Transanal Endoscopic Microsurgery
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This policy governs medical necessity and coverage of transanal endoscopic microsurgery (TEM) for members covered by Aetna, specifying indications considered medically necessary and those considered experimental/investigational.
No material clinical or coverage changes in this revision.
Coverage Criteria for Transanal Endoscopic Microsurgery (TEM)
inv-01: Medically necessary indications
Aetna considers transanal endoscopic microsurgery (TEM) medically necessary when ANY one of the following is met:
inv-02: Experimental / investigational (not covered) indications
Aetna considers TEM experimental and investigational for the following indications (examples, not all-inclusive):
inv-03: Appropriate indications for TEM
Covered when ALL of the following typical selection criteria are met (per guideline summaries cited):
Source: practice parameters and guideline assessments
inv-04: Other supported indications
Additional appropriate uses described in the literature:
Reported in prospective and retrospective series.
inv-05: Evidence-based use cases and cautions
Situations and outcomes described in the evidence:
Supported by low recurrence rates for adenomas and selective use in T1 cancers.
Higher local recurrence and lower unadjusted overall survival reported for TEM-only in pT2-3 compared to completion surgery.
Comparative data cited (ESD vs TEM).
Reported series showed recurrences associated with fibrotic scar tissue.
inv-06: Coverage stance and clinical criteria
Evidence and clinical findings described in the document support selective use of TEM/related techniques under these clinical scenarios and limitations:
Multiple retrospective series and TEM-ESD reports.
Outcomes heterogeneous; prior diversion and scar tissue affect success.
Evidence primarily retrospective and from single groups.
Retrospective data with small samples.
ICD-10 diagnosis codes are used to align the indication for transanal endoscopic microsurgery (TEM) with the policy's covered indications. TEM is considered medically necessary when used for benign rectal tumors (adenomas), low‑risk Tis or T1 rectal carcinoma, or small rectal carcinoids (<2 cm in diameter). Representative ICD‑10 codes listed as covered when selection criteria are met include C20 (malignant neoplasm of rectum [low‑risk]), C7A.026 (malignant carcinoid tumor of the rectum), D01.1–D01.2 (carcinoma in situ of rectosigmoid junction/rectum), and D12.7–D12.9 (benign neoplasms of rectosigmoid/rectum/anus).
High‑risk features and unfavorable tumor characteristics that make a lesion unsuitable for TEM include T‑stage above T1 (T2 or greater), evidence of regional lymphadenopathy, lymphovascular or perineural invasion, and poor (or poorly differentiated) histology. Guideline and workshop summaries recommend TEM only for carefully selected small, well‑ to moderately‑differentiated T1 tumors without nodal disease and limited circumferential involvement, because these high‑risk features are associated with higher recurrence after local excision.
Giant rectal villous polyps (for example, those >8 cm in maximum dimension or circumferential lesions) are generally not amenable to TEM. These large lesions are associated with a high combined risk of dysplasia or malignancy (reported around 83% overall, with frank malignancy in about 33% of lesions >8 cm) and typically require formal radical oncologic resection rather than local endoluminal approaches.
TEM (or TEO) repair for recto‑vesical or other recto‑urinary fistulas may be successful for simple fistulas; however, when the fistula tract is surrounded by wide, tough, fibrotic scar tissue from prior irradiation, HIFU, or multiple previous repair attempts, outcomes are poor and recurrence is common. In such heavily scarred or irradiated tissue, TEM repair is not recommended because closure failures and recurrences were observed in cases with fibrotic surroundings.
This Clinical Policy Bulletin provides a general summary to assist in administering plan or program benefits but does not constitute a contract, an offer of coverage, or medical advice. Actual coverage determinations are governed by the terms of the member's plan or program and applicable contracts; providers should consult benefit documents and plan administrators for member‑specific coverage decisions.
Use of TEM for indications other than the policy's specified medically necessary indications (benign rectal adenomas, low‑risk Tis/T1 rectal carcinoma, or small rectal carcinoids <2 cm) is considered experimental and investigational and therefore not medically necessary. Examples include advanced rectal cancer, anorectal melanoma, rectal GIST, rectal prolapse, recto‑urinary fistula, and other listed conditions.
For more advanced rectal cancers (T2 or greater), TEM is generally considered experimental or palliative rather than curative. Multiple reviews and series indicate higher local recurrence after TEM‑only for pT2–pT3 tumors compared with completion radical resection (TME), and therefore TEM alone should not be used routinely when curative oncologic resection is intended.
Comparative series show that TEM‑only management of pT2–pT3 rectal adenocarcinoma is associated with higher local recurrence and lower unadjusted overall survival compared with patients who underwent completion radical surgery. These findings support recommending completion total mesorectal excision when pathology shows more advanced invasion than anticipated after local excision.
Reports of TEM/TEO for recto‑urinary fistula demonstrate variable outcomes. Pooled literature describes healing in a majority of cases in some series, but a prospective observational series of TEO/TEM repairs for recto‑urethral fistula reported a 25% success rate (2 of 8 repaired cases), with many patients requiring gracilis muscle interposition salvage procedures. These data indicate limited efficacy of TEM/TEO as the primary technique for complex RUF.
Covered CPT code when selection criteria are met: 0184T — Excision of rectal tumor, transanal endoscopic microsurgical approach (TEMS), including muscularis propria (full thickness).
A commonly cited threshold for suitability of rectal carcinoids for local excision/TEM is a maximum diameter of 2 cm; carcinoid tumors smaller than this are listed among the policy's medically necessary indications when other selection criteria are met.
Coding and Diagnosis Codes
| 0184T | Excision of rectal tumor, transanal endoscopic microsurgical approach (ie, TEMS), including muscularis propria (ie, full thickness). |
| C20 | Malignant neoplasm of rectum [low-risk] [not covered for advanced rectal cancer] [giant villous adenoma]. |
| C7A.026 | Malignant carcinoid tumor of the rectum. |
| D01.1 | Carcinoma in situ of rectosigmoid junction. |
| D01.2 | Carcinoma in situ of rectum. |
| D12.7 | Benign neoplasm of rectosigmoid junction. |
| D12.8 | Benign neoplasm of rectum. |
| D12.9 | Benign neoplasm of anus and anal canal. |
| D3A.026 | Benign carcinoid tumor of the rectum. |
| B57.32 | Megacolon in Chagas' disease. |
| C43.51 | Malignant melanoma of anal skin. |
| C49.A0 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A1 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A2 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A3 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A4 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A5 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A6 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
| C49.A7 | Gastrointestinal stromal tumor [rectal gastro-intestinal stromal tumor]. |
Provider Actions, Prior Authorization, and Documentation
Prior Authorization Required
Prior authorization is required for transanal endoscopic microsurgery (TEM, CPT 0184T). Authorization decisions are contingent on the procedure meeting the plan's selection criteria for TEM and other benefit provisions.
- Prior authorization required for CPT 0184T (Excision of rectal tumor, transanal endoscopic microsurgical approach).
- Coverage contingent on meeting documented selection criteria and plan provisions.
Staging and Need for Completion Surgery
Preoperative clinical staging must be documented and the plan for completion radical surgery discussed when appropriate. If final pathology shows higher-stage disease (e.g., T2 or greater) or other high-risk features, completion total mesorectal excision should be considered and documented in the record and prior-authorization notes.
- Document clinical stage (cTNM) and the imaging/staging modalities used (e.g., endorectal ultrasound, pelvic MRI).
- Document counseling on the possibility and timing of completion total mesorectal excision if post‑operative pathology indicates more invasive disease.
Clinical Documentation for Authorization
Clinical documentation submitted with prior authorization requests must include indication for TEM and supporting preoperative data to allow clinical review and determination of appropriateness.
- Primary indication (e.g., adenoma, Tis, T1 rectal cancer, rectal carcinoid) with corresponding ICD-10 code.
- Preoperative staging results (endorectal ultrasound, pelvic MRI, CT as indicated).
- Evidence of absence of nodal disease or documented rationale if nodal evaluation limited.
Prior Authorization Guidance
Prior authorization determinations are administrative and based on the Clinical Policy Bulletin; however, plan benefit provisions (member eligibility, benefit limits, and exclusions) govern final coverage decisions.
- Clinical Policy Bulletin is a reference to assist administration of benefits — it does not guarantee coverage.
- Authorizations do not override plan terms, member eligibility, or contract exclusions.
Selection-Related Denial Risk
Procedures for tumors that do not meet established TEM selection criteria (for example T2 or greater, >3 cm, involving >30% of circumference, fixed/non-mobile tumors, evidence of nodal disease) are at high risk for denial as experimental/investigational or not medically necessary.
- High denial risk when tumor characteristics are inconsistent with covered TEM indications (e.g., T2+, >3 cm, >30% circumference, fixed tumor, lymphadenopathy).
- Procedures performed for indications listed as experimental/investigational in the policy may be denied.
Required Clinical Documentation
Required clinical documentation elements for authorization and medical record retention include explicit tumor characteristics and pathology information used in outcome analyses and selection decisions.
- Tumor size (maximum diameter) and percent circumferential involvement.
- Distance from the anal verge (in cm) and tumor mobility.
- T‑stage (clinical and, when available, pathologic), differentiation, and presence/absence of lympho‑vascular or perineural invasion.
- Margins (expected and post‑operative), and whether excision was en bloc or piecemeal.
Preoperative and Pathology Documentation
Preoperative records and final pathology must be submitted and clearly documented because preoperative staging can understage tumors; final pathology may necessitate additional treatment recommendations.
- Preoperative: imaging reports, endoscopic findings, biopsy results, and multidisciplinary discussion notes.
- Postoperative: operative report, specimen orientation, margin status, pathologic T-stage, grade, and presence of lympho‑vascular invasion.
Technique Selection and Sequencing
Because TEM and alternative techniques (e.g., ESD, TEM‑ESD) have differing indications and outcomes, documentation should include the rationale for technique selection and consideration of less invasive options when appropriate.
- Document why TEM was chosen over ESD or vice versa (lesion depth, size, location, expected en‑bloc resection rate, operator expertise).
- Consider TEM‑ESD or referral to specialized centers when indicated by lesion characteristics.
Pathology and Staging Documentation
Final pathology and staging documentation are required to assess adequacy of local excision and to identify patients who need completion radical surgery; documentation is necessary because preoperative staging may underestimate invasion.
- Submit full pathology report including pathologic T-stage, margin status (R0/R1), grade, and presence of adverse features.
- Document counseling and recommendations for completion surgery if pathology reveals T2+ disease or other high‑risk features.
Radiotherapy Consideration
Guideline-level guidance recommends cautious, selective use of external beam radiotherapy (EBRT) as adjuvant or neoadjuvant therapy; EBRT should only be used in highly selected cases or within clinical trials and documented rationale must be provided when used to augment TEM.
- If adjuvant or neoadjuvant radiotherapy is planned or given, include indication, regimen, timing relative to TEM, and multidisciplinary rationale.
- EBRT should not be used indiscriminately in patients who are potentially surgically resectable.
Refer to Policy Links for Documentation
Providers should consult the policy review history, definitions, and Clinical Policy Bulletin notes for additional documentation instructions and administrative details when preparing authorization requests.
- Refer to the policy's Review History and Definitions pages for terminology and procedural expectations.
- Use the Clinical Policy Bulletin Notes as an administrative reference when submitting documentation for prior authorization.
Background and Clinical Evidence
Rectal cancers are staged using the TNM system (Tis–T4, N0–N3, M0–M1) and assigned stages 0–IV. Surgical decision‑making depends on tumor location, depth of invasion and clinical stage. TEM is a minimally invasive full‑thickness transanal excision technique primarily used for adenomas and selected early rectal carcinomas to preserve the rectum and avoid radical resection in appropriately selected patients.
inv-05: Evidence-based use cases and cautions (additional placement for evidence narrative)
Evidence-based use cases and cautions (additional narrative placement):
See cited series and reviews for recurrence, morbidity, and comparative outcomes.
Reported in multiple series and systematic reviews.
When selecting technique, comparative evidence indicates TEM achieves higher en‑bloc and R0 resection rates compared with endoscopic submucosal dissection (ESD) for large non‑pedunculated rectal lesions, but ESD may offer shorter procedure time and hospital stay in some series. Choice between TEM and alternative techniques (ESD or radical resection) should be based on lesion characteristics, ability to achieve clear margins, staging, and patient fitness for radical surgery.
Definitions
Revision History
Policy became effective.
Policy was last reviewed on October 6, 2023.
Next scheduled review is August 8, 2024.
This Clinical Policy Bulletin is provided to assist in administration of plan benefits and to document the policy's scope and review history. It does not alter plan contract terms. Providers should be aware of the policy's review dates and consult member benefit documents and the policy's review/history pages for administrative details and any updates.
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