Masataka Segawa

Reflux of duodenal or gastro‐duodenal contents induces esophageal carcinoma in rats

Esophageal adenocarcinoma arises from Barretts esophagus, which is induced by gastro‐esophageal reflux. This refluxate often contains duodenal contents, whose backflow triggers gastric carcinoma, suggesting the hypothesis that refluxed duodenal contents cause esophageal carcinoma. This study examines the role of duodenal and gastric reflux in the absence of exogenous carcinogens in esophageal carcinogenesis. Wistar male rats, 120 in all, each weighing approximately 250 g, were used. Three experimental procedures were performed to produce gastro‐duodeno‐esophageal reflux, duodeno‐esophageal reflux and gastro‐esophageal reflux, for comparison with 2 control procedures, Roux‐en‐Y reconstruction and a sham operation. The animals were fed a standard diet and were examined 50 weeks after surgery. While no carcinoma was found among the 16 gastro‐esophageal‐reflux, 11 Roux‐en‐Y and 12 sham‐operation animals, 10 of the 12 animals with gastro‐duodeno‐esophageal reflux (83%) and 10 of the 13 with duodeno‐esophageal reflux (77%) developed esophageal carcinoma. The difference between groups was significant (p < 0.001). Two animals with gastro‐duodeno‐esophageal reflux had esophageal double and triple carcinomas respectively. Of the 23 carcinomas, 16 were adenocarcinoma, 4 adenosquamous carcinoma, and 3 squamous‐cell carcinoma. Adenocarcinoma developed from the columnar‐lined epithelium near the esophago‐jejunostoma, while adenosquamous and squamous‐cell carcinoma arose from the squamous esophagitis. These observations demonstrate that refluxed duodenal contents per se are responsible for esophageal carcinogenesis.

Surgical results of performing R4 gastrectomy for gastric cancer located in the upper third of the stomach

Because gastric cancers located in the upper third of the stomach are difficult to detect at an early stage, the surgical results remain poor. We performed R4 gastrectomy as a radical procedure for 25 patients, involving complete resection of the latero-aortic and interaorticovenous lymph modes above and below the left renal vein, in combination with the ordinary R2 or R3 gastrectomy (the R4 group). These patients were compared with 156 others who underwent R2 gastrectomy alone (the R2 group). There were no significant differences in operation time, blood loss, or the incidence of complications between the two groups; however, when the survival rates of the patients with tumors invading beyond the subserosa were compared, the 5-year survival rate was found to be significantly higher in the R4 group than in the R2 group. Furthermore, in patients with para-aortic nodal involvement, a significant survival advantage was observed in the R4 group, as compared with the R2 group. These results suggest that the R4 gastrectomy is a rational approach for patients with advanced gastric cancer located in the upper third of the stomach.

A retrospective study on the efficacy of cervical lymph node dissection in well-differentiated carcinoma of the thyroid

The management of cervical lymph node metastases in well-differentiated carcinoma of the thyroid is controversial. In our department, from 1963 to 1972, node plucking was performed only in patients with cervical lymphadenopathy whereas, from 1973 to 1983, modified radical neck dissection was therapeutically or electively performed. In order to determine whether the more extensive dissection is adequate, a retrospective analysis was performed using two groups of patients who were managed differently with regard to the treatment of cervical lymph node metastases. From this series of 206 patients with more than five years follow-up, it was found that the rates of survival and lymph node recurrence did not differ between the two groups. However, since the well-differentiated carcinoma of the thyroid has relatively indolent biological behaviour, further long-term follow-up seems to be necessary for demonstrating the efficacy of neck dissection.

Evaluation of Jejunal Pouch Interposition for Subtotal Gastrectomy.

胃癌手術後の残胃十二指腸間にpouchを形成した空腸を間置する再建 (JPI法) を評価した. 術後の胸やけや下痢の出現頻度は, JPI法による再建例で, 従来のBillroth法による再建と比較して低率であった. 残胃からの食物排泄を核医学的に観察すると, JPI法では食物は残胃およびpouchに貯留し, 緩徐に十二指腸へと流出するのが認められ, 残胃からの排泄時間T1/2は, Billroth I法の29±6分, Billroth II法の50±37分に対し, JPI法では104±45分と有意に延長していた. 残胃内への胆汁逆流はBillroth法では全例に認められたが, JPI法では15%にみられるのみであり, 胆汁と食物の混和異常も, Billroth法に比較してJPI法では低率であった. 以上より, JPI法は従来のBillroth法よりも術後愁訴の少ない, より生理的な状態が得られる再建法と考えられた.

Surgical Treatment for Esophageal Cancer After Gastrectomy

Gastroesophageal reflux is associated with a high incidence of complications such as ulcer or cancer of the esophagus [1]. Gastrectomy results in regurgitation of bile into the esophagus. However, the etiologic role of gastrectomy in esophageal cancer is still controversial [2]. Surgical treatment of postgastrectomy esophageal cancer is also investigational, because esophageal reconstruction with vascularized graft in the patient who has undergone gastrectomy is sometimes difficult due to the presence of adhesion. In this connection, we reviewed 14 cases of postgastrectomy esophageal cancer among our series.