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PubMed1992

The appendix as a continence mechanism.

Although we have progressed very well in creating large capacity, low pressure reservoirs, the construction of a simple and reliable continent outlet still remains a problem. The appendix vermiformis serves well as a continence mechanism for either the bladder or intestinal reservoirs for urine. The different surgical techniques described in the literature are reviewed and discussed in this context. Moreover, we report on our clinical and experimental results of using the appendix during the Mainz pouch procedure for continent urinary diversion.

Adolescent↗
PubMed1973

Some characteristics of the rabbit vermiform appendix as a secreting organ.

It has been confirmed that the rabbit vermiform appendix secretes spontaneously at a relatively rapid rate (1-12 ml.h(-1); 1.4+/-0.24 mul.min(-1).cm(-2)). The electrolyte composition is similar to that of ileal fluids and independent of the secretory rate. The transmural potential difference is about 12 mV, mucosa negative. Of the major electrolytes, only HCO(3) (-) is secreted grossly against its electrochemical potential difference. This finding plus the low hydraulic (or osmotic) permeability (L(p)) and high secretory pressures of the organ strongly suggest that the secretion is an active one. The passive permeability to Na(+) and Cl(-) appears to be, at most, somewhat less than for small bowel. Permeability to mannitol was estimated at 2.5 x 10(-7) cm.s(-1). On the basis of reasonable assumptions and results with luminal test solutions of differing osmolarities, it was concluded that (a) the L(p) of the appendiceal epithelium is in the lower range of values reported for small bowel and colon; (b) the L(p) is higher for osmotic absorption than for osmotic secretion; and (c) the rate of spontaneous secretion is insensitive to luminal anisotonicity over a wide range of values. But sufficiently hypotonic solutions can reverse net secretion to net absorption, more by inhibiting spontaneous secretion than increasing osmotic absorption. The rabbit vermiform appendix appears to be a useful model for the elucidation of intestinal secretory processes.

Animals↗
PubMed1988

Blood vascular organization of the human appendix: a scanning electron microscopic study of corrosion casts.

Blood vascular beds of the human appendix were reproduced with a methacrylate casting medium and observed with a scanning electron microscope. The appendix received some small afferent arterial branches of the appendicular artery. These small arterial branches pierced the muscular layer and reached the submucosal plexus. Small arterioles arising from this plexus, climbed the mucosa and formed honeycomb-like capillary meshes at the luminal surface level. These capillaries were drained by the collecting veins, which descended the mucosa and joined the submucosal plexus. The large efferent veins arising from the submucosal plexus passed through the muscular layer and continued with the appendicular vein. In the mucosal and submucosal layers, several spherical basket-like casts of the germinal center (lymphoid follicle) were seen. In the parafollicular region (primary follicle), casts of postcapillary venules with prominent surface undulations were relatively frequently observed.

Adult↗
PubMed1985

Intercellular spaces in the lymph nodule associated epithelium of the rabbit Peyer's patch and appendix.

Intercellular spaces in the epithelium of the rabbit Peyer's patch and appendix were examined by scanning and transmission electron microscopy to elucidate their three-dimensional structure and their relationship to the reticular spaces in the underlying lymph nodule. Two types of intercellular spaces were distinguished: regularly arranged tubular channels and irregularly winding tunnels. The tubular channels were observed around normal enterocytes on the villi or internodular folds and apical portions of nodule domes. The channel spaces were lined with a successive arrangement of belt-like intercrestal surfaces of prismatic enterocytes and variously sized processes on the crests. The processes adjoining opposed crests formed a ladder-like structure or pectinate septa between neighboring channels. The irregularly winding tunnels were formed among processes of irregularly shaped cells corresponding to FAE cells (Bockman and Cooper, 1973) or M cells (Owen and Jones, 1974) in the nodule associated epithelium. In the appendix, the tunnels were frequently organized into two-story spaces, the adlumenal and basal spaces, which were incompletely separated by cytoplasmic processes. These tunnels continued by pores in the basement membrane to the reticular spaces in the underlying lymph nodules. Furthermore, the tunnels and the basement membrane pores constantly contained single or grouped free cells or their processes. The findings in the present study suggest that the tubular channels are intraepithelial compartments for the absorption of nutrients and fluid, and the irregular tunnels are an intraepithelial network of spaces for the housing of lymphoid cells coming from the underlying lymph nodule.

Animals↗
PubMed1977

Gas-filled appendix: lack of diagnostic specificity.

Three patients with a gas-filled appendix in association with acute abdominal symptoms are described. In each case the gas-filled appendix was located in the right lower quadrant. None of the patients had appendicitis. It is emphasized that this combination of findings is not neccessarily diagnostic of appendicitis. Clinical evaluation is important in assessing the significance of this sign.

Abdomen↗
PubMed1987

Natural history of the obstructed rabbit appendix: observations with radiography, sonography, and CT.

Chronic (1-3 months' duration) appendiceal obstruction was induced in 11 rabbits to assess the pathologic consequences and to study the associated radiologic, sonographic, and CT findings. Three pathologic/radiologic groups resulted with approximately equal frequency. In group A, the abscess was characterized by inflammatory cells in the lumen and wall of the appendix without mucin production. Calcification was shown radiographically, and sonography showed an anechoic or complex pattern. Group B, the "mixed response," was characterized by an intact hyperplastic mucosa, mucin secretion, and inflammatory debris in the lumen. Occasional calcification was present radiographically, and sonography showed a complex or hypoechoic pattern. In group C, true mucoceles had an intact hyperplastic mucosa, a mucin-filled lumen, and minimal inflammation. These were anechoic on sonography except for mobile foci of inflammatory debris. Chronic obstruction of the appendix results in a spectrum of pathologic responses with varying degrees of either inflammation and mucosal destruction or mucosal hyperplasia and mucin secretion. An abscess results when infection overwhelms the host's inflammatory responses. If the bacteria are destroyed by these defenses, a mucocele forms. An intermediate situation occurs when there is a mixed response with chronic inflammatory changes and an intact mucosa. This finding supports the existence of chronic appendicitis in humans.

Animals↗
PubMed1977

Pathological changes in the appendix: a review of 1000 cases.

The pathological changes occurring in a series of 1000 consecutive appendicectomies are reviewed. Normal appendix was diagnosed in 14% of cases, while 561 (56%) exhibited acute appendicitis; 53 (5%) had chronic inflammatory infiltrate associated with obliteration of the lumen of the tip of the appendix. Epithelial abnormalities included carcinoid tumours (1.4%), and primary appendiceal adenocarcinoma (1 case). There were a large variety of other abnormalities found and each one is briefly described.

Acute Disease↗
PubMed1992

Age, site and distribution of subepithelial neurosecretory cells in the appendix.

The appearance of subepithelial neurosecretory cells (SNC) was investigated by studying completely sampled appendices of 50 children, adolescents and adults. The cells were demonstrated using lead hematoxylin, a selective stain for neurosecretory cells. Additional routinely sampled specimens were also studied for comparison. In children up to the age of 9 yrs only occasional SNC were found. After this age, however, SNC were present in most appendices and in greater numbers. The majority of SNC were located in the distal portion of the appendix, with only small numbers of these cells being present in the proximal segment. Occasional SNC-like cells were identified in the appendiceal submucosa in all regions of the appendix at all ages. This lends support to the hypothesis that a correlation exists between the presence of increased numbers of SNC, patient age and the site distribution of both acute appendicitis and appendiceal carcinoid tumors.

Adolescent↗
PubMed1975

B cells in the appendix and other lymphoid organs of the rabbit: complement receptor lymphocytes.

Complement receptor lymphocytes were demonstrated in rabbit lymphoid organs, the spleen containing the highest numbers (35%) and the thymus none. Extremely variable numbers (up to 50%) were detectablein the appendix. B and T cell depletion, rosette depletion, and histologic staining indicate that these CRL are B cells in the rabbit as in other species. The variable behavior of B cells in the appendix suggests a difference between this lymphoid organs population and those of other rabbit lymphoid organs.

Animals↗
PubMedDate not supplied

Localization of T and B lymphocytes in human adenoid, tonsil, appendix and Peyer's patches.

T and B lymphocytes were detected in human adenoid, tonsil, appendix and Peyer's patches by adherence to sheep erythrocytes (E) and human erythrocytes sensitized with antibody and complement (HEAC). The percentages of T lymphocytes in adenoid and tonsil cell suspensions averaged 30.9 +/- 3.4 (S.D.) and 35.8 +/- 6.4 (S.D.). The percentages of B lymphocytes in the same tissues were 42.5 +/- 11.3 (S.D.) and 40.1 +/- 34 (S.D.) respectively. In adenoid and tonsil tissue sections, B lymphocytes were found in the follicles and T lymphocytes were detected around the follicular areas. The predominant cell population in Peyer's patches and appendix sections was constituted by B lymphocytes.

Adenoids↗
PubMed1975

Early lymphoepithelial relationships in human appendix. A combined light- and electron-microscopic study.

The fine structure of human appendix was studied from the earliest stages of lymphoid development in fetuses to the definitive relationships found in children up to 8 years old. Follicular accumulations of lymphocytes were observed first in the mesenchyme immediately beneath epithelium which contained a predominance of goblet cells on the surface and in the crypts. Larger accumulations of lymphoid cells in older fetuses were intimately related to surface epithelium but not to the epithelium of crypts. At the point of invasion of lymphoid cells into surface epithelium, the goblet cell population diminished and epithelial cells displaying a morphologically distinct form of differentiation were observed. They were characterized by the presence of irregular microvilli or microfolds and numerous apical micropinocytotic vesciles. This follicle-associated epithelium (FAE) appeared ultrastructurally identical with epithelium in chicken bursa of Fabricius, mouse Peyer's patch, and rabbit appendix, which has been shown to be capable of transporting ferritin and India ink tracer from the lumen to underlying tissue. It appeared identical to specialized epithelial cells of adult human Peyer's patches. FAE was maintained through the neonatal period into childhood. We speculate that the biological significance of FAE is to provide a channel through which antigens may stimulate clonal proliferation and seeding of B-lymphocytes throughout the lamina propria of internal mucous surfaces.

Appendix↗
PubMed1976

Perforated appendix in situs inversus viscerum. A case report.

A patient with situs inversus viscerum and a perforated left-sided appendix is reported. The embryological anomalies which result in a left-sided appendix are mentioned. Although the viscera are transposed, it is thought that the components of the nervous system which supply the affected organs are not reversed. Diagnostic difficulties are mentioned.

Adult↗
PubMed1976

Crohn's disease of the appendix presenting as acute appendicitis.

A patient is reported who initially presented with findings simulating acute appendicitis and who was subsequently found to have Crohn's disease isolated to the appendix. Although the hazard of appendectomy in Crohn's disease is well known, it is interesting that none of the known patients with isolated appendiceal Crohn's disease has developed a fistula. Three of the 15 reported cases of Crohn's disease solely involving the appendix developed granulomatous changes involving other regions of the bowel as long as four years following the initial diagnosis. Because of the rarity of this condition, however, specific conclusions regarding the likehood of future recurrence cannot be drawn. We stress increased physician awareness of this entity in order to emphasize long-term follow-up for such patients.

Acute Disease↗
PubMed1992

Use of the appendix for urethral reconstruction in children with congenital anomalies of the bladder.

BACKGROUND: The presence of the cecal appendix offers a unique opportunity for the achievement of urinary continence and stable access to the reconstructed urinary bladder. METHODS: We have reviewed the cases of 17 children treated over a 56-month period whose urinary anomalies have required the construction of a neourethra. Fourteen of these patients underwent neourethral reconstruction by use of the appendix. RESULTS: All neourethras are easily catheterized, and all are continent. CONCLUSIONS: The ease of application of this reconstructive modality along with its high success rate makes incidental appendectomy contraindicated in children with congenital anomalies of the bladder.

Adolescent↗
PubMed1992

[Ileocecum with appendix in reconstruction of bladder and urethra].

New bladder and urethra were reconstructed by transplanting the ileocecum with appendix and part of the ascending colon. Ileocecal valve was used to prevent urine reflux into the ureters. The appendix and its seromuscular layer were used as "sphincter muscle" to prevent overflow of urine in the cecum. From March, 1988, to October, 1991, 38 cases of carcinoma of bladder were treated by this way. Follow-up for 0.5 to 3.5 years showed that the reconstructed bladder had large capacity, good urination function, no electrolyte disorder, urine reflux and infection of renal pelvis.

Adult↗
PubMed1992

[Mucocele of the appendix in highly differentiated adenocarcinoma].

A patient 69 years old had been admitted at the University Women's Hospital Berlin because of a suspected ovarian tumour. Outside a computed tomography was done. In the small pelvis a tumour partly cystic and partly solid at the right side could be confirmed sonographically. Because this an operation was indicated. After opening the abdomen the internal female genital organs were in conspicuous with the exception of extensive adhesions. Histologically we found a mucocele of the vermiform appendix with a highly differentiated adenocarcinoma. All tissue layers were infiltrated and perforated. This combination of findings is very seldom, because carcinomas of the appendix could be proved only in 0.01 per cent of all appendectomies.

Adenocarcinoma↗
PubMed1992

Appendix as continent urinary reservoir outlet.

The submucosally embedded in situ appendix offers an ideal continence mechanism in patients with ileocaecal urinary reservoir. Ninety-two patients who underwent this procedure at three urology centres (48 patients in Mainz, 20 in Wuppertal-Barmen and 24 in Marburg) are reviewed. The appendicocutaneous stoma was placed in the lower right abdominal quadrant in 12 patients (most of whom previously had bladder exstrophy) and into an umbilical or, in some exstrophy cases, a neoumbilical tunnel in 80 patients. Urodynamic investigations of the submucosally embedded appendix showed maximum closure pressure greater than 80 cm H2O.

Appendix↗
PubMed1992

Mucocele of the appendix: computed tomographic, endoscopic, and pathologic correlation.

Mucoceles of the appendix are a rare group of lesions thought to occur as a sequelae of luminal obstruction as well as certain benign and malignant neoplasms of the appendix. Early, preoperative diagnosis is rare. We report a case of an appendiceal mucocele in which the diagnosis was suggested by computed tomographic imaging and colonoscopy, and confirmed at surgery. Radiologic, endoscopic, and pathologic correlations of this rare entity are discussed.

Aged↗