Location Of Fissure Research Articles

Long-term follow-up (42 months) of chronic anal fissure after healing with botulinum toxin

Background & Aims: Botulinum toxin is an effective treatment in idiopathic chronic anal fissure, but the long-term outcome after healing is not well documented. We analyzed the long-term outcome of patients in whom an anal fissure had healed after botulinum toxin injection and the factors contributing to recurrence. Methods: Fifty-seven patients who had completely healed 6 months after injection of botulinum toxin were reassessed every 6 months. The follow-up was 42 months in all patients. Clinical and manometric differences between the permanently healed and the relapsed group were statistically analyzed. Results: Four patients were lost to follow-up. A fissure recurrence was shown in 22 patients (41.5%). Statistical differences between the permanently healed and the relapsed group were detected when analyzing the anterior location of the fissure (6% vs. 45%), a longer duration of the disease (38% vs. 68%), the need for reinjection (26% vs. 59%), a higher total dose injected to achieve definitive healing (13% vs. 45%), and the percentage decrease of maximum squeeze pressure after injection (−28% vs. −13%; P < 0.05). Conclusions: The late recurrence rate of chronic anal fissure is high when the effect of botulinum toxin disappears. The highest risk of recurrence is associated with anterior location of the anal fissure, prolonged illness, the need for reinjection and for high doses to achieve healing, and a lower decrease of maximum squeeze pressure after treatment.GASTROENTEROLOGY 2002;123:112-117

A silicon array detector for high-energy betas

The detection of significant levels of certain gamma and beta emitting isotopes could allow on-site Inspection teams working under the Comprehensive Test Ban Treaty to localize probable vent and fissure locations. Thus, sophisticated drilling and radionuclide measurements could then be made more effectively allowing for a higher probability of correctly identifying a nuclear event. In order to address this need we have developed a silicon array coupled with a Nal for detecting gammas, high-energy betas, and beta–gamma coincidences. The pursuit of this detection method is now viable since large-area, high-purity silicon wafers are now commercially available making this layered, large-area technique technically and economically feasible. We have designed, constructed, and tested a prototype detector system and we will present out initial test data.

Source modelling of the rolandic focus

In rolandic epilepsy, consideration of the stereotyped ictal symptomatology suggests that the epileptic zone is likely to be in the same cortical structure in different patients. Routine EEG tracings of the interictal spike activity suggests a deep Sylvian fissure location. On the basis of the predominantly tangential potential field at the peak spike negativity seen in this group of patients, the inferior bank of the Sylvian fissure appears to be a good candidate. Without invasive studies, little refinement to this rather imprecise localization can be made as there is neither neurologic deficit nor lesion to provide a marker on radiological imaging. However, the application of source modelling technique using a simple single-dipole spherical head model has resulted in improved understanding of the generator behaviour, and facilitated the generation of new ways of analyzing spikes (e.g., stability index). Review of newer quantitative approaches including matrix and singular value decomposition of the dataset, spatial-temporal constrained source estimates etc. suggest other fruitful approaches. At least in some patients with partial epilepsy, the source characteristics of interictal scalp spikes appear to contain information of the ictal generator. Under certain circumstances, such derived information which is not otherwise available from routine electrophysiology may influence clinical management and prognosis. This is an additional bonus to the primary objectives of quantification and data reduction.

Location and orientation of eruptive fissures and feederdykes at Mount Etna; influence of gravitational and regional tectonic stress regimes

Lava extrusion from fissures on the flanks of the Etna volcano is a common feature of recent activity, as evidenced by the eruptions of 1971, 1981, 1983, and 1985, and was of similar importance during prehistoric times. We propose here a model within which the location and orientations of the large majority of historic eruptive fissures on Etna's flanks, together with their feeder-dykes, are explained within the framework of a gravitational stress regime. Stress orientations within this regime are controlled largely by the gross morphology of the volcano, but are significantly modified by local topographic anomalies. We propose that the gravitational stress regime largely supercedes an earlier developed regional tectonic stress regime, which still operates in the sub-volcanic basement, and may remain the dominant control of eruptive fissure and feeder-dyke disposition at lower altitudes on the flanks. The proposed model is supported by: (1) detailed examination of fissure locations and orientations, and the relationship between fissure azimuths and topography; (2) precise horizontal distance measurement and vertical ground deformation studies of a recent eruption; and (3) qualitative physical modelling experiments in which coloured water is injected into solidified gelatine solutions representing variously shaped volcanic constructs. A cautious approach is advocated when extrapolating trends of spatially limited fissure segments for the purpose of locating potential sites of magma ascent, and implications of the model for hazard analysis are outlined.

The magnetic and electric fields agree with intracranial localizations of somatosensory cortex.

We measured the magnetoencephalogram (MEG), electroencephalogram (EEG), and electrocorticogram (ECoG) after stimulation of contralateral median nerve in four patients with partial epilepsy evaluated for surgery. Quantitative localization estimates from equivalent source modeling were compared with locations of central fissure in hand sensorimotor area determined by cortical stimulations, intraoperative photographs, and examination after excision in frontal lobe. We also measured MEG and EEG in nine control subjects. MEG and EEG localizations were within 2.5 cm of the estimated location of central fissure in all 13 subjects. In the three patients who had complete mapping of all three fields, the average distance of localizations from central fissure was approximately 4 mm in both MEG and EEG, 3 mm in ECoG, and 3 mm in combined MEG and EEG. MEG was simpler than EEG, which was simpler than ECoG. MEG resolved ambiguities in both EEG and ECoG. The combination of the three fields added information about the spatiotemporal activity of somatosensory cortex. Localization of central fissure was essential to surgical treatment.

A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation: XV. Chronic anal fissure: A new theory of pathogenesis

Pathologic changes in chronic anal fissures were studied in 52 patients. In 40 patients, epithelial cells could be identified in the fissure floor superficial to the internal anal sphincter. The cells were rounded, oval, or columnar and were arranged in clumps or pseudoacinar formations. In 10 patients the anorectal sinus was detected in the fissure floor, whereas in 2 patients no epithelial cells could be found. It seems that chronic anal fissure results from disruption of the anal lining, which exposes epithelial cells or the anorectal sinus in the wound floor to repeated infection. It is believed that these epithelial cells are just anorectal sinus remnants that exist in the submucosa of the anal canal proper as epithelial debris or anorectal band. Epithelial cells act as multiple sequestra that harbor the infection and are responsible for fissure chronicity. These patients are predisposed to anal traumatization by feces, owing to the anorectal band's constricting effect on the anal canal proper. The exclusive fissure location in the anal canal proper and not in the rectal neck is due to the anorectal sinus remnants contained therein. The posterior and, rarely, anterior median fissure position is ascribed to the existence of two weak anal areas. The break commonly occurs posteriorly because the posterior anal wall lacks sufficient support. It is concluded that fissure excision, including anorectal bandotomy, at present, is the best treatment to achieve a radical cure.

Water quality as affected by a Wyoming mountain bog

Waters collected July through October 1965 at a Wyoming mountain bog were analyzed for potability and seasonal changes in calcium, magnesium, potassium, iron, and silica. Four locations were sampled: effluent stream, fissure locations in the bog, peat locations in the bog, and ground water. The color and turbidity of peat water greatly exceeded that at other locations and the maximum levels established by the U. S. Public Health Service for drinking water. The dissolved mineral content of all waters was very low, and the waters were of excellent chemical quality. All waters contained coliform organisms, probably of a nonfecal origin in peat and fissure water. The concentration of minerals in peat water remained constant through the sampling period. Mineral concentrations in ground water increased in September, when the water table was at a seasonal minimum, but decreased in October following water table recharge. Silica levels were higher than other ions at all locations; the highest levels were in peat water.

FISSURE OF THE ANUS.Read in the Section on Surgery and Anatomy, at the Forty-fifth Annual Meeting of the American Medical Association, held at San Francisco. June 5-8, 1894.

The lesion known as fissure of the anus is an elongated oval ulcer from one-fourth of an inch to an inch in extent and of variable depth. By many authors it is designated irritable ulcer or painful ulcer of the anus. Bodenhamer classified fissures, according to location, into four varieties; but for the purpose of this paper the term will be applied to those having their seat in the skin and mucous membrane, external to the white line of Hilton, the line of demarkation between the external and internal sphincter muscles. The favorite location of anal fissure is upon the dorsal surface but this general rule has many exceptions. It may consist of a small linear abrasion, capable of detection only by careful inspection, but more often it will be observed as an indolent ulcer with indurated base and rigid walls varying in depth from one to three lines. Externally