Chapter 77 - TAAA open repair Flashcards
Adam’s 1954 paraplegia rate in TAAA open repair
25%
DeBakey 1964 mortality rate in TAAA
50%
Crawford 1974 series of TAAA open repair
Mortality 8% paralysis 16% much improved since then
% of TAAA ruptures under 6 cm
13% rarely below 5.5 cm
Extracorporeal circulation in TAAA repair
Assisted circulation (left heart bypass): left atrial/left pulmonary cannula –> femoral artery Hypothermic cardiac arrest: femoral artery –> femoral vein/right atrium + left ventricular sump drain Cool pt to 16-18C Gott shunt: passive flow from aorta to aorta distally Axillofemoral bypass: passive flow
Anesthetic drug use in TAAA open repair
1) nitroprusside and hydralazine avoided for spinal ischemia 2) sodium bicarb when aorta occluded (0.05 meq/kg/min) 3) methylprednisolone after induction and naloxone after surgery 4) amnnitol before aortic occlusion and after renal reperfusion
Temperature for cooling during surgery
31-34 C
Spinal fluid pressure
< 6 mm during aortic occlusion
MAP during surgery
> 90 mm Hg
TAAA open surgery patient position
Lateral decubitus with left side up Shoulder vertical with pelvix tilted to access left femoral vessels
Rib space for different pathologies
Arch aneurysm = 5th Craford 1-2 = 5-6th Descending = 4th - 7th Type 3-4 = 8th or 9th space
Recurrent laryngeal nerve injury rate in TAAA repair
10% especially when proximal anast is proximal to left subclavian
TAAA exposure
1) cut through rib space as previously determined 2) cut diaphragm at aortic hiatus 3) spare phrenic nerve 4) ligate lumbar vein of left renal 5) retroperitoneal lift up kidney
Dose with hypothermic circulatory arrest heparin
400 units/kg
Condition before cross clamping
1) SBP < 100 2) temp < 34 3) spinal fluid pressure < 6 mmHg 4) MAP > 100
Cooling solution for kidney
300-400 ml of 4C renal perfusion solutio 12.5g mannitol and 1000 Units heparin/L of lactated ringers
Visceral renal reattachment in TAAA
Carrel patch keep narrow to avoid aneurysm SMA-CELIAC +/- right renal left renal alone Coselli branched graft for individual attachment - in connective tissue disease
Dye to test renal perfusion
Indigo carmine given IV to see in urine production
Number of intercostals to reimplant
2-4
Suturing dacron to endograft technique
FIGURE 77.12
Treatment of delayed weakness/paralysis
1) increase MAP 2) drain more spinal fluid 3) restart neuroprotective medication 4) maintain cardiac index
Greater radiculary
Arises from Artery of Adamkiewicz between T8-L2 (85%)
Factors associated with increased spinal paralysis
1) Cardiac index low 2) dissection etiology 3) C2 pathology 4) acute 5) age
Risk of paralysis by age after TAAA mortality
< 60 yo: 1.4% > 60 yo 5.7% MORTALY 0.7% 8.9%
Mathematical model for calculating expected paraplegia based on extent of aortic repair
BELOW FIGURE 77.15
Pulmonary complication after TAAA
27% 8-10% need trach
Mortality after TAAA by age
TABLE 77.3
Mortality by clamping modality and adjuncts in TAAA
TABLE 77.4
Mortality improvements TAAA elective vs urgent and age
Elective < 60 yo 0% > 80 yo 5.7% Urgent < 60 yo 1.6% > 80 yo 42.9% (with renal failure 67%)
Mortality improvements over time in TAAA
Era 1 - 11.34% Era 2 - 7.99% mostly improved because of paraplegia improvement
Post-taaa mortality due to renal failure
50-60%
Rate of permanent dialysis after TAAA with normothermic vs hypothermic
15% normothermic 0.8% hypothermic
Survival after TAAA
69-78% 1 year 45-68% 5 years
