Intestinal Obstruction in Adults 2023 final-1.pptx

Surgical note

1. Presenter: Yismaw M GSR4 Moderator:Dr Erdachew (Consultant General Surgeon) 1 Management of intestinal Obstruction in Adults

2. 2 Outlines Introduction Epidemiology Etiology Classifications Pathophysiology Diagnosis General management Management of specific causes of intestinal obstruction Summary References

3. Epidemiology 3 Intestinal obstruction accounts for 1.2% of all surgical diseases and 5% of emergency surgical admissions. In rural Africa, acute intestinal obstruction accounts for a great proportion of morbidity and mortality, and Ethiopia is one of the countries where intestinal obstruction constitutes a major cause of morbidity and mortality.

4. 4 Bowel obstruction results in substantial overall mortality and morbidity. M ortality rates range from up to 3% for simple obstructions to as great as 30% when there is vascular compromise or perforation of the obstructed bowel. B owel obstruction is frequently a recurrent problem Recurrence rates vary according to method of management (conservative or operative). about 12% after a successful primary conservative treatment and in between 8% and 32% after operative management for adhesive bowel obstruction.

5. 5 3 yr retrospective, cross-sectional study 262 patients admitted with intestinal obstruction intestinal obstruction was 21.8 % of acute abdomen and 4.8 % of total surgical admissions 64 % had SBO and 36.0 % had LBO. mortality rate was 2.5 %

6. 6 Pattern of Acute Abdomen in Adult Patients in Tikur Anbessa Teaching Hospital-1 yr retrospective study B. Kotiso et al., 2007 26% of acute abdomen SBO=52.3%, LBO=46.7% SBO=( adhesions,volvulus,hernia ) LBO=(Sigmoid V,colonic ca,cecal volvulus)

7. 7 Epidemiology and causes of intestinal obstruction in Ethiopia: Gelana Fekadu1 , Abebe Tolera2 , Badhaasaa Beyene Bayissa3 , Bedasa Taye Merga2 , Dumessa Edessa4 and Adugna Lamessa3 Abstract Objective: This systematic review was aimed to address the prevalence and causes of intestinal obstruction in Ethiopia. Results: The reported prevalence of intestinal obstruction in Ethiopia ranges from 18.6% to 50.7% among patients with acute abdomen. However, the prevalence varies from 4.3% to 34.6% among total surgical admissions. The leading causes of small intestinal obstruction were small bowel volvulus , intussusception , and adhesion. Sigmoid volvulus was the most commonly reported cause of large intestine obstruction, followed by colonic cancer. Conclusion: The highest reported prevalence of intestinal obstruction in Ethiopia was 50.7% among patients with acute abdomen and 34.6% among surgical admissions. Small intestine volvulus and sigmoid volvulus were the common causes of small and large bowel obstructions, respectively . Therefore, clinicians have to consider the common causes during the diagnosis and management of intestinal obstruction.

8. Etiology,Mechanical 8 Intraluminal Intramural Extrinsic Foreign bodies Strictures (IBD, Radiation induced ,TB) Adhesions Worm b all (ascariasis) Tumors(Primary or secondary) Volvulus Gallstones Intussusceptions Fecal impaction Hernias (internal or external ) Carcinomatosis Compression

9. Etiology,Functional 9 Paralytic ileus Pseudo-obstruction Intra abdominal inflammation or collection Smooth muscle disorders Abdominal surgery Neurogenic disorders Metabolic causes(Electrolytes imbalance ,uremia ,or hypothyroidism ) Medications (opiods,psychotrotic,anticholinergics) Retroperitoneal inflammation or collections Trauma

10. Etiology 10 About 80–90% of bowel obstructions occur in the small intestine; the other 10–20% occur in the colon.

11. Etiology : Industrialized countries vs Ethiopia 11 LBO: industrialized countries Malignancies(60%) Diverticular ds(20%) Colonic volvulus (1-5%) Miscellaneous (15-20%) LBO: Ethiopia sigmoid volvulus (69.0 %) colonic tumor (13.8 %). ( Soressa et al(2016), Adama LBO: Ethiopia sigmoid volvulus(58.6%) Colonic ca Cecal volvulus ( B.Kotiso et al.(2007 ))

12. Pathophysiology of intestinal obstruction 12 Bacterial translocation =>sepsis

13. Diagnosis 13 Goals: Distinguish mechanical obstruction from ileus Determine the etiology of obstruction Discriminate partial from complete obstruction Discriminate simple from strangulating obstruction The cardinal symptoms of intestinal obstruction : colicky abdominal pain , nausea, vomiting, abdominal distention, and obstipation. G/A: V/S: PR , T , Bp Severe DHN Abdominal exam: Early : a distended abdomen, Previous surgical scars, peristaltic waves , hyperactive bowel sounds with audible rushes associated with vigorous peristalsis ( borborygmi ) Late : minimal or no bowel sounds are noted. Mild abdominal tenderness -/+ a palpable mass; however, localized tenderness, rebound, and guarding suggest peritonitis and the likelihood of strangulation. A careful examination must be performed to rule out incarcerated hernias in the groin, femoral triangle, and obturator foramen. A rectal examination should always be performed to rule out a distal colonic obstruction by intraluminal masses and to examine the stool for occult blood , which may be an indication of malignant disease, intussusception, or infarction. Laboratory tests - not helpful in the actual diagnosis BO, extremely important in assessing the degree of dehydration. serum Na+, Cl -, K+, HCO3-, and creatinine levels. Serum lactic acids CBC( hydration,anemia,leukocytes ) OFT ABG Blood culture Radiographic studies Abdominal series Accuracy in dx of SBO=86% & equivocal or nonspecific in the remainder.

14. 14 Triads : Dilated bowel loop Air-fluid level Paucity of air distally

15. 15 X-ray: Sensitivity in dx of SBO is 70-80% Specificity is low - ileus & colonic obstruction can have similar finding False-negative – closed-loop obstruction , proximal SBO Wide spread availability & low cost

16. 16 Abdoinal x-ray: SBO Valvulae conniventes Central abdomen Multiple air fluid level Paucity/absence gas in the colon LBO Haustral markings Peripheral location

17. 17 CT-scan provide more clinically relevant information. Sensitivity and specificity >94% if bowel obstruction is present localize the obstructive site degree of obstruction closed-loop obstruction Local and regional Mets Limitation :low sensitivity for Partial obstruction(<50%) Complications Ischemia Thickened intestinal walls and poor flow of contrast media into a section of bowel Necrosis and perforation pneumatosis intestinalis pneumoperitoneum , and mesenteric fat stranding suggest

18. General management 18 Fluid Resuscitation and electrolytes Isotonic fluid should be given iv K+ replacement Monitoring: bladder catheter: in stable patients with normal renal function Central venous or pulmonary arterial pressure: unstable patients or those with impaired cardiac, pulmonary or renal function Bowel rest : NPO

19. 19 Tube Decompression NGT Decreases distention Decreases nausea and vomiting Decreases risk of aspiration Improves ventilation in patients with respiratory compromise

20. 20 Broad spectrum antibiotics Bowel ischemia Peritonitis If surgery is planned Operative Management Indication Suspected ischemia/strangulation perforation Closed loop obstruction for those who fail conservative management

21. 21 Nonoperative management Indications: No sign of peritonitis No evidence of bowel ischemia No closed loop obstruction Contraindications Absolute: Closed loop obstruction Evidence of bowel ischemia Sign of peritonitis Relative; Large bowel obstruction Complete obstruction

22. 22 Clinical assessment Q4hr(by same clnician ) Abdominal radiography-Q6hr Duration;3-5days Longer period observation Stable pts with frozen abdomen Recent abdominal surgery Success rate:62-85%:only5-15% have symptoms not substantially not improved within 48hr Measures:Nonoperative management NPO Fluid & electrolyte replacement NGT decompression Close clinical monitoring Hx,P /E & Ix Preferably by the same person. Contrast challenge

23. 23 Contrast challenge Administration of water-soluble contrast has not only diagnostic value but also therapeutic , and prognostic value. Diagnostic : differentiate partial vs complete Predicts the likelihood of success of nonoperative management. Reduces the need for surgery Reduces the length of stay by about 2days Reduces the tie to resolution by about 28hrs Therapeutic The hypertonic water soluble contrast agent causes a shift of fluid into intestinal lumen, thereby increasing the pressure gradient across the site of obstruction accelerating resolution of partial SBO.

24. 24 When to convert to operative management? Worsening of clinical condition continuous abdominal pain Fever Tachycardia Localized/diffuse abdominal tenderness Leukocytosis No improvement in symptoms Complete obstruction Sign of bowel ischemia Signs of peritonitis Imaging(x-ray/CT scan) Signs of complete obstruction Signs of ischemia Signs of perforation

25. Management of some specific causes of intestinal obstruction 25 Sigmoid Volvulus Torsion of sigmoid volvulus along its own mesentery. Torsion 180 degrees results in clinical obstruction, and further torsion to 360 degrees causes strangulation. Perforation occurs in areas of necrosis at the point of torsion, within the closed loop, or in the proximal thin walled cecum.

26. 26 Epidemiology Sv accounts for 1.9% cases of LBO in US and up to 10 to 50% of cases in Africa, the middle east, and south America. Old age Male > female(80% of patients are male).

27. 27 The sigmoid colon is involved in upto 90% of cases of colonic volvulus , but volvulus can involve the cecum(<20%) or transverse colon.

28. Pathophysiology: sigmoid volvulus 28 Risk factors Anatomic risk factors A long redundant sigmoid colon Wide mesentery & narrow mesenteric root attachment.  advancing age(?due to colonic dysmotility) High fecal load- high fiber diet Constipation Pregnancy HSD

29. 29 Volvulus occurs when an air-filled segment of the colon twists about its mesentry. A volvulus can reduce spontaneously, but more commonly produces bowel obstruction ,which can progress to strangulation , gangrene ,and perforation .

30. Diagnosis 30 Clinically: abdominal pain, nausea, abdominal distension, and constipation. more insidious , recurrent attacks of abdominal pain, with resolution presumably due to spontaneous detorsion The big drum-like abdomen is typical. peritonitis and sepsis.

31. 31 Plain AxR establish the diagnosis in approximately 60 % of patients " bent inner tube “ or coffee bean appearance

32. 32 Contrast enema - “ bird’s beak sign ” (~100 %) CT scan: ~ 100%sensitivity and > 90% specificity Typical findings include a whirl pattern Split wall sign

33. Treatment: SV 33 Goals: - To prevent development of gangrene to address the anatomic abnormality that led to the volvulus General management - resuscitation,bowel rest Patients with alarming signs Resuscitation followed by endoscopic detorsion flexible sigmoidoscopy /rigid proctoscopy /colonoscopy leave a rectal tube in place with its proximal end beyond the area of twisting. blind passage of rectal tube rectal tube may lessen colonic distension and reduce the chance of recurrent volvulus in the acute setting. .

34. 34 Advantages of endoscopic decompression: detorse the sigmoid volvulus(success rate  85 to 95 % in some series) blood supply to the affected sigmoid colon is maintained or restored assessment of the viability of the colon converts an emergency surgery into a semi urgent surgery Outcome: Recurrence : up to 60% Mortality : 6.4% (<10%) Elective sigmoid colectomy should be done after the patient has been stabilized and adequate bowel preparation.

35. 35 Conversion to surgery : Endoscopic evidences of bowel gangrene/perforation Failed endoscopic detorsion

36. 36 Patients with alarming signs ( gangrene,peritonitis,perforation ) Immediate surgical exploration without an attempt to detorse is recommended. If dead bowel is present at laparotomy: Two stage- Hatmann’s procedure - may be the safest operation to perform. Single stage - resection and primary anastomosis

37. 37 Is primary resection and anastomosis , without proximal stoma safe in gangrenous sigmoid volvulus ?( Jitin Bajaj et al(2018)( I ndia) 6yr,prospectie ,institution-based study,64 cases Adults older than 18yr with sigmoid volvulus Excluded pts : hemodynamical instablity,ASA >III Primary outcomes: leak(3%),abdominal abscess(3%),wound infection(20%),Mortality(0). Conclusion : ERPA is a safe and effective option for both viable and gangrenous SV in expert hands and in hemodynamically stable patients.

38. 38 Intraoperative finding of Viable sigmoid Non- resective methos Simple detorsion Sigmoidopexy Mesosigmoidoplasty Extraperitonealization Foley Catheter Sigmoidostomy T-Fasteners Sigmoidopexy High recurrence rate:9-44%

39. 39 Overall outcome : Nongangrenous , surgically treated Mortality rate <10% Gangrenous sigmoid volvulus Mortality rate : 11-60%

40. Small bowel volvulus 40 Small bowel volvulus(SBV) is a benign GI surgical condition in which there is a torsion of all or parts of a segment of small bowel on its mesenteric axis. It has been contributed significant burden of surgical emergency as a cause of SBO in developing countries.

41. Small bowel volvulus 41 SBV is responsible for < 5% of SBO in Western series and over half of SBO in some African and Asian series . Young adults are primarily affected, with a strong male preponderance . The incidence of small bowel volvulus is also higher in regions with endemic parasitism , which is known to increase bowel motility . In 80% of cases the intestinal torsion is clockwise, as it is for midgut volvulus associated with congenital malrotation . only a minority of adolescent and adult patients with primary SBO have an identified lack of mesenteric fixation.

42. Pathophysiology: SBV 42 Anatomically, the small bowel in high-risk populations is longer and has a longer mesentery with a narrower insertion and a lack of mesenteric fat . Patients with SBV are not usually emaciated but rather have firm, muscular abdomens , which theoretically might limit the mobility of bowel in the anterior-posterior plane .

43. Pathophysiology: SBV 43 Theory: rapid filling of a segment of proximal intestine with high-bulk chyme pulls it down into the pelvis and displaces empty distal bowel upward, thereby initiating the torsion . In contrast, secondary SBO is much more common than primary SBV in the United States. In secondary SBV, the intestine is twisted around an underlying point of fixation ; as the loop fills with fluid, peristalsis exacerbates the torsion. By far the most common point of fixation is a postoperative adhesion.

44. Diagnosis: SBV 44 Clinically, the findings in patients with small bowel volvulus are nonspecific . Patients have signs and symptoms of small bowel obstruction that are usually sudden in onset. Central abdominal pain is almost always present. a previous history of intermittent obstructive symptoms such as crampy epigastric or periumbilical abdominal pain. “ Pain out of proportion ” to the degree of obstruction should raise suspicion of vascular compromise, as should fever, tachycardia, peritoneal signs, acidosis, and leukocytosis . none of these signs alone are sensitive or specific enough to reliably rule bowel ischemia in or out.

45. 45 Plain abdominal films dilated loops of bowel or air-fluid levels, or both . are usually nonspecific “ gasless” abdomen or even be interpreted as normal (closed-loop obstruction such as volvulus ) pneumatosis or portal venous gas. gangrenous bowel, notoriously insensitive and late signs.

46. 46 computed tomography (CT), is rapid, noninvasive, and widely available . closed-loop obstruction radial distribution of dilated bowel loops converging toward a point of torsion C- or U-shaped loop of horizontally oriented, fluid-filled bowel . “whirl” sign-pathognomonic for SBV Mesenteric thickening small bowel wall thickening, pneumatosis , portal venous gas, and free intraperitoneal fluid suggest small bowel ischemia.

47. 47 Gastrointestinal contrast studies may show a corkscrew pattern or an abrupt “bird beak” at the point of obstruction, and angiography : a spiraling pattern of the mesenteric vessels . Now they are replaced by CT scan.

48. Treatment: SBV 48 Suspicion of volvulus clinically or radiographically should prompt immediate exploration because of the associated risk for ischemia . Evidence of bowel ischemia mandates immediate exploration and resection of the involved, gangrenous small bowel. In Western series, up to 50% of patients with SBV require resection for gangrenous small bowel. For patients without ischemic bowel simple detorsion without resection is recommended T he formation of intraperitoneal adhesions after laparotomy is believed to prevent most recurrences. .

49. 49 Outcome Overall mortality : 10 % to 35% higher than that for small bowel obstruction in general. attributable to the large proportion of patients with gangrenous bowel, in whom mortality rates are between 20% and 60% in most series . Early diagnosis and prompt operative intervention minimizes the morbidity & mortality rate.

50. 50 SBO Adhesions Abnormal fibrous bands between organs or tissues or both in the abdominal cavity that are normally separated . Acquired(most common) or congenital)e.g. Ladd bands 93-100 % who undergo transperitoneal surgery will develop post op adhesion Intraabdominal adhesions related to prior abdominal surgery accounts for upto 75% of cases of SBO.

51. 51 Typical adhesions form after peritoneal injury from abdominal surgery. The risk of SBO due to adhesions depends in part upon the type of surgery being performed and the cause of the SBO inframesocolic compartment and especially in the pelvic region, such as colonic, rectal, and gynecologic procedures . a common predisposition to adhesive obstruction is the presence of a prior episode of adhesive obstruction. Open appendectomy ( 10.7%) Open cholecystectomy (6.4%) ileal pouch–anal anastomosis ( 19%) open colectomy ( 9%). open operations > laparoscopic surgery

52. Pathogenesis of adhesion 52 Damage to peritoneal surfaces induces a repair response F ibrin deposition at the site of injury within 3hrs of the tissue trauma and peaking on day 4 to 5. complete fibrinolysis and resorption of degradation products , reepithelialization a smooth healed tissue surface. connective tissue scars and adhesions develop from in growth of fibroblasts, capillaries, and nerves.

53. 53 Types Fibrinous adhesion-early Avascular and flimsy Get resolved completely Fibrous adhesion Collagenized and vascularized

54. Clinical features 54 Abdominal pain Colicky Recurrent Episodic Distension Constipation Previous surgical scars commonly observed Imaging X-ray CT-scan Gilroy Bevan triad Pain in the region of old scar Pain gets aggravated or relieved on change of posture Tenderness is elicited by pressure over the scar

55. Management 55 general Fluid and electrolytes Bowel rest NG tube Urethral catheter Monitoring Decide on non operative vs operative mgt Non operative ~ 80% success rate

56. Non operative 56 Indications No closed loop obstruction No evidence of bowel ischemia No sign of peritonitis Contraindications Closed loop obstruction Evidence of bowel ischemia Sign of peritonitis LBO Complete obstruction

57. Principles of adhesiolysis 57 Incision planning- entry into a "virgin" area. avoiding adhesions and bowel loops adherent to the abdominal wall at the site of prior incisions D iagnose and resolve the source of the obstruction, resect any nonviable bowel and minimize the occurrence of an incidental enterotomy . H andle dilated bowel proximal to the point of obstruction gently because the bowel wall can be thin and is easily injured. Cultures of any cloudy fluid should be obtained. Ideally , the distal, decompressed bowel loops are identified first and followed to the point of obstruction .

58. 58 minimizing the chances of injury. The precise mechanism for the obstruction should be noted Any internal hernias will require reduction of the herniated intestine and obliteration of the opening that allowed herniation . After the site of obstruction is relieved, the need for lysis of all remaining adhesions is debatable.

59. 59 Intraoperative assessment of viability    visual inspection is usually adequate. Return of normal color, Motility/peristalsis presence of marginal mesenteric pulses Snipping a small piece of mesenteric fat& checking for bleeding IV injection of  fluorescein  & illumination of the intestine using fluorescent light . Standard Doppler examination

60. 60 When bowel is of borderline /questionable viability If removal of the entire length can lead to short gut syndrome ( eg . patient with prior resections for Crohn's disease), preserving the bowel is prudent. re-exploration 24-48 hours later.

61. 61

62. Prevention of adhesion 62 a good surgical technique(the most effective to date). Gentle handling of bowel to reduce serosal trauma Avoidance of unnecessary dissection Exclusion of foreign material from peritoneal cavity( use of absorbable suture material when possible, avoidance of excessive gauze sponge use,& removal of starch from gloves) Adequate irrigation and removal of removal of infectious and ischemic debris Preservation and use of omentum around the site of surgery or in the denuded pelvis. Use of adhesive barriers such as seprafilm

63. Intussusception 63  Intussusception refers to the invagination of a part of the intestine into itself . leads to obstruction and compromise of mesenteric blood flow, with resultant inflammation and the potential for ischemia of the bowel wall

64. 64 I t accounts for only 2% of bowel obstruction in the adult population. An increased incidence of intussusception in patients with HIV/AIDS. The median age : 6 th to 7 th decade. The etiology of intussusception differs greatly between adult and pediatric patients . Adult intussusception commonly involves a distinct pathologic lead point , which is malignant in over half of the cases.

65. 65 In the vast majority of adult intussusceptions , inflammatory lesion or a neoplasm serves as the lead point of the intussusception; however, up to 20% of adult cases are idiopathic. Neoplasms - malignant in almost 50% of patients . Intussusceptions can be classified by etiology or by location.

66. Diagnosis : intussusception 66 Clinical features Symptoms are often chronic. intermittent abdominal pain is the most common presentation in adults. Other : intermittent partial bowel obstruction and can include nausea, vomiting, melena, weight loss, fever, and constipation

67. intussusception 67 Imaging Plain abdominal films show small bowel obstruction . The diagnosis is most often made with computed tomography (CT ) . A " target sign " on perpendicular view, a sausage shaped mass when the CT beam is parallel to the longitudinal axis. The distended loop of bowel (intussuscipiens) has a thickened wall because it represents two layers of bowel. However , target signs are sometimes seen on CT scans of patients who do not have a clinical presentation indicative of bowel obstruction. In such cases, the finding is of little clinical significance and is probably related to normal peristalsis.

68. Treatment : intussusception 68 surgical resection using appropriate oncologic techniques is recommended in most cases . I f a benign diagnosis or the patient is at risk for short bowel syndrome, a combined approach with limited intestinal resections and snare polypectomies is more appropriate.

69. References 69