Akira Arakawa

Early postoperative evaluation of pylorus-preserving gastrectomy for gastric cancer.

Early postoperative evaluation was prospectively performed in 35 gastric cancer patients after pylorus-preserving gastrectomy (PPG) between 1989 and 1991, comparing the results with those of 29 patients who underwent conventional distal gastrectomy (CDG). Surgical stress, including the duration of operation (149.0±4.3 minutes) and the total volume of bleeding at operation (97.0±11.2 g), was significantly less in the PPG patients. Early postoperative complications were seen in 31% after PPG and in 35% after CDG. The most frequent complication in PPG patients was remnant gastric stasis (23%). Endoscopy showed redness or erosion (or both) of the gastric remnant in 17% after PPG and in 81% after CDG. Bile regurgitation was demonstrated in 11% after PPG and in 62% after CDG. In PPG patients, the pyloric ring opened and closed during the examination. Gastric pH was 4.2±0.4 in PPG patients but was significantly lower in CDG patients. The resting gallbladder area, examined by ultrasonography, demonstrated no changes after PPG but was significantly enlarged after CDG (from 11.3±1.2 cm2 to 15.8±1.5 cm2 at 2 weeks). The percentage of the original resting gallbladder area at 20 minutes after injection of cerulein increased slightly in PPG patients but recovered thereafter, whereas in CDG patients it increased significantly (from 39.4±8.3% to 66.7±9.1% at 2 weeks). No gallstone formation was detected throughout the observation period after PPG, whereas after CDG it was detected in two patients at 1 year. These results indicated that PPG for gastric cancer has advantages over CDG in terms of surgical stress, the condition of the gastric remnant, and gallbladder function.RésuméLes différentes formes de tolérance de la gastrectomie avec conservation du pylore (GCP) ont été évaluées chez 35 patients opérés de cancer gastrique entre 1989 et 1991, et comparées aux résultats observés chez 29 patients après une gastrectomie distale conventionnelle (GDC). Le stress chirurgical, défini par la durée de lintervention (149±4.3 min.) et le volume total de saignement au cours de lintervention (97±11.2 g), étaient statistiquement moindres en cas de GCP quen une de GDC. Il y ayait 31% de complications postopératoires après GCP et 35% après GDC. La complication la plus fréquente après GCP a été la stase du moignon gastrique, observée dans 23% des cas. Lendoscopie montrait chez 17% de ces patients opérés de GCP et chez 81% des patients après GDC, une rougeur et/ou des érosions du moignon gastrique. Un reflux bilieux a été constaté chez 11% des patients après GCP et chez 62% après GDC. Chez les patients ayant eu une GCP, on a pu mettre en évidence une ouverture et une fermeture de lanneau pylorique pendant lexamen. Le pH gastrique était de 4.2±0.4 dans la GCP, significativement plus bas quaprès la GDC. Léchographie a montré une augmentation de la surface vésiculaire après GDC, allant de 11.3±2 cm2 à 15.8±5 cm2, statistiquement plus importante quaprès GCP. Après la GCP, la surface a augmenté légèrement 20 minutes après linjection de céruléine, alors quaprès GDC, elle a augmenté significativement de 39.4±8.3% à 66.7±9.1% (à deux semaines). Après GCP, on na pas observé de formation de lithiase pendant toute la période dobservation alors quaprès GDC, deux cas de lithiase ont été observés à un an. Ces résultats indiquent que la GCP pour cancer gastrique a des avantages certains par rapport à la GDC surtout en ce qui concerne le fonctionnement et létat du moignon gastrique et la fonction vésiculaire.ResumenSe hizo una evaluación prospectiva en el período postoperatorio temprano luego de gastrectomía con preservación del píloro (PPG) en 35 pacientes con cáncer gástrico entre 1989 y 1991, comparándolos con 29 pacientes sometidos a gastrectomía distal convencional (CDG). El estrés quirúrgico, incluyendo la duración de la operación (149±4.3 min) y el volumen total de hemorragia durante la operación (97±11.2 g) fueron significativamente menores en la PPG. Complicaciones postoperatorias tempranas aparecieron en 31% de los casos con PPG y en 35% de los casos con CDG. La complicación más frecuente en la PPG fue la estasis del remanente gástrico en 23% de los casos. La endoscopia demostró enrojecimiento y/o erosión del remanente gástrico en 17% de los pacientes luego de PPG, contra 81% luego de CDG. Se demostró regurgitación biliar en 11% luego de PPG, y en 62% luego de CDG. En los pacientes con PPG, el anillo pilórico se vio abrir y cerrar en el curso del examen. El pH gástrico fue 4.2±0.4 en PPG y significativamente más bajo que en los pacientes con CDG. La vesícula biliar en reposo estudiada mediante ultrasonografía señaló que no había cambios luego de PPG; sin embargo, apareció significativamente agrandada de tamaño luego de CDG, de 11.3±1.2 cm2 a 15.8±1.5 cm2 (2 semanas). El porcentaje del área original de la vesícula en reposo a los 20 minutos luego de la inyección de ceruleína aumentó levemente en la PPG pero luego se recuperó, en tanto que en la CDG aumentó significativamente de 39.4±8.3% a 66.7±9.1% (2 semanas). Luego de la PPG no se detectó formación de cálculos biliares durante el período de observación, pero sí se detectó en dos pacientes al año luego de CDG. Estos resultados indican que la PPG para cáncer gástrico tiene ventajas en cuanto a estrés quirúrgico, condición del remanente gástrico y función de la vesícula biliar, sobre la CDG.

A resected case of giant leiomyosarcoma of the pancreas.

Leiomyosarcoma of the pancreas is very rare. We report a case of giant leiomyosarcoma of the pancreas treated by distal pancreatectomy. A 53-year-old female was admitted with an large abdominal mass. Computed tomography, magnetic resonance imaging, and ultrasonography revealed a huge tumor adjacent to the pancreas. However, we could not identify the primary organ with these imagings. Angiographic findings strongly suggested that the tumor originated from the pancreas, as main feeding arteries arose from the great pancreatic artery. Fourteen days after transcatheteric arterial embolization, we performed a distral pancreatectomy with splenectomy; the patients postoperative course was uneventful. Histologically, we confirmed the diagnosis as a leiomyosarcoma originating from the pancreas.

Perpendicular magnetic anisotropy and magnetization of L10 FePt/FeCo bilayer films

Fe40Co60 epitaxial thin films are prepared on L10 ordered Fe60Pt40 underlayer by ultrahigh vacuum multiple dc-sputtering systems. Magnetic properties of the Fe60Pt40 (10u2009nm)/Fe40Co60 (t nm) bilayer films are investigated. When the FeCo thickness is less than 3u2009nm, the easy magnetization axis of FePt/FeCo bilayer film is perpendicular to the film plane. Compared with FePt/Fe and FePt/Co films, FePt/FeCo bilayer films possess not only higher anisotropy field Hk but also larger magnetic anisotropy energy Ku, which may be due to the perpendicular magnetic anisotropy yielded by the tetragonal distorted FeCo layer on FePt, while the magnetic easy axes of Fe and Co layers lie in the film plane. Meanwhile, saturation magnetization of FePt/FeCo film increases reasonably because of the high Ms value of FeCo component. These results indicate that the FePt/FeCo bilayer films which possess both large magnetic anisotropy energy Ku and high saturation magnetization Ms have great potential for using as the magnetic recor...

Investigation of magnetic anisotropy and magnetic moments of tetragonal distorted Fe1−xCox films on L10 FePt underlayer

Tetragonal distorted Fe1−xCox (0 ≤ x ≤ 1) thin films are prepared on L10 ordered Fe0.6Pt0.4 underlayer. The dependences of FeCo alloy composition on magnetic anisotropy energy (MAE) are investigated. Based on the LLG simulation, the tetragonal distorted Fe1−xCox films show maximum positive magnetic anisotropy energy when the Co composition is around 60 at.u2009%, while the MAE decreases and shifts to negative when the composition is close to pure Fe or Co. The experiment results prove that the MAE can be tuned by varying the alloy composition. Furthermore, the magnetic moments of Fe and Co in distorted Fe0.4Co0.6 films are studied by the X-ray magnetic circular dichroism spectroscopy. The enhanced orbit moments which come from the lattice distortion increase the magnetic anisotropy energy of Fe0.4Co0.6 film.

Nanoscale Composition Control Applied on \({\boldsymbol {L}} 1_{\mathrm {\mathbf {0}}}\) FePtRh Film for Dot Patterning Using Magnetic Phase Change

A planar dot pattern was fabricated using the flat-patterning method involving nanoscale composition control. A small percentage of Fe and Pt atoms was locally diffused into an L10 FePtRh film by annealing, resulting in ferromagnetic dots with a diameter of 50 nm and a nonmagnetic spacing with a width of 100 nm. Nanoscale composition profiles around the dots were analyzed by an energy dispersive X-ray detector attached to a transmission electron microscope. Only the area in which the composition crossed the ferromagnetic-nonmagnetic threshold underwent a magnetic phase change. Magnetic force microscopy revealed ferromagnetic dots with a single-domain structure in the nonmagnetic matrix.

The effects of convenient vagorrhaphy on the early recovery of gastric secretion and emptying: An experimental study on function-preserving gastric cancer surgery

An experimental study was conducted using a canine model to elucidate whether the once transected vagal nerve can be conveniently anastomosed, and to determine when and to what degree the vagorrhaphy retains its functions. In the vagorrhaphy group (n=5), the anterior and posterior vagal trunks were transected 1.5 cm above the diaphragma and the cut ends were anastomosed using two stitches of 8-0 nylon and fibrin glue adhesive without microsurgery. In the nonvagorrhaphy group (n=5), a 1-cm length of the nerve segment was resected to prevent reinnervation. A microscopic study of the anastomotic site performed on postoperative day (POD) 10 indicated the intervention of nerve fibers between the cut ends. No differences were found in the gastric secretory function, as assessed by the Hollander insulin test, or in the emptying function, as assessed by the acetaminophen test, between the vagorrhaphy group and the control preoperative values. However, both of these functions were superior in the vagorrhaphy group compared to the nonvagorrhaphy group. These results indicate that the technique of convenient vagal anastomosis could be put to practical use in gastric cancer operations to avoid postvagotomy syndrome.

Gallbladder Function After Pylorus Preserving Gastrectomy for Gastric Cancer

Gallbladder functions were evaluated in patients who had undergone pylorus preserving gastrectomy for early gastric cancer using ultrasonography, comparing with those in patients undergone conventional distal gastrectomy. The resting gallbladder area showed no dilatation after pylorus preserving gastrectomy. The deterioration of the contractile function after pylorus preserving gastrectomy was s1ight, compared with that after conventional distal gastrectomy. It suggested that pylorus preserving gastrectomy had advantage to decrease the incidence of postgastrectomy cho1ecysto1ithiasis.