PSU Volume 54 No 01 JANUARY 2020

Thyroid Pediatric Cancer: Role of CLND

Papillary thyroid differentiated cancer (PTC) is the most common malignancy of the thyroid gland in children. It carries an excellent overall prognosis after surgical and radioiodine (RAI) management in most cases. PTC is associated with neck metastasis in more than 60% of cases along with multifocality at the time of primary diagnosis in children. There is a higher incidence of distant metastasis in children as opposed to adults. The spread of PTC to regional lymph nodes appears to occur in a sequential pattern from the thyroid to the central compartment (Level VI and VII) and then to the ipsilateral compartment (Levels II, III and IV). Data of centers who use routine central lymph node dissection (CLND) during total thyroidectomy for PTC have found: Around 50-60% of those ‘node-negative' metastasis are in the central compartment of the neck rarely diagnosed using FNA. They can even occur in PTC with microcarcinomas (less than 10 mm tumor sizes). Cervical lymph node involvement in PTC does not affect overall survival as residual metastatic disease can be managed effectively with RAI. CLND can be performed without extension of the thyroidectomy. Routine CLND allows accurate staging of the disease. Prophylactic lateral neck dissection for patients with PTC is generally not recommended. Complications after CLND include injury to parathyroid glands, recurrent laryngeal nerve injury, superior laryngeal nerve injury and hematoma/seroma. CLND is recommended at the time of initial surgery for children with identified preoperative nodal metastasis. Since CLND decreases the risk of residual or recurrent locoregional disease and decrease the overall disease burden the efficacy of RAI treatment is increased. The most important deterrent toward prophylactic CLND in PTC in children is the high incidence found of postoperative transient vocal cord paralysis and permanent hypoparathyroidism identified. The use of neuromonitoring and higher expertise in thyroidectomy can reduce the incidence of complications. For children with clinical evidence of gross extrathyroidal invasion, locoregional metastasis on preop evaluation and/or suspicious intraoperative lymph nodes CLND is recommended to increase disease free survival. The lymph node ratio (number positive node/total nodes removed) greater than 0.45 correlates with a high risk for locoregional recurrence. Prophylactic CLND decrease overall tumor burden, guides toward lymph node ratio hence extent of disease and increase the efficacy of RAI improving survival in those children with positive nodal metastasis. Total thyroidectomy with CLND is the most efficient procedure permitting accurate staging and guiding further RAI therapy.

Indocyanine Fluorescence for Parathyroid Glands

PSU Volume 54 NO 02 FEBRUARY 2020

Eppikajutsuto

The most common congenital lymphatic malformation is lymphangioma or cystic hygroma with an incidence of one in 6000 pregnancies. Multiple dilated cysts of lymphatic fluid due to absence of adequate vein drainage develop in the head and neck region, followed in order of preference with the axilla. Lymphangiomas cause cosmetic and functional complications. Management of lymphatic malformations can include observation, sclerotherapy (using K-432, Bleomycin or Doxycycline), or surgical excision. An oral herbal medicine called Eppikajutsuto (TJ-28) is utilized to reduce and eliminate excessive fluid in patient with inflammatory joint disorders and edema caused by nephritis and nephrotic syndrome. The ephedra herb is the main ingredient in Eppikajutsuto and is known to induce pharmacologic effects beyond its sympathomimetics activities such as antiinflammatory, antianaphylactic, antimicrobial and antihistamine effects. Pseudoephredine, a component of the ephedra herb, has inhibitory effects on acute inflammation. TJ-28 produces an inhibitory effect on fibroblast proliferation along with inhibition of prostaglandin E2 biosynthesis as antiinflammatory effect. The main mechanism of action of TJ-28 is by suppressing the activity of vascular endothelial growth factor (VEGF) by inhibiting the synthesis of prostaglandin E2 and cyclooxygenase. Ephedra herbal treatment should not be used in elderly patients or individuals with ischemic heart disease or low appetite because of the risk of tachycardia and hypertension. TJ-28 reduces the accumulation of lymphatic fluid in lymphatic malformations. TJ-28 treatment has led to regression of lymphangiomas in the head, neck, shoulder, retroperitoneum and mediastinum with a response rate above 80% after six months of treatment. TJ-28 can be combined with sclerotherapy and/or surgery. The microcystic or combined variant of the lymphangioma seems to respond better than the macrocystic type-lesions. Difficult located lymphatic lesions can also be managed with TJ-28.

Transanal Rectosigmoidectomy for Constipation

Chronic idiopathic constipation is a common and serious problem in children. Children with chronic constipation suffer from abdominal distension, bloating, fullness, and soiling accidents that result in a poor quality of life and delayed social development. Most cases of constipation can be managed with modification of diet and medicines. A few cases will not respond to diet and medical therapy becoming intractable and developing involuntary soiling (encopresis). With severe constipation manual disimpaction and high dose laxatives are the next steps in management. Laxative therapy in chronic severe constipation can also be associated with abdominal distension, vomiting, crampy abdominal pain and bloating. Even with the colon filled with either solid or liquid stools they will not have a bowel movement. For these intractable children with constipation surgery might be an option. Surgery can consist of fecal diversion, transabdominal resection of sigmoid and rectum, antegrade continence enemas using the appendix (appendicostomy), botulinum toxin injections, posterior rectal sphincteric myectomy or stapled transanal rectal resection. All of these procedures have different results not always optimal. Recently, transanal full-thickness rectosigmoidectomy with primary coloanal anastomosis has been utilized as surgical management of severe intractable constipation in children with good results. The goal of surgical management is to resect the dilated and hypomotile segment of rectum and colon identified on contrast enema bringing down to the anus a normal caliber bowel. The advantage of the transanal approach is that is a minimal invasive procedure that includes the rectum. Major concern when performing a transanal rectosigmoidectomy is damaging the sphincteric mechanism or reducing the rectal volume and leaving the child with postoperative fecal incontinence or urgency. By preserving the dentate line the ability to differentiate between solid, liquid and gas is preserved. By preserving five cm of the rectum proximal to the pectinate line during the rectosigmoidectomy fecal reservoir is preserved reducing the incidence of postop incontinence and laxative use. 

Transanastomotic Tubes

Intraoperative transanastomotic tubes placement have been an integral part of several procedures in the upper gastrointestinal tract of children. Transanastomotic tubes (TT) have been primarily used during repair of esophageal and duodenal atresia for early feeding purpose, avoidance of prolonged total parenteral nutrition, to avoid a gastrostomy, and in the rare multiple jejunoileal atresia defect as an stent. Silastic (silicone) tubes have been preferred over regular plastic tubes. In esophageal atresia, TT has been associated with shorter duration of parenteral nutrition, less TPN-related complications, shorter time to enteral and full oral feedings along with shorter hospitalization. Due to less TPN feeding when using TT the frequency of cholestasis is reduced. Also the incidence of catheter related sepsis is reduced as the need for central venous catheterization is reduced in TT children. Studies have also demonstrated no significant increase in complications caused by the inherent tube such as anastomotic leak, stenosis, stricture, need for postoperative esophageal dilatation or increase in the frequency of gastroesophageal reflux. Others studies have suggested that there is a higher incidence of anastomotic stricture when using TT, though they do not discriminate between silastic or regular plastic tubes. In children born with congenital duodenal obstruction, the use of TT has been found to be a safe and effective way to lead to early full preanastomotic feedings reducing the duration of parenteral feeding hence reducing cost of management. Since parenteral nutrition requirements are reduced while using TT in duodenal obstruction repair the need for central venous access and concomitant complications is also reduced. Finally in the setting of multiple jejunoileal atresias the TT act as a stent while performing multiple anastomoses helping position the multiple loops of bowel accurately during the anastomosis and facilitating accurate placement of sutures. It also allows access postoperatively for enteral feeding and radiological contrast studies if needed.         

PSU Volume 54 No 03 MARCH 2020

Operating Room Fires

Though very rare, fires do occur in the operating room during a surgical procedure. They occur around 600 times per year in the US operating rooms. Two-third of the time surgical fires involve electrosurgical equipment. The most common site of fires is the head, face, neck and upper chest of the patient or personnel. Oxygen use is also documented in most cases. Cuff endotracheal tubes (without leaks) are preferred to serve as barrier of oxygen leak out from the trachea or accumulating around operative sites. For fire combustion to develop it needs three components: oxidizer (oxygen and carbon dioxide), an ignition source (cautery, lasers, light sources, drills, endoscopes, etc.)  and fuel sources (degreaser, prep agents, drapes, gowns, hood masks, ointments, aerosols, alcohol, hair, GI gases, etc.). Alcohol-based skin preparations (chlorhexidine, thimerosal, iodophor) are a common source of fuel and they should be allowed to dry completely avoiding pockets of the solution within the drapes. Electrocautery is the most common ignition source. OR fires occur either in the patient or in the room environment. Should the fire start in the patient the first priority is extinguishing the flames or removing the burning material as soon as possible along with discontinuation of all gases such as oxygen and carbon dioxide. Smoke should be dissipated and notification to the fire department should occur. The fire area must be irrigated with normal saline and moist towels. The fire can also occur on the patient airway during a procedure. In such a case all gases must be discontinued, the endotracheal tube removed and saline or water can be pour into the airway. If needed, reintubate and ventilate the patient with plain air until the fire is extinguished and oxygen can be use safely. The OR should be equipped with sterile saline, CO2 fire extinguisher, tracheal tubes, face masks, laryngoscopes, replacement airway breathing circuit, drapes and sponges to replace in case of a fire. All operating rooms should have fire alarms with fire, smoke and heat sensors. All surgical fires can be prevented. Every year the fire protocol of the hospital must be revised. High volume intraoral suction can inhibit or suppress the onset of combustion in surgical procedures in the oral cavity.         

Neck Hematoma after Thyroidectomy

The most common complications after thyroidectomy include hypocalcemia, damage to the recurrent laryngeal nerve and a neck hematoma. Postoperative neck bleeding can be life threatening due to acute airway obstruction and occur in 1.5 to 4% of all thyroidectomies. The cause of bleeding after thyroidectomy includes slippage of a ligature on major vessels, reopening of cauterized veins, retching and bucking during recovery, Valsalva maneuver, increase blood pressure or oozing from the cut surface of the thyroid gland. Total airway obstruction progress once the critical compression pressure occurs in the compartment below the strap muscles. This leads to compression of the trachea, impairment of venous and lymphatic drainage causing laryngopharyngeal edema and airway obstruction. Incomplete closure of the strap muscles or no reapproximation inferiorly during closure is recommended to allow decompression of the deep space of the neck into the superficial area. Time intervals for most hematomas to develop is less than 24 hrs, though 20% can occur three days after surgery. Patients with a postoperative neck hematoma present with respiratory distress, pain, pressure sensation in the neck, dysphagia and salivation. Signs include progressive neck swelling, suture line bleeding, dyspnea, stridor or ecchymosis in the neck skin. Early recognition with immediate surgical evacuation of the hematoma including intubation due to airway obstruction or bedside decompression of the wound is essential. Once laryngopharyngeal edema occurs there might be inability to intubate the patient with need of immediate tracheotomy. The source of hematoma is almost always found (92%) and most are caused by arterial bleeding (upper pole). The incidence of hematoma or seroma do not change with the use of a postoperative neck drain. The risk of postoperative hemorrhage is a limiting factor for outpatient thyroid surgery or early discharge from the hospital. Age (old), sex (male), race (African-American), obesity, geographic region, comorbidity, alcohol abuse, underlying diagnosis (Grave's disease), bleeding disorders, previous neck surgery, and type of surgical procedure (total thyroidectomy, substernal thyroidectomy, neck dissection) are independent risk factor for neck hematoma. Hospital bed size, location, teaching status or volume is not associated with increase risk of this complication. The incidence of hematoma after parathyroidectomy is lower than after thyroidectomy. Early severe neck hematoma with rapid mucosal edema and airway swelling needs intubation or tracheotomy. With late swelling of the neck a seroma or chyloma should be sought to be the cause.  

Variceal Bleeding

Variceal bleeding from the esophagus or stomach is a symptom of portal hypertension. Portal hypertension (PH) can be classified as presinusoidal, sinusoidal or post-sinusoidal. Presinusoidal portal hypertension in children is most commonly associated with thrombosis of the portal vein. Sinusoidal PH is usually associated with liver fibrosis (cirrhosis) of which the most common etiology is progressive biliary atresia. Post-sinusoidal PH is found in Budd-Chiari syndrome, veno-occlusive and cardiac disease. The primary symptom of variceal bleeding is hematemesis. Bleeding can be massive. Gastric varices have an increased risk of bleeding compared with esophageal varices. Portal vein thrombosis is the most common cause of portal hypertension in children and is associated with exchange transfusions, hypercoagulability states, cirrhosis, congenital portal vein malformation, umbilical vein catheterization, omphalitis, sepsis and trauma. Portal vein thrombosis creates a greater portal vein to hepatic vein gradient having a higher risk of bleeding from varices. With acute upper GI bleeding the child must receive aggressive IV and blood replacement, transfer to an intensive care unit and manage with gastric lavage using saline at room temperature. Vasoactive drugs such as vasopressin, somatostatin, octreotide are indicated. The source of variceal bleeding is diagnosed with upper gastrointestinal endoscopy. In children the preferred management of variceal bleeding is banding since is more safe, effective and leads to resolution of the bleeding in more than 90% of the patients. If the child is small (less than three years of age) banding is more difficult and sclerotherapy is often used. If endoscopic manipulations fails and persistent bleeding occurs the child can be managed with esophago-gastric tamponade using a Linton or Sengstaken-Blakemore tube. This tubes can be left in place for up to 24 hours due to the risk of aspiration, rupture, ulceration, airway obstruction or necrosis of the esophagus. Tamponade is successful in more than 80% of the cases. Should bleeding persist then emergency shunting with  transjugular intrahepatic portosystemic shunt (TIPS) is indicated. Rebleeding occurs in 50% of children in the next six weeks and the mortality in such situations can be very high. 

PSU Volume 54 No 04 APRIL 2020

Thoracic Duct Obstruction

Congenital anomalies if the thoracic duct is very rare, poorly characterized and difficult to manage. Lymphatics from the lower extremity and trunk join those of the bowel mesentery in the cisterna chyli located in the lumbar prevertebral plane posterior to the aorta and inferior vena cava. The thoracic forms from here and ascends in the thoracic prevertebral plane emptying into the central venous system near the junction of the left internal jugular vein and subclavian vein. An accessory thoracic duct occurs in the right side also. Thoracic duct obstruction, slow flow, reflux or leak of lymph or chyle into the pleural, peritoneal and pericardial space cavity causing cause respiratory compromise, chylothorax, chylous ascites, malnutrition, hypoproteinemia, lymphopenia, immunosuppression and bony erosion. Chyle in any other body cavity or tissue implies leakage from the central lymphatic channels. Chronic management with medications (octreotide, sirolimus), diuretics, pleurocenteses, peritoneocenteses, shunting procedures, sclerotherapy, embolization, radiation therapy and TPN can provide short-term palliation. Anatomic delineation of the problem using lymphangiography is essential and the best technique. Dynamic contrast magnetic resonance lymphangiography can also help delineate the obstructing problem. Peristaltic activity and negative intrathoracic pressure causes lymph to move in the thoracic duct. Lymphatic embolization and lymphovenous anastomotic techniques are relatively new technique of management of thoracic duct obstruction with limited long-term results. Thoracic duct bypass (lymphovenous) procedures in the neck appears to be safe treatment option for children with central conducting lymphatic obstruction whose lymphatic imaging indicates possible dysfunction or blockage of the thoracic duct at its terminus draining point into the central system. Thoracic duct to vein anastomosis in the neck can only be performed if the child has a central obstructed thoracic duct present. Utilization of high-power microscope (10x magnification) for the anastomosis is mandatory. Children with high central venous pressure does not respond to the anastomosis. Lymphovenous anastomosis can restore normal lymphatic circulation within two weeks, liberate patients from mechanical ventilation, and enable expeditious return to enteral feeding.

Stridor in Children

Stridor refers to a variable, high-pitched respiratory sound that can occur during breathing. The sound is produced by abnormal flow of air in the upper airways most prominently heard during inspiration, though it can be present during both inspiration and expiration. The resulting turbulent airflow causes abnormal vibrations of the surrounding tissues causing the characteristic noise. Stridor occurs due to congenital malformations and anomalies as well as in an acute life-threatening obstruction or infection of the airway. In infants and young children a small closure of the windpipe due to inflammation or infection can result in rapid airway obstruction. In children the most common cause of a stridor is acquired, such as croup, foreign body aspiration, airways burn, bacterial tracheitis, epiglottis, peritonsillar abscess and vocal cord dysfunction. Congenital causes of stridor include choanal atresia, septum deformities, vestibular atresia, macroglossia, laryngomalacia, webs, clefts, tracheomalacia, tracheal stenosis and subglottic stenosis. The subglottic region is the narrowest portion of the infant airway and normally contains the only complete cartilaginous ring (cricoid cartilage). Stridor secondary to tracheal narrowing is typically expiratory because increased intrathoracic pressure with expiration reduces the tracheal diameter. Stridor is more common in children than adults. Inspiratory stridor is caused by an obstruction in the extrathoracic region, while an expiratory stridor is caused by an airway obstruction in the intrathoracic region. Diagnostic workup includes simple chest films, neck and chest CT or MRI, and laryngotracheobronchoscopy. Laryngeo-bronchoscopy visualizing the airways establish the diagnosis. Should the child appear critically ill, then endotracheal intubation should be performed. Specific management of the stridor depends on the underlying etiology. In general with a child with stridor avoid agitating him further, monitor for rapid respiratory deterioration, secure the airway and oxygenation, examine in controlled environment such as operating room and avoid beta agonist therapy in children with croup as it worsens airway obstruction.

Biliary Cysts after Kasai Procedure

Biliary atresia (BA) is an inflammatory, progressive cholangiopathy affecting the intra- and extrahepatic bile duct system typical of the neonatal period and manifesting with cholestatic jaundice, acholia and hepatomegaly. Without management biliary atresia progress to hepatic cirrhosis and portal hypertension in need of a liver transplant. The Kasai procedure, namely an hepaticoportoenterostomy, is the initial procedure of choice for infants with biliary atresia. It is a definitive procedure for 20-40% of children with biliary atresia and a bridge to transplant to the rest. Biliary atresia is the leading cause of liver transplant in children in the world. Bile lakes also known as parenchymal cystic dilatations of the intrahepatic bile ducts have been described in up to one-third of the patients after the Kasai procedure. They have been described histologically as fibrocystic wall damage bile ducts associated with invasion by inflammatory cells. Bile lakes are almost always preceded to an episode of postoperative cholangitis after the Kasai procedure. Clinical symptoms include fever, jaundice, leukocytosis and acholic stool. Diagnosis is established with ultrasonography. Intrahepatic biliary cysts are divided into two types: solitary simple cystic lesions or multiple continuous oval or beaded lesions. In both categories of lesions prognosis has been established as poor. Intrahepatic biliary cysts without cholangitis are not a source of infection and require no treatment. More than the presence of the cyst is the associated cholangitis and onset of cyst development which is associated with a poor prognosis. Biliary cysts seen with cholangitis and occurring early after the Kasai procedure (less than six months) do carry a poor prognosis. Percutaneous transhepatic cholangiodrainage can help drain the solitary cyst while children with cholangitis and multiple cysts should be managed with intravenous antibiotics. Patients with multiple cysts and intractable cholangitis can develop hepatic deterioration in need of liver transplantation.     

PSU Volume 54 No 05 MAY 2020

Neuromonitoring in Thyroid Surgery

Thyroid surgery can cause temporary or permanent damage to the recurrent laryngeal (RLN) and superior laryngeal nerve (SLN) causing hoarseness, impaired vocal phonation, dysphonia, dysphagia and even aspiration dyspnea. Bilateral damage to the RLN can be life-threatening leading to airway obstruction. Damage to these nerves depends on the type of disease (benign or malignant), extent of thyroid resection (lobectomy vs. total thyroidectomy), type of resection (first surgery or reoperation) and the training and experience of the surgeon. Surgical exposure and identification of both nerves during surgery is the gold standard in avoiding damage. For the past ten years refinement in neuromonitoring (NM) has helped introduced electrodes in the endotracheal tube in contact with the vocal cords to monitor the functional viability of both nerves during thyroid surgery. Throughout this time NM of the RLN/SNL during thyroid surgery has allowed visual identification and exposure of both nerves, allowing recording affording a valid legal protection in case of damage. NM localizes the exact location in case of injury and determines if the injury is reversible by repairing a damage nerve. NM allows young surgeons and surgeons-in-training to approach thyroid surgery more safely. NM can also help identify anatomic variants present in less than 5% of all patients. NM has become and asset in difficult thyroid dissections, substernal goiters, redo surgery and bloody thyroidectomy. Electric nerve testing at the end of the thyroidectomy can serve for postoperative prognostication of nerve function. Detecting nerve injury intraoperatively aids in staging bilateral lobectomies to avoid bilateral vocal cord paralysis and tracheotomy. It is estimated that NM should be included as standard of care of thyroid surgery in children and adults. NM studies are not based in class 1 evidence randomized clinical trials, but in evidence 2 and 3 studies. NM is actually the only way to verify the functional integrity of the RLN and SLN during thyroid procedures. As recurrent laryngeal nerve injury is one of the most common causes of medicolegal litigation after thyroid and parathyroid surgery securing the nerve is an increasing demand in these procedures.

Lupus Associated Pancreatitis

The most common etiologies of acute pancreatitis in children consist of hepatobiliary disorders related with mechanical obstruction such as gallstone, drugs (steroids, cyclophosphamide), infectious (viral), alcohol, hypercalcemia and hypertriglyceridemia. In almost 20% of patient a cause cannot be found (idiopathic). Systemic lupus erythematosus (SLE) can be a rare cause of pancreatitis in children. The incidence of acute pancreatitis associated with SLE varies from 0.7 to 4%. Pathogenic features of SLE pancreatitis may include vasculitis, interstitial edema, arteriolar microthrombus formation from immune complex deposition, anti-pancreatic antibodies, drug toxicity, inflammation due to T-cell infiltration and complement activation. Cytomegalovirus have also been associated with lupus pancreatitis. Patients with lupus associated pancreatitis are typically female with clinically active SLE developing within the first two years of disease onset.  The diagnosis of lupus associated pancreatitis is based on clinical symptoms, pancreatic enzyme elevation and characteristic imaging findings (CT-Scan or US). A diagnosis of SLE pancreatitis can be made after the exclusion of other causes of acute pancreatitis. Clinical signs include abdominal pain, nausea and vomiting. Pancytopenia (anemia, leukopenia and thrombocytopenia) is a distinguishing feature of lupus associated pancreatitis. SLE articular involvement and occurrence of generalized tonic clonic seizures are significantly more common in patients with pancreatitis. Lupus associated acute pancreatitis can be self-limited to severe with fulminant progression. The mortality of acute pancreatitis in pediatric cases of SLE is higher when several organs are involved, in particular renal, hepatic and neurological. Within the context of SLE there are also cases of subclinical pancreatitis in which there is an elevation of pancreatic enzymes without clinical symptoms. Around 30% of asymptomatic SLE patients have hyperamylasemia.  The management of SLE pancreatitis is with steroids and supportive measures. Somatostatin therapy during the acute pancreatitis has helped a few patients. 

Carbuncle

A carbuncle is an infection of the hair follicles extending in the surrounding skin and deep underlying subcutaneous tissue. When two or more furuncles coalesce, a carbuncle develops. Clinically the patient present with a tender, inflamed, erythematous (cellulitis), fluctuant nodule with multiple draining sinus tracts or pustules in the surface of the lesion. The child can have fever, fatigue, malaise and ipsilateral associated lymphadenopathy. Carbuncles develop more commonly in hair bearing areas such as the back of the neck, buttock, axilla, groin, back and thighs. Carbuncles are usually solitary, though multiple can be seen rarely. The most common organism associated with a carbuncle is staphylococcus aureus, including the methicillin resistant variant. When the skin barrier is broken or disrupted by an infected follicle, bacteria proliferate leading to folliculitis, furuncle and then carbuncle. When compared with adults Carbuncles are rare in the pediatric age. They are associated with diabetes, hyperhidrosis, alcohol use, malnutrition, immunodeficiency, obesity and overall poor hygiene. The diagnosis is done by physical examination. There is no need to perform imaging studies for diagnosis or treatment purposes. It is important to culture the carbuncle before antibiotic therapy is started. A carbuncle can cause a diabetic patient to lose control of blood sugar or even develop sepsis. Hemogram can demonstrate leukocytosis with a shift to the left, or it can be normal depending on the systemic response of the patient. Carbuncles are managed with systemic antibiotics and surgical intervention. Antibiotics should be broad-spectrum. In children this is done in the operating room under anesthesia. Incision and drainage of multiple loculations and debridement of necrotic center are the surgical treatment of choice. A drain is usually placed and removed 48 hours later. If methicillin resistant staph aureus (MRSA) grow in culture antibiotics might need to be changed accordingly. Recurrence is rare but may need surgical excision in a few cases. Prognosis is favorable.     

PSU Volume 54 No 06 JUNE 2020

Thyroglossal Duct Cyst Carcinoma

Thyroglossal duct cyst (TDC) is the second most common neck mass in a child occurring in 7% of the population. It's a benign cystic bump in the middle of the neck near the hyoid bone that moves with tongue protrusion. The diagnosis can be corroborated with ultrasound. Excision of the cyst and duct along with the central portion of the hyoid bone is curative (Sistrunk's procedure). A papillary carcinoma (CA) can arise from a preexisting TDC from the thyroembryonic follicular thyroid remnant cells. The incidence of papillary carcinoma is 1% in surgically removed TDC. 90% of TDC carcinomas are papillary or follicular in origin, 5% are squamous cell and the rest is anaplastic, Hurthle cell or adenocarcinoma. Median age of diagnosis of TDC carcinoma is 40 years. TDC-CA occurs de novo arising from ectopic thyroid gland tissue. They are not a metastasis from an occult thyroid primary and any lesion found in the thyroid gland represents a multifocal independent primary cancer. Females are more commonly affected. Cervical node metastasis from papillary TDC carcinoma occurs in 10-25% of cases. After finding a papillary carcinoma in the specimen of the excised TDC in a child there exists controversy whether performing a total thyroidectomy or not. Most cases are found incidentally after examining the specimen histologically. Once the diagnosis is established an ultrasound of the neck and thyroid gland should be performed along with FNA biopsy of any suspicious nodule in the thyroid gland or lymph node. Genetic testing for BRAF, N-RAS, and H-RAS should be performed. Low risk patients should be managed with only Sistrunk procedure and include those with less than 45 years of age, small tumors (< 1 cm), classic histology, no extracapsular spread, no vascular invasion, negative margins, no nodal or distant metastasis and a normal thyroid gland and neck by imaging studies. Without these criteria they are categorized as high risk and managed with total thyroidectomy with or without lymph node dissection if they are found to be FNA-positive, and radioiodine ablation therapy. Long-term follow-up is mandatory after primary Sistrunk procedure without total thyroidectomy. Prognosis of TDC carcinoma is excellent with five ad 10-year overall survivals of 100% and 96% respectively.

Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is the constellation of neurologic and vascular symptoms caused by mechanical compression and entrapment of the subclavian vessels and brachial plexus within a space delimited by the scalene muscle, clavicle and first rib. As these structures pass into the upper extremity they run through three important spaces: the interscalene triangle, the costoclavicular space and the subpectoral space. Compression can occur in any of these spaces secondary to trauma or a structural malformation. A bone abnormality or soft tissue problem usually plays the etiological role. These could be a cervical rib, abnormal first rib, long transverse process of the 7th cervical vertebra or fracture of the clavicle. Soft tissue pathology associated with TOS includes abnormal fibrous bands and ligaments or congenital/acquired alteration of scalenus anterior muscle. In adults more than 90% of TOS cases are neurogenic in origin, with venous compression comprising 5% and arterial compression in 2%. In children arterio-venous ischemic symptoms predominate in 62% with 38% presenting with neurologic symptoms. It is more commonly seen in females. The neurogenic variety of TOS manifests clinically with pain, weakness, cold intolerance, numbness of the hand and occasional loss of muscle at the base of the thumb. The venous TOS manifest with swelling, pain and bluish discoloration of the arm. The arterial TOS shows pain, coldness and paleness of the arm. Pediatric cases presents with neck discomfort, upper limb numbness, weakness and sensory loss. The anatomy of neurogenic TOS is complex and is probably best determine by a combination of plain x-ray, MRI, CT-Scan, duplex scanning,  nerve conduction studies and electromyography. TOS remain a diagnosis of exclusion. Differential diagnosis includes  cervical disk herniation, distal compression neuropathy, syringomyelia, Pancoast tumor and brachial inflammation. Most pediatric patients are managed conservatively correcting posture, exercises and nerve block rather than with surgical intervention. Scalenectomy is suitable for all TOS patients who did not have bony compression. With cervical ribs, the rib is removed after excision the scalenus anterior, medius and minimus muscle. If the transverse process of the 7th cervical vertebra is longer that the first thoracic vertebra, the former should be removed. Surgical complications include brachial plexus injury, pneumothorax, chylous leakage, lymph effusion and hematomas. Postop rehabilitation is imperative.      

Torsion Undescended Testis

Undescended testis (UT) is absence of the testis in the scrotum. Occurs in 2% of the male population. It is more commonly found in babies born prematurely. When diagnosed is done after birth the UT is termed congenital. Acquired UT can occur later in life. 80% of UT are palpable within the inguinal canal, and 20% are non-palpable. Palpable UT are managed with orchiopexy before the age of one year. Imaging studies are not sufficiently reliable to determine presence or absence of a non-palpable UT. Non-palpable UT should undergo laparoscopy early in life to determine if the testis is viable and within an intraabdominal position. UT has a higher incidence than normal testes of infertility, cancer development (seminoma), atrophy, trauma and torsion. The most serious complications of UT are a high rate of infertility and high incidence of testicular cancer. Testicular torsion is 10 times more common in UT than normal positioned testis and 10% of all testicular torsion occur in UT. Most cases of UT torsion occur at an average age of 10 months. Abnormal contractions or spasms of the cremasteric muscle and adduction contractures of the hip called scissor-leg deformity that block entrance of the normal scrotum or forces the testes out are theories of why torsion in UT occurs. This is why is seen a higher incidence of UT torsion in children with cerebral palsy. Diagnosis of UT torsion is more difficult. The clinical symptoms of UT torsion include abdominal pain, groin pain, poor oral intake, vomiting and restlessness. Physical exam might include inguinal swelling and redness if the UT was in an inguinal position, with a painful mass in the inguinal region. Rapid diagnosis of UT torsion or any other gonad torsion is critical to preserve fertility. Doppler ultrasound and technetium scrotal scintigraphy scan studies can be diagnostic with the latter being preferred. US could find decrease or absent flow to the affected testis. Testicular scintigraphy with diffuse increased activity without any photopenic area can be the only sign of torsion in an UT. CT shows a well-circumscribed isodense or heterogenous mass and has fine anatomic detail in locating the affected UT with torsion. The treatment of choice for suspected acute UT torsion is immediate surgical exploration. The rate of testicular loss with UT torsion is very high along with the rate of developing an atrophic testis. With symptoms > 24 hours, no flow and no bleeding of the tunica albuginea orchiectomy is performed.