Antral Wall Research Articles

Whole stomach with antro-pyloric nerve preservation as an esophageal substitute: an original technique.

The paper describes an original technique of gastric tailoring in which the two-thirds of the lesser curvature proximal to the crow's foot are denuded flush with the gastric wall, leaving both nerves of Latarjet and the hepatic branches of the left vagus nerve intact. Maintenance of the vagal supply to the antro-pyloric segment in two patients resulted in the presence of peristaltic contractions sweeping over the antrum on simple observation of the antral wall at the end of the procedure and on both upper G-I series and intragastric manometry tracings 6 weeks postoperatively. Gastric exposure to bile on 24-h gastric bile monitoring was normal 6 weeks after the operation. Neither patient had any gastrointestinal symptoms with the exception of early sensations of postprandial fullness when overeating.

Maxillary sinus floor elevation: review of anatomy and two techniques.

A review of maxillary sinus floor elevation as an integral part of restoring the posterior maxilla is discussed. The related anatomy of the area and the current techniques available are reviewed. The classic lateral antrostomy pioneered by Tatum appears to be the most common sinus lift procedure. The more conservative crestal approach, advocated by Summers, provides another effective way of allowing implant fixture placement in the atrophic maxilla.

Determinants of transpyloric fluid transport: a study using combined real-time ultrasound, manometry, and impedance recording

Intraluminal impedance recording has made it possible to record fluid transport across the pylorus during the interdigestive state without filling the stomach. During antral phase II, fluid transport occurs with and without manometrically detectable antral contraction. Our aim was to investigate the relationships between ultrasonographic patterns of antral contraction, manometric pressure waves, and transpyloric fluid transport during antral phase II. Antral wall movements were recorded by real-time ultrasound (US) in eight healthy volunteers (mean age 24 +/- 7 yr) during 17 +/- 5 min of antral phase II. Concomitantly, a catheter positioned across the pylorus, monitored by transmucosal potential difference measurement, recorded five impedance signals (1 antral, 1 pyloric, and 3 duodenal) and six manometric signals (2 antral, 1 pyloric, and 3 duodenal). Antral contractions detected by US at the level of the two antral impedance electrodes were classified according to their association with a pyloric opening or a duodenal contraction. Transpyloric liquid transport events (impedance drop of >40% of the baseline with an antegrade or retrograde propagation) and manometric pressure waves (amplitude and duration) were identified during the whole study and especially during each period of US antral contraction. A total of 110 antral contractions was detected by US. Of these, 79 were also recorded by manometry. Fluid transport across the pylorus was observed in 70.9% of the US-detected antral contractions. Pyloric opening was observed in 98.6% of the contractions associated with fluid transport compared with 50% in the absence of fluid transport (P < 0.05). Antral contractions associated with fluid transport were significantly (P < 0.05) more often propagated to the duodenum (92%) than those without fluid transport (53%). Pressure waves associated with fluid transport were of higher amplitude (208 mmHg, range 22-493) and longer duration (7 s, range 2.5-13.5 s) than those not associated with fluid transport (102 mmHg, range 18-329 mmHg, and 4.1 s, range 2-8.5 s; P < 0.05). The propagation of the antral contractions in the duodenum in US was always associated with a pyloric opening, whereas only 8 of the 25 contractions without duodenal propagation were associated with a pyloric opening (P < 0.05). The presence of duodenal contractile activity before the onset of an antral contraction in US was always accompanied by pyloric opening and with fluid transport in 93.3%, compared with 56.8% in its absence (P < 0.05). In antral phase II, US is the most sensitive technique to detect antral contractions. Transpyloric fluid transport observed in relation to antral contractions occurs mainly in association with contractions of high amplitude and long duration and is associated with pyloric opening and/or duodenal propagation.

Intramural Gastric AbscessCase History and Review

Intramural Gastric AbscessCase History and Review

Electrical coupling between the myenteric interstitial cells of Cajal and adjacent muscle layers in the guinea-pig gastric antrum.

Intracellular recordings were made from short segments of the muscular wall of the guinea-pig gastric antrum. Preparations were impaled using two independent microelectrodes, one positioned in the circular layer and the other either in the longitudinal layer, in the network of myenteric interstitial cells of Cajal (ICCMY) or in the circular layer. Cells in each layer displayed characteristic patterns of rhythmical activity, with the largest signals being generated by ICCMY. Current pulses injected into the circular muscle layer produced electrotonic potentials in each cell layer, indicating that the layers are electrically interconnected. The amplitudes of these electrotonic potentials were largest in the circular layer and smallest in the longitudinal layer. An analysis of electrical coupling between the three layers suggests that although the cells in each layer are well coupled to neighbouring cells, the coupling between either muscle layer and the network of ICCMY is relatively poor. The electrical connections between ICCMY and the circular layer did not rectify. In parallel immunohistochemical studies, the distribution of the connexins Cx40, Cx43 and Cx45 within the antral wall was determined. Only Cx43 was detected; it was widely distributed on ICCMY and throughout the circular smooth muscle layer, being concentrated around ICCIM, but was less abundant in the circular muscle layer immediately adjacent to ICCMY. Although the electrophysiological studies indicate that smooth muscle cells in the longitudinal muscle layer are electrically coupled to each other, none of the connexins examined were detected in this layer.

Absence of the interstitial cells of cajal in patients with gastroparesis and correlation with clinical findings

The interstitial cells of Cajal (ICCs) are fundamental in the generation of gastric slow waves. The role of these cells in gastroparesis has not been established. We studied 14 gastroparetic patients (9 diabetic, 4 idiopathic, and 1 postsurgical) for whom standard medical therapy had failed and who had been treated with a gastric electrical stimulator for at least 3 months. All patients had a full-thickness antral gastric wall biopsy at the time of surgery. The biopsy samples were stained with c-kit and scored for the presence of ICCs. Baseline electrogastrogram recordings were obtained for 30 minutes in the fasting state and for 2 hours after a test meal. The patients assessed their total symptom score at baseline and at 3 months. Five patients had almost no ICCs and were compared with nine patients with 20% to normal cell numbers. Both groups did respond symptomatically to gastric electrical stimulation. However, patients with depleted ICCs had significantly more tachygastria and had significantly greater total symptom scores at baseline and after 3 months of gastric electrical stimulation. ICCs are absent in some patients (up to a third) with diabetic or idiopathic gastroparesis, and the absence of these cells is associated with abnormalities of gastric slow waves, worse symptoms, and less improvement with gastric electrical stimulation.

Clinical and radiologic characteristics of the imploding antrum, or “silent sinus,” syndrome

Objectives To present the clinical and radiologic details of a series of patients with the imploding antrum, or silent sinus, syndrome, together with examples of the surgical findings and management. Design Retrospective, noncomparative case series. Participants Fourteen patients assessed in the Orbital Service at Moorfields Eye Hospital. Main outcome measures Changes of clinical signs, symptoms, and radiologic signs. Results Seven men and seven women, between the ages of 25 and 78 years (mean, 41.3 years), had unilateral enophthalmos, their having noted the anomaly for an average of 8 months (range, 1–36 months). All patients were nonsmokers. There was no evidence of progression of the condition in eight cases followed up for up to 63 months. On the affected side, there was 1 to 4 mm enophthalmos and up to 4 mm hypoglobus, with secondary narrowing of the vertical palpebral aperture in some cases, but no effect on visual function, and there was significant disturbance of ocular motility in only one case. The condition is characterized radiologically by a smooth inward bowing of the walls of the maxillary antrum on the affected side, with secondary enophthalmos and hypoglobus. In all 14 cases, the maxillary roof (orbital floor) was drawn downwards, and the medial and posterolateral walls of the maxilla were concave in 13 cases where it could be assessed. In one patient, there was associated inward collapse of the ipsilateral ethmoid complex. There was a patchy loss of mineral from the maxillary roof in 9 of 13 cases and, where the posterolateral maxillary wall was affected, there was a concomitant increase in the radiolucency (fat) of the pterygopalatine fossa. Some soft-tissue changes were present in the affected antrum in all 14 patients, and there was an air–fluid level in three patients. In 12 patients where septal deviation was present, this was to the affected side in 10 (83%), and an abnormally directed middle turbinate was also frequently observed (10 of 14 cases). Conclusions The silent sinus syndrome mainly presents as unilateral enophthalmos in younger people and has very characteristic clinical and radiologic signs with, in many cases, abnormal intranasal anatomic characteristics on the affected side. The condition may be exclusive to nonsmokers. The acute onset and long-term stability of the condition suggests that, although chronic and largely asymptomatic sinus disease may be the underlying cause, an acute event precipitates collapse of the orbital floor or (in fact) a widespread “implosion” of all antral walls resulting from maxillary atelectasis. Therefore, we prefer the term imploding antrum syndrome—describing the relatively acute, symptomatic, event—rather than the name silent sinus syndrome, which relates to a putative underlying mechanism.

Influence of Various Feeding Conditions, the Migrating Myoelectric Complex and Cholinergic Drugs on Antral Slow Waves in Sheep

The presented study was designed to elucidate whether the cholinergic mechanisms control ovine antral slow waves in various physiological conditions, including feeding and various phases of migrating myoelectric complex (MMC). The investigations were carried out on six adult sheep of Polish Merino breed with seven bipolar electrodes surgically implanted onto the antral and small intestinal wall. In the course of chronic experiments, the myoelectric activity was recorded from these regions using the multichannel electroencephalograph. Experiments were performed on 48h fasted and non-fasted animals. During some of these experiments, sheep were fed with standard fodder. During control experiments 0.15M NaCl was slowly administered i.v. through the indwelling catheter and during other experiment, hexamethonium bromide (2.0 and 5.0mg/kg), atropine sulfate (0.02; 0.1; 0.5 and 1.5mg/kg) and pirenzepine dihydrochloride (0.02; 0.5 and 2.0mg/kg) were administered i.v. during phase 1-2a or 2b MMC. The drugs were also given in combinations. The recordings were analysed and the antral slow wave amplitudes and frequencies were calculated. Unlike the slow wave amplitude, either feeding or the anticholinergic drugs significantly increased slow wave frequency, especially when the given procedure was started during phase 2b MMC. The most pronounced effects were observed after hexamethonium given alone or in combinations. Thus, the cholinergic system modulates antral slow wave frequency in sheep.

Freeze-dried bone for maxillary sinus augmentation in sheep. Part II: biomechanical findings.

This study examines the biomechanical loading capacity of dental implants placed in the posterior maxilla in conjunction with subantral augmentation with either homogeneous demineralized freeze-dried bone from sheep (s-DFDB) or heterogeneous demineralized freeze-dried human bone (h-DFDB) as grafting material in sheep. In 36 adult female mountain sheep, the Schneiderian membrane was elevated extraorally in both maxillary sinuses, and two titanium plasma-flame-sprayed cylindrical implants were inserted in each lateral antral wall. Three groups of 18 maxillary sinuses each were augmented with s-DFDB, h-DFDB and autogenous bone from the illiac crest, respectively. In the remaining 18 sinuses, the subantral hollow space was left empty. Pull-out tests were carried out after intervals of 12, 16 and 26 weeks. The mean pull-out force needed, irrespective of time, was 259.3 N in the empty control group, 356.7 N in the group augmented with autogenous bone, 278.1 N in the test group augmented with h-DFDB and 365.2 N in the group augmented with s-DFDB, revealing no significant difference between the individual groups (P > 0.05). The implants of the group augmented with autogenous bone showed an increase in the mean pull-out force from 223.8 N after 12 weeks to 523.7 N after 26 weeks. The nonaugmented control group yielded values of 248 N after 12 weeks, which rose to 269.8 N at the last test, while the values of the h-DFDB group increased from 275.4 N to 325.4 N. The highest initial pull-out values were obtained in the s-DFDB group. They amounted to 310.5 N after 12 weeks and rose to 481.4 N after 26 weeks. Time thus proved to have a significant influence on the pull-out forces (P = 0.014) with a statistically proven linear trend (P = 0.007). The findings of this experimental study indicate that the use of homogeneous DFDB in one-stage sinus lift procedures results in a mechanical loading capacity of implants comparable to that achieved by autogenous cancellous bone from the iliac crest. In contrast, the use of heterogenous-DFDB resulted in only slightly higher pull-out forces than those observed in the nonaugmented control group after 26 weeks.

Mechanical properties in the human gastric antrum using B-mode ultrasonography and antral distension

The aims of this study were to investigate gastric antral geometry and stress-strain properties by using transabdominal ultrasound scanning during volume-controlled distensions in the human gastric antrum. Seven healthy volunteers underwent stepwise inflation of a bag located in the antrum with volumes up to 60 ml. The stretch ratio and Cauchy stress and strain were calculated from measurements of pressure, diameter, and wall thickness. A second distension series was conducted in three volunteers during administration of the anticholinergic drug butylscopolamine. Analysis of stretch ratios demonstrated positive strain in the circumferential direction, negative strain in the radial direction, and no strain in the longitudinal direction. The stress-strain relation was exponential and did not differ without or with the administration of butylscopolamine. The wall stress was decomposed into its active and passive components. The well-known length-tension diagram from in vitro studies of smooth muscle strips was reproduced. The maximum active tension appeared at a volume of 50 ml, corresponding to a stretch ratio of 1.5. We conclude that the method provides measures of antral biomechanical wall properties and can be used to reproduce the muscle length-tension diagram in humans.

Endoscopically assisted Le Fort I osteotomy

Objectives: A new technique of the Le Fort I osteotomy using endoscopic techniques through limited approaches has been evaluated. Patients: This technique was first carried out successfully in a study on six cadavers. Thereafter we performed endoscopically assisted Le Fort l osteotomy in two patients. Methods: Four vertical incisions were used in the vestibule (paranasally and posteriorly) as approaches. The endoscope allowed direct visualization of the osteotomy of the maxilla including the pterygomaxillary junction. The osteotomies could be accomplished with a straight 4 mm osteotome for medial and lateral antral walls and nasal septum and a curved osteotome for the pterygomaxillary junction. Results: The procedures were successful. The descending palatal arteries could be preserved in all cases as a result of endoscopic control. Rigid fixation of the downfractured maxillae was carried out using self-drilling titanium screws and plates. Conclusion: Endoscopic visualization allowed safe osteotomy of the medial antral wall preserving the descending palatal artery in all cases and hence less bleeding. Postoperative oedema and swelling in the two clinical cases was definitely reduced when compared with the conventional technique. The time needed for these first two clinical cases was approximately 1 h 30 min, i.e., about 30 min more than with the open technique. Further experience and experimental work, and refinements in technique will help to improve this procedure in its clinical application.

Cocaine-induced midline destructive lesions: clinical, radiographic, histopathologic, and serologic features and their differentiation from Wegener granulomatosis.

Cocaine-induced midline destructive lesions: clinical, radiographic, histopathologic, and serologic features and their differentiation from Wegener granulomatosis.

Do differences exist in electrogastrogram (EGG) parameters among gastroparetic patients refractory to standard therapy compared to those responding to standard prokinetic therapy?

The interstitial cells of Cajal (ICCs) are fundamental in the generation of gastric slow waves. The role of these cells in gastroparesis has not been established. We studied 14 gastroparetic patients (9 diabetic, 4 idiopathic, and 1 postsurgical) for whom standard medical therapy had failed and who had been treated with a gastric electrical stimulator for at least 3 months. All patients had a full-thickness antral gastric wall biopsy at the time of surgery. The biopsy samples were stained with c-kit and scored for the presence of ICCs. Baseline electrogastrogram recordings were obtained for 30 minutes in the fasting state and for 2 hours after a test meal. The patients assessed their total symptom score at baseline and at 3 months. Five patients had almost no ICCs and were compared with nine patients with 20% to normal cell numbers. Both groups did respond symptomatically to gastric electrical stimulation. However, patients with depleted ICCs had significantly more tachygastria and had significantly greater total symptom scores at baseline and after 3 months of gastric electrical stimulation. ICCs are absent in some patients (up to a third) with diabetic or idiopathic gastroparesis, and the absence of these cells is associated with abnormalities of gastric slow waves, worse symptoms, and less improvement with gastric electrical stimulation.

Internal Augmentation of the Alveolar Crest with the Sinus Membrane for Guided Bone Regeneration

Summary The artificially created subantral space is a strongly osteoregenerative host site. Simple elevation of Schneider's membrane can be expected to initiate limited new bone growth and support ridge augmentation. Because of its low complication rate in properly selected patients, internal ridge augmentation is preferred to external augmentation procedures. Porous and bovine HA for augmentation produces a comparable and adequate formation of new bone along the implant surface at 26 weeks. Because bone formation varied considerably within the study groups, the individual outcome of augmentations cannot be predicted with certainty. The retention of the foreign material impairs the pattern of bony consolidation for some time. Freeze-dried bone alone cannot be recommended for internal augmentation of the alveolar ridge. Although subject to considerable shrinkage, free bone autografts produce the most reliable results because they are consistently and completely incorporated in the host bone. Future studies must show whether the negative properties described can be mitigated by mixing different augmentation materials. Because the implants were placed in the lateral antral bony wall in this study without functional loading, an impact of mastication on the bone apposition rate and on bone remodeling was unlikely. Implant placement in the occlusal plane may well result in different remodeling processes.

Relationship between ultrasonically detected phasic antral contractions and antral pressure.

The relationships between gastric wall motion and intraluminal pressure are believed to be major determinants of flows within and from the stomach. Gastric antral wall motion and intraluminal pressures were monitored in five healthy subjects by concurrent antropyloroduodenal manometry and transabdominal ultrasound for 60 min after subjects drank 500 ml of clear soup. We found that 99% of antral contractions detected by ultrasound were propagated aborally, and 68% of contractions became lumen occlusive at the site of the ultrasound marker. Of the 203 contractions detected by ultrasound, 53% were associated with pressure events in the manometric reference channel; 86% of contractions had corresponding pressure events detectable somewhere in the antrum. Contractions that occluded the lumen were more likely to be associated with a pressure event in the manometric reference channel (P < 0.01) and to be of greater amplitude (P < 0.01) than non-lumen-occlusive contractions. We conclude that heterogeneous pressure event patterns in the antrum occur despite a stereotyped pattern of contraction propagation seen on ultrasound. Lumen occlusion is more likely to be associated with higher peak antral pressure events.

Surgical management of chronic maxillary atelectasis

Chronic maxillary atelectasis (CMA) results from valvular occlusion of the natural ostium of the maxillary sinus by the medial infundibular wall. This uncommon condition is characterized by a chronic decrease in sinus volume caused by inward bowing of one or more antral walls. In some instances, visual and cosmetic problems can occur as a consequence of severe osseous wall deformation. CMA is seen in both children and adults, and radiological evidence of complete antral opacification and fontanel retraction is considered diagnostic of the disorder in both populations. Treatment goals are the same for all age groups and include complete antral drainage and restoration of good ventilation.

Heterotopic pancreas in the stomach: CT findings.

To describe the computed tomographic (CT) findings of heterotopic pancreas in the stomach. CT findings in 12 patients with heterotopic pancreas in the stomach were reviewed. Surgical resection (n = 11) or endoscopic excision (n = 1) was performed in cases of symptomatic heterotopic pancreas (n = 4), suspected submucosal tumors (n = 7), and gastric carcinoma (n = 1). Seven patients underwent helical CT with water as an oral contrast agent; five underwent nonhelical CT with water-soluble contrast material. Nine heterotopic pancreata were in the antrum and one each was in the body, fundus, and perigastric fat. Seven lesions were on the greater curvature aspect; five, on the lesser curvature aspect. Common CT findings were well-defined oval or round masses with smooth or serrated margins in the gastric antral wall. Four of the seven lesions in which helical CT was performed enhanced similarly to normal pancreas. Preoperatively, CT depicted 11 of the 12 lesions, but CT findings were interpreted correctly as heterotopic pancreas in only two; the remaining 10 were misinterpreted as other lesions. Atypical findings were cystic dilatation of heterotopic pancreatic duct in two, unusual location in the fundus or perigastric fat in two, and malignant transformation in one. CT findings of heterotopic pancreas in the stomach appear to be nonspecific for diagnosis, except for location.

Cellular expression of the neurokinin 1 receptor in the human antrum

The localization of the neurokinin 1 receptor in rat and guinea pig gastrointestinal tract has been extensively studied but not in human tissues. The present study used antibodies to characterize the cellular expression of neurokinin 1 receptors in human antrum. Cryostat sections (40–80 μm) were immunostained for the neurokinin 1 receptor double labeled with substance P, von Willebrand’s factor, c-kit, fibronectin, S-100, serotonin, gastrin and somatostatin. Neurokinin 1 receptor-immunoreactivity was observed on neurons within the myenteric and submucosal plexuses surrounded by substance P-immunoreactive fibers and on von Willebrand’s factor-immunoreactive endothelial cells lining blood vessels throughout the antral wall. c-Kit-immunoreactive interstitial cells of Cajal and gastrin cells were co-stained by the monoclonal neurokinin 1 receptor antibody. Finally, there was no evidence for the presence of the neurokinin 1 receptor on fibroblasts, Schwann, somatostatin, serotonin or smooth muscle cells. This study clearly demonstrates an expanded cellular expression of the neurokinin 1 receptor in the human antrum.

Motilin receptors in the human antrum.

Motilin is an intestinal peptide that stimulates contraction of gut smooth muscle. The motilin receptor has not been cloned yet, but motilin-receptor agonists appear to be potent prokinetic agents for the treatment of dysmotility disorders. The aim of this study was to determine neural or muscular localization of motilin receptors in human upper gastrointestinal tract and to investigate their pharmacological characteristics. The binding of (125)I-labeled motilin to tissue membranes prepared from human stomach and duodenum was studied; rabbit tissues were used for comparison. Solutions enriched in neural synaptosomes or in smooth muscle plasma membranes were obtained. Various motilin analogs were used to displace the motilin radioligand from the various tissue membranes. The highest concentration of human motilin receptors was found in the antrum, predominantly in the neural preparation. Human motilin receptors were sensitive to the NH(2)-terminal portion of the motilin molecule, but comparison with rabbit showed that both species had specific affinities for various motilin analogs [i.e., Mot-(1-9), Mot-(1-12), Mot-(1-12) (CH(2)NH)(10-11), and erythromycin]. Motilin receptors obtained from synaptosomes or muscular plasma membranes of human antrum expressed different affinity for two motilin-receptor agonists, Mot-(1-12) and Mot-(1-12) (CH(2)NH)(10-11), suggesting that they correspond to specific receptor subtypes. We conclude that human motilin receptors are located predominantly in nerves of the antral wall, are functionally (and probably structurally) different from those found in other species such as the rabbit, and express specific functional (and probably structural) characteristics dependent on their localization on antral nerves or muscles, suggesting the existence of specific receptor subtypes, potentially of significant physiological or pharmacological relevance.

The diagnosis and treatment of chronic maxillary atelectasis in adults and children

Chronic maxillary atelectasis (CMA) is an uncommon condition thought to develop when the medial infundibular wall causes valvular occlusion of the natural ostium. The disorder is characterized by a persistent decrease in maxillary sinus volume due to inward bowing of one or more antral walls. Clinic