254 



DISSECTION OF THE PEKINUEM. 



in reaching 

 the staff, 



and in run- 

 ning knife 

 along staff. 



Parts to be 

 avoided are 

 rectum, 



pudic 

 vessels, 



artery of 

 bulb, 



recto- 



vesical 



fascia, 



and acces- 

 sory pudic 

 artery. 

 Directions. 



hsemorrhoidal vessels and nerve lying across the ischio-rectal fossa.] 

 and possibly the superficial perineal vessels and nerves, will be cut] 

 in this first stage of the operation. 



In the subsequent attempt to reach the staff, when the knife isl 

 introduced into the front of the wound, the hinder part of the! 

 triangular ligament and constrictor urethra), and the fore part of 

 the levator ani will be divided; when the knife is placed within 

 the groove of the staff, the membranous part of the urethra will be 

 cut with the muscular fibre about it. 



Lastly, as the knife is pushed along the staff into the bladder, it 

 incises in its progress the membranous portion of the urethra, part 

 of the prostate with large veins around it, and the neck of the 

 bladder. When the last two parts are being cut, the handle of the 

 knife is to be raised, and the blade depressed ; and the incision is 

 to be made downwards and outwards, in the direction of a line from 

 the urethra through the left lateral lobe of the prostate, above the 

 level of the ejaculatory duct. 



Parts to be avoided. In the first incision in the ischio-rectal fossa, 

 the rectum may be cut if the knife is turned inwards across the 

 intestine, instead of being kept parallel with it ; and if the gut is 

 not held out of the way with the forefinger of the left hand. The 

 pudic vessels on the outer wall of the ischio-rectal fossa may be 

 wounded near the anterior part of the hollow, where they approach 

 the margin of the triangular ligament ; but, posteriorly, they are 

 securely lodged inside the projection of the ischial tuberosity. 



While making the deeper incisions to reach the staff, the artery 

 of the bulb lies immediately in front of the knife, and will be 

 wounded if the incisions are made too far forwards ; but the vessel 

 must almost necessarily be cut, when it arises farther back than 

 usual, and crosses the front of the ischio-rectal fossa in its course to 

 the bulb of the urethra. 



In the last stage of the operation the neck of the bladder should 

 not be incised to a greater extent than is necessary for the extraction 

 of the stone, lest the recto- vesical fascia separating the perineum 

 from the pelvis should be divided, and the abdominal cavity opened. 

 Too large an incision through the prostate may wound also an 

 unusual accessory pudic artery on the side of that body. 



Directions. When the dissection of the perineum is completed, 

 the flaps of skin along the under surface of the penis and the two 

 halves of the scrotum are to be stitched together ; all the parts are 

 to be carefully wrapped in tow containing preservative, and the body 

 will be turned on its face for dissection of the back. On the third 

 day of this dissection the worker on the abdomen will examine the 

 different layers of the lumbar fascia, and the posterior aponeurosis of 

 the transversalis made in conjunction with the dissector of the head 

 and neck. 



