3. Introduction
• The word anastomosis comes from the Greek word ‘ana’, without,
and ‘stoma’, a mouth.
• Intestinal anastomosis is the surgical connection of separate or
severed bowel to form a continuous channel.
• This procedure restores intestinal continuity after removal of a
pathologic condition affecting the bowel.
4. Historical Perspective
• Galen - coined the term anastomosis
• Lembert(1826) - sero-muscular technique
• Halsted (1887) - single layer closure, extramucosal
• Kocher - two layered technique with silk and catgut
• Connell(1963) - single layer continuous, full thickness
• 1976 – first single use mechanical stapler was marketed.
5. Surgical Importance
• Intestinal anastomosis is a common procedure in surgical practice
with associated increased morbidity and mortality when associated
with a leak or dehiscence. Hence, the need for meticulous pre-op,
intra-op and post op care to improve outcome following the
procedure in patient management.
6. Relevant Anatomy
• Develops from primitive gut tube formed by incorporation of yolk sac.
• The primitive gut is divided into foregut, midgut and hindgut.
• Esophagus: a muscular tube about 25cm length.
• Small intestine is 6m in length, mesentry is 15-25cm in length.
• Colon: 150cm
7. Relevant Anatomy
• Bowel wall: serosa, longitudinal and circular muscles, submucosa,
mucosa.
• Submucosa should be included to achieve optimum integrity in
anastomosis.
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11. Peculiarities
• Ileocaecal junction
• Patent ileocaecal valve present in 1/3rd of the population thus, making this
area a high pressure area.
• This junction is consider to have precarious blood supply since up to 20% of
the population lack ileocolic vessel.
• The splenic flexure
• Marginal artery of Drummond which connect the left branch of the middle
colic to the proximal branches of left colic artery is absent in 15-20% of
population making this area have precarious blood supply.
13. Physiology of Intestinal Anastomosis Healing
• Most of the strength of bowel wall resides in the submucosa.
• However, serosa holds sutures better than either the longitudinal or
circular muscular layer.
• Collagen is the single most important molecule; its content is highest
in submucosa.
14. Physiology of Intestinal Anastomosis Healing
Phases of Healing
• Acute inflammatory phase(0-4days)
Acute inflammatory response, but no intrinsic cohesion.
• Proliferative phase (3-14days)
Fibroblast proliferation occurs with collagen formation.
• Maturation phase (>10days)
Collagen remodeling, stability and strength of anastomosis increases.
15. Indications
Restoration of bowel continuity following resection of diseased bowel
• Bowel gangrene due to vascular compromise
• Traumatic perforations
• Infections
TB complicated by stricture or perforation
TIP
• Benign conditions – polyps, intussuception
• Malignancy
• Inflammatory bowel disease that is refractory to medical
therapy/associated with complications.
• Congenital anomalies – Intestinal atresia, Hirschprung disease
16. Indications
Bypass of un resectable diseased bowel
• Locally advanced tumour causing luminal obstruction e.g Ca head
of pancreas (gastrojejunostomy).
• Metastatic disease causing intestinal obstruction e.g metastatic
unresectable caecal pole tumour (ileo-transverse bypass).
• Poor general condition or condition that prevents major
resection.
17. Indications
As part of other surgical procedures
• Kasai portoenterostomy
• Choledochal cyst surgery
• Urinary diversions
• Excision of pancreatic neoplasms
19. Ideal Anastomosis
• Zero leak
• Should promote early recovery to function
• Should not narrow the lumen of viscus
• No vascular compromise at the incised and/or divided margin of a
viscus.
• Easy to learn, teach and perform.
• Technique should preferably be quick to perform.
20. Types of Anastomosis
• Based on orientation of the
bowel
End to End
End to Side
Side to side
• Based on technique
Hand sewn
Stapled; Linear, Circular
21. Types of Anastomosis
Based on number of layers
Single layered
• Interrupted
• Seromuscular
Double layered
• Outer seromuscular,
interrupted.
• Inner full thickness,
continuous.
22. Types of Anastomosis
Based on part of bowel involved
• Oesophago-jejunostomy
• Gastro-jejunostomy
• Entero-eterostomy
• Entero-colic
• Colo-colic
• Colo-rectal
• Colo-anal
• Ileo-anal
25. Intra-op
• Anaesthesia
• GA with good muscle relaxation
• Maintenance of good perfusion and tissue oxygenation
• Prophylactic antibiotics
• Adequate access and exposure
• Adequate lightening
• Gentle bowel handling
• Assess and ensure bowel viability (approximation of well vascularized
bowel).
• Avoid clamping and suturing mesenteric vessels
26. Intra-op
• Decompression of bowel prior to anastomosis.
• Prevention of spillage(non crushing intestinal clamp, proximal and
distal segments).
• Meticulous technique
A point of transection is selected sufficiently distant from the diseased
portion.
The peritoneum of the mesentery is opened without transecting the blood
vessels.
Mesentery is opened in V shaped fashion.
27. Intra-op
• Meticulous Technique cont..
The small vessels crossing the line of transection are clamped and tied
The line of transection in the bowel is oblique rather than perpendicular
A stay suture is applied at the mesenteric and antimesenteric border and
• Ensure patency
• Absence of tension at anastomosis
• Closure of mesenteric defect
• Drain
28. N.B
• Suture bites should be 3-5mm deep and 3-5mm apart depending on the
thickness of bowel.
• Suture materials size 2/0, 3/0, absorbable mounted on round bodied needle.
• Bowel of similar diameter is essential for end to end anastomosis.
• Cheating, cheatling, beveling
• In major size discrepancy; end to side or side to side is preferable.
• Tension free anastomosis.
29. Single Layer Anastomosis
• An interrupted seromuscular suture with absorbable suture. The
submucosal layer is strong and blood supply in only minimally
damage. E.g. Lembert stitch.
Double Layer Anastomosis
• An inner continuous absorbable suture with stitching of all layers.
• An outer seromuscular interrupted nonabsorbable suture.
30. Single vs Two Layers Repair
Single Layer
• Reduced surgery time
• Lower cost of suture materials
• Less chance of narrowing lumen
• Less chance of compromising blood
supply.
Two Layers
• More surgery time
• More cost of suture materials
• Increased chance of narrowing
lumen.
• Increased chance of compromising
blood supply.
31. Interrupted vs Continuous
Interrupted
• More time consuming
• Suture line are less watertight
Continuous
• Less time consuming
• Suture line is more watertight
• Better hemostasis
• Entire suture line is based on a
single stitch.
32. Factors Essential for Safe Bowel Anastomosis
Local Factors
• Good blood supply
• No tension on suture line
• Inverting anastomosis with appropriate suture
• Accurate apposition and suture technique
• Avoidance of tissue damage by clamps
33. Factors Essential for Safe Bowel Anastomosis
Systemic Factors
• Bowel preparation (and avoidance of spillage)
• Antibiotics prophylaxis
• Maintenance of good perfusion and tissue oxygenation during
anaesthesia.
• Adequate nutrition
• Correction of anaemia
• Adequate resection margins
• Avoidance of cytotoxics/Radiotherapy
34. Factors affecting anastomotic healing
• Patient factors
• Technical factors
Good bowel supply + no tension + meticulous technique
35. Patient Factors
• Old age
• Malnourished
• Anaemia; <11g/dL
• Uraemia
• DM
• Steroids
• Smoking
• Alcohol abuse
• High risk of site anastomosis (e.g
low colorectal anastomoses).
• Pre-operative radiotherapy
• Male sex; presumably narrow
pelvis limits visualisation
37. Post-op
• NPO until return of bowel activity (usually btw 3-5 days)
• NG tube
• IVFs
• Antibiotics
• Analgesics
• PCV, E/U/Cr check
38. Controversies
• Type of suture materials
• Single layer vs double layer anastomosis
• Continuous vs interrupted sutures
• Handsewn vs stapled anastomosis
• Inverting vs everting anastomosis
• NG tube decompression
• Abdominal drain
39. Complications
Early
• Anastomotic leak
• Fistula formation
• Bleeding
• Prolonged ileus
• Surgical site infection
• Intra abdominal abscess
Late
• Anastomotic stricture
• Obstruction
40. Conclusion
• Successful bowel anastomosis is attributed to adequate knowledge
on intestinal healing, patient optimization, meticulous surgical
technique and good post op care.
41. References
• Oumar Toure A, Seck M, Lamine Guye. Bowel Anastomosis; Manual or
Mechanical. A breiw overview. IntechOpen;2021.
• Medscpae.net- Overview of bowel anastomosis. May 2022
