Thoracic Surgery Flashcards
(35 cards)
Thoracic Diaphragmatic Anatomy
During expiration the right diaphragm rises to level of the nipple (T4) and the left rises to one rib space lower.
The right diaphragma flattens to level of the 11th rib; the left flattens to the level of the 12th rib.
The IVC hiatus lies at the level of T8 (includes branches of the R phrenic)
The Esophageal aperaure is at the level of T10 (includes the L/R vagal trunks)
The Aortic aperature is at the level of T12 (includes azygous and thoracic duct)
Cervicoaxillary Canal
The cervicoaxillary canal is bounded by the first rib inferiorly, the clavicle superiorly, and the costoclavicular ligament medially.
Includes the subclavian vein and artery and the brachial plexus
Brachial plexus is composed of nerve roots C5-Superior trunk (C5-C6), Middle trunk (C7), and Inferior trunk (C8-T1)
Thoracic surface anatomy
Right manubrial border; Right brachiocephalic vein, origin of superior vena cava, innominate artery
Manubrium; Aortic arch and origin of great vessels, left brachiocephalic vein
Left manubrial border; Left common carotid and left subclavian vessels
The angle of Louis:
Right hemithorax-azygous vein joins SVC
Midline-thoracic duct crosses the midline
Left hemithorax-aortopulmonary window
Left third costal cartilage; origin of aorta and pulmonary artery
Right third costal cartilage; SVC empties into the RA
Right oblique fissure courses anteriorly at the level of the fifth rib.
The posteriorly left oblique fissure starts at a level between the third and fifth ribs and ends anteriorly at the level of the fifth rib.
The horizontal fissure starts anteriorly at the fourth costal cartilage and joins the oblique fissure a the level of the fifth rib.
Endoscopic Ultrasound
Used for staging of esophageal cancer.
Four normal endoluminal findings:
1. Upper esophageal sphincter at the cricopharyngeus (15 cm)
2. Aortic arch (indentation on the left anterolateral wall) (23 cm)
3. Left atrium (wavelike pulsations in anterior wall of distal esophagus)
4. Lower esophageal sphincter (35-40 cm)
The esophagus is seen in 5 layers.
Hyperechoic is white, hypoechoic is black
1. First layer (hyperechoic) = epithelium and lamina propria
2. Second layer (hypoechoic) = muscularis mucosa
3. Third layer (hyperechoic) = submucosa
4. Fourth layer (hypoechoic) = muscularis propria
5. Fifth layer (hyperechoic) = paraesophageal tissue
Main advantage over CT is “differentiation of T stage,” especially between the T3 and T4 stages.
The accuarcy of EUS for staging of regional lymph nodes is 70-80%
Most EUS errors are either understaging T0 or T1 or overstaging T2.
Contraindications to esophagoscopy
Recurrent nerve paralysis Esophageal varices with esophagitis Esophageal diverticulum Aortic aneurysm (pulsatile compression) Corrosive strictures Kyphoscoliosis
Standard acid reflux test
Tests LES competence
300 cc acid infused in the stomach
pH less than 4 is evidence of reflux
Acuracy 81%, Sens 59%, Spec 98%
Esophageal Manometry (Indications, findings)
Indicated for symptoms of dysphagia, chest pain, heartburn, or regurgitation. Diseases such as achalasia, DES, nutcracker esophagus, hypertensive LES.
Mechanically defective sphincter:
Average LES pressure
Evaluation of GE Reflux with 24 hr motility/pH monitoring
24 hr motility monitoring:
Esophageal motility is the most important factor in clearance of gastric reflux.
Efficient peristaltic contractions have an amplitude of >30 mmHg.
Duration of reflux proportional to number of efficient contractions.
Esophageal contractility deteriorates with increasing severity of mucosal injury.
24 hr pH monitoring: Probe positioned 5 cm above GE junction. Stop H2 blockers 48 hrs prior/PPI 2 weeks prior. Evaluation: Time pH less than 4 measured as a percentage of total, upright and supine monitored time. Frequency of reflux episodes Duration of reflux episodes Duration of longest episode of reflux
What is the most common site of distant metastasis for NSCLC?
Brain, Imaging should include CT brain and Bone scan for advanced cases.
What is the most specific predictor of post operative pulmonary complications related to lung resection?
Measurement of maximal oxygen consumption (VO2 max). Patients with VO2max greater than 15 mL/kg/min can undergo surgical resection with an acceptably low mortality rate. Patients with postoperative FEV1 and DLCO less than 40% predicted and VO2max less than 15 mL/kg/min have a very high risk of postoperative com- plications and/or death.
What is the cell site of origin for BAC or Adenocarcinoma in situ of the lung?
Type II pneumocyte (Clara Cell)
Tumors that invade the chest wall, diaphragm, phrenic nerve, parietal pleura, pericardium, or main stem bronchus less than 2 cm from the carina, but without involvement of the carina, are?
T3
Tumors that invade the contents of the mediastinum (i.e., heart, great vessels, trachea/carina, recurrent largyngeal nerve, esophagus) or vertebral body are?
T4
Tumors 7 cm or larger, tumors that result in obstructive atelectasis or pneumonitis of the entire lung, and 2 or more tumors within the same lobe are?
T3
2 or more tumors in different ipsilateral lobes?
T4
Patients with Tumors in the contralateral lung are deemed to have?
M1 Disease
Treatment of MAI or atypical mycobacterial infection?
Indications for operation include concern for underlying cancer, lesions that are growing or refractory to antibiotics, and persistently positive sputum despite antibiotics (particularly clarithromycin, ethambutol, and rifampin).
The primary goal of treatment is symptom improvement and sputum conversion. Elimination of gross structural lesions and focal disease may be required to achieve these goals and to restore optimal lung function. While the infection is often diffuse throughout the lung, there are often a small number of radiographically discrete areas that are amenable to resection. Ideally, resection is anatomic (lobectomy or segmentectomy), although wedge resections may be necessary if the disease is peripheral and involves multiple lobes of the lung
Atypical mycobacterial disease (“MAC” – Mycobacterium avium complex, or “MOTT” - mycobacterium other than M tuberculosis)
Two patient populations at risk: (1) middle-age women with no demonstrable lung disease, and (2) patients of both sexes with pre-existing pulmonary abnormalities.
Preoperative diagnosis is not always possible, and organism identification (M konsasii , m szulgai, M. xenopi. M. chelonae, others) requires DNA hybridization.
Postoperative morbidity is considerable in most published reports and some authors advocate staple line reinforcement with PTFE or pericardial strips. If completion pneumonectomy is required, the bronchial stump should be covered with a viable tissue flap. Both preoperative and protracted postoperative antibiotics are essential, and nutritional supplementation is crucial in many cases.
Most common primary histology for patients evaluated for pulmonary metastasis?
What is the second most frequent source of metastases to the lungs?
Colorectal carcinoma (35-45% five year survival with resection)
Sarcoma (in as many as 50% of patients, the lungs are the only site of metastatic disease)
What is the strongest predictor of survival with pulmonary metastasis?
Complete resection.
Besides histology, factors associated with improved survival in patients undergoing PM include a prolonged disease-free interval from the time of resection of primary tumor to the appearance of pulmonary metastases, and a lower number of pulmonary metastases.
Repeat PM may be required when there are isolated recurrences in the lungs. Of patients undergoing PM, 40% to 80% will suffer a pulmonary recurrence. Repeat PM has been shown in the International Registry and several sub- sequent databases to afford a long-term survival advantage in patients that qualify for repeated procedures.
TEF is the most common anomaly of the trachea.
What is the most commonly used classification (by Gross)?
Which is the most common?
• Type A (8%): esophageal atresia without TEF
• Type B (1%): esophageal atresia with proximal TEF
• Type C (87%): esophageal atresia with distal TEF (Most Common)
• Type D (1%): esophageal atresia with proximal and distal TEF
• Type E (4%): TEF without esophageal atresia
Describe the anatomy of Extra Lobar Sequestrations?
Twenty-five percent of sequestrations are extralobar (ELS), which are distinct from the remaining lung, with their own visceral pleura. They are round soft tissue masses that typically lie just above the dome of the diaphragm, with 90% found at the base of the left lung. The venous return is more often systemic (azygos, hemiazygos), with only 20% draining into the pulmonary veins. ELS are associated with other anomalies (congenital diaphragmatic hernia [CDH], congenital cystic adenomatoid malformation [CCAM], pericardial cysts, cardiac defects, esophageal achalasia), may be found in various locations (pericardium, diaphragm, below the diaphragm ret- roperitoneally), and have been known to contain malignancies.
Describe the findings of Intralobar Sequestrations?
Intralobar sequestrations (ILS) comprise 75% of pulmonary sequestrations and are primarily found in the right and left lower lobes, with the most frequent location being the posterior segment of the LLL. They are cystic abnormalities located within the visceral pleural of the lung that communicate with the normal lung tissue through the pores of Kohn. Ninety-six percent of ILS will have venous drainage to the pulmonary veins. It is rarely associated with other anomalies, but may present antenatally as polyhydramnios.
Describe the classification system of Congenital Cystic Adenomatoid Malformation (CCAM)?
CCAM can be classified (by Stocker) as follows:
• Type I (macrocystic, 60-70%). Large, widely-spaced, irregular cysts that are larger than 2 cm. This type is rarely associated with polyhydramnios or other anomalies. Most patients will reach term, but some are stillborn. Mediastinal shifting can be seen in 75% of patients with some associated cyanosis and grunting. Half will develop pneumonia during infancy or early childhood, but the overall prognosis is good.
• Type II (mixed, 20-40%). The cysts are smaller than 2 cm, and have the appearance of more bronchioles with increased proliferation and less mediastinal shift. Patients tend to be prema- ture or stillborn.
• Type III (microcystic, 10%). The cysts are smaller than 0.5 cm, and the mass is firmer, ap- pearing to encase the entire affected lobe (most commonly LLL). Prognosis is very poor, with life expectancy of hours after birth.
CCAM presents as neonatal acute respiratory distress with multiple air fluid levels on CXR. CT may solidify the diagnosis. Associated anomalies are pectus excavatum (most common) and cardiac and pulmonary vessel malformations
Describe the types of Congenital Tracheal Stenosis?
Congenital tracheal stenosis is classified in three types (by Cantrell and Guild):
• Type 1: involves the entire trachea
• Type 2: funnel shaped stenosis of the upper, lower, or the entire trachea
• Type 3: segmental stenosis of the lower trachea
