Clinicopathologic features and endoscopic treatment of superficially spreading colorectal neoplasms larger than 20 mm

BACKGROUND

A colorectal neoplasm that spreads superficially over the mucosa is known as a laterally spreading tumor. The clinicopathologic features of these large lesions and the efficacy and safety of endoscopic mucosal resection (EMR) were studied retrospectively.

METHODS

Surgically or endoscopically resected laterally spreading tumors larger than 20 mm in diameter were studied. Lesions were divided into 2 macroscopic subtypes: F-type, composed of superficially spreading lesions with a flat and smooth surface, and G-type, composed of superficially spreading aggregates of nodules that form relatively flat, broad-based lesions with granulonodular and uneven surfaces.

RESULTS

Thirty-three lesions were of the F-type and 87 the G-type. G-type (mean +/- SD, 35.3 +/- 11.4 mm) lesions were significantly larger (p < 0.01) than F-type (26.0 +/- 7.2 mm) lesions. F-type lesions had a significantly higher frequency of invasive cancer (27.2%) than G-types (10.3%)(p < 0.05). Of the 120 lesions, 81 (67.5%) were resected endoscopically. Patients with 78 of these lesions were followed postoperatively for 60.8 +/- 20.1 months. The rate of local recurrence of endoscopically treated tumors as determined at colonoscopy was 7.4% (6/78). These lesions were completely resected endoscopically. Distant metastases were not detected. Thirteen (16.0%) patients had local bleeding after EMR that was stopped endoscopically. Microperforation of the colonic wall as a result of EMR was diagnosed in 1 (1.2%) of 81 cases.

CONCLUSIONS

Laterally spreading tumors larger than 20 mm, especially those of the G-type, have a low rate of invasion despite their relatively large size. The F-type lesion has a higher malignant potential than the G-type. EMR is an effective and safe treatment for the large laterally spreading tumor.

[Perioperative management of endovascular stent graft placement for abdominal aortic aneurysm]

We retrospectively examined the changes in hemodynamics, oxygen index and renal function along with the complications in 25 patients who had undergone endovascular stent graft placement (ESG) surgery for abdominal aortic aneurysm. During stent graft placement, mean arterial pressure decreased to 58 +/- 8 mmHg by increasing the dose of anesthetics and/or using vasodilators. Except for this intended hypotensive period, mean arterial pressure and heart rate were relatively stable and adequately maintained during surgical manipulation. Oxygenation index was well maintained. A patient with a high preoperative creatinine level underwent prophylactic hemodialysis postoperatively. In other patients except one who died in early postoperative period, both BUN and creatinine levels were kept within normal ranges. Four patients died postoperatively and the causes of the death in two patients are related to the surgical procedure; one with multiple emboli possibly due to released atheloma from the aortic wall during procedure, the other with sepsis due to infected stent graft. Although ESG is a well tolerated procedure, embolism is the most serious complication. Careful preoperative evaluation of the ascending arch and descending aortic wall and monitoring with transcranial doppler are necessary.

Electrocautery snare resection stimulates cellular proliferation of residual colorectal tumor: an increasing gene expression related to tumor growth

PURPOSE

Recently, endoscopic mucosal resection has been performed commonly for colorectal tumors. However, incomplete endoscopic mucosal resection produces a residual tumor that grows rapidly. The aim of this study was to clarify the characteristics of the residual tumor using the nude mouse model.

METHODS

Human colon cancer cells (colo201 or colo320DM) were implanted subcutaneous into nude mice. We then removed more than one-half of the tumor with an electrocautery snare or a surgical knife, and compared the tumor growth rate with that of control tumors. Before and after resection, we examined the Ki-67 labeling index of the tumors with an immunohistochemical assay and mRNA expression for epidermal growth factor receptor, vascular endothelial growth factor, and transforming growth factor alpha.

RESULTS

Residual tumors showed a higher growth rate in tumor volume than control tumors using both methods (electrocautery snare and surgical knife). Colo201 groups showed a higher total volume change per day than colo320DM groups after resection. Furthermore, these tumors also showed a higher Ki-7 labeling index, and a stronger epidermal growth factor receptor and transforming growth factor alpha mRNA expression than primary and control tumors in the colo201 implanted groups. There was no significant difference in vascular endothelial growth factor mRNA expression between groups implanted with colo201 or colo320DM.

CONCLUSION

Our results suggest that residual tumors caused by incomplete endoscopic mucosal resection may have a higher growth potential than the tumors before resection.

Detailed colonoscopy for detecting early superficial carcinoma: recent developments

Early superficial colorectal carcinoma (CRC) has been commonly detected by routine colonoscopic examination in Japan. A series of 769 early CRCs and 4821 adenomas were diagnosed by colonoscopy at Hiroshima University Medical Hospital between 1991 and 1998. Of early CRCs, macroscopically superficial early CRCs accounted for 209 lesions (28%). Among 5590 lesions of adenomas and carcinomas, depressed-type lesions showed a significantly higher malignant potential for cancerous and submucosal invasion than elevated lesions (polypoid, IIa-type lesions, and G-LST). As one of the quantitative examinations for early CRC, pit pattern observed by magnifying video-colonoscopy was useful. We performed magnifying observations for 265 lesions of colorectal neoplasias using Kudo's pit pattern classification for 2 years. Depressed-type lesions characterized the Ills and V pit patterns, and elevated lesions characterized the III(L) pit pattern. The incidence of cancer was significantly higher in lesions with IIIs and V pit patterns. Furthermore, the V(N) pit pattern was considered a significant indicator of submucosal invasion. These results indicated that superficial early CRC could be considered to constitute about one-third of all early CRCs. Of them, the depressed-type lesions showed a significantly higher malignant potential than elevated lesions. Pit pattern observation by magnifying videocolonoscopy is useful for predicting the histology/invasion depth of early CRC.

Intermittent antegrade warm blood cardioplegia for CABG: extended interval of cardioplegia

BACKGROUND

Intermittent delivery of warm cardioplegia provides a bloodless surgical field, but it is clinically important to evaluate the periods of normothermic ischemia. The aims of this study are to compare intermittent antegrade warm blood cardioplegia (IAWBC) with intermittent antegrade cold blood cardioplegia (IACBC) groups in terms of myocardial protection, and also to evaluate whether the length of ischemic time in the IAWBC group has an effect on myocardial dysfunction.

METHODS

This study is based on a retrospective review of patients who underwent elective coronary artery bypass surgery: 162 consecutive patients with IAWBC and 107 consecutive patients with IACBC.

RESULTS

The creatinine kinase peak was smaller in the IAWBC group compared with the IACBC group (p<0.0001). The cardiac index after cardiopulmonary bypass was higher in the IAWBC group (p<0.02), and the amount of inotropic support required to wean from cardiopulmonary bypass was less in the IAWBC group compared with the IACBC group (p<0.0001).

CONCLUSIONS

IAWBC with 30 minutes of ischemia provides to be clinically acceptable myocardial protection for coronary bypass surgery.

Cerebrovascular CO2 reactivity during anesthesia in patients with diabetes mellitus and peripheral vascular disease

BACKGROUND

Diabetes mellitus (DM) and systemic atherosclerosis are risk factors for stroke. Although the origins of increased risk are complex, one possibility is that cerebrovascular reactivity is impaired and does not allow the brain to compensate for aberrations in physiology. The current study tested this issue by evaluating mean blood flow velocity of the middle cerebral artery (Vmca) and carbon dioxide reactivity during anesthesia in patients with DM and peripheral vascular disease (PVD).

METHODS

Fifty-two patients were observed: 20 patients with DM (the DM group), 12 patients with PVD (the PVD group), and 20 patients classified as American Society of Anesthesiologists physical status 1 or 2 (the control group). The Vmca was measured using transcranial Doppler ultrasonography during isoflurane-nitrous oxide anesthesia. After measuring baseline Vmca at a partial pressure of carbon dioxide in arterial blood (PaCO2) of 37.7 +/- 4.5 mmHg (mean +/- SD), measurements were repeated at a PaCO of 44.2 +/- 3.8 mmHg, and the carbon dioxide reactivity (absolute value: cm x s(-1) x mmHg(-1); relative value: percentage of baseline Vmca/mmHg) was calculated.

RESULTS

The baseline Vmca of the DM group (51 +/- 12 cm/s) was significantly greater than those of the control group (42 +/- 6 cm/s) and the PVD group (42 +/- 13 cm/s). The absolute and relative values of carbon dioxide reactivity in the DM group (3.1 +/- 1.3 cm x s(-1) x mmHg(-1); 6.3 +/- 2.4%/mmHg) were significantly greater than or equivalent to those of the control group (2.3 +/- 0.8 cm x s(-1) x mmHg(-1); 5.3 +/- 1.7%/mmHg), respectively. In the PVD group, the baseline Vmca was equivalent to the control group, but the carbon dioxide reactivity (1.1 +/- 0.5 cm x s(-1) x mmHg(-1) 2.8 +/- 1.2%/mmHg) was significantly less.

CONCLUSIONS

The patients with DM have increased baseline cerebral blood flow velocity and normal carbon dioxide reactivity during anesthesia. The patients with PVD have decreased carbon dioxide reactivity, but baseline flow velocity is maintained.

[Changes in psychological features in patients for anesthesia and operation during perioperative period]

The purpose of this study was to assess perioperative changes in psychological features of patients receiving anesthesia and operation. Anxiety level and desire for obtaining information were evaluated in 37 patients using the Amsterdam preoperative anxiety and information scale (APAIS) at three points: before and after the preanesthetic examination, and 3 to 5 days after the operation. Anxiety scale (4-20) and information scale (2-10) scores decreased postoperatively from 9.8 +/- 3.8 to 7.3 +/- 3.4 and from 6.1 +/- 2.1 to 4.1 +/- 1.9, respectively. There was a significant but weak correlation (rs = 0.35) between the anxiety scale and information scale before the preanesthetic examination. The postoperative information scale score correlated well with preoperative anxiety scale score (rs = 0.61), and this correlation was higher than with preoperative information scale score (rs = 0.37). When patients were divided into two subgroups, namely patients with (U, n = 12) or without (non-U, n = 25) an increase in postoperative information scale score, anxiety scale score before the preanesthetic examination tended to be higher and the postoperative anxiety scale score was significantly higher in the U group than in the non-U group. We conclude that we should provide more information to the patients who have higher anxiety scale score before the preanesthetic examination regardless of their degree of desire for information.

Combined expression of HLA-DR antigen and proliferating cell nuclear antigen correlate with colorectal cancer prognosis

HLA-DR antigen expression and the proliferating cell nuclear antigen labeling index (PCNA-LI) were examined immmunohistochemically in 59 surgically resected advanced colorectal cancers to clarify the clinicopathologic significance of the HLA-DR antigen. HLA-DR antigen expression was detected in 33 (56%) of the 59 lesions, which showed less frequent liver metastasis than lesions without HLA-DR antigen expression (40 vs. 68%; p < 0.05). Five-year survival rates of patients with and without HLA-DR antigen expression were 50 and 19%, respectively. Lesions combining HLA-DR antigen expression and a relatively low PCNA-LI had the best prognosis. These results indicate that HLA-DR antigen expression, particularly combined with a low PCNA-LI, is an important outcome predictor in colorectal cancer.

[Clinical analysis on the course and prognosis of patients with Crohn's disease]

We analyzed 66 cases (47 males and 19 females) of Crohn's disease at Hiroshima University hospital from September 1975 to October 1994 to clarify the course and prognosis of Crohn's disease. The age at onset was 21.1 +/- 7.3 years old (mean +/- SD), terms between onset and diagnosis were 21.5 +/- 33.0 months (mean +/- SD) and observation period was 65.5 +/- 44.6 months (mean +/- SD). Sites of lesion were 18 ileum, 41 ileocolon and 7 colon. Thirty-one cases, 20 cases of which had intestinal obstruction, underwent surgical operation (12 ileum types, 18 ileocolic types, 1 colon type). The cumulative probability of surgery at one, five and ten years after onset of symptoms were 12.1%, 28.8% and 56.9%, respectively. As for cumulative probability of surgical operation at one, five and ten years after diagnosis were 25.8%, 36.7% and 74.4%, respectively. Results of the cumulative probability of surgery by anatomical involvement indicated that the ileum type had a statistically significantly higher risk than other types. In each analysis compliance to nutritional therapy was also an important prognostic factor. Overall, our results indicated that the site of lesion and the compliance to nutritional therapy were important factors which have an effect on the course and prognosis of Crohn's disease patients.

[Clinicopathologic evaluation on colorectal laterally spreading tumor (LST)]

Clinicopathologic characteristics of 92 colorectal laterally spreading tumors (LST) endoscopically or surgically resected were examined. Lesions were macroscopically classified into two categories according to their surface structure :(1) granular type (G type, 47 lesions), (2) flat type (F type, 45 lesions). The size (maximum diameter) of G type lesions was 24.7 +/- 11.3 mm (Mean +/- SD) and that of F type lesions was 14.2 +/- 7.4 mm. The size of G type lesions was significantly larger than that of F type lesions (p < 0.01). Among G type lesions, cancerous lesion was present in 2 (25.0%) of 8 lesions 10-14 mm in diameter, 2 (22.2%) of 9 lesions 15-19 mm in diameter and 19 (63.3%) of 30 lesions more than 20mm in diameter. Regarding F type lesions, cancerous lesion was present in 15 (46.9%) of 32 lesions 10-14 mm in diameter, 4 (80.0%) of 5 lesions 15-19 mm in diameter and 8 (100%) of 8 lesions more than 20mm in diameter. The incidence of carcinoma in F type lesions was higher than that in G type lesions irrespective of size. F type lesions with carcinoma showed a trend toward a higher frequency of submucosal invasion and F type lesions with adenoma revealed tendency of showing severe atypia in comparison with G type lesions. The adenomatous component of LST showed a tubulo-villous architecture in 13 (28.3%) of 46 G type lesions, however none of F type lesions had a tubulo-villous component. These results indicated that clinicopathologic characteristics of F type are obviously different from G type. Furthermore, F type had a higher malignant potential than G type and is thought to have a more important role as a precursor of colorectal carcinoma than G type.

The effects of dopamine infusion during operation on the postoperative liver dysfunction

Dopamine improves renal function and renal blood flow by increasing cardiac output but its effect to ameriolate postoperative liver dysfunction has not yet been defined. Effect of 3-5 microg.kg(-1).min(-1) dopamine was studied in 22 patients who had total gastrectomy (dopamine group), and was compared with 22 patients who underwent the same operation and without dopamine infusion (control group). Liver function was evaluated from serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) values. Although postoperative SGOT and SGPT values in both groups were increased significantly higher than the preoperative values, the increases in SGOT (40 +/- 14 IU) and SGPT (32 +/- 15 IU) values in the dopamine group were significantly less than those in the control group (67 +/- 27 IU, 43 +/- 19 IU) ( P < 0.05, P < 0.01).In conclusion, these results suggested that this observation might be explained by amelioration of the postoperative liver dysfunction by infusion of dopamine. Dopamine infusion at a small dose during upper abdominal surgery is beneficial for liver function.

The effects of inversed ratio ventilation (IRV) on arterial oxygenation during mechanical ventilation in patients with acute respiratory failure

We investigated the effects of inversed ratio ventilation by altering the inspiratory:expiratory (I:E) ratio and assessing the time course changes in the intrapulmonary shunting (Qs/Qt) in 14 patients with acute respiratory failure. Stepwise prolongation of the I:E ratio from 1:1.9 to 2:1 and then to 2.6 or 4:1 was applied when PEEP failed to raise the PaO2 above 80 mmHg while breathing oxygen. A significant decrease in Qs/Qt was observed following prolongation of the I:E ratio from 1:1.9 (Qs/Qt = 45 +/- 9%) to 2:1 (Qs/Qt = 29 +/- 9%) but not with further prolongation of the I:E ratio (Qs/Qt = 27 +/- 7%). Improvement of the pulmonary ventilation/perfusion imbalance became more marked with continued IRV and a significant increase in PaO2 was observed at 6 h after initiating prolongation of the inspiratory time (P less than 0.05). There were no significant changes in hemodynamics, PaCO2, or peak inspiratory pressure during IRV. This ventilatory pattern may be indicated when PEEP fails to improve PaO2, but prolongation of the inspiratory time above an I:E ratio of 2:1 did not produce a greater improvement in Qs/Qt and further increases in PaO2 did not occur after more than 10 h of IRV in our 14 patients.

Purification and properties of human urine ribonucleases

1. Two RNases (RNase UL and RNase US) were purified from the urine of human adults by means of column chromatographies on SP-Sephadex C-50, phospho-cellulose and CM-cellulose and gel-filtration on Sephadex G-75 in homogeneous states obtained by SDS-disc electrophoresis. 2. Molecular weights of these RNases determined by gel-filtration were 38,000 and 13,000 for RNase UL and RNase US, respectively. 3. Optimal pH's of urine RNases were 8.0 and 6.75 for RNase UL and RNase US, respectively. 4. Chemical composition of urine RNases was determined. RNase UL contains about 20.7% of neutral sugar and 7.8% of hexosamine. RNase US contains a very small amount of carbohydrate moiety. 5. Base specificity of urine RNases studied with 2',3'-cyclic nucleotides and dinucleoside phosphates as substrates indicated that both RNases were pyrimidine specific and cytosine preferential enzyme, as is bovine pancreatic RNase A. Although base specificity of RNase UL was qualitatively similar to RNase A, that of RNase US was slightly different. That is, RNase US did not hydrolyze UpU and hydrolyzed UpC and 2',3'-cyclic UMP very slowly. 6. Antigenic properties of human urine RNases were studied by Ouchterlony's double diffusion analysis. RNase UL, RNase US, and RNase A were serologically distinguishable.