Pediatric Surgery 66 - Gastrointestinal system 2

  1. What are the clinical features of congenital hypertrophic pyloric stenosis? What is the operative treatment? What are the post operative complications? [TU 2059]
    What is Congenital Hypertrophic Pyloric Stenosis?
    It is hypertrophy of musculature of pyloric antrum, especially the circular muscle fibres, causing primary failure of pylorus to relax. Duodenum is normal.
  2. Clinical features of CHPS?
    • • Common in first born males (4:1).
    • • It is most common between the ages of 2 and 8 weeks of an infant, the time taken by the hypertrophied muscle to cause complete obstruction.
    • • Vomiting—forcible, projectile and non-bilious.
    • • Visible gastric peristalsis - a wave of contractions from the left upper quadrant to the epigastrium
    • • Palpable lump of hypertrophied pylorus which is better felt from left side, as a mobile, smooth, firm mass (olive shaped), with all borders well made out, moves with respiration, with impaired resonance on percussion. It is the most important clinical feature (95%).
    • • Constipation.
    • • Dehydration and loss of weight.
    • • Electrolyte imbalance – hypokalaemic metabolic alkalosis.
  3. Diagnosis if CHPS?
    • — Clinical examination -
    • — U/S abdomen (very useful)—Doughnut sign. When olive is not appreciated, USG is done. 
    • • Pyloric muscle 4 mm or more in thickness.
    • • Length of pyloric canal > 1.8 cm.
    • — Barium meal shows obstruction.
  4. Treatment of CHPS?
    Short note on  Ramstedt's operation [TU 2067]
    Correction of electrolytes and dehydration - If not, there is a high risk for postoperative apnea because the infant with metabolic alkalosis has a propensity to compensate by retaining respiratory carbon dioxide. Thus, the serum bicarbonate level needs to be normalized before surgery, at least to a value of less than 30 mEq/L.

    Surgery (Ramstedt’s operation) - After laparotomy, hypertrophied muscle is cut along the whole length adequately until the mucosa bulges out. Mucosa should not be opened (pyloromyotomy). If mucosa is injured, it should be sutured horizontally using interrupted vicryl or silk sutures.
  5. What is duodenal atresia?
    • Duodenal atresia is thought to result from failure of vacuolization of the duodenum from its solid cord stage.
    • Atresia is distal to ampulla.
  6. Types of duodenal atresia?
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  7. Associations of duodenal atresia?
    • Prematurity
    • Down syndrome
    • Malrotation
    • Annular pancreas
    • Biliary atresia
  8. Clinical features?
    • • Bilious vomiting
    • • Features of gastric outlet obstruction.
    • • Dehydration. Electrolyte changes are common.
    • • Growth retardation of new born due deprived nutrition (by swallowed amniotic fluid in fetus).
  9. Investigation of duodenal atresia?
    • Infants with duodenal obstruction are generally first detected during a prenatal ultrasound evaluation. Maternal polyhydramnios is present. 
    • Immediately after birth. Plain X-ray shows classic double – bubble sign with absence of air in the distal part.
  10. Management of duodenal atresia?
    • Surgical bypass of the duodenal obstruction as a side-to-side or proximal transverse to distal longitudinal (diamond-shaped) duodenoduodenostomy.
    • At the time of anastomosis, additional intestinal atresia should be ruled out by injecting saline into a distal limb using a soft red rubber catheter.
    • Transanastomotic nasojejunal or gastrostomy tube for feeding purpose is needed as prolonged postoperative ileus is the usual problem. 
    • Tapering duodenoplasty - staples or sutures to narrow the duodenal calliber to lessen duodenal dysmotility.
    • Windsock deformity - web is excised transduodenally, prevent injury to ampulla.
  11. Short note on Anorectal malformations. [TU 2073,70,67]
    Short note on Imperforates anus [TU 2069, 2065, 2063]

    Embryology of anorectal malformation?
    • The Cloaca formed at 21 days of gestation is U-shaped, with allantosis lying anteriorly and hindgut posteriorly. At 6 weeks of gestation, Urorectal septum moves caudally to divide the cloaca
    • - Anterior urogenital sinus and
    • - Posterior anorectal canal

    • Failure of this migration results in fistula formation.
    • Complete or partial failure of anal membrane to resorb results in an anal membrane or stenosis.
    • Perineal body is formed by the fusion of cloacal folds between the anal and the urogenital membranes
    • Breakdown of the cloacal membrane anywhere along the course results in the external opening being anterior to the external sphincter
  12. Classification of anorectal malformation?
    • An anatomic classification of anorectal anomalies is based on the level at which the blind-ending rectal pouch ends—low, intermediate, or high in relationship to the levator ani musculature.
    • High - Supralevator 
    • Low - Infralevator 

    • If an anocutaneous fistula is observed anywhere on the perineal skin of a boy or external to the hymen of a girl, a low lesion can be assumed
    • Rectal atresia refers to an unusual lesion in which the lumen of the rectum is completely or partially interrupted, with the upper rectum being dilated and the lower rectum consisting of a small anal canal.
    • In girls, a single orifice in the perineum indicates a cloaca. If two perineal orifices are seen (i.e., urethra and vagina), the defect represents a high imperforate anus or, less commonly, a persistent urogenital sinus comprising one orifice and a normal anus as the other orifice.

    • Males
    • Low - 
    • Covered canal (Complete)/anal atresia 
    • Anal stenosis 
    • High - 
    • Rectoperineal fistula
    • Rectourethral bulbar fistula
    • Rectourethral prostatic fistula
    • Rectobladder neck fistula
    • Imperforate anus without fistula
    • Rectal atresia/rectal stenosis

    • Females
    • Low - 
    • Covered canal (Complete)/anal atresia 
    • Anal stenosis 
    • High
    • Rectovesical 
    • Rectovaginal 
    • Rectoperineal fistula
    • Rectovestibular fistula
    • Cloaca
    • Complex malformations
    • Imperforate anus without fistula
    • Rectal atresia/rectal stenosis
  13. Management of ARM?
    • A) During the first 24 hours 
    • - NPO
    • - i.v fluids
    • - Antibiotics
    • - Evaluate for any associated anomalies–Nasogastric tube to exclude esophageal atresia, Echocardiogram to exclude cardiac malformations, radiograph of the lumbar spine and the sacrum, Spinal ultrasonogram to evaluate for a tethered cord,  USG of the abdomen to evaluate for renal anomalies, Urine analysis


    • B) Re evaluate after 24 hours
    • 1. Perineal fistula - anoplasty, without a protective colostomy, can be performed during the first 48 hours of life.

    • 2. No meconium on the perineum, obtain cross-table lateral radiograph with the patient in the prone position
    • A. Air in the rectum below the coccyx, with patient in good condition with no significant associated defects - PSARP with or without a protective colostomy.
    • B. If the rectal gas does not extend beyond the coccyx, or the patient has meconium in the urine, an abnormal sacrum, or a flat bottom - colostomy should be done. Perform a PSARP 1 to 2 months later, provided the neonate is gaining weight appropriately.



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  14. Surgical management of ARM?

    Describe the various surgical approaches for the management of imperforated anus. [TU 2063]
    • A) Low lesions -  
    • 1. Anal opening in normal location -  can undergo a primary single-stage repair without colostomy. Serial dilation alone is usually sufficient. Dilations are performed daily with gradual size increase over time.
    • 2. Anal opening  anterior to the external sphincter (i.e., anteriorly displaced anus), with a small distance between the opening and the center of the external sphincter, and the perineal body is intact - a cutback anoplasty 
    • 3. Significant distance between the anal opening and central portion of the external anal sphincter - transposition anoplasty is performed in which the aberrant anal opening is transposed to the normal position within the center of the sphincter muscles, and the perineal body is reconstructed.


    B) Intermediate or High Lesions - Three stage reconstruction

    First stage (Colostomy) - Colon is completely divided & end sigmoid colostomy with a mucous fistula is constructed to minimize contamination into the area of a rectourinary fistula. Furthermore, the distal mucous fistula limb can be used later for a contrast study to determine the rectourinary fistula. 

    Second-stage (PSARP) - Performed at 3 to 6 months of age. 

    Third stage (Colostomy closure) - Followed by anal dilation 2 weeks post anorectoplasty and continuing several months post colostomy closure
  15. What is cutback anoplasty?
    This consists of an incision extending from the ectopic anal orifice to the central part of the anal sphincter, thus enlarging the anal opening
  16. Steps of Posterior sagittal anorectoplasty (PSARP)?
    • Determining the location of the central position of the anal sphincter by electrical stimulation of the perineum.
    • Patients placed in the prone position with the pelvis elevated.
    • A Foley catheter placed before the prone positioning.
    • The posterior sagittal incision length varies with anorectal defect.
    • The skin and subcutaneous tissue are divided, and the parasagittal fibers below are divided in the midline.
    • The levator muscle is then opened, and the rectum is found.
    • Posterior wall of rectum is opened in the midline and is carried down to the fistula site.
    • Meticulous dissection is required to separate the distal rectum from the urethra.
    • This dissection facilitated by placing multiple 6-0 silk sutures in the rectal mucosa to exert uniform traction.
    • The opening in the urethra then closed with absorbable suture.
    • Once the rectum is separated, it is then mobilized down to reach the perineum.
    • The rectum is placed in the limits of the sphincter mechanism, which is reconstructed in the midline.
    • The rectum is sutured to the perineal skin (anoplasty).
  17. Post operative care in PSARP?
    • Oral feeding initiated as soon as possible post operatively
    • Urinary catheter for 7 days
    • In case of cloacal repair urethral catheter for 3 weeks
    • During laparotomy sometimes colostomy care required
    • Dilatation program 2 weeks after surgery
    • Calibration of anus done and dilator that fits snugly is used initially to anus twice a day
    • Dilator size increased by one unit every week until the desired size used
    • After that dilatation schedule reduced to once a day for 1 month
    • After desired size, colostomy closed
  18. Define Intussusception?
    Intussusception is a telescoping of one portion of the intestine . into the other.
  19. Etiology of Intussuception?
    • During weaning, change in diet causes inflammation and oedema of Peyer’s patches
    • Upper respiratory tract viral infection which causes oedema of Peyer’s patches is also thought as an aetiology for intussusception in children.
    • Other causes in adolescents and adults are submucus lipoma, leiomyoma, polyps in jejunum (Peutz-Jegher syndrome), other polyps and carcinomas with papillary projections.
  20. Parts of intussusception?
    • Intussuscipiens is the one which receives (outer sheath)
    • Intussusceptum are the tubes which advances (middle and inner sheath).

    Meckel's diverticulum is found to be the most common lead point for the intussuception.
  21. Clinical features?
    • • Common in 6-9 months. But can also occur at later age grouped children.
    • • Common in spring and winter, coinciding with the gastroenteritis and respiratory infections in respective periods.
    • • Commonest cause of intestinal obstruction in infancy.
    • • Initial colicky abdominal pain (75%) which eventually becomes severe and persistent.
    • • Sudden onset of pain in a male child, with progressive distension of the abdomen, vomiting, with passage of “red-currant-jelly’stool
    • • On examination, a mass is felt either on the left or right of the umbilicus which is sausage shaped with concavity towards umbilicus, smooth, firm, resonant, not moving with respiration, mobile, contracts under the palpating fingers. Often mass appears and disappears.
    • • Right iliac fossa is empty (Sign of Dance).
    • • After 24-48 hours, abdominal distension appears and increases progressively with features of intestinal obstruction.
    • • Features of intestinal obstruction with step-ladder peristalsis.
    • • Blood stained stool is often obvious on digital examination of the rectum. Occasionally ISS can be seen per anally and felt with a long mesentery.
    • • Eventually, gangrene and perforation occurs with features of the peritonitis.
  22. Investigations?
    • • Barium enema shows typical claw sign or coiled spring sign (Pincer end).
    • • Ultrasound - “target sign” of the intussuscepted layers of bowel on a transverse view or the “pseudokidney sign” when seen longitudinally.
    • • Plain X-ray abdomen shows multiple air fluid levels
  23. Treatment?
    Initial management - Ryle's tube, IV fluids, Antibiotics

    Non operative management - Hydrostatic reduction. Hydrostatic reduction by air enema is the standard modality. When it recurs, it is usually managed by another air enema reduction. A third recurrence is an indication for operative management.

    Surgical management - reduced in a retrograde fashion by pushing the mass proximally. Bowel resection is required in cases in which the intussusception cannot be reduced, the viability of the bowel is uncertain, or a lead point is identified. An appendectomy is an essential component, irrespective of bowel resection.
  24. Contraindication of hydroreduction?
    • Presence of peritonitis and hemodynamic instability.
    • Intussusception located entirely within the small intestine - unlikely to be reduced by an enema and more likely to have an associated lead point.
  25. Recurrence rate?
    • • In hydrostatic reduction – 10%.
    • • In open manual reduction – 2%.
    • • In resection – very less < 1%.
  26. Short note on meckel's diverticulum. [TU 2072/6]

    What is Meckel's diverticulum?
    • Failure of normal regression of vitelline duct that occurs in 5-7 weeks of gestation 
    • Most common congenital anomaly of GI tract
  27. Rule of 2 in Meckel's diverticulum?
    • 2% incidence
    • 2 types of heterotopic mucosa - Gastric mucosa and pancreatic tissue 
    • Located within 2 feet of the ileocecal valve
    • 2 inches in length
    • Symptomatic by 2 years of age
  28. Clinical features?
    The clinical symptoms are related to hemorrhage, obstruction, or inflammation; the most common presenting symptom is a painless, massive, lower GI bleeding in children younger than 5 years
  29. Investigation of Meckel's diverticulum?
    99mTc Pertechnetate scan to detect gastric mucosa
  30. Management?
    • A simple V-shaped diverticulectomy with transverse closure of the ileum is an acceptable technique.
    • In patients in whom there is ulceration or inflammation at the base of the diverticulum, a segmental resection of the involved ileum with a primary end-to end anastomosis is preferred.
Author
prem77
ID
329068
Card Set
Pediatric Surgery 66 - Gastrointestinal system 2
Description
CHPS Duodeal atresia Anorectal malformation Intussuception
Updated