Kyotaro Kanazawa

Efficacy of magnifying endoscopy in the differential diagnosis of neoplastic and non-neoplastic polyps of the large bowel

PURPOSE: We have introduced magnifying colonoscopy into clinical practice and analyzed its diagnostic efficacy, especially regarding the ability to distinguish neoplastic from non-neoplastic polyps. METHODS: The materials consisted of 923 polyps. After identifying the lesions during normal colonoscopy, a dye was sprayed, and then the zoom apparatus of the colonoscope was used to make a magnified observation at a maximum 100 times magnification. We classified the crypt orifices into six categories and labeled them A to F as follows: A, a medium round appearance; B, an asteroid appearance; C, an elliptic appearance; D, a small, round appearance; E, a cerebriform appearance; F, no apparent structural appearance. RESULTS: Forty-two of 923 polyps did not reveal any clear images of crypt patterns. The percentage of histologically neoplastic change in the lesions classified as A, B, C, D, E, and F were 10, 15.9, 93.7, 100, 94.8, and 87.5 percent, respectively. When we considered types A and B to represent a crypt pattern of non-neoplastic lesions, and types C, D, E, and F to represent neoplastic lesions, and when the lesions that did not show any clear images were classified as a misjudgment, the diagnostic accuracy of neoplastic lesions (sensitivity) was 92 percent and that of non-neoplastic lesions (specificity) was 73.3 percent. Overall, the diagnostic accuracy in differentiating neoplastic from non-neoplastic lesions was 88.4 percent. Twenty-three neoplastic lesions that were misjudged to be non-neoplastic were histologically adenoma with mild atypia in 22 and adenoma with moderate atypia in 1. CONCLUSION: Magnifying colonoscopy was considered to be useful in determining the indications for colonoscopic removal.

Cytokine and hormonal responses in laparoscopic-assisted colectomy and conventional open colectomy.

P < 0.05). Plasma ACTH, cortisol, and ADH rapidly increased in both groups, but there was no significant difference between them. The IL-6 levels in collected ascites samples were not significantly different between the two groups. The changes in serum IL-6 levels indicate that LAC is less invasive than conventional open colectomy. These findings corresponded well with the clinical courses of the patients who underwent the two types of operations.

Anticarcinogenic Effects of Isoflavones May Be Mediated by Genistein in Mouse Mammary Tumor Virus-Induced Breast Cancer

Isoflavones are known to exert anticancer effects. These effects were examined using two isoflavones, biochanin A and daidzein, in a mouse mammary tumor virus (MMTV)-induced spontaneous breast cancer model. Emphasis was placed on isoflavone metabolism by the intestinal microflora and changes in estrogen levels. Germ-free (Gf) mice and their conventionalized (Cv) counterparts were assigned to three diet groups: (1) control diet, (2) biochanin A and (3) daidzein. In all groups, urine was collected from virgin female mice to analyze isoflavone metabolism by high performance liquid chromatography. These studies revealed changes of biochanin A into genistein, and of daidzein into equol, which were accelerated in the Cv animals. However, the Gf mice could not transform biochanin A into genistein, or daidzein into equol. Estrogen levels in the control and daidzein diet groups were lower in the Gf mice than in the Cv mice. The biochanin A group showed no differences in estrogen levels between the Cv and Gf animals. Four-week-old male and female animals were paired in the Gf and Cv groups. The female animals delivered and lactated repeatedly and were observed for the development of mammary cancer by palpation, twice weekly, until 15 months of age. The Cv mice showed a significantly lower incidence of breast cancer in the biochanin A diet group than in the control or daidzein groups (p < 0.05). These results suggest that the anticarcinogenic effects in this system might be produced not by daidzein or equol, but by biochanin A and/or genistein. In the Gf animals, the incidence of breast cancer was significantly higher in the biochanin A group than in the control group (p < 0.05), probably due to the increased level of estradiol in the former group. The biochanin A group tended to have a higher incidence of breast cancer than the daidzein group in the Gf group, although no significant differences were noted. Thus, no anticarcinogenic effect was produced by biochanin A alone in the Gf mice. In view of the results presented, genistein derived from biochanin A following metabolic processes in the intestinal microflora most likely acts as an inhibitor in breast carcinogenesis; biochanin A is most likely a precursor of genistein.

Intraoperative localization of colorectal tumors in the early stages using a marking clip detector system

In laparoscopic colectomy the identification of the site of a tumor is often difficult. The topical injection of india ink or blue dye by preoperative colonoscopy is the most prevalent method to mark the tumor site; however, such a procedure also includes the intrinsic danger of possibly injecting dye into the peritoneal cavity. In addition, the injected marker may also spread so widely that the intended site may become obscure. A marking clip detector system was used to detect metallic marking clips in the luminal side that had been applied to the mucosa adjacent to the lesion during the course of preoperative colonoscopy. This method was able to identify the marked site in 40 percent of cases in which only one clip was applied to the mucosa. However, when the lesion sites were marked with two or three clips, then the detection rate increased to 100 percent. Based on our findings, this procedure was found to be a safe and reliable method for identifying lesions during laparoscopic-assisted colectomy.

Pancreatoduodenectomy with preservation of the pylorus and gastroduodenal artery.

OBJECTIVE The authors evaluated the rationale for and feasibility of gastroduodenal artery preservation in pylorus-preserving pancreatoduodenectomy (PPPD) for periampullary cancer in which the pancreatic remnant maintains a normal function and morphologic characteristics. SUMMARY BACKGROUND DATA Pylorus-preserving pancreatoduodenectomy has become one of the standard treatments used for benign and malignant diseases of the pancreatoduodenal region, surpassing ordinary pancreatoduodenectomy in terms of technical ease, mortality rate, and postoperative nutrition. Pylorus-preserving pancreatoduodenectomy is usually associated with gastroduodenal artery division, which presents potential risks of insufficient duodenal vascularity and lethal postoperative bleeding from the gastroduodenal artery stump. The latter complication particularly occurs after resection of bile duct or ampullary cancer in a patient whose pancreas remains functionally and morphologically normal to have much more pancreatic secretion than the fibrotic pancreas seen in pancreatic cancer. According to the authors data on the volume of secretion from the residual pancreas via a stent tube after pancreatoduodenectomy, the sclerotic pancreas, as seen in cancer of the pancreatic head, secrets only 20 to 50 mL/day, whereas the secretion from the soft pancreas, as seen in bile duct cancer, amounts to 300 to 600 mL/day, even during the period of nothing by mouth. METHODS Retrospectively, we made a histopathologic study of eight specimens of distal bile duct and ampullary cancer resected by pancreatoduodenectomy or PPPD with gastroduodenal artery division. Prospectively, we performed gastroduodenal artery- preserving PPPD for 10 patients with distal bile duct, ampullary, and islet cell cancers. RESULTS The histopathologic study revealed no invasion or metastasis around the gastroduodenal artery. Clinical application of gastroduodenal artery-preserving PPPD showed no technical difficulty, and neither severe complications nor recurrence around the gastroduodenal artery were observed for up to 22 months after surgery. CONCLUSIONS Gastroduodenal artery- preserving PPPD might be recommended as a safe procedure for patients who have a functionally and morphologically normal pancreas.

Laparoscopic-Assisted Colectomy with Lymph Node Dissection for Invasive Carcinoma of the Colon

The results of performing laparoscopic-assisted colectomy in 20 patients with invasive carcinoma of the colon were analyzed in this study. The site of the lesion was the right colon in 5 patients, the transverse colon in 1, the left colon in 13, and the rectosigmoid in 1. In 2 patients, the laparoscopic procedure needed to be converted to an open laparotomy. Limited lymph node dissection (R1+, R2) was carried out in 10 patients and extensive node dissection (R3) was carried out in 9 patients. The histological depth of invasion in the 18 patients who underwent laparoscopic-assisted colectomy was the submucosa in 9, the muscularis propria in 2, and the extramuscular layer in 7. There were 3 patients who developed postoperative complications, 1 of whom underwent reoperation due to perforation of the colon. The postoperative course of the patients who underwent laparoscopic surgery was compared with that of a retrospectively selected control group of patients who had undergone open laparotomy. The postoperative recovery of the patients who underwent laparoscopic surgery was significantly faster than that of those who had undergone open laparotomy. Thus, we consider that laparoscopic-assisted colectomy with lymph node dissection is technically feasible provided that patients are properly selected. This procedure may be indicated not only for colonic carcinoma in the early stage, but also for that with invasion of the muscularis propria or the extramuscular layer.

Perforation of the sigmoid colon with ischemic change due to polyarteritis nodosa.

Abstract: A 60-year-old man who developed a perforation of the sigmoid colon with ischemic change due to polyarteritis nodosa is described. Histological examination of the resected colon led to the diagnosis of polyarteritis nodosa. Although the gastrointestinal tract is frequently involved with polyarteritis nodosa, it is extremely rare for polyarteritis nodosa to be accompanied by a perforation of the colon, particularly at the initial presentation.

Multiple colorectal cancers in the elderly: a retrospective study of both surgical and autopsy cases

Background. Multiple primary cancers are not rare events in the large intestine, and account for approximately 5–7% of patients with colorectal cancer (CRC). There are few reports demonstrating clinicopathologic features of multiple CRCs in the elderly. Methods. We clinicopathologically investigated 947 surgical patients and 362 autopsy samples from patients aged 65 years or more with CRC, including 81 surgical and 34 autopsy cases of multiple CRCs. We compared the data in the very old group (age ≥ 85 years) with those of the younger age groups, i.e., a young-old group (65–74 years) and a middle-old group (75–84 years). Results. The proportion of multiple CRCs was 8.6% (81/947) in the surgical patients and 9.4% (34/362) in the autopsy cases, with no significant difference among the three age groups. Similar site distributions and sex ratios, indicating proximal shift and female predominance with advancing age, were found in multiple and single CRCs, except for autopsy cases with multiple CRCs. Multiple CRCs in nonadjacent segments of the large intestine accounted for 11% (9/81) in surgical cases and 35% (12/34) in autopsy cases. In autopsy cases, the incidence of extracolorectal malignancies in patients with a single CRC was 22% (17/76) in the young-old group, 27% (39/147) in the middle-old group, and 35% (37/105) in the very old group, whereas the incidences in patients with multiple CRCs were 25% (1/4), 11% (2/18), and 50% (6/12), respectively. Regarding the organs with extracolorectal malignancies, the stomach (29%) was most frequent, followed by lung (14%), hematopoietic system (12%), and pancreatobiliary system (10%). Conclusions. These results indicate that the incidence of multiple CRCs in elderly patients with CRC is approximately 8%–10%, with no age-related difference, while extracolorectal malignancies increase with advancing age.

Ki -ras point mutation in different types of colorectal carcinomas in early stages

PURPOSE: The aim of this study was to elucidate pathways of carcinogenesis in the colon and rectum by investigating Ki-raspoint mutation in different types of colorectal carcinomas in the early stage. METHODS: We analyzed rates of Ki-rascodon 12 mutations in 34 small, polypoid-type carcinomas (Tis or T1), 21 superficial-type carcinomas (Tis or T1), and 42 advanced carcinomas (T2, T3, and T4). RESULTS: Frequency of Ki-rasmutations in superficial-type carcinomas was 14.3 percent (3/21), which was significantly lower than 50 percent (17/34) in small polypoid carcinomas and 40.5 percent (17/42) in advanced carcinomas. These data suggest that another pathway of colorectal carcinogenesis that does not involve Ki-raspoint mutation might exist. Among the 17 small polypoid carcinomas with Ki-raspoint mutation in which both adenomatous and carcinomatous tissue were examined, 12 showed a mutation of the same type in both carcinomatous and adenomatous tissues. In two cases, mutation was present only in carcinomatous tissue and not in adenomatous tissue; in the other three cases, Ki-raspoint mutation was present only in adenomatous tissue but not in carcinomatous tissue. CONCLUSIONS: These data suggest that carcinoma in a small polypoid lesion does not always develop from pre-existing adenoma with Ki-raspoint mutation; in a small number of the polypoid-type early carcinomas, polyclonal composition concerning the Ki-rasgene may exist.

Variations in motor evoked potential latencies in the anal sphincter system with sacral magnetic stimulation

PURPOSE: The anal sphincter system of the skeletal musculature consists of various parts but functions as a single unit. The motor latencies measured at the puborectalis, deep external anal sphincter, superficial external anal sphincter, and subcutaneous external anal sphincter have yet to be clearly elucidated. This study was designed to measure the motor latencies of these sphincters separately and to investigate the electrophysiologic heterogeneity of the anal sphincter system. METHODS: In 20 preoperative patients with colon cancer without either neurologic or anorectal diseases, motor evoked potentials were taken separately bilaterally at levels measuring approximately 5, 3.8, 2.6, and 1.5 cm from the perineal skin using a concentric needle electrode after magnetic stimulation on the sacral region. These latencies were considered to be separately measured at the puborectalis, deep, superficial, and subcutaneous external anal sphincter. RESULTS: The motor latencies (median (95 percent confidence interval)) were 4.33 (4.1–4.93; right) and 4.24 (3.97–5.22; left) ms at the 5 cm level; 5.96 (5.45–7.32; right) and 6.44 (5.49–8.20; left) ms at the 3.8 cm level; 9.28 (7.99–11.21; right) and 8.88 (7.68–10.93; left) ms at the 2.6 cm level; and 11.06 (9.69–14.13; right) and 9.18 (8.09–10.31; left) ms at the 1.5 cm level. Significant differences were seen in the latencies between the 5 cm level and the other levels and between the 3.8 cm level and the other levels. CONCLUSIONS: The motor latencies in the anal sphincter system significantly varied depending on the distance from the skin. The latency may be shortest in the puborectalis and increasingly longer in the deep, superficial, and subcutaneous EAS, in that order.