PSU Volume 49 No 01 JULY 2017

Refeeding Syndrome

Refeeding syndrome (RFS) is a potentially lethal condition defined as severe electrolyte and fluid imbalanced associated with metabolic abnormalities in malnourished patients undergoing refeeding orally, enterally or parenterally. Children at risk for developing RFS include those with chronic malnutrition, protein malnutrition, marasmus, cancer, alcoholism, following prolonged starvation, massive weight loss, prolonged IV repletion and anorexia nervosa. Predominant features of RFS include severe hypophosphatemia, altered glucose metabolism, hypokalemia, hypomagnesemia and thiamine deficiency leading o serious cardiac, pulmonary, hematological and central nervous system complications.  RFS can occur after five to ten days of starvation. Fats become the predominant source of energy. Insulin is suppressed and glucagon increases. Intracellular and extracellular ions are chronically depleted including sodium, potassium, magnesium and phosphorus. When normal nutrition is resumed insulin secretion increases and glycogen, fat and protein synthesis begins. The decreased phosphate depletes ATP and other phosphate-based molecules like 2,3-DPG intracellularly leading to poor oxygen delivery and electrolyte abnormalities from movement of ions into the cell. The patient with RFS can develop arrhythmias and cardiac dysfunction, gastrointestinal complaint, muscle weakness, myalgia, dyspnea, respiratory failure, hematologic disturbances and even death. Labs performed reveal hyponatremia, hypokalemia, hypomagnesemia, hypophosphatemia, hyperglycemia and trace and vitamins' deficiencies. Management of RFS includes slow nutritional supplementation approximately 20 Kcal/kg/day or 25% of calories requirements daily advancing three to five days for the total value with administration of deficient nutrients, trace elements, mineral and vitamins. RFS is most commonly reported in those receiving TPN but can occur also in patients who received intravenous saline-dextrose, tube feeding or an oral diet.

PSU Volume 49 No 02 AUGUST 2017

Gastrojejunostomy Tube

Sutureless Gastroschisis

Fetal Ovarian Torsion

PSU Volume 49 NO 03 SEPTEMBER 2017

Schatzki Ring

Schatzki ring (SR) is a thin diaphragm type of circumferential fold of mucosa that protrude into the lumen of the distal esophagus. It usually measures between one and 2 mm in thickness and is located in the gastroesophageal squamocolumnar junction. Schatzki ring is a very rare condition identified in the pediatric population. SR are found in 6-14% of routine barium esophagograms. Though SR are asymptomatic, they are considered to be the most common cause of episodic dysphagia for solids and food impaction in adults. SR pathogenesis has been associated with congenital, anatomical (hiatal hernia), and inflammatory conditions such as that associated with gastroesophageal reflux or eosinophilic esophagitis. Because SR is located at the squamous columnar junction, the most widely accepted theory of pathogenesis is that it is part of the spectrum of chronic mucosal inflammation resulting from acid reflux which is not always found to be true. The level of esophagitis and positive pH monitoring found in patients with SR is less than 50% of the time. Patients with SR have a normal lower esophageal sphincter pressure. It is suggested that there are two types of SR depending on esophagoscopy findings: a more common intermittent type and a less common fixed one. The intermittent type is produced by mucosal plication and is the type seen associated with eosinophilic esophagitis, while patients with peptic esophagitis may have the fixed type. Most cases of SR are males and the most common clinical presentation is dysphagia and food impaction with a mean duration of four years prior to diagnosis. SC is also associated with hiatal hernia, esophageal web and esophageal diverticula. Diagnosis of SR entail endoscopy with biopsy, esophagogram and manometry studies. Management consist of observation if asymptomatic, proton pump inhibitors if reflux is identified, or esophageal dilatation (balloon or bougie) if fixed, symptomatic and narrow.    

Postsurgical Hypoparathyroidism

Hypoparathyroidism (HypoPT) is an uncommon disorder characterized by hypocalcemia and hyperphosphatemia due to insufficient secretion of parathyroid hormone. By far the most common cause of hypoparathyroidism is postsurgical followed by autoimmune disorders, genetic causes, metastatic disease, iron overload or ionizing radiation. Neck surgery for thyroid cancer, goiter (toxic and nontoxic) and hyperparathyroidism is the most common cause of acquired hypoparathyroidism responsible for 75% of all cases. Almost 7% of surgical procedures related to the thyroid or parathyroid gland results in hypoparathyroidism, with 75% being transient and 25% chronic (> 6 months). Acquired HypoPT occurs after removal, irreversible damage or vascular ischemia of the parathyroid glands. Parathyroid hormone enhances renal tubular calcium reabsorption and increases phosphate excretion. Lack of parathyroid hormone is associated with an increase renal calcium excretion and hyperphosphatemia. Morbidity associated with HypoPT includes neuromuscular excitability (tetany), renal insufficiency, kidney stones, posterior subcapsular cataracts, intracerebral calcifications, reduced skeletal remodeling, alteration in mood, depression, bipolar disorders and increase risk of infection due to altered immune response. Risk of cardiovascular disease, fractures, spinal stenosis and malignant disease are not increased in patients with HypoPT. Management of hypoparathyroidism with calcium and active vitamin D causes an increase in serum calcium and relief of classical symptoms of hypocalcemia. The main problem is compliance with calcium and vitamin D long-term ingestion. The intake of large amounts of soft drinks containing high amounts of phosphoric acid reduces calcium absorption efficiency despite high doses of calcium therapy. Overall, mortality is not increased with hypoparathyroidism. Successful living-donor parathyroid allotransplantation for postsurgical HypoPT represents an innovative therapeutic strategy that could provide definitive management in which the disease is refractory to therapy.

Pinpoint

Fluorescent cholangiography (FC) is a technique that can be easily performed with intravenous fluorophore injection and intraoperative near-infrared imaging (NIR) to view its dissemination throughout the biliary system. The pinpoint endoscopic fluorescence imaging system (Novadaq) overlays florescent and color images in a synchronous manner enabling the simultaneous visualization of normal color and florescent images. This enables the simultaneous viewing of fluorescent images and surgery can be performed watching the anatomy of the biliary system without the need of performing and intraoperative cholangiogram. The advantage is that this system can help discern the anatomy of the biliary system while removing the sick gallbladder specially in cases where there is chronic inflammation or subacute cholecystitis thus avoiding the dreadful complication of bile duct injury. Indocyanine Green (ICG) is injected intravenously at anesthesia induction permitting  the cystic duct and common bile duct to be clearly imaged while performing the laparoscopic procedure using the Pinpoint system. Pressing a camera-mounted button Pinpoint can display simultaneous video modes to include conventional white light high definition, fluorescence only, and composite NIR-ICG overlay modes. ICG binds to plasma proteins after IV injection, but it remains in the intravascular space for a few minutes. Bound ICG is taken by the liver and excreted unchanged through the biliary system. ICG injection is well tolerated with very rare serious risk of anaphylaxis. Since it contains iodide, it should be used with caution in patients who are allergic to iodide or iodinated imaging agents. NIR-FC provides sensitive and prolonged identification of biliary anatomy and assessment of functional status. Other applications of NIR-ICG fluorescence includes vascular perfusion assessment of myocutaneous flaps, hollow viscus anastomosis and oncologic procedures.

PSU Volume 49 NO 04 OCTOBER 2017

Fowler-Stephen Orchidopexy

Epiphrenic Esophageal Diverticulum

Epiphrenic esophageal diverticulum (EED) is a rare out pouching of the lumen of the esophagus originating in the distal end of the esophagus typically four to 10 cm above the cardia and usually projecting from the right posterior wall. EED is a false pulsion diverticulum induced by high intraluminal pressure on the lower esophagus. Herniation of the mucosa and submucosa through the muscle layers of the esophageal wall occurs. Only 15-20% of patient who harbor an EED have symptoms. EED predominant symptoms include dysphagia followed by regurgitation, chest pain, heartburn, weight loss and less frequent atypical respiratory symptoms. The diagnosis of EED should be made performing barium swallow, upper endoscopy and manometry. The size of the diverticulum influences the severity of symptoms. The average size of the diverticulum is 5.5 cm and is associated with an esophageal motility disorder such in 60% of all cases, achalasia leading the list followed by nutcracker esophagus and nonspecific esophageal motor disorder. The  etiology of epiphrenic esophageal diverticulum involves an increased lower esophageal pressure and congenital weakness of the esophageal wall associated with a motor esophageal disorder such as achalasia or diffuse esophageal spasms. The management of an EED consists of laparoscopic diverticulectomy using a linear stapler, long myotomy on the contralateral side of the diverticulum extended to the gastric wall and an anterior Dor partial fundoplication. Complications include leakage at the diverticulum stapled base, empyema, paraesophageal hernia, pneumothorax, atelectasis, pleural effusion and bleeding. Most patient improves significantly with the proposed plan of management. 

Icteropyloric Syndrome

Hypertrophied pyloric stenosis (HPS) is the most common surgical cause of vomiting in the first two months of life occurring mostly in males infants. Management consists of open or laparoscopic pyloromyotomy after adequate hydration from persistent vomiting. Along with HPS some infants develop concomitant jaundice, referred as the icteropyloric syndrome (IPS). The prevalence of icteropyloric syndrome ranges from 8-10% of children with HPS. Initially it was thought that jaundice in the setting of HPS was due to dehydration, mechanical obstruction, decreased carbohydrate intake, decreased hepatic perfusion or a combination of such factors. Later it was believed that these children had Gilbert syndrome genotype. Infants with IPS are younger than infants with HPS suggesting a role for physiologic jaundice. Although prolonged physiologic jaundice could represent a manifestation of Gilbert syndrome, it does not persist into the second month of life. Children with IPS have a significant higher serum bicarbonate and lower serum chloride levels than non-jaundice infants due to greater losses of hydrochloride acid. Metabolic stress potentiates the manifestation of jaundice in infants with IPS along with hepatic levels of residual enzyme activity, bilirubin load and duration of fasting. A Gilbert syndrome genotype is found in 45-65% of infants with IPS. The risk of having Gilbert syndrome genotype is four times higher in IPS than HPS suggesting Gilbert syndrome plays a role in infants with IPS due to molecular defects within the gene promoter. Children with IPS should have genetic workup for Gilbert syndrome mutations. 

PSU Volume 49 NO 05 NOVEMBER 2017

Magnamosis

Magnamosis refers to the concept of performing magnetic compressive anastomosis using two magnets that approach each other due to its attracting forces sloughing the tissue in between them and creating a union. Anastomosis between different parts of our body is a fundamental procedure performed in surgery. Most anastomosis are either hand-sewn or made using mechanical staplers device. Recently a magnamosis device was utilized to perform bowel anastomosis in humans. The magnamosis device is a pair of self-centering rare earth neodymium-iron-boron ring magnets encased in a specially-engineered polycarbonate shell. To create an anastomosis a single magnetic (Harrison ring) is placed within the lumen of each segment of intestine where the union is desired. When the two rings are joined the interposed tissue in between is compressed causing necrosis and anastomosis formation. The device then passes through the newly formed anastomosis and leaves no foreign bodies. The patient then passes the device through the rectum with bowel movement. The magnamosis device has been found to create histologically well-formed anastomosis with burst strength comparable or even better that hand-sen or stapled anastomosis. One side of the device has a slightly convex surface whereas the other side is slightly concave. The compressive forces on the bowel wall causes transmural ischemia and necrosis centrally allowing for remodeling of the bowel in the periphery gradually forming a full-thickness anastomosis. The device is passed in the stools seven to 14 days later depending on the motility of the bowel. Patients can be safely discharge home prior to passing the magnets. The concept of magnamosis has also been utilized for the management of rectal atresia, bilioenteric, esophageal, gastroenteric and vascular anastomosis. It has also been used to managed bile ducts strictures. Magnamosis device is a safe and effective means of sutureless full-thickness bowel anastomosis with serosal apposition.

Granulomatous Lymphadenitis

Granulomatous inflammation of lymph nodes is the second most common finding in histological examination of peripheral lymph nodes. Reactive hyperplasia accounts for the most common finding. Granulomatous disease accounts for almost one-third of biopsies of cervical masses or lymph nodes in children. They are most commonly identified in the head and neck region. The granulomatous response is a generic reaction to the presence of a persistent endogenous or exogenous insoluble irritant characterized by accumulation of macrophages and dependent of the immune system of the host. Non-tuberculous mycobacteria (NTM) is the etiology of most cases of granulomatous lymphadenitis in children. In developed countries Mycobacterium Avium and Intracellulare accounts for most cases of NTM causing granulomatous lymphadenitis. NTM lymphadenitis in immunocompetent children is best managed with complete excision. Other causes of granulomatous lymphadenitis include tuberculosis, sarcoidosis, fungal infections, rheumatoid disease, Cat's scratch disease and foreign body inclusions. NTM are ubiquitous in the environment existing in soil and water (including tap water) and ingestion of contaminated material has been thought to be the principal route of cervicofacial infection in children. Children with NTM granulomatous lymphadenitis are commonly less than five years in age and more likely have multiple lymph nodes involvement in the preauricular/parotid or submandibular/submental area. Granulomatous inflammation in other sites (axilla and upper extremity, inguinal), or older than age 10 years rarely yielded a cause. Surgical excision of granulomatous lymphadenitis has a high cure rate. Surgical excision is also more effective therapy than prolonged antibiotic oral therapy. The complication rate of children who underwent surgical excision is higher including secondary staphylococcal infection and transient or permanent facial nerve damage reason why some physicians prefer to manage deep cervical lymph nodes with antibiotics and watchful waiting.

Pediatric Arterial Catheters

Indwelling arterial catheters are widely used for hemodynamic monitoring and blood sampling purposes in neonatal and pediatric patients. Arterial catheters are inserted through the umbilical artery in premature and term infants, while the radial artery route is utilized in larger children. Other alternative sites for insertion include the ulnar, brachial, axillary, dorsalis pedis and tibialis posterior arteries. Most arterial catheters in children benefit from placing them using ultrasound guidance. Almost one-third of all children with an indwelling arterial catheter will have a complication. The most common complications while using arterial catheters include catheter-related infection or inflammation, mechanical complications, embolic or thrombotic complications and bleeding. Arterial thrombosis may cause serious short-term and/or long-term complications in children, including skin necrosis, threatened limb or organ viability, leg length differences, claudication, and loss of arterial access. Another important complication of arterial catheters is bleeding when antithrombotic therapy is utilized. Possible explanations for the thrombogenicity of intraarterial catheters include damage to the vessel wall, the foreign surface, and disruption of the blood flow. This complication increases when the femoral route is utilized when compared with the radial artery. In cases where the umbilical artery is catheterized, renal flow and changes should be closely monitored. Insertion attempts of the arterial catheter at multiple sites during the admission and the presence of more than one provider participating in line placement are significant risk factors for subsequent complications. Mechanical complications or line malfunction includes leaking, removed by patient, nonfunctional, no blood return, blanching, occluded or swelling at the line site. Pronovost's prospective checklist for arterial line safety has had success in reducing the frequency of at least the most serious complications in children.