Neonatal Surgical Issues (Part 2)

1. Neonatal Surgical Issues(Part 2) Sue Ann Smith, MD Neonatologist

2. Anatomic survey (cont) • Intestinal obstructions • Genitourinary • Abdominal masses • Inguinal hernia • Testicular torsion • Neurosurgical

3. Intestinal obstructions • Atresias – duodenal, jejunal, colonic • Meconium ileus • Meconium plug • Hirschsprung’s disease • Imperforate anus • Malrotation with volvulus • Adhesions and strictures

4. Atresias High obstruction of jejunal atresia Double bubble of duodenal atresia

5. Atresias (cont) • Duodenal atresia associated with trisomy 21, or other anomalies • Hx of polyhydramnios • Delee more than 30-50ml from stomach • Jejunal atresia is rarely associated with other anomalies. • Decompress proximal bowel with repogle tube to low continuous suction

6. Meconium Ileus • Obstruction of bowel by thick tenacious meconium • 30% of intestinal obstruction in neonates • Frequent cause of meconium peritonitis • Most are associated with cystic fibrosis (but only 15% of infants with CF will have meconium ileus) • Abdominal distention is typically present at birth

7. Meconium Ileus (cont) • Diagnosis made with contrast enema • Gastrograffin enema with aggressive hydration can be used to treat some • Operative evacuation of meconium • May require ostomy • Proximal bowel dilated and distal bowel may be very small (microcolon) and require time to dilate with use

8. Meconium plug • Difference between meconium ileus and meconium plug is site and severity of obstruction • Preterm infants, infants of diabetic mothers, IUGR babies, otherwise ill babies • Treatment with glycerin suppositories and warm saline enemas • May require contrast enema to make diagnosis • Normal stooling pattern should follow evacuation of plug

9. Meconium plugs

10. Hirschsprung’s Disease • Colonic agangliosis • Extent can vary from very short segment of rectal tissue to entire colon • Should be considered in any baby who does not pass stool spontaneously by 24 hours of age. • Diagnosis by rectal biopsy to look for ganglion cells

11. Hirschsprung’s Disease (cont) • Barium enema can show transition zone • Short segment disease can be treated with rectal irrigations followed by primary pull through procedure • Longer segment disease requires ostomy followed by pull through when older (months usually).

12. Imperforate Anus • May pass meconium if a rectovaginal or rectourinary fistula exists. • Low imperforate anus: the rectum has descended through the puborectalis sling and exists as a fistula on the perineum. • May see mec on the perineum, may be seen in the rugal folds or scrotum of males and vagina of females. • These fistula may be dilated to temporarily relieve obstruction

14. Imperforate Anus (cont) • High imperforate anus: rectum ends above the puborectalis sling. • No perineal fistula, but may have urinary fistula • Temporary colostomy is necessary in all babies with high imperforate anus.

15. Malrotation with volvulus • Can occur in the fetus – large calcified shadow in midabdomen on x-ray • Sudden onset of bilious emesis in infant – requires rule out • Signs of shock and sepsis can be present • Surgical emergency since intestinal viability is at stake. • UGI to evaluate for position of ligament of Treitz

16. Malrotation Volvulus

17. Adhesions and strictures • Can occur following any abdominal surgical manipulation. • Can occur following NEC even if initial disease process required only medical treatment.

18. Necrotizing Enterocolitis • This is a whole lecture unto itself • Incidence varies from center to center and from year to year within centers • 2-5% of all NICU admissions and 5-10% of VLBW infants • Prematurity is greatest risk factor • Mortality is 9-28% regardless of medical or surgical intervention

19. NEC (cont) • To be continued in future lecture……..?

20. Genitourinary • Posterior urethral valves • Extrophy of the bladder • Cloacal extrophy

21. Posterior Urethral Valves • Obstruction of urinary flow at level of bladder outlet • Exclusively in males • May lead to oligohydramnios and pulmonary hypoplasia • May lead to destruction of renal parenchyma • Symptomatology can sometimes be mild

22. VCUG in pt with Posterior Urethral Valves

24. Posterior Urethral Valves • Place urinary catheter to drain bladder • Obtain VCUG to confirm diagnosis • Urologist to ablate valves – usually with a transurethral approach • Assess renal function – urine output, electrolytes, BUN, creatinine • Bladder may be dysfunctional • Some will be OK in neonatal period and go on to “outgrow” their renal function

25. Extrophy of the Bladder • May range from epispadias to complete extrusion of bladder on to abdominal wall • Initial surgical repair is most critical for best functional outcome • Apply sterile saline and lay saran wrap on top of exposed bladder, but keep any irritants away (no gauze, etc)

27. Extrophy of bladder • 2:1 male to female ratio • Symphysis pubis is widely separated • Is a very complicated and prolonged repair requiring urologist and orthopedist to work together • Patient immobilized for a week or more post-op • Phallic reconstruction may be done in later operation

28. Cloacal Extrophy • More complex than simple bladder extrophy • May include: vesico-intestinal fissure, omphalocele, extrophied bladder, hypoplastic colon, imperforate anus, absence of vagina in female, and microphallus in males. • Series of complex operations needed

30. Abdominal masses • Renal masses • Ovarian cyst • Tumors • Adrenal hemorrhage • Hydrometrocolpos

31. Renal Masses • Polycystic kidneys • Multicystic dysplastic kidneys • Renal duplications • Hydronephrosis

32. Ovarian Cyst • One of the most common abdominal masses in female fetus and newborn • May cause torsion and necrosis of ovary • Surgical resection if >4cm diameter or persistent

33. Tumors • Teratomas are most common. • Sacrococcygeal • About 10% contain a malignant element • Neuroblastoma – 50% of malignant tumors in neonates. Can resolve spontaneously. • Wilm’s tumor • Sarcoma botryoides – grapelike tumor arises from edge of vulva or vagina.

34. Sacrococcygeal teratoma

35. Sarcoma Botryoides

36. Hydrometrocolpos • Imperforate hymen (or other vaginal obstruction) with back up of secretions in the uterus, which can cause intestinal obstruction • Hymen will bulge • May have edema and cyanosis of the legs • May cause hydronephrosis

37. Inguinal Hernia • Frequent in preterm babies, male>female • Usually repair prior to discharge if possible • Monitor for incarceration • Incarcerated hernia can usually be reduced with sedation and steady firm pressure • Even if reduced, should be repaired as soon as edema is resolved

40. Testicular Torsion • 70% occur in fetal life • Testes is tender, firm, swollen with a slightly bluish cast to the scrotum on affected side • Differential dx includes scrotal hematoma • US with doppler flow can be useful • Any possibility of recent torsion – surgery within 4-6 hrs • Orchiopexy of contralateral side

41. Neurosurgical • Myelomeningocele • Hydrocephalus • Intracranial hematoma

42. Myelomeningocele • Saccular outpouching of neural elements through defect in bone and soft tissues in posterior thoracic, sacral and/or lumbar regions (lumbar 80%) • Most common primary neural tube defect • Hydrocephalus in 84% • Arnold-Chiari II malformation in 90%

43. The Chiari II malformation is a complex congenital malformation of the brain, nearly always associated with myelomeningocele. This condition includes downward displacement of the medulla, fourth ventricle, and cerebellum into the cervical spinal canal, as well as elongation of the pons and fourth ventricle, probably due to a relatively small posterior fossa.

44. Chiari II malformation. Sagittal T1-weighted MRI of posterior fossa abnormalities in Chiari II malformation: (1) colpocephaly; (2) beaked tectum; (3) cascade of an inferiorly displaced vermis behind the medulla; (4) elongated tubelike fourth ventricle; (5) low-lying torcular herophili; (6) cerebellar hemispheres wrapping around the brainstem anteriorly; (7) concave clivus; (8) medullary spur; and (9) medullary kink.

48. Hydrocephalus • Associated with MM • Aqueductal Stenosis – male with X-linked • Post-hemmorhagic – most frequent in premature population