Kapitel 104 - thoracic wall Flashcards
What skin flaps can be used for the thoracic wall?
a. thoracodorsal axial pattern flap
b. a composite musculocutaneous flap incorporating the latissimus dorsi muscle.
c. The double-layered elbow fold may be separated from the upper foreleg and unfolded to produce a subdermal plexus flap capable of closing defects of the sternum or lateral thorax.
How can m. scaleus serve as a landmark during intercostal thoracotomy?
An obvious division between its muscular and tendinous portions is visible at the fifth rib, making it a useful landmark.
What are the dorsal and ventral margins during intercostal thoracotomy?
a. dorsally to the point where the ribs angle medially
b. ventrally to a point just below the costochondral junction.
(Continuation of the incision dorsal to these landmarks results in damage to epaxial musculature and potential damage to intercostal arteries. Ventral continuation of the incision should be done very cautiously and only after confirming the location of the internal thoracic artery by digital palpation)
How will you avoid incision of the internal thoracic artery?
Digital palpation of the artery as well as not extent the incision beyond the lateral aspect of the transverse thoracic muscle.
What are the indications for rib resection thoracotomy?
a. wide access to the thoracic cavity (particularly cranially)
b. as part of en bloc excision of a thoracic wall tumor
c. or for removal of large masses that do not fit through a single intercostal space
what are indications to choose a median sternotomy approach?
a. bilateral exploration of the thoracic cavity
b. Need for wide exposure of cranial mediastinal masses (especially those with involvement of the cranial vena cava)
c. access to the right ventricle
d. in patients that may require cranial abdominal exploration.
e. for surgery of the cranial intrathoracic trachea
f. Lung lobectomy if both sides are involved.
When is median sternotomy not the ideal approach?
a. for thoracic duct ligation
b. exploration of the tracheal bifurcation and tracheobronchial lymph nodes
c. surgery of the esophagus or caudal vena cava (unless in association with celiotomy and diaphragmatic incision)
what instruments can be used for sectioning the sternebraes?
a. reciprocating saw
b. osteotome
c. special sternal saw
d. sternal splitter
e. or bone cutters.
Describe how closure of the sternebrae should be done. Why is this method preferred?
a. sternotomy is closed using figure of eight sutures of stainless-steel wire (in patients weighing >10 kg) or 0 polypropylene (in patients weighing <10 kg) in an alternating orientation . At least one suture is applied per sternebra, usually incorporating the costal cartilage
b. Because alternating orientation of sutures:
i. Is mechanically superior to double loop cerclage wire
ii. avoid distraction of the dorsal or ventral edge of the sternotomy during suture tightening
iii. maximize bony contact to reduce pain and facilitate healing
When have xiphoid resection thoracotomy been used clinically in dogs?
For closure of peritoneopericardial hernia
List the indications for a transdiaphragmatic thoracotomy
a. extension of intraabdominal disease into the thorax
b. inspection of the caudal lung lobes
c. location and isolation of a portoazygous or intrahepatic portocaval shunt
d. ligation of the thoracic duct
e. caudal esophagotomy
f. temporary occlusion of the caudal vena cava or aorta as an adjunct to invasive hepatic surgery
g. open cardiopulmonary resuscitation
h. partial pericardiectomy
i. and placement of epicardial leads in patients in which endocardial pacing is not appropriate.
For what types of thoracic wall neoplasia should surgery be considered?
All types of soft tissue sarcoma and chondrosarcoma because they usually have a low metastatic rate.
What are the marginal guidelines for surgical resection of thoracic wall tumors involving the ribs?
a. Resection with 3-cm or larger margins is recommended for most thoracic wall tumors.
b. This often entails en bloc removal of sections of thoracic wall, including at least one unaffected rib cranial and caudal to the lesion.
c. Sections of the sternum or diaphragm may also need to be removed
What is considered the upper limit for adequate thoracic wall reconstruction?
Defects involving 6 ribs
List muscles used for flaps for thoracic wall reconstruction.
a. latissimus dorsi
b. external abdominal oblique
c. transversus abdominis
d. diaphragm.
