Overview

Definition:
-Duodenal atresia is a congenital obstruction of the duodenum, typically occurring distal to the ampulla of Vater, characterized by a complete or near-complete blockage of the intestinal lumen
-Diamond duodenoduodenostomy is a common surgical technique used to bypass this obstruction by creating a side-to-side anastomosis between the proximal and distal duodenal segments in a diamond shape.
Epidemiology:
-Duodenal atresia is the second most common congenital intestinal obstruction, occurring in approximately 1 in 5,000 to 10,000 live births
-It is strongly associated with Down syndrome (trisomy 21), with up to 30% of affected infants having this chromosomal abnormality
-Other associated anomalies include annular pancreas, malrotation, and cardiac defects.
Clinical Significance:
-Prompt diagnosis and surgical intervention are critical for survival
-Delayed diagnosis can lead to severe dehydration, electrolyte imbalances, malnutrition, and increased risk of sepsis and death
-Understanding the management of duodenal atresia is a core competency for pediatric surgeons and essential knowledge for all surgical residents preparing for DNB and NEET SS examinations.

Clinical Presentation

Symptoms:
-Non-bilious vomiting shortly after birth, often projectile
-Abdominal distension, typically in the upper abdomen
-Failure to pass meconium within the first 24-48 hours of life
-Poor feeding and failure to thrive
-Jaundice may be present in some cases.
Signs:
-Visible peristalsis of the stomach (gastric waves)
-Palpable epigastric mass
-Tympanitic abdomen with increased upper abdominal girth
-Dehydration with decreased skin turgor and sunken fontanelles
-Sepsis may be evident in severe cases.
Diagnostic Criteria:
-Diagnosis is typically made based on a combination of clinical presentation and characteristic findings on imaging
-Prenatal ultrasound may detect polyhydramnios and a dilated stomach bubble
-Postnatal diagnosis relies on abdominal radiography and upper gastrointestinal contrast studies.

Diagnostic Approach

History Taking:
-Detailed maternal history regarding prenatal ultrasound findings
-Detailed infant history of feeding, vomiting (character, timing, volume), and stooling pattern
-Assess for any associated congenital anomalies or family history
-Red flags include non-bilious projectile vomiting within hours of birth and failure to pass meconium.
Physical Examination:
-Thorough abdominal examination, noting distension, visible peristalsis, and any masses
-Assess hydration status and vital signs
-Examine for other congenital anomalies, particularly facial features suggestive of Down syndrome, cardiac murmurs, or limb abnormalities.
Investigations:
-Abdominal radiography: may show a dilated stomach and proximal duodenum with an absence of distal gas ("double bubble sign")
-Upper gastrointestinal contrast study (UGI series): essential to confirm the level and type of atresia (e.g., web, diaphragm, or complete discontinuity) and assess for associated malrotation
-Chromosomal analysis: indicated due to the high association with trisomy 21
-Echocardiography and other imaging: to screen for associated anomalies.
Differential Diagnosis:
-Pyloric stenosis (bilious vomiting, usually later onset, olive-like mass)
-Malrotation with duodenal obstruction (bilious vomiting, usually associated with volvulus)
-Jejunal atresia (usually more distal obstruction, bilious vomiting, significant abdominal distension)
-Gastric outlet obstruction
-Congenital duodenal diaphragm or web.

Management

Initial Management:
-Immediate resuscitation with intravenous fluids to correct dehydration and electrolyte imbalances
-Nasogastric (NG) tube decompression to drain gastric contents and reduce distension
-Broad-spectrum antibiotics initiated if sepsis is suspected
-Correction of any coagulopathy.
Surgical Management:
-Surgical repair is indicated for all cases of confirmed duodenal atresia
-The preferred procedure is typically a diamond duodenoduodenostomy or a similar side-to-side anastomosis
-This involves creating a window between the dilated proximal duodenum and the decompressed distal duodenum
-The goal is to restore gastrointestinal continuity and allow passage of contents
-Some cases of duodenal web or diaphragm may be managed with less extensive resection and reconstruction.
Operative Technique Diamond Duodenoduodenostomy:
-A transverse incision is made in the anterior wall of the dilated proximal duodenum and a corresponding incision in the distal duodenum
-These incisions are extended obliquely to create a diamond-shaped opening
-The mucosa of both segments is then approximated and sutured using absorbable or non-absorbable sutures, creating a wide, patent anastomosis
-Care is taken to ensure adequate mobilization and avoid tension on the anastomosis
-The integrity of the anastomosis is tested with saline irrigation.
Postoperative Care:
-Continued NG tube decompression until bowel motility returns (indicated by bowel sounds and passage of flatus/stool)
-Gradual reintroduction of enteral feeds, starting with clear fluids and advancing slowly
-Monitor for signs of anastomotic leak, sepsis, or obstruction
-Strict fluid and electrolyte monitoring
-Pain management
-Early mobilization if appropriate
-Nutritional support may be required via parenteral nutrition until full enteral feeds are tolerated.

Complications

Early Complications:
-Anastomotic leak: the most serious complication, leading to peritonitis and sepsis
-Wound infection
-Sepsis
-Recurrent obstruction due to stenosis at the anastomosis or intussusception
-Ileus
-Bleeding at the anastomosis.
Late Complications:
-Stricture formation at the anastomosis
-Malabsorption
-Chronic abdominal pain
-Intermittent intestinal obstruction
-Gastroparesis.
Prevention Strategies:
-Meticulous surgical technique with tension-free anastomosis
-Adequate decompression of the proximal bowel
-Careful handling of tissues
-Judicious use of sutures
-Aggressive postoperative monitoring for early detection of leaks
-Early mobilization and gradual feeding advancement.

Prognosis

Factors Affecting Prognosis:
-The presence and severity of associated anomalies (especially Down syndrome and cardiac defects)
-Gestational age and birth weight
-Presence of prematurity
-Promptness of diagnosis and treatment
-Development of complications such as anastomotic leak or sepsis.
Outcomes:
-With prompt diagnosis and surgical repair, the prognosis is generally good
-Survival rates are high, especially in infants without significant associated anomalies
-Infants with Down syndrome may have a slightly higher morbidity and mortality due to co-existing conditions
-Long-term outcome depends on the successful management of any associated conditions and the absence of significant anastomotic complications.
Follow Up:
-Regular follow-up in a pediatric surgery clinic is essential
-This includes monitoring for growth and development, assessing nutritional status, and screening for any signs of recurrent obstruction or malabsorption
-Long-term follow-up may involve gastroenterologists
-Parents should be educated on warning signs requiring immediate medical attention.

Key Points

Exam Focus:
-The "double bubble" sign on plain radiography is pathognomonic for duodenal atresia/obstruction
-High association with Down syndrome
-Diamond duodenoduodenostomy is a common surgical repair technique
-Non-bilious projectile vomiting is a hallmark symptom
-NG tube decompression is crucial pre-operatively.
Clinical Pearls:
-Always consider malrotation in any infant with duodenal obstruction, even if the initial UGI series is negative, as volvulus can occur later
-Thorough postnatal assessment for associated anomalies is critical
-Postoperative vigilance for anastomotic leak cannot be overstated.
Common Mistakes:
-Delaying surgical intervention due to misdiagnosis or parental concerns
-Inadequate decompression of the proximal bowel pre-operatively
-Performing an anastomosis under tension
-Failing to adequately screen for or manage associated anomalies
-Inappropriate or delayed reintroduction of feeds post-operatively.