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This article presents an investigation into the mechanical properties of porcine mesocolon, small intestinal mesentery, fascia, and peritoneum tissues to generate a preliminary database of the mechanical characteristics of these tissues as surrogates for human tissue. No study has mechanically characterised porcine tissue correlates of the mesentery and associated structures. The samples were tested to determine the strength, stretch at failure, and stiffness of each tissue. The results indicated that porcine mesenteric and associated tissues visually resembled corresponding human tissues and had similar tactile characteristics, according to an expert colorectal surgeon. Stiffness values ranged from 0.088 MPa to 6.858 MPa across all tissues, with fascia being the weakest, and mesentery and peritoneum being the strongest. Failure stress values ranged from 0.336 MPa to 6.517 MPa, and failure stretch values ranged from 1.766 to 3.176, across all tissues. These mechanical data can serve as reference baseline data upon which future work can expand.

Background: Arteriovenous fistulae (AVF) have superior clinical outcomes compared to central venous catheters (CVC) among haemodialysis (HD) patients. Yet, there is increasing recognition that health-related quality of life (HRQoL) may be more important to patients than survival and that differences may exist between AVF and CVCs in this regard. This study compared HRQoL between AVF and CVC in an Irish cohort. Methods: We conducted a cross-sectional survey among prevalent haemodialysis patients (n=119) dialysing with either an AVF or CVC at a regional programme. The Short Form 36 (SF-36) and a validated Vascular Access Questionnaire (SF-VAQ) compared QoL between AVF and CVC in domains of physical functioning, social functioning and dialysis complications. Multivariable logistic regression compared differences between groups for outcomes of physical functioning, social functioning and dialysis complications expressed as adjusted odds ratios and 95% CI. Results: Mean age was 66.1 years, 52.1% were using an AVF while 47.9% had a CVC. Patients dialysing with an AVF were more satisfied with their access when asked directly (6.2 vs 5.0, P<0.01). Physical functioning scores for bleeding, swelling and bruising were significantly higher for AVF than CVC (P<0.005 for all). In contrast, patients with CVC reported greater difficulties in bathing and showering than those using an AVF (4.4 vs 2.0, P <0.001) whereas patients with AVF expressed greater concerns with physical appearances. Compared to AVF, CVC users were less likely to report difficulties in physical functioning (OR 0.35, 95% 0.12-0.94), P=0.04) but more likely to report dialysis complications (OR 1.94 (0.69-5.87), P=0.22). Conclusion: Vascular access contributes to HRQoL in haemodialysis. CVCs are associated with fewer difficulties from bleeding and bruising but greater negative impact on social activities including bathing and showering. Overall, patients with a CVC had lower dissatisfaction scores than patients with AVF when all 3 domains were added. Innovation in vascular access design and engineering may confer benefits and improve patient comfort on HD.

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The aim of this research was to develop a replicated colorectal region for use in laparoscopic instrument innovation. Testing of both surgical skills and laparoscopic surgical instruments takes place in a controlled lab setting. Cadaverous tissue or laparoscopic simulators are the tools of choice for skill testing. However, in the instance of colorectal surgery, porcine intestines remain the gold standard for laparoscopic testing (Lamata et al. 2004). There exists data in current literature which discuss the use of anatomical simulators (also known as simulator boxes) for both researching surgical methods, and testing laparoscopic instruments. There is little focus in the literature on the materials used to create surrogate environments which mimic those of the real world. Simulator boxes exist, and are of high fidelity, but can be quite cumbersome, with some being left in storage areas indefinitely, with some remaining inaccessible for many centers around the world. There are also many peripheral devices which need to accompany these simulators, such as laparoscopes and external monitoring equipment for recording and review. As they are highly specialized pieces of research equipment, in the majority of cases, they are not designed to be portable or readily reconfigurable. These limitations make high end laparoscopic simulators inappropriate choices for early stage HFE (Human Factors Engineering) studies. The authors propose the creation of a laparoscopic simulator which contains anatomically accurate, 3D printed colorectal sections for use in both surgical training and instrument innovation. The colon is modeled from high quality CT data in DICOM format, using the Material Mimics Innovation Suite (Materialise, 2013). By creating virtual models of the internal anatomical structure of the colorectal region, it allows for a more accurate depiction of the anatomy encountered in a surgical setting. A maximum level of realism is required for a simulator to be effective (Lamata et al. 2004). The future application of this work lies in the validation of the 3D printed anatomy which will lead to innovation of new instruments or approaches to laparoscopic surgery.