Abstracts - Chirurgie Kongress

Butyl-Cyanoacrylat (Histoacryl ® ) instead of sutures. The aim was the comparison of the two methods
in regards to painful fixation-sites and recurrences.
Methods: 264 patients. Including criteria: male sex, first manifestation, hernia on one side, hernia size
LIII, MII-III, al ML (Schumpelick). Randomization preoperatively. Operative exposition of the groin followed
over the usual access in any cases. For the fixation of the mesh we used either PDS 2.0 (Group I)
or Histoacryl ® (Group II). Clinical control after 3, 12 and an average of 57 months.
Results: 264 study patients. Group I (sutured): 140 patients, group II (suture free): 124. The operation
was done in 82.9% (I) or 82.3% (II) under local anaesthesia. No major complication in both groups.
Mean hospitalisation time 3.28 (I) or 3.38 (II) days. Control 3 month postoperative of 140 (I) and 124
(II), after 12 months of 104 (I) and 92 (II) patients and after an average of 57 months of 84 (I) and
68 (II) patients.
Recurrences by 5/140 (3.6%) (I) and 8/124 (6.5%) (II) patients (p= 0.288). Over all recurrences:1
lateral located, 7 medial, and 5 were not operated till this moment. Group I (17.9%) complained after 3
month about much more pain (p = 0.075) in the groin region than group II (10%). After 12 month the
patients in group I were up to 93.3% without pain and those from group II in about 94.6%. (p = 0.773).
After an average of 57 months 13% from group I mentioned complaints, in group II 4.7% (p=0.034)
Conclusion: The study shows after 12 months no significant disadvantage in regard of recurrences
and resistance for suture free mesh fixation. After an average of 57 months we found more recurrences
but patients do much less complain. We think that the suture free mesh fixation is a promising modification
of the hernia repair by Lichtenstein.
Research – Transplantation 48
48.1
Long-term evaluation of myoblast seeded patches implanted on infarcted rat hearts
M.-N. Giraud 1 , R. Flueckiger 1 , S. Cook 1 , M. Siepe 2 , T. P. Carrel 1 , H. T. Tevaearai 1 ( 1 Bern, 2 Freiburg i.B./DE)
Objective: Cell transplantation presents great potential for treatment of patients with severe heart failure
(HF). However, its clinical application revealed to be more challenging than initially expected from
experimental studies. Further investigations need to be undertaken to define the optimal treatment
conditions. We previously reported on the implantation of a bio-engineering of myoblast-seeded polyurethane
patches (PU-MyoB) to the injured myocardium. The progression towards HF was prevented
1 month only after treatment with PU-Myob but not with acellular patches. In the present study, we
evaluate the functional outcome on a long-term basis after biografts implantation.
Methods: Left anterior descending coronary ligation was performed in female Lewis rats. Two weeks
later, animals were treated with epicardial implantation of PU-MyoB (n=7), acellular patches (n=7),
sham operation (n=8) or direct intramyocardial myoblast injection (n=6). Functional assessments
were performed with serial echocardiographies during 12 months and end point left ventricle (LV)
catheterization. Hearts were then harvested for histological examinations.
Results: Infarcted animals showed a slow and progressive reduction in fractional shortening (FS). Progression
toward heart failure was prevented after injection of myoblast or PU-MyoB implantation up to
6 and 9 months, respectively. Nevertheless, one-year post treatment, non-treated and treated hearts
demonstrated poor cardiac contractility. Immunohistological examinations at 12 months revealed an
absence of the transplanted myoblasts within the patches.
Conclusion: We demonstrated that heart function alteration could be stabilized by cell therapy. However,
this effect is transient.
48.2
Design and characterization of a strain stimulation bioreactor for tissue engineering applications
M.-N. Giraud, A. Panos, C. Haller, G. Fortunato, T. P. Carrel, H. T. Tevaearai (Bern)
Objective: Our tissue engineering group focuses on the development of contractile bioconstructs used
as a bandage for akynetic myocardium. In the present study, we aim to define in vitro dynamic culture
conditions to improve cell density, cell organisation and mechanical properties of the construct. Accordingly,
we report our on-going study on the development of a new device for the generation of stretch
culture conditions.
Methods: Latex or custom made silicon bulb (produced with a water-soluble wax mold) were covered
with electrospun poly-caprolactone (PCL) nanoscale fiber matrix. Pump controlled volumetric changes
induced bulb enlargement and resulted in matrix stretching. Spatial characterisation of the stretch
was analysed using finite element method (FEM) based on micro computed tomography (microCT)
images. C2C12 cells were seeded on the matrix and cultured for 1 week in basic culture conditions
under mechanical stimulation. Static, ramp (24h) and cyclic (1.33 Hz) strains were applied. Cellular
responses were investigated by scanning electronic microscopy, immunostaining and 3D confocal
analysis.
Results: 1: Computational modelling: Spatial imaging of the inflatable bulb using micro CT provides
qualitative information about the morphology and volume changes. Quantitative information and
characterisation of the motion distribution and regional strain are obtained with FEM. This computational
model allows quality control of the silicon bulb and the developed regional stretch. 2: Cellular
response to strains: Cell orientation and tissue thickness were investigated. Preliminary data showed
that compared to static culture conditions, dynamic culture induced cellular multilayer formation. In
addition, cyclic strains improved cell orientation and ramp strains induced a 2-times increase in tissue
thickness.
Conclusion: Dynamic conditioning of nanofibers matrices/myoblast based tissue using a bulb shape
30 swiss knife 2009; special edition
carrier provides a promising methodology for muscle tissue engineering. Modelling of the regional
stretch and integration of the cellular response will represent a powerful tool to fine tune optimal dynamic
culture conditions.Engineered tissue will be precondition mechanically prior to epicardial implantation.
48.3
3D radial UTE imaging for quantification of transplanted iron oxide labeled islet cells
F. Ris, L. Crowe, P. Morel, M. Armanet, S. Masson, S. Nielles-Vallespin, D. Bosco, J.-P. Vallee, T. Berney
(Genève)
Objective: Monitoring the fate of transplanted pancreatic islets into the liver is vital for improvement of
treatment for type I diabetes. MR provides quantitative, non-invasive imaging for serial examination of
iron oxide labelled cells.
Methods: SD rats were transplanted with either 0, 500, 1000, 2000 and 4000 islets . The labeling
and transplant method has been optimized so that the maximum number of injected islets remains
in the liver. Imaging was carried out on a 3T MRI. Scanning on D1, 8 and 15 after surgery. Respiratory
triggering used a pressure pad and external trigger input system with a trigger delay of around 150ms
to ensure imaging is at a constant respiratory position over the scan time. Images were compared with
the conventional 2D GRE signal loss sequence. Quantitative assessment for comparison of the numbers
of cells included measurement of the number of pixels (over all slices) containing enhanced UTE
signal and the distribution of the level of this hyperintensity. An intensity threshold was applied within
regions drawn around the liver to quantify the number of enhanced pixels.
Results: The isotropic 3D images can be viewed with the same resolution in all three orientations.
When imaging at D1, surgical disturbance makes visualization of individual clusters difficult. At one
and two weeks, cell visualisation and quantification is more defined with isolated enhanced spots
within an uniform background. With 2D GRE, the outermost axial slices (often where many of the islets
are situated) are lost to motion artifact from the heart or lower abdomen. The GRE signal loss technique
shows larger, more distorted spots than the radial sequence and partial volume effects due to large
slice thickness. Thresholding of the radial UTE difference image is more successful due to the uniform
hypointense background signal throughout the liver.
Conclusion: Reproducible quantification of the total number of cells with thresholding of the UTE difference
image is possible, due to the uniform background and high contrast of this sequence. The
proposed method allows to detect spots as well as assessing and quantifying changes with number
of cells, and progression over time. Application to improve detection and resolution in human clinical
study is promising.
48.4
Titanium IV ions induced human osteoclast differentiation and enhanced bone resorption in vitro
D. Cadosch 1 , O. P. Gautschi 2 , E. Chan 3 , H-P. Simmen 4 , L. Filgueira 3 ( 1 Winterthur, 2 St.Gallen, 3 Perth/AUS,
4 Zürich)
Objective: There is increasing evidence that titanium ions are released from prosthetic and osteosynthetic
metal implants resulting in 1µM concentration in surrounding tissues and blood, and playing a
role in aseptic loosening of metal implants. The aim of this study was to investigate, whether Ti(IV) ions
induce differentiation of monocytic osteoclast precursors (MC) into osteo-resorptive multinucleated
cells and influence the activation and function of in vitro generated osteoclasts (OC).
Methods: Human MC and OC were exposed to 1µM Ti(IV) ions for ten days. Thereafter, OC differentiation,
activation and function were evaluated. Transcription of specific osteoclastic genes, including
tartrate-resistant acid phosphatase (TRAP) and cathepsin K (CATK), was measured using RT-PCR. The
effects of Ti(IV) on the osteoclastic activity and differentiation were also evaluated by measuring the
enzymatic activity of TRAP using ELF97 as a fluorescent substrate. Additionally, functional evidence of
osteoclastic bone resorptive activity was determined by a lacunar resorption assay on dentin slides.
Results: After Ti(IV) treatment blood monocytes from five donors (22.7%) showed a “responsive” pattern
characterized by increased gene expression of OC markers, TRAP activity and bone resorptive ability.
The treated MC of the “responsive” cohort showed an increased expression of TRAP and to a lesser
extent CATK. Detection and quantification of intracellular TRAP activity, by using ELF97 for fluorescence
microscopy and flow cytometry, revealed a significant increase of TRAP-positive cells in Ti(IV) treated
MC of the same “responsive” individuals. Ti(IV) treated MC of the same cohort became functional bone
resorbing cells, as shown on dentin slide cultures, increasing significantly their osteo-resorptive activity
to similar levels of OC in vitro.
Conclusion: The present study provides strong support for the hypothesis that Ti(IV) ions, released
by biocorrosion from metal implants, induce differentiation of MC towards mature, functional OC in
approximately 20% of individuals. Those OC may well be responsible for enhanced periprosthetic bone
resorption. Therefore, these findings may help to explain the pathomechanism of aseptic loosening
in “responsive” individuals, and contribute to understanding and preventing failure of metal implants
used in trauma and orthopedic surgery.
48.5
Amiodarone pretreatment of organ donors exerts anti-oxidative protection but induces excretory
dysfunction in liver preservation and reperfusion
S. Engelberger 1 , M. R. Moussavian 1 , O. Kollmar 1 , M. Schmidt 1 , C. Scheuer 1 , M. Wagner 1 , J. E. Slotta 1 ,
G. Gronow 2 , C. Justinger 1 , M. D. Menger 1 , M. K. Schilling1 ( 1 Homburg, 2 Kiel/DE)
Objective: Continuous organ shortage necessitates the use of marginal organs from do-nors with various
diseases including arrhythmia associated cardiac failure. One of the most frequently used antiarrhythmic
drugs is amiodarone (AM), which is given in particular in emergency situations. Apart from
its anti-arrhythmic actions AM provides anti-oxidative properties in cardiomyocytes. Thus, we were