Showing papers by "Yukihiro Yokoyama published in 2009"

Clinicopathologic study of cholangiocarcinoma with superficial spread.

Abstract: Objective:To review our experience with cholangiocarcinoma with superficial spread, to clarify its clinical features, and to discuss treatment strategies.Summary Background Data:Most of the previous reports on cholangiocarcinoma with superficial spread were case reports. Little is known about this t

Nek2 as a novel molecular target for the treatment of breast carcinoma.

Abstract: We investigated the role of Nek2, a member of the serine-threonine kinase family, in the tumorigenic growth of breast carcinoma. Increased expression of Nek2 was observed in all breast carcinoma cell lines examined (BT20, BT474, Hs578T, MCF7, MDA-MB-231, T47D, and ZR-75-1) by immunoblotting. By treatment with Nek2 short interfering RNA (siRNA), expression of Nek2 was clearly decreased in both estrogen receptor (ER)-positive (MCF7) and ER-negative (MDA-MB-231) breast carcinoma cell lines. Cell growth, colony formation in soft agar, and in vitro invasiveness of these cell lines were substantially suppressed by Nek2 siRNA treatment. In a xenograft nude mouse model with subcutaneous implantation of MCF7 or MDA-MB-231, subcutaneous injection of Nek2 siRNA around the tumor nodules resulted in a reduction of tumor size compared with those of control siRNA injection. Taken together, Nek2 appears to play a pivotal role in tumorigenic growth of breast carcinoma cells, and could be a useful therapeutic molecular target for the treatment of breast carcinoma both in ER-positive and ER-negative cases.

Value of multidetector row CT in the assessment of longitudinal extension of cholangiocarcinoma: correlation between MDCT and microscopic findings.

Abstract: A few authors have reported the value of multidetector row CT (MDCT) for evaluating the longitudinal extent of cholangiocarcinoma. They have not focused on CT attenuation of a tumor and actual tumor extent along the bile ducts. We designed the present study to analyze attenuation. Between January 2003 and July 2005, 113 consecutive patients with cholangiocarcinoma underwent a surgical resection following MDCT. Of these MDCT studies, 73 (perihilar cholangiocarcinoma, n = 62; middle and distal cholangiocarcinoma, n = 11) were suitable for analysis, and the patients were enrolled in the study. Patients were divided according to tumor hypoattenuation and hyperattenuation on MDCT. Histologic differentiation, desmoplastic reaction, and vascular density were microscopically compared with the tumor attenuation to differentiate the characteristics of the attenuation. The extent of cancer along the bile duct diagnosed by MDCT was compared with the actual extent determined by the microscopic findings. Hyperattenuated tumor was observed in 40 patients. There was no difference in histologic differentiation, desmoplastic reaction, or vascular density between the hyperattenuated and hypoattenuated cholangiocarcinomas. Neither the proximal nor the distal borders between the normal and thickened bile duct wall could be determined in the 33 patients with hypoattenuated tumor; in contrast, an accurate assessment of extent of tumor was obtained in 76% of the proximal borders and 82% of the distal borders in the 40 patients with hyperattenuated tumor. Although the cause of the difference between the hyperattenuated and hypoattenuated cholangiocarcinoma still is unclear, MDCT can be an alternative to direct cholangiography in selected patients with hyperattenuated cholangiocarcinoma.

Advances in the treatment of pancreatic cancer: Limitations of surgery and evaluation of new therapeutic strategies

Abstract: Pancreatic ductal carcinoma is one of the most dismal malignancies of the gastrointestinal system. Even after curative resection, the actual 5-year survival is only 10%-20%. Of all the treatments used against pancreatic cancer, surgery is still the only one that can achieve complete cure. Pancreatic cancer spreads easily to the adjacent tissues and distant metastasis is common. Typically, this cancer invades the retropancreatic neural tissue, duodenum, portal vein (PV), and superior mesenteric vein (SMV), or regional lymph nodes. For this reason, aggressive surgery that removes the cancerous lesion completely is recommended. Several retrospective and prospective studies have been conducted to validate the usefulness of aggressive surgery for pancreatic cancer in the past few decades. Surprisingly, the survival benefits of aggressive surgery have been denied by most randomized controlled trials (RCTs). This implies that surgery alone is not enough. Thus, adjuvant therapy, such as radiotherapy and chemotherapy, has been given in combination with surgery to improve survival. Although the benefits of radiotherapy alone are limited, the results of chemotherapy are promising. Other newly evolving molecular targeting drugs may also improve the treatment outcomes of pancreatic cancer.

Estrogen promotes hepatic regeneration via activating serotonin signal.

Abstract: The aim of this study was to determine if estrogen plays any role in the process of hepatic regeneration of nonligated lobe after portal vein branch ligation (PBL). We also investigated whether estrogen has any association with serotonin action during liver regeneration. Ovariectomized female rats with (E group) or without (non-E group) estrogen pellet were subjected to PBL on the left and middle lobes. Thereafter, the rats were killed, and blood, liver, and small intestine were sampled and analyzed. Sham animals underwent only ovariectomy and laparotomy. The E group showed a significantly greater regeneration rate than the non-E group at days 1, 2, and 7 after PBL. The activation of hepatic regeneration-related genes (such as IL-6, TNF-alpha, hepatic growth factor, c-fos, and c-myc) was also significantly higher in the E group as compared with the non-E group. Gene expression of serotonin receptor (5-HT2A) in the liver and tryptophan hydroxylase 1 in the small intestine were also up-regulated in the E group, indicating an activation of serotonin system in the E group. Additionally, total intestinal flow, portal venous flow, and hepatic arterial flow determined by fluorescent microsphere were significantly higher in the E group compared with the non-E group. Moreover, serotonin receptor antagonist (ketanserin) significantly attenuated liver regeneration rate in the E group. These results indicated that estrogen plays an important role in the process of liver regeneration after PBL. Our results also indicated that estrogen is at least partly related to the activation of serotonin system, which is also important in the process of liver regeneration.

A left hepatectomy and caudate lobectomy combined resection of the ventral segment of the right anterior sector for hilar cholangiocarcinoma--the efficacy of PVE (portal vein embolization) in identifying the hepatic subsegment: report of a case.

Abstract: This report presents a case of a left hepatectomy and a caudate lobectomy combined resection of the ventral segment of the right anterior sector for hilar cholangiocarcinoma using percutaneous transhepatic portal vein embolization (PVE). The patient was a 44-year-old man admitted to a local hospital with obstructive jaundice. He was diagnosed to have hilar cholangiocarcinoma and was referred to the hospital for further treatment. Cholangiography revealed stenosis of the left hepatic duct and the hilar bile ducts. The dorsal branch of the right anterior sector joined the right posterior branch and the tumor did not invade to the confluence of these branches. Arteriography and portography reconstructed by multidetector-raw computed tomography revealed the ventral branches of the right anterior sector, which separately diverged from the other right anterior branches. It was therefore necessary to perform a left hepatectomy and caudate lobectomy combined resection of the ventral segment of the right anterior sector to completely remove the tumor. Portal vein embolization was thus performed on the left portal vein and the ventral branches of the right anterior sector. Intraoperatively, when the hepatic artery was temporally clamped, the demarcation between the ventral segment and the dorsal segment of the right anterior sector could be clearly visualized. The planned surgery was performed safely. This case demonstrates that the utilization of PVE is useful for a difficult and intricate hepatectomy, which requires an accurate identification of a hepatic subsegment.

A rare surgical case of multiple liver resections for recurrent liver metastases from pancreatic gastrinoma: liver and vena cava resection.

Abstract: Pancreatic gastrinoma is a rare non-β islet cell tumor. Approximately 60% of gastrinomas are malignant; despite the fact that they are usually slow growing, liver metastases have a major impact on prognosis. Most authors have advocated aggressive surgical management as being the only potentially curative therapy to improve survival as well as to provide outstanding relief from symptoms. We present a case of a 57-year-old man referred to our hospital with a diagnosis of liver metastases from pancreatic gastrinoma, with suspected involvement of the inferior vena cava (IVC). At the age of 37 years, he was diagnosed in his local hospital as having a pancreatic gastrinoma, with liver metastases, and he underwent distal pancreatectomy, splenectomy and enucleation of liver metastases. A liver tumor recurred twice, 7 and 9 years after the first surgery, for which double liver resections were performed: the first time he underwent enucleation of multiple liver metastases in segments II, III, IV, V, VI, VII and VIII, with resection of the right hepatic vein and partially resection of the diaphragm; the second time he underwent enucleation of multiple liver metastases in segments II, III, IV, and V. In our hospital, 8 years after the last surgery, the patient underwent right extended trisectionectomy, resection of segment I, combined resection of the IVC, and partial removal of the diaphragm. To the best of our knowledge, from a review of the literature, this is the first case to achieve successful long-term survival through aggressive surgical management of this type of metastatic endocrine tumor. The patient described here is still alive, free of disease and leading a normal life, 20 years after the initial diagnosis and 3 years after the last surgery.

Treatment of pancreatic fistula after pancreatoduodenectomy using a hand-made T-tube

Abstract: To describe a technique for the treatment of postoperative pancreatic fistula (POPF) after pancreatoduodenectomy (PD) using a hand-made T-tube. Reconstruction after PD was performed by a modified Child’s method. A 3-mm tube and a 2-mm tube were connected in a ‘T’ shape. This hand-made T-tube was inserted into both the pancreatic duct and the jejunal limb, using two guidewires through a sinus tract of POPF. After a few days, the external end of the T-tube was closed with a metallic tip, and the internal pancreatic drainage was completed. The indication criteria for the T-tube treatment are as follows: (1) the pancreatic drainage tube inserted during operation has been dislodged; and (2) either the main pancreatic duct or the jejunal limb can be demonstrated on fistulograms. In the 30 years between 1978 and 2007, 642 patients underwent PD (pylorus-preserving, n = 210; Whipple, n = 302; and hepatopancreatoduodenectomy, n = 130). The T-tube treatment was performed in 9 patients (pylorus-preserving, n = 5; Whipple, n = 1; and hepatopancreatoduodenectomy, n = 3). The median duration between surgery and the T-tube placement was 64 days (range, 22–107 days). The median hospital stay after the T-tube placement was 12 days (range, 7–54 days). Neither major nor minor complications associated with the T-tube treatment occurred. The T-tube was removed in 5 patients after a median of 2 months (range, 2–24 months). Of these patients, 4 are alive without recurrence of carcinoma, and 1 patient died of recurrence 56 months after surgery. The other 4 patients died of recurrence before removal of the T-tube, at 11 months after placement of the tube (range, 7–15 months) without any complications associated with the T-tube treatment. T-tube treatment is a minimally invasive, simple, safe, and reliable technique that can dramatically improve grade C POPF. This procedure should be considered as a first-line treatment of choice in selected patients with refractory grade C POPF.

Superextended hepatectomy for resection of multiple giant hemangiomas: report of a case.

Abstract: Most liver hemangiomas are small, asymptomatic, and require no treatment. Symptoms such as right upper quadrant abdominal pain and fullness are associated only with liver hemangiomas larger than 4 cm in diameter. Serious complications such as jaundice, Kasabach-Merritt syndrome, and rupture are rare. Surgical resection is the only effective treatment, but it is advocated only for patients with incapacitating symptoms or complications. We report a case of successful superextended hepatectomy with resection of segments III-VIII for multiple, bilobar hemangiomas. A 45-year-old woman, who had undergone transcatheter arterial embolization (TAE) for inoperable multiple giant liver hemangiomas 4 years earlier, was referred to our hospital for investigation of abdominal distension and consumption coagulopathy. Because of her severe and progressive symptoms despite treatment, the other hospital had considered her as a candidate for liver transplantation, which she had refused. After careful preoperative assessment of the future liver remnant volume and function, we considered that resection was possible. Based on our review of large surgical series in the literature from 1970, this is the first report of a superextended hepatectomy for a benign liver tumor.

Small pancreatic carcinoma misdiagnosed as superficially spreading cholangiocarcinoma

Abstract: We report a case of small pancreatic carcinoma misdiagnosed as superficially spreading cholangiocarcinoma using percutaneous transhepatic cholangioscopy (PTCS). The patient was a 72-year-old man admitted to a local hospital with obstructive jaundice. The patient underwent percutaneous transhepatic biliary drainage and PTCS. He was referred to our hospital with a diagnosis of superficially spreading cholangiocarcinoma. Cholangiography revealed a stenosis of the common bile duct, and also revealed some irregularities from the common hepatic duct to the left hepatic duct, suggesting a superficial spread of cancer. No pancreatic tumor was identified by endoscopic retrograde pancreatography or by enhanced computed tomography. Cholangioscopy disclosed an elevated tumor with torsional vessels and granular mucosal lesions, which were extended to the left hepatic duct. Repeated cholangioscopic biopsies of the bile duct mucosa revealed adenocarcinoma. The patient was diagnosed with superficially spreading cholangiocarcinoma extending to the left hepatic duct and the right anterior hepatic duct. Left trisectionectomy combined with pancreatoduodenectomy was performed. The cut surface of the resected specimen showed a pancreatic head tumor that was 8 mm in diameter. Histological findings of the resected specimen revealed adenocarcinoma arising from the pancreatic head with invasion in the common bile duct. Additionally, extensive inflammatory granulation tissue was observed along the surface of the bile duct, without any evidence of carcinoma. This case implies to us that the results of PTCS, even after repeated biopsies, should be interpreted with great caution.