Abdominal wall and umbilical disorders — branching viva

Opening — framing the problem

The examiner begins: a baby is delivered at a tertiary centre at 37 weeks, and at birth loops of thickened bowel protrude through a small defect to the right of a normally inserted umbilical cord with no covering membrane. Talk me through your approach. [3]

I would frame this as gastroschisis, distinguished from omphalocele by the bare bowel beside a normally inserted cord and the absence of a covering sac. My priorities would be to protect the bowel, to resuscitate the baby, and to involve the neonatal surgical team, because the exposed bowel loses heat and fluid rapidly and needs urgent stabilisation before closure. [2] [3]

Branch A — the embryology and the associations

Explain the embryology. Why is this defect usually isolated? [1]

Gastroschisis follows disruption of the paraumbilical body wall, most often on the right where the ring is weakest, after the lateral folds have already closed. Because this happens after organogenesis, the bowel is exposed but the chromosomes and the heart are usually normal, which is the opposite of an omphalocele, where the earlier failure of the lateral folds to meet in the midline coincides with cardiac and chromosomal formation and carries a high association rate. [1] [2]

Branch B — resuscitation before closure

What would you do at the bedside before the surgeon arrives? [2]

I would place the baby in a clean plastic bowel bag up to the axillae to keep the bowel moist and warm and to limit evaporative heat loss. I would establish intravenous access, pass a nasogastric tube on free drainage to decompress the stomach, give a dextrose-containing crystalloid at about one and a half times maintenance because the exposed bowel loses large volumes of fluid, start broad-spectrum antibiotics, and begin parenteral nutrition early because the bowel will not function for days. I would support the bowel in the midline to prevent torsion at the mesenteric root. [2] [3]

Branch C — the surgical pathway

Describe the surgical options and what determines the choice. [1]

If the bowel is not too thickened, a primary closure is performed soon after birth. If the bowel is too bulky, a preformed silastic silo is placed over it and suspended, and the bowel is gradually reduced over several days as the oedema settles, followed by delayed closure. The choice depends on the condition of the bowel and whether it fits safely into the abdomen without dangerous intra-abdominal pressure. Complex gastroschisis with atresia or necrosis needs additional bowel surgery and a longer course of parenteral nutrition. [1] [2]

Branch D — the pivot to the ex-preterm infant

Now a six-month-old born at 29 weeks presents with a hard, tender, irreducible right groin mass, crying and vomiting. What is this and what is your management? [7]

This is an incarcerated inguinal hernia, and this baby is at high risk because prematurity carries both a high incidence, up to thirty percent, and the greatest incarceration risk. I would give analgesia and a dose of broad-spectrum antibiotic, attempt a single gentle taxis reduction under sedation if he is stable and there are no signs of strangulation, and prepare for theatre. If the hernia does not reduce, or if there is tenderness, discolouration or systemic compromise, I would proceed to urgent surgical exploration rather than persisting with reduction. [8] [9]

Closing — the umbilical granuloma

A parent asks about treating a moist pink umbilical nodule with silver nitrate. What do you advise? [11]

I would explain that this is an umbilical granuloma, a common, benign nodule left after cord separation. I would recommend common salt as the first choice, because a systematic review supports its effectiveness and it avoids the chemical burns to the surrounding skin that silver nitrate can cause. If silver nitrate is used, it must be applied carefully to the granuloma surface only, with the surrounding skin protected. I would arrange review in a week and refer for excision if it persists or is large. [11]