|A meta-analysis of the short- and long-term results of randomized controlled trials that compared laparoscopy-assisted and conventional open surgery for rectal cancer
|Ohtani H, Tamamori Y, Azuma T, Mori Y, Nishiguchi Y, Maeda K, Hirakawa K
This review compared short- and long-term results of laparoscopy assisted and conventional open surgery for treating rectal cancer and concluded that laparoscopic surgery may be an acceptable alternative treatment option to conventional open surgery. These conclusions reflect the evidence and appear appropriate but the limited quality assessment of the included studies should be borne in mind.
To assess the short- and long-term results of laparoscopy assisted and conventional open surgery for the treatment of rectal cancer.
MEDLINE, EMBASE, Science Citation Index and Cochrane Central Register of Controlled Trials (CENTRAL) were searched (January 1990 to April 2011) for studies in English. Search terms were reported.
Randomised controlled trial (RCTs) that compared laparoscopic with open conventional surgery for rectal cancer and reported at least one of the specified short- and long-term outcome measures were eligible for inclusion. Short-term outcomes included operation time, estimated blood loss, number of transfused patients, number of dissected lymph nodes, hospital stay, time to oral diet, period of parenteral analgesic administration, overall complications, anastomotic leakage, perioperative mortality, circumferential resection margin and distal resection margin. Long-term outcomes included overall recurrence, local recurrence, distant metastasis, wound site recurrence, cancer-related mortality, overall mortality and disease-free survival at three and five years after surgery and urinary and sexual dysfunction.
Most of the included studies were single-institution trials and two were multicentre trials. Where reported, the mean or median duration of follow-up of included trials ranged from 32.8 to 112.5 months. The mean age of included patients was not reported. The included studies were conducted in Brazil, USA, UK, Spain, China, Korea and Singapore
The authors did not state how many reviewers assessed studies for inclusion.
Assessment of study quality
The quality of studies was assessed using the Jadad scale, a five-point scale of randomisation, blinding and withdrawal.
Two reviewers performed quality assessment.
For continuous variables, data were extracted on mean and standard deviations to enable calculation of mean differences with 95% confidence intervals (CIs). For dichotomous variables, data were extracted on even rates to enable calculation of odds ratios (ORs) with 95% CIs. Data were extracted on the intention-to-treat basis.
Three reviewers performed data extraction.
Methods of synthesis
The studies were combined in a meta-analysis. Pooled odds ratios or weighted mean differences (WMDs), with 95% CIs, were calculated using a random-effects model. Statistical heterogeneity was assessed using Χ² and Ι² statistics.
Results of the review
Twelve RCTs were included in the review (2,095 participants). Six RCTs had a Jadad score of at least 3 and six RCTs had a Jadad score of 2.
Compared with open surgery, laparoscopic surgery was associated with a significant reduction in intraoperative blood loss (WMD -123.87mL, 95% CI -157.10 to -90.63; four RCTs) and the number of transfused patients (OR 0.23, 95% CI 0.09 to 0.62; three RCTs), earlier resumption of oral intake (WMD -1.14, 95% CI -2.11 to -0.17; four RCTs) and a shorter duration of hospital stay (WMD -3.61, 95% CI -5.45, to -1.77; five RCTs) over the short-term period post-surgery. However, it was associated with significantly longer operation time (WMD 40.96 minutes, 95% CI 25.53 to 56.38; six RCTs)
There were no significant differences in long-term oncologic outcomes including overall recurrence (seven RCTs), local recurrence (eight RCTs) and distant metastasis (seven RCTs) between the two groups. No significant differences were found between the two groups for long-term outcomes including overall mortality (seven RCTs), cancer-related mortality (five RCTs), disease-free survival at three years after surgery (two RCTs) and disease free survival at five years after surgery (four RCTs).
Significant heterogeneity (Ι²>69%) was only found in the outcomes of operation time, hospital stay and time to oral diet.
The authors reported that there was no significant difference for the cost of surgery between laparoscopy assisted and conventional open surgeries. Three studies reported similar costs of open surgery.
Laparoscopic surgery may be an acceptable alternative treatment option to conventional open surgery for rectal cancer.
This review's inclusion criteria were clear. Several relevant databases were searched. No sufficient attempts were made to find unpublished studies, which increased potential for publication bias. Only studies in English were included, which may have increased the risk of language bias. Steps were made to minimise biases and errors in the processes of quality assessment and data extraction; it was unclear whether the process of study selection was also performed in duplicate. A basic assessment of trial quality was made. Half of included studies were of low quality. It appeared that the authors did not take into account study quality when they interpreted the results of the meta-analyses. Statistical heterogeneity was assessed and appropriate methods were used to pool the results.
The authors' cautious conclusions reflect the evidence presented and appear to be appropriate. Risks of publication and language biases and the limited quality assessment of the included studies should be borne in mind.
Implications of the review for practice and research
The authors did not state any implications for practice and research.
Ohtani H, Tamamori Y, Azuma T, Mori Y, Nishiguchi Y, Maeda K, Hirakawa K. A meta-analysis of the short- and long-term results of randomized controlled trials that compared laparoscopy-assisted and conventional open surgery for rectal cancer. Journal of Gastrointestinal Surgery 2011; 15(8): 1375-1385
Subject indexing assigned by NLM
Blood Loss, Surgical; Blood Transfusion; Disease-Free Survival; Humans; Laparoscopy; Length of Stay; Neoplasm Metastasis; Neoplasm Recurrence, Local; Quality of Life; Randomized Controlled Trials as Topic; Rectal Neoplasms /mortality /pathology /surgery; Time Factors; Treatment Outcome
Database entry date
This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.