Transcript ANTERIOR MEDIASTINUM

The 3rd. Surgical Unit
Feb.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-SUPERIOR
 Fascia endotoracica
 Timus
 Trunchiuri venoase
brahio-cefalice- VCS
 Crosa aortei
 Ganglioni mediastinali
sup.
 Nervii vagi
 Nervii recurenti
 Nervii frenici
LOJA TIMICA-rapoarte
 Anterior:
 Art. sterno-condro-claviculara
 Manubriul sternal
 M. subhioidieni
 Fata post. lig. sterno-pericardic sup.
 Posterior:
 Lama tiro-aorto-pericardica:
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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-rapoarte
 Regiunea cervicala
 Anterior: m. subhiodieni
 Posterior: trahee, vene tir. inf.
 Lateral: a. carotida comuna, vena jugulara interna,
nervul vag
TIMUS-rapoarte
 Mediastinul 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-vascularizatie
 Pedicul 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, inervatie
 Venele timice- tr. venos br-cef., 2mm diam, scurte-
punct critic
 Limfaticele- ggl.parasternali, jugulari, bronhomediastinali- duct toracic
 Nervii timici- din vag, lant simpatic cervico-toracic si
frenic
WHAT’S THAT ?
MEDIASTINAL MASS, RETROSTERNALLY
LYMPHOMA
MEDIASTINAL MASS
THYMOMA
LATERAL VIEW CXR
THYMOMA
GUIDELINES
Whenever 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:
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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 mediastinum
 The 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 TIMICE
TIMUS NORMAL
+/- MIASTENIA GRAVIS
sau alte BOLI AUTOIMUNE
MIASTENIA GRAVIS
Definitie, Kirschner, 1991
 Clinic- fatigabilitatea muschilor voluntari la efort
repetitiv, cu refacere la odihna
 Electrofiziologic- raspuns decrement la stimularea
repetitiva-EMG
 Farmacologic- raspuns pozitiv la tensilon
 Patologic- 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 ABORD
MEDIASTINUL ANTERIOR
 TORACOTOMIE
 STERNOTOMIE
 CERVICOTOMIE
 ABORD MIXT
 TORACOSCOPIC
 MEDIASTINOSCOPIC
TORACOTOMIA ANTERO-LATERALA
 AVANTAJE:
 Poate fi prelungita posterior
 Poate fi prelungita prin sectiunea transversala a
sternului
 Poate fi asociata cu o cervicotomie
 Expune bine pediculul pulmonar si vasele mari
 Incizie estetica situata in santul submamar
 DEZAVANTAJE
 Acces dificil pentru planul traheo-bronsic
 extremitatea 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 prelungita
 Este rezervata prelevarii de tesut biopsic mediastinal
TORACOTOMIA BILATERALA CU
STERNOTOMIE TRANSVERSALA
 Ofera cimp vizual asupra mediastinului si ambelor
cavitati pleurale
 Pentru leziuni mediastinale extinse lateral
 Art. mamara interna ligaturata bilateral
 Se deschid ambele cavitati pleurale
STERNOTOMIA MEDIANA LONGITUDINALA
 Avantaje:
 Acces facil
 Expune bine loja timica
 Expune bine o leziune cu extensie bilaterala
 Poate fi asociata cu cervicotomia
 Permite ventilarea ambilor plamini
 Evita compresiuni, tractiuni pe cord, vase mari, trahee in
cursul manevrelor chirurgicale
STERNOTOMIA MEDIANA LONGITUDINALA
 Dezavantaje:
 Nu da acces bun spre hilul pulmonar
 Lasa 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, PhD
Thorax 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
Technique
 The 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.
Technique
 The anterior mediastinal fat is removed beginning from the
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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.
Arguments
In 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-ASISTATA
 Cerinte:
 Intubare cu sonda cu dublu lumen
 Torace la 45 grade
 4 trocare
 Pneumomediastinul faciliteaza disectia
 Conversia este rara daca se selecteaza
atent pacientii
ALEGEREA CAII DE ABORD IN FUNCTIE
DE LEZIUNEA DE EXTIRPAT
 Leziuni mici- toracotomie antero-laterala
 Leziuni medii-sternotomie mediana sau
toracotomie antero-laterala
 Leziuni mari si bilaterale- sternotomie
transversala cu toracotomie anterioara bilaterala
 Leziuni foarte mari, unilaterale- toracotomie
postero-laterala
Scopul operatiei
 Indepartarea intregului tesut timic din mediastin
 Timus+ectopii mediastinale anterioare
 Chirurgii: minimalisti si maximalisti
 Minimalistii: prin incizii mici, cosmetice,
timectomie adecvata
 Maximalistii: timectomia+excizia grasimii
mediastinului anterior- sternotomie mediana
completa
Gradul de rezecţie a ţesutului timic din mediastinul
anterior după diferite tehnici (după Jeretzki)
Tehnică
 timectomie maximală
 timectomie extinsă
 timectomie toracoscopică
 timectomie transcervicală
 timectomie simplă transsternală
 timectomie simplă transcervicală
Grad de rezecţie timică
98-100%
85-95%
80-85%
75-80%
70-75%
49-50%
Sternotomie mediana longitudinala
Corn timic cervical, prevenos
UG, 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.2008
Insuf. 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