CRD summary

This review compared transanal endoscopic microsurgery (TEM) with alternative surgical techniques for rectal tumours. The few studies found were of a poor quality and/or poorly reported. The authors' conclusion that evidence regarding TEM is limited appears reliable. Their conclusion that TEM may result in fewer recurrences than local excision of adenomas was derived from one poorly reported study and may not be reliable.

Authors' objectives

To assess the safety and efficacy of transanal endoscopic microsurgery (TEM) compared with existing techniques for local excision of rectal tumours.

Searching

The authors searched MEDLINE, PREMEDLINE, EMBASE, Cancerlit, the Science Citation Index, Current Contents, the Cochrane Library (Issue 3, 2002), databases of the Centre for Reviews and Dissemination, trials registers and the Internet (using the Google search engine). There were no language restrictions. Searches were performed between June and August 2002, and the search terms used were reported. The reference lists of retrieved studies were also checked.

Study selection

Assessment of study quality

Randomised controlled trials (RCTs) were assessed for adequacy of allocation concealment, completeness of follow-up, blinding of the outcome assessors, clinical relevance of outcome measures and risk of bias. Non-randomised comparative studies were assessed for basis of patient selection, comparability of groups, completeness of follow-up, blinding of the outcome assessors, clinical relevance of outcome measures and risk of bias. One reviewer assessed validity and a second reviewer checked the results.

Data extraction

One reviewer extracted the data and a second reviewer checked the extraction. Relative risks (for dichotomous outcomes) and weighted mean differences (for continuous outcomes) were calculated for some outcomes in the individual studies.

Methods of synthesis

Results of the review

One RCT (53 patients with carcinoma and 188 with adenoma), two non-randomised comparative studies (103 patients with carcinoma and 104 with adenoma) and 55 case series (5,892 patients with carcinoma, adenoma and other conditions) were included.

All of the included comparative studies were poorly reported. A potential for bias and/or confounding was present in the two non-randomised studies.

Safety.

The RCT found no difference in early complication rates between TEM and control groups.

Survival and recurrence.

In the RCT, TEM was associated with less local recurrence than local excision for patients with adenomas (6 out of 98 versus 20 out of 90; relative risk 0.28, 95% confidence interval: 0.12, 0.66). For patients with carcinoma, no differences in survival or local recurrence between TEM and anterior resection groups were found in the RCT and one non-randomised comparative study. Effectiveness.

In the RCT, TEM was associated with a shorter operating time and hospital stay than anterior resection for patients with carcinoma. For patients with adenoma, the operating time was longer for patients undergoing TEM than for those undergoing local excision.

Cost information

The base cost of treating an adenoma was calculated to be US$2,081 per patient with TEM, compared with US$3,309 for the comparator (local excision or anterior resection). For treating a carcinoma, the calculated base costs were US$2,542 for TEM and US$5,679 for the comparator (anterior resection or abdomino-perineal resection).

Authors' conclusions

The evidence regarding TEM was limited. The procedure appeared to result in fewer recurrences than direct local excision of adenomas.

CRD commentary

The review addressed a clear question, but the inclusion criteria for the participants and study designs were not described clearly. This could have affected the selection of studies for the review, although in practice this was unlikely given the few studies found. The authors searched a range of appropriate sources and included an Internet search. The searches were performed in 2002, and it is possible that new information could have become available between the time of the searches and publication of the report. The authors did not assess publication bias, so this possibility cannot be ruled out. Two reviewers selected studies independently and the data extractions were checked, thus reducing the risk of bias and errors being introduced during the review process. The authors used recognised criteria to assess study validity and made use of this information when synthesising the evidence.

Relevant details of the included studies were presented in the text and tables. The presentation of data in a narrative synthesis was appropriate in view of the small number of comparative studies available, and the synthesis emphasised the better quality evidence. The authors' conclusions appropriately highlighted the limited quantity and poor quality of the available evidence. The conclusion that TEM results in fewer local recurrences than direct local excision of adenomas was derived from a single poorly reported RCT and thus may not be reliable.

Implications of the review for practice and research

Practice: The authors stated that TEM may be useful for patients with large benign lesions of the middle to upper third of the rectum, for those with T1 low-risk rectal cancers, and for palliative use in patients with more advanced tumours.

Research: The authors did not state any implications for further research.

Funding

Australian Government Department of Health and Ageing.

Bibliographic details

Middleton P F, Sutherland L M, Maddern G J. Transanal endoscopic microsurgery: a systematic review. Diseases of the Colon and Rectum 2005; 48(2): 270-284. [PubMed: 15711865]

Other publications of related interest

Medical Services Advisory Committee. Transanal endoscopic microsurgery. MSAC Assessment Report. Canberra: Department of Health and Ageing; 2004. Report No.: 15.

Indexing Status

Subject indexing assigned by NLM

MeSH

Anal Canal; Humans; Microsurgery; Proctoscopy /methods; Rectal Neoplasms /surgery

AccessionNumber

12005000156

Database entry date

28/02/2006

Record Status

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.