Vascular Flashcards
Collateral path to provide blood flow to lower extremity in setting of complete aortoiliac occlusion?
Collaterals of Winslow: subclavian arteries connected to external iliac arteries through the internal mammary (superficial epigastric) and inferior epigastric
How does blood usually reach the foot when SFA is occluded?
Profunda collateralizes through the genicular artery to the popliteal artery
What clinical test is performed to evaluate the patency of ulnar and radial arteries?
Allen’s test
MC site of UE stenosis?
Subclavian artery
Tibioperoneal occlusive disease:
- -who is at increased disease?
- -why are these lesions more dangerous?
- -indications for surgery?
- -diabetes and Bueger’s disease
- -fewer collaterals
- -limb salvage and ischemic ulcers only
Surgical options for tibioperoneal disease?
Femorotibial or femoropopliteal bypass
Causes of UE occlusive disease?
Embolism Trauma Thoracic outlet syndrome Arteritis (Buerger's and Takayasu's) Vasospastic disorders (Raynaud's syndrome)
What is the procedure of choice for subclavian artery stenosis in a patient without carotid occlusive disease?
Common carotid to subclavian artery bypass with PTFE conduit
OR
Can transect the subclavian artery and transpose the distal end to perform an end-to-side anastomosis
Syme’s amputation
Amputation of the foot
Ray amputation
Removal of the MT head and digit of foot
Transmetatarsal amputation (TMA)
Foot amputation at the level of the metatarsals
Which flap as has the blood supply for a BKA - anterior or posterior?
Posterior flap - closer proximity to popliteal artery
Best type of suture for apposing the muscle fascia layer of a BKA or an AKA?
Absorbable (such as vicryl)
Best predictor of failure of a BKA to heal?
Absence of popliteal arterial pulsation on palpation or Doppler
What toe pressure is though to correlate with the failure of a TMA or toe amputation to heal?
Systolic toe pressures <45
How do plaques in carotid disease differ from those in vertebrobasilar disease?
Carotid: high incidence of ulcerated plaques
Vertebral: usually a smooth intimal surface
Drop attacks are associated with what disease?
Vertebrobasilar disease
Patient suddenly falls to the ground because of bilateral LE motor deficit (+/- LOC with rapid recovery)
Three main mesenteric arteries
Celiac: stomach to ampulla of vater (2nd portion of duodenum)
SMA: to the splenic flexure of the colon
IMA: to the rectum
Watershed areas of the colon
Splenic flexure
Branches of the celiac artery?
L gastric
Splenic
Common hepatic
First two branches of the SMA?
Inferior pancreaticoduodenal artery
Middle colic artery
Branches of the IMA?
L colic
Sigmoid
Superior rectal
Collateral pathway between celiac and SMA
Celiac –> Common hepatic –> GDA –> superior PD artery –> inferior PD artery –> SMA
Collateral pathway between SMA and IMA
SMA –> middle colic –> arch of Riolan –>left colic –> IMA
SMA –> marginal artery of Drummond –> IMA
Arch of Riolan (meandering mesenteric artery): runs pRoximal to mesenteric root
marginal artery of Drummond: runs Distal to mesenteric root
Renal arteries located at what lumbar level?
L1 to L2
Is the right renal artery anterior or posterior to the IVC?
Posterior
How is the right renal artery exposed intraoperatively?
Cattel and Kocher maneuvers (medial mobilization of the hepatic flexure of the colon and the third portion of the duodenum) +/- retraction of the IVC for exposure of the most proximal portion of the renal artery
MC site of visceral embolism causing acute mesenteric ischemia?
Proximal SMA
(at the SMA origin or at the takeoff of the middle colic artery)
SMA takeoff is at an acute angle
Symptoms of acute mesenteric ischemia?
severe abd pain, pain out of proportion to the signs on physical exam
When is bowel nonviability determined?
After the revascularization procedure
How is bowel viability assessed intraoperatively?
Gross exam: palpable pulses, pink color, visible peristalsis
Wood’s lamp inspection after IV fluorescein
Doppler US of mesenteric artery adjacent to the bowel in question
Classic angiographic findings for embolus/thrombosis/nonocclusive etiologies?
Embolus: abrupt occlusion with a meniscus sign, usually 5-8 cm from origin of SMA
Revascularization options/treatment for acute mesenteric ischemia
SMA thrombosis: mesenteric bypass or reimplantation of SMA to aorta
SMA embolism: embolectomy +/- SMA patch angioplasty
Non-occlusive mesenteric ischemia: correct underlying condition, consider catheter directed intraarterial infusion of vasodilator
Mesenteric bypass retrograde vs antegrade
Retrograde: from iliac artery or infrarenal aorta to SMA
Antegrade: from supraceliac aorta to SMA
What do the terms antegrade and retrograde refer to in describing aortovisceral bypass?
Site of aortic anastomosis with respect to the origin of the mesenteric vessel being bypassed
Antegrade - proximal to origin
Retrograde - distal to origin
Why is antegrade bypass preferred?
Longer-term patency
but retrograde is faster/easier
Why is mortality rate so high for acute mesenteric ischemia?
Delayed diagnosis
1 peripheral aneurysm
popliteal aneurysm
50% are bilateral
1/3 have AAA
1 visceral aneurysm
splenic aneurysm
Tx if >2 cm, child bearing age or planning pregnancy, or symptomatic
Bloody diarrhea first few days s/p AAA repair
Needs flex sig/colonoscopy to evaluate for ischemic colon (due to loss of IMA)
1 CN injury with CEA
vagus nerve –> hoarseness
fibromuscular dysplasia typical pt
young woman with HTN
usually R renal a.
tx: angioplasty
MC bacteria that cause mycotic AAA?
S. epidermidis
S. aureus
Salmonella
Classic physical exam finding of ruptured AAA?
Ecchymosis in the inguinal and groin region
What is graft material of choice for AAA?
Dacron (woven or knitted, +/- collagen impregnation)
2nd choice - PTFE
What are two surgical approaches for AAA repair?
Midline laparotomy
RP approach through L flank incision
In a patient with a ruptured AAA, what is first step after midline laparotomy?
What are the next steps?
Immediate compression of the supraceliac aorta against the vertebral bodies through the lesser sac
L crus of the diaphragm is divided, the supraceliac aorta is clamped, the neck of the AAA (usually infrarenal) is exposed and clamped, the supraceliac clamp is removed, and the graft is placed
What frequently obstructs access to the neck of the AAA in the transabdominal approach?
L renal vein
What is the presentation of aortocaval fistula?
High output CHF, hypotension, cyanosis, venous distension of the LE, abdominal bruit, and palpable abdominal thrill
What is the treatment of aortocaval fistula?
The fistula is closed:
- -Achieve proximal and distal control of the aorta and IVC
- -make and incision in the aortic graft
- -repair the fistula from within graft with large suture bites
- -close the aortic graft
What is excluded in the setting of pseudoaneurysm?
Graft infection
ACAS trial
asymptomatic, >60% stenosis
CEA reduces 5 year stroke rate from 11 to 5%
NASCET trial
symptomatic, >70% stenosis CEA reduces 5 year stroke rate from 26 to 9%
1 CN injury with CEA
Vagus nerve -> hoarseness
Atherosclerosis pathology
type I foam cells (lipids in macrophages; II fibrointimal lesion = smooth muscle proliferation due to mac’s growth factors; III: disruption exposes collagen -> thrombosis
