Editing Intestinal Segments and Urinary Diversion (section)

== Intestinal Anastomoses ==

* '''Principles of intestinal anastomoses (6):'''
*# '''Adequate exposure'''
*# '''Adequate blood supply'''
*# '''Prevention of local spillage or enteric contents'''
*# '''Serosal apposition (watertight, without tension)'''
*# '''Don’t tie suture so tightly that the tissue is strangulated'''
*# '''Realignment of the mesentery of the two segments of bowel to be joined'''
* '''Types of anastomoses'''
** '''Intestinal anastomoses may be performed with use of sutures or staples'''
*** '''Stapled bowel anastomoses have been shown to be as efficacious as hand-sewn anastomoses because both have similar complication rates'''
**** Leak and fistula rate of 2.8% for stapled and 3% for sutured anastomoses
**** Theoretical benefits of a stapled anastomosis:
****# Provides for a better blood supply to the healing margin
****# Reduced tissue manipulation
****# Minimal edema with uniformity of suture placement
****# Wider lumen is constructed
****# Greater ease and less time involved in performing the anastomosis, and the length of postoperative paralytic ileus is reduced.
** Sutured anastomoses [Further details in Campbell’s]
*** Enteroenterostomy by a Two-Layer Suture Anastomosis
*** Enteroenterostomy by a Single-Layer Suture Anastomosis
*** End-to-Side Ileocolic Sutured Anastomosis
*** Ileocolonic End-to-End Sutured Anastomosis with Discrepant Bowel Sizes
** '''Stapled anastamoses''' [Further details in Campbell’s]
*** '''See video on YouTube (sign-in required to verify age)'''
*** '''Staples should not be used in bowel segments exposed to urine due to the potential for stones to form;''' rather, absorbable suture should be used for this
*** '''The TA (transverse anastomosis) stapled anastomosis everts the suture line. Because staples close in a B configuration and do not crush the tissue, theoretically they prevent ischemia at the suture line'''.
*** The anastomotic stapler places two linear double rows of staggered staples. When the knife is advanced, the staple line is divided. The height of the staples is also chosen according to the tissue to be transected. Most intestinal anastomoses are performed with medium staples, which have a closed height of  ≈1.5 mm (open height of 3.5 mm).
*** Ileocolonic Anastomosis with the Circular Stapling Device
*** [https://www.uptodate.com/contents/image/print?imageKey=SURG%2F118272 Side-to-side Stapled Anastomosis]
****[https://link.springer.com/chapter/10.1007/978-3-319-91164-9_40 Alternative description]
***'''End-to-End Stapled Anastomosis: Ileal-Ileal or Ileocolonic Anastomosis'''
**** Summary of steps:
***** The antimesenteric border of the two bowel segments to be joined is approximated with a 3-0 silk suture 5 to 6 cm from the cut ends of the bowel. A holding suture is placed through both segments of bowel at their cut ends at the midpoint of the antimesenteric borders. Stay sutures are placed at the mesenteric border of each bowel segment, and two other sutures midway between the mesenteric and antimesenteric border on the lateral aspects of the bowel are also placed. The anastomotic stapler is positioned in the lumens of both segments of bowel along the antimesenteric border. The antimesenteric holding suture is pulled up adjacent to the stapler. The anastomotic stapler is locked in place, the staples are fired, and the knife is advanced. The staple lines are inspected for bleeders, which if persistent should be suture ligated with an absorbable suture. It is important for several 3-0 silk sutures to be placed at the apex of the stapled and cut antimesenteric incision. At this point, slight tension on the anastomotic line can place undue stress on the staple margin and cause a leak. The holding sutures are held up, and a linear stapler is placed across the open end of bowel and fired. Care must be taken so that the staples include the serosa in its entire circumference. Excess bowel tissue is excised flush with the instrument before it is disengaged. The mesentery is then reapproximated.
*** Laparoscopic and Robotic Anastomoses
*** Compression Anastomoses and the Biofragmentable Ring
** '''Complications'''
*** '''The most common cause of mortality and morbidity within the immediate postoperative period in urologic procedures in which gut is used relates to complications involving the bowel'''
*** '''Factors that significantly contribute to anastomotic breakdown include:'''
***# '''Poor blood supply'''
***# '''Local sepsis induced by fecal spillage'''
***# '''Drains placed on an intra-abdominal anastomosis'''
***# '''Anastomosis performed in irradiated bowel'''
***#* '''Prior radiation significantly increases the likelihood of serious complications after radical cystectomy'''
*** '''Complications of bowel anastamosis:'''
***# '''Leakage of fecal contents'''
***# '''Sepsis'''
***# '''Wound infections'''
***# '''Abdominal abscesses'''
***# '''Hemorrhage'''
***# '''Anastomotic stenosis'''
***# '''Bowel obstruction'''
***#* '''Postoperative bowel obstruction is most common when the ileum is used for diversion'''
***#* '''The most common cause of post-operative bowel obstruction is adhesions, followed by recurrent cancer'''
***# '''Pseudo-obstruction of the colon (Ogilvie syndrome)'''
***#* Usually occurs within the first 3 days postoperatively in patients with multiple medical illnesses
***#* Cause is not understood
***#* Patient develops severe abdominal pain, and a radiograph of the abdomen reveals a dilated cecum.
***# '''Fistulas'''
***#* Two typyes occur in the postoperative period, fecal and urinary. These generally occur within the first several weeks after the operative event.
***# '''Wound dehiscence'''
***#* May complicate the immediate postoperative period.
*** '''Complications of the isolated intestinal segment'''
**** '''Strictures of intestinal segments'''
**** '''Elongation of the segment, occasionally resulting in massive enlargement'''
***** '''When this occurs in conduits or ureteral substitutes, there is usually a distal obstruction'''
***** In continent diversions, it may signal failure to catheterize the pouch frequently enough.
***** If allowed to persist, the increased pressure may result in deterioration of renal function.
***** Enlargement and elongation of the intestine may also result in a volvulus of the segment