Minimally-Invasive Mitral and Tricuspid Valve Surgery - Direct Vision for Complex Cases

Purpose:
Minimally-invasive access has become routine for mitral and tricuspid valve surgery. We assessed the type of valve exposure (direct vision, video-assisted, fully endoscopic or robotic) and compared pre-operative characteristics and post-operative outcomes of a large cohort of patients (international Mini-Mitral Registry) undergoing mitral and tricuspid valve interventions. 
Methods:
From 2015-2021, 7,513 consecutive patients underwent mini-MVR±TVR in 17 international Heart-Valve-Centres. Data were collected according to MVARC definitions and 6463 patients undergoing first time mitral with or without tricuspid valve surgery were analysed. Uni- and multivariable regression analyses were performed to compare the different approaches. The table shows group sizes and main outcomes.
Results:
All patients were on average 65 years (57% male) with a Median EuroSCORE II of 1.3% (IQR: 0.80-2.63). Endoscopes and specifically the robot were used in selected patients with lower risk profile compared with direct vision (direct vision pts were older, with more comorbitities). The number of robotic cases was miniscule (0.9%) and patients were lowest risk. Concomitant tricuspid repair was performed more using direct vision or video-assisted. Operative times were shortest with direct vision. Main outcomes were similar (mortality, stroke, AKI) with varying individual endpoints (Table 1). On adjusted analysis (with "video-assisted” set as the reference approach), direct vision appeared as protective against long ventilation and wound complications and as risk factor for low cardiac output and longer length of stay. Fully endoscopic approach did not significantly affect any of the outcomes. 
Conclusions:
Direct vision in minimal-access mitral plus/minus tricuspid valve surgery is the preferred choice for more complex cases, while endoscope and robot are used more selectively. Mastering both techniques may optimize patient care.

Table 1: Demographics and Outcomes
   Video assisted

(n= 2850)

N (%)
 Direct-vision

(n=1594)

n (%)

Fully endoscopic

(n=1963)

n (%) 

Robotic

(n=56)

n (%) 
P value 
Male  1619 (57.1)  918 (57.6)  1210 (61.6) 39 (69.6)   0.003
Age, median (IQR)  64 (53–72)  66 (57-74)  64 (53-73)  60 (52-68)  <0.001
NYHA III-IV  1227 (43.3)  689 (51.3)  875 (44.8)  12 (21.4)  <0.001
MV regurgitation (moderate-severe)  2685 (94.3)  1428 (89.6)  1896 (96.6)  56 (100)  <0.001
Tricuspid regurgitation (moderate-severe)  763 (27.3)  374 (23.6)  502 (25.6)  3 (5.4)  <0.001
LVEF<50%  450 (16.0)  339 (22)  264 (13.5) 7 (12.5)  <0.001
ES II, median (IQR)  1.1 (0.7-1.9)  1.5 (0.8-2.8)  1.2 (0.8-2.2)  1.6 (1.3-2.2)  <0.001
Mitral valve repair  2141 (75.1)  1209 (75.8)  1727 (88)  51 (91.1)  
Mitral valve replacement  667 (23.4)  369 (23.1)  222 (11.3)  5 (8.9)  
Concomitant Tricuspid surgery  399 (20)  342 (21.5)  259 (13.3)  2 (3.6)  <0.001
CPB time (minutes), median (IQR)  130 (98-170)  120 (98.8-145.3)  145 (119-182)  129 (99-147)  <0.001
X-Clamp time (minutes), median (IQR)   87 (65-113)  65 (52-84)  90 (71-113)  183 (147-211)  <0.001
Technical success  2653 (96.2)  1365 (99.3)  1880 (97.6)  56 (100)  <0.001
In-hospital mortality   34 (1.2)  22 (1.4)  26 (1.3)  -  0.8
30-day mortality  38 (1.9)  27 (2.2)  29 (1.7)  -  0.5
Stroke  40 (1.4)  16 (1)  22 (1.1)  -  0.5
Intubation time (hours), median (IQR)  9.4 (6-14)  5 (3-8)  7.7 (5-13)  1 (0-6)  <0.001
Low cardiac output  88 (3.2)  83 (5.6)  47 (2.4)  4 (7.4)  <0.001
Acute kidney injury   147 (5.2)  89 (6.5)  109 (7.2)  3 (5.6) 0.06