WHERE THE INJECTION SHOULD BE PLACED.
Some operators have been content to insert a needle over the approximate site of the internal ring and then to force it downward until it lies as close to the internal ring as they can approximate and then to throw in a mass of paraffin sufficient to occlude the canal at this point.
If the needle is inserted about half an inch above the middle of Poupart's ligament it will be over the site of the normal internal ring. After the needle passes through the subcutaneous fat it will be felt to strike the firm fibrinous layers of the external wall of the inguinal canal. After the needle has passed through this firm layer it will enter the loose cellular tissue in the neighborhood of the internal ring. If the injection is diffused over an area of an inch or an inch and a half in circumference the internal ring is likely to be plugged for the time by the injection.
The larger Hernia.
Should the hernia be large the injection should be made closer to the pubes, but injection at the internal ring is not sufficient, the canal should also be injected with a certain amount of the paraffin and vaseline.
The canal may be injected by passing the needle directly through the outer wall of the inguinal canal, remembering its course about one-half inch above the line of Poupart's ligament.
The most satisfactory plan of injecting where the operator can successfully follow the technic is to find the external ring and then insert the needle directly into the external ring close to its upper margin and to carry the needle along for at least two inches. The suction technic should be followed and the needle should be moved in all directions as it is withdrawn and the deposit diffused as much as possible.
About the external ring itself and directly between the pillars of the external ring a certain amount of the injection should be placed.