Case Study: Follow-Up of a 59-Year-Old Male After Diverting Loop Ileostomy and Hartmann’s Reversal, Coloenteric Anastomotic Leak

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 Coloenteric Anastomotic Leak

A coloenteric anastomotic leak is a serious complication that can arise after surgical resection of the colon with an anastomosis to the small intestine, typically performed for conditions like colorectal cancer, inflammatory bowel disease, or trauma. This leak represents a breakdown in the integrity of the surgical connection between the colon and small intestine, leading to the leakage of luminal contents into the peritoneal cavity and potentially resulting in peritonitis, abscess, or sepsis.

1. Cause and Etiology

Primary causes and contributing factors:

  • Technical factors:
    • Inadequate blood supply to the anastomotic ends
    • Tension on the anastomosis
    • Poor surgical technique or inappropriate suture/staple placement
  • Patient-related factors:
    • Malnutrition or hypoalbuminemia
    • Immunosuppression (e.g., steroids, chemotherapy)
    • Diabetes mellitus
    • Smoking
    • Advanced age
  • Disease-related factors:
    • Inflammatory bowel disease (Crohn’s disease or ulcerative colitis)
    • Radiation enteritis
    • Neoplasms involving the anastomotic site
  • Postoperative factors:
    • Hypotension or hypoperfusion
    • Infection
    • Use of NSAIDs or other agents that impair healing

2. Pathophysiology

A coloenteric anastomotic leak results when the mucosal and serosal layers of the colon and small intestine fail to achieve a stable and vascularized healing interface. This failure allows bowel contents, including bacteria and digestive enzymes, to escape into the surrounding tissues. The pathophysiology progresses as follows:

  • Initial insult: Mechanical or ischemic disruption of the anastomosis leads to a local breach.
  • Contamination: Enteric contents, rich in bacteria and inflammatory mediators, leak into the peritoneal or retroperitoneal space.
  • Inflammatory cascade: This contamination initiates a severe inflammatory response, promoting cytokine release (IL-1, IL-6, TNF-α), neutrophil infiltration, and vasodilation.
  • Local or systemic infection: Formation of localized abscess or generalized peritonitis; in severe cases, systemic inflammatory response syndrome (SIRS) and sepsis ensue.
  • Delayed wound healing: Ongoing inflammation and infection inhibit granulation tissue formation, fibroblast activity, and epithelial regeneration, perpetuating the leak.

3. Epidemiology

  • Incidence:
    • Anastomotic leaks occur in approximately 3%–15% of colorectal surgeries, with coloenteric anastomotic leaks being less common but associated with high morbidity.
  • Risk factors:
    • Emergency surgery
    • Low anastomoses (closer to the rectum)
    • Intraoperative blood loss or hypotension
    • Inadequate bowel preparation
  • Mortality and morbidity:
    • Mortality associated with anastomotic leak ranges from 6% to 22%
    • Increased hospital stay, reoperation rates, and long-term complications such as fistula or stricture formation

4. Clinical Presentation

Symptoms and signs may develop early (within 3–7 days post-op) or be delayed:

Local signs:

  • Abdominal pain and tenderness, particularly near the surgical site
  • Fever and tachycardia
  • Prolonged ileus
  • Wound erythema or discharge (if leak tracks externally)
  • Purulent or feculent drain output

Systemic signs:

  • Fever >38.5°C
  • Leukocytosis or left shift
  • Hypotension
  • Septic shock in severe cases

Late presentation:

  • Fistula formation
  • Abscess with systemic signs of sepsis
  • Sinus tract formation

5. Imaging Features

Computed Tomography (CT) Scan (with oral and IV contrast):

  • Most sensitive and specific imaging modality for leak detection
  • Key findings:
    • Extraluminal gas or contrast near the anastomotic site
    • Fluid collections or abscesses
    • Free peritoneal fluid
    • Disruption or discontinuity of the bowel wall
    • Fistulous tracts connecting bowel loops or extending to the skin or other structures

Contrast studies (e.g., contrast enema or enterography):

  • May reveal extravasation of contrast at anastomotic site
  • Used selectively when CT is inconclusive or contraindicated

Ultrasound:


  • Limited utility but may detect abscesses in thin or superficial patients

6. Treatment

Treatment strategy depends on the severity, clinical stability, and extent of leak:

Conservative Management:

  • Indicated for contained leaks in clinically stable patients
  • Components:
    • NPO (nothing by mouth)
    • IV fluid resuscitation
    • Broad-spectrum IV antibiotics covering gram-negative, anaerobic, and aerobic organisms (e.g., piperacillin-tazobactam or ceftriaxone + metronidazole)
    • Percutaneous drainage of localized abscesses under image guidance
    • Nutritional support: Total parenteral nutrition (TPN) or enteral feeding distal to leak

Surgical Management:

  • Required for free leaks with generalized peritonitis or patient deterioration
  • Procedures:
    • Relaparotomy with anastomotic take-down and diversion (e.g., end ileostomy or colostomy)
    • Re-anastomosis in selected stable cases with healthy bowel margins
    • Debridement and irrigation of infected or necrotic tissue

7. Prognosis

  • Prognosis depends on timing of diagnosis, clinical condition, and promptness of treatment
  • Favorable outcomes seen in early-detected and well-managed leaks
  • Poor prognostic factors:
    • Delay in diagnosis >5 days
    • Multiorgan failure or sepsis
    • Malnourished or immunocompromised status
    • Low pelvic anastomosis (higher leak rates)
  • Long-term outcomes:
    • Risk of chronic abscess, enterocutaneous fistula, and bowel obstruction
    • Potential need for reoperation or permanent stoma

Summary Table

Aspect

Details

Etiology

Ischemia, tension, poor technique, infection, malnutrition, immunosuppression

Pathophysiology

Breakdown of healing → contamination → inflammation → abscess/sepsis

Epidemiology

3–15% in colorectal anastomoses; higher in low anastomoses

Clinical Presentation

Fever, pain, ileus, drainage, sepsis

Imaging Features

CT: extraluminal gas/contrast, abscess, fluid collection

Treatment

Conservative (antibiotics, drainage), Surgical (re-anastomosis, diversion)

Prognosis

Good with early treatment; poor if septic shock or delayed diagnosis

 Reference

  1. Alves A, Panis Y, Trancart D, Regimbeau JM, Pocard M, Valleur P. Factors associated with clinically significant anastomotic leakage after large bowel resection: multivariate analysis of 707 patients. World J Surg. 2002 Sep;26(4):499-502. doi:10.1007/s00268-001-0256-0.
  2. Bruce J, Krukowski ZH, Al-Khairy G, Russell EM, Park KG. Systematic review of the definition and measurement of anastomotic leak after gastrointestinal surgery. Br J Surg. 2001 Sep;88(9):1157-68. doi:10.1046/j.0007-1323.2001.01829.x.
  3. Hyman N, Manchester TL, Osler T, Burns B, Cataldo PA. Anastomotic leaks after intestinal anastomosis: it's later than you think. Ann Surg. 2007 May;245(2):254–258. doi:10.1097/01.sla.0000250427.19794.9d.
  4. Rahbari NN, Weitz J, Hohenberger W, Heald RJ, Moran B, Ulrich A, et al. Definition and grading of anastomotic leakage following anterior resection of the rectum: a proposal by the International Study Group of Rectal Cancer. Surgery. 2010 Mar;147(3):339-51. doi:10.1016/j.surg.2009.10.012.
  5. Vignali A, Fazio VW, Lavery IC, Milsom JW, Church JM, Hull TL. Factors associated with the occurrence and management of anastomotic leaks after colorectal surgery. Dis Colon Rectum. 1997 Nov;40(1):9–13. doi:10.1007/BF02053679.

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Case Study: Follow-Up of a 59-Year-Old Male After Diverting Loop Ileostomy and Hartmann’s Reversal
Coloenteric Anastomotic Leak

History and Imaging

  1. A 59-year-old male with a past medical history of Crohn’s disease and perforated sigmoid diverticulitis presented for follow-up after undergoing a diverting loop ileostomy and subsequent Hartmann’s reversal.

The term “diverting loop ileostomy”—also commonly referred to simply as loop ileostomy—describes a surgical procedure in which the intestinal contents are temporarily diverted through a stoma created from the ileum. This technique is typically performed following colorectal surgery to protect a distal anastomosis by reducing the passage of enteric contents through the healing segment.

Hartmann’s procedure is an emergency surgical intervention often performed for acute abdominal conditions, especially left-sided colonic diseases such as perforated diverticulitis or other causes of peritonitis.

Hartmann’s reversal refers to a restorative surgery performed after a Hartmann’s procedure. The aim is to re-establish intestinal continuity by reanastomosing the proximal and distal bowel segments and closing the previously created colostomy.

  1. A single-contrast water-soluble contrast enema was performed under fluoroscopic guidance.

Quiz:

1. What is the most prominent abnormal finding?
(1) Anastomotic leak
(2) Coloenteric fistula
(3) Postoperative bleed
(4) Perianastomotic fluid collection

Explanation: On post-contrast imaging, posterior leakage is observed from the anastomotic suture line.

2. This type of complication is always managed surgically.
(1) False
(2) True


Explanation: While some anastomotic leaks—especially in the presence of sepsis—require surgical intervention, small and asymptomatic leaks may be managed conservatively with close observation and supportive care.

3. Barium is used as the contrast agent when evaluating this complication under fluoroscopy.
(1) False
(2) True


Explanation: Barium should be avoided when assessing for leaks, as its entry into the peritoneal cavity can cause chemical peritonitis. Instead, water-soluble contrast agents such as Gastrografin are preferred.

4. Which of the following CT findings are associated with this complication?
(1) Pneumoperitoneum
(2) Extravasation of contrast
(3) Extraluminal fluid
(4) All of the above


 Explanation: Disruption of the anastomosis can lead to leakage of air and fluid into the peritoneal cavity, all of which can be visualized on CT. Contrast extravasation may also be seen if contrast material has been administered.

Findings and Diagnosis

Findings:
Fluoroscopy: The colorectal anastomotic suture line is visible posterior to the iliac crest. Following contrast administration, posterior leakage is observed from the anastomotic site into the presacral space. The diameter of the leaking tract is approximately 3 mm. In addition, incomplete distension of the proximal colon suggests the presence of inflammation.

Differential Diagnosis

  • Anastomotic leak

  • Coloenteric fistula

  • Colonic diverticulum

Diagnosis:

Anastomotic leak

Discussion

Coloenteric Anastomotic Leak

Pathophysiology
An anastomotic leak is a complication that can occur after surgical creation of a bowel anastomosis, where two segments of the intestine are surgically connected. Leaks occurring within 30 days postoperatively are classified as early leaks, while those identified after 30 days are referred to as late leaks.

Epidemiology
Anastomotic leaks occur in approximately 2% to 10% of patients following colorectal surgery. The associated mortality rate ranges between 6% and 22%.

Clinical Presentation
Small, contained leaks may be asymptomatic and incidentally detected during postoperative imaging, or they may present with localized peritonitis. In contrast, large, free or generalized leaks can result in sepsis and diffuse peritonitis.

Imaging Features
On fluoroscopic examination, extravasation of contrast material from the anastomotic site is observed. On CT, associated findings may include pneumoperitoneum and extraluminal fluid collections.

Treatment

  • Grade A (mild, asymptomatic leaks): may be managed conservatively with close observation.

  • Grade B (clinically significant but non-septic leaks): treated with percutaneous drainage of fluid collections and intravenous antibiotics.

  • Grade C (septic leaks): require prompt surgical intervention.

References

  1. Bruce J, Krukowski ZH, Al-Khairy G, Russell EM, Park KG. Systematic review of the definition and clinical diagnosis of anastomotic leak after gastrointestinal surgery. Br J Surg. 2001;88(9):1157–1168. doi:10.1046/j.0007-1323.2001.01829.x

  2. Alves A, Panis Y, Trancart D, Regimbeau JM, Pocard M, Valleur P. Factors associated with clinically significant anastomotic leakage after large bowel resection: multivariate analysis of 707 patients. World J Surg. 2002;26(4):499–502. doi:10.1007/s00268-001-0256-0

  3. Kulu Y, Ulrich A, Bruckner T, Contin P, Welsch T, Büchler MW, Knebel P. Validation of the International Study Group of Rectal Cancer definition and grading of anastomotic leakage. Surgery. 2013;153(6):753–761. doi:10.1016/j.surg.2012.10.012

  4. Hyman N, Manchester TL, Osler T, Burns B, Cataldo PA. Anastomotic leaks after intestinal anastomosis: it's later than you think. Ann Surg. 2007;245(2):254–258. doi:10.1097/01.sla.0000225083.27182.85

  5. Rahbari NN, Weitz J, Hohenberger W, et al. Definition and grading of anastomotic leakage following anterior resection of the rectum: a proposal by the International Study Group of Rectal Cancer. Surgery. 2010;147(3):339–351. doi:10.1016/j.surg.2009.10.012



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