Intraluminal bioink robotic patch deposition system for complex perianal fistulas in Crohn’s disease

Dear Editor, Crohn’s disease is a chronic inflammatory bowel condition involving transmural inflammation and gastrointestinal tract lesions. Among the complications, perianal fistulas are one of its debilitating manifestations affecting up to 25% of patients. Current medical management includes antibiotics, immunomodulators, anti TNF-α, and biologics such as infliximab or ustekinumab. Surgical management, such as seton insertion, fistulotomy, advancement flaps and LIFT procedure focus on a combination of control of the fistula and preservation of the anal sphincters. Despite biologics and modern surgery, long-term closure remains poor, with high recurrence and frequent fecal incontinence[1]. In this context, intraluminal bioink robotics-based patch-deposition technology has gained traction as a promising new avenue in clinical regenerative endoluminal therapy[2,3]. This minimally invasive technique combines injectable and image-guided robotics with a real-time visualization. It facilitates navigation through tight, networked and complex fistulous or luminal pathways. This approach provides a biocompatible bioink patch placed directly on the luminal surface of tract promoting tissue regeneration as opposed to relying on fibrosis-induced closure alone. Perianal fistulae in Crohn’s disease cause significant problems and often come back, even with standard medical and surgical treatment[4]. Robotics-assisted intraluminal bioink delivery allows for precise placement of a regenerative, cell-based graft into the fistula tract. This method promotes regenerative healing rather than scar mediated closure. Cells embedded in bioink and preconditioned ex vivo may contribute to durable tract closure. As compared to traditional treatments, this approach can provide better functional outcomes and reduce recurrence, although long-term safety and technical effectiveness still need to be confirmed. Robotics-assisted intraluminal bioink therapy shows promise but has some limitations. Biologically, keeping cells alive during deposition is difficult because of shear stress, energy-induced damage, and photo-initiator toxicity with resolution–efficiency trade-offs[5]. It is still hard to navigate through complicated, inflamed fistula tracts with enough accuracy. Clinically, long-term safety, graft integration, and sustained fistula closure are unproven, and immune responses may occur. Thus, despite being highly innovative, this approach requires preclinical and clinical evaluation before safe adoption. In conclusion, robotics-assisted intraluminal bioink therapy represents a novel and transformative approach for the management of complex perianal fistulas in CD. Preclinical optimization and clinical testing are required despite these ongoing challenges, including cell viability, tract navigation precision, graft assimilation promotion, and confirmation of long-term safety. This innovative regenerative therapy has the potential to improve tissue repair and reduce recurrence, with an enhanced functional outcome, and will represent an important advance in the multidisciplinary care of patients with Crohn’s perianal fistulas. This letter to the editor adheres to the Transparency in the Reporting of Artificial Intelligence in Research (TITAN) guideline[6]. Sincerely,