Esophageal length: esophageal manometry remains superior to mathematical equations

Updated KidZ Health Castle Formula for Multichannel Intraluminal Impedance-pH Monitoring Probe Positioning

Purpose

The KidZ Health Castle Formula (KHC-F) was developed to improve the positioning of multichannel intraluminal impedance-pH probes (MII-pH). We hypothesized that the updated formula KHC-Fv2 would performs better than the original formula. This study aimed to evaluate the reliability of KHC-Fv2.

Methods

A prospective cohort study was conducted to assess MII-pH probe positioning in patients aged 1 month to 18 years. Margins of error within 1 cm above or below the target position, as determined using KHC-Fv2 and compared with fluoroscopy, were accepted.

Results

Eighty-four children were included in the study. The mean difference between the KHC-Fv2 and target positions was +0.25 cm cranially. The KHC-Fv2 insertion length fell within the accepted difference of ±1 cm of the target position in 67.9% of the children. This percentage increased in infants under 1 year of age (79.5%) or shorter than 100 cm (74.0%) in height.

Conclusion

KHC-Fv2 demonstrated strong agreement with correct positioning and significantly reduced the need for a second radiologic control after probe repositioning, particularly in infants or children shorter than 100 cm.

A novel piglet model of esophageal stricture following variable segmental esophageal resection and re-anastomosis

BACKGROUND

Esophageal strictures following esophageal atresia repair are a source of significant morbidity. To test new therapeutic approaches, we designed a piglet model of esophageal stricture by resecting variable lengths of esophagus with subsequent re-anastomosis. This study describes the model and validates its physiologic impact by blinded analysis of the weight gains of the piglets.

METHODS

A total of 24 two-week old Pietrain piglets had esophageal resections performed, ranging from 0 to 5 cm, with the goal of inducing postoperative esophageal strictures. Postoperative body-weights were evaluated by repeated analysis of variance followed by pairwise group-comparisons based on estimated marginal means. In addition, body weight was modeled by linear-mixed model regression. Different resection lengths were compared. The esophagi were evaluated postmortem for stricture.

RESULTS

Of 24 operated piglets, 23 reached the endpoint, and 90% developed an esophageal stricture that was radiologically visible in a contrast study, as well as appreciable macroscopically in the necropsy. We found differences in pre- and postoperative body weights for all piglets (F (1, 18) = 298.54, p < 0.001), but no differences between resection lengths (F (4, 18) = 0.36, p = 0.837).

CONCLUSION

Our model of postoperative esophageal stricture offers the opportunity to investigate potential treatments for strictures associated with esophageal atresia, since it reliably induces strictures and results in minimal loss of animals. The similar body weight gain in all groups indicates that stricture is mainly the result of esophageal resection and re-anastomosis, regardless of the length of the resected segment.

Simple Formula for pH/Impedance Probe Positioning in Children-Time to Update Standard Practice?

OBJECTIVE

To develop a novel formula for pH probe placement with adequate accuracy.

METHODS

Children (3-18 y) undergoing pH-metry were prospectively evaluated. Their height and corrected pH probe position under X-ray (2 vertebrae above the diaphragm) was recorded and the linear-regression analysis was performed to derive a novel formula. Its accuracy was checked on an additional group of prospectively included children. The success rate of a newly developed formula was estimated and compared to the performance of previously used formulae. The difference in the suggested placement of the probe (cm from nostrils) was calculated.

RESULTS

Based on 670 children with pH probe placed under X-ray, the following formula was developed using the linear-regression analysis: L = 0.184x + 4.4 (cm) (L = probe placement depth, x = body height). Its accuracy was confirmed on additional 111 children resulting in almost 85% success rate. The formula showed significant difference in the suggested placement from formulae used previously: +4.9 ± 0.8 cm, +2.4 ± 0.1 cm, +0.7 ± 0.6 cm, +1.1 ± 0.4 cm, +1.8 ± 0.3 cm, +2.2 ± 0.5 cm from the one by the Strobel, Moreau, Wilson, Nowak, Staiano-Clouse formulae, and the GOSH table with the calculated success rates of 1.8%, 43.2%, 65.8%, 77.5%, 65.8% and 54.1%, respectively. A table suggesting placement depth based on the body height was developed.

CONCLUSION

The present formula provides 85% success of pH probe placement in children ≥ 3 y suggesting its use in routine practice. More data are needed to confirm that probe adjustment under X-ray is unnecessary.

How Best to Estimate Insertion Length of Multichannel Intraluminal Impedance pH Probes in Children

OBJECTIVE

To assess the reliability of the KidZ Health Castle formula (KHC-F) to determine the correct probe position of a multichannel intraluminal impedance pH.

STUDY DESIGN

A retrospective cohort study was performed on 222 children between 1 month and 18 years of age undergoing multichannel intraluminal impedance pH. The primary outcome was the comparison of the pH sensor location determined by the KHC-F with the radiological target position. The margin of error was defined as 1 cm from the target position. Performance of the KHC-F and existing formulas was determined via the percentage with a correct position, mean error, 95% limits of agreement (Bland-Altman plots), and Spearman correlation. A post hoc analysis was performed with an updated KHC-F v2, subtracting -0.5 cm from the KHC-F.

RESULTS

Positioning with KHC-F was correct in two-thirds of the participants, with a very strong correlation (ρ = 0.91) with the target position. Bland-Altman plots showed good agreement between KHC-F and target position (mean error of -0.44 cm, lower limit -3.2 cm, upper limit 2.3 cm). A post hoc analysis with the KHC-F v2 showed a correct positioning in 74% of patients. Comparison with other formulas showed a stronger performance of KHC-F and KHC-F v2 on correct positioning, mean error, and 95% limits of agreement.

CONCLUSIONS

The KHC-F leads to reliable results. KHC-F v2 outperforms all other existing formulas in children, thereby reducing the need for repositioning and the amount of x-ray exposure. The age distribution of the sample may be a limitation, as well as the retrospective nature of the study.

Defining the Patchy Landscape of Esophageal Eosinophilia in Children With Eosinophilic Esophagitis

BACKGROUND & AIMS

Eosinophilic esophagitis (EoE) is a patchy disease of the esophagus with significant variability in intraepithelial eosinophilia. Three biopsies each from distal and proximal esophagus are recommended for identification of active EoE. Recent work suggests 3 biopsy sites are more optimal. We sought to evaluate 2-site vs 3-site esophageal biopsy combinations for utility to identify active EoE.

METHODS

We prospectively obtained 3-site esophageal biopsies based on rigorous endoscopic measurements of the proximal, mid, and distal esophagus and gastroesophageal junction. Biopsies were reviewed by a pathologist, and those with at least 15 eosinophils per high-power field were considered active EoE. The sensitivity of one or more sites to identify active EoE was determined, and endoscopic measurements were correlated to height and age.

RESULTS

Five hundred ninety-six endoscopies were performed in 217 patients; of these, 304 endoscopies in 167 patients had active EoE. Among the initial esophagogastroduodenoscopies with active EoE, distal biopsies had greater than 80% sensitivity, whereas mid and proximal biopsies had sensitivity of 65% and 62%, respectively, and distal + proximal biopsies had the highest diagnostic sensitivity for a 2-site combination. Among the 304 endoscopies with active EoE, 9 had focal eosinophilia restricted to the mid esophagus, and 8 were restricted to the proximal esophagus. For patients with multiple endoscopies with active EoE, nearly one fourth had reduced sites with eosinophilia at the second time point. Endoscopic measurements strongly correlated with height and age.

CONCLUSIONS

This study supports endoscopic measurement-guided 3-site biopsies for optimal disease assessment of active EoE in children.

Esophageal length in children: Reference data and a novel predictive equation

Minimal information exists on the length of the child's esophagus, namely the distance from the cricopharyngeus to the esophagogastric junction (EGJ). We aimed to investigate the relationship between esophageal length (EL) and the age, height, and weight of the child. Children undergoing upper gastrointestinal endoscopy between February 2019 and May 2021 at our institution were prospectively audited. Children with anatomical esophageal disorders were excluded. Endoscopic distances from the incisors to the cricopharyngeus and EGJ were obtained, and novel predictive equations derived to predict EL. Intra-observer agreement for endoscopic measurements showed an intra-class correlation coefficient of 0.99. A total of 290 children aged 0.4-17.3 years were included in the analysis; they were divided into a model development cohort (n = 261) and a model validation cohort (n = 29). Measured EL correlated best with height (r = 0.92) as compared to age (r = 0.90) or weight (r = 0.83). The optimal equation for predicting EL was 0.156 × height (cm) - 1.336 (adjusted R²  = 0.841); this had a success rate of 76% in the validation cohort. The optimal equation for predicting distance from incisors to EGJ was 0.199 × height (cm) + 6.470 (adjusted R²  = 0.889); this had a success rate of 69% in the validation cohort. This is the first study to report a predictive equation for estimating esophageal length in children. Accurate prediction of esophageal length may assist with clinical esophageal procedures in children such as nasogastric and pH probe placement.

Using multidimensional scaling in model choice for congenital oesophageal atresia: similarity analysis of human autopsy organ weights with those from a comparative assessment of Aachen Minipig and Pietrain piglets

Swine models had been popular in paediatric oesophageal surgery in the past. Although being largely replaced by rodent models, swine experienced a revival with the establishment of minipig models. However, none of them has ever been investigated for similarity to humans. We conducted a pilot study to determine whether three-week old Pietrain piglets and three-month old Aachen Minipigs are suitable for experimental paediatric oesophageal atresia surgery. We tested the operation's feasibility, performed a necropsy, weighed organs, measured organ length and calculated relative weights and lengths, and measured laboratory parameters. We used multidimensional scaling to assess the similarity of the swine breeds with previously published human data. Pietrain piglets had a higher a priori bodyweight than Aachen Minipigs (Δ = 1.31 kg, 95% confidence interval (CI): 0.37-2.23, p = 0.015), while snout-to-tail length was similar. Pietrain piglets had higher absolute and relative oesophageal lengths (Δ = 5.43 cm, 95% CI: 2.2-8.6; p = 0.0062, q1* = 0.0083 and Δ = 11.4%, 95% CI: 5.1-17.6; p = 0.0025, q3* = 0.0053). Likewise, absolute and relative small intestinal lengths were higher in Pietrains, but all other parameters did not differ, with the exception of minor differences in laboratory parameters. Multidimensional scaling revealed three-week old Pietrain piglets to be similar to two-month old humans based on their thoracoabdominal organ weights. This result indicates three-week old Pietrain piglets are a suitable model of paediatric oesophageal atresia surgery, because clinically many procedures are performed at around eight weeks age. Three-month old Aachen Minipigs were more dissimilar to eight-week old humans than three-week old Pietrain piglets.

High-resolution esophageal manometry in pediatrics: Effect of esophageal length on diagnostic measures

BACKGROUND

High-resolution esophageal manometry (HREM), derived esophageal pressure topography metrics (EPT), integrated relaxation pressure (IRP), and distal latency (DL) are influenced by age and size. Combined pressure and intraluminal impedance also allow derivation of metrics that define distension pressure and bolus flow timing. We prospectively investigated the effects of esophageal length on these metrics to determine whether adjustment strategies are required for children.

METHODS

Fifty-five children (12.3 ± 4.5 years) referred for HREM, and 30 healthy adult volunteers (46.9 ± 3.8 years) were included. Studies were performed using the MMS system and a standardized protocol including 10 × 5 mL thin liquid bolus swallows (SBM kit, Trisco Foods) and analyzed via Swallow Gateway (www.swallowgateway.com). Esophageal distension pressures and swallow latencies were determined in addition to EGJ resting pressure and standard EPT metrics. Effects of esophageal length were examined using partial correlation, correcting for age. Adult-derived upper limits were adjusted for length using the slopes of the identified linear equations.

KEY RESULTS

Mean esophageal length in children was 16.8 ± 2.8 cm and correlated significantly with age (r = 0.787, P = .000). Shorter length correlated with higher EGJ resting pressure and 4-s integrated relaxation pressures (IRP), distension pressures, and shorter contraction latencies. Ten patients had an IRP above the adult upper limit. Adjustment for esophageal length reduced the number of patients with elevated IRP to three.

CONCLUSIONS & INFERENCES

We prospectively confirmed that certain EPT metrics, as well as potential useful adjunct pressure-impedance measures such as distension pressure, are substantially influenced by esophageal length and require adjusted diagnostic thresholds specifically for children.

What is the best method for calculating the optimal position of an esophageal pH probe in children?

In assessment of distal esophageal pH, the sensor of the probe should be placed above the upper border of the lower esophageal sphincter. There are several methods to estimate the distance from the nose where the probe should be fixed according to the patient's height. We studied the accuracy of these methods. Data of patients who underwent esophageal monitoring were collected prospectively. The esophageal pH electrode was set with the aid of fluoroscopy in all cases, considering the location recommended by the current guideline. Esophageal probe position and anthropometric data of each patient were recorded. We compared the actual esophageal pH electrode distance from the nose with that estimated by Nowak's, Strobel's, Staiano-Clouse's, and Moreau's formulae and the Great Ormond Street Hospital (GOSH) table. A total of 98 patients were included, with ages ranging from 2 months to 19 years old. The highest success rate (67%) for all age groups was achieved by Nowak's formula (3.2 + 0.2 × height in cm). Considering only children under 3 years old, the GOSH table reached the highest-yet probably overestimated-fraction of adequate predictions. A corrected Staiano and Clouse's formula (4.28 + 0.191 × height in cm) had a slightly lower success rate than Nowak's due to a poorer performance in younger children. In conclusion, Nowak's formula is the most accurate regardless of age. It can help reduce radiation due to systematic fluoroscopy, as well as the subsequent manipulation of the esophageal probe. However, it still leads to pH sensor misplacements in more than one-third of children. In consequence, a confirmatory X-ray is advisable even after using the formula.

Bodyweight, not age, determines oesophageal length and breaking strength in rats

BACKGROUND/PURPOSE

Delayed primary repair is still the method of choice in the management of long-gap oesophageal atresia in many centres, but the timing of anastomoses varies. Some assume the infant's bodyweight to be an important factor, whereas others prefer age. We therefore aimed to clarify whether age or bodyweight determined oesophageal length in a rodent model.

METHODS

We explanted the oesophagi of 20 Sprague-Dawley rats, aged 15 to 444 days (n = two per time point), measured bodyweight, oesophageal length, weight, and linear breaking strength to measure tissue resilience. Univariate and multivariate regression analyses were conducted to determine the influence of age and bodyweight on oesophageal length and linear breaking strength.

RESULTS

All parameters were highly correlated (R > 0.8), except for age and linear breaking strength (R = 0.65). Both age and bodyweight were univariate significant predictors of oesophageal length, weight, and linear breaking strength (p < 0.0001). Multivariate analyses showed bodyweight to be a significant predictor of oesophageal length (p < 0.0001), whereas age was not (p = 0.18) [adjusted R² = 0.9031]. This was also true for linear breaking strength (p = 0.0007 and p = 0.97, respectively) [adjusted R² = 0.71]. Moreover, the influence of age was negligible, as the adjusted R² and the regression coefficient of bodyweight and its 95% confidence interval were almost identical between univariate und multinomial regressions.

CONCLUSIONS

Only weight determines oesophageal length and tissue resilience in rodents, whereas age is irrelevant. If a similar relationship exists in humans, it may facilitate choosing the optimum time point for delayed primary anastomosis.

LEVEL OF EVIDENCE

IV - Experimental Paper.

Gastroesophageal reflux is not associated with short-term variability of parasympathetic activity in children

PURPOSE

A lower parasympathetic activity was described in patients with the gastroesophageal reflux disease. We aimed to determine whether gastroesophageal reflux (GER) episodes are associated with a short-term parasympathetic tone variability in children.

METHODS

In order to address this question we performed simultaneous 24-h esophageal multichannel intraluminal impedance-pH and electrocardiographic monitoring in 16 children (age range 6-18 years), including 8 with asthma and 2 with gastroesophageal reflux disease. After describing duration, height, and acidity of 483 GER episodes we also measured parasympathetic-related heart rate variability parameters in 4 time periods: preceding, containing, following GER, and in-between GERs (control). High frequency (HF) power and root-mean square differences of successive R-R intervals (r-MSSD) were assessed in 2.5-min and 1-min periods, respectively.

RESULTS

We did not identify the searched short-term parasympathetic tone changes.

CONCLUSIONS

In conclusion, GER episodes and their characteristics were not associated with short-term variability of parasympathetic activity in children.

Esophageal pH Monitoring in Children: A Simple Mathematical Formula for pH Probe Positioning

Correct pH probe placement is vital for the precision of esophageal pH monitoring. This study aimed at finding the optimal formula for placement of pH probe in the locus proposed by the European Society for Pediatric Gastroenterology, Hepatology, and Nutrition European Pediatric Impedance Working Group, that is, 2 vertebrae above the diaphragm. An analysis of data regarding 353 children ages 0-18 years in whom the position of the pH sensor was determined radiographically revealed that a mathematical formula (3.2 + 0.2 × body length or height, centimeter) could guide the probe to within 1/12 of thoracic spine length of the desired location in 71.7% of all of the patients.

A new method to estimate catheter length for esophageal multichannel intraluminal impedance monitoring in children

BACKGROUND

Multichannel intraluminal impedance combined with pH (MII-pH) is the gold standard test for diagnosing gastro-esophageal reflux disease (GERD). It provides an opportunity to study acid and non-acid GOR and temporal association between symptoms and reflux. Accurate catheter placement is essential to prevent erroneous recording of reflux events. The aims of our study were to assess the accuracy of our devised method in predicting the catheter length for MII-pH in children (Great Ormond Street Hospital (GOSH) Table) and to compare the results with Strobel and Monreau methods.

METHODS

Retrospective review of all records of infants and children who underwent MII-pH studies between January to October 2014. Desired catheter position was calculated using Strobel, Monreau and GOSH formulas and compared to X ray position.

KEY RESULTS

One hundred and forty-four children were included; mean age was 5.1 (±4.5) years, 73 males and 71 females. In the whole group, the correlation between desired catheter position and GOSH Table was 0.95, for Strobel was 0.84, and Monreau was 0.85. In the first group (age <3 years), the correlation was: GOSH Table 0.91, Strobel 0.56, and Monreau 0.6; in the second group (3-10 years): GOSH Table 0.78, Strobel 0.82, and Monreau 0.82; the third group (>10 years): GOSH 0.81, Strobel 0.43, and Monreau 0.43.

CONCLUSIONS & INFERENCES

GOSH Table is an accurate method to estimate the insertion length of MII-pH catheters from nares to a point of approximately two vertebral bodies above the diaphragm in children. Although radiography is required to confirm final catheter position, using GOSH Table will reduce the need for repeated catheter manipulation after initial insertion and will reduce the use of a mathematically complicated formulae.