The 3rd. Surgical UnitFeb.2009

Limits of the superior mediastinum

anterior - manubrium of the sternum

posterior - anterior surface of bodies of vertebrae T1-T4

superior - plane of the thoracic inlet

inferior - plane of the sternal angle

lateral - mediastinal pleura

Transverse plane

Planes in the superior mediastinum from anterior to posterior

- glandular plane - venous plane - arterial-nervous plane

- visceral plane- lymphatic plane

Manubrium of the sternum + the cartilage of the first rib = anterior boundary of the A-S mediastinum

The first plane is the glandular plane. It consists of two lobes and is mainly fat in the adult with small islets of active thymic cells scattered throughout

The second plane is the venous plane and consists of the: left brachiocephalic vein, right brachiocephalic vein, SVC

The third plane is the arterial-nervous plane aortic arch and its branches : brachiocephalic artery, left common carotid artery, left subclavian artery nerves: left and right vagus nerves, left and right phrenic nerves

The fourth plane is the visceral plane trachea , esophagus , left recurrent laryngeal nerve

Esophagus

Lymphatic plane- thoracic duct

Anatomy

COMPARTIMENT ANTERO-SUPERIORFascia endotoracicaTimusTrunchiuri venoase

brahio-cefalice- VCSCrosa aorteiGanglioni

mediastinali sup.Nervii vagiNervii recurentiNervii frenici

LOJA TIMICA-rapoarteAnterior:

Art. sterno-condro-clavicularaManubriul sternalM. subhioidieniFata post. lig. sterno-pericardic sup.

Posterior:Lama tiro-aorto-pericardica:

Tr. v. br.-cef., VCS, tr. a.br.-cef., carotida stg. Pericard

TIMUS

Marginit de sinusurile pleurale anterioare

Inconjurat de o capsula fibroasa

Periglandular- tesut conj. lax- disectie usoara

Aderentele –lig. timo-tiroidian si timo-pericardic

TIMUS- RAPOARTE

TIMUS-rapoarteRegiunea cervicala

Anterior: m. subhiodieni

Posterior: trahee, vene tir. inf.

Lateral: a. carotida comuna, vena jugulara interna, nervul vag

TIMUS-rapoarteMediastinul anterior

Anterior: sternul+ primele 4-5 cartilaje costale, vase toracice interne

Posterior: pericard, n.cardiaci, tr. pulmonar, aorta ascendenta, crosa, ramuri, VCS, v. br.-cef.

Lateral: pleure M., nervi frenici, vase frenice sup.

TIMUS- RAPOARTE

TIMUS-vascularizatiePedicul superior: art. timice sup. din

art. tiroidiana inf.

Pedicul lateral: art.timice lat. din art. toracice interne sau dfg. sup.

Pedicul mijlociu: art. timica mijlocie din trunchi art. brahiocefalic sau aorta

TIMUS-vascularizatie, inervatieVenele timice- tr. venos br-cef., 2mm diam,

scurte- punct criticLimfaticele- ggl.parasternali, jugulari,

bronho-mediastinali- duct toracic

Nervii timici- din vag, lant simpatic cervico-toracic si frenic

WHAT’S THAT ?

MEDIASTINAL MASS, RETROSTERNALLYLYMPHOMA

MEDIASTINAL MASSTHYMOMA

LATERAL VIEW CXRTHYMOMA

GUIDELINESWhenever you see a mass on a chest x-ray

that is possibly located within the mediastinum, your goal is to determine the following:

Is it a mediastinal mass? Is it in the anterior, middle or posterior

mediastinum? Are you able to characterize the lesion by

determining whether it has any fatty, fluid or vascular components?

Statistically, it is important to remember the following:

Most masses (> 60%) are: Thymomas Neurogenic Tumors Benign Cysts Lymphadenopathy (LAD)

In children the most common (> 80%) are: Neurogenic tumors Germ cell tumors

In adults the most common are: Lymphomas LAD Thymomas Thyroid masses

Localize to the mediastinum Left. A lung mass abutts the mediastinal surface and creates acute angles with the lung. Right. A mediastinal mass will sit under the surface of the mediastinum, creating obtuse angles with the lung.

Localize within the mediastinumThe mediastinum can be divided into

anterior, middle and posterior compartments.It is important to remember that there is no tissue plane separating these compartments.

On the lateral radiograph the anterior and middle compartments can be separated by drawing an imaginary line anterior to the trachea and posteriorly to the inferior vena cava.

The middle and posterior compartments can be separated by an imaginary line passing 1 cm posteriorly to the anterior border of the vertebral bodies.This division allows us to make a more narrow differential diagnosis.

On the PA film there is a lobulated widening of the superior mediastinum.On the lateral chest film the retrosternal clear space is obliterated.

This happened to be a patient with lymphoma.

FDG-PET images of the same patient.There are multiple lymphatic masses in the anterior, middle and even posterior mediastinum, spreading to the neck.

On the chest film there is a mass that has obtuse angles with the mediastinum, so it is a mediastinal mass.The anterior location was confirmed on a CT.Most commonly this will be a mass of thymic or lymphatic origin.This proved to be a lymphoma in a HIV-positive patient.

Substernal parathyroid adenoma CT revealed an encapsulated mass of 3 cm in the upper anterior mediastinum behind the sternum-clavicular joints, with marked peripheral enhancement (arrow).

Tc-99m-sestamibi substraction image showed an area of intense uptake below the inferior pole of the left thyroid lobe, in the upper mediastinum, in the left median position and normal thyroid with homogenous radiopharmaceutical uptake (arrow)

Cystic masses

The anterior mediastinum is an important location

for cystic masses.

Masses can be entirely cystic (thymic cysts) or have solid components (lymphoma or cystic thymoma).

Some masses are cystic with enhancing septations - in these cases you should think of a germ cell tumor.

The CT shows an anterior mediastinal mass with water density attenuation.This is typical for a thymic cyst.

The CT shows a mass located in the anterior mediastinum.The mass is cystic but has solid enhancing septa.This finding is very specific for a germ cell tumor.

The CT shows a mass located in the anterior mediastinum.The mass is cystic but has solid enhancing components, so ? lymphoma, germ cell tumor and cystic thymoma.This proved to be a cystic thymoma.

TIMUS HIPERPLAZIC TIMUS ATROFIC

TUMORI TIMICETIMUS NORMAL

+/- MIASTENIA GRAVIS sau alte BOLI AUTOIMUNE

MIASTENIA GRAVISDefinitie, Kirschner, 1991Clinic- fatigabilitatea muschilor voluntari la

efort repetitiv, cu refacere la odihnaElectrofiziologic- raspuns decrement la

stimularea repetitiva-EMGFarmacologic- raspuns pozitiv la tensilonPatologic- modificari histo-pat. timice si

structurale la nivelul R. Ach. si placa n-m.Imunologic- prezenta Ac. antiR Ach. si

raspuns favorabil la imunosupresie

BV, 17 ani, MG-Oss-IIB, op.1998,AP-HPT, remisie completa

NA, 39ani, MG-Oss-IV (6 ani istoric)op.12-III-1997, AP-HLT, deces- 20.III.1997

MIASTENIA GRAVIS

Boala autoimuna dobindita – necunoscute???Ce declanseaza aparitia bolii?De ce sunt miastenici sero-negativi?De ce exista variabilitate mare de raspuns la

tratament: remisie completa, remisie farmacologica, ameliorare, agravare, fara raspuns, deces- insuf. resp. acuta?

De ce un timus normal poate induce boala?De ce apare miastenia dupa indepartarea unui

timom?

Patogenie autoimuna

Modificari de placa neuro-musculara

MIASTENIA GRAVIS

Tratamentul- nu este inca standardizat;

Discipline implicate in management: neurologie, imunopatologie, histopatologie, endocrinologie, radiologie, medicina nucleara, chirurgie, anesteziologie, oncologie ( radioterapeut, chimioterapeut)

CAI DE ABORDMEDIASTINUL ANTERIORTORACOTOMIESTERNOTOMIECERVICOTOMIEABORD MIXT

TORACOSCOPICMEDIASTINOSCOPIC

TORACOTOMIA ANTERO-LATERALAAVANTAJE:

Poate fi prelungita posteriorPoate fi prelungita prin sectiunea transversala a

sternuluiPoate fi asociata cu o cervicotomieExpune bine pediculul pulmonar si vasele mariIncizie estetica situata in santul submamar

DEZAVANTAJEAcces dificil pentru planul traheo-bronsicextremitatea sa interna ramine un punct slab, greu

de inchis

TORACOTOMIA ANTERIOARA TRANSPECTORALA

Se efectueaza in zona de insertie a m. pectorali(I5 c-ic)

De la linia parasternala ant. pina la linia axilara ant.

Poate fi prelungitaEste rezervata prelevarii de tesut biopsic

mediastinal

TORACOTOMIA BILATERALA CU STERNOTOMIE TRANSVERSALA

Ofera cimp vizual asupra mediastinului si ambelor cavitati pleurale

Pentru leziuni mediastinale extinse lateralArt. mamara interna ligaturata bilateralSe deschid ambele cavitati pleurale

STERNOTOMIA MEDIANA LONGITUDINALAAvantaje:

Acces facilExpune bine loja timicaExpune bine o leziune cu extensie bilateralaPoate fi asociata cu cervicotomiaPermite ventilarea ambilor plaminiEvita compresiuni, tractiuni pe cord, vase mari,

trahee in cursul manevrelor chirurgicale

STERNOTOMIA MEDIANA LONGITUDINALA

Dezavantaje:

Nu da acces bun spre hilul pulmonarLasa cicatrice inestetica

STERNOTOMIE MEDIANA LONGITUDINALA

Incizia longitudinala a periostului sternal

Incizie longitudinala mediana

Sternotomie longitudinala cu sternotomul

Ecartarea celor doua jumatati longitudinale de stern

Ann Thorac Surg 2000;70:1423-1424 Reversed-T Upper Mini-Sternotomy for Extended Thymectomy in Myasthenic Patients

Jan G. Grandjean, MD, PhD, Marco Lucchi, MD, and Massimo A. Mariani, MD, PhDThorax Center, University Hospital of Groningen, Groningen, The Netherlands

Reversed-T Upper Mini-Sternotomy for Extended Thymectomy in Myasthenic Patients

The reversed-T upper mini-sternotomy provides an exposure of the mediastinum that allows us to perform a complete resection of the thymus and of all the anterior mediastinal fatty tissue.

Reversed-T Upper Mini-Sternotomy for Extended Thymectomy in Myasthenic Patients

TechniqueThe patient is positioned as for the standard

sternotomy.An 8- to 10-cm midline skin incision is performed

starting about 1 cm under the jugulum, then the sternum is divided up to the third intercostal space.

At this level, the sternum is transversely transected by means of an oscillating saw .

A Finocchietto-like pediatric retractor is positioned to spread the sternum.

The resection starts from the fat of the inferior mediastinum. This step can easily be accomplished putting a hand-held retractor under the sternum and lifting it.

TechniqueThe anterior mediastinal fat is removed beginning

from the diaphragm going upward. Then, the gland is elevated toward the brachiocephalic

trunk, and the draining veins and the thymic branches of internal mammary artery are ligated.

The cervical horns of each lobe are resected by a blunt dissection.

At the end of the procedure, a 20F drain is placed in the retrosternal space through a subxiphoid incision, if the pleurae was not opened, otherwise in an intercostal space.

The horizontal and vertical sternal edges are wired together with separate wires.

A subcuticular suture is used for skin closure.

An en bloc resection of the thymus and mediastinal fat performed through the mini-sternotomy.

Mediastinal approach

The reversed-T upper ministernotomy is a minimally invasive approach that results in a less operative trauma to the chest structure and function than a full sternotomy.

Rationale

Considering that myasthenic patients with generalized symptoms may have or develop respiratory muscle weakness leading to impaired lung expansion, saving the integrity of the lower part of the chest may further decrease the incidence of respiratory failure requiring mechanical ventilation.

ArgumentsIn this approach, the sternum is divided to the

third intercostal space and there is no need to ligate the internal mammary arteries.

Patients who may later require coronary artery bypass in their future will benefit from the presence of the mammary arteries.

Last, but not least, in case of thymic tumor or bleeding, the skin as well as the sternum incision can be easily extended to a complete median sternotomy.

CERVICOTOMIA

Incizia Kocher

Pentru leziunile cervico-toracice

Cimp vizual limitat

TORACOSCOPIA VIDEO-ASISTATACerinte:

Intubare cu sonda cu dublu lumenTorace la 45 grade4 trocarePneumomediastinul faciliteaza disectiaConversia este rara daca se selecteaza atent pacientii

ALEGEREA CAII DE ABORD IN FUNCTIE DE LEZIUNEA DE EXTIRPAT

Leziuni mici- toracotomie antero-lateralaLeziuni medii-sternotomie mediana sau

toracotomie antero-lateralaLeziuni mari si bilaterale- sternotomie

transversala cu toracotomie anterioara bilaterala

Leziuni foarte mari, unilaterale- toracotomie postero-laterala

Scopul operatieiIndepartarea intregului tesut timic din

mediastinTimus+ectopii mediastinale anterioareChirurgii: minimalisti si maximalistiMinimalistii: prin incizii mici, cosmetice,

timectomie adecvataMaximalistii: timectomia+excizia grasimii

mediastinului anterior- sternotomie mediana completa

Gradul de rezecţie a ţesutului timic din mediastinul anterior după diferite tehnici (după Jeretzki)

Tehnică Grad de rezecţie timică

timectomie maximală 98-100%

timectomie extinsă 85-95% timectomie toracoscopică 80-85% timectomie transcervicală 75-80% timectomie simplă transsternală 70-75%

timectomie simplă transcervicală 49-50%

Sternotomie mediana longitudinala Corn timic cervical, prevenosUG, femeie, 31 ani, MG-OSS.IIB, op. 2008

UG,31 ani, Hiperplazie limfoida timica cu ectopii Remisie completa post op.

Hiperplazie limfoida timica, UD, femeie, 54 ani, MG-Oss.III+Tiroidita Hashimoto, op.2008 iulie, deces-sept.2008Insuf. resp. ac.-ventilatie prelungita, traheostoma gastrostoma percutana, escare, ulcere corneene, sdr.consumptiv

Hiperplazie limfoida timica, ML, femeie, 28 ani, MG-Oss IIB, op. 2008, corn timic retrovenos, RC