The modification of the new type of end-to-side anastomosis between carotid arteries in rats: A technical and Scanning Electron Microscopic study

Summary Modification of a type of end-to-side anastomosis that has been described before is studied. The recipient artery is occluded for only 3–4 minutes to complete the anastomosis by using only the running suture. The anastomotic site was studied by inspection and Scanning Electron Microscope (SEM) at different times after the operation on 30 rats.     

Intestinal plethora: An early sign of acute posttraumatic hepatic artery-portal vein arteriovenous fistula

Traumatic communications between the hepatic artery or its branches and the portal vein or its tributaries usually are clinically occult until the late sequelae of portal hypertension, such as esophageal and mesenteric varices, ascites, or congestive heart failure, become manifest. The authors describe the early diagnosis of such a lesion by computed tomography. The CT findings included a hepatic hematoma and, more significantly, diffuse thickening of the small and large bowel wall. This thickening represents vascular congestion of the bowel caused by acute portal hypertension prior to the development of decompressing portal collateral circuits. When this CT finding is not associated with other signs of intestinal ischemia or infarction, it should suggest portal hypertension and lead to arteriography for diagnosis and therapy of arterioportal fistula.     

The Cathlocator: A novel non-radiological method for the localization of enteral tubes

Safe placement of nasogastric tubes requires reliable positioning of the tip of the tube within the stomach. Radiology and aspiration are currently used to confirm tube position, but suffer from significant problems of cost and efficacy, respectively. We have developed a novel method to locate the position of a catheter tip within the body, using the detection of a low energy electromagnetic field generated in a coil located in the catheter with an external hand-held unit (Cathlocator). In vitro, the unit detected the distance of the coil from the detector with an accuracy of 0.1 cm over a range of 4–12 cm. In vivo studies were performed in 11 healthy volunteers using a purpose-built manometric assembly that incorporated the signal generating coil in its tip. In all subjects the Cathlocator showed the position of the signal generating coil to be cranial to the xiphisternum when manometric and transmucosal potential difference criteria showed it to be located above the lower oesophageal sphincter. When the coil was within the stomach, the Cathlocator identified its position within the epigastric, umbilical and left hypochondrial regions of the abdomen. The distance of the coil from the surface was significantly greater when in the duodenum mean (±s.e.m. 7.6±0.3 cm; P<0.001) and oesophagus (8.6±0.2 cm; P<0.002) than the stomach (5.0±0.4 cm). In one subject studied twice there was a close correlation between the location and depth measured by the device on each occasion. The Cathlocator is a novel non-radiological device that has the potential to be useful in the placement of gastrointestinal catheters.     

Microvascular disturbances in the colonic mucosa in antibiotic-associated haemorrhagic colitis: Involvement of platelet aggregation

An ultrastructural study of the colonic mucosa was performed in four patients with antibiotic-associated haemorrhagic colitis and new findings are reported. Colonoscopy was performed and biopsy specimens were obtained within 24 h of the onset of bloody diarrhoea. Colonoscopy demonstrated diffuse oedematous and haemorrhagic mucosa with erosions and white coat. Light microscopy revealed mucosal haemorrhage and inflammatory cell infiltration. Ultrastructurally, platelet aggregation was frequently present in the lumina of colonic mucosal capillaries, causing engorgement of red blood cells in adjacent microvessels. Mild to severe damage was observed in capillary endothelial cells, including discontinuity of basement membranes, gaps between endothelial cells and the destruction of capillaries. There was no evidence of microvascular spasm. In conclusion, our findings suggest that antibiotics directly or indirectly cause microcirculatory disturbances, which result in tissue damage and haemorrhage, in the colonic mucosa.     

Analysis of Intestinal Perfusion Data for Highly Permeable Drugs Using a Numerical Aqueous Resistance—Nonlinear Regression Method

Purpose. To develop, validate and apply a method for analyzing the intestinal perfusion data of highly permeable compounds using the Numerical Aqueous Resistance (NAR) theory and nonlinear regression (NAR-NLR) and to compare the results with the well-established Modified Boundary Layer (MBL) Analysis. Methods. The NAR-NLR method was validated and the results were compared to the MBL analysis results using previously reported cephradine jejunal perfusion data. Using the Single Pass Intestinal Perfusion (SPIP) method, the concentration dependence of intestinal permeability was investigated for formycin B, proline, and thymidine, three compounds reported to be absorbed by carrier-mediated transport processes. The MBL and NAR-NLR analyses were then applied to the three sets of SPIP data. Results. The results demonstrate that the intrinsic MBL transport parameters were highly variable and, in one case, the analyses failed to give a statistically significant Michaelis constant. The MBL mean dimensionless wall permeabilities (P*_w) were greater than the NAR-NLR P*_w and were also highly variable. In all cases, the NAR-NLR variability was significantly lower than the MBL variability. The extreme variability in the MBL-calculated P*_w is due to the sensitivity of P*_w when the fraction of unabsorbed drug (C_m/C_o) is low or, alternatively, when P*_w approached the aqueous permeability, P*_aq. Conclusions. The NAR-NLR method facilitates the analysis of intestinal perfusion data for highly permeable compounds such as those absorbed by carrier-mediated processes at concentrations below their K_m. The method also allows for the use of a wider range of flow conditions than the MBL analysis resulting in more reliable and less variable estimates of intestinal transport parameters as well as intestinal wall permeabilities.     

Hyperreactio luteinalis in a normal pregnancy: Sonographic and MRI findings

A case of hyperreactio luteinalis in an otherwise normal pregnancy is reported. Ascites was present, but no peritoneal implants or adenopathy were seen. Findings that would have suggested the correct diagnosis are the symmetrical and bilateral pattern of the mass, as well as the rather uniform size of the loculi, which were 1 to 3 cm in diameter.     

The heparin-induced thrombocytopenia and thrombosis syndrome: Treatment with intraarterial urokinase and systemic platelet aggregation inhibitors

We report a case of the heparin-induced thrombocy-topenia and thrombosis syndrome presenting with acute ischemia of a lower limb. The patient was successfully treated by withdrawal of heparin products, intraarterial urokinase, and platelet anti-aggregation therapy consisting of Dextran and aspirin.     

Synovial haemangioma of the knee: a frequently misdiagnosed lesion

Objective The objective of this study was to assess the contribution of magnetic resonance (MR) imaging in the diagnosis and surgical planning of five cases of synovial haemangioma of the knee.Patients and Methods The clinical, radiological and arthroscopic features of five pathologically proven synovial haemangiomas of the knee were retrospectively reviewed.Results A diagnostic delay, on average of 8 years, had occurred in four of the cases. Plain films were unremarkable, except for one case with arthropathy mimicking haemophilia, Arteriography, performed in three patients, was normal in one. CT, performed in three patients, showed the lesion, but the extent of the latter was better demonstrated with MR imaging. Synovial haemangiomas had a high signal intensity on T2-weighted images, without any extensive mass effect. Fibrofatty septa within the lesion were observed in three cases and muscular and/or fatty invasion in two. Arthroscopy allowed diagnosis of the lesion in two cases, but showed only non-specific synovitis in another two.Conclusion This study emphasizes the valuable contribution of MR imaging in the diagnosis and surgical planning of synovial haemangiomas.