1. Ruptured Abdominal Aortic Aneurysms
Eliza Long

2. Treatment of the Ruptured Abdominal Aortic Aneurysm
Diagnosis
Clinical
Imaging
Resuscitation
Surgery
Different options
Complications

3. Diagnosis Clinical Presentation
“Classic triad:”
Severe abdominal pain
Hypotention
An episode of syncope may be a hint
Pulsatile mass
Large girth may obscure
Less common symptoms:
Groin/flank pain, hematuria, groin hernia all secondary to increased intra-abdominal pressure
Congestive Heart Failure with JVD and abdominal bruit if patient has ruptured into the Vena Cava

4. 14 x 8 cm abdominal aortic aneurysm arising from the supraceliac aorta and extending to just above the take off of the left renal artery is visualized with extensive thrombus but also extensive flow

7. Diagnosis Clinical Presentation
RAAA is misdiagnosed 16% - 30% of the time
Common misdiagnosis:
Renal colic, perforated viscous, diverticulitis, gastrointestinal hemorrhage and ischemic bowel
Mortality rates for correctly diagnosed was 58%, and 44% for misdiagnosed
Likely due to fact that less severe ruptures have a more subtle presentation and can survive longer before going to OR

8. Diagnosis Imaging Plain Films Abdominal U/S Abdominal CT
Enlarged outline of calcified aortic wall
A retrospective review showed that 65% of x-rays form RAAA had calcified aortic wall
Loss of psoas shadow
Abdominal U/S
Sensitive in detecting aneurysm but not in detecting rupture
Abdominal CT
Most accurate method
See presence of retroperitoneal blood (77% sensitive and 100% specific)

9. Enlarged outline of calcified aortic wall
Loss of psoas shadow
Enlarged outline of calcified aortic wall

10. Sensitive in detecting aneurysm but not in detecting rupture

11. See presence of retroperitoneal blood
See presence of retroperitoneal blood. Here there is not a large retroperitoneal hematoma, but stranding of blood into surrounding tissues

12. Resuscitation If suspecting rAAA: Confirmed rAAA: 2 Large bore IVs
Type and Cross for at least 6 Units of pRBCs
Confirmed rAAA:
Transfer to Operating room (transfer to center with experienced surgeons prepared for rAAA)
Establish art line and foley
Prep and drape before and during anesthetic induction

13. Resuscitation Actual Pre-Op resuscitation Controversial
Aggressive crystalloid can elevate BP and cause rupture of temporary aortic seal that forms after initial rupture
Minimally resuscitate to “maintain conconsciousness” (~80 systolic) and use blood
No randomized trials testing the different degrees of resuscitation with rAAA
Animal studies show increased mortality when resuscitation occurs before control of hemorrhage

14. Surgery
OPEN TRANSPERITONEAL
OPEN RETROPERITONEAL
ENDOVASCULAR

15. Surgery Open Repair Hypotension No Hypotension
Inspect Retroperitoneum Reflect bowel and duodenum
Supraceliac Clamp
Pararenal Extensive Hematoma
No Hematoma
Careful Dissection for Infrarenal Control
Uncontrolled Bleeding Develops

16. Surgery Open Repair  TRANSPERITONEAL
Transperitoneal allows the fastest and easiest approach for Supraceliac clamp
Retract the left lobe of the liver to right to show supraceliac aorta at diaphragm
NG tube identifies esophagus and proximal stomach and retracts to the left
Enter lesser sac by opening gastrohepatic omentum
Aorta is found between crura of diaphragm and is clamped
Can reposition clamp to infrarenal neck of aneurysm once aneurysm is opened
or can make first anastamosis in aneurysm sac and then transfer clamp to graft to reperfuse kidneys and viscera.

17. Enter lesser sac by opening gastrohepatic omentum
Retract the left lobe of the liver to right to show supraceliac aorta at diaphragm
NG tube identifies esophagus and proximal stomach and retracts to the left
Enter lesser sac by opening gastrohepatic omentum

18. Sometimes crura may need to be split with electrocautery for appropriate visualization

19. Aorta is found between crura of diaphragm and is clamped

20. Surgery Open Repair  TRANSPERITONEAL
Supraceliac Clamp
Coordinate with anesthesia
after clamp “crank up” the resuscitation
before releasing supraceliac clamp prepare for hypotension
Advantages
quick solution to severe hypotension from intraperitioneal rupture.
avoids injury to renal and gonadal vein injury from blind dissection of infrarenal neck
Disadvantage
ischemic injury injury to liver, bowel, and kidneys

21. Surgery Open Repair  RETROPERITONEAL
ESPECIALLY for pararenal or suprarenal RAAA
10th interspace incision
1) Left colon mobilized to incise lateral peritoneal attachments.
2) Colon, pancreas, spleen, and kidney are elevated  access diaphragmatic crura.
3) Divide crura  access entire intra-abdominal aorta and visceral and renal vessels
4) May need a thoracoabdominal incision, or extra thoracic incision for the larger people, or the hostile abdomen

22. Surgery Open Repair  Extras
Brachial/femoral cut-down for occlusive balloon into aorta
Aortic compressor to supraceliac aorta if rapid control needed before establishing exposure for clamp
Aortocaval fistula  direct digital pressure above and below the fistula and suture of the fistula from within the sac
If iliac aneurysms are present leave alone unless ruptured, if so repair easiest first (allow for pelvic reperfusion)
Use cellsaver, its use is justified if anticipate large blood loss

23. Aortic compressor to supraceliac aorta if rapid control needed before establishing exposure for clamp

24. Surgery Open Repair  Anatomic abnormalities
Venous anomalies that can cause bleeeding during clamping:
Retroaortic renal vein
Circumaortic renal vein
Left-sided vena cava
Duplicate inferior vena cava
Horseshoe kidney
If at neck of aneurysm it prevents adequate exposure (another reason to perform supraceliac clamping)
Isthmus often contains renal tissue, collecting system and blood supply
If known before surgery, retroperitoneal approach

25. Surgery Open Repair Closing
25%-30% cases, the abdomen cannot be closed without significant tension from swollen bowel or retroperitoneal hematoma
Abdominal compartment syndrome (ACS) is bladder presser > 30cm H2O or 25mm Hg
Use early mesh to reduce incidence of multi organ failure from ACS
Especially with pre-op anemia, prolonged shock, pre-op cardiac shock, pre-op cardiac arrest, massive resuscitation, profound hypothermia, or severe acidosis
Use nonabsorbable mesh covered with plolyurethane
Early mesh closure vs takeback mesh resulted in 6% and 40% colon ischemia respectively

26. Surgery Endovascular Repair
Institution requirements:
1) Rapid CT scanning
For neck diameter, angulation, and iliac size
Only about 20-46% of rAAA are suitable for EVAR
2) Training
3) Devices
4) Suite for Endovascular procedure

27. Surgery Endovascular Repair
Stratagies for Repair:
Aorto-unifemoral graft  ipisalateral internal iliac exclusion and a femorofemoral crossover graft (Montefiore group)
Modular aortouniiliac and aortobiiliac
Now rupture kits for repair

28. Aorto-unifemoral graft
Endovascular Grafts and Other Image-Guided Catheter-Based Adjuncts to Improve the Treatment of Ruptured Aortoiliac AneurysmsTakao Ohki and Frank J. VeithAnn Surg October; 232(4): 466–479.

29. Modular aortouniiliac and aortobiiliac
Early Experience with the Talent™ Stent-Graft System for Endoluminal Repair of Abdominal Aortic AneurysmsFrank J. Criado, MD, Eric P. Wilson, MD, Eric Wellons, MD, Omran Abul-Khoudoud, MD, and Hari Gnanasekeram, MD Tex Heart Inst J. 2000; 27(2): 128–135.

30. Surgery Endovascular Repair
Anesthesia
Can use local (unless patients are squirming)
Don’t loose the sympathetic tone that can maintain pressure
Some start under local and convert to general for positioning and release of graft

31. Surgery Endovascular Repair
Mortality Rates  10% to 45%, but limited numbers of patients
Causes 
Colon ischemia
MOF
Continued hemorrage
Endoleaks are a much bigger problem in this setting as hemorrhage isn’t controlled

32. RAAA RE-EVALUATED (no.)
Table Reported Data on Ruptured Abdominal Aortic Aneurysms (RAAA) Treated by Endovascular Aneurysm Repair
FIRST AUTHOR
RAAA RE-EVALUATED (no.)
EVAR COMPLETED (%)
EVAR MORTALITY (%)
CONVERSION RATE (%)
Ohki, 25
100 10 20
Hinchliffe, 20019 85 45 15
Lachat, 57 37
9.5
Orend, 21 71 14 29
Resch, 19
Scharrer-Pamler, 24
12.5 4
Peppelenbosch, 40 65
Reichart, 23 17
Totals
219 18
8.5

33. Complications Local
Postoperative bleeding related to coagulapathy from hypothermia (12%-14%)
Limb ischemia  embolization from aortic debris, or clot formed in illiacs if retrograde flushing is not performed
Colonic ischemia (3%-13%) leads to mortality in 73%-100% of time
Degree and duration of hypotension
Patency of IMA
Collateral supply
Site of hematoma
Spinal Cord Injury: incidence 2.3%.
Interuption of pelvic blood supply, prolonged aortic cross-clamping, introperative hypotension, aortic embolization, internal iliac interuption

34. Complications Systemic
Respiratory Failure 
26-47% (mortality up to 68%)
High O2 requirements, increased lung permeability, decrease in lung compliance
Factors that predispose
Large shifts in fluid and blood
Pre-existing pulmonary dysfunction
Long cross-clamp time
Renal Dysfunction 
Incidence is 26-42% in patients in symptomatic aneurysms or rAAA
Higher with suprarenal cross-clamp, longer duration of cross-clamp, pre-existing renal dysfunction, shock, old age

35. Complications Systemic
Irreversible Shock 
10-15% of rAAA mortality
Irreversible state in which aortic clamping, aggressive fluid resuscitation, and inotropic support can fail to reverse hypotension
Cardiac Complications 
MI – mortality of 19-66%
Arrhythmias – mortality 46%
Cardiac arrest – mortality %
CHF – mortality of 41%
Common as patients usually have simultaneous cardiac dz

36. Complications Systemic
Liver Failure 
Due to hypoxic injury
Although the liver is robust; can deal with a large degree of hypoxic injury it still must reabsorb hematoma and the increase in metabolism that is required to do this
Patients usually develop jaundice on day 7
Multisystem Organ Failure 
Incidence of 64%
Most common cause of death after 48 hrs
Also referred to as a systemic inflammatory syndrome

37. Complications Systemic
Multisystem Organ Failure 
“Two hit” hypothesis
1) Hemorrhagic shock – first ischemic insult primes the inflammatory response
2) Aortic Clamping – second ischemic insult
3) Resuscitation – first reperfusion insult
4) Aortic unClamping – second reperfusion insult
Animal models support
PMNs primed by pre-op hemorrhage, and after operative repair there was further activation with elevations of oxidative burst.
These patients are walking into the hospital with oxidative injury

38. Mortality Between 43% to 70% depending on the study Predictors 
Scoring systems
POSSUM – 12 physiologic variables and 6 operative variables for calculated risk
Hardman index – Based on age, creatinine, hemoglobin, EKG evidence of ischemia, h/o loss of consciousness
Multiple Organ dysfunction score (based on respiratory, renal, hepatic, hematologic, neurologic, and cardiac)
Deaths bimodal
Those that died 48 after repair had sig increases in MODS
Renal failure followed by hepatic failure at Day 10 are at highest risk for mortality

39. PROBABILITY OF SURVIVAL (%)
Table Logistic Regression Model Showing the Interaction of Significant Preoperative and Intraoperative Variables That Predicted Early Survival After Ruptured Abdominal Aortic Aneurysm Repair
CREATININE (mg/dL)
CLAMP SITE
URINE OUTPUT (mL)
PROBABILITY OF SURVIVAL (%)
≤1.3
Infrarenal
≥200 90
1-199 76
>1.3 71
Suprarenal 65 52 46 39 33 23 18 15 6

40. MYOCARDIAL INFARCTION PROBABILITY OF SURVIVAL (%)
Logistic Regression Model Showing the Interaction of Significant Postoperative Complications That Predicted Early Survival After Ruptured Abdominal Aortic Aneurysm
MYOCARDIAL INFARCTION
RESPIRATORY FAILURE
COAGULOPATHY
RENAL DYSFUNCTION
PROBABILITY OF SURVIVAL (%) No 96
Yes 91 74 66
↑Cr 58 49 48 21 20 15
Dialysis 11 8 2 1
   
Cr, creatinine. Modified from Johnston KW: Ruptured abdominal aortic aneurysm: Six-year follow-up results of a multicenter prospective study. Canadian Society for Vascular Surgery Aneurysm Study Group. J Vasc Surg 19:888, 1994.
page 1486
page 1487

41. Conclusions
Diagnosis – Have RAAA on the differential, don’t miss the diagnosis
Resuscitation – Less is more until aorta is clamped
Surgery – Quick, safe exposure. Use a method that you are experienced with.
Complications – Expect them

42. I would like to end with one more aorta…
mine

44. If substantial hematoma prevents distal dissection use occlusive balloons placed from inside the aneurysm

45. Surgery Open Repair  TRANSPERITONEAL
Hypotention
Supraceliac Clamp
If no hypotension
Inspect Retroperitoneum Reflect bowel and duodenum
Pararenal Extensive Hematoma
SupraceliacClamp
If no hematoma
Careful Dissection for Infrarenal Control
Uncontrolled Bleeding Developes
SupraceliacClamp

46. She was evaluated for an intra-abdominal process because of abdominal pain. The patient was signed out to me by Dr. Lynn at the end of his shift. The patient suddenly called out to the nurse and was noted to be unresponsive. She was breathing shallow. I was called to the bedside. The patient appeared pale to me with pale conjunctivae. She was breathing shallow. Pulse oximetry was 100%. She had a paced rhythm of about 60. Blood pressure was 175/64. Her abdomen was mildly distended but otherwise soft. Because of the patient's shallow breathing and her low cognitive function, I immediately obtained an Accu-Chek, which was I was concerned about anemia, but the hemoglobin was 10. On the other hand, while we were assessing her, I got a call from the radiologist, who reported that the patient had a ruptured AAA. Advance directives did not show any DNR status. The patient was immediately updated to room 5 for resuscitation. Vascular Surgery was called and immediately came down. We were giving the patient oxygen, attempting a central line placement. O negative blood was ordered. The patient, however, was taken immediately up to a waiting operating room by the vascular surgeons. Transfer nurse helped take the patient up. Oxygen was given 100%.