Paediatrics Flashcards
Dermoid cyst
Dermoid cysts develop at an area where fusion of
sections of the embryo has occurred, and are most
common in the midline of the neck, at the external
angle of the eye, and behind the pinna. They should be removed to prevent secondary infection.
Cleft lip and palate
This is one of the more common congenital anomalies, occurring in 1 in 600 live births.
The face forms during the fifth to the eighth week,
from the maxillary and mandibular prominences of
the first branchial arch.
They grow and fuse together, and if this fusion is incomplete, unilateral or bilateral cleft lip may arise.
The palate develops after the eighth week, and
fusion occurs between the primary palate (the anterior section of the premaxilla and attached four front teeth) and the secondary palate (the hard and soft palate).
The palate may be cleft posteriorly only, a cleft soft palate, or it may extend anteriorly to include the hard palate, cleft palate only, and more commonly it extends further anteriorly to join up with either a unilateral or bilateral cleft lip.
Surgical correction of cleft lip and palate needs to
take the embryological origins and in particular the
blood supply into consideration, in order to allow an
optimum repair and subsequent growth.
Cystic hygroma
The primitive lymph sacs develop in the mesenchyme in the sixth week, and the largest is in the neck, and should resolve, but persistence and sequestration produces a multicystic swelling within the neck which is a lymphangioma, a benign hamartoma (overgrowth of normal tissue), which is also called a cystic hygroma when it occurs in the neck.
Occasionally this is very large and causes respiratory distress in the neonatal age group, but more usually is just a soft swelling in the neck which may extend into the axilla, or even the chest.
A degree of spontaneous resolution can be
hoped for, but often it comes to surgical debulking – a difficult prospect because of the multicystic nature, which makes it difficult to be sure that every bit of the abnormal tissue is removed. If there is a haemangiomatous element as well as the lymphangiomatous part, spontaneous resolution is unlikely.
An MRI scan is recommended to delineate the full extent and nature of the lesion, and the normal structures which are involved, to help plan surgical excision.
Congenital diaphragmatic hernia
The diaphragm develops between the thoracic and abdominal cavity,
finished before the end of the eighth week.
As the embryo folds and carries the primitive heart and septum transversum caudally and ventrally, it carries part of the yolk sac dorsally to develop as the foregut. The lateral mesenchyme develops into the pericardioperitoneal canals,
The motor nerve supply C3–5. can cause shoulder tip pain (which area is also supplied by C4).
Diaphragm develops from the fusion of four
parts
The diaphragm develops from the fusion of four
parts:
• The septum transversum (the fi brous central
tendon);
• The mesentery of the foregut (the area adjacent
to the vertebral column becomes the crura and
median part);
• Ingrowth from the body wall (the peripheral
muscular portion); and
• The pleuroperitoneal membrane (a small dorsal
part).
VACTERL
VACTERL:
• Vertebral anomalies (e.g. hemivertebrae);
• Anorectal anomalies (e.g. imperforate anus);
• Cardiac anomalies;
• Tracheal anomalies (e.g. fi stula, tracheomalacia);
• Esophageal anomalies (the American version!);
• Renal anomalies; and
• Limb anomalies (e.g. radial aplasia).
Pyloric stenosis
The stomach develops from a simple tubular part of the foregut by localised dilatation.
The mesentery which suspends the stomach from the posterior abdominal wall enlarges and becomes the greater omentum. The exit of the stomach into the duodenum is the pyloric canal.
Pyloric stenosis presentation
The baby usually presents after 10–50 days (most commonly 3–5 weeks),
Non-bilious projectile vomiting.
Diagnosis and treatment of pyloric stenosis
The diagnosis is made by feeding the baby, to relax the baby. The visible peristalsis may be seen, feel for the pylorus, which can be felt as a olive like lump in the right upper quadrant,
Ramstedt pyloromyotomy
Pancreas development
The pancreas develops from two outgrowths of the foregut, one ventral and one dorsal.
Due to rotation, the ventral bud and the adjacent gallbladder and common bile duct rotates so that the ventral and dorsal buds lie adjacent to each other and fuse. The two ducts also usually fuse, and the main pancreatic duct enters the duodenum adjacent to the entry of the common bile duct at the ampulla of Vater.
Annular pancreas - outgrowth of ventral duodenum
Duodenal atresia presentation
duodenal atresia present in the first few days of Babies with duodenal stenosis present later
The most common part of the duodenum to be obstructed is just distal to the ampulla of Vater, and so the vomit is most likely to be bilestained. Plain abdominal x-ray in duodenal atresia reveals a ‘double bubble’ – the first bubble being air in the distended stomach, and the second bubble being air in the distended duodenum.
can lead to polyhydramnios.
Duodenal atresia treatment
laparotomy, and a duodenoduodenostomy – which is the most physiological operative correction.
Malrotation
abdominal x-ray may show the small bowel on the right of the abdomen, and the large bowel on the left,
This requires urgent resuscitation, and then laparotomy and correction, before a volvulus occurs.
a contrast meal will demonstrate the position of the duodenojejunal flexure and subsequent lie of the jejunum.
Meconium ileus
Meconium ileus is the term given to ileal obstruction
due to inspissated meconium in the terminal ileum in neonates. Management includes treatment of the obstruction, and then investigation and treatment of the baby for cystic fibrosis.
Anterior abdominal wall defects
These comprise exomphalos and gastroschisis.
Treatment of anterior abdominal wall defects
replace the exteriorised bowel/organs into the abdominal cavity,
feed the baby intravenously .
Umbilical remnant: Meckel’s diverticulum
The vitello-intestinal duct is the remnant of the yolk sac
It should completely obliterate during the sixth week, but may persist If it persists
completely, leads to the Meckel’s diverticulum, which arises from the terminal ileum.
The classical description in adults is that it is present in 2% of the population, is 2 inches (5 cm) long, and 2 feet (60 cm) from the ileocaecal valve.
Meckel’s diverticulum treatment
Asymptomatic - ileal muscosa
Symptomatic - gastric muscosa
may undergo peptic ulceration with subsequent bleeding. It may present with diverticulitis (like appendicitis), or with adhesion/
band obstruction and volvulus because of its persistent attachment to the umbilical cord.
Management is by excision
Umbilical remnant: Urachus
The urachus is the embryonic remnant of the connection between the urinary bladder and the allantois at the umbilicus
can also persist, from which urine comes. Treatment is by surgical excision after accurate diagnosis.
normally urachus is obliterated to form the median umbilical ligament
Hirschsprungs disease
Absence of ganglion cells in the myenteric plexus
Histology of Hirschsprungs disease
As well as aganglionosis, the other
histological abnormality is hypertrophied nerve trunks in the bowel wall, which stain densely for acetylcholinesterase.
Full thickness rectal biopsy
Treatment of Hirschsprungs disease
Treatment is aimed at decompression of the bowel,
either with a stoma in ganglionic bowel just proximal to the transitional zone, or by regular washouts, until a defi nitive operation is performed.
Ano-recatal pull through
Epispadias
This is very rare, the urethral opening being on the
dorsal surface of the penis. It is usually associated with more complex penile anomalies, which may require very complex surgical correction.
Hydrocele
If the PPV remains patent, a congenital hydrocele is found clinically
If the PPV is large enough, it allows abdominal contents to prolapse into the scrotum – an inguinal hernia. Surgical correction of congenital inguinal hernia and PPV ligation are two of the commonest paediatric surgical procedures.
Undescended testis
Failure of the testis to descend fully is known as an
undescended testis. This can lead to the testis being located anywhere along the line of normal descent, down the posterior abdominal wall, in the inguinal canal or in the upper scrotum.
Ectopic testis
If the testis descends, but to an abnormal position, it is called ectopic.
Ectopic testes are very uncommon, but can be found in the perineum, in the upper part of the femoral triangle in the thigh, at the base of the penis, or in the anterior abdominal wall. An undescended testis usually has a patent processus vaginalis associated with it.
Orchidopexy
The surgical procedure for an undescended testis,
an orchidopexy, is similar in principle to a hernia operation. The operation is done via a groin approach, the testis is located, and separated from the PPV. The testis is then mobilised further on the spermatic cord to allow enough length for the testis to be placed in a scrotal pouch.
Causes of the absence of Vas deferens
Can be unilateral or bilateral
Cystic Fibrosis CFTR gene mutation are the cause in 40% of cases
Sometimes due to unilateral renal agenesis
Aetiology of biliary atresia
Biliary tree lumen is obliterated by an inflammatory cholangiopathy causing progressive liver damage
Clinical featres of biliary atresia
Well in the first few weeks of life
No FHx
CONJUGATED BILIRUBIN
Jaundice in infants > 14 days in term ( > 21 days in pre term)
Pale stool
yellow urine
Associated with cardiac malformation, polysplenia and situs invertus
Ix for biliary atresia
Conjugated bilirubin
Ultrasound of the liver
Hepato-iminidiacetic radionuclide scan
Mx of biliary atresia
Nutritional support
Kasai procedure (Roux-en-Y portojejunostomy
If this fails, liver transplant
Causes of bilious vomiting in neonates
Duodenal atresia (AXR - double bubble) - few hours after birth
Malrotation (medial DJ flexure, abnormal orientation of SMA and SMV) 3-7 days after birth
Jejunal / ileal atresia (AXR air fluid level) within 24 hours of birth
Meconium ileus (AXR air fluid levels, sweat test) 24-48 hours after birth
Necrotising enterocolitis (AXR dilated bowel loops - 2nd week of life
Where do bronchogenic cysts typically arise from?
Anamolous development of the ventral foregut
Where are bronchogenic cysts most commonly found?
Midline, most often in the region of the carina (sometimes with attachment to the tracheobronchial tree)
Presenting symptoms of bronchogenic cysts
Asymptomatic or present with respiratory symptoms early in the neonatal period
What is the most common type of foregut cysts?
Enterogenous cysts
Ix for bronchogenic cysts
Antenatal USS, others are detected on conventional CXR
Once suspected, CT
Treatment of bronchogenic cysts
Thorascopic resection, if very young wait until 6 weeks
