Morphologies of the interfaces between the levator ani muscle and pelvic viscera, with special reference to muscle insertion into the anorectum in elderly Japanese.

A specific, smooth muscle-mediated interface between the levator ani muscle (LA) and the pelvic viscera has been reported. Using 110 sagittally trimmed anorectal tissue strips (80 lateral, 15 anterior and 15 dorsal specimens) obtained from the donated cadavers of 46 elderly subjects, we examined variations in the interface between the LA and the rectal muscularis propria, including the so-called conjoined longitudinal muscles. In type A (9/46), little or no tissue connected the LA to the external rectal muscularis propria, but the LA and external sphincteric mass formed a definite complex. In type B (26/46), the covering fascia of the LA changed abruptly into smooth muscles, which merged into the external rectal muscularis propria. In type C (11/46), most of the LA-associated connective tissues, composed of smooth muscles, were tightly connected to the internal and external rectal muscularis propria. These variations seemed to depend on the morphology of the recto-urethralis, the lateral extension of which reinforced the LA-associated smooth muscles sufficiently to form type B and C insertions. We also demonstrated differences in the interfacial tissues between the LA and other pelvic viscera. We hypothesize that, to avoid injury of the LA and its interfaces during strong movement of the pelvic viscera, for example during childbirth, coitus or squeezed evacuation, the pelvic connective tissue-like smooth muscles play an important role as an autonomic buffer and/or modulator of pelvic floor function. Digital examination and transrectal or transvaginal sonography may be useful for evaluating interindividual variation in these interfacial tissues in elderly patients.

[Clinical significance of TS and DPD activities in colorectal carcinoma as a predictive factor of UFT sensitivity].

We measured TS and DPD activities in 40 patients with colorectal cancer who had undergone surgical reduction in our department between May 1997 and April 1998, including 26 patients with preoperative UFT (450 mg/body/day) chemotherapy for 2 weeks, and evaluated the clinical significance of TS and DPD activities as predictive factors of UFT sensitivity. TS activity was collated with histological type from a clinical pathological examination (p = 0.0103). Also, the tendency for TS activity to become high with the stage was observed. According to the evaluation of pathological response, histological effectiveness greater than grade 2 was noted in 7.7%. The apoptosis index (AI) in tumors with preoperative UFT chemotherapy was higher than those without such treatment, which showed a higher correlation with DPD activity of tumor tissue than TS activity (p = 0.0465). Recurrence was seen in 7 cases (lung metastasis: 2, liver metastasis: 4, and local recurrence: 1) in the preoperative chemotherapy group. TS activity was high in all patients with recurrence. TS showed significantly high activity in patients with recurrence compared with the non-recurrence (p = 0.0034) patients. Therefore, these results suggested that activity of both TS and DPD was a key factor for anti-tumor effectiveness of UFT. In particular, TS activity was an important predictive factor for effectiveness of UFT in recurrences.

[A case of metastatic liver tumor of colorectal cancer responding to low-dose CPT-11 chemotherapy].

We report a case in which low-dose CPT-11 chemotherapy was effective for metastatic liver tumor of sigmoid colon cancer. A 49-year-old male with metastatic liver tumor, who had undergone sigmoidectomy with D2 lymphadenectomy, was treated by low-dose CPT-11 chemotherapy (CPT-11 30 mg/m2 x 3 days, every 2 weeks). After 7 courses of this chemotherapy, CT and ultrasound examinations showed a reduction of tumor size in the liver. This chemotherapy also showed no high grade toxicities. Therefore, low-dose CPT-11 chemotherapy seems to be effective for metastatic colorectal cancer, and safe in view of toxicities.

A preliminary study of the draining lymph node basin in advanced lower rectal cancer using a radioactive tracer.

PURPOSE: This study was designed to examine the draining lymph node basin at highest risk of metastasis in lower rectal cancer using 99 mTc-tin colloid. METHODS: In 43 patients, the area with highest hot nodes density was defined as the draining lymph node basin using a gamma probe. Metastatic states of all removed lymph nodes were examined histologically. RESULTS: A total of 203 hot nodes were identified in 39 patients (91 percent) with a mean of 5.2 nodes. The number of removed lymph nodes was 808 nodes: 670 nodes in the mesorectum, and 138 nodes in the pelvis. In 21 patients, the metastatic states of 119 nodes were investigated histologically. From the distribution of the identified hot nodes, the draining lymph node basins were classified into two patterns: lateral type (n = 17), and mesorectal type (n = 22). Only 20 (17 percent) of 119 positive nodes were identified as hot node. Tumor cells that occupied the lymph node diffusely or massively probably interfered with the exact diagnosis of metastasis. Lymph node metastasis in the pelvis was observed in 5 patients (13 percent). One false negative was of the mesorectal type with diffuse metastases in the para-aortic lymph nodes. The remaining four patients were of the lateral type and all positive lymph nodes, including positive nonhot nodes, were located within the draining lymph node basin. Consequently, in 20 (95.2 percent) of 21 patients with lymph node metastasis, all positive lymph nodes were located within the draining lymph node basin of the tumor. CONCLUSIONS: Two types of the draining lymph node basin of advanced lower rectal cancer were identified using this method. The concordance between lymph node metastases and the draining lymph node basin is good.