Difference between revisions of "Endovascular aortic repair"

From WikiAnesthesia
(Chart comparing thoracic and abdominal aortic aneurysms)
 
 
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{{Infobox surgical procedure
{{Infobox surgical procedure
| anesthesia_type = General vs neuraxial (endovascular abdominal aortic aneurysm repair) vs rarely, local with MAC
| anesthesia_type = General
| airway = ETT vs non-invasive O2
Neuraxial (for abdominal aneurysm)
| lines_access = PIV x 2 with at least 1 large bore (14-16 G), arterial line (right sided preferred)
Local with MAC (rare)
| monitors = Standard ASA monitors, 5-lead EKG, arterial line, TEE (endovascular thoracic aortic aneurysm repair)
| airway = ETT if general
| considerations_preoperative =  
| lines_access = PIV x 2 (at least 1 large bore (14-16 G)
| considerations_intraoperative =  
Arterial line (right sided preferred)
| considerations_postoperative =  
| monitors = Standard ASA monitors
5-lead EKG
Arterial line
TEE (for thoracic aneurysm)
| considerations_preoperative = Assess co-existing cardiovascular comorbidities
| considerations_intraoperative = Heparin for anticoagulation
Consider decrease BP immediately prior to stent  deployment and/or increase BP post-deployment
| considerations_postoperative = Monitor for spinal/intraabdominal ischemia due to graft occlusion
}}
}}


Endovascular stent grafting of aortic aneurysm is a surgical procedure by which a stent graft is deployed along the extent of the aortic lesion through vascular access commonly via the common femoral vessels. The stent graft protects the aneurysmal wall from high blood pressure in the aorta decreasing the risk of rupture. This procedure is indicated when aneurysm size is larger than 5.5 cm or if the growth rate of the aneurysm is 10 mm or more per year due to the increased risk of rupture<ref>{{Cite book|url=https://www.worldcat.org/oclc/1280374077|title=Stoelting's anesthesia and co-existing disease|date=2022|others=Roberta L. Hines, Stephanie B. Jones, Robert K. Stoelting|isbn=978-0-323-71861-5|edition=Eighth edition|location=Philadelphia, PA|oclc=1280374077}}</ref><ref name=":0">{{Cite journal|last=Cheruku|first=Sreekanth|last2=Huang|first2=Norman|last3=Meinhardt|first3=Kyle|last4=Aguirre|first4=Marco|date=2019-12|title=Anesthetic Management for Endovascular Repair of the Thoracic Aorta|url=https://pubmed.ncbi.nlm.nih.gov/31677680|journal=Anesthesiology Clinics|volume=37|issue=4|pages=593–607|doi=10.1016/j.anclin.2019.07.001|issn=1932-2275|pmid=31677680}}</ref>. Endovascular stent grafting of aortic aneurysm involves obtaining vascular access to allow introduction of stent deployment apparatus. Prior to introduction of stent deployment apparatus, systemic heparinization is provided. Fluoroscopy is performed with IV contrast to evaluate vascular anatomy and guide stent graft deployment apparatus placement.  Once the stent graft is deployed and fluoroscopy/TEE confirmed optimal placement without the presence of endoleak or aortic dissection, stent graft introducer is removed and vascular access sites are closed to obtain hemostasis <ref name=":0" />.
'''Endovascular aortic repair''' is a surgical procedure by which a stent graft is deployed along the extent of an aortic lesion through vascular access, typically via the common femoral vessels. The stent graft protects the aneurysmal wall from high blood pressure in the aorta decreasing the risk of rupture.


==Preoperative management==
Aortic repair is indicated when an aneurysm is at high risk of rupture, which is defined as<ref>{{Cite book|url=https://www.worldcat.org/oclc/1280374077|title=Stoelting's anesthesia and co-existing disease|date=2022|others=Roberta L. Hines, Stephanie B. Jones, Robert K. Stoelting|isbn=978-0-323-71861-5|edition=Eighth edition|location=Philadelphia, PA|oclc=1280374077}}</ref><ref name=":0">{{Cite journal|last=Cheruku|first=Sreekanth|last2=Huang|first2=Norman|last3=Meinhardt|first3=Kyle|last4=Aguirre|first4=Marco|date=2019-12|title=Anesthetic Management for Endovascular Repair of the Thoracic Aorta|url=https://pubmed.ncbi.nlm.nih.gov/31677680|journal=Anesthesiology Clinics|volume=37|issue=4|pages=593–607|doi=10.1016/j.anclin.2019.07.001|issn=1932-2275|pmid=31677680}}</ref>:


===Patient evaluation<!-- Describe the unique and important aspects of preoperative evaluation. Add or remove rows from the systems table as needed. -->===
*Size larger than 5.5 cm
*Growth of 10 mm or more per year
 
The procedure involves obtaining vascular access to allow the introduction of the stent deployment apparatus. Prior to the introduction of stent deployment apparatus, systemic heparinization is provided. Fluoroscopy is performed with IV contrast to evaluate vascular anatomy and guide stent placement. Once the stent graft is deployed and placement confirmed with fluoroscopy/TEE without the presence of endoleak or aortic dissection, the stent graft introducer is removed and vascular access sites are closed<ref name=":0" />.
 
== Preoperative management==
 
===Patient evaluation<!-- Describe the unique and important aspects of preoperative evaluation. Add or remove rows from the systems table as needed. --> ===
{| class="wikitable"
{| class="wikitable"
|+
|+
Line 20: Line 34:
|-
|-
|Neurologic
|Neurologic
|Assess for presence of history cerebrovascular disease or carotid stenosis by obtaining baseline neurologic exam especially strength of lower extremities and auscultation
|Assess for presence of history cerebrovascular disease or carotid stenosis by obtaining baseline neurologic exam, especially strength of lower extremities and auscultation.
|-
|-
|Cardiovascular
|Cardiovascular
|Assess for presence of myocardial ischemia, previous myocardial infarction, valvular dysfunction, heart failure and peripheral arterial disease. Obtaining baseline EKG and functional status assessment are mandatory. Review diagnostic transthoracic echocardiography (TTE) as most patients have completed as part of their workup. Exercise or pharmacologic stress testing or radionuclide imaging may be warranted in this patient population if there are any abnormal findings.
|Assess baseline functional status and evaluate for myocardial ischemia, previous myocardial infarction, valvular dysfunction, heart failure and peripheral arterial disease.
|-
|-
|Respiratory
|Pulmonary
|Assess for COPD, cigarette smoking, and reversible pulmonary pathology
|Assess for COPD, cigarette smoking, and reversible pulmonary pathology.


Smoking cessation of at least 8 weeks  
Smoking cessation of at least 8 weeks is optimal.
|-
|Gastrointestinal
|
|-
|Hematologic
|
|-
|-
|Renal
|Renal
|Preoperative hydration and avoidance of nephrotoxic drugs during the perioperative period are important to reduce the risk of kidney injury due to IV contrast used during the procedure.
|Preoperative hydration and avoidance of nephrotoxic drugs during the perioperative period are important to reduce the risk of kidney injury due to IV contrast used during the procedure.
|-
|Endocrine
|
|-
|Other
|
|}
|}


===Labs and studies<!-- Describe any important labs or studies. Include reasoning to justify the study and/or interpretation of results in the context of this procedure. If none, this section may be removed. -->===
===Labs and studies<!-- Describe any important labs or studies. Include reasoning to justify the study and/or interpretation of results in the context of this procedure. If none, this section may be removed. -->===


*Type and screen in the occasion that transfusion is needed
*Type and screen
*Contrast-enhanced spiral CT scans of the thorax and thoracic aortography to assess the dimensions of the aneurysms
*Contrast-enhanced spiral CT scans of the thorax and thoracic aortography to assess the dimensions of the aneurysms
**This allows for the assessment of adequate proximal and distal neck for surgical planning. The CT scan also helps assess the adequacy of the vessel used for vascular access for the stent introducer system
**This allows for the assessment of adequate proximal and distal neck for surgical planning. The CT scan also helps assess the adequacy of the vessel used for vascular access for the stent introducer system
*EKG to assess for any myocardial ischemia or previous infarction
* EKG to assess for any myocardial ischemia or previous infarction
*TTE to assess valvular disease, size and extent of aneurysm, and LV function
*TTE to assess valvular disease, size and extent of aneurysm, and LV function
* Exercise or pharmacologic stress testing or radionuclide imaging may be warranted
=== Operating room setup<!-- Describe any unique aspects of operating room preparation. Avoid excessively granular information. Use drug classes instead of specific drugs when appropriate. If none, this section may be removed. -->===


===Operating room setup<!-- Describe any unique aspects of operating room preparation. Avoid excessively granular information. Use drug classes instead of specific drugs when appropriate. If none, this section may be removed. -->===
* Arterial catheter and transducer
* Hotline on fluid warmer
* Infusion pumps
* Vasopressor infusions available (usually norepinephrine on pump)
* Push dose pressors drawn up
* Heparin and protamine
* +/- lumbar drain setup
* Heated circuit (if available)


===Patient preparation and premedication<!-- Describe any unique considerations for patient preparation and premedication. If none, this section may be removed. -->===
===Patient preparation and premedication<!-- Describe any unique considerations for patient preparation and premedication. If none, this section may be removed. -->===


*IV midazolam for anxiety
*IV midazolam (+/- Fentanyl) for anxiety
*PO acetaminophen for pain control
*PO acetaminophen for pain control


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Spinal and/or epidural may be considered for endovascular abdominal aortic aneurysm repair <ref name=":1">{{Cite book|url=https://www.worldcat.org/oclc/1117874404|title=Anesthesiologist's manual of surgical procedures|date=2020|others=Richard A. Jaffe, Clifford A. Schmiesing, Brenda Golianu|isbn=978-1-4698-2916-6|edition=Sixth edition|location=Philadelphia|oclc=1117874404}}</ref>
Spinal and/or epidural may be considered for endovascular abdominal aortic aneurysm repair <ref name=":1">{{Cite book|url=https://www.worldcat.org/oclc/1117874404|title=Anesthesiologist's manual of surgical procedures|date=2020|others=Richard A. Jaffe, Clifford A. Schmiesing, Brenda Golianu|isbn=978-1-4698-2916-6|edition=Sixth edition|location=Philadelphia|oclc=1117874404}}</ref>


==Intraoperative management==
If lumbar drain needed, usually placed by VIR and capped the day prior. When entering the OR, attach the lumbar drain chamber tubing to the lumbar drain before laying the patient down to ensure adequate CSF flow. Once the patient is supine on the OR bed, check again that CSF is freely flowing. At this point, make sure the transducer is zeroed to the level of the subarachnoid space (typically even with the level of the ear).
 
== Intraoperative management==


===Monitoring and access<!-- List and/or describe monitors and access typically needed for this case. Please describe rationale for any special monitors or access. -->===
===Monitoring and access<!-- List and/or describe monitors and access typically needed for this case. Please describe rationale for any special monitors or access. -->===
Line 70: Line 84:
*Standard ASA monitors
*Standard ASA monitors
*5-lead EKG
*5-lead EKG
*Arterial line is required as it allows prompt vasopressor titration in response to blood pressure change, particularly just prior to stent deployment and post stent deployment  
* Arterial line is required as it allows prompt vasopressor titration in response to blood pressure change, particularly just prior to stent deployment and post stent deployment  
**Right sided preference as left sided vascular access from the surgical team may be needed allowing for an easier approach to the aorta compared to right sided approach. Also, the stent graft may block the L subclavian artery leading to false reading <ref name=":1" />
**Right sided preference as left sided vascular access from the surgical team may be needed allowing for an easier approach to the aorta compared to right sided approach. Also, the stent graft may block the L subclavian artery leading to false reading <ref name=":1" />
*TEE used to assist in the identification of aneurysm necks, monitor the deployment of the stent graft, endoleaks status post deployment, and aortic dissection (Endovascular Thoracic Aneurysm Repair)
*TEE used to assist in the identification of aneurysm necks, monitor the deployment of the stent graft, endoleaks status post deployment, and aortic dissection (Endovascular Thoracic Aneurysm Repair)
*Urine output monitoring in the setting of possible renal vessel occlusion from deployment of stent graft and contrast induced nephropathy
*Urine output monitoring in the setting of possible renal vessel occlusion from deployment of stent graft and contrast induced nephropathy
*Spinal drain monitoring if placed for high risk patient undergoing endovascular thoracic aneurysm stent grafting
*Spinal drain (a.k.a. lumbar drain) CSF draining and pressure monitoring if placed for high risk patient undergoing endovascular thoracic aneurysm stent grafting
*Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) may be used to assess for spinal ischemia for patient undergoing endovascular thoracic stent grafting<ref name=":0" />
*Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) may be used to assess for spinal ischemia for patient undergoing endovascular thoracic stent grafting<ref name=":0" />
*At Least 1 large bore IV (14-16G) in the situation of bleeding from vascular injury or rupture
*At Least 1 large bore IV (14-16G) given risk of vascular injury or rupture


===Induction and airway management<!-- Describe the important considerations and general approach to the induction of anesthesia and how the airway is typically managed for this case. -->===
===Induction and airway management<!-- Describe the important considerations and general approach to the induction of anesthesia and how the airway is typically managed for this case. -->===


*Most common anesthesia type is general anesthesia
*Most common anesthesia type is general anesthesia
**Standard induction with propofol or etomidate, short acting opioid to blunt sympathetic response, neuromuscular blockade for endotracheal intubation
**May need to reverse neuromuscular blockade if neuromonitoring is used
*If regional anesthesia is chosen, minimal to deep sedation with midazolam, fentanyl, propofol or dexmedetomidine is reasonable.
*If neuraxial anesthesia is chosen, supplement with minimal to deep sedation as needed
*Rarely, local anesthetic placement by the surgical team with monitored anesthesia care is implemented depending on patient cooperativity. Minimal to deep sedation is reasonable
*Rarely, local anesthetic placement by the surgical team with monitored anesthesia care is used, depending on patient cooperativity.


===Positioning<!-- Describe any unique positioning considerations, including potential intraoperative position changes. If none, this section may be removed. -->===
===Positioning<!-- Describe any unique positioning considerations, including potential intraoperative position changes. If none, this section may be removed. -->===
Line 93: Line 107:
*Volatile anesthetics supplemented with opioids for analgesia if neuromonitoring is not used
*Volatile anesthetics supplemented with opioids for analgesia if neuromonitoring is not used
*If neuromonitoring is used, 0.5 MAC of volatile anesthetic supplemented by IV anesthetic/opioids or TIVA and avoiding neuromuscular blockade after intubating dose
*If neuromonitoring is used, 0.5 MAC of volatile anesthetic supplemented by IV anesthetic/opioids or TIVA and avoiding neuromuscular blockade after intubating dose
*Administration of heparin
*Administration of heparin prior to introducer insertion


*Verification of activated clotting time (ACT) throughout the case with goal of 200 seconds until introducer is removed <ref name=":0" />
*Verification of activated clotting time (ACT) throughout the case with goal of 200 seconds until introducer is removed <ref name=":0" />
*Maintenance of baseline MAP as this patient population have increase risk of CVA, MI, aortic dissection, and paraplegia
* Maintenance of baseline MAP as this patient population have increase risk of CVA, MI, aortic dissection, and paraplegia
*Just prior to stent deployment, BP must be decrease to reduce the risk of graft migration during deployment with vasodilators
*Just prior to stent deployment, BP must be decrease to reduce the risk of graft migration during deployment with vasodilators
*Post stent graft deployment, BP is increased to ensure perfusion especially if there is a risk of spinal ischemia with vasopressors
*Post stent graft deployment, BP is increased to ensure perfusion especially if there is a risk of spinal ischemia with vasopressor
*Closed loop communication with surgical team regarding heparinization and ACT monitoring
*'''Spinal cord ischemia is a rare, but devastating complication of both open and endovascular aortic aneurysm repair. Incidence in EVAR has been reported as 0.21%'''<ref>Koda Y, Yamanaka K, Omura A, Gentsu T, Yamaguchi M, Okada K. Spinal cord ischemia after elective endovascular abdominal aortic aneurysm repair in a patient with multiple occlusions of the intercostal and internal iliac arteries. J Vasc Surg Cases Innov Tech. 2022 Jul 9;8(3):447-449. doi: 10.1016/j.jvscit.2022.06.007. PMID: 36016702; PMCID: PMC9395748.</ref> '''and up to 6.9% in TEVAR'''<ref>Toshifumi Hiraoka, Tatsuhiko Komiya, Hiroshi Tsuneyoshi, Takeshi Shimamoto, Risk factors for spinal cord ischaemia after thoracic endovascular aortic repair, ''Interactive CardioVascular and Thoracic Surgery'', Volume 27, Issue 1, July 2018, Pages 54–59, <nowiki>https://doi.org/10.1093/icvts/ivy037</nowiki></ref>
*'''Remember that spinal cord perfusion pressure is equal to the mean arterial pressure minus the cerebral spinal cord pressure (SCPP = MAP - ICP)'''
*'''The most common mitigation strategy is blood pressure augmentation (increasing MAP) with MAP goals usually >90'''
**SCI is multifactorial, but in endovascular repair, it is usually thought to be the result of the permanent interruption, by covering with the stent, of sufficient sources of cord blood supply to render a portion of the cord nonviable - these sources include the segmental arteries, artery of Adamkiewicz, subclavian, and hypogastric arteries - as well as decrease of pressure in those arteries, by major bleeding or other causes of shock<ref name=":03">Randall B. Griepp, Eva B. Griepp, Spinal cord protection in surgical and endovascular repair of thoracoabdominal aortic disease, The Journal of Thoracic and Cardiovascular Surgery, Volume 149, Issue 2, Supplement, 2015, Pages S86-S90, ISSN 0022-5223, <nowiki>https://doi.org/10.1016/j.jtcvs.2014.10.056</nowiki>. (<nowiki>https://www.sciencedirect.com/science/article/pii/S002252231401561X</nowiki>)</ref>
**Episodes of delayed paraplegia/paraparesis have been reversed by increasing blood pressure and cardiac output. Clearly, both an increase in arterial pressure and a decrease in CSF pressure result in a net increase in perfusion of the spinal cord. Similarly, because central venous pressure and CSF pressure are—at least in part—additive in increasing outflow pressure from the spinal canal, it is important to avoid hemodynamic management strategies that entail high venous pressure<ref name=":03" />
*Larger grafts will cover more of the arteries that supply the spinal cord and, therefore, increase the risk of ischemia. '''In these higher risk cases, a lumbar drain can be used to drain CSF, lowering the ICP, and, therefore, increasing the spinal cord perfusion pressure.''' Whether CSF drainage improves outcomes is not entirely clear<ref>Wong C S, Healy D, Canning C, Coffey J C, Boyle J R, Walsh S R. A systematic review of spinal cord injury and cerebrospinal fluid drainage after thoracic aortic endografting. J Vasc Surg. 2012;56(05):1438–1447.</ref>
**Drainage can be set to an ICP threshold after the drain transducer is "zeroed" to the patients spine (i.e., the drain will drain CSF when the ICP is greater than 12mmHg)
**Drainage can be set as a volume per hour (i.e., drain 10ml per hour)
**Overly aggressive CSF drainage carries a risk of intracranial hemorrhage (related to tearing bridging vessels). This risk can be minimized by not draining more than 20ml per hour and/or targeting ICP of 8-10mmHg<ref>Ellauzi H, Arora H, Elefteriades JA, Zaffar MA, Ellauzi R, Popescu WM. Cerebrospinal Fluid Drainage for Prevention of Spinal Cord Ischemia in Thoracic Endovascular Aortic Surgery-Pros and Cons. Aorta (Stamford). 2022 Dec;10(6):290-297. doi: 10.1055/s-0042-1757792. Epub 2022 Dec 20. PMID: 36539146; PMCID: PMC9767776.</ref>
*Occasionally (rarely at UNC), somatosensory evoked potentials (SSEPs) and/or motor evoked potentials (MEPs) may be used to monitor for SCI<ref>Cheruku, Sreekanth; Huang, Norman; Meinhardt, Kyle; Aguirre, Marco (2019-12). "Anesthetic Management for Endovascular Repair of the Thoracic Aorta". ''Anesthesiology Clinics''. 37 (4): 593–607. doi:10.1016/j.anclin.2019.07.001. ISSN 1932-2275. <nowiki>PMID 31677680</nowiki>.</ref>
*Because of its more tenuous blood supply, the anterior two-thirds of the spinal cord are most at risk for ischemia which presents as a painful myelopathy known as anterior spinal artery syndrome


===Emergence<!-- List and/or describe any important considerations related to the emergence from anesthesia for this case. -->===
===Emergence<!-- List and/or describe any important considerations related to the emergence from anesthesia for this case. -->===
Line 105: Line 131:
*Reversal of neuromuscular blockade if used
*Reversal of neuromuscular blockade if used
*Assessment of hip flexion if spinal cord is at risk for ischemia
*Assessment of hip flexion if spinal cord is at risk for ischemia
*Reversal of heparin with protamine with confirmation of ACT returning to normal value
* Reversal of heparin with protamine with confirmation of ACT returning to normal value
*Maintain BP goals


==Postoperative management==
==Postoperative management==
Line 111: Line 138:
===Disposition<!-- List and/or describe the postoperative disposition and any special considerations for transport of patients for this case. -->===
===Disposition<!-- List and/or describe the postoperative disposition and any special considerations for transport of patients for this case. -->===


*PACU
*PACU then floor
*Floor
* Consider ICU if intraoperative complications occur
*If any complications requiring ICU, then ICU


===Pain management<!-- Describe the expected level of postoperative pain and approaches to pain management for this case. -->===
===Pain management<!-- Describe the expected level of postoperative pain and approaches to pain management for this case. -->===
Line 131: Line 157:
*Vascular injury
*Vascular injury
*Graft migration
*Graft migration
*Stent frame fractures
* Stent frame fractures
*Breakdown of graft material
*Breakdown of graft material
*Spinal cord ischemia or infarction secondary to occlusion of intercostal arteries
*Spinal cord ischemia or infarction secondary to occlusion of intercostal arteries
*Intra-abdominal ischemia secondary to occlusion of vessels supplying the gastro-intestinal organ including the celiac artery, superior mesenteric artery, inferior mesenteric artery, and renal arteries
* Intraabdominal ischemia secondary to occlusion of vessels supplying the gastro-intestinal organ including the celiac artery, superior mesenteric artery, inferior mesenteric artery, and renal arteries


*Bleeding from groin site or retroperitoneal bleeding
*Bleeding from groin site or retroperitoneal bleeding
Line 148: Line 174:
|-
|-
|Unique considerations
|Unique considerations
|Use of TEE and possible neuro-monitoring and lumbar drain
|Use of TEE and possible neuromonitoring and lumbar drain
|
|Neuraxial anesthesia possible
|-
|-
|Position
|Position
Line 168: Line 194:
|-
|-
|Pain management
|Pain management
|Multimodal  
| Multimodal
|Multimodal
|Multimodal
|-
|-
|Potential complications
|Potential complications
|Paraplegia
|Paraplegia
|Intra-abdominal ischemia/infarction
|Intraabdominal ischemia/infarction
|}
|}



Latest revision as of 06:57, 12 November 2024

Endovascular aortic repair
Anesthesia type

General Neuraxial (for abdominal aneurysm) Local with MAC (rare)

Airway

ETT if general

Lines and access

PIV x 2 (at least 1 large bore (14-16 G) Arterial line (right sided preferred)

Monitors

Standard ASA monitors 5-lead EKG Arterial line TEE (for thoracic aneurysm)

Primary anesthetic considerations
Preoperative

Assess co-existing cardiovascular comorbidities

Intraoperative

Heparin for anticoagulation Consider decrease BP immediately prior to stent deployment and/or increase BP post-deployment

Postoperative

Monitor for spinal/intraabdominal ischemia due to graft occlusion

Article quality
Editor rating
In development
User likes
0

Endovascular aortic repair is a surgical procedure by which a stent graft is deployed along the extent of an aortic lesion through vascular access, typically via the common femoral vessels. The stent graft protects the aneurysmal wall from high blood pressure in the aorta decreasing the risk of rupture.

Aortic repair is indicated when an aneurysm is at high risk of rupture, which is defined as[1][2]:

  • Size larger than 5.5 cm
  • Growth of 10 mm or more per year

The procedure involves obtaining vascular access to allow the introduction of the stent deployment apparatus. Prior to the introduction of stent deployment apparatus, systemic heparinization is provided. Fluoroscopy is performed with IV contrast to evaluate vascular anatomy and guide stent placement. Once the stent graft is deployed and placement confirmed with fluoroscopy/TEE without the presence of endoleak or aortic dissection, the stent graft introducer is removed and vascular access sites are closed[2].

Preoperative management

Patient evaluation

System Considerations
Neurologic Assess for presence of history cerebrovascular disease or carotid stenosis by obtaining baseline neurologic exam, especially strength of lower extremities and auscultation.
Cardiovascular Assess baseline functional status and evaluate for myocardial ischemia, previous myocardial infarction, valvular dysfunction, heart failure and peripheral arterial disease.
Pulmonary Assess for COPD, cigarette smoking, and reversible pulmonary pathology.

Smoking cessation of at least 8 weeks is optimal.

Renal Preoperative hydration and avoidance of nephrotoxic drugs during the perioperative period are important to reduce the risk of kidney injury due to IV contrast used during the procedure.

Labs and studies

  • Type and screen
  • Contrast-enhanced spiral CT scans of the thorax and thoracic aortography to assess the dimensions of the aneurysms
    • This allows for the assessment of adequate proximal and distal neck for surgical planning. The CT scan also helps assess the adequacy of the vessel used for vascular access for the stent introducer system
  • EKG to assess for any myocardial ischemia or previous infarction
  • TTE to assess valvular disease, size and extent of aneurysm, and LV function
  • Exercise or pharmacologic stress testing or radionuclide imaging may be warranted

Operating room setup

  • Arterial catheter and transducer
  • Hotline on fluid warmer
  • Infusion pumps
  • Vasopressor infusions available (usually norepinephrine on pump)
  • Push dose pressors drawn up
  • Heparin and protamine
  • +/- lumbar drain setup
  • Heated circuit (if available)

Patient preparation and premedication

  • IV midazolam (+/- Fentanyl) for anxiety
  • PO acetaminophen for pain control

Regional and neuraxial techniques

Spinal and/or epidural may be considered for endovascular abdominal aortic aneurysm repair [3]

If lumbar drain needed, usually placed by VIR and capped the day prior. When entering the OR, attach the lumbar drain chamber tubing to the lumbar drain before laying the patient down to ensure adequate CSF flow. Once the patient is supine on the OR bed, check again that CSF is freely flowing. At this point, make sure the transducer is zeroed to the level of the subarachnoid space (typically even with the level of the ear).

Intraoperative management

Monitoring and access

  • Standard ASA monitors
  • 5-lead EKG
  • Arterial line is required as it allows prompt vasopressor titration in response to blood pressure change, particularly just prior to stent deployment and post stent deployment
    • Right sided preference as left sided vascular access from the surgical team may be needed allowing for an easier approach to the aorta compared to right sided approach. Also, the stent graft may block the L subclavian artery leading to false reading [3]
  • TEE used to assist in the identification of aneurysm necks, monitor the deployment of the stent graft, endoleaks status post deployment, and aortic dissection (Endovascular Thoracic Aneurysm Repair)
  • Urine output monitoring in the setting of possible renal vessel occlusion from deployment of stent graft and contrast induced nephropathy
  • Spinal drain (a.k.a. lumbar drain) CSF draining and pressure monitoring if placed for high risk patient undergoing endovascular thoracic aneurysm stent grafting
  • Somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) may be used to assess for spinal ischemia for patient undergoing endovascular thoracic stent grafting[2]
  • At Least 1 large bore IV (14-16G) given risk of vascular injury or rupture

Induction and airway management

  • Most common anesthesia type is general anesthesia
    • May need to reverse neuromuscular blockade if neuromonitoring is used
  • If neuraxial anesthesia is chosen, supplement with minimal to deep sedation as needed
  • Rarely, local anesthetic placement by the surgical team with monitored anesthesia care is used, depending on patient cooperativity.

Positioning

  • Supine +/- slight right lateral decubitus (endovascular thoracic aortic aneurysm repair)

Maintenance and surgical considerations

  • Volatile anesthetics supplemented with opioids for analgesia if neuromonitoring is not used
  • If neuromonitoring is used, 0.5 MAC of volatile anesthetic supplemented by IV anesthetic/opioids or TIVA and avoiding neuromuscular blockade after intubating dose
  • Administration of heparin prior to introducer insertion
  • Verification of activated clotting time (ACT) throughout the case with goal of 200 seconds until introducer is removed [2]
  • Maintenance of baseline MAP as this patient population have increase risk of CVA, MI, aortic dissection, and paraplegia
  • Just prior to stent deployment, BP must be decrease to reduce the risk of graft migration during deployment with vasodilators
  • Post stent graft deployment, BP is increased to ensure perfusion especially if there is a risk of spinal ischemia with vasopressor
  • Closed loop communication with surgical team regarding heparinization and ACT monitoring
  • Spinal cord ischemia is a rare, but devastating complication of both open and endovascular aortic aneurysm repair. Incidence in EVAR has been reported as 0.21%[4] and up to 6.9% in TEVAR[5]
  • Remember that spinal cord perfusion pressure is equal to the mean arterial pressure minus the cerebral spinal cord pressure (SCPP = MAP - ICP)
  • The most common mitigation strategy is blood pressure augmentation (increasing MAP) with MAP goals usually >90
    • SCI is multifactorial, but in endovascular repair, it is usually thought to be the result of the permanent interruption, by covering with the stent, of sufficient sources of cord blood supply to render a portion of the cord nonviable - these sources include the segmental arteries, artery of Adamkiewicz, subclavian, and hypogastric arteries - as well as decrease of pressure in those arteries, by major bleeding or other causes of shock[6]
    • Episodes of delayed paraplegia/paraparesis have been reversed by increasing blood pressure and cardiac output. Clearly, both an increase in arterial pressure and a decrease in CSF pressure result in a net increase in perfusion of the spinal cord. Similarly, because central venous pressure and CSF pressure are—at least in part—additive in increasing outflow pressure from the spinal canal, it is important to avoid hemodynamic management strategies that entail high venous pressure[6]
  • Larger grafts will cover more of the arteries that supply the spinal cord and, therefore, increase the risk of ischemia. In these higher risk cases, a lumbar drain can be used to drain CSF, lowering the ICP, and, therefore, increasing the spinal cord perfusion pressure. Whether CSF drainage improves outcomes is not entirely clear[7]
    • Drainage can be set to an ICP threshold after the drain transducer is "zeroed" to the patients spine (i.e., the drain will drain CSF when the ICP is greater than 12mmHg)
    • Drainage can be set as a volume per hour (i.e., drain 10ml per hour)
    • Overly aggressive CSF drainage carries a risk of intracranial hemorrhage (related to tearing bridging vessels). This risk can be minimized by not draining more than 20ml per hour and/or targeting ICP of 8-10mmHg[8]
  • Occasionally (rarely at UNC), somatosensory evoked potentials (SSEPs) and/or motor evoked potentials (MEPs) may be used to monitor for SCI[9]
  • Because of its more tenuous blood supply, the anterior two-thirds of the spinal cord are most at risk for ischemia which presents as a painful myelopathy known as anterior spinal artery syndrome

Emergence

  • PONV prophylaxis
  • Reversal of neuromuscular blockade if used
  • Assessment of hip flexion if spinal cord is at risk for ischemia
  • Reversal of heparin with protamine with confirmation of ACT returning to normal value
  • Maintain BP goals

Postoperative management

Disposition

  • PACU then floor
  • Consider ICU if intraoperative complications occur

Pain management

  • Postoperative pain is usually mild
  • Multimodal pain management
    • PO/IV acetaminophen
    • PO/IV opioid
    • Local anesthetic at vascular access sites
    • Epidural analgesia if chosen as anesthetic technique
    • Usually avoiding NSAID due to pre-existing renal disease or potential renal injury

Potential complications

  • Endoleaks
  • Vascular injury
  • Graft migration
  • Stent frame fractures
  • Breakdown of graft material
  • Spinal cord ischemia or infarction secondary to occlusion of intercostal arteries
  • Intraabdominal ischemia secondary to occlusion of vessels supplying the gastro-intestinal organ including the celiac artery, superior mesenteric artery, inferior mesenteric artery, and renal arteries
  • Bleeding from groin site or retroperitoneal bleeding
  • Contrast induced nephropathy

Procedure variants

Thoracic Aortic Aneurysms Abdominal Aortic Aneurysms
Unique considerations Use of TEE and possible neuromonitoring and lumbar drain Neuraxial anesthesia possible
Position Supine +/- slight right lateral decubitus Supine
Surgical time 1-3 hours 1-3 hours
EBL Minimal, unless vascular injury Minimal, unless vascular injury
Postoperative disposition Usually PACU to the floor, possible ICU Usually PACU to the floor
Pain management Multimodal Multimodal
Potential complications Paraplegia Intraabdominal ischemia/infarction

References

  1. Stoelting's anesthesia and co-existing disease. Roberta L. Hines, Stephanie B. Jones, Robert K. Stoelting (Eighth edition ed.). Philadelphia, PA. 2022. ISBN 978-0-323-71861-5. OCLC 1280374077. |edition= has extra text (help)CS1 maint: others (link)
  2. 2.0 2.1 2.2 2.3 Cheruku, Sreekanth; Huang, Norman; Meinhardt, Kyle; Aguirre, Marco (2019-12). "Anesthetic Management for Endovascular Repair of the Thoracic Aorta". Anesthesiology Clinics. 37 (4): 593–607. doi:10.1016/j.anclin.2019.07.001. ISSN 1932-2275. PMID 31677680. Check date values in: |date= (help)
  3. 3.0 3.1 Anesthesiologist's manual of surgical procedures. Richard A. Jaffe, Clifford A. Schmiesing, Brenda Golianu (Sixth edition ed.). Philadelphia. 2020. ISBN 978-1-4698-2916-6. OCLC 1117874404. |edition= has extra text (help)CS1 maint: others (link)
  4. Koda Y, Yamanaka K, Omura A, Gentsu T, Yamaguchi M, Okada K. Spinal cord ischemia after elective endovascular abdominal aortic aneurysm repair in a patient with multiple occlusions of the intercostal and internal iliac arteries. J Vasc Surg Cases Innov Tech. 2022 Jul 9;8(3):447-449. doi: 10.1016/j.jvscit.2022.06.007. PMID: 36016702; PMCID: PMC9395748.
  5. Toshifumi Hiraoka, Tatsuhiko Komiya, Hiroshi Tsuneyoshi, Takeshi Shimamoto, Risk factors for spinal cord ischaemia after thoracic endovascular aortic repair, Interactive CardioVascular and Thoracic Surgery, Volume 27, Issue 1, July 2018, Pages 54–59, https://doi.org/10.1093/icvts/ivy037
  6. 6.0 6.1 Randall B. Griepp, Eva B. Griepp, Spinal cord protection in surgical and endovascular repair of thoracoabdominal aortic disease, The Journal of Thoracic and Cardiovascular Surgery, Volume 149, Issue 2, Supplement, 2015, Pages S86-S90, ISSN 0022-5223, https://doi.org/10.1016/j.jtcvs.2014.10.056. (https://www.sciencedirect.com/science/article/pii/S002252231401561X)
  7. Wong C S, Healy D, Canning C, Coffey J C, Boyle J R, Walsh S R. A systematic review of spinal cord injury and cerebrospinal fluid drainage after thoracic aortic endografting. J Vasc Surg. 2012;56(05):1438–1447.
  8. Ellauzi H, Arora H, Elefteriades JA, Zaffar MA, Ellauzi R, Popescu WM. Cerebrospinal Fluid Drainage for Prevention of Spinal Cord Ischemia in Thoracic Endovascular Aortic Surgery-Pros and Cons. Aorta (Stamford). 2022 Dec;10(6):290-297. doi: 10.1055/s-0042-1757792. Epub 2022 Dec 20. PMID: 36539146; PMCID: PMC9767776.
  9. Cheruku, Sreekanth; Huang, Norman; Meinhardt, Kyle; Aguirre, Marco (2019-12). "Anesthetic Management for Endovascular Repair of the Thoracic Aorta". Anesthesiology Clinics. 37 (4): 593–607. doi:10.1016/j.anclin.2019.07.001. ISSN 1932-2275. PMID 31677680.