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Introduction: Balloon angioplasty is a common endovascular procedure. The balloon for angioplasty sometimes ruptures (incidence, 3.6%–10%), and it is constructed such that it ruptures in a longitudinal direction and complications related to rupture are rare. However, on rare occasions, retrieval is challenging, especially in the case of ruptures with a circumferential tear. There is no established method for retrieval and careful retrieval is required due to the risk of embolization by the residual balloon fragment.Technique: We describe two cases of balloon rupture in the transverse direction during percutaneous transluminal angioplasty for arteriovenous fistula in hemodialysis patients. In these cases, the balloon ruptured with a circumferential tear and dissected into two parts, and the tip edge remained in the vessel. We inserted an additional introducer at the side of the tip edge, caught the guidewire by a gooseneck snare, and hooked the residual balloon fragment. This also stabilized and increased the stiffness of the guidewire through the “pull-through technique.” Then, we reintroduced the gooseneck snare to catch the residual balloon. We then inserted a cobra-head catheter from the first introducer and pushed the residual balloon. We finally retrieved the ruptured balloon by pulling back the gooseneck snare and pushing using the cobra-head catheter simultaneously.Results: We could retrieve the ruptured balloons successfully using this technique and percutaneous transluminal angioplasty was continued in both cases.Conclusion: Our technique of retrieval may be suitable for cases of balloon rupture with a circumferential tear during percutaneous transluminal angioplasty. The technique enables less invasive retrieval and continuation of the percutaneous transluminal angioplasty thereafter.

Massive landslides can generate large tsunamis and endanger human lives and properties. While a number of laboratory experiments on either subaerial or submarine landslide‐tsunamis have been conducted, few studies have focused on partially submerged events. The present study aimed to investigate the characteristics of partially submerged landslide‐tsunamis and to develop a predictive equation that can estimate their heights through three‐dimensional laboratory experiments that used 114 different conditions. The experimental results showed that, while waves generated in the landslide sliding direction had around 1.7 times higher amplitude than those propagating laterally in the near‐field region, the wave period, celerity, and wavelength did not alter significantly according to the propagation angles. The effects of wave dispersion were also shown to be significant during the propagation process. Such wave characteristics were consistent with those reported in existing subaerial landslide tsunami experiments conducted by other researchers. Based on the data set obtained, the authors also derived a predictive equation which was confirmed to be able to estimate the results of other experimental studies on partially submerged landslide‐tsunamis with an error of around ±30%, and thus can be helpful for a rapid tsunami hazard assessment. The developed equation indicated that the volume of a landslide could have more than twice the impact on the height of a partially submerged landslide‐tsunami than other parameters. The effects of the landslide size were also shown to be more significant than in the case of a subaerial landslide‐tsunami, though the wave attenuation process was similar in both types. Massive landslides can generate large tsunamis and endanger human lives and properties. While many laboratory experiments on landslide‐generated tsunamis have been conducted, few studies have investigated on partially submerged landslide‐tsunamis. The present study conducted three‐dimensional laboratory experiments on partially submerged landslide‐tsunamis to investigate the characteristics of such waves and to develop a predictive equation of their likely height. The results showed that waves generated in the landslide sliding direction were higher than those generated in the lateral direction, though other wave properties did not change greatly (which is similar to that reported by other researchers for other types of landslide tsunamis). In addition, the results show that partially submerged landslide tsunamis have similar wave propagation properties as those of other types of landslide tsunamis. Based on the experimental results, the authors also derived a predictive equation and confirmed that it can accurately estimate the heights of partially submerged landslide‐tsunamis. The derived equation can be helpful when conducting a rapid tsunami hazard assessment. It was also found that whereas the generation process of a partially submerged landslide‐tsunami is different from a subaerial landslide‐tsunami, the propagation process is similar in both types. Three‐dimensional laboratory experiments were conducted on partially submerged landslide‐tsunamisWhile the amplitudes of the generated waves differed according to the propagation angles, other wave properties were not clearly differentThe derived predictive equation is able to estimate the height of the partially submerged landslide‐tsunamis well Three‐dimensional laboratory experiments were conducted on partially submerged landslide‐tsunamis While the amplitudes of the generated waves differed according to the propagation angles, other wave properties were not clearly different The derived predictive equation is able to estimate the height of the partially submerged landslide‐tsunamis well

Byline: Hiroshi Miyano, Michihito Inagaki, Naoto Hashimoto, Toshiaki Shishido, Toru Kawada, Yoshihiro Miyake, Kenji Sunagawa Abstract: Background and objectives: Although global measurements of cerebral blood flow and metabolism during and after profoundly hypothermic cardiopulmonary bypass have been performed both in experimental animals and in human beings, little is known about their regional changes. The purpose of this study was to investigate the changes in regional cerebral blood flow during profoundly hypothermic cardiopulmonary bypass and regional cerebral glucose use after cardiopulmonary bypass. Methods: We measured regional cerebral blood flow with positron emission tomography during both the cooling (n = 5) and rewarming (n = 5) of hypothermic cardiopulmonary bypass in anesthetized dogs by continuously infusing.sup.15O-labeled water. We altered the core temperature between 20[degrees] and 37[degrees] C. To assess the integrity of brain metabolism, we measured the regional cerebral glucose use by bolus injections of.sup.18F-labeled 2-fluoro-2-deoxy-d-glucose. Results: Regional cerebral blood flow decreased homogeneously during cooling. The regional cerebral blood flow at 20[degrees] C was about one fourth of that at 37[degrees] C. In contrast, at 24[degrees], 28[degrees], and 32[degrees] C during rewarming, there were significant interregional differences in the regional cerebral blood flow for given temperatures (p = 0.0075, 0.034, and 0.048, respectively). These interregional differences disappeared after rewarming. Although the regional cerebral blood flow significantly correlated with the regional cerebral glucose use in the control condition at 37[degrees] C without cardiopulmonary bypass (r = 0.75; p = 0.00012), this correlation disappeared after profoundly hypothermic cardiopulmonary bypass (r = 0.204; p = 0.388). Regional cerebral blood flow at 32[degrees] C during rewarming positively correlated with the regional cerebral glucose use after cardiopulmonary bypass (r = 0.655; p = 0.0017). Conclusion: The altered regional cerebral blood flow during rewarming of profoundly hypothermic cardiopulmonary bypass might affect regional brain metabolism. (J Thorac Cardiovasc Surg 1998;116:503-10) Article History: Received 4 June 1997; Revised 8 August 1997; Revised 27 February 1998; Accepted 27 February 1998 Article Note: (footnote) [star] From the Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute,a and the Institute for Biofunctional Research,b Osaka, Japan., [star][star] Address for reprints: Hiroshi Miyano, MD, Department of Cardiovascular Dynamics, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Suita, Osaka 565, Japan., a 12/1/90016