Congenital Hypertrophic Pyloric Stenosis
Cannot Miss Diagnosis No.7
- Section Editor: Prof. T.K. Partha Sarathy
A 4 week old normal born child of young parents was doing well till the visit to the Family Practitioner with a history of vomiting once the previous day and twice that morning. The Baby was able to accept breast feeding really well but within a short time after nursing he started to spit the milk. Physical examination revealed that the baby looked healthy and normal and was active. There was no fever, earache, cough, cold or any other symptoms. Cardio respiratory status was normal. Abdomen was soft and the bowel sounds were heard normal. The Family Practitioner reassured the mother and asked her to give electrolyte solution for feeding in between and to bring the baby back if vomiting persists.
Two days later the baby was brought again to the family practitioner with a history that he has been vomiting almost every feed and the vomiting was projectile immediately following each feed. On careful examination the ear, nose and throat were found normal. The fontanelle and the head circumference were normal. Neck was supple. Cardio-respiratory status was normal. Abdomen was soft and bowel sounds were heard normal. Rectal examination revealed presence of soft stool. The child was somewhat sleepy and looked grossly dehydrated, probably because of frequent vomiting. The family practitioner encouraged the mother to admit the baby for further testing. Blood samples were obtained for CBC and electrolytes and an I.V. was started with 5% dextrose in half Normal Saline. The child was kept on minimal oral fluids with electrolyte solution. Even with this the child continued to have projectile vomiting. The CBC was essentially unremarkable given the age of the child (one month). However, electrolytes revealed a low potassium and a high serum bicarbonate levels. There was evidence of hypokalemic alkalosis. After I.V. fluid was started the child had some urine output which was sent for urinalysis. The urine was acidic and other parameters were within normal limits. The family practitioner once again examined the child carefully and he particularly noticed that the vomitus was not bile stained. When the child was sleeping he examined the right side upper abdomen and felt a small olive shaped firm mass. Because of this finding he requested a pediatric surgeon to examine this child.
On consultation the surgeon who examined the baby felt that given the facts of the age (one month), the hypokalemic alkalosis and dehydration secondary to frequent projectile vomiting as well as the confirmed palpatory findings of an olive like lump deep in the right hypochondrium the diagnosis of congenital hypertrophic pyloric stenosis was clear. The fact that the vomitus was free of bile stain further confirmed his suspicion. However, in order to document his impressions he requested an ultrasound examination of the abdomen, particularly to look for the hypertrophic pylorus. Within a short period the sonographer was able to clearly demonstrate the olive shaped lump and the typical appearance of an elongated pylorus with a thickened pyloric wall. The findings were classical and the diagnosis of a congenital hypertrophic pyloric stenosis was well established.
At this point the surgeon felt that without wasting much time, the child should receive an operation to correct the problem. However, because of the hypokalemic alkalosis and dehydration I.V. fluid therapy with potassium supplementation had to be continued. When the child was active well and passing adequate urine which took a few hours, he was taken to the operating room and after emptying the stomach with a small nasogastric feeding tube anesthesia was induced. The surgeon made a small 1” incision in the right upper abdomen transversely and within minutes was able to demonstrate the hypertrophic pylorus. Pyloromyotomy (Ramsted’s procedure) was performed. The hypertrophic pylorus muscle had a firm, consistency and looked tan white which was incised and by gentle separation of the pyloric muscle the underlying mucosa was seen to bulge into the divided muscular portion. When the pyloromyotomy was completed the surgeon checked for any bleeding points and closed the abdomen. Post operatively the child did extremely well and was able to accept feeds within a few hours and retain it well. The baby was discharged on the 4th post operative day for follow up in the clinic.
At the age of 3 to 6 weeks, particularly in a male chid projectile vomiting should raise the suspicion of congenital hypertrophic pyloric stenosis. If prompt surgical care is not given the child continues to vomit and gets progressively dehydrated and management becomes even more difficult. Although simple virus diseases also can cause vomiting, it is rarely projectile and there will be other symptoms of the underlying disease.
Occasionally intracranial space occupying lesions may give rise to projective vomiting in children. However, the diagnosis of congenital pyloric stenosis is rather easy and straight forward if one is aware of the diagnosis and looks for it given the circumstances.
Text : Infantile congenital Hypertrophic Pyloric stenosis.
Infantile hypertrophic pyloric stenosis although less common in Asian population is by no means a rarity. Every family practitioner is likely to come across a situation where this diagnosis has to be considered. It is 4 times more common in male children and although it can occur any time from the day of birth to about 3 to 4 months, most common presentation is between the 3rd and 6th week. Rarely these babies could have other congenital abnormalities and at times jaundice. The presenting symptoms are almost always projectile- non bilious vomiting in a baby hitherto normal with no other accompanying findings of upper respiratory infection etc. The presence of an ovoid olive shaped mass in the right upper quadrant area close to the epigastrium is a very important sign and conclusive enough to proceed with further care. However, ultrasonographic examination may be considered for the confirmation of palpatary findings. Occasionally when palpation becomes difficult either because the child is crying and not relaxed and ultrasonographic examination is limited, consideration may be given for a Barium enema (Gastrograffin) upper GI study. This will show the so called string sign - the contrast going through the pylorus through a narrow channel from the stomach into the duodenum. There is no point in waiting for this test to be done unless the diagnosis is very doubtful. It should be used more to rule out a pyloric stenosis than to establish the diagnosis. The significant aspect of congenital pyloric stenosis is the fact that it causes rapid dehydration in a child. Because of the frequent vomiting and loss of hydrogen, and chloride ions from the stomach it leads to hypochloremia and hypokalemia. In order to preserve the sodium (Na+) and water and also maintain the fluid volume, potassium (K+), Hydrogen (H+) irons are excreted in the urine. The bicarbonates also get reabsorbed leading to a status of metabolic alkalosis. However, the loss of hydrogen iron in urine makes the urine acidic. The acidic urine in the presence of a metabolic alkalosis is frequently referred to as paradoxical aciduria. It becomes mandatory to correct the alkalosis, dehydration and hypo potassemia before taking a child to surgery. This may take about 6 to 12 hours to accomplish. Once adequate fluid and electrolyte correction is obtained, the stomach is emptied by nasogastric tube aspiration under general anesthesia and Ramsted pyloromyotomy has to be performed by a competent surgeon. It is not necessary at this stage to go through an elaborate testing and work ups to look for other anomalies. These can be taken up later depending on any specific presentation. The operated child recovers very quickly and is able to accept feeds within hours and start to gain weight within days. Congenital hypertrophic pyloric stenosis is a disease to be kept in mind while dealing with infants in the age group 3 to 6 weeks particularly.
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