Tsutomu Ishikawa

Iatrogenic perforation associated with therapeutic colonoscopy: A multicenter study in Japan

Background and Aim:  Colonic perforation is the serious accidental complication. The aim of this study is to analyze the clinical presentation and management of recent iatrogenic perforations during therapeutic colonoscopy.

Matched case‐control study comparing endoscopic submucosal dissection and endoscopic mucosal resection for colorectal tumors

Background and Aim:  For large colorectal tumors, the en bloc resection rate achieved by endoscopic mucosal resection (EMR) is insufficient, and this leads to a high rate of local recurrence. As endoscopic submucosal dissection (ESD) has been reported to achieve a higher rate of en bloc resection and a lower rate of local recurrence in the short‐term, it is expected to overcome the limitations of EMR. We conducted a matched case‐control study between ESD and EMR to clarify the effectiveness of ESD for colorectal tumors.

Tumor staging of advanced esophageal cancer: combination of double-contrast esophagography and contrast-enhanced CT.

OBJECTIVE The objective of this study was to compare the diagnostic accuracy of tumor staging in patients with advanced esophageal cancer based on contrast-enhanced CT findings alone with that based on a combination of CT and double-contrast esophagography and to evaluate the relevance of tumor stage to survival rate. MATERIALS AND METHODS In 94 patients who underwent surgery as the primary treatment for esophageal cancer and had a diagnosis of postoperative T stage 3 (pT3) or pT4 disease based on pathologic examination, T stage was evaluated using CT alone and using a combination of CT and double-contrast esophagography. The diagnostic criterion for T4 disease using CT alone was tumor strongly displacing or deforming adjacent organs. The diagnostic criterion for T4 disease using the combined method was tumor displacing or deforming adjacent organs in the direction that corresponded to the direction of the location of the tumor or the deepest ulcer as diagnosed by barium esophagography. Concordance of T staging based on imaging with postoperative T staging based on pathology results, the gold standard, and survival rate were assessed for CT alone and for the combined method. RESULTS The concordance rate with postoperative T staging pathology results was 78% for CT alone and 84% for CT and double-contrast esophagography combined, with a significant difference between the two diagnostic methods. For patients with a diagnosis of T3 and those with a diagnosis of T4 using CT alone, the 3-year survival rate was 42% and 26%, respectively, with no significant difference between the two. For patients with a diagnosis of T3 and those with a diagnosis of T4 using the combined method, the 3-year survival rate was 42% and 21%, respectively, with a significant difference between the two. CONCLUSION The diagnostic performance of contrast-enhanced CT and double-contrast esophagography combined in staging advanced esophageal tumors is better than that of CT alone and thus has potential for estimating prognosis.

A solitary colonic metastasis from gastric cancer detected at an early stage.

1. Liang KV, Sanderson SO, Nowakowski GS, et al. Metastatic malignant melanoma of the gastrointestinal tract. Mayo Clin Proc 2006;81:511-6. 2. Malladi V, Palanivelu C, Mathew S, et al. Malignant melanoma metastatic to the stomach and duodenum. Indian J Gastroenterol 2005;24:133. 3. Telerman A, Gerard B, van den Heule B, et al. Gastrointestinal metastasis from extraabdominal tumor. Endoscopy 1985;17:99-101. 4. Oda HK, Yamao TS, Ono HG, et al. Metastatic tumors to the stomach: analysis of 54 patients diagnosed at endoscopy and 347 autopsy cases. Endoscopy 2001;33:507-10. 5. Marin M, Vlad L, Grigorescu M, et al. Metastasis of malignant melanoma in the small intestine: a case report. Rom J Gastroenterol 2002;11: 53-6. 6. Michelassi F. Experience with 647 consecutive tumors of the duodenum, ampulla, head of the pancreas and distal common bile duct. Ann Surg 1989;210:554-6. 7. Geboes K, de Jaeger E, Rutgeerts P, et al. Symptomatic gastrointestinal metastases from malignant melanoma: a clinical study. J Clin Gastroenterol 1988;10:64-70. 8. Delmonte JS, Gay GJ, Houcke PH, et al. Intraoperative endoscopy. Gastrointest Endosc Clin N Am 1999;9:61-9. 9. Blake MA, Owens A, O’Donoghue DP, et al. Embolotherapy for massive upper gastrointestinal haemorrhage secondary to metastatic renal carcinoma: report of three cases. Gut 1995;37:835-7.

Development of a high-definition real-time digital radiography system using a 4-million-pixel CCD camera

In order to improve image quality of a high definition real- time I.I-DR system, we have developed an evaluation system using a 4M-CCD camera modifying a conventional system using a pick-up tube camera. An analysis of the conventional system shows that the image quality of total system is expected to be improved by changing camera. Basing on the analysis, we select a FFT type 4M-CCD camera for our purpose. From comparative evaluations of the 4M-CD DR system and the conventional system, the following results are obtained: (1) the image quality of high definition real-time DR is effectively improved by changing a conventional pick- up tube camera to a 4M-CCD camera; (2) the image quality of improved system is almost equal to that of S-F system, in case that the FOV of I.I is in 9 inch mode, which is most usual in GI-tract examination.

Narrow Duplicated Internal Auditory Canal: A Rare Inner Ear Malformation With Sensorineural Hearing Loss

Anarrow duplicated internal auditory canal (IAC) is a very rare congenital inner ear malformation, with only 5 cases (to our knowledge) reported in the literature. 1-5 A 14-year-old girl with unilateral sensorineural hearing loss (SNHL) showed 2 narrow 1 mm) bony canals in the inner ear portion of the left temporal bone on computed tomograms (CTs). The anterior canal continued to the bony canal of the facial nerve, and the posterior canal continued to the cochlea. Other than a lack of development of the canal for the cochlear nerve, the cochlea was normal. High-resolution magnetic resonance images (MRIs) revealed a single thin cranial nerve located in the anterior canal. However, a cranial nerve was not found in the posterior canal. Therefore, a diagnosis of a unilateral narrow duplicated IAC with a hypoplastic vestibulocochlear nerve and vestibular-semicircular canal malformation was made. Computed tomography plays an important role in the evaluation of the bony structure; however, assessment of the neural contents on MRIs is important for the appropriate diagnosis and treatment of patients with a narrow duplicated IAC. We report a case of a unilateral narrow duplicated IAC, with a particular emphasis on the imaging findings of thin-slice high-resolution CTs and MRIs.

Synchronous colitic cancers and microcarcinoids in a patient with long-standing and extensive ulcerative colitis: a case report and review of the literature.

We report a case of colitic cancer detected by target biopsies at surveillance colonoscopy in a patient with long-standing and extensive ulcerative colitis. At first, the detected colitic cancer was removed by endoscopic mucosal resection as the patient refused surgical resection. However, total proctocolectomy with an ileal-J-pouch anal anastomosis was performed additionally after informed consent had been obtained from the patient, as the resected specimen included invasive cancer histologically. Surprisingly, histologic examination of the surgical specimens revealed another flat invasive colitic cancer and 2 microcarcinoids, which were not detectable by preoperative colonoscopy or by macroscopic investigation of the surgically resected specimen. The occurrence of carcinoid in patients with ulcerative colitis has been reported only sporadically. In addition, coexistence of colitic cancer and carcinoids is extremely rare. Cases of this rare combination reported previously in the English literature are summarized and discussed.