AA Aneurysm Open - Revision history

Danesthesia at 14:37, 21 July 2024

2024-07-21T14:37:40Z

Danesthesia at 14:30, 21 July 2024

2024-07-21T14:30:18Z

← Older revision		Revision as of 10:30, 21 July 2024
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	[[Category:Surgery]]		[[Category:Surgery]]
	[[Category:Vascular]]		[[Category:Vascular]]

			== Open Abdominal Aortic Aneurysm (AAA) Repair ==

			=== Overview ===
			* The open AAA repair procedure is becoming rarer due to the rise of endovascular stent placements.
			* It is associated with significant blood loss and complexity.

			=== Procedure Description ===
			* Repair is performed through a midline abdominal incision.
			* Most open AAA procedures have been replaced by endovascular AAA repair.
			* Elective surgery is recommended for aneurysms greater than 5 cm in diameter.
			* Repair methods include:
			* Straight tube graft
			* Aorta to bilateral iliac graft replacement

			=== Symptoms ===
			* Typically asymptomatic, but may present with lumbar back or abdominal pain.

			=== Imaging ===
			* Methods include CT scan, MRI, basic x-ray, or angiography.
			* CT angiography is preferred as it provides details on size, location (infra- or supra-renal), and the status of major branches (e.g., inferior mesenteric artery).

			=== Causes ===
			* Atherosclerosis
			* Marfan syndrome
			* Ehlers-Danlos syndrome
			* Dissection
			* Congenital vasculitis
			* Infections, including syphilis

			=== Preoperative Tips ===
			* Maintain patient warmth.
			* Keep heart rate slow (avoid tachycardia).
			* Prevent anemia (keep hematocrit (HCT) >25-30).
			* Prevent hypertension to avoid stressing the aneurysm.

			=== Procedure Details ===
			* The surgeon cross-clamps above and below the aneurysm, opens the aorta, removes the diseased section, and replaces it with a graft.
			* Clamps are then removed; estimated blood loss (EBL) can be substantial.
			* Be aware of hemodynamic changes during clamping and unclamping.

			=== Preoperative Preparation ===
			* Verify if the patient has had a thorough cardiac workup; if not, treat them as a coronary artery disease (CAD) patient.
			* Line and Monitoring:
			* Use the largest bore peripheral IVs available (14G if possible).
			* Right internal jugular (IJ) line is recommended.
			* Consider a transesophageal echocardiogram (TEE) instead of a Swan-Ganz catheter for monitoring left ventricular filling status.
			* Have fluid warmers (1-2) and rapid transfusers or pressure bags ready.
			* Prepare blood transfusion tubing (2) with normal saline (NSS).
			* Use a cell saver and warming blankets (2).

			=== Induction and Intubation ===
			* To avoid hypertension with direct laryngoscopy:
			* Consider adding Esmolol to induction to mitigate BP spikes.
			* Use Remifentanil (0.5-1 mcg/kg/min) 8 minutes before intubation.
			* High narcotic induction doses may be used.
			* Consider a GlideScope to reduce stimulation.
			* Anesthesia:
			* General anesthesia with endotracheal tube (ETT).
			* Thoracic epidural is recommended; administer before the incision.
			* Rapid Sequence Induction (RSI) is often utilized.
			* Nasogastric (NG) tube is advisable.
			* Duration: 3-5 hours.
			* Position: Supine with arms tucked.
			* Estimated Blood Loss (EBL): 500-1,000 mL.

			=== Common Intubation Doses ===
			* Fentanyl: 10-20 mcg
			* Midazolam (Versed): 5 mg
			* Large narcotic doses may cause rigidity; these reduce the need for volatile agents during induction.

			=== Pre-Induction ===
			* Use a priming dose of a non-depolarizing muscle relaxant or succinylcholine for RSI.
			* Connect fluids to the warmer as soon as possible.
			* Keep the patient covered; use a Bair Hugger after central line placement.
			* Administer a 200-500 cc fluid bolus before induction.

			=== Induction to Pre-Clamp Period Goals ===
			* Avoid hypertension to prevent aneurysm rupture.
			* Administer 0.5 g/kg Mannitol (typically 12.5-25 g) 30 minutes before cross-clamping.
			* Have Lasix available and follow the surgeon’s instructions for administration.

			=== Preparation for Aortic Cross-Clamping ===
			* Ensure nitroglycerin and/or Milrinone are available.
			* Monitor ionized calcium (Ca) levels.
			* Maintain volume and prepare to manage BP drops when unclamping.

			=== Complications of Aortic Cross-Clamping ===
			* Renal failure:
			* Increased risk with preexisting renal disease, cross-clamp time >30 minutes, and hypovolemia/decreased cardiac output without bypass.
			* Renal protection may include Mannitol (0.5-1.0 g/kg) before clamping, and potentially Lasix, Dopamine, and Fenoldopam.
			* Paraplegia:
			* The anterior spinal cord is most prone to ischemia due to its single arterial supply.
			* Prolonged ischemia can occur with cross-clamping times >30-45 minutes or during perioperative hypotension.

			=== Methods to Prevent BP Drops with Unclamping ===
			* Decrease anesthetic depth.
			* Maintain a hypervolemic state while clamped.
			* Infuse Neosynephrine before clamp removal.
			* Unclamp slowly as per the surgeon’s direction.

			=== Unclamping Effects ===
			* Reactive hyperemia due to reduced systemic vascular resistance (SVR) from metabolites in ischemic tissue.
			* Lactic acid causes vasodilation.
			* Consider NaHCO3 if requested by the surgeon.
			* Increase minute ventilation to manage acidosis; hypocarbia will constrict vessels and redirect blood flow to ischemic tissues.

			=== Late Operative and Postoperative Considerations ===
			* Common issues:
			* Facial, scalp, and airway edema.
			* Recommendations:
			* Delay extubation until edema subsides.
			* Elevate the head of bed (HOB) overnight.
			* Monitor for fluid shifts postoperatively to address potential pulmonary issues.

			=== Spinal Cord Blood Supply ===
			* Supplied by:
			* One anterior spinal artery.
			* Two posterior spinal arteries.
			* A network of small segmental spinal arteries.
			* The anterior spinal cord is particularly vulnerable to ischemia due to its single arterial supply.

			=== Possible Complications ===
			* Ruptured aneurysm
			* Cardiac and pulmonary problems
			* Nerve damage causing pain or numbness in the legs
			* Damage to intestines or nearby organs
			* Graft infection
			* Injury to the ureter(s)
			* Incisional hernia
			* Spinal cord injury
			* Sexual dysfunction
			* Lower extremity paralysis
			* Death

Danesthesia: Replaced content with "Category:Surgery Category:Vascular"

2024-07-21T14:29:30Z

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Danesthesia at 14:28, 21 July 2024

2024-07-21T14:28:13Z

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Danesthesia at 14:26, 21 July 2024

2024-07-21T14:26:39Z

← Older revision		Revision as of 10:26, 21 July 2024
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	[[Category:Surgery]]		[[Category:Surgery]]
	[[Category:Vascular]]		[[Category:Vascular]]
			== Open Abdominal Aortic Aneurysm (AAA) Repair == * Overview: * Open AAA repair is becoming less common due to the availability of endovascular stent placements. * The procedure is associated with significant blood loss and is generally more complex. * Procedure Description: * Involves repairing the AAA through a midline abdominal incision. * Most open AAA repairs have been replaced by endovascular AAA repairs. * Elective surgery is recommended for aneurysms >5 cm in diameter. * Repair methods: * Straight tube graft * Aorta to bilateral iliac graft replacement * Symptoms: * Usually asymptomatic, but may present with lumbar back or abdominal pain. * Imaging: * Methods include CT scan, MRI, basic x-ray, or angiography. * CT angiography is preferred for assessing size, location (infra- or supra-renal), and major branch status (e.g., inferior mesenteric artery). * Causes: * Atherosclerosis * Marfan syndrome * Ehlers-Danlos syndrome * Dissection * Congenital vasculitis * Infections, including syphilis * Preoperative Tips: * Keep the patient warm. * Maintain a slow heart rate (avoid tachycardia). * Avoid anemia (keep hematocrit (HCT) >25-30). * Prevent hypertension (avoid stressing the aneurysm). * Procedure Details: * The surgeon cross-clamps above and below the aneurysm, opens the aorta, removes the diseased section, and replaces it with a graft. * Clamps are removed with potential for large estimated blood loss (EBL). * Hemodynamic changes should be managed carefully. * Preoperative Preparation: * Ensure thorough cardiac workup; treat as a coronary artery disease (CAD) patient if not done. * Line and Monitoring: * Place the largest bore peripheral IVs possible (14G if possible). * Use a right internal jugular (IJ) line. * Consider a transesophageal echocardiogram (TEE) instead of a Swan-Ganz catheter for monitoring left ventricular filling status. * Have fluid warmers (1-2) and rapid transfusers or pressure bags ready. * Blood transfusion tubing (2) should be set up with normal saline (NSS). * Prepare a cell saver and warming blankets (2). * Induction and Intubation: * Methods to avoid hypertension with direct laryngoscopy: * Consider adding Esmolol to induction to blunt BP spikes. * Use Remifentanil (start at 0.5-1 mcg/kg/min) 8 minutes before intubation. * High narcotic induction doses can be used, similar to heart cases. * Consider using a GlideScope to reduce stimulation. * Anesthesia: * General anesthesia with endotracheal tube (ETT). * Thoracic epidural is recommended; dose or start an infusion before incision. * Rapid Sequence Induction (RSI) is commonly used. * Nasogastric (NG) tube is advisable. * Duration: 3-5 hours. * Position: Supine with arms tucked. * Estimated Blood Loss (EBL): 500-1,000 mL. * Common Intubation Doses: * Fentanyl: 10-20 mcg * Midazolam (Versed): 5 mg * Be prepared for rigidity with large narcotic doses. * Pre-Induction: * Use a priming dose of a non-depolarizing muscle relaxant or succinylcholine for RSI. * Connect fluids to the warmer as soon as possible. * Keep the patient covered; use a Bair Hugger after central line placement. * Administer a 200-500 cc fluid bolus before induction. * Induction to Pre-Clamp Period Goals: * Avoid hypertension to prevent aneurysm rupture. * Administer 0.5 g/kg Mannitol (usually 12.5-25 g) 30 minutes before cross-clamping. * Have Lasix available; follow the surgeon’s instructions for administration. * Preparation for Aortic Cross-Clamping: * Ensure nitroglycerin and/or Milrinone are available. * Monitor ionized calcium (Ca) levels. * Maintain volume and prepare to manage BP drop when unclamping. * Complications of Aortic Cross-Clamping: * Increased risk of renal failure: * Preexisting renal disease * Cross-clamp time >30 minutes * Hypovolemia and decreased cardiac output without partial or complete bypass * Renal protection: * Mannitol (0.5-1.0 g/kg) is crucial before clamping. * Consider Lasix, Dopamine, and Fenoldopam based on surgeon's needs. * Paraplegia: * The anterior spinal cord, supplied by a single artery, is most prone to ischemia. * Prolonged spinal cord ischemia occurs with cross-clamping times >30-45 minutes or during perioperative hypotension. * Methods to Prevent BP Drops with Unclamping: * Decrease anesthetic depth. * Maintain hypervolemia while clamped. * Infuse Neosynephrine before clamp removal. * Unclamp slowly as directed by the surgeon. * Unclamping Effects: * Reactive hyperemia due to a drop in systemic vascular resistance (SVR) from metabolites in ischemic tissue. * Lactic acid causes vasodilation. * Increased minute ventilation may help control acidosis and manage blood flow distribution. * Late Operative and Postoperative Considerations: * Common issues: * Facial, scalp, and airway edema. * Recommendations: * Delay extubation until edema subsides. * Elevate the patient’s head of bed (HOB) overnight. * Monitor fluid shifts postoperatively to address potential pulmonary issues. * Spinal Cord Blood Supply: * Supplied by: * One anterior spinal artery. * Two posterior spinal arteries. * A network of small segmental spinal arteries. * The anterior spinal cord is most susceptible to ischemia due to single arterial supply. * Possible Complications: * Ruptured aneurysm * Cardiac and pulmonary issues * Nerve damage causing pain or numbness in the legs * Intestinal or organ damage * Graft infection * Ureter injury * Incisional hernia * Spinal cord injury * Sexual dysfunction * Lower extremity paralysis * Death

Danesthesia: Replaced content with "Category:Surgery Category:Vascular"

2024-07-21T14:26:28Z

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Danesthesia at 14:26, 21 July 2024

2024-07-21T14:26:05Z

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Danesthesia at 21:48, 9 May 2023

2023-05-09T21:48:04Z

← Older revision		Revision as of 17:48, 9 May 2023
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Danesthesia at 21:36, 9 May 2023

2023-05-09T21:36:29Z

← Older revision		Revision as of 17:36, 9 May 2023
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			{{Surgicalcase}}

Danesthesia at 03:10, 9 June 2021

2021-06-09T03:10:49Z

← Older revision		Revision as of 23:10, 8 June 2021
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