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ZusammenfassungGegenstand und Ziel: Die Hüftgelenkskapsel unterliegt bei der Hüftgelenksdysplasie (HD) erhöhten Zugkräften, die zu einer Entzündung des Kapselgewebes führen. Eine entzündungsassoziierte Zunahme der Nervenverteilungsdichte wurde in verschiedenen Organen nachgewiesen und könnte auch im Rahmen einer HD Ursache für Hüftgelenksschmerz und Koxarthrose sein. Ziel dieser Studie war, bei Hunden mit normo- bzw. dysplastischen Hüftgelenken Unterschiede in der Nervenverteilungsdichte innerhalb der Hüftgelenkskapsel aufzuzeigen. Material und Methoden: Bei 16 aus anderen Gründen euthanasierten Labrador Retrievern erfolgte anhand des radiologischen Befunds eine Kate gorisierung der Hüftgelenke als normoplastisch (Gruppe 1, n = 18) oder dysplastisch (Gruppe 2, n = 14). Die histologischen Präparate der Hüftgelenkskapseln wurden nach Färbung der Nerven fasern mit der Sihler-Färbemethode eingescannt und mittels einer Matrix in 10 gleich große Quadranten, nummeriert von dorsomedial (Q01) nach kraniodorsolateral (Q10), unterteilt. Durch Berechnung des prozentualen Anteils schwarzer Pixel mittels halbautomatischer Bildanalyse wurde die Nervenverteilungsdichte für jeweils das gesamte Präparat und die einzelnen Quadranten analysiert. Der statistische Vergleich erfolgte mittels t-Test für unabhängige Stichproben. Ergebnisse: Bei Hunden mit HD zeigte sich im kraniodorsolateralen Anteil der Hüftgelenkskapsel eine signifikant höhere Nervenverteilungsdichte (p = 0,03). Die mittlere Nervenverteilungsdichte für die gesamte Hüftgelenkskapsel differierte zwischen den beiden Gruppen nicht signifikant. Schlussfolgerung: Eine erhöhte Nervenverteilungsdichte im kraniodorsalen Anteil der Hüftgelenkskapsel bei Hunden mit HD könnte Folge der großen Zugkräfte in diesem Bereich und eine Ursache für die mit der HD einhergehende Schmerzhaftigkeit und Koxarthrose sein. Klinische Relevanz: Die Ergebnisse liefern die pathophysiologische Grundlage für den Erfolg der Deperiostierung des kranialen Azetabulumrandes im Rahmen einer Hüftgelenksdenervation zur Erzielung einer suffizienten Schmerzlinderung und Entzündungsreduktion bei Hunden mit HD.

The hip-joint capsule is exposed to increased tension forces during canine hip dysplasia, resulting in inflammation of the capsular tissue. It has been postulated that inflammation is associated with an increased nerve-distribution density. Therefore, it could be supposed that the nerve-distribution density in the hip-joint capsule is higher in dogs with dysplastic hip compared to healthy dogs.In 16 Labrador Retriever dogs that had been euthanised due to unrelated reasons, the hip joints were classified as normoplastic (group 1, n = 18) or dysplastic (group 2, n = 14) based on radiography. Following staining of the capsular nerve fibres by the Sihler method, histological specimens of the hip-joint capsules were scanned. By subdividing each specimen into 10 quadrants numbered from dorsomedial (Q01) to craniodorsolateral (Q10), the ratio of black to white pixels was calculated digitally for each specimen and each quadrant by using a semiautomatic image analysis. Statistical analysis was performed using an independent t-test.Comparison of the mean values of each quadrant showed a significantly higher (p 0.03) nerve distribution density for the craniodorsolateral quadrant (Q10) in group 2 when compared to group 1. Mean nerve-distribution density for all quadrants combined was not significantly different between the two groups.The increase in nerve-distribution density of the craniodorsal region of the hip-joint capsule in dogs with dysplastic hip could be the result of increased tension forces on this area following hip-joint dysplasia. The craniodorsal region of the hip-joint capsule is an important origin of pain and coxarthrosis in canine hip dysplasia.The results provide the pathophysiological basis for the efficacy of hip-joint denervation. Denervation of the cranial region of the acetabular rim is essential to reduce capsular inflammation and joint-related pain in canine hip dysplasia.

Background— The detection and differentiation of intracardiac masses is still challenging and may include neoplasms and thrombi. The aim of this study was the investigation of a targeted, fibrin-specific contrast agent (EP-2104R) for molecular targeted magnetic resonance imaging (MRI) of left atrial clots. Methods and Results— Chronic human thrombi were surgically implanted in the left atrial appendage of 5 swine. Molecular MRI was performed with a navigator-gated, free-breathing, cardiac-triggered 3D inversion-recovery, black-blood, gradient-echo sequence before and after systemic administration of 4 μmol/kg EP-2104R. MR images were analyzed by 2 investigators, and the contrast-to-noise ratio was calculated. Location of clots was confirmed by autopsy, and the gadolinium concentration in the clots was assessed. Before contrast agent administration, thrombi were not visible on black-blood MR images. After contrast administration, all atrial clots (n=5) were selectively visualized as white spots with a high contrast-to-noise ratio (clot/blood, 29.7±8.0). The gadolinium concentration in the clots averaged 74±45 μmol/L. Conclusions— The fibrin-specific MR contrast agent EP-2104R allows for selective and high-contrast visualization of left atrial clots by means of molecular targeted MRI.

To assess the feasibility of percutaneous magnetic resonance (MR)-guided intramyocardial injection of gadodiamide by using real-time imaging and to quantify T1 values and the size of the enhanced region for different concentrations of contrast agent for 30 minutes after injection.Animal care committee approval was obtained. A catheter with a needle tip was advanced into the left ventricle in seven pigs by using real-time imaging with radial steady-state free precession. After intramyocardial injection of 2 mL of solution at concentrations of 0.05 or 0.10 mmol/mL gadodiamide, local changes in T1 values and size of the contrast material-enhanced region were sequentially measured at 3, 15, and 30 minutes after injection by using the Look-Locker sequence. Two-tailed paired Student t tests were used for statistical analysis.Catheter guidance and visualization of contrast agent distribution were feasible in all animals. Regional changes in T1 values were significantly different for different contrast agent concentrations (for 0.05 mmol/mL, 456 msec +/- 5 [+/- standard error of the mean]; for 0.10 mmol/mL, 228 msec +/- 4; P.001) measured 3 minutes after injection. T1 values increased significantly (P.05) to 720 msec +/- 7 for 0.05 mmol/mL gadodiamide and 445 msec +/- 6 for 0.10 mmol/mL gadodiamide 30 minutes after injection but remained significantly lower than those of remote myocardium (879 msec +/- 8). The size of the contrast-enhanced region increased from 13 mm(2) +/- 2 at 3 minutes to 30 mm(2) +/- 3 at 30 minutes (P.05).Catheter MR-guided percutaneous intramyocardial injection is feasible; after intramyocardial injection of gadodiamide at concentrations of 0.05 and 0.10 mmol/mL, T1 values decreased over the observation time.

Ten dogs suffering from discospondylitis were treated by percutaneous discectomy and local and systemic antibiotic therapy. With fluoroscopic guidance, a cylinder 5 mm in diameter was removed from the centre of the intervertebral space, yielding a fenestration and decompressing the disc without producing any spinal instability. The causative bacteria were identified in nine of the 10 biopsy specimens, but in only three urine cultures and four blood cultures. In two cases, the antibiotics used initially had to be changed owing to the organisms' antibiotic resistance. The clinical signs of the dogs improved markedly after two to nine days (mean 4.2 days) and had resolved completely after five to 14 days (mean 9.1 days). In all the cases the disease could be classified histologically as either acute or chronic, and the disease was classified as chronic in one dog. No side effects were observed.

Metallic guide wires can be subject to substantial heating when used in the magnetic resonance (MR) environment. Therefore, animal experiments were performed to test the feasibility of a non-metallic and MR-safe guide wire with passive markers for catheterization of coronary arteries under MR guidance.Self-made guide wires consisting of a resin-microparticle compound covered by polytetrafluoroethylene were used to catheterize both coronary arteries of swine together with a non-braided catheter. Time needed for catheterization was recorded.MR-guided coronary artery catheterization with passive visualization of a self-made non-metallic guide wire is possible. In average 141 seconds (SD 68) were needed to manipulate the guide wire together with a catheter from the carotid artery into the left or right coronary artery ostium.Standard nitinol guide wires have to be considered unsafe for MR-guided interventions due to possible heating of electrical conducting structures in the MR environment. Passive visualization techniques allow MR-guided catheterization of small arteries like coronaries. However, there is the substantial disadvantage of obscuring the underlying anatomy of small vessels by the passive markers needed for real-time MR guidance.

The aim of this study was to assess imaging findings of posterior semicircular dehiscence on computed tomography and to evaluate incidence of posterior and superior semicircular canal dehiscence in patients presenting with vertigo, sensorineuronal hearing loss or in a control group without symptoms related to the inner ear. Computed tomography was performed in 507 patients presenting either with vertigo ( n=128; 23 of these patients suffered also from sensorineuronal hearing loss), other symptoms related to the inner ear, such as hearing loss or tinnitus ( n=183) or symptoms unrelated to the labyrinth ( n=196). All images were reviewed for presence of dehiscence of the bone, overlying the semicircular canals. Twenty-nine patients had superior semicircular canal dehiscence. Of these patients, 83% presented with vertigo, 10% with hearing loss or tinnitus and the remaining 7% with symptoms unrelated to the inner ear. In 23 patients dehiscence of the posterior semicircular canal was encountered. Of these patients, 86% presented with vertigo, 9% with hearing loss or tinnitus and 5% with symptoms unrelated to the inner ear. Defects of the bony overly are found at the posterior semicircular canal, in addition to the recently introduced superior canal dehiscence syndrome. Significant prevalence of vertigo in these patients suggests that posterior semicircular canal dehiscence can cause vertigo, similar to superior semicircular canal dehiscence.

SummaryIt was the aim of this study to evaluate denervation of the canine hip joint capsule as a newly developed surgical method for treatment of hip joint dysplasia and arthrosis of dogs. Denervation by surgical deperiostation of the cranio-lateral acetabulum is the presumed mechanism. We performed the denervation in 117 cases between 1997 and 1999. Clinical evaluation was documented by physical examination by a veterinarian immediately before and two months after the operation and a questionnaire completed by the dog owners. 90.6% of the patients showed an improvement of the clinical signs yielding a significant treatment effect (p

OBJECTIVES To assess the feasibility of magnetic resonance (MR)-guided delivery of a solution containing contrast-medium and immediate online monitoring of its distribution to the vessel wall during MR-guided angioplasty in peripheral arteries. MATERIALS AND METHODS In 3 pigs, the feasibility of MR-guided atraumatic delivery of a solution containing contrast-medium and tissue dye (0.05 mmol/mL Gd-DTPA, 3% Evans blue dye) into the vessel wall of the iliac arteries was tested using a permeable balloon catheter (8 mm). Catheter placement was monitored using a steady-state free precession real-time imaging sequence.Additionally, in 5 pigs, surgically created bilateral stenoses in the external iliac artery were dilatated with the porous balloon. In these animals, contrast-enhanced MR angiography was performed before and after the interventions to assess the degree of the stenosis. In all animals, the vessel wall was delineated before and after dilatation using a T1-weighted gradient echo (GE) sequence. RESULTS In the 3 animals without stenosis, contrast medium was successfully applied to the vessel wall. On the GE images, the normalized signal intensity of the vessel wall was 0.95 +/- 0.015 arbitrary units (a. u.) prior and 2.15 +/- 0.105 a. u. after the intervention (P < 0.01). In the animals with stenosis, MR angiography performed before and after the intervention demonstrated successful dilatation of 9 of the 10 stenoses. Before the intervention, 7 stenoses were severe (76%-99%) and 3 moderate (50%-75%), and after the intervention, 4 stenoses were completely removed and 5 mild (

We modified the Günther Tulip Filter to allow long-term retrieval and tested this modified filter design in an animal experiment. Fourteen modified Günther Tulip Filters (Celect filter) were inserted percutaneously into the inferior venae cavae of 7 domestic adult sheep (2 filters per animal). Before removal, 3 months after filter placement, cavography was performed and the filters were removed. Subsequently, cavography was obtained to check for any signs of bleeding. All venae cavae were prepared, removed, and macroscopically examined for bleeding. Filter placement was easy and successfully performed in all cases. No thrombi were detected inside the filters. All cases showed some narrowing of the vena cava at the level, where the filter legs were connected with the vessel wall. Neither cavograms after filter removal nor macroscopic examinations of the perivascular vena cava tissue showed any significant bleeding. The modified Günther Tulip Filter allowed for successful and uncomplicated filter removal up to 3 months after placement.

The purpose of this study was to intraindividually evaluate myocardial late enhancement on multislice spiral computed tomography (MSCT) for the assessment of the different stages of myocardial infarction (MI) in comparison with magnetic resonance (MR) imaging. Reperfused MI was successfully induced in seven pigs. Delayed enhancement MR imaging and late-phase MSCT were performed on day 0 as well as 7, 28 and 90 days after the procedure. The pigs were sacrificed, and 2,3,5-triphenyltetrazolin-chloride (TTC) staining was acquired. MI size was compared between the different imaging techniques and over time applying Bland-Altman plots and multivariate analysis with repeated measures. On day 0 the mean MI size was 23.7 +/- 11.8% of the left ventricular area on MSCT and 24.5 +/- 10.6% on MR imaging. On day 90 infarct sizes decreased significantly to 16.9 +/- 8.4% and 18.9 +/- 8.0%, respectively (P = 0.0019). On TTC staining the size of MI was 16.8 +/- 8.2%. Bland-Altman plots showed a good agreement between MSCT and MR imaging with mean deviations ranging from -3.4% to -1.9%. No significant difference between MSCT and MR imaging was found. Myocardial late enhancement on MSCT correlates well with delayed enhancement MR imaging during the different stages of MI and allows for reliable assessment of reperfused MI during acute, subacute and chronic stages.

Objectives: To determine retrospectively the prognosis and outcome for dogs diagnosed with thoracolumbar intervertebral disc disease treated with partial percutaneous discectomy (PPD). Methods: Three hundred and thirty-one dogs presenting with symptoms of thoracolumbar intervertebral disc disease from 1998 to 2003 were treated with PPD. Diagnosis and location of intervertebral disc disease was confirmed by clinical examination, radiography, myelography and magnetic resonance imaging. PPD was performed via fluoroscopy-guided removal of a 5 mm bore cylinder out of the central intervertebral space. Results: Clinical success after surgery was achieved in 159 (88·8 per cent) grade II to IV patients and 58 (38·2 per cent) grade V patients. The mean (sd) time from percutaneous discectomy to first improvement was 8·3 (13·2) days. Clinical Significance: The PPD approach to the thoracolumbar spine involves minor trauma (yielding rapid recovery) and less pain, and produces results comparable with open fenestration. Consequently, this simple minimal invasive technique can be recommended as an alternative to the technique of fenestration and can be easily performed in addition to open surgical decompression techniques or prophylactically. However, it is not a replacement for surgical treatment in dogs with thoracolumbar disc disease that require removal of disc fragments causing spinal cord or nerve root compression.

We sought to evaluate a closed-chest model for reperfused and occlusive myocardial infarction (MI) in pigs and to report experiences and pitfalls.In 44 pigs, a balloon catheter was advanced into the left descending coronary artery (LAD) under fluoroscopic guidance. The balloon was inflated and occlusion of the vessel angiographically confirmed while ECG was continuously monitored. In case of ventricular fibrillation, direct current defibrillation was performed. In 6 animals, the balloon was left inflated during the following experiments, to obtain occlusive MI. In all other cases, the balloon was deflated after 45 minutes. After the experiments were finished, the hearts were stained with 2,3,5-triphenyltetrazolium chloride for assessment of infarct size.MI was successfully induced in 34 animals (28 reperfused and 6 occlusive). Mean size of MI was 15.8 +/- 5.1% of left ventricular surface area for reperfused and 21.5 +/- 8.7% for occlusive infarcts. In one pig, 2,3,5-triphenyltetrazolium chloride did not confirm infarction. In 26 pigs, ventricular fibrillation occurred. Defibrillation was successful in 17 pigs. Failure rate because of ventricular fibrillation decreased from 42% (6) in the first 14 to 10% (3) in the next 30 animals. One animal died due to technical failure of the ventilator. After initial experiences, we used balloon catheters with a diameter of 2-3 mm, instead of 4 mm. The smaller balloon sizes were used so as to decrease the incidence of fibrillation.The described technique of LAD occlusion presents a less invasive alternative to open chest models. The major pitfall, causing fatal arrhythmia in our series, was over-dilatation of the LAD with the balloon catheter.

We report our results of partial lumbosacral laminectomy for treatment of canine Cauda equina Compression Syndrome due to a lumbosacral stenosis. Opposite to conventional techniques of dorsal laminectomy, only widening of the Spatium interarcuale is performed. This is achieved by exstirpation of the Lig. flavum and partial dorsal laminectomy of the first sacral segment. The Proc. spinosi and integrity of facet joints are fully maintained by this technique. In 96.5% of 86 dogs treated with this method relief of dorsal pressure and permanent rapid regression of clinical symptoms was achieved. In two cases recurrence of clinical symptoms was observed during follow up and one case showed no improvement at all. In conclusion partial dorsal laminectomy is a minimal invasive technique for treatment of Cauda equina compression syndrome expressed by pain reaction accompanied by minor neurological deficits caused by lumbosacral stenosis. Maintained spinal stability allows short reconvalescence and the unrestricted use of dogs immediately post operation.

Rationale and Objectives: The objective of this study was to investigate the potential for artifact-free coronary magnetic resonance angiography (cMRA) in the presence of dedicated metallic MR stents in vitro and in a swine model. Methods: All investigations were performed at 1.5 T, applying a standard cMRA gradient echo sequence with a T2 preparation pulse. Two prototypes of each hand-woven, mechanically woven, and lasered Aachen Resonance Coronary MR Stents made out of an MR-compatible metallic alloy and dilated to 2.5 mm and 4 mm were examined in a water bath. Results: Artifact behavior was judged independently by 2 radiologists as showing "no artifacts" for all tested stent types. Signal-to-noise ratios inside and outside of the stents were measured yielding a Pearson correlation coefficient of 0.98 (y = 1.22 + 0.92x). Nineteen stents (8 hand woven, 3 mechanically woven, 8 lasered) were deployed in coronary arteries of 19 domestic pigs and were examined by cMRA. Artifact behavior of the stents was analyzed by measuring the signal-to-noise ratio at the stent positions and compared with signal-to-noise ratio measurements outside of the stents, yielding a Pearson correlation coefficient of 0.90 (y = -0.75 + 1.06x). Conclusions: All 3 prototypes of coronary MR stents allowed complete visualization of the stent lumen and consequently determination of stent patency by cMRA.

This study describes the experience with hypofractionated radiation therapy of squamous cell carcinoma and melanoma in dogs and cats. A total dose of 32-48 Gray (Gy) was delivered once a week in 8 Gy fractions. 34 animals in which a complete surgical excision was impossible were treated. There was no tumor detectable macroscopically in 14 patients at the beginning of radiation therapy. In 20 animals the median volume of the tumor was 9.9 cm3. The median survival times and the local tumor control of squamous cell carcinoma of the oral and nasal cavities and of the body are comparable to results which were reached with a Monday-Wednesday-Friday scheme. For the treatment of Melanoma the hypofractionated radiation therapy is first choice. There are no significant side effects. Late side effects did not occur. 88% of the owners are satisfied with this kind of treatment and would choose it again.

We assessed the value of MRI for delineation of dehiscence of the superior or posterior semicircular canal, as compared with CT, the current standard study for this entity. We reviewed heavily T2-weighted fast spin-echo images and high-resolution CT of the temporal bones of 185 patients independently semicircular canal dehiscence and its extent. In 30 patients (19 men, 11 women) we identified dehiscence of the bone over the superior and/or posterior semicircular canal on MRI. In 27 of these cases CT also showed circumscribed bone defects. In one patient dehiscence of the superior semicircular canal was initially overlooked on MRI, but seen on CT. MRI imaging thus had a sensitivity of 96% and specificity of 98%. Knowledge of the appearances of this entity on MRI may contribute to early diagnosis in patients with vertigo due to semicircular canal dehiscence.

Denervation of the canine hip joint capsule is described as a surgical therapy method in the treatment of canine hip joint dysplasia and arthrosis. The goal of this operation is a removal of the pain immediately and a reactivation of the dynamic active component of the hip joint in moving the body forward. Simple removal of the periosteum of the craniolateral acetabulum edge destroys the rami articulares of the cranial glutaeal nerve and the rami articulares dorsalis of the sciatic nerve. Within 10 years now we performed the denervation of the canine hip joint capsule. Evaluation of the post operative clinical course in 269 cases revealed an impressive improvement of lameness due to pain relief in almost 92% of the cases.

Hypothesis Phospholipids and icodextrin reduce peritoneal adhesions resulting from general peritonitis without promoting abscess formation. Design Evaluation of adhesion reduction fluids in a randomized animal study using a standardized peritonitis model. Setting Experimental animal model in a university laboratory. Interventions In 60 rats, experimental peritonitis was induced using the cecal ligation and puncture model. On day 1, the abdominal cavity was rinsed with 10 mL of isotonic sodium chloride solution and the cecum was resected. Animals were randomly assigned to 3 groups: the RL group, which received Ringer lactate intraperitoneally; the PL group, which received phospholipids intraperitoneally; and the ID group, which received icodextrin intraperitoneally. In each group, 50% of the animals were humanely killed at day 11 and 50% at day 21. Main Outcome Measures The areas of adhesions were measured and the abscess formation was scored according to location and size. Abscesses, abdominal fluid, and blood were sampled for microbiologic workup. Results The median area of adhesions was significantly lower in the PL groups (PL 11 , 43.7 mm 2 ; PL 21 , 20.4 mm 2 ) than in the RL groups (RL 11 , 163.8 mm 2 ; RL 21 , 120.9 mm 2 ) and ID groups (ID 11 , 418.5 mm 2 ; ID 21 , 218.6 mm 2 ). Abscess formation was increased by icodextrin but not influenced by phospholipids, whereas microbiologic investigations did not reveal any differences among these 3 groups. Conclusions In this model of general peritonitis, phospholipids significantly reduced adhesion formation without promoting septic complications. Icodextrin enhanced adhesion and abscess formation in this peritonitis model. Phospholipids may be beneficial for adhesion control in general peritonitis.