Surgery Section - Transanal Endoscopic Microsurgery (TEMS)

IMPORTANT REMINDER

This Medical Policy has been developed through consideration of medical necessity, generally accepted standards of medical practice, and review of medical literature and government approval status.

Benefit determinations should be based in all cases on the applicable contract language. To the extent there are any conflicts between these guidelines and the contract language, the contract language will control.

The purpose of medical policy is to provide a guide to coverage. Medical Policy is not intended to dictate to providers how to practice medicine. Providers are expected to exercise their medical judgment in providing the most appropriate care.

Description

Transanal endoscopic microsurgery (TEMS) involves the use of specialized equipment including an operating proctoscope, insufflation, and magnified stereoscopic views for resection of rectal tumors. Use of this equipment deals with limitations on local resection due to the anal sphincter and boney confines of the pelvis. Lesions that could not be removed through the anus under usual circumstances become accessible with the use of TEMS. Use of this technique should not change the type of rectal lesion that is or is not removed by a localized resection; this only changes the surgical approach.
This procedure has been available for nearly 20 years in Europe but has not been used widely in the United States. Two reasons for this slow diffusion are the steep learning curve for the procedure and the limited indications. As examples, most rectal polyps can be removed endoscopically and many rectal cancers need a wide excision and are thus not amenable to local resection.
TEMS has potential use when traditional transanal approaches are not possible. TEMS has been used in benign conditions such as large rectal polyps (that cannot be removed through a colonoscope), retrorectal masses, rectal strictures, rectal fistulae, and pelvic abscesses, and in malignant conditions such as malignant polyps, T1 –T2 rectal cancer, and palliative excision of T3 rectal cancers. When these lesions cannot be removed through the anus, an anterior abdominal approach or abdominoperineal resection would often be used. TEMS is viewed as an alternative in these cases.

As noted, this procedure requires use of specialized equipment. The Transanal Endoscopic Microsurgery (TEM) Combination System and Instrument Set (Richard Wolf Medical Instruments Corp) received 510(k) marketing clearance from the U.S. Food and Drug Administration (FDA) in 2001.

Policy/Criteria

Use of transanal endoscopic microsurgery is considered investigational for treatment of rectal conditions including rectal cancers and rectal polyps.

Scientific Background

Despite many years of experience using this device in Europe, comparative data are very limited. A search of the MEDLINE database through July, 2008 identified a systematic review by Middleton authored   in 2005 based on published results through August 2002.  (2) Three comparative studies, including 1 randomized controlled trial, and 55 case series were included in the analysis. The first area of study was the safety and efficacy in removal of adenomas. In the randomized controlled trial, no difference could be detected in the rate of early complications between transanal endoscopic microsurgery (10.3% of 98 patients) and direct local excision (17% of 90 patients) for a relative risk of 0.61 (95% confidence interval, 0.29-1.29). Transanal endoscopic microsurgery resulted in less local recurrence (6/98; 6%) than direct local excision (20/90; 22%) (relative risk, 0.28; 95% confidence interval, 0.12-0.66). The 6% rate of local recurrence for transanal endoscopic microsurgery in this trial is consistent with the rates found in case series of transanal endoscopic microsurgery. The second area of study was the safety and efficacy of carcinoma excision. In the randomized controlled trial of 53 patients, no difference could be detected in the rate of complications between transanal endoscopic microsurgery and direct local excision. No differences in survival or local recurrence rate between transanal endoscopic microsurgery and anterior resection could be detected in either the randomized, controlled trial (hazard ratio, 1.02 for survival) or the nonrandomized, comparative study. There were 2 of 25 (8%) transanal endoscopic microsurgery recurrences in the randomized, controlled trial, but no figures were given for recurrence after anterior resection. In the case series, the median local recurrence rate for transanal endoscopic microsurgery was 8.4%, ranging from 0% to 50%. The authors concluded that the evidence regarding transanal endoscopic microsurgery is very limited, being largely based on a single relatively small randomized, controlled trial. However, they also concluded that transanal endoscopic microsurgery does appear to result in fewer recurrences than those with direct local excision in adenomas and thus may be a useful procedure for several small niches of patient types, e.g., for large benign lesions of the middle to upper third of the rectum, for T1 low-risk rectal cancers, and for palliative use in more advanced tumors.

An updated search of the MEDLINE database through August 17, 2009 did not identify any additional large comparative studies of this technique. Reports involved only small numbers of patients and/or involved case series. For example, a European study reported comparable results between TEMS and laparoscopic resection (both with adjuvant radiochemotherapy) for 40 patients with T2 rectal cancer.(3) The probability of local or distant failure was 10% for TEMS and 12% for laparoscopic resection. Survival (median follow-up of 56 months) also favored TEMS. However, results from this small series must be interpreted with caution.

Zacharakis reported results on 76 patients from a single British hospital who were treated with this technique between 1996 and 2005.  (4) Forty-eight patients had adenomas and 28 had adenocarcinoma. Overall morbidity was 18.9%; 14 patients had minor complications, and 4 had major complications. During follow-up, benign tumor recurrence was 8% (3 patients), and recurrence rates among patients with T1, T2, and T3 malignancies were 7%, 43%, and 67% respectively.

Additional details are also needed about complications from this procedure. As noted in an article by Cataldo, complications are rare but can be significant.  (5) This article notes that major complication rates around 5% are reported in some series; these complications include intraperitoneal sepsis, rectovaginal fistulae, and postoperative hemorrhage requiring reoperation. This article also notes that some investigators have found that the anal dilation and insertion of the 40-mm special proctoscope has been associated with a temporary decrease in postoperative continence while others have not found a change in clinical continence.

References

1. BlueCross BlueShield Association Medical Policy Reference Manual, Policy No. 7.01.112
2. Middleton PF, Sutherland LM, Maddern GJ. Transanal endoscopic microsurgery: a systematic review. Dis Colon Rectum 2005; 48(2):270-84
3. Lezoche E, Guerrieri M, Paganini AM et al. Transanal endoscopic versus total mesorectal laparoscopic resections of T2-N0 low rectal cancers after neoadjuvant treatment: a prospective randomized trial with a 3-years minimum follow-up period. Surg Endosc 2005; 19(6):751-6
4. Zacharakis E, Freilich S, Rekhraj S et al. Transanal endoscopic microsurgery for rectal tumors: the St. Mary’s experience. Am J Surg 2007; 194:694-8
5. Cataldo PA. Transanal endoscopic microsurgery. Surg Clin North Am 2006; 86(4):915-25

Cross References

None

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