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Post operative management of vascular surgery patients
All vascular patients
- assess peripheral circulation including Doppler assessment of pulses and
ankle brachial index. This is the ratio of the Doppler BP at the ankle to the
Doppler BP in the brachial artery. In patients who have undergone aortic or
extra-anatomic reconstructions neither distal pulses nor Doppler signals may
be present because of vasoconstriction from hypothermia. In nearly all these
patients a signal will be audible in the feet once the patient becomes
normothermic (6-8 h). If the pulses remain absent at this time surgeon should
be informed. Doppler signal should always be present at the level of the
distal anastamosis for all reconstructions. For upper extremity of
infrainguinal reconstructions a Doppler signal is nearly always audible in the
wrist or foot in the immediate postoperative period
- cardiac monitoring: increased risk of cardiac complications
- control BP
- respiratory management: no evidence that "prophylactic"
ventilation reduces hospital stay or respiratory complications and patients
can be extubated in early postoperative phase
- analgesia
Problems common to all vascular reconstructions
Bleeding
- major bleeding uncommon
- wound bleeding: if superficial this is not usually associated with
significant swelling and the bleeding vessel can usually be seen
- intra-abdominal bleeding. Measurable increase in abdominal girth is a late
finding: detectable only after 2-3 l of blood have accumulated. In general
failure to stabilize after 2 units of packed cells over 2-3 h suggests
significant bleeding
Graft thrombosis
- incidence of early thrombosis: subclavian/vertebral 2%, aortic 3%,
axillofemoral 2-25%, fem-fem 0-13%, fem-pop 5-15%, fem-tib 15-30%
- most commonly due to technical error. Other causes include stenosis or
occlusion of distal outflow vessels, low cardiac output, graft compression,
small-diameter vein graft. Rarely due to hypercoagulable state
- diagnosis is suggested by disappearance of a pulse that was initially
present, disappearance of a Doppler signal or a change from a biphasic to a
monophasic signal. Decrease in ankle-brachial index from initial post-op value
to pre-op value is additional evidence. Clinical signs such as pallor, mottled
skin, coolness of peripheries unreliable in initial post-op period
- treatment: heparin 5000 U followed by thrombectomy and correction of any
technical error
Wound infection
Graft infection
Management of specific reconstructions
Carotid reconstruction
- BP: maintain systolic BP between 110 and 160
- Neurological assessment: detailed baseline assessment in ICU essential
before sedation
- antiplatelet therapy
- Complications
- Stroke/TIA:2-5%. Post-operative neurological complications most commonly
due to thrombosis of internal carotid or intracerebral embolism. Other
causes: ICH, cerebral hypoperfusion due to MI, cardiac arrhythmia, severe
bleeding, hypotension due to drugs
- Headache. Mild headache common. If severe and especially if associated
with symptoms of raised ICP consider ICH
- Nerve injuries: recurrent laryngeal 6.5%, hypoglossal 6%, marginal
mandibular 2% and superior laryngeal 2%. Rarely due to transection and 80%
recover within 3 months
- Thoracic duct injury in 3%
Aortic reconstruction
CXR of thoracic aortic aneurysm
Complications
- Clinically manifest in about 2% of elective cases but in up to 60% of
ruptured AAA repairs.
- High index of suspicion required to make an early diagnosis: essential if
death is to be prevented.
- Most common symptom is diarrhoea (75%). May be bloody and usually occurs
24-48 h post op. May occur up to 14 days post op.
- Other signs include marked increase in abdo pain, prolonged ileus with
abdo distention, tachycardia, hypotension, increased fluid requirement,
metabolic acidosis, raised WCC and platelets.
- Investigation: colonoscopy
- Treatment: if ischaemic lesions appear superficial and involve only mucosa
safe to observe patient with repeat colonoscopy. Otherwise colectomy
- proposed pathogenesis: ischaemia due to pancreatic emboli and mechanical
trauma during dissection of proximal aorta near left renal vein
- suspect in any patient who develops prolonged ileus (>5 days) or in any
patient with increased abdo pain, nausea and vomiting after starting oral
feeding
Renal artery reconstruction
- large volume deficit and high urine output (>300 ml/h) common in initial
post-op phase especially in patients who have undergone bilateral
reconstruction
- labile BP common
- complications
- renal artery stenosis/thrombosis. Signs include hypertension, renal failure,
flank pain due to renal infarction. However these signs may be present when
graft is patent. Equally patient may have no signs yet have an occluded graft.
Anuria despite adequate hydration requires urgent investigation
Further reading
Hurst JM, Frost RJ. Vascular surgery and trauma. In Civetta 2nd
ed, 1992
© Charles Gomersall July 1999
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