Biomedical subjects
Publications and source records attributed to C Y Genton.
We report a rare case of benign granular cell tumor of the breast associated with multiple similar lesions of the scalp, the right shoulder, the right flank, the abdominal wall and the vulva, treated with wide excisions.
Myocardial angiogenesis induction with vascular growth factors constitutes a potential strategy for patients whose coronary artery disease is refractory to conventional treatment. The importance of angiogenesis in bone formation has led to the development of growth factors derived from bovine bone protein. Twelve pigs (mean weight, 73 +/- 3 kg) were chosen for the study. In the first group (n = 6, growth factor group) five 100 micrograms boluses of growth factors derived from bovine bone protein, diluted in Povidone 5%, were injected in the lateral wall of the left ventricle. In the second group (n = 6, control group), the same operation was performed but only the diluting agent was injected. All the animals were sacrificed after 28 days and the vascular density of the left lateral wall (expressed as the number of vascular structures per mm2) as well as the area of blood vessel profiles per myocardial area analysed were determined histologically with a computerised system. The growth factor group had a capillary density which was significantly higher than that of the control group: 12.6 +/- 0.9/mm2 vs 4.8 +/- 0.5/mm2 (p < 0.01). The same holds true for the arteriolar density: 1 +/- 0.2/mm2 vs 0.3 +/- 0.1/mm2 (p < 0.01). The surface ratios of blood vessel profiles per myocardial area were 4900 +/- 800 micron 2/mm2 and 1550 +/- 400 micron 2/mm2 (p < 0.01) respectively. In this experimental model, bovine bone protein derived growth factors induce a significant neovascularisation in healthy myocardium, and appear therefore as promising candidates for therapeutic angiogenesis.
BACKGROUND: An animal study was carried out to compare long-term patency rates of coronary anastomoses performed with the GraftConnector versus running suture technique. METHODS: 10 sheep, 45 to 55 kg, underwent off-pump coronary artery bypass grafting (right internal mammary artery to left anterior descending artery). In 5 animals, the anastomosis was performed with a GraftConnector and in 5 animals with 7-0 running suture. Intraoperative fluoroscopy and a fluoroscopic control at 6 months were performed. After 6 months, the animals were sacrificed and the anastomoses were examined histologically. RESULTS: All animals survived at 6 months with 100% anastomosis patency rates in both groups. In the GraftConnector group, the anastomosis diameter at 6 months fluoroscopy was 118% of native left anterior descending artery versus 97% of the control group. Luminal anastomotic width at histology was 1.7 +/- 0.2 mm in the device group versus 1.6 +/- 0.1 mm in the control group. Mean intimal hyperplasia thickness was 0.21 +/- 0.1 mm in the device group versus 0.01 mm in the control group. CONCLUSIONS: The GraftConnector provides a consistent and reproducible coronary artery anastomosis and reduces technical demand and manual dexterity in coronary operations. Long-term results demonstrate that off-pump coronary artery bypass grafting performed with the GraftConnector had the same patency rate and luminal width as those performed with running suture.
BACKGROUND AND OBJECTIVE: Theoretically myocardial angiogenesis of laser injury can be further enhanced by the addition of angiogenic growth factors. The influence of the way of administration of these factors on vascular growth around the channels is still unclear. MATERIALS AND METHODS: 18 pigs (mean weight 72 +/- 5.2 kg) were randomized to either triads of transmyocardial laser revascularization (TMLR) channels (group 1, n = 6) or isolated channels (group 2, n = 6), or a control group (n = 6). The animals had injections of bovine bone derived growth factor mixture either in the center of the triads in group 1 or within the channels themselves in group 2. Animals were sacrificed one month later for histological analysis. RESULTS: The vascular densities of myocardial areas within the triads of group 1 and around the channels in group 2 were significantly larger than in the control group: 15.2 +/- 3.7/mm2 and 14.2 +/- 3.5/mm2 respectively vs 5.3 +/- 1.6/mm2 (p < 0.001 for both differences). Differences of densities between group 1 and 2 were not statistically significant (p = 0.6). CONCLUSIONS: In this porcine model, the addition of a bovine bone derived growth factor mixture to TMLR significantly stimulates angiogenesis in the areas adjacent to the channels. The place of injection does not influence the angiogenesis intensity.
AIM: To analyse the arteriolar pattern of laser induced channels and their surroundings compared with mechanical and ischaemic injury. METHODS: 24 pigs were randomised to a myocardial infarction group, a transmyocardial laser revascularisation group, a needle group, or a control group. In the laser revascularisation and needle groups, five channels were created either with a 1.75 mm probe holmium-YAG laser or a Tru-cut needle of the same size. Animals were killed 28 days later. Morphometric analysis of vascular density was expressed as the mean (SD) number of arteriolar structures/cm(2). RESULTS: Laser and needle channels were completely invaded by granulation tissue. Their surface areas did not differ significantly: 2.28 (0.7) mm(2) and 2.38 (1.1) mm(2), respectively (p = 0.82). Within both types of channel, arteriolar density was significantly increased in comparison with the myocardial infarction scar: 197 (52)/cm(2) and 190 (64)/cm(2), respectively (p = 0.8) versus 56 (20)/cm(2) (p < 0.001 for both comparisons). The area of 1 mm width immediately adjacent to the laser and needle channels showed a density of 25 (16)/cm(2) and 23 (18)/cm(2), respectively, which is similar to that of normal tissue (28 (10)/cm(2); p = 0.6 and p = 0.4, respectively). The mean arteriolar diameter was similar throughout all the regions analysed. CONCLUSIONS: Both laser and needle channels produce a similar increase in arteriolar structures, which is limited to the lesion itself. This suggests that laser injury is not more potent as an angiogenic stimulator than mechanical injury, which in turn is superior to infarction.
Morphological and functional effects of transmyocardial laser revascularization (TMLR) are analyzed in an acute setting on a porcine model. Ten channels were drilled in the left lateral wall of the heart of 15 pigs (mean weight, 73 +/- 4 kg) with a Holmium-YAG laser (wavelength: 2.1 mu, probe diameter: 1.75 mm). Echocardiographic control was performed before the TMLR procedure as well as 5 min and 30 min thereafter. Echocardiographic parameters were recorded in short-axis at the level of the laser channels, and included left ventricular ejection fraction, fractional shortening and segmental wall motility of the channels' area (scale 0-3: 0 = normal, 1 = hypokinesia, 2 = akinesia, 3 = dyskinesia). After sacrifice the lased region was sliced perpendicularly to the channels for histological and morphometrical analysis. Five minutes after the drilling of the channels, all the echocardiographic index worsened significantly in comparison with baseline values (p < 0.01). All recovered after 30 min and showed no difference with baseline values. Cross-section of the channel lesions measured 8.8 +/- 2.4 mm2 which is more than three times that of the probe (p < 0.01). In acute conditions, the lesions due to the TMLR probe are significantly larger than the probe itself and cause a transient drop of the segmental wall motility on a healthy myocardium. These results suggest that TMLR should be used cautiously in the clinical setting for patients with an impaired ventricular function.
Intra-aortic balloon pump (IABP) is the most frequently used mechanical circulatory support. Repeated trauma on the aortic wall has been reported as a cause of balloon perforation by endothelial denudation of atheromatous plaque. This study analyses the effect of IABP on the endothelium of the calf aorta. In 12 calves (mean weight: 72 +/- 6 kg) an IABP was inserted by femoral route and left during 6 hours on internal mode with a frequency of 80 cycles/min. The animals were sacrificed after the procedure (n = 4), at postoperative day (POD) 7 (n = 4), and at POD 14 (n = 4). In the aorta facing the balloon, nine transmural samples were taken proximally (n = 3), at mid height (n = 3) and distally (n = 3), for histological analysis of the percentage of aortic surface covered with endothelium. The percentage of aortic surface covered with endothelium at POD 0, 7 and 14 was proximally: 72.5 +/- 27.5%, 83.7 +/- 16.9% and 93.3 +/- 8.9% respectively; at mid-height: 50.8 +/- 30.7%, 65 +/- 25% and 95 +/- 5%; and distally: 31.4 +/- 20.1%, 48.3 +/- 34.4% and 85 +/- 10%. A large portion of the aortic endothelium is abraded after 6 hours of IAB pumping. This effect is more important at the distal level of the aorta. After two weeks, most of the endothelium has regenerated.
This case report concerns a 35-year-old woman suffering from gravidic cholestasis, thrombocytosis and iterative vomiting episodes who underwent an elective cesarean section at week 35 because of recent herpetic vulvitis. Large bilateral ovarian tumors were observed which were interpreted as pregnancy luteomas. Nevertheless a biopsy of the right ovary was performed. Histologic examination revealed massive luteinization of the ovarian stroma. In addition, large tumor cells were found dispersed throughout the ovary as well as in vascular spaces as either isolated or clustered signet-ring cells. In search of the primary tumor, gastroscopy revealed a gastric ulcer in the antrum. The biopsies of the ulcer margins as well as those taken at distance demonstrated signet-ring cells in the lamina propria. Bilateral salpingo-oophorectomy and total gastrectomy were performed. In spite of postoperative chemotherapy, the patient died of disease 5 months after diagnosis.
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A total of 40 patients (mean age 51 yrs; 36-89 yrs) with clinically T1-T2(< 3 cm)N0M0 breast cancer underwent sentinel node (SN) mapping with radioactive tracer (99mTc) injection only in 21 patients, with Patent blue V in 1 patient, or with both techniques in 19 patients. The preoperative injection of 99mTc (20-40 MBq) was followed by lymphoscintigraphy. A handheld gamma probe was used to detect the SN in the operative room. A lumpectomy and an axillary dissection were performed in all the patients. SNs could be identified in 39/40 patients, resulting in a sensitivity of 98%. Successful localization of the SNs was accomplished by isotope only in 19/20 patients, by blue dye only in 1/1 patient, and by both methods in 19/19 patients; in 2 of these 19 patients, SNs were identified by blue dye only. Axillary metastases were found in 12/40 patients (30%), the SN being the only nodal metastasis in 8/12 patients (75%). Six of these 12 patients (50%) had only evidence of micrometastasis. Negative SNs on serial sections stained with hematoxylin-eosin (H&E) were evaluated with cytokeratin immunostain (C11). In all cases of negative SNs the remaining axillary nodes were also free of tumor, resulting in a negative predictive value of 100%. We conclude that SN mapping is a highly accurate method for staging the axillary node status in breast cancer patients. Optimal localization is achieved by the combination of injection of 99mTc-colloid and blue dye as evidence by the cases of positive SN identified by only one of both methods.
Recent research has revealed neoangiogenesis as a basic phenomenon in transmyocardial laser revascularization (TMLR). Theoretically, myocardial neoangiogenesis could be further enhanced by the addition of angiogenic growth factors. Triads of TMLR channels were created in the lateral wall of the left ventricles of 12 pigs (mean body weight 73+/-5 kg), using a holmium:yttrium-aluminium garnet (YAG) laser. The animals were allocated randomly either to receive an injection of 100 microg of a bovine bone-derived growth factor mixture within the triads (n=6), or to a control group (n=6). Animals were killed 1 month later. Capillary and arteriolar densities were determined by computed morphometric analysis of histological sections of the triads. The capillary density of myocardial areas within the triads was significantly greater in the group receiving the bovine bone-derived growth factor mixture than in the control group (14.3+/-3.5/mm(2) and 5.7+/-1.4/mm(2) respectively; P<0.001). The difference was also significant when considering arteriolar density (0.7+/-0.4/mm(2) and 0.2+/-0.1/mm(2) respectively; P<0.001). For comparison, capillary and arteriolar densities of the TMLR channel scars were 48.7+/-9.7 and 1.9+/-0. 5/mm(2) respectively in the angiogenic group, and 46.3+/-13.7 and 2. 3+/-1.3/mm(2) respectively in the control group (no significant differences). These results demonstrate that the addition of angiogenic factors to TMLR stimulates neoangiogenesis significantly in the areas adjacent to the channels, but not within the channel scars. The latter are themselves strongly vascularized. Hence this combined approach, potentiating the effect of TMLR by establishing vascular connections between the neovessels of the channel scars, has the potential for improved clinical outcome.
Transmyocardial laser revascularisation (TMLR) has emerged as an efficient treatment for angina refractory to conventional therapies. Moreover, some studies have suggested improvement of cardiac function. Its mechanism of action, initially attributed to blood flow from the ventricular cavity through the channels toward the ischaemic myocardium, remains to be defined. 21 pigs were randomised to TMLR of the left lateral wall (TMLR group; n = 7), to myocardial infarction (MI group; n = 7), or to both (TMLR-MI group; n = 7). In each group one animal was sacrificed at postoperative day 0, 7, 14 and 21, and 3 animals at postoperative day 28. The lateral wall of the left ventricle was fixed in 4% formaldehyde and sliced in a plane perpendicular to the channels for histological analysis. The evolution of the cross-section area of the lesions as well as their vascular densities at postoperative day 28, expressed as number vascular structures per mm2, were studied. All the channels were occluded by a clot at postoperative day 0 and by scar tissue at postoperative day 28. The cross-section area of the lesions diminished from 8.1 +/- 1.3 mm2 at postoperative day 0 to 2.4 +/- 0.2 mm2 at postoperative day 28. At postoperative day 28, the vascular density of scar tissue of the channels in the TMLR group was significantly increased in comparison with that of myocardial infarction in the MI group (47.1 +/- 10.2 vs. 23.8 +/- 9.1; p < 0.01). In the TMLR-MI group, channels scar became indistinguishable from surrounding myocardial infarction scar. In this model, laser channels are occluded early and do not salvage acute ischaemic myocardium. Mechanisms which could explain clinical improvement, as suggested by the results, are intense laser-induced neovascularisation and channel scar retraction (Laplace's law).
UNLABELLED: The University Institute of Pathology (IUP), Lausanne, has established a system designed to continuously document and manage the quality of its diagnostic activity in surgical pathology. To realize the system a few tools were created. Several "free codes" were introduced into the general computer system in order to register and evaluate (1) the quality of frozen section diagnoses, (2) the relevance of the use of this type of examination and (3) the frequency of spontaneous "official" internal consultations in search of a second opinion. Further, an evaluation checklist including all steps leading to the diagnosis (some of which were facultative*) was established. Eleven items were evaluated and registered in this way: quality of slides and staining, reporting time, selection of tissue blocks*, macro- and microscopic descriptions*, appropriateness of special stains and/or techniques and their quality*, final diagnosis, accuracy of codes for invoicing and diagnoses, quality of the final report. The relevance of the furnished clinical data was also evaluated and recorded. RESULTS: Of all registered frozen section examinations (397), 86.6% showed identity of provisional and definitive diagnoses. In 11.6% of cases there was a difference between the two diagnoses without clinical relevance, and in 1.8% the discrepancy was clinically significant. These percentages are comparable with those published in the literature. Internal consultation for second opinion is a current habit in our institution, and 980 cases (4%) were registered as such. Among the 25,249 cases received for histopathological examination during 1998 (each case may concern more than one specimen from the same patient), 495 (2% = 2-3 cases/day) were evaluated in detail by two reviewers throughout the year. The statistical results obtained demonstrate that our diagnostic performance in histopathology is very satisfactory: 43% of the analysed cases bear no deficit and 67.3% present two or less points in deficit; no diagnostic error was evidenced; 70% of the reports are signed-out within 3 days after reception of the material (mean delay < 3 days). CONCLUSIONS: The adopted system represents an excellent tool by which to continuously document and manage the quality of our diagnostic performances. It is reliable, efficient, sensitive and also feasible, as it does not require significant or exaggerated additional investments. The results obtained after one year confirm the high quality of the IUP's diagnostic activity.
BACKGROUND AND OBJECTIVE: The morphological evolution of transmyocardial laser channels was analyzed in a pig model. MATERIALS AND METHODS: Five channels were created in the lateral wall of the left ventricle of 12 animals, using a Ho:YAG laser. In half of the animals, an additional infarction was induced in the same area. Animals were sacrificed at one-week intervals until week 5 and the critical regions of the left ventricular wall were subjected to microscopic computed morphometrical analysis. RESULTS: There was no clearly patent lumen at any stage. Cross-sectional area of the channels fell from 8.5 +/- 1.2 mm(2) at day 0 to 2.1 +/- 0.1 mm(2) at day 35. From day 7 onward, the channel area was gradually replaced by granulation tissue and the proportion of the channel occupied by granulation scar tissue increased from 37 +/- 2% at day 7 to 100% at day 28. In the subgroup with concomitant infarction, granulation tissue of both channel and infarction became indistinguishable from day 14 onward. CONCLUSIONS: These results suggest strongly that channel patency is not the mechanism of angina relief after transmyocardial laser revascularization with Ho:YAG laser.
Although the presence of valves in the distal portion of the internal jugular veins has been widely described by anatomists and pathologists, their existence remains underscored in the medical literature. We set out to demonstrate their sonographic aspect and to evaluate their morphology, location and prevalence. Seventy-five cadavers were evaluated for the presence and aspect of such valves through neck dissections. Concurrent evaluation of the sonographic character of these structures was performed in another cohort of 75 adults. Valves of the distal portion of the internal jugular veins were found in 93 % of the cadaveric studies. Ultrasonography easily demonstrated the valve leaflets in 87 % of patients; all were observed in the distal portion of the internal jugular (IJ) veins. Sixty percent were bilateral with the majority of unilateral veins found on the right side. High-resolution ultrasonography easily demonstrates valves in the distal portion of the IJ veins which are present in the great majority of persons. Their evaluation may be of use in percutaneous procedures using this venous access.
A 30-year-old woman with mixed connective tissue disease was admitted with Wernicke's aphasia and progressive dyspnoea with chest pain. Multiple brain infarcts on a computed tomographic scan were compatible with a thromboembolic aetiology. Echocardiography showed marked hypokinesia of the posterior wall, biventricular dilatation and a decreased left-ventricle ejection fraction (40%). A diagnosis of myocarditis was made on myocardial biopsies disclosing interstitial lymphocytic infiltrates and myocardial fibre necrosis. A treatment with steroids and monthly pulsed cyclophosphamide was introduced. The heart function rapidly improved as assessed by a left-ventricle ejection fraction of 55% and remained stable 17 months thereafter.
BACKGROUND: Clinical studies suggest that transmyocardial laser revascularization may improve regional blood flow of the subendocardial layer. The vascular growth pattern of laser channels was analyzed. METHODS: Twenty pigs were randomized to undergo ligation of left marginal arteries (n = 5), to undergo transmyocardial laser revascularization of the left lateral wall (n = 5), to undergo both procedures (n = 5) or to a control group (n = 5). All the animals were sacrificed after 1 month. Computed morphometric analysis of vascular density of the involved area was expressed as number of vascular structures per square millimeter (+/-1 standard deviation). RESULTS: The vascular density of the scar tissue of the laser channel was significantly increased in comparison with myocardial infarction alone: 49.6+/-12.8/mm2 versus 25.5+/-8.6/mm2 (p < 0.0001). The vascular densities of subendocardial and subepicardial channel areas were similar: 52.9+/-16.8/mm2 versus 46.3+/-13.6/mm2 (p = 0.41). The area immediately adjacent to the channels showed a vascular density similar to that of normal tissue: 6.02+/-1.7/mm2 versus 5.2+/-1.9/mm2 (p = 0.08). In the infarction + transmyocardial laser revascularization group, the channels were indistinguishable from infarction scar. CONCLUSIONS: Scars of transmyocardial laser revascularization channels exhibit an increased vascular density in comparison with scar tissue of myocardial infarction, which does not extend into their immediate vicinity. There was no vascular density gradient along the longitudinal axis of the channels.