8 CLINICAL APPLIED ANATOMY. 



In the treatment of these collections of tuberculous material, 

 it is important to recollect the above anatomical bearings. 

 Effective treatment must be thorough, and to be thorough both 

 the mtra-abdommal as well as the crural compartments, if they 

 exist, must be attacked. An incision into the thigh portion from 

 the front is a comparatively easy procedure, due attention being 

 paid to the vessels of the groin. A vertical lumbar incision just 

 external to the outer margin of the erector spinse is necessary to 

 open that portion of the abscess which occupies the sheath of 

 the psoas. This incision should be the first that is made. After 

 division of the skin a dense aponeurosis is met with, and requires 

 division in the whole length of the wound. The actual sheath 

 of the erector spinae is best left unopened. The lumbar trans- 

 verse processes are now felt for round the outer margin of the 

 erector muscle, the quadratus lumborum intervening. This also 

 will require vertical division, care being exercised not to wound 

 the lumbar arteries. As soon as the quadratus is cut through 

 the psoas, which slightly overlaps it, is exposed, and the cavity 

 of its sheath, containing the caseous material, can be readily 

 reached. Stretching across the interior of the abscess cavity 

 there can often be felt the lumbar plexus of nerves, which has 

 been dissected out where it lies in the substance of the muscle. 

 Care must be taken not to perforate extra-peritoneal tissue, 

 and still more so the posterior layer of the parietal peritoneum, 

 which covers the anterior surface of the psoas. The actual seat 

 of the tuberculous disease in the centre of the vertebrae may 

 often be reached and dealt with through this incision. 



Retro-pharyngeal Abscess, A collection of pus may occur in 

 the loose cellular tissue between the prevertebral layer of deep 

 cervical fascia and the posterior wall of the pharynx. 



An acute abscess in this region may be induced by punctured 

 wounds of the pharyngeal wall, by septic processes tracking from 

 the surrounding parts, and by acute suppurative lymphadenitis 

 of the retro-pharyngeal gland. 



As a rule the suppuration takes place about the level of the 

 mouth, and the swelling caused by the pushing forwards of the 



