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Objective: The development of a novel surgical tool or technique for mitral valve repair can be hampered by cost, complexity, and time associated with performing animal trials. A dynamically pressurized model was developed to control pressure and flowrate profiles in intact porcine hearts in order to quantify mitral regurgitation and evaluate the quality of mitral valve repair., Methods: A pulse duplication system was designed to replicate physiological conditions in explanted hearts. To test the capabilities of this system in measuring varying degrees of mitral regurgitation, the output of eight porcine hearts was measured for two different pressure waveforms before and after induced mitral valve failure. Four hearts were further repaired and tested. Measurements were compared with echocardiographic images., Results: For all trials, cardiac output decreased as left ventricular pressure was increased. After induction of mitral valve insufficiencies, cardiac output decreased, with a peak regurgitant fraction of 71.8%. Echocardiography clearly showed increases in regurgitant severity from post-valve failure and with increased pressure., Conclusions: The dynamic heart model consistently and reliably quantifies mitral regurgitation across a range of severities. Advantages include low experimental cost and time associated with each trial, while still allowing for surgical evaluations in an intact heart.

Objective: A substantial barrier to widespread adoption of robotically assisted mitral valve repair surgery is increased operative time compared with that of median sternotomy. Nitinol U-clips (Medtronic, Minneapolis, Minn) made of a shape-memory alloy eliminate intrathoracic suturing and may reduce operative times., Methods: A retrospective review of robotically assisted mitral valve repair surgery was done at East Carolina University, where preoperative, intraoperative, and postoperative data were collected prospectively. The total time for U-clip or suture placement, as well as those for cardiopulmonary bypass, crossclamp, and annuloplasty band placement, were studied. Patients in whom only U-clips were used ("U-clips" cohort) were compared with those in whom only sutures were used ("sutures" cohort). Comparisons between groups were by two-tailed Student t test., Results: Between May 2000 and June 2004, U-clips were used exclusively in 50 patients (mean age 58.4 +/- 13.2 years), and sutures were used exclusively in 72 patients (mean age 56.2 +/- 12.9 years). The mean total time for placement and deployment of U-clips was shorter than for placement and tying of sutures (101 +/- 45 seconds vs 186 +/- 79 seconds, respectively, P < .001). Cardiopulmonary bypass, crossclamp, and annuloplasty band placement times were shorter in the U-clips cohort (144 +/- 50 minutes vs 169 +/- 35 minutes, 105 +/- 30 minutes vs 132 +/- 29 minutes, and 26 +/- 5 minutes vs 40 +/- 10 minutes, U-clips vs sutures, respectively, all P < .01)., Conclusions: Significantly shorter times were observed for placement and deployment of U-clips versus placement and tying of sutures, resulting in a reduction in mean band placement time of 14 minutes and significantly shorter cardiopulmonary bypass and crossclamp times in the U-clips cohort. Therefore, use of Nitinol U-clips instead of sutures may allow for significantly faster robotically assisted mitral valve repair surgery.

Background and Aim of the Study: Successful mitral valve repair (MVP) is dependent on accurate annuloplasty band sizing. This is difficult and time-consuming when performed via port-access, or through a 4-cm minithoracotomy used in robotically assisted MVP. With the goal of moving toward a less-invasive approach and minimizing cross-clamp time, an attempt was made to determine annuloplasty band size using transesophageal echocardiography (TEE) alone., Methods: The intertrigonal distance (ITD) was determined by dividing the left ventricular outflow tract diameter (LVOT: measured on standard midesophageal aortic valve long-axis view) by 0.8. The ITD was compared to a nomogram developed to select the best Cosgrove-Edwards annuloplasty band size., Results: Between July and October, 2004, 11 patients (mean age 52.6 +/- 17.9 years; four Barlow's valves with bileaflet prolapse, four posterior leaflet prolapses, one anterior leaflet prolapse, one rheumatic, one dilated annulus) undergoing robotically assisted MVP had the annuloplasty band chosen using TEE alone. Seven patients (63.6%) had no or mild mitral regurgitation (MR) on postoperative TEE. Three patients (27.2%) had some systolic anterior motion (SAM), with one (Barlow's valve) requiring a second repair (same operation). One patient (9.1%, rheumatic) had grade 2+ MR on postoperative TEE., Conclusion: In this small case series, a substantial proportion of patients had suboptimal immediate postoperative results. This suggests that selection of the annuloplasty band should not be based on a single echocardiographic variable as it depends on the etiology of the MR, and other dimensions of the mitral valve. Further studies are ongoing to develop a non-invasive method for the selection of annuloplasty band size.