the robotic cases were a consecutive group of all-comers with no exclusion criteria based on patients’ characteristics. A second comparison was made between RSSC before and after our initial robotic experience to assess our learning curve. The time cutoff for ‘‘early’’ versus ‘‘later’’ experiences was defined as the date of our 50th RSSC, all RSSCs included. These 50 cases included outpatient-elective cases, elective cases that were admitted and inpatient-emergent cases. Cost comparisons were only for outpatient-elective cases of RSSCs and LCs to ensure comparing uncomplicated procedural costs only, as mentioned earlier (Fig. 1). Cost data were obtained and categorized with the aid of our institutional financial department. We report actual hospital cost in US dollars, not billed amount or hospital revenue. Our cost categories are first divided into fixed and variable costs. Only variable costs are included in our report. Fixed costs include fixed salaries and hospital infrastructure, i.e., buildings, machines, robots, nondisposable instruments and other non-disposable hospital property. Fixed costs do not differ from one procedure to
123
another. Variable costs reported are divided into the following categories: (1) Operating room (OR), (2) Supplies, (3) Anesthesiology, (4) Drugs, (5) Radiology, (6) Laboratory and (7) Respiratory. Category definitions are shown in Table 1. Categorical variables were compared using the Chisquare test and described in percentages. For continuous variables, central tendency was described in means/standard deviations for normally distributed variables and medians/inter-quartile ranges for abnormally distributed ones. In comparisons, the student t test was used for the former and the Mann–Whitney U test for the latter. Normality of distribution was defined using the Shapiro–Wilk test. Significance was based on a 95 % confidence interval (CI). Analysis was performed using the Statistical Package for the Social Sciences (SPSS) v.17 (SPSS Inc, Chicago, IL).
Results Over the 18-month period of the study, a total of 458 cholecystectomies were done (177 RSSCs and 281 LCs). There were significantly more emergent RSSC than LC (70 vs. 22 %, CI 95 % p \ 0.001). Among the elective cases, there was no difference in the rate of admission (13 vs. 11 %, CI 95 % p = 0.075). A total of 46 RSSC and 195 LC-elective outpatient cases were included in the cost analysis (Table 2). Costs with RSSC were significantly less under the categories of the ‘‘Operating room’’ ($196 vs. $239, CI 95 % p \ 0.001), ‘‘Supplies’’ ($913 vs. $1277, CI 95 % p \ 0.001) and ‘‘Anesthesiology’’ ($127 vs. $169, CI 95 % p \ 0.001). Other cost categories were not significantly different between the two groups. Total cost was less with RSSC ($1319 vs. $1737, CI 95 % p \ 0.001) (Table 4). Before the 50th RSSC case in our institution, 12 cases were outpatient elective. The remaining 34 cases were after the 50th RSSC (Table 3). The later 34 cases had shorter OR time (98 vs. 87 min, CI 95 % p \ 0.006) and less ‘‘Operating room’’ and ‘‘Anesthesiology’’ cost categories compared with the earlier RSSC cases ($210 vs. $191, CI 95 % p \ 0.006 and $147 vs. $127, CI 95 % p \ 0.026, respectively) (Tables 4, 5).
Discussion Nearly three quarters of a million LCs are performed in the USA every year [10]. With the current US healthcare model, little or no room for profit exists from LC in centers with small-to-medium volumes [9]. This triggered a search for cheaper alternatives. On the other hand, the utility of
Surg Endosc
Fig. 1 Case volume and setting, as well as approach to dividing early and late cases compared
Table 1 Definitions of cost categories Cost Category
Definition
‘‘Operating room’’
Including costs of OR time, OR circulating nurse and scrub technician, as well as PACU stay
‘‘Supplies’’
Including all non-anesthesia and non-respiratory disposable or semi-disposable material as dispensed and billed by our OR central distribution. These include but are not limited to disposable instruments, endoscopic retrieval bags, clip appliers, ports, cautery, sequential compression devices, bair huggers and other similar supplies. Multi-use disposable instruments used in robotic cases are calculated per case as instrument price divided by the number of uses allowed by the manufacturer prior to being discarded
‘‘Anesthesiology’’
Include but are not limited to medications used by the anesthesiologist, disposable supplies for ventilators and airways as well as fluids and vascular access
‘‘Drugs’’
Includes all medications administered to the patient in the preoperative holding area and in the PACU
‘‘Radiology’’
Includes intraoperative cholangiograms as well as any X-rays obtained in PACU
‘‘Laboratory’’
Includes any laboratory tests ran while the patient stayed in the PACU
‘‘Respiratory’’
Includes any respiratory support the patient required while in PACU
OR operating room, PACU postoperative care unit
robotic techniques in general surgery have been criticized for trading surgeon’s convenience with a higher cost, while little outcome benefit is added over laparoscopic techniques [11–13]. This has been a major impediment to the widespread use of robotic surgery. Robotic-assisted multiport cholecystectomy has been studied, and cost analysis concluded that despite its feasibility, the technique is more expensive than standard LC with no added benefit and therefore was deemed unnecessary [14]. Single-site surgery generally provides patient benefits in terms of cosmesis, pain and faster recovery [1–4]. This technique has been made more feasible with robotic
assistance and thus added patient benefit to surgeon convenience with single-site robotic surgery. The feasibility of RSSC has been described in the literature [15–18]. Cost comparison of this technique to standard LC is the knowledge gap our study addresses. Over the period of the study, we had 177 RSSCs done in our institution, and almost 75 more cases till the time of submission of this manuscript. This experience is considered one of the larger ones in the USA. There was no difference in the rates of admission of elective case after either technique, which agrees with the feasibility and safety reports of RSSC published [15–18]. It is of note that
123
Surg Endosc Table 2 Volume of non-open cholecystectomies during the study period RSSC
LC
n = 177
n = 281
Emergent [n (%)]
124 (70)
61 (22)
Elective [n (%)]
53 (40)
220 (78)
Total cases
Elective cases
p
\0.001
n = 53
n = 220
Admitted [n (%)]
7 (13)
25 (11)
Outpatient [n (%)]
46 (87)
195 (89)
RSSC robotic single-site cholecystectomy
cholecystectomy,
0.749
LC
laparoscopic
Table 3 Robotic single-site cholecystectomy cases before and after the first 50 cases
Emergent
First 50 cases
Subsequent cases (n = 127)
35
89
Elective, admitted
3
4
Elective, outpatient
12
34
during the period of the study, zero RSSC cases required conversion to LC or open cholecystectomy, and we had no common or hepatic duct injuries or bile leak. We had more acute cases that were done robotically, which is probably related to two reasons: (1) that the robotic surgeon also functions as an acute care surgeon, and (2) the fact that all his cholecystectomies done during the period of the study
were done exclusively robotic. Neither the acute cases nor the elective cases that were admitted were included in the cost analysis to compare only uncomplicated procedures on similar elective patients with minimal inflammation and adhesions. With small early experiences with multi-port roboticassisted cholecystectomy (RAC), increased operative time has been reported and shared to the increased costs [19, 20]. With increasing experience, 50 cases of multi-port RAC were reported by Breitenstein and colleagues [14] and showed no increase in operative time. This suggests a learning curve, and similarly, early experience of 20 RSSC cases reported by Buzad and colleagues [21] showed equivalent operative times with LC, and with our larger report, we show an operative time using RSSC that is shorter than with standard LC. We believe that results from operative time and cost reports with earlier experiences are misleading. We thus showed a 10 % decrease in RSSC OR time and cost after our 50th institutional case. The learning curve represented in OR times is illustrated in Fig. 2. There was a decrease of 45 % of OR time between the first and last case in our series. We had an overall decreased cost with RSSC compared with standard LC. This was mainly driven by OR costs and supplies. The decrease in costs of supplies alone equaled 21 % of the median total cost of LC. This was also equivalent to 87 % of the median total cost difference between RSSC and LC. The decrease in supply costs was secondary, making in our institution
Table 4 Cost comparison between RSSC and LC
RSSC (n = 46)
LC (n = 195)
p
Operating room [median (IQR)]
196 (181–215)
239 (211–289)
\0.001*
Supplies [median (IQR)]
913 (886–1014)
1277 (114–1578)
\0.001*
Anesthesiology [median (IQR)]
127 (126–148)
169 (146–209)
\0.001*
Drugs [median (IQR)]
28 (20–39)
29 (17–49)
0.624
Radiology [median (IQR)]
0 (0)
0 (0)
0.024*
Total range
0
0–106
Laboratory [median (IQR)]
30 (27–30)
30 (27–37)
0.391
Respiratory [median (IQR)]
0 (0)
0 (0)
0.750
Other [median (IQR)]
0 (0)
0 (0)
Total [median (IQR)]
1319 (1236–1462)
1737 (1568–2098)
0.109 \0.001*
RSSC robotic single-site cholecystectomy, LC laparoscopic cholecystectomy, IQR inter-quartile range * Values listed are actual hospital costs per case described in US dollars Table 5 Comparison of operating time and operating-time-related costs between elective outpatient RSSC within the first 50 all institutional RSSC cases and subsequent cases Early cases (n = 12) Operating room time [median (IQR)] (min) Operating room [median (IQR)] (USD) Anesthesiology [median (IQR)] (USD)
123
Late cases (n = 34)
p
98 (92–114)
87 (75–95)
0.006*
210 (200–236) 147 (146–167)
191 (172–204) 127 (123–148)
0.006* 0.026*
Surg Endosc
Fig. 2 Learning curve over time for elective outpatient robotic single-site cholecystectomies
limit costs by significantly limiting non-essential instruments in the standard set, and creating peel packs should a specific instrument be needed. Hook cautery, crocodile grasper, scissor, and clip appliers remained standard within the trays. We included a bariatric length grasper and minimal open instruments within the single-site tray and removed the single-site Maryland dissector. The avoidance of opening a full laparoscopic cholecystectomy tray or minor instrument tray during the procedure decreased overall costs. Not utilizing a retrieval bag for specimen removal also decreased disposable costs without evidence of increased wound infection rates. While the same attempts at cost reduction took place with the laparoscopic group, these cases were done by five different surgeons. Due to variability in techniques and preferences, we assume that those attempts were less uniform when compared to the RSSC group performed by a single surgeon. To a lesser extent, reduced operative time shared 10 % of total cost difference between the two groups. This might be secondary to enhanced ergonomics and visualizations. This has in turn but to a lesser extent, impacted costs related to anesthesiology. Resident participation, although difficult to quantify, was more or less equal between the
two groups. Our institution developed a resident robotic curriculum with advancing resident role with advancing PGY level. Residents operate at the console as early as their PGY-2 level. Even if slight differences existed in the extent of resident role between the two groups, the total cost difference that is secondary to OR time was minimal compared with costs of supplies. Robotic single-site cholecystectomy can be made cheaper than standard laparoscopic cholecystectomy in a hospital setting that already owns the infrastructure for robotic surgery. This is mainly driven by consciousness toward robotic supplies with minimalist standard sets and selective additions as needed per case. There is a further decrease of almost 10 % in operating-room-related costs after the institutional 50 first cases of RSSC. Results from our study should be interpreted in the context of a retrospective observational study. While we attempted to rule out confounders by strict inclusion and exclusion criteria, the potential for unmeasured confounders cannot be excluded. Further limitations to our study include being a single institution analysis, and attempts at cost reduction in the RSSC group performed by a single surgeon may have been more uniform than the LC group performed by different surgeons. Our results should
123
Surg Endosc
trigger a multicenter randomized controlled study to confirm or refute our observation. Disclosures Yassar Youssef has lectured for intuitive surgical LLC and proctored other surgeons on robotic surgery. Kareem Bedeir and Andrew Mann have nothing to disclose.
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