Related Experiment Video
Updated: Oct 9, 2026
A Structured Rehabilitation Protocol for Improved Multifunctional Prosthetic Control: A Case Study
Published on: November 6, 2015
[An experience with St. Jude medical prosthetic 19A-HP which resulted in restricted opening at an early stage after
K Mashiko1, S Ishii, H Naganuma
1Department of Cardiovascular Surgery, Fuji City Hospital, Shizuoka, Japan.
Insights
Aortic valve replacement using the St. Jude Medical Hemodynamic Plus prosthesis showed leaflet restriction. This complication may stem from structural issues in the prosthesis, potentially due to implantation forces.
Area of Science:
- Cardiovascular Surgery
- Biomedical Engineering
- Prosthetic Valve Design
Background:
- Aortic valve replacement (AVR) is a common procedure for aortic stenosis and regurgitation.
- The St. Jude Medical Hemodynamic Plus (HP) series is designed to improve orifice area in small aortic roots.
- This case involves AVR using a 19A-HP prosthesis in a patient with a small aortic orifice (18.9 mm).
Observation:
- The patient underwent uneventful AVR with a 19A-HP prosthesis.
- Nine days post-operation, cinefluoroscopy revealed symmetrical restriction of the prosthetic valve leaflets.
- Doppler echocardiography showed a significant left ventricular-aortic (LV-Ao) pressure gradient of 60 mmHg, despite the absence of symptoms.
Findings:
- The symmetrical nature of the leaflet restriction suggests a structural issue with the prosthesis rather than surgical technique.
- The unreinforced orifice ring of the HP prosthesis may be susceptible to deformation from longitudinal forces.
- It is hypothesized that the forceful insertion of the 19A-HP prosthesis, potentially instead of a smaller size (17-HP), induced these forces, altering the hinge mechanism and restricting leaflet motion.
Implications:
- This case highlights a potential structural vulnerability in the St. Jude Medical HP series, specifically the orifice ring's susceptibility to deformation.
- The findings suggest that careful consideration of prosthesis size and implantation technique is crucial to avoid inducing forces that could compromise valve function.
- Further investigation into the biomechanics of HP prosthesis implantation and long-term structural integrity is warranted to prevent such complications.
Abstract:
St. Jude medical hemodynamic plus series is positively used for aortic valve replacement (AVR) of small orifice because it can increase the orifice area by 26% compared with conventional prosthetic valves of the same size. We performed AVR with SJM 19A-HP on a patient having aortic stenosis with regurgitation using horizontal mattress suturing technique. The aortic orifice size was 18.9 mm at the preoperative measurement. The course after the operation was uneventful until 9 days after the operation when cinefluoroscopy revealed symmetrical restriction of opening of valve leaflets. We are now monitoring the clinical course at the patient has not developed any symptoms though the LV-Ao pressures gradient is 60 mmHg by Doppler echocardiography. As the restriction of valve leaflet opening was symmetrical, it is not likely that an excess of the ligature or remnant caused the restriction; structural problems of St. Jude medical prosthesis appear to be a more reasonable explanation. Since the orifice ring of this prosthesis is not reinforced, longitudinal forces applied to the hinge may alter the shape of the ring, thus restricting the movement of valve leaflets. In the present case, forced insertion of 19A-HP instead of more desirable 17-HP is considered to have caused longitudinal forces acting on the hinge.
