ransection của bức tường sau của một UPJ bị che khuất do tàu cực lưu qua thấp hơn. Một người mổ xẻ Maryland, tổ chức trong tay không thuận của bác sĩ phẫu thuật điều hành được đặt trong cửa sổ mô periureteric mềm được tạo ra bằng cách bóc tách chu vi của phần trên của niệu quản. | 244 Hedican Fig- 7. Transection of the posterior wall of an obstructed UPJ due to lower pole crossing vessels. A Maryland dissector held in the nondominant hand of the operating surgeon is placed in the periureteric soft tissue window created by circumferential dissection of the upper portion of the ureter. Downward retraction with the Maryland draws the UPJ below the vessels to allow unimpeded transection. Once the anterior wall is cut exposing the indwelling stent the upper jaw is passed beneath the stent to transect the posterior wall. The assistant utilizes the irrigator-aspirator device to help maintain exposure of the stent. from the ureter as the upper portion is drawn out of the pelvis. It is important to avoid pulling out the portion of the stent contained within the ureter during manipulations because this can result in the distal pigtail being withdrawn through the ureteral orifice into the intravesical tunnel. Preparation of the Anastomosis If lower pole crossing vessels are present the pelvis is elevated cephalad using the stay suture or by gently grasping the upper portion of the pelvis and lifting until it relocates anterior to the vessels. Often additional fibrous attachments to the pelvis remain which inhibit its tension-free anterior positioning. These must be transected using the Harmonic shears or electrocautery hook. Once tension-free anterior positioning is established the Endoshears are used to spatulate the ureter laterally. Caution should be exercised to avoid spiraling the incision. The gentle curve of the Endoshears facilitates this lateral-based cut by using only the tips of the shears to cut with the concavity of the shear facing anteriorly. The previously established landmark on the anterior surface of the ureter also assists in maintaining orientation during this maneuver. The length of the spatulation can vary depending on the size of the patient s ureter and whether or not the edges of the spatulated ureter need to be excised. .
