遠藤 和洋

BACKGROUND: In natural orifice transluminal endoscopic surgery (NOTES), the endoscope has the disadvantages of an unstable visual field and wide blind space. We developed a compact charge-coupled device (CCD) camera unit that can be transgastrointestinally placed in the abdominal cavity. METHODS: The requisites for a wireless CCD camera unit for use in NOTES have been cited as: monitoring performance, fixation to the abdominal wall, attitude control, and antifogging functionality. Models to meet these requisites were prepared to assess their performance. The monitor had a CCD with dimensions of 7 x 7 x 7 mm and resolution of 410,000 pixels. The unit had a structure that allowed its attachment to the endoscope apex when placed to the abdominal wall. The abdominal wall fixation unit was equipped with a pantograph-type needle structure that was easily activated and retained by changing the polarity of an electromagnetic force. The pantograph-type needle head was designed to rotate by 360 degrees as an attitude-control mechanism, and both the pantograph and attitude-control mechanisms enabled attitude control in horizontal and vertical directions by a magnetic force applied from outside the body. Fogging was prevented by a vibration mechanism that physically cleaned the CCD lens surface and by titanium dioxide coating of the lens surface. RESULTS: The CCD camera unit was confirmed to have sufficient performance as an auxiliary monitor for endoscopy in terms of visual field and resolution. The pantograph-type needle structure successfully completed fixation of the CCD camera unit to the abdominal wall. Unit attitude was easily controlled, and fogging could be addressed by water supply before insertion of the CCD camera unit into the peritoneal cavity. CONCLUSIONS: The wireless CCD camera unit was verified to function as an effective second eye in NOTES by using the described mechanisms and antifogging coating.

CONTEXT: Although rare, a pancreatic arteriovenous malformation can have serious consequences. A diagnosis of arteriovenous malformation requires evidence of aberrant communication between the arterial and the venous systems. This report describes a case where the use of multi-detector row CT and specific post-processing methods provided a diagnosis of arteriovenous malformation. This minimally invasive diagnostic approach resulted in a clear, precise and comprehensive visual representation of the pancreatic arteriovenous malformation. CASE REPORT: A 60-year-old man with right hypochondriac pain presented with a mass in the head of the pancreas. The hypochondriac pain resolved spontaneously and physical examination revealed no abnormal findings. A multi-detector row CT study was performed. The data obtained in the arterial phase demonstrated a high-contrast mass in the head of the pancreas and early enhancement of the portal vein. A maximum intensity projection method clarified the aberrant vascular communication. Changes in Hounsfield numbers were observed using a multi-planar reformation method. A volume-rendering method was used to create a 3D model which demonstrated the spatial relationship between the aberrant vascular communication and the surrounding tissue. An annual follow-up study using this technique showed no significant alteration. CONCLUSIONS: Multi-detector row CT with specific post-processing methods is a useful diagnostic tool for pancreatic arteriovenous malformation.

BACKGROUND/PURPOSE: We tried to determine whether the customization of an X-TRACT Tissue Morcellator could avoid the laceration-induced distension of surgical incisions/openings when transintestinally removing resected liver tissue from the body, when the greatest dimension of the tissue exceeded the dimension of the opening. METHODS: Pigs were used to examine changes in the caliber and shape of surgical incisions made with a conventional hook knife and insulation-tipped diathermic (IT) knife for electrodissection in endoscopy, and to examine changes in circular incision made with a customized X-TRACT Tissue Morcellator. The ENDO CATCH II device was used to remove tissue. RESULTS: Laceration occurred in the "roundness-lost portion" of the surgical incisions made with the hook knife, thus confirming the greatest dimension of the distended incisions and the occurrence of an irregular laceration. In the circular incision that were made with the customized X-TRACT Tissue Morcellator, by contrast, the removal of resected liver tissue whose greatest dimension was fivefold greater than that of the surgical openings did not increase the caliber of the openings. The shape of the openings remained round, and no laceration was observed. CONCLUSIONS: The use of the customized X-TRACT Tissue Morcellator with an electrifiable round cutter allowed the performance of transintestinal hepatectomy and the removal of a solid organ through surgical openings that had been made in the gastrointestinal wall.

PURPOSE: This study was designed to estimate the accuracy of CT colonography for the assessment of T stage in colorectal cancer. METHODS: CT colonograms obtained from 246 lesions were reviewed by 3 investigators. Intestinal wall deformity on shaded-surface display and rough appearance around the intestine were studied to assess their relations to T stage. Intestinal wall deformity was classified into arc type, trapezoid type, and apple-core type, defined as a trapezoidal wall deformity involving > or = 50 percent of the circumference of the lumen. RESULTS: As for intestinal wall deformity, the rate of arc type was higher in Tis/T1 than in T2 (74 percent: 17/23 vs. 24 percent: 8/34, P < 0.0001); the rate of trapezoid type was 17 percent (4/23) in Tis/T1, 59 percent (20/34) in T2, and 15 percent (28/189) in T3/T4 (Tis/T1 vs.T2, P < 0.0001; T2 vs. T3/T4, P < 0.0001); and the rate of apple-core type was lower in T2 than in T3/T4 (18 percent: 6/34 vs. 81 percent: 154/189, P < 0.0001). Arc type, trapezoid type, and apple-core type were primarily associated with T1, T2, and T3/T4, respectively. When these criteria were used, the overall accuracy for T stage was 79 percent. Rough appearance was specific for T3/T4, but insensitive. CONCLUSIONS: CT colonography can provide important information for the preoperative assessment of T stage in colorectal cancer.

CONTEXT: Primary pancreatic lymphoma is a rare form of extranodal lymphoma originating in the pancreas. The present report describes a case of follicular lymphoma of the pancreas with unique CT and MRI findings. CASE REPORT: A 58-year-old male complained of sudden abdominal pain, and routine ultrasonography detected an 8 cm hypoechoic tumor in the head of the pancreas. The 3D image generated using multi-cholangiography and virtual duodenography provided the information necessary for a laparotomy. The tumor was enucleated for diagnosis. Follicular lymphoma is quite rare in the pancreas and gastrointestinal tract. A considerable number of pancreatic lymphoma subtypes have been reported. The expression "pancreatic lymphoma" has been used to describe both primary lymphoid neoplasms originating in the pancreatic parenchyma and tumors invading from a peri-pancreatic lymphadenopathy. The present case belongs to the latter, which might explain the unique imaging findings and histological type. These subtypes display different imaging findings and different clinical characteristics. In the future, primary pancreatic lymphoma should be discussed separately depending on the subtype. CONCLUSION: We propose a new subtype of primary pancreatic lymphoma. Multi-cholangiography and virtual duodenography provided the information necessary for a laparotomy in the present case. Enucleation is indicated for benign and low-grade malignant tumors of the pancreas, even if the tumor is located in the head of the pancreas.