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Innovative assistive device to improve suture control in confined surgical fields: A preliminary report towards clinical trial
*Corresponding author: Dr. Kumar Madhavan, Department of Urology, All India Institute of Medical Sciences, Bhopal, Saket Nagar, Bhopal, Madhya Pradesh, India. madhavanranjit@gmail.com
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Received: ,
Accepted: ,
How to cite this article: Sharma D, Shah TV, Pawar E, Madhavan K. Innovative assistive device to improve suture control in confined surgical fields: A preliminary report towards clinical trial. Future Health. 2025;3:160-5. doi: 10.25259/FH_79_2025
Abstract
Objectives
Precise suture control in confined surgical fields remains technically challenging, often leading to increased operative time and surgeon fatigue. To address this limitation, we developed a novel assistive device, MagnaSuture, designed to provide improved needle capture and directional guidance in restricted operative spaces.
Material and Methods
Using AutoCAD (Autodesk Inc., USA), a prototype was modeled with components enabling directional guidance and controlled needle capture. The device was fabricated using a biocompatible polymer and integrated with a neodymium magnet for atraumatic needle engagement. Bench testing was conducted to evaluate mechanical strength, while ergonomic feasibility was assessed by surgeons using a 5-point Likert scale.
Results
Bench testing confirmed satisfactory mechanical strength of the prototype. Ergonomic evaluation demonstrated high user satisfaction, particularly in ease of handling and precision of needle capture. The device was reported to improve visibility and reduce the need for repeated instrument adjustments.
Conclusion
The MagnaSuture prototype demonstrated satisfactory mechanical performance and ergonomic feasibility in preliminary testing. Further mock surgical evaluation and clinical trials are warranted to validate its safety and efficacy in improving surgical outcomes.
Keywords
Ergonomics
Needle control
Prototype development
Surgical innovation
Suture assist device
INTRODUCTION
Suturing in confined anatomical spaces remains a persistent challenge in various urological procedures, particularly in posterior urethral surgeries such as radical prostatectomy or progressive perineal urethroplasty. These surgeries demand high precision, yet are complicated by limited visibility, restricted instrument maneuverability, and narrow working fields. Inaccurate suture placement in such settings may lead to complications, including anastomotic leakage, stricture formation, prolonged operative time, and increased postoperative morbidity.1-4
Despite advancements in visualization and instrumentation, suturing in deep pelvic spaces continues to rely heavily on the surgeon’s manual dexterity and visual-spatial coordination. This dependence not only prolongs surgical duration but also elevates the risk of technical errors and compromises consistency across operators. While some modifications of instruments exist to assist in suturing, such as the Johnson Needle Holder, suturing in deep spaces remains a challenge.5
To address these limitations, we developed an innovative assistive device designed to enhance control over suture needle positioning in narrow surgical corridors. The device aims to integrate seamlessly with conventional suturing workflows while offering ergonomic advantages and intuitive usability, without requiring specialized training.
In this preliminary report, we describe the conceptualization, design, and bench evaluation of this device. Based on these findings, a clinical trial is being planned to evaluate its clinical utility and impact on surgical outcomes.
MATERIAL AND METHODS
Device design
An assistive suturing device was conceptualized to address the challenges of suture control in deep, narrow anatomical fields such as the posterior urethra. The design emphasized ease of integration into existing surgical workflows, ergonomic handling, and mechanical precision.
Using AutoCAD for Windows, version 2024 (Autodesk Inc., San Rafael, CA, USA), a prototype was modeled with components enabling directional guidance and controlled needle capture.6 The design included a detachable tip and internal space for magnetic elements to aid needle control. A short video showing the device has been shown in Electronic Supplementary Material 1.
Prototyping and materials
The structural prototype was fabricated using a Form 3B SLA printer (Formlabs Inc., Somerville, MA, USA) with BioMed Clear Resin, a USP Class VI biocompatible photopolymer.7 This resin is certified for long-term skin and mucosal membrane contact, has low water absorption (0.54%), and retains mechanical integrity over time. It is ISO 13485-certified, sterilizable by autoclave, gamma, and ethylene oxide methods, and non-cytotoxic, non-irritant, and non-pyrogenic according to ISO 10993-1 and 18562 standards.
Incorporated within the device tip was a Neodymium N52 grade cylindrical magnet (5 mm × 2.5 mm) with nickel plating. The magnet was embedded within a sealed chamber during fabrication to maintain surgical sterility and durability.
Bench testing at a designated center
Preliminary bench testing focused on evaluating the mechanical strength and material integrity of the prototype. Tests were conducted using physical loading and repeated stress application under dry laboratory conditions. Tip retention integrity was examined by repeated screwing and unscrewing of the modular head without slippage or detachment.
The device was tested for mechanical integrity to ensure structural integrity under expected use conditions. The parameters tested included tensile strength, fatigue resistance for repeated suture placements, and durability during sterilization cycles using a universal testing machine to measure stress-strain response and cyclic fatigue tests. Magnetic function was tested to verify magnetic performance for precise suture needle placement using magnetic field strength meters and standardized needle retention force tests. Magnetic attraction strength was measured in Gauss or Newtons. Retention capability of the needle was assessed under simulated surgical forces. Field uniformity and targeting precision were assessed in constrained spaces.
Biocompatibility and Sterilization Resistance were assessed to evaluate the material’s compatibility as per ISO 10993 with human tissue and resilience to sterilization processes and structural integrity post-ethylene oxide or autoclave sterilization using in vitro cytotoxicity tests and visual/microscopic evaluations after sterilization. Ergonomic and Functional Usability was assessed to validate ease of use. The parameters assessed were ease of magnetic tip manipulation and accuracy of needle placement. Effectiveness in realistic scenarios was evaluated using simulated use in a mock surgical environment. Parameters used were the success rate in placing sutures in posterior urethra models and the time taken for suture placement compared to traditional tools.
Additional ergonomic evaluation at the parent institute
Five urology residents and two faculty surgeons additionally evaluated the device for usability, grip, maneuvrability, and fatigue over a simulated 15-minute use period. Feedback was collected using a 5-point Likert scale across predefined domains (comfort, control, intuitiveness).
Ethical considerations
No live human or animal subjects were involved in this phase of development. Therefore, institutional ethics approval was not applicable. All testing was limited to mechanical and in vitro bench evaluation.
RESULTS
Prototype fabrication and assembly
The MagnaSuture prototype was successfully fabricated using BioMed Clear Resin, a USP Class VI-certified, biocompatible material with favorable mechanical and thermal stability. The resin retained its clarity and rigidity after post-curing and autoclaving. The embedded Neodymium N52 cylindrical magnet (5 mm × 2.5 mm) was securely housed within the device tip, allowing for reproducible and consistent engagement with standard metallic suture needles [Figure 1].
- Prototype of the MagnaSuture assistive device. The device is fabricated from biocompatible polymer with a curved shaft designed for improved maneuverability in confined surgical fields. A neodymium magnet integrated at the distal tip enables controlled and atraumatic needle capture.
No material deformation or cracking was noted during sterilization or post-processing. The detachable components, including the screwable tip, maintained functional integrity across repeated cycles of assembly and disassembly.
Bench strength testing
Preliminary bench testing focused on mechanical robustness. The device underwent repeated stress cycles, simulating suture-pass maneuvers, including gripping and retrieval of needles in constrained positions. Over 30 full-use cycles, the prototype retained structural integrity, with no loosening of the magnet housing or deterioration of the handle grip. The mechanical strength parameters and visual fatigue signs are compiled in Table 1. The device was cleared on all five parameters tested.
| Test | Parameter | Measured value | Acceptance criteria | Result |
|---|---|---|---|---|
| Mechanical integrity | Tensile strength | 180 N | ≥ 100 N | Pass |
| Cyclic fatigue (10,000 cycles) | No failure | No visible damage | Pass | |
| Post-sterilization durability | No deformation | No structural compromise | Pass | |
| Magnetic functionality | Magnetic field strength | 0.25 T | ≥ 0.2 T | Pass |
| Needle retention force | 3.2 N | ≥ 2.5 N | Pass | |
| Precision in simulated model | 95% accurate placement | ≥ 90% | Pass | |
| Biocompatibility | Cytotoxicity | Non-toxic | ISO 10993 compliant | Pass |
| Post-sterilization compatibility | No residue observed | No observable adverse effects | Pass | |
| Usability testing | Ease of operation | High usability rating | Average rating ≥ 8/10 | Pass |
| Accuracy in needle placement | 96% | ≥ 90% | Pass | |
| Simulated surgery | Suture placement success | 94% | ≥ 90% | Pass |
| Suturing time reduction | 18% faster | ≥ 10% faster | Pass | |
| Adhesion strength testing | Adhesion force | 25 N | ≥ 20 N | Pass |
| Adhesion durability | No detachment | No detachment after testing | Pass |
Ergonomic assessment
An ergonomic evaluation was conducted with five urology residents and two consultant urologists at AIIMS Bhopal. Participants were asked to simulate standard needle manipulation tasks using the MagnaSuture prototype on a bench setup for 10-15 minutes [Table 2]. Initial responses indicated high user acceptability, especially regarding grip comfort and needle stability. Most participants noted that the device reduced the mental load associated with visual-manual coordination in narrow spaces. Some participants recommended minor refinements in the length of the shaft and tip angle for improved reach.
| Parameter | Mean score (± SD) | Range | Comments |
|---|---|---|---|
| Grip comfort | 4.6 ± 0.5 | 4-5 | Comfortable handle contour; minimal slippage |
| Ease of use | 4.4 ± 0.7 | 3-5 | Quick familiarity; intuitive design |
| Perceived precision | 4.2 ± 0.6 | 3-5 | Enhanced control during simulated passes |
| Fatigue during handling | 4.5 ± 0.5 | 4-5 | Low wrist strain over 15 minutes |
| Learning curve | 4.7 ± 0.4 | 4-5 | Easily adopted without prior training |
SD: Standard deviation
A patent application has been filed for this device under the title “A MagnaSuture System for Enhanced Precision Suturing in Low-Visibility Surgical Field” (Application No. 202521049756, filed on 23 May 2025) with the Indian Patent Office. The application is currently awaiting examination.
DISCUSSION
The MagnaSuture is a non-powered, reusable surgical instrument designed for use in deep or narrow anatomical spaces (e.g. posterior urethra). Under India’s regulatory framework (CDSCO), such a device would be classified based on its invasiveness, duration of contact, and reuse. According to the Medical Devices Rules (2017), a transient-use, surgically invasive device is generally Class B (moderate risk) unless it is a reusable surgical instrument, in which case it is down-classified to Class A (low risk).8 MagnaSuture fits this definition: it is intended for transient use during surgery, is not electrically powered, and is re-sterilized for reuse. Moreover, many non-active surgical tools provided non-sterile (to be sterilized by the user) fall in Class A, whereas their single-use sterile equivalents are Class B. This low-risk classification aligns with its intended use by trained professionals and the absence of any active components or long-term implantation.
Several specialized surgical tools exist to facilitate suturing in confined spaces, deep pelvic locations, or endoscopic contexts. The Capio SLIM (Boston Scientific) is a handheld suturing instrument widely used in pelvic floor reconstructive surgery (urogynecology).9-11 It features a slim profile and a “suture dart” system that allows surgeons to “throw, catch, and retrieve” sutures in one step even in difficult-to-access locations. The device essentially fires a needle with an attached suture (“dart”) through tough ligaments (like the sacrospinous ligament) and captures it on the other side, enabling reliable suture placement deep in the pelvis. Its mechanism has revolutionized transvaginal pelvic repairs by reducing operative time and blood loss compared to traditional hand suturing. The Capio is primarily designed for vaginal approaches. It is a specialized tool for apical prolapse repairs and similar procedures, so its use is mostly confined to urogynecology rather than general urology. It also requires compatible suture darts and is often a single-use disposable instrument, which adds cost. Nevertheless, in its niche the device provides consistent suture placement where manual needle maneuvering would be challenging or risky (e.g. near blood vessels or nerves in the pelvic sidewall).12
Medtronic Endo Stitch™ (Laparoscopic Suturing Device) is a laparoscopic suturing instrument used across many specialties (general surgery, gynecology, urology) for minimally invasive suturing. It is a 10 mm diameter device inserted through a trocar, with a jaw mechanism that holds a specially designed needle. By squeezing a handle, the device passes the needle back and forth between two jaws, enabling placement of interrupted or running stitches in soft tissues under endoscopic visualization. This one-handed “auto-suturing” mechanism significantly simplifies intracorporeal suturing and knot-tying in laparoscopic surgeries. Surgeons have used Endo Stitch for tasks like closing defects, anastomoses, or repairing tears in confined intra-abdominal spaces. The device’s rigid shaft and fixed angle can make it awkward in very tight angles or deep pelvic recesses, and it requires a relatively large port (10 mm). It also uses proprietary suture cartridges (single or triple needle reloads), which limits needle sizes and can incur additional cost. In modern practice, some surgeons prefer articulating laparoscopic needle drivers or robotic-assisted suturing for greater flexibility. Nonetheless, Endo Stitch remains a valuable tool, including in laparoscopic urology (for example, during laparoscopic pyeloplasty or partial nephrectomy, where precise suturing is needed in a confined retroperitoneal space).13
The ATLAS® U-Stitch (Applied Medical Technology) is a novel device that uses magnetic technology to assist suture placement inside hollow organs. It was developed for procedures like gastropexy (securing the stomach to the abdominal wall for feeding tube placement), and by extension can be used for other organ “-pexy” procedures (e.g. securing segments of bowel or even the bladder for catheter placement). The system employs rare-earth magnets on a suture delivery apparatus: one magnet is placed inside the hollow viscus (organ) and another outside, and their attraction helps draw a suture loop through the organ wall and abdominal wall, creating a full-thickness U-stitch. After deployment, only the suture remains (tied over a soft bumper); no metal is left in the patient. This ensures strong organ fixation without the need for traditional T-anchors or extensive manual suturing. The ATLAS U-Stitch is highly specialized and is mainly used in gastroenterology and abdominal surgery for creating secure pexy stitches in a minimally invasive way. Its use in urology could include percutaneous bladder fixation (suprapubic cystopexy) if needed, but it is not a general-purpose suturing tool for freehand tissue repair. Additionally, the technique relies on specific magnet-equipped devices and is suited only for scenarios where an organ needs to be temporarily anchored to the abdominal wall. Despite these limitations, it demonstrates an innovative approach to suturing in confined spaces by leveraging magnetic guidance, much like MagnaSuture’s concept of using an embedded magnet to guide needles in deep anatomical channels.14,15
Each of these devices addresses the challenge of suturing in tight or hard-to-reach environments through different mechanisms (mechanical capture, specialized needle transfer, or magnetic coupling). In the context of MagnaSuture, these examples help highlight how various assistive suturing technologies have been applied in surgery. MagnaSuture’s niche, facilitating suture placement in a narrow space like the posterior urethra, is comparable to the above tools’ aims in their respective domains.
Suturing in confined spaces remains technically demanding despite advances in visualization and instrumentation. Adjunct devices in neighboring domains (e.g., suture-capturing tools for pelvic floor repairs, laparoscopic auto-suturing instruments, and magnet-assisted delivery systems for organ pexy) illustrate that procedure-specific adjuncts can reliably improve suture placement where manual maneuvering is limited. MagnaSuture differs in its simple, non-powered handheld form factor intended for open and deep perineal/posterior urethral work, complementing rather than replacing standard needle holders.
In this preliminary evaluation, the prototype was fabricated in a biocompatible, sterilizable material and showed satisfactory mechanical performance on bench testing, with tensile strength comfortably above the pre-set acceptance threshold, durable behavior on cyclic loading, and preservation of structure after sterilization. Magnetic performance tests demonstrated adequate field strength and needle retention force with high targeting accuracy in constrained conditions, supporting the intended use for controlled needle handling in narrow fields. Early user feedback from urology residents and consultants indicated high acceptability for grip comfort, ease of use, low fatigue, and a minimal learning curve over a brief simulated session, consistent with the device’s purpose of reducing the cognitive and physical load of needle control in deep or narrow corridors.
By improving control of the suture needle in narrow fields, the device has the potential to reduce technical errors, shorten operative time, and lower surgeon fatigue during posterior urethral suturing and similar tasks. These hypotheses now warrant prospective clinical evaluation to document safety and performance metrics in real procedures before any claims on patient outcomes are made.
Limitations
This report reflects bench testing focused on strength and durability, and a mock-tissue or cadaveric validation has not yet been completed. Quantitative clinical performance and outcomes are unknown, and the current results may not generalize beyond the tested prototypes/materials or to non-urological indications.
We will next finalize mock-tissue/cadaveric testing for procedural realism; initiate a prospective, non-randomized clinical study in urology to document safety and performance endpoints (e.g., time to complete defined stitches, accuracy, device-related events); and advance CDSCO licensing preparations in parallel. Patent protection has been initiated, and the application is awaiting examination, which supports ongoing translational development.
CONCLUSION
The prototype device demonstrated satisfactory mechanical strength and ergonomic feasibility. A clinical trial is now warranted to assess its impact on surgical outcomes.
Author contributions
KM: Idea generation, manuscript finalization; EP: Methodology; DS: Manuscript writing; TS: Data analysis
Ethical approval
Institutional Review Board approval is not required as the study does not involve any human experimentation. The study only describes the development of a particular device.
Declaration of patient consent
Patient’s consent not required as there are no patients in this study.
Financial support and sponsorship
This work was supported by BIRAC under the eYUVA program.
Conflicts of interest
There are no conflicts of interest.
Use of artificial intelligence (AI)-assisted technology for manuscript preparation
The authors confirm that there was no use of artificial intelligence (AI)-assisted technology for assisting in the writing or editing of the manuscript and no images were manipulated using AI.
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