Masao Tani

Endoscopic Mucosal Resection Using a Cap: Techniques for Use and Preventing Perforation

Endoscopic mucosal resection (EMR) is one of several local treatments that provide a specimen for histopathological analysis. The authors developed a technique of EMR using a transparent plastic cap (EMRC) in 1992. By using the EMRC procedure, any part of the gastrointestinal tract mucosa can be easily accessed. The technical details of EMRC are described. The authors have performed EMR in 380 cases of gastrointestinal lesions. The most serious complication may be perforation. Two perforations (one in the esophagus and one in the colon) have occurred. By evaluating recorded videotapes, it was determined that the lack of submucosal saline injection was the major cause. Therefore, large volume injection, which creates a large bleb and potentially reduces the risk of perforation, is recommended. Furthermore, target mucosa should be strangulated at the middle part of the created bleb (never strangulated at the base). Particularly in the colon, injecting a sufficient volume of saline and controlling the power of suction are extremely important, because the cap on the colonoscope is relatively large in size.

Proximal gastrectomy and jejunal pouch interposition for the treatment of early cancer in the upper third of the stomach: Surgical techniques and evaluation of postoperative function

BACKGROUND Limited surgery for the treatment of early gastric cancer located in the upper third of the stomach should be based on a well-balanced reduction in the extent of lymph node dissection and gastric resection while assuring a favorable quality of life and prognosis after operation. METHODS We have used interposition of a double jejunal pouch between the esophagus and the remnant stomach after performing proximal gastrectomy. To assure anastomosis and hemostasis during this operation, we currently use a surgical stapler with a vaginoscope and our new edge clamps. This method has been used in 12 patients to date. RESULTS On histopathologic examination the 12 cases comprised 11 early cancers (seven mucosal and four submucosal cancers) and one subserosal cancer. There was no evidence of lymph node metastasis of postoperative complications such as anastomotic leakages or hemorrhage, demonstrating the low-risk nature of this procedure. CONCLUSIONS The evaluation of postoperative quality of life, in terms of clinical signs and symptoms and dietary status, yielded favorable results. Thus our method has the important advantage of allowing good organ preservation.

Ultra‐high Magnification Endoscopy of the Normal Esophageal Mucosa

Abstract: The normal esophageal mucosa was observed in detail using ultra‐high magnification endoscopy (UHM endoscopy). The UHM endoscope has a magnification capacity ranging from eight to 150x. High‐quality UHM endoscopic pictures can be continuously obtained by attaching a 2‐mm depth soft distal attachment to the tip of the UHM endoscope. The vascular architecture, which extends from the submucosal vessels through the proper mucosal layer, can be continuously visualized, thereby demonstrating the characteristic fine‐vascular network pattern, and the intrapapillary capillaries in the epithelium. With UHM endoscopy, intrapapillary capillaries can be clearly demonstrated as single loop vessels which we have termed “intrapapillary loops.” These structures cannot be observed with an ordinary magnifying endoscope which is capable of only 35x magnification. We conclude that a technique for obtaining high‐resolution endoscopic pictures has been established. The images obtained are useful for elucidating the microstructure of the esophageal mucosa, especially the fine‐vascular network and the newly recognized intrapapillary loop.

Endosonography during endoscopic mucosal resection to enhance its safety : A new technique

AbstractBackground: We have performed endoscopic mucosal resection of the esophagus (172 cases), stomach (102 cases), and colon (28 cases) using a transparent plastic cap. Because the lesion-bearing mucosa is suctioned up inside the cap under endoscopic suction, the mucosa should be dissected sufficiently from the proper muscle layer to prevent perforation. Methods: To avert the risk of perforation, we introduced endosonographic assessment of submucosal dissection (47 cases). In all cases, just keeping the ultrasonic probe on the surface of the mucosa allowed us to evaluate whether the mucosal lesion was lifted up sufficiently from the proper muscle layer after local saline injection. Results: It was possible to confirm that the muscle layer was kept outside the strangulating snare by the same procedure (32 of 37 cases, 86.5%). Conclusions: We experienced five muscular resections in cases without the ultrasonic probe and no muscular resection with the ultrasonic probe. Thus we recommend endosonographic assessment during endoscopic mucosal resection to enhance its safety.

Treatment of primary multiple early gastric cancer: from the viewpoint of clinicopathologic features.

Abstract. The treatment of multiple early gastric cancer was investigated through the clinicopathologic assessment of 61 cases of primary multiple early gastric cancer (82 accessory lesions) treated by surgical resection over a 15-year period. These cases accounted for 11.7% of all cases of early gastric cancer resected during the same period. The 61 patients included 48 men (mean age 64 years) and 13 women (61 years). Of the 82 accessory lesions, 41 (50%) were located in the same region as the main lesion. The most frequent combination of macroscopic types of the main lesion and the accessory lesion was depressed type/depressed type (28 cases). The main lesion was of the well differentiated type in 39 (64%) of the 61 cases; the accessory lesion was also well differentiated in 37 of the 39 cases. Of the 82 accessory lesions, 29 (35%) had been overlooked preoperatively; most of them were located in the middle third of the stomach and included 17 depressed and 10 flat lesions, most of which measured no more than 1 cm. Cases of multiple early gastric cancer are characterized by the predominance of male patients of advanced age (>60 years), a combination of the same macroscopic type of the main and accessory lesions, and well differentiated carcinoma. Lymph node metastasis and vascular invasion are equally or less frequent than in cases of solitary early gastric cancer. The postoperative crude survival rate in patients with multiple gastric cancer is similar to that in those with solitary gastric cancer. Therefore we believe that multiple early gastric cancer does not require extended operative procedures. Endoscopic treatment may be indicated if each lesion fits the criteria for treatment and careful follow-up is ensured.

Medium- and Long-Term Results of Jejunal Pouch Reconstruction After a Total and Proximal Gastrectomy

PurposeWe developed several kinds of jejunal (J)-pouch reconstruction after a gastrectomy for gastric cancer. The aim of this study was to investigate the advantages of these methods.MethodsAs for the treatment of malignant gastric diseases at stage II or earlier, we employed the J-pouch reconstruction (Roux-en-Y method: JPRY, or J-pouch interposing: JPI) following a total gastrectomy. We also used JPI after a proximal gastrectomy for early gastric cancer located in the upper third of the stomach.ResultsOut of a total of 80 patients, JPRY was performed in 40 patients and JPI in 40. No anastomotic leaks were associated with the use of an automatic stapler. The stapler (Endo GIA; U.S. Surgical, Norwalk, CT, USA) with a 60-mm-long white cartridge minimized bleeding from the anastomotic site and reduced the operative time. While two patients died of recurrence, all other patients are alive and well for a maximum of 15 years after surgery. The motility of the J pouch was satisfactory after both surgical procedures, as measured by the bile regurgitation test or the transit test employing radiopaque markers. The mean percentage of the radiopaque markers eliminated from the J pouch 1 h after breakfast was 7.5% in the JPRY group and 0%–33% in the JPI group. After another hour, the corresponding percentage was 19.5% in the JPRY group and 14%–60% in the JPI group.ConclusionOur procedures for J-pouch reconstruction are considered to result in a favorable postoperative quality of life and prognosis. J-pouch reconstruction is therefore advantageous in terms of operative morbidity, postoperative clinical signs, symptoms, and dietary status.

Rational lymphadenectomy for early gastric cancer with submucosal invasion: A clinicopathological study

Among all the patients who underwent gastrectomy for primary solitary gastric cancer at our department from 1979 to 1994, 228 patients had gastric cancer that invaded the submucosal layer. These cases were thus examined clinicopathologically, including the extent of submucosal invasion. No lymph node metastasis was found in any of the cancers measuring less than 2 cm in diameter. Macroscopic type I lesions or various combined types (IIa 1 IIc, IIc 1 IIa, IIc 1 III) were more likely to infiltrate deeply and were also associated with a high incidence (18%–25%) of lymph node metastasis. No lymph node metastasis or vascular invasion was found in any simple type IIa lesions. The incidence of lymph node metastasis was 3% in simple type IIc cancers measuring 3 cm or less. In addition, submucosal microinvasion (sm1) simple type IIc cancers showed no accompanying lymph node metastasis or vascular invasion. We thus conclude that a full-thickness partial resection of the stomach, such as a laparoscopic local resection, is applicable to cancers measuring 3 cm or less provided that they are either simple macroscopic type IIa or simple type IIc sm1 cancers.

Adequate endoscopic mucosal resection for early gastric cancer obtained from the dissecting microscopic features of the resected specimens

Background. We have employed endoscopic mucosal resection (EMR), using a cap-fitted panendoscope (EMRC), for early gastric cancer since 1992. The presence of an adequate surgical margin is a requirement because of the radicality of EMR, and dissecting microscopic examination is useful in regard to the diagnosis of spread of the disease. Methods. To devise an adequate method of EMR that allows no lateral residue, we examined gastric mucosal specimens obtained by EMRC. One hundred and sixty-seven specimens from 97 lesions in 85 patients treated by EMRC were examined in regard to characteristic features, the recovery of marks made around the lesion, and the frequency of residue, and comparisons were made between the dissecting microscopic and histopathological findings. Results. The first specimen obtained with a large cap under full suction was a circular shape measuring 21 × 19 mm. The second specimen from fractionated resection was a half-moon or crescent shape, and the third specimen had a ginkgo leaf-like or irregular shape. In the elevated lesions, coincidence regarding the spread, as determined by dissecting microscopy and histopathology, was present in 62 (93%) of the 67 lesions. In 16 (53%) of 30 flat or depressed lesions, there was a difference of 2 to 5 mm between the spread determined by these two examinations. Conclusion. It is important to place an adequate number of marks around the lesion and recover all marks by resection. When an elevated lesion measures 15 mm or more, and a flat or depressed lesion is not clearly demarcated, aggressive use of planned fractionated resection seems to be the best way to prevent a lateral residue in EMR.

Intracranial hemorrhage in patients treated with bevacizumab: Report of two cases

Treatment with bevacizumab, an antiangiogenic agent, in patients with metastatic or unresectable colorectal cancer was approved less than 4 years ago in Japan. Bevacizumab improves the survival of patients with metastatic colorectal cancer; however, it may lead to complications such as bleeding, which are sometimes fatal. Bevacizumab should be administered only after careful consideration because the potential risks of therapy outweigh its benefits. Therefore, pharmaceutical companies do not recommend bevacizumab therapy for patients with brain metastases. While some reports support the cautious use of bevacizumab, others report that it is not always necessary to prohibit its use in patients with metastases to the central nervous system (CNS), including the brain. Thus, bevacizumab therapy in colorectal cancer patients with brain metastases is controversial, and it is unclear whether brain metastases are a risk factor for intracranial hemorrhage during anti-vascular endothelial growth factor (VEGF) therapy. We report a 64-year-old man and a 65-year-old man with recurrent colorectal cancer without brain metastases; these patients developed multifocal and solitary intracranial hemorrhage, respectively, after the administration of bevacizumab. Our findings suggest that intracranial hemorrhage can occur even if the patient does not have brain metastases prior to bevacizumab treatment and also suggest that brain metastases are not a risk factor for intracranial hemorrhage with bevacizumab treatment. These findings also question the necessity of excluding patients with brain metastases from clinical trials on anti-VEGF therapy.

Monocyte function associated with intermittent lentinan therapy after resection of gastric cancer

The effect of lentinan administration on monocyte function in the peripheral blood were examined in 33 patients who underwent resection of gastric cancer. As parameters of monocyte function, IL-1 production, C3b receptor, Fc gamma receptor and monocyte ratio were determined every 4 weeks for a maximum of 24 weeks. Among patients who were taking combined therapy with lentinan, an increase in IL-1 beta production of more than 50% was found 8 weeks (2 months) after the initiation of therapy in 8 of 12 patients given 2 mg at 2-week intervals, and in 11 of 16 patients given the same dose at 4-week intervals. This increase was particularly clear in stage II or more advanced cases. There were no significant changes in the other parameters studied. It has been considered that lentinen is effective when administered once a week. The results of the present study, however, suggest that lentinan given every 4 weeks also stimulates monocyte function enough to maintain immunological activity.