Hideto Sakimoto

Auxiliary Heterotopic Partial Liver Transplantation in Pigs with Acute Liver Failure

Fulminant hepatic failure is usually fatal without liver transplantation; however, orthotopic liver transplantation is often difficult to perform due to the high risk of coagulopathy and the development of multiple organ failure. Auxiliary heterotopic partial liver transplantation (APLT), however, has the potential to provide an effective hepatic support system considering that the host liver is left in situ and the surgical procedure is less invasive. In this report, we describe the beneficial effects of performing 60% APLT on the hepatic function and survival of pigs with acute hepatic failure induced by hepatic artery ligation. The pigs were divided into a control group of nine animals (group 1) that had portal vein and hepatic artery ligation with a side-to-side portacaval shunt, and an APLT group of seven animals (group 2) that had portal vein and hepatic artery ligation with APLT. The two left lateral lobes of the donor liver were resected, reducing the liver weight to about 60%, and the graft was placed in the right subhepatic space. No deaths occurred intraoperatively. In group 1, eight pigs died of massive liver necrosis within 48 h and one died between 48 and 72 h (median surivival 23 h). In group 2, two pigs died within 72 h due to preservation or anesthetic problems, but five survived for more than 3 days (median survival 13.4 days), with a significant difference between the two groups (P<0.05). One animal was killed 30 days after APLT and excellent graft function was demonstrated by the synthesis of clotting factors, ammonia detoxification, and glucohomeostasis. Moreover, evidence of hepatic regeneration was found in the transplanted livers. These results indicate that APLT provides metabolic support and improves survival in animals with induced acute liver failure.

A mixed adenoneuroendocrine carcinoma of the pancreas: a case report

A tumor consisting of an adenocarcinoma component and a neuroendocrine carcinoma component, with each component accounting for at least 30% of the tumor, is defined as a mixed adenoneuroendocrine carcinoma (MANEC). We report a case of MANEC of the pancreas. A 63-year-old man presented with hyperglycemia and was referred to our hospital for further examination. Abdominal contrast-enhanced computed tomography (CT) revealed a mass of 2xa0cm in size in the pancreas head with portal vein narrowing. Fluorin-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) CT revealed increased accumulation in the mass of the pancreas head. Endoscopic retrograde cholangiopancreatography (ERCP) showed severe narrowing of the main pancreatic duct. Cytological analysis by endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) suggested a neuroendocrine tumor. Under the diagnosis of neuroendocrine tumor, pancreaticoduodenectomy with portal vein resection and regional lymph node dissection was performed with curative intent. Histological examination revealed that the tumor consisted of two cell populations. One was well- to moderately differentiated tubular adenocarcinoma. This cell component accounted for 45% of the whole tumor. The second component was non-adenocarcinoma cells arranged in a nest, and the cells had round nuclei, abundant cytoplasm, and coarse chromatin. The Ki67 labeling index was 40%. Immunohistochemically, the adenocarcinoma cells were positive for CEA but negative for chromogranin A (CgA) and synaptophysin (Syn), while the non-adenocarcinoma cells were positive for the expression of CgA and Syn but negative for CEA. Based on the findings, a diagnosis of MANEC of the pancreas was made. Postoperatively, lymph node metastasis and peritoneal dissemination developed rapidly and he died the 6xa0months after the operation. Due to the small number of reported cases of MANEC of the pancreas, its clinical behavior remains unclear and a standardized management protocol has not been established. Further investigation of more cases of this rare entity is necessary.

Intermittent intraperitoneal implantation of islets in rat islet transplantation

Two critical issues need to be addressed regarding islet cell transplantation: obtaining sufficient supply of cells for implantation, and the maintenance of the viability of these cells. Our present study has two protocols. One is islet cell implantation under the renal capsule, and the other, repeated injection of islet cells into the peritoneal cavity. These two methods were compared in an isogeneic transplant model in the rat to determine the more clinically beneficial method. Transplantation of 2000-2500 islet under the capsule of the kidney resulted in normalized blood sugar levels for more than 100 days in four of five rats with hyperglycemia. However, normalization for the same duration by islet cell injection into the peritoneal cavity necessitated repetition of injections in two out of three tested rats. In view of the similarity of the results obtained with these two protocols, intraperitoneal implantation of a few cells is preferable, because the need for prolonged cell preservation is avoided.

Sphincter-saving resection by cluneal arched skin incision for a gastrointestinal stromal tumor (GIST) of the lower rectum: a case report

BackgroundPlanning the surgical strategy for a gastrointestinal stromal tumor (GIST) at the posterior wall of the lower rectum is difficult, as the procedures for the lower rectum are hampered by poor visualization and may cause anal dysfunction or discomfort. We report a novel procedure to resect a submucosal tumor of the rectum.Case presentationA 75-year-old woman presented with metrorrhagia. Endovaginal ultrasonography showed a low echoic tumor. Computed tomography showed an enhanced tumor, measuring 5.3u2009×u20094.2xa0cm, behind the rectum. Magnetic resonance imaging revealed a submucosal tumor of the rectum, measuring 5.3xa0cm at its greatest dimension. Colonoscopy showed that the distal tumor margin was 1xa0cm above the dentate line. Core needle biopsy of the tumor revealed the rectal GIST. After receiving neoadjuvant imatinib treatment, the tumor size decreased to 3.5xa0cm. During the operation, we approached the rectum and resected the posterior rectal wall, including the 3.5u2009×u20093.5xa0cm tumor with a safety margin, making an arched incision at the buttocks to form a skin flap with the patient in a jackknife position. The histopathological diagnosis was GIST of the rectum. Her anorectal sphincter function was well preserved. No recurrence was seen during the 2-year follow-up.ConclusionsThis novel approach improves the operative field visibility in resecting a tumor with a safety margin and preserves a patient’s anorectal sphincter function.

A solid pseudopapillary neoplasm of the pancreas in a man presenting with acute pancreatitis: A case report

Highlights • Small SPN of the pancreas is sometimes difficult to diagnose preoperatively and mimicking pancreatic cancer.• The clinical presentation of SPNs is nonspecific, but acute pancreatitis is rare in the reported literature.• We should be aware that SPN of the pancreas can become a cause of acute pancreatitis.