This document discusses anastomotic leak following low anterior resection for rectal cancer. It covers the definition, risk factors, diagnosis, and management of anastomotic leaks. Some key points: - Anastomotic leak is a serious complication with increased morbidity, mortality, and decreased survival. Risk factors include patient comorbidities, technical factors, and disease factors. - Leaks are classified based on their severity from Grade A (managed non-operatively) to Grade C (requiring reoperation). Diagnosis can be difficult as leaks often present after discharge. Imaging and biochemical markers like CRP can help in diagnosis. - Management depends on the severity of the leak and patient stability. Options include medical

1. Anastomotic Leak Following Low
Anterior Resection For Rectal Cancer

2. Introduction
• Most common cause of death after colorectal surgery
• Most feared complication
• Reported incidence - 1% to 30%
Isbister WH. Anastomotic leak in colorectal surgery: A single surgeon's experience. ANZ J Surg 2001
Matthiessen P et al. Risk factors for anastomotic leakage after anterior resection of the rectum. Colorectal Dis 2004
Tsai YY, Chen WT. Management of anastomotic leakage after rectal surgery: a review article. J Gastrointest Oncol 2019

3. Consequences- Early
• Increased perioperative morbidity and mortality
• Prolonged length of stay
• Higher readmission rates
• Potential need for further operative interventions/ stoma
Turrentine FE et al. Morbidity, mortality, cost, and survival estimates of gastrointestinal anastomotic leaks. J Am Coll Surg 2015
Tsai YY, Chen WT. Management of anastomotic leakage after rectal surgery: a review article. J Gastrointest Oncol 2019

4. Late consequences
• Higher local recurrence rate (OR- 2.05)
• Delay in starting chemotherapy
• Worsen survival (5YOSR- 35% VS 53%)
• Decreased quality of life
McArdle CS, McMillan DC, Hole DJ. Impact of anastomotic leakage on long-term survival of patients undergoing curative resection for colorectal cancer. Br
J Surg 2005
Lu ZR et al. Anastomotic leaks after restorative resections for rectal cancer compromise cancer outcomes and survival. Dis Colon Rectum 2016
Mirnezami A et al. Increased local recurrence and reduced survival from colorectal cancer following anastomotic leak: systematic review and meta-
analysis. Ann Surg 2011.

5. What constitutes an anastomotic leak?
• Extravasation of contrast
• Perirectal abscess
• Faecal output from drain
• Sepsis – need for laparotomy
• Enterocutaneous fistula

6. Definition
International Study Group of Rectal Cancer (2010)
• Defect at anastomotic site leading to communication between intraluminal
and extraluminal compartments
• Also perirectal abscess
Rahbari, N.N. 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

7. Grading of anastomotic leak
• Grade A
-those managed without an invasive intervention
• Grade B
- those managed with invasive intervention other than repeat surgery
(percutaneous drainage)
• Grade C
- those requiring repeat surgical intervention and often diversion
- Life threatening

8. Risk Factors
• Preoperative and intraoperative
• Modifiable and non-modifiable
• Patient factors, technical factor, disease factor, surgeon factor
Midura EF et al. Risk factors and consequences of anastomotic leak after colectomy: a national analysis. Dis Colon Rectum 2015
Trencheva K, Morrissey KP, Wells M, et al. Identifying important predictors for anastomotic leak after colon and rectal resection: prospective
study on 616 patients. Ann Surg 2013
Sparreboom CL et al. Different Risk Factors for Early and Late Colorectal Anastomotic Leakage in a Nationwide Audit. Dis Colon Rectum 2018

9. McDermott, F. et al. Prevention, Diagnosis and Management of Colorectal Anastomotic Leakage; Issues in Professional Practice; Association of
Surgeons of Great Britain and Ireland, Lincoln’s Inn Fields: London, UK, 2016

10. McDermott, F. et al. Prevention, Diagnosis and Management of Colorectal Anastomotic Leakage; Issues in Professional Practice; Association of
Surgeons of Great Britain and Ireland, Lincoln’s Inn Fields: London, UK, 2016

11. Doubtful factors Factors definitely helpul
Type of anastomosis Proper technique (no tension, vascularity)
Reinforcements Proximal diversion
Prophylactic drainage Surgery in high volume centres
Open/laparoscopic MBP with antibiotics
Goal directed fluid therapy
McDermott, F. et al. Prevention, Diagnosis and Management of Colorectal Anastomotic Leakage; Issues in Professional Practice;
Association of Surgeons of Great Britain and Ireland, Lincoln’s Inn Fields: London, UK, 2016

12. • Role of microbiota
• Macrophages
• MMPs
• NSAIDS
• Simultaneous liver resection- no increased risk (iCral study group
2021)
van Praagh JB et al. Intestinal microbiota and anastomotic leakage of stapled colorectal anastomoses: a pilot study. Surg Endosc 2016
Gaines S, Shao C, Hyman N, et al. Gut microbiome influences on anastomotic leak and recurrence rates following colorectal cancer surgery. Br J
Surg 2018
Shogan BD, Belogortseva N, Luong PM, et al. Collagen degradation and MMP9 activation by Enterococcus faecalis contribute to intestinal
anastomotic leak. Sci Transl Med 2015

13. Intraoperative assessment
• Laser fluorescence angiography
• Air leak test
• Dye test
• Intraoperative endoscopic visualization

14. Laser Fluorescence Angiography
Indocyanine green dye (ICG-FA) - to assess tissue perfusion
• Indocyanine green intravenously  near-infrared imaging system
• Subjective assessment
• Variable evidence
• Good screening tool
• PILLAR III trial- multicentre, no difference in leak rates (9 vs 9.8%)
Intraoperative ICG fluorescence angiography to prevent anastomotic leak after LAR : a meta- analysis. Shen et al.ANZ J Surg 2020
Jafari et al. Perfusion assessment in left sided/LAR (PILLAR III): A randomized, multicentre study assessing perfusion outcomes with PINPOINT near
infra-red flouroscence imaging. Dis Col Rectum 2021

16. Air leak test
• Filling pelvis with warm saline - distention of anastomosis with air
• Objective assessment
• Not effective
Wu, Z. et al. Is the intraoperative air leak test effective in the prevention of colorectal anastomotic leakage? A systematic review and
meta-analysis. Int. J. Color. Dis. 2016

18. • Dye Test
- Easier detection and localization of leaks than air leak testing

19. Intraoperative endoscopic visualization
To assess for –
• Mucosal viability
• Staple line disruptions
• Bleeding
No objective criteria
Inadequate evidence

20. Prophylactic drain
• Extensively debated
• Pelvic drains after low anterior resection - greater utility
• Do not reduce postoperative anastomotic complications
• Many leaks do not present through surgical drain
• Removed early
Tsujinaka S, Konishi F. Drain vs No Drain After Colorectal Surgery. Indian J Surg Oncol 2011

21. Diverting Stoma
Benefits of Diversion Complications of Diversion Decision to Divert
Reduced risk of clinically
symptomatic leaks
Impaired quality of life High risk of leak versus stomal
complications
Reduced need for urgent
reoperation
Stoma-related complications Individualised
Reduced severe septic
complications
Increased readmission rates
Shiomi, A. et al. Effects of a diverting stoma on symptomatic anastomotic leakage after low anterior resection for rectal cancer:A propensity score
matching analysis. J. Am. Coll. Surg. 2015
Lightner, A.L.; Pemberton, J.H. The role of temporary fecal diversion. Clin. Colon Rectal Surg. 2017

22. Not to anastomose
• Haemodynamic instability
• Peritonitis
• Ischaemia
• Disseminated malignancy
• Immunosuppressed
• When in doubt

23. Mechanical bowel preparation and oral antibiotics
• Growing evidence - significantly decrease incidence of infectious complications
including anastomotic leak (2.8 vs 5.7%)
• Not antibiotics alone
• ? Increased Clostridium difficile infections
Scarborough JE et al. Combined mechanical and oral antibiotic bowel preparation reduces incisional SSI and anastomotic leak rates after elective colorectal resection:
an analysis of colectomy- targeted ACS-NSQIP. Ann Surg. 2015
Argyrios et al. Current evidence of combination of oral antibiotics and mechanical bowel preparation in elective colorectal surgery and their impact on anastomotic
leak. Surgical Innovation 2020
ASCRS clinical practice guidelines for use of bowel preparation in elective colon and rectal surgery. Dis Colon Rectum 2019

24. Transanal decompression devices
• Large-diameter soft rubber tubes placed above anastomosis for 5 to 7
days - decrease intraluminal pressure
• No definite benefit seen in RCTs

25. Diagnosis
• Early diagnosis –difficult
• Classic presentations
• Positive predictive value of abnormal vital signs - 4% to 11%
• Drains - ? early clues
• Small, contained leaks - present late, D/D- postoperative abscesses
Erb L, Hyman NH, Osler T. Abnormal vital signs are common after bowel resection and do not predict anastomotic leak. J Am Coll Surg
2014

26. • Majority - diagnosed between 7th - 12th postoperative days
• Upto 42% diagnosed after discharge
• Upto 12% occur beyond postoperative day 30
Hyman N et al. Anastomotic leaks after intestinal anastomosis: it's later than you think. Ann Surg 2007

27. Early and late anastomotic leaks
• Early - Within postoperative day 6, due to technical failure of anastomosis
• Late - After postoperative day 6, due to frailty of patients and tissues, poor
healing process
• Different pathophysiology
Sparreboom CL et al. Different Risk Factors for Early and Late Colorectal Anastomotic Leakage in a Nationwide Audit. Dis Colon Rectum 2018

28. Biochemical markers
CRP-
• Most extensively studied
• Negative predictive value - 89–97% for AL
• Postoperative days 3 and 5
• Cutoff levels - variable (range- 100 to 172 mg/L)
Singh PP et al. Systematic review and meta-analysis of use of serum C-reactive protein levels to predict anastomotic leak after
colorectal surgery. Br J Surg 2014

29. Procalcitonin (PCT) –
• More specific marker of bacterial infection than CRP
• Low PCT levels on POD 3 and 5 - high negative predictive values, reliably excludes
• Serial values - more potential
• Decrease in PCT levels from admission through hospital days 3 to 5 - predict survival in patients
with sepsis and septic shock
Hyponatraemia (water retention)
Cousin F et al. Diagnostic Accuracy of Procalcitonin and C-reactive Protein for the Early Diagnosis of Intra-abdominal Infection After Elective Colorectal
Surgery: A Metaanalysis. Ann Surg 2016

30. Imaging
CT-
• Most employed test
• Specificity >84% , sensitivity - 68–71%
• Contrast extravasation -most reliable sign (present in 15% - 17%)
• Perianastomotic air/fluid levels
• Fluid and inflammatory stranding- D/D early postoperative changes
• Use of rectal contrast
Kornmann VN et al. Systematic review on the value of CT scanning in the diagnosis of anastomotic leakage after colorectal surgery. Int J
Colorectal Dis 2013

31. Postoperative endoscopy
• Safety and efficacy in early postoperative period
• High predictive values
• Early diagnosis

32. Management
Goals Decisive factors
Early recognition Site of leak
Resuscitation Patient stability
Prevention of contamination/ source control Interval
Free/ contained leak
Degree of dehiscence

33. Available options
• Medical management
• Drainage- percutaneous, transanal
• Endoscopic- stents, clips, vaccum assisted closure
• Operative management

34. Medical management
Antibiotics
• Broad-spectrum
• Combination therapy (≥2 different classes of antibiotics)
• Antifungal agents – Indicated in severe sepsis, septic shock, postoperative
intraabdominal infection
• Abscesses <3 cm- only antibiotics if patient stable
• Abscesses >3 cm- percutaneous drains
Montravers P, Dupont H, Leone M, et al. Guidelines for management of intra-abdominal infections. Anaesth Crit Care Pain Med 2015

35. Nonoperative interventions
Percutaneous drainage – indicated if
-Haemodynamically stable
-No signs of diffuse peritonitis
Result in chronic sinus tract - requiring permanent stoma
Transanal drainage
- Malecot catheter
-Follow-up radiographic surveillance by instillation of contrast through drain
Khurrum Baig M et al. Percutaneous postoperative intra-abdominal abscess drainage after elective colorectal surgery. Tech Coloproctol 2002
Thomas MS, Margolin DA. Management of Colorectal Anastomotic Leak. Clin Colon Rectal Surg 2016
Sirois-Giguère E et al. Transanal drainage to treat anastomotic leaks after low anterior resection for rectal cancer: a valuable option. Dis Colon
Rectum 2013

36. Endoscopic options- Stent
• For end-to-end anastomosis
• Distal end of stent >5 cm above anal verge
• Stent migration - major issue
• Current covered stents - not large enough diameter to minimize stent
migration
• Use of endoclips to secure - not effective
Lamazza A et al. Endoscopic placement of self-expanding stents in patients with symptomatic anastomotic leakage after colorectal
resection for cancer: long-term results. Endoscopy 2015
Lamazza A et al. Treatment of anastomotic stenosis and leakage after colorectal resection for cancer with self-expandable metal
stents. Am J Surg 2014

37. Endoscopic options
• Endoscopic transanal vacuum-assisted rectal drainage (E-vac)
Impressive closure rates (85.7%) and low permanent stoma rates (18.9%)
In stable patients, without peritonitis, early cases
Time and resource intensive
• Endoscopic clip application- limited data, for small leaks
Weidenhagen R et al.Endoscopic vacuum-assisted closure of anastomotic leakage following anterior resection of the rectum: a new method. Surg Endosc 2008
Arezzo A, Verra M, Passera R, et al. Long-term efficacy of endoscopic vacuum therapy for the treatment of colorectal anastomotic leaks. Dig Liver Dis 2015
Shalaby et al.Systematic review of endoluminal vaccum assisted therapy as salvage treatment for rectal anastomotic leakage. BJS 2018

38. Endoscopic transanal vacuum-assisted rectal drainage (E-vac)

39. Operative management
• Challenging- gross contamination, severe inflammation
• Need- sepsis, peritonitis, failure of non-operative management
• Goal- source control with washout and faecal diversion
• Faecal diversion by-
Takedown of anastomosis and creating end colostomy
Proximal diversion loop ileostomy
Repair or revision of leaking anastomosis with proximal diversion

40. Anastomotic salvage versus takedown
• Takedown of anastomosis with creation of an endostomy - most
frequent approach
• Reduced quality of life - ostomy-associated complications
• Anastomotic salvage with loop diversion - statistically fewer
complications than anastomotic takedown
• ASCRS advocates- anastomosis be taken down if more than a third of
its circumference has broken down

41. • Traditionally- Exteriorization, resection with creation of end stoma
and Hartmann pouch or mucus fistula
• Many end stomas may never be reversed
• Resection of anastomosis- not always feasible, may be deleterious
• Drainage and proximal diversion- more desirable

42. Minimally invasive techniques
• ASCRS recommends- laparoscopic management be considered if
surgeon has sufficient laparoscopic skills and experience
• Active area of study, limited evidence
• Feasible, safe (early leak)
• Possibly reduce postoperative morbidity
Joh YG, Kim SH, Hahn KY, et al. Anastomotic leakage after laparoscopic protectomy can be managed by a minimally invasive approach. Dis Colon
Rectum 2009
Chen WT, Bansal S, Ke TW, et al. Combined repeat laparoscopy and transanal endolumenal repair (hybrid approach) in the early management of
postoperative colorectal anastomotic leaks: technique and outcomes. Surg Endosc 2018
Tsai YY, Chen WT. Management of anastomotic leakage after rectal surgery: a review article. J Gastrointest Oncol 2019

43. • Boyce et al, ASCRS, Dis Colon Rectum 2017

44. Emerging techniques
• Fibrin glue
Inconclusive evidence
Effectiveness - largely dependent on site and size
• Reinforcing staple line
Bovine pericardium strips
Safe
? decrease AL
Cliord et al. Early anastomotic complications in colorectal surgery: A systematic review of techniques for endoscopic salvage. Surg.
Endosc. 2019
Senagore A et al. Bioabsorbable staple line reinforcement in restorative proctectomy and anterior resection. Dis. Colon Rectum 2014

45. • Buttresses- provide additional support and apposition
• Polyphosphate Therapy (Ppi-6) –
To suppress bacterium that cause leak (collagenase production) such as Serratia
marcescens and Pseudomonas aeruginosa
Non-invasive method
• Marine-Inspired Immunogenic Hydrogel Adhesive
Hydrogel adheres to wet tissue surfaces, improving bursting pressure
Mery, C.M. et al. Profiling surgical staplers: Effect of staple height, buttress, and overlap on staple line failure. Surg. Obes. Relat. Dis. 2008
Hyoju, S.K. et al. Oral Polyphosphate Suppresses Bacterial Collagenase Production and Prevents Anastomotic Leak. Ann. Surg. 2018
Huang, J. et al. Marine-inspired molecular mimicry generates a drug-free, but immunogenic hydrogel adhesive protecting surgical anastomosis.
Bioact. Mater.2021

46. Need of future research
• Comparing anastomotic healing to cutaneous healing
• Using surrogate markers- bursting pressure, measuring
hydroxyproline
• Ignoring role of microbiota- potential driver of leak
• Role of macrophages- active participants in healing

47. Take home message
• Serious complication
• Multitude of factors
• Early diagnosis and individualised management
• Future research

48. Thank you