True Learn- Thoracic Surgery Flashcards
Superior vena cava syndrome
Compression/ invasion of SVC from malignant masses (lymphoma, lung cancer), infection (tuberculosis), central venous stenosis (in-dwelling catheters, pacemaker leads)
Dyspnea (MC presenting symptom), swelling of head, neck, & arms; headache, conjunctivae edema
Contrast CT of chest; MR venography if contrast allergy
Chest tube placement
5th intercostal in mid axillary line, inserted over rib to avoid neurovascular bundle, directed posterior and cephalad
Absence of water chamber oscillation -> malposition, kinking, occlusion -> obtain CXR
Incidental pulmonary nodule
Pulmonary nodule found on CXR should be assessed by CT scan
Any pulmonary nodule > 6 mm on CT scan should have repeat interval CT scan for surveillance or other advanced assessment (PET/CT scan, biopsy- bronchoscopic, CT-guided needle biopsy, VATS vs robotic wedge resection)
Light’s criteria
-Determine if pleural effusion is transudative or exudative
-If any 1 criterion is met, then exudative
Pleural:serum fluid protein > 0.5
Pleural:serum lactate dehydrogenase > 0.6
Pleural fluid LDH > 2/3 upper limit of normal
Transudate: CHF, cirrhosis, nephrotic syndrome
Exudate: malignancy, pneumonia, tuberculosis, pancreatitis, pulmonary embolism, esophageal rupture, chylothorax, hemothorax
-Must have volume greater than 300 mL to be detected on standard upright posteroanterior chest radiograph
-Also may indicate effusion: accentuation of fissure, increased separation b/n lung and subdiaphragmatic gas, elevation of hemidiaphragm
Chylothorax
-Chyle (or lymphatic fluid) from thoracic duct in pleural space
-Dyspnea, heavy feeling in chest, fatigue, weight loss
-Ongoing chyle leak can lead to nutritional deficiences & loss of Ig (risk of infection)
-Thoracic duct: runs from cisterna chyli at L2 and ascends through aortic hiatus of diaphragm between aorta and azygos vein on right side; then runs posterior to esophagus at T7, crosses to the left side at T5, and drains into the junction of the left subclavian and jugular veins
-If on normal diet- fluid is milky; serous or serosanguineous if NPO
-Seen after an esophagectomy or in patients with a thoracic malignancy
-Should be drained and fluid analyzed to measure triglycerides and cholesterol levels
-Low output (less than 500 cc): dietary modification (diet consisting of medium-chain triglycerides) or TPN, octreotide
-Surgical management: if conservative methods fail after 7 days or drainage exceeds 1 L/day; ligation of thoracic duct through right chest; alternative- chemical pleurodesis, lymphangiography with possible embolization of thoracic duct
-For cancer-related chylothorax & persistent draiange despite optimal chemotherapy & radiation therapy, pleurodesis is highly succesful
Chylothorax vs Empyema vs Cholesterol Effusion
-Chylothorax: predominant lymphocytes, LDH < 1,000 IU/L, glucose level= serum glucose level, pH 7.4-7.8, triglyceride > 110 mg/dL, cholesterol < 200 mg/dL, Sudan III stain= fat globules
-Empyema: predominant neutrophils, LDH > 1,000 IU/L, glucose < 40 mg/dL, pH < 7.2, triglyceride level < 110 mg/dL, cholesterol level < 200 mg/dL, Sudan III stain= no fat globules
-Cholesterol effusion: predominant lymphocytes, LDH < 1,000 IU/L, glucose level= serum glucose level, pH 7.4-7.8, triglyceride > 110 mg/dL, cholesterol > 200 mg/dL, Sudan III stain= fat globules
Neurogenic tumors
-Most common posterior mediastinal mass- in particular Schwannoma and neurofibroma (malignant equivalent is neuroblastoma and ganglioneuroblastoma but rarer)
-CT chest, followed by MRI to assess for potential spinal canal involvement “dumbbell tumors”
-If spinal canal involvement: may require hemilaminectomy or laminectomy
-Bx only if dx unclear
-Complete surgical resection is treatment of choice for all neurogenic tumors, if cannot be completely excised then add chemoradiation
Mediastinal masses
Thymoma: anterior; encapsulated, well-defined, soft-tissue mass, often with hemorrhage, necrosis, cyst formation
Teratoma: anterior; well-defined, round, lobulated with sebaceous elements and fat
Lymphoma: anterior; adenopathy, soft-tissue attenuating mass, with smooth or lobulated margins which conform to surrounding structures; cystic/low-density areas; systemic signs- fever, weight loss, night sweats; chemoradiation
Cyst: middle; thin-walled, well-defined round masses with homogenous density similar to water
Neurogenic: posterior; well-defined hypodense mass without invasion may have cystic changes, hemorrhage, or lipid within myelin; originate from elements of sympethetic chain; may grow large before detection; may have sxs of Horner syndrome or tracheal displacement
Pediatric:
-Hodgkin lymphoma more common in anterior & middle mediastinum in older children
-Non-Hodgkin lymphoma: more common in anterior & middle mediastinum in children younger than 10
-Neurogenic tumors most common in posterior mediastinum
-Germ cell tumors 3rd most common mediastinal tumor; teratomas most common among germ cell
Pericardial window
Subxiphoid approach
-Vertical incision 5-8 cm over xiphoid toward abdomen, linea alba incised, exposing xiphoid
-Xiphoid completely removed, retrosternal space entered using finger dissection
-Upward retraction, diaphragmatic aspect of pericardium visualized, grasped with Allis clamp, sharply incised
-Fluid aspirated, drainage tube inserted through separate stab incision, surgical incision closed in layers
Initial management?
Lung abscess: intraparenchymal collection of fluid and air
Empiric antibiotics= 1st line treatment; must cover anaerobes especially when aspiration suspected
Beta-lactam + Beta-lactamase inhibitors= first choice: ampicillin-sulbactam
Beta-lactam allergies: levofloxacin + metronidazole, clindamycin
Endobronchial Ultrasound (EBUS)
-Procedure of choice for lymph node sampling
-Visualizes superior and inferior mediastinal lymph nodes at stations 1-4, 7, 10-12
-Level 5, subaortic lymph nodes (aortopulmonary window) are lateral to ligamentum arteriosum and are difficult to access by EBUS
-Cervical mediastinoscopy: historic gold standard, access to lymph node stations 2L, 2R, 4L, 4R, 7
-VATS: evaluate aortopulmonary nodes in stations 5 and 6 in addition to 2, 4R, 8, and 9; also evaluate lung parenchyma and pleura
-Esophageal ultrasound (EUS): stations 7, 8, 9
Diaphragmatic hernias
-Large/ long-standing diaphragmatic hernias: best approached through thoraco-abdominal approach -> often dense adhesions that make reduction via pure abdominal or thoracic approach difficult
-Once contents released and returned to abdomen, abdominal approach allows best visualization of the entire diaphragm
Major preoperative tests performed prior to lung resection
If preoperative testing suggests that patient will not tolerate procedure, perform ventilation-perfusion scan, which will show distribution of ventilation and blood flow to each lobe of the lungs. If the desired lobe has a minimal contribution to the FEV1, then the patient can still likely tolerate a resection.
Tracheoinnominate fistula bleed
-75% of tracheoinnominate fistula bleeds occur within 3 weeks s/p tracheostomy placement but may occur at any time
-50% of tracheoinnominate fistula bleeds have sentinel event- tracheostomy site bleeding, hemoptysis, or blood seen with tracheal suctioning
-90% mortality rate
Causes:
-Cuff over inflation-> tracheostomy tube to erode -> mucosal ischemia of anterior aspect of trachea and into innomate artery
-Injury to innominate artery in bronchoscopy
-Poorly positioned tracheostomy tube: innominate artery usually crosses trachea at 9th cartilage ring but can vary from 6th to 13th; tracheostomies placed beneath 3rd tracheal ring or with innominate artereies crossing higher
-Steroids: weaken endotracheal mucosa, hypotension: tracheostomy tube pressure exceeds endotracheal mucosa pressure, radiation therapy
Repair:
-Overinflation of existing tracheostomy tube cuff, digital compresion of vessel against sternum through stoma; secure endotracheal tube distal to compressing finger
-Access vessel with collar incision and sternotomy extension; proximal & distal control should be obtained; resect affected portion of vessel, oversew ends; proximal relocation of tracheostomy
-Local strap muscle flaps should be used to cover initial tracheostomy stoma to encourage healing; if field contaminated, then can use omentum
Paget-Schroetter syndrome
-Effort thrombosis
-Due to compression of subclavian vein by either cervical rib or muscular tissue (repetitive motion: swimmers, baseball pitchers)
-Primary axillary-subclavian thromboses: no clear cause; venous thoracic outlet syndrome
-Secondary ASVT: more common; usually associated with indwelling catheter or hypercoagulable state
-Present with UE swelling & tenderness; duplex US confirms dx
-Thrombolytic therapy: venogram performed through catheter placed in basilic vein; catheter placed within thrombus & lytic agent infused; balloon angioplasty for residual venous narrowing; heparin also administered; first rib resection or decompression of thoracic outlet
Staging guidelines of lung cancer
Massive hemoptysis management
-600 cc or more of expectorated blood in 24 hours; usually from bronchial artery
-Pre-emptive intubation
-Rigid bronchoscopy and airway packing
-Epinephrine-soaked gauze or foley balloon insertion for tamponade
-Once bleeding identified and controlled, defitintive control- surgical resection, angiographic embolization, laser ablation
-Acutely decompensating patient with massive pulmonary hemorrhage, hilar clamping or a 180-degree hilar twist - last result
-Trauma pneumomectomy usually not well tolerated
Lung cancer paraneoplastic syndromes
-Small cell: overproduction of ADH or ACTH
-Squamous cell cancer: overproduction of PTH-related peptide= hypercalcemia
Tension pneumothorax
-Tracheal deviation, hypotension, absent/decreased breath sounds
-Immediate decompression with needle or finger thoracostomy*
Pediatric (< 15): 2nd intercostal space, mid-clavidular line
Adults: 4th-5th intercostal space, mid-axillary lien
Spontaneous pneumothorax
Risk factors: Marfan syndrome, homocystinuria, thoracic endometriosis, family history, malnutrition, smoking
Most common cancers with pulmonary metastases
-Malignant melanoma, sarcoma, carcinomas of the bronchus, colon, breast, kidney, and testicle
-Colorectal cancer is among the most common malignancies overall and frequently mestastizes to the liver and lungs
Internal thoracic artery
-Branches off subclavian artery, continues on as superior epigastric artery, provides blood supply to the anterior chest wall and breasts
-Courses inferiorly between the internal oblique and transverse thoracic mucles until bifurcation at 6th intercostal space into musculophrenic & superior epigastric arteries
Lung anatomy
-Left upper lobe: 2 bronchopulmonary segmentsr (apicoanterior & posterior segments); lingula also contains 2 bronchopulmonary segments (superior & inferior segments); right upper lobe contains 3 bronchopulmonary segments (apical, anterior, posterior)
Pancoast tumor
-Superior sulcus tumor; usually non-small cell lung cancer; located near the thoracic inlet at the apex of the lung
-Presenting sx: shoulder pain, paresthesia, weakness within an ulnar distribution, Horner syndrome
-Locally advanced, unresectable, or medically unfit should receive chemotherapy
