PSU Volume 51 No 01 JULY 2018

Ventral Hernia Mesh Repair

Giant omphalocele are defects larger than 10 centimeters encompassing the liver within the defect with a total loss of abdominal cavity domain. Babies born with giant omphalocele are seldom closed primarily during the neonatal due to the development of abdominal compartment syndrome, compression of the inferior vena cava  and suprahepatic veins leading to multisystemic organ failure and death. The defect is covered with some bacteriostatic ointment and the amnion left to granulate creating neoskin as simple cover. Once the defect is covered with the growing skin the hernia is closed either using a prosthetic mesh, component separation or primarily. Primary repair has a 25-52% recurrence rate and is used for small < 5 cm defect. The component separation technique (CST) enlarges the abdominal wall surface by translation of the muscular layer without compromising the blood supply and innervation of the muscles. A longitudinal cut is made in the external aponeurotic fascia lateral to the rectum encompassing closure in the midline. This can be used when closing hernias between 5 and 10 cm in diameter. CST technique has a 33% of wound complications and 30% re-herniation rate. Transection of the perforating branches of the epigastric artery interfere with the blood supply of the skin of the ventral abdominal wall who will need collaterals from the intercostal artery and pudendal artery to survive. Prosthetic material can be synthetic or biologic. Prolene is a cheap synthetic mesh that creates adhesion, erosions and fistula. Biologic mesh are biodegradable unless process like cross-linking the collagen fibers take place. This extracellular material derived from human or other mammalian animal. Broad range of size helps repair larger hernia defects. Biologic mesh minimized adhesions between the mesh and viscera and incites fibrous tissue to grow and create a tough fascia with secure fixation of the mesh to the abdominal fascia. Biologic mesh are preferred to be placed underneath the peritoneal fascia (sub-lay or underlay). Biologic mesh should be biocompatible, non-toxic and nonimmunogenic. Neither antibiotic coverage nor subcutaneous drainage has an effect in the incidence of wound-related complications when placing this mesh.

Sibson Hernia

Sibson's fascia also called the suprapleuralis membrane is the thickened portion of the endothoracic fascia extending over the cupola of the parietal pleura and reinforcing it. It is attached to the inner border of the whole length of the first rib and the first costal cartilage and transverse process of the 7th cervical vertebra. With increase in intrapleural pressure the lung apex may protrude into or through the fascia and rise a variable distance into the neck. This protrusion is referred as Sibson's hernia or apical lung hernia. The protrusion of the lung apex may be unilateral or bilateral. The right side is more frequently involved than the left. The apical segment of the lung protrudes between the scalenus anterior and sternocleidomastoid muscle. Sibson hernia is generally asymptomatic except for a swelling in the neck during coughing or Valsalva maneuver. Also, it can be associated with dysphagia. It can be diagnosed on posteroanterior and lateral chest films but CT-Scan of the chest provides a confirmatory diagnosis. It may cause problems during insertion of internal jugular or subclavian catheters and may result in inadvertent pneumothorax if not diagnosed properly. Sibson hernia has been associated with Ehlers-Danlos syndrome. Most cases of Sibson or apical lung hernia in children are identified incidentally, have a benign clinical course and resolve without surgical intervention. Surgical management is reserved for traumatic hernias and lung tissue at risk for strangulation, incarceration or punctured. The hernia resolves after discontinuation of continuous positive airway pressure breathing when physiologic tidal pressures are obtained.  

Beta Thalassemia

Sickle cell anemia and beta thalassemia are considered the most frequent inherited blood disorders around the world. Thalassemia is a genetic disease involving the genesis of hemoglobin either chains alpha or beta. Beta thalassemia refers to defective production of the beta chain of hemoglobin. Beta thalassemia occurs when one or both Beta globin genes are either abnormal or absent. The child with thalassemia develops anemia from lower levels of hemoglobin and lacks good quality hemoglobin for oxygenation due to ineffective erythropoiesis. The gene mutation in beta thalassemia can be mild to severe, also classified as thalassemia minor or major respectively. Some patients will only need iron supplementation (non transfusion dependent thalassemia), while major cases of mutation might need regular blood transfusions for life. Hemolysis of blood is rapid, hence an overload of bilirubin is managed within the liver, reasons why some patients developed bilirubin gallstones (black pigmented stones). Patients with thalassemia experience loss of appetite, jaundice, an enlarged spleen or liver and several bone problems (osteoporosis). Iron building up in the heart leads to failure and death. A family history if thalassemia increases the chances of an individual being affected by the disease. Thalassemia affects patients with Italian, Asian, African, Middle Eastern and Greek ancestry. Whenever operating in a child with thalassemia the type of thalassemia should be ascertain as major, minor or intermedia. Also, the present of hemoglobin and iron overload must be measured.  Current management of thalassemia involves red blood cell transfusions and iron chelation. Allogeneic bone marrow transplant is the only curative option limited by the availability of matching donors and graft-versus-host disease. Gene therapy using lentiviral vectors aim to correct the mutated beta-globin gene or add back a functional copy of beta or gamma-globin. 

PSU Volume 51 No 02 AUGUST 2018

Diabetes Insipidus

Diabetes insipidus (DI) is a condition that occurs when there is insufficient production of antidiuretic hormone (ADH), also known as vasopressin. ADH is a hormone that helps the kidney and body to conserve the correct amount of water by controlling the output of urine ADH is secreted by the hypothalamus to decrease the amount of urine output so that dehydration does not occur, stored in the pituitary gland and released into the blood. Diabetes insipidus can be of central and nephrogenic origin. Central DI occurs after damage to hypothalamus or pituitary due to head injury, surgery, genetic disorders or brain tumors (craniopharyngioma), while nephrogenic DI is a lack of response of the kidney to normal ADH levels due to drugs, chronic disorders, sickle cell disease or polycystic kidney disease. Most common symptoms of DI are excessive thirst (polydipsia) and urine production (polyuria), inability to concentrate the urine along with hypernatremia, seizures and dehydration. In addition children develop irritability, poor feeding, failure to thrive and fever. DI is diagnosed with history, labs (urine /blood tests), water deprivation test DDAVP trial (which should be done in the hospital) and imaging (MRI/CT Scan), Diabetes insipidus can lead to further brain damage, impaired mental function, intellectual disability, hyperactivity and restlessness. Management of diabetes insipidus depends on the cause of DI. Treatment includes adequate hydration and antidiuretic hormone medication (oral, injection or nasal spray), or medications that stimulate the production of ADH such as Non-steroidal antiinflammatory or chlorpropamide. Depending on the cause of diabetes insipidus the disease can be temporary or permanent. Children with central and nephrogenic diabetes insipidus can lead full healthy lives with proper and monitored management.  

Bariatric Surgery

Childhood obesity has reached global epidemic proportions. Obesity is defined as BMI > 95th percentile for sex and age, with severe obesity within the 99th percentile. Pediatric obesity affects health by causing metabolic syndrome, hypertension, dyslipidemia, diabetes (insulin resistance), obstructive sleep apnea, musculoskeletal complains (fracture, low extremity misalignment), nutritional deficiencies (Vit D and iron deficiency), depression and poor self-esteem. Screening for obesity after age of two years should be standard of care for primary physicians. Breast feeding has a protective effect in childhood obesity and should be encouraged. The basis of management of child obesity remains a goal of energy expenditure that surpasses energy consumption. Daily physical activity of 60 minutes daily should be encouraged between families. If lifestyle modification does not produce significant weight loss bariatric surgery might be needed in the adolescent age. Adolescent considered for bariatric surgery should be severely obese with BMI > 40 and comorbid conditions described above, attained adult stature, failed six months of conventional weight management, demonstrate comprehensive psychological evaluation, avoid pregnancy for at least one year postoperatively, be capable to adhere to nutritional guidelines postoperatively and have decisional capacity. Both Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are effective in achieving significant weight loss. Obesity related comorbidities resolve almost universally with remission of diabetes, hypertension, dyslipidemia and sleep apnea. Metabolic syndrome and concomitant cardiovascular morbidity and mortality is decreased in severely obese adolescent undergoing bariatric surgery. RYGB increases insulin sensitivity by four times in adolescent with and without diabetes after surgery. Perioperative complications seen in 22% and include anastomotic stricture, reoperation, anastomotic leak, dumping syndrome and dehydration. In absence of supplementation inadequate absorption of calcium, Vit D, iron, Vit B1, B12, A and folate can occur resulting in nutritional deficiencies.

London Sign

The London sign is a trivial looking circular bruising in the epigastric area after blunt abdominal trauma. The London sign usually corresponds to the shape and size of the bicycle handle. The sign means that the impact was sharp and strong enough to cause some kind of internal visceral damage to the child. This type of epigastric blunt trauma blow can cause pancreatic or duodenal injury of sufficient severity since these two organs get crushed between the blow and the vertebral column. Presence of the London sign needs hospital admission and further imaging investigation in most cases as an underlying internal organ injury might be missed. The shape and size of the bruising depends on the object transmitting the impacting force. As such the victim can present bicycle handle, tire marks, shirt buttons, knuckles of hand or wrist watch marked in the epigastrium all conforming and representing the London sign. The damage to the internal viscera might include pancreatic contusion with or without main duct transection, intramural duodenal hematoma and perforation of the duodenum. A similar sign, known as the seatbelt sign occurs after high impact blunt injury from motor vehicle accidents. The seatbelt sign is a linear ecchymosis of the abdominal wall corresponding to the belt. The seatbelt complex describes an injury to the intestine (including the rectum), lumbar spine and other abdominal organs associated with the belt. Chest injury, fracture of the sternum and ribs along with injury of the major vessels are also included in this complex. The prevalence of intestinal injury in patients with the seatbelt sign is almost 15%. Physical examination is sometimes inaccurate in the diagnosis of blunt abdominal injury and requires a high index of clinical suspicion. Children with the London and Seatbelt sign should undergo further abdominal imaging such as US and CT-Scan in search of missed visceral injury.

PSU Volume 51 No 03 SEPTEMBER 2018

Traumatic Pneumatocele

A pneumatocele is defined as a thin-walled air-filled cyst of the lung most often seen in children after bacterial pneumonia. Traumatic pneumatocele, also referred as traumatic pulmonary pseudocyst or lung cyst, is a rare complication occurring 4% of the time after blunt chest trauma (mostly car accidents). Traumatic pneumatocele can also arise from continuous positive airway pressure mechanical ventilation. Represent air-filled lesions within the pulmonary parenchyma after laceration and recoil of the affected chest cage. It represents a greater transmission of energy to the lung and a more severe injury than pulmonary contusion by itself. Traumatic pneumatoceles occurs more commonly in children and young adults due to the pliability of the pediatric rib cage and relative increased fragility of the lung parenchyma. The condition is radiologically characterized by the appearance of pulmonary cavities with no epithelial lining filled with air, fluid or blood. Pneumothorax or pneumomediastinum might also coexist. Only 20% of associated patients have rib fractures. Any number of pneumatoceles can exist at any location except the apices of the lung. Though they are appreciated in simple chest films, CT-Scan is more accurate and sensitive in detecting them. The formed cavities filled with fluid, blood or air continues to increase in size until a balance of lung pressures is achieved between the cavities and the surrounding tissue. Pneumatoceles can be single, multiple, uniloculate or multiloculated, elliptical or spherical cavities. Symptoms include chest pain, dyspnea, cough, tinges of blood in sputum, mild fever or leukocytosis 12 to 36 hours after trauma. Fever and leukocytosis results from absorption of damaged lung tissue or blood clot and not from infection. Management of traumatic pneumatoceles is conservative as observation is what is required. They usually require several weeks to months to resolve in time. Prophylactic antibiotics usage is controversial. Surgical management is needed with large pneumatoceles associated with life-threatening hemoptysis, persistent infections, hematocele and respiratory compromise. 

Secondary Malignancy

The cure for children cancer has improved during the past decades with five-year survival rates approaching 80%. As the numbers in survival improves there is increased awareness of the risk of developing a secondary malignancy due to therapy. Subsequent malignant neoplasms are the most common non-relapse cause of late mortality  accounting for almost half of all non-relapse deaths among five-year survivors. Radiotherapy has been strongly associated with development of secondary malignancy, and dose-response relationship has also been identified for specific chemotherapeutic agents including alkylating and epipodophyllotoxins agents. Hodgkin lymphoma survivors are at particular high-risk for subsequent secondary malignancies with an almost one-third cases in this group of survivors. Secondary malignancy of the breast and gastrointestinal tract most commonly follows a primary diagnosis of Hodgkin lymphoma (HL). Female breast cancer accounts for almost 20% of subsequent malignant neoplasms of most cohort groups studied. Second thyroid cancers are most common in leukemia and HL survivors as were skin melanomas. The thyroid gland is highly susceptible to the carcinogenic effects of ionizing radiation. Secondary sarcomas with 15% incidence predominantly occur among survivors of primary soft tissue sarcoma or HL and the risk is associated to exposure to anthracyclines, alkylating agents and radiation therapy. Secondary hematopoietic cancers most commonly follow a primary diagnosis of HL or leukemia. Second malignancy of the central nervous system (CNS) with an almost 10% incidence most commonly occurs after an original diagnosis of a CNS tumor or leukemia. There is a linear relation between radiation doses received during treatment for childhood cancer and the relative risk of subsequent gliomas or meningiomas. Non-melanoma skin cancer (basal cell and squamous cell) is another secondary malignancy rarely fatal occurring with an increase incidence in survivors of HL, leukemia and CNS tumors related to radiation therapy exposure. Females are at increased risk for breast, thyroid, non-melanoma skin and meningiomas. The period of higher risk for secondary malignancy occurs before age of 40 years.   

Opioid Abuse

Opioid overdose has become an epidemic and significant health problem in the United States taking the life of thousands of adolescents per year. Prescribed opioids and mostly synthetic opioids are involved in almost two-third of all types of drug overdose with 42,249 deaths in 2016. Opioid overdose began in the 1990's with prescribed opioids, then it changed in 2010 characterized by heroin deaths. Now potent synthetic opioids mainly involved in the last wave of 2013 include illicitly manufactured fentanyl and fentanyl analogs. Opioid poisoning in children one to four years of age has increased 200% between 1997 and 2012. Opioid abuse in adolescent causes problems in continuous appropriate acute pain management. Children who abuse opioids and are in household where parents struggle with substance abuse are more likely to experience neglect and nonaccidental trauma. Availability of FDA approved opioid medications, pharmaceutical companies marketing campaigns and inadequate education or knowledge about the risk of prescribing opioids from managing chronic noncancer pain has contributed to the increased in prescribed opioids. There has also been a substantial increase in the risk of hospital readmissions in the first years of life among children with neonatal abstinence syndrome and documented exposure to maternal opioids. Physicians must prescribe opioids more cautiously for acute and chronic pain. They should also use nonopioid substitutes analgesics and non-pharmaceutical approach more often. Patient education should include the risk of using prescribed opioids. By decreasing the quantity of prescribed opioids and discarding or returning unused medication less nonmedical use will occur. Easy access to medical treatment programs using buprenorphine, naltrexone and methadone should be encouraged.  

PSU Volume 51 No 04 OCTOBER 2018

Electric Burns

Electrical burns and injury are the third most common cause of burns after scald and flame injury. The population most prone to electrical injury is young children and teenagers. In children, the injuries tend to occur in the household. In adolescents, they are most often associated with misguided youthful exploration outside the home.  Electrical current can reach deep tissues and cause extensive deep injury to tissues including nerve, bone, tendon tissue, muscle and skin. The injury caused by electrical burns depends on the magnitude of the electric current, the duration of exposure and the resistance of the tissue involved. They are classified as high voltage when above 1000 volts or low voltage if it's less. The morbidity and mortality in cases of high voltage injury are significant. Most cases involve males. Hospitalization is longer for children with high-voltage burns. Electrical burns accompanied by trauma are the result of falls from height. Once the child arrives at the ER an assessment of total body surface area compromised should be done and hydration according to Parkland formula instituted. Cardiac rhythm and renal function should also be examined with appropriate labs (myoglobinuria, BUN, serum creatinine, CPK, etc). Clinical parameters such as the mechanism of injury, voltage, burn size and depth, gross urine color and myoglobinemia can be easily used to predict and estimate the muscle damage. Myoglobulin and hemoglobin pigment in the child urine present risk of acute renal failure and must be cleared promptly.  Wound dressing should be done daily and wound debridement, tangential excision and grafting performed when necessary. Since it's difficult to asses internal damage the child is observed closely for signs of compartment syndrome and escharotomy or fasciotomy performed as needed. Gadolinium-enhanced MRI has demonstrated potential viability in zones of tissue edema with good correlation with histopathology of the lesion. Wound complications and infections are associated with electrical burns with Pseudomonas, Acinetobacter and Escherichia coli leading the organism spectrum. Intravenous antibiotics are essential component of management. Sepsis and renal failure are a common cause of late death. Electrical burns are associated with complications including orthopedic injury, amputation, and sensory and neuropsychiatry disturbances. They reduce cardiopulmonary functional exercise capacity to a greater degree than flame injuries.

Calcinosis Cutis

Calcinosis cutis means that aberrant calcium deposits have developed in the skin and subcutaneous tissue of the patient. According to the etiology four types of calcinosis cutis have been described: dystrophic, metastatic, iatrogenic and idiopathic. Dystrophic calcinosis is a calcification associated with infection, inflammatory process, cutaneous neoplasm or connective tissue disorders (juvenile dermatomyositis, systemic lupus erythematous and systemic sclerosis). Metastatic calcinosis cutis results from an elevated calcium or phosphate level in a child with cancer. Subepidermal calcified nodules and tumoral calcinosis are idiopathic form of calcifications. Idiopathic calcinosis as the names implies has no known cause for the calcinosis or when neither local tissue damage nor systemic metabolic disorder can be demonstrated. In all types of calcinosis cutis insoluble compounds of calcium (hydroxyapatite crystals or amorphous calcium phosphate) are deposited within the skin due to local or systemic factors. Commonly the skin and subcutaneous fat are involved, but deeper tissues such as muscle and visceral organs might also be affected. When muscle is affected this might cause contractures. If the calcium extrudes it will cause local ulceration and inflammation. Should the biopsy revealed calcinosis cutis serum calcium, serum phosphorus and ALP should be obtained along with a detailed history and physical exam looking for a malignant process, collagen vascular disease, renal insufficiency, excessive milk ingestion or Vitamin D poisoning. There is a very rare idiopathic calcinosis cutis known as milia-like characterized by multiple whitish to skin colored, firm, tiny milia-like papules mostly in the hands and feet. This subtype is equally frequent in both sexes and most commonly found in childhood and disappears spontaneously by adulthood without scarring. This milia-type has been associated with Down syndrome. Surgical excision of calcinosis cutis is both needed for establishing a diagnosis and symptomatic relief.  

Suicide

Suicide rates has increased in all ages groups during the past ten years. Suicide is the second leading cause of death in children aged 10 to 15 years. The risk factors associated with suicide in adolescents include mental health problems, family history of suicidal behavior, biologic factors, problems with family and most importantly peer victimization and bullying. Relationship problems with parents are the most common antecedents within these risk factors. There is a strong correlation between adolescent smoking and substance use with psychosocial context and suicidal behavior. Addressing these predictors would be crucial in the development of effective strategies targeting the prevention of smoking and substance use, which might consequently reduce suicidal behaviors among adolescents. Suicidal thoughts and behaviors are prevalent among young people with psychotic disorders relative to the general population. Victims of cyber-bullying and school bullying have a significantly higher risk of suicidal ideas, plans, and attempts. The "Zero suicide" model developed by the US Action Alliance Strategy for Suicide prevention provides administrators and providers the resources for a systematic approach to quality improvement for suicidal prevention in health care systems via seven essential elements (Lead, Train, Identify, Engage, Treat, Transition, Improve). The Center for Disease Control has published charts demonstrating that an increase number of suicides in children/adolescent involve the use of firearms. Case control and ecological studies investigating geographic and temporal variations in firearm ownership and firearm suicide rates indicate that greater firearm availability is associated with higher firearm suicidal rates. Effective strategy for reducing the use of lethal weapons as arms of self destruction include eliminating access to guns in the house by storing them in locked firearm safes or handgun lock boxes or outside the home. Also, having access to effective management and care for adolescents with mental health and substance abuse conditions working toward remission and reducing self harm injury.

PSU Volume 51 NO 05 NOVEMBER 2018

Graves Postoperative Hypocalcemia

Grave's thyrotoxicosis is initially managed with antithyroid blocking agents, followed by surgery and/or radioiodine therapy. In children if medical therapy fails, total thyroidectomy is the next treatment of choice. Overall the most common complication after total thyroidectomy is hypocalcemia or tetany which occurs with a greater incidence in patients with Graves disease when compared with the same procedure in children with nodular disease or thyroid cancer. Most cases of postop hypocalcemia are transient with less than 5% permanent. Several mechanisms for the development of hypocalcemia in Graves disease after total thyroidectomy are proposed. They include parathyroid hormone (PTH) insufficiency related to injury, devascularization or inadvertent removal of the parathyroid glands. Also, increase release of thyrocalcitonin during gland manipulation. This are not the principal mechanisms of hypocalcemia. The most principal mechanism of hypocalcemia after Graves thyroidectomy is rapid reversal of an osteodystrophy that existed before surgery caused by the elevated thyroid hormone level. Grave's children develop a negative calcium level and loss of bone in the hyperthyroid state something that is partially reversed with antithyroid blocking therapy known as recalcification tetany or hungry bone syndrome. When the excess secretion of hormone is eliminated with surgery the extent of bone restoration will be replenish with calcium hence lowering the ionized calcium blood levels and causing symptoms of tetany. With excess hormone there is reduced calcium bowel absorption in addition to bone resorption due to osteoclast activation and loss of calcium in the urine. Also, antithyroid drug therapy causes calcium and vitamin D deficiency. Twofold increase rate of a negative calcium slope in the first six hours after surgery or very low iPTH levels (< 10 pg/ml) predicts severe hypocalcemia. Risk factors that enhance the state of postop hypocalcemia are younger age and obesity. Preoperative calcium supplementation for Graves children before surgery replenishes calcium body stores and reduces symptomatic hypocalcemia. Teriparatide (PTH 1-34) therapy in post-thyroidectomy patients can control and prevent symptomatic hypocalcemia and reduce hospitalization (THYPOS trial).

Non-invasive Thyroid Follicular Neoplasm

Papillary thyroid cancer (PTC) is the most common histologic thyroid cancer in children. Follicular thyroid carcinoma (FC) is the second most common thyroid cancer in children occurring less than 5% of the time. FC is associated with TSH elevation, iodine deficiency areas and radiation exposure. FC is a tumor composed of neoplastic follicles rather than papilla but with follicular cells showing nuclear features characteristic of papillary thyroid carcinoma. Two subtypes of FC are recognized: encapsulated or minimally invasive FTC and widely invasive FC. Encapsulated FC has increased its incidence during the past 10 years. It is a tumor with an indolent behavior. In 2012 the National Cancer Institute revised this pathology and determined to call it Non-invasive follicular neoplasm with papillary-like nuclear features (NIFTP) if it reflected the following characteristics: follicular growth pattern, lack of invasion, nuclear features of papillary carcinoma comprising less than 1% of the tumor, absent psammoma calcifications, the lesion had clonal origin determine by findings a driver mutation (biologically a neoplasm) and a very low risk of adverse outcome. NIFTP also has a lack of common somatic mutation like BRAF and/or RAS. Studies have found that NIFTP has a low recurrent rate over the years, low metastatic rate, can be managed with lobectomy only obviating the need for completion thyroidectomy and subsequent radio-iodine therapy. This proposed reclassification will reduce overtreatment of this condition and the psychological and clinical consequences associate with a diagnosis of cancer. NIFTP is a surgical disease and its diagnosis can only be rendered upon excision and depends totally on adequate or entire sampling of the interface between tumor and its capsule/periphery to exclude invasive characteristics. To ensure a lack of infiltrative or invasive growth the entire tumor capsule/periphery should be submitted for histologic evaluation. A diagnosis of NIFTP cannot be rendered using fine needle aspiration cytology only. Lymph nodes metastasis are incompatible with NIFTP.

Renovascular Hypertension

Renovascular hypertension (RVH) in children if untreated leads to ischemic nephropathy, chronic kidney disease, myocardial infarction, stroke and encephalopathy. RVH is defined as high blood pressure which results from a lesion reducing blood flow to part or all of one or both of the kidneys associated with alteration in the renin-angiotensin mechanism. Incidental hypertension in an asymptomatic child is the most common presentation of RVH. Younger children are more likely to have neurological sequelae like seizures, left ventricular hypertrophy, congestive heart failure, lethargy or poor growth. The most common cause of RVH in children is renal artery stenosis caused by fibromuscular hyperplasia (FMH) and Takayasu arteritis. Syndromes such as Neurofibromatosis, Williams, tuberous sclerosis and vasculitis comprised other less common causes of RVH. FMH is a non-atherosclerotic, non-inflammatory idiopathic angiopathy affecting medium-size arteries. Mid-aortic syndrome is another etiology of RVH referring to localized narrowing of the distal thoracic  or abdominal aorta involving the renal vessels as well. Diagnosis of RVH includes Doppler ultrasound, CT-angiography Scan and MRI, though digital substraction angiography is the gold standard. More than 50% of RVH arterial lesions are bilateral. Management of RVH entails medical, surgical or endovascular options. Medical management only has the least opportunity of cure. Surgical management includes revascularization, bypass or nephrectomy. Endovascular options developed in the adult population are increasing use in children. This endovascular options include mainly percutaneous balloon angioplasty. The use of stents is reserved for severe or recurrent stenosis or management of complications. Open surgical intervention has a higher rate of cure higher than 70%. Angioplasty is often utilized for short arterial narrowing while open surgery is used for long diffuse arterial narrowing or complete occlusion of renal arteries. Residual hypertension is found in one-third of the children managed surgically or percutaneously. Other postop morbidity includes aortic rupture, dissection, bleeding, thrombosis and graft stenosis. Management should be individualized.    

PSU Volume 51 NO 06 DECEMBER 2018

Cecal Diverticulum

Diverticulum in the cecum are very rare in children and adults. It is estimated that for every 300 appendectomies the surgeon will encounter one cecal diverticulum. Most cecal diverticulum are congenital in origin containing all four layers of the bowel (true diverticulum), instead of the more common false diverticulum that does not contain the muscular layer in the left colon seen mostly in adults patients. Cecal diverticulum results from pulsion of the fetal cecum in the 6th week of pregnancy. Cecal diverticulum can cause inflammation, hemorrhage or perforation. The incidence of right colon diverticulum among all patients with diverticulosis is between 60-80% in the Asian population. Since the child develops right lower quadrant pain the initial diagnosis is appendicitis. Fecal material can accumulate in the most distal part of the diverticulum leading to ruptured. The diverticulum is solitary and tends to produce problems in younger patients. Most are situated posteriorly and near to the ileocecal valve. In the less common anterior diverticulum there might be more rapid progression to perforation and peritonitis. Finding an unexpected inflammatory mass in the cecum during an emergency laparoscopy or laparotomy for appendicitis might end in a right hemicolectomy if the diagnosis of a benign solitary diverticulum is not entertained. Symptoms mimic those of acute appendicitis (right iliac fossa pain, fever and leukocytosis) depending on the grade of inflammation and walling off from the omentum. Diagnosis of a cecal diverticulum can be made or suggested with CT-Scan. Colonoscopy is a valuable diagnostic tool in the diagnosis of diverticular disease. Preoperative diagnosis is difficult in emergency cases. Management of cecal diverticulitis is segmental resection of the diverticulum base (diverticulectomy) along with concomitant appendectomy. In few occasions right hemicolectomy might be required in cases with perforation risk or severe surrounding tissue inflammation. 

Mayer-Rokitansky-Kuster-Hauser Syndrome

Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome refers to a normal female karyotype 46XX with congenital aplasia or severe hypoplasia of the structures that derived from the müllerian ducts including the upper two-third of the vagina, uterus and fallopian tubes. Occurs in one of 4500 female births. The syndrome becomes type II when other associated malformations are found such as renal unilateral agenesis, renal ectopia, horseshoe kidney, skeletal-vertebral anomalies, scoliosis, auditory system anomalies, heart defects and syndactylism or polydactylism. Associated malformations are present in almost half of patients with unilateral renal agenesis the most common. The defect occurs during organogenesis 4th to 8th week gestation transmitted as a dominant autosomal with incomplete penetration and variable expression. The patient presents with primary amenorrhea as initial symptom with normal secondary sexual characteristics since the ovaries are normal. Pelvic ultrasound is the first diagnostic study to perform. This is followed by MRI which is usually diagnostic of the anomaly. This is followed with X chromatin, karyotype and female hormones plasma levels. In case of doubt diagnostic laparoscopy can precise anatomy. Management should start in late adolescent. The objective of treatment is the creation of a functional neovagina satisfactory for intercourse. Progressive perineal dilatation is the preferred initial approach due to the minimally invasive nature, high success rate and low cost. If this method fails then surgical vaginoplasty using inverted skin flap (McIndoe method) or U-flap (William method) is indicated. Some authors use a piece of sigmoid colon as neovagina. This is a major procedure with potential complications such as excess mucous production, vaginal stenosis, prolapse, diversion colitis, bowel obstruction and even neovaginal carcinoma. To have children these patients will need in vitro fertilization with a gestational carrier.  

DICER1 Syndrome

DICER1 syndrome also known as pleuropulmonary blastoma familial tumor susceptibility syndrome is a rare genetic disorder that predisposes patents to development of benign and malignant tumors. They include cystic nephroma, embryonal rhabdomyosarcoma, multinodular goiter, thyroid cancer, ovarian Sertoli-Leydig cell tumor, pituitary blastoma and others. The DICER1 gene is located in chromosome 14, position q32.13 and encodes an endoribonuclease Dicer protein playing a role in protein translational control. The mutation causes loss of function of cancer suppressors genes or gain of function in genes that contribute to the onset of cancer in an active manner (oncogenes). Pleuropulmonary blastoma, a rare cancer of the lung or pleura in children, is a manifestation of DICER1 syndrome. The simultaneous occurrence of Sertoli-Leydig ovarian cell tumor and thyroid carcinoma is a reliable indicator of DICER1 syndrome. A rare form of Hodgkin lymphoma arising from T cells, instead of mature B cells, has been associated with DICER1 syndrome. Pineoblastoma may be associated with a DICER1 mutation. Other rare associations with DICER1 syndrome include developmental delay, lung cyst, overgrowth, macrocephaly and Wilms tumor. DICER1 syndrome has been recognized as an autosomal dominant disease, inherited and expressed in a haploinsufficient manner. The DICER1 gene encodes an enzyme that is involved in the biogenesis of microRNAs. DICER1 Germline mutations are identified as nonsense mutations leading to stop codons within the coding sequence leading to cancerous and noncancerous tumors. The spectrum of DICER1-related tumors and the young age at presentation suggest early surveillance of at-risk patients is critical.