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Intestinal Atresia, Stenosis, and Webs
Updated: May 11, 2009
Duodenal Stenosis and Atresia
Embryology
The hepatobiliary system and pancreas form during the third week of gestation, as the second portion of the duodenum gives rise to biliary and pancreatic buds at the junction of the foregut to the midgut. The duodenum also undergoes a solid phase during this time; between 8-10 weeks' gestation, the duodenal lumen is reestablished by the gathering of vacuoles, and recanalization occurs. Insults during this crucial period of development are believed to result in failure of recanalization and consequent atresias, stenoses, and webs. In addition, duodenal atresias have been associated with a closely surrounding piece of pancreatic tissue. Whether this tissue is an annular pancreas or merely a failure of duodenal development is debatable.1,2
Classification
A stenosis is an incomplete obstruction with a small opening secondary to a diaphragm or web, whereas an atresia is a complete obstruction. Unlike other intestinal atresias, duodenal atresias are associated with other congenital anomalies. Approximately 50% of patients with duodenal atresias have some form of anomaly (eg, cardiac, anorectal, genitourinary), and as many as 40% have trisomy 21.3,4,5 Esophageal atresia and the VATER (ie, vertebral defects, anal atresia, tracheoesophageal fistula with esophageal atresia, and renal and radial anomalies) syndrome have also been associated with duodenal atresia.6 Hence, all neonates with duodenal atresia should be assessed for concomitant malformations. Growth retardation and polyhydramnios are often present prenatally.
Anatomically, most congenital duodenal obstructions are considered periampullary, with the biliary outlet occurring proximal or distal to the site of obstruction. The degree of obstruction dictates the amount of resulting pathology. The obstruction causes dilation of the proximal duodenum and stomach as well as hypertrophy and distension of the pylorus. A common variation is the windsock anomaly, in which the duodenum is dilated distal to the point of obstruction because of a prolapsing membrane or web (see Media file 1). This may be confused with a more distal duodenal obstruction.
Duodenal web windsock deformity.
Diagnosis
Prenatal ultrasonography may indicate structural and associated abnormalities, such as a dilated stomach and proximal duodenum. Polyhydramnios is suggestive of a proximal GI tract obstruction because the fetus is unable to swallow the amniotic fluid. Common associated anomalies and chromosomal defects may be assessed by screening maternal serum and amniotic fluid.
In the newborn, clear or bilious emesis is evident within hours of birth, with or without abdominal distension. An output of more than 20 mL of gastric contents is indicative of possible obstruction.7 Because of incomplete obstruction, patients with a stenosis or web may present later with dehydration or failure to thrive.
Plain radiography is helpful and may reveal the classic double bubble sign, representing air in the stomach and proximal duodenum, which is associated with complete or near complete duodenal obstruction. Upright and contrast radiography using air or contrast may confirm the diagnosis (see Media files 2-3). Malrotation with volvulus may also result in duodenal obstruction with a double-bubble sign and can coexist with duodenal atresia in as many as 30% of cases.8
A contrast study illustrating duodenal stenosis.
Plain radiograph of duodenal stenosis.
Treatment
Gastric decompression is essential to prevent aspiration, and thermoregulation should be monitored at all times. Unless malrotation with volvulus remains a concern, preoperative assessment of other associated anomalies should be performed. When fluid resuscitation and a full assessment have been accomplished, the neonate may proceed to surgery.
Two basic options for repair of duodenal obstruction secondary to a web or atresia are noted: duodenoduodenostomy and duodenotomy with excision of the web. The most common repair is a duodenoduodenostomy. The classic approach is through a supraumbilical transverse abdominal incision that provides adequate exposure of the duodenum once the ascending and transverse colon are mobilized to the left. A catheter is inserted through the stomach to help define the site of obstruction. In addition, the entire small bowel is carefully explored for other sites of obstruction. Care is taken to examine the gallbladder to ensure that a preduodenal portal vein is not evident and to locate the ampulla of Vater to avoid inadvertent injury. Recently, laparoscopy has also been shown to be a safe and effective approach to repair of congenital duodenal obstruction.9
The proximal duodenum is usually dilated, compared with the thin-walled and flat distal duodenum and jejunum. A diamond-shaped anastomosis may be fashioned between a longitudinal incision made in the distal collapsed end of the duodenum and a transverse incision made in the inferior aspect of the bulbous blind ended proximal duodenum. In the laparoscopic approach, U-clips are used to fashion the duodenoduodenostomy.9 Additionally, tapering of the proximal duodenum is sometimes performed by plicating its lateral antimesenteric side. A Ladd procedure is warranted if malrotation is present.
If a web is present, a duodenotomy with excision of the web may be performed instead of a duodenoduodenostomy. The web should be defined with the aid of a tube through the stomach, and the ampulla of Vater should be carefully identified prior to excision. A longitudinal incision is then made directly on the web, and the web is excised. The duodenum is then closed transversely, to avoid narrowing.
Feeding may be started when GI function is established. In some patients, this may take up to 2 weeks. Gastric decompression with nasogastric tube is required until that time.
Outcome
An anastomotic leak, injury to the bile duct, and sepsis are early complications. Late complications include peptic ulceration secondary to alkaline reflux, blind-loop syndrome due to duodenal stasis, and recurrent obstruction.10,11,12 In one series, as many as 12% of patients had late complications requiring reoperation for a number of reasons, including reflux and peptic ulcer disease, associated biliary abnormalities, and bowel obstruction.8
The prognosis is good for patients with a repaired duodenal stenosis or atresia; however, coexisting diagnoses, such as Down syndrome and cardiac anomalies, affect the outcome.13 Recent long-term data demonstrated that a 9% combined early and late mortality rate over an average 6-year follow-up period was due almost exclusively to associated congenital anomalies.8 In addition, birth weight has been shown to be a predictor of mortality. Infants with duodenal atresia who weigh less than 2 kg at birth have poorer survival, regardless of the presence of other congenital abnormalities.14
Jejunoileal Stenosis and Atresia
Etiology
Multiple theories regarding the etiology of jejunoileal atresias have been studied in many animal models, including puppies, ewes, rabbits, and chick embryos.15,16,17,18,19 Studies in mouse models suggest that some forms of atresia may be hereditary and result from dysregulation of proliferation and apoptosis of the developing intestine through the fibroblast growth factor pathways.20 To date, the most accepted theory regarding the etiology of jejunoileal atresia is that of an intrauterine vascular accident resulting in necrosis of the affected segment, with subsequent resorption.4,16
Classification
The 2 broad categories of jejunoileal defects are stenoses and atresias. A stenosis has an intact mesentery and is a localized narrowing of the bowel. No loss of continuity of the lumen exists, and the stenotic portion generally has an irregular muscularis and thickened submucosa. Four types of jejunoileal atresias are described.4,16,21 The different types represent a spectrum of severity, from a simple web to full atresia with loss of bowel length. This classification system generally guides prognosis and therapy (see Media file 4).
This illustration shows the classification system of jejunoileal atresias.
Atresias
- Type I: In type I atresias, the mucosa and submucosa form a web or intraluminal diaphragm, resulting in obstruction. As in duodenal webs, a windsock effect may be evident secondary to an increase in intraluminal pressure in the proximal bowel causing a prolapse of a portion of the web into the distal part of the bowel. A mesenteric defect is not present, and the bowel length is not affected.
- Type II: The mesentery is intact in type II atresias; however, the bowel is not joined. The dilated proximal portion has a bulbous blind end connected by a fibrous cord to the blind end of the distal flattened bowel. The overall length of the small bowel is not usually shortened.
- Type IIIa: The defect in type IIIa is similar to that in type II in that both types have blind proximal and distal ends; however, in type IIIa, no bridging fibrous cord is present, and a V-shaped mesenteric defect is present. The proximal blind end is usually markedly dilated and aperistaltic. The intervening bowel has undergone intrauterine resorption, and, as a result, the bowel in this category is variably shortened.
- Type IIIb: In addition to a large defect of the mesentery, the bowel is significantly shortened in type IIIb. This lesion is also known as a Christmas tree or apple peel deformity because of the appearance of the bowel as it wraps around a single perfusing vessel.22,23 The distal small bowel receives its blood supply from a single ileocolic or right colic artery because the better part of the superior mesenteric artery is absent. Prematurity, malrotation, and subsequent short bowel syndrome have been linked to this deformity, with increased morbidity and mortality rates.24,25
- Type IV: Type IV involves multiple small-bowel atresias of any combination of types I to III. This defect often takes on the appearance of a string of sausages because of the multiple lesions. The cause is unknown, and theories range from multiple ischemic infarcts, possibly from a more global placental insufficiency, to an early embryologic defect of the GI tract, to an inflammatory process occurring in utero.19,21,26
Diagnosis
Prenatal diagnosis of jejunoileal lesions by means of ultrasonography and prenatal screening is possible. Whereas associated anomalies are found in 30-40% of neonates with duodenal atresias, associated anomalies are found in only 10% of neonates with jejunoileal atresias.6
Stenosis in a neonate is difficult to diagnose and it may not manifest for some time. The clinical presentation is dependent on the severity of disease, and these patients have a history of intermittent emesis and failure to thrive. An upper GI with small-bowel follow-through is indicated in these patients.
Clinically, neonates with a proximal atresia develop bilious emesis within hours, whereas patients with more distal lesions may take longer to begin vomiting. A normal or scaphoidlike abdomen in a neonate with bilious emesis should be considered indicative of a proximal obstruction until proven otherwise. Abdominal distension is more pronounced with distal lesions.
Radiography is helpful to confirm the diagnosis. With more proximal atresias, few air-fluid levels are evident with no apparent gas in the lower part of the abdomen. The more distal lesions demonstrate more air-fluid levels, although the distal intestine remains gasless (see Media file 5). Although a plain radiograph can depict the presence of an obstruction, it is not the best method of showing the location of the abnormality. A barium enema may be used to define a microcolon indicative of a distal small-bowel obstruction; it is also capable of establishing the diagnosis of other causes of lower obstruction, such as Hirschsprung disease or a meconium plug. The contrast enema may also reflux into the small bowel and help define the level of a distal obstruction (see Media files 6-7).
Plain radiograph demonstrating jejunal atresia.
Contrast study of jejunal atresia.
Stenosis in a neonate is more difficult to diagnose, and it may not manifest for some time. The clinical presentation is dependent on the severity of disease, and these patients have a history of intermittent emesis and failure to thrive. An upper GI with small-bowel follow-through is indicated in these patients.
Treatment
Preoperative care should be the same as that described for repair of duodenal lesions. Once the diagnosis is made, the patient should be fully resuscitated before surgical correction is attempted unless a perforation or volvulus is suspected. Gastric decompression, fluid resuscitation, and thermoregulation are essential. Preoperative antibiotics should be administered.
In the operating room, a transverse supraumbilical incision affords adequate exposure of the abdominal contents. The full length of the bowel is manually explored for malrotation, other atresias, or stenoses; care is taken to keep the bowel moist and protected at all times. Malrotation should be treated with a Ladd procedure. The length of intestine that appears functional is measured along the antimesenteric border because bowel length affects the procedure and overall prognosis. Sodium chloride solution is injected into the distal bowel and followed closely to the cecum to ensure patency. The same is done for the colon.
Once patency of the entire length of the bowel is established, the repair may proceed. The dilated proximal bulb generally does not have normal function and, as a result, should be resected up to a more suitable size to avoid problems with abnormal peristalsis postoperatively. If the bowel length is limited, a tapering enteroplasty should be considered rather than resection. An end-to-end anastomosis can then be performed (see Media file 8). A new technique, serial transverse enteroplasty, has been used to both taper and lengthen the bowel in neonates with atresia and shortened bowel.27,28 In addition, in the specific case of type IV atresia with minimal remnant bowel, creative techniques such as stenting of multiple bowel segments has been performed with some success.29
Jejunal atresia after end-to-end anastomosis.
Postoperatively, gastric drainage should continue until the return of bowel function. Total parenteral nutrition (TPN) should be started shortly after surgery and continued until enteral feeds are tolerated. The baby must be closely monitored after surgery for abdominal girth, vital signs, temperature, fluid status, urine output, gastric drainage, and level of activity.
Outcome
In general, children with atresia do well, postoperatively. Type IIIb atresia, by its nature, has a relatively poor prognosis, although in one long-term series, even these children had a relatively low rate of late morbidity.30 As with duodenal atresias, mortality is primarily associated with the presence of other congenital anomalies, and birth weight.14 Dysmotility of the remnant bowel near sites of atresia does occur, as mentioned above, and may be related to a dysgenesis of enteric neuronal structures.31 If the bulbous portions of atretic bowel are not resected because of limited bowel length, this dysmotility can cause late complications of stasis, bacterial overgrowth, and feeding intolerance.
The overall prognosis for patients with jejunoileal atresia is dependent upon the amount of residual functional bowel that exists after surgery. In general, 40 cm of functional small bowel is considered adequate, even without an ileocecal valve; however, neonates with as little as 10 cm of small bowel have been successfully weaned from parenteral nutrition.32 Children with jejunoileal atresias take longer to reach full enteral nutrition than those with either duodenal or colonic atresias, with an average time to enteral autonomy of greater than 2 weeks.14 These neonates with intestinal inadequacy require careful follow-up care with surgeons, pediatric gastroenterologists, and dietitians to optimize results.
Colonic Atresia
Etiology and classification
Similar to jejunoileal atresia, colonic atresia (see Media files 9-10) is believed to be caused by an in utero vascular accident resulting in ischemic injury, likely after the midgut has returned to the coelomic cavity. Some animal evidence is noted, as discussed above, that ties colonic atresia to a heritable defect in the FGF regulatory pathway.20,33 Colonic atresia is the least common and comprises 1.8-15% of all intestinal atresias and stenoses.34,35 Atresias may occur throughout the colon; however, lesions proximal to the splenic flexure and distal to the vascular watershed area are the most common.34 Colonic atresias are frequently associated with other anomalies, including jejunoileal atresia, Hirschsprung disease, and genitourinary malformations. They can generally be classified in the same fashion as small intestinal atresias.
Contrast study of colonic atresia.
Gross example of colonic atresia.
Diagnosis
Prenatal ultrasonography may detect a colon larger than that expected for gestational age in patients with colonic atresia.36 Diagnosis after birth is usually timely because the newborn demonstrates signs of distal bowel obstruction. Abdominal distension is prominent in the first 24 hours, and the hugely dilated proximal loop is often palpable. Radiographs depict a large loop of bowel with proximal air-fluid levels. A contrast enema can provide a definitive diagnosis and provide anatomic information about the location of the lesion (see Media file 11). This study can usually be used to differentiate colonic atresia from meconium ileus, Hirschsprung disease, and other intestinal atresias.
Gross example of colonic atresia.
Treatment
Treatment depends on the extent and location of the lesion and the clinical presentation of the patient. Care should be taken to avoid perforation secondary to severe distension. A staged procedure beginning with resection of the affected portion and colostomy with mucous fistula is generally the preferred initial treatment of choice because of the extreme dilation of the proximal colon. Ileocolic or colocolic anastomosis should be performed as a second procedure. In addition, care must be taken to rule out other anomalies, including multiple atresias and Hirschsprung disease.37
Outcome
Outcome is dependent on associated anomalies, including small-bowel atresias and birth weight.14 The prognosis is generally good.
Multimedia
 | Media file 1: Duodenal web windsock deformity. |
 | Media file 2: A contrast study illustrating duodenal stenosis. |
 | Media file 3: Plain radiograph of duodenal stenosis. |
 | Media file 4: This illustration shows the classification system of jejunoileal atresias. |
 | Media file 5: Plain radiograph demonstrating jejunal atresia. |
 | Media file 6: Contrast study of jejunal atresia. |
 | Media file 7: Contrast study of jejunal atresia. |
 | Media file 8: Jejunal atresia after end-to-end anastomosis. |
 | Media file 9: Contrast study of colonic atresia. |
 | Media file 10: Gross example of colonic atresia. |
 | Media file 11: Gross example of colonic atresia. |
Keywords
intestinal atresia, stenosis, webs, duodenal atresia, duodenal stenosis, duodenal obstruction, jejunoileal atresia, jejunoileal stenosis, jejunoileal lesion, colonic atresia, annular pancreas, esophageal atresia, growth retardation, polyhydramnios, dehydration, failure to thrive, Down syndrome, peptic ulcer disease, prematurity, malrotation, short bowel syndrome, Hirschsprung disease, meconium plug
More on Intestinal Atresia, Stenosis, and Webs |
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References
Jackson JM. Annular pancreas and duodenal obstruction in the neonate: a review. Arch Surg. Sep 1963;87:379-83. [Medline].
Elliott GB, Kliman MR, Elliott KA. Pancreatic annulus: a sign or a cause of duodenal obstruction?. Can J Surg. Jul 1968;11(3):357-64. [Medline].
Grosfeld JL, Rescorla FJ. Duodenal atresia and stenosis: reassessment of treatment and outcome based on antenatal diagnosis, pathologic variance, and long-term follow-up. World J Surg. May-Jun 1993;17(3):301-9. [Medline].
Louw JH. Congenital intestinal atresia and stenosis in the newborn. Observations on its pathogenesis and treatment. Ann R Coll Surg Engl. Nov 1959;25:209-34. [Medline].
Bodian M, White LL, Carter CO, Louw JH. Congenital duodenal obstruction and mongolism. Br Med J. Jan 12 1952;1(4749):77-9. [Medline].
Touloukian RJ. Intestinal Atresia and Stenosis. In: Raffensperger JG, ed. Pediatric Surgery. 2nd ed. Norwalk, CT: Appleton and Lange; 1993:305-19.
Britton JR, Britton HL. Gastric aspirate volume at birth as an indicator of congenital intestinal obstruction. Acta Paediatr. Aug 1995;84(8):945-6. [Medline].
Escobar MA, Ladd AP, Grosfeld JL, et al. Duodenal atresia and stenosis: long-term follow-up over 30 years. J Pediatr Surg. Jun 2004;39(6):867-71; discussion 867-71. [Medline].
Spilde TL, St Peter SD, Keckler SJ, Holcomb GW 3rd, Snyder CL, Ostlie DJ. Open vs laparoscopic repair of congenital duodenal obstructions: a concurrent series. J Pediatr Surg. Jun 2008;43(6):1002-5. [Medline].
Kokkonen ML, Kalima T, Jaaskelainen J, Louhimo I. Duodenal atresia: late follow-up. J Pediatr Surg. Mar 1988;23(3):216-20. [Medline].
Ein SH, Shandling B. The late nonfunctioning duodenal atresia repair. J Pediatr Surg. Sep 1986;21(9):798-801. [Medline].
Spigland N, Yazbeck S. Complications associated with surgical treatment of congenital intrinsic duodenal obstruction. J Pediatr Surg. Nov 1990;25(11):1127-30. [Medline].
Dalla Vecchia LK, Grosfeld JL, West KW, et al. Intestinal atresia and stenosis: a 25-year experience with 277 cases. Arch Surg. May 1998;133(5):490-6; discussion 496-7. [Medline].
Piper HG, Alesbury J, Waterford SD, Zurakowski D, Jaksic T. Intestinal atresias: factors affecting clinical outcomes. J Pediatr Surg. Jul 2008;43(7):1244-8. [Medline].
Baglaj SM, Czernik J, Kuryszko J, Kuropka P. Natural history of experimental intestinal atresia: morphologic and ultrastructural study. J Pediatr Surg. Sep 2001;36(9):1428-34. [Medline].
Louw JH, Barnard CN. Congenital intestinal atresia; observations on its origin. Lancet. Nov 19 1955;269(6899):1065-7. [Medline].
Abrams JS. Experimental intestinal atresia. Surgery. Jul 1968;64(1):185-91. [Medline].
Koga Y, Hayashida Y, Ikeda K, et al. Intestinal atresia in fetal dogs produced by localized ligation of mesenteric vessels. J Pediatr Surg. Dec 1975;10(6):949-53. [Medline].
Tsujimoto K, Sherman FE, Ravitch MM. Experimental intestinal atresia in the rabbit fetus. Sequential pathological studies. Johns Hopkins Med J. Oct 1972;131(4):287-97. [Medline].
Fairbanks TJ, Sala FG, Kanard RM, et al. The fibroblast growth factor pathway serves a regulatory role in proliferation and apoptosis in the pathogenesis of intestinal atresia. J Pediatr Surg. Jan 2006;41(1):132-6; discussion 132-6. [Medline].
Martin LW, Zerella JT. Jejunoileal atresia: a proposed classification. J Pediatr Surg. Jun 1976;11(3):399-403. [Medline].
Weitzman JJ, Vanderhoof RS. Jejunal atresia with agenesis of the dorsal mesentery. With "Christmas tree" deformity of the small intestine. Am J Surg. Mar 1966;111(3):443-9. [Medline].
Santulli TV, Blanc WA. Congenital atresia of the intestine: pathogenesis and treatment. Ann Surg. Dec 1961;154:939-48. [Medline].
DeLorimier AA, Fonkalsrud EW, Hays DM. Congenital atresia and stenosis of the jejunum and ileum. Surgery. May 1969;65(5):819-27. [Medline].
Seashore JH, Collins FS, Markowitz RI, Seashore MR. Familial apple peel jejunal atresia: surgical, genetic, and radiographic aspects. Pediatrics. Oct 1987;80(4):540-4. [Medline].
Komuro H, Amagai T, Hori T, et al. Placental vascular compromise in jejunoileal atresia. J Pediatr Surg. Nov 2004;39(11):1701-5. [Medline].
Kim HB, Lee PW, Garza J, Duggan C, Fauza D, Jaksic T. Serial transverse enteroplasty for short bowel syndrome: a case report. J Pediatr Surg. Jun 2003;38(6):881-5. [Medline].
Ismail A, Alkadhi A, Alnagaar O, Khirate A. Serial transverse enteroplasty in intestinal atresia management. J Pediatr Surg. Feb 2005;40(2):E5-6. [Medline].
Alexander F, Babak D, Goske M. Use of intraluminal stents in multiple intestinal atresia. J Pediatr Surg. Nov 2002;37(11):E34. [Medline].
Festen S, Brevoord JC, Goldhoorn GA, et al. Excellent long-term outcome for survivors of apple peel atresia. J Pediatr Surg. Jan 2002;37(1):61-5. [Medline].
Khen N, Jaubert F, Sauvat F, et al. Fetal intestinal obstruction induces alteration of enteric nervous system development in human intestinal atresia. Pediatr Res. Dec 2004;56(6):975-80. [Medline].
Andorsky DJ, Lund DP, Lillehei CW, et al. Nutritional and other postoperative management of neonates with short bowel syndrome correlates with clinical outcomes. J Pediatr. Jul 2001;139(1):27-33. [Medline].
Fairbanks TJ, Kanard RC, De Langhe SP, et al. A genetic mechanism for cecal atresia: the role of the Fgf10 signaling pathway. J Surg Res. Aug 2004;120(2):201-9. [Medline].
Boles ET Jr, Vassy LE, Ralston M. Atresia of the colon. J Pediatr Surg. Feb 1976;11(1):69-75. [Medline].
Benson CD, Lotfi MW, Brogh AJ. Congenital atresia and stenosis of the colon. J Pediatr Surg. Apr 1968;3(2):253-7. [Medline].
Anderson N, Malpas T, Robertson R. Prenatal diagnosis of colon atresia. Pediatr Radiol. 1993;23(1):63-4. [Medline].
Cox SG, Numanoglu A, Millar AJ, Rode H. Colonic atresia: spectrum of presentation and pitfalls in management. A review of 14 cases. Pediatr Surg Int. Oct 2005;21(10):813-8. [Medline].
Tandler J. Zur Entwicklungsgeschichte des Menschlichen Duodenums im frühen Embryonal stadiem. Gegenhaur Morphol Jahrbuch. 1900;29:187.
Further Reading
Keywords
intestinal atresia, stenosis, webs, duodenal atresia, duodenal stenosis, duodenal obstruction, jejunoileal atresia, jejunoileal stenosis, jejunoileal lesion, colonic atresia, annular pancreas, esophageal atresia, growth retardation, polyhydramnios, dehydration, failure to thrive, Down syndrome, peptic ulcer disease, prematurity, malrotation, short bowel syndrome, Hirschsprung disease, meconium plug
