Principles of Bowel Anastomosis (s&l)-1.pptx

The surgical principles to follow when joining bowel segments together.

1. Principles of Bowel Anastomosis By Obateru P. A. Supervising SR – Dr Sayomi

2. Outline Introduction Historical Perspective Surgical Importance Relevant Anatomy Indications for Anastomosis Types of Anastomosis Principles Complications Follow up Conclusion References

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.

8. Peculiarities Ileocaecal junction Patent ileocaecal valve present in 1/3 rd 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.

9. Physiology Functions Ingestion Propulsion Secretion Digestion Absorption Excretion of waste Normal GIT secretion Saliva: 1000L Gastric: 1500L Intestinal: 4000L Bile: 1000l Pancreas: 1500L

10. 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.

11. 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.

12. 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

13. 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.

14. Indications As part of other surgical procedures Kasai portoenterostomy Choledochal cyst surgery Urinary diversions Excision of pancreatic neoplasms

15. Contraindications Non viable bowel Doubtful bowel viability Gross feacal peritoneal contamination Persistent intra-op haemodynamic instability Malnutrition

16. 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.

17. 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

18. Types of Anastomosis Based on number of layers Single layered Interrupted Seromuscular Double layered Outer seromuscular, interrupted. Inner full thickness, continuous.

19. 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

20. Principles of Anastomosis

21. Pre-op Resuscitation Optimization Correct dehydration and electrolyte derangement Correct Anaemia Treat infection Assess nutritional status Bowel preparation Antibiotic prophylaxis DVT prophylaxis NG tube & urethral catheterization Counselling & obtain informed consent

22. 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

23. 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.

24. 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

25. 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.

26. 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.

27. 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.

28. 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.

29. 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

30. 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

31. Factors affecting anastomotic healing Patient factors Technical factors Good bowel supply + no tension + meticulous technique

32. 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

33. Technical Factors Inaccurate seromuscular apposition Poor blood supply -Tension -Twisting -Mesenteric haematoma -Open mesenteric window Distal obstruction Faecal contamination

34. Post-op NPO until return of bowel activity (usually btw 3-5 days) NG tube IVFs Antibiotics Analgesics PCV, E/U/Cr check

35. 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

36. Complications Early Anastomotic leak Fistula formation Bleeding Prolonged ileus Surgical site infection Intra abdominal abscess Late Anastomotic stricture Obstruction

37. Conclusion Successful bowel anastomosis is attributed to adequate knowledge on intestinal healing, patient optimization, meticulous surgical technique and good post op care.

38. 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

39. Thank You For Listening… 4/22/2024 42