The effect of traction on esophageal structure in children with long-gap esophageal atresia

Outcome of long gap esophageal atresia at 6 years: A prospective case control cohort study

BACKGROUND DATA

EA is the most frequent congenital esophageal malformation. Long gap EA remains a therapeutic challenge for pediatric surgeons. A case case-control prospective study from a multi-institutional national French data base was performed to assess the outcome, at age of 1 and 6 years, of long gap esophageal atresia (EA) compared with non-long gap EA/tracheo-esophageal fistula (TEF). The secondary aim was to assess whether initial treatment (delayed primary anastomosis of native esophagus vs. esophageal replacement) influenced mortality and morbidity at ages 1 and 6 years.

METHODS

A multicentric population-based prospective study was performed and included all patients who underwent EA surgery in France from January 1, 2008 to December 31, 2010. A comparative study was performed with non-long gap EA/TEF patients. Morbidity at birth, 1 year, and 6 years was assessed.

RESULTS

Thirty-one patients with long gap EA were compared with 62 non-long gap EA/TEF patients. At age 1 year, the long gap EA group had longer parenteral nutrition support and longer hospital stay and were significantly more likely to have complications both early post-operatively and before age 1 year compared with the non-long gap EA/TEF group. At 6 years, digestive complications were more frequent in long gap compared to non-long gap EA/TEF patients. Tracheomalacia was the only respiratory complication that differed between the groups. Spine deformation was less frequent in the long gap group. There were no differences between conservative and replacement groups at ages 1 and 6 years except feeding difficulties that were more common in the native esophagus group.

CONCLUSIONS

Long gap strongly influenced digestive morbidity at age 6 years.

Magnet-Assisted Hydraulic Bougienage for Correction of Long-Gap Esophageal Atresia

OBJECTIVE

An infant born with long-gap esophageal atresia has its esophagus separated into two pouches, and typically undergoes multiple open-chest surgeries for esophageal reconstruction. In this paper, we study a possible approach for less invasive correction of long-gap esophageal atresia.

METHODS

Our technique utilizes a magnet-tipped catheter with a piston on the end to push the esophageal pouch from the inside. The attractive magnetic force helps the catheter stretch the esophageal pouches, while the hydraulic piston prevents the magnet from applying too large force. The piston also enables estimation of the esophageal tension based on the hydraulic pressure measurement.

RESULTS

We have built a prototype system and performed bench-level tests on an esophageal mock-up. A hydraulic dither is applied to the piston to average out seal friction, thereby improving the tension estimation performance.

CONCLUSION

The bench-level tests demonstrate that the prototype bougienage system gives a reliable low-frequency estimate of the esophageal tension in real-time, and also enables longitudinal bougienage by a desired amount of load, e.g., 2N, for various gap sizes.

SIGNIFICANCE

This study provides a foundation for the next step of designing a system for use on actual patients.

Update on Foregut Molecular Embryology and Role of Regenerative Medicine Therapies

Esophageal atresia (OA) represents one of the commonest and most severe developmental disorders of the foregut, the most proximal segment of the gastrointestinal (GI) tract (esophagus and stomach) in embryological terms. Of intrigue is the common origin from this foregut of two very diverse functional entities, the digestive and respiratory systems. OA appears to result from incomplete separation of the ventral and dorsal parts of the foregut during development, resulting in disruption of esophageal anatomy and frequent association with tracheo-oesophageal fistula. Not surprisingly, and likely inherent to OA, are associated abnormalities in components of the enteric neuromusculature and ultimately loss of esophageal functional integrity. An appreciation of such developmental processes and associated defects has not only enhanced our understanding of the etiopathogenesis underlying such devastating defects but also highlighted the potential of novel corrective therapies. There has been considerable progress in the identification and propagation of neural crest stem cells from the GI tract itself or derived from pluripotent cells. Such cells have been successfully transplanted into models of enteric neuropathy confirming their ability to functionally integrate and replenish missing or defective enteric nerves. Combinatorial approaches in tissue engineering hold significant promise for the generation of organ-specific scaffolds such as the esophagus with current initiatives directed toward their cellularization to facilitate optimal function. This chapter outlines the most current understanding of the molecular embryology underlying foregut development and OA, and also explores the promise of regenerative medicine.

The effects of acute tension increase on rat esophageal muscle contractions: An in vitro study

In long-gap esophageal atresia surgeries, anastomoses can be tensioned by several traction methods in order to establish esophageal continuity. It is unclear whether the etiology of esophageal dysmotility after traction is related with esophageal atresia itself or tensioned esophagus. Therefore, we evaluated the effects of acute in vitro esophageal tension application on esophageal muscle contractility in rats. 26 Wistar rats weighing 250-300 g were included to the study. After diethyl ether anesthesia, proximal segment (PS) and distal segment (DS) of esophagus were removed and suspended in an isolated organ bath kept at 37°C, Krebs-Henseleit solution. Rats were enrolled into four groups including control group (CG, n=14) without tension, 5 g (5G, n=4), 15 g (15G, n=4) and 25 g (25G, n=4) tension groups. In all groups, contractile responses to electrical field stimulation (EFS), carbachol and KCl, and relaxation responses to serotonin were obtained. In CG, higher contractile responses were obtained in PS than DS after EFS. Both PS and DS showed higher contractile amplitudes in 5G with respect to that of CG, 15G and 25G (p<0.05). In 5G, contractile responses to carbachol were significantly increased in both PS and DS with respect to CG (p<0.05). However, contractile amplitudes in response to carbachol were decreased in PS when tension was increased to 15 g and 25 g. In DS, contractile responses in 15G and 25G were lower than 5G, and still higher than CG. Serotonin relaxation responses in PS were decreased when compared to CG at tension levels of 5 g, 15 g and 25 g (p<0.05). In DS, responses to serotonin were also decreased in tension groups. PS had higher contraction amplitudes than DS when contractile responses were obtained by high K(+) (p<0.05). Tension groups of both PS and DS showed increased contractions to high K(+) compared to CG (p<0.05). Increased esophageal tension led to increase in cholinergic responses of smooth muscles as well as in EFS-induced skeletal muscle responses. On the other hand, relaxation responses induced by serotonin decreased. These data indicate that esophageal tension increase impairs esophageal motility in both segments.

Histological study of the elongated esophagus in a rat model

BACKGROUND

Esophageal elongation by traction suture is used in pediatric patients to manage long-gap esophageal atresia (EA). There was no histological evidence of the esophageal elongation. Here, we sought to clarify the histologic effects of traction on the esophagus by using a rat EA model simulating Foker's method.

MATERIALS AND METHODS

Rats were randomly assigned into three groups (n = 5 each). The traction group underwent daily stretching of the distal segment of the esophagus. The nontraction group underwent a sham operation, and the normal group served as controls. Seven days after the operation, the distal segments of the esophagus were removed. The length and thickness were measured, and samples were stained with Ki-67, nNOS, and S-100.

RESULTS

The whole length of the esophagus in the traction group was significantly longer than that in the nontraction group (P < 0.01). The thickness of esophageal mucosa and muscle tended to become thin by traction, but not significantly. The Ki-67-positive ratio of mucosa and muscle was significantly higher in the traction group (P < 0.05). There were no significant differences in Ki-67 between two segments (cardia-middle and middle-stump) in any group. Auerbach's plexus was identified at all sites of elongated esophagus by nNOS and S-100 staining.

CONCLUSIONS

By traction, the esophagus was elongated uniformly and cell proliferation activity was promoted in all parts of the elongated esophagus in the rat EA model.

Surgical advances in the fetus and neonate: esophageal atresia

This article focuses on selected topics in the diagnosis and management of patients with esophageal atresia (EA) with or without tracheoesophageal fistula. The current status of prenatal diagnosis and recent advances in surgical techniques, including thoracoscopic repair for short-gap EA and tension-induced esophageal growth for long-gap EA, are reviewed. Although no consensus exists among pediatric surgeons regarding the role of these procedures in the treatment of EA, one can reasonably expect that, as they evolve, their application will become more widespread in this challenging patient population.

Esophageal stenting in children: indications, application, effectiveness, and complications

BACKGROUND

Use of esophageal stents is uncommon in children, and there are few reports. We report the first experience in predominantly small children and infants with retrievable, flexible stents designed for tracheobronchial use.

OBJECTIVE

Evaluation of initial experience with placement of esophageal stents for benign esophageal disorders in children.

DESIGN

A retrospective study.

SETTING

A pediatric, academic, tertiary-referral center.

PATIENTS

This study involved 7 pediatric patients.

INTERVENTIONS

Covered tracheobronchial stents were endoscopically placed in pediatric patients with benign esophageal conditions. Removal involved using forceps to pull the purse-string suture into the endoscope channel and collapsing the top of the stent for easy removal.

MAIN OUTCOME MEASUREMENTS

To evaluate the safety and feasibility of performing endoscopic stent placement in children and to establish criteria for early stent removal.

RESULTS

Six of 7 patients benefitted from stenting. There were no complications of placement. Novel techniques were developed for difficult retrievals. One patient did not benefit from esophageal stent placement, because the stent migrated downward from the uppermost part of the esophagus. One patient had some gagging, which led to early removal of the stent. A stent was removed emergently in 1 patient for respiratory distress.

LIMITATION

Small number of patients.

CONCLUSIONS

Retrievable, covered stents are easily placed and removed from the esophagus in small children. They should be considered for severe unrelenting strictures, especially when associated with esophageal leaks. A need exists for development of esophageal stents designed for pediatric use.

Achievement of feeding milestones after primary repair of long-gap esophageal atresia

OBJECTIVES

To determine the pattern of feeding milestones following primary repair of long-gap esophageal atresia (EA).

METHOD

A questionnaire based upon well established feeding milestones was used. Children after long-gap EA repair, n=40, were compared from after primary repair to healthy children from birth, n=102.

RESULTS

The age when surveyed of the EA group and controls was different: 6.2+/-4.7 (mean+/-standard deviation) years, range 1.1-20.9, versus 2.5+/-2.4 years, range 0.0-12.1, p=0.00. The esophageal gap length in the EA group was 5.1+/-1.2 cm and age at repair was 5.5+/-5.0 months. There was no statistically significant difference between the atresia group and controls for feeding milestones; Self feeding finger foods approached significance. There was, however, greater variability in the timing of milestones in the atresia group compared to controls. Feeding milestones were negatively correlated with age at primary repair: drinking with a covered sippy cup, rho=-0.51, p=0.01 and self feeding finger foods, rho=-0.36, p=0.04 were statistically significant. Drinking from a cup correlated with gestational age, rho=0.38, p=0.04, and negatively correlated to esophageal gap length, rho=-0.45, p=0.01.

CONCLUSIONS

Despite delayed onset of feeding, major milestones after EA repair occurred in similar pattern to normal infants. An early referral for primary repair is beneficial for earlier acquisition of milestones for infants with long-gap EA.