Clinical Case Summary

Gastrointestinal neuroendocrine tumours (NETs) are low-grade malignant tumours in the GI tract. They account for 0.4% to 1.8% of GI malignancies. Duodenal NETs are relatively rare tumours and only accounts for 2% to 3% of GI NETs.
The patient, a 68 year old male, had dyspepsia and OGD showed a 10mm subepithelial lesion (SEL) (Insert image here) in the second part of the duodenum. Biopsies revealed polypoid foveolar hyperplasia. An endoscopic ultrasound (EUS) was done to evaluate the SEL which showed a 7mm x 8mm hypoechoic lesion within the submucosal layer (insert image). There was a slit within the SEL which corresponds to the previous biopsy sampling. Differentials were GIST or pancreatic rest. Further biopsies were taken from the within the slit which concluded as a well-differentiated NET, Grade 1.
PET DOTATE scan showed tracer-avid focus in the duodenum. Chromogranin A was elevated at 1056ug/L.
In view of previous sampling with a biopsy scar now, removal of the duodenal NET was carefully thought out. Endoscopic mucosal resection (EMR) has a higher risk of perforation due to the possibility of fibrosis from the biopsies. Laparoscopic endoscopic cooperative surgery was discussed with the surgeons, however, it is invasive.
Patient then underwent underwater EMR. The duodenal NET had sufficient buoyancy whilst underwater (Insert image). A 10mm snare was used, and polypectomy with Endocut Q mode done with good margins. There was no intraprocedural bleeding nor perforation. Two clips were used to close the polypectomy site prophylactically (Insert image).
Histology demonstrated tumour cells within the lamina propria and submucosa with salt and pepper like chromatin and round nuclei. They were positive for synaptophysin and chromogranin. Ki-67 index was 2%, and the margins were clear. This was conclusive of a NET Grade 1.
This case highlights the approach and differentials to duodenal lesions, and points to be considered for endoscopic resection in the duodenum.

References

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Introduction

Nowadays, endoscopic treatment for esophageal Zenker's diverticulum is considered the standard of care, with flexible endoscopic septotomy (FES) being the first technique to be widely adopted. Since 2016, submucosal tunneling Per-Oral Endoscopic Myotomy (Z-POEM) has emerged as an innovative therapeutic approach. However, medium-term efficacy comparisons between Z-POEM and FESremain limited.

Aims & Methods

The aim of this study was to compare the clinical success and safety of Z-POEM and FES.
This study was a retrospective analysis of a large group of patients treated for Zenker's diverticulum across two tertiary care centers. The patients were divided into two groups: those who underwent Z-POEM between 2021 and 2024, and those who underwent FES between 2008 and 2024. Demographic and clinical data, including Charlson Comorbidity Index, Kothari scores, clinical success rates, adverse events, and follow-up duration, were analyzed and compared among the two groups.

Results

Treatment in the study period. Of these, 32 patients (mean age 66.8 ± 10.7 years) underwent Z-POEM, while 34 patients (mean age 73.5 ± 10.2 years) underwent FES. The mean Charlson Comorbidity Index was similar between groups (Z-POEM: 3.28 ± 1.80 vs. FES: 3.4 ± 1.6; p = 0.708). The pre-procedural Kothari-Haber score was comparable (mean 7.3 ± 1.4 for Z-POEM vs. 7.3 ± 1.1 for FES; p= 0.981). The post-procedural Kothari-Haber score was significantly lower in the ZPOEM group (1.3 ± 1.3) compared to the FES group (2.7 ± 2.8; p = 0.010), indicating better symptom resolution. The median follow-up period was 37.7 months (IQR: 14.8 – 74.6 months) for the FES group and 12.2 months (IQR: 7.4 – 21.9 months) for the Z-POEM group (p < 0.0001). Technical success was achieved in 100% in both groups. Clinical success was significantly higher in the Z-POEM group (93.8%; 95% CI: 75% - 99%) compared to the FES group (64.5%; 95% CI: 50% - 82%; p= 0.005). The rate of adverse events was lower in the Z-POEM group (6.25%) compared to the FES group (23.53%), however this difference did not reach statistical significance (p= 0.084).

Conclusion

This multicenter retrospective study suggests that Z-POEM is an effective and safe alternative to FES for the treatment of Zenker’s diverticulum. The Z-POEM technique demonstrated a significantly higher clinical success rate and a trend towards fewer adverse events. Of particular interest, no differences in terms of efficacy and adverse events were observed between the first 10 patients (during the learning curve) treated with Z-POEM and those treated thereafter. It should be noted that although the follow-up period for Z-POEM was generally shorter, no recurrence of symptoms was observed even in patients with longer follow-up durations. These findings support the use of Z-POEM as a viable and effective approach, warranting further investigation in larger multicenter cohorts to confirm its advantages.

References

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Disclosure

Giuseppe Grande is consultant for Olympus, Boston Scientific, ERBE, Fujifilm