Objective
To assess the current evidence regarding the efficiency, safety, and potential advantages of laparoendoscopic single-site surgery (LESS) for treating gynecologic diseases.
Study Design
We comprehensively searched PubMed, Embase, and the Cochrane Library from their inception to December 2012. Two authors screened out duplicates and independently reviewed eligibility of each study. We included randomized controlled trials comparing LESS with conventional laparoscopy (CL) for treating gynecologic diseases. The primary outcomes were perioperative complication rate, conversion rate, postoperative pain, and cosmetic satisfaction.
Results
We included 6 randomized controlled trials with 439 participants in the final analysis. There were no significant differences between LESS and CL in terms of perioperative complication rate (15.5% and 14.3%; risk ratio, 1.11; 95% confidence interval [CI], 0.74–1.67; P = .61), conversion rate (3.8% and 1.1%; risk ratio, 2.75; 95% CI, 0.73–10.33; P = .13), postoperative pain (weighted mean difference [WMD], −0.22; 95% CI, −1.29 to 0.85; P = .68), analgesic requirement (WMD, 0.41; 95% CI, −1.69 to 2.51; P = .70), and cosmetic satisfaction (WMD, 0.19; 95% CI, −0.30 to 0.68; P = .46). There were also no differences in terms of operative time ( P = .65), hemoglobin change ( P = .23), time to first flatus ( P = .17), and length of hospital stay ( P = .99) between both techniques.
Conclusion
This metaanalysis provides evidence that LESS is comparable in the efficacy and safety, but does not offer potential advantage such as better cosmesis and lesser pain compared with CL for treating gynecologic diseases.
Laparoscopic surgery is a well-established alternative of laparotomy in various fields of gynecology. It has many advantages such as less pain, quicker recovery, shorter hospital stay, and a better cosmesis. In recent years, the laparoendoscopic single-site (LESS) technique was created to improve cosmesis by reducing the number of incisions. This technique has been applied to a number of surgical procedures including hysterectomy, adnexal surgery, cholecystectomy, appendectomy, nephrectomy, and colectomy.
Even though randomized controlled trials (RCTs) comparing LESS and conventional laparoscopy (CL) for gynecologic diseases have been reported, most used small sample sizes and have shown conflicting results. A metaanalysis could solve this limitation by pooling all available data together instead of another large-sized RCT. The aim of this study was to search and systematically analyze available RCTs to evaluate the efficacy, the safety, and the potential advantages of LESS in comparison with CL for gynecologic diseases.
Materials and Methods
The review was planned and conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for systematic reviews and metaanalysis and the recommendations of the Cochrane Collaboration. This was a metaanalysis of published summary data and therefore did not require ethics approval.
The literature search comprised the following electronic databases from their inception through December 2012 without restriction to regions, publication types, or languages: Medline (via PubMed), Embase, and the Cochrane Library. The literature search was constructed using key words such as “uterus,” “ovary,” “adnexa,” tube,” or “salpinx” for organ; “myoma,” “leimyoma,” “fibroid,” “cyst,” or “tumor,” for disease; “single site,” “single incision,” “single port,” “laparoendoscopy,” “laparoscopy,” “pelviscopy,” “hysterectomy,” “cystectomy,” or “enucleation” for intervention; and “complication,” “conversion,” “pain,” “cosmetic,” or “operative time” for outcome. The complete search strategy for PubMed was as follows: (“single port” OR “single incision” OR “single site”) AND (laparoendoscop* [Title/Abstract] OR laparoscop* [Title/Abstract] OR pelviscop* [Title/Abstract]) AND (uter* [Title/Abstract] OR ovar* [Title/Abstract] OR adnexa* [Title/Abstract] OR tub* [Title/Abstract] OR salping* [Title/Abstract] OR hysterectomy [Title/Abstract] OR cystectomy [Title/Abstract] OR enucleation [Title/Abstract] OR myom* [Title/Abstract]) and adapted for each database as necessary. Studies and abstracts that were presented at recent congresses (American College of Obstetricians and Gynecologists [2007-2012], American Association of Gynecologic Laparoscopists [2007-2012], International Federation of Gynecology and Obstetrics [2007-2012]) were also searched. The Clinical Trials database ( http://clinicaltrials.gov ) was searched for articles in other archived registries. The bibliographies from the included trials were manually searched to identify additional trials. The “Related citations in PubMed” function of PubMed articles was also used to expand our search criteria. Two authors (TS and SJS) screened all abstracts that were identified by the literature search and reviewed the full articles of potentially eligible studies to determine whether they met inclusion criteria.
Study selection
A study should meet the following conditions to be eligible: (1) the type of a study should be a RCT; (2) the participants of a study should be women who received laparoscopy for gynecologic diseases; (3) as for the type of intervention, a study should compare LESS with CL. Studies were excluded if LESS was not the main intervention but a part of multimodal intervention; and (4) as for the type of outcome, a study should measure at least 1 of the outcomes of interest as mentioned below.
A study should be excluded from the metaanalysis in the following conditions: (1) if it was a retrospective comparative study (cohort or case-control study), an editorial, a letter to the editor, a review article, a case report, or a study of animal experiment; (2) if 2 or more studies were reported by the same surgical department and/or authors and showed an overlap between the results; (3) if multicenter studies contained data that were already included in other single-center study; (4) if the necessary data was extrapolated from the reported outcomes; and (5) if the outcomes of interest were not evidently described for LESS and CL.
Outcomes of interest
The following outcomes were used to compare LESS and CL. The primary outcomes were perioperative complication rate, conversion rate, postoperative pain, and cosmetic satisfaction. If sufficient data were available, perioperative complications were subdivided into intraoperative complications and postoperative complications within 30 days of operation. Postoperative complications were classified according to the Clavien-Dindo grading system. Conversions were defined as follows: (1) addition of trocars, or (2) conversion to laparotomy. Postoperative pain was measured using a visual analog scale (VAS) and analgesic requirement. Cosmetic satisfaction was measured according to a scale that was administered to the patient 30 days postsurgery. The secondary outcomes were operative time, estimated blood loss (EBL), hemoglobin change, time to first flatus, and length of hospital stay.
Data extraction
Two of the authors (TS and SJS) independently extracted data from the included studies. They extracted the study identification (first author, year of publication), country where the trial was conducted, source of data, indication of surgery, number of patients, age, body mass index (BMI), duration of follow-up, period of each trial, and the outcomes of interest, which were mentioned previously, from all the studies finally selected. Data were entered into 2 separated databases for double-check. When the 2 entries did not match, it was resolved by the adjudicating senior author (YWJ and WDJ) with consensus achieved by discussion.
Risk of bias in individual studies
The risk of bias was independently assessed by 2 authors (WDJ and SSJ) using the 12 criteria (rating: yes, no, unclear) recommended by the Cochrane Back Review Group. These criteria assessed the risk of bias on the following domains: selection bias, performance bias, attrition bias, reporting bias, and detection bias. If necessary, discrepancies were rechecked by the third reviewer (YWJ) and consensus was achieved by discussion. Studies that met at least 6 of the 12 criteria had no serious flaw and they were rated as having a low risk of bias.
Statistical analysis
All metaanalyses were performed using Review Manger 5.2 (Cochrane Collaboration, Oxford, UK). The weighted mean difference (WMD) and risk ratio (RR) were used to compare continuous and dichotomous variables, respectively. All results were reported with 95% confidence intervals (CIs). Heterogeneity between studies was assessed using the Higgins I 2 . A value greater than 50% was considered to have substantial heterogeneity. The random-effects model was used if there was heterogeneity between studies; otherwise, the fixed-effects model was used. Subgroup analyses were performed to compare LESS adnexal surgery and hysterectomy with CL procedures. Funnel plots were used to assess for potential publication bias. Sensitivity analyses were used to estimate the influence of studies with a high risk of bias on the overall effect.
Results
Studies identified
A total of 6 RCTs were identified from 497 citations ( Figure 1 ). One of 6 RCTs had insufficient data, but the author responded to our request for the supplementary data. Therefore, 439 patients in 6 RCTs were included in our analysis. Although 1 study was sponsored in part by Olympus Winter and IBE, Hamburg, Germany, the other 5 studies were not in a relationship with industry. All included studies reported that the authors had nothing to disclose and did not report any potential conflicts of interest. Two hundred nineteen patients received LESS and 220 patients received CL. The characteristics of the included studies are summarized in Table 1 .
| Trials | Years | Country | Data source | Industry-sponsored | Indication | No. of participants | Age | BMI | Duration of follow-up | Period of trial |
|---|---|---|---|---|---|---|---|---|---|---|
| Cho et al LESS CL | 2012 | Korea | Single center | No | Adnexal | 33 30 | 29.5 ± 6.2 31.1 ± 7.2 | 21.4 ± 3.2 22.5 ± 3.3 | 1 month | December 2009 to September 2010 |
| Hoyer-Sorensen et al LESS CL | 2012 | Norway | Single center | No | Adnexal | 20 20 | 55.1 ± 16.2 58.7 ± 10.8 | 25.1 ± 5.5 25.4 ± 4.8 | 2 months | December 2010 to August 2011 |
| Fagotti et al LESS CL | 2011 | Italy | Single center | Yes a | Adnexal | 30 30 | 49 (20–73) 42 (15–73) | 22.8 (17.6–37.0) 22.1 (18.2–30.0) | 1 month | August 2009 to September 2010 |
| Chen et al LESS CL | 2011 | Taiwan | Single center | No | Uterine | 50 50 | 45.7 ± 5.4 48.3 ± 8.2 | 24.2 ± 3.0 25.0 ± 4.0 | 2-10 months | September 2009 to June 2010 |
| Jung et al LESS CL | 2011 | Korea | Single center | No | Uterine | 34 34 | 48.0 ± 8.7 48.1 ± 5.9 | 23.4 ± 3.1 23.5 ± 3.2 | Not reported | October 2009 to March 2010 |
| Li et al LESS CL | 2012 | China | Single center | No | Uterine | 52 56 | 46 (36–61) 48 (37–65) | 24 (22–27) 24 (22–28) | 6 months | February 2009 to September 2011 |
a The study was sponsored in part by Olympus Winter and IBE, Hamburg, Germany.
Risk of bias in individual studies
Four studies had a low risk of bias whereas 2 studies had a high risk of bias ( Table 2 ). The risk of selection bias was mainly low; all but 2 studies reported adequate randomization, although only 3 studies reported adequate allocation concealment. Three studies reported double blinding of participants and providers, although only 1 reported adequate blinding of outcome assessors. Only 2 studies included an adequate intention-to-treat analysis.
| Trials | Risk of bias assessment using the Cochrane Back Review Group risk of bias tool | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Selection bias | Performance bias | Attrition bias | Reporting bias | Detection bias | Total (max. 12) a | ||||||||
| Adequate random sequence generation | Adequate allocation concealment | Similar baseline characteristics | Adequate participant blinding | Adequate provider blinding | Similar or no co-intervention | Acceptable compliance | Acceptable and described drop-out rate | Inclusion of an intention-to-treat analysis | No selective outcome reporting | Adequate outcome assessor blinding | Similar timing of outcome assessment | ||
| Cho et al | Unclear | Unclear | Yes | Unclear | Unclear | Yes | Yes | Unclear | No | Unclear | Yes | Yes | 5 |
| Hoyer-Sorensen et al | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Unclear | Yes | 11 |
| Fagotti et al | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | 11 |
| Chen et al | Yes | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No | Yes | Unclear | Yes | 10 |
| Jung et al | Yes | Unclear | Yes | Unclear | Unclear | Yes | Yes | Yes | No | Yes | Unclear | Yes | 7 |
| Li et al | No | No | Yes | Unclear | No | Yes | Yes | Yes | Unclear | Unclear | No | Yes | 5 |
Primary outcomes
Perioperative complication rate
Pooling the data from 6 studies that assessed the perioperative complication rate in 439 participants showed no significant differences between the LESS and CL approaches (15.5% and 14.3%; RR, 1.11; 95% CI, 0.74–1.67; P = .61) ( Figure 2 ). Intraoperative and postoperative complication rates were available in 5 studies and 6 studies, respectively, and the pooled data showed no significant differences between the 2 techniques (0.5% and 0%; RR, 3.00; 95% CI, 0.13–71.15; P = .50; and 15.1% and 14.5%; RR, 1.08; 95% CI, 0.71–1.62; P = .73, respectively). When postoperative complications were further divided into minor (Clavien-Dindo grade I/II) and major complications (Clavien-Dindo grade III/IV/V), all complications were classified as minor. In addition, no port site herniation occurred in either group during the study period.
Conversion rate
Nine events of conversion were reported in 6 studies. The reasons of conversion were severe adhesion (5 cases), frozen biopsy-proven malignant tumor (1 case), bladder injury (1 case), and not stated (4 cases). The conversion rate was higher in the LESS group than the CL group, but it was not significant (3.8% and 1.1%; RR, 2.75; 95% CI, 0.73–10.33; P = .13). When conversions were further divided into addition of trocars and laparotomic conversion, no significant differences were found between the 2 groups (4.5% and 0%; RR, 7.00; 95% CI, 0.88–55.58; P = .07; and 0.04% and 0.09%; RR, 0.54; 95% CI, 0.05–5.76; P = .61, respectively).
Postoperative pain
Five studies including 331 participants evaluated postoperative pain using a VAS at different time pain points ranging from the first postoperative day to the day of discharge. The VAS scores at 6 hours, 24 hours, and 48 hours postoperatively were available in 4 studies, 4 studies, and 3 studies, respectively. The pooled data showed no significant differences between the 2 techniques at any time points (WMD, −0.17; 95% CI, −1.04 to 0.70; P = .70; and WMD, −0.22; 95% CI, −1.29 to 0.85; P = .68; and WMD, −0.09; 95% CI, −0.68 to 0.49; P = .76, respectively) ( Figure 3 ; Forest plots at 6 hours and 48 hours were not shown). The pooled data of 4 studies that included 271 participants showed that the LESS group was similar with the CL group in their analgesic requirement (WMD, 0.41; 95% CI, −1.69 to 2.51; P = .70).
Cosmetic satisfaction
Three studies reported cosmetic satisfaction scores using a VAS, and 1 study reported using the Manchester scar scale. Pooling the data of the 271 participants from these 4 studies showed that the LESS group had no cosmetic advantage compared with the CL group (WMD, 0.19; 95% CI, −0.30 to 0.68; P = .46) ( Figure 4 ).
Secondary outcomes
Operative time, estimated blood loss, and hemoglobin change
All studies reported operative time, but one was excluded because the data were presented in median (interquartile range). Pooling the data from 5 studies involving 399 participants showed that the operative time was longer in the LESS group than the CL group, but this difference was not shown to be significant (WMD, 6.02 minute; 95% CI, −3.56 to 15.60; P = .22) ( Figure 5 ). EBL was reported in 4 studies including 336 participants and the 2 groups were found not to be different (WMD, −4.30 mg/dL; 95% CI, −22.81 to 14.22; P = .65). Two studies reported hemoglobin change in their 121 included participants, which was also found to be different between the 2 groups (WMD, 0.16 mg/dL; 95% CI, −0.10 to 0.41; P = .23) ( Table 3 ).
| Factor | No. of study | No. of patients | RR or WMD | 95% CI | Overall effects ( P value) | Subgroup Difference ( P value) | Heterogeneity ( I 2 ) |
|---|---|---|---|---|---|---|---|
| Perioperative complication | 6 | 442 | RR, 1.11 | 0.74–1.67 | .61 | .18 | 36% |
| Adnexal surgery | 3 | 166 | RR, 3.00 | 0.63–14.39 | .17 | 0% | |
| Hysterectomy | 3 | 276 | RR, 0.99 | 0.65–1.50 | .95 | 63% | |
| Intraoperative | 1 | 68 | RR, 3.00 | 0.13–71.15 | .50 | NA | NA |
| Postoperative | 6 | 439 | RR, 1.08 | 0.71–1.62 | .73 | .18 | 27% |
| Adnexal surgery | 3 | 163 | RR, 2.91 | 0.60–14.02 | .18 | 0% | |
| Hysterectomy | 3 | 276 | RR, 0.95 | 0.62–1.46 | .82 | 57% | |
| Conversion rate | 5 | 276 | RR, 2.75 | 0.73–10.33 | .13 | NA | 24% |
| Postoperative pain, 6 h | 3 | 231 | WMD, –0.17 | –1.04 to 0.70 | .70 | .34 | 71% |
| Adnexal surgery | 2 | 163 | WMD, –0.36 | –1.56 to 0.83 | .55 | 74% | |
| Hysterectomy | 1 | 68 | WMD, 0.30 | –0.37 to 0.97 | .38 | NA | |
| Postoperative pain, 24 h | 4 | 241 | WMD, –0.22 | –1.29 to 0.85 | .68 | .29 | 77% |
| Adnexal surgery | 2 | 73 | WMD, 0.50 | –0.63 to 1.63 | .39 | NA | |
| Hysterectomy | 2 | 168 | WMD, –0.58 | –2.24 to 1.08 | .50 | 87% | |
| Postoperative pain, 48 h | 3 | 231 | WMD, –0.09 | –0.68 to 0.49 | .76 | .58 | 67% |
| Adnexal surgery | 1 | 63 | WMD, 0.10 | –0.65 to 0.85 | .79 | NA | |
| Hysterectomy | 2 | 168 | WMD, –0.27 | –1.33 to 0.80 | .63 | 83% | |
| Analgesic requirement | 4 | 271 | WMD, 0.41 | –1.69 to 2.51 | .70 | .49 | 90% |
| Adnexal surgery | 2 | 103 | WMD, 0.07 | –0.22 to 0.36 | .62 | 0% | |
| Hysterectomy | 2 | 168 | WMD, –9.42 | –36.42 to 17.59 | .49 | 94% | |
| Cosmetic satisfaction | 4 | 271 | WMD, 0.19 | –0.30 to 0.68 | .46 | .33 | 77% |
| Adnexal surgery | 3 | 163 | WMD, –0.02 | –0.91 to 0.87 | .97 | 82% | |
| Hysterectomy | 1 | 108 | WMD, 0.44 | 0.24–0.64 | < .0001 | NA | |
| Operative time | 5 | 399 | WMD, 6.02 | –3.56 to 15.60 | .22 | .54 | 79% |
| Adnexal surgery | 2 | 123 | WMD, 3.25 | –5.17 to 11.68 | .45 | 15% | |
| Hysterectomy | 3 | 276 | WMD, 8.34 | –5.75 to 22.42 | .25 | 83% | |
| Estimated blood loss | 4 | 336 | WMD, –4.30 | –22.81 to 14.22 | .65 | .001 | 75% |
| Adnexal surgery | 1 | 60 | WMD, –19.10 | –28.49 to –9.71 | < .0001 | NA | |
| Hysterectomy | 3 | 276 | WMD, 6.29 | –6.14 to 18.71 | .32 | 0% | |
| Hemoglobin change | 2 | 131 | WMD, 0.16 | –0.10 to 0.41 | .23 | .14 | 53% |
| Adnexal surgery | 1 | 63 | WMD, 0.30 | –0.02 to 0.62 | .07 | NA | |
| Hysterectomy | 1 | 68 | WMD, –0.10 | –0.53 to 0.33 | .65 | NA | |
| Time to first flatus | 2 | 208 | WMD, –1.16 | –2.81 to 0.49 | .17 | 0% | |
| Length of hospital stay | 4 | 336 | WMD, 0 | –0.32 to 0.33 | .99 | .62 | 81% |
| Adnexal surgery | 1 | 60 | WMD, –0.10 | –0.41 to 0.21 | .52 | NA | |
| Hysterectomy | 3 | 276 | WMD, 0.03 | –0.40 to 0.46 | .88 | 86% | |
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