Masatoshi Oya

Plasma D-Dimer Level in Patients with Colorectal Cancer : Its Role as a Tumor Marker

The purpose of this study was to explore the relationship between the preoperative plasma D-dimer (DD) levels and the tumor pathology of colorectal cancer. The plasma DD levels were measured preoperatively in 108 patients with colorectal cancer, and then were correlated with the tumor pathology and stage. The diagnostic value of the DD levels for the tumor stage was then compared with that of the preoperative carcinoembryonic antigen (CEA) levels. The preoperative DD levels were higher in patients with either a large-sized tumor or a tumor showing deep wall penetration. Lymph-node metastasis, lymphatic invasion, hepatic metastasis, and peritoneal dissemination were all associated with higher DD levels. A stepwise increase in the median DD level was found with the tumor stage. The preoperative DD levels also significantly correlated with CEA levels. When a cutoff value of 0.6μ/ml was used in the DD assay, the sensitivity and specificity for Dukes C or D cancer were 67.2% and 64.0%, and those for Dukes D cancer were 91.3% and 57.6%, respectively. Although the DD assay was less specific, its diagnostic value in the preoperative staging of colorectal cancer was comparable to that of the CEA assay. The measurement of the preoperative DD level is thus considered to be useful for the preoperative staging of colorectal cancer.

Comparison of Defecatory Function After Colonic J-Pouch Anastomosis and Straight Anastomosis for Stapled Low Anterior Resection: Results of a Prospective Randomized Trial

AbstractPurpose. Although defecatory function after low anterior resection for rectal cancer is reported to be better following colonic J-pouch than straight anastomosis, few prospective randomized trials comparing the two forms of anastomosis have been reported. We performed a prospective randomized trial comparing straight anastomosis with colonic J-pouch anastomosis both clinically and physiologically in patients undergoing stapled low colorectal anastomosis. Methods. A total of 42 consecutive patients were intraoperatively randomized to undergo either straight anastomosis or colonic J-pouch anastomosis. Clinical defecatory function was evaluated by a questionnaire answered preoperatively, then 6 and 12 months postoperatively. Anorectal physiological assessment was also carried out before surgery, then 12 months postoperatively. Results. The clinical defecatory function assessed 6 months and 12 months after surgery did not differ between the two groups. However, while the length of high-pressure zone was significantly shortened, and (neo)rectal capacity was significantly reduced postoperatively in the straight group, none of these physiological parameters were significantly altered in the pouch group. Conclusion. Although the aim of colonic J-pouch to preserve reservoir function was physiologically achieved, the improvement in clinical defecatory function was not significant. Thus, further prospective studies are needed to confirm the functional superiority of colonic J-pouch anastomosis for stapled low colorectal anastomosis after low anterior resection.

A Prospective Randomized Comparison Between an Open Hemorrhoidectomy and a Semi-Closed (Semi-Open) Hemorrhoidectomy

Abstract A semi-closed hemorrhoidectomy is a popular surgical procedure among Japanese coloproctologists because it is thought that the risk of postoperative bleeding is reduced, and postoperative pain is milder after a semi-closed hemorrhoidectomy than after an open hemorrhoidectomy. However, no prospective randomized trial comparing an open and semi-closed hemorrhoidectomy has yet been published. We conducted a prospective randomized trial comparing both clinically and physiologically an open and semi-closed hemorrhoidectomy. Thirty-four consecutive patients undergoing a hemorrhoidectomy for third-degree hemorrhoids were randomized to receive either an open hemorrhoidectomy (n = 17) or a semi-closed hemorrhoidectomy (n = 17). Postoperative pain was evaluated using an analog scale by the patients themselves. An anorectal physiological study was performed before the operation and 2 months after the operation. Pain at 1 week after operation was significantly more severe after a semi-closed hemorrhoidectomy than after an open hemorrhoidectomy. The postoperative physiological parameters including sphincter pressures did not differ between the two forms of hemorrhoidectomy. However, younger patients and patients having higher sphincter pressures preoperatively had more severe pain at 2 weeks after a semi-closed hemorrhoidectomy. Although both forms of hemorrhoidectomy appear to be almost equivalent, the degree of early postoperative pain may be less after an open hemorrhoidectomy in both young patients and in those patients having high preoperative anal sphincter pressures.

Preoperative anal sphincter high pressure zone, maximum tolerable volume, and anal mucosal electrosensitivity predict early postoperative defecatory function after low anterior resection for rectal cancer

PURPOSE: The aims of this study were to correlate postoperative defecatory function after low anterior resection with clinical factors and physiologic parameters and to explore the possibility of predicting early postoperative defecatory function after low anterior resection. METHODS: Thirty-two patients who underwent low anterior resection for rectal cancer were studied. Anorectal physiologic studies were performed preoperatively and six months postoperatively; maximum resting pressure, maximum squeeze pressure, length of the high pressure zone, neorectal sensory threshold, neorectal maximum tolerable volume, and anal mucosal electrosensitivity were recorded. Preoperative and postoperative defecatory function was scored between 0 (worst) and 6 (best) on the basis of bowel frequency, fecal incontinence, and urgency. RESULTS: In univariate regression analyses, a longer preoperative high pressure zone and a more sensitive anal mucosa were associated with better postoperative defecatory function. Using multiple regression analysis, in which age, gender, the level of anastomosis, and preoperative physiologic parameters were examined as independent variables, a longer preoperative high pressure zone, a larger preoperative maximum tolerable volume, and lower sensory threshold of the anal canal were associated with better postoperative defecatory function. Postoperative function score was found to be predictable using the following formula: 1.47+0.496×high pressure zone (cm)+0.007×maximum tolerable volume (ml)−0.247×sensory threshold (mA) of the anal canal. CONCLUSION: Early postoperative defecatory function after low anterior resection is predictable from preoperative high pressure zone, maximum tolerable volume, and anal mucosal electrosensitivity.

Clinical and Functional Comparison Between Stapled Colonic J-Pouch Low Rectal Anastomosis and Hand-Sewn Colonic J-Pouch Anal Anastomosis for Very Low Rectal Cancer

AbstractPurpose. We investigated intersphincteric resection with hand-sewn coloanal anastomosis, which may be an alternative to standard low anterior resection for very low rectal cancer when stapled anastomosis is technically impossible. Methods. The present study compared the clinical and functional results of 16 patients who underwent stapled colonic J-pouch low rectal anastomosis (CJLRA) with those of 15 patients who underwent intersphincteric excision and hand-sewn colonic J-pouch anal anastomosis (CJAA). Results. After a median follow-up period of 59 months, local recurrence was found in four patients from the CJAA group, three of whom subsequently underwent curative abdominoperineal resection. Defecatory function 6 and 12 months after surgery did not differ between the groups, although pads were used significantly more frequently in the CJAA group. Anorectal physiologic study before and 12 months after surgery revealed that the internal anal sphincter function was impaired to a larger extent after CJAA than after CJLRA, probably due to the partial or subtotal resection of the internal sphincter, and the anal dilatation during resection and anastomosis. Conclusion. Although the prevention of intraoperative tumor implantation and the early detection of local recurrence is of utmost importance, CJAA may be an acceptable sphincter-preserving procedure for selected patients in whom stapled anastomosis is impossible.

Quantitative assessment of anal canal sensation in patients undergoing low anterior resection for rectal cancer

To determine the influence of anal canal sensation on anal function after low anterior resection (LAR) for rectal cancer, anal canal sensation was quantitatively evaluated before and after LAR by measuring anal mucosal electrosensitivity (AMES), and the relationship between AMES and postoperative anal function was explored. Sensory thresholds 1, 2, and 3 cm from the anal margin were recorded in 21 patients who underwent LAR for rectal cancer (LAR-I) before, then 1 and 4 months after their operation. Another 14 patients who had been followed up for more than 1 year (LAR-II) after LAR and 21 control subjects were also studied. The median preoperative sensory thresholds in the LAR-I group were higher than those in the controls, though the differences were not significant. The sensory thresholds in the LAR-I group 4 months after LAR were lower than those preoperatively, but they did not significantly differ from those in the LAR-II and control groups. Although the postoperative sensory thresholds did not correlate with postoperative anal function, the preoperative sensory thresholds were higher in patients who were experiencing episodes of fecal incontinence 4 months after their operation. These results suggests that the preoperative measurement of AMES is useful for identifying patients who are likely to have a poor quality of continence after LAR.

The tight junction of pancreatic exocrine cells is a morphometrically dynamic structure altered by intraductal hypertension.

Abstract: The tight junction of pancreatic exocrine cells is thought to regulate paracellular permeability, and is a possible reflux route of pancreatic juice into the blood flow. Morphological changes in the tight junction of canine pancreatic acinar cells following intraductal hypertension and secretin stimulation were morphometrically analyzed to obtain evidence of the control of the paracellular reflux. Pancreatic tissues obtained from 25 dogs after intraductal hypertension, 3 dogs after secretin stimulation, and 5 control dogs were studied. Intraductal pressure was either 20 cmH2O, 30 cmH2O, or 40 cmH2O. Freeze fracture replicas of these pancreatic tissues were observed by electron microscopy. Tight junctions were classified into six morphometric types. Reticular type, parallel type, and mixed type comprised the common types predominantly found in all groups, and three special types were found, infrequently, only after intraductal hypertension. The percentages of the common types were significantly different between the groups. The areas of the tight junctions, and other morphometric parameters, were significantly less after 20 cmH2O intraductal hypertension and secretin stimulation than in the controls. However, these findings after 30 cmH2O or 40 cmH2O intraductal hypertension did not differ from those in the controls. The areas of the three special types of tight junctions were larger than those of the common types. These results suggest that the tight junction of pancreatic exocrine cells is a morphologically dynamic structure that is altered by the extent of intraductal hypertension, and support the hypothesis that paracellular permeability is the mechanism of the reflux of pancreatic juice.

Recovery of upper gastrointestinal bowel movement after rectosigmoid cancer surgery: a pilot transit analysis.

Postoperative gastrointestinal bowel transit right after colorectal resection has not yet been clarified. Thirty patients with rectosigmoid cancer were treated in this pilot study. The nasogastric tube was removed on the first postoperative day. One Sitzmarks capsule was given to each patient on the second postoperative day. Abdominal X-rays were taken at 3, 6, 8, 24, 48, and 72 hours after capsule intake. Distribution of the remaining Sitzmarks capsules were counted on X-ray films to clarify postoperative gastrointestinal movement after bowel resection. All Sitzmarks capsules were observed in the stomach at 3 and 6 hours after capsule intake. At 8 hours (second postoperative day), the Sitzmarks capsules were distributed from the stomach to the small intestine. Sitzmarks capsules were distributed in the right side colon at 24 hours (third postoperative day) after intake. Although the main distribution was still in the right side colon, several patients had evacuations accompanied by the disappearance of the Sitzmarks capsules. In 50% of the patients, it took approximately 72 hours (fifth postoperative day) for the first defecation after intake of the capsules. However, the Sitzmarks capsules remained mainly in the right side colon. Eight hours after intake, the majority of the Sitzmarks capsules shifted to the small intestine. Therefore, medication or feeding should be safely possible starting on the second postoperative day. There was no particular impact of bowel resection on upper gastrointestinal transit in patients with rectosigmoid cancer.

Vasoactive intestinal peptide and its relationship to tumor stage in colorectal carcinoma: an immunohistochemical study

Background:Background: Vasoactive intestinal peptide (VIP) is considered to influence cellular proliferation through its action on adenylate cyclase. This study examined VIP in the tumor-neighboring mucosa (TM) and remote normal mucosa (RM) in patients with colorectal carcinoma, and explored its relationship to tumor stage. Methods: Immunohistochemical staining of VIP, using the avidin-biotin peroxidase complex technique, was performed on TM and RM from 55 patients, surgically resected colorectal carcinomas. The VIP immunoreactivity in the lamina propria (LP) of TM and RM was semi-quantitatively graded, according to the density of VIP immunoreactive fibrous strands, and correlated with clinical characteristics, pathological findings, and tumor stage. Results: VIP immunoreactivity in the LP of TM and RM was found mainly as fibrous strands, some of which were nerve fibers. A few pericryptal myofibroblasts also showed VIP immunoreactivity. The VIP immunoreactivity in the LP was significantly greater in TM than in RM. The VIP immunoreactivity in the LP of TM was marginally greater in lesions with distant metastasis. The VIP immunoreactivity in the LP of RM was significantly greater in lesions with deeper wall penetration, in those with lymph node metastasis, and in those at more advanced stages. Conclusions: These results suggest a possible trophic role of VIP in the progression of colorectal carcinoma, or enhanced VIP secretion secondary to or in parallel with the progression of carcinoma.