Keywords
transanal endoscopic microsurgery - postoperative complications - suture techniques
- cautery - fistula - colonic polyp
Introduction
Since the Development of Transanal Endoscopic Microsurgery (TEM) by Gerhard Buess
the number of published articles with application of this technique has increased
and today there are lots of colorectal centers that use this method. In early 1980s
with introduction of TEM it takes time to master the technique but now with development
of endoscopic and laparoscopic skills mastering the learning curve is becoming quicker.[1]
Comparing with other endoscopic modalities TEM has the advantage of full thickness
manipulation of rectum which gives surgeon the ability to handle high risk patients
and alleviate the necessity of major trans abdominal operations.[2] Because of its low complication rate TEM is considered as gold standard modality
for local transanal operations and new armaments are added to its capabilities.[3]
As TEM experience grows colorectal centers publish their experience regarding operation
technique,[4] devices that used,[3] efficacy and complications.[5] although these studies have some suggestions for application of TEM but all of them
suggest further studies with larger sample size and longer follow-up period.
In this study the authors describe all of TEM operations in a tertiary colorectal
referral center during eight years and follow the patients for possible complication
to demonstrate TEM applicability in middle east countries.
Materials and Methods
After approval by the ethical committee, the data gathering was started by reviewing
the charts of patients who undergone TEM in our center. Patients who were operated
via Transanal rout without using TEM device were excluded.
In our center all of TEM candidates are admitted day before surgery and receive whole
bowel preparation and procedure is done under general anesthesia. Prior to TEM setup
a rigid rectosigmoidoscopy is performed to determine lesion distance from anal verge
and the exact site of lesion to choose patient's position for example in posterior
lesions the procedure is done in supine lithotomy position and for anterior lesions
the position changed to prone. All patients received prophylactic antibiotic and liquid
diet started after first bowel movement and advanced gradually.
Patients' chief complain, colonoscopic findings and pathology of colonoscopy biopsies
were entered as preoperative findings. Intraoperative findings and technical issues
such as closing the defect or leaving the defect open or energy devices that used
during the operation were also recorded. The postoperative course or events happened
during hospital stay also reviewed. After that history of further admissions were
checked. After that histopathologic report of patients were extracted from pathology
database in order to compare colonoscopy and TEM histopathology report.
The data were entered in to SPSS database and for demonstrating quantitative indices
mean with standard deviation were used in order to compare means of variables paired
t-test was applied. To compare different prevalence between groups chi-square test
used and P value less than 0.05 considered significant.
Results
From 2012 TEM device was setup in our center and with reviewing the archive 150 patients
were operated with this device till the end of 2020.
Patients Demographic Profile
Most of patients were male with prevalence of 64%. The mean age of patients was 52.1 ± 16.62
years old. The youngest patient was 18 and the oldest one was 87 years old, the age
groups were shown in table one. The most common symptom was rectal bleeding. Table
one describe the primary demographic features of patients ([Table 1]).
Table 1
Basic Demographic Features
|
Sex
|
Male(n)
|
64% (96)
|
|
|
|
Female(n)
|
36% (54)
|
|
|
|
Age Groups
|
<30 Y/O
|
12.6% (19)
|
Mean ± SD: 52.1 ± 16.62
|
|
31-60 Y/O
|
53.3% (80)
|
|
>60 Y/O
|
34% (51)
|
|
Symptom
|
Rectal Bleeding
|
64.7% (97)
|
|
|
|
Constipation
|
11.3% (17)
|
|
|
|
Diarrhea
|
4% (6)
|
|
|
|
Abdominal Pain
|
3.3% (5)
|
|
|
|
Y/O: Years Old
|
Procedures
As shown in table two the most common procedure that was done with TEM were resectional
procedures (97%) followed by Stricturoplasty (1%) and endorectal flap (1%). Stricturoplasty
was performed due to anastomosis stricture following low anterior resection and mucosal
defect was closed with PDS 3-0 in one case and left open in the other case and it
was based on surgeon decision during the operation. Endorectal flap was done in a
case of extra sphincteric fistula and the flap was sutured with PDS 3-0. This patient
was come back with recurrence of fistula six months after initial operation that was
manage with seton insertion. Another case of endorectal flap was due to rectovaginal
fistula this case was also closed with PDS 3-0 ([Table 2]).
Table 2
Procedures done with TEM
|
Resectional Procedure
|
146 (97.3%)
|
|
Stricturoplasty
|
2 (1.3%)
|
|
Endorectal Flap
|
2 (1.3%)
|
Follow-up and Complications
The mean duration of patient's follow-up was 31.6 ± 21.7 months although six patients
lost the follow-up. Complication following TEM were one case of in hospital mortality,
Colon perforation and fistula development. The expired patient was a 71 Y/O female
with rectal bleeding that colonoscopy showed a mass in the rectum and biopsy showed
villous adenoma with high grade dysplasia that was referred for TEM the mass was found
12 cm above anal verge and it was excised and defect was closed and TEM biopsy revealed
well differentiated adenocarcinoma. This patient was expired with the picture of sudden
cardiac arrest and family refuse to do autopsy. Following resectional procedures only
one case developed with perianal fistula, in this case the defect following excision
was closed with PDS 3-0 and Harmonic scalpel was used as energy device. The case of
colon perforation was diagnosed during operation and Site of perforation was at rectosigmoid
junction that was repaired with laparoscopy and patient discharged without complication.
All of operated patients were continent subjectively so we did not evaluate them for
fecal incontinence.
Energy Devices
Regarding the availability of different energy devices in our center surgeons have
options to select the device regarding the location and size of lesion. Ligasure is
the most frequent energy device that was used with frequency of 75.3%, after that
electrocautery was used in 16.7% of cases. Harmonic was the least energy device which
was used in 8% of patients. There is no specific correlation between complications
and use of energy device however in patient with recurrence after endorectal flap
Ligasure was used as energy device.
Suturing
In 7.3% of patients the defect after resection was left open and not sutured it was
based on surgeon decision although these all of these lesions were located in lower
and mid part of rectum. PDS 3-0 is the most frequent suture material that was used
in 81.3% of cases followed by PDS 2-0 that was used in 6% of cases.
One of the cases that develop with fistula after resection of polyp was sutured with
PDS 3-0 and there was no complication in patients that the defect was not closed.
Correlation between Colonoscopy and TEM
The mean distance of lesion from anal verge measure by colonoscopy versus TEM is described
in table three. The difference between two mean is not statistically significant showed
by paired t-test ([Table 3]).
Table 3
Distance Measurement Using TEM Versus Colonoscopy
|
Distance (cm from anal verge)
|
Standard Deviation
|
P value
|
|
Colonoscopy
|
8.06
|
3.91
|
0.06
|
|
TEM
|
8.56
|
3.83
|
In colonoscopy two cases had pathology of well differentiated adenocarcinoma that
were referred for evaluation of tumor remnant following colonoscopic polypectomy and
in both of them resection of site of excision with TEM did not revealed remnant malignant
pathology. None of them had recurrence after 33- and 53-months follow-up.
Colonoscopic biopsy of patients with TEM proved malignant lesions are showed in table
four. As it is shown the most colonoscopy biopsy that is associated with malignancy
is villous adenoma even with low grade or high-grade dysplasia ([Table 4]).
Table 4
Prevalence of Colonoscopy Biopsy Result in Patients with Malignant lesion Proved with
TEM
|
Adenomatous Villous Adenoma with High Grade Dysplasia
|
36%
|
|
Adenomatous Villous Adenoma with Low Grade Dysplasia
|
20%
|
|
Adenomatous Tubulo-villous Adenoma with Low Grade Dysplasia
|
16%
|
|
Adenomatous Tubulo-villous Adenoma with High Grade Dysplasia
|
8%
|
|
Adenomatous Tubular Adenoma with High Grade Dysplasia
|
8%
|
Prevalence of malignancy in premalignant lesions that were detected in colonoscopy
were also demonstrated in table five. Adenomatous villous polyps with high grade dysplasia
detected in colonoscopy had the highest rate of malignancy (52.63%) and none of the
patients with adenomatous tubular polyps with low grade dysplasia had malignancy ([Table 5]).
Table 5
Prevalence of Malignancy in Pre-Malignant Lesions Detected by Colonoscopy
|
Lesion in Colonoscopy
|
Prevalence of Malignancy
|
|
Villous Polyp with High Grade Dysplasia
|
52.63%
|
|
Villous Polyp with Low Grade Dysplasia
|
29.41%
|
|
Tubulovillous Polyp with Low Grade Dysplasia
|
22.22%
|
|
Tubulovillous Polyp with High Grade Dysplasia
|
20%
|
|
Tubular Polyp with High Grade Dysplasia
|
15.38%
|
|
Tubular Polyp with Low Grade Dysplasia
|
0%
|
|
Tubulovillous Polyp with Moderate Dysplasia
|
0%
|
Evaluation of Lesion Base
Base evaluation was done only in 77 lesions that were resected with TEM in 29 patients
the base was involved and in 48 patients the base was free. Chi square analysis showed
no significant effect of specific energy device on base involvement (P value:0.63).
The mean distance from anal verge measured during TEM was not also associated with
base involvement (P value: 0.27). 62% of patients with involved base had malignant
pathology that undergone radical resection. The aim of TEM in this group of patients
is to obtain adequate excisional biopsy for better histopathologic evaluation. There
were six cases of neuroendocrine tumors that all of them resected with free base.
Discussion
This study was conducted to demonstrate the efficacy of TEM and its applicability
in management of different proctologic procedure regarding the instruments available
in middle eastern hospitals. Like previous reports[6] most of operation that were done in our center were resectional procedures for management
of premalignant lesions. These lesions had grossly malignant features in colonoscopy,
but colonoscopy biopsy failed to show malignancy, so TEM was applied in order to have
an excisional biopsy of lesion. As shown in Table five and six the prevalence of malignancy
in these patients is considerable. We have not started managing malignant lesions
or doing palliative resections using TEM. The feasibility of TEM for endorectal flap
or Stricturoplasty is demonstrated before.[7]
[8]
Previous reports showed the 10% rate of complications for TEM. The major complications
are bowel perforation, fecal incontinence, and pelvic sepsis. Mortality is also reported
in some cases and is mostly related to advanced metastatic disease in patients undergone
palliative resections. Comparing with rectal resection this rate of complication and
mortality is acceptable.[6] The rate of complications in our study is similar to universal reports and even
lower that might be related to not operating palliative patients or not resecting
large malignant lesions in our center. The other explanation for our lower complication
rate is the mean age of patients which is 52.1 ± 16.62 years old, and most patients
were in 30-60 years old age groups which had acceptable operative risk.
One of the weak points of our study is the lack of standard tool for evaluation of
postoperative fecal incontinence although none of the patients had subjective complaint
of fecal incontinence. Previous reports showed different incidence of fecal incontinence
after TEM from 28.8% to 2.3% and multi variate analyses showed age at the time of
operation is single independent risk factor for this complain.[9]
There is a relative contraindication for doing TEM in high anterior lesions because
of risk of peritoneal penetration. In a series of 303 TEM cases 26 patients had peritoneal
entry and, in this report, they repair 88% of them with TEM without abdominal operation.
They also showed perforation in lateral and even posterior lesions.[10] we had a case of peritoneal entry located anteriorly in rectosigmoid junction because
full bowel preparation we performed laparoscopic repair without diverting ostomy and
patient discharged without complication.
Currently Electrocautery, Ligasure and Harmonic are available energy devices in Iran.
In our patients using these devices were not associated with increased complication
and could not help to obtain free margin resection. In the case of fistula recurrence
Ligasure was the energy device that was used and regarding previous reports[11] lateral thermal injury is higher with Ligasure which was not statistically significant.
We used Ligasure in 75% of TEM cases and none of them had serious complication and
this recurrence after endorectal flap could be incidental. We also did not find reduced
complication with use of harmonic as other studies were found.[3]
Closing lumen defect above peritoneal reflection is mandatory but It is optional to
suture the rectal defect after resection of lesions below the reflection and it is
assumed that closing the defect is associated with better hemostasis, improved healing
and reduced risk of stricture. Meta-analysis of studies showed that closing the rectal
defect is only improve bleeding control and leaving the defect open is not associated
with infection, hospital stay or reduced time of surgery.[12] Our data also revealed the same findings and there no significant difference in
rate of complication following closing the defect or leaving it open. In case of fistula
development after TEM the defect was closed and since it happens in only one case,
could not be ascribed to suturing.
Interestingly comparison of TEM and colonoscopic findings showed borderline significant
difference between lesion distance measured by colonoscopy and TEM which was previously
thought to be shorter with rigid instruments.[13] This finding might be related to location of lesions which were mostly in the midpart
of rectum where loop formation of colonoscope is not happening.
Unlike distance measurement, which was similar in colonoscopy and TEM, pathologic
findings of biopsies taken with TEM are different from samples taken with colonoscope.
The most relevant explanation for this finding is due to possibility of excision the
lesion with TEM while in colonoscopy piece meal techniques usually applied so evaluation
of base is not possible. It is advised to perform endoscopic resection when all requirements
of complete excision are available to reduce the risk of unsatisfactory incomplete
excision.[14] Since it might not be possible to have a complete excision in all colonoscopy facilities
TEM should be considered in cases of premalignant lesions which were not excised completely
as an excisional biopsy.
One of the weak points of our study is the high number of unevaluated and involved
margins which were mostly at the first years of starting TEM in our center and these
cases were reduced with increasing the experience of our pathologists and surgeons.
This is the first report about TEM experience in Iran which showed its feasibility
for management of different proctologic conditions. It is highly advised to develop
multiple tertiary colorectal referral centers with TEM capability in the country.
