A modular 2-dof force-sensing instrument for laparoscopic surgery

Abstract. Minimally Invasive Surgery (MIS) has enjoyed increasing attention and development over the last two decades. As MIS systems evolve, the surgeon is increasingly insulated from patient contact, creating a trade-off between surgical sensory information and patient invasiveness. Incorporation of haptic feedback into MIS systems promises to restore sensory information surrendered in favor of minimal invasiveness. We have developed a novel, biocompatible 2-DOF force-sensing sleeve that can be used modularly with a variety of 5mm laparoscopic instruments. The functional requirements for such a device are defined, and design strategies are explored. Our formal device design is outlined and device calibration is presented with derived calibration functions. Illustrative experimental force data from a porcine model is presented. This device can be used for intra-abdominal force recording and feedback in laparoscopic environments; the implications and future potential for this technology are explored.

Multicenter, Prospective, Longitudinal Study of the Recurrence, Surgical Site Infection, and Quality of Life After Contaminated Ventral Hernia Repair Using Biosynthetic Absorbable Mesh: The COBRA Study

OBJECTIVE: The aim of the study was to evaluate biosynthetic absorbable mesh in single-staged contaminated (Centers for Disease Control class II and III) ventral hernia (CVH) repair over 24 months. BACKGROUND: CVH has an increased risk of postoperative infection. CVH repair with synthetic or biologic meshes has reported chronic biomaterial infections and high hernia recurrence rates. METHODS: Patients with a contaminated or clean-contaminated operative field and a hernia defect at least 9 cm had a biosynthetic mesh (open, sublay, retrorectus, or intraperitoneal) repair with fascial closure (n = 104). Endpoints included overall Kaplan-Meier estimates for hernia recurrence and postoperative wound infection rates at 24 months, and the EQ-5D and Short Form 12 Health Survey (SF-12). Analyses were conducted on the intent-to-treat population, and health outcome measures evaluated using paired t tests. RESULTS: Patients had a mean age of 58 years, body mass index of 28 kg/m, 77% had contaminated wounds, and 84% completed 24-months follow-up. Concomitant procedures included fistula takedown (n = 24) or removal of infected previously placed mesh (n = 29). Hernia recurrence rate was 17% (n = 16). At the time of CVH repair, intraperitoneal placement of the biosynthetic mesh significantly increased the risk of recurrences (P </= 0.04). Surgical site infections (19/104) led to higher risk of recurrence (P < 0.01). Mean 24-month EQ-5D (index and visual analogue) and SF-12 physical component and mental scores improved from baseline (P < 0.05). CONCLUSIONS: In this prospective longitudinal study, biosynthetic absorbable mesh showed efficacy in terms of long-term recurrence and quality of life for CVH repair patients and offers an alternative to biologic and permanent synthetic meshes in these complex situations