Hiroyoshi Matsuoka

A comparison between dynamic pelvic magnetic resonance imaging and videoproctography in patients with constipation

PURPOSE: This study attempts to compare the diagnostic efficacy of dynamic pelvic magnetic resonance imaging with that of videoproctography for the presence of rectocele, sigmoidocele, and intussusception as well as the measurement of anorectal angle and perineal descent in constipated patients. METHODS: Patients volunteering for the study and fulfilling the criteria for videoproctography to evaluate constipation were also scheduled for dynamic pelvic magnetic resonance imaging. Patients undergoing videoproctography were placed in the left lateral decubitus position, after which 50 ml of liquid barium paste was introduced into the rectum. After this, approximately 100 ml of thick barium paste similar to stool in consistency was injected into the rectum, and the patient was instructed to defecate while video images were taken. For dynamic pelvic magnetic resonance imaging, air, to be used as contrast, was allowed to accumulate in the rectumvia examination with the patient in the prone position. A capsule was taped to the perineal skin immediately posterior to the anal orifice for marking. Sagittal and axial T1 images were obtained through the pelvis at 8-mm intervals with dynamic breathhold sagittal images of the anorectal region obtained at rest and during strain and squeeze maneuvers. Total acquisition time per maneuver was approximately 19 seconds. The tests were performed by different examiners blinded to the result of the other evaluation. The investigations were independently interpreted, findings compared, and patients questioned regarding their impression of dynamic pelvic magnetic resonance imaging and videoproctography. RESULTS: From June 1996 to April 1997, 22 patients (15 females) with a mean age of 68 (range, 21–85) years underwent both videoproctography and dynamic pelvic magnetic resonance imaging. Dynamic pelvic magnetic resonance imaging was only able to detect 1 of 12 (8.3 percent) anterior rectoceles and one of two (50 percent) posterior rectoceles identified by videoproctography. It failed to recognize any of the rectoanal intussusception (zero of four) but did show 9 of 12 (75 percent) sigmoidoceles. Significant discrepancy of measurement of the anorectal angle and perineal descent exists between the two studies, and dynamic pelvic magnetic resonance imaging was not able to detect any (0 of 11) of the patients with increased fixed perineal descent and only half (one of two) of the patients with increased dynamic perineal descent noted on videoproctography. All 22 patients preferred dynamic pelvic magnetic resonance imaging over videoproctography because of greater comfort. CONCLUSION: Occasionally, the increased cost of new technology can be justified by the enhanced diagnostic yield. The ability to avoid unnecessary surgery or, conversely, to continue to search for otherwise occult pathology that can be surgically corrected justifies routine application of these new tools. However, this study has shown that, despite a cost of approximately ten times more for dynamic pelvic magnetic resonance imaging than for videoproctography, no clinical changes were made. Thus, on the basis of this study, we cannot endorse the routine application of dynamic pelvic magnetic resonance imaging for the evaluation of constipated patients. In certain selected individuals, it may play a role, but further study is necessary to clarify its exact role.

Comparison between endorectal coil and pelvic phased-array coil magnetic resonance imaging in patients with anorectal tumor

BACKGROUND Magnetic resonance imaging (MRI) has been used as one of the diagnostic tools in the preoperative evaluation of rectal cancer. However, the usefulness of endorectal coil (ERC) compared with phased array coil (PA) MRI is still unknown. PATIENTS AND METHODS Nineteen patients with rectal (17 patients) and anal (2 patients) tumors undergoing both ERC-MRI and PA-MRI preoperatively were included in the study. Seventeen patients had advanced stage tumors, and the remaining 2 had early stage tumors. The diagnostic accuracy of depth tumor invasion and lymph node metastasis were compared with reference to the histopathologic findings as the gold standard. RESULTS ERC-MRI was evaluable in only 10 (52.6%) of 19 patients, because of difficulties in ERC placement, whereas PA-MRI could be obtained in all patients (100%). In 10 patients examined by both modalities, the diagnostic accuracy of depth of tumor invasion was 80% by ERC-MRI and 80% by PA-MRI. In lymph node staging, ERC yielded sensitivity of 100%, specificity of 62.5%, and overall accuracy of 70.0%. The corresponding values for PA-MRI were 50%, 100% and 90.0%, respectively. These figures were not significantly different between the two modalities. CONCLUSIONS ERC-MRI and PA-MRI showed similar diagnostic accuracy. ERC-MRI may be abandoned in the preoperative staging of patients with locally advanced anorectal tumors because of its limited clinical utility.

Coexpression of Matrilysin and Laminin-5 γ2 Chain May Contribute to Tumor Cell Migration in Colorectal Carcinomas

We attempted to examine the correlation between matrilysin and laminin-5 γ2 chain expression with reference to the number of dedifferentiation units along the entire invasive front (tumor budding). Immunostaining for hMMP-7 and laminin-5 γ2 chain was performed in 50 T1 colorectal carcinomas, and immunoreactivity was evaluated at the invasive front of the tumor. On hematoxylin–eosin sections, the number of tumor budding was counted. The localization of matrilysin tended to be widespread compared with that of laminin-5 γ2 chain. Matrilysin and laminin-5 γ2 chain expression were positive in 28 (56%) and 15 (30%) tumors respectively. There was a significant correlation between matrilysin and laminin-5 γ2 chain expression (P = 0.02). Matrilysin(+)/laminin-5 γ2 chain(+) tumors had a significantly greater amount of tumor budding than matrilysin(−)/laminin-5 γ2 chain(−) tumors (P = 0.003) or matrilysin(+)/laminin-5 γ2 chain(−) tumors (P = 0.03). In conclusions, coexpression of matrilysin and laminin-5 γ2 chain may contribute to tumor cell migration in colorectal carcinomas.

Preoperative staging by multidetector-row computed tomography in patients with rectal carcinoma

BACKGROUND Multidetector-row computed tomography (MDCT, or multi-slice CT) has been introduced in 2000. So far, there has been no published study on this modality in patients with rectal carcinoma. METHODS Twenty patients with rectal carcinoma were preoperatively examined by MDCT and conventional CT (CCT). Diagnostic accuracies of both modalities were compared regarding the evaluation of depth of tumor invasion (Tis/T1/T2, T3, T4) and lymph node metastasis based on the pathologic findings. RESULTS Although CCT detected a tumor in 13 (65%) of 20 patients, MDCT revealed a tumor in all 20 patients (P = 0.004). Regarding depth of tumor invasion, the concordance rate was significantly higher for MDCT (20/20: 100%) than for CCT (12 of 20: 60%; P = 0.002). Regarding lymph node metastasis, the overall accuracy was 70.0% in CCT, and also 70.0% in MDCT. CONCLUSIONS MDCT was superior to CCT in the evaluation of depth of tumor invasion, but was equal to CCT in the evaluation of lymph node metastasis.

A prospective comparison between multidetector-row computed tomography and magnetic resonance imaging in the preoperative evaluation of rectal carcinoma

BACKGROUND Multidetector-row computed tomography (MDCT, or multislice CT) is a new modality with four detectors, which makes examination time shorter and produces higher resolution and multiplanar reformation of the images. Its diagnostic role in patients with rectal carcinoma has not been determined. METHODS Twenty-one patients with rectal carcinoma were preoperatively examined by both MDCT and magnetic resonance imaging (MRI). Diagnostic accuracies of both modalities were compared regarding depth of tumor invasion and lymph node metastasis based on the pathologic findings. RESULTS Both examinations detected all tumors. Regarding depth of tumor invasion, the concordance was 95.2% (20 of 21) for MDCT and 100% (21 of 21) for MRI. Regarding lymph node metastasis, the overall accuracy was 61.9% for MDCT and 70.0% for MRI. CONCLUSIONS Multidetector-row computed tomography was equal to MRI in the preoperative local staging of rectal carcinoma.

Actual number of tumor budding as a new tool for the individualization of treatment of T1 colorectal carcinomas

Background and Aim:  Treatment of T1 colorectal carcinomas, either local excision including endoscopic polypectomy or radical surgery, has always been problematic in everyday practice. Although previous studies have revealed that tumor budding at the invasive margin can be a marker for the malignant potential of T1 colorectal carcinomas, the evaluation of tumor budding has not been standardized as yet. In the present study, we attempted to apply the actual number of tumor budding units for the individualization of treatment in T1 colorectal carcinomas.

Preoperative evaluation by magnetic resonance imaging in patients with bowel obstruction.

BACKGROUND Bowel obstruction is a problematic condition because the main clinical issue is to determine whether emergency laparotomy or observation with a long tube is required. The recent development of imaging diagnostic modalities such as magnetic resonance imaging (MRI) is thought to be promising to support therapeutic decisions in patients with bowel obstruction. METHODS Twenty-seven patients with bowel obstruction who underwent laparotomy were evaluated by plain x-ray film, computed tomography (CT) scan, and MRI preoperatively with regard to the presence or absence of bowel obstruction, and the site and cause of bowel obstruction. Diagnostic accuracies were compared among these radiological modalities. RESULTS The presence of bowel obstruction was detected in 22 (81.5%) of 27 patients by plain abdominal x-ray film, in 24 (92.3%) of 26 patients by CT scan, and in 25 (92.6%) of 27 patients by MRI. The sites of obstruction were consistent with surgical findings in 25 (92.6%) of 27 patients by MRI, and in 15 (57.7%) of 26 patients by CT scan. The causes of bowel obstruction were accurately diagnosed by MRI in 25 (92.6%) of 27 patients, and in 23 (88.5%) of 26 patients by CT scan. CONCLUSIONS MRI could identify the presence and the site and cause of bowel obstruction in most of the cases. MRI is assumed to be superior to CT scan in the preoperative diagnosis of bowel obstruction.

Laminin-5 γ2 Chain Expression as a Possible Determinant of Tumor Aggressiveness in T1 Colorectal Carcinomas

This study was undertaken to clarify the associations between laminin-5 γ2 chain expression, and tumor budding and lymph node metastasis or local recurrence (locoregional failure) of 50 T1 colorectal carcinomas immunohistochemically. Fifteen (30%) of 50 lesions were positive for laminin-5 γ2 chain expression. By univariate analysis, less histological differentiation (P = 0.02), nonpolypoid growth pattern (P = 0.03) and tumor budding (P < 0.001) were associated with laminin-5 γ2 chain positivity. By multivariate analysis, tumor budding alone was significantly associated with laminin-5 γ2 chain positivity (P = 0.006), and correlation between nonpolypoid growth pattern and laminin-5 γ2 chain positivity lost its significance (P = 0.09). Tumor budding (P = 0.004) and laminin-5 γ2 chain expression (P = 0.001) were significantly associated with locoregional failure. Laminin-5 γ2 chain expression may contribute to the formation of budding tumor cells at the invasive front, and immunostaining of this adhesion molecule may be useful in identifying high-risk patients for locoregional failure in T1 colorectal carcinomas.

Modified Glasgow prognostic score in patients with incurable stage IV colorectal cancer

BACKGROUND The modified Glasgow prognostic score is an inflammation-based prognostic score. This study examined whether this score, measured before surgical procedures, could predict postoperative cancer-specific survival. METHODS We retrospectively studied 79 colorectal cancer patients who underwent a surgical procedure for incurable stage IV disease. The modified Glasgow prognostic score (0 to 2) comprises C-reactive protein (≤10 vs >10 mg/L) and albumin (<35 vs ≥35 g/L) measurements. RESULTS In terms of overall survival, univariate analysis revealed significant differences in the status of lung metastasis, peritoneal dissemination, distant metastasis, hemoglobin, C-reactive protein, albumin, tumor resection, adjuvant chemotherapy, and modified Glasgow prognostic score. Multivariate analysis revealed that hemoglobin (P = .019), adjuvant chemotherapy (P = .002), and modified Glasgow prognostic score (0 and 1, low; 2, high) (P = .0001) were significant predictive factors for postoperative mortality. CONCLUSIONS The modified Glasgow prognostic score is simple to obtain and useful in predicting survival in incurable stage IV colorectal cancer patients undergoing surgery.

The indication of local excision for T2 rectal carcinomas

BACKGROUND Several researchers reported that local excision with or without postoperative chemo-radiation therapy is an alternative approach for sphincter preservation in patients with locally invasive rectal carcinoma. However, indications and long-term results have not yet been determined. METHODS Seventy-two patients with T2 colorectal carcinomas underwent bowel resection with regional lymph node dissection. The associations between lymph node metastasis (LNM) and clinicopathologic factors were examined with special reference to the presence or absence of moderate to severe degree of focal dedifferentiation or mucinous component at the invasive margin (unfavorable histology). RESULTS Multivariate logistic regression analysis revealed that both sex and unfavorable histology were significantly associated with LNM (P = 0.0102, 0.0226, respectively). However, the associations between LNM and lymphatic invasion or tumor location were not statistically significant (P = 0.0947, 0.1738). CONCLUSIONS When locally resected T2 rectal carcinoma specimens have unfavorable histology at the invasive margin, additional bowel resection with lymph node dissection should be recommended.