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Meta-Analysis
. 2013 Aug 1;2013(8):CD006804.
doi: 10.1002/14651858.CD006804.pub3.

Miniports versus standard ports for laparoscopic cholecystectomy

Kurinchi Selvan Gurusamy  1 , Jessica Vaughan, Rajarajan Ramamoorthy, Giuseppe Fusai, Brian R Davidson
Affiliations
Meta-Analysis

Miniports versus standard ports for laparoscopic cholecystectomy

Kurinchi Selvan Gurusamy et al. Cochrane Database Syst Rev. .

Abstract

Background: In conventional (standard) port laparoscopic cholecystectomy, four abdominal ports (two of 10 mm diameter and two of 5 mm diameter) are used. Recently, use of smaller ports, miniports, have been reported.

Objectives: To assess the benefits and harms of miniport (defined as ports smaller than the standard ports) laparoscopic cholecystectomy versus standard port laparoscopic cholecystectomy.

Search methods: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, and Science Citation Index Expanded until February 2013 to identify randomised clinical trials of relevance to this review.

Selection criteria: Only randomised clinical trials (irrespective of language, blinding, or publication status) comparing miniport versus standard port laparoscopic cholecystectomy were considered for the review.

Data collection and analysis: Two review authors collected the data independently. We analysed the data with both fixed-effect and random-effects models using RevMan analysis. For each outcome we calculated the risk ratio (RR), mean difference (MD), or standardised mean difference (SMD) with 95% confidence intervals (CI).

Main results: We included 12 trials with 734 patients randomised to miniport laparoscopic cholecystectomy (380 patients) versus standard laparoscopic cholecystectomy (351 patients). Only one trial which included 70 patients was of low risk of bias. Miniport laparoscopic cholecystectomy could be completed successfully in more than 80% of patients in most trials. The remaining patients were mostly converted to standard port laparoscopic cholecystectomy but some were also converted to open cholecystectomy. These patients were included for the outcome conversion to open cholecystectomy but excluded from other outcomes. Accordingly, the results of the other outcomes are on 343 patients in the miniport laparoscopic cholecystectomy group and 351 patients in the standard port laparoscopic cholecystectomy group, and therefore the results have to be interpreted with extreme caution.There was no mortality in the seven trials that reported mortality (0/194 patients in miniport laparoscopic cholecystectomy versus 0/203 patients in standard port laparoscopic cholecystectomy). There were no significant differences between miniport laparoscopic cholecystectomy and standard laparoscopic cholecystectomy in the proportion of patients who developed serious adverse events (eight trials; 460 patients; RR 0.33; 95% CI 0.04 to 3.08) (miniport laparoscopic cholecystectomy: 1/226 (adjusted proportion 0.4%) versus standard laparoscopic cholecystectomy: 3/234 (1.3%); quality of life at 10 days after surgery (one trial; 70 patients; SMD -0.20; 95% CI -0.68 to 0.27); or in whom the laparoscopic operation had to be converted to open cholecystectomy (11 trials; 670 patients; RR 1.23; 95% CI 0.44 to 3.45) (miniport laparoscopic cholecystectomy: 8/351 (adjusted proportion 2.3%) versus standard laparoscopic cholecystectomy 6/319 (1.9%)). Miniport laparoscopic cholecystectomy took five minutes longer to complete than standard laparoscopic cholecystectomy (12 trials; 695 patients; MD 4.91 minutes; 95% CI 2.38 to 7.44). There were no significant differences between miniport laparoscopic cholecystectomy and standard laparoscopic cholecystectomy in the length of hospital stay (six trials; 351 patients; MD -0.00 days; 95% CI -0.12 to 0.11); the time taken to return to activity (one trial; 52 patients; MD 0.00 days; 95% CI -0.31 to 0.31); or in the time taken for the patient to return to work (two trials; 187 patients; MD 0.28 days; 95% CI -0.44 to 0.99) between the groups. There was no significant difference in the cosmesis scores at six months to 12 months after surgery between the two groups (two trials; 152 patients; SMD 0.13; 95% CI -0.19 to 0.46).

Authors' conclusions: Miniport laparoscopic cholecystectomy can be completed successfully in more than 80% of patients. There appears to be no advantage of miniport laparoscopic cholecystectomy in terms of decreasing mortality, morbidity, hospital stay, return to activity, return to work, or improving cosmesis. On the other hand, there is a modest increase in operating time after miniport laparoscopic cholecystectomy compared with standard port laparoscopic cholecystectomy and the safety of miniport laparoscopic cholecystectomy is yet to be established. Miniport laparoscopic cholecystectomy cannot be recommended routinely outside well-designed randomised clinical trials. Further trials of low risks of bias and low risks of random errors are necessary.

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Conflict of interest statement

None known.

Figures

1
1
Study flow diagram.
2
2
Methodological quality graph: review authors' judgements about each methodological quality item presented as percentages across all included studies.
3
3
Methodological quality summary: review authors' judgements about each methodological quality item for each included study.
4
4
Trial sequential analysis of mortality 
 The diversity‐adjusted required information size (DARIS) was calculated to 352,564 patients, based on the proportion of patients in the control group with the outcome of 0.2%, a relative risk reduction of 20%, an alpha of 5%, a beta of 20%, and a diversity of 0%. To account for zero event groups, a continuity correction of 0.01 was used in the calculation of the cumulative Z‐curve (blue line). After accruing a total of 397 patients in seven trials, only 0.12% of the DARIS has been reached. Accordingly, the trial sequential analysis does not show the required information size and the trial sequential monitoring boundaries. As shown, the conventional boundaries have also not been crossed by the cumulative Z‐curve.
5
5
Trial sequential analysis of serious adverse events 
 The diversity‐adjusted required information size (DARIS) was calculated to 52,796 patients, based on the proportion of patients in the control group with the outcome of 1.28%, a relative risk reduction of 20%, an alpha of 5%, a beta of 20%, and a diversity of 0%. To account for zero event groups, a continuity correction of 0.01 was used in the calculation of the cumulative Z‐curve (blue line). After accruing a total of 460 patients in eight trials, only 0.87% of the DARIS has been reached. Accordingly, the trial sequential analysis does not show the required information size and the trial sequential monitoring boundaries. As shown, the conventional boundaries have also not been crossed by the cumulative Z‐curve.
6
6
Trial sequential analysis of conversion to open cholecystectomy 
 The diversity‐adjusted required information size (DARIS) was calculated to 36,124 patients, based on the proportion of patients in the control group with the outcome of 1.88%, a relative risk reduction of 20%, an alpha of 5%, a beta of 20%, and a diversity of 0%. To account for zero event groups, a continuity correction of 0.01 was used in the calculation of the cumulative Z‐curve (blue line). After accruing a total of 670 patients in 11 trials, only 1.85% of the DARIS has been reached. Accordingly, the trial sequential analysis does not show the required information size and the trial sequential monitoring boundaries. As shown, the conventional boundaries have also not been crossed by the cumulative Z‐curve.
7
7
Trial sequential analysis of operating time 
 Trial sequential analysis of operating time showing that the accumulative Z‐curve crosses the trial sequential monitoring boundary after the fourth trial. The diversity‐adjusted required information size (DARIS) was 189 participants based on a minimal relevant difference (MIRD) of 15 minutes, a variance (VAR) of 509.29, an alpha (a) of 5%, a beta (b) of 20%, and a diversity (D2) of 61.91%. The results are compatible with significantly higher operating time in the miniport laparoscopic cholecystectomy group compared with standard laparoscopic cholecystectomy group without risk of random errors.
8
8
Trial sequential analysis of length of hospital stay 
 The diversity‐adjusted required information size (DARIS) was 20 participants based on a minimal relevant difference (MIRD) of 1 day, a variance (VAR) of 0.61 (we used the variance from all the trials rather than the variance of low bias‐risk trial since the variance from the low bias risk trial was 0.13 which will further reduce the required sample size), an alpha (a) of 5%, a beta (b) of 20%, and a diversity (D2) of 0%. Trial sequential boundaries were not drawn since the information fraction exceeded the required sample size after one trial. The Z‐curve does not cross the conventional boundary suggesting that there is no significant difference in the length of hospital between miniport laparoscopic cholecystectomy and standard laparoscopic cholecystectomy.
9
9
Trial sequential analysis of length of hospital stay (post hoc analysis) 
 The diversity‐adjusted required information size (DARIS) was 479 participants based on a minimal relevant difference (MIRD) of 0.2 days, a variance (VAR) of 0.61, an alpha (a) of 5%, a beta (b) of 20%, and a diversity (D2) of 0%. This was a post hoc decision.After accruing 351 participants in six trials, the cumulative Z‐curve (blue line) lies in the futility area. The conventional statistical boundaries were not crossed by the cumulative Z‐curve. This suggests that future trials are unlikely to detect a difference as small as 0.2 days in the length of hospital between miniport laparoscopic cholecystectomy and standard laparoscopic cholecystectomy irrespective of the sample size in those trials.
10
10
Trial sequential analysis of return to work 
 The diversity‐adjusted required information size (DARIS) was calculated to 670 patients, based on on a minimal relevant difference (MIRD) of 1 day, a variance (VAR) of 12.51, an alpha (a) of 5%, a beta (b) of 20%, and a diversity (D2) of 41.35%. After accruing 187 patients in two trials, only 27.91% of the DARIS has been reached. Accordingly, the futility area was not drawn. Neither the conventional statistical boundaries nor the trial sequential monitoring boundaries for benefits or harms of miniports versus standard ports were crossed by the cumulative Z‐curve (blue line).
11
11
Funnel plot of comparison: 1. Miniport laparoscopic cholecystectomy versus standard port laparoscopic cholecystectomy, outcome: 1.6 Conversion to open cholecystectomy. Five trials did not have any event (conversion to open cholecystectomy) in any of the groups and were not included in this funnel plot. So, this funnel plot has to be interpreted with caution.
12
12
Funnel plot of comparison: 1 Miniport laparoscopic cholecystectomy versus standard port laparoscopic cholecystectomy, outcome: 1.4 Operating time [minutes].
1.1
1.1. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 1 Serious adverse events.
1.2
1.2. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 2 Quality of life.
1.3
1.3. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 3 Conversion to open cholecystectomy.
1.4
1.4. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 4 Operating time.
1.5
1.5. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 5 Hospital stay.
1.6
1.6. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 6 Return to activity.
1.7
1.7. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 7 Return to work.
1.8
1.8. Analysis
Comparison 1 Mini‐laparoscopic cholecystectomy versus standard laparoscopic cholecystectomy, Outcome 8 Cosmesis.
2.1
2.1. Analysis
Comparison 2 Subgroup and sensitivity analysis, Outcome 1 Serious adverse events.
2.2
2.2. Analysis
Comparison 2 Subgroup and sensitivity analysis, Outcome 2 Conversion to open cholecystectomy.
2.3
2.3. Analysis
Comparison 2 Subgroup and sensitivity analysis, Outcome 3 Operating time (sensitivity analysis).
2.4
2.4. Analysis
Comparison 2 Subgroup and sensitivity analysis, Outcome 4 Hospital stay.
2.5
2.5. Analysis
Comparison 2 Subgroup and sensitivity analysis, Outcome 5 Cosmesis.
2.6
2.6. Analysis
Comparison 2 Subgroup and sensitivity analysis, Outcome 6 Operating time (subgroup analysis).
See this image and copyright information in PMC

Update of

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Ainslie 2003 {published data only (unpublished sought but not used)}
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References to other published versions of this review

Gurusamy 2010
    1. Gurusamy KS, Samraj K, Ramamoorthy R, Farouk M, Fusai G, Davidson BR. Miniport versus standard ports for laparoscopic cholecystectomy. Cochrane Database of Systematic Reviews 2010, Issue 3. [DOI: 10.1002/14651858.CD006804.pub2] - DOI - PubMed

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