Covered self-expandable metallic stents could be used successfully in the palliation of malignant cervical esophageal strictures: preliminary report.

PURPOSE: To present the authors' preliminary experience with covered self-expandable metallic stents in the palliation of malignant cervical esophageal strictures. METHODS: Covered self-expandable metallic stents were placed into the cervical esophagus of 6 patients with malignant cervical esophageal strictures under fluoroscopic guidance. RESULTS: Stent placement was technically successful in all patients, and the mean dysphagia score decreased from 3.3 to 0.5 according to the Ogilvie Dysphagia Scoring. Two patients complained of chest pain, which lasted for 24 to 48 hours. Foreign body sensation disappeared spontaneously within a week in all patients, but one. Migration, dysphagia, or obstruction was not observed in any of the patients during the follow-up period (47 d to 8 mo). CONCLUSIONS: According to our limited number of cases, placement of covered self-expandable metallic stents into the cervical esophagus can be performed safely, and significant improvement of dysphagia scores and life quality of patients can be obtained instantly after the procedure.

The role of dura mater and free peritoneal graft in the reinforcement of colon anastomosis.

Anastomotic leakage is the most important complication leading to morbidity and mortality in colorectal surgery. To prevent anastomotic leakage, a number of drugs with different mechanisms of action were tested, and autogenic grafts and various synthetic materials were used for reinforcement of the anastomotic region. In this experimental study aimed at preventing anastomotic leakage and dehiscence, we used dehydrated, lyophilized human dura mater and free peritoneal graft for reinforcement of anastomotic region after primary repair in rats, and investigated whether they are superior to primary anastomosis. The rats were sacrificed 3 and 7 days postoperatively. The anastomotic region was observed macroscopically for adhesions, bursting pressure of bowel was measured for tensile strength of the anastomosis, and histopathologic evaluation was performed for anastomotic healing. Compared to the control group, dura mater and free peritoneal graft groups displayed a lower bowel bursting pressure (p < .05), worse anastomotic healing (p < .05), a higher number of adhesions, and presence of anastomotic stricture. In conclusion, both human dura mater and free peritoneal graft reinforcement groups had worse anastomosis healing. The results could be attributed to avascularity of grafts and to aggravated adhesions between anastomosis and intra-abdominal organs, which created a favorable environment for reproduction and dispersion of bacteria and consequently led to decreased anastomosis healing.

Nitric oxide and antioxidant defense in patients with gastric cancer.

In the present study, total nitrate and nitrite level (as end product of nitric oxide), superoxide dismutase activity, and glutathione peroxidase activity in leukocytes were determined in patients with gastric cancer, and the relationship between measured parameters and tumor grade were evaluated. Leukocyte nitrate and nitrite level was found to be increased and superoxide dismutase activity was found to be decreased in patients compared to controls. When the patient group was categorized, nitrate and nitrite level was found to be higher in patients with a high-grade tumor than in patients with a grade I tumor. We concluded that an increased level of leukocyte nitrate and nitrite is related to tumor grade in patients with gastric cancer; antioxidant activity is also impaired in these patients but it does not seem to be related to grade of tumor.

Evaluation of O6-methylguanine DNA methyltransferase activity in patients with gastric cancer.

O6-Methylguanine DNA methyltransferase (O6-MGMT) reverses DNA alkylation damage produced alkylating agents. O6-MGMT is also a major determinant of cellular resistance to adjuvant chemotherapy with alkylating drugs. O6-MGMT activity was measured in samples from patients with gastric cancer, including tumor, adjacent normal appearing mucosa, and peripheral blood leukocytes (PBL). O6-MGMT activity of PBL from healthy individuals was evaluated as control. There was no significant difference between controls and patients for O6-MGMT activity in PBL. O6-MGMT activity was significantly increased in tumor tissue. Tumor O6-MGMT activity was found to be independent from tumor subgroups and tumor grade. A positive correlation was determined between O6-MGMT activity in tumor and in circulating PBL. The results indicate that O6-MGMT, a defense protein against alkylating agent-mediated carcinogenesis, increased in gastric tumors. This may explain the low response rate to drug combinations, including chloroethylnitrosoureas, exhibited by patients with gastric cancer.