Dynamic measurement of centering forces on transvalvular cannulas

Abstract

In heart failure therapy, minimally invasive devices (transcatheter valves, catheter‐based cannulas or pumps) are increasingly used. The interaction with the valve is of special importance as valve damage, backflow, and thrombus formation are known complications. Therefore, the aim of this in vitro study was to characterize the forces acting on different sized transvalvular cannulas at various transvalvular pressures for four different valves. In a pulsatile setup radial and tangential forces on transvalvular cannulas were measured for bioprosthetic, artificial pericardial tissue, fresh, and fixated porcine valves. The cannula position was varied from a central position to the wall in 10° rotational steps for the whole circular range and the use of different cannula diameters (4, 6, and 8 mm) and transvalvular pressures (40‐100 mmHg). Centering forces of four different aortic valve types were identified and the three leaflets were visible in the force distribution. At the mid of the cusps and at the largest deflection the forces were highest (up to 0.8 N) and lowest in the commissures (up to 0.2 N). Whereas a minor influence of the cannula diameter was found, the transvalvular pressure linearly increased the forces but did not alter the force patterns. Centering forces that act on transvalvular cannulas were identified in an in vitro setup for several valves and valve types. Lowest centering forces were found in the commissures and highest forces were found directly at the cusps. At low pressures, low centering forces and an increased cannula movement can be expected.

Tool-tissue forces in surgery: A systematic review

“…In regard to study demographics, all studies were primarily conducted at North American (n = 19) [ 2 , 4 , 14 , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] ] or European (n = 26) [ 1 , 3 , 5 , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] ] institutions ( Supplementary Information 2 ). Articles were published in medical (n = 26) [ [2] , [3] , [4] , 14 , [21] , [22] , [23] , 25 , 27 , 29 , 35 , 36 , 43 , [46] , [47] , [48] , [49] , 51 , 53 ] or engineering (n = 19) [ <...>…”

“…Articles were published in medical (n = 26) [ [2] , [3] , [4] , 14 , [21] , [22] , [23] , 25 , 27 , 29 , 35 , 36 , 43 , [46] , [47] , [48] , [49] , 51 , 53 ] or engineering (n = 19) [ 1 , 5 , [17] , [18] , [19] , [20] , 24 , 26 , 28 , [30] , [31] , [32] , [33] , [34] , [37] , [38] , [39] , [40] , [41] , [42] , 44 , 45 , 50 , 52 , 54 , 55 ] journals between 1999 and 2020 ( Supplementary Information 3 ). Evidently, this is a new and expanding field, with more articles published in the last 5 years (n = 24) [ [2] , [3] , [4] , 14 , 17 , 19 , 22 , 23 , 25 , 26 , 28 , [32] , [33] , [34] , [35] , 39 , 41 , [45] , [46] , …”

“…In terms of surgical specialty ( Supplementary Information 2 , Table 1 ), the highest proportion of studies (in-vivo and ex-vivo models) were in general surgery (n = 14, 31.1%) [ 3 , 5 , 20 , 26 , 27 , 35 , 38 , [41] , [42] , [43] , 49 , 51 , 54 ] with the majority of these involving laparoscopic procedures (n = 11) [ 3 , 5 , 26 , 34 , 38 , [41] , [42] , [43] , 49 , 54 , 55 ]; followed by neurosurgery (n = 13, 28.89%) [ 1 , 2 , 4 , 14 , 22 , 23 , 25 , 28 , 33 , 37 , 44 , 52 ], ophthalmology (n = 5, 11.11%) [ [17] , [18] , [19] , 21 , 32 ], cardiothoracic (n = 3, 6.67%) [ 26 , 30 , 53 ], vascular surgery (n = 3, 6.67%) [ 29 , 40 , 50 ], obstetrics & gynaecology (n = 2, 4.4%) [ 39 , 45 ], orthopaedics (n = 2, 4.4%) [ 47 , 48 ], otorhinolaryngology (n = 2, 4.4%) [ 36 , 46 ] and urology (n = 1, 2.2%) [ 24 ]. Ten studies (22.2%) involved robotic surgery platforms [ 1 , 14 , [17] , [18] ,…”

“…2 . Generally, across tasks and models, specialities requiring the smallest amount of mean forces were: ophthalmology (mean of average 0.04N) [ [17] , [18] , [19] , 21 , 32 ], vascular (mean of average 0.07N) [ 29 , 40 , 50 ], neurosurgery (mean of average 0.68N) [ 1 , 2 , 4 , 14 , 22 , 23 , 25 , 28 , 33 , 37 , 44 , 52 ] and cardiothoracic surgery (mean of average 1.47N) [ 26 , 30 , 53 ]. Higher mean of average forces, in ascending order, were seen in general surgery (mean of average 4.67N) [ 3 , 5 , 20 , 26 , 27 , 35 , 38 , [41] , [42] , [43] , 49 , 51 , 54 ], otorhinolaryngology (mean of average 8.49N) [ 36 , 46 ], obstetrics and gynaecology (mean of average 8.69N) [ 39 , 45 ], urology (mean of average 9.79N) [ 24 ] and orthopaedic surgery (mean of average 210N) [ 47 , 48 ].…”

Validation study of computational fluid dynamics models of hemodynamics in the human aorta

“…A transparent human aortic block model (root diameter 19.5 mm) was created by a lost-core technique [9] and flow patterns were analyzed with a Particle Image Velocimetry (PIV) system (Dantec Dynamics, Skovlunde, Denmark). A defined inflow section into the aortic model was used to create a parabolic inflow into the model.…”