The cause of pyloric stenosis revisited

Prof. Dr Ian M Rogers has had a strong interest in infant pyloric stenosis (“PS”) throughout his long career in the practice and teaching of paediatrics and paediatric surgery.

A year ago I posted an overview in two parts of one of Prof. Rogers’ articles on the essential cause of PS.  His interest in this and a friend’s blog projects to publicize some of the patient issues around infant surgery and PS in particular has been a tremendous encouragement.  So also his willing and generous help in getting some of the benefits of his lifetime of knowledge and work onto the computer screens of those interested and affected.

Some months ago Dr Rogers wrote another article, The whole Story of Pyloric Stenosis, on this subject.  I have not found it published online, but it should be of great interest to all specialist paediatricians and to some of those personally affected by PS; this is why I am so grateful I can overview it here.

Med research1Dr Rogers restates some of the research and conclusions reported on in his 2012 article, but the 2013 report is not as readily accessible to the general reader.  Rather, it very much (and appropriately) addresses his colleagues.  The 2013 essay again reflects Dr Rogers’ career-long interest in IHPS and the progress of his and others’ research, discoveries and reports on hyperacidity as the cause of IHPS.

The article necessarily includes a lot of the language of bio-chemistry and reasoning and refutation on this basis.  I found this interesting, but without help much of it was hard to understand, let alone assess.

Dr Rogers has been very generous with his time and help, giving me a quick lesson in the biology of the stomach and making detailed corrective explanations to several parts of my first draft.  He has kindly added some more explanatory notes to make this post as clear as possible.

So I am now able to pass on the main points of significance to those who like me are interested in the causes and treatment of PS, as well as Dr Rogers’ answers to several of my questions.  This means this post is now quite lengthy, but those interested will be happy to read on!

In his email to me Dr Rogers first gave this most helpful explanation of how the stomach works; this helps us understand what happens when PS develops.

When you eat and food enters the stomach a chemical is released from the lining cells of the stomach into the blood stream.  It is called gastrin.  It is an internal messenger or hormone, and rises naturally during feeding and passes into the circulation when the stomach is distended and alkaline.

Gastrin circulates and causes other cells in the stomach lining to secrete acid: these cells are called parietal cells.

bub w bottle1The stomach contents then become acid – and this acidity stops the secretion of acid since gastrin secretion is switched off when the stomach becomes acid.  It is called a negative feed-back mechanism and you will see that acid secretion is controlled and extreme hyperacidity or hypoacidity (i.e., lower than normal acidity) are avoided by this mechanism.  If acidity falls, gastrin rises and if it rises, gastrin falls.  Hence acidity is under control.

Acid causes the pyloric sphincter to contract; if there is undue acidity the sphincter contracts frequently and, as with any exercising muscle, it becomes stronger and larger – resulting in the narrowing of the exit passage, i.e. pyloric stenosis.

That is all the physiology you need to know!

Prof. Rogers starts his article by mentioning that as far back as 1972 he was interested and became involved in the then recent discovery that the excessive release of the hormone gastrin is responsible for stimulating high levels of acid in the stomach which causes the pylorus to overwork, enlarge, and close to the passage of food.  His team discovered however that gastrin is not passed on to any great extent from mother to baby, but rises to very high levels about 4 weeks after birth.  This is the time when most PS develops.  Let me again allow Dr Rogers to explain this in more detail –

Miller in 1947 thought that the observed wave of neonatal hyperacidity might be due to a chemical being transferred from mother to baby at the time of birth.  Naturally I thought of maternal gastrin and that is why I measured blood gastrins in mother and baby – on day 1 and day 4.

[I found that] baby gastrins were higher than fasting maternal gastrins at the time of birth (on Day 1).  On Day 4, the fasting baby gastrins were several times higher than those in fasting normal adults.  (Because gastrins do not last long in the body (a short half-life of 17 minutes) it was presumed that Day 4 must be coming from the baby – and since a low level on Day 1 meant a low level on Day 4, the baby gastrin at Day 1 etc (they were individually statistically related) was likely to also be largely baby in origin.  We did not prove that gastrin did not transfer from Mother to baby.  It might for example be concentrated in the placenta before being transferred.  (Maternal transfer has been clearly shown to occur in the dog!)

The peak gastrin level has not been clearly shown but the experiments of Rodgers and MacGuigan strongly suggest the peak at around 15-17 days.  Acidity in NORMAL babies peaks at around that time.

I have suggested that in NORMAL babies the negative feed-back takes time to mature — this would not matter in babies with the normal number of parietal cells – but in those with a super-normal number of parietal cells, dangerous hyperacidity (leading to pyloric stenosis) would occur before the feed-back is established, at the best guess time of around 4 weeks.

In his main article Dr Rogers wrote –

We concluded that neonatal gastrin secretion was present at birth and became greatly increased by Day 4… the rising gastrin should be considered as an independent primary phenomenon causing acid secretion.

Our paper was the first time that neonatal hypergastrinaemia (i.e., high blood levels of gastrin) had been documented.  It has now been confirmed many times.

Our hypothesis then was that a self-perpetuating process would have begun in which hypergastrinaemia, by causing hyperacidity, would induce pyloric contractions; pyloric sphincter work hypertrophy and eventually IHPS.  Babies destined to develop IHPS would self-select by starting out with an acid secreting ability at the top end of normal.

We found that basal acid secretion rates were greatly increased in the IHPS babies… This was the first time that hypersecretion (i.e., a higher than normal level of acid secretion) had been shown to be associated with IHPS.  Many others have confirmed hyperacidity and hypersecretion of acid.

Mum w baby me 1945This conclusion of Dr Rogers would seem to give the lie to my understanding (based on much earlier medical articles) that my mother’s stressful condition in 1945 may have triggered my PS.  A friend reports (see a Comment with this post) that Dr. Robert Sapolsky has done extensive research and concluded that stress hormones of the mother do affect the baby in utero.  I will pass on Dr Rogers’ comments to me on this subject in another post soon.

Dr Rogers comments that this finding agrees with all the features of PS and its effective treatment.  (For details of this see my previous posts.)  He adds that both the surgical and medical (with the atropine family of drugs and reduced feeding) treatments of PS both allow acid to leave the stomach, thereby greatly reducing gastric acidity and allowing the pylorus to resume its normal size and functioning.

He adds something that is significant for many who have had PS surgery as babies –

Long term analyses have repeatedly found evidence of clinical hyperacidity in adult survivors – either from the need for duodenal ulcer surgery or for anti-acid treatment.  Hypersecretion of acid must surely have a major part to play.

This will be of interest to many, as one of the most common (but often dismissed) complaints of PSers is of reflux (GERD) and other gastric discomfort.

The report then addresses three remaining questions –

  1. What is the specific cause of neonatal hypergastrinaemia?
  2. When does developmental neonatal hypergastrinaemia subside?
  3. Why is the presentation (and by implication, hypersecretion of acid) provoked so often at around 4 weeks of age?

He offers some considerations, and I pass on this emailed comment –

…the basic problem leading to PS is the inheritance of a larger than normal number of parietal cells (parietal cell mass PCM) — hence when stimulated by normal levels of gastrin there is a hyperacid state which is uncontrolled within the 2-3 weeks after birth due to an immature feedback process.  The further week necessary for maternal concern to lead to admission is likely to lead to a common presentation at 4 weeks.

Thickening of the pylorus has in itself been found to stimulate acid secretion: the process once begun has an element of fatal self-perpetuation unless there is surgical or medical intervention.

Mother and baby3I asked Dr Rogers why a sizeable minority of babies have PS surgery well before the most common age of 4-6 weeks.  I have read of a very few babies going to surgery only days after their birth, and I had my operation when just 10 days old.  He explained –

Earlier occurrences may be due to this process starting earlier — for example, there are an increased incidence and earlier presentation in babies whose gullet (oesophagus) is not open (oesophageal atresia).  The stomach is not alkalinized by swallowed saliva in these babies, hence – as far as acidity is concerned, they hit the ground running!  You are correct in citing the additional effect of pyloric stenosis itself for any reason, causing further acid secretion.  Gastrin is also secreted when the gastric antrum is distended due to a narrowed exit.

Finally, Prof. Rogers in his article makes some practical recommendations.

Because gastric acid secretion has been shown to be the main factor in the development of PS, babies who secrete high levels are most at risk.  How do we manage this risk?  Dr Rogers writes –

Medical control of acid secretion is now easy and safe and very effective.  We ought to use it – especially when pediatric surgical expertise is not available.  Medical treatment at present with atropine and controlled underfeeding with gastric washouts does reduce acidity and does produce enduring cures despite the temporary treatment.

He adds that the cause and character of duodenal ulcers in adults is similar to those of infant PS, and that medical treatment of duodenal ulcers is highly successful… so why, Prof. Rogers asks, should PS not be treated in a similar way?

Note:  Readers interested in obtaining a copy of Dr Ian M Rogers’ report including detailed references should request this in an email to the owner of this blog (see the About  page at top).

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6 thoughts on “The cause of pyloric stenosis revisited

  1. Wendy

    Excellent synopsis of the article. I appreciate your articulating the questions that remain unanswered. btw, Dr. Robert Sapolsky has done extensive research and concluded that stress hormones of the mother affect the baby in utero. It still amazes me that the cause of pyloric stenosis remains unidentified. I hope that Dr. Rogers’ work helps medicine make the determination once and for all.

    Reply
  2. Fred Vanderbom Post author

    Thanks for your comment and input, Wendy. I’m not surprised that stress hormones like the well-known adrenalin affect a baby in utero, and could it be that these can trigger the release of gastrin? Who can say for sure?
    Several times I have read a medical report on a PS-related subject that contradicts an earlier report’s findings. It seems there are many possible variables that can affect research results, so although I welcome the publication of such results I shouldn’t accept any set of findings as the final word but await confirmation from other studies.
    Re-reading Dr Rogers’ two articles with their mention of the links between PS and gastric ulcers in adults reminded me that an uncle of mine had ulcer surgery long ago (but I don’t know any details). Could it be that more PS cases than realized are caused by genes which trigger hyper-acidity (genes which have been identified), and less than we think caused “multi-factorially”?

    Reply
  3. Fred Vanderbom Post author

    Wendy and other readers, I have re-posted this essay to incorporate the valuable input and answers Dr Rogers has given me since I posted the original. I am very grateful to Dr Ian Rogers for his willingness to spend considerable time to help me and the readers of this blogsite to understand a lot better what happens with the development of a pyloric stenosis.

    Reply
  4. julie lee

    would like to know when the first surgeries were done on this infant problem – i had a brother that died from pyloric stenosis and would like information on the early days of treatment – he was born may 8 1940 and died july 12 1940. could this have been prevented by treatment – was surgery available then? more information is needed. he was the second boy in the family and there is question re the first born’s paternity – need the answers so I can figure out the whats and whys of a family problem. thank you. julie lee

    Reply
    1. Fred Vanderbom Post author

      Thanks for your query, Julie.
      The first PS surgeries were done in the late 19th century but the technique was more radical and more often than not a death sentence: most parents refused surgery and tried to tough it out with the alternative treatments then available. In 1912 a German doctor discovered and published the technique which is almost always used to this day. In 1940 the “Ramstedt pyloromyotomy” surgery was quite common but the death rate could still be quite high – between 1% and 40% depending on where, how and by whom you had the operation done. I have written a series of posts surveying this: in the “Categories” box click on “History” and then page through the articles until you find the one on the 1940s.
      The medical treatment option was more widely used in the 1930s and 40s than today. Do you know if your brother had surgical or medical or no treatment? He died just over 2 months old which is the period PS strikes most often. Depending on several considerations, all 3 options have both their place and their risks.
      This should give you some idea of the “landscape” and I hope it clears the picture for you and your family. Do let me know if you need more detailed information.

      Reply

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