Comparison of outcomes of single incision robotic cholecystectomy and single incision laparoscopic cholecystectomy.

BACKGROUNDS/AIMS: Multiport laparoscopic cholecystectomy is the standard surgical procedure for symptomatic gallbladder diseases. However, as a result of the ongoing trend toward minimally invasive laparoscopy, single-incision laparoscopic cholecystectomy (SILC) has evolved. Single-incision robotic cholecystectomy (SIRC) can overcome several limitations of manual SILC. The purpose of this study is to evaluate and compare the safety and feasibility of SIRC and SILC.
METHODS: This study retrospectively reviewed data for all patients who underwent SIRC or SILC from March 2018 to July 2019 in a single institution. The following variables were analyzed: age, sex, body mass index, pain scale, length of stay, and complications. The data were analyzed using the Independent two sample t-test or the Fisher's exact test.
RESULTS: A total of 343 patients underwent SIRC or SILC during the study period. After excluding patients with acute cholecystitis, 197 SIRC and 103 SILC patients were analyzed in this study. The surgery time and postoperative hospital stay did not differ between SIRC and SILC. However, the SIRC patients experienced less bile spillage during the surgery than did the SILC patients (SIRC vs. SILC: 24 (23.3%) vs. 11 (5.6%) cases, respectively; p<0.001). Although there was no difference in the incidence of postoperative complications between procedures, additional pain control was administered more frequently in SILC patients (SILC 1.08±0.893, SIRC 0.58±0.795; p<0.001).
CONCLUSIONS: While both SILC and SIRC are effective for single-incision cholecystectomy, SIRC was superior to SILC in terms of technical stability. Moreover, it has the advantage of postoperative pain control.

INTRODUCTION

Laparoscopic cholecystectomy is the standard treatment for symptomatic gallstones and benign pathologies of the gallbladder,[1] and the latest evolution of cholecystectomy is single incision surgery. Single incision laparoscopic cholecystectomy (SILC), which was first introduced in 1995, is considered an effective, minimally invasive method of managing benign gallbladder diseases.[2] This technique been widely applied in appendectomy, gastric binding, colectomy, donor nephrectomy, and sleeve gastrectomy.[3-6] It seems to be a no scar surgery because the entry point is hidden in the umbilicus. When compared with multiport laparoscopic surgery, SILC shows better cosmetic outcomes, post-operative pain control, and patient satisfaction, as well as shorter hospital stays.[7-9]

However, SILC is not widely performed because the narrow working space limits the movement of instruments and causes crowding between instruments.[10-12] In 2011, the da Vinci Single-Site Instrumentation and Accessories (Intuitive Surgical, Inc., Sunnyvale, CA, USA) system was developed to overcome these limitations.[12] The semirigid instruments cross each other within the trocar, so that the cannula entering from the left becomes the right-side operative instrument and vice-versa. This right to left and left to right conversion system creates an effective working space for instrument movement. The three- dimensional endoscope provides extremely fine visualization and avoids the problem of collisions between intra-abdominal instruments.[10,12] However, the advantage of single incision robotic cholecystectomy (SIRC) over SILC remains questionable. The aim of this study was to evaluate the feasibility and efficacy of SIRC and to compare clinical outcomes between SIRC and SILC.

MATERIALS AND METHODS

From June 2018 to February 2019, 343 patients underwent single-incision cholecystectomy, among whom 220 had SIRC and 123 received SILC at Gangnam severance institution. The indications for cholecystectomy were symptomatic gallbladder stone (with or without acute cholecystitis) and gallbladder benign disease (polyps or adenomyomatosis). Due to the high cost of instruments for robotic procedures, SIRC was limited to those who were able to pay an additional expense. The exclusion criteria were patients over 70 years old, patients who could not tolerate single port laparoscopic surgery, and patients with a history of upper abdominal surgery, gallbladder empyema, xanthogranulomatous cholecystitis, pancreatitis, or malignancy. After excluding 43 patients with acute cholecystitis (23 SIRC, 20 SILC), the data from 300 patients (197 SIRC, 103 SILC) were analyzed in this study.

Clinical data were retrospectively collected from the hospital records, including baseline parameters (age, sex, body mass index [BMI], American Society of Anesthesiologists Score Scale [ASA], and diagnosis); perioperative data (surgery time, rate and cause of conversion to open, and intraoperative complications); and postoperative findings (complications, length of stay, pain scale score and the number of additional treatments for pain). The patient’s pain was measured immediately upon return to the ward and every 8 hours after the surgery using the visual analog scale (VAS).

Surgical procedure

All surgeries were performed under general anesthesia with the patient in the supine position. In the SIRC group, the da Vinci Single-Site surgical system was used to perform cholecystectomy. After a 2 cm vertical incision was made through the umbilicus, a glove port was introduced into the peritoneal cavity, and the pneumoperitoneum was created by injecting carbon dioxide gas under 15 mmHg of intra-abdominal pressure. Curved cannulas were inserted into the port under endoscopic visualization and the robotic surgical system was automatically established. After safe retraction and visualization of Calot’s triangle, the cystic duct and cystic artery were skeletonized by Maryland robotic forceps and clipped with Hemo-O-lock clips. The cystic duct and artery were resected by hook electric cutting, and the gallbladder was detached from the liver in a retrograde manner. For SILC, skin incision and glove port insertion were identical to that used in SIRC. A 12 mm conventional rigid two-dimensional scope and a conventional rigid laparoscopic instrument were then introduced. The gallbladder was manipulated by a laparoscopic grasper, and the cystic duct and cystic artery were skeletonized by a traditional rigid laparoscopic dissector. Hemo-O-lock clips were applied, and the cystic duct and artery were resected by laparoscopic scissors. Again, the gallbladder was detached from the liver in a retrograde manner. For both SIRC and SILC, the fascial defect was closed using a 2-0 monofilament non-absorbable suture, and the skin incision wase closed with absorbable sutures.

Postoperative pain management

Patients were routinely prescribed 100 mg of Aceclofenac twice a day for pain control. For pain persisting more than 1 hour after pain control, a 50 mg intramuscular injection of tramadol HCl was administered. If pain persisted after the additional injection, a 30 mg intravascular injection of ketorolac tromethamine was administered after a physical examination.

Statistical analysis

Continuous variables data are expressed as means± standard deviations, while categorical variables are expressed as frequencies and percentages. The Student t test and Fisher’s exact test were used as appropriate to analyze and identify statistically significant parameters. Two-tailed p values were calculated, and a p value <0.05 was considered statistically significant. All statistical analyses were conducted with the SPSS statistical software (Version 25.0; SPSS, Inc., Chicago, IL, USA).

RESULTS

There were no significant differences in age, gender, BMI, or ASA score between groups (Table 1). The mean age of SILC and SIRC patients was 48.11±12.750 (range, 16-68) years and 45.63±10.461 (range 19-66) years, respectively. The mean BMI was 24.16±3.627 (range, 15.51- 32.24) kg/m2 for SILC patients and 24.84±4.284 (range, 13.87-44.34) kg/m2 for SIRC patients. Regarding the preoperative and pathological diagnoses, there were no significant differences between SILC and SIRC patients (Table 1).

Table 1

Patient demographic and clinical characteristics

Characteristic	SILC (n=103)	SIRC (n=197)	p value
Age, year, mean±SD	48.11±12.750	45.63±10.461	0.092
Sex, n (%)			1.000
Male (%)	47 (45.6)	90 (45.7)
Female (%)	56 (54.4)	107 (54.3)
BMI (kg/m2), mean±SD	24.16±3.627	24.89±4.212	0.137
ASA			<0.832
1 (%)	31 (30.1)	62 (31.5)
2 (%)	64 (62.1)	123 (62.4)
3 (%)	8 (7.8)	12 (6.1)
Preoperative diagnosis			0.748
Chronic cholecystitis (%)	77 (74.8)	151 (76.6)
Cholelithiasis (%)	12 (11.7)	16 (8.1)
Gallbladder polyp (%)	9 (8.7)	17 (8.6)
Gallbladder adenomyosis (%)	5 (4.9)	13 (6.6)
Pathologic diagnosis			0.170
Gallbladder adenomyosis (%)	1 (1.0)	0 (0.0)
Chronic cholecystitis (%)	100 (97.1)	185 (93.9)
Gallbladder polyp (%)	1 (1.9)	9 (1.5)
Gallbladder adenoma (%)	1 (1.0)	3 (1.5)

SILC, single incision laparoscopic cholecystectomy; SIRC, single incision robotic cholecystectomy; BMI, body mass index; ASA, American Society of Anesthesiologists Scale

Table 2 shows the perioperative and postoperative outcomes. The total operating time did not differ between SILC and SIRC (p=0.526): the mean surgery time for SILC was 60.66±39.810 (range, 22-283) minutes and that of SIRC was 63.35±22.185 (range, 28-154) minutes. There was no difference in the amount of bleeding between SILC and SIRC (13.98±65.543 [range, 0-400] ml vs. 13.48±52.921 [range 0-600] ml, respectively, p=0.954). Bile spillage during the surgery occurred more often with SILC (23.30%) than with SIRC (5.6%) (p<0.001). One patient with SILC was converted to multiport laparoscopic cholecystectomy due to hepatic artery bleeding. There were no cases of open conversion, and no significant difference in the conversion rate between groups.

Table 2

Perioperative and postoperative outcomes

Outcome	SILC (n=103)	SIRC (n=197)	p value
Total surgery time, minute	60.66±39.810	63.35±22.185	0.526
Amount of bleeding, ml	13.98±52.921	13.58±65.543	0.954
Conversion rate, n (%)	1 (1.0)	0 (0)	0.343
Bile spillage during surgery, n (%)	24 (23.3)	11 (5.6)	<0.0001
Postoperative complications			0.707
Wound complication	0 (0)	3 (6.6)
Complication without wound complication	0 (0)	1 (0.5)
Length of postoperative hospital stay, day	1.51±0.989	1.46±0.866	0.635
Visual analog scale score of pain
Before surgery	0.99±1.876	0.65±1.226	0.098
Max	6.02±1.188	5.96±1.351	0.704
At 1 hour	5.64±1.282	5.52±1.188	0.486
At discharge	2.40±0.856	2.43±0.882	0.753
Number of additional pain control treatment, n	1.08±0.893	0.58±0.795	<0.001

SILC, single incision laparoscopic cholecystectomy; SIRC, single incision robotic cholecystectomy

Although there was no statistically significant difference in postoperative complications between groups (p= 0.707), they were observed in four patients in the SIRC group. One patient developed high fever after discharge. He visited emergency department and was diagnosed with subhepatic abscess by computed tomography and successfully treated with sonographic drainage and antibiotics. The remaining three patients experienced postoperative wound problems: one was diagnosed with incisional hernia and underwent incisional hernioplasty one year after SIRC, and the other two patients had wound seroma.

There was no difference in the average length of the postoperative hospital stay between SILC and SIRC (1.51± 0.989 [range 1-7] days vs. 1.46±0.866 [range 1-7] days, respectively, p=0.635). The preoperative VAS score, postoperative VAS score MAX, and the VAS score at 1 hr after surgery and at discharge were not significantly different between SIRC patients and SILC patients (p=0.098, 0.704, 0.486, and 0.753, respectively). However, additional pain control was administered more frequently in SILC patients than in SIRC patients. (SILC 1.08±0.893 vs. SIRC 0.58±0.795, p<0.001).

DISCUSSION

Since its inception, single incision laparoscopic cholecystectomy has gained popularity as it is associated with better cosmetic outcomes,[13,14] and trends indicate that it may replace conventional multi-port laparoscopic cholecystectomy. Recently, single incision robot cholecystectomy has been developed to overcome the limitations of SILC. However, there are only a few published studies comparing SILC with SIRC. Thus, in this study, we compared the clinical outcomes of SILC and SIRC and found that SIRC was superior to SILC in the aspects of technical stability and pain control.

Grochola et al.[15] reported that single incision robot cholecystectomy provides significant benefits in terms of the surgeon’s stress load, but they could not show a patient advantage. Furthermore, as there was no reported advantage in the patient outcome between laparoscopic and robotic cholecystectomy, the increased cost associated with the latter is prohibitive. Han et al.[16] reported better ergonomics with SIRC because the incidence of bile spillage is more frequent in SILC. However, in that study, the pain was higher for the SIRC patients immediately after the surgery.

During cholecystectomy, care should be taken to avoid perforating the gallbladder. Bile spillage during laparoscopic cholecystectomy can provoke tumor recurrence in patients with a hidden malignancy of the gallbladder.[17] Many reports have shown that bile spillage negatively affects progression free survival in patients with incidental gallbladder cancer discovered during laparoscopic cholecystectomy.[18-20] Moreover, bile spillage is a risk for surgical site infection. Peponis et al.[21] reported that patients who experience bile spillage are over two times more likely to develop surgical site infection. Moreover, Rice et al.[22] reported that intraperitoneal bile spillage during laparoscopic cholecystectomy was associated with intra-abdominal abscesses. Bile spillage has been associated with old age, high body weight index, and the presence of omental adhesions,[21,22] which indicates that bile spillage can be an indicator of surgical stability. In our study, we found bile spillage to be more common in SILC patients.

Early postoperative pain following laparoscopy is influenced by several factors, including trauma from the abdominal wall incision, the visceral surgery field range, and peritoneal irritation from the pneumoperitoneum.[23,24] In addition, it is well-known that visceral and shoulder tip pain have their maximum impact in the first few hours after surgery.[23] Therefore, it is unlikely that the difference in instrument between SILC and SIRC has a great influence on pain because they are basically the same procedure. It is reasonable to presume that the predominant factor affecting the difference in pain experienced following either SILC and SIRC would be whether the surgery was stably performed, without affecting other abdominal organs, such as the liver and the peritoneum around the surgical site. In our study, there was no significant difference between the two surgical methods regarding the pain experienced immediately after surgery. However, SIRC showed a smaller number of additional pain control treatments; these patients may have experienced more rapid pain relief because robotic surgery has a smaller impact on the surrounding organs.

There was no significant difference in the total surgery time between SILC and SIRC in this study. Generally, SIRC has a longer surgery time than SILC does.[16,25] Han et al.[16] reported an overall operative time of 56.68 minutes in the SILC group and 101.57 minutes in the SIRC group. Lee et al.[25] also reported a longer surgery time in the SIRC group. In this study, the surgeon was sufficiently experienced in both SIRC and SILC to overcome the learning curve associated with SIRC. As previously published, the docking time initially had an average learning curve period of about 10 minutes in other institutions,[26] which was recently reduced to an average of less than three minutes. Thus, after mastering the learning curve, the surgery time for robotic surgery can be markedly shortened.[27]

Although the cosmetic outcome is better in single incision surgery, wound complications have been more frequently reported.[28,29] In our study, only one patient required conversion to multiport laparoscopic cholecystectomy because of massive bleeding of the hepatic artery, for a total conversion rate of 0.3%. We concluded that the reason for the low open conversion/additional port insertion rate was because the single incision surgery was not performed in patients with a history of upper abdominal surgery, gallbladder empyema, or xanthogranulomatous cholecystitis. In this study, wound complications appeared only in patients who underwent SIRC; however, there was no statistical significance.

A meta-analysis by Sun et al.[30] found no differences in the surgery time, intraoperative and postoperative complications, length of hospital stay, readmission rate, and conversion rate. between SILC and SIRC. In our study, patients who underwent SIRC demonstrated a significantly positive bile leakage rate and a reduced need for additional pain control compared to patients who underwent SILC. Although bile leakage is not an intraoperative complication, it is a good method for evaluating the stability of cholecystectomy. Moreover, the frequency of additional pain treatment is an alternative method for assessing the effectiveness of surgery.

This study had several limitations. This was a short- term analysis based on data collected retrospectively from only a single hospital setting. Therefore, large randomized controlled trials are needed to validate the evidence of the SIRC advantage.

This study showed that SILC and SIRC yielded similar perioperative outcomes for most of the measured parameters. Although both SILC and SIRC were effective for single-incision cholecystectomy, SIRC was superior to SILC in terms of technical stability and postoperative pain control.