DEMOGRAPHY AND ULTRASOUND MEASURES IN INFANTILE HYPERTROPHIC PYLORIC STENOSIS-OUR INSTITUTIONAL EXPERIENCE

Dr. Mohan Lal Kajala, Dr. Dinesh Kumar Barolia, Dr. Prameshwar Lal, Dr. Ramesh Tanger, Dr. Ravitej Singh Bal and Dr. Vinita Chaturvedi Department of Pediatric Surgery, S.M.S. Medical College, Jaipur, Rajasthan, India. ...................................................................................................................... Manuscript Info Abstract ......................... ........................................................................ Manuscript History Received: 05 July 2020 Final Accepted: 10 August 2020 Published: September 2020

17 history of IHPS are risk factors for infants. Etiology of IHPS is multifactorial including environmental factors, genetic factors and others [7,8,9].
Historically, IHPS was first described as a disease entity in 1888 by Harald Hirschsprung [2].Clinical presentation of IHPS is progressive projectile non-bilious vomiting. Infants brought by parents to hospital with this symptom mostly between 2nd and 8th weeks of age [10,11]. Some patients may present with emaciated and severely dehydrated condition. There is visible peristalsis in upper abdomen of infant progressing from left to right side. An "olive-like" tumor may be palpable at the lateral edge of the rectus abdominus muscle in the epigastrium or right upper quadrant of the abdomen. Olive like tumor becomes palpable in calm and sleeping infants when abdominal muscles are relaxed [11].
The diagnosis of IHPS is confirmed by ultrasound of abdomen. In IHPS, ultrasonography abdomen showed increased pyloric muscle thickness and length of pyloric canal [12,13].Ultrasonographic diagnostic criteria for IHPS are pyloric muscle thickness of 3.5 -4 mm or more and pyloric canal length of 16 mm or greater. Infants with IHPS showed hypokalemia, hyponatrimia, hypochloremia, and metabolic alkalosis with paradoxical aciduria. This occurs due to loss of large amounts of gastric hydrochloric acid with recurrent vomiting. The severity of electrolyte imbalance and metabolic alkalosis depends upon the duration of symptoms (vomiting) prior to hospital admission [14].
The study was conducted to describe our experience for IHPS about age of presentation, male female sex ratio, clinical presentation, laboratory findings, USG findings, management and outcome, and identify factors responsible for poor outcome of these patients. We postulated in this study that preoperative pyloric muscle wall thickness and pyloric canal length has correlation with weight and age of patients with surgically proven IHPS.

Methods and Material:-Study design-
This is a prospective study, conducted in 80 infants (66 male,14 female) at J. K. Lone Hospital, SMS Medical College Jaipur, Rajasthan, India. This study conducted from September 2018 to April 2020 over period of 20 months. We describe the experience in the management of patients with IHPS admitted to our Department of pediatric surgery.
The data collection included age, sex, weight at admission, clinical presentation, serum electrolytes, signs of dehydration, USG abdomen findings, treatment and outcomes, duration of hospital stay and mortality.

Operative procedure
Planning of surgery for IHPS depends upon the clinical condition of the infants. If serum electrolytes are normal and no sign of dehydration then the surgery can do on the day of diagnosis [15].
Surgery should be delayed if there are signs of dehydration and/or electrolyte derangements [16]. A nasogastric tube should not be placed routinely because it removes additional fluid and hydrochloric acid from the stomach, which precipitate the electrolyte and acid-base imbalance. Intravenous administration of 5% dextrose in normal saline (1:1 ratio of both) containing 20 mEq/L of potassium chloride is the optimal resuscitation regimen for fluid and electrolyte replacement. 18 Ramstedt pyloromyotomy is the procedure of choice [17]. We did this procedure in our all cases. Operation was done by right upper quadrant transverse incision. After opening of peritoneum, pyloric tumor delivered out and hold between index finger and thumb. Longitudinal incision was given at anterosuperior avascular surface of pylorus with back of knife handle. Widening of incision was done with pyloromyotomy forcep up to visibility of pouting mucosa. Completion of procedure confirm by freely side to side movement of both margins. Finally pylorus replaced in abdominal cavity and wound closed in layers.

Results:-
Total 80 patients of IHPS were included in this study. Out of them 66 were males and 14 females. The male female ratio was 4.7:1. The mean age of presentation was 6.26 weeks. The Age of younger most infant was16 days and the oldest was of 15.28 weeks (107 days).  Infants were divided in four groups according to their age of presentation. Maximum 47.5% (38) patients present in age group of >4-8 weeks. Infants presenting in age group 0-4 week were 36.25% (29), in 8-12 weeks 13.75% (11), and above 12 weeks 2.5% (2).Weight of infants at the time of admission was recorded. The mean weight of infants was 3.32kg. Weight of infants ranges between 1.7 kg to 5.5 kg.  Correlation of USG findings with age and weight of patients -We studied here relation of pyloric muscle wall thickness and length of pyloric canal in USG with age and weight of patients at time of presentation. Results are following:  As shown in table 6, muscle thickness and pyloric canal length both had no proportional increasing pattern relation with weight of patient.

Discussion:-
Infantile hypertrophic pyloric stenosis (IHPS) was first described by Harald Hirschsprung in 1888 [18]. IHPS is the most common cause of gastric outlet obstruction and most common surgical cause of vomiting in infants [19].
Diagnosis of IHPS is done by clinical features like non bilious projectile vomiting, palpable olive tumor, and visible peristalsis. Upper GI dye study is also helpful to diagnose the IHPS. Ultrasonographic findings like pyloric wall thickness and canal length confirm the clinical diagnosis. Lowe et al gives a new USG based diagnostic criteria named pyloric ratio. Pyloric ratio is the ratio of pyloric wall thickness and diameter. A ratio 0.27 or more is diagnostic for pyloric stenosis. Sensitivity and specificity of pyloric ratio is 96% and 94% respectively [20,21]. Serum electrolytes imbalance in our study was present in 61.25% of cases. Most common cause of this imbalance was due to late admission after appearing of symptoms. Normal serum electrolytes were present in 38.25% of patients in our study. These patients operated early and duration of hospital stay became short.
USG abdomen was imaging modality of choice for confirmation of diagnosis. All patients operated after confirmation by USG abdomen.
A study by Said Meena et al suggests that there was a statistically significant relationship between pyloric muscle wall thickness and patient age as well as wall thickness and patient weight. The same analysis proved that there was no significant relationship between pyloric length and patient age or weight. In our study pyloric muscle wall thickness had proportional increasing pattern with age of patient but not with weight. In this study same analysis proved that there was no significant relationship between pyloric length and age or weight of patient [24].

Conclusion:-
IHPS is more common in male infants. Most common age of presentation was between 4 to 8 weeks. Clinical presentation was triad of non-bilious vomiting, visible peristalsis and palpable olive tumor. Delayed presentation and Serum electrolytes imbalance are most common causes of poor outcome. USG abdomen is best imaging modality for confirmation of diagnosis. Pyloric muscle wall thickness had proportional increasing pattern correlation with age of patients but not with weight.