Non traumatic acute abdominal conditions .pptx

Non traumatic acute abdominal conditions

1. Non traumatic acute abdomen Dr. M Dinesh

2. Introduction Term acute abdomen refers to sudden severe abdominal pain of unclear etiology that is less than 24 hrs in duration. The 'acute abdomen ' is a clinical condition characterized by severe abdominal pain, requiring the clinician to make an urgent therapeutic decision. This may be challenging, because the differential diagnosis of an acute abdomen includes a wide spectrum of disorders, ranging from life-threatening diseases to benign self-limiting conditions. Indicated management may vary from emergency surgery to reassurance of the patient and misdiagnosis may easily result in delayed necessary treatment or unnecessary surgery.

3. LEARNING OBJECTIVES Review commonly encountered causes of non-traumatic acute abdominal pain in a case-based format. Explore five major categories of potential complications (obstruction, ischemia, perforation, infection, and bleeding) that can require emergency intervention. Discuss pertinent findings to include in the radiology report to aid the surgical team in acute management decisions.

4. What does the surgeon want to know? In addition to making the diagnosis, consider reporting these 5 categories of complications that can influence acute patient management.

5. THE ACUTE ABDOMEN Accounts for up to 10% of visits to the emergency department annually. Radiographs, US, CT, and MRI can be used based on the clinical scenario. MDCT has become the imaging modality of choice . Data can be acquired in different phases making MDCT an ideal modality for evaluation of suspected mesenteric ischemia or vascular disorders such as abdominal aortic aneurysms. However, MRI is still not routinely used for evaluation of an acute abdomen except in situations where iodinated contrast cannot be administered or in pregnant patients .

6. Case list Appendicitis ( 28%) Cholecystitis( 9.7%) Small bowel obstruction( 4.1 %) Gynecological disorders( 4%) Pancreatitis(2.9 %) Renal colic ( 2.9%) Peptic ulcer disease(2.5%) Diverticulitis( 1.9%) Ruptured AAA Necrotizing soft tissue infection(Fournier’s gangrene)

7. The upright chest film is ideal for demonstrating free air as the X-ray beam strikes the hemidiaphragms tangentially at their highest point and at an optimal exposure. If the patient cannot sit or stand up a left lateral decubitus film will demonstrate air between the opacity of the liver and the abdominal wall. If the patient is too ill to roll over, a cross-table lateral view of the abdomen is obtained . Distinction between small and large bowel loops on plain films is based on the central position of the small bowel, presence of valvulae conniventes in the jejunum and tubular featureless appearance of the ileum. Plain Radiographs in Evaluation of the Acute Abdomen Plain radiographs still remain an important initial investigation in the evaluation of a patient with acute abdomen. Abdominal plain films are of greatest value in cases of hollow viscus perforation and intestinal obstruction. Dilatation of both small and large bowel loops from stomach to rectum indicates a diagnosis of paralytic ileus .

8. Chest X-ray reveals absence of free air under the domes of diaphragm; Supine film shows dilated jejunal and ileal loops with no air in the large bowel; Erect film demonstrates multiple air-fluid levels in a case of distal small bowel obstruction.

9. Various signs of pneumoperitoneum can be seen even on supine films if carefully searched for. The signs include “ Rigler's or “double wall ” sign describing visualization of both the mucosal and serosal aspect of the bowel wall due to presence of intra- and extraluminal air Plain radiograph abdomen, erect film shows large amount of free air in the upper abdomen. Retroperitoneal perforation of a duodenal ulcer results in air outlining the renal or psoas shadows .

10. small gas bubbles get trapped between the valvulae conniventis resulting in the “string-of-beads” sign . This appearance is virtually diagnostic of mechanical obstruction as it is never seen with paralytic ileus. A barium examination will reveal the coil-spring appearance of the intussuscipiens with the “claw” sign . X-ray of abdomen, supine view shows a hugely dilated a haustral loop arising from the pelvis with the “ coffeebean ” sign in a case of sigmoid volvulus.

11. Acute appendicitis Mcc for surgery in acute abdomen. Causes : Proximal luminal obstruction causing appendiceal dilatation resulting in wall ischemia and necrosis. Obstruction may be caused by fecal material, appendicolith , lymphoid hyperplasia, crohns disease or obstructing mass. Diagnosis : Dilatation of the appendix, wall thickening and hyperenhancement with localized inflammatory findings such as mesenteric fat stranding and free fluid. Complications : Ischemia and perforation.

12. Reporting tips : Diameter of the appendix. Traditional cutoff >6mm is derived from US evaluation and should be used with caution and correlated with other signs of appendicitis Diameter >13mm is associated with conservative treatment failure. Underlying etiology Appendicolith : higher rate of perforation and conservative treatment failure. Obstructing mass: may change operative plan from simple appendectomy to more extensive ileocolic resection.

13. Perforation Abscess Size and location Include possible non emergent mimics Mucinous neoplasm : dilated appendix without inflammation Other inflammatory state: crohn disease,caecal diverticulitis

14. Appendicitis: uncomplicated Cect images demonstrate a dilated blind ending tubular structure in right lower abdomen with surrounding inflammation.

15. Learning point : Appendicolith often present in asymptomatic patients The presence of appendicolith in appendicitis increases the risk of failed conservative management and perforation. Extraluminal appendicoliths in a fliud collection suggests perforated appendicitis and abscess formation. Enlarged appendix with surrounding inflammatiory stranding fat strandings Consisitent with acute appendicitis.No complications an obstructing appendicolith was present at the site of origin of appendix

16. Appendicitis perforated Present with generalized abdominal pain ,nausea, vomiting for 1 day The appendix is dilated and there is focal wall discontinuity ,consistent with necrosis and perforation.

17. Learning point : always evaluate the for the integrity of the appendiceal wall. Findings of perforation or impending perforation may prompt more immediate treatment The presence of appendicolith are a risk factor for perforation. Gas within an inflamed appendix is suspicion for gangrenous appendicitis.

18. Cholecystitis Causes : Calculous( 90-95) impaction of stone in GB neck or cystic duct Acalculous : bile stasis, ischemia , cystic duct obstruction Diagnosis : USG : cholelithiaisis wall thickening >3mm , GB distension , pericholecystic fluid, hyperemia . Hepatic artery velocity > 100 cm /sec CT : wall thickening , inflammatory fat strandings , +/-cholecystitis. Complications : Gangrenous cholecystitis perforation Emphysemtaous cholecystitis

19. Reporting tips Cholelithiasis +/- best seen as shadowing at us may be occult on CT images Wall thickness : > 3mm is abnormal but not specific Surrounding inflammation fat stranding ( CT) , hyperemia and hyperechoic fat ( USG) Pericholecystic fliud COMPLICATIONS : EMPYEMA GANGERENOUS EMPHYSEMATOUS GB PERFOARTION Axial CECT abdomen. The gallbladder has thick, enhancing walls with a hypodense rim of pericholecystic fluid. The lumen is filled with high density bile resulting in the calculi appearing as filling defects

20. UNCOMPLICATED

21. Cholecystitis : gangrenous

22. Cholecystitis : perforated Symptoms and clinical signs are variable and can range from benign non-specific abdominal symptoms to acute generalized peritonitis

23. Learning points : Perforation is the end result of gangrenous cholecystitis . Spillage of contents can result in peritonitis and abscesses. High moratality approaching 16% Hemorrhagic cholecystitis can occur from long standing gangrenous cholecystitis causing pseudoanueurysm formation in the cystic duct. . Identification of perforated cholecystitis with active bleeding prompted emergency surgery.

24. Cholecystitis : emphysematous Abdominal pain for 2 weeks

25. Caused by infection with gas forming bacteria. Most likely occur in diabetes patients. High morbidity and mortality. Gas at USG has a dirty posterior shadow compared to clean shadowing seen with calcified gall stones. Identification of perforated emphysematous cholecystitis directed the team towards emergent surgical management. Learning points :

26. SMALL BOWEL OBSTRUCTION Presentation : It includes complaints of abdominal pain, distention, nausea, and vomiting. Pain – progressive  or intermittent in nature. Bowel sounds may be reduced and high pitched . Causes :- Intrinsic : crohn disease, mass, vascular causes Extrinsic : adhesions (mc), hernias, metastatic implants, closed-loop obstruction Intra-luminal: foreign bodies, gallstones Diagnosis :- Small bowel diameter >2.5cm Transition zone with decompressed bowel distal to the obstruction Complications : Ischemia Perforation

27. Reporting tips : Transition point Location Severity High grade or complete: severe dilatation minimal distal gas or fluid Low grade or partial: mild dilatation, some distal gas and fluid Potential cause Intrinsic, extrinsic, intraluminal Is there a focal mass or peritoneal implant? Is there a closed-loop obstruction? Complications Closed-loop obstruction Ischemia or strangulation Perforation

28. Presenting with generalized abdominal pain, nausea and vomiting for 1 day SMALL BOWEL OBSTRUCTION - UNCOMPLICATED

29. LEARNING POINT : Adhesions are the most common cause of adult small bowel obstruction . Patients identified to have suspected adhesions may undergo conservative therapy with bowel rest and water-soluble contrast material challenge. If contrast material passes the area of obstruction, the patients are often discharged without the need for surgery. SMALL BOWEL FECES SIGN :- The “small bowel feces” sign refers to the presence of gas bubbles mixed with particulate matter in dilated loops proximal to the site of obstruction. This is a less common but reliable indicator of mechanical obstruction

30. SMALL BOWEL OBSTRUCTION : CLOSED LOOP OBSTRUCTION

31. Circumferential mural thickening of the dilated bowel loops with increased attenuation in the mesentery or bowel wall denotes the presence of strangulation. Fixed radial distribution of several dilated small bowel loops with stretched and prominent mesenteric vessels converging towards the point of torsion (whirl sign) with mesenteric edema indicates a small bowel volvulus . A target appearance on cross-section with a bowel-within-bowel appearance on longitudinal scans suggests a diagnosis of intussusception. Mesenteric fat and vessels can be identified within the mass and the lead point if present

32. Gastroduodenal perforation Causes : perforated ulcer disease is mcc. others are trauma, malignancy infection, ischemia. presentation  is sudden and severe abdominal pain, sometimes with localized peritonism or a rigid abdomen on examination. Diagnosis : On plain radiograph : free gas under the diaphragm   is a classic sign of pneumoperitoneum on the erect chest and abdomen radiographs and it is suspicious for bowel perforation Best diagnosed with CT images that show adjacent inflammatory fat strandings ,upper abdominal pnemoperitoneum . Complications :peritonitis is common due to acidic contents. abscess

33. Acute pancreatitis Acute pancreatitis   is an acute inflammation of the pancreas and potentially life-threatening. Classical Clinical presentation : acute onset of severe central epigastric pain (over 30-60 min) poorly localized tenderness and pain exacerbated by supine positioning radiates through to the back in 50% of patients Elevation of serum  amylase  and  lipase  are 90-95% specific for the diagnosis  (Rare) signs of hemorrhage on the physical exam include: Cullen sign : periumbilical bruising Grey-Turner sign : flank bruising

34. TYPES OF PANCREATITIS ACUTE PANCREATITIS CHRONIC PANCREATITIS 2 PHASES SEVERITY 2 TYPES (complications) LATE EARLY MILD MODERATE SEVERE OEDEMATOUS NECROTISING 1ST WEEK AFTER 1ST WEEK NO ORGAN FAILURE ORGAN FAILURE < 48 HR ORGAN FAILURE > 48 HR <4 wk : acute peripancreatic collection <4 wk : pseudocyst <4 wk : acute necrotic collection <4 wk : walled-off collection

35. Sentinel loop sign and colon cut-off sign in a similar plain abdominal radiograph.

36. USG : Enlarged heterogeneous pancreas shows anterior bowing and surface irregularity surrounded by a rim of peri-pancreatic fluid. Contrast-enhanced CT is the modality of choice not only to confirm the diagnosis or detect extrapancreatic intra-abdominal disease, but also to stage the severity of disease which is required for prognostication. It is also highly accurate for the detection of necrosis and complications

37. Diagnostic criteria Two of the following three criteria are required for the diagnosis : acute onset of persistent, severe epigastric pain (i.e. pain consistent with acute pancreatitis) lipase / amylase   elevation >3 times the upper limit of normal characteristic imaging features on contrast-enhanced CT, MRI, or ultrasound

38. ACUTE PANCREATITIS cont … increased pancreatic volume with a marked decrease in echogenicity volume increase quantified as a pancreatic body exceeding 2.4 cm in diameter, with marked anterior bowing and surface irregularity  decreased echogenicity secondary to fluid exudation, which may result in a marked heterogeneity of the parenchyma To identify gallstones as a possible cause Identify areas of necrosis that appear as hypoechoic regions Peripancreatic collections, pseudocysts, walled off necrotic collections Associated features like ascites, pleural effusion, air within peripancreatic collection suggestive of abscess formation.

39. ON ct

40. The CT shows an acute necrotizing pancreatitis. The body and tail of the pancreas do not enhance. There is normal enhancement of the pancreatic head (arrow).

41. RUPTURED ABDOMINAL AORTIC ANUERYSM Defect in all three walls of aorta. Rupture rate related to abdominal aortic aneurysm size > 7cm has a 20% risk of rupture per year. Mortality near 80% when ruptured. FINDINGS : Non contrast examination rapidly enlarging abdominal aortic aneurysm wall calcification discontunity Draped aorta sign Retroperitoneal hematoma Contrast examination : Active extravasation

42. Patients presented with acute abdominal pain and weakness Learning point : ruptured abdominal aortic aneurysm carries a high mortality with 50% of patients not reaching the hospital and up to 90% mortality for all patients. Prompt identification and communication is necessary to limit delay in care.

43. Young females in the reproductive age group with acute abdomen Ovarian torsion Ruptured ectopic pregnancy Fibroids if there is any torsion or degeneration of submucosal or subserosal fibroid Pelvic inflammatory disease Hemorrhage into a corpusluteal cyst or follicular cyst Ovarian vein thrombosis ( seen in postpartum period, recent abdo surgery, malignancy)

44. Ovarian torsion Ovarian torsion  occurs when the ovary rotates around its supporting ligaments, twisting and squashing the accompanying blood vessels and lymphatics. The term  adnexal torsion  is preferred because a portion of the fallopian tube is commonly torsed along with the ovary. Ultrasound is the initial imaging modality of choice. Sonographic features include: enlarged edematous globular ovary is the key finding  ovary >5 cm in maximum diameter or >20 cc in volume if the ovaries are normal in size and symmetric, torsion is unlikely. Peripherally displaced follicles with hyperechoic central stroma. Follicular ring sign    most likely due to hemorrhage in the thecal layer. Midline ovary position. Whirlpool sign   of twisted vascular pedicle is pathognomic .

45. An underlying ovarian lesion may be seen (possible lead point for torsion). Ovary tenderness to transducer pressure. Free pelvic fluid may be seen in >80% of cases. Doppler findings in torsion are widely variable  little or no ovarian venous flow (common; sensitivity of 100% and specificity of 97%)  absent arterial flow (a less common, sign of poor prognosis) absent or reversed diastolic flow normal vascularity does not rule out intermittent torsion normal Doppler flow can also occasionally be found due to dual supply from both the ovarian and uterine arteries

46. Mesenteric ischemia Causes Arterial Embolic (most common) Atherosclerosis with luminal narrowing and eventual thrombosis Venous Occlusion of the superior and/or inferior mesenteric vein Seen in hypercoagulable states or extension of portal vein thrombus Nonocclusive Diffuse bowel hypoperfusion , low flow states Diagnosis Bowel hypoenhancement , bowel wall thickening, dilatation, mesenteric edema Complications Bowel infarction and perforation Contrast-enhanced CT cine shows acute mesenteric ischemia with occlusion of the superior mesenteric artery. The bowel from the proximal jejunum through the ileum is thin-walled, non-enhancing, and dilated. Diffuse bowel pneumatosis and mesenteric venous gas are present. A wedge-shaped liver infarction was also present, suggesting an embolic cause.

47. Reporting Tips Involved bowel Distribution (defined territory or multifocal) Wall characteristics (thickened, thinned, hyperattenuated , hypoenhancing ) Patency of mesenteric vessels Focal occlusion Stenosis Presence of gas Pneumatosis, mesenteric venous gas, free air Additional infarcted organs Involvement of other organs such as liver, spleen, and renal infarcts suggest an embolic cause. Detect and report any potential embolic sources such as cardiac thrombi.

48. Mesenteric ischemia arterial

49. Learning point ! Thickening of bowel wall may be due to edema ( low attenuation) or intramural hemorrhage (high attenuation). With prolonged arterial ischemia, the bowel becomes dilated due to absent peristalsis and develops a “paper-thin” appearance.

50. Mesenteric ischemia : venous

51. Learning Point ! Venous thrombosis often occurs in the setting of hypercoagulability. A thickened bowel wall can be seen with both venous and arterial mesenteric ischemia, but mesenteric edema is more associated with venous occlusion. Venous occlusion can mimic findings of enteritis. Always evaluate the venous outflow. Mesenteric Ischemia: Venous This patient was deemed to be a poor surgical candidate due to decompensated cirrhosis. Systemic anticoagulation was attempted, but the patient further deteriorated with eventual perforation and transitioned to comfort care.

52. Large Bowel Obstruction Large Bowel Obstruction Less common than small bowel obstruction More insidious onset with high mortality and morbidity if not treated Diagnosis Dilated colon with a focal transition point and decompressed distal bowel Cecal diameter greater than 9 cm Remaining colon greater than 6 cm Causes Mass (most common), volvulus, stricture Other causes include inflammation, intussusception, stool impaction, hernias Complications Upstream dilatation leads to wall edema and ischemia, which can progress to infarction and perforation.

53. Reporting Tips Location of obstruction Length of obstructing segment Short (<10 cm) vs long (>10 cm) Longer segment favors nonmalignant causes Potential cause Evidence of mass Secondary signs such as a lymphadenopathy, carcinomatosis, or metastasis Volvulus Sigmoid colon (most common), cecum, or transverse colon (rare) Inflammation Diverticulitis, inflammatory bowel disease Complications Vascular compromise Pneumatosis Free air or fluid

54. Large bowel Obstruction: Malignant

55. Large bowel Obstruction: Volvulus

56. Companion Case: Sigmoid Volvulus Twisting of the sigmoid colon Because this is a distal obstruction, there is a diffuse distension involving most of the colon. This was managed with endoscopic decompression and was not a surgical case.

57. Large bowel Obstruction: Diverticulitis

58. diverticulitis Most common occurs in sigmoid colon but can occur in anywhere in Git . The tetrad of left lower quadrant pain and tenderness, fever and leukocytosis is the classic presentation of diverticulitis. CAUSES : bowel diverticula proposed cause is obstruction of diverticula from fecal matter leading to ischemia and inflammation of bowel. Diagnosis : barium enema : diverticulae , muscular wall hypertrophy, intramural or extramural mass effect , colonic obstruction ON CT : diverticulae , muscular wall hypertrophy, symmetrical mural thickening >4 mm, pericolonic fat stranding, phlegmon , extraluminal gas bubbles, extravasation of contrast in case of perforation and paracolic abscess formation. complications : perforation with diverticular abscess peritonitis

59. Reporting Tips Location of involvement Length of involvement Short (<10 cm) versus long (>10 cm) Long segment favors nonmalignant causes. Complication? Free air Abscess Peritonitis Obstruction Evidence of malignancy Mildly local lymph nodes may be reactive, but markedly enlarged or distant lymphadenopathy should be suspicious. Metastases, peritoneal implants

60. localized inflammation without evidence of perforation or drainable fliud collections to treat conservatively. DIVERTICULITIS : UNCOMPLICATED

61. Diverticulitis : perforated

62. Thank you