Role of omentectomy as part of radical surgery for gastric cancer.

BACKGROUND: A complete omentectomy is recommended as part of radical (sub)total gastrectomy for gastric cancer, but there is little evidence to suggest any survival benefit. The aim of this study was to evaluate the incidence of, and risk factors for, metastases in the greater omentum in patients undergoing gastrectomy for gastric cancer. METHODS: This was a multicentre prospective cohort study (OMEGA trial) of consecutive patients with gastric cancer undergoing (sub)total gastrectomy with complete en bloc omentectomy and modified D2 lymphadenectomy. After resection, the omentum was separated from the gastrectomy specimen distal to the gastroepiploic vessels and sent separately for pathological examination. The primary endpoint was the presence of metastases in the greater omentum. RESULTS: Of 100 included patients, five (5·0 per cent) had metastases in the greater omentum. Pathology results showed advanced tumours in all five (pT4b N1 M1, pT4b N2 M1, ypT4a N1 M1, ypT3 N2 M0, ypT3 N3 M0). The resection was microscopically non-radical at the proximal (3) or distal (2) resection margin in all of these patients. Metastases in the greater omentum correlated significantly with a microscopically non-radical resection, tumour expansion in the oesophagus or duodenum, linitis plastica or a proximal gastric tumour with diameter of at least 5 cm, stage III-IV disease and (y)pM1 category. CONCLUSION: In resectable gastric cancer, the incidence of metastases in the greater omentum is low, and when present associated with advanced disease and non-radical features. Thus, omentectomy as part of a radical gastrectomy may be omitted. REGISTRATION NUMBER: NCT02050659 ( http://www.clinicaltrials.gov).

[Cause of death: from primary disease to direct cause of death]. / Doodsoorzaak: van primair grondlijden tot directe doodsoorzaak.

Following the death of a patient, the treating physician in the Netherlands is required to fill out two forms. Form A, which is the certificate of death and Form B, which is used by the Statistics Netherlands to compile data on causes ofdeath. The latter form often poses difficulty for the physician with respect to the primary cause of death. This applies particularly to cases of sudden death, which account for one third of all deaths in the Netherlands. As a result, the statistical analyses appear to lead to an incorrect representation of the distribution of causes of death. A more thorough investigation into the primary cause of death is desirable, if necessary, supported by a request for an autopsy. The primary cause of death is to be regarded as the basic disease from which the cascade of changes ultimately leading to death originated.

A 4-year-old boy with neurofibromatosis and severe renovascular hypertension due to renal arterial dysplasia.

A 4-year-old boy had severe hypertension, cardiac failure, and signs of neurofibromatosis. Arteriography disclosed renal artery stenosis in both kidneys with signs of ischemia, particularly in the right kidney. Because of insufficient response to antihypertensive therapy, a right-sided nephrectomy was performed. Histological examination of this kidney showed segmental stenosis in all branches of the renal artery. The vascular lesions were characterized by an intimal proliferation of spindle cells in a mucoid matrix with destruction of the internal elastic membrane frequently accompanied by loss or attenuation of the media and fibrosis of the adventitia. Occasionally, a nodular arrangement of the spindle cells at the interface between intima and media was observed. Immunohistochemical studies demonstrate a smooth-muscle cell origin for these cells.

Keratins 7 and 20 as diagnostic markers of carcinomas metastatic to the ovary.

The most common carcinomas metastatic to the ovary that mimic ovarian primaries are colonic adenocarcinomas and endometrial carcinomas. Conventional histochemical staining procedures, even in combination with additional immunohistochemical assays, are of limited value in distinguishing between these metastases and primary ovarian carcinomas. In this study we investigated whether the application of monoclonal antibodies against keratins 7, 8, and 20 could help in differentiating between these categories. The reactivity patterns of 40 carcinomas metastatic to the ovary were compared with those of their primary carcinomas on the one hand and with various primary ovarian carcinomas and mesotheliomas on the other. Colon cancer metastatic to the ovary was keratin 7 negative and keratin 20 positive in 94% of the cases; in contrast, all primary ovarian carcinomas were keratin 7 positive and keratin 20 negative, with the exception of two cases of mucinous cystadenocarcinoma. Ovarian metastases of gastric cancer usually contained keratins 7 and 20. Metastases of endometrial cancer to the ovary and primary ovarian carcinomas usually showed similar keratin expression. We propose that keratin 7 and 20 antibodies may be of help to distinguish between primary ovarian carcinomas and carcinoma metastases in the ovary.

Comparative anatomic studies of various arterial conduits for myocardial revascularization.

Comparison was made between the morphologic condition of the left anterior descending artery and four arterial conduits: the internal mammary, right gastroepiploic, inferior epigastric, and radial arteries, harvested from 17 patients (aged 15 to 85 years, mean 64 years) who had died of nonvascular diseases. Proximal, mid, and distal segments were examined microscopically. The internal mammary artery was elastic, but the others were muscular. In all four conduits, atherosclerosis was absent to mild, the internal elastic lamina showed only minimal defects, and the vasa vasorum were confined to the adventitia. In all cases the left anterior descending artery showed mild to severe atherosclerosis and substantial defects in the internal elastic lamina with penetration of the vasa vasorum into the media and intima. Comparison of the mean distance (+/- standard deviation) from the lumen to the outermost portion of the media for the left anterior descending artery (320 +/- 63 microns) with the four conduits gave comparable values for the internal mammary artery (350 +/- 92 microns); p = not significant) and the right gastroepiploic artery (291 +/- 109 microns; p = not significant), versus 529 +/- 52 microns; p less than 0.002) for the radial artery and 249 microns (+/- 87 microns) (p less than 0.04) for the inferior epigastric artery (Kruskal-Wallis and Mann-Whitney U tests). The relatively scanty presence of smooth muscle cells in the thin-walled media of the internal mammary artery combined with a well-formed internal elastic lamina, even at advanced age, may be an important cause for its low susceptibility to atherosclerosis and a major determinant in its superior long-term patency as a coronary artery bypass graft. This finding emphasizes the justification of continued use of the ideally matching internal mammary artery, either as in situ or free graft, in coronary artery bypass grafting. In contrast to the thick-walled radial artery, which may be relatively prone to ischemia, an acceptable long-term patency of the inferior epigastric artery and right gastroepiploic artery, if harvested as pedicled grafts, is anticipated.

Histologic processing of microbiopsies from cervical smears is diagnostically useful in selected cases.

We analyzed the value in cervical cytology of a recently developed technique by which it is possible to remove thick tissue specimens, called microbiopsies, from cervical smears and to process them for histologic examination. In 12 (48%) of 25 cervical smears in which microbiopsies were found, the histologic sections from them confirmed the cytologic diagnosis. Most cases involved classification of lesions diagnosed as cervical intraepithelial neoplasia. In 13 (52%) of 25 smears, processing the microbiopsy allowed considerable modification of the cytologic diagnosis. In six of these cases, microbiopsies consisted of groups of columnar cells that were incorrectly classified as atypical on the basis of cytologic criteria. After histologic processing, the microbiopsies revealed nonatypical columnar cells in four cases and only mildly atypical columnar cells in two cases. In 3 of 13 smears, there were insufficient dispersed atypical cells for a conclusive diagnosis. Processing the microbiopsies in these cases allowed classification into one of the cervical intraepithelial neoplasia categories.

The applicability of a keratin 7 monoclonal antibody in routinely Papanicolaou-stained cytologic specimens for the differential diagnosis of carcinomas.

The monoclonal antibody OV-TL 12/30, which detects keratin 7, was tested for its usefulness in cytologic diagnosis by reincubating previously Papanicolaou-stained slides. For this purpose malignant effusions of 73 patients with histologically confirmed cancers of the colon, ovary, mesothelium, breast, lung, esophagus, pancreas, urinary bladder, stomach, kidney, and prostate were used. All malignant cells from ovarian adenocarcinomas were positive, whereas malignant cells from colonic adenocarcinomas and malignant mesotheliomas were negative. Adenocarcinomas of gastric, renal, pancreatic, esophageal, and mammary origin demonstrated variable staining. Transitional cell carcinomas were positive, whereas squamous and small cell lung carcinomas were negative. Because OV-TL 12/30 does not react with normal and atypical mesothelial cells in these preparations, this reagent is a valuable tool in distinguishing benign mesothelial cells and adenocarcinoma cells. The authors' results demonstrate that this antibody is an excellent tool in the differential diagnosis of malignant cells in effusions and can be used in routinely stained cytologic specimens to determine primary tumor localization. In addition to its ability to distinguish between ovarian and colonic adenocarcinomas, its negativity in mesotheliomas may prove helpful in several diagnostic considerations.

Immunoperoxidase staining for identification of Aspergillus species in routinely processed tissue sections.

AIMS: To evaluate the performance of an immunoperoxidase stain using the monoclonal antibody EB-A1 to detect Aspergillus species in formalin fixed, paraffin wax embedded tissue. METHODS: The monoclonal antibody EB-A1 directed against galactomannan was used to detect Aspergillus species in 23 patients with suspected or confirmed invasive aspergillosis. Immunostaining was performed on formalin fixed, paraffin wax embedded tissue using the streptavidin-biotin method and compared with conventional haematoxylin and eosin, periodic acid-Schiff, and Gomori-Grocott stains. Results of immunostaining were semiquantitatively analysed with regard to both intensity of staining and number of positively staining micro-organisms. Tissue sections from 16 patients with confirmed invasive mycoses due to Candida species, Apophysomyces elegans, Rhizopus oryzae, Pseudallescheria boydii and Histoplasma capsulatum were used as controls. RESULTS: In 19 (83%) of 23 cases invasive aspergillosis was confirmed by both histological examination and culture (18 Aspergillus fumigatus and one A flavus). Immunoperoxidase stains were positive in 17 (89%) of 19 cases including one case of disseminated infection due to A flavus. Furthermore, the immunoperoxidase stain was positive in a culture negative tissue section with histological evidence of mycelial development, indicating the presence of Aspergillus species. Some cross-reactivity was observed with the highly related fungus P boydii, although the number of mycelial elements that stained was low. CONCLUSIONS: Immunoperoxidase staining using the monoclonal antibody EB-A1 performs well on routinely processed tissue sections and permits detection and generic identification of Aspergillus species, although it was no better than conventional histopathology in identifying the presence of an infection. An additional advantage is that the immunostain may help to provide an aetiological diagnosis when cultures remain negative.

Detection of keratin subtypes in routinely processed cervical tissue: implications for tumour classification and the study of cervix cancer aetiology.

We investigated the expression of keratin subtypes 7, 8, 10, 13, 14, 17, 18 and 19 in the normal cervix, in cervical intraepithelial neoplasia (CIN) lesions and in cervical carcinomas, using a selected panel of monoclonal keratin antibodies, reactive with routinely processed, formalin fixed paraffin embedded tissue fragments. The reaction patterns derived for each keratin antibody were compared with known expression patterns of the various epithelia, previously examined in frozen tissues. Although the reactivity of the antibodies was generally acceptable, considerable modifications to the manufacturers' staining instructions were often necessary. For some antibodies, which were previously thought to be reactive with fresh frozen tissue only, we developed staining protocols rendering them reactive with routinely processed material. As with previous findings in frozen sections we observed increasing expression of keratins 7, 8, 17, 18 and 19 with increasing grade of CIN. In cervical carcinomas the differences in keratin detectability between the main categories were more pronounced than in frozen sections, probably due to fixation and processing. For routine pathology, keratin phenotyping of cervical lesions may be of value in classification. The fact that keratin 7 was detected for the first time in reserve cells, and that this keratin was also found to be expressed in a considerable number of CIN lesions and cervical carcinomas supports the suggestion that reserve cells are a common progenitor cell for these lesions.

The dynamics of keratin expression in malignant transformation of cervical epithelium: a review.

OBJECTIVE: To review basic and clinical aspects of cytoskeletal keratin expression in normal cervical epithelia as well as in preneoplastic and malignant epithelia of the uterine cervix. DATA SOURCES: The results of extensive studies from our group and other groups on keratin phenotyping in normal premalignant and malignant cervical epithelia were summarized. METHODS OF STUDY SELECTION: All studies involving keratin expression in the cervix were reviewed, as were general studies on keratin expression in which the cervix was mentioned and studies relevant to understanding cervical cancer etiology (36 studies). DATA EXTRACTION AND SYNTHESIS: From these studies, keratin phenotypes of the various epithelia were derived. The phenotypes were correlated to existing theories on the development of cervical carcinoma. CONCLUSIONS: It is possible to distinguish the various epithelial types in the normal cervix based on their keratin expression patterns. Reserve cells display a bidirectional keratin pattern, comprising keratins typical of both squamous and simple types of differentiation, reflecting the bipotential nature of these cells. Cervical intraepithelial neoplasia can be divided into two subpopulations, one characterized by the reserve cell keratin phenotype and the other by a keratin phenotype typical of nonkeratinizing squamous epithelia. The first population also contains the simple keratins, the relative percentage of which increases with increasing degree of dysplasia. We therefore suggest that these lesions are progressive in nature. Carcinomas show a differentiation-related keratin expression pattern in addition to the basic reserve cell keratin phenotype. Adenocarcinomas also have been shown to express most of the reserve cell keratins. The latter observation indicates a common progenitor for both carcinoma types.

Relationship between human papillomavirus type 16 in the cervix and intraepithelial neoplasia.

OBJECTIVE: To evaluate a temporal relationship between the presence of cervical human papilloma virus (HPV) type 16 and the risk of developing cervical intraepithelial neoplasia (CIN). METHODS: Fifty-four women with HPV 16 polymerase chain reaction (PCR)-positive tests were selected from the gynecologic outpatient clinic of the Reinier de Graaf Hospital, Delft, The Netherlands. At least three successive PCR tests were performed in each woman at intervals of 6 months. The PCR HPV 16 assay was performed in conjunction with cervical smear, and colposcopy and biopsy, if indicated. Women with at least three consecutive positive PCR tests were defined as having persistent HPV 16 infections. Women with one positive test followed by two negative tests were defined as having transient infections. Subdivided into two groups, 25 women had persistent infections and 29 had transient infections. RESULTS: In significantly more women in the persistent group compared with the transient group, CIN developed (11 of 25 versus six of 29, P = .036). Lesions in women with persistent HPV 16 infection were more severe (six of 11 were CIN III versus one of six P = .041). CONCLUSION: Persistent infection with HPV 16 is associated with a higher risk of developing CIN, which is often high-grade.

Retrogastric versus antegastric routing and histology of the right gastroepiploic artery.

To maximize use of the right gastroepiploic artery in myocardial revascularization 11 cadavers were studied to determine the shortest route (retrogastric versus antegastric) of the right gastroepiploic artery from its origin to the recipient coronary artery. Any coronary artery could be reached with an in situ right gastroepiploic artery. There was no significant difference between the retrogastric and antegastric routes for any coronary artery, although the former generally is slightly shorter to the vessels on the posterior surface of the heart and the latter to vessels on the anterior surface of the heart. Histological examination of the right gastroepiploic artery in its proximal, mid, and distal segments showed a similar width of intima and media and invariably an almost purely muscular media. Based on the histological similarity of the right gastroepiploic artery to the coronary artery, some scepticism toward liberal use of the right gastroepiploic artery, especially if used as a free graft, is warranted until clinical studies on its long-term patency have been performed.

Intercostal artery: histomorphometric study to assess its suitability as a coronary bypass graft.

To assess potential suitability of the intercostal artery as a conduit in myocardial revascularization a histomorphometric study of the fifth intercostal artery (n = 11) and intercostal arteries other than the fifth (n = 9) was conducted. All arteries were harvested at autopsy in 11 individuals (mean age, 75 years). The length of the intercostal arteries varied from 22 to 35 cm (mean, 29.4 cm). Three combinations of histologic patterns were seen along the course of the intercostal artery: a proximal elastic segment followed by subsequent elastomuscular and muscular segments (n = 3), a proximal elastomuscular segment with the remainder of the artery being muscular (n = 6), and a completely muscular pattern (n = 2). The mean luminal diameter of the fifth intercostal arteries varied from 1.4 +/- 0.3 mm at the origin to 0.9 +/- 0.2 mm at 30 cm (30% to 40% decrease in diameter due to the flaccid state and rigor mortis). The mean intimal thickness at these locations was 54 +/- 38 microns and 25 +/- 16 microns and the mean thickness of the media was 205 +/- 38 microns and 70 +/- 45 microns. The histologic findings, mean luminal diameter, and mean diameter of the intima and the media were similar in the intercostal arteries other than the fifth. Our study demonstrates that the intercostal artery has a relatively thin intima and media, the latter being elastic or elastomuscular in the proximal segment in the majority of the investigated arteries, which are favorable properties with regard to its potential suitability as a coronary bypass conduit.

Low-grade intimal hyperplasia in internal mammary and right gastroepiploic arteries as bypass grafts.

BACKGROUND: Knowledge is limited regarding the histology of the internal and right gastroepiploic arteries that have been functioning as coronary artery bypass conduits. METHODS: Four internal mammary arteries, 3 right gastroepiploic arteries, and 1 saphenous vein graft that had been functioning as coronary artery bypass grafts were harvested and examined histologically in 3 male patients who had died at 19, 38, and 47 months after coronary revascularization. RESULTS: All grafts were patent. The mean thicknesses of the intima in the proximal, middle, and distal segments were 41.0, 31.8, and 25.8 microns for the internal mammary artery and 58.0, 40.3, and 34.3 microns for the right gastroepiploic artery. The saphenous vein graft showed severe focal atherosclerosis. CONCLUSIONS: This histologic study in a small number of patients corroborates the reported excellent patency rates at medium- to long-term follow-up of the internal mammary and right gastroepiploic arteries used as coronary artery bypass grafts.

Histological study of the internal mammary artery with emphasis on its suitability as a coronary artery bypass graft.

The internal mammary, musculophrenic, and superior epigastric arteries were unilaterally harvested from 11 individuals (aged 49 to 83 years; mean age, 67 years) and were examined histologically at 1-cm intervals. In 2 individuals the media of the entire internal mammary artery was elastic, whereas in the other 9 individuals we observed an alternating histological pattern in the media of the internal mammary artery, that of the proximal and distal segments being elastomuscular and that of the mid segment being elastic. In 4 of the latter 9 individuals the distal 10% to 20% of the media of the internal mammary artery was muscular with rare elastic lamellae. The media of the first 1 to 2 cm of the musculophrenic and superior epigastric arteries was elastomuscular or muscular with rare elastic lamellae, whereas more distally the media was purely muscular. The degree of intimal hyperplasia was significantly greater in arterial segments with a purely muscular media (25.6%) than in those with elastic (16.7%), elastomuscular (15.3%), and muscular (with rare elastic lamellae) (17.5%) types of media (p < 0.01). The mean cross-sectional luminal area of the elastic segment (1.9 mm2) and proximal and distal elastomuscular segments (1.9 and 1.2 mm2, respectively) of the internal mammary artery was significantly greater than that of the muscular segments of the musculophrenic artery (0.9 mm2) and the superior epigastric artery (0.7 mm2) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Morphometric study of the right gastroepiploic and inferior epigastric arteries.

BACKGROUND: Based on earlier observations that the thickness of the intima and structure of the media may have an impact on the long-term patency of arterial conduits and the lack of detailed histologic studies of the right gastroepiploic and inferior epigastric arteries, we subjected both vessels to morphometric analysis with emphasis on their suitability as conduits in myocardial revascularization. METHODS: The right gastroepiploic and inferior epigastric arteries were harvested from 28 unselected individuals (mean age, 73.2 years) at autopsy, and the luminal diameter and the width of the intima and media were measured. RESULTS: At all levels of measurement (origin, 10 cm, and 15 cm), the luminal diameter of the inferior epigastric artery was significantly smaller than that of the right gastroepiploic artery (p < 0.05). The right gastroepiploic artery demonstrated only mild intimal hyperplasia. In contrast, the inferior epigastric artery showed substantial intimal hyperplasia within the first 1-cm segment (mean, 134 +/- 131 microns versus 50 +/- 49 microns for the corresponding segment of the right gastroepiploic artery; p = 0.01). Intimal hyperplasia was only mild in the remainder of the inferior epigastric artery. In both vessels, the media was muscular with rare dispersed elastic fibers. The mean thickness of the media ranged from 380 +/- 116 microns proximally to 155 +/- 70 microns distally for the right gastroepiploic artery, and from 316 +/- 86 to 165 +/- 70 microns, respectively, for the inferior epigastric artery. CONCLUSIONS: In myocardial revascularization, use of the right gastroepiploic artery may generally be preferable to use of the inferior epigastric artery. This recommendation is based on the larger luminal diameter of the right gastroepiploic artery as compared with the inferior epigastric artery, the significantly greater intimal hyperplasia in the first segment of the inferior epigastric artery, and the limitation that the inferior epigastric artery can be used only as a free graft. The rate of development of intimal hyperplasia in the right gastroepiploic artery, if used as an in situ coronary artery bypass graft, may be slow, approximating that of the right gastroepiploic artery in its natural environment.

Glutathione S-transferase pi is expressed in (pre) neoplastic lesions of the human uterine cervix irrespective of their degree of severity.

BACKGROUND: Glutathione S-transferase pi (GST pi) is involved in a variety of cell detoxification processes. In the uterine cervix its presence has been associated with high grade cervical intraepithelial neoplasia (CIN), but the reports are conflicting. For this reason we immunohistochemically investigated glutathione S-transferase pi expression in a well documented sequence leading to cervical cancer. MATERIALS AND METHODS: The series of tissue samples that were examined comprised normal, metaplastic, dysplastic (CIN 1, 11 and 111) and malignant cervix. GST pi expression was examined in 15 cases of uterine cervix lined with normal epithelia, in 11 cases of CIN 1, 9 cases of CIN 11, 10 cases of CIN 111, 6-cases of squamous cell cervical carcinomas and 5 cases of adenocarcinoma of the cervix. RESULTS: Both nuclear and cytoplasmic staining reactions were noted. In normal ectocervical epithelia a moderately strong nuclear and cytoplasmic staining reaction was noted, while in immature squamous metaplasia staining was more intense. Only 50% of the endocervical cells were immunostained while almost 100% of the reserve cells stained weakly, mainly restricted to the cytoplasm. Irrespective of severity, CIN lesions showed a moderate staining intensity in both cytoplasm and nuclei. Cervical carcinoma, irrespective of their type, showed significantly less staining activity. CONCLUSIONS: GST pi occurs in normal cervical epithelium and in all stages of premalignant cervix, suggesting an important role in the detoxification process in all these stages. Its ubiquitous presence indicates, in contrast to the earlier reports, that the enzyme does not play a crucial role in the initiation of the carcinogenic cascade. However, the absence of this detoxificating enzyme in the nucleus of the majority of cervical carcinomas may indicate that xenobiotic compounds are not catabolized and may therefore exert their mutagenic activity, resulting in tumor progression.

Tenascin-C expression in prostatic intraepithelial neoplasia (PIN): a marker of progression?

BACKGROUND: Tenascin (tenascin-C) has been suggested to be associated with active epithelial-stromal interactions. We evaluated tenascin expression in tissue remodelling processes presumably associated with PIN and prostate carcinoma (PCa). MATERIALS AND METHODS: Tenascin immunoreactivity was evaluated in 38 PIN lesions (low-grade = 5, high-grade = 33) from 27 paraffin-embedded PCa specimens, and compared with expression in pre-existent (normal) prostate, benign prostatic hyperplasia (BPH), and PCa. RESULTS: Periepithelial stromal tenascin expression was low in low-grade PIN, and similar to normal glands and BPH, whereas expression in high-grade PIN was high and partly overlapped that of well-/moderately differentiated PCa. High-grade PCa usually expressed little, if any tenascin. CONCLUSIONS: The variable periglandular tenascin expression in high-grade PIN may reflect the biologic behaviour of this lesion, and may be indicative of variable levels of tissue remodelling. In well/moderately differentiated PCa tenascin expression levels may be an indicator of tumour progression.

Obstructive colitis: an analysis of 50 cases and a review of the literature.

Obstructive colitis is an ulcero-inflammatory and necrotizing condition that occurs in the colon proximal to benign or malignant stenosing lesions. it is the result of ischemia due to impairment of blood supply secondary to elevation of the endoluminal pressure, distension of the colonic wall and other factors which impair adequate perfusion. The incidence among patients with colonic obstruction is reported at between 1 and 7%. Of 50 patients with this condition in this series, 30 female and 20 male, 2/3rds were well over 70 yrs of age. Obstruction was most common in the rectosigmoid. In half the patients this was due to adenocarcinoma, 24 were due to benign obstruction and 15 were caused by diverticular disease. Type, extent and depth of ischemic lesions were highly variable and comprised early mucosal hemorrhage and edema, ulcero-hemorrhagic lesions and transmural necrosis. There was always an abrupt transition between affected and normal bowel. A segment of preserved mucosa was usually present on the proximal side of the stenosis. In 16 patients massive dilatation with stretching and thinning of the bowel wall, associated with a blow-out type of perforation or with transmural necrosis, was observed and was considered to have resulted from a rapid rise of endoluminal pressure to high levels. The microscopic and macroscopic features are described in detail and histological factors discussed in relation to the pathological lesions encountered. Emphasis is placed upon the range of appearances and similarities are shared with other inflammatory colonic diseases, particularly idiopathic inflammatory bowel disease. The importance of recognition of this disease entity, not only by pathologists but by surgeons dealing with the disease at operation, is stressed.

Prevention of adhesion formation around the internal mammary artery pedicle by Gore-Tex surgical membrane. An experimental study in goats.

The effects of wrapping the internal mammary artery in Gore-Tex surgical membrane on the formation of adhesions were investigated. In seven goats both internal mammary arteries were dissected free from the thoracic wall. In six goats the internal mammary arteries were wrapped in Gore-Tex surgical membrane. In the remaining animal both arteries were removed and used as controls. After 6 months the goats were reoperated and it was found that the wrapped segments of all arteries were completely free of adhesions, whereas the non-wrapped segments showed severe adhesion formation. Histologic examination could not detect differences between the wrapped arteries and the controls. One of the 12 wrapped arteries was occluded by a longer existing thrombus, which is attributed to the surgical technique and the fact that postoperatively no anticoagulation was given. The beneficial effect of the use of Gore-Tex surgical membrane on the prevention of adhesion formation is excellent and this implies that it could be used in coronary artery bypass operations, thus reducing the chance of damage to the bypass in case of reoperation.