Factors Responsible for the Effectiveness of the Lund Technique for De-airing Following Open Left Heart Surgery.
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- Lund University
- Enrollment
- 20
- Locations
- 2
- Primary Endpoint
- Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.
Study Overview
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.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Parallel
- Primary Purpose
- Supportive Care
- Masking
- Single (Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 90 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- No
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
Arms & Interventions
Open pleurae & conventional filling of heart
In this group both pleurae will be opened and the ventilator disconnected during cardiopulmonary bypass to ensure bilateral pulmonary collapse. However, after completion of the left heart procedure, the heart will be filled with blood actively from the heart-lung machine and manual de-airing performed in a conventional manner and de-airing monitored by intraoperative trans-esophageal echocardiography (TEE). After de-airing is complete and patient has been weaned off the cardiopulmonary bypass the residual air in the left heart will be quantitatively assessed by TEE and Trans-cranial Echo-Doppler (TCD) over a period of 10 minutes.
Intervention: Open pleurae & conventional filling of heart (Procedure)
Intact pleurae & staged filling of heart
In this group both pleurae will be left intact and the ventilator disconnected during cardiopulmonary bypass. After completion of the left heart procedure, the heart will be filled with blood actively from the heart-lung machine in a staged manner after adequate cardiac contraction has been established. De-airing will be obtained by active cardiac contraction and staged mechanical ventilation and de-airing monitored by intraoperative trans-esophageal echocardiography (TEE). After de-airing is deemed complete and patient has been weaned off the cardiopulmonary bypass (CPB) the residual air in the left heart will be quantitatively assessed by TEE and Trans-cranial Echo-Doppler (TCD) over a period of 10 minutes.
Intervention: Intact pleurae & staged filling of heart (Procedure)
Outcomes
Primary Outcomes
Participants With <=Grade I Air Emboli as Assessed by Trans-esophageal Echocardiography (TEE) After Finished De-airing.
Time Frame: 6-10 minutes 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.
Duration of the De-airing Procedure
Time Frame: Time from release of aortic crossclamp to finished de-airing
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.
Quantitative Assessment of Air Embolism to the Brain After Completion of Open Left Heart Surgery
Time Frame: Period of ten minutes after finished de-airing
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.
Secondary Outcomes
No secondary outcomes reported
Investigators
Bansi Lal Koul
Med dr. Ph. D.
Lund University