Ryuichi Kubo

Functional outcome after low anterior resection with low anastomosis for rectal cancer using the colonic J-pouch. Prospective randomized study for determination of optimum pouch size.

PURPOSE: Functional outcome after low anterior resection with ultralow coloanal anastomosis for rectal cancer is improved by construction of a colonic J-pouchvs.straight anastomosis. Optimum size of this pouch has yet to be determined. Therefore, we initiated a prospective, randomized trial using 5-cm and 10-cm pouches to determine this size. METHODS: Patients with tumors 5 to 10 cm from the anal verge were included in the study. Before a low anterior resection anastomosis was performed, patients were randomized to either a 5-cm J-pouch group (5-J group) or a 10-cm J-pouch group (10-J group). Functional assessments were performed one year postoperatively. Clinical functions were evaluated using a functional scoring system. Physiologic functions, such as sphincter and reservoir function, were evaluated by anorectal manometry and evacuation function by the balloon expulsion and saline evacuation tests. RESULTS: Forty patients among 43 randomized patients were assessed for functional outcome one year postoperatively (5-J group, n=20; 10-J group, n=20). The functional score was similar for the two groups, although reservoir function in the 5-J group was significantly less than in the 10-J group. Sphincter function was similar between the two groups. Evacuation function in the 5-J group was significantly superior to that in the 10-J group. CONCLUSIONS: The 5-cm J-pouch conferred adequate reservoir function without compromising evacuation.

Distribution of metastatic lymph nodes in colorectal cancer by the modified clearing method

PURPOSE: The aim of this study was to clarify the distribution of lymph node metastasis in colorectal cancer. We also examined the relationship between the primary tumor (T) and the regional node (N) categories of the TNM (primary tumor, regional nodes, metastasis) classification. METHOD: Lymph nodes of surgical specimens in 311 consecutive patients with colorectal cancer were studied using the modified clearing method. RESULTS: Lymph node metastasis was seen in 59.2 percent of the total cases. The upward metastasis rate was 30.7 percent. In the longitudinal spread, most of the lymph node metastasis was seen within 10 cm. On the oral side in rectal cancer, there was no metastasis beyond 4 cm. The lateral metastasis rate in rectal cancer was 8.8 percent and in the lower rectum, the rate of cancer within 6 cm from the anal verge or beyond pT3 was much higher. CONCLUSION: In the TNM classification, there was no significant difference between colon and rectal cancer except pT1 with rectal cancer. In the lower rectal cancer within 6 cm from the anal verge or beyond pT3, there is a high risk of lateral metastasis, and lateral lymph node dissection or radiation therapy should be performed.

Indications for colonic J-pouch reconstruction after anterior resection for rectal cancer

PURPOSE: Functional outcome after anterior resection for rectal cancer is improved by colonic J-pouch reconstruction compared with straight anastomosis. The indications for colonic J-pouch reconstruction have yet to be determined. Therefore, we attempted to determine the level at which J-pouch reconstruction provides an advantage over straight anastomosis. METHODS: A total of 48 patients who underwent 5-cm colonic J-pouch reconstruction (J-pouch group) and 80 patients who underwent straight anastomosis (straight group) underwent functional assessment one year postoperatively. RESULTS: The functional outcome in the J-pouch group was significantly better than that in the straight group when the distance of the anastomosis from the anal verge was less than 8 cm. The difference was particularly obvious when the level of the anastomosis was below 4 cm. However, functional outcome in the straight group when the anastomosis was between 9 and 12 cm from the anal verge was also satisfactory and did not differ from that in the J-pouch group when the anastomosis was between 5 and 8 cm from the anal verge. CONCLUSIONS: Colonic J-pouch reconstruction is indicated when the distance of anastomosis from the anal verge is less than 8 cm, and it is essential when the distance is less than 4 cm.

Second-look operation for recurrent colorectal cancer based on carcinoembryonic antigen and imaging techniques

PURPOSE: The usefulness of postoperative carcinoembryonic antigen (CEA) monitoring and improvements in imaging techniques have renewed enthusiasm for second-look operations (SLO) as the most effective treatment for recurrent colorectal cancer by reresection following early detection. The aim of our study is to evaluate the role of CEA and imaging techniques-directed SLO. METHODS: Seven hundred fifty-six patients with Dukes Stages B and C, who had undergone curative resection, were monitored postoperatively using CEA and imaging techniques. An SLO was performed on any potentially resectable recurrence, and in addition, an SLO was done when a persistently rising CEA value was detected. RESULTS: Recurrence developed in 18.8 percent (142/756) of patients, and 90.8 percent (129/ 142) of the recurrences were detected within the first three years following curative resection. When comparing carcinomas of the colon with that of the rectum, the former were associated with significantly more hepatic and intra-abdominal recurrences, whereas the latter had significantly more locoregional and pulmonary recurrences. Seventy-two patients underwent SLO. Of these patients, 54.2 percent (39/72) had all of their disease resected, and 1.4 percent (1/72) had no detectable disease at the SLO. Among the 142 patients with recurrence, 71 (50 percent) patients underwent SLO. The resectable group at SLO carried a significantly better survival than the unresectable recurrence group (41.3vs.5.2 percent;P<0.01). CONCLUSIONS: Complete removal of colorectal cancer recurrences by SLO, on the basis of postoperative, follow-up CEA and imaging technique findings, results in improved survival.

Indication for using high ligation of the inferior mesenteric artery in rectal cancer surgery

PURPOSE: In surgery for rectal cancer, it is unclear whether the inferior mesenteric artery should be ligated at a high or low position. The study contained herein was undertaken to clarify the indications for high ligation of the inferior mesenteric artery. METHODS: Subjects included 198 patients with rectal cancer who underwent resection with high ligation of the inferior mesenteric artery. Nodal metastases were examined by the clearing method. RESULTS: The incidence of metastases to the lymph nodes surrounding the origin of the inferior mesenteric artery (root nodes) was 8.6 percent. Inferior mesenteric artery root nodal metastases occurred more frequently with pT3 and pT4 cancer. The five-year survival rate in patients with inferior mesenteric artery root nodal metastases was 38.5 percent; this rate was significantly lower than in those without inferior mesenteric artery root nodal metastases (73.4 percent). CONCLUSIONS: Although the five-year survival rate in patients with inferior mesenteric artery root nodal metastases was lower than in those without metastases, inferior mesenteric artery root nodal dissection should be performed after high ligation of the inferior mesenteric artery for patients with pT3 and pT4 cancers.

The role of basement membrane in colorectal cancer invasion and liver metastasis

Background. Basement membrane (BM) is a specialized extracellular matrix component that plays a key role in tumor invasion and metastasis.

Examination of nodal metastases by a clearing method supports pelvic plexus preservation in rectal cancer surgery.

PURPOSE: In rectal cancer surgery preservation of urinary and sexual function is attempted by means of operations preserving the autonomic nerves of the pelvic plexus. Emergence of residual cancer because of a more shallow plane of dissection is a problem of concern with these methods, so we examined indications for pelvic plexus preservation. METHODS: We studied 198 patients with rectal carcinoma who underwent abdominopelvic lymphadenectomy. Lymph nodes along the superior hemorrhoidal artery and middle hemorrhoidal artery medial to the pelvic plexus were defined as perirectal nodes, and nodes along the middle hemorrhoidal artery lateral to the pelvic plexus and along the internal iliac artery represented lateral intermediate nodes. Node metastases were examined by the clearing method. RESULTS: Metastasis to perirectal nodes occurred in 12.5 percent in patients with pT1 tumors, 28.9 percent of those with pT2 tumors, and 50.0 percent of those with rectosigmoid junctional cancer. Metastasis to lateral intermediate nodes was absent in patients with pT1 or pT2 tumors and was as low as 2.5 percent in patients with rectosigmoid junctional cancer. CONCLUSIONS: In patients with T1, T2, and rectosigmoid junctional cancer, perirectal node dissection is necessary, but chances of residual cancer should remain minimal when the pelvic plexus is preserved.

Horizontal inclination of the longitudinal axis of the colonic J-pouch

PURPOSE: Functional outcome after low anterior resection for rectal cancer is improved by the construction of a colonic J-pouch. One disadvantage of this type of reconstruction is evacuation difficulty, which has been associated with large pouches. The purpose of this study was to elucidate the causes of evacuation difficulty in large pouches using pouchography. METHODS: The angle between the longitudinal axis of the pouch and the horizontal line (pouch-horizontal angle) on lateral pouchography was determined in 26 patients with 10-cm J-pouch reconstructions (10-J group) and 27 patients with 5-cm J-pouch reconstructions (5-J group). Measurement were made at three months, one year, and two years after surgery. Clinical function was evaluated using a questionnaire one year postoperatively. RESULTS: The pouch-horizontal angle in the 10-J group was significantly smaller than that in the 5-J group at all three time points. In both groups the pouch-horizontal angle at one year was significantly smaller than that at three months. There were no significant differences between the pouch-horizontal angles at one and two years. An evacuation difficulty was significantly more common in the 10-J group than the 5-J group. CONCLUSIONS: The evacuation difficulty observed in patients with large colonic J-pouch reconstructions may be attributed to the development of a horizontal inclination within one year of surgery.

Analysis of regional lymph node metastases from rectal carcinoma by the clearing method: Justification of the use of sigmoid colon in J-pouch construction after low anterior resection

PURPOSE: It has been reported that functional outcome following low anterior resection of rectal cancer is improved by construction of a colonic J-pouch compared with straight anastomosis. Hence, we tried to justify use of the sigmoid colon in the construction of a J-pouch by the analysis of regional lymph node metastases. METHODS: A total of 182 patients underwent resection for rectal cancer. Node metastases were examined by the clearing method. According to Japanese General Rules for Clinical and Pathological Studies on Cancer of the Colon, Rectum and Anus (JGR), nodes were classified into the perirectal nodes (PR-N), pericolic nodes (PC-N), central intermediate nodes (C-IM-N), central main nodes (C-M-N), lateral intermediate nodes (L-IM-N), and lateral main nodes (L-M-N). RESULTS: Metastatic rate (number of patients with node metastases/ total number of patients) of PR-N was 57.1 percent. Metastatic rate of C-IM-N was 18.7 percent and that of C-M-N was 7.1 percent. Metastatic rates of L-IM-N and L-M-N were 8.8 and 3.3 percent, respectively, and both were highest in the case of lower rectal cancer. Metastatic rate of PC-N was only 1.1 percent. The number of cases without node metastases (n(−) cases) was 78, that with only PR-N metastases (PR-N cases) was 63, that with intermediate but not main node metastases (IM-N cases) was 29, and that with main node metastases (M-N cases) was 12. Five-year survival rate after curative resection was 88.5 percent for n(−) cases, 70.9 percent for PR-N cases, 65.9 percent for IM-N cases, and 41.7 percent for M-N cases. CONCLUSIONS: In low anterior resection, high ligation of the inferior mesenteric artery and dissection of C-M-N, C-IM-N and PR-N are necessary, with the addition of the L-IM-N and L-M-N in the case of lower rectal cancer. Resection of sigmoid colon is not required, and therefore, a J-pouch can be constructed using the sigmoid colon. Nodal classification according to the JGR was predictive of case distribution and five-year survival rate.

High ligation of the inferior mesenteric artery with hypogastric nerve preservation in rectal cancer surgery

We describe herein a technique of performing upward node dissection following high ligation of the inferior mesenteric artery for patients with T3 and T4 rectal carcinomas. The course of the hypogastric nerve is confirmed macroscopically during the procedure to ensure its preservation. This technique offers both increased radicality and the prevention of ejaculatory dysfunction.