Neonatal intestinal obstruction

Neonatal intestinal obstruction, algorithms for evaluation and management

1. Del a yed passa g e of m e conium Dr. Faheem ul Hassan Andrabi M Ch Pediatric Surgery Dr. Gowhar Mufti Assist. Professor Pediatric & Neonatal Surgery

2. Delayed passage of Meconium Timely passage of the first stool is a hallmark of the well-being of the newborn infant.

3. DPM suspected in any full-term infant who does not pass meconium in the first 24 hours of life and in the premature infants who have excessively delayed the passage of meconium (7–8days)

4. DPM Delayed passage of meconium is a frequent finding in patients with distal intestinal obstruction and is observed in 90% of infants with Hirschsprung’s disease .

5. DPM The passage of meconium does not indicate that a complete intestinal obstruction is not present, since meconium formed distal to an obstruction may be evacuated.

6. causes Hirschsprung's disease 1/4,000 Meconium ileus 1/3000 Meconium plug syndrome 1/500 to 1/1,000 Anorectal malformation 1/4,000 to 1/8,000 Small left colon syndrome Rare Hypoganglionosis Rare Neuronal intestinal dysplasia Rare Megacystis-microcolon-I ntestinal Hypoperistalsis syndrome Very rare Distal Ileal or colonic atresia Rare

7. Medical causes of DPM Infant of diabetic mother Downs Syndrome hypermagnesemia Maternal drugs like opiods Already passed meconium in utero. Eg Fetal distress 1% normal Term neonates have DPM 5% normal preterm neonates have DPM

8. Presentation Proximal obstruction presents earlier than the distal esophageal atresia or gastroduodenal obstruction, usually present within the first 24 to 48 hours of life. Distal obstructions, such as ileal or colorectal atresias, may present a few days after birth , while functional obstructions, such as Hirschsprung’s disease, may present later

9. DPM DPM associated with Vomiting Abdominal distension Poor feeding Signs of peritonitis and shock

10. Vomiting Non-bilious or bilious Non-bilious Proximal to Ampulla of Vater Examples are pyloric atresia and pyloric stenosis

11. Vomiting Bilious Distal to Ampulla of Vater Obstruction in Duodenum, jejunum, Ileum or colon Medical conditions, such as GERD, and sepsis, can also cause vomiting, and these need to be investigated as part of the diagnostic workup. About 25% of neonates with BV eventually require abdominal surgery.

12. Abdominal distension The degree of abdominal distention depends on the level of obstruction. More distal the obstruction, the greater will be the distention. Proximal obstructions, such as duodenal atresia and malrotation, present with minimal epigastric distention, whereas ileal and colonic obstructions present with prominent distention.

13. Abdominal distension Abdominal distention that is present at birth can result from meconium ileus meconium peritonitis antenatal intestinal obstruction and perforation usually due to volvulus & intestinal atresia

14. Abdominal distension Abdominal masses like choledochal cyst, mesenteric cyst, duplication cyst ovarian cyst Hydronephrosis or ascites. May also present as abdominal distension at birth

15. Abdominal distension Abdominal distention can develop in the first hours after birth in neonates with esophageal atresia due to air passing through a concomitant TEF, particularly if the infant is ventilated mechanically. Neonates with malrotation and midgut volvulus also may develop abdominal distention due to dilatation of a closed segment of bowel distal to the usual site of duodenal obstruction. ( closed loop Obstruction)

16. Abdominal distension Abdominal distention usually is delayed in distal or functional obstructions and may appear 24 hours or later after birth. (microcolon, ARM, Hirschsprung's Disease)

17. DPM The cardinal features of NIO are vomiting, abdominal distension and failure to pass meconium. Secondary symptoms such as brady - or tachycardia , temperature instability , and lethargy are usually a because of dehydration , electrolyte imbalance , and sepsis

18. As the patient arrives Prenatal history forms the cornerstone of diagnosis History of Polyhydroamnios Cystic fibrosis Drug intake like opoids and MgSO4 Gestational diabetes Prematurity and fetal distress Sepsis

19. History Siblings of children with esophageal atresia may exhibit features of the VACTERL family history of epidermolysis bullosa may be observed in neonates with pyloric atresia. Almost half of neonates with small left colon syndrome are infants of diabetic mothers.

20. Assessment Vital signs Cry, suck and activity Signs of hypothermia HR, RR, CRT and skin turgor AF, dry mucosae and U.O should be assessed After proper assessment, appropriate measures should be taken to address the Issues (like fluid bolus and addressing hypothermia)

21. Abdominal assessment Color Erythema blue shiny Size distended, taut, scaphoid measurement of girth every 2-4 hourly

22. Abdominal assessment Visible/prominent vascular markings Visible bowel loops, peristalsis evident Tenderness Temperature Palpation for masses Presence/absence of bowel sounds or flatulence

23. Assessment Color , volume and consistency of NG Aspirate should be noted (for presence of BBF) Similarly color , volume and consistency of stools should be assessed Daily weight of neonate should be followed

24. Intervention 8–10 French FT should be used to provide adequate drainage and decompression of the stomach to decrease restriction of the diaphragm. To decrease the risk of emesis and the potential for aspiration Gastric decompression

25. Intervention Regular flushing of the tube with air & saline ensures patency. Accurate measurements of drainage are necessary to assist with maintaining fluid balance. Gastric decompression

26. Intervention Establishing adequate vascular access is essential for any resuscitative and therapeutic measures to be successful. Warming the neonate initially makes vascular access easy Vascular access

27. Intervention The fluids lost in vomitus and gastric aspirates are easily quantified. Intraperitoneal, interstitial (“ third space ”) losses from the obstructed intestine cannot be easily measured. In the circumstance of hypovolemic shock , fluid resuscitation with NS boluses is essential to maintain blood pressure and adequate perfusion to all vital organs. Maintenance of Fluid and Electrolyte Balance

28. Intervention Gastric losses should be replaced. maintenance fluid volume needs to be above the norms (by approximately 10–20 percent) to compensate for the third space losses Maintenance of Fluid and Electrolyte Balance

29. Intervention Immediate measurement of electrolytes is vital when an obstruction is suspected. The common practice of waiting to measure electrolytes until the “obligatory” diuresis phase occurs in the newborn infant with suspected intestinal obstruction is unwarranted. Maintenance of Fluid and Electrolyte Balance

30. Intervention Clinical presentation, age, duration, location, and degree of obstruction are key factors in the calculation of estimated fluid and electrolyte requirements. Measuring trends over time is essential because changes in electrolytes also reflect fluid balance. Maintenance of Fluid and Electrolyte Balance

31. Intervention Assessing weight, skin turgor, serum electrolytes and urine output, and renal function helps in estimating fluid and electrolyte. Maintenance of Fluid and Electrolyte Balance

32. Intervention A history of dehydration and inadequate fluid intake may lead to hypoglycemia . Conversely, the stress response to sepsis and obstruction may lead to hyperglycemia. Frequent measurement of serum glucose is essential . Maintenance of BS

33. Intervention Observation for pH imbalance is essential Both metabolic acidosis and alkalosis may occur with intestinal obstruction, depending on the level of obstruction, Upper GI tract obstruction may lead to a loss of chloride in the vomitus subsequently resulting in hypochloremic metabolic alkalosis. Maintenance of Normal pH Balance

34. Intervention Acidosis and increased lactate levels are indicators of shock Respiratory acidosis may also occur secondary to sepsis and to the respiratory decompensation due to abdominal distention and decreased lung volumes Maintenance of Normal pH Balance

35. Diagnostic work-up (disease-specific) Polyhydroamnios ( s/o proximal obstruction , EA, PA, DA, MI) Echogenic contents of bowel in MI Double Bubble sign in DA Presence of other abdominal masses like a Choledochal cyst or renal mass Presence of distended bladder in megacystis microcolon Syndrome Prenatal USG

36. Diagnostic work-up (disease-specific) Prenatal ultrasound image shows fluid-filled distended stomach (S) and duodenal bulb (D),producing prenatal ultrasound double bubble sign Prenatal USG

37. Diagnostic work-up (disease-specific) Echogenic bowel (MI) Free abdominal fluid ( perforation) Relation of SMA and Vein (in Malrotation) Distended bowel ( atresia) Postnatal USG

38. Diagnostic work-up (disease-specific) Abdominal x-ray with GI tract anatomic landmarks. Radiograph (X-Ray)

39. Diagnostic work-up (disease-specific) Air is generally present in the stomach of the neonate within 5 minutes of life, in the jejunum within 15 minutes, and in the cecum by 2 to 3 hours. Air usually reaches the sigmoid colon and the rectum within 6 to 12 hours. Radiograph (X-Ray)

40. Diagnostic work-up (disease-specific) Although radiographs permit visualization of the bowel gas pattern, it is difficult to differentiate between the small bowel and the colon in a neonate. Radiograph (X-Ray)

41. Radiograph Characteristic gas pattern in proximal gut obstruction

42. Radiograph Gas pattern in mid GIT obstruction

43. Radiograph Gas pattern in distal GIT obstruction

44. Diagnostic work-up (disease-specific) Posteroanterior and lateral decubitus abdominal radiographs should be obtained in all neonates with suspected intestinal obstruction. Radiograph (X-Ray)

45. Diagnostic work-up (disease-specific) Pyloric atresia. Single bubble sign. Epidermolysis bullosa is an association of PA Radiograph (X-Ray)

46. Duodenal atresia Double bubble sign on X-Ray Distal gas absent in complete atresia

47. Distended stomach and duodenum with traces of contrast distally. ( Partial obstruction; Duodenal stenosis and duodenal web)

48. Diagnostic work-up (disease-specific) UGI depicting malrotation with all of the small bowel on the right side of the abdomen. Malrotation

49. Diagnostic work-up (disease-specific) Upper GI barium study demonstrates the classic ‘corkscrew’ appearanc e of the duodenum and proximal jejunum. Midgut volvulus

50. Diagnostic work-up (disease-specific) Diagram of small bowel volvulus with secondary ischaemia of the midgut. UGIS of volvulus showing the characteristic “corkscrew” appearance. Midgut volvulus

51. Diagnostic work-up (disease-specific) Jejunal atresia. Triple bubble sign Radiograph (X-Ray)

52. Diagnostic work-up (disease-specific) Ileal atresia. Multiple air fluid levels in proximal two-third of abdomen. No gas in lower abdomen. Note the large AF level in distal most part of proximal bowel Ileal Atresia

53. Diagnostic work-up (disease-specific) Ileal atresia . Contrast enema shows a microcolon but unable to reflux contrast into the terminal ileum. Ileal Atresia

54. Meconium Ileus dilated small bowel loops of different size, few air-fluid levels, and a “ground-glass” or “soap-bubble ”

55. Radiology Meconium Ileus There are distended bowel loops of disparate size, Few air-fluid levels, and a “soap bubble” right lower quadrant appearance.

56. Meconium Ileus Meconium Ileus CE depicting a micro colon inspissated intraluminal pellets of meconium are seen

57. MI- Laboratory Testing Gastrograffin is both diagnostic and therapeutic in MI Other tests used to diagnose MI are sweat chloride in excess of 60 mEq /L is diagnostic of CF. Meconium albumin> of 80 mg/g genetic analysis for CFTR

58. Diagnostic work-up (disease-specific) MPS . Contrast enema shows intraluminal filling defect in the rectosigmoid colon. Patient later passed meconium plug and obstruction was relieved Meconium plug syndrome

59. Diagnostic work-up (disease-specific) MPS . Lateral and frontal images demonstrate a microcolon involving the entire colon. Inspissated meconium (arrows) is seen throughout the small- calibered colon Meconium Plug Syndrome

60. Diagnostic work-up (disease-specific) Hirschsprung’sDisease . distended loops of intestine with paucity of air in rectum Hirschsprung’s Disease .

61. Diagnostic work-up (disease-specific) Hirschsprung’s Disease . Transition zone at RS junction Hirschsprung’s Disease .

62. Diagnostic work-up (disease-specific) Hirscpsrungs Disease

63. Diagnostic work-up (disease-specific) Colonic atresia

64. Microcolon Microcolon is a radiographic feature of low intestinal obstruction that results from underutilization of colon It is also called “unused colon,” includes entities in which meconium is not passed through the colon during in fetal life.

65. Microcolon Disease entities manifesting as microcolon include . meconium ileus, small left colon syndrome, small intestinal and colonic atresia, and Hirschsprung disease Etiology Microcolon has also been defined by a luminal diameter less than the height of an upper lumbar vertebral body.

66. There are 4 patterns of contrast enema Normal (normal length and caliber) No obstruction. Microcolon

67. Normal length and small caliber Normal length and small caliber Meconium ileus Jejuno-ileal Atresia Total Colonic Aganglionosis Microcolon

68. Short length and small caliber Short length and small caliber Colonic Atresia Microcolon

69. Change in Caliber Change in Caliber Small Left Colon Syndrome Hirschsprung Disease Microcolon

70. A word about Contrast Study Two types of contrast studies generally rule out obstruction. The choice ( upper vs lower ) and the sequence of studies are determined by the clinical presentation , the x-ray findings , and the suspicion of upper vs lower GI tract obstruction.

71. A word about Contrast Study If a proximal obstruction such as duodenal atresia or malrotation is suspected, upper GI series (e.g., ESSB) is instituted If a mid to distal obstruction is suspected, the contrast enema is done first to assess the patency of the distal bowel.

72. Contrast Study Traditionally, barium has been used as a contrast medium. It is inexpensive , readily available, and provides good contrast images. However, disadvantages for its use in the neonate include aspiration into the lung or solidification in dilated bowel

73. Contrast Study In cases of perforation, barium may lead to peritonitis and granuloma formation . Preferably, water–soluble, nonionic, or low- osmolar contrast solutions that, in cases of perforation, are reabsorbed are used.

74. Algorithm In cases of perforation, barium may lead to peritonitis and granuloma formation. Preferably, water–soluble, nonionic, or low- osmolar contrast solutions that, in cases of perforation, are reabsorbed are used.

75. Algorithm In cases of perforation, barium may lead to peritonitis and granuloma formation. Preferably, water–soluble, nonionic, or low- osmolar contrast solutions that, in cases of perforation, are reabsorbed are used.

76. Current Diagnostic Protocol - HD

77. Current Diagnostic Protocol - HD The diagnosis requires histopathological demonstration of the complete absence of enteric ganglion cells and presence of hypertrophied AchE-positive nerve trunks Therefore, rectal biopsies with appropriate processing and interpretation by an experienced pathologist are the criterion standard to diagnose HD.

78. Current diagnostic protocol; HD Anorectal manometry (ARM) may be a confirmatory investigation or a tool to exclude HD in older children with a history of constipation from infancy. A BE but may be indicated in Histologically confirmed cases to provide information on the length of the aganglionic bowel.

79. Biopsy-HD The easiest means of obtaining adequate diagnostic tissue in rectal biopsies in infants is by rectal suction biopsy (RSB).

80. Biopsy - HD Compared with full-thickness rectal biopsies, RSB can be performed without general anesthesia or even sedation. The rates for major complications such as perforation, bleeding, and infection are between 1.3% and 2.9%

81. Biopsy - HD An accurate diagnosis is only possible if 2 to 3 suction biopsies are taken 2 to 3 cm above the dentate line and if they include sufficient submucosa. Biopsies taken closer to the dentate line may be misleading because of a normal zone of submucosa l hypoganglionosis.

82. Biopsy- HD This zone of hypoganglionosis is 10 mm in neonates to 25 mm in children 3 years old and Older. If a full-thickness biopsy is obtained, this could be done as low as 1 cm above the dentate line because the myenteric plexus extends more distally.

83. Biopsy-HD Between 9% and 30% of RSBs are inadequate and must be repeated, primarily because of insufficient submucosa in the biopsy. This is particularly a problem in children older than 1 year.

84. Anorectal manometry ARM assesses the rectoanal inhibitory reflex ( RAIR ), which is absent in HD . Although the absence of the rectoanal inhibitory reflex is specific for the diagnosis of HD, the role of ARM is still debated .

85. ARM has the advantages of being a less-invasive method without the exposure to ionizing radiation . The limitations include the need for the patient to be in a normal physiologic and quiet state to avoid possible artifacts Anorectal manometry

86. Inconclusive results , however, are more common in ARM because of patient agitation. Specificity is lower for ARM compared with RSB. ARM cannot reliably replace histology and biopsies. Anorectal manometry

87. ARM should not be used as a sole diagnostic tool for HD in neonates and infants. ARM is a useful screening test in older children presenting with symptoms of HD. If the RAIR is absent, these patients should be referred for Bx . If the rectoanal inhibitory reflex is present , HD could be reasonably excluded . Anorectal manometry

88. In comparison with ARM and RSB, BE has a low sensitivity and specificity for the diagnosis of HD. The transitional zone is difficult to demonstrate in young infants . The technique also fails in children with total colonic aganglionosis . Furthermore, BE may not distinguish HD from other newborn’s pathologies, such as allergic colitis . Barium enema

89. It is also unreliable in short-segment HD. If a BE is performed, this should be done without previous bowel preparation or recent digital rectal examination Barium enema

90. DPM

91. Barium Enema does not represent a valid alternative to RSB or ARM to exclude or diagnose HD, regardless of age; however, BE may have some use as an additional investigation in diagnosed cases to assess the length of the rectosigmoid aganglionic segment before surgery.

92. Tha n k Yo u [email protected]