Tension of knotted surgical sutures shows tissue specific rapid loss in a rodent model

<p>Abstract</p> <p>Background</p> <p>Every surgical suture compresses the enclosed tissue with a tension that depends from the knotting force and the resistance of the tissue. The aim of this study was to identify the dynamic change of applied suture tension with regard to the tissue specific cutting reaction.</p> <p>Methods</p> <p>In rabbits we placed single polypropylene sutures (3/0) in skin, muscle, liver, stomach and small intestine. Six measurements for each single organ were determined by tension sensors for 60 minutes. We collected tissue specimens to analyse the connective tissue stability by measuring the collagen/protein content.</p> <p>Results</p> <p>We identified three phases in the process of suture loosening. The initial rapid loss of the first phase lasts only one minute. It can be regarded as cutting through damage of the tissue. The percentage of lost tension is closely related to the collagen content of the tissue (r = -0.424; p = 0.016). The second phase is characterized by a slower decrease of suture tension, reflecting a tissue specific plastic deformation. Phase 3 is characterized by a plateau representing the remaining structural stability of the tissue. The ratio of remaining tension to initial tension of phase 1 is closely related to the collagen content of the tissue (r = 0.392; p = 0.026).</p> <p>Conclusions</p> <p>Knotted non-elastic monofilament sutures rapidly loose tension. The initial phase of high tension may be narrowed by reduction of the surgeons' initial force of the sutures' elasticity to those of the tissue. Further studies have to confirm, whether reduced tissue compression and less local damage permits improved wound healing.</p

Impact of Preoperative Three-Dimensional Computed Tomography Cholangiography on Postoperative Resection Margin Status in Patients Operated due to Hilar Cholangiocarcinoma

Introduction. The purpose of this study was to analyse the value of 3-dimensional computed tomography cholangiography (3D-ERC) compared to conventional retrograde cholangiography in the preoperative diagnosis of hilar cholangiocarcinoma (HC) with special regard to the resection margin status (R0/R1). Patients and Methods. All hepatic resections performed between January 2011 and November 2013 in patients with HC at the Department of General, Visceral and Transplant Surgery of the RWTH Aachen University Hospital were analysed. All patients underwent an ERC and contrast-enhanced multiphase CT scan or a 3D-ERC. Results. The patient collective was divided into two groups (group ERC: n=17 and group 3D-ERC: n=16). There were no statistically significant differences between the two groups with regard to patient characteristics or intraoperative data. Curative liver resection with R0 status was reached in 88% of patients in group ERC and 87% of patients in group 3D-ERC (p=1.00). We could not observe any differences with regard to postoperative complications, hospital stay, and mortality rate between both groups. Conclusion. Based on our findings, preoperative imaging with 3D-ERC has no benefit for operative planning and R0 resection status. It cannot replace the exploration by an experienced surgeon in a centre for hepatobiliary surgery