Thoracic Surgery

CHAPTER 27
Thoracic Surgery


Timothy Misselbeck


Test Taking Tip


All general surgery residents should have a working knowledge of basic thoracic surgical conditions. Focus on the common problems you may encounter as incidental findings—such as managing a solitary pulmonary nodule or a newly found mediastinal mass. Be familiar with the common surgical approaches such as median sternotomy, posterolateral thoracotomy, etc.


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FIGURE 27-1. The thorax, showing rib cage, pleura, and lung fields. (Reproduced from Doherty GM. Current Diagnosis and Treatment: Surgery. 13th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


ANATOMY/PHYSIOLOGY


Which ribs are true ribs (directly articulate with the sternum by means of cartilages)?


The upper 7 ribs (numbered 1–7)


Which ribs are false ribs (no direct connection with sternum anteriorly; usually connect with the costocartilage above)?


The lower 5 ribs (numbered 8–10)


Which ribs are floating ribs (articulate only with thoracic spine)?


Ribs 11 and 12


What structure perforates and connects the alveoli?


The pores of Kohn


What type of epithelium lines the larger upper airways as a single layer?


Ciliated tall columnar epithelium


What are type I pneumocytes?


Gas exchange; constitute ~40% of the number of cells lining the alveoli and cover >90% of the alveolar lining


What are type II pneumocytes?


Granular pneumocytes that contain lipid inclusion bodies and manufacture surfactant, a lipoprotein (dipalmitoyl-lecithin) that decreases surface tension.


What are the lobes and fissures of the right lung?


The right lung is composed of 3 lobes: the upper, middle, and lower.


The major (oblique) fissure separates the right lower lobe from the right upper and middle lobes.


The minor (horizontal) fissure separates the right upper lobe from the right middle lobe.


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FIGURE 27-2. Segmental anatomy of the lungs and bronchi. (Reproduced from Brunicardi FC, Andersen DK, Billiar TR, et al. Schwartz’s Principles of Surgery. 9th ed. www.accessmedicine.com. Copyright © The McGraw-Hill Companies, Inc. All rights reserved.)


What are the lobes and fissures of the left lung?


The left lung has 2 lobes—the left upper lobe and the left lower lobe.


The lingula is a portion of the left upper lobe and corresponds embryologically to the right middle lobe.


A single oblique fissure separates the left upper lobe from the left lower lobe.


What is the blood supply to the lung?


Unoxygenated blood is pumped to the lung from the right ventricle through the pulmonary artery.


Oxygenated blood is returned to the left atrium through the pulmonary veins.


Blood supply to the bronchi is from the systemic circulation by bronchial arteries arising from the superior thoracic aorta or the aortic arch (discrete branches or in combination with intercostal arteries).


In most individuals, there are 2 left and 1 right main bronchial artery but ~25% of patients have the bronchial arteries arise as a common trunk.


What lobe of the lung is more commonly affected by pulmonary arterial branching variation?


Left upper lobe


What is actually associated with increased surgical risk when performing lung surgery: hypercarbia or hypoxia?


Elevated pCO2 is actually associated with increased surgical risk more significantly than hypoxia.


pCO2 >43 to 45 mm Hg suggests severe disease (50% functional loss of the lung) and may be associated with underlying pulmonary hypertension (relative contraindication to surgical resection).


What is the most commonly used predictor of postoperative pulmonary reserve?


The predicted postoperative forced expiratory volume in 1 second (FEV1)


What percentage of predicted FEV1 should most patients exceed to tolerate an anatomic lobectomy?


FEV1 in excess of 60% of predicted


What carbon monoxide diffusing capacity (DLCO) levels are associated with increased perioperative risk following lung surgery?


DLCO levels <40% to 50% are associated with increased perioperative risk.


CHEST WALL CONDITIONS


What is the most common chest wall deformity?


Pectus excavatum (also called funnel chest)


How does pectus excavatum arise?


Pectus excavatum results from an imbalance/excessive growth of the lower costal cartilages leading to posterior sternal depression.


What is pectus excavatum associated with?


Other musculoskeletal abnormalities (~20%) such as scoliosis (15%) and Marfan syndrome and congenital heart disease (1.5% of patients)


Name the defect characterized by an anterior protrusion deformity of the sternum and costal cartilages:


Pectus carinatum (also called pigeon breast)


Which is more common pectus carinatum or pectus excavatum?


Pectus excavatum is more common than pectus carinatum (5:1)


What is Poland syndrome?


The absence of the pectoralis major muscle, absence or hypoplasia of the pectoralis minor muscle, absence of costal cartilages, hypoplasia of breast and subcutaneous tissue (including the nipple complex), and a variety of hand anomalies.


Is Poland syndrome more common on the right side or left side?


Poland syndrome in 2X more common on the right side of the body than on the left


Where do most bony chest wall tumors arise?


In the ribs (85%)


What is the most common malignant chest wall tumor?


Metastatic disease to the ribs


Primary bone tumors account for what percentage of all chest wall malignancies?


7% to 8% of all chest wall malignancies


What is the preferred method to obtain pathologic confirmation of a chest wall tumor?


Excisional biopsy with a minimum of a 1 to 2 cm margin (incisional biopsy may be appropriate for a large tumor)


Fibrous dysplasia of bone accounts for what percentage of benign chest wall tumors?


>30% of benign chest wall tumors


How does fibrous dysplasia most commonly present?


As an asymptomatic mass in the lateral or posterior aspect of the rib


What does fibrous dysplasia look like on chest radiography?


A fusiform expansion in the posterior aspect of the rib with a characteristic soap bubble, or ground glass appearance


When is excision of fibrous dysplasia indicated?


For relief of symptoms (pain) and for confirmation of the diagnosis


What syndrome might you suspect in a patient with multiple areas of fibrous dysplasia, precocious puberty, and skin pigmentation?


Albright syndrome


Chondromas account for what percentage of benign chest wall tumors?


15% to 20% of benign chest wall tumors


How does chondroma usually present?


As an asymptomatic, slowly growing tumor at the anterior costochondral junction


From where do chondromas arise?


Chondromas can arise from the medulla (enchondroma) or the periosteum (periosteal chondroma).


How do chondromas appear on chest radiography?


Chondromas appear as lytic lesions with sclerotic margins.


What is the treatment for chondroma?


Although benign, wide excision to rule out malignancy (chondrosarcoma)


What kind of benign chest wall tumor presents as a mass originating from the cortex of the rib?


Osteochondroma


What of patients are most commonly affected by osteochondromas?


Young males


What is the characteristic finding on chest radiography for osteochondroma?


A pedunculated bony mass capped with viable cartilage


What might you suspect if multiple osteochondromas are found in the same patient?


Familial osteochondromatosis


What is the treatment for osteochondroma?


Treatment of choice is complete excision


What is the term for the benign component of malignant fibrous histiocytosis?


Eosinophilic granuloma


What is the most common malignant tumor of the chest wall?


Chondrosarcoma (20% of all bone tumors)


What is the appearance on chest radiography of chondrosarcoma?


A poorly defined tumor mass that destroys cortical bone


What site is most frequently involved by chondrosarcoma?


The anterior costochondral junctions of the sternum


What is the treatment of choice for chondrosarcoma?


Resection with wide margins


What is the reported 5-year survival rate after complete excision of a chondrosarcoma?


70% 5-year survival rate


What tumor arises most frequently in the long bones of adolescents and young adults, accounts for 10% to 15% of malignant tumors in the chest, and typically presents as a rapidly enlarging mass with a characteristic sunburst pattern on chest radiography?


Osteosarcoma (osteogenic sarcoma)


What is the 5-year survival for osteosarcoma with complete excision and adjuvant chemotherapy?


The 5-year survival approaches 60%


What is the third most common chest wall malignant chest wall tumor?


Ewing sarcoma (10%–15%)


What bones are commonly affected by Ewing sarcoma?


Pelvis, humerus, femur


What is the characteristic appearance of Ewing sarcoma on chest x-ray?


Onion peel appearance (caused by periosteal elevation and bony remodeling)


What is the 5-year survival in a patient with Ewing sarcoma treated with multimodality therapy (chemotherapy, radiotherapy, and surgery)?


~50%


How does multiple myeloma appear on chest x-ray?


A diffuse, punched-out appearance of the bone (caused by myelogenous deposits)


How does multiple myeloma commonly present?


Multiple myeloma commonly presents as pain without a mass


What is the primary mode of therapy for multiple myeloma?


Radiotherapy


What syndrome is characterized by a benign inflammation of one or more of the costal cartilages?


Tietze syndrome


What is the difference between Tietze syndrome and costochondritis?


Tietze syndrome is characterized by swelling of the costal cartilages.


Costochondritis is characterized by the absence of swelling of the costal cartilages.


THORACIC OUTLET SYNDROME (TOS)


What syndrome is characterized by compression of the subclavian vessels and nerves of the brachial plexus in the region of the thoracic inlet?


Thoracic outlet syndrome


Name the various anatomic structures that may compress the neurovascular structures of the upper extremity:


Bone (cervical rib, long transverse process of C7, abnormal first rib, osteoarthritis)


Muscles (scalenes)


Trauma (neck hematoma, bone dislocation)


Fibrous bands (congenital and acquired)


Neoplasm


What type of symptoms commonly develop in patients with TOS?


Neurologic


What patient population is most commonly affected by TOS?


Middle-aged women


Name the borders of the scalene triangle:


Scalenus anticus anteriorly, scalenus medius posteriorly, first rib inferiorly


What might you expect with ulnar nerve (C8–T1) involvement by TOS?


Motor weakness and atrophy of the hypothenar and interosseous muscles, pain and paresthesia along medial aspect of arm and hand, fifth finger, and medial aspect of fourth finger


Where might you expect symptoms with median nerve (C5–8, T1) involvement by TOS?


Symptoms in the index and middle fingers and the flexor compartment of the forearm


What symptoms might be seen with subclavian artery compression from TOS?


Fatigue, weakness, coldness, ischemic pain, paresthesia

Aug 13, 2019 | Posted by in ABDOMINAL MEDICINE | Comments Off on Thoracic Surgery
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