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Transanal Endoscopic Microsurgery (TEM)

Policy Number: MP-313

Latest Review Date: November 2023

Category: Surgery                                                                  


Transanal endoscopic microsurgery (TEM) may be considered medically necessary for treatment of rectal adenomas, including recurrent adenomas that cannot be removed using other means of local excision.

Transanal endoscopic microsurgery (TEM) may be considered medically necessary for treatment of T1 rectal adenocarcinomas than cannot be removed using other means of local excision and that meet all of the following criteria; 

  • Located in the middle or upper part of the rectum, AND
  • Well or moderately differentiated (G1 or G2) by biopsy, AND
  • Without lymphadenopathy or microscopic angiolymphatic invasion, AND
  • Less than 1/3 the circumference of the rectum

Transanal endoscopic microsurgery is considered investigational for the treatment of rectal tumors that do not meet the previously listed criteria.


Transanal endoscopic microsurgery (TEM) is a minimally invasive surgical approach to local excision of rectal lesions that cannot be directly visualized. It is an alternative to open or laparoscopic excision and has been studied in the treatment of both benign and malignant conditions of the rectum.

Transanal Endoscopic Microsurgery

Transanal Endoscopic Microsurgery (TEM) has been used in benign conditions such as large rectal polyps (that cannot be removed through a colonoscope), retrorectal masses, rectal strictures, rectal fistulae, rectal pelvic abscesses, and in malignant conditions such as malignant polyps. Use of TEM for resection of rectal cancers is more controversial. TEM can avoid morbidity and mortality associated with major rectal surgery including fecal incontinence related to stretching of the anal sphincter, and can be performed under general or regional anesthesia.

The TEM system has a specialized magnifying rectoscope with ports for insufflation, instrumentation, and irrigation. This procedure has been available 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.  For example, most rectal polyps can be removed endoscopically and many rectal cancers need a wide excision and are thus not amenable to local resection.

Other Treatment Options

The most common treatment for rectal cancer is surgery; the technique chosen will depend on several factors. The size and location of the tumor, evidence of local or distal spread, and individual’s characteristics and goals are all attributes that will affect the treatment approach. Open, wide resections have the highest cure rate but may also have significant adverse effects. Most individuals find the potential adverse effects of lifelong colostomy, bowel; bladder; or sexual dysfunction, acceptable in the face of a terminal illness. Laparoscopic-assisted surgery, with lymph node dissection as indicated, is technically difficult in the pelvic region but is being investigated as a less invasive alternative to open resection.

Local excision (LE) alone does not offer the opportunity for lymph node biopsy and therefore has been reserved for patients in whom the likelihood of cancerous extension is small. LE can occur under direct visualization in rectal tumors within 10cm of the anal verge. TEM extends LE ability to the proximal rectosigmoid junction. Adenomas, small carcinoid tumors, and nonmalignant conditions; such as strictures or abscesses; are amenable to LE by either method.

The use of LE in rectal adenocarcinoma is an area of much interest and may be most appropriate in small tumors (<4 cm) confined to the submucosa (T1, as defined by the TNM staging system). Presurgical clinical staging, however, may miss up to 15% of regional lymph node spread. During an LE, the excised specimen should be examined by a pathologist; if adverse features such as high-grade pathology or unclear margins are observed, the procedure can be converted to a wider resection. Despite this increased risk of local recurrence, LE may be an informed alternative for patients. TEM permits LE beyond the reach of direct visualization equipment.


The most recent update with literature review covers through September 13, 2023.

Summary of Evidence

For individuals who have rectal adenomas who receive transanal endoscopic microsurgery (TEM), the evidence includes a few nonrandomized comparative studies, and numerous single-arm case series. The relevant outcomes are overall survival (OS), functional outcomes, health status measures, quality of life (QOL), and treatment-related morbidity. The evidence supports conclusions that the removal of polyps by TEM is associated with low postoperative complications low-risk of recurrence.

For individuals with early rectal adenocarcinoma who receive TEM, the evidence includes two small randomized controlled trials (RCTs), a few nonrandomized comparative studies, numerous single-arm case series, and systematic reviews of these studies. The relevant outcomes are OS, functional outcomes, health status measures, QOL, and treatment-related morbidity. The evidence supports the conclusions that TEM is associated with fewer postoperative complication but higher local recurrence rates and possibly higher rates of metastatic disease. One systematic review indicates improved OS with radical surgery compared with TEM; however, the majority of systematic reviews did not demonstrate significant differences in OS.

Based on clinical input supplemented by the outcomes of single-arm series that have shown low complication rates and low recurrence rates of lesions supporting use of TEM when lesions are not amenable to standard excision, TEM may be considered medically necessary for excision of rectal adenomas and early carcinomas that cannot be removed by standard approaches when specific criteria are met. These criteria are clinical stage T1 cancers that are located in the middle or upper part of the rectum, are well- or moderately differentiated (G1 or G2) by biopsy, are without lymphadenopathy, and involve less than one-third of the circumference of the rectum.

Practice Guidelines and Position Statements

National Comprehensive Cancer Network

The National Comprehensive Cancer Network (v.4.2023) in its updated guidelines on the treatment of rectal cancer states, “When the lesion can be adequately localized to the rectum, local excision of more proximal lesions may be technically feasible using advanced techniques, such as transanal endoscopic microsurgery or transanal minimally invasive surgery (TAMIS).”

However, under discussion is the statement, “TEM can facilitate excision of small tumors through the anus when lesions can be adequately identified in the rectum. TEM may be technically feasible for more proximal lesions.”

National Cancer Institute

The NCI (2021) guidelines on treatment of rectal cancer indicate the management of rectal cancer is multimodal and involves a multidisciplinary team of cancer specialists with expertise in gastroenterology, medical oncology, surgical oncology, radiation oncology, and radiology.  Based on the increased risk of local recurrence and poor overall prognosis, management of rectal cancer diverges from colon cancer. The differences include surgical technique, use of radiation therapy and method of chemotherapy administration. Additional issues are maintenance or restoration of normal anal sphincter and genitourinary function. The NCI recommends as a primary treatment for patients with rectal cancer. The NCI guidance specific to this policy includes, “…Transanal local excision and transanal endoscopic microsurgery for select clinically staged T1/T2 N0 rectal cancers.”

American Society of Colon and Rectal Surgeons

The American Society of Colon and Rectal Surgeons published updated guideline recommendations for the management of rectal cancer in 2020. The guidelines indicated that curative local excision is an appropriate treatment modality for carefully selected, well to moderately differentiated T1 rectal cancers. Tumor size must be less than 3 cm in diameter and less than 30% of the bowel lumen circumference. Additionally, patients must not have a lymphovascular or perineural invasion. The guidelines noted that visualization with TEM appears to be superior to the transanal approach, but randomized controlled trials are lacking. T2 lesions should be treated with radical resection unless the patient is a poor candidate for a more extensive surgical procedure.

American College of Radiology

The ACR;(2015) updated its 2010 appropriateness criteria on local excision of early-stage rectal cancer in 2015. The ACR notes TEMS is an appropriate operative procedure for locally complete excision of distal rectal lesions and has been “evaluated for curative treatment of invasive cancer.” TEMS is noted to have “been shown to be as effective and associated with less morbidity than conventional transanal excision” and is considered safe after treatment with chemoradiation. These ACR guidelines are based on expert consensus and analysis of current literature.

U.S. Preventive Services Task Force Recommendations

Not applicable.


Transanal endoscopic microsurgery, TEMS, TEM, rectal cancer, adenocarcinoma, adenoma


In 2001, the TEM Combination System and Instrument Set (Richard Wolf Medical Instruments) was cleared for marketing by the U.S. Food and Drug Administration (FDA) through the 510(k) process. The FDA determined that this device was substantially equivalent to existing devices for use in inflating the rectal cavity, endoscopically visualizing the surgical site, and accommodating up to 3 surgical instruments. In 2011, the SILS™ Port (Covidien) was cleared for marketing by the FDA through the 510(k) process. The SILS Port is a similar instrument that can be used for rectal procedures including TEM. Another device determined by the FDA to be substantially equivalent to these devices is the GelPOINT® Path (Applied Medical Resources). Table 1 lists some of the TEM devices cleared by the FDA.

Table 1. Transanal Endoscopic Microsurgery Devices Cleared by the U.S. Food and Drug Administration



Date Cleared

510(k) No.


Applied Medical Anoscope Applied Medical Resources 01/06/2021 K200021 For use in transanal endoscopic microsurgery

AP50/30 Insufflator with Insuflow Port

Lexion Medical LLC



For use in transanal endoscopic microsurgery


ConMed Corporation



For use in transanal endoscopic microsurgery

GRI-Alleset Veress Needle

GRI Medical and Electronic Technology Co. Ltd.



For use in transanal endoscopic microsurgery

SurgiQuest AIRSEAL iFS System

ConMed Corporation



For use in transanal endoscopic microsurgery

TEMED Gas Diffuser




For use in transanal endoscopic microsurgery

Veress Needle

WickiMed (Huizhou) Medical Equipment Manufacturing Co.Ltd.



For use in transanal endoscopic microsurgery

GelPOINT Path Transanal Access Platform

Applied Medical Resources Corp.



For use in transanal endoscopic microsurgery

HumiGard Surgical Humidification System HumiGard Humidified Insufflation Kit





For use in transanal endoscopic microsurgery

LaparoLight Veress Needle

Buffalo Filter LLC



For use in transanal endoscopic microsurgery


W.O.M World Of Medicine GmbH



For use in transanal endoscopic microsurgery





For use in transanal endoscopic microsurgery

U-Blade Veress Needle




For use in transanal endoscopic microsurgery

S698 Symbioz flow




For use in transanal endoscopic microsurgery

Insufflator 50L FM134





For use in transanal endoscopic microsurgery

Unimicro Veress Needle

Unimicro Medical Systems (ShenZhen) Co.Ltd.



For use in transanal endoscopic microsurgery

SurgiQuest AirSeal iFS System




For use in transanal endoscopic microsurgery


Coverage is subject to member’s specific benefits.  Group-specific policy will supersede this policy when applicable.

ITS: Home Policy provisions apply

FEP: Special benefit consideration may apply. Refer to member’s benefit plan. 


CPT Codes:


Excision of rectal tumor, transanal endoscopic microsurgical approach (i.e., TEMS), including muscularis propria (i.e., full thickness)


  1. Al-Najami I, Rancinger CP, Larsen MK, et al. Transanal endoscopic microsurgery for advanced polyps and early cancers in the rectum-Long-term outcome: A STROBE compliant observational study. Medicine (Baltimore). Sep 2016;95(36):e4732.
  2. Bach SP, Gilbert A, Brock K, et al. Radical surgery versus organ preservation via short-course radiotherapy followed by transanal endoscopic microsurgery for early-stage rectal cancer (TREC): a randomised, open-label feasibility study. Lancet Gastroenterol Hepatol. Feb 2021; 6(2): 92-105.
  3. Barendse RM, van den Broek FJ, Dekker E, et al. Systematic review of endoscopic mucosal resection versus transanal endoscopic microsurgery for large rectal adenomas. Endoscopy. Nov 2011; 43(11): 941-9.
  4. Chan T, Karimuddin AA, Raval MJ, et al. Predictors of rectal adenoma recurrence following transanal endoscopic surgery: a retrospective cohort study. Surg Endosc. Aug 2020; 34(8): 3398-3407.
  5. Clancy C, Burke JP, Albert MR, et al. Transanal endoscopic microsurgery versus standard transanal excision for the removal of rectal neoplasms: a systematic review and meta-analysis. Dis Colon Rectum. Feb 2015;58(2):254-261.
  6. D'Ambrosio G, Paganini AM, Balla A, et al. Quality of life in non-early rectal cancer treated by neoadjuvant radio-chemotherapy and endoluminal loco-regional resection (ELRR) by transanal endoscopic microsurgery (TEM) versus laparoscopic total mesorectal excision. Surg Endosc. Feb 2016; 30(2): 504-511.
  7. Hompes R, Ashraf SQ, Gosselink MP, et al. Evaluation of quality of life and function at 1 year after transanal endoscopic microsurgery. Colorectal Dis. Feb 2015;17(2):O54-61.
  8. IOM (Institute of Medicine). 2011. Clinical Practice Guidelines We Can Trust. Washington, DC: The National Academies Press.
  9. Issa N, Murninkas A, Schmilovitz-Weiss H, et al. Transanal Endoscopic Microsurgery After Neoadjuvant Chemoradiotherapy for Rectal Cancer. J Laparoendosc Adv Surg Tech A. Aug 2015;25(8):617-624.
  10. Laliberte AS, Lebrun A, Drolet S, et al. Transanal endoscopic microsurgery as an outpatient procedure is feasible and safe. Surg Endosc. Dec 2015; 29(12): 3454-9.
  11. Lezoche E, Baldarelli M, Lezoche G et al. Randomized clinical trial of endoluminal locoregional resection versus laparoscopic total mesorectal excision for T2 rectal cancer after neoadjuvant therapy. Br J Surg Sep 2012; 99(9):1211-8.
  12. Li W, Xiang XX, Da Wang H, et al. Transanal endoscopic microsurgery versus radical resection for early-stage rectal cancer: a systematic review and meta- analysis. Int J Colorectal Dis. Feb 17 2023; 38(1): 49.
  13. Lu JY, Lin GL, Qiu HZ, et al. Comparison of Transanal Endoscopic Microsurgery and Total Mesorectal Excision in the Treatment of T1 Rectal Cancer: A Meta-Analysis. PLoS One. 2015;10(10):e0141427.
  14. Monson JR, Weiser MR, Buie WD et al. Standards Practice Task Force of the American Society of Colon and Rectal Surgeons. Practice parameters for the management of rectal cancer (revised). Dis Colon Rectum. 2013 May; 56(5):535-50. doi: 10.1097/DCR.0b013e31828cb66c
  15. Mora Lopez L, Serra Aracil X, Hermoso Bosch J, et al. Study of anorectal function after transanal endoscopic surgery. Int J Surg. Jan 2015;13:142-147.
  16. Motamedi MAK, Mak NT, Brown CJ, et al. Local versus radical surgery for early rectal cancer with or without neoadjuvant or adjuvant therapy. Cochrane Database Syst Rev. Jun 13 2023; 6(6): CD002198.
  17. National Cancer Institute (NCI). Rectal Cancer Treatment (PDQ). Healthcare Provider Version. 
  18. National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guidelines in Oncology: Rectal Cancer. Version 4.2023. 
  19. Restivo A, Zorcolo L, D'Alia G, et al. Risk of complications and long-term functional alterations after local excision of rectal tumors with transanal endoscopic microsurgery (TEM). Int J Colorectal Dis. Feb 2016; 31(2): 257-66.
  20. Russo S, Blackstock AW, Herman JM, et al. ACR Appropriateness Criteria(R) Local Excision in Early Stage Rectal Cancer. Am J Clin Oncol. Oct 2015;38(5):520-525.
  21. Sajid MS, Farag S, Leung P, et al. Systematic review and meta-analysis of published trials comparing the effectiveness of transanal endoscopic microsurgery and radical resection in the management of early rectal cancer. Colorectal Dis. Jan 2014;16(1):2-14.
  22. Samalavicius N, Ambrazevicius M, Kilius A, et al. Transanal endoscopic microsurgery for early rectal cancer: single center experience. Wideochir Inne Tech Maloinwazyjne. Dec 2014;9(4):603-607.
  23. Sgourakis G, Lanitis S, Gockel I, et al. Transanal endoscopic microsurgery for T1 and T2 rectal cancers: a meta-analysis and meta-regression analysis of outcomes. Am Surg. Jun 2011; 77(6): 761-72.
  24. Stipa F, Picchio M, Burza A, et al. Long-term outcome of local excision after preoperative chemoradiation for ypT0 rectal cancer. Dis Colon Rectum. Nov 2014;57(11):1245-1252.
  25. van Heinsbergen M, Leijtens JW, Slooter GD, et al. Quality of Life and Bowel Dysfunction after Transanal Endoscopic Microsurgery for Rectal Cancer: One Third of Patients Experience Major Low Anterior Resection Syndrome. Dig Surg. 2020; 37(1):39-46.
  26. Verseveld M, Barendse RM, Dawson I, et al. Intramucosal carcinoma of the rectum can be safely treated with transanal endoscopic microsurgery; clinical support of the revised Vienna classification. Surg Endosc. Nov 2014;28(11):3210-3215.
  27. Verseveld M, Barendse RM, Gosselink MP, et al. Transanal minimally invasive surgery: impact on quality of life and functional outcome. Surg Endosc. Mar 2016; 30(3): 1184-7.
  28. Verseveld M, de Graaf EJ, Verhoef C, et al. Chemoradiation therapy for rectal cancer in the distal rectum followed by organ-sparing transanal endoscopic microsurgery (CARTS study). Br J Surg. Jun 2015;102(7):853-860.
  29. Xiong X, Wang C, Wang B, et al. Can transanal endoscopic microsurgery effectively treat T1 or T2 rectal cancer?A systematic reviewand meta-analysis. Surg Oncol. Jun 2021; 37: 101561.
  30. You YN, Hardiman KM, Bafford A, et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines forthe Management of Rectal Cancer. Dis Colon Rectum. Sep 2020; 63(9): 1191-1222.
  31. Zhang Y, Yu P, Wang P, et al. Analysis of the therapeutic effect of transanal endoscopic microsurgery on large rectal adenoma. J Minim Access Surg. 2022; 18(4): 571-577.


Medical Policy Group, December 2007 (2)

Medical Policy Administration Committee, January 2008

Available for comment January 5-February 20, 2008

Medical Policy Group, November 2009 (1)

Medical Policy Administration Committee, November 2009

Available for comment November 6-December 21, 2009

Medical Policy Group, November 2010 (1): Key Points, Approved by Governing Bodies updated, Verbiage update for coding update to 0184T, Reference Update.

Medical Policy Group, April 2012 (4): Updated Key points, Approved Governing Bodies and References.

Medical Policy Panel, November 2013

Medical Policy Group, March 2013 (2): Policy updated with literature search. Policy statement unchanged.  Key Points and References updated.

Medical Policy Panel, September 2013

Medical Policy Group. October 2013 (2): Policy updated with literature search.  Policy statement unchanged.  Key Points and References updated

Medical Policy Panel, September 2015

Medical Policy Group, September 2015 (4): Updates to Description, Key Points, Key Words, and References.  Clarified policy statement by adding “by biopsy” to policy statement and added “AND” for clarification purposes.  Policy statement intent unchanged.

Medical Policy Panel, November 2016

Medical Policy Group, November 2016 (4): Updates to Key Points, Approved Governing Bodies, and References. Removed “effective for dates of service prior to October 6, 2009”. No change to policy statements.

Medical Policy Panel, November 2017

Medical Policy Group, November 2017 (4): Updates to Key Points, Key Words, and References.  No change to policy statements.

Medical Policy Panel, December 2018

Medical Policy Group, December 2018 (4): Updates to Key Points and Practice Guidelines. No change to policy statements.

Medical Policy Panel, November 2019

Medical Policy Group, November 2019 (5): Updates to Description, Key Points, Approved by Governing Bodies, Practice Guidelines, and References. No changes to Policy Statement.

Medical Policy Panel, November 2020

Medical Policy Group, November 2020 (5): Updates to Key Points, Practice Guidelines and Position Statements, and References. No changes to Policy Statement.

Medical Policy Panel, November 2021

Medical Policy Group, November 2021 (5): Updates to Key Points, Practice Guidelines and References. Policy statement updated to remove “not medically necessary,” no change to policy intent.

Medical Policy Panel, November 2022

Medical Policy Group, November 2022 (5): Updates to Description, Key Points, Approved by Governing Bodies, Practice Guidelines and Position Statements, and References. No change to Policy Statement.

Medical Policy Panel, November 2023

Medical Policy Group, November 2023 (11): Updates to Key Points, Approved by Governing Bodies, Benefit Application, and References.

This medical policy is not an authorization, certification, explanation of benefits, or a contract. Eligibility and benefits are determined on a case-by-case basis according to the terms of the member’s plan in effect as of the date services are rendered. All medical policies are based on (i) research of current medical literature and (ii) review of common medical practices in the treatment and diagnosis of disease as of the date hereof. Physicians and other providers are solely responsible for all aspects of medical care and treatment, including the type, quality, and levels of care and treatment.

This policy is intended to be used for adjudication of claims (including pre-admission certification, pre-determinations, and pre-procedure review) in Blue Cross and Blue Shield’s administration of plan contracts.

The plan does not approve or deny procedures, services, testing, or equipment for our members. Our decisions concern coverage only. The decision of whether or not to have a certain test, treatment or procedure is one made between the physician and his/her patient. The plan administers benefits based on the member’s contract and corporate medical policies. Physicians should always exercise their best medical judgment in providing the care they feel is most appropriate for their patients. Needed care should not be delayed or refused because of a coverage determination.

As a general rule, benefits are payable under health plans only in cases of medical necessity and only if services or supplies are not investigational, provided the customer group contracts have such coverage.

The following Association Technology Evaluation Criteria must be met for a service/supply to be considered for coverage:

1. The technology must have final approval from the appropriate government regulatory bodies;

2. The scientific evidence must permit conclusions concerning the effect of the technology on health outcomes;

3. The technology must improve the net health outcome;

4. The technology must be as beneficial as any established alternatives;

5. The improvement must be attainable outside the investigational setting.

Medical Necessity means that health care services (e.g., procedures, treatments, supplies, devices, equipment, facilities or drugs) that a physician, exercising prudent clinical judgment, would provide to a patient for the purpose of preventing, evaluating, diagnosing or treating an illness, injury or disease or its symptoms, and that are:

1. In accordance with generally accepted standards of medical practice; and

2. Clinically appropriate in terms of type, frequency, extent, site and duration and considered effective for the patient’s illness, injury or disease; and

3. Not primarily for the convenience of the patient, physician or other health care provider; and

4. Not more costly than an alternative service or sequence of services at least as likely to produce equivalent therapeutic or diagnostic results as to the diagnosis or treatment of that patient’s illness, injury or disease.