Optimizing a MitraClip procedure with high frequency jet ventilation

Abstract

This report demonstrates the successful deployment of MitraClip with the use of high frequency jet ventilation to stabilize the surgical field in a technically challenging case.

MitraClip is a catheter-based technology used to deliver a small metal clip to a regurgitant mitral valve. The clip connects the middle scallops of the anterior and posterior leaflets of the regurgitant valve, ensuring its proper closure. High frequency jet ventilation (HFJV) involves intermittent delivery of airflow from a high-pressure source, generating a high-frequency, near static field. This mode of ventilation has been used to stabilize surgical fields in noncardiac interventions and catheter ablations.^1,2 Here we report the first case of using this mode of ventilation to optimize the surgical field for MitraClip deployment in a technically challenging case.

CASE DESCRIPTION

A 74-year-old woman with known hypertension, diabetes mellitus, and coronary artery disease treated by coronary bypass presented to our hospital with progressively worsening dyspnea on exertion (New York Heart Association class III symptoms). Transthoracic echocardiogram demonstrated moderate to severe mitral valve regurgitation of mixed etiology. After medical optimization with intravenous diuretics and discharge from the hospital, she was scheduled for outpatient follow-up with cardiology and cardiothoracic surgery.

Transthoracic echocardiogram during hospitalization demonstrated moderate to severe mitral regurgitation and mild mitral annular calcification (Figure 1a). Transesophageal echocardiography (TEE) confirmed the presence of mildly thickened leaflets with some tethering/restriction of the posterior mitral valve leaflet (Figure 1b-1f). The effective regurgitant orifice was 0.37 cm² and the regurgitant volume, 50 mL (Figure 1g). Pulmonary vein flow showed systolic blunting. The posterior leaflet length was 1 cm. She had severe three-vessel native coronary artery disease, with patent in situ left internal mammary artery to left anterior descending artery and patent vein grafts from the aorta to the diagonal system and posterior descending artery. The case was reviewed by a multidisciplinary team (that included a cardiothoracic surgery team), and given the patient’s age, multiple comorbidities, and failure of medical management, it was decided that she was not a surgical candidate. As a result, elective MitraClip deployment (Generation 3 XTR clip) was pursued.

Figure 1.

(a) Echocardiography demonstrating mitral regurgitation of approximately 16 mL. (b–g) 2D and 3D transesophageal images showing the mitral valve and annulus. (h) Intraoperative x-ray fluoroscopy demonstrating successful MitraClip placement.

The procedure was performed in the catheterization laboratory with the patient under general anesthesia. Two- and three-dimensional TEE was used for guidance of the catheter during the MitraClip procedure. A 7 French sheath was placed in the right common femoral vein, followed by dilation up the vein. This was followed by transseptal puncture, and an optimal puncture site was located using TEE. This allowed advancement of the steerable guide catheter into the left atrium. Once the catheter was in the left atrium, maneuvering to the correct position for clip deployment was challenging due to the patient’s valve anatomy and cardiac movement artifact caused by respiratory variations. Three-dimensional echocardiographic imaging was used to determine the appropriate predeployment approach for direction, orientation, and trajectory. It was technically difficult to grasp the posterior leaflet for MitraClip deployment in two attempts. As a result, HFJV was utilized to stabilize the surgical field and reduce motion artifact. The clip was then moved to the correct position below the mitral valve. Once this was accomplished, the leaflet was successfully grasped, the result was assessed using TEE imaging, and the clip was successfully released (Figure 1h).

DISCUSSION

MitraClip placement has gained popularity and is indicated for chronic moderate to severe symptomatic primary mitral regurgitation. It is also indicated in heart failure patients who have failed medical therapy and are not candidates for surgery.³ This technique has clear utility for use in high surgical-risk patients, especially older patients with multiple comorbidities. Overall, mortality rates are similar when compared to surgical mitral repair.

HFJV is a ventilatory support therapy that involves low volumes and high respiratory frequencies expelled at high pressures. It is known to reduce movement artifact during procedures.⁴ The technique has been studied for atrial fibrillation ablation and has been shown to improve precision and reduce technical difficulties.⁵ However, HFJV requires highly trained personnel for its use and monitoring.⁵ Additional considerations include risk of barotrauma, close monitoring in patients with chronic obstructive pulmonary disease, hypoventilation, and hypercapnia. Trained anesthesia teams, in addition to carbon dioxide monitoring and transcutaneous capnography, can help mitigate these risks.⁶

With increased case volumes for minimally invasive cardiovascular techniques, HFJV can serve as a viable alternative ventilation strategy in technically complex cardiac cases where field stability and precision are critical. More data are needed to further explore the use of this mode of ventilation for interventional cardiac procedures, determine optimal patient selection, and ultimately expand its use in additional cardiovascular procedures.