Aims
Endoscopic intermuscular dissection (EID) is an emerging, organ-preserving technique for rectal tumors; however, its clinical value necessitates further evidence. This study aimed to evaluate the efficacy and safety of EID for rectal tumors using multicenter data.
Methods
This retrospective cohort study included patients who underwent EID for rectal tumors at two tertiary centers between January 2019 and January 2025. Inclusion criteria were: (1) pathological confirmation of rectal tumor; (2) no distant metastasis on preoperative imaging (contrast-enhanced CT/MRI, endoscopic ultrasound, or 68Ga PET-CT); and (3) complete follow-up of ≥3 months. The primary outcome was R0 resection rate. Secondary outcomes included en bloc resection rate, procedure time, complication rate, and postoperative hospital stay.
Results
A total of 31 patients (mean age 45.3±13.0 years; 58.1% male) were analyzed. Most tumors (87.1%) were located in the middle/lower rectum. Preoperative diagnoses were predominantly submucosal tumors (93.6%). EID achieved 100% technical success and en bloc resection rates. The median procedure time was 60 minutes (IQR 42.3–68.0). Final pathology identified neuroendocrine tumors (G1, 87.1%), leiomyoma (3.2%), stromal tumor (3.2%), and pT1 adenocarcinoma (6.5%). The mean tumor diameter was 9.00±3.86 mm. R0 resection was achieved in all cases (100%), with no lymphovascular or perineural invasion. The complication rate was 9.7% (3/31; fever: 2, pain: 1), all managed conservatively without re-intervention or surgery conversion. Median hospital stay was 5 days (IQR 5–6). Over a median follow-up of 22.5 months (IQR 11–62), no recurrence or metastasis was observed.
Table1, Patients basline charceteristics and endoscopic findings
|
Outcomes |
Results |
|
|
Number |
33 |
|
|
Gender, male, n(%) |
20（60.61） |
|
|
Age, mean(SD), years |
45.30±13.00 |
|
|
Location, n(%) |
Upper |
4（12.12） |
|
Middle Low |
2（6.06） 27（81.82） |
|
|
Diameter, mean(SD),（mm） Subepithelial lesion Mucosal lesion |
9.86±3.86 20-25 |
|
|
EUS, n(%)
|
Submucosal Mucosal and submuscoal Muscularis propria |
21（63.64） 9（27.37） 3（9.09） |
|
Paris classifcation, n(%) |
0-Is |
17（51.52） |
|
IIa Isp 0-IIa+IIc |
14（42.42） 1（3.03） 1（3.03） |
|
|
Color, n(%) |
Yellow |
26（78.79） |
|
White Red |
5（15.15） 2（6.06） |
|
Conclusions
EID is an effective and safe treatment for selected rectal tumors, offering high rates of R0 and en bloc resection with minimal complications. It represents a promising organ-preserving option for submucosal and early-stage rectal lesions. Larger prospective studies are warranted to confirm its long-term oncologic outcomes.