Paediatric surgery

CHAPTER 20 Paediatric surgery



Alimentary tract emergencies in the newborn 449

Abdominal wall defects 454

Alimentary tract problems in older infants and children 455

Infants with jaundice 459

Abdominal masses in childhood 460

Abdominal malignancies in childhood 461

Rectal bleeding in children 462

Chronic and recurrent abdominal pain 464

Neck lumps in children 464

This chapter will cover some of the paediatric surgical emergencies that arise in the newborn and also the more common paediatric surgical problems presenting at outpatient departments and common paediatric surgical emergencies.



Alimentary tract emergencies in the newborn




Oesophageal atresia


The commonest type is a blind-ended, upper oesophagus associated with a tracheo-oesophageal fistula involving the lower oesophagus (→ Fig. 20.1). Oesophageal atresia may occur alone or with a tracheo-oesophageal fistula. The incidence is approximately 1:3000 births. There may be co-existing anomalies of the heart, kidneys and intestines.


image

Figure 20.1 The commonest form of oesophageal atresia.




Symptoms and signs

Association with maternal polyhydramnios. Dribbling of saliva, inability to swallow feeds, production of frothy mucus, choking, cyanotic attacks, aspiration pneumonia.



Investigations


• Pass an orogastric tube – it will arrest at the obstruction

• CXR including neck to see the position of tube at obstruction: cardiac anomalies, aspiration pneumonia

• AXR: gas in stomach and intestine will indicate the presence of a tracheo-oesophageal fistula.


Treatment

Rehydration. Treat any chest infection. Keep upper oesophageal pouch empty by continuous aspiration. Urgent surgical ligation of tracheo-oesophageal fistula and correction of atresia by primary end-to-end anastomosis of the oesophagus.



Prognosis

There is a 90% survival in regional paediatric surgical centres in the UK.



Duodenal atresia


This occurs in 1:6000 births. The common bile duct may open proximal or distal to an atresia. There is an association with Down’s syndrome and congenital heart disease.




Symptoms and signs

Associated with maternal polyhydramnios. Vomiting in first few hours of life usually bile-stained.



Investigations


• Antenatal diagnosis is possible with USS

• AXR shows ‘double bubble’ sign, i.e. gas bubble and fluid level on each side of upper abdomen owing to gas in stomach and proximal duodenum (→ Fig. 20.2).

image

Figure 20.2 Duodenal atresia. AXR with ‘double bubble’ gas sign and no gas pattern beyond the duodenum.



Treatment

Rehydration. Urgent surgery. Duodenoduodenostomy, i.e. a side-to-side anastomosis between proximal and distal duodenal segments.



Prognosis

Mortality depends on associated abnormalities and is high with Down’s syndrome and cardiac anomalies.



Small bowel atresia


The incidence is 1:20 000 births in the UK. It is somewhat more common in other parts of the world. It may occur at any level and may be multiple.




Signs and symptoms

Bilious vomiting. Abdominal distension. Visible peristalsis.



Investigations

AXR: distended bowel with fluid levels.



Treatment

Rehydration. Urgent surgery. Resection of areas of atresia or stenosis with end-to-end anastomosis.



Malrotation (volvulus neonatorum)


In the first trimester, the midgut herniates outside the abdominal cavity but returns at the end of the 3rd month, rotating as it does so. Several rotational abnormalities may result. Obstruction may consequently result from a variety of causes from peritoneal bands to volvulus of the midgut. Failure of normal rotation invariably occurs in patients with exomphalos and diaphragmatic hernia.




Symptoms and signs

Bile-stained vomiting and abdominal distension. The symptoms are similar initially to duodenal atresia. However, volvulus will lead to venous and subsequently arterial obstruction, gut infarction and consequent potential short bowel syndrome.



Investigations


• USS to identify mesenteric vein/artery relations – the position of the vein and artery in relation to one another changes with rotation

• Contrast meal: abnormally placed duodenojejunal junction

• Contrast enema: may show abnormally placed caecum but the latter may also be normal in position.


Treatment

Emergency laparotomy. Untwist the volvulus. Tease out mesenteric base to prevent recurrence. Excise any gangrenous bowel.



Meconium ileus


This occurs in 15% of patients with cystic fibrosis. Meconium becomes inspissated in the terminal ileum with soft meconium above associated with distended proximal small bowel.




Symptoms and signs

Infant born with distended abdomen. Bilious vomiting. Meconium is not passed and the rectum is empty.



Investigations


• AXR: dilated loops of bowel

• Gastrografin enema will show an empty colon and may relieve the obstruction by refluxing into the terminal ileum and ‘loosening’ the meconium

• Prenatal diagnosis may be made with USS.


Treatment

Some 50% may have associated atresia, perforation, or volvulus and then laparotomy is required. The terminal ileum is opened and the inspissated meconium washed out. A temporary ileostomy may be required.



Complications

Meconium peritonitis. May occur in utero or postnatally. The chemical peritonitis resulting is treated by peritoneal lavage and repair of the perforation. The mortality rate is 10%.



Anorectal abnormalities


These occur with an incidence of 1:5000 births. Management depends on accurate definition of the abnormality.




Symptoms and signs

Infant fails to pass meconium. Rectal inspection reveals imperforate anus or other abnormality. There may be associated abnormalities of the GU system.



Investigations


• Tape a metal marker over the anus (or if absent, anal dimple)

• Place infant in knee–elbow position for 2 min and take a lateral shoot-through pelvic radiograph

• Assess the distance between the gas shadow and metal marker.


Treatment

Low lesions can be treated by a simple anoplasty. Higher lesions should be managed with a sigmoid loop colostomy, allowing further evaluation prior to a more complicated reconstructive procedure.



Necrotizing enterocolitis


This is an ischaemic disorder of the intestine of the newborn. The aetiology of the disease is unknown but bacterial infection, hypoxia and umbilical artery cannulation have been implicated. It is more common in premature infants and ‘epidemics’ have occurred on neonatal intensive therapy units, suggesting an infective aetiology.




Symptoms and signs

Diarrhoea, blood, mucus per rectum. Abdominal distension and bilious vomiting.



Investigations


• AXR shows distension of bowel with fluid levels

• Later, a diagnostic radiological sign is intramural gas indicative of bowel wall necrosis

• Free gas confirms intestinal perforation.


Treatment

This is initially non-operative unless perforation occurs. Resuscitation includes i.v. fluids and NG suction together with intravenous broad-spectrum antibiotics. Laparotomy is required if there is evidence of perforation or failure of patient to improve on medical treatment. Gangrenous bowel is excised with a temporary ileostomy or colostomy.



Prognosis

The mortality rate is high in severe cases. Stricture may develop in healing bowel and present later.



Diaphragmatic hernia


This occurs with an incidence of 1:4000 births. A hernia may occur through the foramen of Bochdalek, i.e. a defect in the pleuroperitoneal canal; through the foramen of Morgagni, between the xiphoid and costal margin; through a deficiency in the central tendon; or through a congenitally large oesophageal hiatus. Herniae through the foramen of Bochdalek are most common. Normal development of the ipsilateral lung is impaired and that of the contralateral lung may also be impaired.




Symptoms and signs

May be diagnosed by prenatal USS. Presents with respiratory distress at birth. Apex beat displaced. Bowel sounds in chest. Scaphoid abdomen if the hernia is large and most of the bowel is in the chest.



Investigations


• CXR

• AXR: mediastinal shift, abdominal viscera in thorax; lack of intestinal gas pattern in abdomen (→ Fig. 20.3).

image

Figure 20.3 CXR of a neonate with a left diaphragmatic hernia. Note the hypoplastic lungs, mediastinal shift to the right, and gas in abdominal viscera in the left chest.



Treatment

Urgent respiratory assistance and maintenance of circulation. When ventilation is adequate and the patient is haemodynamically stable, closure of the defect is undertaken. May require prosthetic patch.



Prognosis

Mortality is high, especially with large defects, and is due to consequences of pulmonary hypoplasia.



Hirschsprung’s disease


This occurs in 1:5000 births. There is a defect in the parasympathetic ganglia in the submucosal and myenteric plexus of the bowel wall. The aganglionic segment is present for a varying distance upwards from the anus and always involves the rectum. Rarely it affects the whole colon and even more rarely, the small bowel. The peristaltic waves stop at the affected segment and the proximal bowel becomes dilated and hypertrophied. The aganglionic segment remains contracted. It is more common in males than females.




Symptoms and signs

Delayed passage of meconium in the newborn period. However, presentation may be delayed, especially with short segment involvement, when it presents in infants and older children with constipation and abdominal distension. Digital rectal examination may demonstrate an empty rectum, which feels ‘tight’ on the examining finger.



Investigations


• AXR: dilated loops of bowel with fluid levels

• Barium enema will demonstrate the level of obstruction

• Rectal biopsy shows absence of ganglion cells.


Treatment


1. If the baby is healthy, and only rectosigmoid Hirschsprung’s is suspected, it may be managed by regular rectal washouts to clear the bowel and early operation at 4–6 weeks, avoiding a colostomy if possible.

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Jun 14, 2017 | Posted by in GENERAL SURGERY | Comments Off on Paediatric surgery

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