Outcomes of open Ramstedt’s pyoloromyotomy among infantile hypertrophic pyloric stenosis patients at governmental hospitals in Amhara Region, Ethiopia, 2023

Abstract

Background

Infantile hypertrophic pyloric stenosis is characterized by enlarged pyloric musculature and gastric outlet obstruction. In developing countries, it results in a high rate of malnutrition, dehydration, electrolyte and acid-base imbalance and associated mortality. Ramstedt’s pyloromyotomy is the commonest procedure used to treat Infantile hypertrophic pyloric stenosis in Ethiopia, particularly in the study area. However, treatment outcomes of the procedure were not well addressed in Ethiopia, particularly at the study area.

Objective

To assess outcomes of open Ramstedt’s pyloromyotomy among Infantile hypertrophic pyloric stenosis patients who underwent open Ramstedt’s pyloromyotomy at government hospitals in Amhara Region, Ethiopia, 2023.

Methods

A facility based cross-sectional study was conducted among 119 Infantile hypertrophic pyloric stenosis patients operated with open Ramstedt’s pyloromyotomy at government hospitals. Hospitals were selected by simple random sampling. The data were collected using a data extraction checklist prepared in English language. The data were analyzed using Statistical Package for Social Science (SPSS) version 27. Descriptive statistics was used to describe the characteristics of the study participants.

Results

In this study the clinical records of 119 infants were retrieved from three government hospitals. Majority (78.2%) of the study participants were male. All infants had nonbilious vomiting and more than one thirds (34.5%) had malnutrition during admission. The overall proportion of poor outcome was 35.3% (mortality = 0.8% and morbidities = 34.5%). Prolonged preoperative hospital stay, hypokalemia and hypochloremia were the common poor outcome.

Conclusion

The mortality rate is significantly decreased, but there were still significant morbidities in this group of patients. High proportion of malnutrition, hypokalemia, and hypochloremia found at the time of admission underscores a critical pattern of delayed healthcare-seeking.

Introduction

Infantile hypertrophic pyloric stenosis (IHPS) is a disorder of pyloric region of stomach in infants characterized by hyperplasia of smooth muscle fibers of the pylorus, that cause increase in thickness of pyloric wall and length of pyloric canal [1]. It is characterized by postprandial progressive non-bilious vomiting which may become bloody if stayed longer untreated from resulting gastritis [2]. The diagnosis is confirmed by ultrasound of abdomen which shows pyloric muscle thickness of 3.5–4 mm or more and pyloric canal length of 16 mm or greater [3]. Evidences show that the incidence of IHPS is increasing [4]. Currently the laparoscopic technique becomes a safe and effective method of management with a shorter length of hospital stay and less complication rates [5]. Longitudinal myotomy remains the treatment of choice for IHPS [3, 6]. Because Ramstedt’s principle of splitting the hypertrophied muscle layer, leaving an intact bulging mucosa, is simple and effective in relieving the obstruction, few significant technical modifications have been introduced [7].

Infantile hypertrophic pyloric stenosis is most commonly found in first-born males [8]. Its incidence ranges from 0.5 to 5 per 1, 000 live births and is more common in Western countries than in African countries [9]. Infantile hypertrophic pyloric stenosis is the most common cause of gastric outlet obstruction in infancy, and common indication of surgeries in early infancy [8, 10, 11]. However, in developing countries, it is misdiagnosed as gastroenteritis, gastroesophageal reflux disease (GERD) and milk allergies and only considered after vomiting persists. These conditions contributing to the late presentation of infants which is associated with worse outcomes due to dehydration, malnutrition and electrolyte and acid-base imbalances [6, 12]. The development of IHPS is found higher among males, first born, white race, those with history of IHPS, postnatal direct erythromycin exposure, and artificial feeds [1, 2, 8, 13, 14].

The outcome after pyoloromyotomy is determined by adequate preoperative resuscitation and correction of fluid and electrolyte imbalances, the availability of a specialist pediatric surgeon and expert pediatric anesthetist [15]. A study conducted in Nigeria found complication rate of 15% and a mortality rate of 11.5% [16]. In Cameroon nearly half of the infants had developed mild to severe post-operative complications including persisted vomiting [17]. Another study in Nigeria found chest infection (33.3%), and vomiting (23.3%) as the common postoperative complications [18].

Ramtsedt’s pyloromyotomy done by general surgeons were four fold more likely to have post-operative complication than by subspecialist [19]. On the other hand, another study found that infants operated by general surgeons had almost comparable outcome with those operated by pediatric surgeons [20]. In Italy, the incidence of post-operative apnea was found to be associated with postoperative anemia [21]. A similar study revealed a strong association between prolonged postoperative length of stay and dehydration or delayed presentation. Hypochloremia at the time of diagnosis was also found significantly affected the post-operative clinical course [5]. Moreover, uncorrected metabolic alkalosis was identified as a determinant of perioperative respiratory events [22]. A study done in Nigeria, found a significant association between serum potassium level and duration of preoperative hospital stay [13]. Another study done in Cameroon revealed severe dehydration on admission was the main predictors of mortality followed by hypokalemia on admission and surgical site infection [17].

In a descriptive retrospective study of infants with IHPS admitted to Bugando Medical Centre, intraoperative mucosal perforation which required repair was encountered in 5.9% of patients and postoperative complications reported in 11.8%. The median length of hospital stay was 12 days which is significantly associated with prolonged preoperative hospitalization. The mortality rate was 4.9% with age < 2 weeks, late presentation (≥ 14 days), severe dehydration on admission, hypokalaemia on admission and surgical site infection as the main predictors of mortality. The overall mortality was high and all mortalities occurred on the first postoperative day after a smooth operation emphasizing the postoperative care both in terms of human power and facilities to care for postoperative infants who need strict fluid balance, ambient environment to prevent hypothermia and other supportive cares [9].

Evidences regarding the treatment outcomes of IHPS are scarce in Ethiopia, particularly in Amhara region. Hence this study was aimed to assess the outcomes of open Ramstedt’s pyloromyotomy among IHPS patients who underwent open Ramstedt’s pyloromyotomy at government hospitals in Amhara Region, Ethiopia.

Methods and materials

Study design, area and period

The study was conducted in three randomly selected hospitals located in the Amhara region of Ethiopia including Dessie comprehensive specialized hospital (DCSH), University of Gondar comprehensive specialized hospital (UoGCSH) and Kemise General Hospital (KGH). The UoGCSH and DCSH were the major teaching referral centers in Amhara region of Ethiopia. The UoGCSH was staffed with dedicated pediatric surgery sub-specialists and specialized pediatric intensive care units. The DCSH was handling high volumes of pediatric emergencies managed mainly by general surgeons and recently by pediatric surgeons. The anesthesia personnel mainly consisted of bachelor of science and master’s degree holder anesthetists. On the other hands, KGH provides general surgical services by general surgeons in Kemise town, the Oromia special zone of Amhara region. The hospitals were equipped with appropriate resuscitation and electrolyte correction capabilities, and postoperative monitoring services for infants who underwent open Ramtsedt’s pyloromyotomy. The data collection was conducted from December 1 to December 30, 2023.

Study design

A facility-based cross-sectional study was conducted by retrospectively reviewing patients’ charts.

Population

All infants who got open Ramstedt’s pyloromyotomy at government hospitals in Amhara Region, Ethiopia were the source population for this study. Infants who underwent open Ramstedt’s Pyloromyotomy at the three selected hospitals (DCSH, UoGCSH and KGH) from December 2019 to December 2023 were the study populations.

Inclusion and exclusion criteria

Inclusion criteria

The study included all patients diagnosed with and operated for infantile hypertrophic pyloric stenosis (IHPS) over a three-year period preceding data collection (December 2019 to December 2023) at selected hospitals.

Exclusion Criteria

Those incomplete charts particularly on the pre-operative and postoperative patient status were excluded from the analysis.

Sample size determination and sampling technique

The sample size was determined using single population proportion estimation formula, considering the overall poor outcome of open Ramstedt’s pyloromyotomy of 29% in a study done in Addis Ababa, 95% confidence level and, marginal error taken as 5% and 10% for missing charts, which gave us the final sample size of 347. However, since the disease was rare with limited number of cases, all cases who fulfilled the eligibility criteria were included in this study. Simple random sampling technique was used to select three hospitals from total eligible government hospitals. Then, a census type of study was conducted by including all eligible charts of infants who got surgical treatment at three hospitals. Hence, further sampling procedure was not used.

Operational definitions

Outcomes of open Ramtsedt’s pyloromyotomy

were defined as the outcomes of this procedure measured in terms of morbidity, mortality and the length of hospital stay [1, 3, 9, 20].

Good outcome

was defined when there was a smooth intraoperative and postoperative course and patient discharged within one week of admission to the hospital [2, 15].

Poor outcome

was the occurrence of death, any intraoperative or postoperative complications, reoperation, and readmission [15, 23].

Prolonged Hospital stay

a longer hospital stays with total length of hospital stay more than a week was considered as prolonged hospital stay.

Morbidity

referred as any postoperative complication that occurred secondary to the surgical management and was not present at admission [2, 9, 10]. In this study, mortality was defined as deaths that occurred intraoperatively or postoperatively directly or indirectly related to the surgical management and not explained by other causes [15].

Incomplete pyloromyotomy – Inability to move side to side freely the two edges of the pyloromyotomy incision on the pylorus after completion of splitting the pyloric muscles intraoperatively and/or the vomiting persisted postoperatively and incompleteness diagnosed by barium meal requiring repeat surgery for completion [9, 15].

Infantile Hypertrophic Pyloric Stenosis (IHPS) - an abnormal hypertrophy of the muscle at the pylorus that results in gastric outlet obstruction and characterized sonographically by pyloric muscle thickness of 3.5–4 mm or more and pyloric canal length of 16 mm or greater [3, 24].

Mucosal perforation

defined as any accidental entry into the pyloric or duodenal lumen during the procedure which is detected intraoperatively or diagnosed postoperatively [9, 15].

Ramstedt’s pyloromyotomy

pyloromyotomy surgical technique, was first described by Ramstedt in 1912, in which the hypertrophied pyloric muscle is divided longitudinally at anterosuperior avascular surface and widened with pyloromyotomy forceps or back of a scalpel up to visibility of pouting mucosa through a right upper quadrant transverse incision and permits gastric emptying [9].

Data collection and data quality control

Data were collected through review of patients’ charts. Medical record number (MRN) of IHPS patients admitted and operated between December 2019 and December 2023 were obtained from operation room logs, surgical ward records and liaison office registries. These MRNs were then used to retrieve charts from the medical records or chart room. A data extraction checklist developed in English after reviewing different literatures was used to collect socio-demographic, clinical, laboratory, imaging, morbidity and mortality data by reviewing patient charts. Data were collected by trained two general surgery residents, one internal medicine resident, one pediatrics and child health resident, one innovative emergency surgery and obstetrics (IESO) professional, one clinical pharmacist and one general practitioner. Card room workers from each hospital retrieved patient charts from card room. To ensure the quality of data, all the data collectors were trained on the study objective and relevance of the study, data collection tool, and data collection procedure. During the data collection period, the collected data were checked for completeness by principal investigator. Data collection was conducted using paper-based forms. The principal investigator was available in person for the data at DCSH. The principal investigator was closely following the data quality and completeness on a daily basis.

Data processing and analysis

After the completion of data collection, the data were entered in to a computer using Epi-data version 4.6 and exported to SPSS version 27 for editing, cleaning, coding and checking the completeness and further analysis. The outcome variable was assessed by computing and dichotomizing in to “good” and “poor” surgical outcomes based on the operational definition. Characteristic of the study participants were described using frequency and percentage.

Results

Socio- demographic characteristics of study participants

In this study a total of 119 participants’ charts were involved. Out of which, 93 (78.2%) were male and 26 (21.8%) were females making the male: female ratio of 3.6:1. The mean age was 51.79 days (standard deviation of 21.41 days), majority (65.5%) of them being between 31 and 60 days old during admission. More than half 68 (57.1%) of the participants were first born followed by second birth order 22 (18.5%) (Table 1).

Table 1.

Sociodemographic characteristics of patients who underwent open Ramstedt’s pyloromyotomy at government hospitals in Amhara Region, Ethiopia, 2023

Variables	Category	Frequency	Percentage
Age (days)	< 30	24	20.2
	31–60	78	65.5
	61–90	12	10.1
	91–120	2	1.7
	> 120	3	2.5
Sex	Male	93	78.2
	Female	26	21.8
Birth order	First	68	57.1
	Second	22	18.5
	Third	20	16.8
	Fourth and above	9	7.5

Clinical, laboratory and imaging related characteristics

All infants presented with non-bilious vomiting which was projectile in 89 (74.8%), noticeable weight loss in 89 (74.8%), abdominal mass (the so-called olive) was felt in 36 (30.3%) and visible peristalsis appreciated in 24 (20.2%) infants. There was some or severe dehydration in 49 (41.2%) of the infants. The duration of symptoms ranged from a few days to more than months. More than one-thirds of the infants, 41(34.5%) presented too late (> 30 days), 32 (26.9%) within 21–30 days, 25 (21%) between 11 and 20 days and the remaining within 10 days. More than half, 69 (58%) of infants were clinically diagnosed as acute malnutrition. Regarding electrolyte abnormality at admission to the hospitals, 45 (37.8%) had hypokalemic, 56 (47.1%) had hyperchloremia and 64 (53.8%) had hyponatremia.

General anesthesia was used in all the cases. Most of the procedures were performed by residents with the guidance of senior surgeons 45 (37.8%), by a pediatric surgeon 44 (37%), by a general surgeon 26 (21.8%) and by the residents alone 4 (3.4%). Regarding the operation procedures, transverse right upper quadrant skin incision was done for 77 (64.7%) of the cases, circum-umbilical for 40 (33.6%) and epigastric midline for 2 (1.7%) of the cases.

Outcome of Ramstedt’s pyloromyotomy

The overall proportion of poor outcomes was 35.3% (including mortality = 0.8% and morbidities = 34.5%). There were 4 (3.4%) intraoperative mucosal perforations and there was no incomplete myotomies. Wound infection encountered in 8 (6.7%), wound dehiscence in 4 (3.4%), prolonged postoperative vomiting in 17 (14.3%), evidence of paralytic ileus in 2 (1.7%) and postoperative apnea in 2 (1.7%). Four patients re-operated for complete wound dehiscence with 2 at the index admission and 2 readmitted. There was one mortality making the mortality rate 0.8% in the study period (Fig. 1).

Fig. 1.

Common complications encountered during or after open Ramstedt’s pyloromyotomy among patients who underwent open Ramstedt’s pyloromyotomy at government hospitals in Amhara region, Ethiopia, 2023

Prolonged hospital stays and postoperative feeding

About one in five, 26 (21.8%) of the patients stayed at hospitals for more than one week after operation. Whereas more than half (59.8%) of the patients stayed in the hospital for less than a week. Regarding post-operative feedings, adlibitum feeding protocol was used in 111 (97.4%) and structured in 3 (2.6%) among 114 infants for whom the feeding regimen was documented. In most of the cases feeding was initiated within 6–12 hours postoperatively (Table 2).

Table 2.

Time of i postoperative feeding initiation and length of hospital stays of patients with IHPS at government hospital in Amhara Region, Ethiopia, 2023

Time	Category	Frequency	Percent
Preoperative length of hospital stays	< 24 h	16	13.4
	1–3 days	51	42.9
	4–6 days	32	26.9
	1 week and above	20	16.8
Postoperative length of hospital stays	< 24 h	1	0.8
	24–48 h	24	20.2
	48 h − 1 week	68	57.1
	Beyond 1 week	26	21.8
Total length of hospital stays	< 24 h	1	0.8
	24–48 h	3	2.5
	48–72 h	8	6.7
	72 h − 1 week	58	48.7
	Beyond 1 week	49	41.2
Time of initiation of postoperative feeding (hours)	4–6	40	36.7
	6–12	47	43.1
	12–24	16	14.7
	> 24	6	5.5

Discussion

In this study, the overall proportion of poor outcome of open Ramstedt’s pyloromyotomy among IHPS patients was 35.3%. Prolonged postoperative vomiting (14.3%), wound infection (6.7%), and wound dehiscence (3.4%) were the commonest post-operative complication. About one in five (21.8%) of the patients stayed at hospitals postoperatively for more than one week. The proportion of poor treatment outcome was higher than the study conducted in Hiwot Fana Comprehensive Specialized Hospital, Harar, Ethiopia which found the magnitude of unfavorable IHPS was 17.1% [25]. The reason for the observed discrepancy could be due to delayed presentation as observed in this study and associated with poor outcomes. There was a significant difference between the mean time of presentation in our study as compared to the study done in Harar.

There was only 0.8% death reported in the study period which was lower than the finding by other studies which showed the prevalence of mortality was 3.5% and 9.5% in Addis Ababa, Ethiopia and Cameroon respectively [6, 17]. The possible reason for this discrepancy might be due to difference in sample size with the studies done in Addis Ababa and Cameroon, which used smaller sample sizes, 61 and 21 respectively. The actual numbers the deaths were 2 in each of the above studies. In high-income countries, IHPS is typically diagnosed within days of symptom onset due to advanced diagnostic imaging and high parental awareness. As a result, global mortality rates and morbidity is minimal, almost less than 2%. In this study, mortality rate was remarkably close to these international reports, suggesting that the surgical execution of the open Ramstedt’s pyloromyotomy in the study setting potentially effective to reduce mortality.

Mortality in IHPS is usually from fluid and electrolyte depletion in infants presenting late, and inadequately corrected electrolyte problems before surgery and is < 1% in most centers [17] and < 0.4% in most major centers [10]. This may show the increased understanding of the physiologic disturbance in these infants and better resuscitation measures taken before surgery.

The predominance of male infants (78.2%) observed in this study is consistent with the well-documented epidemiology of IHPS. Previous studies report that IHPS is significantly more common in males, often accounting for about 80% of cases. For instance, a large retrospective studies reported that 82% cases were males [26]. Similarly, another study reported that the disease occurs up to four times more frequently in males [27]. Moreover, a population-based study by MacMahon B demonstrated a marked male predominance in IHPS, which has been attributed to genetic susceptibility and hormonal influences [28]. Similar findings have been reported in contemporary studies across both high- and low-income settings [29].

All infants in this study presented with non-bilious vomiting, which is the hallmark clinical feature of IHPS. This finding was consistent with previous evidence that IHPS causes gastric outlet obstruction proximal to the duodenum, leading to non-bilious vomiting [25, 30].

A considerable proportion of infants (34.5%) were malnourished at admission, indicating delayed healthcare-seeking behavior and prolonged illness. This finding is consistent with studies from low- and middle-income countries, where late presentation is common due to limited access to pediatric surgical care [31]. A study conducted in a resource-limited setting reported that delayed diagnosis of IHPS often leads to dehydration, weight loss, and malnutrition, which subsequently worsen surgical outcomes [32]. Prolonged vomiting reduces caloric intake and contributes to catabolic states, further aggravating nutritional deficits [31, 33].

In general, this study estimated the proportion of surgical outcomes using multicenter data which helped to incorporate representative patient characteristics and health care related diversities. However, since this was a cross- sectional study with small sample size, it lacks adequate power to show determinants factors of IHPS surgical procedures. Moreover, while using chart review as a data source, this study missed variables of interest.

Conclusion and recommendation

This study showed the proportion of poor outcome following open Ramstedt’s pyloromyotomy among IHPS patients remains high in the study setting. This high morbidity was primarily attributable to systemic and metabolic complications. High proportion of malnutrition, hypokalemia, and hypochloremia found at the time of admission underscores a critical pattern of delayed healthcare-seeking behavior and prolonged illness before reaching tertiary care. Hence, poor outcomes observed were largely a reflection of the infants’ physiological depletion upon arrival. These findings called the need for early involvement of pediatric nutritional intervention to manage the catabolic state and optimize wound healing potential. Healthcare workers and caregivers should be alerted to recognize non-bilious projectile vomiting as a surgical emergency and reduce the first delay in seeking intervention.

Abbreviations

IHPS

Infantile Hypertrophic Pyloric Stenosis

LOS

Length of Hospital Stay

MRN

Medical Registration Number

WU

Wollo University

Authors’ contributions

All authors had contributed to the conception, study design, execution, and acquisition of data, analysis, and interpretation of the results, drafting, reviewing articles, and approval of the version for publication, and agreed to share accountability for all aspects of the work.

Funding

The authors did not receive any funds to conduct this study.

Data availability

All relevant data are included in the manuscript. Additional data are available at the corresponding author.

Declarations

Ethics approval and consent to participate

Ethical clearance was obtained from the Institutional Review Committee (IRC) of Wollo University (Ref: CMHS 698/20/16). Since this study used secondary data extracted from patients’ medical charts, the requirement for individual informed consent was formally waived by the IRC of Wollo University, and administrative permission to access the records was granted by the hospital management. To ensure patient privacy, data collection was conducted anonymously, and strict confidentiality was maintained throughout the research process by removing personal identifiers. Furthermore, all procedures and methods in this study were performed in strict accordance with the Declaration of Helsinki.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.