1A-S5-3

 

GASTROESOPHAGEL REFLUX DISEASE IN CHILDREN

Prof. Jose Boix-Ochoa,

Chairman of Department of Pediatric Surgery, H.U.M.I. “Vall d’Hebron”, Autonomous University of Barcelona (Spain)

 

The digestive tube is a one-way street. If one fail to follow this traffic rule the casualties can be frightening.

 

The presence of gastric juice in the oesophagus burns its mucosa, this fire, if not stopped start a vicious circle that ends in its destruction.

 

The only defense against this pathology is to extinguish the fire and to allow the oesophagus to rest, that is the aim of the medical treatment, and if all else fails the only hope is to reinforce the anatomical security measures by means of surgical procedure.

 

Gastroesophageal reflux (GER) is an extremely common pediatric problem, but only in the past few years have we developed a better understanding of its pathophysiology. This is related to the wider use of invetigative tools such as flexible endoscopy, 24-hour pH monitoring, and more recently, micromanometric methods and moninvasive breath test, which have been particularly useful in infants. This paper reviews our current understanding of the esophageal and gastric mechanisms contributing to the pathophysilogy of GER. In this context, we also highlight areas where new therapeutic approaches may be beneficial.

 

A person can stand upside down after eating a large meal, yet there is no reflux of food into the mounth or esophagus. Why is this so? It is clear that there must be a valve or sphincter mechanism at the lower end of the esophagus building an antireflux barrier. We have conducted several laboratory investigations and have experienced with this pathology during 30 years, with more than 3000 children.

 

The concept of an antireflux barrier or lower esophageal sphincter (L.E.S.) covers all these factors, anatomical and functional, static and dynamic, congenital and acquired which on their own or together work to prevent G.E.R. The L.E.S. does not operate on an only point; it is really an area of 2 to 6 cms. Which forms a crossroad where all the antireflux factors act to obstruct the G.E.R.

 

The L.E.S. is the interplay of several factors. The intrinsic muscles of the distal esophagus along with the sling fibers of the proximal stomach constitute the internal mechanisms of the L.E.S. (High pressure zone, intraabdiminal esophagus, Hiss angle, mucosal choke) and the crural diaphragm constitutes the external mechamisms, the author explain why we need two L.E.S. based in the fact that the pressure gradient between the stomach and the esophagus is constantly changing linked with respiration and abdominal contractions.

 

The reflux occurs when opening pressures exceeds closing pressures, that is to say, that reflux is not always due to the incompetence of the antireflux barrier but also be due to a pathologic increase of opening pressures.

 

Over the recent years, considerable evidence has accumulated indicating that the major mechanisms of G.E.R. ARE THE TRANSIENT RELAXATION OF THE L.E.S. (T.L.E.S.R.).

 

The transient lower sphincter relaxation occurs as a sudden collapse of L.E.S. pressures lasting 5 to 30 seconds, in spite of normal resting and intragastric pressures, due to the collapse of the internal sphincter and the inhibition of the crural diaphragm, giving way in some patients to G.E.R.

 

In our experience children who reflux, do not have an increase in number of T.L.E.S.R., but there is an increase in refluxes resulting from transient relaxations.

 

Why normal patients with the same number of T.L.E.S.R. have less refluxes than the patients with G.E.R.?

 

Acturelly, the best explanation is that all depends on the residual L.E.S. pressure after a T.L.E.S.R., and this residual L.E.S. pressure depends in all the other anatomical and physiological factors not affected by the T.L.E.S.R., and these factor are which the surgeon try by surgical procedures to improve and enhance, as we have demonstrated.

 

So much for the mechanisms of G.E.R. What is the effect of reflux once in the oesophagus? The answer isn’t easy since all patients do not respond to reflux in the same way. Here again, the concept should be considered that everything will depend on the balance between the attack of reflux and the defence of the oesophageal mucosa. So, in the assault of the “oesophageal castle”, on one hand we have the acidity and the volume of refluxing fluid and the duration of oesophageal contact, and on the other, for the defence of the castle there is oesophageal clearance and the resistance of the oesophageal mucosa.

 

Clinical symptoms and their complications are exposed. The diagnostic methods offer a variety of sophisticated possibilities and their results are highly accurate.

 

But once G.E.R. has been detected and diagnosed, the question is, which treatment should be applied, conservative or surgical? The decision should be individual, depending on age, anatomical type, severity and social environment. In the majority of cases conservative treatment is the therapeutic of choice.

 

Conservative treatment is based on three pillars, feeding, postural and drugs, which combined have the effect of potentiating the natural tendency of G.E.R. towards cure.

 

Empiric therapy assumes importance in infants with GERD because of the limited differential diagnoses in consideration. Conservative therapy is of utmost importance because of the unique provocative factors in the pathophysiology of infantile GERD. Prokinetic pharmacotherapy takes precedence over acid suppression because of the more important role of motility factors compared with acid secretion in infantile GERD.

 

With this treatment, we have obtained 95% of good results in 2000 patients of less than one year, with a follow up of more than 25 years in some cases, and with the experience that each single patient needs his own tailored treatment.

 

However, when conservative treatment fails, or age, type of anatomical anomaly, severity, respiratory complications or social environment make it necessary surgery is the next step, and one that should be effected without delay.

 

All the surgical techniques are good, but are different in philosophy.

 

Our philosophy is based on the fact that in dealing with children we are treating a patient with an altered L.E.S. and not a seriously damaged one, as is often seen in the adult. Therefore, any operation which restores the anatomic relationships and the conditions for physiological action will allow growth and evolution to restore the whole function.

 

Our technique is to reinforce the anatomical relationship based on the described physiology.

 

Therefore, what we do is what we already know by investigation:

A).   Restore the length of the intraabdominal oesophagus.

B).   Tighten the hiatus, anchor the oesophagus and reconstruct the Hiss angle.

 

In summary, what have we achieved with this operation? An intraabdominal segment of the oesophagus has been developed which restores normal closing pressures, the sharpening angle assures the mechanical action of compressing the oesophagus and closing it, and unfolding the fundus of the stomach causes buffering of intragastric pressure and mechanical closing of the oesophagus.

 

The few complications experienced and the results obtained with a follow up of up to 25 years demonstrate the value of this method and its physiological basic; this technique places the system in physiological conditions for its function instead of substituting it.

 

The pros and cons of other surgical procedures are analyzed and discussed, because in Medicine as in life, the time teaches you that nothing is absolute and therefore none technique is the best.

 

We would however stress that conservative treatment should be thought of first, as it is impossible to improve an already healthy child by surgery.