Ruptured Abdominal Aortic Aneurysm.ppt - Ruptured Abdominal Aortic ...

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Ruptured Abdominal Aortic Aneurysm.ppt - Ruptured Abdominal Aortic ...

  1. 1. Sarah Alarabi PGY-2 7/28/2009
  2. 2. Cc: low back and right buttock pain HPI: 56M brought by ambulance to ED with a two day history of progressive low back pain. Patient has described it as occasionally sharp. He took ibuprofen and tylenol to help alleviate the pain to no avail. On the morning of his presentation, the pain radiated to the right buttock and became very sharp and unbearable enough to come to the ED. He began to feel weak upon his arrival. PMH: perforated ulcer PSH: ex lap for perforated ulcer with “patch” repair according to family members
  3. 3. SH: Smokes 1ppd Occassional ETOH No admitted hx of illicit drug use Allergies: NKDA Meds: ibuprofen and tylenol
  4. 4. Initial ED course prior to exam: Pt had arrived with bp 60/40 BP rose, without resuscitation, to 90/50 Pt underwent CT and surgery was called secondary to results PE: 128/90 92 50 afebrile Generally fatigued appearance Rapid rhythm Tachypniec, CTABL Distended, firm abdomen, +BSAFQ, no pulsatile mass on palpation
  5. 5. Aneurysm is defined as a permanent and irreversible localised dilation of a blood vessel At least 50% increase compared to normal M aorta 1.4-2.4 cm infrarenal aorta (AAA 3cm<) F 1.2-2.1 cm infrarenal aorta (AAA 2.6cm<)
  6. 6. First described in Ebers Papyrus (2000 BC) in peripheral arteries Antyllus performed first repair of aneurysm in 2nd century by incising it and evacuating its contents Hunter “fixed” a popliteal artery on a coachman by ligating it after concluding that the patient had developed enough collateral arteries for the limb to survive (1785) Cooper (one of Hunter’s pts) performed a similar repair for an iliac artery, but the pt did not survive the aortic ligation for more than 2d. Matas (from New Orleans) buttressed the vessels and ligated the collaterals, 1906 Carrell won Nobel prize 1912 for anastomoses techniques Debakey, Hopkins, Vorhess (prosthetic graft) added to the developments Juan Parodi introduced EVAR (endovascular aortic aneurysm repair) History
  7. 7. True  All 3 layers are involved False  (pseudoaneurysms) not all 3 layers By morphology  Fusiform: symmetrical  Saccular: only part of the circumference (higher risk for rupture) By etiology  Degenerative: by atherosclerotic changes  Congenital: rare  Other etiologies include mycotic infection, blunt trauma, iatrogenic  (most common site is infrarenal aorta, 65%)  (most common site peripherally is the popliteal, 70%)
  8. 8.  No single theory has been accepted  What we do know is the following:  90% are associated with athersclerosis  Elastin and collagen play a key role with respect to their degeneration  Elastases to memorise: MMP-2, 9, and 12 have increased expression in aneurysmal tissue (they return to normal levels once repair is made)  Histologically you will find a lot of plasma cells in the media & t cells in the adventitia, leading many to believe that cytokine release has a significant role in aneurysm formation  As many as 50% of aortic aneuryms demonstrate chlamydia pneumoniae  Genetics plays a role in 15-25% of pts  Enlargement is governed by Laplace’s Law:  T=PR (t=tangential stress, r=radius, p=transmural pressure)  This does not take into account wall thickness (where t=pr/gamma)  Pediatric diseases associated include:  Tuberous sclerosis, behcet disease, marfan syndrome, ehlers-danlos syndrome, infection from umbilical artery catheters
  9. 9. Most common in infrarenal region Classification: I – infrarenal II – juxtarenal III – pararenal IV – suprarenal Iliacs involved in 40% (90% of which are in common iliacs) Generally increasing in frequency secondary to increasing aging population and increase in diagnostic imaging
  10. 10. Exact cause is unknown Age Increases in M over 55 (peak at 6% in 80-85) Increase after 70 in F (peak at 4.5% in 90+) • Gender – 4-5:1 b/n 60-70, then 1:1 after 80 Race - Caucasian (2-3:1::C:B) Tobacco use – 78% assoc with tobacco (8:1) Family hx – 11:1 if first degree relative
  11. 11. Only 50% of ruptures arrive alive at the hospital 7% died before surgery 17% died during surgery 37% died within 30 days of surgery Overall mortality post op is 45%
  12. 12. Risk Factor Low Risk Avg Risk High Risk Diameter <5cm 5-6cm >6cm Expansion <0.3cm/yr 0.3-0.6cm/yr >0.6cm/yr Smoke/COPD None, mild Mod Sever/steroids FMH No relatives One rel Many rel’s HTN n/l bp Controlled Poorly controlled Shape Fusiform Saccular Very eccentric Gender Male female
  13. 13. Good Risk Moderate Risk High Risk >70 years 70-80 years 80 years Physically active Active Inactive, poor stamina No clinically overt cardiac disease Stable coronary disease; remote MI; EF >35% Sig. CAD, recent MI, freq. angina; CHF; EF <25% Creatinine 2.0-3.0 n/l anatomy Adverse anatomy or AAA characteristics Creatinine >3 No adverse AAA characteristics Liver disease (albumin <2) Anticipated operative mortality 1%-3% Anticipated operative mortality, 3%-7% Anticipated operative mortality, at least 5%- 10%; each comorbid condition adding approximately 3%-5% mortality risk
  14. 14. In a consecutive series of 180 pts w/ ruptured AAA,the following factors were independently related to the mortality rate:  age systolic BP < 80 mm Hg history of hypertension Angina myocardial infarction (MI) In pts who survived surg, causes of death were as follows:  Renal /multisystem failure (32%)  Cardiac failure (29%)  Resp failure (17%)  Coagulopathy (12%)  GI hemorrhage (3%)  Perf duod ulcer (1.5%)  Renal hemorrhage (1.5%)  Hemorrhage from graft anastomosis (1.5%)  Stroke (1.5%)  Aspiration (1.5%)
  15. 15. "Blue Toe Syndrome" Livedo Reticularis: Atheroemboli from small abdominal aortic aneurysms
  16. 16. In a series of 226 AAAs in Italy, bleeding occurred into the following regions: Retroperitoneal - 85.3% Peritoneal - 7.1% Inferior vena cava (IVC) or iliac vein - 5.8% Enteric - 1.8% ruptures into the retroperitoneum typically originate from the L posterior aspect of the AAA ruptures into the intestine tend to occur from the right anterior aspect
  17. 17.  Routine PE  Pulsatile mass  Radiographic study  Sx  Compression by bowel may cause early satiety/n/v  Chronic, vague abdominal/back pain  Severe/sharp/tearing back pain  groin pain  syncope, paralysis  flank mass  Ruptured Triad:  Sudden onset midabdominal/flank pain  Shock  Presence of a pulsatile abdominal mass  The diagnosis may be confused with renal calculus, diverticulitis, incarcerated hernia, or lumbar spine disease.
  18. 18. PE Firm, pulsatile abdominal mass “eggshell” calcification on plain film u/s CT with IV contrast is most precise Screening is encouraged for pts with risk factors due to the fact that 33% will rupture if undiagnosed; screening cuts risk of rupture by 49% Once found, if AAA is more than 4.5cm, continued monitoring every 6 months is recommended
  19. 19. Abdominal ultrasonography: used as prelim. determination of aneurysm presence, size, type, & extent. CT scanning: helps define anatomy of aneurysm & other intra-abdominal pathologies. location of the renal arteries length of the aortic neck condition of the iliac arteries anatomic variants (e.g. retroaortic left renal vein or horseshoe kidney) Enhanced spiral CT of abdomen & pelvis with multiplanar reconstruction & CT angiography is the test of choice for preop eval for open & endovascular repair Nonenhanced CT scanning is used to size aneurysms.
  20. 20. Reduce Risk factors Smoking cessation is of paramount importance Aggressively control HTN Institute beta-blocker tx, when possible, to reduce BP & stress on the artery wall. Repair if 5cm or more for men. Female pt unfortunately do not have a predetermined size for repair, although it is agreed that it is smaller than the size recommended for men.
  21. 21. AAA diametre (cm) Rupture risk (%/y) <4 0 4-5 o.5-5 5-6 3-15 6-7 10-20 7-8 20-40 >8 30-50
  22. 22. Transperitoneal Approach: Midabdominal incision is made, pertinent anatomy retracted, aneurysm opened, and graft sutured in place Retroperitoneal Approach: For pt’s with hostile abdomens (e.g. too many adhesions) Incision in 10th costal interspace, then on to similar procedure to TP approach
  23. 23. Prepare the skin from the nipples to the mid thigh. Administer general anesthesia (with or without epidural anesthesia). Cell Saver use has become popular. Place nasogastric tube. T & C blood. Administer prophylactic antibiotics (cefazolin, 1 g IVPB) Foley catheter Large-bore IV access Monitor CVP or establish Swan-Ganz catheterization (if indicated)
  24. 24. Depending pt's anatomy, the aorta can be reconstructed with: tube graft aortic iliac bifurcation graft Aortofemoral bypass
  25. 25. proximal infrarenal control: identify the L renal (patients may have a retroaortic vein, <5%). Division of L renal vein is usually required to clamp above the renal arteries inferior mesenteric artery is sacrificed To prevent colon ischemia, restore at least one hypogastric (internal iliac) artery perfusion If hypogastric arteries are sacrificed (associated aneurysms), reimplant the inferior mesenteric artery Identification of the ureters is important
  26. 26. Pt is heparinized (5000 U IV) prior to aortic cross- clamping. If significant intraluminal debris, juxtarenal thrombus, or prior peripheral embolization is present, the distal arteries are clamped first, followed by aortic clamping. Before restoring lower extremity blood flow, both forward flow (aortic) and back flow (iliac) are allowed to remove debris. The graft is also irrigated to flush out debris. Before the patient leaves the OR, determine lower extremity circulation. If a clot was dislodged at the time of aortic clamping, it can be removed with a Fogarty embolectomy catheter. Heparin reversal is not usually required.
  27. 27. By Catheterisation Intraoperative angiogram performed Very successful Very low risk But has distinct complications…
  28. 28. Requires CVP and vent placement CXR to confirm placement of above 24 hrs of beta-blockade to keep HR below 80 bpm Peri-operative Abx should be stopped within the first 24 hrs
  29. 29. Event Percentage of Patients Affected, % Case Fatality Rate, % Respiratroy failure 48 34 Tracheostomy 14 44 Renal Failure 29 76 Sepsis 24 45 MI/CHF 24 66 Bleeding 17 90 Stroke 6 50 Ischemic colitis 5 67 Lower extremity ischemia 3 17 Paraplegia/paraparesis 2 50
  30. 30. Death - 50% if ruptured Pneumonia - 5% MI - 2-5% Groin infxn - <5% Graft infxn - <1% Colon ischemia - 15-20% if ruptured Blue toe syndrome and cholesterol embolization to feet Renal failure related to preoperative creatinine level, intraoperative cholesterol embolization, & hypotension Incisional hernia - 10- 20% Bowel obstruction
  31. 31. Amputation from major arterial occlusion Impotence in males - Erectile dysfunction and retrograde ejaculation (>30%) Paresthesias in thighs from femoral exposure (rare) Lymphocele in groin - Approximately 2% Late graft enteric fistula
  32. 32. Type Causes Tx options I Inadequate seal of proximal or distal end of endograft Balloon dilation Placement of additional stents or cuffs Open conversion II Flow from backbleeding aa Pt lumbar, mid sacral, inf mesenteric, hypogastric, accessory renal aa Observation Coil embolisation or glue Laparoscopic ligation Open conversion III Fabric disruption or tear Module disconnection Placement of additional stents or cuffs Secondary endograft IV Flow from fabric porosity observation
  33. 33. Types of aortic stent grafts and their locations for use
  34. 34. Ali Azizzadeh; Martin A. Villa; Charles C. Miller III; Anthony L. Estrera; Sheila M. Coogan; Hazim J. Safi, 11/2008  Thirty-four publications representing 1,200 patients with RAAA analysed. Of the 1,200 patients 531 (44.3%) underwent endovascular aneurysm repair (EVAR average age was 74 years 13% were female Aortouni-iliac grafts were used in 49.4% of patients 50.6% received bifurcated grafts technical success rate was 94.9% The mortality rate following EVAR of RAAA is 30% 3.8% reduction in mortality was found for each 10% increase in the percentage of ruptures repaired endovascularly at each center
  35. 35. Baseline CT obtained at 3 months post Then 6, 12, and 18 months If leak is more than 5mm, then reintervention should be considered.
  36. 36. The long-term prognosis is related to associated comorbidities. Long-term survival is shortened by CHF & COPD. Rupture of assoc. thoracic aneurysms also causes late death.

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