Clinical trial NCT01757704: Factors Responsible for the Effectiveness of the Lund De-airing Technique
Official title: Factors Responsible for the Effectiveness of the Lund Technique for De-airing Following Open Left Heart Surgery.
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Complication of Surgical Procedure
Keywords: Cardiac de-airing
Air emboli
Trans-cranial Echo-Doppler
Intraoperative Trans-esophageal Echocardiography
Lead sponsor: Lund University
Sponsor class: OTHER
First posted: 2012-12-31
Enrollment: 20
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: SUPPORTIVE_CARE

Brief summary: The Lund de-airing technique is employed for cardiac de-airing in open left heart surgery. It consists of two main elements namely, opening of both pleura after the patient is on CPB (cardiopulmonary bypass)and disconnection of the ventilator before opening the left heart to ensure bilateral pulmonary collapse and a staged filling of the heart at termination of the CPB. The aim of this study is to analyze in a randomized manner two groups of patients to establish if one or both components are of primary importance for the effectiveness of the de-airing technique.

Detailed description: Patients planned for open left heart surgery, mainly aortic valve replacement, will be included in the study. Patients with aortic valve replacement and concomitant coronary artery bypass with vein grafts only can also be included.

Exclusion criteria are; significant chronic obstructive pulmonary disease/emphysema, significant (\>50%)carotid artery disease, need of concomitant internal mammary harvesting, prior cardiac or pulmonary surgery, pulmonary adhesions preventing pulmonary collapse, previous radiation to the chest and prior severe chest trauma. Intraoperative exclusion criteria are; failure to obtain adequate bilateral Trans-cranial Echo-Doppler signals from the medial cerebral arteries, finding of adherent pleurae and accidental opening of the pleurae.

Twenty patients will be randomized to two groups:

Group I: Intact pleura bilaterally, disconnection of the ventilator during cardiopulmonary bypass (CPB), followed by staged filling of the heart.

Group II: Open pleura bilaterally, disconnection of the ventilator during cardiopulmonary bypass to ensure bilateral pulmonary collapse followed by conventional filling of the heart.

Data will be compared to a third historical control group, consisting of ten patients with open pleurae with the ventilator disconnected followed by staged filling of the heart.

Primary outcomes:

* Duration of the de-airing procedure from the release of the aortic cross clamp to finished de-airing.
* Air microemboli to the brain registered on-line as gaseous microembolic signals on Trans-cranial Echo-Doppler (TCD). The sum of signals from the right and left middle cerebral artery are registered during the following time periods; from the release of the aortic cross clamp to start of cardiac ejection, from cardiac ejection to finished de-airing, and during ten minutes after finished de-airing.
* Magnitude of residual air emboli in the heart after finished de-airing as monitored by Trans-esophageal Echocardiography (TEE) with a Three-chamber view. The severity of residual air is classified in four grades after the appearance of visible air on TEE in left atrium (LA), left ventricle (LV) and aortic root (AO)as follows; Grade 0: no residual air, grade I: gas emboli detected in one of three anatomic areas during one cardiac cycle, grade II: gas emboli detected simultaneously in two of three anatomic areas during one cardiac cycle; grade III: gas emboli detected in all three anatomic areas during one cardiac cycle.

Eligibility criteria: Inclusion Criteria:

* Patients planned for aortic valve replacement with or without coronary vein bypass grafts

Exclusion Criteria:

* Significant chronic obstructive pulmonary disease and emphysema
* Previous history of thoracic or cardiac surgery
* Patients requiring internal mammary artery harvesting
* Unilateral or bilateral pulmonary adhesions to chest wall
* Previous radiation to the chest

Intraoperative Exclusion Criteria:

* Inability to obtain adequate bilateral Trans-cranial Echo-doppler signals
* Adherent pleurae
* Accidental opening of the pleurae

Primary outcomes:
measure: Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery
timeFrame: Time from the release of the aortic crossclamp to cardiac ejection, an average of 10-15 minutes
measure: Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery
timeFrame: Time from cardiac ejection to finished de-airing, an average of 5-10 minutes
measure: Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery
timeFrame: Period of ten minutes after finished de-airing
measure: Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.
timeFrame: 0-3 minutes after finished de-airing
measure: Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.
timeFrame: 3-6 minutes after finished de-airing
measure: Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.
timeFrame: 6-10 minutes after finished de-airing
measure: Duration of the De-airing Procedure
timeFrame: Time from release of aortic crossclamp to finished de-airing
Secondary outcomes:
Other outcomes:
Locations:
city: Lund
country: Sweden
facility: Lund University
state: Skåne
Study officials:
affiliation: Cardiothoracic Surgery, Skåne University Hospital Lund, Sweden
name: Bansi Koul, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Al-Rashidi F, Blomquist S, Hoglund P, Meurling C, Roijer A, Koul B. A new de-airing technique that reduces systemic microemboli during open surgery: a prospective controlled study. J Thorac Cardiovasc Surg. 2009 Jul;138(1):157-62. doi: 10.1016/j.jtcvs.2009.02.037.
citation: Al-Rashidi F, Landenhed M, Blomquist S, Hoglund P, Karlsson PA, Pierre L, Koul B. Comparison of the effectiveness and safety of a new de-airing technique with a standardized carbon dioxide insufflation technique in open left heart surgery: a randomized clinical trial. J Thorac Cardiovasc Surg. 2011 May;141(5):1128-33. doi: 10.1016/j.jtcvs.2010.07.013. Epub 2010 Sep 3.