Newborn with Bilious Emesis 31 Ziyad Jabaji, Veronica F. Sullins, and Steven L. Lee A term newborn female presents with bilious vomiting 12 hours after an uneventful delivery. A prenatal ultrasound showed polyhydramnios, but the mother was lost to follow up. The infant passed meconium soon after birth. All vital signs are normal, and on physical examination the infant is well appearing. Her abdomen is soft and nontender with epigastric distension. She has a single palmar crease in both hands. An abdominal radiograph shows a “double-bubble.” Diagnosis What Is the Differential Diagnosis for Bilious Emesis in a Newborn? The differential diagnosis of bilious emesis in a newborn is shown in below table. It is important to note that ileus secondary to sepsis or metabolic disorders may also manifest as bilious emesis (see chapter on infant with bilious emesis). Differential Diagnosis of Bilious Emesis in Neonatal Period (0–1 Month) Diagnosis Duodenal atresia Hirschsprung’s disease Imperforate anus Incarcerated inguinal hernia Jejunoileal/colonic atresia Malrotation with midgut volvulus Meconium ileus/plug Necrotizing enterocolitis Specific findings “Double bubble” on AXR, no distal bowel gas Transition zone (caliber change) on contrast enema, absence of ganglion cells with hypertrophied nerve trunks on rectal biopsy Bowel gas present, no anus on physical examination Inguinal hernia with evidence of incarceration on physical exam Distal obstruction, microcolon on contrast enema Corkscrew appearance of duodenum on contrast UGI, misplaced ligament of Treitz No passage of meconium, distended abdomen Prematurity, fixed dilated loop, or pneumatosis intestinalis on AXR AXR, abdominal radiograph; UGI, upper gastrointestinal study Z. Jabaji, MD (*) Department of Surgery, UCLA Medical Center, 10833 Le Conte Avenue, 72-229 CHS, Los Angeles, CA 90095, USA e-mail: zjabaji@mednet.ucla.edu V.F. Sullins, MD Department of Surgery, Harbor-UCLA Medical Center, 1000 W. Carson Street, Box 25, Torrance, CA 90509, USA e-mail: ronniesullins@gmail.com S.L. Lee, MD Department of Surgery, Division of Pediatric Surgery, Harbor-UCLA Medical Center, 1000 W. Carson Street, Box 25, Torrance, CA 90509, USA e-mail: slleemd@yahoo.com C. de Virgilio (ed.), Surgery: A Case Based Clinical Review, DOI 10.1007/978-1-4939-1726-6_31, © Springer Science+Business Media New York 2015 329 330 Z. Jabaji et al. What Is the Most Likely Diagnosis? In this instance, the relatively well-appearing baby and classic “double-bubble” (discussed in Work-Up) finding with absent distal gas on radiography is diagnostic of duodenal atresia. The epigastric distention on physical examination is caused by dilation of the stomach and proximal duodenum and should resolve after nasogastric tube placement. The incidence of this congenital malformation is 1 in 5,000 to 1 in 10,000 live births. History and Physical Examination What Is the Significance of Bilious Vomiting in a Newborn? Vomit is bilious when it is yellow or green stained and implies reflux of enteric contents from distal to the ampulla of Vater. It indicates that the pylorus is patent and effectively rules out common stomach pathology such as pyloric stenosis. Bilious emesis in a newborn is usually caused by a surgical problem unless proven otherwise. What Is the Significance of Polyhydramnios? Amniotic fluid volume is determined by a steady state between in utero swallowing and fetal urine production. Polyhydramnios is an excess amount of amniotic fluid for a given gestational age. While 50 % of pregnancies with polyhydramnios are idiopathic, known causes can be grouped into diseases that impair swallowing (congenital diaphragmatic hernia, duodenal atresia, esophageal atresia, gastroschisis, neck mass, neurologic devastation, tracheoesophageal fistula) or diseases that increase urine production (maternal diabetes, twin pregnancy). Does the Passage of Meconium Exclude the Diagnosis of an Intestinal Obstruction? No. It is still possible to have a neonatal bowel obstruction with passage of meconium. Meconium is composed of ingested lanugo (fine body hair), amniotic fluid, bile, mucus, and shed epithelial cells. Though the former three will not pass with intestinal obstruction, mucus is secreted and epithelium is shed along the entire length of the intestine. Therefore, any meconium distal to the point of obstruction may still be passed. Pathophysiology What Is the Etiology of Duodenal Obstruction? While the most common cause of congenital duodenal obstruction is duodenal atresia, rarely other congenital anomalies may be found. Causes of duodenal obstruction are classified as intrinsic (duodenal atresia versus intraluminal web) or extrinsic (adhesive Ladd’s bands, annular pancreas). Distal bowel gas may be seen in partial rather than complete duodenal obstruction. This is common with extrinsic causes and in cases of duodenal stenosis or web. What Is the Pathophysiology of This Condition? Intrinsic duodenal obstructions arise from embryologic events around 6 weeks of gestation. Normal development causes rapid proliferation of the primitive gut epithelium and obliteration of the duodenal lumen, with recanalization over the next several weeks. Duodenal atresia results when there is a failure of the gut to recanalize and the lumen remains obliterated. This differs from the pathophysiology of jejunoileal atresias, which are thought to be a result of in utero vascular accidents leading to segmental intestinal ischemia and subsequent resorption. 31 Newborn with Bilious Emesis 331 Watch Out While the point of obstruction in the majority of infants with duodenal atresia is distal to the ampulla of Vater, in 20 % the obstruction is proximal to the ampulla. This group of patients will present with nonbilious instead of bilious emesis. What Are the Associated Abnormalities? More than half of all babies with duodenal atresia or stenosis will have another congenital anomaly. Table 31.1 lists frequencies of the most common associated anomalies. In this patient, the single palmar crease is highly suggestive of Down syndrome, which can be confirmed with either ante- or postnatal chromosomal testing. Although nearly one third of patients with duodenal atresia have Down syndrome, it is not itself a risk factor for the development of duodenal atresia. Work-Up What Is the First Imaging Study to Obtain? In stable patients, a 2-view plain abdominal radiograph after naso- or orogastric tube placement should be the first imaging study to obtain. It may help exclude gross perforation and give essential diagnostic information. The presence or absence and amount of bowel gas also will help differentiate between proximal and distal, and partial or complete obstruction. The patient’s abdominal radiograph is shown in Fig. 31.1. Note the two large upper abdominal gas collections indicative of the dilated stomach and duodenal bulb. This is classically described as a “double-bubble.” Table 31.1 Incidence of anomalies associated with duodenal atresia Associated anomalies Down syndrome (Trisomy 21) Annular pancreas Congenital heart disease Malrotation Esophageal atresia/TEF Genitourinary Anorectal Other bowel atresia Others (vertebral, musculoskeletal, biliary malformations, antral web) Any associated anomaly TEF, tracheoesophageal fistula Fig. 31.1 Anteroposterior abdominal radiograph showing the stomach (S) and duodenal bulb (D) Incidence (%) 28 23 23 20 9 8 4 4 11 55 332 Z. Jabaji et al. Neonate with bilious emesis IV access and fluid resuscitation, NGT placement Unstable Stable AP/lateral abdominal radiographs Suspect malrotation with midgut volvulus ABX and OR for exploratory laparotomy Proximal obstruction (minimal bowel gas) “Double bubble” and no distal bowel gas Duodenal atresia Distal bowel gas ± “double bubble” UGI contrast study Distal obstruction (multiple dilated loops of bowel) Contrast enema Intestinal atresia Meconuim ileus Hirshsprung’s disease Malrotation ± midgut volvulus Fig. 31.2 Diagnostic algorithm for neonatal bilious emesis. IV, intravenous; NGT, nasogastric tube; AP, anteroposterior; ABX, antibiotics; OR, operating room; UGI, upper gastrointestinal What Is the Next Step in Diagnosis? The absence of distal bowel gas in the above radiograph secures the diagnosis of a complete duodenal obstruction, and no further testing is indicated. If any distal gas is seen, an upper gastrointestinal (UGI) contrast study is necessary to rule out malrotation with midgut volvulus, the most life-threatening condition. The UGI contrast study may also be helpful in diagnosing other etiologies of partial duodenal obstruction. A diagnostic algorithm is shown in Fig. 31.2. 31 Newborn with Bilious Emesis 333 Management What Are the Initial Steps in the Management? Since patients with duodenal atresia are rarely unstable, a thorough work-up and optimization should be performed prior to surgery. This includes securing intravenous access, initiating replacement of GI fluid and electrolyte losses, and placing a nasogastric tube for decompression of the stomach and proximal duodenum. If the patient is unstable these steps should be performed while preparing the operating room for laparotomy and the diagnosis of duodenal atresia should be questioned, as the most likely etiology is malrotation with midgut volvulus. In stable patients a peripherally inserted central catheter line should be considered for nutritional support, as feeds typically do not start until a few days after surgery. What Is the Timing of Surgery? The timing of surgery depends on the clinical condition of the patient. In stable patients, surgery may be delayed until a thorough work-up has been completed, and the infant is hemodynamically optimized, typically within the first few days of life. To evaluate for associated anomalies, a careful history and physical examination, echocardiography, renal ultrasound, and spinal radiographs should be performed. Testing for chromosomal abnormalities may be initiated, but results are not necessary prior to surgery. If the child is extremely premature, surgery may be delayed for several weeks to allow for neonatal lung maturation and growth. If malrotation has not been adequately ruled out by the initial evaluation, surgery is considered urgent or emergent, especially if the patient is clinically unstable. What Are the Surgical Options? If malrotation (with or without volvulus) is found, it should be corrected first. The treatment of choice for duodenal atresia is a duodenoduodenostomy to bypass the atretic segment. If this cannot be accomplished safely, a duodenojejunostomy may be performed. Areas Where You Can Get in Trouble Inadequate Preoperative Resuscitation Since duodenal atresia is rarely a true surgical emergency, it is important that the child be adequately fluid resuscitated with correction of electrolyte imbalances preoperatively. If the patient is hypovolemic, induction of anesthesia or surgery itself may worsen existing hypotension or precipitate seizures due to electrolyte imbalances, end-organ damage from hypoperfusion, or cardiovascular collapse. Failure to Rule Out Cardiac Defects Prior to Surgery Greater than 20 % of infants with duodenal obstructions also have cardiac defects. There is typically ample time to perform a thorough work-up before taking the patient to the operating room. Certain defects (typically cardiac), depending on the severity, will take precedence over repairing the duodenal atresia. Injury to an Annular Pancreas or the Ampulla An annular pancreas is found in 1 in 5 children with duodenal obstruction. The cause of the obstruction in patients who have an annular pancreas is still intrinsic (duodenal atresia or web). It is important to recognize this early in the operation and avoid dividing or injuring the encircling ring of pancreatic tissue. Injury to the pancreatic ducts traversing the ring can lead to pancreatic enzyme leak and pancreatitis. 334 Z. Jabaji et al. Areas of Controversy Laparoscopic Versus Open Surgery The role of laparoscopy in treating duodenal atresia is still being defined. Current reports of laparoscopic duodenoduodenostomy show good outcomes; however, operative times are longer than open procedures and the conversion rates to open operation can be high (>25 %). Although short-term outcomes are promising, long-term data are not yet available. Partial Duodenal Obstruction Versus Malrotation In cases where the contrast UGI shows a “double-bubble” with distal gas, suggesting a partial duodenal obstruction, there may be a duodenal web with a small hole that allows some gas to pass distally. In stable patients, some advocate for performing surgery within 24–48 hours. In this case, the authors prefer to operate urgently, as the presence of the classic duodenal atresia radiographs does not rule out malrotation in the presence of distal gas. Summary of Essentials History, Physical Examination, and Diagnosis • Bilious (green or yellow) vomiting in newborn (0–1 month) is a surgical problem until proven otherwise • Passage of meconium does not rule out obstruction • Stable patient: plain abdominal radiograph first → rule out gross perforation, proximal versus distal obstruction, presence or absence of distal gas • “Double-bubble” + no distal gas = complete duodenal obstruction (usually duodenal atresia) • If distal gas, suspect malrotation with midgut volvulus before duodenal web or partial duodenal obstruction Pathophysiology • Etiology of duodenal obstruction: intrinsic versus extrinsic • Duodenal atresia is due to failure of recanalization early in development • >50 % have associated anomalies: Trisomy 21, annular pancreas, cardiac most common Management • • • • Correct fluid and electrolyte imbalances and place NGT first Rule out other anomalies prior to surgery Unstable patient → suspect malrotation with midgut volvulus, go to OR emergently Duodenoduodenostomy is procedure of choice Suggested Reading Godbole P, Stringer MD. Bilious vomiting in the newborn: how often is it pathologic? J Pediatr Surg. 2002;37(6):909–11. Kimura K, Mukohara N, Nishijima E, Muraji T, Tsugawa C, Matsumoto Y. Diamond-shaped anastomosis for duodenal atresia: an experience with 44 patients over 15 years. J Pediatr Surg. 1990;25(9):977–9. Infant with Bilious Emesis 32 Veronica F. Sullins and Steven L. Lee A 7-month-old male infant presents with 2 episodes of green emesis, decreased stool and urine output, and lethargy. The mother states he was a full-term baby with no prior illnesses or surgery. He fed normally for months until the day prior to presentation. He had a normal, nonbloody bowel movement 24 hours ago. His heart rate is slightly elevated and he is normotensive and afebrile. He is lethargic but otherwise has a normal physical examination. His abdomen is soft, nontender, and nondistended. Diagnosis What is the Differential Diagnosis for Bilious Emesis in an Infant? Diagnosis Adhesions Enteric duplication cyst Gastroenteritis Hirschsprung’s disease Ileus secondary to other medical disease Incarcerated inguinal hernia Intussusception Malrotation with midgut volvulus Specific findings Prior abdominal surgery, dilated loops of bowel with transition point to decompressed bowel on contrast study Fluid-filled structure not contiguous with stomach or small bowel on MRI/US History of fever, diarrhea, initial nonbilious emesis, diagnosis of exclusion Transition zone (caliber change) on contrast enema, absence of ganglion cells with hypertrophied nerve trunks on rectal biopsy Metabolic derangements, electrolyte abnormalities, sepsis, multiple etiologies Inguinal hernia with evidence of incarceration on physical exam Target sign on US, possible preceding viral upper respiratory illness, “currant-jelly” stool “Corkscrew” appearance of duodenum on contrast UGI, misplaced ligament of Treitz MRI magnetic resonance imaging, US ultrasound, UGI upper gastrointestinal study V.F. Sullins, MD (*) Department of Surgery, Harbor-UCLA Medical Center, 1000 West Carson Street, Box 25, Torrance, CA 90509, USA e-mail: ronniesullins@gmail.com S.L. Lee, MD Department of Surgery, Division of Pediatric Surgery, Harbor-UCLA Medical Center, 1000 W. Carson Street, Box 25, Torrance, CA 90509, USA e-mail: slleemd@yahoo.com C. de Virgilio (ed.), Surgery: A Case Based Clinical Review, DOI 10.1007/978-1-4939-1726-6_32, © Springer Science+Business Media New York 2015 335 336 V.F. Sullins and S.L. Lee How does age Affect the Differential Diagnosis of Bilious Emesis? All agesa Neonate (0–1 month) Infant (1–24 months) Child (2–12 years) Adhesions Hirschsprung’s disease Incarcerated inguinal hernia Malrotation with midgut volvulus Annular pancreas Duodenal atresia Imperforate anus Jejunoileal/colonic atresia Meconium ileus/plug Necrotizing enterocolitis Intussusception Ileus secondary to appendicitis Intussusception a In all ages, underlying sepsis or metabolic derangements may lead to ileus and bilious vomiting What is the Diagnosis? Malrotation with midgut volvulus (Fig. 32.1) should always be suspected in an infant with bilious vomiting or any child with bilious vomiting and abdominal pain. While over half of children with malrotation present before 1 month of age with volvulus, or the twisting of the small bowel around its mesentery leading to intestinal ischemia, one third present between 1 month and 1 year of age. Watch Out Malrotation with midgut volvulus may present with either bilious or nonbilious vomiting depending on where the obstruction occurs. All cases of suspected duodenal obstruction should be evaluated for malrotation with midgut volvulus. History and Physical Why Is It Important to Distinguish Between Bilious and Nonbilious Vomiting in an Infant? Bilious emesis is any green or yellow emesis. The presence of bile in an infant’s vomit is essential diagnostic information because bilious emesis is most likely due to a surgically correctable lesion until proven otherwise. Obstructive processes proximal to the pylorus always cause nonbilious emesis, whereas bilious emesis implies a patent pylorus with obstruction distal to the ampulla of Vater. Distinguishing between proximal and distal causes of obstruction will determine what type of diagnostic study to perform. What Are the Associated Risk Factors? Rotational defects are thought to be present in nearly all patients with congenital diaphragmatic hernia and abdominal wall defects such as gastroschisis and omphalocele. In children with these conditions, volvulus is rare due to both the abnormal anatomy and adhesions that develop after surgical repair. Patients with heterotaxy syndrome, or abnormal positioning of intrathoracic or intra-abdominal organs, are likely to have malrotation and should therefore undergo a diagnostic workup. Intestinal atresias, in particular duodenal atresia, are also associated with and perhaps in part caused by malrotation and should therefore be assessed during surgical repair of the atresia. There are some syndromic associations that have been described including Trisomy 21 (Down syndrome). 32 Infant with Bilious Emesis 337 Fig. 32.1 Photograph of malrotation with midgut volvulus Workup What Is the First Imaging Study to Obtain? Given that the patient is hemodynamically stable, the first study to obtain is a plain abdominal radiograph. While plain radiographs are rarely diagnostic, they may exclude gross perforation, which would reveal free air under the diaphragm. If there is evidence of perforation, no additional studies are needed and the patient should be taken to the operating room for urgent laparotomy. The presence and location of bowel gas on plain radiographs may also help determine whether the patient has a proximal (duodenum or proximal jejunum) or distal (ileum or colon) obstruction, which will then guide further workup based on the differential diagnosis (Fig. 32.2). What Is the Next Step in Diagnosis? If no free perforation is seen, an upper gastrointestinal (UGI) contrast series (Fig. 32.3) should be obtained to visualize the duodenum and proximal small intestine. Pathophysiology What Defines the Midgut? The midgut is the portion of the gut receives its blood supply from the superior mesenteric artery. In a fully developed fetus, it extends from the second part of the duodenum to two-thirds of the way across the transverse colon. The foregut structures are supplied by the celiac axis and the hindgut structures by the inferior mesenteric artery. What Is the Normal Developmental Sequence of Events of the Human Midgut? During the 6th week of gestation, the midgut elongates very rapidly and therefore must temporarily grow outside of the embryo. During this stage of umbilical herniation, the midgut rotates 90° counterclockwise around the axis of the superior V.F. Sullins and S.L. Lee 338 Infant with bilious emesis IV access and fluid resuscitation, NGT placement Stable Unstable with concerning abdominal exam AP/lateral abdominal radiographs ABX and OR for exploratory laparotomy Distal obstruction (multiple dilated loops of bowel) Proximal obstruction (minimal bowel gas) Abdominal US UGI contrast study Malrotation ± midgut volvulus Suspect malrotation with midgut volvulus Negative study + Intussusception - Intussusception Workup other etiologies based on history: • Hirschsprung’s disease (contrast enema) • Adhesions (CT scan, history) • Incarcerated hernia (physical exam) Fig. 32.2 Diagnostic algorithm for bilious emesis in infancy. IV intravenous, NGT nasogastric tube, AP anteroposterior, ABX antibiotics, OR operating room, UGI upper gastrointestinal, CT computed tomography mesenteric artery so that the proximal limb (small bowel) lies on the right side and the distal limb (colon) lies on the left side of the artery. Between the 10th and 12th week of gestation, the developing midgut returns into the abdominal cavity. The proximal limb passes behind the superior mesenteric artery and fixes to the left side of midline to form the duodenojejunal flexure or ligament of Treitz. The distal limb rotates counterclockwise a further 180° to place the cecum in its final position in the right lower quadrant and the transverse colon anterior to the superior mesenteric artery. The duodenum and ascending colon then become fixed in their final retroperitoneal positions. Proper midgut rotation allows the base of the small bowel mesentery to extend from the ligament of Treitz diagonally down to the ileocecal junction, ensuring a broad base of attachment to the posterior abdominal wall. 32 Infant with Bilious Emesis 339 Fig. 32.3 UGI contrast study with small bowel follow through Fig. 32.4 Schematic of (a) malrotation (dotted line encircles the narrow base at risk for volvulus) and (b) midgut volvulus (From O’Neill, J. Principles of Pediatric Surgery, 7th edition. 2003, Mosby. Reprinted with permission from Elsevier) What Is the Etiology of This Condition? Malrotation results from failure of the midgut to rotate and fix properly, typically during its return into the abdominal cavity. Although there are various degrees of malrotation, classically the ligament of Treitz is situated to the right of midline and the cecum fails to rotate the final 180° down to the right lower quadrant, placing it in the epigastrium. In attempts to fix the malpositioned colon into position, peritoneal attachments form between the right upper quadrant and the ascending colon, crossing the duodenum. Whether these bands cause duodenal obstruction is unclear. Most importantly, the base of the mesentery is narrow, thereby predisposing it to rotation about its axis or midgut volvulus (Fig. 32.4). This rotation gives the classic radiographic finding of a “corkscrew” appearance of the contrast in the lumen of the bowel (see arrow in Fig. 32.3). When acute midgut volvulus occurs, it results in duodenal obstruction and bilious vomiting. As it progresses, a strangulated, closed loop obstruction occurs and the intestine becomes ischemic. Does Malrotation Always Result in Midgut Volvulus? Is It Always Acute? No. The diagnosis of malrotation is not itself a surgical emergency. However, it predisposes the infant to midgut volvulus. It is also not always acute, and acute presentations vary from intermittent to complete obstruction. If the acute volvulus is 340 V.F. Sullins and S.L. Lee incomplete or intermittent, the infant may appear well between episodes of vomiting. If the volvulus is chronic, the patient may present in childhood with chronic vomiting and recurrent abdominal pain or failure to thrive. Workup Are Plain Radiographs Necessary? No. It is important to understand that if an infant has symptoms of acute gastrointestinal obstruction and is hemodynamically unstable, no additional evaluation is necessary. Rapid fluid resuscitation and immediate surgical intervention will provide the best chance at saving ischemic bowel. Watch Out In a patient with midgut volvulus, the most common bowel gas pattern seen on plain radiograph is normal. Suspicion should actually be heightened when a “normal” abdominal gas pattern is observed in an infant with bilious vomiting. Management What Is the Most Important Immediate Management Issue? Acute midgut volvulus is a surgical emergency and any delay in operating may result in the loss of intestine. The patient should be rapidly fluid resuscitated and taken to the operating room for urgent laparotomy. An orogastric or nasogastric tube should be placed to decompress the stomach and broad-spectrum antibiotics should be given while preparing for the operating room. Delays in diagnosis may worsen intestinal ischemia, leading to loss of more intestinal tissue. In the most severe cases, the infant suffers a complete midgut infarction or loss of blood flow to intestine from the proximal jejunum to the mid-transverse colon. If this occurs, a massive small bowel resection is necessary and may result in an insufficient length of intestine to sustain the infant’s nutritional needs. This condition is called short bowel syndrome. Even with some intestinal adaptation after massive small bowel resection, short bowel syndrome patients may become dependent on lifelong total parenteral nutrition (TPN) or require small intestinal transplantation. What Operation Is Required? The goals of the Ladd’s procedure are to relieve any intestinal obstruction and prevent the risk of recurrent volvulus. First, because volvulus typically occurs in a clockwise direction, the volvulus must be reduced by gently rotating the gut counterclockwise. Next, Ladd’s bands, or the peritoneal attachments from the right upper quadrant to the ascending colon, must be divided. The duodenum is then straightened and examined for intrinsic obstruction. The base of the mesentery must be widened by dividing peritoneal adhesions. Finally, the small bowel is positioned on the right side of the abdomen and the large bowel on the left, in complete nonrotation. These positions ensure the maximum distance between the duodenum and the ileocecal junction. Because the cecum and appendix are now in the left upper quadrant, most surgeons perform an appendectomy to avoid future misdiagnosis in the event that the patient develops appendicitis. Areas Where You Can Get in Trouble Delay in Diagnosis While the emergent nature of malrotation with midgut volvulus may be obvious when an infant with bilious vomiting presents late and is extremely sick, most patients are not yet in extremis. Between attacks, infants with intermittent obstruction or incomplete volvulus may appear well. This may prompt additional tests and imaging studies (such as a contrast enema) 32 Infant with Bilious Emesis 341 that will delay the diagnosis and worsen intestinal ischemia. Conversely, a patient who has incidentally been found to have malrotation and has no symptoms should have surgery at the earliest convenience. Intraoperative Evaluation In some infants with malrotation, duodenal stenosis or atresia is present and is the cause of the duodenal obstruction. Therefore, to exclude these diagnoses, a large bore orogastric or nasogastric tube must be passed through the second part of the duodenum during surgery. Alternately, because a significant number of infants with atresias have associated malrotation, during surgery to repair a duodenal or jejunoileal atresia, the intestine must be evaluated for malrotation. Areas of Controversy Management of Minor Degrees of Malrotation While asymptomatic patients incidentally found to have classic malrotation (with the cecum in the mid-upper abdomen and the ligament of Treitz abnormally fixed) should have surgery at the earliest possible time, it is not clear how best to manage patients with minor degrees of malrotation or nonrotation. These patients have a wider mesenteric base and therefore a much lower likelihood of developing a midgut volvulus. In addition, a mobile or high position of the cecum may be present in normal, healthy individuals. In cases of chronic symptoms in older patients, surgery may not be beneficial, especially with evidence of nonclassical or minor degrees of malrotation. Infants with Complete Midgut Infarction Although the incidence of infants presenting with complete midgut infarction is low, the consequences are devastating. Mortality rates are approximately 65 % when more than 75 % of the bowel is necrotic and much higher in the presence of other congenital anomalies. In the tragic case of complete midgut infarction, some advocate for closing the abdomen without resection and providing palliative care. If a massive small bowel resection is performed and the patient subsequently develops short gut syndrome (inadequate intestinal length to absorb sufficient nutrients), a future small bowel transplant may be necessary. Short bowel syndrome patients who are TPN dependent may develop TPN-associated liver failure and require a liver transplantation as well. Summary of Essentials History, Physical Examination, and Diagnosis • • • • • Must determine bilious versus nonbilious emesis. Remember: green or yellow emesis = bilious emesis Bilious vomiting during infancy (1–24 months) is a surgical problem until proven otherwise Stable patient: plain abdominal radiographs first to exclude gross perforation If initial radiograph is negative: UGI contrast study to evaluate the duodenum and proximal small intestine Always suspect malrotation with midgut volvulus in infants with bilious vomiting or children with bilious vomiting and abdominal pain Etiology/Pathophysiology • Midgut is supplied by the superior mesenteric artery: second portion of duodenum → two-thirds of transverse colon • Malrotation due to developmental failure of normal 270-degree counterclockwise midgut rotation 342 V.F. Sullins and S.L. Lee • Classic malrotation = narrow mesenteric base, ligament of Treitz located right of midline, cecum in the epigastrium, Ladd’s bands from cecum to right upper quadrant, crossing duodenum • Volvulus = midgut rotates around superior mesenteric artery axis → duodenal obstruction, vascular compromise of bowel • Classic UGI radiograph: “corkscrew” appearance of contrast in bowel lumen Management • Place nasogastric tube to decompress stomach; give antibiotics and IVF while preparing for laparotomy • Hemodynamically unstable infant with acute gastrointestinal obstruction → rapid fluid resuscitation, immediate surgical intervention without additional studies • Ladd’s procedure: relieve obstruction by untwisting bowel; prevent future episodes by broadening mesenteric base Watch Out • • • • Malrotation with midgut volvulus may present with bilious or nonbilious vomiting depending on location of obstruction Most common bowel gas pattern on plain radiograph is normal During surgery, must exclude duodenal stenosis or atresia as cause of obstruction Delay in diagnosis may result in complete midgut infarction Suggested Reading Lampl B, Levin TL, Berdon WE, Cowles RA. Malrotation and midgut volvulus: a historical review and current controversies in diagnosis and management. Pediatr Radiol. 2009;39(4):359–66. Millar AJ, Rode H, Cywes S. Malrotation and volvulus in infancy and childhood. Semin Pediatr Surg. 2003;12(4):229–36. O’Neill J. Chapter 47: Rotational anomalies and volvulus. In: Principles of pediatric surgery. 7th ed. Mosby; 2003, pp 477–58. Strouse PJ. Disorders of intestinal rotation and fixation (“malrotation”). Pediatr Radiol. 2004;34(11):837–51.
