PLATE III.
Plate 3.
Drawn by F.F. Giraud. 1823. Engraved by J. Stewart.
London. Published 1824, by Longman, Hurst, Rees, Orme, Brown & Green.
In this plate the section of the prostate gland is shewn; the parts being viewed obliquely from before. The left hand of the operator holding the staff is depressed to conduct the knife into the cavity of the bladder. If attempt be made to depress the handle lower, the operator will feel his hand checked by the ligament of the arch. The knife is seen piercing the prostate in the direction which most nearly accords with Cheselden’s section. This inclination of the knife will enable the operator to make a very free incision, with great facility, without incurring any risk of wounding the pudic artery, the rectum, or the veins surrounding the neck of the bladder; unless a very large incision be required by the size of the calculus, in which case some of the veins must necessarily be divided.
In contrasting this view with [Plate I], it will be observed that the prostate is carried somewhat upward from the rectum; this effect is produced by the depression of the handle and the consequent elevation of the extremity of the director. The danger of wounding the rectum is thus still farther diminished.
One great advantage of conducting the operation on this principle arises from the operator not being under the necessity of withdrawing the knife from the groove of the staff, after he has once entered it, during the subsequent steps of the operation. The extent of the incision in the prostate and neck of the bladder may be regulated by the angle which the knife makes in its introduction with the staff. Supposing that an opening be required extending through the prostate from d to b, (which for the majority of calculi, even above the ordinary size, will be quite sufficient, as the neck of the bladder will dilate considerably), the point of the knife must be carried on as far as a in the groove of the staff. For it will be evident that if the same angle be maintained in the act of carrying on the knife, the line c b a will be the position of the knife when the point has reached a. The edge of the knife, although brought apparently so near to the rectum, will not injure it, from its oblique inclination to the patient’s left side.