Pediatric Duodenal Atresia and Stenosis Surgery 

The first two recorded cases of duodenal atresia were described by Calder in 1733. The first successfully treated case was reported by Vidal in 1905; a gastrojejunostomy was performed. In 1914, Ernest performed the first successful duodenojejunostomy in an infant with duodenal atresia. Current surgical management more commonly includes duodenoduodenostomy and duodenoplasty.

Fonkalsrud et al reviewed 503 cases of congenital duodenal obstruction treated between 1957 and 1967.[1] Of patients who were surgically treated, 64% survived. Deaths were attributed to associated malformations, respiratory complications, prematurity, and anastomotic complications.

Subsequent survival rates for infants born with duodenal atresia or stenosis have been in the range of 90-95%.[2, 3] Improved survival rates can be attributed to advances in respiratory care, hyperalimentation, improved pediatric anesthesia, improvements in the recognition and management of associated anomalies, and more refined surgical techniques (eg, the diamond-shaped anastomosis[4] ).

Duodenal atresia or stenosis usually occurs in the first or second part of the duodenum, most often near the papilla of Vater. The common bile duct (CBD) may open into an intraluminal mucosal web.

The three anatomic types of duodenal atresia, as described by Gray and Skandalakis, are as follows (see the image below):

• Type 1 (most common type) - A membrane composed of mucosa and submucosa traverses the internal diameter of the duodenum; the duodenum and stomach proximal to the obstruction are dilated and hypertrophied, and the duodenum distal to the obstruction is narrowed; a variation of this occurs when the membrane is elongated in the shape of a windsock, and the site of origin of the membrane is proximal to the level of obstruction
• Type 2 - The atretic ends of the duodenum are connected by a fibrous cord.
• Type 3 - Complete separation of the atretic segments occurs; most of the biliary duct anomalies associated with duodenal atresia are observed in type 3 defects ^[5]

Three anatomic types of duodenal atresia are recognized. In type 1 atresia, a membrane traverses the internal diameter of the duodenum. This membrane may be elongated, giving rise to the windsock type 1 duodenal atresia. In type 2 atresia, the atretic ends of the duodenum are connected by a fibrous cord. In type 3 atresia, the atretic segments are completely separated.

Various biliary tract and pancreatic anomalies have been demonstrated in patients with duodenal atresia or stenosis. These include stenosis and duplication of the distal CBD, choledochal cysts, and annular pancreas. Air in the distal duodenum and gallbladder on plain radiography is suggestive of a bifid CBD. Double duodenal atresia or stenosis is less frequently reported.[6]

In 1900, Tandler described the traditionally accepted theory on the normal development of the duodenum.[7] The duodenum develops from the caudal part of the foregut and the cranial part of the midgut. At 4 weeks' gestation, it consists of an epithelial tube surrounded by mesenchyme. At 5-6 weeks' gestation, the epithelium proliferates while the surrounding mesenchymal walls are still narrow; the epithelial cells fill the lumen, completely obliterating it.

Subsequent epithelial apoptosis at 8-10 weeks' gestation leads to vacuolation and recanalization of the duodenum. Failure of vacuolation may lead to intrinsic duodenal obstruction.

Most cases of duodenal atresia are sporadic. Investigations of familial cases of duodenal atresia suggest an autosomal recessive inheritance in these individuals.[1, 8]

The incidence of duodenal atresia is 1 case per 5000-10,000 live births.

Survival rates for infants with duodenal atresia or stenosis range from 90% to 95%. Higher mortality figures are associated with prematurity and multiple congenital abnormalities.

Postoperative complications are reported in 14-18% of patients; some necessitate reoperation.[2] Possible indications for reoperation include anastomotic leak, functional duodenal obstruction, adhesions, and missed atresias.

Long-term follow-up of these patients reveals that most of these patients are asymptomatic with a normal nutritional status. In a 1988 study, Kokkonen et al found a poor correlation between symptoms and radiologic and endoscopic findings; the megaduodenum failed to return to normal caliber, and duodenogastric reflux and duodenal dysmotility persisted decades after the initial surgery in asymptomatic patients.[9]

Approximately 12% of patients develop late complications. Late deaths occur in approximately 6% of patients, and 50% of these are related to complex cardiac conditions. Fewer than 10% of patients require fundoplication for gastroesophageal reflux, and fewer than 10% require revision of the initial repair.[10]

Dysmotility disorders associated with megaduodenum can be managed with an antimesenteric tapering duodenoplasty or duodenal plication.

In 38-55% of patients, intrinsic duodenal obstruction is associated with another significant congenital anomaly.[1, 11, 12, 13] Approximately 30% of cases are associated with Down syndrome, and 23-34% of cases are associated with isolated cardiac defects. Esophageal atresia may be present in 7-12% of patients.[14] Other gastrointestinal anomalies include the following:

• Malrotation
• Anterior portal vein
• Second distal web
• Anorectal anomalies ^[15]
• Intestinal atresias
• Cloacal anomalies
• Renal tract anomalies

Duodenal atresia is associated with prematurity and low birth weight.[16, 12] Rarely, duodenal atresia is seen as a part of Feingold syndrome.[17]

Duodenal atresia

Duodenal atresia is detected antenatally in 32-57% of patients.[11, 18] Sonographic features of high intestinal obstruction (ie, duodenal obstruction with a dilated stomach [double-bubble sign]) become apparent in the third trimester. Polyhydramnios develops in 32-59% of cases; in the presence of polyhydramnios, normal findings on ultrasonography of the fetus do not exclude duodenal atresia.[19, 11, 5] A similar appearance can be observed in fetuses with a choledochal cyst, external duodenal compression, and a normal stomach with a sharp incisura. Approximately 80% of cases are diagnosed antenatally, with confirmation following delivery.[18]

Antenatal diagnosis of duodenal atresia should lead to a search for other associated anomalies and amniocentesis for karyotype analysis.

After delivery, a thorough physical examination should be performed, including careful examination of the anus.

Healthy newborn infants have gastric aspirates that measure less than 5 mL. Congenital intestinal obstruction is associated with gastric aspirates that measure more than 30 mL.[20] An infant with a gastric aspirate larger than 30 mL in the delivery room or newborn nursery should be evaluated for duodenal atresia and other causes of upper intestinal obstruction.

Symptoms of upper intestinal obstruction commence within the first 24 hours after birth. However, patients may present hours or days after delivery. Sustained vomiting (bilious or nonbilious) is the most common symptom, occurring in approximately 85% of cases.[2, 1, 3] Nonbilious vomiting occurs when atresia is present above the papilla of Vater. Vomiting is associated with variable dehydration, changes in serum electrolytes, and weight loss.

Normal meconium may be observed in the early stages.[19, 3] The high level of the obstruction makes global abdominal distention an infrequent finding, but fullness in the epigastrium, caused by the dilated duodenum and stomach, may be noted.

Differentials include malrotation and volvulus, intestinal atresia or stenosis in other locations, and extrinsic duodenal obstruction, duodenal duplication, or congenital bands.

Duodenal stenosis

The incomplete nature of the obstruction in duodenal stenosis results in a variable and often delayed presentation. It usually results in recurrent episodes of vomiting, aspiration, or failure to thrive. Some patients present in adulthood with gastroesophageal reflux, peptic ulceration, or obstruction of the duodenum proximal to the stenosis by a bezoar.

The following studies are commonly ordered:

• Serum electrolytes - Infants with duodenal atresia have large gastric aspirates; consequently, duodenal atresia is associated with loss of fluid and electrolytes secreted by the stomach and, in 85% of cases, pancreatic and biliary fluid
• Hematocrit - The hematocrit gives an indication of the oxygen-carrying capacity of the neonate before general anesthesia and surgery
• Karyotype analysis - Duodenal atresia is associated with trisomy 21 in 30% of cases ^[21]
• Blood glucose - Duodenal atresia is associated with premature onset of labor; the premature infant has limited glycogen supplies and is more likely to become hypoglycemic
• Blood type and cross-match

Radiography

Plain abdominal radiography usually reveals a dilated stomach, a dilated first part of duodenum (double bubble),[22] and absence of air beyond the second air bubble. Aspiration of the stomach contents followed by gentle air insufflation makes the double-bubble sign more apparent (see the image below).

This is a radiograph of a 1-day-old infant presenting with duodenal atresia. Note the distended stomach and first part of the duodenum and the absence of air distal to the duodenal bubble.

If a scattered small amount of air is observed distal to the obstruction, duodenal stenosis may be present or other causes of partial intestinal obstruction may exist. Occasionally, air may be seen distally when duodenal atresia is associated with a biliary communication between proximal and distal segments.[23] However, malrotation with volvulus is the leading diagnosis until proven otherwise.

An upper gastrointestinal contrast study should be performed. This is useful in making the diagnosis of duodenal stenosis, malrotation or volvulus, annular pancreas, duodenal duplications, and duodenal webs.

Ultrasonography

Echocardiography should be performed. Common cardiac defects include endocardial cushion defects and patent ductus arteriosus (PDA).

Abdominal/renal ultrasonography is useful in detecting renal anomalies and an annular pancreas.

Rectal biopsy findings exclude Hirschsprung disease in patients with intrinsic duodenal obstruction and Down syndrome.

Immunohistochemistry of proximal and distal duodenal samples of neonates with duodenal atresia demonstrated a decrease in the number and size of neuronal cells, decreased number of interstitial cells of Cajal, and hypertrophy of the circular muscles. These findings may help to explain persistent duodenal dysmotility seen in some patients long after their primary repair.[24]

The definitive management of patients with intrinsic duodenal obstruction is surgical correction. In a patient with associated tracheoesophageal fistula, ligation of the fistula should precede correction of the duodenal atresia. This can be performed on two occasions or simultaneously. Repair of the atresia before ligation of the tracheoesophageal fistula could lead to duodenal rupture.

Duodenal webs can be diagnosed and excised by an expert surgical endoscopist. This is feasible in patients who present after the neonatal period with duodenal stenosis. The morbidity and complications associated with a megaduodenum may require further surgical intervention.

Transanastomotic feeding tubes or gastrostomies were used in the past but have been demonstrated to offer no clear advantage; instead, they result in a delay in establishing oral feedings and an increase in the duration of hospitalization.[25, 3, 26]

Soutter and Askew reported successful results with a transumbilical approach to duodenal atresia.[27]

Operative management of duodenal atresia is determined by the anatomic findings and associated anomalies noted upon laparotomy. Bypass procedures for duodenal atresia or stenosis include duodenoduodenostomy and duodenojejunostomy. Although many surgeons prefer the former for duodenal atresia, there is evidence to suggest that the two procedures have similar outcomes.[28] Type 1 duodenal atresia can also be managed by performing a simple duodenotomy with web excision.

Preparation for surgery

Orogastric decompression of the stomach and fluid resuscitation should be promptly initiated. Orogastric losses are monitored and replaced. Broad-spectrum antibiotics and 1 mg vitamin K are administered. Parenteral nutrition is instituted on the first day of life via a peripherally inserted central catheter. When stable, the infant is taken to the operating room.

Operative details

Once precautions have been taken against hypothermia, the abdomen is entered via a transverse right upper quadrant incision. The stomach and first part of the duodenum are usually dilated and thickened and must be decompressed via the orogastric tube.

The gallbladder and spleen are examined. The viscera are examined for other anomalies, including malrotation, an anterior portal vein, and an annular pancreas. The liver is padded and gently retracted superiorly. The duodenum is mobilized via the Kocher maneuver.

The site of obstruction is detected by noting the discrepancy in the size of the bowel above and below the obstruction and by passing the orogastric tube down to the level of the obstruction. In patients with a windsock web, an indentation at a site proximal to the site of obstruction may be observed. This marks the site of origin of the web and the location where the duodenotomy should be made.

The duodenotomy is made, and the papilla of Vater is identified by gently pressing on the gallbladder and observing the proximal and distal segments. In patients with type 3 defects, dual biliary ducts may be present.

Once it has been confirmed that no distal obstruction is present, a proximal transverse–to–distal longitudinal (diamond-shaped) anastomosis may be created with interrupted stitches. A direct duodenoduodenostomy is believed to result in a earlier recovery of anastomotic function than a duodenojejunostomy.[11]

During the diamond-shaped anastomosis, the midpoint of the proximal incision is approximated to the end of the distal incision.[4] This creates a larger stoma and allows the proximal duodenum to overlie the distal duodenum. (See the image below.) As an alternative, a standard side-to-side duodenoduodenostomy may be performed.

During the diamond-shaped anastomosis, a proximal transverse to distal longitudinal anastomosis is performed; the midpoint of the proximal incision is approximated to the end of the distal incision.

Alternatively, type 1 defects may be treated by excising the web. An anterior duodenotomy is performed, and the web is opened along the lateral side. The web is carefully excised, leaving the medial portion containing the papilla in situ.

When the proximal duodenum is floppy and dilated, an antimesenteric duodenoplasty may be performed either by excising excess tissue or by plicating the anterior wall with interrupted sutures or a stapling device over a dilator. This is believed to decrease the complications of a megaduodenum.[29]

If an annular pancreas is present, it should not be divided. The anastomosis is formed anterior to the pancreatic mass.

If a preduodenal portal vein is identified, it should not be divided.  The anastomosis is formed anterior to the vein.

In patients with malrotation, a Ladd procedure is performed; Ladd peritoneal bands are divided, the small bowel mesentery is widened, an appendectomy is performed, and the cecum and colon are placed on the left.

Laparoscopic approaches

Several reports and case series have looked at short-term outcome for laparoscopic duodenoduodenostomy.[30, 31] The basic principles described above for the open technique are carried out; however, this procedure requires advanced laparoscopic skills. This approach is facilitated by the use of 3-mm short instruments, better visualization at laparoscopy, the use of nitinol U-clips (Medtronic Surgical, Minneapolis, MN), and the decompressed distal bowel associated with the atresia.

Theoretically, assessment of the distal bowel for associated atresias is more difficult; however, there are no reports of missed distal atresias using the laparoscopic approach. Long-term outcomes and the ease with which other pediatric surgeons adopt this approach will determine how widely available laparoscopic duodenoduodenostomy becomes in the future. Laparoscopic duodenojejunostomy has also been performed.[32]

In a small single-center series (N=29), Parmentier et al compared laparoscopic repair (n=10) with laparotomy repair (n=19) for treatment of congenital duodenal atresia or stenosis.[32] They found laparoscopy to be safe and reproducible in this setting and to yield outcomes comparable to those of laparotomy. Laparoscopy was not associated reductions in time to full oral intake or length of stay.

Cho et al found laparoscopic duodenoduodenostomy to be comparable to to the equivalent open procedure for repair of congenital duodenal obstruction (duodenal atresia, stenosis, or web or annular pancreas) in neonates, though operating time was longer for the former.[33]  A single-center study by Son et al found that laparoscopic surgical treatment of neonatal congenital duodenal obstruction was associated with lower postoperative morbidity, shorter recovery time, reduced postoperative hospital stay, and better postoperative cosmesis than laparotomy.[34]

The orogastric tube is left on free drainage. The patient is not given oral feedings until bowel sounds are heard, stool is passed, and the gastric drainage is limited (< 1 mL/kg/hr of clear or pale-green fluid). This may take 7-10 days but can be prolonged in the premature infant with other significant anomalies that necessitate venous access for parenteral nutrition. Patients with marked delay in establishing enteral feeding and delayed initiation of parenteral nutrition may show poor weight gain over long periods and increased sepsis.[35]

Oral feedings are gradually introduced, commencing with clear fluids and aspirating the stomach prior to each feed. These infants can be placed in a right-side-down position after feeds to enhance gastroduodenal emptying. Some surgeons choose to interrogate the anastomosis between postoperative days 5 and 7 by performing a limited upper contrast study before initiating feeds.

Early postoperative complications are frequently related to prematurity, coexisting congenital anomalies, and parenteral nutrition. Intestinal obstruction secondary to adhesions may also occur in the early postoperative period.

Long-term complications occur at any time from a few months to years after the primary procedure. Hence, long-term follow-up is compulsory for infants treated for intrinsic duodenal obstruction (see Long-Term Monitoring).

Late complications include the following[29, 9, 36] :

• Duodenal dysmotility
• Megaduodenum with blind loop syndrome
• Duodenogastric reflux and gastritis
• Peptic ulcer disease
• Gastroesophageal reflux
• Cholelithiasis
• Cholecystitis

Poor peristalsis in the proximal duodenum leads to functional obstruction in some patients. This may predispose the patient to blind loop syndrome and duodenogastric reflux. Alkaline biliary reflux leads to gastritis and peptic ulceration.

Reports of functional obstructions occurring more than 20 years after primary repair suggest that survivors of duodenal atresia should receive the following long-term follow-up care:

• Clinical examination - Special attention is paid to the abdominal examination and the nutritional status of the patient
• Radiologic examination - A barium meal may demonstrate a mildly dilated duodenum, megaduodenum, delayed emptying, diminished peristalsis, slight luminal narrowing, or bezoars
• Endoscopy - Findings on esophagogastroduodenoscopy may include esophageal irritation, reflux gastritis, megaduodenum, or delayed emptying