Efficacy and safety of a novel submucosal lifting gel used for endoscopic submucosal dissection: a study in a porcine model.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is technically demanding. A viscous gel for submucosal lifting might induce mechanical submucosal dissection facilitating easier and safer ESD. METHODS: In 12 female pigs (median 64 kg), ESDs of simulated lesions were performed at the posterior wall and greater curvature in the gastric body (one ESD per location) with randomly assigned injection fluids: gel or control fluid (0.9% saline with hydroxypropyl methylcellulose 3 mg/ml [7:1] and indigo carmine droplets). Additionally, 10 cc gel was injected into the submucosa at the anterior wall without ESD to assess effects of inappropriate injection. Pigs were euthanized at day 0, 3 or 28. In four additional pigs (euthanized day 3 or 28) 10 cc gel was injected into the muscularis propria (MP) after four endoscopic mucosal resections in the gastric body. RESULTS: Both fluid groups showed equal ESD-procedure times (28 [gel] vs. 26 min [control]) and complications. Gel-ESDs required less accessory interchanges (3.5 vs. 5.5; p = 0.01). Mechanical dissection after circumferential incision was achieved in 25% of gel-ESDs; none in control-ESDs. The severity of inflammation and fibrosis was equal in both fluid groups. Normal architecture and vital mucosa were found after inappropriate submucosal injection. MP-injections resulted in one transmural hematoma (day 3), and intramuscular encapsulation in 25% of the sites (day 28). LIMITATIONS: A pig's stomach differs from the human stomach. CONCLUSIONS: The mechanical dissection properties of the gel may reduce the need for submucosal dissection during ESD. The gel is safe when advertently injected in the submucosa and MP. The porcine model appeared suboptimal to evaluate the true mechanical dissection properties of the gel.

Long-term outcomes of endoscopic submucosal dissection for colorectal epithelial neoplasms.

BACKGROUND AND AIMS: Endoscopic submucosal dissection (ESD) provides a high en bloc resection rate with less invasiveness than surgical resection for large or scarring gastrointestinal neoplasms. However, detailed outcomes in colorectal ESD are still lacking. The aim of our study was to elucidate short- and long-term outcomes of colorectal ESD. PATIENTS AND METHODS: 310 consecutive colorectal epithelial neoplasms (146 adenomas, 164 carcinomas), in 290 patients, which fulfilled our indication criteria and were treated with ESD between July 2000 and December 2008 were studied. ESD was done by three skilled endoscopists. As short-term outcomes, rates of en bloc resection, en bloc plus R0 resection, and major complications were analyzed. As long-term outcomes, disease-free and overall survival were assessed in 224 patients. RESULTS: Rates of en bloc resection and en bloc plus R0 resection were 90.3 % and 74.5 %, respectively. Eight patients underwent additional colectomy due to histopathologically proven possible node-positive cancer. Intraoperative perforations occurred with 14 lesions (4.5 %), which were treated successfully only by endoscopic clipping. Emergent surgery was needed for one case of postoperative perforation. Blood transfusion due to intraoperative massive bleeding was required in 1 case (0.3 %). Postoperative bleeding occurred with four lesions (1.3 %), and was endoscopically managed without blood transfusion. Local recurrence was detected in 4 lesions (4/202 patients, 2.0 %); resection had been piecemeal in all 4. During a median follow-up of 38.7 months (range 12.8 - 104.2), the 3- and 5-year overall/disease-specific survivals were 97.1/100 % and 95.3/100 %, respectively. CONCLUSIONS: Colorectal ESD showed favorable long-term outcomes. It may largely replace colectomy for node-negative colorectal epithelial neoplasia.

Predictors of postoperative stricture after esophageal endoscopic submucosal dissection for superficial squamous cell neoplasms.

BACKGROUND AND STUDY AIMS: Although endoscopic submucosal dissection (ESD) is becoming accepted as an established treatment for superficial esophageal squamous cell neoplasms, the risks for developing postoperative stricture have not been elucidated. PATIENTS AND METHODS: This was a retrospective study at a single institution. From January 2002 to October 2008, 65 patients with high-grade intraepithelial neoplasms (HGINs) or m2 carcinomas treated by ESD were enrolled. Predictors of postoperative stricture were investigated by comparing results from 11 patients who developed strictures with those from 54 patients who did not. RESULTS: Significant differences between the two groups were observed in longitudinal diameter (45.0 +/- 15.9 mm vs. 31.5 +/- 13.6 mm) and circumferential diameter (37.2 +/- 8.6 mm vs. 26.8 +/- 9.7 mm) of the resected specimens, and the proportion of extension to the whole circumference of the lumen (< 1 / 2/ > 1 / 2/ > 3 / 4 : 2 / 4 / 5 vs. 40 / 13 / 1), histologic depth (HGIN/m2 : 2 / 9 vs. 41 / 13), and procedure time (85.6 +/- 42.8 minutes vs. 53.3 +/- 30.1 minutes). Multivariate analysis revealed that circumferential extension of > 3 / 4 (odds ration [OR]: 44.2; 95 % confidence interval [CI]: 4.4 - 443.6) and histologic depth to m2 (OR: 14.2; 95 %CI: 2.7 - 74.2) are reliable risk factors. Subanalysis for each category by combinations of these risk factors revealed that patients with lesions in > 3 / 4 of the circumferential area were associated with a high rate of postoperative stricture. By contrast, patients with HGIN lesions in < 3 / 4 extension have no probability of postoperative strictures. Additionally, subanalysis of patients with m2 lesions in < 3 / 4 circumferential extension revealed that circumferential diameter can be a reliable predictor for postoperative stricture. CONCLUSIONS: Circumferential extension and histologic depth are the reliable risk factors for postoperative strictures. In combination with circumferential diameter, we can perform effective and appropriate preventive balloon dilatations after esophageal ESD.

Technical feasibility of endoscopic submucosal dissection for early gastric cancer in patients taking anti-coagulants or anti-platelet agents.

BACKGROUND: Endoscopic submucosal dissection is a novel technique that is expected to be a curative treatment for early gastric cancers. Anti-coagulants and anti-platelet agents are widely used, especially in elderly patients, to prevent thromboembolic disease. However, the feasibility of endoscopic submucosal dissection for such patients has not been investigated. AIMS: To determine the feasibility of endoscopic submucosal dissection for patients using anti-coagulant and anti-platelet agents via retrospective investigation of clinical outcomes. METHODS: Of 408 patients with 444 early gastric cancers consecutively treated by endoscopic submucosal dissection from January 2000 to December 2007 in our hospital, 47 patients with 56 early gastric cancers were receiving anti-coagulants or anti-platelet agents. All patients were classified into groups for high and low risk of thromboembolism. In 44 low-risk patients, these agents were stopped for 1 week before and after treatment. Only three high-risk patients underwent intravenous heparin replacement during the cessation period. RESULTS: Comparison with other patients showed no significant differences in complete en-bloc resection (96.4%) or perforation (1.8%). Postoperative bleeding requiring endoscopic treatment occurred for six early gastric cancers (10.7%) in the anti-coagulant and anti-platelet group; this frequency was slightly higher than that observed for other patients (5.2%). The healing of endoscopic submucosal dissection ulcers was not delayed by anti-coagulant and anti-platelet treatment (91% in the scarring stage) when checked at the 8th week after endoscopic submucosal dissection. CONCLUSION: The clinical outcomes of endoscopic submucosal dissection for early gastric cancers in patients receiving anti-coagulants or anti-platelet agents indicated that endoscopic submucosal dissection for low-risk patients could be a reliable technique with equivalent efficacy and risk in comparison with that for other early gastric cancer patients.

Outcomes of endoscopic submucosal dissection for early gastric cancer with special reference to validation for curability criteria.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is a novel, promising endoscopic technique for gastrointestinal neoplasms. We aimed to elucidate the feasibility of ESD as curative treatment for intestinal-type early gastric cancer (EGC) potentially without lymph-node metastases. PATIENTS AND METHODS: For the short-term analysis, 276 consecutive, intestinal-type EGCs, which fulfilled the criteria for node-negative EGC in 231 patients who had undergone ESD from January 2000 to March 2007, were retrospectively investigated. For the long-term analysis, 212 lesions checked by endoscopy later than 1 year or recurrence within 1 year after ESD were assessed for local recurrence, and 208 patients followed for over 1 year or to death within 1 year after ESD were assessed for metastases and survival. All lesions/patients were divided into three groups: intramucosal cancer without ulcerative findings (M-Ul[-]); intramucosal cancer with ulcerative findings, < or = 3 cm (M-Ul[+]); and slight invasive cancer into submucosa (< 500 microm), < or = 3 cm (SM1). RESULTS: En bloc and complete resection rates were 96.7 % and 91.7 %, respectively. During a median follow-up of 36 months (range 2 - 93 months), two local recurrences occurred (0.9 %), which were detected at 2 and 6 months after ESD, respectively. During a median follow-up of 38 months (range 6 - 97 months), the 5-year overall and disease-specific survival rates were 96.2 % and 100 %, respectively, with neither lymph node nor other-organ metastasis; one patient died due to other disease 6 months after ESD. No disease-related death occurred. No significant differences were found between the groups in short- and long-term analyses. CONCLUSIONS: The prognostic analyses demonstrated the validity of the criteria of node-negative intestinal-type EGC as curability criteria for ESD. ESD can be proposed as an alternative method to gastrectomy for the treatment of these EGCs.

Feasibility of electrocautery snaring as the final step of endoscopic submucosal dissection for stomach epithelial neoplasms.

BACKGROUND: Endoscopic submucosal dissection (ESD) is a novel endoluminal technique that permits the resection of gastric neoplasms. AIM: To analyse the feasibility of snaring as the final step of ESD. PATIENTS AND METHODS: One hundred and ninety-nine consecutive gastric neoplasms resected by four ESD experts from January 2004 to May 2007 were investigated. Forty-five (22.6%) were finally resected finally using a snare. Rates of en bloc resection, complete (R0 plus en bloc) resection, mean operation time, and complications were assessed between the snaring and the non-snaring groups. RESULTS: En bloc resection rate was significantly lower and delayed bleeding rate was significantly higher in the snaring group than in the non-snaring group (91.1% [41/45] vs. 100% [154/154], 11.1% [5/45] vs. 1.9% [3/154], respectively), although complete resection rate (86.7% [39/45] vs. 92.9% [143/154]) and mean operation time (70.2 min vs. 75.8 min) were not significantly different between the two groups. Six perforation cases (3 [6.7%] in the snaring group, 3 [1.9%] in the non-snaring group) were observed, but snaring did not lead to perforation in any case. When the subjects were divided into small (< or = 2 cm) and large (> 2 cm) tumours, en bloc resection rate in large tumours was still significantly different between the groups (76.9% [10/13] vs. 100% [67/67]), whereas in small tumours it was no longer significantly different (96.9% [31/32] vs. 100% [87/87]). CONCLUSIONS: Snaring may facilitate successful ESD for smaller tumours, but multiple-piece resection should be taken into account especially for larger tumours.

Endoscopic submucosal dissection as a staging measure may not lead to worse prognosis in early gastric cancer patients with additional gastrectomy.

BACKGROUND: Endoscopic submucosal dissection is a novel endoluminal technique that enables resection of early stage gastrointestinal malignancies in an en bloc fashion. AIM: To assess whether preceding endoscopic submucosal dissection affected the prognoses of patients who underwent additional gastrectomy with lymph node dissection due to suspicion of nodal metastasis from endoscopic submucosal dissection specimens. PATIENTS AND METHODS: Thirty-one patients with early gastric cancer who underwent gastrectomy after endoscopic submucosal dissection were retrospectively investigated in terms of their survival and tumour recurrence. Additional gastrectomy was performed when histology of the endoscopic submucosal dissection specimens revealed that the tumours did not meet the criteria for node-negative cancers. RESULTS: Twenty-three (74%) and eight (26%) patients had undergone endoscopic submucosal dissection previously due to clinical diagnoses of node-negative cancers and possible node-positive cancers, respectively. Histology of the resected stomachs and lymph nodes revealed residual carcinoma of the stomach in two (6.5%) patients and nodal metastases in four (13%) patients. All patients remain alive without recurrence (median follow-up, 3.4 years; range, 0.6-5.2 years). CONCLUSIONS: Based on the histology of endoscopic submucosal dissection specimens, preceding endoscopic submucosal dissection itself had no negative influence on a patient's prognosis when additional gastrectomy was performed. It may be permissible to resect some early gastric cancers by endoscopic submucosal dissection as a first step to prevent unnecessary gastrectomy, if technically resectable.

Ex vivo pilot study using computed analysis of endo-cytoscopic images to differentiate normal and malignant squamous cell epithelia in the oesophagus.

BACKGROUND AND STUDY AIMS: An endo-cytoscopy system allows acquisition of optical biopsies that are quite similar to conventional histology. To simplify discrimination between normal and malignant tissue in the oesophagus using endo-cytoscopy system, we analysed the nuclear (dark staining) area in the obtained images with the goal of an accurate, automatic diagnosis. PATIENTS AND METHODS: Ex vivo endo-cytoscopic observation was performed using endoscopically or surgically resected oesophagus from 10 enrolled patients. Oesophageal tissues were stained using 1% methylene blue, and endo-cytoscopic images were obtained at normal and malignant areas (two areas of each) in each oesophagus. The centre of each image (4x10(-2) mm(2)) was processed by computer, and the area occupied by the total nuclei in each selected field and its ratio to the entire field were calculated. RESULTS: The mean area of the total nuclei was 0.10x10(-2)+/-0.03x10(-2) mm(2) (range 0.05x10(-2) to 0.18x10(-2) mm(2)) in the normal group and 0.40x10(-2)+/-0.06x10(-2) mm(2) (range 0.33x10(-2) to 0.55x10(-2) mm(2)) in the malignant group (P<0.001). The mean ratio of total nuclei to the entire selected field was 6.4+/-1.9% (range 3.1-11.3%) in the normal tissues and 25.3+/-3.8% (range 20.5-34.5%) in the malignant samples (P<0.001). CONCLUSIONS: Endo-cytoscopy system allowed automatic differentiation of normal and malignant tissues in the oesophagus, which could simplify endo-cytoscopic diagnosis. Further study will elucidate whether such analysis is applicable to inflammatory or pre-malignant epithelia in the oesophagus or other gastrointestinal organs.

Endoscopic submucosal dissection of stomach neoplasms after unsuccessful endoscopic resection.

BACKGROUND: Endoscopic submucosal dissection is a novel endoluminal endoscopic surgery that enables resection of pre-malignant and early-stage malignant gastrointestinal neoplasms in an en bloc fashion. AIM: To assess the feasibility of endoscopic submucosal dissection of stomach neoplasms with submucosal fibrosis caused by unsuccessful endoscopic resection. PATIENTS AND METHODS: Stomach endoscopic submucosal dissection was performed in ten consecutive patients who had unsuccessful endoscopic tumour resection at another hospital between 2003 and 2006. Seven patients had recurrent tumours after complete endoscopic resection, and three patients had incomplete resections due to complications or technical difficulties. Technical feasibility and follow-up data were collected from the patients' reports. RESULTS: All tumours were resected by endoscopic submucosal dissection in one piece without complications. R0 resection (en bloc resection with tumour-free margins) was achieved in nine patients (90%). One patient received additional surgery (gastrectomy) because of submucosal deep invasion with vascular infiltration of the cancer. All patients, including the patient with gastrectomy, have survived without recurrence during a mean follow-up period of 21.4 months (range 3-36 months). CONCLUSIONS: Endoscopic submucosal dissection is an effective and safe method for resection of stomach neoplasms after unsuccessful endoscopic resection.

[Morphological changes of platelets in disturbed cerebral microcirculation--a clinical study using a scanning electron microscope (author's transl)].

Many factors are known that contribute to the pathogenesis of the cerebral microcirculatory disturbances, but, there are few reports investigating the roles of the intravascular components directly. The present study was undertaken to evaluate morphological changes of platelets in patients with cerebral damage, in relation to neurological signs, especially consciousness levels. Morphological changes of platelets were observed in 72 patients with intracranial organic lesions. These lesions included subarachnoid hemorrhages, hypertensive cerebral hemorrhages, cerebral infarctions, brain tumors, chronic subdural hematomas, and acute epidural hematomas. Two blood samples were taken, one from the internal jugular vein (the blood after cerebral perfusion), the other from the cubital vein (systemic blood). After fixative procedures with 1% glutaraldehyde, the differences in the three-dimensional structures of platelets were compared, using a scanning electron microscope. In general, remarkably activated forms of platelets were found in the blood after cerebral perfusion in cases with severely impaired consciousness in the acute stage. But, in cases without severe neurological deficits, such changes of platelet forms were rarely seen. A close relationship was suggested between the degree of neurological damage (especially consciousness levels) and that of platelet activation in the acute stage. In the chronic stage, these changes of platelets in the cerebral blood disappeared. Changes of platelet forms were not found in the systemic blood from the cubital vein, even in the acute stage. It is clinically suggested that morphological changes of platelets play an important role in the pathogenesis of the disturbed cerebral microcirculation. Obstruction of cerebral microvasculature may be caused, mechanically by the activated platelets themselves, and/or chemically by vasoconstrictive substances released from these platelets. Therefore, in the treatment of these intracranial organic lesions, it is concluded that the possible roles of activated platelets should be taken into consideration.