Duodenal atresia

congenital disease

1. Duodenal Atresia Dr S hambhavi S harma

2. Duodenal atresia - Introduction D uodenal atresia and stenosis – common cause for intestinal obstruction 1/5000-10000 live births Boys commonly affected than girls associated with other congenital anomalies (45-65%) Down’s syndrome (50%) Gut malrotatation (30%) Congenital heart diseases (25-65%) Anorectal and genitourinary anomalies

3. Embryology Fourth week of development Endoderm gives rise to the gut tube S ixth week G ut epithelium proliferates rapidly, resulting in obliteration of the intestinal lumen O ver the next several weeks Intestine then gradually recanalize Errors in recanalization primary cause of duodenal atresia and stenosis.

4. Duodenal atresia - Etiology Intrinsic lesion Failure of recanalization of fetal duodenum resulting in complete obstruction Extrinsic lesion Annular pancreas Preduodenal portal vein Malrotation Ladd’s band

5. Classification(Gray and Skandalakis ) Type I More than 90% Obstructing septum (web) formed from mucosa and submucosa with no defect in the muscularis . Mesentery intact Variant: “windsock deformity” Membrane is thin and elongated Base of the membrane usually lies in the second portion of the duodenum balloons out distally distending 3rd and 4th portion Windsock deformity

6. Type II Dilated proximal and collapsed distal segments connected by fibrous cord Type III Obvious gap separating proximal and distal segment

7. Duodenal atresia - pathology Obstruction level – pre- ampullary or post- ampullary More than 85% distal to ampulla Stomach and proximal bowel dilated Pylorus hypertrophic and distended Distal bowel collapsed Windsock deformity : distal bowel dilated

8. Clinical presentation Depends on Whether obstruction is complete or incomplete Location of ampulla in relation to obstruction Classic presentation Bilious vomiting within first few hours of life in otherwise healthy neonates In less than 15 % non bilious vomiting seen ( preampullary obstruction) P artial obstruction: symptoms may present later in the 1 st year of life with the introduction of solid foods I n rare cases, diagnosis may even be delayed into later childhood or adulthood usually in association with GERD, esophagitis, duodenal ulcer

9. Physical E xamination : U pper abdominal distention that resolves with placement of a NG tube With complete obstruction, placement of a NG tube may result in a scaphoid abdomen due to the absence of distal gas GI tract Aspiration via NG tube of >20 mL of gastric contents suggests intestinal obstruction

10. Duodenal atresia – diagnosis Antenatal diagnosis Detected between 7 and 8 months Poly- hydraminos Two fluid filled structures – consistent with double bubble in up to 44%

11. Duodenal atresia – diagnosis Postnatal diagnosis Double bubble sign with no distal bowel gas Proximal left sided bubble – air and fluid filled stomach Second bubble to right – dilated proximal duodenum In doubtful cases 40/60ml of air instilled in stomach – reproduce sign

12. Duodenal atresia – diagnosis Role of Upper GI contrast study D ifferentiating intrinsic duodenal obstruction from midgut volvulus Intrinsinc duodenal obstruction Smooth rounded end seen at level of obstruction in second portion of duodenum M idgut volvulus Distal beaking effect in third part of duodenum Web Distal part of duodenum

13. Duodenal atresia –preoperative preparation Work up Complete blood counts Electrolytes Abdominal USG extrinsic causes of compression: anomalies of the pancreas or biliary tree , preduodenal portal vein or duodenal duplication. Echocardiography to rule out cardiac anomalies

14. E mergency intervention only in cases of suspected midgut volvulus Gastric decompression using NG tube Maintenance intravenous fluids , with replacement fluid added to account for gastric losses Prophylactic preoperative antibiotic (ampicillin and gentamicin in neonates ) 1 mg of intramuscular vitamin K In premature infants with extremely low birth weight (<1,000 g) delayed operative intervention for several weeks with nasogastric decompression and parenteral nutrition to allow for growth of the infant

15. Surgical techniques Diamond shaped duodenoduodenostomy (preferred) Side-to-side duodenoduodenostomy Duodenojejunostomy Web resection with duodenoplasty

16. S ide-to-side duodenoduodenostomy : associated with a high incidence of anastomotic dysfunction and prolonged obstruction Duodenojejunostomy : associated with Blind-loop syndrome Gastrojejunostomy should not be performed as it is associated with a high incidence of marginal ulceration and bleeding

17. Diamond shaped Duodenoduodenostomy Approach : Open Laparoscopic Steps Open approach Incicion : RUQ supraumbilical transverse incision or an umbilical crease incision After mobilizing the ascending and transverse colon to the left, the duodenal obstruction is readily exposed

18. Malrotation should be evaluated (can occur in 30% of cases ) Sufficient length of duodenum distal to the atresia is mobilized to allow for a tension-free anastomosis transverse duodenotomy is made in the anterior wall of the distal portion of the dilated proximal duodenum Similar length duodenotomy made in a vertical orientation on the antimesenteric border of the distal duodenum

19. Small red rubber catheter placed distally into the jejunum to assess for a rare second duodenal atresia. Saline injected to distend the distal bowel to rule out any jejunoileal atresia . Anastomosis approximating the end of each incision to the appropriate mid-portion of the other incision S ingle-layered technique with silk or absorbable suture Use of a transanastomotic feeding tube is left the surgeon’s preference

20. When the proximal duodenum is markedly dilated , tapering duodenoplasty with staples or sutures should be considered to narrow the duodenal caliber to lessen dysmotility .

21. Windsock deformity : identification of the constricting ring from which the web originates by passage of a nasogastric tube longitudinal dodenotomy on the antimesenteric wall is made, which centers on the constricting ring Web resected laterally, anteriorly, and posteriorly, Avoid and preserve the medial third of the web Minimizes the risk of injury to the ampulla Hemostatic, running absorbable suture is placed along the cut edge of the web, medial portion is left to hang distally into the lumen Doudenoplasty is then completed by closing the duodenotomy transversely in a single layer with silk or absorbable suture to further open the constricting ring

22. Laparoscopic approach first described by Rothenberg in 2002 patient supine abdomen insufflated through the umbilicus Two other ports: Baby’s RLQ R ight mid- epigastric region cranial

23. Duodenal atresia – surgery Duodenojejunostomy Only done if duodenoduodenostomy not possible existence of large gap between the proximal and distal duodenal segments in patients with normal rotation and a normal ligament of Treitz infants less than 1,000 g Equivalent outcomes but more post operative complications

24. Post operative care Monitor NG effluent Feeding NPO till return of normal bowel function and no evidence of anastomotic leak May require TPN depending on neonate status S tarted once NG effluent diminished and becomes clear Started with small volume feed and gradually increase if tolerated

25. Duodenal atresia - prognosis Outcomes More than 95% will recover successfully Mortality – associated with other associated anomalies Long-term complications Delayed gastric emptying Severe gastroesophageal reflux and bleeding peptic ulcer Megaduodenum Duodenogastric reflux I ntestinal obstruction related to adhesions

26. References Ashcraft’s Pediatric Surgery 7 th edition Fischer’s mastery of surgery 7 th edition Grosfeld Pediatric Surgery 6 th edition

27. Take Home Messages Duodenal atresia – common causes for intestinal obstruction in neonates Presents with classical features of intestinal obstruction Diagnosis is often clinical with radiological investigations to support for diagnosis Operative treatment has good outcome

28. THANK YOU