Comparison of contrast-enhanced multidetector computed tomography angiography and splenoportography for the evaluation of portosystemic-shunt occlusion after cellophane banding in dogs

BACKGROUND Many patients with a congenital extrahepatic portosystemic shunt (PSS) do not tolerate an immediate shunt closure. Therefore, slow progressive techniques were developed. To evaluate the success of shunt closure diagnostic imaging is essential to identify possible residual blood flow through the shunt vessel. There is a lack of information about the reliability of computed tomography angiography (CTA) for evaluating residual flow through a PSS after treatment. The purpose of this prospective study was to compare the results of CTA with splenoportography. Three months after cellophane banding CTA and splenoportography were performed in 20 dogs and reviewed by three independent examiners, respectively. In both imaging modalities the presences of a residual shunt was judged as present or absent and the extent of visibility of portal vasculature was recorded. RESULTS Based on the evaluation of the splenoportography residual flow through shunt was present in 6 dogs. The classification of residual shunt present or absent showed a substantial to perfect agreement (κ = 0.65-1.00) between the observers in splenoportography and a slight to moderate agreement (κ = 0.11-0.51) for CTA. Sensitivity and specificity varied between 0.50 and 1.00 and 0.57-0.85, respectively. Significant correlation between CTA and splenoportography for the classification of residual shunt was present only in one observer but not in the other two. CONCLUSION More studies were classified as residual shunt positive with CTA compared to splenoportography. It remains unclear which methods do reflect reality better and thus which method is superior. The greater inter-rater agreement for splenoportography suggests a greater reliability of this technique

The Effects of Interlocking a Universal Hip Cementless Stem on Implant Subsidence and Mechanical Properties of Cadaveric Canine Femora

OBJECTIVE: To determine if an interlocking bolt would limit subsidence of the biological fixation universal hip (BFX(®)) femoral stem under cyclic loading and enhance construct stiffness, yield, and failure properties. STUDY DESIGN: Ex vivo biomechanical study. ANIMALS: Cadaveric canine femora (10 pairs). METHODS: Paired femora implanted with a traditional stem or an interlocking stem (constructs) were cyclically loaded at walk, trot, and gallop loads while implant and bone motions were captured using kinematic markers and high‐speed video. Constructs were then loaded to failure to evaluate failure mechanical properties. RESULTS: Implant subsidence was greater (P = .037) for the traditional implant (4.19 mm) than the interlocking implant (0.78 mm) only after gallop cyclic loading, and cumulatively after walk, trot, and gallop cyclic loads (5.20 mm vs. 1.28 mm, P = .038). Yield and failure loads were greater (P = .029 and .002, respectively) for the interlocking stem construct (1155 N and 2337 N) than the traditional stem construct (816 N and 1405 N). Version angle change after cyclic loading was greater (P = .020) for the traditional implant (3.89 degrees) than for the interlocking implant (0.16 degrees), whereas stem varus displacement at failure was greater (P = .008) for the interlocking implant (1.5 degrees) than the traditional implant (0.17 degrees). CONCLUSION: Addition of a stabilizing bolt enhanced construct stability and limited subsidence of a BFX(®) femoral stem. Use of the interlocking implant may decrease postoperative subsidence. However, in vivo effects of the interlocking bolt on osseointegration, bone remodeling, and stress shielding are unknown

Cenozoic environmenal shifts and foraminiferal evolution

The dense record of Cenozoic foraminifera simultaneously supplies a mosaic of biostratigraphy, a rich field for evolutionary studies and the vehicles for geochemical environmental proxies. Four groups are discussed: the larger foraminifera on the warm-water shelves and platforms, the planktonics, the deep-sea faunas and the southern-extratropical benthics. The environmental trajectory from greenhouse in the later Cretaceous and earlier Paleogene to icehouse in the Neogene is not smooth but punctuated, and there are two particularly critical intervals, later Eocene and early-middle Miocene. The foraminiferal record is not smooth but chunky at 107 years’ scale. There are several good examples of two powerful synchroneities, one being between the faunas of the different realms and the other between the fossil record and the physical-environmental record.Brian McGowra