World J Surg DOI 10.1007/s00268-014-2535-x
Systematic Review and Meta-Analysis of Randomized Controlled Trials Comparing Single Incision versus Conventional Laparoscopic Appendectomy Michael Clerveus • Antonio Morandeira-Rivas • Carlos Moreno-Sanz • Maria Luz Herrero-Bogajo • Joaquin Salvelio Picazo-Yeste • Gloria Tadeo-Ruiz
Ó Socie´te´ Internationale de Chirurgie 2014
Abstract Background Single incision laparoscopic appendectomy (SILA) has been proposed as an alternative to conventional laparoscopic appendectomy (CLA). Objective The aim of this study was to evaluate the safety and efficacy of SILA when compared with CLA through a systematic review. Methods We performed an electronic search of EMBASE, PubMed, MEDLINE, and Cochrane Central Register of Controlled Trials. Randomized controlled trials (RCTs) that compared SILA with CLA were included. Results Six RCTs met eligibility criteria, which included a total of 800 patients, 401 in the SILA group and 399 in the CLA group. There were no significant differences in terms of overall complications (odds ratio [OR] 0.93; 95 % confidence interval [CI] 0.59–1.47; p = 0.77). SILA had a higher technical failure rate (OR 3.30; 95 % CI 1.26–8.65; p = 0.01) and required a longer operative time (mean difference [MD] 4.67; 95 % CI 1.76–7.57; p = 0.002). SILA was associated with better cosmetic results (standardized MD –0.4; 95 % CI –0.64 to –0.16; p = 0.001) and earlier return to normal activity (MD –0.64; 95 % CI –1.09 to –0.20; p = 0.005), although these advantages should be taken with caution due to the small number of studies reporting these two items and the short follow-up in the evaluation of cosmetic results. There were no significant differences in terms of postoperative pain or length of hospital stay between groups.
M. Clerveus (&) A. Morandeira-Rivas C. Moreno-Sanz M. L. Herrero-Bogajo J. S. Picazo-Yeste G. Tadeo-Ruiz Department of Surgery, ‘‘La Mancha Centro’’ General Hospital, Avd. de la Constitucio´n n8 3. 13600, Alca´zar de San Juan, Ciudad Real, Spain e-mail: [email protected]
Conclusions SILA is comparable to CLA in selected patients, although it is associated with a higher technical failure rate and longer operative time. Further randomized trials are needed to determine if SILA really offers benefits over CLA.
Introduction Acute appendicitis is one of the most common causes of gastrointestinal emergencies [1], appendectomy still being the treatment of choice [2]. Although conventional laparoscopic appendectomy (CLA) is not yet unanimously considered the gold standard over the open approach [3], it admittedly contributes to this field the advantages of minimally invasive surgery such as better cosmetic results, less postoperative pain, and shorter recovery time [4, 5]. In order to enhance all those benefits, single incision laparoscopic appendectomy (SILA) has been proposed as an alternative to CLA. The first SILA was reported in 1992 [6] and, since then, several studies have suggested that its results may be at least similar to those of CLA [7–10]. Recently, three reviews have been published on this topic [11–13]. Gill et al. [11], in a systematic review of non-randomized trials, suggested that SILA is comparable to CLA in terms of operative time, length of hospital stay, pain score, complications, and failure of the surgical technique. Rehman et al. [13] reviewed 44 case series studies and one randomized controlled trial (RCT), with a total of 2,806 SILA procedures reporting an overall complication rate of 4.13 %, a mean operating time of 41.3 min, and a mean hospital stay of 2.79 days. Finally, Pisanu et al. [12] identified two RCTs and 11 observational studies comparing SILA with CLA and also found no differences between the two approaches.
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The lack of strong recommendations on this topic and the availability of new RCTs motivated us to conduct this systematic review and meta-analysis comparing the results of both techniques.
Evaluating the risk of bias Two reviewers independently analyzed the methodological quality of the articles reviewed using the tools for evaluating risk of bias in the Cochrane Handbook for Systematic Reviews of Interventions [15].
Materials and methods This review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement [14]. Literature search We took into account all studies published between 1983 and April 2013, with no limitations on the language of publication. A comprehensive search of the main electronic databases was performed: EMBASE, PubMed, MEDLINE, Cochrane Central Register of Controlled Trials (CCTR), and www.clinical-trials.gov. In our searches, the medical subject heading (MeSH) ‘Appendectomy’, the word roots ‘endoscop*’, ‘laparoscop*’, and ‘laparoendoscop*’, and the keywords ‘single incision’, ‘single site’, ‘single port’, ‘single access’, ‘single trocar’, ‘one trocar’, ‘one port’, ‘one wound’, ‘transumbilical’, ‘embryonic’, and ‘embryologic’ were used. In addition, we reviewed the summaries of the 2006–2012 presentations at the European Association for Endoscopic Surgery (EAES), American Society of Endoscopic Surgery, and Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). We also performed a non-systematic search on Google Scholar, reviewed the references of selected studies, and contacted the authors of included studies when necessary.
Statistical analysis Statistical analyses were performed using Review Manager v.5. The random effect model was used for the meta-analysis given the heterogeneity of the single-port devices and techniques employed, the different levels of experience of the surgeons in this new laparoscopic approach, and the inclusion of patients with complicated appendicitis in some studies. For continuous variables, we calculated mean differences (MDs) or standardized mean differences (SMDs) with 95 % confidence intervals (CIs). For dichotomous variables, we used odds ratios (ORs). A p value of \0.05 was considered to be statistically significant. When the results of the studies were expressed in terms of median (range), or only mean values were reported, we contacted the authors or estimated the mean and standard deviation using the methodology proposed by Hozo et al. [16] and the recommendations in the Cochrane Handbook [15]. The statistical heterogeneity between studies was evaluated using Cochrane’s Q-statistic, considering homogeneity to be absent when the significance level was below 0.20. We used the I2 statistic to estimate the magnitude of this heterogeneity, considering the heterogeneity to be significant when exceeding 50 %.
Study selection
Results
This review included RCTs that compared SILA with CLA for suspected acute appendicitis. Non-randomized studies, studies including only pediatric patients, and those that failed to adequately report the incidence and types of complications were excluded.
Search result
Data extraction The results from each study were transferred to our dataset by two independent reviewers, and a third reviewer collaborated for a final decision in the case of any discrepancies. The primary objective of our analysis was to evaluate the incidence of complications during surgery and in the postoperative period. Secondary objectives included an analysis of failure of surgical technique, duration of surgery, length of hospital stay, postoperative pain, cosmetic results, and return to normal daily activities.
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A total of 640 studies were identified by the electronic searches. After excluding duplicated articles and those that did not comply with the inclusion criteria, we selected a total of 36 studies that were reviewed in depth. The full text of these studies was retrieved and 30 of them were excluded: 24 non-randomized comparative studies, two quasi-randomized trials [17, 18], one study protocol [19], one study containing duplicated data [20], and two publications of pediatric patients [21, 22], one of them with transumbilical extracorporeal appendectomy [22]. Six studies [23–28] were finally included for qualitative and quantitative synthesis, with a total of 800 patients, 401 (51 %) in the SILA group and 399 (49 %) in the CLA group. A flow diagram of the literature search is shown in Fig. 1.
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used to generate the random sequence and sealed opaque envelopes were used for allocation concealment. In only one study [28], double blinding involving both the patients and the assessors of outcomes was described, using identical dressings in both groups following surgery. One study [23] reported the blinding of researchers. In three studies [23, 25, 27], no losses were recorded or the analysis was based on an intention to treat. Three studies [25, 26, 28] presented results with post-randomization drop-out, which implies a risk of attrition bias. The results from the study of the quality analysis and bias evaluation can be seen in Fig. 2. Study and patient characteristics
Fig. 1 Flow diagram of selection of studies for meta-analysis. RCT randomized controlled trial, SILA single incision laparoscopic appendectomy
Selected studies were conducted in Europe and Asia and published between 2010 and 2013. Three studies [23, 25, 26] described surgeons with extensive experience in CLA and advanced laparoscopic surgery. Additionally, two RCTs [25, 28] reported that surgeons had pre-trial experience of more than ten SILA procedures. There was only one multicenter trial [28]. The sample size ranged from 40 to 229 patients, and the studies included patients aged from 12 to 80 years. Four trials [23, 24, 26, 28] excluded patients in whom complicated appendicitis was suspected. However, the proportion of patients with gangrenous or perforated appendicitis was similar across the studies, with an overall percentage of 17.8 % in the SILA group and 20.6 % in the CLA group. Characteristics of included studies and baseline characteristics of patients are summarized in Tables 1 and 2. Primary outcomes Overall complications
Fig. 2 Risk of bias summary: review author’s judgments about each risk of bias item for each included study. ? low risk of bias, ? unclear risk of bias, – high risk of bias
All six RCTs reported postoperative complications (Table 3). The overall morbidity rate was similar in both groups (SILA 10.5 %, CLA 11 %), and there were no significant differences in the combined analysis (OR 0.93; 95 % CI 0.59–1.47; p = 0.77). There was no significant heterogeneity among studies (v2 = 0.44, 5 d.f., I2 = 0 %) (Fig. 3). Publication bias could not be explored using funnel plots due to the small number of studies included in this review. Two patients in the CLA group required reoperation, one for bleeding of a trocar wound [23] and another for appendiceal stump leakage [25]. One patient in the SILA group developed an incisional hernia [23]. Wound infection, intra-abdominal infection, and prolonged postoperative ileus were the most common complications.
Assessment of methodological quality and risk of bias Wound infection The random-sequence generation was correctly described in five studies [23–25, 27, 28] and the allocation concealment in only three [23, 25, 28]. In general, computer programs were
There were no significant differences in wound infection between the two approaches (SILA 4 %, CLA 5 %). The
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World J Surg Table 1 Characteristics of included studies Study, y of publication, country
Inclusion criteria
Exclusion criteria
Frutos et al. [23], Spain
Clinical and radiological evidence of AA, age [ 11 y
Cirrhosis or coagulopathy, CA, septic shock, contraindications for general anesthesia or laparoscopic surgery, pregnancy
Kye et al. [24], South Korea
Clinical and radiological evidence of AA, \ ASA IV
Lee et al. [25], Korea Rep.
Patients (n)
SILA device
Instruments
SILA: 91CLA: 93
SILSÒ
Appendicitis with palpable mass, bleeding tendency, pregnant
SILA: 51CLA: 51
Clinical and radiological evidence of AA, age 5–80 y
Pregnant or lactating, uncontrolled undercurrent infections, concomitant disease, previous cytotoxic CTX, RTX or immunotherapy, cardiac disease
Park et al. [26], Korea Rep.
Clinical and radiological evidence of AA
Sozutek et al. [27], Turkey
Clinical and radiological evidence of AA
Teoh et al. [28], Hong Kong
Clinical evidence of AA, age 18–75 y
Technique
Follow-up
Mesoappendix
Appendix base
Articulating/ conventional
Endoloop
Endostapler
NR
AlexisÒ
Conventional
US
Endoloop
20.8 ± 5.1 wks
SILA: 116CLA: 113
OctoportÒ
Conventional
US
Endoloop
14 days
Cirrhosis or coagulopathy, CA, septic shock, pregnancy, previous laparotomy, cardiac or pulmonary disease ASA IV–V; \ 18 y old, pregnancy, anticoagulant therapy, intraoperative negative
SILA: 20CLA: 20
AlexisÒ
Articulating/ conventional
US or endoclips
Endoloop
NR
SILA: 25CLA: 25
SILSÒ
Conventional
EnsealÒ
Suture
1 month
Symptoms [ 5 days and/ or palpable mass, cirrhosis and coagulation disorders, generalized peritonitis, shock, previous abdominal surgery, ascites, malignancy, contraindication, no informed consent, pregnancy
SILA: 98CLA: 97
Multiport
Articulating/ conventional
US
Suture
1y
AA acute appendicitis, ASA American Society of Anesthesiologists, CA complicated appendicitis, CLA conventional laparoscopic appendectomy, CTX chemotherapy, NR not reported, Rep republic, RTX radiotherapy, SILA single incision laparoscopic appendectomy, SILS single incision laparoscopic surgery, US ultrasound, wks weeks
pooled OR was 0.79 (95 % CI 0.39–1.58; p = 0.50) without significant heterogeneity among studies (v2 = 2.96, 4 d.f., I2 = 0 %) (Fig. 4a).
0.70–5.04), but this difference was not statistically significant (p = 0.21). There was no evidence of statistical heterogeneity among studies (v2 = 0.82, 3 d.f., I2 = 0 %) (Fig. 4b).
Intra-abdominal infection Postoperative ileus Four studies [24–26, 28] reported intra-abdominal infections. There was an increased number of abdominal abscesses in the SILA group (OR 1.88; 95 % CI
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Five trials [24–28] reported postoperative ileus. There was neither significant difference between the two groups nor
World J Surg Table 2 Baseline characteristics Study
Age (y)
Sex (F/M)
BMI (kg/m2)
Complicated appendicitis (%) CLA
SILA
CLA
P
SILA
CLA
P
SILA
CLA
P
SILA
Frutos et al. [23]
28.04 ± 11.03
31.02 ± 12.41
0.08
49/ 42
46/ 47
0.45
23.84 ± 3.98
24.02 ± 3.84
0.75
14/91 (15.4)
12/93 (12.9)
Kye et al. [24] Lee et al. [25]
27.55 ± 12.40
29.20 ± 13.98
0.531
NR
NR
NR
22.03 ± 4.07
21.97 ± 3.49
0.930
7/51 (13.7)
28.04 ± 15.4
28.5 ± 17.2
0.298
52/ 64
45/ 68
0.444
21.4 ± 3.2
22.7 ± 4.4
0.081
9/51 (17.6) 18/116 (15.5)
Park et al. [26]
25 (mean)
27.2 (mean)
0.539
11/9
12/8
0.749
NR
NR
NR
NR
NR
Sozutek et al. [27]
30.6 ± 12.4
30 ± 11
0.777
13/ 12
18/7
0.124
23.2 ± 3.79
23.1 ± 2.58
0.959
4/25 (16)
6/25 (24)
Teoh et al. [28]
39.19 ± 15.55
40.65 ± 15.68
0.515
40/ 58
38/ 59
0.861
NR
NR
NR
23/98 (23.5)
25/97 (25.8)
28/113 (24.8)
Data are expressed as mean ± standard deviation, unless otherwise indicated BMI body mass index, CLA conventional laparoscopic appendectomy, F/M female/male ratio, NR not reported, SILA single incision laparoscopic appendectomy
Secondary outcomes
Table 3 Overall complications Type of complications
Wound seroma or hematoma
Intervention
Operative time
SILA
CLA
3
2
Wound infection
16
20
Intra-abdominal infection
12
6
Bleeding of the trocar wound
0
1
Stump leakage
0
1
Incisional hernia
1
0
Prolonged ileus
4
6
Incoercible vomiting
0
1
Postrenal acute failure
1
0
Acute tubular necrosis
0
1
Pneumonia
0
1
Non-specific colitis Drug side effect
0 2
2 0
Urinary tract infection
1
1
Unspecified
2
2
Total
42 (10.5 %)
44 (11 %)
CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
Operative time was longer in the SILA group in five of the six trials [23, 25–28]. The pooled analysis showed significant difference in favor of the CLA group (MD 4.67 [95 % CI 1.76–7.57; p = 0.002]), although there was evidence of moderate statistical heterogeneity (v2 = 8.13; 5 d.f.; I2 = 39 %) (Fig. 5). A sensitivity analysis excluding studies with unclear or high risk of selection bias decreased I2 to 0 (MD 6.23; 95 % CI 3.37–9.09; p \ 0.0001). Technical failure All the studies reported whether patients in either group required conversion to open surgery or the use of an additional trocar, the latter also being considered a procedure failure. The incidence of technical failure was significantly greater in the SILA group (OR 3.30; 95 % CI 1.26–8.65; p \ 0.01). There was no significant heterogeneity among studies (v2 = 3.29, 5 d.f.; I2 = 0 %) (Fig. 6). Length of hospital stay
significant heterogeneity among studies. The pooled OR was 0.68 (95 % CI 0.20–2.35; p = 0.55) and I2 = 0 % (v2 = 1.26; 3 d.f.) (Fig. 4c).
The length of hospital stay was reported in all the studies. The pooled analysis showed no significant differences between the two approaches (MD –0.04; 95 % CI –0.12 to
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Fig. 3 Forest plot and meta-analysis for overall complications. CI confidence interval, CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
–0.04; p = 0.27). There was no significant heterogeneity among studies (v2 = 2.90, 5 d.f.; I2 = 0 %) (Fig. 7). Postoperative PAIN Postoperative pain was evaluated by means of visual analog scales (VAS) in all studies. Two reported significant difference on pain score in favor of the SILA group during the first 24 h [23, 24]. No differences were found in another two studies [25, 27]. In contrast, Park et al. [26] found better pain control in the CLA group and Teoh et al. [28] described no significant difference in pain score when evaluated at rest but a decrease in this score in the CLA group during coughing and standing. In three studies [25– 27], pain scores were displayed in a graph and it was impossible to extract the raw data. Analgesic consumption was investigated in five trials [24–28], with no statistical differences between the two groups. It was not possible to conduct a combined analysis due to heterogeneity in the route of administration of analgesics. Return to activity Only two [24, 28] RCTs examined the time taken to return to normal activity. The pooled analysis favored the SILA group, with an MD of –0.64 (95 % CI –1.09 to –0.20; p = 0.005). There was no significant heterogeneity between studies (v2 = 0.63, 1 d.f., I2 = 0 %) (Fig. 8). Cosmesis In four trials [25–28], the cosmetic result was evaluated during the first postoperative month, with a higher score among patients who underwent SILA in the four studies. Data amenable for pooling from three studies [26–28] showed an SMD of –0.4 (95 % CI –0.64 to –0.16; p = 0.001; v2 = 1.48, 2 d.f., I2 = 0 %) (Fig. 9).
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Discussion In this systematic review and meta-analysis of the medical literature, we identified and analyzed six RCTs, with a total of 800 patients operated on, to compare results between SILA and CLA [23–28]. Although the SILA technique was first described more than 20 years ago [6], it has only gained substantial interest among the surgical community over the last 4 years, as is shown by the fact that all studies included in our analysis were published after 2010. Given its novelty, we considered the safety of the technique to be the most essential parameter to measure and chose the incidence of complications as our primary endpoint. In this review, the overall morbidity rate in the SILA group was slightly higher than in a previous multicenter registry (10.5 vs. 8.4 %) [29] and a recent review of 2,806 SILA patients (4.1 %) [30]. However, we did not observe statistically significant differences between groups. The most frequently reported surgery-related complications were wound infection, prolonged postoperative ileus, and intra-abdominal infection. Complications associated with the abdominal wall have received a great deal of interest during the development of SILS. At least in theory, the use of a single incision should be correlated with a decrease in wound complications. In contrast, many authors maintain that this approach gives rise to a more severe parietal contusion and a larger umbilical incision that could increase the risk of wound infection and incisional hernia [31, 32]. In our review, we observed no difference between groups in the incidence of seroma, hematoma, or wound infection. However, we must highlight that the follow-up in most studies was too short to assess long-term complications, and the incisional hernia rate might be underestimated. The feasibility and safety of laparoscopic surgery in complicated appendicitis is still debated, since it has been associated with an increased risk of intra-abdominal infections when compared with open appendectomy [4, 33]. In this review, we found an increased incidence of
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Fig. 4 Forest plot and meta-analysis for specific complications. a Wound infection, b intra-abdominal abscess, c ileus. CI confidence interval, CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
Fig. 5 Forest plot and meta-analysis for duration of operation. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
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Fig. 6 Forest plot and meta-analysis for incidence of procedure failure rate. CI confidence interval, CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
Fig. 7 Forest plot and meta-analysis for length of hospital stay. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
Fig. 8 Forest plot and meta-analysis for time to return to normal activity. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
Fig. 9 Forest plot and meta-analysis for cosmetic results. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
intra-abdominal infections in the SILA patients. Although this difference was not statistically significant, it is noteworthy because most studies have excluded patients with suspicion of complicated appendicitis. Single incision laparoscopic surgery is more technically demanding than conventional laparoscopy, and surgeons are less
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experienced with this new access. These facts could lead to increased tissue manipulation and poor peritoneal lavage, which could explain this trend towards higher incidence of intra-abdominal infections in the SILA group. Finally, although other complications such as bleeding from the orifices of the trocars and appendiceal stump
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leakage were only found in the CLA group [23, 25], these and other adverse events (adhesions, chronic postoperative pain, etc.) will rarely be evaluated in RCTs because of the low incidence. In any case, with the available scientific evidence, SILA for complicated appendicitis should not be recommended outside controlled trials, and further studies are still needed to assess the safety of this new access. Failure of the surgical technique in the SILA group was generally low (6 %) and similar to that in other reviews (7.7 %) [30]. In the combined analysis, the conversion rate was significantly higher in the SILA group. These differences could be due in part to the complexity of the SILA technique and the lower overall experience with this technique among surgeons, which could also explain the longer duration of the surgical procedures. Postoperative hospital stays varied among the studies, with an average stay less than 24 h in one study [23] and up to 3 days in others [25, 28], but with no significant differences between the two techniques in the majority of studies. One of the theoretical advantages to reducing the number of incisions is the decrease in postoperative pain. The results from this systematic review are very heterogeneous in this regard, with results on both sides of the noeffect line, making these data inappropriate for performing a meta-analysis. In the evaluation of this variable, the use of different protocols for anesthesia/analgesia hindered the comparison of results between studies. In addition, the absence of blinding of patients and evaluators may also have influenced the results in some studies. The cosmetic result was better rated by SILA group patients, although this should be considered with caution since, in this review, no study evaluated this outcome after the first month post-surgery. As has been previously highlighted [34], cosmesis should be evaluated in the longer term because the initial cosmetic advantage of the single-incision approach may disappear with time evaluation. Moreover, the absence of blinding of outcome assessors in most of the included studies may have also influenced this result. In this review, patients in the SILA group returned to normal activities sooner, but only two studies contributed to this result, so evidence in this regard is weak. Finally, a cost analysis would be of interest in the future to determine whether the cosmetic benefits and early recovery supposedly offered by SILA could offset the higher cost of a more expensive technique with a longer operative time and higher conversion rate. Our review does have certain limitations. The fact that the majority of the studies included data from selected patients might make them unsuitable for extrapolation to patients with complicated appendicitis. Other limitations are the heterogeneity among the different studies in terms
of the types of equipment and specific techniques used in the SILA group, the lower level of experience among surgeons using the single-incision technique as compared with conventional laparoscopy, and the absence of blinding of patients and evaluators in many of the studies. Conclusions Given our results, we can consider SILA to be a feasible option in selected patients in whom uncomplicated appendicitis is expected. However, there is insufficient evidence to recommend its widespread use compared with CLA. SILA is associated with longer surgical times and a higher incidence of failure of the surgical technique. The incidence of complications is similar between the two groups, although there is a clear tendency towards a greater incidence of intra-abdominal infections in the SILA group. This approach could be associated with a better cosmetic result and earlier return to daily activities, although these advantages should be considered with caution due to the small number of studies reporting these outcomes and the short follow-up in the evaluation of cosmetic results. Finally, new studies are needed following the initial period of implementation and learning curve and with a longer follow-up, to analyze the safety of this technique and determine whether it really offers benefits over CLA.
Disclosure
The authors have no conflicts of interest to declare.
References 1. Addiss DG, Shaffer N, Fowler BS et al (1990) The epidemiology of appendicitis and appendectomy in the United States. Am J Epidemiol 132:910–925 2. Wilms IM, de-Hoog DE, de-Visser DC et al (2011) Appendectomy versus antibiotic treatment for acute appendicitis. Cochrane Database Syst Rev 11:CD008359 3. Vettoretto N, Gobbi S, Corradi A et al (2011) Consensus conference on laparoscopic appendectomy: development of guidelines. Colorectal Dis 13:748–754 4. Sauerland S, Jaschinski T, Neugebauer EA (2010) Laparoscopic versus open surgery for suspected appendicitis. Cochrane Database Syst Rev 10:CD001546 5. Tiwari MM, Reynoso JF, Tsang AW et al (2011) Comparison of outcomes of laparoscopic and open appendectomy in management of uncomplicated and complicated appendicitis. Ann Surg 254:927–932 6. Pelosi MA, Pelosi MA III (1992) Laparoscopic appendectomy using a single umbilical puncture (minilaparoscopy). J Reprod Med 37:588–594 7. Vidal O, Valentini M, Ginesta` C et al (2010) Laparoendoscopic single-site surgery appendectomy. Surg Endosc 24:686–691 8. Park J, Kwak H, Kim SG et al (2012) Single-port laparoscopic appendectomy: comparison with conventional laparoscopic appendectomy. J Laparoendosc Adv Surg Tech A 22:142–145
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World J Surg 9. Raakow R, Jacob DA (2011) Initial experience in laparoscopic single-port appendectomy: a pilot study. Dig Surg 28:74–79 10. Kim HO, Yoo CH, Lee SR et al (2012) Pain after laparoscopic appendectomy: a comparison of transumbilical single-port and conventional laparoscopic surgery. J Korean Surg Soc 82:172–178 11. Gill RS, Shi X, Al-Adra DP et al (2012) Single-incision appendectomy is comparable to conventional laparoscopic appendectomy: a systematic review and pooled analysis. Surg Laparosc Endosc Percutan Tech 22:319–327 12. Pisanu A, Porceddu G, Reccia I et al (2013) Meta-analysis of studies comparing single-incision laparoscopic appendectomy and conventional multiport laparoscopic appendectomy. J Surg Res 183:e49–e59 13. Rehman H, Mathews T, Ahmed I (2012) A review of minimally invasive single-port/incision laparoscopic appendectomy. J Laparoendosc Adv Surg Tech A 22:641–646 14. Moher D, Liberati A, Tetzlaff J et al (2010) Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 8:336–341 15. Higgins J, Green S (eds) (2011) Cochrane handbook for systematic reviews of interventions version 5.1. 0 [updated March 2011]. The Cochrane Collaboration 16. Hozo SP, Djulbegovic B, Hozo I (2005) Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol 5:13 17. Kang J, Bae BN, Gwak G et al (2013) Comparative study of a single-incision laparoscopic and a conventional laparoscopic appendectomy for the treatment of acute appendicitis. J Korean Soc Coloproctol 28:304–308 18. Vilallonga R, Barbaros U, Nada A et al (2012) Single-port transumbilical laparoscopic appendectomy: a preliminary multicentric comparative study in 87 patients with acute appendicitis. Minim Invasive Surg 2012:492409 19. Malik M, McCormack K, Krukowski ZH et al (2012) Single port/ incision laparoscopic surgery compared with standard three-port laparoscopic surgery for appendicectomy: a randomised controlled trial. Trials 13:201 20. Knott EM, Gasior AC, Holcomb GW III et al (2012) Impact of body habitus on single-site laparoscopic appendectomy for nonperforated appendicitis: subset analysis from a prospective, randomized trial. J Laparoendosc Adv Surg Tech A 22:404–407 21. Perez EA, Piper H, Burkhalter LS et al (2013) Single-incision laparoscopic surgery in children: a randomized control trial of acute appendicitis. Surg Endosc 27:1367–1371 22. St Peter SD, Adibe OO, Juang D et al (2011) Single incision versus standard 3-port laparoscopic appendectomy: a prospective randomized trial. Ann Surg 254:586–590
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23. Frutos MD, Abrisqueta J, Lujan J et al (2013) Randomized prospective study to compare laparoscopic appendectomy versus umbilical single-incision appendectomy. Ann Surg 257:413–418 24. Kye BH, Lee J, Kim W et al (2013) Comparative study between single-incision and three-port laparoscopic appendectomy: a prospective randomized trial. J Laparoendosc Adv Surg Tech A 23:431–436 25. Lee WS, Choi ST, Lee JN et al (2013) Single-port laparoscopic appendectomy versus conventional laparoscopic appendectomy: a prospective randomized controlled study. Ann Surg 257:214–218 26. Park JH, Hyun KH, Park CH et al (2010) Laparoscopic vs transumbilical single-port laparoscopic appendectomy; results of prospective randomized trial. J Korean Surg Soc 78:213–218 27. Sozutek A, Colak T, Dirlik M et al (2013) 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 23:74–78 28. Teoh AY, Chiu PW, Wong TC et al (2012) A double-blinded randomized controlled trial of laparoendoscopic single-site access versus conventional 3-port appendectomy. Ann Surg 256:909–914 29. Moreno-Sanz C, Morandeira-Rivas A, Morales-Conde S et al (2012) Single incision laparoscopic surgery: analysis of the national register. Cir Esp 90:298–309 30. Rehman H, Ahmed I (2011) Technical approaches to single port/ incision laparoscopic appendicectomy: a literature review. Ann R Coll Surg Engl 93:508–513 31. Alptekin H, Yilmaz H, Acar F et al (2012) Incisional hernia rate may increase after single-port cholecystectomy. J Laparoendosc Adv Surg Tech A 22:731–737 32. Marks JM, Phillips MS, Tacchino R et al (2013) Single-incision laparoscopic cholecystectomy is associated with improved cosmesis scoring at the cost of significantly higher hernia rates: 1-year results of a prospective randomized, multicenter, singleblinded trial of traditional multiport laparoscopic cholecystectomy vs single-incision laparoscopic cholecystectomy. J Am Coll Surg 216:1037–1047 33. Swank HA, Eshuis EJ, van Berge Henegouwen MI et al (2011) Short- and long-term results of open versus laparoscopic appendectomy. World J Surg 35:1221–1226. doi:10.1007/s00268-0111088-5 34. Saad S, Strassel V, Sauerland S (2013) Randomized clinical trial of single-port, minilaparoscopic and conventional laparoscopic cholecystectomy. Br J Surg 100:339–349
Systematic Review and Meta-Analysis of Randomized Controlled Trials Comparing Single Incision versus Conventional Laparoscopic Appendectomy Michael Clerveus • Antonio Morandeira-Rivas • Carlos Moreno-Sanz • Maria Luz Herrero-Bogajo • Joaquin Salvelio Picazo-Yeste • Gloria Tadeo-Ruiz
Ó Socie´te´ Internationale de Chirurgie 2014
Abstract Background Single incision laparoscopic appendectomy (SILA) has been proposed as an alternative to conventional laparoscopic appendectomy (CLA). Objective The aim of this study was to evaluate the safety and efficacy of SILA when compared with CLA through a systematic review. Methods We performed an electronic search of EMBASE, PubMed, MEDLINE, and Cochrane Central Register of Controlled Trials. Randomized controlled trials (RCTs) that compared SILA with CLA were included. Results Six RCTs met eligibility criteria, which included a total of 800 patients, 401 in the SILA group and 399 in the CLA group. There were no significant differences in terms of overall complications (odds ratio [OR] 0.93; 95 % confidence interval [CI] 0.59–1.47; p = 0.77). SILA had a higher technical failure rate (OR 3.30; 95 % CI 1.26–8.65; p = 0.01) and required a longer operative time (mean difference [MD] 4.67; 95 % CI 1.76–7.57; p = 0.002). SILA was associated with better cosmetic results (standardized MD –0.4; 95 % CI –0.64 to –0.16; p = 0.001) and earlier return to normal activity (MD –0.64; 95 % CI –1.09 to –0.20; p = 0.005), although these advantages should be taken with caution due to the small number of studies reporting these two items and the short follow-up in the evaluation of cosmetic results. There were no significant differences in terms of postoperative pain or length of hospital stay between groups.
M. Clerveus (&) A. Morandeira-Rivas C. Moreno-Sanz M. L. Herrero-Bogajo J. S. Picazo-Yeste G. Tadeo-Ruiz Department of Surgery, ‘‘La Mancha Centro’’ General Hospital, Avd. de la Constitucio´n n8 3. 13600, Alca´zar de San Juan, Ciudad Real, Spain e-mail: [email protected]
Conclusions SILA is comparable to CLA in selected patients, although it is associated with a higher technical failure rate and longer operative time. Further randomized trials are needed to determine if SILA really offers benefits over CLA.
Introduction Acute appendicitis is one of the most common causes of gastrointestinal emergencies [1], appendectomy still being the treatment of choice [2]. Although conventional laparoscopic appendectomy (CLA) is not yet unanimously considered the gold standard over the open approach [3], it admittedly contributes to this field the advantages of minimally invasive surgery such as better cosmetic results, less postoperative pain, and shorter recovery time [4, 5]. In order to enhance all those benefits, single incision laparoscopic appendectomy (SILA) has been proposed as an alternative to CLA. The first SILA was reported in 1992 [6] and, since then, several studies have suggested that its results may be at least similar to those of CLA [7–10]. Recently, three reviews have been published on this topic [11–13]. Gill et al. [11], in a systematic review of non-randomized trials, suggested that SILA is comparable to CLA in terms of operative time, length of hospital stay, pain score, complications, and failure of the surgical technique. Rehman et al. [13] reviewed 44 case series studies and one randomized controlled trial (RCT), with a total of 2,806 SILA procedures reporting an overall complication rate of 4.13 %, a mean operating time of 41.3 min, and a mean hospital stay of 2.79 days. Finally, Pisanu et al. [12] identified two RCTs and 11 observational studies comparing SILA with CLA and also found no differences between the two approaches.
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The lack of strong recommendations on this topic and the availability of new RCTs motivated us to conduct this systematic review and meta-analysis comparing the results of both techniques.
Evaluating the risk of bias Two reviewers independently analyzed the methodological quality of the articles reviewed using the tools for evaluating risk of bias in the Cochrane Handbook for Systematic Reviews of Interventions [15].
Materials and methods This review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement [14]. Literature search We took into account all studies published between 1983 and April 2013, with no limitations on the language of publication. A comprehensive search of the main electronic databases was performed: EMBASE, PubMed, MEDLINE, Cochrane Central Register of Controlled Trials (CCTR), and www.clinical-trials.gov. In our searches, the medical subject heading (MeSH) ‘Appendectomy’, the word roots ‘endoscop*’, ‘laparoscop*’, and ‘laparoendoscop*’, and the keywords ‘single incision’, ‘single site’, ‘single port’, ‘single access’, ‘single trocar’, ‘one trocar’, ‘one port’, ‘one wound’, ‘transumbilical’, ‘embryonic’, and ‘embryologic’ were used. In addition, we reviewed the summaries of the 2006–2012 presentations at the European Association for Endoscopic Surgery (EAES), American Society of Endoscopic Surgery, and Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). We also performed a non-systematic search on Google Scholar, reviewed the references of selected studies, and contacted the authors of included studies when necessary.
Statistical analysis Statistical analyses were performed using Review Manager v.5. The random effect model was used for the meta-analysis given the heterogeneity of the single-port devices and techniques employed, the different levels of experience of the surgeons in this new laparoscopic approach, and the inclusion of patients with complicated appendicitis in some studies. For continuous variables, we calculated mean differences (MDs) or standardized mean differences (SMDs) with 95 % confidence intervals (CIs). For dichotomous variables, we used odds ratios (ORs). A p value of \0.05 was considered to be statistically significant. When the results of the studies were expressed in terms of median (range), or only mean values were reported, we contacted the authors or estimated the mean and standard deviation using the methodology proposed by Hozo et al. [16] and the recommendations in the Cochrane Handbook [15]. The statistical heterogeneity between studies was evaluated using Cochrane’s Q-statistic, considering homogeneity to be absent when the significance level was below 0.20. We used the I2 statistic to estimate the magnitude of this heterogeneity, considering the heterogeneity to be significant when exceeding 50 %.
Study selection
Results
This review included RCTs that compared SILA with CLA for suspected acute appendicitis. Non-randomized studies, studies including only pediatric patients, and those that failed to adequately report the incidence and types of complications were excluded.
Search result
Data extraction The results from each study were transferred to our dataset by two independent reviewers, and a third reviewer collaborated for a final decision in the case of any discrepancies. The primary objective of our analysis was to evaluate the incidence of complications during surgery and in the postoperative period. Secondary objectives included an analysis of failure of surgical technique, duration of surgery, length of hospital stay, postoperative pain, cosmetic results, and return to normal daily activities.
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A total of 640 studies were identified by the electronic searches. After excluding duplicated articles and those that did not comply with the inclusion criteria, we selected a total of 36 studies that were reviewed in depth. The full text of these studies was retrieved and 30 of them were excluded: 24 non-randomized comparative studies, two quasi-randomized trials [17, 18], one study protocol [19], one study containing duplicated data [20], and two publications of pediatric patients [21, 22], one of them with transumbilical extracorporeal appendectomy [22]. Six studies [23–28] were finally included for qualitative and quantitative synthesis, with a total of 800 patients, 401 (51 %) in the SILA group and 399 (49 %) in the CLA group. A flow diagram of the literature search is shown in Fig. 1.
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used to generate the random sequence and sealed opaque envelopes were used for allocation concealment. In only one study [28], double blinding involving both the patients and the assessors of outcomes was described, using identical dressings in both groups following surgery. One study [23] reported the blinding of researchers. In three studies [23, 25, 27], no losses were recorded or the analysis was based on an intention to treat. Three studies [25, 26, 28] presented results with post-randomization drop-out, which implies a risk of attrition bias. The results from the study of the quality analysis and bias evaluation can be seen in Fig. 2. Study and patient characteristics
Fig. 1 Flow diagram of selection of studies for meta-analysis. RCT randomized controlled trial, SILA single incision laparoscopic appendectomy
Selected studies were conducted in Europe and Asia and published between 2010 and 2013. Three studies [23, 25, 26] described surgeons with extensive experience in CLA and advanced laparoscopic surgery. Additionally, two RCTs [25, 28] reported that surgeons had pre-trial experience of more than ten SILA procedures. There was only one multicenter trial [28]. The sample size ranged from 40 to 229 patients, and the studies included patients aged from 12 to 80 years. Four trials [23, 24, 26, 28] excluded patients in whom complicated appendicitis was suspected. However, the proportion of patients with gangrenous or perforated appendicitis was similar across the studies, with an overall percentage of 17.8 % in the SILA group and 20.6 % in the CLA group. Characteristics of included studies and baseline characteristics of patients are summarized in Tables 1 and 2. Primary outcomes Overall complications
Fig. 2 Risk of bias summary: review author’s judgments about each risk of bias item for each included study. ? low risk of bias, ? unclear risk of bias, – high risk of bias
All six RCTs reported postoperative complications (Table 3). The overall morbidity rate was similar in both groups (SILA 10.5 %, CLA 11 %), and there were no significant differences in the combined analysis (OR 0.93; 95 % CI 0.59–1.47; p = 0.77). There was no significant heterogeneity among studies (v2 = 0.44, 5 d.f., I2 = 0 %) (Fig. 3). Publication bias could not be explored using funnel plots due to the small number of studies included in this review. Two patients in the CLA group required reoperation, one for bleeding of a trocar wound [23] and another for appendiceal stump leakage [25]. One patient in the SILA group developed an incisional hernia [23]. Wound infection, intra-abdominal infection, and prolonged postoperative ileus were the most common complications.
Assessment of methodological quality and risk of bias Wound infection The random-sequence generation was correctly described in five studies [23–25, 27, 28] and the allocation concealment in only three [23, 25, 28]. In general, computer programs were
There were no significant differences in wound infection between the two approaches (SILA 4 %, CLA 5 %). The
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World J Surg Table 1 Characteristics of included studies Study, y of publication, country
Inclusion criteria
Exclusion criteria
Frutos et al. [23], Spain
Clinical and radiological evidence of AA, age [ 11 y
Cirrhosis or coagulopathy, CA, septic shock, contraindications for general anesthesia or laparoscopic surgery, pregnancy
Kye et al. [24], South Korea
Clinical and radiological evidence of AA, \ ASA IV
Lee et al. [25], Korea Rep.
Patients (n)
SILA device
Instruments
SILA: 91CLA: 93
SILSÒ
Appendicitis with palpable mass, bleeding tendency, pregnant
SILA: 51CLA: 51
Clinical and radiological evidence of AA, age 5–80 y
Pregnant or lactating, uncontrolled undercurrent infections, concomitant disease, previous cytotoxic CTX, RTX or immunotherapy, cardiac disease
Park et al. [26], Korea Rep.
Clinical and radiological evidence of AA
Sozutek et al. [27], Turkey
Clinical and radiological evidence of AA
Teoh et al. [28], Hong Kong
Clinical evidence of AA, age 18–75 y
Technique
Follow-up
Mesoappendix
Appendix base
Articulating/ conventional
Endoloop
Endostapler
NR
AlexisÒ
Conventional
US
Endoloop
20.8 ± 5.1 wks
SILA: 116CLA: 113
OctoportÒ
Conventional
US
Endoloop
14 days
Cirrhosis or coagulopathy, CA, septic shock, pregnancy, previous laparotomy, cardiac or pulmonary disease ASA IV–V; \ 18 y old, pregnancy, anticoagulant therapy, intraoperative negative
SILA: 20CLA: 20
AlexisÒ
Articulating/ conventional
US or endoclips
Endoloop
NR
SILA: 25CLA: 25
SILSÒ
Conventional
EnsealÒ
Suture
1 month
Symptoms [ 5 days and/ or palpable mass, cirrhosis and coagulation disorders, generalized peritonitis, shock, previous abdominal surgery, ascites, malignancy, contraindication, no informed consent, pregnancy
SILA: 98CLA: 97
Multiport
Articulating/ conventional
US
Suture
1y
AA acute appendicitis, ASA American Society of Anesthesiologists, CA complicated appendicitis, CLA conventional laparoscopic appendectomy, CTX chemotherapy, NR not reported, Rep republic, RTX radiotherapy, SILA single incision laparoscopic appendectomy, SILS single incision laparoscopic surgery, US ultrasound, wks weeks
pooled OR was 0.79 (95 % CI 0.39–1.58; p = 0.50) without significant heterogeneity among studies (v2 = 2.96, 4 d.f., I2 = 0 %) (Fig. 4a).
0.70–5.04), but this difference was not statistically significant (p = 0.21). There was no evidence of statistical heterogeneity among studies (v2 = 0.82, 3 d.f., I2 = 0 %) (Fig. 4b).
Intra-abdominal infection Postoperative ileus Four studies [24–26, 28] reported intra-abdominal infections. There was an increased number of abdominal abscesses in the SILA group (OR 1.88; 95 % CI
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Five trials [24–28] reported postoperative ileus. There was neither significant difference between the two groups nor
World J Surg Table 2 Baseline characteristics Study
Age (y)
Sex (F/M)
BMI (kg/m2)
Complicated appendicitis (%) CLA
SILA
CLA
P
SILA
CLA
P
SILA
CLA
P
SILA
Frutos et al. [23]
28.04 ± 11.03
31.02 ± 12.41
0.08
49/ 42
46/ 47
0.45
23.84 ± 3.98
24.02 ± 3.84
0.75
14/91 (15.4)
12/93 (12.9)
Kye et al. [24] Lee et al. [25]
27.55 ± 12.40
29.20 ± 13.98
0.531
NR
NR
NR
22.03 ± 4.07
21.97 ± 3.49
0.930
7/51 (13.7)
28.04 ± 15.4
28.5 ± 17.2
0.298
52/ 64
45/ 68
0.444
21.4 ± 3.2
22.7 ± 4.4
0.081
9/51 (17.6) 18/116 (15.5)
Park et al. [26]
25 (mean)
27.2 (mean)
0.539
11/9
12/8
0.749
NR
NR
NR
NR
NR
Sozutek et al. [27]
30.6 ± 12.4
30 ± 11
0.777
13/ 12
18/7
0.124
23.2 ± 3.79
23.1 ± 2.58
0.959
4/25 (16)
6/25 (24)
Teoh et al. [28]
39.19 ± 15.55
40.65 ± 15.68
0.515
40/ 58
38/ 59
0.861
NR
NR
NR
23/98 (23.5)
25/97 (25.8)
28/113 (24.8)
Data are expressed as mean ± standard deviation, unless otherwise indicated BMI body mass index, CLA conventional laparoscopic appendectomy, F/M female/male ratio, NR not reported, SILA single incision laparoscopic appendectomy
Secondary outcomes
Table 3 Overall complications Type of complications
Wound seroma or hematoma
Intervention
Operative time
SILA
CLA
3
2
Wound infection
16
20
Intra-abdominal infection
12
6
Bleeding of the trocar wound
0
1
Stump leakage
0
1
Incisional hernia
1
0
Prolonged ileus
4
6
Incoercible vomiting
0
1
Postrenal acute failure
1
0
Acute tubular necrosis
0
1
Pneumonia
0
1
Non-specific colitis Drug side effect
0 2
2 0
Urinary tract infection
1
1
Unspecified
2
2
Total
42 (10.5 %)
44 (11 %)
CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
Operative time was longer in the SILA group in five of the six trials [23, 25–28]. The pooled analysis showed significant difference in favor of the CLA group (MD 4.67 [95 % CI 1.76–7.57; p = 0.002]), although there was evidence of moderate statistical heterogeneity (v2 = 8.13; 5 d.f.; I2 = 39 %) (Fig. 5). A sensitivity analysis excluding studies with unclear or high risk of selection bias decreased I2 to 0 (MD 6.23; 95 % CI 3.37–9.09; p \ 0.0001). Technical failure All the studies reported whether patients in either group required conversion to open surgery or the use of an additional trocar, the latter also being considered a procedure failure. The incidence of technical failure was significantly greater in the SILA group (OR 3.30; 95 % CI 1.26–8.65; p \ 0.01). There was no significant heterogeneity among studies (v2 = 3.29, 5 d.f.; I2 = 0 %) (Fig. 6). Length of hospital stay
significant heterogeneity among studies. The pooled OR was 0.68 (95 % CI 0.20–2.35; p = 0.55) and I2 = 0 % (v2 = 1.26; 3 d.f.) (Fig. 4c).
The length of hospital stay was reported in all the studies. The pooled analysis showed no significant differences between the two approaches (MD –0.04; 95 % CI –0.12 to
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Fig. 3 Forest plot and meta-analysis for overall complications. CI confidence interval, CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
–0.04; p = 0.27). There was no significant heterogeneity among studies (v2 = 2.90, 5 d.f.; I2 = 0 %) (Fig. 7). Postoperative PAIN Postoperative pain was evaluated by means of visual analog scales (VAS) in all studies. Two reported significant difference on pain score in favor of the SILA group during the first 24 h [23, 24]. No differences were found in another two studies [25, 27]. In contrast, Park et al. [26] found better pain control in the CLA group and Teoh et al. [28] described no significant difference in pain score when evaluated at rest but a decrease in this score in the CLA group during coughing and standing. In three studies [25– 27], pain scores were displayed in a graph and it was impossible to extract the raw data. Analgesic consumption was investigated in five trials [24–28], with no statistical differences between the two groups. It was not possible to conduct a combined analysis due to heterogeneity in the route of administration of analgesics. Return to activity Only two [24, 28] RCTs examined the time taken to return to normal activity. The pooled analysis favored the SILA group, with an MD of –0.64 (95 % CI –1.09 to –0.20; p = 0.005). There was no significant heterogeneity between studies (v2 = 0.63, 1 d.f., I2 = 0 %) (Fig. 8). Cosmesis In four trials [25–28], the cosmetic result was evaluated during the first postoperative month, with a higher score among patients who underwent SILA in the four studies. Data amenable for pooling from three studies [26–28] showed an SMD of –0.4 (95 % CI –0.64 to –0.16; p = 0.001; v2 = 1.48, 2 d.f., I2 = 0 %) (Fig. 9).
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Discussion In this systematic review and meta-analysis of the medical literature, we identified and analyzed six RCTs, with a total of 800 patients operated on, to compare results between SILA and CLA [23–28]. Although the SILA technique was first described more than 20 years ago [6], it has only gained substantial interest among the surgical community over the last 4 years, as is shown by the fact that all studies included in our analysis were published after 2010. Given its novelty, we considered the safety of the technique to be the most essential parameter to measure and chose the incidence of complications as our primary endpoint. In this review, the overall morbidity rate in the SILA group was slightly higher than in a previous multicenter registry (10.5 vs. 8.4 %) [29] and a recent review of 2,806 SILA patients (4.1 %) [30]. However, we did not observe statistically significant differences between groups. The most frequently reported surgery-related complications were wound infection, prolonged postoperative ileus, and intra-abdominal infection. Complications associated with the abdominal wall have received a great deal of interest during the development of SILS. At least in theory, the use of a single incision should be correlated with a decrease in wound complications. In contrast, many authors maintain that this approach gives rise to a more severe parietal contusion and a larger umbilical incision that could increase the risk of wound infection and incisional hernia [31, 32]. In our review, we observed no difference between groups in the incidence of seroma, hematoma, or wound infection. However, we must highlight that the follow-up in most studies was too short to assess long-term complications, and the incisional hernia rate might be underestimated. The feasibility and safety of laparoscopic surgery in complicated appendicitis is still debated, since it has been associated with an increased risk of intra-abdominal infections when compared with open appendectomy [4, 33]. In this review, we found an increased incidence of
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Fig. 4 Forest plot and meta-analysis for specific complications. a Wound infection, b intra-abdominal abscess, c ileus. CI confidence interval, CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
Fig. 5 Forest plot and meta-analysis for duration of operation. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
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Fig. 6 Forest plot and meta-analysis for incidence of procedure failure rate. CI confidence interval, CLA conventional laparoscopic appendectomy, SILA single incision laparoscopic appendectomy
Fig. 7 Forest plot and meta-analysis for length of hospital stay. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
Fig. 8 Forest plot and meta-analysis for time to return to normal activity. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
Fig. 9 Forest plot and meta-analysis for cosmetic results. CI confidence interval, CLA conventional laparoscopic appendectomy, SD standard deviation, SILA single incision laparoscopic appendectomy
intra-abdominal infections in the SILA patients. Although this difference was not statistically significant, it is noteworthy because most studies have excluded patients with suspicion of complicated appendicitis. Single incision laparoscopic surgery is more technically demanding than conventional laparoscopy, and surgeons are less
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experienced with this new access. These facts could lead to increased tissue manipulation and poor peritoneal lavage, which could explain this trend towards higher incidence of intra-abdominal infections in the SILA group. Finally, although other complications such as bleeding from the orifices of the trocars and appendiceal stump
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leakage were only found in the CLA group [23, 25], these and other adverse events (adhesions, chronic postoperative pain, etc.) will rarely be evaluated in RCTs because of the low incidence. In any case, with the available scientific evidence, SILA for complicated appendicitis should not be recommended outside controlled trials, and further studies are still needed to assess the safety of this new access. Failure of the surgical technique in the SILA group was generally low (6 %) and similar to that in other reviews (7.7 %) [30]. In the combined analysis, the conversion rate was significantly higher in the SILA group. These differences could be due in part to the complexity of the SILA technique and the lower overall experience with this technique among surgeons, which could also explain the longer duration of the surgical procedures. Postoperative hospital stays varied among the studies, with an average stay less than 24 h in one study [23] and up to 3 days in others [25, 28], but with no significant differences between the two techniques in the majority of studies. One of the theoretical advantages to reducing the number of incisions is the decrease in postoperative pain. The results from this systematic review are very heterogeneous in this regard, with results on both sides of the noeffect line, making these data inappropriate for performing a meta-analysis. In the evaluation of this variable, the use of different protocols for anesthesia/analgesia hindered the comparison of results between studies. In addition, the absence of blinding of patients and evaluators may also have influenced the results in some studies. The cosmetic result was better rated by SILA group patients, although this should be considered with caution since, in this review, no study evaluated this outcome after the first month post-surgery. As has been previously highlighted [34], cosmesis should be evaluated in the longer term because the initial cosmetic advantage of the single-incision approach may disappear with time evaluation. Moreover, the absence of blinding of outcome assessors in most of the included studies may have also influenced this result. In this review, patients in the SILA group returned to normal activities sooner, but only two studies contributed to this result, so evidence in this regard is weak. Finally, a cost analysis would be of interest in the future to determine whether the cosmetic benefits and early recovery supposedly offered by SILA could offset the higher cost of a more expensive technique with a longer operative time and higher conversion rate. Our review does have certain limitations. The fact that the majority of the studies included data from selected patients might make them unsuitable for extrapolation to patients with complicated appendicitis. Other limitations are the heterogeneity among the different studies in terms
of the types of equipment and specific techniques used in the SILA group, the lower level of experience among surgeons using the single-incision technique as compared with conventional laparoscopy, and the absence of blinding of patients and evaluators in many of the studies. Conclusions Given our results, we can consider SILA to be a feasible option in selected patients in whom uncomplicated appendicitis is expected. However, there is insufficient evidence to recommend its widespread use compared with CLA. SILA is associated with longer surgical times and a higher incidence of failure of the surgical technique. The incidence of complications is similar between the two groups, although there is a clear tendency towards a greater incidence of intra-abdominal infections in the SILA group. This approach could be associated with a better cosmetic result and earlier return to daily activities, although these advantages should be considered with caution due to the small number of studies reporting these outcomes and the short follow-up in the evaluation of cosmetic results. Finally, new studies are needed following the initial period of implementation and learning curve and with a longer follow-up, to analyze the safety of this technique and determine whether it really offers benefits over CLA.
Disclosure
The authors have no conflicts of interest to declare.
References 1. Addiss DG, Shaffer N, Fowler BS et al (1990) The epidemiology of appendicitis and appendectomy in the United States. Am J Epidemiol 132:910–925 2. Wilms IM, de-Hoog DE, de-Visser DC et al (2011) Appendectomy versus antibiotic treatment for acute appendicitis. Cochrane Database Syst Rev 11:CD008359 3. Vettoretto N, Gobbi S, Corradi A et al (2011) Consensus conference on laparoscopic appendectomy: development of guidelines. Colorectal Dis 13:748–754 4. Sauerland S, Jaschinski T, Neugebauer EA (2010) Laparoscopic versus open surgery for suspected appendicitis. Cochrane Database Syst Rev 10:CD001546 5. Tiwari MM, Reynoso JF, Tsang AW et al (2011) Comparison of outcomes of laparoscopic and open appendectomy in management of uncomplicated and complicated appendicitis. Ann Surg 254:927–932 6. Pelosi MA, Pelosi MA III (1992) Laparoscopic appendectomy using a single umbilical puncture (minilaparoscopy). J Reprod Med 37:588–594 7. Vidal O, Valentini M, Ginesta` C et al (2010) Laparoendoscopic single-site surgery appendectomy. Surg Endosc 24:686–691 8. Park J, Kwak H, Kim SG et al (2012) Single-port laparoscopic appendectomy: comparison with conventional laparoscopic appendectomy. J Laparoendosc Adv Surg Tech A 22:142–145
123
World J Surg 9. Raakow R, Jacob DA (2011) Initial experience in laparoscopic single-port appendectomy: a pilot study. Dig Surg 28:74–79 10. Kim HO, Yoo CH, Lee SR et al (2012) Pain after laparoscopic appendectomy: a comparison of transumbilical single-port and conventional laparoscopic surgery. J Korean Surg Soc 82:172–178 11. Gill RS, Shi X, Al-Adra DP et al (2012) Single-incision appendectomy is comparable to conventional laparoscopic appendectomy: a systematic review and pooled analysis. Surg Laparosc Endosc Percutan Tech 22:319–327 12. Pisanu A, Porceddu G, Reccia I et al (2013) Meta-analysis of studies comparing single-incision laparoscopic appendectomy and conventional multiport laparoscopic appendectomy. J Surg Res 183:e49–e59 13. Rehman H, Mathews T, Ahmed I (2012) A review of minimally invasive single-port/incision laparoscopic appendectomy. J Laparoendosc Adv Surg Tech A 22:641–646 14. Moher D, Liberati A, Tetzlaff J et al (2010) Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. Int J Surg 8:336–341 15. Higgins J, Green S (eds) (2011) Cochrane handbook for systematic reviews of interventions version 5.1. 0 [updated March 2011]. The Cochrane Collaboration 16. Hozo SP, Djulbegovic B, Hozo I (2005) Estimating the mean and variance from the median, range, and the size of a sample. BMC Med Res Methodol 5:13 17. Kang J, Bae BN, Gwak G et al (2013) Comparative study of a single-incision laparoscopic and a conventional laparoscopic appendectomy for the treatment of acute appendicitis. J Korean Soc Coloproctol 28:304–308 18. Vilallonga R, Barbaros U, Nada A et al (2012) Single-port transumbilical laparoscopic appendectomy: a preliminary multicentric comparative study in 87 patients with acute appendicitis. Minim Invasive Surg 2012:492409 19. Malik M, McCormack K, Krukowski ZH et al (2012) Single port/ incision laparoscopic surgery compared with standard three-port laparoscopic surgery for appendicectomy: a randomised controlled trial. Trials 13:201 20. Knott EM, Gasior AC, Holcomb GW III et al (2012) Impact of body habitus on single-site laparoscopic appendectomy for nonperforated appendicitis: subset analysis from a prospective, randomized trial. J Laparoendosc Adv Surg Tech A 22:404–407 21. Perez EA, Piper H, Burkhalter LS et al (2013) Single-incision laparoscopic surgery in children: a randomized control trial of acute appendicitis. Surg Endosc 27:1367–1371 22. St Peter SD, Adibe OO, Juang D et al (2011) Single incision versus standard 3-port laparoscopic appendectomy: a prospective randomized trial. Ann Surg 254:586–590
123
23. Frutos MD, Abrisqueta J, Lujan J et al (2013) Randomized prospective study to compare laparoscopic appendectomy versus umbilical single-incision appendectomy. Ann Surg 257:413–418 24. Kye BH, Lee J, Kim W et al (2013) Comparative study between single-incision and three-port laparoscopic appendectomy: a prospective randomized trial. J Laparoendosc Adv Surg Tech A 23:431–436 25. Lee WS, Choi ST, Lee JN et al (2013) Single-port laparoscopic appendectomy versus conventional laparoscopic appendectomy: a prospective randomized controlled study. Ann Surg 257:214–218 26. Park JH, Hyun KH, Park CH et al (2010) Laparoscopic vs transumbilical single-port laparoscopic appendectomy; results of prospective randomized trial. J Korean Surg Soc 78:213–218 27. Sozutek A, Colak T, Dirlik M et al (2013) 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 23:74–78 28. Teoh AY, Chiu PW, Wong TC et al (2012) A double-blinded randomized controlled trial of laparoendoscopic single-site access versus conventional 3-port appendectomy. Ann Surg 256:909–914 29. Moreno-Sanz C, Morandeira-Rivas A, Morales-Conde S et al (2012) Single incision laparoscopic surgery: analysis of the national register. Cir Esp 90:298–309 30. Rehman H, Ahmed I (2011) Technical approaches to single port/ incision laparoscopic appendicectomy: a literature review. Ann R Coll Surg Engl 93:508–513 31. Alptekin H, Yilmaz H, Acar F et al (2012) Incisional hernia rate may increase after single-port cholecystectomy. J Laparoendosc Adv Surg Tech A 22:731–737 32. Marks JM, Phillips MS, Tacchino R et al (2013) Single-incision laparoscopic cholecystectomy is associated with improved cosmesis scoring at the cost of significantly higher hernia rates: 1-year results of a prospective randomized, multicenter, singleblinded trial of traditional multiport laparoscopic cholecystectomy vs single-incision laparoscopic cholecystectomy. J Am Coll Surg 216:1037–1047 33. Swank HA, Eshuis EJ, van Berge Henegouwen MI et al (2011) Short- and long-term results of open versus laparoscopic appendectomy. World J Surg 35:1221–1226. doi:10.1007/s00268-0111088-5 34. Saad S, Strassel V, Sauerland S (2013) Randomized clinical trial of single-port, minilaparoscopic and conventional laparoscopic cholecystectomy. Br J Surg 100:339–349
