Toshiyuki Natsume

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.

Surgical advantages of gastric SMTs by laparoscopy and endoscopy cooperative surgery.

BACKGROUND/AIMS The treatment of gastric submucosal tumors (SMTs) is strictly surgical and enucleation of the tumor or wedge resection of the stomach is efficient to achieve R0 resection. Laparoscopic and endoscopic cooperative surgery (LECS) can be safely performed with adequate cutting lines. This study describes the initial 16 cases treated by LECS and evaluates the advantages by LECS for gastric SMTs retrospectively. METHODOLOGY Sixteen patients with gastric SMT underwent LECS from June 2007 to December 2010, their surgical data, clinical characteristics and surgical specimens of SMTs were compared. The surgical specimens of 9 gastric SMTs treated by laparoscopic wedge resection (LWR) were compared as a control. RESULTS The median (range) length of operation time, blood loss, hospital stay after surgery were minutes 172 (115- 220), <5mL (<5-115) and 10 days (6-17), respectively. The median (range) ratio of the longest diameter of the tumor divided by the longest diameter of the surgical specimen in LECS and LWR were 0.86 (0.625-1.0) and 0.69 (0.44-1.0), respectively (p=0.0189, Wilcoxon rank sum test). CONCLUSIONS LECS minimizes the surgical specimen while still providing sufficient surgical margins to successfully cure gastric SMTs.

A case of neurilemmoma of the breast

Neurilemmoma of the breast is rarely seen, although it is common at intracranial or peripheral sites. There have been only 14 cases described in the literature. We present the fifteenth case of a 64-year-old woman with neurilemmoma of the breast, the first to be diagnosed by fine needle aspiration cytology. Fibroadenoma must be distinguished from this tumor. Complete removal is the treatment of choice, considering the possibility of local recurrence and malignant change.

Clinical Application of 11c-methionine Positron Emission Tomography for Evaluation of Pancreatic Function

Introduction In recent years, it has become increasingly necessary to evaluate pancreatic function after pancreatectomy, but few precise methods are available. Aims To evaluate different surgical techniques for pancreatectomy in terms of the preservation of pancreatic function by 11C-methionine positron emission tomography (PET), which determines amino acid metabolism in the pancreas. Methodology The study included 33 pancreatectomy cases: 5 of distal pancreatectomy, 5 of pancreaticoduodenectomy, 10 of pylorus-preserving pancreaticoduodenectomy, 7 of duodenum-preserving pancreatic head resection, and 6 of inferior pancreatic head resection. The method was as follows. Approximately 370 MBq 11C-methionine was intravenously injected. Cross-sectional imaging of the pancreas was performed by PET after 30 minutes. The images obtained were used to determine the radioactivity concentration in the pancreas. By adjustment of the radioactivity concentration for body weight and dosage, the differential absorption ratio could be determined to indicate the level of accumulation in the pancreas. Each surgical method used was evaluated on the basis of the differential absorption ratio. Postoperative total pancreatic accumulation was divided by preoperative level to calculate the total preserved pancreatic function rate (TPPFR), and postoperative local pancreatic accumulation was divided by preoperative level to calculate the local preserved pancreatic function rate (LPPFR). These rates were then compared for the individual techniques used. Results The results indicated that TPPFR and LPPFR were 61.2 ± 20.0% and 114.6 ± 29.4% for distal pancreatectomy (n = 5), 31.8 ± 20.0% and 58.7 ± 30.0% for pancreaticoduodenectomy (n = 5), 21.6 ± 14.7% and 58.4 ± 29.8% for pylorus-preserving pancreaticoduodenectomy (n = 10), 47.9 ± 35.5% and 67.7 ± 30.6% for duodenum-preserving pancreatic head resection (n = 7), and 48.1 ± 29.5% and 83.9 ± 30.5% for inferior pancreatic head resection (n = 6). TPPFR was highest in distal pancreatectomy cases. Among the pancreatic head resections, TPPFR was quite high for both inferior pancreatic head resection and duodenum-preserving pancreatic head resection. In contrast, TPPFR for pancreaticoduodenectomy and pylorus-preserving pancreaticoduodenectomy was quite low. LPPFR was highest for distal pancreatectomy and only slightly lower for inferior pancreatic head resection. In contrast, LPPFR was markedly lower for pancreaticoduodenectomy and pylorus-preserving pancreaticoduodenectomy. Conclusion In conclusion, this method using 11C-methionine PET is clearly useful for the evaluation of pancreatic function after pancreatectomy.

Survival predictors of patients with primary duodenal adenocarcinoma.

This single-institution experience retrospectively reviewed the outcomes in 21 patients with primary duodenal adenocarcinoma. Twelve patients underwent curative surgery, and 9 patients underwent palliative surgery at the Chiba University Hospital. The maximum follow-up period was 8650 days. All pathologic specimens from endoscopic biopsy and surgical specimens were reviewed and categorized. Twelve (57.1%) patients underwent curative surgery (R0): 4 pancreaticoduodenectomies (PD), 4 pylorus-preserving PDs (PpPD), 2 local resections of the duodenum and 2 endoscopic mucosal resections (EMR). Palliative surgery was performed for 9 patients (42.9%) following gastro-intestinal bypass. The median cause-specific survival times were 1784 days (range 160-8650 days) in the curative surgery group and 261 days (range 27-857 days) in the palliative surgery group (P = 0.0003, log-rank test). The resectability of primary duodenal adenocarcinoma was associated with a smaller tumor size, a lower degree of tumor depth invasiveness, and less spread to the lymph nodes and distant organs.

Antecolic Reconstruction Is a Predictor of the Occurrence of Roux Stasis Syndrome After Distal Gastrectomy

BackgroundRoux-en-Y reconstruction after distal gastrectomy can result in delayed gastric emptying, called Roux stasis syndrome (RSS). The cause of RSS has not been completely identified. This study retrospectively investigated the development of RSS.MethodsBetween April 2008 and March 2014, we performed 138 procedures with distal gastrectomy using Roux-en-Y reconstruction. The development of RSS was analyzed and examined for correlations with the length of the operation, amount of blood loss, and surgical procedure.ResultsRSS was observed in 16 of the 138 patients. There were no relationships between the length of the operation or amount of blood loss and the development of RSS according to the Mann-Whitney U test. There were also no significant differences in the development of RSS between the patients treated with laparotomy and laparoscopic surgery, end-to-side, side-to-side, or end-to-end anastomosis or isoperistaltic or antiperistaltic anastomosis, as determined using the chi-square test. However, the development of RSS tended to lower in the patients who underwent laparoscopic surgery, side-to-side anastomosis, and isoperistaltic anastomosis. In addition, there was a significant difference between the patients who received antecolic and retrocolic reconstruction (p = 0.005).ConclusionsOur findings suggest that antecolic reconstruction correlates with a lower likelihood of developing RSS.

The Outcome of Laparoscopic Surgery With and Without Short Gastric Vessel Division for Achalasia

Short gastric vessel division (SGVD) has been performed as a part of fundoplication for achalasia. However, whether or not SGVD is necessary is still unknown. Forty-six patients with achalasia who underwent a laparoscopic surgery with or without SGVD were analyzed. A questionnaire was administered to assess the postoperative improvement. Regarding improvement of dysphagia and postoperative reflux, there were no significant differences between SGVD (+) group and SGVD (-) group (P = 0.588 and P = 0.686, respectively). Nineteen patients (95%) in the SGVD (+) group and 24 (92%) in the SGVD (-) group answered that the surgery was satisfactory (P = 0.756). In the SGVD (+) group, the pre- and postsurgical body weight increase was +7.3%. In the SGVD (-) group, it was 8.2%. There was no significant difference of body weight increase between the 2 groups (P = 0.354). SGVD is not always required in laparoscopic surgery for achalasia.