Ch29: Thoracic Surgery — Chest Trauma, Lung, Esophageal & Mediastinal Tumors（胸部外科）

Preparatory Mindset

Thoracic surgery combines chest trauma emergencies (胡创 lecture, 13KB), lung cancer (16.1), esophageal cancer (16.2), and mediastinal tumors (16.3). The exam tests: chest trauma life threats (tension PTX, massive hemothorax, flail chest, cardiac tamponade), lung cancer (NSCLC vs SCLC, staging, lobectomy), esophageal cancer (SCC vs adenocarcinoma, dysphagia, esophagectomy), and mediastinal masses by compartment (CM exam tested).

Exam mindset: the six immediately life-threatening chest injuries (airway obstruction, tension pneumothorax, open pneumothorax, massive hemothorax, flail chest, cardiac tamponade), closed thoracic drainage indications, lung cancer staging & management, and esophageal cancer (SCC in Asia; dysphagia progression; surgery + neoadjuvant).

Core Concepts

1. Chest trauma — overview (MUST KNOW)

1. Airway obstruction 2. Tension pneumothorax — needle decompression 3. Open pneumothorax — 3-sided occlusive dressing 4. Massive hemothorax — chest drain + volume 5. Flail chest (with pulmonary contusion) — O2, analgesia, ± ventilation 6. Cardiac tamponade — pericardiocentesis

• Chest = chest wall + chest cavity; cavity = potential space between parietal & visceral pleura containing lungs & mediastinum
• Functions: bony chest protects vital organs; respiratory mechanics
• Immediately life-threatening (ATLS — must recognize & treat on the spot):
• Potentially life-threatening (detected later): simple PTX, hemothorax, pulmonary contusion, tracheobronchial injury, aortic injury, diaphragmatic rupture, esophageal injury

2. Rib fractures & flail chest (MUST KNOW)

• Rib fractures: painful, splinting → atelectasis/pneumonia; upper ribs (1-3) = high-energy → great vessel injury; lower ribs (8-12) → liver/spleen injury
• Flail chest: ≥2 adjacent ribs fractured in ≥2 places (or costochondral separation) → paradoxical movement (segment moves inward on inspiration) + underlying pulmonary contusion
• Treatment: analgesia (epidural), O2, physiotherapy, ventilation if respiratory failure; surgical fixation (plate) in selected
• Simple pneumothorax: chest drain (5th ICS anterior/mid-axillary, above the rib — the "safe triangle")

3. Pneumothorax & hemothorax (MUST KNOW)

• Tension pneumothorax: one-way valve → air accumulates → mediastinal shift AWAY, tracheal deviation, hyperresonance, absent breath sounds, distended neck veins, hypotension → EMERGENCY needle decompression (2nd ICS midclavicular) → chest drain
• Open (sucking) pneumothorax: chest wall defect → air enters during inspiration → occlusive 3-sided dressing → chest drain → wound closure
• Simple pneumothorax: chest drain (or observation/aspiration for small); underwater seal
• Hemothorax: blood in the pleural cavity (intercostal vessels, lung, great vessels) → chest drain (indication: any significant hemothorax); massive hemothorax (>1500 ml initial or >200 ml/h for 2-4 h) → volume resuscitation + emergency thoracotomy
• Traumatic asphyxia: severe crush → cyanosis of the face/neck, petechiae, subconjunctival hemorrhage; supportive

4. Closed thoracic drainage (闭式胸腔引流) (MUST KNOW)

• Indications: pneumothorax (tension/open/not resolving), hemothorax, pleural effusion/empyema, post-thoracotomy
• Site: 5th ICS, anterior to the midaxillary line (safe triangle: anterior border of latissimus, lateral border of pectoralis, apex below the axilla), above the upper border of the rib (avoid the intercostal neurovascular bundle)
• System: underwater seal (bubbling = air leak; swinging = intrapleural pressure changes); clamp only when changing the bottle / testing for air leak — NEVER clamp a draining pneumothorax during transport (tension risk)
• Removal: when the lung is expanded & no air leak (or drainage <50-100 ml/24 h) — after clamping trial & CXR
• Complications: insertion injury (lung, liver, spleen), infection/empyema, re-expansion pulmonary edema, kinking/disconnection

5. Lung cancer (肺癌) (MUST KNOW)

| Type | % | Features | |---|---|---| | NSCLC (non-small cell) | 85% | — | | — Adenocarcinoma | 40% | Most common now (also non-smokers, women); peripheral | | — Squamous cell | 25-30% | Central, cavitation, hypercalcemia (PTHrP) | | — Large cell | 10-15% | Peripheral, aggressive | | SCLC (small cell) | 15% | Central, rapid, paraneoplastic (SIADH, Cushing, Lambert-Eaton), early mets — treat with chemo/RT (rarely surgical) |

- NSCLC stage I-II: surgical resection — lobectomy (standard) with mediastinal lymph node dissection; segmentectomy/wedge for small/peripheral; VATS preferred — ± adjuvant chemo (II) - Stage IIIA (N2): neoadjuvant chemo(±RT) then surgery, or definitive chemoradiation (multimodality) - Stage IIIB-IV: systemic — chemo + immunotherapy (PD-1/PD-L1), targeted (EGFR/ALK/ROS1 if mutated), palliative RT (bone/brain mets, SVC obstruction); no curative surgery - SCLC: chemo + RT (limited), chemo (extensive); prophylactic cranial irradiation (responders); surgery only for very early - Post-op care: chest drains, physiotherapy, pain control

• Epidemiology & risk: most common cancer death; smoking (main), asbestos, radon, family history, COPD/fibrosis
• Types:
• Clinical: cough, hemoptysis, weight loss, chest pain, dyspnea, hoarseness (recurrent laryngeal invasion), SVC obstruction (facial swelling), Horner's (Pancoast — apex), finger clubbing, paraneoplastic syndromes
• Diagnosis & staging: CXR (hilar mass, effusion) → CT chest (staging + biopsy planning) → tissue (bronchoscopy/EBUS-TBNA, CT-guided biopsy) → PET-CT (metastasis) → mediastinoscopy/EBUS for N staging → TNM staging
• Treatment (MUST KNOW):
• Prognosis: stage-dependent; early resected NSCLC 5-yr survival 60-80%; advanced poor

6. Esophageal cancer (食管癌) (MUST KNOW)

- Squamous cell carcinoma (SCC): the common type in Asia/China — smoking, alcohol, hot beverages/diet, nitrosamines, achalasia, Plummer-Vinson - Adenocarcinoma: Western type — Barrett's esophagus (chronic GERD — intestinal metaplasia), obesity, male

- Early (T1): endoscopic resection (EMR/ESD) or esophagectomy - Resectable (T2-4a/N+): neoadjuvant chemoradiotherapy (CROSS trial — SCC & adenocarcinoma) or perioperative chemo (FLOT) → esophagectomy (transthoracic Ivor-Lewis or McKeown; transhiatal for distal) with 2-3 field lymphadenectomy - Unresectable/metastatic: definitive chemoradiotherapy (SCC), palliative (stenting — self-expanding metal stent for dysphagia, radiotherapy, chemo, feeding tube) - Adjuvant therapy for high-risk features

• Types & risk (MUST KNOW):
• Clinical: progressive dysphagia (solids → liquids), weight loss, odynophagia, regurgitation; hoarseness (RLN), cough (tracheoesophageal fistula — late), anemia
• Diagnosis: barium swallow (shouldering/apple-core stricture), endoscopy + biopsy (gold standard), EUS (depth/nodes), CT/PET (staging), bronchoscopy (if proximal — tracheal invasion)
• Staging: TNM; resectable vs locally advanced vs metastatic
• Treatment (MUST KNOW):
• Post-op complications: anastomotic leak (most feared — fever, mediastinitis), stricture, reflux, delayed gastric emptying, recurrent laryngeal palsy, chylothorax (thoracic duct)
• Prognosis: poor overall (~20% 5-yr); early disease better; neoadjuvant CRT improves survival

7. Mediastinal tumors (纵隔肿瘤) (MUST KNOW)

| Compartment | Common masses | |---|---| | Anterior (superior) mediastinum — "the terrible T's" | Thymoma (most common), Teratoma/germ cell, Thyroid (substernal goiter), Terrible lymphoma, parathyroid | | Middle mediastinum | Lymphadenopathy (lymphoma, sarcoid, TB, mets), bronchogenic cyst, pericardial cyst | | Posterior mediastinum | Neurogenic tumors (schwannoma, neurofibroma, ganglioneuroma — most common posterior), esophageal lesions, paravertebral abscess |

• Mediastinal divisions: superior, anterior (prevascular), middle (visceral), posterior (paravertebral)
• Masses by compartment (MUST KNOW):
• Thymoma (MUST KNOW): associated with myasthenia gravis (30-50%); anterior mediastinal mass; treatment: thymectomy (transsternal/VATS) — for the tumor & often improves myasthenia; locally invasive → RT
• Teratoma/germ cell: young adults; benign teratoma vs malignant (seminoma, yolk sac — AFP/β-hCG); surgical
• Clinical: often asymptomatic (incidental); mass effects: cough, dysphagia, chest pain, SVC syndrome (anterior), hoarseness
• Diagnosis: CT chest (first), MRI (neurogenic), biopsy (mediastinoscopy/EBUS/CT-guided) + tumor markers (AFP, β-hCG), myasthenia workup
• Treatment: surgical resection for most (thymoma, teratoma, neurogenic); lymphoma → chemo; germ cell → chemo

High-Yield Points

• 6 immediately life-threatening chest injuries: airway obstruction, tension PTX, open PTX, massive hemothorax, flail chest, tamponade
• Tension PTX: needle decompression 2nd ICS MCL → chest drain; Open: 3-sided dressing; Massive hemothorax: drain + >1500 ml → thoracotomy
• Chest drain: 5th ICS anterior-midaxillary (safe triangle), above the rib; underwater seal; never clamp a draining PTX during transport
• Flail chest: paradoxical movement + contusion; analgesia/ventilation
• Lung cancer: NSCLC (adeno/squamous/large) vs SCLC (central, paraneoplastic, chemo); lobectomy for early NSCLC; SCLC = chemo/RT
• SVC obstruction & Horner (Pancoast) & paraneoplastic — classic presentations
• Esophageal: SCC (Asia — smoking/alcohol/hot drinks) vs adenocarcinoma (Barrett/GERD); progressive dysphagia; endoscopy + biopsy; neoadjuvant CRT then esophagectomy; stenting for palliation
• Anterior mediastinum = "terrible T's" (thymoma, teratoma, thyroid, lymphoma); posterior = neurogenic
• Thymoma ↔ myasthenia gravis; thymectomy
• Traumatic asphyxia: facial cyanosis/petechiae after crush

Topic Summary

Thoracic surgery: chest trauma (6 life threats: airway, tension PTX, open PTX, massive hemothorax, flail chest, tamponade; needle decompression & chest drain techniques; rib fractures/flail chest; traumatic asphyxia); lung cancer (NSCLC — adeno/squamous/large; SCLC — chemo-based; staging with CT/PET/EBUS; lobectomy for early NSCLC; paraneoplastic syndromes & SVC/Horner presentations); esophageal cancer (SCC in Asia vs adenocarcinoma from Barrett; progressive dysphagia; endoscopy + biopsy; neoadjuvant CRT + esophagectomy; palliative stenting); mediastinal tumors by compartment (anterior "terrible T's" — thymoma with myasthenia; middle — nodes/cysts; posterior — neurogenic; thymectomy for thymoma).