SURGICAL DISORDERS OF SURGICAL DISORDERS OF MEDIASTINUM AND MEDIASTINUM AND

DIAPHRAGMDIAPHRAGM

Sina Ercan MDSina Ercan MD

Professor of Thoracic SurgeryProfessor of Thoracic Surgery

Anatomy of the Anatomy of the MediastinumMediastinum

Mediastinum is the Mediastinum is the central space within the central space within the thoracic cavity bounded thoracic cavity bounded by:by: Sternum anteriorlySternum anteriorly Lungs and parietal pleura Lungs and parietal pleura

laterallylaterally The vertebral column The vertebral column

posteriorlyposteriorly The thoracic inlet superiorlyThe thoracic inlet superiorly The diaphragm inferiorlyThe diaphragm inferiorly

Compartments of Compartments of mediastinummediastinum

Anterior mediastinum:Anterior mediastinum: the area the area posterior to the sternum and anterior posterior to the sternum and anterior to the heart and great vesselsto the heart and great vessels Thymus, substernal thyroid Thymus, substernal thyroid

glands, parathyroid, glands, parathyroid,

lymph nodes, lymph nodes,

connective tissueconnective tissue

Middle mediastinum:Middle mediastinum: the area the area between the posterior border of the between the posterior border of the anterior mediastinum and a line anterior mediastinum and a line placed along the posterior aspect of placed along the posterior aspect of the trachea and the heartthe trachea and the heart Heart, pericardium, aortic arc, Heart, pericardium, aortic arc,

brachiocephalic vessels, vena cava ,brachiocephalic vessels, vena cava ,

main pulmonary vessels, trachea, main pulmonary vessels, trachea,

main bronchi, phrenic and uppermain bronchi, phrenic and upper

parts of the vagus nerve, parts of the vagus nerve,

lymph nodeslymph nodes

Posterior MediastinumPosterior Mediastinum: The area : The area between the posterior aspect of between the posterior aspect of middle mediastinum and the middle mediastinum and the vertebraevertebrae Esophagus, azygos and hemiazygos Esophagus, azygos and hemiazygos

veins, thoracic duct, descending aorta, veins, thoracic duct, descending aorta, autonomic ganglia, symphathetic chain, autonomic ganglia, symphathetic chain,

lower portions of the vagus nerve, lower portions of the vagus nerve,

lymph nodes and connective tissuelymph nodes and connective tissue

Mediastinal PathologiesMediastinal Pathologies

Non neoplastic diseasesNon neoplastic diseases MediastinitisMediastinitis PneumomediastinumPneumomediastinum

Congenital pathologiesCongenital pathologies CystsCysts HerniasHernias

Acquired lesionsAcquired lesions BenignBenign MalignantMalignant

In adults 65% of the mediastinal lesions In adults 65% of the mediastinal lesions are anteriorare anterior

In children 52% of the mediastinal lesions In children 52% of the mediastinal lesions are posterior are posterior

40-50% of the mediastinal lesions are 40-50% of the mediastinal lesions are malignant in children compared to 25% malignant in children compared to 25% malignancies in adultsmalignancies in adults

Mediastinal Pathologic Mediastinal Pathologic LesionsLesions

Anterior mediastinal Anterior mediastinal disordersdisorders

TThymic disordershymic disorders Thymoma, Thymic Thymoma, Thymic

carcinomacarcinoma Thymic carcinoidThymic carcinoid ThymolipomaThymolipoma Thymic cystThymic cyst Thymic hyperplasiaThymic hyperplasia

TThyroid disordershyroid disorders Intrathoracic goiterIntrathoracic goiter

Germ cell tumorsGerm cell tumors TTeratomaeratoma SeminomaSeminoma OthersOthers

LymphomaLymphoma Hodgkin’s diseaseHodgkin’s disease Non-Hodgkin’s Non-Hodgkin’s

Parathyroid adenomaParathyroid adenoma Mesenchymal tumorsMesenchymal tumors

ThymomaThymoma Most common adult 1Most common adult 100 mediastinal mediastinal

neoplasm neoplasm Usually >40 y/oUsually >40 y/o 40-70% have symptoms related to 40-70% have symptoms related to

parathymic syndromesparathymic syndromes Myasthenia Gravis,Myasthenia Gravis, HypogammaglobulinemiaHypogammaglobulinemia Pure red cell aplasiaPure red cell aplasia Nonthymic malignanciesNonthymic malignancies

Thymomas represent neoplastic Thymomas represent neoplastic proliferation of thymic epithelial cells proliferation of thymic epithelial cells mixed with mature lymphocytesmixed with mature lymphocytes

CT demonstrates a homogenious soft CT demonstrates a homogenious soft tissue masstissue mass

CT guided needle biopsy, CT guided needle biopsy, mediastinoscopy, mediastinotomy or mediastinoscopy, mediastinotomy or VATVATS for diagnosisS for diagnosis

ThymomaThymoma

Thymic Carcinoma:Thymic Carcinoma: Malignant histologic featuresMalignant histologic features Pulmonary, regional lymph node or Pulmonary, regional lymph node or

pleural metastasis can be presentpleural metastasis can be present Thymic carcinoid: Thymic carcinoid:

a rare agressive neoplasm that originates a rare agressive neoplasm that originates from thymic neuroendocrine cellsfrom thymic neuroendocrine cells

Thymolipoma: Thymolipoma: a rare benign tumor composed of mature a rare benign tumor composed of mature

adipose and thymic tissueadipose and thymic tissue

CT image of a Thymolipoma (Exhibits fat and thymic soft tissue)

Mediastinal LymphomaMediastinal Lymphoma 10-20% of all mediastinal neoplasms in adults 10-20% of all mediastinal neoplasms in adults

May be 1May be 1oo in anterior or middle mediastinum in anterior or middle mediastinum or part of systemic malignancy or part of systemic malignancy

20-30% of patients are asymptomatic20-30% of patients are asymptomatic

Symptoms of local invasion or systemic Symptoms of local invasion or systemic symptoms (fever, weight loss, pruritis)symptoms (fever, weight loss, pruritis)

Hodgkin’s disease:Hodgkin’s disease: Bimodal age peak Bimodal age peak (20-30 years; >50 years)(20-30 years; >50 years)

Majority of patients have Majority of patients have asymmetric, bilateral mediastinal asymmetric, bilateral mediastinal LAPLAP

Non-Hodgkin’s Lymphoma:Non-Hodgkin’s Lymphoma: Usually in Usually in older patientsolder patients

Usually systemic upon presentation Usually systemic upon presentation and spreads unpredictablyand spreads unpredictably

Diffuse Large B-cell LymphomaDiffuse Large B-cell Lymphoma

Lymphoblastic LymphomaLymphoblastic Lymphoma

Mediastinal Germ-Cell Mediastinal Germ-Cell TumorsTumors

Teratomas:Teratomas: Account 60-70% of cases Account 60-70% of cases Consist of tissue that may derive from Consist of tissue that may derive from

more than one of the germ cell layersmore than one of the germ cell layers Mostly benign, radiologically spheric, Mostly benign, radiologically spheric,

lobulated, well circumscribed and may lobulated, well circumscribed and may contain calcificationcontain calcification

Seminomas:Seminomas: Affect men in 3rd and 4th decades Affect men in 3rd and 4th decades 40-50% of mediastinal malignant germ 40-50% of mediastinal malignant germ

cell tumorscell tumors

Teratoma (well formed teeth within the mass is diagnostic)

Germ cell tumor

MIDDLE MEDIASTINAL MIDDLE MEDIASTINAL DISORDERSDISORDERS

LymphomaLymphoma Benign Benign

lympadenopathylympadenopathy Granulomatous diseaseGranulomatous disease

InfectiousInfectious Non infectiousNon infectious

MiscellaneousMiscellaneous AmyloidosisAmyloidosis DrugsDrugs

Metastatic Metastatic lymphadenopathylymphadenopathy

CystsCysts Bronchogenic cystsBronchogenic cysts Pericardial cystPericardial cyst

Vascular LesionsVascular Lesions AneurismAneurism HemangiomaHemangioma

MiscellaneousMiscellaneous Diaphragmatic Diaphragmatic

herniashernias Pancreatic Pancreatic

pseudocystpseudocyst

Benign mediastinal Benign mediastinal lymphadenopathylymphadenopathy

InfectiousInfectious Tuberculosis: Usually unilateral and Tuberculosis: Usually unilateral and

asymmetric, may have calcificationasymmetric, may have calcification Fungal infectionsFungal infections

HistoplasmosisHistoplasmosis coccidioidomycosiscoccidioidomycosis

Non infectiousNon infectious Sarcoidosis: Usually bilateral, symmetricSarcoidosis: Usually bilateral, symmetric Silicosis: nodal calsification with Silicosis: nodal calsification with

eggshell configurationeggshell configuration

Normal mediastinal lymph nodes

Sarcoidosis

Unilateral hiler enlargement

CystsCysts

Bronchogenic cyst:Bronchogenic cyst: Originate from Originate from abnormal budding of ventral foregutabnormal budding of ventral foregut

Commonly in subcarinal and Commonly in subcarinal and paratracheal regions 15% in pulmonary paratracheal regions 15% in pulmonary paranchymeparanchyme

Lined by respiratory epithelium and may Lined by respiratory epithelium and may contain serous fluid, mucus, milk of contain serous fluid, mucus, milk of calcium, blood or purulent materialcalcium, blood or purulent material

Bronchogenic cyst

Enterogenous cysts:Enterogenous cysts: Esophageal dublication and neurenteric cysts Esophageal dublication and neurenteric cysts Located in the middle or posterior Located in the middle or posterior

mediastinummediastinum Pericardial Cysts:Pericardial Cysts:

In the cardiophrenic angles (R>L)In the cardiophrenic angles (R>L) Fibrous walls and contain clear fluidFibrous walls and contain clear fluid

Diaphragmatic hernias:Diaphragmatic hernias: Hiatal herniaHiatal hernia Morgagni herniaMorgagni hernia Bochdalek herniaBochdalek hernia

Pericardial cyst

Thoracic aortic aneurisym

Vascular lesionsVascular lesions

Posterior Mediastinal Posterior Mediastinal DisordersDisorders

Neurogenic tumorsNeurogenic tumors Peripheral nervePeripheral nerve

Schwannoma, Schwannoma, neurofibroma etcneurofibroma etc

Sympathetic gangliaSympathetic ganglia Ganglioneuroma, Ganglioneuroma,

neuroblastoma etcneuroblastoma etc Paraganglionic Paraganglionic

tumorstumors pheochromocytomapheochromocytoma

Esophageal Esophageal disordersdisorders Benign tumorsBenign tumors Esophageal Esophageal

diverticulumdiverticulum SpinalSpinal

Lateral thoracic Lateral thoracic meningocelemeningocele

Paraspinal abscessParaspinal abscess MiscellaneousMiscellaneous

Thoracic duct cystsThoracic duct cysts

CT of neurofibromaExtramedullary hematopoiesis

Diagnostic ProceduresDiagnostic Procedures

Physical examination Physical examination (Signs of Sup. V. (Signs of Sup. V. Cava or Horner Syndrome)Cava or Horner Syndrome)

Plain Chest Radiography Plain Chest Radiography (PA and Left (PA and Left lateral)lateral)

CTCT

Arteriography/ VenographyArteriography/ Venography

UltrasoundUltrasound MRIMRI Barium esophagramBarium esophagram Histologic evaluationHistologic evaluation

Fine needle aspirationFine needle aspiration Mediastinoscopy/mediastinotomyMediastinoscopy/mediastinotomy Thoracoscopy (VATS)Thoracoscopy (VATS) ThoracotomyThoracotomy

Non neoplastic Disorders of the Non neoplastic Disorders of the MediastinumMediastinum

PneumomediastinumPneumomediastinum

PneumopericardiumPneumopericardium

Acute MediastinitisAcute Mediastinitis

Chronic MediastinitisChronic Mediastinitis

PneumomediastinumPneumomediastinum Caused by alveolar overdistention Caused by alveolar overdistention

and ruptureand rupture

Etiology of Etiology of pneumomediastinumpneumomediastinum

SpontaneousSpontaneous Acute asthma attackAcute asthma attack Scuba divingScuba diving Mechanic ventilationMechanic ventilation VomitingVomiting

TraumaTrauma SurgerySurgery TracheostomyTracheostomy

Bronchoscopic Bronchoscopic proceduresprocedures

Respiratory tract Respiratory tract infectionsinfections

Dental infections or Dental infections or proceduresprocedures

Acute mediastinitisAcute mediastinitis PneumoperitoneumPneumoperitoneum Esophageal Esophageal

perforationperforation

Substernal chest pain is the most Substernal chest pain is the most frequent symptomfrequent symptom

Crepitation; air dissecting under the Crepitation; air dissecting under the skinskin

DyspneaDyspnea DysphagiaDysphagia DysphoniaDysphonia Hypotension (hemodynamic changes)Hypotension (hemodynamic changes)

Physical examination reveals Physical examination reveals palpable subcutaneous emphysema palpable subcutaneous emphysema in the neckin the neck

On auscultation of the chest a On auscultation of the chest a clicking sound over the pericardium clicking sound over the pericardium synchronous with the heartbeat synchronous with the heartbeat (Hamman’s sign)(Hamman’s sign)

Treatment:Treatment: SupportiveSupportive Supplemental oxygenSupplemental oxygen Management of causesManagement of causes Surgery, chest tube insertion when Surgery, chest tube insertion when

hemodynamic deterioriation is present hemodynamic deterioriation is present or when associated with mechanical or when associated with mechanical ventilationventilation

Iatrogenic esophageal perforation is the most Iatrogenic esophageal perforation is the most common cause of acute mediastinitiscommon cause of acute mediastinitis

Can also be:Can also be: Postemetic (Boerhaave’s syndrome)Postemetic (Boerhaave’s syndrome) TraumaTrauma Operative injuryOperative injury Cancer erosionCancer erosion Foreign bodyForeign body

Esophageal perforationEsophageal perforation

Esophageal perforationEsophageal perforation

Clinical signs and symptomsClinical signs and symptoms

Abrupt onset of severe chest pain, fever, Abrupt onset of severe chest pain, fever, dyspnea, SVC symptomsdyspnea, SVC symptoms

Tachypnea, tachycardia, hypotension, Tachypnea, tachycardia, hypotension, cervical emphysemacervical emphysema

Shock develops quicklyShock develops quickly Chest Radiology:Chest Radiology: Upper mediastinal Upper mediastinal

enlargement, emphysema, enlargement, emphysema, hydropnomothorax, multiple air fluid hydropnomothorax, multiple air fluid levelslevels

Mediastinitis

Treatment:Treatment: Surgical debridement of the necrotic Surgical debridement of the necrotic

tissuetissue Closure of the perforationClosure of the perforation DrainageDrainage Broad spectrum antibiotics with Broad spectrum antibiotics with

anaerobic coverageanaerobic coverage Mortality rises when the treatment delay Mortality rises when the treatment delay

is more than 24 hoursis more than 24 hours

Diseases of the DiaphragmDiseases of the Diaphragm Diaphragma is a dome shaped Diaphragma is a dome shaped

musculotendinous structure that musculotendinous structure that separates thoracic and abdominal separates thoracic and abdominal cavitiescavities

It consists of two parts:It consists of two parts: Right hemidiaphragmRight hemidiaphragm Left hemidiaphragmLeft hemidiaphragm

Middle portion is made of the central Middle portion is made of the central tendon that doesn’t contract, it has two tendon that doesn’t contract, it has two holes onholes on The caval openingThe caval opening The esophageal hiatusThe esophageal hiatus

Diaphragma thoracic view

Diaphragma abdominal view

The muscle fibers of the crural part The muscle fibers of the crural part originate from lomber vertebraeoriginate from lomber vertebrae

The muscle fibers of the costal part The muscle fibers of the costal part originate from the processus originate from the processus xiphoideus and 7-12 ribsxiphoideus and 7-12 ribs

The costal part contraction lowers The costal part contraction lowers the diaphragm and increases the rib the diaphragm and increases the rib cagecage

When the crural part contracts only When the crural part contracts only the diaphragm moves downwardthe diaphragm moves downward

Motor inervation comes from cervical Motor inervation comes from cervical motor neurons (C3-5) conducted via motor neurons (C3-5) conducted via N. FrenicusN. Frenicus

Diaphragm is the major inspiratuar Diaphragm is the major inspiratuar muscle responsible from 70% of muscle responsible from 70% of normal breathing.normal breathing.

Contraction of the diaphragm has the Contraction of the diaphragm has the following effects that promote air following effects that promote air movement into the lungsmovement into the lungs It decreases intrapleural pressureIt decreases intrapleural pressure It raises and inflates the rib cageIt raises and inflates the rib cage It expands the rib cage by generating It expands the rib cage by generating

positive intraabdominal pressurepositive intraabdominal pressure

Diaphragmatic paralysis:Diaphragmatic paralysis:

Can be bilateral or involve only one Can be bilateral or involve only one side (unilateral)side (unilateral)

In this setting the accessory muscles In this setting the accessory muscles of the respiration assume some or all of the respiration assume some or all the work of breathingthe work of breathing

Patients with Patients with bilateral diaphragmatic bilateral diaphragmatic paralysisparalysis typically present with typically present with dyspneadyspnea.. It is associated with It is associated with tachypnea and rapid shallow breathingtachypnea and rapid shallow breathing

Paradoxal motion of the anterior Paradoxal motion of the anterior abdominal wall during inspiration can abdominal wall during inspiration can be detectedbe detected

Hypoxemia is common due to Hypoxemia is common due to atelectasis and V/Q mismatch which atelectasis and V/Q mismatch which worsens with sleepworsens with sleep

Disease progression is associated with Disease progression is associated with progresive hypercapniaprogresive hypercapnia

Unilateral diaphragmatic paralysisUnilateral diaphragmatic paralysis is is more commonmore common

Often discovered incidentally on a chest Often discovered incidentally on a chest radiograph and diagnosis can be made radiograph and diagnosis can be made only by radiology (fluoroscopic sniff test)only by radiology (fluoroscopic sniff test)

Patients who do not have underlying Patients who do not have underlying lung disease are usually asymphtomaticlung disease are usually asymphtomatic

In fluoroscopic sniff test paradox In fluoroscopic sniff test paradox elevation of the paralysed elevation of the paralysed hemidiaphragm is positive >90% of the hemidiaphragm is positive >90% of the patientspatients

Diaphragmatic EventrationDiaphragmatic Eventration

Eventration of the diaphragm is a Eventration of the diaphragm is a disorder in which all or part of disorder in which all or part of the the diaphragmatic muscle is diaphragmatic muscle is replaced by fibroelastic tissuereplaced by fibroelastic tissue..

Eventration of the diaphragm can be Eventration of the diaphragm can be congenital or acquiredcongenital or acquired

Many patients are asymptomatic, Many patients are asymptomatic, especially when the eventration is especially when the eventration is localized localized

Can be seen incidentally on chest x Can be seen incidentally on chest x ray and ray and The diagnosis is confirmed The diagnosis is confirmed by fluoroscopy or ultrasonography. by fluoroscopy or ultrasonography.

In infants the management depends In infants the management depends on the extent of the respiratory on the extent of the respiratory distress, often no need to treatment distress, often no need to treatment

Diaphragmatic HerniaDiaphragmatic Hernia

Hiatal Hernias:Hiatal Hernias:Result when an abdominal structure usually Result when an abdominal structure usually the stomach extends through the the stomach extends through the diaphragmatic esophageal hiatus into the diaphragmatic esophageal hiatus into the thorax. Manifests as a retrocardiac mass in thorax. Manifests as a retrocardiac mass in the middle mediastinumthe middle mediastinum

Traumatic ruptureTraumatic ruptureSeen in 1-4% of blunt chest or abdominal Seen in 1-4% of blunt chest or abdominal trauma usually on the left posterolateral trauma usually on the left posterolateral regionregion

Traumatic rupture of the left hemidiaphragm

Congenital Hernias:Congenital Hernias:These are due to the failure of the normal fusion These are due to the failure of the normal fusion of the diaphragmatic components during of the diaphragmatic components during embryologic developmentembryologic development Morgagni hernias:Morgagni hernias: herniation of omentum and herniation of omentum and

other abdominal contents into the thorax other abdominal contents into the thorax manifest as a right cardiophrenic angle massmanifest as a right cardiophrenic angle mass

Bochdaleks hernias:Bochdaleks hernias: May protrude into the May protrude into the posterior mediastinumposterior mediastinum

Diagnosis can be established in diaphragmatic Diagnosis can be established in diaphragmatic hernias by gastrointestinal barium study or CT. hernias by gastrointestinal barium study or CT. Treatment is surgical in symptomatic cases.Treatment is surgical in symptomatic cases.

Morgagni hernia

Bochdaleks hernia