THE THERAPEUTICS OF COLIC. 
461 
the trocar should be carefully sterilized, and, when practicable, 
that part to be selected for the operation should also be 
cleansed, although this is not generally so important, for if 
the trocar be properly made, as described, it cannot well drag 
foreign matter far into the tissues. The incision of the skin 
at the point of operation by means of a lancet, is unsurgical, 
producing a larger and more open wound than that caused 
by the trocar through which infection may the more readily 
occur. The skin serves as an important bulwark against sep¬ 
tic infection and should be left as nearly intact as practicable, 
which is best done by using the small trocar with its sharp, 
well tapered point, which cuts like a lancet and leaves when 
withdrawn a wound almost undiscoverable. The trocar should 
be held loosely in one hand, and perpendicular to the abdomi¬ 
nal walls, and its insertion accomplished by a quick stroke 
with the palm of the other hand, driving it to its desired 
depth at a single blow. The trocar is then withdrawn and 
the canula is retained in position with the hand, being careful 
to prevent its dislodgment from the intestine by peristaltic 
action. After the gas has escaped, the trocar should be rein¬ 
serted into the canula so that on withdrawal the intestinal 
walls catch and wipe off any ingesta which might otherwise 
adhere to the mouth of the canula, and drop into the peri¬ 
toneal cavity or lodge in the abdominal walls. More abscesses 
and septic inflammations are probably due to drawing septic 
material from the intestine and depositing it in the tissues, 
than are caused by the introduction of septic material from 
without. Should the escape of gas be unsatisfactory the 
depth of introduction may be varied by placing the trocar 
within the canula and pressing it forward or drawing it out¬ 
ward. Frequently it is found that a small amount of gas 
escapes from the intestine just punctured when it collapses, 
and the pressure of the other portions of the intestine is such 
that the portion encountered does not refill. In such a case 
the collapsed part of the bowel is to be passed through and 
the distended portion entered. If success is wanting on the 
right side there should be no hesitation in trying the left. 
Fatal sequelae from the use of the trocar have been recorded, 
