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A Comparison of Renal Perfusion in Thoracoabdominal Aortic Aneurysm (TAAA) Repair

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00691756
Recruitment Status : Completed
First Posted : June 5, 2008
Last Update Posted : February 24, 2020
Gillson-Longenbaugh Foundation
Texas Heart Institute
Information provided by (Responsible Party):
Scott Lemaire, Baylor College of Medicine

Brief Summary:
The purpose of this randomized trial was to determine whether renal perfusion with cold blood provides better protection against renal ischemia than perfusion with cold crystalloid in patients undergoing TAAA repair with left heart bypass.

Condition or disease Intervention/treatment Phase
Renal Failure Procedure: Cold blood renal perfusion Procedure: Cold crystalloid renal perfusion Not Applicable

Detailed Description:
Despite improvements in surgical techniques and postoperative care, renal dysfunction has consistently remained a significant and potentially lethal complication after thoracoabdominal aortic aneurysm (TAAA) repair. In an attempt to alleviate postoperative renal failure and its associated mortality, several techniques and intraoperative strategies have been used including: intraoperative administration of diuretics, steroids, or prostaglandins; minimization of ischemic times; renal hypothermia with cold crystallid solutions; selective warm (normothermic) blood perfusion as part of a left heart bypass (LHB) system; and hemodilution. However, despite the use of adjuvant techniques, the incidence of renal failure after TAAA repair still ranges from 3% to 27%. One of the techniques mentioned above involves cold crystalloid renal artery perfusion. This method aims to reduce metabolic needs of the renal system by inducing local hypothermia. Because oxygen consumption decreases 7% for each degree Celsius that temperature is reduced, the metabolic needs of tubular cells are reduced by almost 50% at 30 degrees Celsius. After the aorta is clamped and opened, the renal arteries are perfused with lactated Ringers solution (LR) that has been cooled to 4 degrees Celsius utilizing a roller pump to transport the LR through an appropriately cooled ice bath. This decreases the temperature of the kidneys to an average of 20 degrees Celsius. The volume of LR required to achieve this temperature ranges from 600 to 1800 ml. Renal cooling has been shown to preserve renal tissue as long as warm ischemic time is kept to a minimum. We recently compared renal artery cold crystalloid perfusion with normothermic blood perfusion in a randomized clinical trial involving 30 patients and discovered via multivariable analysis that cold LR was protective against acute postoperative renal dysfunction. In this study, we found that 62.5% of patients receiving normothermic blood perfusion developed acute postoperative renal dysfunction versus 21.4% in the cold LR group (p = 0.03). One method of renal protection not often used involves selective cold blood perfusion of the renal arteries. This technique also aims to reduce renal ischemic time during aortic cross-clamping and improve oxygenation to renal tissues; thereby, preventing reperfusion injury and organ dysfunction often associated with this operation. During aneurysm repair, left atrio-distal aortic bypass is performed using a centrifugal pump. Tubing connected to the distal end of this circuit passes through a container of ice allowing the perfusion of both renal arteries with cold blood. The flow rates into the renal arteries range from 100 to 450 ml/min. The celiac axis and superior mesenteric artery remain individually perfused in the standard fashion using normothermic blood. The best method of achieving renal protection remains unclear. Currently, normothermic blood and cold LR remain the two most commonly used methods of renal artery perfusion during TAAA repair. This randomized trial compared the effectiveness of two forms of renal artery perfusion, cold LR versus cold blood, to identify which method is more beneficial in the prevention of postoperative renal dysfunction.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 172 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Participant)
Primary Purpose: Treatment
Official Title: A Comparison of Cold Blood Versus Cold Crystalloid Renal Perfusion for Prevention of Acute Renal Failure Following Thoracoabdominal Aortic Aneurysm Repair: A Randomized Study
Study Start Date : January 2002
Actual Primary Completion Date : December 2006
Actual Study Completion Date : December 2006

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Experimental: 1
Cold blood renal perfusion
Procedure: Cold blood renal perfusion
Both kidneys receive intermitent perfusion with cold (4 degrees C) autologous blood during thoracoabdominal aortic aneurysm repair.

Active Comparator: 2
Cold crystalloid renal perfusion
Procedure: Cold crystalloid renal perfusion
Both kidneys receive intermittent perfusion with cold (4 degrees C) lactated Ringer's solution during thoracoabdominal aortic aneurysm repair. This is the standard renal perfusion technique in our practice.

Primary Outcome Measures :
  1. Renal dysfunction [ Time Frame: 10 postoperative days ]

Secondary Outcome Measures :
  1. Renal injury (increase in urinary biomarkers) [ Time Frame: 7 postoperative days ]

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • age equal to or greater than 18
  • planned extent II or III thoracoabdominal aortic aneurysm repair
  • planned left heart bypass
  • patient consent obtained

Exclusion Criteria:

  • impaired left ventricular function
  • impaired renal function
  • prior thoracoabdominal aortic aneurysm repair
  • pseudoaneurysm
  • pre-existing liver disease
  • free aortic aneurysm rupture
  • inability to measure renal temperature
  • extent I or IV thoracoabdominal aortic aneurysm repair

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00691756

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United States, Texas
Baylor College of Medicine
Houston, Texas, United States, 77030
Sponsors and Collaborators
Baylor College of Medicine
Gillson-Longenbaugh Foundation
Texas Heart Institute
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Principal Investigator: Scott A. LeMaire, MD Baylor College of Medicine
Publications of Results:
Other Publications:
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Responsible Party: Scott Lemaire, Professor, Surgery/Cardio/Thoracic Surg., Baylor College of Medicine Identifier: NCT00691756    
Other Study ID Numbers: H-9764
First Posted: June 5, 2008    Key Record Dates
Last Update Posted: February 24, 2020
Last Verified: February 2020
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Scott Lemaire, Baylor College of Medicine:
renal failure
thoracoabdominal aortic aneurysm repair
cold crystalloid
cold blood
renal perfusion
Additional relevant MeSH terms:
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Renal Insufficiency
Aortic Aneurysm
Aortic Aneurysm, Thoracic
Vascular Diseases
Cardiovascular Diseases
Kidney Diseases
Urologic Diseases
Aortic Diseases