Koichi Hayano

Role of Perfusion CT in Assessing Tumor Blood Flow and Malignancy Level of Gastric Cancer

Background/Aims: Intratumoral hemodynamics or tumor perfusion is useful in understanding the pathological background of the cancer. A parameter for a non-invasive, preoperative assessment of tumor perfusion has yet to be developed. Methods: The study included 50 patients who underwent surgery for gastric cancer. Perfusion computed tomography (P-CT) was performed using a 16-row multidetector CT, and tumor blood flow (ml/min/100 g tissue) values were measured. We compared blood flow with histopathological characteristics and evaluated its correlation with microvessel density and tumor stromal density and calculated the ratio of vessels and stromal tissue. Results: There was a significant decrease in blood flow in advanced tumor depth, peritoneal dissemination and undifferentiated subtypes. Cases with Lauren’s diffuse type carcinoma were found to have decreased blood flow compared to the mixed or intestinal type. As for the stromal structure, despite the lack of correlation with microvessel density, blood flow significantly decreased with increased stromal density. Conclusions: Decreased blood flow value acquired from P-CT may reflect a progressive state of gastric cancer. The pathological background for this relation involves the tumor stroma. Tumor perfusion decreased as the stage and malignant character of the tumor advanced, and therefore P-CT could be a better strategy to estimate the malignancy level of cancer.

Evaluation of portal vein invasion of distal cholangiocarcinoma as borderline resectability

The concept of borderline resectability has not yet been introduced for extrahepatic cholangiocarcinoma (ECC). In this study, the surgical results of ECC patients were analyzed to clarify the implications of surgery for distal ECC with portal vein (PV) invasion as a preliminary step for the introduction of the concept of borderline resectability.

Eleven Cases of Postoperative Hepatic Infarction Following Pancreato-Biliary Surgery

BackgroundPostoperative hepatic infarction is rare; therefore, clinical characteristics and outcomes of postoperative hepatic infarction after pancreatobiliary surgery have not been obvious.MethodsEleven patients encountered hepatic infarction after pancreato-biliary surgery. Management, clinical course, and outcome of these 11 patients were retrospectively analyzed.ResultsPossible causes of the hepatic infarction were inadvertent injury of the hepatic artery during lymph node dissection in five patients, right hepatic artery ligation in two patients, long-term clamp of the hepatic artery during hepatic arterial reconstruction in two patients, suturing for bleeding from the right hepatic artery in one patient, and celiac axis compression syndrome in one patient. Five of the 17 infarcts extended for one whole section of the liver, and distribution of the other 12 was less than one section. Ten patients discharged from hospital; however, one patient died of sepsis of unknown origin.ConclusionsAttention should be paid to inadvertent injury of hepatic artery to prevent hepatic infarction. Hepatic infarctions after pancreato-biliary surgery seldom extend to the entire liver and most of them are able to be treated without intervention.

Probable IgG4-related sclerosing disease presenting as a gastric submucosal tumor with an intense tracer uptake on PET/CT: a case report

A 44-year-old man consulted an internist because of abnormalities in an upper gastrointestinal series. It showed an elevated lesion with central depression in the greater curvature of the middle part of the stomach. Upper gastrointestinal endoscopy showed an elevated lesion with central depression, bridging hold, and no abnormalities of the gastric mucosa in the greater curvature of the middle part of the stomach. Endoscopic ultrasonography showed a submucosal tumor derived from the muscle layer of the stomach. Computed tomography showed a 22-mm tumor in the upper part of the stomach. Integrated position emission tomography/computed tomography (PET/CT) showed an intense tracer uptake by the tumor. Based on these findings, a gastrointestinal stromal tumor was suspected and laparoscopic endoscopic cooperative surgery was performed. A histopathological examination showed lymphoplasmacytic infiltration and fibrosis, and an immunohistochemical analysis showed the infiltration of IgG4-positive lymphoplasmacytic cells. The probable diagnosis was IgG4-related sclerosing disease of the stomach. We herein describe a rare case of probable IgG4-related sclerosing disease which presented as a gastric submucosal tumor. PET/CT is a useful imaging technique for the diagnosis and follow-up of this disease.

Preoperative hepatic CT perfusion as an early predictor for the recurrence of esophageal squamous cell carcinoma: Initial clinical results

Reports suggest that hepatic blood flow may have an association with cancer progression. The aim of the present study was to evaluate whether the hepatic blood flow measured by CT perfusion (CTP) may identify patients at high-risk for postoperative recurrence of esophageal squamous cell carcinoma (ESCC). Prior to surgery, hepatic CTP images were obtained using a 320-row area detector CT. The data were analyzed by a commercially available software based on the dual input maximum slope method, and arterial blood flow (AF, ml/min/100 ml tissue), portal blood flow (PF, ml/min/100 ml tissue) and perfusion index [PI (%) = AF/AF + PF × 100] were measured. These parameters were compared with the pathological stage and outcome of the ESCC patients. Forty-five patients with ESCC were eligible for this study. The median follow-up period was 17 months, and recurrences were observed in 9 patients (20%). The preoperative PI values of the 9 patients with recurrence were significantly higher than those of the 36 patients without recurrence (23.9 vs. 15.9, P=0.0022). Patients were categorized into the following two groups; high PI (>20) and low PI (<20). The recurrence-free survival of the low PI group was significantly better than that of the high PI group (P<0.0001). A multivariate analysis showed that a high PI was an independent risk factor for recurrence (odds ratio, 19.1; P=0.0369). Therefore, the preoperative PI of the liver may be a useful imaging biomarker for predicting the recurrence of patients with esophageal cancer.

Arterio-biliary fistula as rare complication of chemoradiation therapy for intrahepatic cholangiocarcinoma

Significant hemobilia due to arterio-biliary fistula is a very rare complication of chemoradiation therapy (CRT) for unresectable intrahepatic cholangiocarcinoma (ICC). Here we report a case of arterio-biliary fistula after CRT for unresectable ICC demonstrated by angiographic examinations. This fistula was successfully treated by endovascular embolization. Hemobilia is a rare complication, but arterio-biliary fistula should be considered after CRT of ICC.

Is “functional end-to-end anastomosis” really functional? A review of the literature on stapled anastomosis using linear staplers

PurposesAnastomosis is one of the basic skills of a gastrointestinal surgeon. Stapling devices are widely used because stapled anastomosis (SA) can shorten operation times. Antiperistaltic stapled side-to-side anastomosis (SSSA) using linear staplers is a popular SA technique that is often referred to as “functional end-to-end anastomosis (FEEA).” The term “FEEA” has spread without any definite validation of its “function.” The aim of this review is to show the heterogeneity of SA and conventional hand-sewn end-to-end anastomosis (HEEA) and to advocate the renaming of “FEEA.”MethodsWe conducted a narrative review of the literature on SSSA. We reviewed the literature on ileocolic and small intestinal anastomosis in colonic cancer, Crohn’s disease and ileostomy closure due to the simplicity of the technique.ResultsThe superiority of SSSA in comparison to HEEA has been demonstrated in previous clinical studies concerning gastrointestinal anastomosis. Additionally, experimental studies have shown the differences between the two anastomotic techniques on peristalsis and the intestinal bacteria at the anastomotic site.ConclusionsSSSA and HEEA affect the postoperative clinical outcome, electrophysiological peristalsis, and bacteriology in different manners; no current studies have shown the functional equality of SSSA and HEEA. However, the use of the terms “functional end-to-end anastomosis” and/or “FEEA” could cause confusion for surgeons and researchers and should therefore be avoided.

Diffusion-weighted MR imaging of pancreatic cancer and inflammation: Prognostic significance of pancreatic inflammation in pancreatic cancer patients

BACKGROUND Pancreatic cancer often accompanies chronic obstructive pancreatitis (COP) due to obstruction of the main pancreatic duct, and the inflammatory environment may enhance cancer progression. The purpose of this study is to evaluate COP using the apparent diffusion coefficient (ADC) value measured by diffusion-weighted MR imaging (DWI), and to assess its prognostic significance in pancreatic cancer. METHODS Twenty-eight patients (16 men, 12 women; mean age 67.1 years) with pancreatic cancers who underwent DWI followed by curative surgery were evaluated. The ADC value of pancreatic parenchyma upstream to the tumor (upstream pancreas) was measured and compared with the upstream pancreatic duct dilatation to assess whether DWI could reflect COP. The ADC values of tumor and upstream portion were compared with overall survival (OS) using Cox regression and Kaplan-Meier analysis. RESULTS The ADC value of upstream pancreas was significantly lower in patients with greater dilated pancreatic duct than those with less (P = 0.03). In univariate Cox regression analysis, the ADC value of upstream pancreas showed a significant association with OS (P = 0.01), but that of tumor did not (P = 0.06). In Kaplan-Meier analysis, patients with lower ADC value of upstream pancreas (<1.36 × 10(-3) mm(2)/s) were significantly associated with poor OS (P = 0.0006). In multivariate analysis, the ADC value of upstream pancreas was identified as an independent prognostic factor (P = 0.01; hazards ratio, 0.05; 95% CI, 0.004-0.59). CONCLUSIONS The ADC value of upstream pancreas was an independent prognostic factor for OS in pancreatic cancer patients. Inflammatory environment may play an important role in pancreatic cancer progression.

Huge mucinous cystic adenocarcinoma of the pancreas.

pected to be a mucinous cystic adenocarcinoma. We performed en bloc distal pancreatectomy and splenectomy. The macroscopic appearance was consistent with mucinous cystic neoplasm ( fig. 3 ). Microscopy showed epithelium composed of mucin-secreting cells and a dense cellular ovarian-type stroma ( fig. 4 ). Adenocarcinoma was A 41-year-old woman was referred to our hospital for evaluation of an abdominal tumor. Contrast-enhanced CT and MRI showed a cystic tumor, 21 cm in diameter, with internal septa localized in the tail of the pancreas ( fig. 1 ). FDG-PET revealed significantly increased uptake in the solid component ( fig. 2 ). Thus, this tumor was susPublished online: November 10, 2010

Incidence and risk factor of outlet obstruction after construction of ileostomy

There are several reports on the usefulness of diverting ileostomy for decreasing the incidence of anastomotic leakage and the severity of pelvic peritonitis. However, a number of complications induced by ileostomy itself have also been reported, including a special condition induced by obstruction at the outlet of the stoma known as “outlet obstruction.” In this study, we examined the frequency and risk factors of this complication based on the data of ileostomy cases in our institution. Methods: One hundred and seven patients who received ileostomy creation at our department from January 2010 to December 2015 were included. The incidence of outlet obstruction and risk factors were analyzed. Results: Outlet obstruction occurred in 18 cases (16.8%). The incidence was significantly higher in total colectomy or proctocolectomy cases as well as in those with left side construction and laparoscopic surgery than in other patients in a univariate analysis. However, in a multivariate analysis, no risk factors were extracted. Conclusions: To determine the true cause of this disease, a prospective study with a large number of cases is needed. Since multiple terms are used for this condition, resulting in confusion, a consensus on the appropriate terms is also important.