OBSTRUCTIVE PROBLEMS - LOGICAL APPROACH TO NEONATAL INTESTINAL OBSTRUCTION
Signs and Symptoms
1. Bilious vomiting is always abnormal.
2. Abdominal distention (scaphoid abdomen possible).
3. Delayed, scanty or no passage of meconium.
4. Polyhydramnios in mother.
5. Down's syndrome
6. Family history
a. Hirschsprung's disease
b. Diabetic mother
c. Jejunal atresia
Work‑up (Logical approach)
1. While the infant is being studied, it must be kept in mind that the problem may be 'non‑surgical'.
a. Sepsis of the newborn with associated ileus is the most important cause of non‑surgical bilious vomiting and abdominal distention.
b. Intracranial lesions
ii. Subdural hemorrhage
c. Renal disease associated with uremia.
I. Renal agenesis
ii. Polycystic disease
iii. Other urinary tract anomalies, which may be associated with severe hydronephrosis.
2. Plain roentgenograms of the abdomen.
a. Diagnostic in complete high intestinal obstruction‑no gas in distal small bowel.
I. Double bubble in duodenal obstruction.
ii. Few gas filled loops beyond duodenum indicates jejunal atresia.
b. Many gas filled loops (requires 24 hours) indicates some form of low intestinal obstruction.
I. Ileal atresia
ii. Meconium ileus (an unfortunate misnomer)‑obstruction of the distal small intestine by thick undigested meconium.
iii. Meconium plug syndrome‑obstruction of colon by a plug of meconium.
iv. Small left colon syndrome.
v. Hirschsprung's disease‑congenital aganglionosis of colon starting with the rectum.
vi. Colonic atresia.
c. May be nonspecific in instances of malrotation of the intestines. This diagnosis must always be considered in neonates with unexplained bilious vomiting.
d. Calcifications‑at some time during fetal life meconium was (is) present in the abdomen.
3. Contrast enema will differentiate the various types of low intestinal obstruction.
a. Microcolon‑complete obstruction of the small bowel.
b. Meconium plug syndrome‑colon dilated proximal to an intraluminal mass.
c. Hirschsprung's disease‑although it may appear to be diagnostic, not reliable in the newborn.
d. Small left colon syndrome‑colon dilated to the splenic flexure, then becomes narrow.
4. Upper G.I.‑ the procedure of choice in diagnosing malrotation of the intestines. In the past a contrast enema was thought to be the diagnostic test of choice in instances of malrotation but the cecum and ascending colon can be in normal position in an infant or child with malrotation of the intestines.
5. Rectal biopsy‑ a pathologist competent in reading the slides is essential and should not be taken for granted.
a. Suction biopsy of the rectal mucosa and submucosa‑ best screening procedure to rule out Hirschsprung's disease (ganglion cells are present in the submucosa), and is diagnostic in experienced hands.
b. Full thickness biopsy of the rectal wall may be necessary if the suction biopsy is non‑diagnostic or if the pathologist is unwilling or unable to make the diagnosis of aganglionosis on a suction biopsy specimen. This procedure is difficult in the small infant and has been replaced by the suction biopsy in most centers.
c. All newborns who have delayed passage of meconium associated with a suspicious contrast enema should have a suction biopsy of the rectal mucosa and submucosa. With this technique, Hirschsprung's disease will be diagnosed early before it is complicated with enterocolitis. If delayed passage of meconium is 'cured' by rectal stimulation (suppository, thermometer, or finger), it must be kept in mind that the diagnosis of Hirschsprung's disease is still a possibility. Whether or not a suction biopsy of the rectum is done before the infant goes home depends on the clinical setting but the safe course of action is to do the rectal biopsy before discharge. Parents may not call before the infant gets into trouble with enterocolitis.
d. Suction biopsy of the rectum is probably indicated in all cases of so called meconium plug syndrome or small left colon syndrome. If the suction biopsy is not done, the infant must be observed for recurrent gastrointestinal symptoms. A breast‑fed infant who has Hirschsprung's disease can 'get by' for a prolonged period of time.
6. Concluding comments:
The newborn suspected of having intestinal obstruction should be studied in a logical step by step manner. It is important that it be definitely established that the infant has a surgical problem before surgery is performed. This is usually not difficult in instances of complete high small bowel obstruction or when plain films of the abdomen show calcification and/or a distal small bowel obstruction with the contrast enema showing a microcolon or a definite malrotation of the colon (cecum in upper mid‑abdomen or left upper quadrant).
When plain films are suggestive of a high small bowel obstruction but there is gas in the distal small bowel, an upper GI rather than a contrast enema should be performed. It is critically important that the diagnosis of malrotation of the intestines be always considered and ruled out in a neonate with bilious vomiting. Prompt recognition and treatment of malrotation of the intestines which is often associated with a midgut volvulus avoids the dire consequences of the problems associated with a massive small bowel resection.
Mistakes are frequently made when the contrast enema is interpreted as normal, meconium plug syndrome, small left colon syndrome or Hirschsprung's disease. In all of these clinical situations, a suction biopsy of the rectum is an excellent screening procedure. If ganglion cells are present, Hirschsprung's disease is ruled out and the infant probably has a non‑surgical diagnosis. If ganglion cells are absent, the next step depends on the clinical picture and setting. If the pathologist is experienced and confident of the interpretation, the diagnosis of Hirschsprung's disease can be made with confidence. If there is any doubt about the absence of ganglion cells in the suction biopsy, a full thickness biopsy of the rectum (a difficult technical procedure requiring a general anesthetic) can be done to settle the issue. If Hirschsprung's disease is believed to be the problem, it must be diagnosed histologically before the infant is operated upon because at the time of surgery the site of obstruction may not be apparent and the abdomen may be closed because no obvious site of obstruction is found.
Hypothyroidism in the first two to three months of life can mimic Hirschsprung's disease in all aspects except for a normal rectal biopsy.
Another important point to remember is that duodenal atresia is a different disease from jejunal or ileal atresia in terms of their cause. Jejunal and ileal atresia occur as a result of a vascular accident in the small bowel mesentery during fetal life. Consequently, there is a relatively low incidence of other congenital anomalies except for cystic fibrosis. Duodenal atresia is a different disease in that there is a very high incidence of associated anomalies‑‑ (Down's syndrome, imperforate anus, renal anomalies, congenital heart disease, etc.).
Malrotation of the intestines and Hirschsprung’s disease must be ruled out before a newborn with unexplained bilious vomiting and/or abdominal distention is sent home. It can be unsafe to rely on parents to observe their infant for problems resulting from the above conditions. If diagnosed late, malrotation of the intestines or Hirschsprung’s disease can become life threatening or result in life long problems.
A. Esophageal Atresia a/o Tracheo-esophageal fistula
The trachea and esophagus initially begin as a ventral diverticulum of the foregut during the third intrauterine week of life. A proliferation of endodermal cells appears on the lateral aspect of this growing diverticulum. These cell masses will divide the foregut into trachea and esophageal tubes. Whether interruption of this normal event leads to tracheo-esophageal anomalies or during tracheal growth atresia of the esophagus results because of fistulous fixation of the esophagus to the trachea remnant to be proven.
EA with distal TEF (87% )- the most common anomaly, the NG tube coiled at T4-5 level and gas will be seen in the KUB. EA without TEF (8%) - pure esophageal atresia, NG coiled at T4-5 level with airless abdomen. TEF without atresia (4%) - pure tracheo-esophageal fistula. EA with proximal TEF (<1%). EA with proximal and distal TEF (<1%)
Congenital isolated tracheo‑esophageal fistula (TEF) occurs as 4‑6% of the disorders of the esophagus bringing problems during early diagnosis and management. More than H‑type is N‑type, due to the obliquity of the fistula from trachea (carina or main bronchi) to esophageal side (see the figure) anatomically at the level of the neck root (C7‑T1). Pressure changes between both structures can cause entrance of air into the esophagus, or esophageal content into the trachea. Thus, the clinical manifestation that we must be aware for early diagnosis are: cyanosis, coughing and choking with feedings, recurrent chest infections, persistent gastrointestinal distension with air, and hypersalivation. Diagnosis is confirmed with a well‑done esophagogram, or video‑esophagogram (high success rates, establish level of the TEF). Barium in the trachea could be caused by aspiration during the procedure. Upon radiologic doubt bronchoscopy should be the next diagnostic step. Any delay in surgery is generally due to delay in diagnosis rather than delay in presentation. Management consists of surgical closure of the TEF through a right cervical approach. Hint: a small guide‑wire threaded through the fistula during bronchoscopy may be of some help. Working in the tracheo‑esophageal groove can cause injury to the recurrent laryngeal nerve with vocal cord paralysis. Recurrence after closure is rare.
3. Diagnostic characteristics:
incidence is one in every 2500 live births. We see between 8-10 per year at the
Correct dehydration, acid-base disturbances, respiratory distress and decompress proximal esophageal pouch (Replogle tube). Evaluate for associated conditions such as VACTERL association (3 or more):
-Vertebral anomalies i.e. hemivertebrae, spina bifida
-Anal malformations i.e. imperforate anus
-Cardiac malformations i.e. VSD, ASD, Tetralogy Fallot
-Tracheo-Esophageal fistula (must be one of the associated conditions)
-Renal deformities i.e. absent kidney, hypospadia, etc.
Early surgical repair (transpleural or extrapleural) for those babies with no evidence of pneumonia, adequate weight (>1200 gm) and no significant associated anomalies. Babies with Chest-X-Ray positive findings, but adequate ABG's can also be primarily repaired. Delayed repair (gastrostomy first) for all other patients. Surgical repair consist of a 4th intercostal space right muscle-sparing thoracotomy (side of thoracotomy is contralateral to side of aortic arch of patient), closure of tracheo-esophageal fistula and primary esophago-esophagostomy. Esophagogram is done 7-10 days after repair.
Complications after surgery are: Anastomotic leak, anastomotic stricture, gastroesophageal reflux, tracheomalacia, and recurrent TEF. The three most common anastomotic complications are in order of frequency: stricture, leakage and recurrent TEF. Recurrent TEF after surgical repair for esophageal atresia occurs in approximately 3‑15% of cases. Tension on the anastomoses followed by leakage may lead to local inflammation with breakage of both suture lines enhancing the chance of recurrent TEF. Once established, the fistula allows saliva and food into the trachea, hence clinical suspicion of this diagnosis arises with recurrent respiratory symptoms associated with feedings after repair of esophageal atresia. Diagnosis is confirmed with cineradiography of the esophagus or bronchoscopy. A second thoracotomy is very hazardous, but has proved to be the most effective method to close the recurrent TEF. Either a pleural or pericardial flap will effectively isolate the suture line. Pericardial flap is easier to mobilize, provides sufficient tissue to use and serves as template for ingrowth of new mucosa should leakage occur. Other alternatives are endoscopic diathermy obliteration, laser coagulation, or fibrin glue deposition.
Achalasia in children is an uncommon esophageal motor disorder distinguished by clinical, radiological and manometrics features. Incidence is estimated in 0.1 cases/year per 100,000 populations under 14 years of age. Clinical presentation is characterized by progressive dysphagia, regurgitation, weight loss, chest pain and nocturnal cough. Infants exhibit failure to thrive. Diagnosis is established by barium swallow and confirmed by manometry and motility studies. Barium swallows shows' esophageal dilatation, motility alteration and a small caliber (bird‑beak) cardio‑esophageal junction. Manometry reveals elevated E‑G sphincter pressure, non‑ peristaltic esophageal contraction and failed relaxation of lower esophageal sphincter upon swallowing. Videofluoroscopy can be of help in the screening of esophageal motors disorders. Esophageal pneumatic balloon dilatation is not an effective method of treatment in children due to the high rate of recurrence of symptoms. Primary therapy is surgical (Heller's modified esophagomyotomy), and results are similar after a transabdominal or thoracic approach. Many authors favor a concomitant antireflux procedure in these patients. Nifedipine can be of help as a short management in preparation for surgery. Long‑term result presents' a connection between achalasia and malignant disease of the esophagus.
C. Gastro-duodenal Anomalies
1. Gastric Anomalies
Congenital gastric outlet obstruction is extremely rare. It occurs either in the pyloric or antral region. Antral membranes (web or diaphragm) are thin, soft and pliable, composed of mucosa/submucosa, and located eccentric 1‑3 cm proximal to pyloro‑duodenal junction. They probably represent the developmental product of excess local endodermal proliferation and redundancy. The diagnosis should rely on history, contrast roentgenology studies and endoscopic findings. Symptoms are those of recurrent non‑bilious vomiting and vary according to the diameter of aperture of the membrane. There is a slight male predominance with fair distribution between age groups in children. Associated conditions: pyloric stenosis, peptic ulcer and cardiac. History of polyhydramnios in the mother. Demonstration of a radiolucent line perpendicular to the long axis of the antrum is diagnostic of a web. Endoscopy corroborates the diagnosis. Management can be either surgical or non‑surgical. Surgical Tx is successful in symptomatic pt. and consist of pyloroplasty with incision or excision of the membrane. Other alternative is endoscopic balloon dilatation or transection of the web. Non‑obstructive webs found incidentally can be managed medically with small curd formula and antispasmodics. The presence of an abnormally dilated gastric bubble in prenatal sonography should alert the physician toward the diagnosis of congenital antro‑pyloric obstruction.
2. Pyloric Stenosis
Is an abnormality of the pyloric musculature (hypertrophy) causing gastric outlet obstruction in early infancy. The incidence is 3 per 1000 live births. The etiology is unknown, but pylorospasm to formula protein cause a work hypertrophy of the muscle. Diagnostic characteristics are: non-bilious projectile vomiting classically 3-6 weeks of age, palpable pyloric muscle 'olive', contrast studies are not necessary when the pyloric muscle is palpated, enlarged width and length in ultrasonography.
The treatment consists in correction of hypochloremic alkalosis and state of dehydration and performing a Fredet-Ramstedt modified pyloromyotomy. Post-operative management consist of: 50% will have one to several episodes of vomiting, usually can feed and go home in 24-36 hours, initial feeds start 8-12 hours after surgery.
3. Duodenal Malformations
Can be intrinsic (Atresia, Stenosis, Webs) or extrinsic (Annular pancreas, Ladd's bands). Occur distal or proximal to the ampulla of Vater. Most commonly distal to ampulla and therefore bilious vomiting is present. (Note: Bilious vomiting is surgical until proven otherwise in a baby).
'Windsock' webs have clinical importance because of their tendency to be confused with distal duodenal obstruction and because of the frequent occurrence of an anomalous biliary duct entering along their medial margin.
Embryology: The first major event in the differentiation of the duodenum, hepatobiliary tree, and pancreas occurs at about the third week in gestation, when the biliary and pancreatic buds form at the junction of the foregut and the midgut. The duodenum at this time is a solid cord of epithelium, which undergoes vacuolization followed by recanalization and restitution of the intestinal lumen over 3-4 weeks of normal development. Failure of recanalization of the second part of the duodenum results in congenital obstruction of the lumen, often in conjunction with developmental malformation of the pancreatic anlagen and the terminal part of the biliary tree. In support of this concept is the high incidence of annular pancreas observed, believed to represent a persistence of the ventral pancreatic anlage in association with intrinsic duodenal obstruction.
The diagnostic characteristics are: bilious vomiting, history of polyhydramnios in mother, KUB with classic 'Double-bubble' appearance, a microcolon in barium enema study or malrotation.
Treatment consists in: (1) duodeno-duodenostomy bypass for atresias, annular pancreas, and some stenosis. (2) duodenoplasty for webs, and stenosis, and (3) lysis of Ladd’s bands and Ladd’s procedure for malrotation.
Associated anomalies are: Down's syndrome (20-30%), VACTERL syndrome, CNS anomalies and cardiac anomalies.
D. Malrotation and Volvulus
Embryology: The rotation and normal fixation of the intestinal tract takes place within the first three months of fetal life. In the earliest stages when the intestinal tract is recognizable as a continuous tube, the stomach, small intestine, and colon constitute a single tube with its blood supply arising posteriorly. The midgut portion of this tube, from the second portion of the duodenum to the mid-transverse colon, lengthens and migrates out into an extension of the abdomen, which lies at the base of the umbilical cord. Here this loop of bowel undergoes a 270‑degree counterclockwise twist at its neck. In the center of the twisted loop lie the blood vessels that will become the superior mesenteric artery and vein. After rotation, the small intestine quite rapidly withdraws into the abdominal cavity, with the duodenum and the proximal jejunum going first. During this process the duodenojejunal junction goes beneath and to the left of the base of the superior mesenteric vessels. This leaves the upper intestine, including the stomach and the duodenum, encircling the superior mesenteric vessels like a horseshoe with its opening on the left side of the embryo. The small intestine then follows into the abdomen, and withdrawal of the right half of the colon takes place so that it lies to the left. At the next step, the cecum and the right colon begin to travel across the top of the superior mesenteric vessels and then down to the right lower quadrant. The colon now lies draped across the top of the superior mesenteric vessels, again like a horseshoe, with its opening placed inferiorly. The duodenojejunal loop is said to attach to the posterior abdominal wall soon after its turn, whereas the mesenteric attachments of the entire colon and of the remaining small bowel gradually adhere after they arrive in their normal positions. In malrotation the right colon can create peritoneal attachments that include and obstruct the third portion of the duodenum (Ladd’s bands).
The diagnostic hallmarks are: bilious vomiting (the deadly vomit), abdominal distension and metabolic acidosis. A UGIS is more reliable than barium enema, most patients present in first month of life (neonatal), but may present at any time.
The treatment is immediate operation; volvulus often means strangulation. Needs fluid and electrolyte replacement. Ladd’s procedure consist of: reduce volvulus with a counterclockwise rotation, place small bowel in right abdomen, lysed Ladd’s bands, place large bowel in left abdomen, do an appendectomy. In cases of questionable non-viable bowel a second look procedure is required.
Failure to make early diagnosis and operate may lead to dead midgut with resultant short bowel syndrome.
E. Intestinal Atresias
Intestinal atresias are the product of a late intrauterine mesenteric vascular accident (blood supply was not received by a portion of bowel) as attested by Louw and Barnard in 1955. They are equally distributed from the ligament of treitz to the ileocecal junction. Colonic atresias are very rare. There is proximal bowel dilatation, with distal (unused) micro-bowel. The diagnosis is suspected with maternal history of polyhydramnios (the higher the atresia), bilious vomiting, abdominal distension and obstipation. KUB shows Athumb-size@ dilated bowel loops, and barium enema a microcolon of disuse. Louw classified them into: Type I: an intraluminal diaphragm with seromuscular continuity. Type II: cord-like segment between the bowel blinds ends. Type IIIA: atresia with complete separation of blind ends and V-shaped mesenteric defect (see figure), the most commonly found. Type IIIB: jejunal atresia with extensive mesenteric defect and distal ileum acquiring its blood supply entirely from a single ileocolic artery. The distal bowel coils itself around the vessel, giving the appearance of an 'apple peel'deformity. Type IV: multiple atresias of the small intestine. After preoperative stabilization (GI decompression, electrolytes disturbances= correction, antibiotherapy, and normothermia), treatment consists of exploratory laparotomy, resection of proximal dilated intestine, and end to oblique anastomosis in distal jejuno-ileal atresias. Tapering jejunoplasty with anastomosis is preferred in proximal defects.
F. Meconium Ileus
Meconium ileus is a neonatal intraluminal intestinal obstruction caused by inspissated meconium blocking the distal ileum. Occurs in 10-15% of all patients with cystic fibrosis, and 85-95% of patients with meconium ileus have cystic fibrosis. The meconium has a reduced water, abnormal high protein and mucoprotein content, the result of decreased pancreatic enzyme activity and prolonged small bowel intestinal transit time.
Meconium Ileus is classified into two types: (1) Simple meconium ileus: The distal small bowel (10-30 cm of distal ileum) is relatively small, measuring less than 2 cm in diameter and contains concretions of gray, inspissated meconium with the consistency of thick glue or putty. It is often beaklike in appearance, conforming to the shape of the contained pellets. Proximally, the mid‑ileum is large, measuring up to 7 cm in diameter. It is greatly distended by a mass of extremely thick, tenacious, dark green or tarry meconium. The unused small colon (microcolon) contains a small amount of inspissated mucus or grayish meconium. (2) Complicated meconium ileus: usually occurs during the prenatal period associated to volvulus, atresias, gangrene, perforation or peritonitis. A cystic mass or atresia of the bowel may occur.
The degree of obstruction varies, may be cured in mild cases by rectal irrigations. Failure to pass meconium, abdominal distension and vomiting are seen in more severe cases. The diagnosis is suspected with findings of: multiple loops of dilated small bowel and coarse granular 'soap-bubble' appearance on plain abdominal films. Some cases may show calcifications in the peritoneum (Meconium peritonitis). The Sweat Test is diagnostic of cystic fibrosis (value over 60 meq/L of sweat sodium or chloride are diagnostic). This test is not useful in infant during first weeks of life.
Therapy is either: (1) Nonoperative- should be tried first. It consists of a careful gastrografin enema after the baby is well-hydrated. Gastrografin is a hyperosmolar aqueous solution of meglumine diatrizoate containing 0.1% polysorbate-80 (tween-80, a wetting agent) and 37% iodine. Its success is due to the high osmolarity (1700 mOsm/liter) which draws fluid into the bowel and softens and loosens the meconium. (2) Surgical therapy that has included: ileostomy with irrigation, resection with anastomosis, and resection with ileostomy (Mikulicz, Bishop-Kopp, and Santulli). Post-operative management includes: 10% acetylcysteine p.o., oral feedings (Pregestimil), pancreatic enzyme replacement, and prophylactic pulmonary therapy. Long-term prognosis depends on the degree of severity and progression of cystic fibrosis pulmonary disease.
G. Hirschsprung's Disease
Hirschsprung's is the congenital absence of parasympathetic innervation of the distal intestine. The colon proximal to the aganglionic segment, in an effort to overcome the partial obstruction, becomes distended and its wall markedly thickened because of muscle hypertrophy. Occurs 1 in 1000-1500 live births with a 4:1 male predominance. 96% are TAGA. 4% prematures.
The parasympathetic ganglion cell network located between the circular and longitudinal muscle layers is referred to as Auerbach's plexus, whereas Meissner's plexus is the submucosal layer of ganglion cells just beneath the muscularis mucosa. In Hirschsprung's disease, ganglion cells are absent from all layers. That aganglionic segment usually involves the terminal intestine, i.e. the rectum or rectosigmoid. The aganglionic segment may, however, include the entire large bowel and even small bowel.
Hirschsprung's disease (HD) is characterized by lack of enteric ganglion cells, hyperplasia of abnormal nerve fibers and a non-propulsive, non-relaxing segment of bowel. Classically the etiology is attributed to a failure of cranio-caudal migration of parasympathetic neural crest cells to the distal bowel. A plausible explanation for the failure of relaxation of the bowel involved is a deficiency of enteric inhibitory nerves that mediates the relaxation phase of peristalsis. These nerves are intrinsic to the gut and are classify as non-adrenergic and non-cholinergic. Nitric oxide (NO) has recently been implicated as the neurotransmitter which mediates the relaxation of smooth muscle of the GI tract in HD. It's absence in aganglionic bowel might account for the failure of relaxation during peristalsis. Besides, adhesions molecules (absent in aganglionic bowel) during early embryogenesis might restrict the neuro-ectodermal origin involved in the initial contact between nerves and muscle cell (synaptogenesis) suggesting that developmental anomaly of innervated muscle and absent NO causes the spasticity characteristic of HD.
Symptoms usually begin at birth, frequently with delayed passage of meconium. Any newborn who fails to pass meconium in the first 24-48 hours of life should be evaluated for possible Hirschsprung's disease. In some infants, the presentation is that of complete intestinal obstruction. Others have relatively few symptoms until several weeks of age, when the classic symptom of constipation has its onset. Diarrhea is not uncommon but differs from the usual infantile diarrhea in that it is associated with abdominal distension. Occasionally the patient will go many years with mild constipation and diagnosis will be delayed.
The diagnosis is first suspected based on history and physical examinations (characteristically there is no stool in rectum and abdominal distension is painless). Initial evaluation includes an unprepped barium enema (the first enema should be a barium enema!). The aganglionic rectum appears of normal caliber or spastic, there is a transition zone and then dilated colon proximal to the aganglionic segment. 24-hrs delayed films shows poor emptying with barium throughout the colon, as opposed to the child with psychogenic stool holding in whom the barium generally collects in the distal rectosigmoid. Rectal suction biopsy is then performed. This can be done without anesthesia and the submucosal plexus is examined for ganglion cells. With experience, a good pathologist (should be an expert!), can identify the presence or absence of ganglion cells in this specimen without a full thickness biopsy. Difficulty in interpreting the specimen or not enough to include several slides of submucosa would require a full-thickness biopsy for definitive diagnosis generally done under general anesthesia. Some centers employ manometry, histochemical studies or special stains for diagnosis. These special studies are only as good as the person performing them and interpreting the results.
The initial treatment requires performing a 'leveling' colostomy in the most distal colon with ganglion cells present. This requires exploration with multiple seromuscular biopsies of the colon wall to determine the exact extend of the aganglionosis. The colostomy is placed above the transition zone. Placement of the colostomy in an area of aganglionosis will lead to persistent obstruction. Once the child has reached an adequate size and age (6-12 months; 20 pounds or more), a formal pull-through procedure is done. Some of this are: Swenson, Duhamel and Soave procedures. Current preference is for Soave procedure (modified endorectal pull-through) and consists of resection of the majority of aganglionic bowel except for the most distal rectum, the mucosa and submucosa of this rectum is excised and the normally innervated proximal bowel is pulled through the seromuscular coat of retained rectum and suture immediately above the dentate line. Recently a laparoscopic pull-through procedure avoiding the colostomy is being used in early life with promising results.
Neuronal Dysplasia (IND) is a colonic motility disorder first described in 1971
by Meier-Ruge associated to characteristic histochemical changes of the bowel
wall (hyperplasia of submucous & myenteric plexus with giant ganglia
formation, isolated ganglion cells in
lamina propria and muscularis mucosa, elevation of acetylcholinesterase in
parasympathetic fiber of lamina propria and circular muscle, and myenteric
plexus sympathetic hypoplastic innervation), also known as hyperganglionosis
associated to elevated acetylcholinesterase parasympathetic staining. The
condition can occur in an isolated form (either localized to colon or
disseminated throughout the bowel), or associated to other diseases such as
Hirschsprung's (HD), neurofibromatosis, MEN type IIB, and anorectal malformations.
It is estimated that 20-75% of HD cases have
H. Imperforate Anus
Embryology- Between 4-6 weeks, the cloaca becomes the common depository for the developing urinary, genital and rectal systems. The cloaca is quite promptly divided into an anterior urogenital sinus and a posterior intestinal canal by the urorectal septum. Two lateral folds of cloacal tissue join the urorectal septum to complete the separation of the urinary and rectal tracts.
Diagnostic evaluation include physical exam for clues such as: meconium 'pearls', bucket handle anus, a fistula or meconium at meatus (urethra). Radiography could be of help initially by using the Wangensteen-Rice 'upside-down' film with opaque marker, sacral films, urogram (IVP and cystourethrogram). Through the distal stoma of the initial colostomy a contrast study (colostogram) can be done to further delineate the recto-urethral fistula associated.
Associated Anomalies: (1) Gastrointestinal- 10-20% of patients with imperforate anus have another GI lesion such as esophageal atresia, intestinal atresia or malrotation. (2) Cardiovascular- approximately 7% have associated CV lesions. (3) Skeletal- approximately 6% have skeletal lesions such as spina bifida or agenesis of the sacrum. (4) Genitourinary- 25-40% of patients will have associated genitourinary anomalies. The incidence is higher with supralevator lesions than with infralevator lesions.
The repair has been revolutionized by Peña approach (Posterior sagittal anorectoplasty procedure). The most important decision in the initial management of Imperforate Anus (IA) male patient during the neonatal period is whether the baby needs a colostomy and/or another kind of urinary diversion procedure to prevent sepsis or metabolic derangements. Male patients will benefit from perineal inspection to check for the presence of a fistula (wait 16-24 hours of life before deciding). During this time start antibiotherapy, decompress the GI tract, do a urinalysis to check for meconium cells, and an ultrasound of abdomen to identify urological associated anomalies. Perineal signs in low malformations that will NOT need a colostomy are: meconium in perineum, bucket-handle defect, anal membrane and anal stenosis. These infants can be managed with a perineal anoplasty during the neonatal period with an excellent prognosis. Meconium in urine shows the pt has a fistula between the rectum and the urinary tract. Flat 'bottom' or perineum (lack of intergluteal fold), and absence of anal dimple indicates poor muscles and a rather high malformation needing a colostomy. Patients with no clinical signs at 24 hours of birth will need a invertogram or cross-table lateral film in prone position to decide rectal pouch position. Bowel > 1 cm from skin level will need a colostomy, and bowel < 1 cm from skin can be approach perineally. Those cases with high defect are initially managed with a totally diverting colostomy. Diverting the fecal stream reduces the chances of genito-urinary tract contamination and future damage.
The most frequent defect in females’ patient with imperforate anus (IA) is vestibular fistula, followed by vaginal fistulas. In more than 90% of females cases perineal inspection will confirm the diagnosis. These infants require a colostomy before final corrective surgery. The colostomy can be done electively before discharge from the nursery while the GI tract is decompressed by dilatation of the fistulous tract. A single orifice is diagnostic of a persistent cloacal defect usually accompany with a small-looking genitalia. Cloacas are associated to distended vaginas (hydrocolpos) and urologic malformations. This makes a sonogram of abdomen very important in the initial management of these babies for screening of obstructive uropathy (hydronephrosis and hydroureter). Hydrocolpos can cause compressive obstruction of the bladder trigone and interfere with ureteral drainage. Failure to gain weight and frequents episodes of urinary tract infections shows a poorly drained urologic system. A colostomy in cloacas is indicated. 10% of babies will not pass meconium and will develop progressive abdominal distension. Radiological evaluation will be of help along with a diverting colostomy in these cases. Perineal fistulas can be managed with cutback without colostomy during the neonatal period.
Duplications of the gastrointestinal tract are considered uncommon congenital anomalies usually diagnosed or unexpectedly encountered intraoperatively during the first two years of life. The duplicated bowel can occur anywhere in the GI tract, is attached to the mesenteric border of the native bowel, shares a common wall and blood supply, coated with smooth muscle, and the epithelial lining is GI mucosa. May contain ectopic gastric or pancreatic tissue. Most are saccular, other tubular. Theories on their origin (split notochord syndrome, twining, faulty solid‑stage recanalization) do not explain all cases of duplicated bowel. Three‑fourth are found in the abdomen (most commonly the ileum and jejunum), 20% in the thorax, the rest thoraco‑abdominal or cervical. Symptoms vary according to the size and location of the duplication. Clinical manifestations can range from intestinal obstruction, abdominal pain, GI bleeding, ulceration, or mediastinal compression. Ultrasound confirms the cystic nature of the lesion (muscular rim sign) and CT the relationship to surrounding structures. Management consists of surgical excision avoiding massive loss of normal bowel and removing all bowel suspect of harboring ectopic gastric mucosa.
Although intussusception can occur at any age, the greatest incidence occurs in infants between 4-10 months of age. Over half of the cases are in the first year of life. Frequently occurs after a recent upper respiratory infection, by Adenovirus type 3 that causes a reactive lymphoid hyperplasia that act as lead point (of Peyer's patch).
A definite lead point is identified in about 5% of patients. These include: Meckel's diverticulum, polyps, Henoch's Schönlein purpura, hematoma, lymphoma, foreign bodies, and duplications. Most children have no lead point and it is felt that enlarged mesenteric nodes or swollen Peyer's patches may be the cause. The baby has intermittent periods of severe discomfort with screaming, stiffening and drawing up of the legs, followed by periods of rest. Vomiting may occur and bloody, mucoid (currant jelly) stool may be passed. The baby may become dehydrated and appear acutely ill. Frequently, lethargy may be an early sign. The diagnosis is made by water soluble contrast colon enema. Hydrostatic reduction of the intussusception with the contrast material is successful in approximately 50% of cases. To be successful, the water soluble material must reflux into the terminal ileum. The surgeon should be notified before an attempt at hydrostatic reduction. Recently the use of gas enema reduction has been successful in patients with: (1) symptoms less than 12 hours, (2) no rectal bleeding, (3) absence of small bowel obstruction, and (4) normally hydrated. Ultrasonography can be used as a rapid sensitive screening procedure in the initial diagnosis of intussusception. Previous adverse clinical features that precluded barium reduction can be replaced during gas reduction. Predictors of failure of reduction are: (1) ileocolic intussusception, (2) long duration of symptoms, (3) rectal bleeding, and (4) failed reduction at another institution. Air reduction (pneumocolon) is a very effective alternative method since it brings less radiation (shorter fluoroscopy time), less costs and less morbidity in cases of perforations.
Failure of hydrostatic reduction requires urgent operation through a right lower quadrant horizontal incision. The intussusception is reduced by pushing on the distal bowel like a tube of toothpaste rather than pulling the proximal bowel and appendectomy is added as cecopexy and avoidance of future diagnostic problems of a RLQ incision. Most cases are ileo-colic intussusception, and a few are jejuno-jejunal or ileo-ileal intussusception.
Included in this group because is caused by obstruction of the appendiceal lumen, most commonly by fecaliths. When obstruction occurs, secretions from the appendix accumulate and acutely distend the lumen. The pressure eventually produces arterial obstruction leading to infarction. Bacteria initially invade the mucosa and produce intramural infection. Other causes include pinworm infestation, carcinoids and lymphoid hyperplasia.
Initially periumbilical pain secondary to distension of the lumen of the appendix occurs. Pain impulses from the wall of the distended appendix are carried by visceral afferent sympathetic fibers through the celiac ganglion to T10 and then referred to the umbilical area in the tenth dermatome. Later the pain shifts to the right lower quadrant of the abdomen, where it localizes. The shift in location is an important diagnostic sign and indicates the formation of irritating exudate around the inflamed appendix that stimulates the pain receptors of the peritoneum locally. Anorexia, nausea and vomiting follow the onset of abdominal pain.
Physical findings include an obviously ill-appearing child who usually will walk slowly and bent over. Motion, heel tap, or bouncing on the heels will elicit pain in the right lower quadrant. Point tenderness in the right lower quadrant (or the persistence of right lower quadrant pain) is the most reliable physical finding. There is usually rebound and referred pain to the right lower quadrant, indicating peritoneal inflammation. Fever is usually present. Laboratory findings are an elevated white blood cell count in most instances. Very high WBC's > 18,000 may indicate perforation. Urinalysis is generally clear, but occasionally RBC's or WBC's may be associated with the inflamed appendix adjacent to the bladder or ureter. Radiographic findings may include ileus, appendicolith (pathognomonic finding), splinting, abdominal wall edema, and only very rarely, free air.
Initial treatment is rehydration to establish adequate urinary output. Any evidence of possible perforation should mandate the use of appropriate antibiotics. Once adequate then surgical intervention proceeds quickly. Most patients are approached through a right lower quadrant horizontal muscle splitting incision. Removal of the appendix, irrigation and, when localized abscesses are identified, institution of drainage.
Appendicitis is usually diagnosed from signs, symptoms and results of simple laboratory tests a/o simple abdominal films. After simple abdominal films an appendicolith (coprolith, fecalith, retained barium or foreign body) is sometimes found in the symptomatic child with right lower quadrant pain or less commonly in an asymptomatic situation. In the child WITH SYMPTOMS of low abdominal pain this finding should be followed by appendectomy. Appendiceal fecaliths and calculi play a role in the pathogenesis of appendicitis and are associated with perforation and gangrene. In the ASYMPTOMATIC situation a prophylactic appendectomy is NOT justified when an appendicolith, retained barium or another foreign body within the lumen of the appendix is identified. A normal appendix will expel the appendicolith or barium in a variable period. The parents should be informed that appendicitis may develop and that the child should seek a physician if abdominal symptoms develop. A note should appear in the record explaining this conversation.
In the event of right lower abdominal pain caused by appendicitis, almost 15% of children will present with a right lower quadrant mass effect. The mass can be a phlegmon with a central inflamed appendix which appears after four to five days from the onset of abdominal pain accounting for 50% of appendiceal masses. Almost 20% of these masses will contain a frank abscess cavity. Periappendiceal masses are the result of perforated appendicitis. Due to the increase use of abdominal CT in the setting of abdominal pain more cases of periappendiceal phlegmon/abscess are discovered with this diagnostic modality. CT is reliable in distinguishing periappendiceal abscesses from phegmons and its use can be extended into percutaneously draining the abscess cavity. US with color Doppler demonstrate a hyperemic periappendiceal or pelvic fluid collection and periappendiceal soft-tissue hyperemia. Management of a periappendiceal abscess depends on the clinical condition of the child. Nontoxic patient with mild peritoneal signs warrants non-operative management with intravenous fluids and antibiotics until the acute process subsides. Rising heart rate, continued spiking fever, worsening peritoneal signs, intestinal obstruction or enlargement of the mass may require urgent surgery. Patients undergoing initial nonoperative management have a lower rate of complications. Six to eight weeks after resolution of the inflammatory process interval appendectomy is recommended to avoid recurrent abdominal pain. Laparoscopic appendectomy can be performed safely and effectively in such interval cases.
Mesenteric lymphadenitis is the condition most commonly mimicking acute appendicitis resulting in a high rate of negative appendectomies in children. Mesenteric adenitis is frequently associated with an upper respiratory infection. Clinical presentation includes fever, leukocytosis and low abdominal pain. Mesenteric adenitis can be the result of a viral or bacterial infection. Viruses implicated include Epstein-Barr; Adenovirus type 3, influenza B and Coxsackie B. Bacteria associated with mesenteric adenitis includes hemolytic streptococci, Yersinia and Salmonella species. The diagnosis of mesenteric adenitis is principally one of exclusion. CT-Scan can help decide whether the child has mesenteric adenitis when the lymph nodes aggregates can be clearly seen. Otherwise, since it can be very difficult to distinguish appendicitis from mesenteric adenitis the diagnosis is establish at surgery. Laparoscopy can also be useful to differentiate appendicitis from mesenteric adenitis. After surgery the postoperative course of children with mesenteric adenitis is usually uneventful and recovery is rapid.
L. Chronic Intestinal Pseudo-Obstruction
Chronic Intestinal Pseudo-Obstruction is a rare disorder of intestinal motility in infants and children characterized by recurrent attacks of abdominal pain, distension, vomiting, constipation and weight loss in the absence of obvious mechanical lesions. The disease can be familial or sporadic. Suggested etiology is degeneration of enteric nervous or smooth muscle cells. The diagnosis is based on history, physical exam, radiographies and motility studies. X-Ray hallmarks are: absent strictures, absent, decreased or disorganized intestinal motility, and dilated small/large bowel loops. Associated conditions identified in 10-30% of patients are bladder dysfunction (megacystis) and neurological problems. Histologic pattern portrayed: myenteric plexus hyperplasia, glial cell hyperplasia, and small ganglion cells (hypoganglionosis). Management is primary supportive: intestinal decompression (NG), long-term TPN and antibiotic prophylaxis. Motility agents are unsuccessful. Venting gastrostomy with home parenteral nutrition has shortened the high hospitalization rate associated to this disease process. A similar condition can be seen in early fed prematures due to immaturity of intestinal motility.
are rare foreign body concretions formed in the stomach and small bowel
composed mainly of hair (tricho), vegetable matter (phyto) or milk curds
(lacto). Most cases are females’ children, 6-10 years old, with bizarre
appetite (trichophagia) and emotional disturbances. Originally the mass forms
in the stomach and can move to the small bowel by fragmentation, extension or
total translocation. Diagnosis can be confirmed by
This argentaffin cell tumor causes interest because of its diverse presentation, hormonal secretion, and malignant potential. The carcinoid is the most common neoplasm of the GI tract in childhood and may occur at any site along the alimentary tract. Above the diaphragm is commonly identified in the bronchus, and below the diaphragm in the appendix. Female predominates, the tumor is seldom life‑threatening, and children rarely develop hormonal hypersecretion of 5‑hydroxy indole acetic acid (Carcinoid syndrome). Carcinoids are usually discovered as an incidental finding during surgery done for other reasons. The appendix tumor arises from subepithelial endocrine cells with exclusive growth in the lamina propria beneath the epithelial crypts. Most tumors are found in the tip of the appendix. Simple appendectomy is curative in most cases. Tumors larger than 2 cm invading neighboring structures may need right hemicolectomy. Long term follow‑up is imperative.
The carcinoid syndrome (fascial flushing, diarrhea, tricuspid regurgitation, pulmonic stenosis, valvular fibrosis and wheezing) is the result of serotonin overproduction by a carcinoid tumor. Carcinoid tumors arise from enterochromaffin cells (APUD cells from the neural crests), occur in virtually every organ, could be multiple, metastatic and associated with a second malignancy. Patients are diagnosed biochemically from increased urinary excretion of 5‑hydroxyindoleacetic acid (5‑HIAA). Platelet serotonin levels are more sensitive for detecting carcinoids that secrete small amounts of serotonin. Jejunum‑ileum, bronchus and appendix are the most common sites of origin. Carcinoid of the appendix is the most common neoplasm of the GI tract in childhood. Metastasis to liver of midgut carcinoids produces the syndrome. Tumors greater than 2 cm are more prone to metastasis needing aggressive surgical management. Octreotide scan and I‑131 MIBG are useful in determination of location and extent of some carcinoid tumors, particularly those of midgut origin. A positive scan may predict the ability of Octreotide therapy to control symptoms of hormonal hypersecretion. Scans provide localization of the primary tumor that should be widely excised including lymph nodes. Higher survival rates are found for patients with midgut lesions who undergo intra abdominal debulking procedures excluding the liver. For single liver lesion resection is justified, otherwise with multiple diffuse disease hepatic artery ligation or embolization has been tried. Symptomatic metastasis should be managed with Octreotide. Prognosis is associated with the presence of liver metastasis, syndrome development and level of tumor markers (chromogranin A).
O. Meconium-related Disease
1. Meconium Ileus
Meconium Ileus (MI) is a neonatal intraluminal intestinal obstruction associated with Cystic Fibrosis (10‑20%). The distal ileum is packed with an abnormally thick, viscous, inspissated meconium. The meconium has reduced water content the result of decreased pancreatic enzyme activity and a prolonged small bowel intestinal transit time. MI can be classified as simple or complicated. Simple MI appears in the first 48 hrs of life with abdominal distension and bilious vomiting. Complicated MI is more severe (< 24 hrs) with progressive abdominal distension, respiratory distress, and peritonitis. X‑Ray findings are: dilated bowel loops, absent air‑fluid levels, 'soap‑bubble' granular appearance of distal ileum due to a mixture of air with the tenacious meconium. Therapy consists of Gastrografin enema for simple cases: hyperosmolar solution draws fluid to the bowel lumen causing an osmotic diarrhea. Operative therapy is reserved for failed gastrografin attempts and complicated cases (associated to volvulus, atresias, gangrene, perforation or peritonitis). Surgical procedures have included: ileostomy with irrigation, resection with anastomosis, and resection with ileostomy (Mikulicz and Bishop‑ Kopp). Post‑operative management includes: 10% acetylcysteine p.o., oral feedings (Pregestimil), pancreatic enzyme replacement, and prophylactic pulmonary therapy. Long‑term prognosis depends on the degree of severity and progression of cystic fibrosis pulmonary disease.
2. Meconium Peritonitis
Meconium peritonitis (MP) is a chemical peritonitis that occurs following bowel perforation during fetal life. It is generally looked upon as benign, resulting in no long‑term sequelae. The peritonitis occurs when the meconium leaves the bowel, enters the peritoneal cavity and spreads throughout causing a sterile inflammatory reaction. Most common site of bowel perforation is the distal ileum, and 50% of babies with MP develop intestinal obstruction. Prenatal ultrasound findings include ascites, intraabdominal masses, bowel dilatation and the development of intraabdominal calcifications. Bowel disorders which lead to MP in utero are those resulting in bowel obstruction and perforation, such as small bowel atresias, volvulus and meconium ileus. MP can be divided into simple or complex. Cases with spontaneously healed perforation (simple MP) need observation as they rarely develop symptoms. Newborns with complex MP are born with bowel obstruction a/or pseudocyst formation (localized collection of meconium contained in a cyst made of fibrous granulation tissue). Complex MP needs surgical therapy.
3. Meconium plug syndrome/Left hypoplastic colon syndrome
Colonic obstruction in the newborn child could be the result of necrotizing enterocolitis, atresia, meconium plug syndrome, duplication cyst, Hirschsprung disease or the small left colon syndrome. In meconium plug syndrome the baby expels a grey-meconium and the obstruction subsides. Meconium plug syndrome can be associated with Hirschsprung’s disease so a rectal biopsy is in order. The left (small) hypoplastic colon syndrome (LHCS) is a very rare cause of colonic obstruction identified in newborns with characteristic roentgenographic features resembling those of Hirschsprung's disease. Manifesting in the first 24‑48 hours of life, LHCS is a functional disturbance related to immaturity of the intrinsic innervation of the colon that is especially common in low birth weight neonates or of diabetic mothers. Intestinal perforation, sepsis, hypoglycemia and death may occur. The diagnosis is suggested in a barium enema when the caliber of the left colon is small with a transitional zone at the splenic flexure. Management consists of hypoglycemia correction, antibiotics, nasogastric decompression and observation. In most babies the obstruction clears in 48‑72 hours. When the clinical diagnosis is not readily apparent a rectal biopsy and sweat chloride test should be done to differentiate LHCS from Hirschsprung disease and cystic fibrosis respectively. The narrowed left colon remains narrow in follow‑up.
P. Fecal Incontinence
Fecal incontinence (FI) in children is usually the result of a congenital (imperforate anus, Hirschsprung's disease and myelomeningocele) or acquired (trauma, pelvic tumor resection and spinal cord injury) condition. FI causes a psychological, developmental and social stress of great magnitude. Assessment of the problems includes the use of anal tonometry, electromyography and pudendal nerve terminal motor latencies. Rectal emptying and angulation can be evaluated with defecogram, MRI or scintigraphic proctography. The management of FI is complex. For HD biopsychosocial treatment consisting of explanation, extinction of fear and avoidance behavior, learning new defecation behavior, learning an adequate straining technique, and generalization toward daily life have been effective. Biofeedback is a harmless and inexpensive treatment coordinating pelvic floor muscle contraction with the sensation of rectal filling but has brought partial success in children with FI. Other less effective forms of treatment are dynamic graciloplasty and sacral nerve stimulation. Functional constipation associated with fecal incontinence and the presence of segmental dilatation of the sigmoid or rectum responds poorly to medical management. The mega-bowel lacks an adequate anorectal reflex, shows decrease propulsive function causing a functional obstruction. Segmental resection of the dilated segment has brought successful relief of symptoms. Antegrade enemas by way of an appendicocecostomy or cecostomy tube can achieve total colonic evacuation and socially controlled continence in children with anorectal malformations and caudal agenesis in a high percentage of cases.
Q. Inflammatory Bowel Disease
1. Crohn's Disease
Crohn's (terminal ileitis) is a chronic, transmural inflammatory bowel disease most frequently involving the terminal ileum and proximal colon that adversely affect growth and sexual maturation in children. Incidence is growing and etiology is undetermined. Diarrhea, abdominal pain, failure to thrive and weight loss is the most frequent clinical feature. Diagnosis is established by colonoscopy or imaging studies (CT-Scan). Initial management is medical and consists of Azulfidine or 5-amino salicylic acid preparations, local and systemic steroids, metronidazole, immunosuppressives, and enteral and/or parenteral nutrition. Indication for surgery is limited to complications of the disease process and includes failure of medical therapy, perforation, abscess, severe malabsorption and growth retardation, persistent bowel obstruction, fistulas (entero-enteric and entero-urinary) and strictures. Surgery can be accomplished using limited resection and anastomosis or stricturoplasty. Best long-term results after surgery occurs in children with disease confine to the small bowel and ileocecal region. Diffuse ileocolonic involvement (Panenteritis), preoperative use of 6-MP, and colonic involvement is associated with early relapse. Early relapse after surgery is also seen after failure of medical therapy independent of disease location as the sole indication for surgery and in children undergoing resection within one year of the onset of symptoms. 2.
2. Ulcerative Colitis
Ulcerative colitis (UC) is a chronic debilitating inflammatory disease of the bowel affecting primarily the mucosa and to a lesser extent to the adjacent submucosa. UC affects mainly the rectum and colon causing delayed growth and development. In some children the terminal ileum is affected. Cause of UC remains unknown. Peak incidence is between 1.5 and 17 years (mean 11 years). UC originates as an acute inflammation of the crypts (cryptitis) developing tissue reaction of chronicity. More than 90% children with UC have moderate to severe disease. Clinically, the child with UC develops bloody diarrhea, abdominal cramps, anemia, fever, tachycardia, hypoalbuminemia and weight loss. Colonoscopy is diagnostic. Medical management includes restriction of milk protein from diet, parenteral nutrition, steroids, sulfasalazine, metronidazole, 6-mercaptopurine, cyclosporine and tacrolimus. UC can be cured by surgical resection of the colon. Indications for surgery in UC include inability to attain growth and development under medical therapy, fulminant disease refractory to medical therapy, extensive rectal bleeding, perforation and toxic megacolon. Surgical management consists of total proctocolectomy and ileal pouch anal anastomosis. The J-pouch is the simplest to construct. Retention of mucosa above the dentate line after surgery produces recurrent inflammatory disease and high risk of developing carcinoma. A low risk of bladder dysfunction and impotence due to damage to pelvic nerves is associated with proctocolectomy. Postop complications are associated with duration of the disease and length/dosage of medication (steroids). Long-term function after surgery is good in more than 90% of children with high patient satisfaction.
R. Intractable Constipation & Encopresis
Constipation is a common abdominal symptom in childhood. In the majority of cases no cause is identified and the condition is labeled as idiopathic. More than 90% of children with idiopathic constipation respond to medical treatment (bulk diet, laxatives and enemas). Less than 10% develops intractable constipation. Intractable constipation, not associated to Hirschsprung's disease, neuromuscular disease or repaired anorectal malformations, that fails to respond to aggressive medical management is one of the most difficult conditions to manage in children. Children have duration of symptoms for a period beyond five years. Intractable constipation produces progressive fecal retention, fecal incontinence, distension of the rectum and sigmoid colon with loss of rectal sensory and motor function. Encopresis ensues when fecal soiling results from the retained fecal material. Idiopathic constipation is associated with a thickened internal anal sphincter. Colonic manometry helps differentiate causes of intractable constipation in childhood showing the length of the abnormal colonic involved segment. Surgical management for intractable constipation can consist of internal myectomy, placement of cecostomy or left-colon tubes for antegrade enema cleansing, or resection of the disease colonic segment when there is severe stasis and luminal dilatation. Outcomes have thrown mixed results.
Encopresis refers to the involuntary loss of formed, semiformed, or liquid stools into the child's underwear in the presence of constipation Solid fecal material accumulated in the distal rectum unable to be discharged appropriately produces seepage of more proximally fecal fluid which escapes unconsciously into the cloths of the child. It's a very difficult social and physical problem to manage satisfactorily in the child. Encopresis is a complex abnormal motility disorder, requiring a multidisciplinary approach. The most common causes associated with encopresis consist of slow transit functional constipation, Hirschsprung's disease and anorectal malformations. Severely constipated children with encopresis in whom outpatient management has failed frequently require several days of hospitalization, as well as conventional treatments involving cathartics and enemas. A balanced electrolyte solution of the nonabsorbable polymer polyethylene glycol (Golytely) offers a safe and efficient method for clearing the intestine in such cases. Children with encopresis have normal functioning internal sphincter and can acquire normal bowel control using biofeedback therapy to correct the abnormal defecation dynamics. A continent appendicostomy (Malone procedure) is a promising treatment that completely cleanses the colon, increases the child's autonomy, and decreases the chance of soiling in intractable cases of encopresis with pseudo-incontinence.
S. Short Bowel Syndrome
Short bowel syndrome is a very serious gastrointestinal disorder characterized by the absence of significant length of bowel capable of normal digestion and absorption. It is estimated that more than 70% of small bowel length must be lost to develop a short bowel syndrome. The three most common causes of short bowel syndrome in the pediatric age are necrotizing enterocolitis, midgut volvulus and gastroschisis. Intestinal adaptation can occur when the neonate is left with more than thirty (30) centimeters of small bowel with an intact ileo-cecal valve. Though the prospect of bowel transplant continues to develop better forms of avoiding acute rejection, still the median survival after transplantation is short (mean of 15 months). Recently, a novel experimental procedure has attained the attention of surgeons managing this devastating disease complication. The operation is termed serial transverse enteroplasty (STEP) procedure. After short bowel ensues the process of adaptation includes mucosal hyperplasia and bowel dilatation. The STEP procedure is based on the anatomic principle that the blood supply to the bowel comes from the mesenteric border traversing along the perpendicular long axis of the bowel. Multiple stapler lines are placed perpendicularly alternating the direction of the stapler creating a channel of bowel smaller in diameter and longer in length than the original bowel. Advantages of STEP: easy to do, no anastomosis needed, does not result in intestinal obstruction, mesentery is not jeopardized, the length is almost double, the tapering is customizable, and can be performed in sequence after a successful Bianchi procedure. STEP could become the lengthening bowel procedure for short bowel syndrome.
T. Gardner’s & Turcot Syndrome
Gardner's syndrome refers to a group of children born with familial adenomatous (multiple) polyposis and significant extracolonic manifestations. Familial adenomatous polyposis is an autosomal dominant disorder originating from a germline alteration of the adenomatous polyposis coli gene in the long arm of chromosome 5. The most significant extracolonic manifestation of Gardner's syndrome consists of soft tissue (desmoid) tumors and osteomas. Bowel cancer develops in one-third of patients with Gardner's syndrome from malignant degeneration of the adenomatous polyps. Desmoid tumors are typically benign but locally aggressive slow-growing tumors that surround and compress adjacent vascular structures and viscera. Affected children are asymptomatic until they manifest rectal bleeding or multiple soft/hard tissue tumors. Osteomas appear in the mandible causing dental abnormalities (odontomas, cementomas, cysts, supernumerary teeth). Surveillance by colonoscopy is imperative in affected family members. Development of a subcutaneous fibroma single or multiple that recurs as a desmoid tumor is a sentinel event identifying children with Gardner's syndrome. Management of Gardner's syndrome consists of excision of the soft/hard tissue tumor and removal of the affected colon (proctocolectomy) with preservation of the sphincteric muscle mechanism. Sulindac has been reported to produce drug-induced complete regression of colonic adenomas in Gardner's syndrome.
Turcot (glioma-polyposis) syndrome refers to the presence of multiple adenomatous polyposis coli associated with glioblastoma multiforme, medulloblastoma, or glioma developing during the pediatric teens. The polyposis in Turcot is associated with a low number of polyps, large polyps over three cm in diameter, and complication by colonic cancer occurring during the second or third decades of life. Turcot syndrome is determined by an autosomal gene with pleiotropic effect and variable expressivity. Children with Turcot syndrome can develop multiple regions of congenital hypertrophy of the retinal pigment epithelium with areas of surrounding hypopigmentation in the fundi of both eyes, a fact which can help in the diagnosis. Two types of Turcot syndrome have been identified: Type I, also known as true Turcot syndrome (autosomal recessive) with less than 100 intestinal polyps, large size and apt to transform to the malignant tumor. Brain tumor is mainly diagnosed as glioblastoma or astrocytoma and mismatch repair genes might be involved. Type II with FAP-associated type (autosomal dominant) predisposing to medulloblastoma. Management in both cases is surgical.
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