Tsutomu Sakamoto

Isolated dissection of the superior mesenteric artery

Abstract Dissection of the superior mesenteric artery (SMA) not associated with aortic dissection is rare. The purpose of this study is to describe the computed tomographic (CT) findings of this condition. We studied the CT findings of six patients with isolated dissection of the SMA. CT demonstrated thrombosis of the false lumen or intramural hematoma (n = 4) and/or intimal flap (n = 4) in all six patients. Other CT findings were enlarged diameter of the SMA (n = 5), increased attenuation of the fat around the SMA (n = 5), and hematoma in the mesentery with hemorrhagic ascites (n = 1). CT is useful for the diagnosis of isolated dissection of the SMA, and increased attenuation of the fat around the artery is considered the key to the diagnosis when no definite findings are evident.

Gastrointestinal tract perforation: CT diagnosis of presence, site, and cause

Gastrointestinal tract perforation is an emergent condition that requires prompt surgery. Diagnosis largely depends on imaging examinations, and correct diagnosis of the presence, level, and cause of perforation is essential for appropriate management and surgical planning. Plain radiography remains the first imaging study and may be followed by intraluminal contrast examination; however, the high clinical efficacy of computed tomographic examination in this field has been well recognized. The advent of spiral and multidetector-row computed tomographic scanners has enabled examination of the entire abdomen in a single breath-hold by using thin-slice sections that allow precise assessment of pathology in the alimentary tract. Extraluminal air that is too small to be detected by conventional radiography can be demonstrated by computed tomography. Indirect findings of bowel perforation such as phlegmon, abscess, peritoneal fluid, or an extraluminal foreign body can also be demonstrated. Gastrointestinal mural pathology and associated adjacent inflammation are precisely assessed with thin-section images and multiplanar reformations that aid in the assessment of the site and cause of perforation.

Differentiation of Femoral Versus Inguinal Hernia: CT Findings

OBJECTIVE The purpose of our study was to investigate the CT findings of femoral hernias, focusing on their differentiation from inguinal hernias. MATERIALS AND METHODS We reviewed the records of 46 femoral hernias in seven centers (review of femoral hernias) and those of 215 groin hernias (femoral hernias, 11; inguinal hernias, 204) in one center (review of groin hernias). We evaluated the presence of hernia, extent of hernia sac based on the relationship between the hernia sac and the pubic tubercle (localized sac: sac was localized lateral to the pubic tubercle; or extended sac: sac extended medial to the pubic tubercle), and compression of the femoral vein on CT images. The chi-square test was used to assess the relationship between the CT findings and femoral versus inguinal hernias in the review of groin hernias. RESULTS In the review of 46 femoral hernias, the lesions were detected on CT in 45. In the 45 lesions, all hernia sacs were localized, and 42 lesions showed venous compression. In the review of 215 groin hernias, all 11 femoral hernias had localized sacs with venous compression on CT. Of the 204 inguinal hernias, 98 lesions were detected on CT, 65 had extended sacs, and only 10 showed venous compression. Localized sacs with venous compression were seen much more often in the femoral hernias (11/11, 100%) than in the inguinal hernias (1/92, 1.1%) (p < 0.0001). CONCLUSION CT images are useful to differentiate femoral hernias from inguinal hernias.

Endoscopic transanal decompression with a drainage tube for acute colonic obstruction

PURPOSE: The study was undertaken to evaluate the clinical usefulness of endoscopic transanal decompression with a newly developed drainage tube for the treatment of acute colonic obstruction. METHODS: Thirty-six patients ranging in age from 46 to 87 years (average age = 69 years) with acute colorectal obstruction secondary to carcinoma were treated by means of intubation with a flexible drainage tube using combined endoscopic and fluoroscopic guidance. After tube placement, the obstructed colon was aspirated, decompressed, and cleaned with a 50 ml syringe and saline solution. The drainage tube was kept inserted and the colon was irrigated two or three times per day using 500 to 1,000 ml of saline until there were no contents in the colon. The colon was almost empty at the time of operation. The success rate, benefits, and complications of this technique were evaluated. RESULTS: Placement of the drainage tube was successful in 34 (94.4 percent) of 36 patients. Immediately after aspiration and decompression, symptoms related to obstruction were relieved in 21 patients (61.8 percent), within one hour in 9 patients (26.5 percent) and within four hours in 4 patients (11.8 percent). All 34 patients had elective single-stage surgery without severe complications at the anastomotic site such as anastomotic leakage and postanastomotic stenosis that needed treatment a few days after placement of the drainage tube. In the two cases of unsuccessful placement of the drainage tube, emergent colostomy was performed. CONCLUSION: Decompression with a transanal drainage tube is an easy and safe technique to relieve colonic obstruction effectively without any excess burden to patients. Because the procedure permits single-stage surgery in most cases, it is also cost effective.

An initial clinical study on the efficacy of cisplatin-releasing gelatin microspheres for metastatic liver tumors

PURPOSE To evaluate the antitumor effect and side effects of cisplatin-releasing gelatin microspheres (Cis-GMSs) for metastatic liver tumors. METHODS Cis-GMSs that degraded over 14 days were employed. The subjects comprised a total of nine cases. Transcatheter hepatic artery embolization (TAE) using Cis-GMSs (Cis-GMSs-TAE) was performed 13 times in total. Six cases, each containing one to five tumors in a single segment to an entire lobe were treated by Cis-GMSs-TAE. In the remaining three cases with six or more metastatic liver tumors, the right and left lobes were treated by Cis-GMSs-TAE at a 2-week interval. RESULTS There were two complete response (CR), one partial response (PR) and six stable disease (SD) cases. The response rate was 33.3%. The average rate of reduction in tumor diameter was 32%. Disappearance of metastatic liver tumors was observed in only two of the nine cases. As for side effects and complications, post-embolization syndrome was observed in eight cases, but no severe complications such as cholangitis or liver abscess were observed. CONCLUSION Considering the mild side effects by Cis-GMSs-TAE, it is suggested that Cis-GMSs-TAE should be tried at least once as topical therapy for metastatic liver tumors when the response to systemic chemotherapy and other treatments is not satisfactory.

Embolization Materials Made of Gelatin: Comparison Between Gelpart and Gelatin Microspheres

Purpose:The object of this study was to assess the level of embolization in the embolized artery and the degradation period of these two embolic agents in the renal arteries using rabbit models.Materials and Methods: The renal artery was embolized using 5 mg of gelatin microspheres (GMSs; diameter, 35–100 μm; group 1) or 1 mg of Gelpart (diameter, 1 mm; group 2). For each group, angiographies were performed on two kidneys immediately after the embolic procedure and on days 3, 7, and 14 after embolization. This was followed by histopathological examinations of the kidneys.Results:Follow-up angiograms on each day revealed the persistence of poorly enhanced wedge-shaped areas in the parenchymal phase in all cases. In group 1, four of six cases showed poorly enhanced small areas in the follow-up angiograms. In group 2, all cases showed poorly enhanced large areas. In the histopathological specimens, it was observed that immediately after embolization, the particles reached the interlobular arteries in group 1 and the interlobar arteries in group 2. In all cases in group 1, the particles were histologically identified even on day 14. In one case in group 2 on day 14, the particles were not identified.Conclusion:In conclusion, although GMSs and Gelpart were similar in the point of gelatin particles, the level of embolization and the degradation period were different between GMSs and Gelpart.

Pluronic F127: Application in Arterial Embolization

PURPOSE Pluronic is a substance that is widely used in medical and pharmaceutical fields. In particular, 20% Pluronic F127 solution is a unique substance that is liquid at less than 15 degrees C and gelatinous at 25 to 60 degrees C. In this study, the authors took advantage of the gelation property of Pluronic F127 at human body temperature to simulate embolization and dissolution of the embolism in the renal artery and the superior mesenteric artery (SMA) using a rabbit model. MATERIALS AND METHODS Four female Japanese rabbits (weight, 2.5-3 kg each) were used. The renal artery was fitted with a 4-F cobra-type catheter and embolized with a 20% Pluronic F127 solution at a temperature of 20 degrees C. The embolic effect was evaluated by angiography immediately after the initial injection and every 15 minutes for 2.5 hours after embolization. After 24 hours, pathologic changes of the renal parenchyma were also evaluated. The embolic effect for SMA and ischemic changes of the intestine were evaluated in the same manner. RESULTS Angiographic findings showed that Pluronic F127 caused embolization immediately after injection and dissolved in the renal artery and the SMA after 90 to 120 minutes. The pathologic findings showed no ischemic change in the renal parenchyma. Necrosis was not found in the intestine, but focal hemorrhagic changes were extensively present when the gel had dissolved. This suggested that Pluronic F127 dissolved before severe tissue damage could occur. CONCLUSION Pluronic F127 can potentially be used as a temporary embolic material.

CT Diagnosis of Ileocecal-Appendiceal Lesions

Computed tomography demonstrates the precise anatomy and various pathologic processes of the gastrointestinal tract in the ileocecal-appendiceal region. The examination should be performed with intravenous contrast approximately 1 hour after the oral administration of 700 to 1000 mL diluted barium.

Facet formation sign in sarcoidosis: a new sign in endoscopic ultrasonography

Endoscopic ultrasound was performed in 56 patients with histologically or clinically proven mediastinal or lung diseases. These 56 patients comprised 12 with sarcoidosis, 8 with lymphoma, 20 with lung cancer, 10 with oesophageal cancer, and 6 with other diseases. A 7.5 MHz electronic linear-arrayed ultrasonic endoscope was used. In 38 of the 56 patients lymph nodes were detected by endoscopic ultrasound. Eleven patients with sarcoidosis showed lymph nodes in a “facet formation” (like stones in an old stone wall), while lymph nodes in the other 27 patients were round in shape and did not form facets. The “facet formation sign”, evaluated by endoscopic ultrasound, may be a characteristic finding in sarcoidosis.