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Peter J Kahrilas - One of the best experts on this subject based on the ideXlab platform.
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the diagnosis and management of Hiatus hernia
BMJ, 2014Co-Authors: Sabine Roman, Peter J KahrilasAbstract:#### Summary points Hiatus hernia is a condition involving herniation of the contents of the abdominal cavity, most commonly the stomach, through the diaphragm into the mediastinum. In the United States, Hiatus hernia was listed as a primary or secondary cause of hospital admissions in 142 of 10 000 inpatients between 2003 and 2006.1 However, the exact prevalence of Hiatus hernia is difficult to determine because of the inherent subjectivity in diagnostic criteria. Consequently, estimates vary widely—for example, from 10% to 80% of the adult population in North America.2 It is, however, accepted that the prevalence of Hiatus hernia parallels that of obesity and that it increases with age. The typical symptom of Hiatus hernia is gastroesophageal reflux (heartburn, regurgitation). Less common symptoms are dysphagia, epigastric or chest pain, and chronic iron deficiency anaemia. This clinical review summarises the current evidence for the diagnosis and management of Hiatus hernia. #### Sources and selection criteria We based this review on articles identified through a search of PubMed using the term “hiatal hernia” on 12 August 2014. Largely because of the extensive literature on reflux disease and the overlap between reflux disease and Hiatus hernia, the search returned over 4500 citations, even when limited to publications in the English …
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approaches to the diagnosis and grading of hiatal hernia
Best Practice & Research in Clinical Gastroenterology, 2008Co-Authors: Peter J Kahrilas, Hyon C Kim, John E PandolfinoAbstract:Hiatus hernia refers to conditions in which elements of the abdominal cavity, most commonly the stomach, herniate through the oesophageal Hiatus into the mediastinum. With the most common type (type I or sliding Hiatus hernia) this is associated with laxity of the phrenooesophageal membrane and the gastric cardia herniates. Sliding Hiatus hernia is readily diagnosed by barium swallow radiography, endoscopy, or manometry when greater than 2 cm in axial span. However, the mobility of the oesophagogastric junction precludes the reliable detection of more subtle disruption by endoscopy or radiography. Detecting lesser degrees of axial separation between the lower oesophageal sphincter and crural diaphragm can only be reliably accomplished with high-resolution manometry, a technique that permits real time localization of these oesophagogastric junction components without swallow or distention related artefact.
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increased frequency of transient lower esophageal sphincter relaxation induced by gastric distention in reflux patients with hiatal hernia
Gastroenterology, 2000Co-Authors: Peter J Kahrilas, Michael Manka, Guoxiang Shi, Raymond J JoehlAbstract:Abstract Background & Aims: This study aimed to determine if hiatal hernia influences vulnerability to reflux and transient lower esophageal sphincter relaxation (tLESR) during gastric distention in patients with gastroesophageal reflux disease (GERD). Methods: Eight normal subjects and 15 patients with GERD were studied. A metal clip attached to the squamocolumnar junction (SCJ) was beneath the Hiatus in all control subjects. Eight GERD patients with ≥1-cm SCJ-Hiatus separation were considered hernia patients, and 7 with Results: Baseline reflux was comparable among groups. Gastric distention increased the frequency of reflux by the tLESR mechanism in all groups. Controls and nonhernia patients had median increases of 4.0 and 4.5 in tLESR frequency, respectively, and hernia patients had a median increase of 9.5/h. tLESR frequency was highly correlated with the SCJ-Hiatus separation ( r = 0.76; P Conclusions: Gastric air infusion was a potent stimulus for tLESR and reflux. The resultant tLESR frequency was directly proportional to the separation between the SCJ and Hiatus, suggesting that the perturbed anatomy associated with hiatal hernia predisposed to eliciting tLESRs in patients with GERD. GASTROENTEROLOGY 2000;118:688-695
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the effect of Hiatus hernia on gastro oesophageal junction pressure
Gut, 1999Co-Authors: Peter J Kahrilas, Shezhang Lin, J Chen, Michael MankaAbstract:BACKGROUND Hiatus hernia and lower oesophageal sphincter hypotension are often viewed as opposing hypotheses for gastro-oesophageal junction incompetence. AIMS To examine the interaction between Hiatus hernia and lower oesophageal sphincter hypotension. METHODS In seven normal subjects and seven patients with Hiatus hernia, the squamocolumnar junction and intragastric margin of the gastro-oesophageal junction were marked with endoscopically placed clips. Axial and radial characteristics of the gastro-oesophageal junction high pressure zone were mapped relative to the Hiatus and clips during concurrent fluoroscopy and manometry. Responses to inspiration and abdominal compression were also analysed. RESULTS In normal individuals the squamocolumnar junction was 0.5 cm below the Hiatus and the gastro-oesophageal junction high pressure zone extended 1.1 cm distal to that. In those with Hiatus hernia, the gastro-oesophageal junction high pressure zone had two discrete segments, one proximal to the squamocolumnar junction and one distal, attributable to the extrinsic compression within the hiatal canal. Inspiration and abdominal compression mainly augmented the distal one. Simulation of hernia reduction by algebraically summing the proximal segment pressures with the hiatal canal pressures restored normal maximal pressure, radial asymmetry, and dynamic responses of the gastro-oesophageal junction. CONCLUSIONS Hiatus hernia reduces lower oesophageal sphincter pressure and alters its dynamic responsiveness by spatially separating pressure components derived from the intrinsic lower oesophageal sphincter and the extrinsic compression of the oesophagus within the hiatal canal.
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the role of Hiatus hernia in gerd
Yale Journal of Biology and Medicine, 1999Co-Authors: Peter J KahrilasAbstract:Increased esophageal acid exposure in gastroesophageal reflux disease has several potential causes, some related primarily to physiological dysfunction of the LES and others related to anatomic distortion of the gastroesophageal junction as occurs with Hiatus hernia. One attractive feature of implicating hiatal hernias in the pathogenesis of reflux disease is that, like reflux disease, axial hernias become more common with age and obesity. However, the importance of Hiatus hernia is obscured by imprecise definition and an all-or-none conceptualization that has led to wide variation in estimates of prevalence among normal or diseased populations. There are at least three potentially significant radiographic features of a Hiatus hernia: axial length during distention, axial length at rest, and competence of the diaphragmatic Hiatus. Although any or all of these features may be abnormal in a particular instance of Hiatus hernia, each is of different functional significance. Grouping all abnormalities of the gastroesophageal junction as "Hiatus hernia" without detailing the specifics of each case defies logic. Mechanistically, the gastroesophageal junction must protect against reflux both in static and dynamic conditions. During abrupt increases in intra-abdominal pressure, the crural diaphragm normally serves as a "second sphincter," and this mechanism is substantially impaired in individuals with a gaping Hiatus. Large, non-reducing hernias also impair the process of esophageal emptying, thereby prolonging acid clearance time following a reflux event (especially while in the supine posture). These anatomically-determined functional impairments of the gastroesophageal junction lead to increased esophageal acid exposure. Thus, although Hiatus hernia may or may not be an initiating factor at the inception of reflux disease, it clearly can act as a sustaining factor accounting for the frequently observed chronicity of the disease.
Hans Peter Dietz - One of the best experts on this subject based on the ideXlab platform.
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levator morphology and strength after obstetric avulsion of the levator ani muscle
Female pelvic medicine & reconstructive surgery, 2020Co-Authors: Victoria L Handa, Joan L Blomquist, Alvaro Munoz, Jennifer Roem, Hans Peter DietzAbstract:OBJECTIVES Obstetric levator avulsion may be an important risk factor for prolapse. This study compares the size of the levator Hiatus, the width of the genital Hiatus, and pelvic muscle strength between vaginally parous women with or without levator avulsion, 5 to 15 years after delivery. METHODS Parous women were assessed for levator ani avulsion, using 3-dimensional transperineal ultrasound. Women with and without levator ani avulsion were compared with respect to levator Hiatus areas (measured on ultrasound), genital Hiatus (measured on examination), and pelvic muscle strength (measured with perineometry). Further analysis also considered the association of forceps-assisted birth. RESULTS At a median interval of 11 years from first delivery, levator avulsion was identified in 15% (66/453). A history of forceps-assisted delivery was strongly associated with levator avulsion (45% vs 8%; P < 0.001). Levator avulsion was also associated with a larger levator Hiatus area (+7.3 cm; 95% confidence interval [CI], 4.1-10.4, with Valsalva), wider genital Hiatus (+0.6 cm; 95% CI, 0.3-0.9, with Valsalva), and poorer muscle strength (-14.5 cm H2O; 95% CI, -20.4 to -8.7, peak pressure). Among those with levator avulsion, forceps-assisted birth was associated with a marginal increase in levator Hiatus size but not genital Hiatus size or muscle strength. CONCLUSIONS Obstetric levator avulsion is associated with a larger levator Hiatus, wider genital Hiatus, and poorer pelvic muscle strength. Forceps-assisted birth is an important marker for levator avulsion but may not be an independent risk factor for the development of pelvic muscle weakness or changes in Hiatus size in the absence of levator avulsion.
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pelvic organ prolapse as a function of levator ani avulsion Hiatus size and strength
American Journal of Obstetrics and Gynecology, 2019Co-Authors: Victoria L Handa, Hans Peter Dietz, Joan L Blomquist, Jennifer Roem, Alvaro MunozAbstract:Background Obstetrical levator ani muscle avulsion is detected after 10%–30% of vaginal deliveries and is associated with pelvic organ prolapse later in life. However, the mechanism by which levator avulsion may contribute to prolapse is unknown. Objectives This study investigated the extent by which size of the levator Hiatus and pelvic muscle weakness may explain the association between levator avulsion and pelvic organ prolapse. Study Design This was a supplementary study of a longitudinal cohort of parous women enrolled 5–10 years after first delivery and assessed annually for prolapse (defined as descent beyond the hymen) for up to 9 annual visits. For this substudy, vaginally parous participants were assessed for levator avulsion using 3-dimensional transperineal ultrasound. Ultrasound was performed at a median interval of 11 years from delivery. Ultrasound volumes also were used to measure levator Hiatus area with Valsalva. Pelvic muscle strength was measured with perineometry. Women with and without pelvic organ prolapse were compared for levator avulsion, levator Hiatus area, and pelvic muscle strength, using multivariable logistic regression yielding a measure of mediation. Bootstrap methods were used to calculate the confidence interval corresponding to the measure of mediation by Hiatus area and pelvic muscle strength. Results Prolapse was identified in 109 of 429 (25%) and was significantly associated with levator avulsion (odds ratio, 4.17; 95% confidence interval, 2.28–7.31). Prolapse also was associated with levator Hiatus area (odds ratio, 1.52 per 5 cm2; 95% confidence interval, 1.34–1.73) and inversely with muscle strength (odds ratio, 0.87 per 5 cm H2O; 95% confidence interval, 0.81–0.94). In a multivariable logistic model including levator avulsion, levator Hiatus area, and strength, the association between levator avulsion and prolapse was substantially attenuated and indeed was no longer statistically significant (odds ratio, 1.75; 95% confidence interval, 0.91–3.39). Hiatus area and strength mediated 61% (95% confidence interval, 34%–106%) of the association between avulsion and prolapse. Furthermore, since the 95% confidence interval for this estimate contained 100%, it cannot be ruled out that the 2 markers fully mediate the effect of avulsion on prolapse. Conclusions The strong association between pelvic organ prolapse and levator avulsion can be explained to a large extent by a larger levator Hiatus and weaker pelvic muscles after levator avulsion.
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how best to measure the levator Hiatus evidence for the non euclidean nature of the plane of minimal dimensions
Ultrasound in Obstetrics & Gynecology, 2010Co-Authors: Jennifer Kruger, S W Heap, Bernadette Murphy, Hans Peter DietzAbstract:Objective To clarify whether the ‘plane of minimal dimensions’ of the levator Hiatus on three-dimensional (3D) ultrasound accurately represents the minimal anatomical transverse hiatal dimension during a Valsalva maneuver. Methods In this retrospective study of 3D transperineal ultrasound and magnetic resonance (MR) imaging, datasets from 19 female participants were used to measure the transverse diameter of the levator Hiatus using the plane of minimal dimensions on maximum Valsalva maneuver. The term ‘apparent minimal transverse diameter’ (aMTD) was used to define the transverse diameter measured using axial ultrasound and comparable axial or coronal MR images. Coronal MR images, using the plane of the vagina as a reference, were also obtained on maximum Valsalva. The transverse diameter measured between the caudal margin of the pubococcygeus/puborectalis on the MR coronal image is denoted by the term ‘true minimal transverse diameter’ (tMTD). Statistical comparisons between the aMTD and tMTD were made using Student's t-test. Results No significant difference was demonstrated between the aMTD as measured by ultrasonography and MRI. However, there were significant differences found between the aMTD measured by both ultrasound and MRI and the tMTD measured on coronal MR images (both P < 0.01), with mean ( ± SD) values of 4.36 ± 0.85, 4.13 ± 1.09 and 3.23 ± 0.49 cm, respectively. Conclusion This study highlights the complexity and 3D nature of the levator Hiatus and pelvic floor muscles. Investigators have previously assumed that the plane of minimal dimensions of the Hiatus can be measured in a flat plane, however, the 3D nature of the Hiatus means that the true levator Hiatus occupies a warped (non-Euclidean) plane. Hiatal measurements on Valsalva may be subject to systematic error if performed in a single section, i.e. using a flat (Euclidean) plane. Copyright © 2010 ISUOG. Published by John Wiley & Sons, Ltd.
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biometry of the pubovisceral muscle and levator Hiatus by three dimensional pelvic floor ultrasound
Ultrasound in Obstetrics & Gynecology, 2005Co-Authors: Hans Peter Dietz, C Shek, B ClarkeAbstract:Objective Until recently, magnetic resonance was the only imaging method capable of assessing the levator ani in vivo. Three-dimensional (3D) ultrasound has recently been shown to be able to demonstrate the pubovisceral muscle. The aim of this study was to define the anatomy of the levator Hiatus in young nulliparous women with the help of 3D ultrasound. Methods In a prospective observational study, 52 nulligravid female Caucasian volunteers (aged 18–24 years) were assessed by two-dimensional (2D) and 3D translabial ultrasound after voiding whilst supine. Pelvic organ descent was assessed on Valsalva maneuver. Volumes were acquired at rest and on Valsalva maneuver, and biometric indices of the pubovisceral muscle and levator Hiatus were determined in the axial and coronal planes. Results In the axial plane, average diameters of the pubovisceral muscle were 0.4–1.1 cm (mean 0.73 cm). Average area measurements were 7.59 (range, 3.96–11.9) cm2. The levator Hiatus at rest varied from 3.26 to 5.84 (mean 4.5) cm in the sagittal direction, and from 2.76 to 4.8 (mean 3.75) cm in the coronal plane. The Hiatus area at rest ranged from 6.34 to 18.06 (mean 11.25) cm2 increasing to 14.05 (6.67–35.01) cm2 on Valsalva maneuver (P = 0.009). There were significant correlations between pelvic organ mobility and Hiatus area at rest (P = 0.018 to P < 0.001) and on Valsalva maneuver (all P < 0.001). Conclusions Biometric indices of the pubovisceral muscle and levator Hiatus can be determined by 3D ultrasound. Significant correlations exist between hiatal area and pelvic organ descent. These data provide support for the hypothesis that levator ani anatomy plays an independent role in determining pelvic organ support. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Ravinder K Mittal - One of the best experts on this subject based on the ideXlab platform.
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morphology of the esophageal Hiatus is it different in 3 types of Hiatus hernias
Journal of Neurogastroenterology and Motility, 2020Co-Authors: Dushyant Kumar, Ali Zifan, Gary G Ghahremani, David C Kunkel, Santiago Horgan, Ravinder K MittalAbstract:Author(s): Kumar, Dushyant; Zifan, Ali; Ghahremani, Gary; Kunkel, David C; Horgan, Santiago; Mittal, Ravinder K | Abstract: Background/aimsThe esophageal Hiatus is formed by the right crus of the diaphragm in the majority of subjects. Contraction of the Hiatus exerts a sphincter-like action on the lower esophageal sphincter (LES). The aim is to study the hiatal anatomy (using CT scan imaging) and function (using high-resolution manometry [HRM]), and esophageal motor function in patients with sliding and paraesophageal hiatal hernia.MethodsWe assessed normal subjects (n = 20), patients with sliding type 1 hernia (n = 18), paraesophageal type 2 hernia (n = 19), and mixed type 3 hernia (n = 19). Hernia diagnosis was confirmed on the upper gastrointestinal series. The hiatal morphology was constructed from the CT scan images. The LES pressure and relaxation, percent peristalsis, bolus pressure, and hiatal squeeze pressure were assessed by HRM.ResultsThe CT images revealed that the esophageal Hiatus is formed by the right crus of the diaphragm in all normal subjects and 86% of hernia patients. The Hiatus is elliptical in shape with a surface area of 1037 mm2 in normal subjects. The hiatal dimensions were larger in patients compared to normal subjects. The HRM revealed impaired LES relaxation and higher bolus pressure in patients with paraesophageal compared to the sliding hernia. The hiatal pinch on HRM was recognized in significantly higher number of patients with sliding as compared to paraesophageal hernia.ConclusionsUsing a novel approach, we provide details of the esophageal Hiatus in patients with various kinds of hiatal hernia. Impaired LES relaxation in paraesophageal hernia may play a role in its pathophysiology and genesis of symptoms.
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the reliability of puborectalis muscle measurements with 3 dimensional ultrasound imaging
American Journal of Obstetrics and Gynecology, 2007Co-Authors: Milena M Weinstein, Sungae Jung, Derkina Den J Boer, Charles W. Nager, Dolores H. Pretorius, Ravinder K MittalAbstract:Objective Our aims were to: (1) recognize the anatomic landmarks for measurement of puborectalis muscle on 3-dimensional ultrasound images, (2) assess intra- and interobserver reliability of puborectalis muscle measurements, (3) determine whether there is measurable puborectalis muscle shortening with pelvic floor squeeze, and (4) assess pelvic Hiatus symmetry. Study design Twenty-seven nulliparous asymptomatic women were imaged with 3-dimensional ultrasound at rest and squeeze. Three-dimensional ultrasound volumes were rotated by using a standardized technique and analyzed by 2 observers. Results Anatomic landmarks (lower end of pubic bone and apex of anorectal angle) were recognized consistently. There is significant shortening of puborectalis muscle and pelvic floor Hiatus dimensions with squeeze. Inter- and intraobserver correlations demonstrate reproducibility of measurements. Both halves of pelvic floor Hiatus are mirror images of each other. Conclusion Three-dimensional ultrasound imaging allows localization of anatomic landmark and yields reliable measurements of the puborectalis muscle and pelvic floor Hiatus.
Shangping Xie - One of the best experts on this subject based on the ideXlab platform.
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recent global warming Hiatus tied to equatorial pacific surface cooling
Nature, 2013Co-Authors: Yu Kosaka, Shangping XieAbstract:Despite the continued increase in atmospheric greenhouse gas concentrations, the annual-mean global temperature has not risen in the twenty-first century, challenging the prevailing view that anthropogenic forcing causes climate warming. Various mechanisms have been proposed for this Hiatus in global warming, but their relative importance has not been quantified, hampering observational estimates of climate sensitivity. Here we show that accounting for recent cooling in the eastern equatorial Pacific reconciles climate simulations and observations. We present a novel method of uncovering mechanisms for global temperature change by prescribing, in addition to radiative forcing, the observed history of sea surface temperature over the central to eastern tropical Pacific in a climate model. Although the surface temperature prescription is limited to only 8.2% of the global surface, our model reproduces the annual-mean global temperature remarkably well with correlation coefficient r = 0.97 for 1970-2012 (which includes the current Hiatus and a period of accelerated global warming). Moreover, our simulation captures major seasonal and regional characteristics of the Hiatus, including the intensified Walker circulation, the winter cooling in northwestern North America and the prolonged drought in the southern USA. Our results show that the current Hiatus is part of natural climate variability, tied specifically to a La-Nina-like decadal cooling. Although similar decadal Hiatus events may occur in the future, the multi-decadal warming trend is very likely to continue with greenhouse gas increase.
Abbas S Shobeiri - One of the best experts on this subject based on the ideXlab platform.
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levator plate descent correlates with levator ani muscle deficiency
Neurourology and Urodynamics, 2015Co-Authors: Ghazaleh Rostaminia, Dena White, Lieschen H Quiroz, Abbas S ShobeiriAbstract:Aims Measurements such as the minimal levator Hiatus dimension, levator plate angle, iliococcygeal angle, and anorectal angle have been used for assessing the impact of levator damage on static and dynamic imaging features. The primary aim of this study was to investigate the association between levator ani muscle deficiency (LAD) and the position of the levator plate. Methods 3D endovaginal ultrasounds of 186 women were reviewed. The levator ani muscle groups, the puboanalis, puborectalis, and pubovisceralis, were scored for abnormalities, (0 no defect and 3 total absence of the muscle). The levator plate descent angle, minimal levator Hiatus dimensions, and the anorectal angle were measured. Levator plate descent towards the perineum was assessed and correlated with levator ani muscle deficiency. Results The correlation between puborectalis scores and minimal levator Hiatus area, anorectal angle and levator plate descent angle were 0.43 (P < 0.0001), 0.22 (P = 0.0045), and −0.40 (P < 0.0001), respectively. The correlation between pubovisceralis scores and minimal levator Hiatus area, anorectal angle and levator plate descent angle were 0.36 (P < 0.0001), 0.38 (P < 0.0001), and −0.40 (P < 0.0001), respectively. The correlation between the total levator ani muscle scores and the minimal levator Hiatus area, anorectal angle and the levator plate descent angle were 0.45 (P < 0.0001), 0.31 (P < 0.0001), and −0.45 (P < 0.0001) respectively. Conclusion Worsening LAD score is associated with levator plate descensus and with decreasing levator plate descent angle. We can use levator plate descent angle along with the minimal levator Hiatus and anorectal angle as objective measurements to assess levator ani muscle deficiency. Neurourol. Urodynam. 34:55–59, 2015. © 2013 Wiley Periodicals, Inc.
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the determinants of minimal levator Hiatus and their relationship to the puborectalis muscle and the levator plate
British Journal of Obstetrics and Gynaecology, 2013Co-Authors: Abbas S Shobeiri, Ghazaleh Rostaminia, Dena White, Lieschen H QuirozAbstract:Objective To determine the muscles comprising the minimal levator Hiatus. Design Cross-sectional study. Setting The University of Oklahoma Health Sciences Center, USA. Population Eight female fresh frozen pelves and 80 nulliparouswomen. Methods Three-dimensional endovaginal ultrasound was performed in eight fresh frozen female pelves. The structures of the levator Hiatus were tagged with needles and the cadavers were dissected to identify the tagged structures. A group of 80 nullipara underwent 3D endovaginal ultrasound, and the minimal levator Hiatus area, puborectalis area, and anorectal angle were assessed, and normal values were obtained. Main outcome measures Anatomic borders of minimal levator Hiatus and normality in pelvic floor measurements. Results The pubococcygeus forms the inner lateral border and anterior attachment of the minimal levator Hiatus to the pubic bone. The puboanalis fibres are immediately lateral to pubococcygeus attachments. There are variable contributions of the puborectalis fibres lateral to the puboanalis attachment. The posterior border of the minimal levator Hiatus is formed by the levator plate. Eighty community-dwelling nulliparous women underwent 3D endovaginal ultrasound. The median age was 47 years (range 22–70 years). The mean of minimal levator Hiatus and puborectalis Hiatus areas were 13.4 cm2 (±1.89 cm2 SD) and 14.8 cm2 (±2.16 cm2 SD). The mean anorectal and levator plate descent angles were 156° (±10.04° SD) and 15.9° (±8.28° SD). Conclusion Anterior and lateral borders of the minimal levator Hiatus are formed mostly by pubococcygeus. The puborectalis, pubococcygeus, and iliococcygeus form the bulk of the levator plate.
