On the Track of New Endoscopic Alternatives for the Treatment of Selected Gastric GISTs-A Pilot Study.

Background and Objectives: GISTs (Gastrointestinal stromal tumors) are the most common mesenchymal gastrointestinal tract tumours and are mainly located in the stomach. Their malignant potential depends on size, location, and type. Endoscopic techniques are a less invasive modality for patients not eligible for surgery. ESD (endoscopic submucosal dissection) is mainly used for the removal of smaller GISTs, with intraluminal growth and a more superficial location. Thus, R0 resection capability in some cases may be not sufficient, limited by tumour size, location in the gastric wall, and its connection level with the muscularis propria. In such cases, an endoscopic full-thickness resection can become a new alternative. In this retrospective pilot study, we evaluated ESD and hybrid resection techniques in terms of safety, efficacy, and disease recurrence for selected types of gastric GISTs. Materials and Methods: A retrospective comparison was conducted in a group of patients who underwent ESD or a hybrid technique combining endoscopic resection with endoscopic suturing using the OverStitch system (HT) for type II or III gastric GISTs. A total of 21 patients aged 70 ± 8 years underwent endoscopic resection. Seventeen lesions were treated with ESD and four with the HT. Results: R0 resection was achieved in all patients treated using HT (type III lesions) and in 53% of those treated with ESD (p = 0.08). None of the type III lesions treated with ESD were excised with R0. Lesions treated with R0 ESD resections were significantly smaller (1.76 ± 0.35 cm) than those with R1 ESD resections (2.39 ± 0.40 cm) (p < 0.01). The mean lesion size treated with the HT was 2.88 ± 0.85 cm. Conclusions: HT may be a new resection modality for large gastric GISTs with high muscularis propria connection grades. Further studies are required to evaluate its safety and efficacy and to form precise inclusion criteria for endoscopic resection techniques.