Yoichi Kamiyama

18F-Fluorodeoxyglucose Positron Emission Tomography: Useful Technique for Predicting Malignant Potential of Gastrointestinal Stromal Tumors

The malignant potential of gastrointestinal stromal tumors (GISTs) is difficult to diagnose before surgery because the diagnoses are based on tumor diameter and mitotic index. The progression of small GISTs is always observed because they do not seem to have malignant potential. 18F-Fluorodeoxyglucose (FDG)-positron emission tomography (PET) is a useful technique for assessing tumor activity. The objective of this study was to determine if FDG-PET is useful for predicting the malignant potential of gastric GISTs. Ten patients diagnosed with gastric GISTs participated. FDG-PET was performed on all of them before tumor resection. A whole-body image was initiated 40 minutes after the injection of 275 to 370 MBq FDG. FDG uptake was assessed by a standardized uptake value. All tumors had FDG uptake. There was a significant correlation between the FDG uptake and both the Ki67 index and the mitotic index but not the tumor diameter. The FDG uptake and malignant potential of gastric GISTs had a significant correlation. FDG-PET may be of considerable value for predicting the malignant potential of gastric GISTs before surgery. A gastric GIST with a high FDG uptake should be regarded as having malignant potential.

Effect of distal subtotal gastrectomy with preservation of the celiac branch of the vagus nerve to gastrointestinal function: an experimental study in conscious dogs.

Objective:To evaluate the effects of distal subtotal gastrectomy with preservation of the celiac branch of the vagus nerve on gastrointestinal function. Summary Background Data:The operative procedure of distal subtotal gastrectomy with preservation of the celiac branch of the vagus nerve is now in the spotlight in Japan with the goal of finding a function-preserving surgical technique. However, there has been no analysis of the effect of this type of surgery on gastrointestinal function. In this article, we describe the results of a fundamental experiment on distal subtotal gastrectomy with preservation of the celiac branch of the vagus nerve. Methods:Twenty conscious dogs were divided into 2 groups, each subdivided into 2 groups of 5: a normal intact dog group (NG) divided into 2 groups, with preservation (PNG) and resection (RNG; these dogs were truncally vagotomized including transaction of the celiac branch) of the celiac branch, and a gastrectomy dog group (GG) divided into 2 groups, with preservation (PGG) and resection (RGG) of the celiac branch. The motility of the dogs was recorded using strain gauge force transducers. The effects of the preservation of the celiac branch of the vagus nerve on gastrointestinal motility, gastric emptying, and pancreatic insulin release were evaluated. Results:The motility index of gastrointestinal motility with preservation of the celiac branch was higher than the motility index with resection of the celiac branch in fasted and fed of NG and GG. In gastric emptying, significant differences were found between the PNG and RNG but not between the PGG and RGG. In the fasted state for 80 minutes of the PNG and PGG, the serum insulin concentration reached a peak during the early phase III at 20 minutes in the gastric body and the antrum. Conclusions:This study has shown that it is effective to preserve the celiac branch of the vagus nerve for gastroduodenal motility, gastric emptying, and pancreatic insulin release after a gastrectomy.

Mucin phenotypic expression in early signet ring cell carcinoma of the stomach: its relationship with the clinicopathologic factors.

Gastric early-stage signet ring cell carcinoma (SIG) has been reported to have a lower rate of lymph node metastasis and a higher rate of favorable prognosis than other histological types. However, the development and progression mechanisms of early-stage SIG (early SIG) are controversial. This study examined the correlation between the mucin phenotype of early SIG and its clinicopathologic factors, particularly for the sake of less invasive surgery. Sixty-nine early SIGs were studied immunohistochemically with gastric mucin (M1 and MUC6) and intestinal mucin (MUC2). SIGs were classified into gastric (G), intestinal (I), gastrointestinal (GI), or unclassified (U) type. The intramucosal spreading patterns of SIG were investigated and then classified as either expansive or infiltrative. SIGs were classified into G-type (59.4%) and GI-type (40.6%). Neither the I- nor the U-type was observed. The GI-type expression correlated with the depth of tumor invasion in SIGs (P <0.05). In contrast, there was no increase in GI-type expression in relation to tumor size. Intramucosal infiltrative growth correlated with intestinal metaplasia (IM) of background mucosa of SIGs (P <0.01). There was no significant correlation between phenotypes and intramucosal spreading pattern. In conclusion, the GI-type expression of SIG is a clinically useful factor for predicting submucosal invasion. The findings of SIG surrounded with IM revealed the need to exercise great care in determining the surgical margin.

Peritoneal Recurrence of Gastric Cancer with Mucin Phenotype 12 Years After Curative Resection: Report of a Case

We report a case of peritoneal recurrence of gastric cancer in a 58-year-old man, 12 years after curative surgery. Urinary wall thickness was seen on follow-up computed tomography and magnetic resonance imaging scans. We performed total nephroureterectomy and cystectomy for urinary tract cancers, but histological examination of the resected specimen revealed poorly differentiated adenocarcinoma with severe fibrosis, resembling the gastric cancer resected 12 years earlier. Immunohistological examination revealed human gastric mucin (45M1) and intestinal mucin (MUC2) phenotype in both the original gastric cancers and the urinary tract cancers. Thus, we concluded that the second cancer was a peritoneal recurrence of gastric cancer with gastric and intestinal mucin phenotypes. Although peritoneal recurrence so many years after curative gastrectomy is rare, careful long-term follow-up should be done for all patients undergoing surgery for gastric cancer with mucin phenotype.

Impact of Gastropyloric Motor Activity on the Genesis of Reflux Esophagitis After an Esophagectomy With Gastric Tube Reconstruction

BACKGROUND Reflux esophagitis is a significant problem in patients after an esophagectomy with gastric tube reconstruction. The pathogenesis of reflux esophagitis is not fully understood. The aim of the present study was to evaluate whether gastropyloric motility influences the pathogenesis of reflux esophagitis after an esophagectomy. METHODS Thirty esophagectomized patients were assessed by endoscopy and manometry. The patients were classified into 3 groups according to the postoperative period as follows: Group 1 (less than 12 months), group 2 (12 to 24 months), and group 3 (more than 24 months). Gastropyloric motor activity was quantified by calculating the motility index, which is equivalent to the area under the contractile waves. RESULTS Reflux esophagitis was observed in 80% of group 1, 80% of group 2, and 30% of group 3. The severity of reflux esophagitis decreased with time. Contractions of the gastric body were not observed in any of the patients. The antral motility index in group 3 was significantly greater than that in groups 1 and 2. The pyloric motility index progressively increased. The severity of reflux esophagitis is significantly associated with gastropyloric motor activity. CONCLUSIONS The severity of reflux esophagitis decreases with time, coupled with recovery of antropyloric motor activity. Gastropyloric motor activity plays an important role in the genesis of reflux esophagitis after an esophagectomy.

Gastric Motor Activity in Gastric Pull-Up Esophagectomized Patients With and Without Reflux Symptoms

BACKGROUND Patients frequently experience reflux symptoms of heartburn and regurgitation after a gastric pull-up esophagectomy. The pathogenesis of reflux symptoms is not fully understood. The gastrointestinal tract exhibits a temporally coordinated cyclic motor pattern, termed interdigestive migrating motor contraction, during the interdigestive state. Phase III of interdigestive migrating motor contraction is important in cleaning indigestible solids and basal secretions. Impairment of phase III may result in reflux symptoms of heartburn and regurgitation. The present study evaluated whether gastropyloroduodenal motility after gastric pull-up esophagectomy influences the pathogenesis of reflux symptoms. METHODS Gastropyloroduodenal motility was recorded by manometry in 20 patients after a gastric pull-up esophagectomy. Esophagectomized patients were questioned about the presence of heartburn or regurgitation, or both. RESULTS Of 20 patients, 8 (40%) were considered the symptomatic group. Phase III, in which contractions originating from the antrum migrate to the pylorus and then move to the duodenum, was observed in only 1 of 8 patients. In the asymptomatic group, phase III was observed in 8 of 12 patients. A significant correlation was found between the presence of reflux symptoms and the paucity of phase III activity (p=0.02). CONCLUSIONS The presence of reflux symptoms after gastric pull-up esophagectomy is significantly associated with the paucity of gastric phase III. Gastric motor activity is important in the occurrence of reflux symptoms.

The Utility of a Noninvasive 13C-Acetate Breath Test to Predict Quality of Life After Gastrectomy

BackgroundThe radioscintigraphic technique has been accepted as the standard by which to measure gastric emptying but it is invasive and expensive. A 13C-acetate breath test was reported to be a noninvasive and reliable method. The aim of this study was to investigate the accuracy of a 13C-acetate breath test in reflecting gastric function and the relationship between food intake and change in body weight after distal gastrectomy.MethodsTwenty-five patients who had undergone curative distal gastrectomy with Billroth-I reconstruction for gastric cancer and ten healthy volunteers were included in the study. The gastrectomy group was divided into two groups: the stasis group and the nonstasis group. The breath test was performed on the patients with gastrectomy and the healthy volunteers, and the time lag between ingestion and the peak of 13CO2 expiration (T lag) was calculated. The manometry study was performed on the patients who underwent gastrectomy and the motility index (MI) was calculated. The relationships between T lag and food intake and body weight were examined.ResultsThe T lag was significantly shorter in the nonstasis group than in the stasis group. The MI in the duodenum in the nonstasis group was significantly larger than that in the stasis group. There was significant correlation between T lag and food intake, but no significant correlation between T lag and body weight.ConclusionThe 13C-acetate breath test might be useful not only for the evaluation of the function of the remnant stomach, but also for the prediction of postoperative status.