EFR has achieved an effective treatment for SMT, which involves performing “active perforation” to remove the tumor. Since perforation is unavoidable during the procedure, ensuring secure closure of the incision is crucial. Therefore, it is valuable to explore a convenient and effective method for securely closing the defect to complete endoscopic therapy.

To the best of our knowledge, current sealing instruments include conventional metallic clips with or without nylon purse-string sutures, over-the-scope clips (OTSC), and high-end suture devices [7,8,9,10,11,12,13]. Although the above techniques seem to be safe and effective alternative to surgical intervention to perform defect closure after EFR, however, these are time-consuming, high-cost, and difficult to use. Conventional metallic clips can close part of gastrointestinal perforations. Nevertheless, closing large gastric perforations with clips alone is more difficult [14]. The thick and irregular gastric folds at the edge of the perforation make it easy for conventional clips to slip when released. This leads to longer sealing times and a lower success rate.

In the past two years, a new sealing instrument called TTS twin clip (TTS-TC, which is expected to achieve efficient closure of large perforations at difficult locations has been used in China [15]. Using the characteristics of the TTS-TC, the two sides of the mucous are first closed at the widest part of the perforation, which then significantly narrows down the perforation and made it easier to continue to complete the sealing with conventional metallic clips. The procedure for using the TTS-TC is as follows: (1) insert the TTS-TC through the biopsy channel of the endoscope, clamp one side of the gastric wall near the perforation, position the other side, and release the TTS-TC, a technique known as “kissing closure” and (2) insert metallic clips to seal the perforation along both sides of the TTS-TC. Our study demonstrates that the TTS-TC is a safe and effective tool for closing gastric defects following endoscopic full-thickness resection (EFR) for gastric submucosal tumors (SMTs). Use of this instrument can shorten the operation time. On account of the “kissing close,” the TTS-TC is more suitable for the lesions located at the gastric fundus, the greater curvature, or anterior wall of the gastric body. This method can be done using only a single-channel endoscopy, has the advantage of being a simple procedure and does not require complex or specialized equipment, and save the average time spent in closing the gastric wall defects. In addition, no single case had severe complications, such as gastric bleeding, perforation, peritonitis, or surgical intervention.

One of the notable advantages of the TTS-TC is its potential applicability in closing larger perforations, particularly those exceeding 1 cm in diameter. Traditional metallic clips often struggle to effectively close larger defects due to the limitations in their grasping capacity and the tendency to slip on thicker gastric folds. The TTS-TC, with its unique “kissing close” mechanism, can initially approximate the edges of larger perforations, significantly reducing the defect size and making subsequent closure with metallic clips more manageable. This feature suggests that TTS-TC could be particularly beneficial in cases where large perforations are encountered, such as in more extensive EFR procedures or in cases of accidental perforations during complex endoscopic interventions. However, further studies are needed to validate the efficacy and safety of TTS-TC in larger perforations, as our current study primarily focused on defects within a specific size range. Future research should explore the upper limits of defect size that can be effectively managed with TTS-TC and compare its performance with other closure techniques in larger perforations.

Despite the promising results, this study has several limitations that should be acknowledged. Firstly, the sample size was relatively small, with only 19 patients included in the analysis. This limits the statistical power of the study and may affect the generalizability of the findings. Secondly, the study was conducted at a single center, which may introduce bias related to the specific patient population, endoscopic techniques, and postoperative management protocols used at that institution. Thirdly, the study design was retrospective, which inherently carries the risk of selection bias and limits the ability to establish causal relationships. Prospective, multicenter studies with larger sample sizes are needed to confirm the efficacy and safety of TTS-TC in a broader patient population. Additionally, the follow-up period, although extended to 6 months, may still be insufficient to fully assess long-term outcomes, such as recurrence rates or delayed complications. These limitations highlight the need for further research to validate the findings and explore the broader applicability of TTS-TC in different clinical settings.

During the application, two major issues were identified: first, the angle of the TTS-TC device cannot be adjusted freely after entering the endoscope's biopsy channel, requiring the endoscope to be rotated for adjustments. Second, although TTS-TC can decrease reliance on metallic clips, its high cost leads to total expenses that surpass those of using metallic clips alone.