# Design and Development of a Flexible 3D-Printed Endoscopic Grasping Instrument
## 4 Discussion  
Interventional endoscopic procedures seem to have no limits regarding innovative procedures. The border between established surgical procedures and feasible endoscopic procedures is continually shifting [1; 2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38]. An important result of this shift was the increased experience of physicians who perform complex endoscopic procedures. Recent advancements in interventional endoscopy have allowed for planned access to the abdominal cavity or the mediastum, reducing fears of handling closure issues of the gut. Furthermore, clinical experience has shown that full-thickness lesions of the gut do not necessarily create problems if they undergo sufficient and competent closure. These developments have expanded the scope of endoscopic interventions, providing physicians with a wider range of options for the treatment of various conditions [11; 29; 30; 31; 38]. The latter development in interventional endoscopy has led to the need for special instruments that can solve rare clinical problems [39; 40]. Ideally, one would need a stable grasper for the adequate endoscopic resection and improved maneuverability of the instrument distal tip for endoscopic dissection [5; 9; 22; 24; 39; 40; 41; 42]. The commercially based development of endoscopic instruments can be very time consuming and expensive, if it ever happens, since the necessity for a specific use-case tailored instrument may not appear frequently enough to make a business out of it [25; 28]. To address this challenge, the concept of creating affordable endoscopic instrument prototypes using 3D printing has emerged. This approach enables the early assessment of the instrument, highlighting its potential practical benefits before upscaling production. The initial results have been very promising, with several success stories reported [17; 18; 22; 26; 43]. Our work focuses on applying 3D-printing technology to develop a highly flexible instrument that would overcome current technological limitations in interventional therapeutic endoscopy. To our knowledge, there was no previous work that developed an instrument that achieves a comparable bending angle. Several previous works reported instruments that could achieve bending angles from 50 to 90\({}^{\circ}\)[27; 44; 45; 46; 47]. In the work by [PERSON] et al., an instrument that facilitates the insertion of additional endoscopic instruments was developed [15]. It has a hollow body that is 8 mm in diameter and is split into several compartments, creating a number of additional working channels. With unoccupied working channels, this instrument demonstrated bending angles of up to 160\({}^{\circ}\). This is still lower than the bending angle of the instrument presented in our study, with measured angles of 216\({}^{\circ}\). Moreover, the most-presented instruments, up until now, have a rigid shaft that cannot be inserted through the curved GI tract, while our instrument has a fully flexible shaft that can be expanded to lengths up to 200 cm. Several works explored the concept of add-on devices on endoscopes, building additional working channels for the insertion of different resection tools, such as graspers [25; 26; 28]. Although they provide additional procedural capabilities, they are still firmly attached to the endoscope. This limits the number of options that a physician has during the procedure since the positioning of the endoscope can often be challenging. Our work presents an instrument that is completely independent from the endoscope, which is mainly used to provide vision of the operating region. This approach provides physicians with an additional level of freedom when performing technically complex procedures in the GI tract. The measurement of bending force achieved by the distal tip showed a comparable performance (7.85 N) to the combination of gastroscope and biopsy forceps (7.68 N).