“This meta-analysis included seven studies with 400,822 patients. Our results demonstrated that ketorolac administration after surgery increases the risk of anastomotic leak [OR = 1.41, 95% CI: 0.81–2.49, Z = 1.21, P = 0.23].”
“Anastomotic leak is a serious complication that occurs after colorectal surgery, which can lead to increased morbidity and mortality. Non-selective NSAIDs (such as ketorolac) may affect the healing of the intestine by inhibiting the action of cyclooxygenase. NSAIDs have been shown to weaken granulocyte function, which is an essential part of the acute phase of wound healing. NSAIDs may also inhibit epithelial cell migration and mucosal recovery, which are important in the pathophysiology of intestinal ulcer healing. These findings suggest a potential biological mechanism that may explain the association identified in this study.”
A generally accepted explanation for the etiology of anorectal abscess and fistula-in-ano is that the abscess results from obstruction of an anal gland and the fistula is due to chronic infection and epithelialization of the abscess drainage tract. Anorectal abscesses are defined by the anatomic space in which they develop and are more common in the perianal and ischiorectal spaces and less common in the intersphincteric, supralevator,and submucosal locations.
“Fecal diversion is an important tool in the surgical armamentarium. There is much controversy regarding which clinical scenarios warrant diversion. Some of the most common applications for the use of a diverting stoma include construction of diverting ileostomy or colostomy, ostomy for low colorectal/coloanal anastomosis, inflammatory bowel disease, diverticular disease, and obstructing colorectal cancer with the conclusion that diverting loop ileostomy is preferred to loop colostomy” (Plasencia)
“The use of prophylactic ureteral stents remains controversial and could help in the intraoperative identification of ureteral injury.”
Methods: Patients undergoing elective abdominal colorectal surgery and preoperative ureteral stent placement at three enterprise-wide tertiary referral hospitals between 2015 and 2021 were retrospectively identified through their billing records. The main study endpoint was ureteral injury identified within 30 days postoperatively. The decision to place ureteral stents was at the discretion of the treating surgeon. A number of demographic, disease-related, and treatment-related variables were examined for possible association with ureteral stent placement. We compared the incidence of ureteral injury and timing of the identification according to use of ureteral stents. Bivariate associations were examined using Kruskal-Wallis tests for continuous variables and Chi-square tests for categorical variables.
“A recent retrospective population-based study of patients in the United States undergoing colorectal surgery found the overall incidence of ureteral injury to be 0.28%. The incidence was found to be significantly higher in patients with stage 3 or 4 cancer, malnutrition, steroid use, and in operations done at teaching hospitals. Rectal cancer cases were found to have the highest rates of ureteral injuries (7.1/1,000), followed by Crohn’s disease and diverticular disease (2.9/1,000 each). In this review, laparoscopic surgery was associated with a lower incidence of ureteral injuries when compared with open (1.1 vs. 2.8/1,000, p < 0.001). Of the specific operations reviewed, abdominoperineal resection (APR) was found to have the highest rate of ureteral injury at 7.1/1,000 cases.” (Ferrara, 2019, p. 196)
Patients with acute anorectal abscess should be treated promptly with incision and drainage. Grade of recommendation: strong recommendation based on low-quality evidence, 1C.
“Abscesses that cross the midline (ie, horseshoe) can be challenging to manage. These abscesses most often involve the deep postanal space and extend laterally into the ischiorectal spaces. [40,71] Under these circumstances, primary lay-open fistulotomy should typically be avoided because these fistulas tend to be transsphincteric. The Hanley procedure, a technique that drains the deep postanal space and uses counter incisions to address the ischiorectal spaces, is effective in the setting of a horseshoe abscess,  although it may negatively impact anal sphincter function. [40,71] A modified Hanley technique using a posterior midline partial sphincterotomy to unroof the postanal space plus seton placement has a high rate of abscess resolution and has been reported to better preserve anorectal function compared to other operative interventions. [40,72,73]” (p. 969)
“After drainage, abscesses may recur in up to 44% of patients, most often within 1 year of initial treatment. [2,10,70] Inadequate drainage, the presence of loculations or a horseshoe-type abscess, and not performing a primary fistulotomy are risk factors for recurrent abscess (primary fistulotomy is further addressed in recommendation no. 4). [10,71,72]” (p. 969)
“Comparison studies in animal models and clinical experience featuring fluorescein flowmetry have consistently demonstrated the superiority of dye-based perfusion monitoring for intraoperative bowel assessment as compared to standard clinical criteria, DUS, and pulse oximetry/PPG. (45,46,47,53,54) However, these results are not universal, with some large animal models demonstrating no difference between fluorescein, DUS, and PPG, and an additional study showing that DUS actually outperforms fluorescein for intraoperative bowel assessment. (13,18,43)” (p. 312)