Minimally Invasive Therapy. 2015; Early Online, 1–9
REVIEW ARTICLE
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Single-incision versus conventional three-port laparoscopic appendectomy: A meta-analysis of randomized controlled trials
JIANG-MING CHEN1*, WEI GENG2*, SHENG-XUE XIE1, FU-BAO LIU3, YI-JUN ZHAO3, LI-QUAN YU1 & XIAO-PING GENG1 1
Department of surgery, The Second Affiliated Hospital of Anhui Medical University, Anhui, China, 2Department of Liver Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, and 3Department of surgery, The First Affiliated Hospital of Anhui Medical University, Anhui, China
Abstract Purpose: The aim of this article was to compare the advantages and disadvantages of single-incision laparoscopic appendectomy (SILA) and conventional three-port laparoscopic appendectomy (CTLA). Material and methods: A meta-analysis was performed by analyzing all randomized controlled trials (RCTs) published in English that compared SILA and CTLA for appendicitis in adults and children. These studies compared these two methods from different angles including outcomes of interest, patient characteristics, operative time, pain visual analogue scales scores (VAS scores), length of hospital stay, time to return to full activity, resumption of diet, postoperative complications and cosmetic results The risk ratios (RR) and mean difference (MD) with 95% confidence intervals (CIs) were employed to assess the outcome. Results: Seven recent RCTs encompassing 1170 patients (586 SILA and 584 CTLA cases) were included in this meta-analysis. The pooled results demonstrated that conversion rate, drain inserted, reoperation, length of hospital stay, resumption of normal diet and postoperative complications were statistically comparable between the two groups. The postoperative abdominal pain within 24 h was -0.57 in favor of the SILA technique (p = 0.05). Compared with CTLA, SILA showed a better cosmetic satisfaction score (SMD, 0.58; 95% CI, 0.32-0.83; p < 0.0001) and shorter time to recover normal activity (WMD, -0.69; 95% CI, -1.11–0.26; p = 0.001). However, SILA has a longer operative time (WMD, 5.38; 95% CI, 2.94-7.83; p < 0.0001). Conclusions:In selected patients, SILA was confirmed to be as safe and effective as CTLA. Despite the longer operative time, SILA has higher cosmetic satisfaction and shorter recovery time to normal activity. Due to the limitations of the available data, further research is needed.
Key words: Laparoscopic appendectomy, general surgery, abdominal surgery
Introduction Acute appendicitis is a common indication for abdominal surgery with a lifetime incidence of approximately 8% (1). Open appendectomy, which was first described by McBurney in 1894 (2), has been considered the gold standard for appendectomy for approximately 100 years. The laparoscopic approach was introduced by Semm in 1983 (3) and has since been performed more frequently than the open procedure because of several advantages, including minimal invasiveness, small incisions, less postoperative pain and fewer wound infections.
As technology and innovation have continuously improved in the field of minimally invasive surgery, single-incision laparoscopic surgery (SILA) was first introduced by Pelosi in 1992 (4). SILA gained popularity as a method of achieving a perceived “scarless” abdomen through placement of the single incision within the umbilicus. However, some randomized controlled trials (RCTs) failed to demonstrate a better result than for conventional three-port laparoscopic appendectomy (CTLA) regarding pain and cosmesis (5), and there has been increasing doubt as to whether the new technique could actually fulfill its primary promises.
Correspondence: Xiao-ping Geng, Department of surgery, The Second Affiliated Hospital of Anhui Medical University, Furong Road 678#, Shushan District, Hefei, Anhui 230022, China. Tel: +86 15305609606. E-mail: [email protected] *Jiang-ming Chen and Wei Geng contributed equally to this article. ISSN 1364-5706 print/ISSN 1365-2931 online 2015 Informa Healthcare DOI: 10.3109/13645706.2014.995675
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To compare these two methods, we performed a meta-analysis of randomized controlled trials (RCTs) conducted between 1992 and 2013 to evaluate patient characteristics, operative time, the pain visual analogue scales scores (VAS scores), hospital stay, time to return to full activity, resumption of diet, postoperative complications and cosmetic results.
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Material and methods Literature search The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for conducting meta-analyses were followed (6). A thorough literature search was performed through Pubmed, Web of Science, Science Direct, and ClinicalTrials.gov for potentially relevant randomized controlled trials comparing SILA and CTLA from January 1992 to August 2013. The electronic search strategy included the following terms: single access OR single incision OR single port OR single trocar OR single site OR one access OR one incision OR one port OR one trocar AND appendectomy AND laparoscopy. References within the articles were also analyzed to search for relevant studies. All PRISMA steps were used, including flowchart (File S1) and checklist (File S2). Inclusion and exclusion criteria The goal of this meta-analysis was to compare the surgical procedures and outcomes of SILA and CTLA. The inclusion criteria for the studies were as follows: . written in English; . compared SILA and CTLA; . randomized controlled trial; . reported at least one outcome; . clearly documented the procedure. If an overlap existed between two studies, the higher quality study was selected. The articles were excluded if they did not fulfill any of the criteria above. Subgroup analysis The following two subgroups were evaluated: children and adults. Data extraction and quality assessment Once eligible studies had been identified, the data extraction and critical appraisal were performed independently by two authors. Any disagreement was discussed and resolved by consensus. The details
included patient characteristics, outcome, postoperative recovery, morbidity, mortality, and wound healing. Patient characteristics included age, sex, body mass index (BMI), and leukocyte count. Operative outcome was analyzed based on operative time, conversion to open procedure, drain insertion and reoperation. Postoperative recovery such as VAS scores, hospitalization, return to full activity, resumption of diet and cosmetic satisfaction were also reviewed. Furthermore, other data including morbidity, incidence of complications, wound infections, and development of ileus and abscesses were examined. In case of missing or unclear information, we contacted the authors of the original studies. The quality of all studies was evaluated using Jadad’s scoring system (7). According to the Kjaergard recommendation, low-quality studies were defined by a score 3 were classified as high quality (8).
Statistical analysis All statistical analyses were carried out with Rev Man 5.1. Continuous data (e.g., operative time and hospitalization) were analyzed using weight difference mean (WMD) or standard mean difference (SMD) with 95% confidence interval (CI). Dichotomous data (e. g., postoperative complications) were analyzed using the odds ratio (OR) and a fixed-effects model. A random-effects model was used if there was significant heterogeneity. Heterogeneity was evaluated with a chisquared test, and p < 0.1 was considered significant. A p value of < 0.05 indicated statistical significance. Risk of bias was evaluated using a funnel plot.
Results Results of the search The literature search strategy and trial selection are shown in the PRISMA flow chart (Figure 1) according to the PRISMA guidelines. Through the electronic database search, we identified 1315 references, 315 from Pubmed, 352 from Web Science, and 648 from ScienceDirect. No references were identified by scanning the reference lists of the identified randomized trials and ClinicalTrials.gov. In total, seven RCTs (9–15) were included in the meta-analysis, of which two were related to children. All of these RCTs were published after 2011 and comprised 1170 patients (586 SILA and 584 CTLA cases). The sample size of the trials ranged from 50 to 360. All pooled RCTs were high-quality trials classified by the modified Jadad scale. The main characteristics of the seven included RCTs
Identification
Single-incision vs. conventional three-port appendectomy
Records identified through database searching (n = 1315)
3
Additional records identified through other sources (n = 0)
Screening
Records excluded (n = 660 ) Irrelevant to PG&PJ (n = 389) Nonrandomized (n = 171) Review (n = 76) Meta-analysis (n = 9) Letters to the editor (n = 7) Non-English (n = 8)
Eligibility
Records screened (n = 672)
Full-text articles assessed for eligibility (n = 12 )
Full-text articles excluded, with reasons (n = 5) Not real RCTs (n = 3) Duplication data (n = 1) Incomplete information on outcomes (n = 1)
Studies included in qualitative synthesis (n = 7 )
Included
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Records after duplicates removed (n = 672)
Studies included in quantitative synthesis (meta-analysis) (n = 7 )
Figure 1. PRISMA flow chart of the meta-analysis.
and the different surgical methods used for singleincision laparoscopy are shown in Tables I and II Risk of publication bias. A funnel plot analysis (Figure 2) was applied to evaluate the possibility of a publication bias, and no significance was revealed.
Meta-analysis results Patient characteristics. Table I presents the demographic data of the seven RCTs included in this
meta-analysis. There was no statistical significance in the demographic characteristics, including age, gender, body mass index and leukocyte count.
Operative outcome Operative time. Operative time was reported in all these studies. Our meta-analysis indicated that operative time was significantly longer in SILA than in CTLA (random-effects model, WMD, 6.67; 95% CI, 3.11-10.23; p = 0.0002; Figure 3), with evidence
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Table I. Methods for single-incision laparoscopic appendectomy.
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Study
Device
Umbilicus
Mesoappendix
Appendicular stump
Specimen delivery
St Peter
Three access ports through the same umbilical incision
1-2cm
Individual surgeon’s technique
Individual surgeon’s technique
Directly
Teoh et al
Two 5-mm ports and one 10-mm port introduced through a single incision
13-mm
Ultrasonic dissector (Sonosury, Olympus surgical, Japan)
Polydioxanone suture loop
Plastic bag
Lee et al
Octoport (Dalim, Seoul, Korea)
15-mm
Ultrasonic coagulating shears (Ethicon EndoSurgery Inc, Cincinnati, OH, USA)
Endoloop
Endobag
Frutos et al
SILS port (Covidien, Mansfield, MA, USA)
20-mm
Articulated endoscopic scissors
Endoloop
Retrieval bag (Endocatch; Covidien)
Kye et al
Surgical glove with three 5-mm trocars connected to the double-ringed wound retractor (Applied Medical, Rancho Santa Margarita, CA, USA)
20-mm
Ultrasound-activated scissors
Endoloop
Diaposable bag
Perez et al
Three access ports though the same umbilical incision
-
stapler
stapler
Endobag (Covidien, Mansfield, MA, USA)
Sozutek et al
SILS port (Covidien, Mansfield, MA, USA)
20-mm
Vessel sealing shear (Enseal, Ethicon)
2/0 polypropylene suture
Endobag
of significant heterogeneity (I2 = 83%; p < 0.0001). Five comparative (10–13,15) trials reported the operative time for adults. The pooled results showed that SILA requires more time than CTLA for adults (WMD, 5.38; 95% CI, 2.94-7.83; p < 0.0001; Figure 3). There was no statistical heterogeneity among these five studies (I2 = 0%; p = 0.5).
Conversion rate. Five studies (10,12–15) reported conversion rates for appendectomies. Nine (3.1%) SILA procedures and four (1.4%) CTLA procedures were converted to open appendectomies. There was no significant difference in the conversion rate between these two groups (OR, 2.32; 95% CI, 0.70-7.71; p = 0.17). The I2 was 0%, which means no statistical heterogeneity.
Table II. Demographics of patients with the seven included studies. No. of patients Author (Year)
Age (y)
Jadad grade SILA CTLA SILA
Sex M/F
CTLA
SILA
CTLA SILA
11.1 ± 3.3
11:9
23:22
St Peter et al (2011)
6
180
180
11.1 ± 3.5
Teoh et al (2012)
6
98
97
39.19 ± 15.55 40.65 ± 15.68
Lee et al (2013)
4
116
113
28.4 ± 15.4
Frutos et al (2013)
5
91
93
28.04 ± 11.03 31.02 ± 12.41
Kye et al (2013)
4
51
51
27.55 ± 12.40 29.20 ± 13.98
Perez et al (2013)
6
25
25
8.7 ± 0.6
8.9 ± 0.6
2:3
Sozutek er al (2013)
4
25
25
30.6 ± 12.4
30 ± 11
12:13 7:18
Leukocyte count (1000 cell/mm3)
BMI (Kg/m2) CTLA
SILA
CTLA
19.4 ± 4.9
19.6 ± 4.5
14.6 ± 5.4 14.6 ± 5.2
21.4 ± 3.2
22.7 ± 4.4
12.0432 ± 3.8933
12.6665 ± 4.5538
11.26 ± 3.89
12.93 ± 4.05
29:20 59:38
28.5 ± 17.2 16:13 68:45 46:45 51:42
23.84 ± 3.98 24.02 ± 3.84 22.03 ± 4.07 21.97 ± 3.49
3:2 23.2 ± 3.79
23.1 ± 2.58
Single-incision vs. conventional three-port appendectomy 0
SE(log[OR])
Postoperative recovery Hospitalization. Hospitalization was reported in all studies. However, two studies (11,14) were excluded because of missing information regarding standard deviation. The hospital stay was comparable between the two groups (WMD, 0.03; 95% CI, -1.18-1.24; p = 0.96). It did not have significant heterogeneity (I2 = 29%; p = 0.23).
0.5
1
1.5
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5
2 0.01
OR 0.1
1
10
100
Subgroups 1 adults 2 children
Figure 2. Funnel plots of total postoperative wound infection. The dashed line represents 95% CI.
Drain insertion. Two studies (10,11) reported drain insertion following SILA or CTLA. There was no significant difference in the rate of drain insertion between these two groups (OR, 0.68; 95% CI, 0.36-1.29; p = 0.24). There was no evidence of heterogeneity between these two studies (I2 = 0%; p = 0.76). Reoperation. Reoperation was compared in three studies (11,12,15). Two patients underwent reoperation in the CTLA group, one for appendiceal stump leakage (15), the other for bleeding of epigastric vessels (12). None of the patients required reoperation in the SILA group. In conclusion, there was no significant difference between these two groups (OR, 0.33; 95% CI, 0.03-3.19; p = 0.34). No heterogeneity was found (I2 = 0%; p = 0.98). SILA Study or subgroup Mean 2.1.11 adults Frutos 2013 Kye 2013 Lee 2013 Sozutek 2013 Teoh 2012 Subtotal (95% CI)
Return to normal activity. Three studies (9,10,13) reported the time required for patients to return to normal activity. Pooling the results, there was significant difference in the time required to return to normal activity between the two groups (WMD, -0.69; 95% CI, -1.11–0.26; p = 0.001; Figure 4), and there was no significant heterogeneity among these three studies (I2 = 0%; p = 0.64). Resumption of normal diet. Three studies (9,10,15) reported the time required for resumption of a normal diet. Our meta-analysis showed WMD of -0.04 days (95% CI, -0.34-0.27; p = 0.80) in favor of SILA patients. However, no significant difference and no heterogeneity were discovered. (I2 = 13%; p = 0.31) Postoperative pain. Six studies reported on postoperative pain; however, only three of them (12,13,15) provided sufficient data to describe postoperative pain scores by using VAS on the first day after surgery. A slight difference was reported in these studies without any statistical significance (random-effects model, WMD, -0.57; 95% CI, -1.16-0.01; p = 0.05).
CTLA SD Total Mean
38.13 13.49 37 15.46 43.8 21.3 32.6 9.9 63 27.2
SD
91 32.12 12.44 51 38.45 15.26 116 35.8 18.9 25 29.5 6.8 98 60.2 31.7 330
Total Weight
Mean difference IV, Random, 95% CI
93 51 113 25 97 328
6.01 [2.26, 9.76] -1.45 [-7.41, 4.51] 8.00 [2.79, 13.21] 3.10 [-1.61, 7.81] 2.80 [-5.49, 11.09] 5.38 [2.94, 7.83]
17.9% 0.0% 15.1% 16.0% 10.1% 59.1%
Mean difference IV, Random, 95% CI
Heterogeneity: Tau2 = 0.00; Chi2 = 2.35, df = 3 (p = 0.50); I2 = 0% Test for overall effect: Z = 4.32 (p < 0.0001) 2.1.2 2 children Perez 2013 2.5 21.2% 12.00 [10.25, 13.75] 25 25 34.8 3.7 46.8 5.40 [2.69, 8.11] 19.7% 35.2 14.5 180 29.8 11.6 180 St Peter 2011 205 40.9% 205 Subtotal (95% CI) 8.78 [2.32, 15.25] Heterogeneity: Tau2 = 20.42; Chi2 = 16.05, df = 1 (p < 0.0001); I2 = 94% Test for overall effect: Z = 2.66 (p = 0.008) 535 533 100.0% Total (95% CI) Heterogeneity: Tau2 = 14.79; Chi2 = 28.73, df = 5 (p < 0.0001); I2 = 83% Test for overall effect: Z = 3.67 (p = 0.002) Test for subgroup differences: Chi2 = 0.93. df = 1 (p = 0.34). I2 = 0%
Figure 3. Forest plot for operative time in SILA vs CTLA group
6.67 [3.11, 10.23] –20
–10
Favours experimental
0
10
20
Favours control
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J. -M. Chen et al. SILA CTLA Mean difference Study or subgroup Mean SD Total Mean SD Total Weight IV, Fixed, 95% CI 3.3.11 adults 3.22 1.04 51 3.94 1.43 51 Kye 2013 75.4% -0.72 [-1.21, -0.23] 6.17 4.21 98 6.38 4.1 97 13.1 % -0.21 [-1.38, 0.96] Teoh 2012 148 88.5% -0.64 [-1.09, -0.20] 149 Subtotal (95% CI) Heterogeneity: Chi2 = 0.63, df = 1 (p = 0.43); I2 = 0% Test for overall effect: Z = 2.82 (p = 0.005)
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3.3.2 2 children 7.5 5.8 180 8.5 St Peter 2011 180 Subtotal (95% CI) Heterogeneity: Not applicable Test for overall effect: Z = 1.58 (p = 0.11)
6.2
180 180
Mean difference IV, Fixed, 95% CI
11.5% -1.00 [-2.24, 0.24] 11.5% -1.00 [-2.24, 0.24]
Total (95% CI) 328 100.0% -0.69 [-1.11, -0.26] 329 Heterogeneity: Chi2 = 0.90, df = 2 (p = 0.64); I2 = 0% -1 0 -2 1 2 Test for overall effect: Z = 3.19 (p = 0.001) Test for subgroup differences: Chi2 = 0.28. df = 1 (p = 0.60). I2 = 0% Favours experimental Favours control
Figure 4. Forest plot for return to normal activity in SILA vs CTLA group
However, significant heterogeneity was found among these studies (I2 = 74%; p = 0.02). Cosmetic satisfaction. The cosmetic score was reported in three studies (10,11,15); however, one study (11) was excluded because it did not provide information regarding standard deviation. The cosmetic outcome was significantly better in the SILA group than in the CTLA group (SMD, 0.58; 95% CI, 0.32-0.83; p < 0.0001; Figure 5). There was no significant heterogeneity (I2 = 0%; p = 0.49). Postoperative morbidity and mortality Mortality. No mortality was reported in either group. Postoperative morbidity. All trials provided specific information about all complications. There was no heterogeneity among the trials (I2 = 0%; p = 0.90). In the fixed-effects model (OR, 1.15; 95% CI, 0.74-1.80; p = 0.53; Figure 6), the risk of developing complications was statistically similar in both groups. There was no significant difference in the incidence of postoperative wound infections (OR, 0.99; 95% CI, 0.54-1.79; p = 0.96), ileus (OR, 0.81; 95% CI, 0.23-2.84; p = 0.74) and abscess formation (OR,
1.53; 95% CI, 0.60-3.89; p = 0.37). There was no significant heterogeneity for wound infections or the development of ileus and abscess (I2 = 0%; p > 0.1
Discussion This meta-analysis of seven RCTs provided pooled data comparing SILA and CTLA. The pooled results showed that the safety and morbidity of SILA is statistically similar to that of CTLA while having significantly higher cosmetic scores and earlier return to normal activity. Less pain, higher cosmetic scores, earlier recovery and a lower complication rate are the major advantages of laparoscopic surgery over open surgery (16– 19). Our pooled analysis of postoperative abdominal pain evaluation demonstrated that the VAS score was insignificantly lower in SILA within 24 h after the operation. Teoh (10) concluded that significantly worse postoperative pain was experienced in SILA after activation. Instead, Frutos (12) and Kye (13) reported that there is a significant reduction in postoperative pain in SILA compared to that in CTLA on the first postoperative day (2.76 ± 1.64 vs 3.78 ± 1.76; p < 0.001 and 3.22 ± 1.22 vs 3.90 ± 1.46; p = 0.012, respectively). This difference may be related to the larger size of the port that penetrates the skin and
SILA CTLA Std.Mean difference Study or subgroup Mean SD Total Mean SD Total Weight IV, Random, 95% CI 82.5 20.17 25 73.43 24.09 25 20.8% 0.40 [-0.16,0.96] Sozutek 2013 7.2 0.8 98 6.7 Teoh 2012 0.8 97 79.2% 0.62 [0.33,0.96] 122 100.0% Total (95% CI) 123 Heterogeneity: Chi2 = 0.47, df = 1 (p = 0.049); I2 = 0% Test for overall effect: Z = 4.42 (p < 0.0001)
Figure 5. Forest plot for cosmetic satisfaction in SILA vs CTLA group
Std.Mean difference IV, Fixed, 95% CI
0.58 [0.32, 0.83] –0.5 –0.25 0 0.25 0.5 Favours experimental Favours control
Single-incision vs. conventional three-port appendectomy
Study or subgroup
CTLA SILA Events Total Events Total Weight
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4.1.11 adults 93 4 Frutos 2013 5 91 51 2 51 2 Kye 2013 20 113 116 17 Lee 2013 1 25 25 1 Sozutek 2013 97 98 9 14 Teoh 2012 379 Subtotal (95% CI) 381 Total events 39 36 Heterogeneity: Chi2 = 1.60, df = 4 (P = 0.81); I2 = 0% Test for overall effect: Z = 0.31 (P = 0.076) 4.1.2 2 children Perez 2013 1 25 25 0 St Peter 2011 180 6 4 180 205 205 Subtotal (95% CI) 4 7 Total events Heterogeneity: Chi2 = 0.16, df = 1 (p = 0.69); I2 = 0% Test for overall effect: Z = 0.87 (p = 0.38)
Odds ratio M-H, Fixed, 95% CI
10.4% 5.3% 48.0% 2.7% 21.5% 88.0%
1.29 [0.34, 4.98] 1.00 [0.14, 7.39] 0.80 [0.39, 1.62] 1.00 [0.06, 16.93] 1.63 [0.06, 3.97] 1.08 [0.67, 1.75]
1.3% 10.7% 12.0%
3.12 [0.12, 80.39] 1.52 [0.42, 5.47] 1.69 [0.52, 5.53]
7
Odds ratio M-H, Fixed, 95% CI
584 100.0% Total (95% CI) 586 1.15 [0.74, 1.80] 46 Total events 40 Heterogeneity: Chi2 = 2.22, df = 6 (p = 0.90); I2 = 0% 10 100 0.01 1 0.1 Test for overall effect: Z = 0.62 (p = 0.53) Favours experimental Favours control 2 2 Test for subgroup differences: Chi = 0.47. df = 1 (p = 0.49). I = 0%
Figure 6. Forest plot for total complications in SILA vs CTLA group
umbilical fascia and therefore offsets the advantage of requiring a reduced number of trochars (20). Therefore, further technical research is required to reduce the port site access while allowing surgeons to perform the procedure comfortably. Previous meta-analyses have demonstrated that a significantly higher cosmetic satisfaction was shown in single-incision laparoscopic cholecystectomies than in conventional cholecystectomies (21,22). Similarly, our meta-analysis showed that cosmetic satisfaction was significantly higher in SILA than in CTLA. Although it was statistically significant, the difference should be interpreted with caution. Only two trials reported this result. In these two studies, the patients were only given the opportunity to rate the cosmetic benefit of their own abdominal scars without making a comparison between the potential cosmetic outcomes. Their postoperative cosmetic satisfaction score may have been different if they had reviewed other cosmetic outcomes. Moreover, the scales used to assess the appearance of the wound varied across the studies, and the satisfaction must be verified through longterm follow-up as it could depend upon the timing of the survey (23). Further RCTs with long follow-up periods and standard scar assessment are required to confirm the cosmetic benefits of SILA. With the development of minimally invasive surgery and laparoscopic techniques, postoperative recovery after laparoscopic appendectomy is faster than after open appendectomy (16,24). The results from three RCTs included in this meta-analysis
showed that SILA leads to faster recovery. However, the length of hospital stay and the time to resumption of normal diet were similar in our results. Therefore, further randomized trials should be performed to assess the true impact of SILA on postoperative recovery. SILA has higher technical requirements than CTLA, which may be associated with more postoperative complications, a higher reoperation rate and a longer operative time (25,26). Regretfully, our metaanalysis failed to find significant differences between the SILA and CTLA groups regarding postoperative complication and reoperation rates. The complications from laparoscopic appendectomies were rare and the time of the follow-up was insufficient in most of these studies. Therefore, further randomized trials with a larger patient population and long-term follow-up are required to measure the rate of complications accurately. In the SILA group, the reoperation rate was zero; in the CTLA group one patient required reoperation for bleeding of the surgical wound from the trocar in the left iliac fossa and ligation of the left epigastric vessels, and one patient required reoperation for appendiceal stump leakage. Nevertheless, the difference in postoperative complications and reoperation rates was not significant, and the safety of SILA and CTLA is quite similar. Unlike the previous meta-analysis of nonRCTs, our study demonstrated that the operative time for SILA was significantly longer than that for CTLA (p < 0.0001). In addition to the technical difficulty,
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the steep learning curve may contribute to the difference in the mean operative time. In uncomplicated appendicitis or appendixes with normal characteristics, the operative time was similar or even shorter in SILA. However, in complicated surgeries, such as cases with a retrocecal appendix or severe adhesions, the CTLA procedure allows the dissection and mobilization to be performed more expeditiously without compromising operative safety. Technical difficulty can also be surmised from additional port sites and instruments outside the umbilicus. According to the study by Liao (27), an operative duration equivalent to that of the CTLA method could be achieved after 30 cases. Lee (28) reported that the operative time tended to shorten when the surgeon gained more experience and accumulated more cases. This may mean that it is the surgical experience and not the technique itself that causes the longer operative time. There are several limitations to the present review. Although no detectable publication bias was found on funnel plotting, the number of included RCTs was small and the sample size of the two RCTs was insufficient, which may bias the results. In addition, there was significant heterogeneity among the studies in terms of several outcomes, including pain score and operative time, which was an important outcome variable in our pooled analysis. Heterogeneity in pain score may be caused by variations in the postoperative pain reduction management, the severity of appendicitis and surgical injury. Definitions of operative time varied or were not mentioned, which could cause heterogeneity. Moreover, none of the studies described long-term postoperative mortality or morbidity, which are crucial in evaluating the curative effects of SILA and CTLA. Despite these limitations, we believe SILA is comparable to CTLA in selected patients and represents a possible alternative to CTLA, with better cosmetic satisfaction and earlier return to normal activity, but longer operative time. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
References 1. Addiss DG, Shaffer N, Fowler BS, Tauxe RV. The epidemiology of appendicitis and appendectomy in the United States. Am J Epidemiol. 1990;132:910–25. 2. McBurney C. IV. The incision made in the abdominal wall in cases of appendicitis with a description of a new method of operating. Ann Surg. 1894;20:38–43.
3. Semm K. Endoscopic appendectomy. Endoscopy. 1983;15: 59–64. 4. Pelosi MA, Pelosi MA 3rd. Laparoscopic appendectomy using a single umbilical puncture (minilaparoscopy). J Reprod Med. 1992;37:588–94. 5. Kim HO, Yoo CH, Lee SR, Son BH, Park YL, Shin JH, et al. Pain after laparoscopic appendectomy: a comparison of transumbilical single-port and conventional laparoscopic surgery. J Korean Surg Soc. 2012;82:172–8. 6. Moher D, Liberati A, Tetzlaff J, et al. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. 2009;6:e1000097. 7. Jadad AR, Moore RA, Carroll D, Jenkinson C, Reynolds DJ, Garaghan DJ, et al. Assessing the quality of reports of randomized clinical trials: is blinding necessary? Control Clin Trials. 1996;17:1–12. 8. Kjaergard LL, Villumsen J, Gluud C. Reported methodologic quality and discrepancies between large and small randomized trials in meta-analyses. Ann Intern Med. 2011;135:982–9. 9. St Peter SD, Adibe OO, Juang D, Sharp SW, Garey CL, Laituri CA, et al. Single incision versus standard 3-port laparoscopic appendectomy. Ann Surg. 2011;254:586–90. 10. Teoh AY, Chiu PW, Wong TC, Poon MC, Wong SK, Leong HT, et al. A double-blinded randomized controlled trial of laparoendoscopic single-site access versus conventional 3-port appendectomy. Ann Surg. 2012;256:909–14. 11. Lee WS, Choi ST, Lee JN, Kim KK, Park YH, Lee WK, et al. Single-port laparoscopic appendectomy versus conventional laparoscopic appendectomy. Ann Surg. 2013;257:214–18. 12. Frutos MD, Abrisqueta J, Lujan J, Abellan I, Parrilla P. Randomized prospective study to compare laparoscopic appendectomy versus umbilical single-incision appendectomy. Ann Surg. 2013;257:413–18. 13. Kye BH, Lee J, Kim W, Kim D, Lee D. Comparative study between single-incision and three-port laparoscopic appendectomy: a prospective randomized trial. J Laparoendosc Adv Surg Tech A. 2013;23:431–6. 14. Perez EA, Piper H, Burkhalter LS, Fischer AC. Singleincision laparoscopic surgery in children: a randomized control trial of acute appendicitis. Surg Endosc. 2013;27: 1367–71. 15. Sozutek A, Colak T, Dirlik M, Ocal K, Turkmenoglu O, Dag A. A prospective randomized comparison of single-port laparoscopic procedure with open and standard 3-port laparoscopic procedures in the treatment of acute appendicitis. Surg Laparosc Endosc Percutan Tech. 2013; 23:74–8. 16. Ohtani H, Tamamori Y, Arimoto Y, Nishiguchi Y, Maeda K, Hirakawa K. Meta-analysis of the results of randomized controlled trials that compared laparoscopic and open surgery for acute appendicitis. J Gastrointest Surg. 2012;16:1929–39. 17. Southqate E, Vousden N, Karthikesalinqam A, Markar SR, Black S, Zaidi A. Laparoscopic vs open appendectomy in older patients. Arch Surg. 2012;147:557–62. 18. Markar SR, Blackburn S, Cobb R, Karthikesalingam A, Evans J, Kinross J, et al. Laparoscopic versus open appendectomy for complicated and uncomplicated appendicitis in children. J Gastrointest Surg. 2012;16:1993–2004. 19. Sauerland S, Jaschinski T, Neugebauer EA. Laparoscopic versus open surgery for suspected appendicitis. Cochrane Database Syst Rev. 2010;6(10):CD001546. 20. Lai EC, Yang GP, Tang CN, Yih PC, Chan OC, Li MK. Prospective randomized comparative study of single incision laparoscopic cholecystectomy. Am J Surg. 2011;202: 254–8.
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Single-incision vs. conventional three-port appendectomy 21. Wang Z, Huang X, Zheng Q. Single-incision versus conventional laparoscopic cholecystectomy: a meta-analysis. ANZ J Surg. 2012;82:885–9. 22. Wu XS, Shi LB, Gu J, Dong P, Lu JH, Li ML, et al. Single-incision laparoscopic cholecystectomy versus multiincision laparoscopic cholecystectomy: a meta-analysis of randomized clinical trials. J Laparoendosc Adv Surg Tech A. 2013;23:183–91. 23. Pisanu A, Reccia I, Porceddu G, Uccheddu A. Meta-analysis of prospective randomized studies comparing single-incision laparoscopic cholecystectomy and conventional multiport laparoscopic cholecystectomy. J Gastrointest Surg. 2012;16: 1790–801. 24. Wei B, Qi CL, Chen TF, Zheng ZH, Huang JL, Hu BG, et al. Laparoscopic versus open appendectomy for acute appendicitis: a meta-analysis. Surg Endosc. 2011;25:1199– 208.
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25. Pisanu A, Proceddu G, Reccia I, Saba A, Uccheddu A. Metaanalysis of studies comparing single-incision laparoscopic appendectomy and conventional multiport laparoscopic appendectomy. J Surg Res. 2013;183:e49–59. 26. Rehman H, Mathews T, Ahmed I. A review of minimally invasive single-port/incision laparoscopic appendectomy. J Laparoendosc Adv Surg Tech A. 2012;22:641–6. 27. Liao YT, Lin TH, Lee PC, Chou TH, Liang JT, Liu MT. Learning curve of single-port laparoscopic appendectomy for noncomplicated acute appendicitis: a preliminary analysis compared with conventional laparoscopic appendectomy. J Laparoendosc Adv Surg Tech A. 2013;23:441–6. 28. Lee JS, Choi YI, Lim SH, Hong TH. Transumbilical single port laparoscopic appendectomy using basic equipment: a comparsion with the three ports method. J Korean Surg Soc. 2012;83:212–17.
REVIEW ARTICLE
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Single-incision versus conventional three-port laparoscopic appendectomy: A meta-analysis of randomized controlled trials
JIANG-MING CHEN1*, WEI GENG2*, SHENG-XUE XIE1, FU-BAO LIU3, YI-JUN ZHAO3, LI-QUAN YU1 & XIAO-PING GENG1 1
Department of surgery, The Second Affiliated Hospital of Anhui Medical University, Anhui, China, 2Department of Liver Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China, and 3Department of surgery, The First Affiliated Hospital of Anhui Medical University, Anhui, China
Abstract Purpose: The aim of this article was to compare the advantages and disadvantages of single-incision laparoscopic appendectomy (SILA) and conventional three-port laparoscopic appendectomy (CTLA). Material and methods: A meta-analysis was performed by analyzing all randomized controlled trials (RCTs) published in English that compared SILA and CTLA for appendicitis in adults and children. These studies compared these two methods from different angles including outcomes of interest, patient characteristics, operative time, pain visual analogue scales scores (VAS scores), length of hospital stay, time to return to full activity, resumption of diet, postoperative complications and cosmetic results The risk ratios (RR) and mean difference (MD) with 95% confidence intervals (CIs) were employed to assess the outcome. Results: Seven recent RCTs encompassing 1170 patients (586 SILA and 584 CTLA cases) were included in this meta-analysis. The pooled results demonstrated that conversion rate, drain inserted, reoperation, length of hospital stay, resumption of normal diet and postoperative complications were statistically comparable between the two groups. The postoperative abdominal pain within 24 h was -0.57 in favor of the SILA technique (p = 0.05). Compared with CTLA, SILA showed a better cosmetic satisfaction score (SMD, 0.58; 95% CI, 0.32-0.83; p < 0.0001) and shorter time to recover normal activity (WMD, -0.69; 95% CI, -1.11–0.26; p = 0.001). However, SILA has a longer operative time (WMD, 5.38; 95% CI, 2.94-7.83; p < 0.0001). Conclusions:In selected patients, SILA was confirmed to be as safe and effective as CTLA. Despite the longer operative time, SILA has higher cosmetic satisfaction and shorter recovery time to normal activity. Due to the limitations of the available data, further research is needed.
Key words: Laparoscopic appendectomy, general surgery, abdominal surgery
Introduction Acute appendicitis is a common indication for abdominal surgery with a lifetime incidence of approximately 8% (1). Open appendectomy, which was first described by McBurney in 1894 (2), has been considered the gold standard for appendectomy for approximately 100 years. The laparoscopic approach was introduced by Semm in 1983 (3) and has since been performed more frequently than the open procedure because of several advantages, including minimal invasiveness, small incisions, less postoperative pain and fewer wound infections.
As technology and innovation have continuously improved in the field of minimally invasive surgery, single-incision laparoscopic surgery (SILA) was first introduced by Pelosi in 1992 (4). SILA gained popularity as a method of achieving a perceived “scarless” abdomen through placement of the single incision within the umbilicus. However, some randomized controlled trials (RCTs) failed to demonstrate a better result than for conventional three-port laparoscopic appendectomy (CTLA) regarding pain and cosmesis (5), and there has been increasing doubt as to whether the new technique could actually fulfill its primary promises.
Correspondence: Xiao-ping Geng, Department of surgery, The Second Affiliated Hospital of Anhui Medical University, Furong Road 678#, Shushan District, Hefei, Anhui 230022, China. Tel: +86 15305609606. E-mail: [email protected] *Jiang-ming Chen and Wei Geng contributed equally to this article. ISSN 1364-5706 print/ISSN 1365-2931 online 2015 Informa Healthcare DOI: 10.3109/13645706.2014.995675
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To compare these two methods, we performed a meta-analysis of randomized controlled trials (RCTs) conducted between 1992 and 2013 to evaluate patient characteristics, operative time, the pain visual analogue scales scores (VAS scores), hospital stay, time to return to full activity, resumption of diet, postoperative complications and cosmetic results.
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Material and methods Literature search The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for conducting meta-analyses were followed (6). A thorough literature search was performed through Pubmed, Web of Science, Science Direct, and ClinicalTrials.gov for potentially relevant randomized controlled trials comparing SILA and CTLA from January 1992 to August 2013. The electronic search strategy included the following terms: single access OR single incision OR single port OR single trocar OR single site OR one access OR one incision OR one port OR one trocar AND appendectomy AND laparoscopy. References within the articles were also analyzed to search for relevant studies. All PRISMA steps were used, including flowchart (File S1) and checklist (File S2). Inclusion and exclusion criteria The goal of this meta-analysis was to compare the surgical procedures and outcomes of SILA and CTLA. The inclusion criteria for the studies were as follows: . written in English; . compared SILA and CTLA; . randomized controlled trial; . reported at least one outcome; . clearly documented the procedure. If an overlap existed between two studies, the higher quality study was selected. The articles were excluded if they did not fulfill any of the criteria above. Subgroup analysis The following two subgroups were evaluated: children and adults. Data extraction and quality assessment Once eligible studies had been identified, the data extraction and critical appraisal were performed independently by two authors. Any disagreement was discussed and resolved by consensus. The details
included patient characteristics, outcome, postoperative recovery, morbidity, mortality, and wound healing. Patient characteristics included age, sex, body mass index (BMI), and leukocyte count. Operative outcome was analyzed based on operative time, conversion to open procedure, drain insertion and reoperation. Postoperative recovery such as VAS scores, hospitalization, return to full activity, resumption of diet and cosmetic satisfaction were also reviewed. Furthermore, other data including morbidity, incidence of complications, wound infections, and development of ileus and abscesses were examined. In case of missing or unclear information, we contacted the authors of the original studies. The quality of all studies was evaluated using Jadad’s scoring system (7). According to the Kjaergard recommendation, low-quality studies were defined by a score 3 were classified as high quality (8).
Statistical analysis All statistical analyses were carried out with Rev Man 5.1. Continuous data (e.g., operative time and hospitalization) were analyzed using weight difference mean (WMD) or standard mean difference (SMD) with 95% confidence interval (CI). Dichotomous data (e. g., postoperative complications) were analyzed using the odds ratio (OR) and a fixed-effects model. A random-effects model was used if there was significant heterogeneity. Heterogeneity was evaluated with a chisquared test, and p < 0.1 was considered significant. A p value of < 0.05 indicated statistical significance. Risk of bias was evaluated using a funnel plot.
Results Results of the search The literature search strategy and trial selection are shown in the PRISMA flow chart (Figure 1) according to the PRISMA guidelines. Through the electronic database search, we identified 1315 references, 315 from Pubmed, 352 from Web Science, and 648 from ScienceDirect. No references were identified by scanning the reference lists of the identified randomized trials and ClinicalTrials.gov. In total, seven RCTs (9–15) were included in the meta-analysis, of which two were related to children. All of these RCTs were published after 2011 and comprised 1170 patients (586 SILA and 584 CTLA cases). The sample size of the trials ranged from 50 to 360. All pooled RCTs were high-quality trials classified by the modified Jadad scale. The main characteristics of the seven included RCTs
Identification
Single-incision vs. conventional three-port appendectomy
Records identified through database searching (n = 1315)
3
Additional records identified through other sources (n = 0)
Screening
Records excluded (n = 660 ) Irrelevant to PG&PJ (n = 389) Nonrandomized (n = 171) Review (n = 76) Meta-analysis (n = 9) Letters to the editor (n = 7) Non-English (n = 8)
Eligibility
Records screened (n = 672)
Full-text articles assessed for eligibility (n = 12 )
Full-text articles excluded, with reasons (n = 5) Not real RCTs (n = 3) Duplication data (n = 1) Incomplete information on outcomes (n = 1)
Studies included in qualitative synthesis (n = 7 )
Included
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Records after duplicates removed (n = 672)
Studies included in quantitative synthesis (meta-analysis) (n = 7 )
Figure 1. PRISMA flow chart of the meta-analysis.
and the different surgical methods used for singleincision laparoscopy are shown in Tables I and II Risk of publication bias. A funnel plot analysis (Figure 2) was applied to evaluate the possibility of a publication bias, and no significance was revealed.
Meta-analysis results Patient characteristics. Table I presents the demographic data of the seven RCTs included in this
meta-analysis. There was no statistical significance in the demographic characteristics, including age, gender, body mass index and leukocyte count.
Operative outcome Operative time. Operative time was reported in all these studies. Our meta-analysis indicated that operative time was significantly longer in SILA than in CTLA (random-effects model, WMD, 6.67; 95% CI, 3.11-10.23; p = 0.0002; Figure 3), with evidence
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Table I. Methods for single-incision laparoscopic appendectomy.
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Study
Device
Umbilicus
Mesoappendix
Appendicular stump
Specimen delivery
St Peter
Three access ports through the same umbilical incision
1-2cm
Individual surgeon’s technique
Individual surgeon’s technique
Directly
Teoh et al
Two 5-mm ports and one 10-mm port introduced through a single incision
13-mm
Ultrasonic dissector (Sonosury, Olympus surgical, Japan)
Polydioxanone suture loop
Plastic bag
Lee et al
Octoport (Dalim, Seoul, Korea)
15-mm
Ultrasonic coagulating shears (Ethicon EndoSurgery Inc, Cincinnati, OH, USA)
Endoloop
Endobag
Frutos et al
SILS port (Covidien, Mansfield, MA, USA)
20-mm
Articulated endoscopic scissors
Endoloop
Retrieval bag (Endocatch; Covidien)
Kye et al
Surgical glove with three 5-mm trocars connected to the double-ringed wound retractor (Applied Medical, Rancho Santa Margarita, CA, USA)
20-mm
Ultrasound-activated scissors
Endoloop
Diaposable bag
Perez et al
Three access ports though the same umbilical incision
-
stapler
stapler
Endobag (Covidien, Mansfield, MA, USA)
Sozutek et al
SILS port (Covidien, Mansfield, MA, USA)
20-mm
Vessel sealing shear (Enseal, Ethicon)
2/0 polypropylene suture
Endobag
of significant heterogeneity (I2 = 83%; p < 0.0001). Five comparative (10–13,15) trials reported the operative time for adults. The pooled results showed that SILA requires more time than CTLA for adults (WMD, 5.38; 95% CI, 2.94-7.83; p < 0.0001; Figure 3). There was no statistical heterogeneity among these five studies (I2 = 0%; p = 0.5).
Conversion rate. Five studies (10,12–15) reported conversion rates for appendectomies. Nine (3.1%) SILA procedures and four (1.4%) CTLA procedures were converted to open appendectomies. There was no significant difference in the conversion rate between these two groups (OR, 2.32; 95% CI, 0.70-7.71; p = 0.17). The I2 was 0%, which means no statistical heterogeneity.
Table II. Demographics of patients with the seven included studies. No. of patients Author (Year)
Age (y)
Jadad grade SILA CTLA SILA
Sex M/F
CTLA
SILA
CTLA SILA
11.1 ± 3.3
11:9
23:22
St Peter et al (2011)
6
180
180
11.1 ± 3.5
Teoh et al (2012)
6
98
97
39.19 ± 15.55 40.65 ± 15.68
Lee et al (2013)
4
116
113
28.4 ± 15.4
Frutos et al (2013)
5
91
93
28.04 ± 11.03 31.02 ± 12.41
Kye et al (2013)
4
51
51
27.55 ± 12.40 29.20 ± 13.98
Perez et al (2013)
6
25
25
8.7 ± 0.6
8.9 ± 0.6
2:3
Sozutek er al (2013)
4
25
25
30.6 ± 12.4
30 ± 11
12:13 7:18
Leukocyte count (1000 cell/mm3)
BMI (Kg/m2) CTLA
SILA
CTLA
19.4 ± 4.9
19.6 ± 4.5
14.6 ± 5.4 14.6 ± 5.2
21.4 ± 3.2
22.7 ± 4.4
12.0432 ± 3.8933
12.6665 ± 4.5538
11.26 ± 3.89
12.93 ± 4.05
29:20 59:38
28.5 ± 17.2 16:13 68:45 46:45 51:42
23.84 ± 3.98 24.02 ± 3.84 22.03 ± 4.07 21.97 ± 3.49
3:2 23.2 ± 3.79
23.1 ± 2.58
Single-incision vs. conventional three-port appendectomy 0
SE(log[OR])
Postoperative recovery Hospitalization. Hospitalization was reported in all studies. However, two studies (11,14) were excluded because of missing information regarding standard deviation. The hospital stay was comparable between the two groups (WMD, 0.03; 95% CI, -1.18-1.24; p = 0.96). It did not have significant heterogeneity (I2 = 29%; p = 0.23).
0.5
1
1.5
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5
2 0.01
OR 0.1
1
10
100
Subgroups 1 adults 2 children
Figure 2. Funnel plots of total postoperative wound infection. The dashed line represents 95% CI.
Drain insertion. Two studies (10,11) reported drain insertion following SILA or CTLA. There was no significant difference in the rate of drain insertion between these two groups (OR, 0.68; 95% CI, 0.36-1.29; p = 0.24). There was no evidence of heterogeneity between these two studies (I2 = 0%; p = 0.76). Reoperation. Reoperation was compared in three studies (11,12,15). Two patients underwent reoperation in the CTLA group, one for appendiceal stump leakage (15), the other for bleeding of epigastric vessels (12). None of the patients required reoperation in the SILA group. In conclusion, there was no significant difference between these two groups (OR, 0.33; 95% CI, 0.03-3.19; p = 0.34). No heterogeneity was found (I2 = 0%; p = 0.98). SILA Study or subgroup Mean 2.1.11 adults Frutos 2013 Kye 2013 Lee 2013 Sozutek 2013 Teoh 2012 Subtotal (95% CI)
Return to normal activity. Three studies (9,10,13) reported the time required for patients to return to normal activity. Pooling the results, there was significant difference in the time required to return to normal activity between the two groups (WMD, -0.69; 95% CI, -1.11–0.26; p = 0.001; Figure 4), and there was no significant heterogeneity among these three studies (I2 = 0%; p = 0.64). Resumption of normal diet. Three studies (9,10,15) reported the time required for resumption of a normal diet. Our meta-analysis showed WMD of -0.04 days (95% CI, -0.34-0.27; p = 0.80) in favor of SILA patients. However, no significant difference and no heterogeneity were discovered. (I2 = 13%; p = 0.31) Postoperative pain. Six studies reported on postoperative pain; however, only three of them (12,13,15) provided sufficient data to describe postoperative pain scores by using VAS on the first day after surgery. A slight difference was reported in these studies without any statistical significance (random-effects model, WMD, -0.57; 95% CI, -1.16-0.01; p = 0.05).
CTLA SD Total Mean
38.13 13.49 37 15.46 43.8 21.3 32.6 9.9 63 27.2
SD
91 32.12 12.44 51 38.45 15.26 116 35.8 18.9 25 29.5 6.8 98 60.2 31.7 330
Total Weight
Mean difference IV, Random, 95% CI
93 51 113 25 97 328
6.01 [2.26, 9.76] -1.45 [-7.41, 4.51] 8.00 [2.79, 13.21] 3.10 [-1.61, 7.81] 2.80 [-5.49, 11.09] 5.38 [2.94, 7.83]
17.9% 0.0% 15.1% 16.0% 10.1% 59.1%
Mean difference IV, Random, 95% CI
Heterogeneity: Tau2 = 0.00; Chi2 = 2.35, df = 3 (p = 0.50); I2 = 0% Test for overall effect: Z = 4.32 (p < 0.0001) 2.1.2 2 children Perez 2013 2.5 21.2% 12.00 [10.25, 13.75] 25 25 34.8 3.7 46.8 5.40 [2.69, 8.11] 19.7% 35.2 14.5 180 29.8 11.6 180 St Peter 2011 205 40.9% 205 Subtotal (95% CI) 8.78 [2.32, 15.25] Heterogeneity: Tau2 = 20.42; Chi2 = 16.05, df = 1 (p < 0.0001); I2 = 94% Test for overall effect: Z = 2.66 (p = 0.008) 535 533 100.0% Total (95% CI) Heterogeneity: Tau2 = 14.79; Chi2 = 28.73, df = 5 (p < 0.0001); I2 = 83% Test for overall effect: Z = 3.67 (p = 0.002) Test for subgroup differences: Chi2 = 0.93. df = 1 (p = 0.34). I2 = 0%
Figure 3. Forest plot for operative time in SILA vs CTLA group
6.67 [3.11, 10.23] –20
–10
Favours experimental
0
10
20
Favours control
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J. -M. Chen et al. SILA CTLA Mean difference Study or subgroup Mean SD Total Mean SD Total Weight IV, Fixed, 95% CI 3.3.11 adults 3.22 1.04 51 3.94 1.43 51 Kye 2013 75.4% -0.72 [-1.21, -0.23] 6.17 4.21 98 6.38 4.1 97 13.1 % -0.21 [-1.38, 0.96] Teoh 2012 148 88.5% -0.64 [-1.09, -0.20] 149 Subtotal (95% CI) Heterogeneity: Chi2 = 0.63, df = 1 (p = 0.43); I2 = 0% Test for overall effect: Z = 2.82 (p = 0.005)
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3.3.2 2 children 7.5 5.8 180 8.5 St Peter 2011 180 Subtotal (95% CI) Heterogeneity: Not applicable Test for overall effect: Z = 1.58 (p = 0.11)
6.2
180 180
Mean difference IV, Fixed, 95% CI
11.5% -1.00 [-2.24, 0.24] 11.5% -1.00 [-2.24, 0.24]
Total (95% CI) 328 100.0% -0.69 [-1.11, -0.26] 329 Heterogeneity: Chi2 = 0.90, df = 2 (p = 0.64); I2 = 0% -1 0 -2 1 2 Test for overall effect: Z = 3.19 (p = 0.001) Test for subgroup differences: Chi2 = 0.28. df = 1 (p = 0.60). I2 = 0% Favours experimental Favours control
Figure 4. Forest plot for return to normal activity in SILA vs CTLA group
However, significant heterogeneity was found among these studies (I2 = 74%; p = 0.02). Cosmetic satisfaction. The cosmetic score was reported in three studies (10,11,15); however, one study (11) was excluded because it did not provide information regarding standard deviation. The cosmetic outcome was significantly better in the SILA group than in the CTLA group (SMD, 0.58; 95% CI, 0.32-0.83; p < 0.0001; Figure 5). There was no significant heterogeneity (I2 = 0%; p = 0.49). Postoperative morbidity and mortality Mortality. No mortality was reported in either group. Postoperative morbidity. All trials provided specific information about all complications. There was no heterogeneity among the trials (I2 = 0%; p = 0.90). In the fixed-effects model (OR, 1.15; 95% CI, 0.74-1.80; p = 0.53; Figure 6), the risk of developing complications was statistically similar in both groups. There was no significant difference in the incidence of postoperative wound infections (OR, 0.99; 95% CI, 0.54-1.79; p = 0.96), ileus (OR, 0.81; 95% CI, 0.23-2.84; p = 0.74) and abscess formation (OR,
1.53; 95% CI, 0.60-3.89; p = 0.37). There was no significant heterogeneity for wound infections or the development of ileus and abscess (I2 = 0%; p > 0.1
Discussion This meta-analysis of seven RCTs provided pooled data comparing SILA and CTLA. The pooled results showed that the safety and morbidity of SILA is statistically similar to that of CTLA while having significantly higher cosmetic scores and earlier return to normal activity. Less pain, higher cosmetic scores, earlier recovery and a lower complication rate are the major advantages of laparoscopic surgery over open surgery (16– 19). Our pooled analysis of postoperative abdominal pain evaluation demonstrated that the VAS score was insignificantly lower in SILA within 24 h after the operation. Teoh (10) concluded that significantly worse postoperative pain was experienced in SILA after activation. Instead, Frutos (12) and Kye (13) reported that there is a significant reduction in postoperative pain in SILA compared to that in CTLA on the first postoperative day (2.76 ± 1.64 vs 3.78 ± 1.76; p < 0.001 and 3.22 ± 1.22 vs 3.90 ± 1.46; p = 0.012, respectively). This difference may be related to the larger size of the port that penetrates the skin and
SILA CTLA Std.Mean difference Study or subgroup Mean SD Total Mean SD Total Weight IV, Random, 95% CI 82.5 20.17 25 73.43 24.09 25 20.8% 0.40 [-0.16,0.96] Sozutek 2013 7.2 0.8 98 6.7 Teoh 2012 0.8 97 79.2% 0.62 [0.33,0.96] 122 100.0% Total (95% CI) 123 Heterogeneity: Chi2 = 0.47, df = 1 (p = 0.049); I2 = 0% Test for overall effect: Z = 4.42 (p < 0.0001)
Figure 5. Forest plot for cosmetic satisfaction in SILA vs CTLA group
Std.Mean difference IV, Fixed, 95% CI
0.58 [0.32, 0.83] –0.5 –0.25 0 0.25 0.5 Favours experimental Favours control
Single-incision vs. conventional three-port appendectomy
Study or subgroup
CTLA SILA Events Total Events Total Weight
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4.1.11 adults 93 4 Frutos 2013 5 91 51 2 51 2 Kye 2013 20 113 116 17 Lee 2013 1 25 25 1 Sozutek 2013 97 98 9 14 Teoh 2012 379 Subtotal (95% CI) 381 Total events 39 36 Heterogeneity: Chi2 = 1.60, df = 4 (P = 0.81); I2 = 0% Test for overall effect: Z = 0.31 (P = 0.076) 4.1.2 2 children Perez 2013 1 25 25 0 St Peter 2011 180 6 4 180 205 205 Subtotal (95% CI) 4 7 Total events Heterogeneity: Chi2 = 0.16, df = 1 (p = 0.69); I2 = 0% Test for overall effect: Z = 0.87 (p = 0.38)
Odds ratio M-H, Fixed, 95% CI
10.4% 5.3% 48.0% 2.7% 21.5% 88.0%
1.29 [0.34, 4.98] 1.00 [0.14, 7.39] 0.80 [0.39, 1.62] 1.00 [0.06, 16.93] 1.63 [0.06, 3.97] 1.08 [0.67, 1.75]
1.3% 10.7% 12.0%
3.12 [0.12, 80.39] 1.52 [0.42, 5.47] 1.69 [0.52, 5.53]
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Odds ratio M-H, Fixed, 95% CI
584 100.0% Total (95% CI) 586 1.15 [0.74, 1.80] 46 Total events 40 Heterogeneity: Chi2 = 2.22, df = 6 (p = 0.90); I2 = 0% 10 100 0.01 1 0.1 Test for overall effect: Z = 0.62 (p = 0.53) Favours experimental Favours control 2 2 Test for subgroup differences: Chi = 0.47. df = 1 (p = 0.49). I = 0%
Figure 6. Forest plot for total complications in SILA vs CTLA group
umbilical fascia and therefore offsets the advantage of requiring a reduced number of trochars (20). Therefore, further technical research is required to reduce the port site access while allowing surgeons to perform the procedure comfortably. Previous meta-analyses have demonstrated that a significantly higher cosmetic satisfaction was shown in single-incision laparoscopic cholecystectomies than in conventional cholecystectomies (21,22). Similarly, our meta-analysis showed that cosmetic satisfaction was significantly higher in SILA than in CTLA. Although it was statistically significant, the difference should be interpreted with caution. Only two trials reported this result. In these two studies, the patients were only given the opportunity to rate the cosmetic benefit of their own abdominal scars without making a comparison between the potential cosmetic outcomes. Their postoperative cosmetic satisfaction score may have been different if they had reviewed other cosmetic outcomes. Moreover, the scales used to assess the appearance of the wound varied across the studies, and the satisfaction must be verified through longterm follow-up as it could depend upon the timing of the survey (23). Further RCTs with long follow-up periods and standard scar assessment are required to confirm the cosmetic benefits of SILA. With the development of minimally invasive surgery and laparoscopic techniques, postoperative recovery after laparoscopic appendectomy is faster than after open appendectomy (16,24). The results from three RCTs included in this meta-analysis
showed that SILA leads to faster recovery. However, the length of hospital stay and the time to resumption of normal diet were similar in our results. Therefore, further randomized trials should be performed to assess the true impact of SILA on postoperative recovery. SILA has higher technical requirements than CTLA, which may be associated with more postoperative complications, a higher reoperation rate and a longer operative time (25,26). Regretfully, our metaanalysis failed to find significant differences between the SILA and CTLA groups regarding postoperative complication and reoperation rates. The complications from laparoscopic appendectomies were rare and the time of the follow-up was insufficient in most of these studies. Therefore, further randomized trials with a larger patient population and long-term follow-up are required to measure the rate of complications accurately. In the SILA group, the reoperation rate was zero; in the CTLA group one patient required reoperation for bleeding of the surgical wound from the trocar in the left iliac fossa and ligation of the left epigastric vessels, and one patient required reoperation for appendiceal stump leakage. Nevertheless, the difference in postoperative complications and reoperation rates was not significant, and the safety of SILA and CTLA is quite similar. Unlike the previous meta-analysis of nonRCTs, our study demonstrated that the operative time for SILA was significantly longer than that for CTLA (p < 0.0001). In addition to the technical difficulty,
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J. -M. Chen et al.
the steep learning curve may contribute to the difference in the mean operative time. In uncomplicated appendicitis or appendixes with normal characteristics, the operative time was similar or even shorter in SILA. However, in complicated surgeries, such as cases with a retrocecal appendix or severe adhesions, the CTLA procedure allows the dissection and mobilization to be performed more expeditiously without compromising operative safety. Technical difficulty can also be surmised from additional port sites and instruments outside the umbilicus. According to the study by Liao (27), an operative duration equivalent to that of the CTLA method could be achieved after 30 cases. Lee (28) reported that the operative time tended to shorten when the surgeon gained more experience and accumulated more cases. This may mean that it is the surgical experience and not the technique itself that causes the longer operative time. There are several limitations to the present review. Although no detectable publication bias was found on funnel plotting, the number of included RCTs was small and the sample size of the two RCTs was insufficient, which may bias the results. In addition, there was significant heterogeneity among the studies in terms of several outcomes, including pain score and operative time, which was an important outcome variable in our pooled analysis. Heterogeneity in pain score may be caused by variations in the postoperative pain reduction management, the severity of appendicitis and surgical injury. Definitions of operative time varied or were not mentioned, which could cause heterogeneity. Moreover, none of the studies described long-term postoperative mortality or morbidity, which are crucial in evaluating the curative effects of SILA and CTLA. Despite these limitations, we believe SILA is comparable to CTLA in selected patients and represents a possible alternative to CTLA, with better cosmetic satisfaction and earlier return to normal activity, but longer operative time. Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
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