Factors Responsible for the Effectiveness of the Lund De-airing Technique

Complication of Surgical Procedure Clinical Trial

Official title:

Factors Responsible for the Effectiveness of the Lund Technique for De-airing Following Open Left Heart Surgery.

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01757704
• Other study ID #: BKML-003
• Status: Completed
• Phase: N/A
• First received: September 22, 2012
• Last updated: January 11, 2014
• Start date: September 2012
• Est. completion date: January 2014

Study information

• Verified date: January 2014
• Source: Lund University
• Contact: n/a
• Is FDA regulated: No
• Health authority: Sweden: Medical Products AgencySweden: Regional Ethical Review BoardSweden: Swedish Data Inspection BoardSweden: Swedish National Council on Medical EthicsSweden: Swedish Research Council
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 20
• Est. completion date: January 2014
• Est. primary completion date: December 2013
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 90 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Single Blind (Outcomes Assessor), Primary Purpose: Supportive Care

Related Conditions & MeSH terms

• Complication of Surgical Procedure

Intervention

Procedure:
• Open pleurae & conventional filling of heart
After completion of the left heart surgery, the heart will be actively filled with blood from the cardiopulmonary bypass circuit and lungs fully ventilated with positive end-expiratory pressure to flush out all air trapped in the lung veins and left heart. When there is no more visible air seen on Trans-esophageal echocardiography, the patient is weaned from cardiopulmonary bypass.
• Intact pleurae & staged filling of heart
After the end of the left heart surgery, the heart is gradually filled with blood from the cardiopulmonary bypass circuit. Cardiac contractions fill the lungs with blood til no more air is seen in left heart on Trans-esophageal Echocardiography. Thereafter the lungs are ventilated with 50% of the estimated lung minute volume and 5 cm positive end-expiratory pressure and cardiac filling and de-airing continued. If no air is seen in the left heart full ventilation is started and the patient is weaned from cardiopulmonary bypass.

Locations

Country	Name	City	State
Sweden	Lund University	Lund	Skåne

Sponsors (1)

Lead Sponsor	Collaborator
Lund University

Country where clinical trial is conducted

Sweden, 

References & Publications (2)

Al-Rashidi F, Blomquist S, Höglund 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. — View Citation

Al-Rashidi F, Landenhed M, Blomquist S, Höglund 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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery	Cerebral air emboli will be assessed quantitatively by On-line counting of gaseous microembolic signals (MES) by Trans-cranial Echo-Doppler (TCD) monitoring of the right and left middle cerebral artery. The sum of the gaseous microembolic signals registered from the right and left middle cerebral artery will be reported.	Time from the release of the aortic crossclamp to cardiac ejection, an average of 10-15 minutes	Yes
Primary	Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery	Cerebral air emboli will be assessed quantitatively by On-line counting of gaseous microembolic signals (MES) by Trans-cranial Echo-Doppler (TCD) monitoring of the right and left middle cerebral artery. The sum of the gaseous microembolic signals registered from the right and left middle cerebral artery will be reported.	Time from cardiac ejection to finished de-airing, an average of 5-10 minutes	Yes
Primary	Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery	Cerebral air emboli will be assessed quantitatively by On-line counting of gaseous microembolic signals (MES) by Trans-cranial Echo-Doppler (TCD) monitoring of the right and left middle cerebral artery. The sum of the gaseous microembolic signals registered from the right and left middle cerebral artery will be reported.	Period of ten minutes after finished de-airing	Yes
Primary	Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.	The severity of residual air emboli in three anatomic areas; left atrium, left ventricle and aortic root, is assessed by Trans-esophageal Echocardiography (TEE) and classified in grade 0-3 as follows, Grade o: 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 simultaneously in all three anatomic areas during one cardiac cycle.	0-3 minutes after finished de-airing	Yes
Primary	Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.	The severity of residual air emboli in three anatomic areas; left atrium, left ventricle and aortic root, is assessed by Trans-esophageal Echocardiography (TEE) and classified in grade 0-3 as follows, Grade o: 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 simultaneously in all three anatomic areas during one cardiac cycle.	3-6 minutes after finished de-airing	Yes
Primary	Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.	The severity of residual air emboli in three anatomic areas; left atrium, left ventricle and aortic root, is assessed by Trans-esophageal Echocardiography (TEE) and classified in grade 0-3 as follows, Grade o: 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 simultaneously in all three anatomic areas during one cardiac cycle.	6-10 minutes after finished de-airing	Yes
Primary	Duration of the De-airing Procedure	The de-airing procedure is deemed completed when the Trans-esophageal Echocardiography (TEE) no longer visualizes air emboli in the heart Chambers. The duration is likely to vary between individuals and reflects the complexity of the de-airing procedure.	Time from release of aortic crossclamp to finished de-airing	No