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

TES may be considered medically necessary for treatment of clinical stage T1
rectal adenocarcinomas that cannot be removed using other means of local
excision and that meet _all_ of the following criteria:

  * Located within 8 cm of the anal verge.
  * Less than 3 cm in size
  * Well to moderately differentiated (G1 or G2) by biopsy
  * Without lymphadenopathy
  * Less than 30% of the circumference of the rectum

TES may be considered medically necessary for treatment of rectal carcinoid
tumors that cannot be removed using other means of local excision and that
meet all of the following criteria:

  * Located within 8 cm of the anal verge.
  * Less than 2 cm in size
  * No radiologic evidence of metastasis.
  * Less than 30% of the circumference of the rectum

TES is considered investigational for treatment of rectal tumors that do not
meet the criteria noted.

**Credentialing and Accreditation Standards**

Optimal outcomes of TES procedures depend on the knowledge, skill and
experience of the provider. Services will be considered medically reasonable
and necessary only if performed by appropriately trained providers.

**FDA Indications**

[Transanal Endoscopic microsurgery (TEM) combination system and instrument
set. 510K Summary:
K000180.](https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K000180)

[GelPOINT Path Transanal Access Platform. 510K Summary:
K133393](https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K133393).

[GelPOINT Path Transanal Access Platform. 510K Summary:
K171701](https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm?ID=K171701).

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

The TEMS system has a specialized magnifying rectoscope with ports for
insufflation, instrumentation, and irrigation. This procedure has been
available for over 20 years in Europe but has not been widely used in the
United States. Two reasons for this slow adoption 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.

Transanal minimally invasive surgery (TAMIS) was introduced in 2010 and
utilizes a single incision laproscopic surgery port. The advantage of this
technique is lower cost and ease of patient positioning. TAMIS appears to
require less training and skill for surgeons already proficient in single
incision laproscopic surgery due to its utilization of the same platform and
instruments.

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 patient characteristics and goals are all
attributes that will affect treatment approach. Open, wide resections have the
highest cure rate but may also have significant adverse effects. Most patients
find the potential adverse effects of lifelong colostomy and/or 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 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. local excision can occur under direct visualization in
rectal tumors within 10 cm of the anal verge. TEMS extends local excision
ability to the proximal rectosigmoid junction. Adenomas, small carcinoid
tumors, and nonmalignant conditions (e.g., strictures, abscesses) are amenable
to local excision by either method.

The use of local excision 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 local
excision, 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, local excision may be an informed alternative for
patients. TEMS permits local excision beyond the reach of direct visualization
equipment.

Barendse et al (2011) reported on a systematic review compared TEMS with
endoscopic mucosal resection (EMR) for rectal adenomas larger than 2 cm.1
Included in the review were 48 TEMS and 20 EMR studies; all were treated as
single-arm studies. No controlled trials were identified that compared TEMS
with EMR directly. Early adenoma recurrence rates, within 3 months of the
procedure, were 5.4% (95% confidence interval [CI], 4.0% to 7.3%) with TEMS
and 11.2% (95% CI, 6.0% to 19.9%) with EMR (p=0.04) in pooled estimates. After
3 months, late adenoma recurrence rates in pooled estimates were 3.0% (95% CI,
1.3% to 6.9%) with TEMS and 1.5% (95% CI, 0.6% to 3.9%) for EMR (p=0.29).
Lengths of hospitalization and readmission rates did not differ significantly
between procedures. For TEMS, mean hospital length of stay was 4.4 days and
2.2 days for EMR (p=0.23). Hospital readmission rates were 4.2% for TEMS and
3.5% for EMR (p=0.64). Complication rates after TEMS, for rectal adenomas
only, were 13.0% (95% CI, 9.8% to 17.0%) and 3.8% (95% CI, 2.8% to 5.3%) after
EMR, for colorectal adenomas (p<0.001). Postoperative complications increased
significantly with larger polyp size (p=0.04). However, postoperative
complication rates remained higher for TEMS after adjusting for a larger mean
polyp size in the TEMS studies (8.7%; 95% CI, 5.8% to 12.7%) than in EMR
studies (4.2%; 95% CI, 2.9% to 6.3%; p=0.007). These results would suggest
that TEMS may be associated with lower early cancer recurrence than with EMR
but late cancer recurrence (after 3 months) may not differ significantly
between procedures. Complications were significantly higher with TEMS for
rectal adenomas larger than 2 cm. This systematic review was limited by the
low quality of the available studies, particularly on the single-arm study
evidence base.

Middleton et al (2005) conducted a systematic review of TEMS based on
published results through August 2002. **2** Three comparative studies,
including a randomized controlled trial (RCT), and 55 case series were
included. The first area of study was the safety and efficacy in the removal
of adenomas. In the RCT, no difference could be detected in the rate of early
complications between TEMS (10.3% of 98 patients) and direct local excision
(17% of 90 patients) (relative risk, 0.61; 95% CI, 0.29 to 1.29). TEMS
resulted in lower local recurrence (6% [6/98]) than direct local excision (22%
[20/90]) (relative risk, 0.28; 95% CI, 0.12 to 0.66). The 6% local recurrence
rate for TEMS in this trial is consistent with rates found in TEMS case
series.

Al-Najami et al (2016) reported on longer term follow-up for a prospective
cohort study of 280 patients with advanced polyps and early rectal cancer
treated with TEMS.16 Most patients (n=163 [63%]) had benign disease.
Postoperative complications were more frequent in malignant cases (24.0%) than
in benign cases (10.8%; p=0.03). A standard follow-up protocol was followed by
83% and 85% of benign and malignant cases, respectively. Over a mean follow-up
of 16.4 and 15.2 months in the benign and malignant groups, recurrence rates
were 8.3% and 13.5%, respectively.

A meta-analysis by Lu et al (2015) compared TEMS with total mesorectal
excision for T1 rectal cancer.17 Studies selected included 1 RCT and 6 non-
RCTs (303 treated with TEMS; 557 treated with total mesorectal excision). For
the outcome of postoperative recurrence, the rate of local recurrence was
higher after TEMS (odds ratio [OR], 4.63; 95% CI, 2.03 to 10.53; p<0.001, _I_
2=0%). For the 6 studies reporting on OS, there were no significant
differences between the TEMS and total mesorectal excision groups (OR=0.87;
95% CI, 0.55 to 1.38; p=0.55, _I_ 2=0%).

Clancy et al (2015) published a systematic review of the comparative efficacy
of TEMS and standard transanal excision (TAE) for early rectal cancer.18 Six
studies including outcomes for 927 excisions were selected, all of which were
nonrandomized. On combined analysis, TEMS had a higher rate of negative
surgical margins (OR=5.3; 95% CI 3.2 to 8.7) and a lower rate of recurrence
(OR=0.25; 95% CI, 0.15 to 0.40) compared with standard excision. Complication
rates did not differ significantly between techniques (OR=1.018; 95% CI, 0.658
to 1.575).

Sajid et al (2014) reported on a systematic review and meta-analysis of TEMS
and radical resection for stage T1 and T2 rectal cancers.19 Included in the
review were 5 RCTs and 5 cohort studies (445 TEMS patients, 438 radical
resection patients). In random-effects models, there was a greater risk of
local recurrence with TEMS than with radical resection (OR=2.78; 95% CI, 1.42
to 5.44; p<0.003) and a greater risk of overall recurrence (OR=2.01; 95% CI,
1.18 to 3.42; p<0.01). The risk of distant recurrence did not differ
significantly between procedures (OR=0.87; 95% CI, 0.41 to 1.83; p=0.71) nor
did OS rates (OR=0.90; 95% CI, 0.49 to 1.66; p=0.74). In a subgroup analysis
of the 5 RCTs, the risk of overall recurrence remained higher with TEMS
(OR=2.21; 95% CI, 1.10 to 4.41; p<0.03). OS rates, however, did not differ
significantly between TEMS and radical resection (OR=0.80; 95% CI 0.43 to
1.47; p=0.47), and postoperative complications were significantly lower with
TEMS (OR=0.19; 95% CI, 0.08 to 0.44; p<0.001).

Wu et al (2011) published a meta-analysis on TEMS and conventional surgery for
stage T1 rectal cancers.20 Five studies were selected, including a prospective
RCT and 4 retrospective, nonrandomized studies for a total of 397 (216 TEMS,
181 conventional rectal surgery) patients. Combined analyses were performed
for mortality, postoperative complications, recurrence rates, and 5-year
survival. No deaths were reported from either procedure, and TEMS had fewer
postoperative complications (16/196) than conventional surgery (77/163). On
combined analysis, the odds for complications was 0.10 (95% CI, 0.05 to 0.18).
There was a higher rate of local recurrence or distant metastasis at 40-month
follow-up for TEMS (12% [26/216]) than for conventional radical surgery (0.5%
[1/181]). On combined analysis, the odds for recurrence in the conventional
surgery group was 8.64 (95% CI, 2.63 to 28.39). The 5-year survival (not
specified as disease-specific or overall), as reported in 4 studies, did not
differ significantly between groups (80.1% [157/196] for TEMS vs 81% [132/163]
for conventional surgery). These results supported the conclusion that TEMS is
associated with fewer early complications but higher rates of recurrence than
standard resection, with no demonstrable differences in open surgery (OS).

Sgourakis et al (2011) conducted a meta-analysis of stage T1 and T2 rectal
cancer treatment that compared TEMS with standard resection and TAE.21 Eleven
studies were selected for analysis and included 3 randomized controlled, 1
prospective, and 7 retrospective trials (total N=1191 patients; 514 TEMS, 291
standard resections, 386 TAE). Numerous combined analyses were performed to
measure mortality, complications, and recurrence rates. For postoperative
complication rates, combined analysis showed a significantly lower rate of
major complications for TEMS than for standard resection (OR=0.24; 95% CI,
0.07 to 0.91). Minor complications did not differ significantly between
groups. Overall postoperative complications did not differ significantly
between TEMS and TAE when stage T1 and T2 tumor data were pooled. Follow-up
for all studies was a mean or median of more than 30 months (except for
follow-up >20 months in 1 treatment arm in 2 studies). For T1 tumors, local
recurrence was significantly higher for the TEMS group than for the standard
resection group (OR=4.92; 95% CI, 1.81 to 13.41), as was overall recurrence
(OR=2.03; 95% CI, 1.15 to 3.57). Distant metastasis (OR=1.05; 95% CI, 0.47 to
2.39) and OS (OR=1.14; 95% CI, 0.55 to 2.34) did not differ significantly
between groups. Results were similar when data were analyzed for T1 and T2
tumors, except that disease-free survival was significantly longer with TEMS
than with TAE. There was less evidence for T2 tumors, and conclusions for that
group of patients were less clear. The results of this review also supported
conclusions that TEMS is associated with fewer postoperative complications
than standard resection, higher local and distant recurrence rates, and no
differences in the long-term OS.

Doornebosch et al (2009) discussed weaknesses in the evidence and unresolved
issues about the role of TEMS.22 Reviewers posed 3 questions: "First, is there
enough evidence to propagate LE [local excision] as a curative option in
selected (T1) rectal carcinomas? Second, if LE is justified, which technique
should be the method of choice? Third, can we adequately identify, pre- and
postoperatively, tumors suitable for LE?" They noted that selection bias in
studies complicated answering the first question; and a significant portion of
tumors recurred in all studies using various techniques for LE (including
TEMS), although it seemed not to influence survival rates. Reviewers noted
that the published case series reporting outcomes after TEMS for T1 rectal
carcinomas used inclusion criteria that were not always clear and used salvage
procedures that could introduce bias. TEMS was demonstrated to be a safe
procedure in all series; complication rates varied between 5% and 26%, and
complications were generally minor. Local recurrence rates for TEMS varied
between 4% and 33% in the studies reviewed. On the third question, reviewers
assessed whether high recurrence rates could be improved by better tumor
selection. They noted that TEMS had been incorporated into surgical practice
based largely on retrospective case series, and noted that, despite the lack
of level I evidence, its use seemed justified in well-selected T1 rectal
cancers. They also indicated that some view TEMS as an alternative for
patients with T1 lesions who are currently undergoing other methods of LE (eg,
using the Parks technique instead of radical surgery).

E. Lezoche et al (2012) published an RCT of 100 patients with T2 rectal
cancers without evidence of lymph node or distant metastasis randomized to
TEMS or laparoscopic total mesorectal excision.23 All patients also received
neoadjuvant chemoradiation before surgery. All patients in the TEMS group
completed the procedure. With laparoscopic resection, 5 (10%) patients
required conversion to open surgery (p=0.028), and 23 patients required a
stoma. Postoperative complications did not differ significantly between
groups. Disease-free survival also did not differ significantly between groups
(p=0.686) at a median follow-up of 9.6 years (range, 4.7-12.3 years for
laparoscopic resection; range, 5.5-12.4 years for TEMS). Local recurrence or
metastases occurred in 6 TEMS patients and 5 laparoscopic patients.

G. Lezoche et al (2008) reported on a similar RCT evaluating of 70 subjects
with stage T2 rectal cancer without evidence of lymph node or distant
metastasis on imaging.24Patients were randomized to TEMS or laparoscopic
resection via total mesorectal excision. All patients received chemoradiation
before surgery. Median follow-up was 84 months (range, 72-96 months). Two
(5.7%) local recurrences were observed after TEMS and 1 (2.8%) after
laparoscopic resection. Distant metastases occurred in 1 patient in each
group. The probability of survival from rectal cancer was 94% for both groups.
Overlap of patients studied in the 2008 and 2012 trials could not be
determined.

A large number of case series and retrospective nonrandomized comparative
reviews have been published.3-13 The case series offer useful information on
the completeness of resection, local recurrence, and complications, but does
not provide definitive evidence on the comparative efficacy of TEMS because
the comparisons were limited by potential selection bias leading to
differences in patient characteristics.

Much of the research has focused on the technical aspects of TEMS and on
other, non-neoplastic applications. Other studies have investigated the use of
TEMS with adjuvant therapy or additional techniques. For example, Walega et al
(2010) reported on a small study that added endoscopic mesorectum resection to
TEMS.25

Moore et al (2008) retrospectively reviewed patients who underwent TAE for
rectal neoplasms and compared results for traditional transanal resection with
TEMS.26 Of 296 patients identified, 76 were excluded because of surgery due to
abscesses, fistulas, inflammatory bowel disease, or multiple lesions. Forty-
nine patients were excluded because of incomplete or missing charts. Records
of 171 patients were analyzed; 82 patients who underwent TEMS and 89 who had a
transanal resection. For patients who received TEMS, those with stage T1
lesions without adverse histologic features (poor differentiation,
lymphovascular invasion) received local excision alone. Patients with T1
lesions with adverse features or T2 lesions received postoperative
chemoradiation. Local excision was performed for T3 lesions only in high-risk
patients or those who refused radical resection. In the TEMS group, there were
40 polyps, 5 carcinoma in situ, 21 T1 lesions, 7 T2 lesions, 8 T3 lesions, no
indeterminate lesions, and 1 carcinoid lesion; in the transanal resection
group, there were: 38 polyps, 4 carcinoma in situ, 20 T1 lesions, 19 T2
lesions, 6 T3 lesions, 1 indeterminate lesion, and 1 carcinoid lesion. There
were 12 (15%) postoperative complications (4 major) in the TEMS group and 15
(17%) complications in the transanal resection group (6 major). In the TEMS
group, 90% had negative tumor margins, and none had indeterminate margins vs
71% negative and 15% indeterminate margins in the transanal resection
patients. Local recurrence was less frequent after TEMS (4%) than after
transanal resection (24%; p=0.004). The difference between groups in distant
recurrence was not statistically significant. Three TEMS patients with
malignant lesions underwent radical resection and were excluded from
recurrence analyses. The recurrence rate among cancer patients did not differ
statistically between groups. For patients with adenomas, the overall
recurrence rate after TEMS was 3% and 32% for transanal resection. In patients
with polyps, clear margins were achieved more frequently after TEMS (83%) than
after transanal resection (61%).

A number of studies identified have raised questions about disease recurrence
after TEMS for stage T1 rectal cancer.27-29 For example, Doornebosch et al
(2010) reported on TEMS for 88 patients, 18 (20.5%) of whom had a local
recurrence.27 Of them, 16 patients had salvage surgery. At the 3-year follow-
up, the OS rate was 31%, and the cancer-related survival rate was 58%. Authors
concluded that further tailoring patient and tumor selection before a decision
for LE might improve survival.

In an editorial accompanying this study, Friel (2010) commented on the use of
LE in the treatment of T1 rectal lesions.30 He noted that the reported
recurrence rate should raise concerns and calls for additional studies of
recurrence with LE to verify the Doornebosch findings. Friel also noted that
LE must still be considered as an oncologic compromise between lower surgical
morbidity but higher disease recurrence and that, once fully informed,
patients may find this compromise acceptable.

**National Comprehensive Cancer Network**

The National Comprehensive Cancer Network (NCCN) guidelines on the treatment
of rectal cancer (v.3.2018) state that, when criteria for transanal resection
are met, TEMS can be used when the tumor can be adequately identified in the
rectum.31 The Network further states that TEMS for more proximal lesions (>8
cm from anal verge) may be technically feasible. The guidelines are based on
level 2A evidence.

**National Cancer Institute**

The 2018 National Cancer Institute (NCI; 2018) 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.32 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 radiotherapy, and method of
chemotherapy administration. Additional issues are maintenance or restoration
of the normal anal sphincter and genitourinary function. NCI recommends as a
primary treatment for patients with rectal cancer surgical resection of the
primary tumor. NCI guidance specific to this evidence review 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 (2013) updated its 2010
practice parameters for the management of rectal cancer.33 The 2013 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 one-third of the
bowel lumen circumference. Additionally, patients must not have lymphovascular
or perineural invasion. The guidelines noted that visualization with TEMS
appears to be superior to the transanal approach, but randomized controlled
trials are lacking. T2 lesions should be treated with radical mesenteric
excision unless the patient is a poor candidate for a more extensive surgical
procedure.

**American College of Radiology**

The American College of Radiology (ACR; 2015) updated its 2010 appropriateness
criteria on local excision of early-stage rectal cancer.34,35 ACR noted that
TEMS is an appropriate operative procedure for locally complete excision of
distal rectal lesions and has been "evaluated for curative treatment of
invasive cancer." ACR also noted that TEMS has "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
were based on expert consensus and analysis of current literature.

**Regulatory Status**

In March 2001, the TEMS 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. 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 SILSTM Port (Covidien)
was cleared for marketing by FDA through the 510(k) process. The SILSTM Port is
a similar instrument that can be used for rectal procedures including TEMS.
Another device determined by the FDA to be substantially equivalent to these
devices is the GelPOINT Path (Applied Medical Resources). FDA product codes:
HIF, GCJ, FER.

TES has a large body of evidence for treatment of benign adenomas, carcinoid
tumors and malignant tumors. When used according to the appropriate guidelines
it is a safe and effective alternative to radical resection. In addition to
the evidence reviewed in this policy practice guidelines supports its use most
notable the NCCN guideline on treatment of rectal cancer (v.1.2020) supports
its use based on level 2A evidence.