PEDIATRIC SURGERY UPDATE ©
VOLUME 01, 1993

VOL 01 NO 01 JULY 1993

The Pediatric Inguinal Hernia: Is contralateral exploration justified?

To determine if contralateral inguinal hernia exploration is justified we decided to study our past experience with 161 consecutive cases who underwent bilateral hernia repair during a 30 month period at Hospital San Pablo and Ramon Ruiz Arnau University Hospital. 61% of the population were infants younger than two years of age, and 19% prematures babies. 69 pts presented with a RIH (Right Inguinal Hernia), 47 with a LIH (Left Inguinal Hernia), and 45 pts with BIH (Bilateral Inguinal Hernias). 16% suffered an episode of incarceration preop all reduced satisfactorily and operated promptly. A contralateral positive finding (either an hernial sac or a patent procesus vaginalis) was identified in 74% RIH and 72% LIH patients upon exploration. No incidence of testicular edema/atrophy, vas deferens injury, or recurrence was reported in the six year follow-up of the study. Statistical analysis of the contralateral findings during surgery with sex, gestational age, and age at operation showed that females and infants younger than two months of age had a higher probability of having positive findings. We could not demonstrate that prematurity or left-sided hernias were associated with a higher positive rate. The major benefit of contralateral exploration is that it allows discovery and elimination of a patent procesus vaginalis so an hernia cannot develop. We conclude by establishing some criterias to justify routine contralateral exploration of the pediatric hernia: the surgeon should be experienced in child care, associated conditions should not increase the surgical risks significantly, time-consuming dissections of the cord structures should be discouraged, andthe operating time should be kept to a minimum.

Prenatal Choledochal Cyst

Prenatal sonography will increase the incidence of subhepatic cysts later confirmed as choledochal cysts. Optimal timing for excision will depend on age, weight, associated conditions, biochemical alterations, development of complications, and the sonographic surveillance of size. We present a prenatal choledochal cyst (the 6th reported case in the literature) with an abnormal choledocho- pancreatico ductal junction and a high amylase content which exhibited a linear pattern of growth in size as a measure of time. Upon reviewing all other case reports recommendations for managing the asymptomatic, anicteric infant are discussed.

Malrotation: The Deadly Vomit

Post-prandial bilious vomiting in the early stages of life (usually the first three months) should always prompted the diagnosis of malrotation associated to midgut volvulus. There can be mild to none abdominal distension, the child can be acidotic and obstipated. A initial Barium enema will help to decide if there's a high-medial lying malrotated cecum, a transitional zone of Hirschsprung's, or a coil spring pattern of intussusception. An UGIS is more direct since the third portion of the duodenum will be obstructed by Ladd's bands and volvulus if present will be seen. Ischemic bowel will die in a six to eight hour period if not treated promptly by detorsion and Ladd's procedure.

VOL 01 NO 02 AUGUST 1993

Congenital Hydrocele: When to do Surgery?

Congenital hydroceles are common during the first six months of life (prevalence 58%). They can either be found in the scrotum, the cord, or intra-abdominally. Most are extravaginal (communicating) type. They generally are round, movable, non-tender, non-reducible and can be trans-iluminated with a short intensity light. Most (>90%) resolve spontaneously between nine months and a year of age. Surgery is indicated for those which persist after the first year of life, produce discomfort, cannot be differentiated from an inguinal hernia, or are associated to hydrocephalus and V-P shunts (the tubing tend to migrate into the hydrocele) . They are not associated to testicular damage or late infertility. What cause them?: a pathological increase filtration of fluid (lymph) from the parietal tunica vaginalis rich in proteins which cannot be drained into the peritoneal cavity because the procesus vaginalis closes too early.

Biliary Atresia

Biliary Atresia continues to create controversy in management among surgeons. There is agreement that persistent direct hyperbilirubinemia beyond the first two weeks of life demands thourough work-up to rule out biliary atresia. This should include: HIDA scan with five day phenobarbital p.o. preinduction, TORCH, alpha-1-antitrypsin levels, and if there is no hepatobiliary excretion a percutaneous liver biopsy. After work-up patients will undergo mini-lap, cholangiogram and hepatic biopsy. A Kasai procedure (hepatico-portoenterostomy) will then follow in most cases during this initial diagnostic procedure. Cholangitis is the most common post-op complication which will reduced bile flow. Long-term survival is determine by: age at time of surgery, size of fibrous cord ductules (>150 microns), and degree of hepatic fibrosis. Significant predictors of poor outcome are: 1) Caucasian race; 2) operative age over 60 days; 3) cirrhosis at initial biopsy; 4) non-patent extrahepatic ducts; 5) absent ducts at the plane of hepatic hilar transection; and 6) postoperative varices or ascites. Antibiotics (trimethoprim-sulfamethoxazole) and choleretics (phenobarbital, ursodeoxycholic acid) are recommended as long term therapy. As Dr. Hoffman has stated in his recent book "Current Controversies in Biliary Atresia", the Kasai procedure is best viewed as a staging operation which provides cure for some and a bridge to liver transplantation for others. The single most telling prognostic sign of operative success is bile drainage which is reported in 60-80% of children after Kasai is undertaken before 10 weeks of life. Portal hypertension is a common late complication in both jaundice and jaundice-free patients. Long term survival for pts undergoing Kasai ranges from 29-66% at five years.

Golytely: How much to give?

Golytely a polyethylene glycol (PEG) electrolyte solution introduced in 1980, has proven safe in infants and children. PEG is an osmotic agent which eliminates water absortion or secretion from the GI tract. Rates of administration of 25-35 cc/kg/hr for 4-6 hrs given by NG tube causes a mechanical washout effect reducing 80% of viable bacterias of colon, but no qualitative change in fecal flora. Uses: colo-recto-urinary surgery and colonoscopy. Few complications: vomiting, abdominal distension or lung aspiration. Series in children are too small to imply an isolated effect in reducing septic complications without use of systemic antibiotherapy.

VOL 01 NO 03 SEPTEMBER 1993

Hirschsprung's Associated Enterocolitis (HAEC)

Enterocolitis is the most common complication (incidence 15%), and a major cause of death in children (30%) with Hirschsprung's disease (HD). Can occur before, at the time of, or after definite surgical treatment and is associated to increased morbidity and extended hospitalization. Clinical characteristics are: onset of fluid stools, abdominal distension, and fever in a child with proven HD.
HAEC can be classified as: (1) inflammatory- most common type, mucosa affected only, or (2) ischemic- rare, most serious, affects the entire wall with gangrenous bowel. Risk factors identified in the development of HAEC are: (1) delay in diagnosis beyond one week of age; (2) presence of trisomy 21; (3) post-operative anorectal stricture. Histological changes of enterocolitis occur in both the ganglionic and aganglionic bowel.
Management consists of: decompressive enterostomy above the level of aganglionosis, fluid resuscitation, NG decompression, and broad spectrum antibiotherapy.
Pathogenesis is associated to: (1) proximal colonic dilatation with mucosa ischemia and bacterial invasion; (2) hypersensitivity reaction to bacterial antigens; (3) infection with C. Difficile enterotoxin (there is pathological confirmation that some colitis can be of the pseudomembranous type); (4) deficient mucosal transfer and defense of secretory IgA in GI tract; (5) a triggering event in bowel alters the composition of mucin leaving the colonic mucosa susceptible to infection by enterocyte-adherent organism producing toxins which elicit an inflammatory response.

Congenital Diaphragmatic Hernia: Intrauterine Repair

The mortality of CDH is directly related to the degree of lung hypoplasia associated. Prospective studies of prenatally diagnosed fetus prior to 25 wk. gestation has shown that 60% will die despite optimal postnatal care. This unsolved problem has prompted investigators to develop new treatment options such as preoperative stabilization, jet-frequency ventilation, and ECMO. Another area of development is intrauterine fetal surgical repair. To achieve success fetal surgery should: (1) pose no risk to the mother (innocent bystander) or her future reproductive capacity; (2) tocolytic therapy in the post-op weeks should proved effective to avoid prenatal stillbirths; and (3) the procedure should be superior to conventional therapy. Intrauterine repair has meet with limited success due to herniation of the fetal liver into the chest through the defect. Disturbance of the umbilical circulation during or after liver reduction causes fetal death. Positive-pressure ventilation after birth reduces the liver before the baby comes for surgical repair. Dr. Harrison (USFC Fetal Treatment Center) has devised separate fetal thoraco-abdominal incisions to deal with this problem ("two-step dance"), reducing or amputating the left lateral segment of the liver. Another less invasive approach is enlarging the hypoplastic lungs by reducing the normal egress of fetal lung fluid with controlled tracheal obstruction called PLUGS (Plug Lung Until it Grows).

Did You Know...

Is estimated that medical students are expected to learn 50,000 facts during their first two years at school. They generally prefer to learn concepts.

VOL 01 NO 04 OCTOBER 1993

Congenital Pre-pyloric Antral Membrane

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 radioluscent 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-obtructive 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.

Baker Cysts

Popliteal (synovial) cyst are swelling that originate between medial head of gastrocnemius and the semimembranosus, semitendinosus tendons usually found in children between the ages of 2-7 y/o. Minor trauma is the leading etiology. Diagnosis can be confirmed by sonography: thin wall echo-free cyst. Most will probably disappear spontaneously (73% over a mean of 20 months). Indication for surgery are: limping, pain, size enlargement, cyst does not resolves with time, and questionable nature. Recurrence after surgery is high. Calf swelling and pain secondary to a ruptured baker cyst could be an early manifestation of juvenile rheumatoid arthritis. Compression pressure of knee vein and lymphatics can cause edema of lower extremity in adults.

Midline Neck Masses

Midline neck masses in children can either be: thyroglossal, submental adenopathies or epidermal cysts. By far the most common is thyroglossal duct cyst. Etiology: failure of obliteration of the duct after descent of the thyroid gland during 6th week of gestation. Clinically the cyst arise upon tongue protrusion. They are lined with stratified squamous columnar epithelium. Treatment is excision of cyst along central portion of hyoid bone. Recurrence is caused by failure to remove hyoid portion which can be demonstrated by a simple lateral neck Xray. Excision of adenopathies (larger than 2 cm), and epidermal cysts is done for diagnostic purposes. Sonography can be of help in discriminating between them.

New ECMO System

The Japanese have designed a new automatic veno-arterial ECMO system using an artificial heart as a blood pump. The artificial heart changes the output automatically in proportion to venous return (computerized), does not generate excessive negative or positive pressure, uses a small priming volume, and can be handle safely by a small number of less-skilled staff workers. This means that more institutions will probably gain access to this mode of treatment since the economical burden will be reduced.

VOL 01 NO 05 NOVEMBER 1993

Thyroid Cancer

In spite of presenting with advanced, multicentric and larger tumors children have a better survival than adults. Populations at risk: past radiation to head and neck, nuclear waste radiation, MEN II kindred. Clinical presentation is a solitary cervical mass or metastatic lymph node. Diagnostic work-up should include: sonogram (cystic or solid), thyroid scan (cold or hot), Fine-needle aspiration cytology(FNA), and Chest-X-Ray (lung metastasis 20% at dx). Pathology of tumors: papillary (majority, psammomas bodies), follicular (vascular or capsular invasion), medullary (arise from C-cells, multicentric, locally invasive), anaplastic (rare, invasive and metastatic). Management is surgical. Complications of surgery increase with decreasing age of patient: temporary hypoparathyroidism, recurrent nerve injury. Prognostic factors associated to higher mortality are: non-diploid DNA, psammomas bodies, over 2 cm diameter nodule, and anaplastic histology. Follow-up for recurrence with serum thyroglobulin level and radioisotope scans. Adjunctive therapy: thyroid suppression and radio-iodine for lymph nodes and pulmonary metastasis.

Cervical Lymphadenopathy

An enlarged lymph node is the most common neck mass in children. Most are anterior to the sternocleidomastoid muscle. Infection is the usual cause of enlargement; viral etiology and persist for months. Acute suppurative submandibular adenitis occur in early childhood (6 mo-3 yrs), is preceded by pharyngitis or URI, the child develops erythema, swelling and cellulitis, and management is antibiotics and drainage. Chronic adenitis: persistent node (> 3 wk., tonsillar), solitary, non-tender, mobile and soft. Generally no tx if < 1 cm, for nodes above 2 cm sizes with rapid growth, clustered, hard or matted do biopsy. Other causes are: (1) Mycobacterial adenitis- atypical (MAIS complex), swollen, non-tender, nor -inflamed, positive skin test, excision is curative, chemotx is of no value. (2) Cat-Scratch adenitis- caused by A. Fellis, transmitted by kittens, positive complement fixation test, minimally tender, fluctuant regional nodes, spontaneous resolution. (3) Hodgkin's disease mostly teenager and young adults, continuing growth, non-tender node, associated to weight loss, biopsy is diagnostic.

Undescended Testis: Early Surgery

The undescended testis found in 0.28% of males can be palpable (80%; most at inguinal canal), or non-palpable (20%). Testes that can be manually brought to the scrotum are retractile and need no further treatment. Parents should know the objectives, indications and limitations of an orchiopexy: that the testis could not exist (testicular vanishing syndrome), even after descend can atrophy, that it cannot be fixed and removal is a therapeutic possibility. To improve spermatogenesis (producing an adequate number of spermatozoids) surgery should be done before the age of two. Electron microscopy has confirmed an arrest in spermatogenesis (reduced number of spermatogonias and tubular diameter) in undescended testis after the first two years of life. Other reasons to pex are: a higher incidence of malignancy, trauma and torsion, and future cosmetic and psychological problems in the child. The management is surgical; hormonal (Human Chorionic Gonadotropin) treatment has brought conflicting results except bilateral cases. Surgery is limited by the length of the testicular artery. Palpable testes have a better prognosis than non-palpable. Laparoscopy can be of help in non-palpable testis avoiding exploration of the absent testis.

VOL 01 NO 06 DECEMBER 1993

Prenatal Ovarian Cysts

Ovarian cysts in fetus and infants are usually follicular in nature and less than 2 cm in size. They are commonly diagnosed between the 28th and 39th wk. of gestation by sonography. Hypotheses on etiology are: (1) Excessive fetal gonadotropic activity, (2) enzymatic abnormalities of the theca interna, and (3) abnormal stimulation by the mother HCG. Obstetric management consists on observation and vaginal delivery. After birth, diagnostic assessment and management will depend on the size and sonographic characteristics of the cyst. Simple anechoic cysts, and those less than 5 cm in size can be observed for spontaneous resolution. Cyst with fluid debris, clot, septated or solid (complex nature), and larger than 5 cm should undergo surgical excision due to the higher incidence of torsion, perforation and hemorrhage associated to them. Percutaneous aspiration of large simple cysts with follow-up sonography is a well -accepted therapy, preserving surgery for recurrent or complicated cases. Surgical therapy is either cystectomy or oophorectomy that can result in loss of normal ovarian tissue.

Intussusception: Air or contrast reduction?

The traditional method of diagnosing and managing ileo-colic intussusception is barium enema contrast reduction. In China where this is the most common surgical emergency in childhood, pneumatic reduction has been used for more than 25 years. A recent tendency toward this approach is seen in recent years in Occident. This consist of rectal insufflation of oxygen at a flow rate of 2 L/min, controlling pressure by adjusting the height of the mercury column, and using maximal pressures of 80 mm Hg. Small bowel aeration is a sign of complete reduction. Series are successful in 70-90% of cases. Gas enema reduction is very 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 flouroscopy time), less costs and less morbidity in cases of perforations.

Labial Adhesions in Infants

Minor labial adhesions is a common pediatric gynecologic problem occasionally confused with imperforate hymen. Most cases are in children 2-6 y/o and involve labial adhesions secondary to diaper rash. The process causing fusion is a natural one: two normally covered surfaces with squamous epithelium in contact with each other is traumatized eventually forming a fibrous tissue union (agglutinate) between them when healing occurs. A small opening near the clitoris is always present through which urine escapes.This seldom causes symptoms except recurrent UTI if it covers the urethral meatus. Treatment consists of applying estrogenic creams (0.1%) for two weeks. Manual separation can be painful and adhesion recurs. Unless the urethral meatus is covered, there is no reason to be further aggressive in management. Prolonged use of estrogenic cream can cause precocious isosexual development.