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Background
Idiopathic hypertrophic pyloric stenosis (IHPS) affects approximately 2 infants out of each 1000 live births and usually presents at between 3 and 12 weeks after birth. It is characterized by hypertrophy of the pyloric muscle, causing pyloric channel narrowing and elongation, which results in nonbilious projectile vomiting. This disorder probably develops postnatally although there is an incomplete understanding of the pathogenesis.
SYNONYMS Idiopathic hypertrophic pyloric stenosis (IHPS) INCIDENCE 2/1000 live births
EPIDEMIOLOGY CHARACTERIZATION Infantile hypertrophic pyloric stenosis after pertussis prophylaxis with erythromcyin: a case review and cohort study.
Honein MA, Paulozzi LJ, Himelright IM, Lee B, Cragan JD, Patterson L, Correa A, Hall S, Erickson JD.
Division of Birth Defects, Child Development, and Disability and Health, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA 30341-3724, USA.
Lancet 1999 Dec 18-25;354(9196):2101-5 Abstract quote
BACKGROUND: In February, 1999, a local US health department identified a cluster of pertussis cases among neonates born at a community hospital and recommended oral erythromycin for post-exposure prophylaxis for about 200 neonates born at that hospital between Feb 1 and Feb 24, 1999. We investigated a cluster of seven cases of infantile hypertrophic pyloric stenosis (IHPS) that occurred the following month among the neonates who had received erythromycin.
METHODS: We obtained a masked, independent review of the IHPS ultrasonography diagnoses, calculated the monthly IHPS incidence, and compared index and historical (1998-99) IHPS cases with respect to several characteristics including erythromycin exposure. We used a retrospective cohort of infants born in January and February, 1999, to investigate further erythromycin exposure and development of IHPS.
FINDINGS: An independent review confirmed the ultrasonographic diagnoses of all seven index IHPS cases. All index cases versus none of the historical IHPS cases had been given erythromycin for pertussis prophylaxis. The IHPS rate for infants born in the hospital in February, 1999, was 32.3 per 1000 liveborn infants, representing nearly a seven-fold increase over 1997-98 (relative risk 6.8 [95% CI 3.0-15.7]). Among infants born in January and February, 1999, erythromycin was associated with IHPS (absolute risk 4.5%, relative risk infinity [1.7-infinity]).
INTERPRETATION: Neonates receiving oral erythromycin may have an increased risk of IHPS. The risks and benefits of erythromycin for neonatal pertussis prophylaxis should be re-evaluated, and caution should be used in defining risk groups for prophylaxis.
The epidemiology of infantile hypertrophic pyloric stenosis in Sweden 1987-96.
Hedback G, Abrahamsson K, Husberg B, Granholm T, Oden A.
Department of Pediatric Surgery, Drottning Silvias Barn-och Ungdomsjukhus, Sahlgrenska University Hospital, S-416 85, Gothenburg, Sweden.
Arch Dis Child 2001 Nov;85(5):379-81 Abstract quote
AIMS: To find out whether the incidence of infantile hypertrophic pyloric stenosis (IHPS) has changed over the past decade, and if so, to investigate possible contributory factors.
METHODS: All infants undergoing pyloromyotomy for IHPS in Sweden between 1987 and 1996 were studied. Using the national patient registers the yearly incidence was determined and evaluated in relation to sex, latitude, urbanisation, and type of surroundings by use of a Poisson model.
RESULTS: There was a substantial decline from 2.7/1000 to 0.85/1000 over the time period. The incidence in the south was almost three times greater than in the north.
CONCLUSION: The declining incidence and geographical difference suggest that environmental factors are of importance in this disorder.
Maternal and infant use of erythromycin and other macrolide antibiotics as risk factors for infantile hypertrophic pyloric stenosis.
Mahon BE, Rosenman MB, Kleiman MB.
Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
J Pediatr 2001 Sep;139(3):380-4 Abstract quote
OBJECTIVES: To evaluate the risk for infantile hypertrophic pyloric stenosis (IHPS) among infants prescribed systemic erythromycin, infants prescribed a course of erythromycin ophthalmic ointment, and infants whose mothers were prescribed a macrolide antibiotic during pregnancy.
STUDY DESIGN: Retrospective cohort study of infants born at an urban hospital from June 1993 through December 1999.
RESULTS: Of 14,876 eligible infants, 43 (0.29%) developed IHPS. Infants prescribed systemic erythromycin had increased risk of IHPS, with the highest risk in the first 2 weeks of age (relative risk = 10.51 for erythromycin in first 2 weeks, 95% CI 4.48, 24.66). Erythromycin ophthalmic ointment for conjunctivitis was not associated with increased risk of IHPS. Maternal macrolide antibiotics within 10 weeks of delivery may have been associated with higher risk of IHPS but the data were not conclusive.
CONCLUSIONS: This study confirms an association between systemic erythromycin in infants and subsequent IHPS, with the highest risk in the first 2 weeks of age. No association was found with erythromycin ophthalmic ointment. A possible association with maternal macrolide therapy in late pregnancy requires further study. Systemic erythromycin should be used with prudence in early infancy.
DISEASE ASSOCIATIONS CHARACTERIZATION Epidermolysis bullosa Parallel incidences of sudden infant death syndrome and infantile hypertrophic pyloric stenosis: a common cause?
Persson S, Ekbom A, Granath F, Nordenskjold A.
Department of Molecular Medicine, Karolinska Institutet.
Pediatrics 2001 Oct;108(4):E70 Abstract quote
Objective. To determine whether there was a correlation between the incidence of infantile hypertrophic pyloric stenosis (IHPS) and the incidence of sudden infant death syndrome (SIDS) during the period 1970 to 1997 and to discuss different causative factors that could be influencing the changing trend in incidence.
Methods. We compared the incidence of IHPS in the Stockholm Health Care Region with the incidence of SIDS in Sweden each year between 1970 and 1997. First, the relation was assessed by calculation of a correlation coefficient; second, the relative linear decrease was estimated for the time period 1990 to 1997.
Results. The incidence of IHPS increased steadily during the 1970s, from 0.5 per 1000 live births in 1970 to 2.7 in 1979. During the 1980s, the average incidence was 2.8. During the 1990s, there was a significant decrease in the number of IHPS cases in Stockholm. The incidence rate of IHPS parallels the incidence of SIDS during the study period (r = 0.58). The incidence of SIDS dropped after the risk-reduction campaign in the beginning of the 1990s, which recommended that infants sleep on their back. We could not identify any other changes of behavioral risk factors in early exposures that could explain the temporal trends.
Conclusions. The statistical findings suggest that IHPS and SIDS have causative factors in common. We suggest that prone sleeping is one of those factors.
Infantile hypertrophic pyloric stenosis and asymptomatic joint hypermobility.
De Felice C, Di Maggio G, Toti P, Parrini S, Salzano A, Lagrasta UE, Bagnoli F.
Department of Preventive Pediatrics and Neonatology, Institute of General Surgery and Surgical Specialties, University of Siena, Siena, Italy.
J Pediatr 2001 Apr;138(4):596-8 Abstract quote
A significant association with asymptomatic joint hypermobility was observed in 37 children with a history of infantile hypertrophic pyloric stenosis (P =.0016) and their parents (mothers, P <.0001; fathers, P <.05).
The subjects with articular hypermobility showed an increased frequency of absent mandibular frenulum, thereby suggesting the presence of a previously unrecognized, systemic abnormality of the extracellular matrix.
PATHOGENESIS CHARACTERIZATION Abnormalities of elastin and elastic fibers in infantile hypertrophic pyloric stenosis.
Oue T, Puri P.
Children's Research Centre, Our Lady's Hospital for Sick Children, Crumlin, Dublin, Ireland.
Pediatr Surg Int 1999;15(8):540-2 Abstract quote
Infantile hypertrophic pyloric stenosis (IHPS) is characterized by hypertrophy of the pyloric muscle, causing pyloric-channel narrowing and elongation. The rigidity of the muscle is increased, which is characterized as an "olive." Elastin is an insoluble protein that forms the major structural component of the elastic fibers and maintains the tensile strength of the tissues.
To understand the possible histologic and molecular basis of the elasticity of the hypertrophic muscle in IHPS, we determined the distribution of the elastic fibers and elastin expression using Victoria blue van Gieson (VVG) staining and immunohistochemistry. In IHPS, the number of elastic fibers in the connective tissue was significantly increased in the thickened connective-tissue septa (CTS) compared with normal control specimens. In normal pyloric muscle, weak to moderate elastin immunoreactivity was observed in the CTS while no immunoreactivity was observed among the muscle fibers.
In IHPS, strong immunoreactivity of elastin was observed in the CTS and moderate immunoreactivity among the hypertrophic smooth-muscle fibers. Our findings suggest that the increase on elastic fibers and elastin expression in the pyloric muscle in IHPS may play an important role in the development of pyloric-muscle rigidity, causing pyloric-canal obstruction.
Increased local synthesis of epidermal growth factors in infantile hypertrophic pyloric stenosis.
Shima H, Ohshiro K, Puri P.
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland
Pediatr Res 2000 Feb;47(2):201-7 Abstract quote
Infantile hypertrophic pyloric stenosis (IHPS) is characterized by hypertrophy of the pyloric muscle. The growth of smooth muscle cells is regulated by several growth factors. Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor are potent mitogens for smooth muscle cells.
In the present study, we investigated immunohistochemical localization of EGF and EGF-related peptides and EGF mRNA expression in pyloric smooth muscle cells to determine whether the EGF family is involved in the process of pyloric muscle hypertrophy in IHPS. Pyloric muscle biopsy specimens were obtained at the time of pyloromyotomy from 10 patients with IHPS. Control material included 10 pyloric muscle specimens taken at autopsy from age-matched cases without evidence of gastrointestinal disease. Indirect immunohistochemistry was performed using the avidin-biotin-peroxidase complex method with anti-EGF, anti-EGF receptor, and anti-heparin-binding EGF-like growth factor antibody. In situ hybridization was performed using digoxigenin-labeled EGF-specific oligonucleotide probe. The pattern of immunoreactivity in pyloric muscle with EGF, EGF receptor, and heparin-binding EGF-like growth factor was similar in all specimens. There was a marked increase in EGF, EGF receptor, and heparin-binding EGF-like growth factor immunoreactivity and EGF mRNA expression in smooth muscle cells in pyloric circular and longitudinal muscle from patients with IHPS compared with control specimens.
These data suggest that the upregulated local synthesis of EGF and EGF-related peptides in pyloric muscle may play a critical role in the development of pyloric muscle hypertrophy in IHPS.
Glial-derived growth factor signaling pathway in infantile hypertrophic pyloric stenosis.
Guarino N, Shima H, Oue T, Puri P.
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland.
J Pediatr Surg 2000 Jun;35(6):835-9 ABSTRACT QUOTE
BACKGROUND/PURPOSE: Glial-derived growth factor (GDNF), which is the ligand of RET is reported to be essential for the development of enteric nervous system. A GDNF knockout mouse model has shown that the gastric region is a critical passing site between GDNF-RET-independent neuroblasts (colonizing the esophagus) and GDNF-RET-dependent neuroblasts (colonizing the small and large bowel). The earliest GDNF site of production is the mesenchyme and the outer smooth muscle cell (SMC) layer of the developing bowel. In the mature gastrointestinal tract the presence of GDNF is restricted to enteric glial cells. The aim of this study was to investigate the expression of GDNF and RET in infantile hypertrophic pyloric stenosis (IHPS).
METHODS: Full-thickness muscle biopsy specimens were obtained from 8 IHPS patients at pyloromyotomy and from 8 age-matched controls without gastrointestinal disease. Indirect immunohistochemistry was performed using avidin-biotin-peroxidase complex method with anti-GDNF and anti-RET antibodies. Quantitative analysis was performed using sandwich-type enzyme-linked immunosorbent assay (ELISA) for GDNF.
RESULTS: GDNF- and RET-positive nerve fibers were absent or markedly reduced in IHPS compared with controls. GDNF was expressed strongly by smooth muscle cells of both muscular layers in IHPS, whereas no GDNF expression was detected in pyloric muscle of controls. The quantity of total GDNF in IHPS was significantly higher than in controls (P < .01).
CONCLUSIONS: The lack or markedly decreased number of GDNF-positive nerve fibers in IHPS supports the hypothesis of a selective immaturity of the enteric glia in the muscular layers in IHPS. The strong expression of GDNF in smooth muscle cells in IHPS and the increased levels of GDNF in IHPS suggest a compensatory mechanism by which the smooth muscle cells continue to produce GDNF until maturation of the enteric glial cells occurs.
Molecular cytogenetic characterisation of partial trisomy 9q in a case with pyloric stenosis and a review.
Heller A, Seidel J, Hubler A, Starke H, Beensen V, Senger G, Rocchi M, Wirth J, Chudoba I, Claussen U, Liehr T.
Institut fur Humangenetik und Anthropologie, Kollegiengasse 10, D-07740 Jena, Germany.
J Med Genet 2000 Jul;37(7):529-32 Abstract quote
Partial trisomy 9q represents a rare and heterogeneous group of chromosomal aberrations characterised by various clinical features including pyloric stenosis.
Here, we describe the case of a 1 year old female patient with different dysmorphic features including pyloric stenosis and prenatally detected partial trisomy 9q. This partial trisomy 9q has been analysed in detail to determine the size of the duplication and to characterise the chromosomal breakpoints. According to the data gained by different molecular cytogenetic techniques, such as fluorescence in situ hybridisation (FISH) with whole and partial chromosome painting probes, yeast artificial chromosome (YAC) probes, and comparative genomic hybridisation (CGH), the derivative chromosome 9 can be described as dup(9)(pter-->q22. 1::q31.1-->q22.1::q31.1--> q22.1::q31.1-->qter). Four breakpoint spanning YACs have been identified (y806f02, y906g6, y945f5, and y747b3) for the proximal breakpoint.
According to this new case and previously published data, the recently postulated putative critical region for pyloric stenosis can be narrowed down to the subbands 9q22.1-q31.1 and is the result of either partial trisomy of gene(s) located in this region or a gene disrupted in 9q31.
Motor abnormality in the gastroduodenal junction in patients with infantile hypertrophic pyloric stenosis.
Kawahara H, Imura K, Yagi M, Kubota A, Okada A. Osaka, Japan.
J Pediatr Surg 2001 Nov;36(11):1641-5 Abstract quote
BACKGROUND/PURPOSE: Periodic clusters of phasic pressure waves in the gastroduodenal junction (GDJ) have been seen in patients with infantile hypertrophic pyloric stenosis (IHPS). This study investigated the details of these pressure waves in relation to disturbed transpyloric flow in IHPS.
METHODS: Manometric study was performed in 11 IHPS patients before and after atropine therapy and 2 non-IHPS infants. Pressure changes in the GDJ were measured with an 8-channel sleeve or a 9-channel sidehole micromanometric assembly under fluoroscopic control for 2 hours.
RESULTS: Clusters of phasic pressure waves (365 +/- 42 mm Hg) associated with an increase in basal pressure (10 +/- 3 mm Hg) were intermittently observed in the GDJ in all IHPS patients. Similar observations were not made in the non-IHPS infants. Most antral pressure waves occurred simultaneously with those pressure waves in the GDJ in the IHPS patients. Atropine (0.01 mg/kg) transiently abolished the phasic and tonic pressure waves for 19 +/- 10 minutes. Significantly fewer phasic pressure waves were observed after atropine therapy.
CONCLUSIONS: Characteristic phasic and tonic contractile activity in the GDJ is uncoordinated with the antral contractions in IHPS patients. Such incoordination may be an important factor in the disturbed transpyloric flow in IHPS.
In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role?
Hernanz-Schulman M, Lowe LH, Johnson J, Neblett WW, Polk DB, Perez R Jr, Scheker LE, Stein SM, Heller RM, Cywes R.
Department of Pediatric Radiology, Vanderbilt Children's Hospital, University Medical Center North D-1120, 21st Ave. S., Nashville, TN 37232-2675, USA.
AJR Am J Roentgenol 2001 Oct;177(4):843-8 Abstract quote
OBJECTIVE: Infantile hypertrophic pyloric stenosis (IHPS) is a common condition which presents in infants at 2-12 weeks of postnatal life, and whose cause remains obscure. Multiple associated abnormalities have been recognized within the external hypertrophied pyloric muscle layer, but the internal component of the pyloric mucosa has received scant attention in the literature to date. Our purpose in this study was to show that pyloric mucosal redundancy is a constant finding in infants with IHPS, to discuss its possible cause, and to explore the hypothesis of a relationship between pyloric mucosal redundancy and the development of IHPS.
MATERIALS AND METHODS: We identified 102 consecutive infants with surgically confirmed IHPS and determined the thickness of the pyloric mucosa compared with the thickness of the surrounding hypertrophied muscle. Fifty-one infants who did not have pyloric stenosis served as controls.
RESULTS: Mean mucosal thickness in patients with IHPS approximated mean muscle thickness, with a ratio of 0.89. In infants with IHPS, the pyloric mucosa constitutes approximately one third of the cross-sectional diameter of the pyloric mass and fills and obstructs the pyloric canal.
CONCLUSION: Mucosal redundancy is a constant associated finding in IHPS. Although the origin of the redundancy and a cause-and-effect relationship are difficult to establish, our findings support the hypothesis that hypergastrinemia may be implicated in the pathogenesis of IHPS, and suggest that mucosal thickening could be implicated as one of the initiating factors in its development.
Gastrin, somatostatin and infantile hypertrophic pyloric stenosis.
Dick AC, Ardill J, Potts SR, Dodge JA.
Royal Belfast Hospital for Sick Children, Belfast, UK.
Acta Paediatr 2001 Aug;90(8):879-82 Abstract quote
Despite multiple and often contradictory research, no firm conclusions regarding the role of hypergastrinaemia in infantile hypertrophic pyloric stenosis (IHPS) have been established. Evaluation of somatostatin, the main physiological antagonist of gastrin, has not been assessed in previous studies. Long-term evaluation following pyloromyotomy suggests persistent abnormalities in gastrin and somatostatin in IHPS.
The objective of this case-controlled study was to compare fasting serum gastrin and somatostatin levels in IHPS.
Serum sample were collected from 39 children with IHPS at the time of pyloromyotomy and 20 age-matched controls with no evidence of gastrointestinal disease. Standard radioimmunoassay techniques were used to detect circulating levels of the hormones. A two-tailed t-test was used for statistical analysis.
The levels of the two hormones (mean +/- SEM) revealed that there was no evidence of hypergastrinaemia in IHPS compared with controls (75.6 +/- 16.1 and 68.1 +/- 7.8 ng l(-1), respectively), but that the level of somatostatin was significantly elevated (38.9 +/- 6.4 and 30.5 +/- 5.8 ng l(-1), p = 0.016). An inverse trend in the gastrin/somatostatin levels could not be identified in IHPS.
CONCLUSION: Somatostatin but not gastrin is raised in IHPS. Somatostatin is known to inhibit the actions of inhibitory neurotransmitters in the pylorus and may explain the development of pylorospasm, which is believed to be important in the development of pyloric tumours. These results do not agree with a previous long-term follow-up study, but reflect the hormonal imbalance at the time of pyloric hypertrophy.
Selective neurotrophin deficiency in infantile hypertrophic pyloric stenosis.
Guarino N, Yoneda A, Shima H, Puri P.
Children's Research Centre, Our Lady's Hospital for Sick Children, Dublin, Ireland.
J Pediatr Surg 2001 Aug;36(8):1280-4 Abstract quote
BACKGROUND/PURPOSE: Increasing evidence suggests that the enteric nervous system is under the control of neurotrophins. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and neurotrophin-4/5 (NT-4/5), promote differentiation, growth, and survival of various central and peripheral nervous system neurons. The biological effects of neurotrophins are mediated by the interactions with high-affinity tyrosine kinase receptors (TrkA, TrkB, TrkC). Recently, abnormalities of intramuscular innervation have been reported in infantile hypertrophic pyloric stenosis (IHPS). To further understand the reported abnormalities in pyloric innervation in IHPS, the authors analyzed the expression of Trk receptors and the neurotrophins content in IHPS.
METHODS: Full-thickness muscle biopsy specimens were obtained from 8 IHPS patients (age range, 23 to 41 days) at pyloromyotomy and from 8 age-matched controls without gastrointestinal disease at autopsy performed within 12 hours after death. Indirect immunohistochemistry was performed using ABC (Avidin Biotin peroxidase Complex) method with anti-Trk specific antibodies (A,B,C). Quantitative analysis was performed using sandwich-type ELISA for NGF, BDNF, NT-3, and NT-4/5. RESULTS: The intensity of staining of the myenteric plexus for TrkA, TrkB, and TrkC was similar among IHPS and controls. There was a lack of TrkA-positive nerve fibers in IHPS compared with controls. The quantity of total NGF, NT-3, and BDNF in IHPS was significantly lower than in controls.
CONCLUSIONS: The reduced production of neurotrophins in IHPS may be responsible for the delay in the functional and structural maturation of pyloric innervation in IHPS. The lack of TrkA-positive nerve fibers in pyloric muscle may explain the abnormal intramuscular innervation in IHPS.
Nitric oxide synthase is absent in only a subset of cases of pyloric stenosis.
Subramaniam R, Doig CM, Moore L.
Department of Paediatric Surgery and Pathology, Booth Hall Children's Hospital, Blackley, Manchester, England.
J Pediatr Surg 2001 Apr;36(4):616-9 Abstract quote
PURPOSE: The aim of this study was to study nitric oxide synthase (NOS) immunohistochemistry in the pyloric muscle and establish the role of nitric oxide in pyloric stenosis.
METHODS: Pyloric muscle biopsy specimens were obtained from 20 patients with pyloric stenosis during pyloromyotomy. Ten control specimens without pyloric disease were obtained from autopsy performed less than 4 hours after death on age-matched babies who died of other causes. Tissues were fixed in 4% paraformaldehyde immediately. A monoclonal antibody against the neuronal form of NOS (bNOS) was used for immunohistochemistry.
RESULTS: Immunohistochemistry showed activity of bNOS in the control specimens and some pyloric stenosis specimens. This shows that NOS is present in the pylorus in normal cases as well as in a few cases of pyloric stenosis.
CONCLUSIONS: NOS deficiency leading to lack of locally available nitric oxide causes a failure of smooth muscle relaxation. This may account for the cause of pyloric stenosis in infants. However, this study shows that this is true probably only in a subset of cases. The etiology of pyloric stenosis may still be multifactorial. Further investigations are required regarding the etiology of pyloric stenosis.
Absence of Epstein-Barr virus in smooth muscle cells of idiopathic hypertrophic pyloric stenosis.
Jenson HB, Gulley ML, Puri P.
Department of Pediatrics , The University of Texas Health Science Center at San Antonio, 78229-3900, USA.
Arch Pathol Lab Med 2001 Mar;125(3):361-3 Abstract quote
CONTEXT: The etiology of idiopathic hypertrophic pyloric stenosis (IHPS) is unknown. Epstein-Barr virus (EBV) infects smooth muscle cells and is associated with leiomyomas and leiomyosarcomas of immunocompromised persons, including persons with the acquired immunodeficiency syndrome.
OBJECTIVE: To determine whether EBV is causally associated with IHPS.
DESIGN: Biopsy samples of the pylorus were obtained from 10 infants with projectile vomiting and pyloric hypertrophy on ultrasound, with confirmation of hypertrophy at the time of pyloromyotomy. The presence of EBV infection was tested by in situ hybridization for EBV-encoded RNA 1 (EBER1) in smooth muscle cells of IHPS.
SETTING: Biopsy specimens were obtained from children treated for IHPS at a tertiary referral hospital and were tested in a clinical molecular diagnostics laboratory.
RESULTS: All of the 10 smooth muscle biopsies were negative for EBER1. Cellular U6 RNA was detected in all smooth muscle samples, confirming that the RNA in the specimens was intact and capable of detection by in situ hybridization.
CONCLUSIONS: The absence of EBER1 in 10 cases of clinically diagnosed and histopathologically confirmed cases of IHPS effectively excludes EBV infection of smooth muscle cells as a causal factor in the pathogenesis of IHPS.
LABORATORY/RADIOLOGY/OTHER CHARACTERIZATION RADIOLOGIC Ultrasonographic diagnosis criteria using scoring for hypertrophic pyloric stenosis.
Ito S, Tamura K, Nagae I, Yagyu M, Tanabe Y, Aoki T, Koyanagi Y.
Department of Surgery, Tokyo Medical University Hospital, Tokyo, Japan.
J Pediatr Surg 2000 Dec;35(12):1714-8 Abstract quote
PURPOSE: For diagnosis of infantile hypertrophic pyloric stenosis (HPS), ultrasonography (US) is a useful and objective diagnostic method. In the current study, pyloric diameter, muscular thickness, and pyloric length were measured in normal infants (n = 26) and infants which is an adequate (n = 57). Each score was assigned to relevant measurements, and diagnostic criteria obtained with a scoring system were prepared using statistical skills by the probit analysis.
METHODS: For scoring, points were given to relevant measurements in conformity with the probit analysis. Zero points were given to patients with no possibility of HPS, 1 point to those with less than 25% probability, 2 points to those with 25% or more but less than 50% probability, and 3 points to patients with 50% or more probability. Points were totaled, and analysis was performed.
RESULTS: The composite score was evaluated by probit analysis, and cases with a composite score of 2 or less were all included in the normal group, whereas those with a composite score of 3 or more were all in the HPS group. Both groups could thereby be 100% identified.
CONCLUSION: US was able to diagnose cases with overall score of 2 or less as normal and those with overall score of 3 or higher as having HPS. In addition, after the current diagnostic criteria were prepared, preoperative diagnoses were performed prospectively using them for vomiting neonates and infants, and all cases were correctly discriminated and diagnosed. These findings indicate our ultrasonographic diagnosis criteria are useful for diagnosing HPS.
Sonography and color Doppler sonography for monitoring conservatively treated infantile hypertrophic pyloric stenosis.
Riccabona M, Weitzer C, Lindbichler F, Mayr J.
Universitatsklinik fur Radiologie, Klinische Abteilung fur Kinderradiologie, Graz, Austria.
J Ultrasound Med 2001 Sep;20(9):997-1002 Abstract quote
OBJECTIVE: To evaluate the role of sonography in infants with hypertrophic pyloric stenosis undergoing conservative medical treatment.
METHODS: Twenty-two infants (17 male and 5 female; age range, 1-12 weeks) were clinically and sonographically considered suitable for conservative treatment and underwent follow-up during the course of the disease. Sonography was performed under a standardized protocol and included color Doppler sonography.
RESULTS: Fifteen infants (mean age, 9 weeks) needed surgery. They initially had a mean pyloric length of 18 mm, a diameter of 10.5 mm, and a wall thickness of 4 mm, with visible passage of food into the duodenum. These values deteriorated during follow-up (mean preoperative values: length, 20 mm; diameter, 12 mm; and wall thickness, 4.5 mm); furthermore, passage of food through the pyloric canal ceased. Seven infants (mean age, 3 weeks) were successfully treated conservatively Their initial mean pyloric measurements were slightly smaller (length, 15 mm; diameter, 10 mm; and wall thickness, 3.8 mm) and did not deteriorate during follow-up. In all of them, sonography showed improvement of passage through the pyloric canal within several days, as shown and documented by color Doppler sonography; morphologic changes persisted longer despite clinical improvement.
CONCLUSIONS: Sonography, including color Doppler sonography, is a valuable tool for monitoring infants with hypertrophic pyloric stenosis undergoing conservative treatment; however, initial sonograms cannot predict the further course of the disease.
Ultrasonographic features of normalization of the pylorus after pyloromyotomy for hypertrophic pyloric stenosis.
Yoshizawa J, Eto T, Higashimoto Y, Saitou T, Maie M.
Department of Pediatric Surgery, Chiba Children's Hospital, Chiba City, Japan.
J Pediatr Surg 2001 Apr;36(4):582-6 Abstract quote
PURPOSE: The purpose of this study was to describe the time course, early postoperative changes, and morphologic features of normalization of the pylorus after pyloromyotomy for hypertrophic pyloric stenosis.
METHODS: The subjects were 17 infants (9 boys, 8 girls) who underwent umbilical incision Ramstedt pyloromyotomy. The pyloric muscle mass was measured immediately before the operation and then at intervals from 3 days to 6 months after the operation using a 7.5-MHz ultrasound probe.
RESULTS: In longitudinal section, the dorsal part of the pyloric muscle thickened transiently and then thinned to normal values by 5 months after the operation. It was 5.1 +/- 0.8 mm (mean +/- SD) preoperatively, increased to 6.0 +/- 0.3 mm by day 3 after the operation (P <.05), and thinned to 2.8 +/- 0.2 mm by 5 months after the operation. Concomitantly, the length of the pylorus gradually decreased (from 20.1 +/- 2.9 mm preoperatively to 16.9 +/- 2.7 mm by 3 days postoperatively [P <.05] and to less than 15 mm, by 4 months). In transverse section, the muscle normalized as in the longitudinal section. At the site of the incision it was 4.3 +/- 0.4 mm thick preoperatively, thickened to 4.6 +/- 0.4 mm by 3 days after the operation (P <.05), thinned to 2.1 +/- 0.9 mm by 7 days (P <.05), and then increased slightly, but always was less than 3.0 mm. Morphologically, in transverse section, the incised area looked like a wedge by 3 days after the operation.
CONCLUSIONS: After pyloromyotomy for hypertrophic pyloric stenosis, there is an early transient increase in muscle thickness within the first few postoperative days followed by a slow decrease that reaches normal thickness (<3 mm) by 5 months. This decrease in thickness is accompanied by a gradual decrease in length to 75% of the preoperative value by 5 months. The morphologic features in this normalization are first a wedge (day 3), then a flat tire (days 7 and 14), and finally an elongated ring (5 months).
LABORATORY Is acid base determination an accurate predictor of pyloric stenosis?
Oakley EA, Barnett PL.
Department of Emergency Medicine, Royal Children's Hospital, Parkville, Victoria, Australia.
J Paediatr Child Health 2000 Dec;36(6):587-9 Abstract quote
OBJECTIVE: To determine if acid base status predicts which vomiting patients have pyloric stenosis.
DESIGN: Retrospective chart review.
SETTING: Tertiary paediatric hospital.
METHODOLOGY: We compared the clinical and biochemical parameters of 100 patients with a discharge diagnosis of pyloric stenosis and 84 patients of a similar age who presented to the emergency department with vomiting and who had an acid base determination. Patients were included from January 1995 to January 1997. Clinical correlates consisted of age, duration of vomiting, weight loss, gestation, and family history of pyloric stenosis. Biochemical correlates were pH, bicarbonate, base excess (BE), chloride, potassium, and sodium.
RESULTS: Independent variables of significance were pH, BE, chloride, bicarbonate, potassium, weight loss (all of which had a P value < 0.0001), and sex (P = 0.006). Each variable was placed in a logistic regression equation with pyloric stenosis being the dominant variable. Variables of significance were pH (P = 0.0001), BE (P = 0.0001), and chloride (P = 0.009). A model for predicting pyloric stenosis using these variables was then created with pH > 7.45, chloride < 98, and BE > +3, with a positive predictive value of 88%.
CONCLUSION: Acid base determination is a useful screening tool when considering pyloric stenosis. This model now needs to be validated on a prospective series of patients with vomiting.
CLINICAL VARIATNS/GROSS APPEARANCE CHARACTERIZATION Hypoplastic or absent mandibular frenulum: a new predictive sign of infantile hypertrophic pyloric stenosis.
De Felice C, Di Maggio G, Zagordo L, Parrini S, Toti P, Tota G, Bagnoli F.
J Pediatr 2000 Mar;136(3):408-10 ABSTRACT QUOTE
Among 25 patients with hypertrophic pyloric stenosis, a hypoplastic or absent mandibular frenulum was noted in 92%, compared with 1.6% of 319 control infants (P Y.001).
This previously unrecognized sign may prove helpful in identifying newborns at risk of developing the disorder.
HISTOPATHOLOGY CHARACTERIZATION Pyloric stenosis: new histopathologic perspective using confocal laser scanning.
Kobayashi H, Miyahara K, Yamataka A, Lane GJ, Sueyoshi N, Miyano T.
Department of Pediatric Surgery and the Central Laboratory, Juntendo University School of Medicine, Tokyo, Japan.
J Pediatr Surg 2001 Aug;36(8):1277-9 Abstract quote
BACKGROUND/PURPOSE: Idiopathic hypertrophic pyloric stenosis (IHPS) is a common infantile disorder characterized by enlargement of the pylorus and gastric outlet obstruction. Its complete etiology is still not fully understood, but recent research has focussed on abnormalities of nerve distribution. The authors used confocal laser scanning microscopy to perform 3-dimensional studies of pylorus biopsy specimens taken from cases of IHPS and present their findings.
METHODS: Pylorus biopsy specimens obtained at pyloromyotomy from 6 infants with IHPS were studied using confocal microscopy and compared with 6 control pylorus biopsy specimens from patients without gastrointestinal disease. Biopsy specimens were pretreated to enhance nerve expression by using protein gene product 9.5 (PGP9.5) polyclonal antibody to identify enteric nerve system fibers. Double staining immunofluorescence was used to detect alpha smooth muscle actin (SMA), a smooth muscle marker.
RESULTS: Control pylorus biopsy specimens showed many thin PGP9.5-positive nerve fibers in the circular and longitudinal muscle layers that communicated with each other to create a 3-dimensional meshlike network. Muscle cells stained by alpha SMA antibody were thin. In contrast, muscle cells from IHPS patients were fat and round. The PGP9.5 staining nerve fibers from IHPS patients formed numerous, thick, and contorted bundles that did not communicate.
CONCLUSIONS: By using confocal laser microscopy the authors were able to identify abnormally thick contorted nerve bundles in the pyloric muscle layers of infants with IHPS. These anormal nerve bundles have not been described previously because of the limitations of 2-dimensional microscopy. The authors suspect that the etiology of IHPS may be related to these abnormal fibers.
PROGNOSIS AND TREATMENT CHARACTERIZATION PROGNOSIS Long-term investigations after pyloromyotomy for infantile pyloric stenosis.
Dietl KH, Borowski U, Menzel J, Wissing C, Senninger N, Brockmann J. Klinik und Poliklinik fur Allgemeine Chirurgie der WWU Munster, Germany.
Eur J Pediatr Surg 2000 Dec;10(6):365-7 Abstract quote
Between 1919 and 1941, 71 infants suffering from pyloric hypertrophy were operated on by Ramstedt performing an extramucosal pyloromyotomy.
Of these patients, we could identify and investigate 41. Four out of 31 long-term surviving patients have been Billroth II-resected (BII). One of these needed re-resection because of an anastomotic ulcer. None of all the long-term survivors developed a carcinoma. Two patients were treated conservatively because of gastritis and one because of esophagitis. All patients, except the one requiring re-resection and one suffering from maldigestion, were absolutely free of complaints. The average time between operation and re-checking was 57 years. The oldest patient was examined 72 years after the operation.
Long-term effects of pyloromyotomy on pyloric motility and gastric emptying in humans.
Sun WM, Doran SM, Jones KL, Davidson G, Dent J, Horowitz M.
Department of Medicine, Royal Adelaide Hospital, South Australia, Australia.
Am J Gastroenterol 2000 Jan;95(1):92-100 Abstract quote
OBJECTIVE: The aim of this study was to determine the long term effects of pyloromyotomy for infantile hypertrophic pyloric stenosis (IHPS) on gastric emptying and pyloric motility.
METHODS: Concurrent measurements of gastric emptying and antropyloroduodenal pressures were performed in six volunteers (aged 24-26 yr) who had had pyloromyotomy performed in infancy because of IHPS, and in six normal subjects. Subjects were studied on 2 days, once sitting and once in the left lateral position. Gastric emptying of 300 ml 25% dextrose labeled with 20 MBq 99mTc sulfur colloid was measured. Antropyloroduodenal motility was evaluated with a sleeve/multiple sidehole manometric assembly, which was also used to deliver an intraduodenal triglyceride infusion at 1.1 kcal/min for 60 min, starting 30 min after ingestion of the dextrose.
RESULTS: In both body positions, gastric emptying and intragastric distribution of the drink did not differ between the two groups. In both groups and postures, the amount emptied was less during intraduodenal lipid infusion. The number (p]0.01) and amplitude (p<0.02) of isolated pyloric pressure waves (IPPWs) was greater in the control subjects, whereas basal pyloric pressure was greater in the pyloromyotomy subjects (p<0.02). In both groups, the rate of gastric emptying in the sitting position was related to the number of IPPWs (r> or =0.40, p<0.05), but not to basal pyloric pressure.
CONCLUSIONS: These results indicate that, in adults who have had pyloromyotomy for IHPS in infancy, patterns of pyloric motility are abnormal; pyloric tone is higher, whereas the number and amplitude of phasic pyloric pressure waves are less. In contrast, the overall rate of gastric emptying of a nutrient liquid meal is normal. These observations are consistent with the concept that the stomach has the capacity to compensate for changes in pyloric motility to minimize effects on gastric emptying.
Multiple gastric carcinomas 21 years after gastrojejunostomy without gastrectomy. Report of a case.
Takeno S, Noguchi T, Sato T, Uchida Y, Yokoyama S.
Department of Surgery II, Oita Medical University, Oita, Japan.
Dig Surg 2000;17(5):531-7 Abstract quote
We report a case of gastric carcinoma after gastrojejunostomy (GJ-stomy) without gastrectomy.
Multiple gastric carcinomas were discovered 21 years after GJ-stomy without gastrectomy which had been performed for treatment of pyloric stenosis due to severe gastric ulcer. Multiple gastric carcinomas were found in the stomach, or the esophagocardiac junction, and in the corpus and anastomotic lesion of the GJ-stomy. Under the light microscope, intestinal metaplasia was detected in the antral mucosa and the area around the anastomosis.
In immunohistochemical analysis, p53-specific antibodies gave a positive reaction in every gastric carcinoma and in the noncancerous gastric glands around the carcinoma at the anastomosis and in the corpus. Cells positive for immunostaining with Ki-67-specific antibodies were more numerous in all gastric carcinomas and in the area around the anastomotic lesion than in the normal gastric mucosa. Hsp70-specific antibodies reacted with cells in the noncancerous glands around the carcinoma in the anastomotic area.
Mucosal injury and the potential for carcinogenesis due to exposure to gastroduodenal reflux are discussed. The results of this study suggest that similar cases with gastroduodenal reflux should be followed carefully.
TREATMENT Pyloromyotomy versus atropine sulfate for infantile hypertrophic pyloric stenosis.
Yamataka A, Tsukada K, Yokoyama-Laws Y, Murata M, Lane GJ, Osawa M, Fujimoto T, Miyano T.
Department of Pediatric Surgery, Juntendo University School of Medicine, Tokyo, Japan.
J Pediatr Surg 2000 Feb;35(2):338-41 Abstract quote
PURPOSE: Atropine sulfate (atropine) and pyloromyotomy were compared for managing infantile hypertrophic pyloric stenosis (IHPS).
METHODS: From 1996 to 1998, cases of IHPS treated surgically (pyloromyotomy; n = 20) or medically (atropine; n = 14) at separate institutions were compared retrospectively with regard to status on presentation, physical symptoms and signs, progress, and costs. Atropine was given orally, then intravenously if ineffective. Refractory cases were referred for pyloromyotomy.
RESULTS: All subjects were matched for clinical and physiological status on admission. Oral atropine alone was effective in 11 cases, was converted to intravenous atropine in 2 cases, and was terminated in 1 case because of hematemesis. Two cases were referred for pyloromyotomy. All pyloromyotomies were successful. Atropine took on average, 2.6 days to take effect. The difference in time taken for normalization of pyloric muscle thickness between the 2 groups was not significant. Average time to return to full feeding was longer in the atropine group (P<.01). Costs were lower in the atropine group (P<.01). There were 2 wound infections in the pyloromyotomy group, but no adverse effects of atropine. There were no recurrences in either group.
CONCLUSION: This study provides reasonable evidence to support a trial of atropine in IHPS.
Infantile hypertrophic pyloric stenosis: a comparative study of pyloric traumamyoplasty and Fredet-Ramstedt pyloromyotomy.
Ordorica-Flores R, Leon-Villanueva V, Bracho-Blanchet E, Reyes-Retana R, Davila-Perez R, Varela-Fascinetto G, Tovilla-Mercado JM, Lezama-DelValle P, Nieto-Zermeno J.
Department of Surgery, Hospital Infantil de Mexico "Federico Gomez," Mexico City, Mexico.
J Pediatr Surg 2001 Jul;36(7):1000-3 Abstract quote
PURPOSE: The aim of this study was to compare the incidence of surgical complications (duodenal perforation, postoperative vomiting, wound infection or dehiscence, incisional hernia) between 2 different surgical techniques for the resolution of hypertrophic pyloric stenosis in children.
METHODS: A clinically controlled, randomized study with follow-up from 24 to 36 months was conducted. One hundred children between 15 days and 2 months old, who underwent surgical resolution of hypertrophic pyloric stenosis, were put randomly into 2 groups: I, pyloric traumamyoplasty (n = 43); II, Fredet-Ramstedt pyloromyotomy (n = 57). Both groups were controlled for the main demographic variables. Postoperative follow-up was blind for the surgical team. Statistical analysis was done with simple frequencies, percentages, Student's t test, and chi(2).
RESULTS: There was not a single case of duodenal perforation, incomplete pyloromyotomy, wound infection, dehiscence, or incisional hernia in any group (P value, not significant). Postoperative emesis was present in 8 patients, uniformly distributed between groups. The operating room time for traumamyoplasty was 39.3 +/- 16.4 minutes versus 54 +/- 16.4 minutes for pyloromyotomy (P =.0003).
CONCLUSIONS: This controlled study proves that traumamyoplasty is a simple procedure, quicker to perform, and as safe as pyloromyotomy for the treatment of infantile hypertrophic pyloric stenosis in children. For these reasons, the authors believe it should be considered as an alternative.
Combined use of electrosurgical incisions and balloon dilatation for the treatment of refractory postoperative pyloric stenosis.
Hagiwara A, Sonoyama Y, Togawa T, Yamasaki J, Sakakura C, Yamagishi H.
Department of Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Gastrointest Endosc 2001 Apr;53(4):504-8 Abstract quote
BACKGROUND: Drug therapy plus balloon dilatation without gastroscopic incision does not always relieve postoperative pyloric stenosis.
METHODS: Five patients with postoperative pyloric stenosis whose symptoms did not improve with drug therapy and balloon dilatation underwent a combination of gastroscopic incision and balloon dilatation. Two or 3 small radial incisions were made in the stenotic muscle of the pylorus electrosurgically at gastroscopy. Then the stenotic muscle layer was loosened and split bluntly along the incisions with balloon dilatation for 15 to 20 minutes. One week later, the combination procedure or balloon dilatation alone was repeated to prevent restenosis.
RESULTS: In the 5 patients, the stenosis was improved with the combination therapy. No complications were observed.
CONCLUSIONS: Combined use of gastroscopic incision and balloon dilatation may be considered for patients with refractory pyloric stenosis caused by surgical truncal vagotomy.
Arch Dis Child 1989;64:138–139.
Last Updated 11/20/2001
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