Figure 103-34. Soave endorectal procedure. A: Endorectal dissection initiated. B: Endorectal dissection complete. C: Eversion of

the aganglionic segment and rectal mucosal tube. D: Incision of everted rectal tube. E: Endorectal pull-through. F: Colorectal

anastomosis. G: Completed procedure.

Swenson Procedure. The Swenson procedure is the original definitive procedure for the treatment of

Hirschsprung disease. It is somewhat more demanding from a technical standpoint, and, as such, it has

been reported to have a slightly higher incidence of postoperative complications. However, long-term

outcome in children who undergo a properly performed Swenson procedure is equivalent to other

procedures. The basic strategy is outlined in Figure 103-35. The aganglionic segment of colon is

resected and a careful, nearly complete extramural dissection of the distal rectum is performed. Care

must be taken to avoid inadvertent injury to the seminal vesicles, vas deferens, ureters, and pelvic

splanchnic nerves. The dissected rectum is everted through the anus onto the perineum and excised.

Normal proximal bowel is pulled through and a colorectal anastomosis is performed.

Laparoscopically Assisted Endorectal Pull-through. A multi-institutional clinical experience with a

laparoscopically assisted endorectal pull-through technique for the treatment of Hirschsprung disease

has been reported.125 Potential advantages of this approach include excellent visibility of the distal

rectum during dissection, early return of postoperative bowel function, and decreased length of hospital

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stay. The early results report outcomes similar to the other established procedures. The procedure is

reviewed in Figure 103-36. Complete transanal excision of the distal aganglionic segment with primary

coloanal anastomosis has also been performed for short-segment or typical rectosigmoid aganglionosis

as well.

Rectal Myectomy. Resection of a longitudinal strip of the posterior rectal muscular wall has been used

for definitive management of ultrashort-segment Hirschsprung disease. This procedure can be

performed via transanal approach combined with submucosal dissection or by a posterior sagittal

approach. Although controversial, the use of rectal myectomy as a definitive operation for Hirschsprung

disease may be considered most useful in the selected older child identified with ultrashort-segment

disease.128

Figure 103-35. Swenson procedure. A: Extramural rectal dissection. B,C: Eversion of aganglionic segment and full-thickness

rectum. D: Pull-through of normal, ganglionic bowel. E: Colorectal anastomosis. F: Completed procedure.

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Figure 103-36. Laparoscopically assisted pull-through for Hirschsprung disease. A: Sites for operative trocar placement. B: Division

of colon and rectal mesentery with mobilization of proximal colon. C: Circumferential incision in rectal mucosa 5- to 10-mm

cephalad to the pectinate line. D: Mucosal traction sutures to facilitate further dissection from rectal muscular cuff. E: Transanal

submucosal dissection is continued cephalad to meet the caudal extent of the transperitoneal rectal dissection. F: Circumferential

incision of rectal muscular cuff. G: Rectal muscular cuff is split posteriorly to accommodate the pull-through segment (the pullthrough segment is not shown here to clarify this maneuver). H: Rectum and sigmoid colon are pulled through the rectal muscular

cuff to the anastomotic site. I: Colon is transected at appropriate site with confirmation of ganglion cells by frozen section. J:

Transanal, end-to-end single layer colorectal anastomosis.

Total Colonic Aganglionosis. Total colonic aganglionosis is complex and, fortunately, relatively rare.

Several different operative procedures have been described and treatment must be individualized. The

endorectal pull-through with ileoanal anastomosis has been used with good success when most or all of

the small bowel is normal. For extensive small bowel aganglionosis, an extended side-to-side

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anastomosis of normally innervated proximal small bowel to the aganglionic colon has been successfully

performed. For complete intestinal aganglionosis, extended intestinal myectomy has been described.

Complications and Outcome

Complications resulting from definitive procedures for Hirschsprung disease include anastomotic leak,

stricture, pelvic or rectal muscular cuff abscess, intestinal obstruction, and wound infection. These occur

with a frequency of 1% to 10% with most experienced pediatric surgeons. Mortality from Hirschsprung

disease is distinctly unusual unless enterocolitis is the presenting feature or associated medical problems

or anomalies are present.

A unique complication following definitive repair of Hirschsprung disease is postoperative

enterocolitis. The clinical presentation and pathogenesis have been discussed, and it remains an

important and significant cause of morbidity. The incidence of postoperative enterocolitis ranges from

10% to 30% in most large series. Although rare, Hirschsprung enterocolitis can occur even in the

presence of a diverting colostomy. Long-term outcomes appear quite good for all the procedures used,

with 80% to 90% of patients maintaining good to excellent bowel function.

OTHER CHILDHOOD GASTROINTESTINAL DISORDERS

This review is limited to relatively common surgical conditions that are either congenital or unique in

children. For other surgical conditions that can affect both children and adults, the reader is referred to

other chapters in this text.

Infantile Hypertrophic Pyloric Stenosis

Anatomy and Pathophysiology

The pathogenesis of infantile hypertrophic pyloric stenosis is unknown, but data suggest that local

deficiency of neuronal nitric oxide synthase in the pylorus may be responsible for the clinical

manifestations of the disease.129,130 The deficiency of neuronal nitric oxide synthase leads to a lack of

nitric oxide–mediated relaxation of smooth muscle and subsequent pyloric obstruction. Luminal

narrowing occurs as a result of concentric hypertrophy of the pyloric smooth muscle. Clinically, this

presents as progressive gastric outlet obstruction that becomes symptomatic by 2 to 4 weeks of age. The

maximal narrowing and clinical symptoms of hypertrophic pyloric stenosis occurs between 4 and 8

weeks of age. The hypertrophic pyloric muscle ultimately undergoes gradual involution over a period of

weeks to months.

Clinical Presentation

The reported incidence rate of hypertrophic pyloric stenosis is approximately 0.1% to 0.4% among

white infants and is slightly lower in the black population. There is a distinct familial predisposition

with an approximate 7% incidence rate in children of parents with a history of pyloric stenosis. The

incidence rate is about four times higher in males than in females and is higher in first-born infants.131

There is an apparent increased risk of hypertrophic pyloric stenosis in infants receiving oral

erythromycin for pertussis prophylaxis.132 Association of pyloric stenosis in infants treated for

esophageal atresia and in infants with Smith–Lemli–Opitz syndrome has been reported.133

Infants with hypertrophic pyloric stenosis have a history of nonbilious, postprandial emesis that

becomes progressively projectile. The infant otherwise appears well and will feed vigorously until late

in the clinical course. The typical age at diagnosis is between ages 2 and 12 weeks of age. A history of

identified feeding intolerance and formula change is common.

The definitive clinical finding on examination is a palpable, hypertrophied pylorus in the right upper

quadrant to midepigastric region, often described as a firm, mobile “olive” on examination. This is a

pathognomonic finding, and in the correct clinical setting, no further diagnostic imaging studies are

required. An experienced clinician should be able to palpate a hypertrophied pylorus in nearly all cases.

A successful physical examination requires an empty stomach, a quiet infant, and patience; repeated

examinations may be necessary. Inability to palpate the pyloric mass in a quiet or anesthetized infant

should place the diagnosis of hypertrophic pyloric stenosis in question. Other physical findings include

visible or palpable gastric peristaltic waves, which can also be seen with any cause of gastric or

duodenal obstruction.

Late findings with advanced symptoms include dehydration and a hypochloremic, hypokalemic

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metabolic alkalosis from gastric fluid losses. Profound metabolic alkalosis is less common in current

practice but occasionally can be encountered in an extremely dehydrated infant with a long-standing

history of emesis. The intravascular volume depletion and chloride-responsive alkalosis must be

corrected prior to operative repair. The serum chloride should be restored to at least 90 to 95 mEq/L,

and the measured CO2 should be less than 30 mEq/L prior to induction of general anesthesia.

Diagnosis

If the examination is equivocal, either an upper gastrointestinal contrast series or a pyloric ultrasound

examination can be performed. Both examinations are highly accurate and have sensitivity and

specificity exceeding 95% in experienced hands. A typical contrast study demonstrating a narrowed,

elongated pyloric channel is shown in Figure 103-37. Contrast studies have the advantage of evaluating

other causes of symptomatic emesis, including gastroesophageal reflux disease, malrotation, and

antroduodenal webs. The disadvantage of this approach is the presence of contrast in a poorly emptying

stomach. Ultrasound examination of the pylorus is a preferred diagnostic test in most pediatric

institutions. Ultrasound criteria for hypertrophic pyloric stenosis include a pyloric muscle thickness of 4

mm or greater and a pyloric channel length of 15 mm or greater. In general, the diagnosis of

hypertrophic pyloric stenosis is being made at an earlier age compared with several decades ago.

Figure 103-37. Infantile hypertrophic pyloric stenosis demonstrated by barium upper gastrointestinal series showing pyloric

channel narrowing (N) and elongation with antral shouldering or cushioning (arrows).

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Figure 103-38. Ramstedt pyloromyotomy for infantile hypertrophic pyloric stenosis. The cross-sectional view shows herniation of

the submucosa into the myotomy site, indicative of an adequate myotomy.

Treatment

Hypertrophic pyloric stenosis is a progressive situation that subsequently resolves over several weeks to

months. Nonoperative treatment during this period requires either long-term parenteral or enteral

nutrition and is not practical from a risk or cost standpoint. The Ramstedt pyloromyotomy has achieved

universal acceptance because it offers definitive, rapid cure in virtually all infants, and morbidity rates

have been negligible (Fig. 103-38). The operation is performed once the infant is rehydrated and the

serum electrolytes are corrected. Typically, the pylorus is delivered through a transverse right upper

quadrant incision. A single longitudinal incision is made in the hypertrophied pyloric muscle. The

hypertrophied circular pyloric muscle must be meticulously divided from the stomach to the junction of

the proximal duodenum. An adequate pyloromyotomy is achieved when the submucosa bulges into the

myotomy site and both edges of the divided pyloric muscle are freely mobile. Laparoscopic

pyloromyotomy has been demonstrated to be efficacious and safe with similar operative times and

outcome to the open repair; laparoscopic pyloromyotomy has become a standard approach at most

children’s hospitals.134,135

Postoperative feeding typically is started within 6 to 8 hours after recovery from anesthesia. Most

infants are tolerant of enteral feeding and can be discharged home safely within 24 hours of operation.

The surgical treatment of pyloric stenosis is straightforward, and the recovery is typically

uncomplicated. A population-based study reviewing 1,777 infants with pyloric stenosis demonstrated a

shorter length of stay and a lower overall complication rate in infants operated on by specialty-trained

pediatric surgeons compared to general surgeons.136 Mortality following pyloromyotomy is distinctly

unusual in the absence of concomitant medical problems. Complications are rare and usually represent

wound infection, technical failures related to an inadequate pyloromyotomy, or inadvertent entry into

the duodenum or the stomach. Rarely, infants with inadequate pyloromyotomy may require

reexploration and a second myotomy on the posterior pyloric wall. Inadvertent duodenotomy or

gastrotomy must be recognized and repaired.

Intussusception

Anatomy and Physiology

6 Intussusception is defined as the invagination or telescoping of a proximal segment of intestine into an

adjacent distal segment and is the most common cause of intestinal obstruction in infants and children

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aged 3 months to 3 years (Fig. 103-39). The invaginated proximal bowel is referred to as the

intussusceptum and the recipient distal bowel is called the intussuscipiens. This process most commonly

originates in the small intestine either at or near the ileocecal valve, with the terminal ileum passing

into the cecum and colon (ileocolic intussusception). In the pediatric population, the vast majority

(95%) of cases are considered idiopathic because of a lack of an identifiable anatomic lesion causing the

intussusception. Older children are more likely to have a pathologic lead point causing the

intussusception. In similar fashion, infants and children with repeated episodes of intussusception have a

greater probability of a pathologic lead point. Table 103-6 describes several factors that have been

associated with the development of intussusception.

Figure 103-39. Ileocolic intussusception with the intussusceptum and intussuscipiens indicated.

Many cases of idiopathic intussusception in infants are probably caused by the normally prominent

intramural lymph nodes (Peyer patches) in the terminal ileum acting as functional lead points. The

anatomic consequence of intussusception is obstruction of the distal bowel. As bowel edema and

inflammation progress, mesenteric vascular insufficiency from compression and congestion may occur.

Incarceration, strangulation, and intestinal perforation ultimately may result if this condition remains

unrecognized or untreated.

Clinical Presentation

Intussusception is estimated to occur with an incidence rate of one to four cases per 1,000 children.

There is a slight (3:2) male predominance; in a large retrospective series of children with

intussusception, 79% were younger than 12 months, and seasonal variation in incidence was not

observed.137 An association between the development of intussusception and the administration of a

previously available, tetravalent rhesus-based rotavirus vaccine (RotaShield, Wyeth Laboratories, Inc.,

Marietta, PA) was reported.138 The currently available rotavirus vaccine does not appear to be

associated with intussusception.139

Table 103-6 Predisposing Factors Leading to Intussusception

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Otherwise healthy infants who develop intussusception may have a characteristic clinical triad of

abdominal pain, vomiting, and bloody stool. The typical infant develops the acute onset of severe,

colicky abdominal pain. Intermittent episodes of irritability and crying may be associated with drawing

the legs up to the abdomen. Between bouts of colic, the infant is often lethargic or sleepy. During

periods of relative exhaustion, the abdominal examination may not be impressive; however, on careful

physical examination, a palpable mass in the right abdomen may be appreciated in 80% to 90% of cases.

Emesis is common and is often the presenting complaint. As intestinal obstruction progresses,

intractable vomiting with abdominal distention and intravascular volume depletion may occur. Guaiacpositive stool is present in 90% to 95% of infants as a result of the ischemic mucosal injury to the

intussusceptum. The passage of bloody stool mixed with mucus, classically described as currant-jelly

stool, may be observed.

Diagnosis

Plain radiographs of the abdomen are generally nonspecific and may show a paucity of gas in the right

lower quadrant with a mass effect in the ascending colon. Late findings demonstrate mechanical smallbowel obstruction with proximal distention, air–fluid levels, and a decrease or absence of gas distally.

Diagnostic enema techniques using either air or contrast approach 100% accuracy with typical ileocolic

intussusception (Fig. 103-40). An approach using hydrostatic or pneumatic enema allows therapeutic

reduction of intussusception as well. Ultrasound examination typically reveals a mass resembling a bull’s

eye or target sign, corresponding to the intussusceptum within the intussuscipiens. The target sign of

intussusception also may be demonstrated by CT. Both these latter modalities do not allow for potential

therapeutic reduction and may be more useful in diagnosing suspected cases of proximal jejunoileal or

enteroenteral intussusception.

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Figure 103-40. Contrast enema demonstrating classic ileocolic intussusception with the intussusceptum visible in the ascending

colon (arrows).

Treatment

Any infant with suspected intussusception in the absence of peritonitis should undergo diagnostic

hydrostatic or pneumatic enema. A high index of clinical suspicion and liberal application of this

approach should be maintained. The incidence of normal contrast enema examinations in this setting

may exceed 75% in most pediatric centers, and this is justified by the considerable risk inherent in a

missed diagnosis. An experienced pediatric radiologist and surgical evaluation are essential. Intravenous

access and resuscitation should occur before attempts are made at diagnostic or therapeutic enemas.

Successful hydrostatic or pneumatic reduction of ileocolic intussusception is achieved in 60% to 80%

of infants in most pediatric centers in the United States. Some centers prefer pneumatic enema using air

as a contrast agent, and this technique appears comparable to the hydrostatic approach in both diagnosis

and therapeutic reduction of intussusception. The ability to reduce intussusception using these

techniques is time dependent and diminishes substantially after the duration of symptoms exceeds 24

hours. In this setting, a contrast enema is still diagnostic and potentially therapeutic if carefully

performed.140 With most experienced pediatric radiologists, the risk of perforation or reduction of a

strangulated intussusceptum is low.

The technique of retrograde reduction of intussusception is straightforward. Contrast or air is

introduced into the rectum by a balloon catheter, with the height of the hydrostatic column 1 m or less.

Most centers use three attempts at reduction, with each attempt no longer than 3 minutes in duration.

As long as progress is being made, however, attempts can be repeated until reduction is achieved.

Successful reduction of ileocolic intussusception is demonstrated by observing retrograde flow of

contrast or air into the terminal ileum. Inability to demonstrate retrograde flow into the ileum suggests

incomplete reduction requiring surgical exploration.

Operative Management. Infants presenting with peritonitis and small-bowel obstruction with a clinical

diagnosis of intussusception should undergo immediate resuscitation and exploration without attempts

at retrograde enema. Surgical exploration is also required after incomplete retrograde enema reduction

of intussusception or in the relatively infrequent situation of bowel perforation during diagnostic or

therapeutic enema. The operative strategy is dictated by the findings. Spontaneous reduction of the

intussusception is reported to occur in up to 20% to 30% of infants following induction of general

anesthesia. In this situation, exploration confirming the reduction and examining the bowel for a

pathologic lead point is sufficient. With persistent intussusception and viable bowel, the bowel is

manually reduced, generally pushing the intussusceptum out of the distal bowel. If manual reduction

cannot be performed or the intussusceptum is strangulated, then segmental resection with primary

anastomosis is performed. Attempts at reducing intussusception with clearly necrotic bowel should be

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avoided. Diverting enterostomy as a result of peritoneal contamination usually is not required.

Appendectomy is routinely performed in all infants undergoing operative exploration for

intussusception. As with many aspects of pediatric surgery, a successful laparoscopic approach to the

diagnosis and management of intussusception has been reported in approximately two-thirds of selected

patients.141–143

Complications and Outcome

Retrograde techniques are successful at reducing idiopathic ileocolic intussusception in 60% to 80% of

cases. Following successful enema reduction, the infant is given intravenous fluids and usually observed

for 24 hours. Tolerance of oral feeding is predictably rapid. Recovery from operative reduction or

bowel resection is generally no different than from other similar gastrointestinal procedures. Most

infants enjoy a complete recovery with minimal or no morbidity. Recurrent intussusception after either

nonoperative or operative reduction occurs in about 5% of infants and usually can be treated with

repeat enema. Mortality from intussusception is rare and is almost always the result of systemic sepsis

and shock from unrecognized, strangulated intestine.

Figure 103-41. Normal embryonic relations of the yolk sac, yolk stalk, and developing gut.

Meckel Diverticulum and Related Disorders

Embryology and Anatomy

The most frequently encountered congenital anomaly of the gastrointestinal tract is Meckel

diverticulum, representing one of several malformations resulting from persistence of the yolk stalk

(synonymous with vitelline duct and omphalomesenteric duct) and its components. The embryonic yolk

stalk connects the yolk sac and the developing midgut (Fig. 103-41). Between weeks 5 and 7 of

gestation, the yolk sac involutes and the stalk fuses with the umbilical cord. Developmental failure or

arrest of yolk sac involution creates a spectrum of clinical malformations as outlined in Figure 103-42,

with Meckel diverticula constituting greater than 95% of these anomalies. Meckel diverticulum is a true

diverticulum of variable size derived from the intestinal remnant of the yolk stalk. Typically, it is found

on the antimesenteric border of the terminal ileum approximately 40 to 50 cm from the ileocecal valve

in adults. The blood supply is derived from persistent vitelline vessels supplied from the SMA. About

25% of the diverticula have a fibrous or vascular attachment to the anterior abdominal wall at the

umbilicus (Fig. 103-42C). Heterotopic gastric mucosa or pancreatic tissue is found in about half of the

diverticula examined at autopsy. In about 75% of patients with symptomatic diverticula, gastric mucosa

is present. When symptoms occur, bleeding or perforation is generally the result of peptic ulceration of

the adjacent ileal mucosa and not from the diverticulum itself.

Clinical Presentation

Symptomatic yolk stalk anomalies are usually diagnosed by history and clinical examination. Umbilical

drainage from a persistent fistula or sinus tract may be noted in a newborn following separation of the

umbilical cord. Intestinal prolapse or passage of stool from the umbilicus signifies a patent

omphalomesenteric duct. Small bowel obstruction in an otherwise healthy infant without a history of

laparotomy may be a result of volvulus around an omphalomesenteric band or intussusception from a

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