Risk of lymph node metastasis after endoscopic treatment for rectal NETs 10 mm or less

PURPOSE

For rectal neuroendocrine tumors (NETs) ≤ 10 mm, endoscopic resection is a standard treatment. However, there is no consensus whether additional surgery should be performed for patients at risk of lymph node metastasis (LNM) after endoscopic resection. The purpose of this study was to analyze the results of endoscopic resection and additional surgery of rectal NETs, thereby clarify the characteristics of cases with LNM.

METHODS

This study was a multicenter retrospective cohort study conducted at 12 Japanese institutions. A total of 132 NETs ≤ 10 mm were analyzed regarding various therapeutic results. A comparative analysis was performed by dividing the cases into two groups that underwent additional surgery or not. Furthermore, the relationship between tumor size and LNM was examined.

RESULTS

The endoscopic treatments were 12 endoscopic mucosal resections (EMR), 58 endoscopic submucosal resections with ligation (ESMR-L), 29 precutting EMRs, and 33 endoscopic submucosal dissections (ESD). The R0 resection rates of EMR were 41.7%, and compared to this rate, other three treatments were 86.2% (p < 0.001), 86.2% (p = 0.005), and 97.0% (p < 0.001), respectively. There were 41 non-curative cases (31.1%), and 13 had undergone additional surgery. Then, LNM was observed in 4 of the 13 patients, with an overall rate of LNM of 3.0% (4/132). The rate of positive lymphatic invasion and the rate of LNM by tumor size ≤ 6 mm and 7-10 mm were 9.7 vs. 15.4% (p = 0.375) and 0 vs. 10.3% (p = 0.007).

CONCLUSIONS

A multicenter study revealed the priority of each endoscopic resection and the low rate of LNM for rectal NETs ≤ 6 mm.

Fatal gastrointestinal bleeding due to IgA vasculitis complicated with tuberculous lymphadenitis: A case report and literature review

We report a case of IgA vasculitis that developed during the treatment of tuberculosis. Patients with tuberculosis who are on antituberculosis treatment can be administered steroids for severe disease or complications.

High incidence of metachronous advanced adenoma and cancer after endoscopic resection of colon polyps ≥20 mm in size

BACKGROUND AND AIM

There are limited studies on incidence rates of metachronous neoplastic lesions after resecting large colorectal polyps. In the present study, we analyzed metachronous lesions after endoscopic resection of colorectal polyps ≥20 mm in size.

METHODS

We retrospectively analyzed consecutive patients who underwent endoscopic resection of polyps from 2006 to 2013 at two affiliated hospitals. All patients underwent at least two total colonoscopies before follow up to ensure minimal missed polyps. Only patients who had follow-up colonoscopy annually after resection were recruited. We separated patients according to size of polyp resected; there were 239 patients in the ≥20-mm group and 330 patients in the <20-mm group. Clinical characteristics and cumulative rates of metachronous advanced adenoma and cancer in both groups were analyzed. Advanced adenoma was defined as a neoplastic lesion ≥10 mm in size and adenoma with a villous component.

RESULTS

Cumulative rate of development of metachronous advanced adenoma and cancer in the ≥20-mm group was significantly higher than in the <20-mm group (22.9% vs. 9.5%, P < 0.001) at 36 months. There was also more development of small polyps 5-9 mm in the ≥20-mm group than in the <20-mm group (45.2% vs. 28.8%, P < 0.001). With respect to metachronous lesions, there were more right-sided colonic lesions in the ≥20-mm group than in the <20-mm group (78.8% vs. 50.0%, P = 0.015).

CONCLUSION

High incidence rates of development of metachronous neoplastic lesions were detected after resection of colorectal polyps ≥20 mm in size.

Ability of a novel blue laser imaging system for the diagnosis of colorectal polyps

BACKGROUND

A new endoscope system with a laser light source, blue laser imaging (BLI), has been developed by Fujifilm that allows for narrow-band light observation. The aim of the present study was to evaluate the utility of BLI for the diagnosis of colorectal polyps.

METHODS

We retrospectively analyzed 314 colorectal polyps that were examined with BLI observation at Kyoto Prefectural University of Medicine between September 2011 and January 2013. The surface and vascular patterns of polyps detected by published narrow-band imaging magnification: Hiroshima classification were used. Correlations were determined between the classifications and the histopathological diagnoses. Additionally, the ability of BLI without magnification to differentiate between neoplastic or non-neoplastic polyps was analyzed.

RESULTS

A total of 41 hyperplastic polyps, 168 adenomas, 80 intramucosal cancer, 11 shallowly invaded submucosal cancer, and 14 deeply invaded submucosal cancer were analyzed.Hyperplastic polyp was observed in 100% of Type A lesions (39 lesions), adenoma was observed in 89.3% of Type B lesions (159 lesions), intramucosal cancer and shallowly invaded submucosal cancer was observed in 69.6% of Type C1 (92 lesions) and in 84.6% of Type C2 (13 lesions), and deeply invaded submucosal cancer was observed in 81.8% of Type C3 lesions (11 lesions). The overall diagnostic accuracy of BLI with magnification was 84.3%. Additionally, the diagnostic accuracy of BLI without magnification for differentiating between neoplastic and non-neoplastic polyps <10 mm in diameter was 95.2%, which was greater than that of white light (83.2%).

CONCLUSION

BLI was useful for the diagnosis of colorectal polyps.

MDR1 is related to intestinal epithelial injury induced by acetylsalicylic acid

BACKGROUND/AIMS

Although the cytotoxicity of aspirin against the intestinal epithelium is a major clinical problem, little is known about its pathogenesis. We assessed the involvement of Multi Drug Resistance (MDR) 1 in intestinal epithelial cell injury caused by aspirin using MDR1 gene-transfected Caco2 cells.

METHODS

Caco2 cells were treated with various concentrations of aspirin for 24 h. After treatment of Caco2 cells with verapamil, a specific inhibitor of MDR1, we assessed the extent of cell injury using a WST-8 assay at 24 h after aspirin-stimulation. We performed the same procedure in MDR1 gene-transfected Caco2 cells. To determine the function of MDR1 in the metabolism of aspirin, flux study was performed using (14)C-labeled aspirin.

RESULTS

The level of aspirin-induced cell injury was higher in verapamil-treated Caco2 cells than in control cells and was less serious in MDR1-transfected Caco2 cells than in control vector-transfected cells. The efflux of (14)C-labeled aspirin was higher in verapamil-treated Caco2 cells than in control cells.

CONCLUSION

These data suggest that aspirin effux occurs through the MDR1 transporter and that the MDR1 transporter is involved in the pathogenesis of aspirin-induced cell injury.

Multicenter study of endoscopic mucosal resection using 0.13% hyaluronic acid solution of colorectal polyps less than 20 mm in size

PURPOSE

Endoscopic mucosal resection (EMR) of colorectal polyps should be curative and safe. This study aimed to determine the efficacy and safety of colorectal EMR using 0.13% hyaluronic acid (HA) solution.

METHODS

This was a single-armed multicenter prospective open trial conducted at 11 Japanese institutions. Lesion characteristics and various measures of clinical outcome, including en bloc resection, histopathologically complete resection, and postoperative bleeding were analyzed for 624 consecutive patients who underwent EMR of colorectal polyps at ≤20 mm in size from August 2010 to September 2011.

RESULTS

En bloc and complete resection were achieved in 93.3 and 78.3% of 624 lesions. The median EMR procedure time was 2.1 ± 1.5 min. The rates of postoperative bleeding and perforation were 1.1 and 0%. The rate of en bloc resection was higher for polyps at 5-10 mm than for polyps at 11-20 mm (95.1 vs. 85.1%; P < 0.001) and was higher for protruding polyps than for superficial polyps (94.5 vs. 87.1%; P < 0.05). The rate of en bloc resection was also higher for polyps in the left-side colon than for those in the right-side colon or rectum (96.7 vs. 91.6 vs. 90.8%; P < 0.05). Multivariate analysis showed that polyp at 11-20 mm in size and location not on the left-side colon was significantly independent risk factors for failure of en bloc resection.

CONCLUSION

EMR using 0.13% HA of colorectal polyps less than 20 mm in size had high rates of en bloc and complete resection and few complications.

Hemin ameliorates indomethacin-induced small intestinal injury in mice through the induction of heme oxygenase-1

BACKGROUND AND AIM

Although non-steroidal anti-inflammatory drugs can induce intestinal injury, the mechanisms are not fully understood, and treatment has yet to be established. Heme oxygenase-1 (HO-1) has recently gained attention for anti-inflammatory and cytoprotective effects. This study aimed to investigate the effects of hemin, an HO-1 inducer, on indomethacin-induced enteritis in mice.

METHODS

Enteritis was induced by single subcutaneous administration of indomethacin (10 mg/kg) in male C57BL/6 mice. Hemin (30 mg/kg) was administered by intraperitoneal administration 6 h before indomethacin administration. Mice were randomly divided into four groups: (i) sham + vehicle; (ii) sham + hemin; (iii) indomethacin + vehicle; or (iv) indomethacin + hemin. Enteritis was evaluated by measuring ulcerative lesions. Myeloperoxidase activity was measured as an index of neutrophil accumulation. The mRNA expression of inflammatory cytokines and chemokines, such as tumor necrosis factor-α, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, and keratinocyte chemoattractant, were analyzed by real-time polymerase chain reaction.

RESULTS

The area of ulcerative lesions, myeloperoxidase activity, and mRNA expression of inflammatory cytokines and chemokines were significantly increased in mice administrated with indomethacin compared with vehicle-treated sham mice. Development of intestinal lesions, increased levels of myeloperoxidase activities, and mRNA expressions of inflammatory cytokines and chemokines were significantly suppressed in mice treated with hemin compared with vehicle-treated mice. Protective effects of hemin were reversed by co-administration of tin protoporphyrin, an HO-1 inhibitor.

CONCLUSIONS

Induction of HO-1 by hemin inhibits indomethacin-induced intestinal injury through upregulation of HO-1. Pharmacological induction of HO-1 may offer a novel therapeutic strategy to prevent indomethacin-induced small intestinal injury.

Acetyl salicylic acid induces damage to intestinal epithelial cells by oxidation-related modifications of ZO-1

Acetyl salicylic acid (ASA) is one of the most frequently prescribed medications for the secondary prevention of cardiovascular and cerebrovascular events. It has recently been reported to cause small intestinal mucosal injury at a considerably higher rate than previously believed. The aim of this study is to investigate the mechanism by which this occurs using an in vitro small intestine model focusing on the role of oxidative stress and cell permeability. Differentiated Caco-2 exhibits a phenotype similar to human small intestinal epithelium. We measured whether ASA induced the increase of differentiated Caco-2 permeability, the decrease of tight junction protein expression, the production of reactive oxygen species (ROS), and the expression of ROS-modified zonula occludens-1 (ZO-1) protein. In some experiments, Mn(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP, a superoxide dismutase mimetic) was used. The nontoxic concentration of ASA decreased transepithelial electrical resistance and increased the flux of fluorescein isothiocyanate-conjugated dextran across Caco-2 in a time-dependent manner. The same concentration of ASA significantly decreased ZO-1 expression among TJ proteins as assessed by Western blot and immunocytochemistry and increased ROS production and the expression of oxidative stress-modified ZO-1 protein. However, MnTMPyP suppressed the ASA-induced increased intercellular permeability and the ASA-induced ROS-modified ZO-1 expression. Our findings indicate that ASA-induced ROS production can specifically modify the expression of ZO-1 protein and induce increased cell permeability, which may ultimately cause small intestinal mucosal injury.

Endoscopic mucosal resection with 0.13% hyaluronic acid solution for colorectal polyps less than 20 mm: a randomized controlled trial

BACKGROUND AND AIM

Adequate mucosal elevation by submucosal injection is important for definitive en bloc resection and prevention of perforation during endoscopic mucosal resection (EMR). The objective of this study is to determine the efficacy of 0.13% hyaluronic acid (HA) solution for high and sustained mucosal elevation during colorectal EMR.

METHODS

The study was a prospective randomized controlled trial; a total of 196 patients with colon polyps of < 20 mm diameter were enrolled and randomized in a 1:1 ratio to undergo EMR using either 0.13% HA or normal saline (NS). The primary outcome of the study was histopathologically confirmed complete resection. The secondary outcomes such as maintenance of high mucosal elevation and development of complications were also evaluated. Moreover, the relationship between complete resection and the experience of the endoscopist (veteran vs less experienced) was analyzed.

RESULTS

Compete resection was achieved in 74 of 93 polyps (79.5%) in the 0.13% HA group and 63 of 96 polyps (65.6%) in the NS group (P < 0.05). High mucosal elevation was maintained in 83.9% of procedures in the 0.13% HA group and 54.1% in the NS group (P < 0.01). The frequency of complete resection achieved by less-experienced endoscopists was higher in the 0.13% HA group (79.3%) than in the NS group (62.1%; P < 0.05).

CONCLUSIONS

Endoscopic mucosal resection using 0.13% HA to colon polyps of less than 20 mm diameter is more effective than NS for complete resection and maintenance of mucosal elevation.

The detection of surface patterns by flexible spectral imaging color enhancement without magnification for diagnosis of colorectal polyps

PURPOSE

Flexible spectral imaging color enhancement (FICE), or image-enhanced endoscopy, can enhance visualization of surface and vascular patterns of colorectal polyps. Resolution of FICE has recently been improved. We evaluated diagnostic accuracy for neoplastic and non-neoplastic colorectal polyp differentiation with detection of surface patterns by FICE without magnification.

METHODS

Retrospective analysis of 151 colorectal polyps evaluated by FICE without magnification was performed. Neoplastic surface patterns were defined as tubular and oval pit. We aimed to determine sensitivity, specificity, positive and negative predictive values (PPV and NPV), and accuracy in correlating diagnosis by FICE without magnification with histology. Moreover, findings were compared to those of white-light endoscopy (WL) and chromoendoscopy (CHR).

RESULTS

Of the 151 colorectal polyps, 95 were identified as neoplastic and 56 were identified as non-neoplastic. FICE without magnification had a sensitivity of 89.4%, specificity of 89.2%, PPV of 93.4%, NPV of 83.3%, and accuracy of 89.4%. The accuracy of FICE value was higher than that of WL (sensitivity of 74.7%, specificity of 73.2%, PPV of 82.5%, NPV of 63.0%, and accuracy of 74.1%) and was worse than that of CHR (sensitivity of 96.8%, specificity of 89.2%, PPV of 93.9%, NPV of 96.1%, and accuracy of 94.7%). Imaging evaluation was validated by inter-/intra-observer measurements, demonstrating consistent results.

CONCLUSIONS

The detection of surface patterns by FICE without magnification is useful for differential diagnosis of colorectal polyps. We believe that FICE without magnification is more convenient and easier method than CHR.

Efficacy of hyaluronic acid in endoscopic mucosal resection of colorectal tumors

BACKGROUND AND AIM

Endoscopic mucosal resection (EMR) is the standard procedure for colorectal tumors. High mucosal elevation by submucosal injection is important for definite en bloc resection and the prevention of perforation. Hyaluronic acid (HA) is a reportedly useful injection solution for high and long-lasting mucosal elevation, but the ideal HA concentration for optimization of mucosal elevation maintenance, injection pressure, and cost is unknown. In the present study, we assessed the appropriate concentration of HA for EMR.

METHODS

A resected porcine colon and esophagus were used. The injection solutions examined were 0.9% normal saline (NS) and four concentrations of an 800-KDa HA preparation (0.4%, 0.2%, 0.13%, and 0.1%). Each solution (2 mL) was injected into the submucosa; injection pressure was calculated, and elevation was measured. The durations of mucosal elevation and EMR were additionally assessed in the living minipig colon.

RESULTS

In the resected porcine colon, the mucosal elevation was measured 0, 2, 4, and 6 min after the submucosal injection. All concentrations of HA solution maintained greater mucosal elevation at all times than NS (P < 0.05). An almost similar result was obtained in the resected porcine esophagus. The injection pressure correlated with the HA concentration. In the living minipig colon, mucosal elevation diminished 2 min after the submucosal injection with NS, but was maintained 2 min after injection with 0.4%, 0.2%, and 0.13% HA. The average duration of EMR was 139 s.

CONCLUSIONS

Mucosal elevation by HA was greater than that by NS in resected and living animal models. We recommend 0.13% HA for maintaining mucosal elevation, injection pressure, and cost.

Efficacy of magnifying endoscopy with flexible spectral imaging color enhancement in the diagnosis of colorectal tumors

BACKGROUND

Magnifying endoscopy with flexible spectral imaging color enhancement (FICE) is an image-enhanced endoscopy that captures the surface and vascular patterns of colorectal tumors. We evaluated and compared FICE magnification to narrow-band imaging (NBI) magnification.

METHODS

Flexible spectral imaging color enhancement or NBI magnification was performed to the visualize surface and vascular patterns of colorectal tumors, classified into 4 types: Type A, Type B, Type C1/C2, and Type C3, as previously reported. A total of 235 colorectal tumors were examined. The correlations between classifications found by FICE or NBI magnification and histopathological diagnoses were examined. Image evaluation was validated by assessing inter-observer and intra-observer agreements on examinations.

RESULTS

Twenty-eight hyperplastic polyps (HPs), 115 tubular adenomas (TAs), 72 mucosal and slightly invaded submucosal cancers (M-sSM), and 20 massively invaded submucosal cancers (mSM) were diagnosed. By FICE magnification, HP and TA were observed in 93.3 and 6.7% of Type A (15 lesions), respectively. TA, M-sSM, and HP were observed in 82.6, 15.4, and 2.0% of Type B (52 lesions),respectively. M-sSM, TA, and mSM were observed in 50.0,46.0, and 4.0% of Type C1/2 (50 lesions), respectively.mSMs were observed in all 7 Type C3 lesions. In diagnosing mSM in Type C3, the sensitivity and specificity of FICE magnification were 77.7 and 100%, respectively, compared to those of NBI, at 63.6 and 99.0%, respectively. Imaging evaluation was validated accurately by intra- and intraobserver measurements showing consistent results.

CONCLUSIONS

The classification of colorectal tumors by FICE magnification correlated well with the histopathological diagnoses, similar to findings for NBI magnification. FICE magnification can be evaluated accurately with the same diagnostic classifications as those used for NBI magnification.

Efficient hemostatic method for endoscopic submucosal dissection of colorectal tumors

AIM: To evaluate a new hemostatic method using hemostatic forceps to prevent perforation and perioperative hemorrhage during colonic endoscopic submucosal dissection (ESD).

METHODS: We studied 250 cases, in which ESD for colorectal tumors was performed at the Kyoto Prefectural University of Medicine or Nara City Hospital between 2005 and 2010. We developed a new hemostatic method using hemostatic forceps in December 2008 for the efficient treatment of submucosal thick vessels. ESD was performed on 126 cases after adoption of the new method (the adopted group) and the new method was performed on 102 of these cases. ESD was performed on 124 cases before the adoption of the new method (the unadopted group). The details of the new method are as follows: firstly, a vessel was coagulated using the hemostatic forceps in the soft coagulation mode according to the standard procedure, and the coagulated vessel was removed using the forceps in the “endocut” mode without perioperative hemorrhage. Secondly, the partial surrounding submucosa was dissected using the forceps in the endocut mode. In the current study, we evaluated the efficacy of this method.

RESULTS: Coagulated vessels were successfully removed using the hemostatic forceps in all 102 cases without severe perioperative hemorrhage. Moderate perioperative hemorrhage occurred in five cases (4.9%); however, it was stopped by immediately reuse of the hemostatic forceps. The partial surrounding submucosa was dissected using the forceps in all 102 cases. In the adopted group, the median operation time was 105 min. The proportion of endoscopic en bloc resection was 92.8% (P < 0.01) compared to 80.6% in the unadopted group. The postoperative hemorrhage and perforation rates were 2.3% and 2.3%. The rate of perforation was significantly lower than that in the unadopted group (9.6%, P < 0.01). We evaluated the ease of use of this method by allowing our three trainees to performed ESD on 46 cases, which were accomplished without any severe hemorrhage.

CONCLUSION: The new method effectively treated submucosal thick vessels and shows promise for the prevention of perforation and perioperative hemorrhage in colonic ESD.

[A case of hypervascular hyperplastic nodule in chronic alcoholic liver disease with corona-like enhancement in the late phase image of CT during hepatic arteriography]

A 46-year-old woman was admitted to our hospital with hepatic encephalopathy due to alcoholic liver disease. A hepatic nodule (20 mm in diameter) in S7 was enhanced in the early phase of contrast CT. No significant findings were observed in the late phase of contrast CT and SPIO MRI. The late phase of CT during hepatic arteriography showed corona-like enhancement of the nodule. The nodule was diagnosed as a hypervascular hyperplastic nodule, based on histological examinations and immunohistochemical results with antibodies against CD68 and CD34.

Stenting for atherosclerotic stenosis of the intracranial or skull base cerebral arteries. Effectiveness and problems

SUMMARY

Since May 1992, we have performed percutaneous transluminal angioplasty (PTA) or stenting 70 times for 65 lesions in 62 patients with atherosclerotic stenosis of the intracranial or skull base cerebral arteries. Stenting was carried out nine times for nine lesions in nine cases. Stenting was performed on patients with an average age of 62. The patients were eight men and one woman. The stenotic lesions involved the internal carotid artery (petrous portion) in four cases, the internal carotid artery (cavernous portion) in two cases, the internal carotid artery (supraclinoid portion) in one case, the middle cerebral artery (M1) in one case, and the vertebral artery (V4) in one case. The degree of stenosis ranged from 70% to 99%, with a mean of 80%. A stent for coronary arteries was used in all cases. After PTA was carried out in four cases, their initial extension was inadequate, and dissection was performed in five cases after PTA. As for the results of the treatment, subarachnoid haemorrhage occurred in one case due to perforation by the guidewire, and a major deficit was accepted. During the operation, asymptomatic cerebral infarction by distal embolism occurred in one case. Although obstruction of the lesion occurred three months after treatment in one case, symptoms did not appear. Stents used for atherosclerotic stenosis of the intracranial or skull base cerebral arteries still do not have sufficient performance. Although the stenting had problems, such as a prolonged patent, in the present condition, it was effective in terms of recovery from complications due to PTA.

Education and propagation of intravascular surgery in okinawa

SUMMARY

Okinawa is an island located on the southwest edge of the Japanese Islands in which about 1,300,000 people live, and is an area where selfconclusion type medical treatment is desired. In this area, intravascular surgery was only performed for several cases per year until 1998. From May 1999, intravascular surgery started being performed in earnest, and 140 or more cases of intravascular surgery per year were performed in 2002. In the meantime, various measures for the propagation and development of intravascular surgery that we undertook led to the increase in the number of cases. As a result, the choice of medical treatment has increased by propagating these medical treatments, and it seems that this has contributed to the welfare of the people of Okinawa.

Microvascular anastomoses using an Nd-YAG laser

The authors performed anastomoses of small vessels with the Nd-YAG laser, comparing these with conventional suture anastomoses. Some arteries were sutured with 10-0 nylon with about eight suture sites, and others were held by stay sutures at three points with laser irradiation performed between them. Two surgeons performed the anastomoses in the same way. The first was well-trained and experienced, and the second was technically inexperienced. The authors evaluated clamping time, patency rate, and endoscopic and histologic findings. The patency rate of the first surgeon was 100 percent (30/30) in the suture anastomoses and was 97 percent (29/30) in the laser anastomoses. For the second surgeon, the rates were 60 percent (18/30) in the suture group and 80 percent (24/30) in the laser group. On histologic examination, the suture group showed inflammatory cells around the suture site at the fourth week after the operation. In the laser group, an inflammatory reaction around the suture material was observed, but the other areas recovered. For the experienced surgeon, the patency rate and clamping time of the laser anastomosis provided no statistically significant difference to those of the suture anastomosis. On the other hand, for the inexperienced surgeon, the patency rate of the laser anastomosis was superior to that of the suture anastomosis, and the clamping time of the laser anastomosis was shorter than that of the suture anastomosis. Therefore, the authors concluded that the Nd-YAG laser anastomosis is useful for small vessels.